io6 REPORT OF NEW JERSEY STATE MUSEUM. 



in bunches of from ten to twenty individuals, so that even the 

 thick skin of the host is quickly penetrated by the combined lacer- 

 ation of the sharp claws and probosces of the parasites. Thus 

 groups of parasites are found lying in the bottoms of depres- 

 sions or pits, which have been eaten through the host's skin and 

 into the raw flesh below. The edges of these pits are often 

 raised above the surrounding surface and calloused. Thus while 

 themselves free from some dangers due to their fixed habit, their 

 chitinous plates covering the dorsal surface often invite different 

 vegetable and animal forms of the sea to a good anchorage. Thus 

 the back of an Orthagoriscicola may be found covered with 

 algse, infusoria, hydrozoa or barnacles. Sometimes a huge Lepos 

 may be foimd attached, and while not in sense a parasite, its 

 heavy weight upon the copepod's back is likely a sore burden." 



Genus CECROPS Leach. 



Cerops Leach, Encyclop. Britan. Suppl. (Annulosa), 1816, p. 405. Type 

 Cerops lafreillii Leach, monotypic. 



Female. — Carapace oval, stout, strongly arched, deeply 

 notched behind. Frontal plates fused with carapace. Cephalic 

 and thoracic portions of lateral areas separated by transverse 

 groove. Second thorax segment with large lateral lobes. Third 

 segment with pair of small dorsal plates. Fourth segment with 

 pair of larger plates. Genital segment small, carries pair of 

 dorsal plates larger than carapace extending back beyond tips of 

 anal lamiuce and forms dorsal half of bag in which eggs are 

 carried. Abdomen ventral, large as genital segment in front of 

 its base, strongly flattened dorso-ventrally. Ventral surface of 

 abdomen produced laterally and anteriorly into large lobes, form- 

 ing ventral surface of egg-bag. Egg-strings very narrow, twenty 

 or thirty times body length, irregularly convoluted and entirely 

 hidden by above-mentioned bag. First antennse two- jointed, 

 second pair and second maxillipeds stout and furnished with 

 strong curved claws for prehension. Maxillae huge, club-shaped, 

 two- jointed, terminal joint covered with small spines. Legs all 



