614 CRUSTACEA. 



In the other series, there is only a single type, the Squilloid, 

 divisible into two families upon the existence or not of a rostral seg- 

 ment independent of the carapax (those having this segment being of 

 a higher grade), and the presence of large branchial appendages to 

 the abdominal members or their obsolescence. The Amphionoid 

 species in the first series, are analogous in depressed form to the Squil- 

 loidea. 



We thus make three prime divisions or tribes of the Anomobran- 

 chiates : 



I. SQUILLOIDEA. Pedes antici octo vel decim prehensiles, juxta aream 

 buccalem insiti ; 6 postici debiles. Corpus depressum. 



II. MYSIDEA. Pedes nulli prehensiles, graciles, saepius palpigeri, palpo 

 prope corpus insito. Corpus non depressum. 



III. AMPHIONIDEA. Pedes nulli prehensiles, graciles, longi, saepius 

 palpigeri, palpo corpore remoto. Corpus depressum, plus minusve 

 foliaceum. 



Among the Mysidea, the Lucifers have a very long, slender, an- 

 tennary segment, as already stated. The species, moreover, have no 

 palpus to the legs or but a trace of one, and in this respect, also, they 

 show that they are an aberrant type in the tribe Mysidea. 



TRIBE I. SQUILLOIDEA. 



THE Squilloidea embrace two families, Sguillidce and JEhichthidce, 

 the former having the beak pertaining to a distinct segment of the 

 body, separated by a suture from the carapax, and the latter, having 

 it a part of the carapax. The former have abdominal branchial 



