REPORT ON THE CRUSTACEA MACRURA. 



XI 



present, being absent only in those genera of the aberrant Trichobranchiata that 

 approximate to the Anomural type ; but, strange to say, Cheiroplatea, or the most 

 Anomnral form of the group, has three pairs of pleurobranchiaa. 



These statements will, however, be better understood by an examination of the 

 following tables, which are compiled from a large series of specimens of different species 

 of the several genera : — 



1 According to Huxley. 



