First description of the male of Cyclocosmiaricketti (Araneae, Halonoproctidae) from China

Abstract Background The genus Cyclocosmia Ausserer, 1871 of the spider family Halonoproctidae Pocock, 1901 includes ten known species from North America and Asia. Since Cyclocosmiaricketti was described by Pocock in 1901, no males of this species have ever been reported. New information The male of Cyclocosmiaricketti is described for the first time, based on a specimen collected near the type locality in Fujian Province, China. A morphological description and illustrations are given.

Cyclocosmia ricketti was initially reported as Halonoproctus ricketti, based on one female specimen from Kuatun, north-western Fokien in China, now known as Guadun (27.7359°N,117.6408°E) in Fujian Province. A Cyclocosmia male was collected 130 km (in a straight line) away from the type locality, which we believe to be conspecific and which we describe here (Fig. 6)   First description of the male of Cyclocosmia ricketti (Araneae, Halonoproctidae) ...

Materials and methods
The specimen was preserved in 80% ethanol and examined under a LEICA M205C stereomicroscope. Images were taken with an Olympus C7070 zoom digital camera (7.1 megapixels). Habitus photographs of the preserved specimen were taken with a Sony A7RIV digital camera, equipped with a Sony FE 90mm Goss lens. Photos were stacked with Helicon Focus (Version 7.6.1) and processed with Adobe Photoshop CC2019.
All measurements are in millimetres and were obtained with an Olympus SZX16 stereomicroscope with a Zongyuan CCD industrial camera. The total length does not include the chelicerae. Eye sizes are measured as the maximum diameter in either dorsal or frontal view. Leg measurements are given as follows: total length (femur, patella, tibia, metatarsus, tarsus).
Specimens, reported here, are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing and Muséum d'histoire naturelle (MHN) in Geneva.
Chelicerae relatively slender, similar to carapace in pigmentation, retrolaterally with dark reticular pattern and thin wrinkles; promargin of groove with seven principal teeth and five denticles, retromargin with ten sizable denticles, arranged in regular rows; dense hair covering retromargin; prolateral surface of fang with serrated longitudinal keel; rastellum conspicuously projected, with about eight distal spines. bearing few scattered black hairs; tibia cylindrical, basal half slightly inflated and distal part narrow, ventrally covered with hairs; tarsus short, dorsally with several hairs, with vaulted emarginate apex; width of bulbous part of palpal organ in retrolateral view 1.33 (Fig. 4), divided into left and right parts by deep angular distal invagination (Fig. 3A); embolus linear in ventral and dorsal view, slightly curved in lateral view, its apex tapering, length about 2.39 (Fig. 4); apophysis of embolic apex pointing dorsad, with tip of embolus narrowly rounded (Fig. 5d).
Legs distinctly more slender and smoother than in female, light reddish-brown, with conspicuous longitudinal bands on dorsal surface and fine transversal fissures; tarsi, metatarsi and tibiae armed with blunt setae and black spines scattered on ventral side; ventral side of all tarsi, except tarsus IV, with dense short, white scopula covering about distal half of the segment. Legs I and II with setae and spines denser than on legs III and IV; patellae and femora almost glabrous; two spines inside tarsal scopula on leg I, three spines on leg II, five spines on leg III, seven spines on leg IV; few short spines present laterally on dorsal side of all patellae; distal part of tarsus IV ventrally with a few gracile, serrate white hairs. Trichobothria tibia, metatarsus and tarsus surface with few, terminal one longest.
Paired tarsal claws with two teeth near the base; unpaired claws bare. First description of the male of Cyclocosmia ricketti (Araneae, Halonoproctidae) ... Abdomen (Fig. 1D) 7.22 long, its rounded disc 5.17 in diameter, dark yellow-brown, clearly less sclerotised than in female; tergum with few adnate blunt bristles and an conspicuous cardiac mark mid-dorsally; abdominal disc with narrow ribs and shallow grooves, 30 radiating ribs on each side; margins of abdominal seam inconspicuous, rib angles slightly elevated, each with several small hairs; positions and shapes of muscle impressions as in female, but only two pairs of short bristles on their rims.
Spinnerets: posterior median spinnerets thin, one-segmented, 0.71 long; posterior lateral spinnerets relatively thick, three-segmented, 1.51 long (proximal segment 0.57, median 0.36, distal 0.57) with with distal segment narrower than others; anus covered by crescent-shaped sclerite, not connected to ventral median rib angle (Fig. 1E). The male of C. ricketti can be distinguished by the following characters: in the ventral view of the palp organ, the diameter of the bulb is about 1/2 of the embolus length (vs. 1/3 in C. latusicosta and C. sublatusicosta (Yu and Zhang 2018 Figs. 1D and 3D)), both sides of the bulb are separated by an angular invagination in ventral view ( Fig. 4A and B) (vs. rounded invagination in C. lannaensis (Schwendinger 2005 Figs. 41-44)) and in prolateral view, the apophysis of the embolic tip points dorsally (vs. points laterally in C. latusicosta, C. siamensis and C. lannaensis) (Fig. 5).