CRUSTACEA MALACOSTRACA. Ill 125 



From these enumerations it is seen that this species goes down to 1199 Iat h- in the warm 

 area, to 1333 fath. in the cold area, and that in high latitudes it has been taken in depths of 10 and 

 of about 35 fath. 



79. Ilyarachna bicornis n. sp. 

 (PL XI, figs. 8 a— 8 c). 



Female (without marsupium). Closely allied to I. hirticeps, but distinguished by a few fea- 

 tures. — The head, which is about as broad as first thoracic segment (fig. 8 a), has its upper surface 

 smooth, excepting that it possesses a single pair of conspicuous, robust, somewhat conical, acute pro- 

 tuberances or teeth, placed at some distance from the hind margin and considerably apart from one another. 

 — The basal joint of the antennulse (fig. 8 b) about as broad as the length of its inner margin, while 

 the distal part outside the articulation of next joint is produced into a good-sized triangle terminating 

 in a spine; the outer margin of the joint has no spines, but at most some short setse. — The basal 

 joint of the antennae (fig. 8 b) is broad, with the outer corner considerably produced and terminating 

 in a thick spine. 



Second thoracic segment broader than the head and considerably broader than fifth segment 

 (fig. 8 a). The four anterior segments with partly moderately small, partly very small spines along their 

 anterior margins, about ten spines on the second and only a few on fourth segment; the shape of the 

 sides of the four anterior segments and the epimera may be sufficiently seen on the figure. — The 

 abdominal operculum has a high keel with many spines; the uropods without exopod. 



Length of the largest specimen 87 mm. 



Remarks. This species is certainly valid, not a variety of / hirticeps; the curious armature 

 of the head and the absence of spines on the outer margin of the basal antennular joint must be 

 good characters. 



Occurrence. Gathered by the "Ingolf" at a very deep station in the warm area. 



Davis Strait: Stat. 36: L,at. 6i°5o' N., Long. 56°2i' W., 1435 fath., temp. 1-5°; 2 spec. 



80. Ilyarachna dubia n. sp. 

 (PI. XI, figs. 9 a— 9 c). 



Female (without marsupium) and Male. Closely allied to I. hirticeps. — Head distinctly nar- 

 rower than the first and somewhat narrower than second segment; its surface is completely smooth, 

 without any trace of spines. — Basal joint of the antennulse (fig. 9 b) scarcely as broad as the length 

 of its inner margin, while the distal outer part is produced into a considerable or even rather long 

 triangle terminating in a small spine and a feathered seta; the outer margin with at most a few thin, 

 nearly setiform spines; in the female (fig. 9b) the flagellum consists of five joints, the four distal very 

 slender and moderately long, while in the male the flagellum is considerably thicker and longer, with 

 about nineteen short joints. — The anterior margin of the four anterior thoracic segments without 

 spines or distinct crenulation. The shape of the epimera may be seen on fig. 9 a. — The female oper- 

 culum has a high keel with strong setae; the uropods without exopod. 



