MICKONISCID^— CYPEONISCIDiE 397 



The type, Microniscus fuscus, found by MuUer on a species 

 of Galanuts on the coast of Brazil, is characterised by 

 having ' the third pair of thoracic feet longer than the 

 others, and terminating in an oval lamella, by which the 

 animal fixes itself on its host.' Microniscus calani, Sars, 

 1882 (see Plate XVII.), with all seven pairs of feet 

 similar, fastens itself to the back of Calanus finmarchicus, 

 Gunner, and, according to Sars, also to Pseudocalanvs 

 elongatus, Boeck. It is possible, however, that the para- 

 sites on the latter Copepod have not been specially ex- 

 amined to determine their identity with those on the 

 former. Microniscus calani has the pleopods two-branched, 

 a character which ' is only met with exceptionally in the 

 cryptoniscian embryo of the Entoniscidaa and the Bopyridee, 

 while it is the rule in the Cryptoniscidse.' 



Family 2. — Cyproniscidce. 



They are parasitic on Ostracoda. 



Cyproniscus, Eossmann, 1884. The characters of the 

 family and genus rest on those of a single species, Cypro- 

 niscus cypridince (Sars), 1882 (see Plate XVII.), which is 

 thus described : — ' The adult female, deprived of all the 

 mouth-organs and appendages, with the whole body filled 

 with eggs, sack-like, curved, the arched middle of the back 

 divided into six or seven indistinct segments, the ventral 

 side flattened, the sides slightly expanded, the frontal part 

 widely cordate, exserted, defined by an emargination on 

 either side from the lateral parts. The male (? when adult) 

 like the female devoid of appendages, with the body 

 spindle-shaped, indistinctly segmented, the anterior ex- 

 tremity furnished on either side with a long flexuous root- 

 like process for fixation. An advanced larval stage re- 

 sembling Cryptothiria p>yf)'>ncea in form and structure, but a 

 little more elongate, and quite without eyes.' Sars found 

 these queer animals at the Lofoden Isles fixed within the 

 valves of Gypridina norvegica, Baird, to the hindmost part 

 of the animal's back, calmly occupying the space properly 

 belonging to the eggs of its host. As a rule he found what 



