lÓI 



breadth of carapace. Anterior margin of meropodites of 



walkino- leo-s witli a series of spines Ps. sii'idiilans Wood-Mason 



Distance between external orbital ang-les about three-fourths 

 the greatest width of the carapace. Anterior margin of mero- 

 podites of walkings legs with a single (subdistal) spine . . Ps. insignis Alcock ') 



I. Psophciic7is slridiilans Wood-Mason. 



1892. Psopheticus stridulans Wood-Mason. 111. Zool. "Investigator", Crust., prt i, pi. 5, f. i. 



1894. Psopheticus stridulans Alcock. Ann. Mag. Nat. Hist. (6), v. 13, p. 402. 



1899. Psopheticus stridulans Alcock. "Investigator" Deep-Sea Brachyura, p. 73. 



1900. Psopheticus stridulans Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 309. 



1904. PsopJieticus stridulans üoflein. Wiss. Erg. "Valdivia", Bd 6, Brachyura, p. 1 18, pi. 30, f. 4. 



Stat. 38. 7°35'.4S., ii7°28'.6E. North of Paternoster Islands, Bali Sea. Depth 521 m. -). i cf. 



It would not be worth while to give a new description of this species or to figure it 

 acrain, for Alcock's diagnosis is rather complete and though I could not see the figure in the 

 111. Zool. "Investigator", the photographic reproduction provided by Doflein conveys an excellent 

 idea of this deep-sea inhabitant. As my specimen happens to be considerably larger than those 

 of Alcock (whose largest cT is only 20 mm. broad) some few remarks may be of use. 



In the first place Alcock notes that the carapace is "crossed transversely in its posterior 

 half by a broad groove which is continued obliquely across the pterygostomian regions to the 

 angles of the mouth", and further remarks, that this groove which is sharply defined and of 

 a red colour, divides the carapace into an anterior "livid red or almost violet" portion and a 

 posterior one of a dusky red colour. I do not see anything of this kind in my specimen : there is 

 no transverse groove at all, save the short, ill-defined cervical groove ^), and the whole animal 

 is of a uniform ivory-white colour. 



Secondly it is true, that the suborbital and subhepatic regions in my specimen are 

 somewhat inflated, but they are covered with very minute granules only, and do not constitute 

 a "granular eminence" (Alcock). 



The eye-stalks are short, but the cornea of the. eye, which does not quite reach to the 

 flattened, much prominent e.xternal orbital angle, is very large, rounded and forms, with the 

 stalk, a hammer-shaped structure, as in Hexaplax Doflein. The upper orbital margin presents 

 an obtuse prominence in the middle, the inferior margin is entire, finely beaded, and projects 

 inwardly into a large, obtuse tooth, leaving a wide gap between it and the external angle of 

 the front, which gap is partly filled by the antenna, the flagellum of which is nearly twice as 

 long as the eye-stalk; the orbit itself is nearly as wide as the square-cut, overhanging front, 

 beneath which the elongate antennulae are transversely folded. 



1) Journ. .\s. Soc. Bengal, v. 69. prt 2, 1900, p. 310; 111. Zool. "Investigator", Crust., prt 9, 1902, pi. 54, f. 2. Hab. Gulf 

 of Martaban, in only 60 — 67 fathoms depth. 



2) According to list of stations. On label in bottle a considerably greater depth is indicated (400 — 500 fathoms, about 

 720—900 metres). 



3) Xeither do I detect a distinct indication of this transverse groove in Dofi.ein's figure. 



13 



