Crocydocinus beauchampi ( Alcock & Anderson, 1894 ) Lee & Forges & Ng, 2019

Lee, Bee Yan, Forges, Bertrand Richer De & Ng, Peter K. L., 2019, Deep-sea spider crabs of the family Epialtidae MacLeay, 1838, from Papua New Guinea, with a redefinition of Tunepugettia Ng, Komai & Sato, 2017, and descriptions of two new genera (Crustacea: Decapoda: Brachyura: Majoidea), Zootaxa 4619 (1), pp. 1-44 : 27-28

Crocydocinus beauchampi ( Alcock & Anderson, 1894) comb. nov.

( Fig. 20A, B )

Anamathia beauchampi Alcock & Anderson, 1894: 185 (type locality: Bay of Bengal).

Scyramathia beauchampi— Alcock 1895: 204, 205.— Alcock & Anderson 1896: pl. 20 fig. 2, 2a.— Alcock, 1899: 5 (list), 54– 55.

Rochinia beauchampi— Serène & Lohavanijaya 1973: 56 (key).—Griffin & Tranter 1986: 175 (key).— Tavares, 1991: 161 (list).— Casadío et al. 2005: 158 (list).— Ng & Richer de Forges 2007: 62 (list).— Ng et al. 2008: 105 (list).

Remarks. Crocydocinus beauchampi comb. nov. was originally described as Anamathia beauchampi Alcock & Anderson, 1894 , based on a single ovigerous female specimen from the Bay of Bengal ( Alcock & Anderson 1894: 185). The specimen is relatively large at 21 mm maximum carapace length and 14 mm maximum carapace width (cf. Alcock & Anderson 1894: 185). Alcock (1895: 204–205) re-described this species using more specimens collected from the same locality, Bay of Bengal, with measurements for one male and one female specimen provided. The figures by Alcock & Anderson (1896: pl. 20 fig. 2, 2a; reproduced here as Fig. 20 ) of a male specimen were published subsequently. The illustrated male specimen is probably based on the material discussed in Alcock (1895: 204–205) as stated in the explanation for the plate ( Alcock & Anderson 1896: pl. 20). There was neither a clear designation of type material for the species nor a clear indication of the institutional repository; although it is likely that the specimen was deposited in the Indian Museum. No material was examined for this species.

Alcock & Anderson (1894) and Alcock (1895) noted that C. beauchampi comb. nov. is morphologically close to the description and figures of Rochinia tanneri Smith, 1883 (cf. Pettan & Tavares 2014: fig. 2B). Several differences, however, were also noted by Alcock & Anderson (1894: 185): the carapace and legs covered with dense layer of setae; short pseudorostral spines of approximately half the carapace length; strong epibranchial spines; and small pre-orbital spines, all of which are characteristic of Tunepugettia Ng, Komai & Sato, 2017 , and Crocydocinus n. gen. Based on the figures by Alcock & Anderson (1896; Fig. 20 ), the specimen lacks distinct carapace spines that are characteristic of R. tanneri (cf. Pettan & Tavares 2014: fig. 2B). The authors have transferred this species to Crocydocinus n. gen., because its pseudorostral spines are short, straight and cylindrical, the basal antennal article has a slight convex outer margin; and the ambulatory legs are not carinate (cf. Alcock 1895: 204–205; Alcock & Anderson 1986: pl. 20 fig. 2, 2a; Fig. 20 ). In addition, Alcock (1895: 205; 1899: 54) described the fresh colouration of the species as “Earth-colour with the chelipeds pink”, which is similar to the other species of Crocydocinus recognised here ( Fig. 10B, C ). The branchial regions of C. beauchampi , however, are rather unusual in that they are laterally swollen, so much so that the margins meet medially in the gastro-cardiac part of the carapace ( Fig. 20A ); a character not known in any other species of Crocydocinus n. gen., Tunepugettia , Rochinia s. str., Neophrys n. gen. or Samadinia . This suggests that this species may need to be referred to its own genus when specimens can be examined and characters found.

Crocydocinus beauchampi comb. nov. is only known from its type locality, Bay of Bengal.

Figures

FIGURE 10. Color in life. A, Tunepugetia corbariae n. sp., paratype. male (22.8 × 14.4 mm) (MNHN-IU-2013-2352), Papua New Guinea; B, Crocydocinus ewok n. sp., paratype, male, (19.7 × 13.4 mm) (MNHN-IU-2013-1517), Papua New Guinea; C, C. porg n. sp., holotype, female (28.5 × 19.3 mm) (MNHN-IU-2013-3042), Papua New Guinea; D, Neophrys inopinata n. sp., holotype, ovigerous female (27.1 × 19.2 mm) (MNHN-IU-2013-3022), Papua New Guinea.

FIGURE 20. Illustration of Crocydocinus beauchampi (Alcock & Anderson, 1894) comb. nov., Bay of Bengal. A, overall dorsal view; B, frontal ventral view. (After Alcock & Anderson, 1896: pl. 20 fig. 2, 2a)