very useful, although most of the new nomea-~ 

 clature proposed for the regions of the body 

 and appendages is very objectionable. Pro- 

 fessor Packard says, " For the primary regions 

 of the head (sic) , the only scientific terms as 

 yet in use are those pioposed by Prof. J. O. 

 Westwood, in Bate and Westwood's History 

 of British sessile-eyed Crustacea (vol. i. p. 3). 

 These are cephalon for the head, pereion for 

 the thorax, and pleon for the abdomen ; while 

 the thoracic feet are termed pereiopoda^ and the 

 abdominal legs pleopoda ; the three terminal 

 pairs being called uropoda. As the names 

 applied to the thorax and abdomen have no 

 especial morphological significance, the Greek 

 Trepaiov, simply meaning ulterior, and -n-Xeov, 

 more, we would suggest that the head be 

 termed the cephalosome, the cephalic segments, 

 cephalomeres , and the cephalic appendages in 

 general, protopoda, the term ' cephalopoda ' 

 being otherwise in use. The thorax of insects 

 and of most Crustacea might be designated the 

 baenosome (^aivo, to walk, locomotion), and 

 the thoracic appendages, baenopoda, the seg- 

 ments being called baenomeres ; while urosome 

 might be applied to the abdomen, the abdomi- 

 nal segments being called urovieres. West- 

 wood's term uropoda might be extended so as 

 to include all the abdominal appendages." If 

 mere names of parts are to be rejected, simply 

 for want of 'morphological significance,' the 

 language of the morphologist would soon be- 

 come a meaningless jargon, to which it is near 

 enough already ; but, even as to ' morphological 

 significance,' there appears to be little choice 

 between the new and old terms. Bate, when 

 first proposing the terms ' pereion' ^ and ' pleon,' 

 expressly states that he derives the terms from 

 Trepaiod) {'' to walk about ') and TrAeco (navigo) . 

 The proposed term ' protopoda ' is quite as un- 

 fortunate as ' cephalopoda,' since ' protopodite' 

 and ' protopod ' are already in use for parts of 

 crustacean appendages, the former even in the 

 present work. The extension of the terra 

 ' uropoda ' so as to make it synon3-mous with 

 ' ])leopoda ' would also be unfortunate, since, as 

 now employed, it is a very useful term to des- 

 ignate th e modified caudal pleo poda, whether 



1 According to eithfir Bate's or Packard's derivation, this 

 would be mure properly vftitlon peraeon, as has sometimes been 

 done, or even pereun. 



