species which in the ovigcrous female aliain the most remarkable 

 diversities of form- Professor Sars unites in the single family 

 Cryptoniscidae parasites which M M. Giard and Bonnier distri- 

 bute among the Cryptoniscidae, Cyproniscidae. Podasconidac, 

 and Cabiropsidac, according as they respectively infest Th}ros- 

 traca, Ostracoda, Amphipoda, or Isopoda. The latter 

 arrangement is confessedly provisional, and viewed in that 

 light it may be allowed to have the considerable merit of 

 convenience. 



Cyproniscus CROSSoi'iioRL, Stebbing. 



Plate 15B. 



1901- CyprojNisiUs ci-ossopJwri, Stcl)bing, Knowledge, vol. 24, p- 

 100. 



An ovigcrous female, somewhat longer than broad and slightly 

 imsymmetrical, shows no definite division into segmentts- Of 

 lateral lobes the two or three in the centre are well defined, and 

 from these sutures run both dorsally andventrally, but without 

 meeting in the middle either of the convex side or the flattened 

 opposite side- Both apices are broadly rounded. The flexible 

 cord is attached high up on the convex surface. 



In the last larval stage the animal is somewhat fusiform, with 

 fine strife across the back. The head is rather narrowly rounded 

 in front, widening greatly to the strongly-produced subacute 

 postero-lateral angles, the under surface of the front showing a 

 reflexed median point. Of the seven segments of the peraeon the 

 first is completely overlapped by the angles of the head, the sixth 

 is the widest and slightly the longest; all have denticulate sides- 

 The six segments of the pleon are, together, about as long as the 

 six preceding segments, and taper gradually to the inserltion of 

 the uropods, behind ^vhich the telsonic part of the sixth segment 

 is triangular with somewhat sinuous sides and a rather rounded 

 apex, the whole margin being cut into fourteen teeth, or twelve, 

 if the uppermost points are not included in the reckoning. 



Eyes not perceived and probably absent, in accord with the 

 generic definition. First antennae adjacent on underside of head ; 

 the basal expansion hand-like, showing on the inner side a short 

 thumb and towards the outer side four fingers, and besides these 

 two others not accurately in the same plane, one lying on the first 

 finger, the other projecting between it and the thumb. The 

 second joint is nearly as broad as long, and carries two short 

 branches, of which one at least is tipped with a long seta; the 

 small third joint carries a great tuft of divergent hyaline fila- 

 ments- 



The second antennae arc much longer, with a tapering peduncle 

 of four joints, of which the first is much the stoutest, the second 

 considerably the longest; the slender flagellum is about as long 



