LEPEOPTHEIRUS. 
273 
Abdomen exceedingly small ; completely concealed by 
the ovarian tubes when filled with ova ; of a somewhat 
square shape, and terminating in two rounded caudal 
lobes, each of which gives off four short, plumose setae. 
Sternal fork well developed, with simple, stout, and sharp- 
pointed branches. Fourth pair of feet short and stout. 
Ovarian tubes nearly of the length of the whole body. 
Male. Carapace as in female, but much larger in pro- 
portion to the size of the whole animal. Thorax much 
smaller; more completely quadrangular in shape, and 
more deeply crescentic on lower margin ; broader than 
long ; the inferior angles more acute, and giving off three 
short, stout setae at a little distance from each other. 
Abdomen very small, in shape of a half circle, the 
lower margin straight. Caudal segments large in pro- 
portion, oval, curved inwards, and giving off five stout, 
plumose setae, the three internal ones the longest. The 
second pair of foot-jaws is very large. 
Hab . — Taken from the tail and fins of the Fagellus 
centrodonti , October 29th, 1837; Dublin, Dr. Bellingham, 
W. Thompson, Esq. 
Genus 2 — Lepeoptheirus.* 
Lepeoptheirtjs, Nordmann , Microgr. Beit., ii, 28. 
Caxigus ( pars), Kroyer , M. Edwards, Blainville , Cuvier. 
Character . — Fourth pair of feet slender, of only one 
branch, and serving the animal for walking. Thorax 
exhibiting only two distinct articulations. Frontal plates 
destitute of the small sucking-discs or lunules, on their 
under surface. 
* From \e7r0c, a scab ; and <p9eip, a louse. 
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