CRUSTACEA MALACOSTRACA III ij 



of first segment and of the three posterior segments is undivided and rounded. All segments have 

 a somewhat small epimeral protuberance very visible from above; the epimeral protuberance of first 

 segment is longer than broad, those of second to fourth segments are bipartite, with their posterior 

 lappet from a little to much shorter than their anterior lappet, and when the posterior lappet is small, 

 it is covered by the plate of the segment. (In one of my two specimens, a female, the posterior lappet 

 of these epimeral protuberances is quite small and invisible from above; in the other specimen, a male, 

 the posterior lappet is narrower but only a little shorter than the anterior, and its tip is visible from 

 above). The lateral plates of the three posterior segments are rounded and short; the epimeral protuber- 

 ances of these segments are small and rounded. 



The posterior half of each lateral margin of the abdomen (figs. 2 b and 2 c) is adorned with 

 about eight obliquely triangular saw-teeth, and the margin in each interval between two teeth is bent 

 at the insertion of a strong seta. The median, flatly convex portion of the hind margin protrudes 

 slightly more backwards than the convex postero-lateral part of the abdomen. The uropods (in the 

 male) about as long as the abdomen. 



Length of the male 7 mm., of the female without marsupium 67 mm. 



Remarks. Harger's figure of I.alta from above is on the whole good. The species is closely 

 allied to I. maculosa, but the last-named species is separated from I. alta in having no median frontal 

 process, the antero-lateral angles of the head not produced forwards, rounded, and measuring more than 

 90 , finally the two incisions on the hind margin of the median lamella of the male abdominal oper- 

 culum are much deeper and the rounded minute protuberance in each incision considerably smaller in 

 /. maculosa (fig. 1 f) than in I. alta (fig. 2 d). 



Occurrence. Taken by the "Ingolf" at a single station. 



West of Iceland: Stat. 96: Lat. 65°24' N., Long. 29°oo' W., 735 fath., temp. 12 ; 2 spec. 



Distribution. Off the east coast of North America at a number of places between Lat. 38° N. 

 and 44 N., several of the localities not far from the U. States, others in the Bay of Fundy, and, besides, 

 it has been taken far south of Nova Scotia and east of Sable Island; depths 35 to 487 fathoms (Richardson). 



4. Ianira tricornis Kroyer. 

 (PI. I, figs. 3 a— 3 b). 

 ?i846. Hcuopomus tricornis Kroyer, in Gaimard, Voy. en Scaud., Crust., PI. 30, figs. 2 a— 2 q. 

 ! 1847. — — Kroyer, Nat. Tidsskr. Ny Rajkke, Vol. II, p. 372. 



1901. Tole libbcyi Ortmann, Proc. Acad. Nat. Sc. Philadelphia, 1901, p. 157, with fig. (Tolc a misprint 



for Iole). 

 ! 1913. Janthe libbeyi Stephensen, Meddelelser 0111 Gronland, Vol. 51, p. 70; PI. 3. 



Description. Stephensen's figures in the paper quoted convey a fairly accurate idea of this 

 species. — The median frontal process is somewhat long; each antero-lateral angle is produced into a 

 well developed process as long as, or a little longer than, broad, and terminating in a spine articulated 

 to its end; each half of the anterior margin between the median and the lateral process is conspicuously 

 convex. Eyes large and close to the lateral margins. 



The Ingolf-Expedilion. III. ;. 3 



