Hephthopelta Alcock. 



1899. Hephthopelta Alcock. Deep Sea Brachyura "Investigator", p. ^6. 



With Camatopsis and Megaesthesius this genus is distinguished by the antennulae being 

 too laro-e to be folded up in their fossae beneath the front. The present genus presents 

 well-pigmented, nor mal eyes, on the ventral side of the movable eye-stalks; 

 the merus of the e.xternal maxilüpeds is rounded laterally and anteriorly, and the inner angle 

 of the wHst of the chelipeds is largely produced ^). 



Two species of this genus are known, both obtained at rather great depths (175 and 

 490 fathoms). The "Siboga" collection contains a single specimen, which I take to represent 

 a new species. 



Key to the species : 



1. Carapace as broad as long. Posterior border of meropodites of first 



two pairs of ambulator)' legs spinulose H. luguèris Alcock '') 



Carapace broader than long. Meropodites of ambulatory legs unarmed 

 at posterior margin 2 



2. Eye-stalks constricted near corneae, pigment of eye dull. Lower 



surface of left (smaller) chela flattened, with pronounced margins, 



the outer margin ending in a spine //. apta Rathbun ') 



Eye-stalks not constricted, pigment of eye black. Lower surface of 



left chela rounded, not flattened . H. littoralis n. sp. 



I. Hephthopelta littoralis n. sp. PI. 9, Fig. 3. 



Stat. 174. Waru Bay, north coast of Ceram. Depth 18 m. i O. 



The carapace, which is pubescent throughout, with some longer and thicker hairs near 

 the margins, and, save for the very long and straight cervical groove and two branchio-cardiac 

 grooves, does not show any distinct sculpture, is broader than that of H. apta : in Miss Rathbun's 

 species its breadth is 1.2 times, in the present one nearly 1.5 times its length. The anterior 

 third part is rather strongly defle.xed, so that the anterior edge of the front, which is straight 

 and measures one-fourth of the total breadth of the carapace, is not visible in dorsal view. 

 The eye-peduncles are cylindrical, shorter than the breadth of the front, somewhat bulging at 

 base and with a perfectly-developed eye at the ventral side of the tip. The fronto-orbital 

 distance is more than one-half the greatest breadth of the carapace and so larger than that of 

 //. apta. The lateral margins of the carapace soon curve backward behind the eyes and are 



1) Miss Rathbun (Proc. U. S. N.-it. Mus., v. 48, 1914, p. 149) pretends that the narrow plate, inteicalated between the fourth 

 and the fifth segment of the steinum of the (^ and covering the genital canal leading from the coxopodites of the last pair of legs, 

 represents a generic character. The same, however, occurs in the (^ of Caviatopsis. 



2) Deep Sea Brachyura '•Investigator"', 1899, p. 77, pi. 4, f. 2: Journ. As. Soc. Bengal, v. 69, prt 2, 1900, p. 327. Hab. Andaman 

 Sea, 490 fathoms. 



3) Proc. U.S. Nat. Mus., v. 48, 1914, p. 148. Hab. Philippine waters, 175 fathoms. Among the dififerences between this species 

 and H. lugubris Miss Rathbun also cites those taken from the chelipeds, but in Alcock's only specimen these were wanting. 



85 



