New microhylid frogs from the Muller Range , Papua New Guinea

We describe, from the Muller Range of New Guinea, three new species of microhylid frogs, one each in the genera Albericus, Cophixalus, and Oreophryne. Th e new Albericus is unique in its combination of having an infrequent peeping call, oblique lores, wide snout and fi nger discs, and distinct tympanum. Th e new Cophixalus is distinguished by its combination of fi nger discs larger than toe discs, third toe longer than fi fth, distinct tympanum, curved scapular ridges, dark postocular stripe, dark W-shaped mark above the shoulders, and having a call consisting of a rapid series of 6–9 musical peeps. Th e Oreophryne is unique in its combination of having a cartilaginous connection of the procoracoid to the scapula, no webbing between the toes, fi fth toe longer than third, short snout, dark face, and call consisting of an extended multi-note chuckle or cackle. Each species was either common or abundant. Th e new Cophixalus shows a predilection for caves, although it is not restricted to them. Many frogs occurring in the central highlands of New Guinea are wide-ranging across much of this high-elevational region, but others are of restricted distribution. Th e species described herein are likely members of the latter group, although it remains to be determined whether each will prove endemic to the Muller Range.


Introduction
Th e herpetofauna of the central highlands of Papua New Guinea is relatively well known due to the pioneering studies of Tyler (1961Tyler ( , 1962Tyler ( , 1963aTyler ( , b, 1968)), Menzies (1976Menzies ( , 1987Menzies ( , 1993Menzies ( , 1999)), Zweifel (1958Zweifel ( , 1962Zweifel ( , 1972)), and others.However, two semi-isolated ranges straddling the upper Strickland River at the southwestern end of the central highlands remain poorly known: the Blucher Range and the Muller Range (sometimes known as the Muller Plateau).
Th e Muller Range is composed largely of limestone that has heavily weathered into megadolines (James 2006) and is riddled with caves, including Atea Kanada, the largest cave complex in the Southern Hemisphere.Th e underlying rocks are part of thick marine sequences that began forming in the late Oligocene on a subsiding shelf at the northern edge of the Australian Craton.Subsidence stopped by the early Pliocene and was followed in the late Pliocene by uplift and erosion in association with emplacement of the Star Mountain Intrusives (Francis 1980, James 2006).
Much of the Muller Range forms a plateau at roughly 2600 m elevation, with several peaks above 3600 m, including Mt. Karoma, which at 3623 m is the highest mountain in the area.Th e surrounding region is mostly isolated from adjacent ranges by highland valleys at elevations of 1200-1400 m.
Only six species of amphibians and reptiles, all widespread montane forms, are currently known from the Muller Range (Smith 1980).Th ese include two species of skinks, Papuascincus stanleyanaus (Boulenger) and Lobulia elegans (Boulenger); an unidentifi ed snake that was seen but not captured; a hylid frog, Litoria angiana (Boulenger); and two species of microhylid frogs, Callulops wilhelmanus (Loveridge) and Cophixalus cryptotympanum Zweifel.In April 2009 biologists from a joint Bishop Museum/PNG National Museum expedition spent 20 days surveying the herpetofauna at elevations of approximately 1700-2200 m in the vicinity of Mt.Itukua of the Muller Range.Th ese collections included three new species of microhylid frogs, which we describe herein.

Materials and methods
All measurements were made with digital calipers or an optical micrometer to the nearest 0.1 mm, with the exception that disc widths were measured to the nearest 0.01 mm.Measurements, terminology, and abbreviations follow Zweifel (1985) and Kraus and Allison (2006): body length from snout−vent (SV); tibia length from heel to outer surface of fl exed knee (TL); horizontal diameter of eye (EY); distance from anterior corner of eye to center of naris (EN); internarial distance, between centers of external nares (IN); distance from anterior corner of eye to tip of snout (SN); head width at widest point, typically at the level of the tympana (HW); head length, from tip of snout to posterior margin of tympanum (HL); horizontal tympanum diameter (TY); hand length, from proximal edge of palm to tip of 3 rd fi nger (HandL); arm length, from elbow to tip of 3 rd fi nger (ArmL); width of the third fi nger disc (3 rd F); width of the fourth toe disc (4 th T).
We recorded calls in the fi eld using a Sennheiser ME66 microphone and a Marantz 660 audio recorder.Call structure was analyzed using the computer program , available from Avisoft Bioacoustics (http://www.avisoft.com/).
Type specimens are deposited in the Bernice P. Bishop Museum, Honolulu (BPBM) and Papua New Guinea National Museum and Art Gallery, Port Moresby (PNGNM).Unless otherwise noted, all latitude and longitude coordinates use the Australian Geodetic Datum, 1966 (AGD 66).
Comparisons with other species.Th e new species diff ers from all congeners except A. swanhildae Menzies and A. exclamitans Kraus and Allison in having a call consisting of a peep; all other Albericus have calls consisting of a single honk/buzz or a series of clicks.From A. swanhildae the new species diff ers in its larger size (SV = 13.6-15.4mm in A. swanhildae), oblique (vs.vertical) lores, wider fi nger discs (3rdF/ SV = 0.055-0.061 in A. swanhildae), and in having a single broad dark band across the center of each shank (vs.three narrow dark bars across each shank in A. swanhildae).From A. exclamitans the new species diff ers in having the tympanum evident (vs.hidden) in males and in having the call consist of an infrequently produced single peep (vs.rapid burst of 3-48 peeps in A. exclamitans).Albericus murritus is also slightly smaller than A. exclamitans (male SV = 14.6-18.3mm, female SV = 15.0-18.3mm in A. murritus vs. 15.3-20.7 and 18.0-22.0 in A. exclamitans) and has a somewhat broader snout (IN/SV = 0.074-0.085,mean 0.079 in A. exclamitans).
Description of holotype.Adult male.Head relatively wide (HW/SV = 0.38), with oblique and shallowly concave loreal region; canthus rostralis broadly rounded; nostrils small, crescent-shaped, much closer to tip of snout than to eyes; distance from external naris to eye larger than internarial distance (EN/IN = 1.14, IN/SV = 0.083, EN/SV = 0.095); snout bluntly rounded when viewed from above, truncate when viewed from side; eyes moderately large (EY/SV = 0.13), eyelid approximately 2/3 width of interorbital distance; tympanum indistinct, partially hidden by surrounding skin.Dorsum pustulose on body and limbs; supratympanic fold absent
In preservative, dorsal ground color an irregular mix of yellow-tan and brown, with the former predominating dorsolaterally and the latter mid-dorsally; parts of both fi elds suff used with russet.Irregular black fl ecks and markings scattered throughout, concentrated above shoulders, on rear of head, and above tympana.Traces of a short, lighter, yellow-brown bar on each scapula; similar-colored interocular bar and vestiges of lumbar ocelli.Sides dark gray fl ecked with black and light blue-gray.Face yellow-tan fl ecked with black and russet.Legs yellow-tan with one broad, dark, centrally placed band on each thigh and shank.Rear of thighs dark brown with narrow yellow-tan band proximally.Venter dirty light gray evenly and densely peppered with dark gray; palmar and plantar surfaces same.Front margin of mandible russet.Iris black fl ecked with silver.
Variation.Mensural variation for the type series is shown in Table 1.Th ere is no obvious sexual dimorphism in morphometric features, although there is slight evidence that females may average larger in body size.However, this diff erence is slight considering the normal pattern of larger female size in most Papuan frogs.
Most specimens appear dark brown in preservative (darker than the holotype), with a few contrasting light-brown streaks or lines scattered on dorsum.Th ese typically involve a single short line on each scapula, an interocular bar, and often traces of lumbar ocelli.Lighter specimens are similar but show more clearly the variable mottling seen in the holotype.Density of dark ventral stippling varies from sparse to dense, making the overall appearance of the venter vary from light gray to black.Both ventral extremes appear in frogs with both light and dark dorsa, but venters of frogs that are lighter dorsally average somewhat paler than those of dark frogs.
Color in life.BPBM 33636: "Dorsum dark tan with irregular black blotches and tiny white or tan dots on some warts; fairly warty.Orange-brown interocular bar, suprascapular marks, and on arms and heels.Venter charcoal gray with tiny light-gray punctations.Light-tan patch from eye to rictus.Iris brown."BPBM 33637 was yellow-brown with cream and black markings, venter densely punctated with light gray, and iris tan.
Call.Th is species begins calling at dusk and calls in highest numbers during the fi rst few hours of darkness.Th e call consists of a single "peep" note uttered in a continuous series with occasional breaks (Fig 2).We recorded calls of two individuals, BPBM 33641 and BPBM 33657 (Table 2).Th e notes had a mean duration of 0.151 s (range 0.093-0.213).Th e inter-note interval for BPBM 33641 ranged from 4.1-9.0s (n = 20), except for two instances of 31.6 and 35.9 s.Many species of Albericus produce calls in groups separated by periods of silence (A.Allison, pers.obs.), and our brief recording suggests that this is occurring in BPBM 33641.Th e call of BPBM 33657 was similar.Th e interval between the 36 notes in our recorded sequence ranged from 2.7-6.5 s, except in four instances that ranged in duration from 11.4-57.8s.Again, the interval sequence suggests that the calls are produced in groups separated by periods of silence (Fig. 3).Th e call note is unpulsed (Fig. 2A) and fi nely tuned, with a mean dominant frequency of 3520 Hz (range 3180-3650) and a well-developed harmonic structure (Fig. 2B-C).
Etymology.Th e name is a masculine Latin adjective meaning "to squeak like a mouse".
Range.Known only from the vicinity of the type locality on the northeastern slopes of the Muller Range, Southern Highlands Province, Papua New Guinea (Fig. 4).
Diagnosis.A moderately large species of Cophixalus (adult SV = 25.5-36.7 mm) distinguished by its combination of expanded fi nger discs larger than toe discs (3rdF/ SV = 0.069-0.107,3rdF/4thT = 1.27-1.70);long legs (TL/SV = 0.50-0.59);third toe distinctly longer than fi fth; distinct tympanum; curved scapular ridges; pustulose skin; short, dark postocular stripe; dark W-shaped mark above the shoulders; lacking a dark   face and yellow spotting on the rear of thighs; and having a call consisting of a rapid series of 6-9 musical peeps.
Comparisons with other species.Th e new species diff ers from all congeners except C. balbus Günther, C. biroi (Méhelÿ), C. cheesmanae Parker, C. cryptotympanum, C. nubicola Zweifel, C. riparius Zweifel, and C. verrucosus (Boulenger) in its combination of SV > 25 mm, fi nger discs larger than toe discs, and third toe longer than fi fth.It diff ers from C. balbus and C. biroi in having (vs.lacking) raised scapular ridges, lacking (vs.having) a triangle of pale coloration on the top of the snout, having a call consisting of only 6-9 peeps (vs.long trains of peeps), and from C. biroi in having (vs.lacking) a dark W-shaped mark above the shoulders; from C. cheesmanae in having pustulose (vs.smooth) skin and in lacking the dorsolateral ridge and uniformly dark face of that species; from C. cryptotympanum in having an exposed (vs.obscure or hidden) tympanum, pustulose (vs.smooth) skin, a dark (vs.light) postocular stripe, and a dark W-shaped mark above the shoulders (absent in C. cryptotympanum); from C. nubicola in its longer legs (TL/SV = 0.35-0.38 in C. nubicola), thighs same color as (vs.conspicuously paler than) dorsum, and dorsum yellow or greenish-yellow with a dark W-shaped mark above the shoulders (vs.reddish-brown with light spots in C. nubicola); from C. riparius in its smaller size (SV = 40-50mm in C. riparius) and dorsum yellow or greenish-yellow with a dark W-shaped mark above the shoulders (vs.brown with two elongated and irregular dark dorsolateral patches or network in C. riparius); and from C. verrucosus in having larger fi nger discs (3rdF/SV = 0.052-0.073,3rdF/4thT = 0.96-1.26),a dark W-shaped mark above the shoulders (absent in C. verrucosus), and rear of thighs yellow dusted with brown (vs.spotted with yellow on dark brown in C. verrucosus).
Description of holotype.Adult male with small lateral incision on right side.Head moderately wide (HW/SV = 0.39), with steep, almost vertical, loreal region and slightly infl ated lip; canthus rostralis rounded, straight when viewed from above; nostrils directed laterally, much closer to tip of snout than to eyes; internarial distance larger than distance from naris to eye (EN/IN = 0.83, IN/SV = 0.106, EN/ SV = 0.088); snout rounded and somewhat projecting when viewed from the side, broadly angulate when viewed from above; eyes moderately large (EY/SV = 0.12); eyelid approximately 2/3 width of interorbital distance; tympanum indistinct and small (TY/SV = 0.049), with a slightly raised annulus anteriorly but covered by ridge of skin dorsally and posteriorly.Skin pustulose dorsally and laterally, with prominent pair of scapular ridges, granulose ventrally.Supratympanic fold present, distinct ventrally but merging with pustulose skin dorsally.Fingers unwebbed, bearing discs with terminal grooves; relative lengths 3>4>2>1; fi rst fi nger and disc well-developed.Finger discs approximately 3 times widths of penultimate phalanges, except for the fi rst fi nger disc, which is approximately 2 times width of penultimate phalanx.Subarticular tubercles low; inner metacarpal tubercle weakly developed, outer absent.Toes unwebbed, bearing discs with terminal grooves; relative lengths 4>3>5>2>1.Toe discs smaller than those of fi ngers (3 rd F/4thT = 1.33); approximately twice widths of penultimate phalanges.Subarticular tubercles weakly developed; inner metatarsal tubercle narrow, elongate, and low; outer lacking.Hind legs moderately long (TL/ SV = 0.54).
In preservative, dorsum brown with broken, dark-brown scapular W, and indistinct dark-brown markings scattered throughout.Dark-brown interocular bar, postocular stripe, and loreal stripe.Face light brown with small dark-brown fl ecks and smudges.Rear of thighs pale straw suff used with brown stippling and having dark-brown blotching distally.Ventral surfaces pale straw yellow heavily stippled with black, this more evenly distributed on chin and throat, and more broken on abdomen and under legs.Few white fl ecks along margin of mandible and sparsely scattered on throat and chest.Palmar and plantar surfaces brown, latter darker.Iris very dark brown, densely fl ecked with brass.
Variation.Mensural variation for the type series is shown in Table 3. Sexual dimorphism is slight except that females are of larger size than males.Th ere is relatively little variation in dorsal color pattern.Most specimens are similar to the holotype, but four or fi ve have a slightly lighter ground color, and four are darker; all have the scapular W. Similarly, ventral color pattern varies little.Most specimens are like the holotype, but a few (7 or 8) have darker stippling, which gives a higher contrast to the ventral pattern.
Color in life.BPBM 33708: "Mustard yellow with irregular dark-brown markings; dark-brown suprascapular W and dorsolateral lines which are ridges.Iris bronze punctated with brown.Venter yellow with blue-white punctations."BPBM 33728 was mustard yellow with black spots dorsally.Th e yellow color was prominent in all specimens collected.
Call.We heard this species call only in the morning between 0500-0930 h.We obtained good recordings of 16 calls produced by two individuals, BPBM 33747 and 33748 (Table 4).Both calls were similar, so we combined data for analysis.Th e call consists of 5-9 (mode = 7) regularly spaced notes delivered at a mean rate of 6.63 notes/s (range 5.65-7.57)with the acoustic impression of bell-like peeping.Th e mean duration of calls was 1.77 s (range 1.50-2.18).Th e fi rst note, with one exception, was the longest note in the call, averaging 0.2933 s (range 0.0920-0.3280)(Fig. 5A).
If the exception is excluded, the mean duration of the fi rst note increases to 0.3067 (range 0.2818-0.3280).Th is note also generally had a lower amplitude than that of subsequent notes.Th e second note tended to be the second longest in the call, averaging 0.1556 s (range 0.0790-0.1990).Subsequent notes were generally similar, averaging 0.1324 s in duration (range 0.0602-0.1960),but in nine of the 16 calls the last note was the shortest in the call, with a duration ranging from 0.0602-0.1100s.
Th ere was a slight tendency for pulsing of the fi rst note (Fig. 6A-B).Th is is more apparent in the second and subsequent notes, particularly in BPBM 33748 (Fig. 6B), in which the fi rst note generally included upwards of 8-9 irregular, often partial pulses.Subsequent notes, particularly in BPBM 33748, generally had at least two components: a short, high-amplitude pulse of ~0.03-04 s followed by a longer, lower-amplitude pulse that was generally 0.07 s or more in duration.Mean interval between notes was 0.1033 s (range 0.0380-0.1360)with no obvious tendency for the interval to lengthen or shorten over the course of the call.Notes are fi nely tuned, with a mean dominant frequency of 2510 Hz (range 2430-2570) (Fig. 5B), only weakly developed harmonic structure, and little or no change in note frequency over the duration of the call (Fig. 5C).
Range.Known only from the vicinity of the type locality on the northeastern slopes of the Muller Range, Southern Highlands Province, Papua New Guinea (Fig. 4).
Ecological notes.Animals inhabit primary and secondary rainforest but were also common around largely cleared village areas.We found only one animal in primary rainforest, but they were common in highly disturbed areas around villages.In the latter areas, animals were abundant inside caves comprised of a hard, slick clay surface, but they were also common in grassy and lightly treed areas outside of caves.Within caves they could be found active on or calling from both horizontal and vertical surfaces or within horizontal or vertical cracks during the day.Th ey were not limited to the mouths of the caves but were found well back into the caves in areas having little, if any, light.
In the caves, calling occurred in waves, with silence predominating, but then followed by a one-or two-minute spate of calling.Some animals were calling from deep, inaccessible fi ssures at least 20 m from the mouth of the cave.During our observations, calling in caves occurred during the morning (until at least 0900 h); however, it is possible the frogs call throughout the day in such circumstances.Outside of caves, calling occurred primarily on wet mornings following night-time rain, with calling beginning at approximately 0500 h, diminishing after daylight (~0600 h), but continuing until at least 0930 h.One animal found calling during this time was perched approximately 1 m above the ground on Dicranopteris linearis.We never heard these frogs calling in the evening or night-time until the hour before dawn.
When disturbed, this frog plays dead, often lying on its back and refusing to move.However, unlike Albericus darlingtoni, they do not roll into a tight ball, but lie limply.One of us (FK) initially thought several animals in a collection bag were dead because of this habit, but they become active once righted and left undisturbed for a few moments.
Remarks.A distinctive aspect of the vocalization of this species is that it delivers a series of 8-10 calls at frequent, regular intervals (every 1.6 s for BPBM 33747 and every 2.3 s for BPBM 33748) (Fig. 7), with each series punctuated by a short period of silence of approximately the same duration.Other species of New Guinean Cophixalus that produce multi-note calls generally deliver them at irregular, much lengthier intervals.For example, the upper montane species, Cophixalus sphagnicola Zweifel and Allison, which has a call of 15-27 peeps, generally calls every 30-60 s (Zweifel and Allison 1982).
Th is same behavior is seen in four recently described species of Cophixalus (Kraus and Allison, 2009).Th e holotype of Cophixalus kethuk (BPBM 20203) from Rossel Island in Milne Bay Province produced a call of 12-13 notes that sounded similar to "a marble falling and quickly coming to rest on a hard surface" (Kraus and Allison 2009).It called on average every 13 s (range 9-18 s, n = 5).Cophixalus phaeobalius, from 1520 m in the Bowutu Mts in Morobe Province, produces a call of 4-7 peeps.We recorded a paratype (BPBM 26194) that called at fairly regular intervals of 32-43 s (mean 37, n = 4).A morphologically similar species, C. tomaiodactylus, has a call consisting of 2-13 rapid peeps.Two paratypes (BPBM 23720, 26183)    Diagnosis.A medium-sized species of Oreophryne (adult SV = 23.4-29.7 mm) distinguished by its combination of a cartilaginous connection of the procoracoid to the scapula, no webbing between the toes, fi fth toe longer than the third, relatively short snout (EN/SV = 0.073-0.086),dark face, venter with a dense array of darkbrown fl ecks, and call consisting of an extended multi-note chuckle or cackle.
Comparisons with other species.(23.4-29.7 mm vs. maximum of 21 mm in those four species) in having a uniformly dark face, and in its call (call a series of peeps in the other species, but call unknown in O. fl ava); it further diff ers from O. asplenicola and O. pseudasplenicola in its shorter snout (EN/SV > 0.086 in those species), from O. notata and O. pseudasplenicola in lacking (vs.having) an inverted white U on the face, and from O. fl ava in having an abdomen with dark-brown fl ecking (vs.immaculate yellow-white), and lacking (vs.having) a dark W-shaped mark between the shoulders.
Description of holotype.Adult female with incision on right side.Head wide (HW/SV = 0.40), with steep, slightly concave loreal region.Canthus rostralis rounded, concave when viewed from above.Nostrils directed laterally, closer to tip of snout than to eyes.Internarial distance broader than distance from naris to eye (EN/IN = 0.80, IN/SV = 0.101, EN/SV = 0.081).Snout truncate when viewed from the side, shallowly angulate when viewed from above.Eyes moderately large (EY/SV = 0.11); eyelid approximately two-thirds width of interorbital distance.Tympanum distinct but small (TY/SV = 0.047).Dorsal skin granular with series of weakly raised parallel ridges and scattered small pustules; ventral surfaces coarsely granular.Supratympanic fold narrow.Fingers unwebbed, bearing discs with terminal grooves; relative lengths 3>4>2>1.Finger discs approximately 3 times widths of penultimate phalanges, except for fi rst fi nger, which is approximately twice width of penultimate phalanx.Subarticular tubercles well developed; inner metacarpal tubercle oval and low; outer rounded and obscure.Toes unwebbed, bearing discs with terminal grooves; relative lengths 4>5>3>2>1.Toe discs smaller than those of fi ngers (3 rd F/4thT = 1.37), approximately twice width of penultimate phalanges.Subarticular tubercles low but arms and tarsi burnt orange."BPBM 33765 was uniform brown dorsally with a dark face mask and postocular stripe (Fig. 1D); rear and front of thighs, and groin, uniform brown, slightly darker than dorsum; venter dirty cream fl ecked with gray; iris dark brown.BPBM 33766 had black fl ecks on sides and venter brighter yellow but with fewer gray fl ecks and with white chromatophores; BPBM 33767 had the dorsum and rear of thighs burnt orange and venter pale yellow; BPBM 33769 and 33771 had a tan vertebral line.BPBM 33774 had a metallic green sheen on eyelids and top of snout; BPBM 33776 same but less extensive.PNGNM 24097 was light brown with straw yellow on sides, with dark-brown spots dorsally and laterally, denser on sides; face to rictus and short postocular stripe dark brown; rear of thighs brown like dorsum but unspotted; venter pale yellow spotted with dark-gray fl ecks; iris brown.
Call.Animals called during the fi rst few hours of darkness.We recorded ten calls from two individuals (Table 6).Th e calls from both were similar, so we combined data from both for analysis.
Th e call consists of 17-22 pulsed notes (Figs.8A, 9A).Note duration was similar over the course of the call and averaged 0.0569 s (range 0.0266-0.0681).Internote intervals were also similar throughout the call and were similar in duration to the notes, averaging 0.0563 s (range 0.0390-0.0942).Mean call duration was 2.10s (range 1.77-2.33),and notes were delivered at a mean repetition rate of 18.5 notes/s (range 17.3-20.3).Number of pulses/note ranged from 3-11 (Fig. 9A), with a strong tendency to decrease over the course of the call (Fig 10).Modal number of pulses in the fi rst three notes in each call ranged from 10-11, producing a mean rate for those notes of 200.9 pulses/s, while modal number of pulses in the last three notes ranged from 7-9, producing a mean rate for those notes of 146.4 pulses/s (Table 7).Notes are fi nely tuned, with a mean dominant frequency of 2490   Etymology.Th e species is named for Jim Anamiato of the Papua New Guinea National Museum for his considerable assistance on several of our expeditions, including the one during which this frog was discovered.
Range.Known only from the vicinity of the type locality on the northeastern slopes of the Muller Range, Southern Highlands Province, Papua New Guinea (Fig. 4).
Ecological notes.Animals inhabited both primary and secondary rainforest at elevations ranging from 1870-2180 m.Most animals were found in the immediate vicinity of stream banks, but a few were found several meters away in adjacent forest.Males called from dense moss mats on standing or fallen trees from 1-5 m above the ground,  7 for additional details.Remarks.Several species of Oreophryne give loud, rattling calls similar to that of O. anamiatoi.Th ese include Oreophryne clamata, which gives a call of 10-23 pulsed notes (Günther 2003a); O. kapisa Günther, which produces 26-47 pulsed notes (Günther 2003b); and O. waira, which produces 6-11 pulsed notes (Günther 2003b).Th e call of Oreophryne anamiatoi is most similar to that of O. clamata but diff ers from that species in having a slightly longer duration (1.77-2.33 s vs. 0.58-1.41s),a longer mean note duration (57 ms vs. 21 ms), a longer mean internote duration (56 ms vs. 39 ms), and a slightly lower dominant frequency (2460-2540Hz vs. 2700-3600 Hz).Internote duration is fairly constant in O. anamiatoi but tends to lengthen over the course of the call in O. clamata (Günther 2003a).

Discussion
With the addition of the three species described herein and other species recently collected by us, there are now at least nine species of microhylid frogs known from the Muller Range.Th ese include four species that are endemic to but relatively widespread in the central highlands of Papua New Guinea (Albericus darlingtoni, Callulops wilhelmanus, Oreophryne notata, Xenorhina parkerorum) and two species (Choerophryne burtoni, Hylophorbus richardsi) that were recently described from uplands approximately 90 km and 60 km, respectively, to the southeast of the Muller Range.In addition, Smith (1980) listed Cophixalus cryptotympanum from the Muller Range.Th is taxon was originally described from Mt. Dayman on the Southeast Peninsula of Papua New Guinea and has been recorded from numerous montane localities throughout much of Papua New Guinea (Menzies 2006).However, the taxonomic status of this species is uncertain, and it is likely that it is a species complex, with the named form known with certainty only from Mt. Dayman.Hence, the record of C. cryptotympanum from the Mullers is best treated with caution at present.
A similar distributional pattern characterizes the hylid frogs that we found in the Muller Range.We obtained Litoria angiana (Boulenger), L. arfakiana (Peters and Doria), L. darlingtoni (Loveridge), L. iris (Tyler), L. kumae Menzies and Tyler, L. micromembrana (Tyler), and L. modica (Tyler).All of these except L. kumae are widespread montane species across Papua New Guinea (Litoria angiana, L. arfakiana, L. micromembrana, L. modica), or widespread within the central highlands (L.darlingtoni, L. iris).Only L. kumae is endemic to a small portion of the central highlands, being previously known from the vicinity of Tari, 35 km southeast of our collection site, and a couple of points a short distance south of Tari but still in Southern Highlands Province.
Th ese rather limited details suggest that the frog fauna of the Muller Range is broadly representative of that of the central highlands but with a signifi cant endemic element that appears to be restricted to uplifted limestone regions and adjacent volcanoes of the Southern Highlands.Additional endemic species may be expected in the subalpine and alpine regions (>3000 m) of the Muller Range.

Figure 2 .
Figure 2. A Waveform, B power spectrum, and C spectrogram of call "T" of Albericus murritus sp.n. (BPBM 33641) recorded on E slope Mt.Itukua, Muller Range, Southern Highlands Province, Papua New Guinea on 27 March 2009 at 2020 h.Air temperature 14.7 °C.

Figure 3 .
Figure 3. Duration of the interval between call notes in the complete recorded sequence of Albericus murritus sp.n. (BPBM 33657) recorded at Mt. Paramo, Muller Range, Southern Highlands Province, Papua New Guinea on 2 April 2009 at 2215 h.Air temperature 18.8 °C.

Figure 4 .
Figure 4. Map showing known distribution of three new species of microhylid frogs from along the eastern slope of Mt.Itukua, Muller Range, Southern Highlands Province, Papua New Guinea (star).

Figure 5 .
Figure 5.A Waveform, B power spectrum, and C spectrogram of the complete call of call "H" (Table 4) of Cophixalus caverniphilus sp.n. (BPBM 33748) recorded from a cave at Mt. Paramo, Muller Range, 1720 m, Southern Highlands Province, Papua New Guinea at 0830 h, 5 April 2009.Air (cave) temperature 17.6 °C.

Figure 9 .
Figure 9. Detail of the middle three notes of call "D" of Oreophryne anamiatoi sp.n. (BPBM 33774).A Waveform, B power spectrum, and C spectrogram.Note the pulsing of the notes.

Figure 10 .
Figure 10.Number of pulses/note of Oreophryne anamiatoi sp.n. recorded at Mt. Paramo, Muller Range, Southern Highlands Province, Papua New Guinea on 3 April 2009.BPBM 33774 was recorded at 2000 h and BPBM 33775 at 2100 h.Air temperatures were 17.0 and 17.7 °C, respectively.See Table7for additional details.

Table 1 .
Mensural data for type series of Albericus murritus sp.n.Data include only adult animals.

Table 2 .
Call statistics of Albericus murritus sp.n. recorded by Fred Kraus on E slope Mt.Itukua, Muller Range, Southern Highlands Province, Papua New Guinea.BPBM 33641 was recorded on 27 March 2009 at 2020 h, BPBM 33657 on 2 April 2009 at 2215 h.Air temperatures were 14.7 and 18.8 °C, respectively.

Table 3 .
Mensural data for type series of Cophixalus caverniphilus sp.n.Data include only adult animals.
Figure 6.A Waveforms of the fi rst four notes of the call of Cophixalus caverniphilus sp.n.Call "J" of BPBM 33747 B Call "D" produced by BPBM 33748.SeeTable 4 for details.

Table 6 .
Call statistics of Oreophryne anamiatoi sp.n. recorded on Mt.Paramo, Muller Range, Southern Highlands Province, Papua New Guinea on 3 April 2009.BPBM 33774 was recorded at 2000 h and BPBM 33775 at 2100 h.Air temperatures were 17.0 and 17.7 °C, respectively.