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 setse. 

 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 setse, the three internal ones the longest. The 

 second pair of foot-jaws is very large. 



Hab. Taken from the tail and fins of the Pagcttus 

 centrodonti, October 29th, 1837; Dublin, Dr. Bellingham, 

 W. Thompson, Esq. 



Genus 2 LEPEOPTHEIRUS.* 



LEPEOPTHEIETJS, Nordmann, Microgr. Beit., ii, 28. 

 CALIGUS ( pars), Kroyer, M. Edwards, Elainville, 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 XtTTot-, a scab; and <t>0np, a louse. 



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