No. 26.] 



ARTHROSTRACA OF CONNECTICUT. 



2O5 



Antennae directed laterally; first pair shorter than second 

 pair and originating close together; both pairs with distinct 

 multiarticulate flagella. 



Mouth parts adapted for piercing and tearing; first maxillae 

 with only a single lobe which is tipped with short spines. Second 

 maxillae armed with recurved teeth, as is also the terminal joint 

 of palp of maxilliped. 



Thoracic segments with coxal plates defined distinctly except 

 on the first. First three legs short and thick, prehensile; last 

 four more slender and ambulatory. 



Abdomen composed of six well defined segments, the last 

 one large, scutiform and ciliated on hind margin. Uropods 

 attached laterally beneath the terminal segment. Pleopods 

 adapted for swimming and respiration. 



Parasitic, usually attached to the skin of fishes. 



psora (Linnaeus). 



FIG. 61 



psora. 



1880. 2Ega psora, Harger, Rep. U. S. Com. Fish, for 1878, 

 p. 384, pi. 10, fig. 64. 



