2l8 CRUSTACEA MALACOSTRACA. III. 



1895. Podascon (?) Stcbbingi Giard & Bonnier, Bull. Sci. France et Belgiqne, Vol. XXV, p. 456. (Trans- 

 lation of Stebbing's text, with his figures). 

 1899. Cryptoniscid No. i, in G. O. Sars, Account, II, p. 244; PI. 100, fig. 2. 



Female. Nothing can be added to the brief generic diagnosis; fig. 4 a shows all that could 

 be seen on the specimen, which is 2-4 mm. long. 



' Male. Body somewhat robust (fig. 4b), about three times as long as broad. Head with the 

 front margin broadly and evenly rounded. - Antennulee (fig. 4 c) considerably smaller than in the 

 preceding forms; first joint (fig. 4d) with the anterior margin of very moderate length, outer margin 

 long and somewhat concave, posterior margin and the most posterior part of the inner margin with 

 in all seven teeth, all with the end obtuse, excepting the anterior triangular tooth on the inner mar- 

 gin and the outer tooth on the posterior margin; the fourth tooth, counted from the outer margin, 

 is much broader than the others. Second joint proportionately somewhat large, with the anterior 

 margin very long and much longer than the outer margin, which has four saw-teeth, all acute and, 

 excepting the posterior tooth, low and very oblique; the two rami subequal in length. -- Antennae 

 normal, reaching nearly beyond the middle of fifth thoracic segment (fig. 4b). 



The comb-teeth are very conspicuous on all pairs of epimera. The three posterior pairs of 

 thoracic legs have a tiny spine at the middle of the lower margin of the hand. On fifth pair (fig. 4e) 

 the hand is about four times as long as deep, distinctly curved, somewhat tapering from before the 

 middle to the moderately broad, truncate end; seventh joint a little more than half as long as the 

 hand, normally shaped, and a little more than twice as long as the claw. In seventh pair (fig. 4 g) 

 the hand is straight and a little more slender than in fifth pair, the claw is longer and extremely 

 thin, but otherwise these distal parts are nearly as in fifth pair. Sixth pair (fig. 4 f) are more aber- 

 rant; the hand is distinctly narrower, and tapers considerably from near the base to the narrow end; 

 seventh joint is somewhat longer than in the other pairs, very slender, but widens a little at the distal 

 end, which shows a structure about as in Arcturochcrcs though much less developed; the claw as long 

 as in fifth pair. Pleopods, sixth abdominal segment, and uropods nearly as in Arcturochcres 

 pulchripes. 



Length 1-06 mm. 



Remarks. It is after prolonged hesitation that I refer the specimens examined to Podascon (?) 

 Slcbbingii G. & B., as established by the French authors on Stebbing's description and figures of a 

 male taken in the marsupium of Onisimus plautus Kroyer, which generally occurs in very moderate 

 depths. My specimens, female and male, were taken in the marsupium of Onisimus Icucopis G. O. Sars, 

 a deep-sea species of the same genus, which rendered the reference of its parasite to a species occur- 

 ring on a host from much lower water less advisable, but Stebbing's figure of the right antennula and 

 its teeth agrees so closely with that found in my specimen, that I must consider the males seen re- 

 spectively by Stebbing and by me as belonging to the same species. Sars has decribed and figured 

 a Cryptoniscid and says that he had found specimens both in Plankton samples and in the marsupium 

 of Onisimus plautus, but his figure of the antennula differs considerably from mine, and differences 

 are also found between his figures of the posterior pairs of legs and corresponding figures of mine, but 



