A new Tithaeus species from Hainan Island, China (Arachnida, Opiliones, Laniatores, Epedanidae), with a key to the Chinese species

Abstract A new species of the harvestmen Tithaeus calyptratus sp. n. (Epedanidae, Opiliones) from Hainan Island (China) is diagnosed, described and illustrated. A key to the two Chinese species of Tithaeus is provided.

During a 2009 faunal survey of tropical Hainan Island, a few specimens of the Laniatores were collected. Among them, one species of Tithaeus was identifi ed as new to science and is described in this paper.

Marterials and methods
Two males and one female were collected from Hainan Island in south China (Fig. 1). All type specimens are deposited in the Museum of the Hebei University (MHBU), Baoding, China. Specimens were preserved in 75% ethanol, examined and drawn using a Leica M165c stereomicroscope equipped with a drawing apparatus. Th e genitalia were fi rst placed in hot lactic acid then moved to distilled water in order to expand them for observation (Schwendinger and Martens 2002). All measurements are in mm.
Diagnosis and distribution: see Lian et al. (2008). Etymology. Th e specifi c name is derived from the Greek word "calyptra" meaning a cap or hat, referring to the straw-hat type stylar lobe of the penis.

Key to species of Tithaeus known in China
Diagnosis. Th e new species is similar to T. kokutnus Suzuki, 1985, recorded from northern Th ailand (Suzuki, 1985: fi g. 4), but can be easily distinguished from it by the following characters: (1) Cheliceral proximal segment armed with a large tooth and two smaller ones, situated medially on the ventral surface and the second segment is covered with granules on its frontal surface; (2) Both the dorsal margin of pedipalpal femur and its ventral margin between two setiferous tubercles are fi nely serrated; (3) Penis with a straw-hat shaped stylar lobe.
Comments. T. calyptratus sp. n. has various morphological characters that support its placement in the genus Tithaeus: viz., scutal region with fi ve areas, eye tubercle without a median spine, pedipalpus relatively short and thick, tarsi III and IV without scopulae and distitarsus I with two tarsalia. Furthermore, the genital characters (such as, the distal margin of the penial ventral plate with a deep cleft, glans with simple mem-branous lobe and each lobe of the ovipositor with two ventral and two dorsal setae) are also in agreement with to the generic disagnosis of Tithaeus (as per Lian et al. 2008).
Description. Male (holotype) habitus as in Figs 2-3. Coloration: body rusty yellow; carapace and ocularium with yellow-brown reticulation; lateral margins and opisthosomal areas of scutum, and free tergites banded with blackish brown; all coxae and genital plate yellowish, free sternites somewhat clouded; chelicerae and pedipalpus yellowish, with brown reticulate markings above; trochanters of legs yellowish; femora to tarsi slightly darker. Body from above as a trapezoid, wider posteriorly than anteriorly. Ocularium ovoid, only with a few granules. A low hump, lower than the ocularium, is situated between it and the anterior margin of carapace. Abdominal scutum, as well as each free tergite, with a transverse row of very small tubercles, and with a longitudinal row of granules on their lateral margins. Anal plate with scattered tubercles. Each of the free sternites with a row of obsolete granules. Coxa I with irregular hair-tipped granules, coxae II-IV smooth. Dorsal surface of coxa IV with several rather coarse granules. Coxa III with a few humps along the frontal and rear margins. Tracheal stigma clearly visible.
Chelicera (Figs 7-9). Proximal segment disto-dorsally visibly swollen, armed with a large tooth and two smaller ones, situated medially on the ventral surface. Second segment with some hair-tipped tubercles on frontal surface. Fingers relatively short but stout; inner edges toothed as shown in Fig. 8.
Pedipalpus (Figs 4-5) short and robust, trochanter with a ventral setaceous tubercle. Femur ventrally with three strong and a small setiferous tubercles; on the prolateral distal side with a setiferous tubercle. Femur dorsally with a minutely serrate margin (Fig. 6). Such a margin also between the two ventral setiferous tubercles. Patella disto-medially with a setiferous tubercle. Tibia ventro-laterally with two small and two prominent setiferous tubercles, ventro-medially with two stout and two reduced setiferous tubercles. Tarsus ventrally with three setiferous tubercles on each side.
Female. Similar to male in general appearance but with a slightly larger body. Ovipositor as illustrated (Fig. 10

Discussion
Th e opilionids genus Tithaeus was established by Th orell in 1891 (type species: T. laevigatus Th orell, 1891). Later, Roewer (1912Roewer ( , 1927Roewer ( , 1949 placed it in the subfamily Phalangodinae of Phalangodidae and Suzuki (1969aSuzuki ( , 1969bSuzuki ( , 1972Suzuki ( , 1985 supported this assignment. However, recently Kury (2003Kury ( , 2010  genus reasoning both from its somatic and from male genital morphology. Having compared Tithaeus similis Suzuki, 1985 with representatives of two subfamilies, the phalangodid and the epedanid, they found out that its male genitalia could be evidence of its relationship with the epedanid. We follow Kury' opinion and consider Tithaeus a member of the Epedanidae on the basis of its genital characters, such as, a well developed immovable sac and the absence of complex introverting structures in the penis.