5. Cryptonistidce parasitic on Cirripedia. 



6. EntoniscidoB Brachyura. 



7 BopyridoB. decapoclous Crustacea. 



Of these families, the 1st must be wholly cancelled, as only representing 

 transitory larval stages of different Epicarida, and the 3 families Cyproniscidce, 

 Caliropsidce and Cryptoniscidce ought to be combined into one family only, for 

 which the name of CryptoniscHdoB may be retained. The number of families is 

 thereby reduced to 4 in all. It is not improbable that these families in future 

 may assume the character of superior groups, and that each of them may be 

 again subdivided. At present, however, I consider it convenient to maintain the 

 above-named 4 families as such. 



Of Entoniscidce no form has hitherto been recorded from Norway; but I 

 regard it as beyond doubt, that, on a closer investigation, also this family will 

 be found to be represented in the fauna of this country. Of the other 3 

 families several genera and species will be described in the following pages. 



Fam. 1. Bopyridae. 



Characters. Body of female distinctly segmented, more or less asym- 

 metrical, twisted now to the right, now to the left, dorsal face flattened. 

 Cephalon deeply sunk into the mesosome, and carrying in front 2 pairs of rudi- 

 mentary antennae; eyes, when present, dorsal. Maxillipeds lamellar, biarticulate, 

 obtecting the oral area below, and more frequently exhibiting a small terminal 

 joint, and at the base 2 curved lanceolate appendages (epignaths). Legs 7 pairs, 

 sometimes obsolete on one side, and all of the same structure, short, prehensile ; 

 coxal plates obsolete or distinctly defined. Incubatory plates 5 pairs, more or 

 less arching over the ventral face of the mesosome ; 1st pair, as a rule, con- 

 cealed by the 2nd and divided by a transversal fold into 2 segments, of which 

 the distal one projects freely within the incubatory cavity. Metasome more or less 

 distinctly segmented, pleopoda, forming simple or double lamellae, all of the same 

 structure, rarely obsolete. Uropoda, when present, simple, lanceolate. Male 

 more or less slender, perfectly symmetrical, with the cephalon evenly rounded in 

 front, and all the segments of mesosome sharply defined, those of metasome 

 sometimes distinct, sometimes confluent. Last larval stage with the mouth 



