Arcuphantes arcuatulus Chamberlin & Ivie, 1943

Jin, Miao, Ma, Shuangchun & Tu, Lihong, 2018, A review of the Arcuphantes species with the genitalia of arcuatulus - type (Araneae, Linyphiidae), Zootaxa 4425 (3), pp. 498-510 : 502

Arcuphantes arcuatulus Chamberlin & Ivie, 1943

Figs 2A–E , 3A–C , 4 , 7A–B

Linyphia arcuata Keyserling, 1886: 74 , pl. 13, f. 173 (Df; preoccupied by Thorell, 1856).

Lepthyphantes arcuatus Petrunkevitch, 1911: 244 .

Lepthyphantes arcuatulus Roewer, 1942: 560 (replacement name).

Arcuphantes arcuatus Chamberlin & Ivie, 1943: 21 , f. 37-40 (Tf from Lepthyphantes, Dm ; specific name is a primary homonym replaced by Roewer); Tu & Hormiga, 2010: 61, f. 2a-f, 9a (f).

Material examined. 1♂, USA: Washington: Arlington , 48°N, 122°W, 9.ix.1935, Chamberlin & Ivie leg. (AMNH-161) ; 1♀ Washington: 10 miles north of Vancouver , 45°N, 122°W, 10.ix.1935, Chamberlin & Ivie leg. (AMNH-165).

Diagnosis. The male A. arcuatulus can be distinguished from A. cruciatus n. sp., and A. denticulatus n. sp. by the bifid outer paracymbial arm with a blunt inner apophysis ( Fig. 7B ), and by the terminal apophysis having the anterior process turning backwards ( Fig. 7A ). The female can be distinguished by the epigynum in ventral view more slender than that of A. cruciatus n. sp., the prolonged basal part under the extensible base is almost square, with the parallel lateral margins slightly incurved ( Fig. 3A–C ).

Description. Male (AMNH-161): Total length 1.94. Carapace 0.78 long, 0.63 wide. Abdomen 1.11 long, 0.53 wide. Female (AMNH-165): Total length 1.26. Carapace 0.57 long, 0.54 wide. Abdomen 0.75 long, 0.49 wide. Legs broken, data on leg lengths absent.

Other somatic and genital characters: see the general description for the Arcuphantes species with arcuatulus - type genitalia.

Distribution. USA (Washington).

Figures

FIGURE 2. Male palp. A–E. Arcuphantes arcuatulus. A, prolateral; B, ventral; C, retrolateral; D, embolic division, ventral; E, ditto, dorsal; F–J, A. denticulatus n. sp., F, prolateral; G, ventral; H, retrolateral; I, embolic division, ventral; J, ditto, dorsal. Arrows in D, E, I, J refer to serrate area on radix. [Scale bars, mm]

FIGURE 3. Epigynum. A–C. Arcuphantes arcuatulus, A, ventral; B, lateral; C, dorsal, arrow points to the proximal end of fertilization groove; D–C, A. cruciatus n. sp., D, ventral; E, lateral; F, dorsal; G–I, A. semiorbiculatus n. sp., G, ventral; H, lateral; I, dorsal. [Scale bars, mm]

FIGURE 4. Arcuphantes arcuatulus. A–C, male palp, with embolic division removed, A, prolateral; B, ventral; C, retrolateral; D–E. embolic division, arrows point to central serrated area of radix, D, ventral; E, dorsal. [Scale bars, mm]

FIGURE 7. Male palpal embolic division and paracymbium. A–B, Arcuphantes arcuatulus, C–D, A. cruciatus n. sp., E–F, A. denticulatus n. sp., A, C, E, embolic division, anterior, embolus apex artificially broken in E, arrows point to anterior process of terminal apophysis turning backwards in A and extending forward in E, and bulged anterior part of terminal apophysis in C; B, D, F, paracymbium, arrows in B and F point to basal fold of paracymbial middle arm. [Scale bars, mm]