Male in UBC-SEM, with labels: “TEXAS: Jeff Davis Co.: Davis Mountains State Park103.939°W, 30.593°N, 22-23 April 1997 Maddison/Hedin/Hebets WPM#97-001” and “♂W167”.

(5♂♂ 3♀♀). 1♂ (specimen W328) 1♀ (specimen W332) in UBC-SEM; 1♂ 1♀ in AMNH; 1♂ 1♀ in MCZ; 2♂ in OSAC; all with same data as holotype.

The name is an arbitrary combination of letters, including the syllable “arc”, included to evoke the rainbow of colors in the male ornaments.

The large triangular patella of the third leg of males is distinctive in salticids. Habronattus viridipes (Hentz, 1846) has a triangular patella also (Griswold 1987: figure 99), but it is different from that of H. arcalorus in colour (orange-yellow with a black spot, rather than grey) and in having a terminal apophysis. Habronattus californicus (Banks, 1904), also of the clypeatus group, has a triangular patella (Griswold 1987: figure 107), but the patella is smaller and yellow and red. H. arcalorus also differs from H. californicus in having green first legs with a much denser fringe. Females of H. arcalorus are distinctive from most specimens of other clypeatus group species in having a distinct black triangle on the thorax (Figs 19–20).

Figures 10–21. 

Habronattus arcalorus sp. n. All specimens from Davis Mountains, Texas except Fig. 12, from Cañon City, Colorado. (10–11 paratype male W328) 10 left palp, ventral view 11 left palp, retrolateral view. 12 epigynum, ventral view, paratype female W332. Scale bar = 0.1 mm. 4 third leg femur, patella and tibia 13–18 living male 19–20 living females. 21 male in courtship pose. All photos credit W. P. Maddison.

This species was referred to by Maddison and Hedin (2003) as H. sp. (CNCTY) (and possibly also H. sp. (CHIH); see note below on Chihuahuan form). Molecular data suggest that H. arcalorus and H. forticulus (Gertsch & Mulaik, 1936) are outside the clade containing the bulk of the clypeatus group species – H. aztecanus (Banks, 1898), H. californicus (Banks, 1904), H. clypeatus, H. divaricatus (Banks, 1898), H. dossenus, H. formosus, and H. velivolus Griswold, 1987. H. arcalorus and H. forticulus are the easternmost representatives of the clypeatus group.

Male (focal specimen: holotype, specimen W167). Carapace length 2.3; abdomen length 2.3. Structure of chelicerae, legs, and body typical for Habronattus and the clypeatus group. Palp (Figs 10, 11) standard for the clypeatus group (Griswold 1987 figures 180, 181, 203), with the embolus arising at about 3:00 and the basal portion of the terminal apophysis pointing to 6:00. The tibial apophysis is hooked from ventral view (Fig. 10); in retrolateral view it narrows abruptly before its tip leans ventrally (Fig. 11). First legs (Figs 14, 15, 18, 21): Fringed laterally on the femur, patella, and tibia. Femur prolaterally and ventrally covered with spoon-shaped setae, swollen at the tips. Tibia with two large spatulate macrosetae prolaterally. Third legs (Figs 13, 16, 17): Patella swollen into a large triangle. Colour in life (Figs 14–18, 21): Chelicerae dark, with white setae medially. Palp femur and patella covered with beige scales above; cymbium with scattered white erect setae, especially retrolaterally. First leg dark above, but with light green integument below, and with dense fringes of erect setae prolaterally and retrolaterally on the femur, patella and tibia. These fringes are orange on the femur prolaterally, grading to white elsewhere on femur, patella, and tibia. Spoon-shaped setae on underside of first femur are white at tips. Femur of third leg with transverse white and dark bands (Figs 13, 16) in basal half, blue-white scales in distal half that match similar blue-white scales at front of abdomen (Figs 14–18). Third patella steel-grey with a white fringe above; tibia black with pale band rising obliquely toward the distal and dorsal (Figs 13, 17). Clypeus covered in white setae except for a dark band descending obliquely from each AME. Ocular area rust-coloured, with thin tan band arching between PMEs. Pale thoracic bands wide anteriorly, narrowing to a point at back margin. Abdomen with generous basal band of blue-white scales, broken at the front by two small black lines (Fig. 14). Longitudinal medial band of pale scales on dorsum of abdomen triangular, much wider at front than back. Colour in alcohol: more or less as in life, but with first leg integument yellow-orange, no longer green, and bluish cast of third femur and abdominal basal band not visible.

Female (focal specimen: paratype, specimen W332). Carapace length 2.7; abdomen length 2.8. Structure typical for Habronattus and the clypeatus group. Epigynum (Fig. 12) with long narrow central pocket in front of which is a small semicircular atrium, as is usual for the species group. Colour (Figs 19–20): Uniform beige to tan, with black triangular patch on posterior thorax. Some specimens show two longitudinal dark bands on abdomen (Fig. 20). The clypeus is covered with white scales, but a hint of the dark oblique bands of the male can be seen beneath the white scales. Likewise, there is a hint of the transverse bands on the third femur.

USA: TEXAS: Jeff Davis Co.: Davis Mountains State Park103.939°W, 30.593°N, 22–23 April 1997 Maddison/Hedin/Hebets WPM#97-001 (11 ♂♂, 2 ♀♀, 6 subadult ♂♂, 16 other juveniles). TEXAS: Jeff Davis Co.: Davis Mountains, roadside, highway 118 104.098°W, 30.704°N, 23 April 1997 Maddison/Hedin/Hebets WPM#97-003 (2 ♂♂ 1 ♀). COLORADO: Fremont Co., Royal View Campground. ~9 mi W of Cañon City on HWY 50. N38.495° W105.354°. 24 May 1982 D. & W. Maddison WPM#82-108 (10 ♂♂, 6 ♀♀).

Specimens of a form that may be either a geographical variant of H. arcalorus, or a distinct species, were found in the Tomochic area of Chihuahua, Mexico (Figs 22–26). This is the form referred to by Maddison and Hedin (2003) as “H. sp. (CHIH)”. The markings, robust body, and dense fringes on the male first leg match those of H. arcalorus, but the third patella is different (Figs 24, 26): smaller, rounded, dark red in the distal half. The tip of the femur is dark red with white bands, not blue-white as in H. arcalorus. The front of the abdomen is not bluish, nor does the basal band have two clear dark stripes. Habronattus arcalorus and the Chihuahuan form do not group together by mitochondrial data in Maddison and Hedin’s (2003) gene tree, but Maddison and Hedin suggest there is introgression from the coecatus group into the Chihuahuan form, and nuclear data are lacking. It seems likely that a diversity of geographic forms exists in satellite ranges of the Sierra Madre Occidental and Sierra Madre Oriental in Chihuahua and Coahuila, yet to be discovered. Until more detailed studies are done, we will avoid giving a new taxon name to the Chihuahan form, and call it H. cf. arcalorus (“CHIH”). The material examined of the Chihuahuan form (all in UBC-SEM) is: MEXICO: CHIHUAHUA: 1 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (6 ♂♂, 5 ♀♀). CHIHUAHUA: 2.7 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (2 ♀♀). CHIHUAHUA: 10.1 mi E of Tomochic on HWY 16. 14 Mar 1996 Susan Masta (4 ♂♂, 4 ♀♀). CHIHUAHUA: 15 mi N of Madera road to 40 Casas archaeological zone. 15 Mar 1996 Susan Masta (2 ♂♂, 1 ♀).

Figures 22–26. 

Habronattus cf. arcalorus (“CHIH”). All specimens from near Tomochic, Chihuahua. 22–23 living male. 24 third leg, living male 25 female 26 third leg in alcohol. All photos credit W. P. Maddison.

Habronattus arcalorus was found abundantly in both areas in which it was collected. At the Cañon City locality it was found on rocks on a dry hillside with sparse vegetation and pinyon pines (Fig. 33). In the Davis Mountains of Texas it was found on oak leaf litter mixed with grass and rocks in a stream valley, and on rocks mixed with grass in a juniper-pinyon-oak woodland. Fig. 21 shows a male in courtship pose. Maddison and Leduc-Robert (2013) report the karyotype of H. arcalorus as 26 acrocentric autosomes plus 2 acrocentric X chromosomes in males, as is typical for salticids.

male in UBC-SEM, with labels “USA: New Mexico: Grant Co., Bill Evans Lake, 1400 m. 32.865°N, 108.5784°W, 10 April 1996 D.R. Maddison DRM96.015” and “W123”.

(5♂♂ 2♀♀). New Mexico: Grant Co., Gila River, Billings Vista, 32.8137°N, 108.6011°W, 11 August 2005 D.R. Maddison DRM 05.042 (1♂ in each of AMNH, MCZ, OSAC; 1♀ in UBC-SEM); New Mexico: Grant Co., Bill Evans Lake, 1400 m. 32.865°N, 108.5784°W, 10 April 1996 D.R. Maddison DRM96.015 (1♂ in UBC-SEM); New Mexico: Grant Co., route 90 S of Tyrone, 1755 m. 32.702°N, 108.3043°W, 10 April 1996 D.R. Maddison DRM96.016 (1♂ in UBC-SEM); New Mexico: Walnut Creek Road NW of Silver City, 32.8309°N, 108.3326°W, 6 April 2012, C. Wu (1♀ in UBC-SEM, “female 434” of D. Elias laboratory);

The name refers to the known distribution of this species, in the region of the Gila River drainage of New Mexico.

The third leg has an unornamented patella and tibia (Fig. 30), unlike all other members of the H. clypeatus group (Figs 1–9). The only other species of the group with green first legs in the male are H. dossenus and H. arcalorus. From H. arcalorus, H. gilaensis differs in many details of ornamentation, especially the third leg. H. gilaensis is most similar to H. dossenus, but differs (in males) in almost complete lack of ornamentation on the third leg, in the paler ocular area, denser and longer fringes on the first leg, denser covering of white setae on the cymbium, and in having the white scales on the side of the carapace broken by a black band extending posteriorly.

Figures 27–32. 

Habronattus gilaensis, sp. n. 27–28 male holotype left palp 29 Paratype female epigynum, ventral view 30–32 living male from south of Tyrone, New Mexico (32.702°N 108.3043°W) 30 is anterior lateral view of third leg. All photos credit W. P. Maddison.

This species was referred to as H. cf. dossenus by Maddison and Hedin (2003).

Male (focal specimen: holotype, specimen W123). Carapace length 2.2; abdomen length 2.0. Structure of chelicerae, legs, and body typical for Habronattus and the clypeatus group. Palp (Figs 27–28) standard for the clypeatus group, very similar to that of H. arcalorus. First legs (Figs 31, 32): Dense fringes of erect setae retrolaterally on the femur, and prolaterally and retrolaterally on the patella and tibia. The setae of these fringes are simple, not swollen as in H. arcalorus. Tibia with two large spatulate macrosetae prolaterally. Third legs (Figs 30, 32): Almost as in female, little modified. Colour in life (Figs 31, 32): Chelicerae dark, with white setae medially. Palp femur and patella covered with beige scales above; cymbium fairly densely covered with white setae. First leg dark above, but with green integument below, and fringes tan to white. Femur of third leg with indistinct transverse bands (Figs 30, 32). Clypeus covered in white setae except for a dark band descending obliquely from each AME. Ocular area light brown to tan, with thin tan bands arching between PMEs. Pale thoracic bands wide anteriorly, narrowing to a point at back margin. Abdomen with basal band of white scales broken at the front by two small black lines (Fig. 31). Longitudinal medial band of pale scales on dorsum of abdomen narrow. Medial longitudinal dark band on underside of abdomen. The dark clypeal bands, pale arching band in the ocular area, and broken basal band are also typical for the clypeatus group. Colour in alcohol: more or less as in life, but with first leg integument yellow-orange, no longer green.

Female (focal specimen: paratype, “female 434”). Carapace length 2.6; abdomen length 3.2. Structure typical for Habronattus and the clypeatus group. Epigynum (Fig. 29) with long narrow central pocket in front of which is a small semicircular atrium, as is usual for the species group. Colour: uniform beige to tan scales covering body. Clypeus covered with white scales. Third femur with a hint of the transverse bands seen in the male.

USA: New Mexico: Grant Co., route 90 S of Tyrone, 1755 m. 32.702°N, 108.3043°W. 10 April 1996. D.R. Maddison. DRM96-016 (3 ♂♂). New Mexico: Grant Co., Big Burro Mountains, road from Lordsburg to Silver City. 32.505°N, 108.464°W. 9 August 1997. W. Maddison & M. Hedin. WPM#97-028 (1 ♂).

Found on open dry ground, on rocks and leaf litter (Fig. 34).

Figures 33–34. 

Habitats of H. arcalorus and H. gilaensis. 33 H. arcalorus habitat with second author searching for specimens, USA: Colorado: ~9 mi W of Cañon City, 38.495°N, 105.354°W, 24 May 1982 WPM#82–109 34 H. gilaensis habitat (on ground in foreground), USA: New Mexico: Grant Co., Gila River, Billings Vista, 32.8137°N, 108.6011°W, 11 August 2005 DRM 05.042.