466 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



SYSTEMATIC DISCUSSION. 

 . Genus CECROPS Leach. 



Cecrops (C. latreillii) Leach, 181(5, j). 405, pi. xx, 8 figures. 



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

 posteriorly; frontal plates fused with the carapace; cephalic and tho- 

 racic portions of the lateral areas separated by a transverse groove. 

 Second thorax segment with large lateral lobes; third segment with 

 a pair of small dorsal plates; fourth segment with a pair of larger 

 plates; genital segment small, but carrying a pair of dorsal plates 

 larger than the carapace, and extending back beyond the tips of the 

 anal laminje, forming the dorsal half of the bag in which the eggs are 

 carried. Abdomen ventral and as large as the genital segment in 

 front of its base, strongly flattened dorso-ventrally ; its ventral sur- 

 face produced laterally and anteriorly into large lobes, forming the 

 ventral surface of the egg bag. 



Egg-strings very narrow, twenty or thirty times the length of the 

 body, irregularly convoluted and entirely hidden in the above-men- 

 tioned bag. First antenna^ two-jointed; second pair and second max- 

 illipeds stout and furnished with strong curved claws for prehension. 

 Maxillae huge, club-shaped, two-jointed, the terminal joint covered 

 with small spines. Legs all biramose, rami of first three pairs two- 

 jointed, of fourth pair one-jointed and enlarged into flattened laminae 

 with a large fold of skin on the ventral surface. 



Male. — A fixed and degenerate form, similar in all respects to the 

 female, except as follows: Genital segment without dorsal plates, but 

 covered by those of the fourth segment, which also reach nearly to 

 the end of the abdomen. The latter is phmip, not flattened, twice 

 as wide as long, and without lateral lobes; anal laminae close to- 

 gether, armed with good-sized setae. 



Fourth legs but little enlarged, rami one-jointed, but without the 

 ventral fold of skin; plumose setae on the first three pairs of legs 

 less rudimentary than in the female. 



{Cecrops, the fabulous first king of Athens.) 



This genus was established by Leach in 1816, who gave a fairly 

 good description of the female with figures of both sexes. The figures 

 are good for their time, but are too small to give details. In the 

 ninety years since the above date the genus with its single species 

 has been noted by nearly every investigator who has dealt with the 

 parasitic copepods. But only in a very few instances have any figures 

 been given. Guerin published a single figure, the dorsal view of a 

 female, in 1817; Desmarest in 1825 published a set of figures almost 

 exactly like those of Leach, but in which the details are more clearly 

 shown. Latreille gave similar figures in 1835, and Baird a single 



