A PROBLEM IN CLASSIFICATION 223 



The ingenious comparison instituted by Darwin between 

 the Macruran Leucifer and the Cirripede Lepas is well 

 known, and, as the illustrative figures have often been 

 reproduced, the long neck, the projecting eyes, and feeble 

 limbs of Leucifer are comparatively familiar. The petasma, 

 or curtain, at the first pleopods of the male, is in this 

 genus a very conspicuous object. 



Schizojwda. 



Spence Bate regards the Schizopods as an aberrant 

 group of his Macrura dendrobranchiata, and urges that, 

 ' with the exception of the variable condition of the pereio- 

 poda, the several genera do not possess a single character 

 that is not held in common with some genus of the 

 Macrura.' Without any wish to pronounce upon the 

 validity of the arguments and facts which he adduces in 

 support of his view, I must here simply follow the dictates 

 of convenience, and leave the Schizopoda to be treated 

 later on as a separate sub-order. 



