BOPYRID^E. 213 



Bopyriens and loniens, established upon the foliaceous or 

 filiform structure of the appendages of the tail, cannot 

 be maintained, as several genera have been lately dis- 

 covered which are truly Bopyrideous, although furnished 

 with filiform and even clavate caudal appendages. The 

 genera Prosthetes and Athelges, parasites on the tails of 

 hermit crabs (Paguri), are, in respect to the peculiar 

 formation of their pleonic appendages, amongst the most 

 remarkable of crustaceous animals. In lone, these organs 

 are singularly branched, resembling pieces of coral, and 

 the incubatory plates are furnished with long clavate 

 appendages. We have added the anomalous parasitic 

 genus Liriope to this family (rather than place it near 

 Tanais, as done by Dana), from a consideration of its 

 general character. The entire want of limbs in the 

 female, and the somewhat indistinctly articulated body 

 of the males, with the pleon destitute of lateral terminal 

 appendages, are very characteristic distinctions, separating 

 it from the majority of the family, but, at the same 

 time, removing it still farther from the Tanaides. The 

 genus Cryptothir of Dana appears to us to be founded 

 upon a carelessly examined male of a species of Liriope, 

 as may be at once perceived by comparing Dana's figure 

 of Crypt, minutum with our figure of Liriope pygmcea. 



The family, at first, comprised only the genus Bopyrus, 

 a separate family having been proposed for lone, but 

 more recent observations have fully proved, as stated above, 

 not only that the two animals are closely united together 

 by the intervention of several genera discovered since the 

 publication of M. Milne Edwards's general work on the 

 Crustacea, such as Kepon, Phryxus, and Athelges, &c., but 

 that the genera Gyge of Cornalia and Panceri, Dajus of 

 Kroyer, Ledya of Cornalia, and Argeia of Dana must be 

 added to the family. 



