CRUSTACEA MALACOSTRACA. II. 65 



ends; on the three posterior segments their broadest part is behind the middle and in the seventh 

 somewhat near the posterior margin. The broadest part of eaeli segment has instead of lateral angles 

 a pair of rounded protuberances on which the legs are inserted. — Thoracic legs moderately long 

 and very slender. Second (fig. 51) and third pairs completely similar (fig. 5 b); fifth joint of very 

 moderate length, with a somewhat long seta on the posterior angle; fifth joint very long, much longer 

 than the fourth and slightly shorter than the sixth, with a very long seta from the anterior distal 

 angle; seventh joint and claw equal in length and together somewhat shorter than sixth joint. Three 

 posterior pairs of legs (fig. 5 k) with second joint extremely long, about as long as the five following 

 joints and the claw combined; sixth joint slightly longer than the fifth, and both these joints with 

 some terminal spines, two of which are somewhat long; the claw much longer than seventh joint and 

 sometimes even about as long as the sixth joint. 



Abdomen somewhat shorter than the two posterior thoracic segments combined ; the five seg- 

 ments somewhat narrower than seventh thoracic segment (fig. 5 a); the last segment broadly cordiform, 

 conspicuously broader than the preceding segment and as long as two segments combined. — Pleopods 

 and uropods mentioned in the description of the genus. 



.Length of the largest specimen 3.8 mm . 



Subadult Male. The antennulse (fig. 511) are much thicker than in the female; first joint 

 about three times as long as deep, and nearly as deep at the end as at the base, but narrower at the 

 middle, as the lower margin of the joint is somewhat concave; second joint considerably deeper than 

 long; third joint divided by a transverse suture a little before the middle and the proximal part 

 marked off in this way much thicker than the distal. Antennae consist of a single joint about three 

 times as long as in the female, about as long as the depth of first autennular joint at its base. — 

 Abdomen somewhat longer in proportion to the posterior thoracic segments than in the female; the 

 pleopods have been described in the diagnosis of the genus. 



Length of a subadult male 3"' m . 



Remarks. As to this extremely interesting species it may be sufficient to refer to the re- 

 marks on the genus. The animals are completely white. 



Occurrence. Taken by the "Ingolf" at three stations in the warm area. 



Davis Strait: St. 24: Lat. 63°o6' N., Long. 56°oo' W., 11991111., temp. 2.4 ; 1 spec. 



Denmark Strait: St. 10: Lat. 64°24' N., Long. 28° 50' W., 788 fm., temp. 3.5 ; 8 spec. (3 females, 3 



males and 2 young spec). 



South of Iceland: St. 40: Lat. 62 00' N., Long. 21° 36' W., 845 fm.. temp. 3.3 ; 1 spec. 



Leptognathia g. o. Sars. 



This genus comprises 14 species already established in the literature. In the following pages 

 25 species are described, 19 of which are considered new to science. The genus is thus very large, 

 comprising 33 species. For reasons mentioned on p. 9, I do not divide it into three or four genera, 

 though it comprises types not only very different in general aspect but also showing considerable 



The Ingolf-Expedition. III. 5. 9 



