76 



species wliich in the ovig'crous female attain the most remarkable 

 •diversities of form- Professor Sars unites in the singfle family 

 •Cryptoniscidae parasites which MIM. Giard and IJonnier distri- 

 bute among- the Cryptoniscidae, Cyproniscidae. Podasconidae. 

 .and Cabiropsidae, according as they respectively infest Thyros- 

 traca, Ostracoda, Amphipoda, or Lsopoda. The latter 

 arrangement is confessedly provisional, and viewed in that 

 light it may be allowed to have the considerable merit of 

 •convenience. 



Cypronjscus CKussoi'iioRi. Stebljing. 



Plate 15B. 



1901- Cyproiiiiscits crossopJiori, Stc])l)ing, Knowledge, vol. 24, p. 



JOG. 



An ovigcrous female^ somewhat long-er than broad and slightly 

 .unsymmetrical, shows no definite division into segmenlts- (if 

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

 from these sutures run both dorsally and ventrally, 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 headis raihernarrowlyrounded 

 in front, widening- greatly to the strongly-produced subacute 

 jjostero-latcral angles, the under surface of the front showing a 

 reflexed median point. ( )f the seven segments of the peraeon the 

 first is completely ovcrlajjped 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 which 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 i)oints are not included in the reckoning. 



Eyes not ])erceived and probably absent, in accord with the 

 generic definition- I'irst 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 ])lane, 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 ti])ped with a long seta; the 

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

 mcnts- 



Thc second antennae arc nmch longer, with a tapering peduncle 

 of four joints, of which the first is much the stoiVtest, tlie second 

 considerably the Utngost: the slender llagellum is about as long 



