64 AMPniPODA NORMALIA. 



short. The tliree posterior paiis of pleopoda double-branched, 

 styliform, naked, the last not longer than the preceding. Telson 

 squamiform, narrowing from the base, cleft at the apex. 

 Length rather more than one inch. 



Hnh. Northimiborland Sound {Sir Echvard Belcher). Spitzhergen 

 and other places in the Arctic regions. 



A specimen lent to me by Mr. Albany Hancock was dredged in 

 about <)6° 30' N. lat. and 68° W. long., by Messi-s. Warham and 

 Hariison. 



Subfamily 2. LYSIANASSIDES. 



Superior antennae very short, thick at the base and suddenly tapering. 

 Coxae of the ioxxr anterior pairs of appendages veiy deep, the 

 foiu'th not broader than the preceding. 



This subfamily may be readily distinguished by the form of the 

 animal, which is not much compressed, the shortness of the second 

 and third joints of the peduncle of the superior antennae, and the 

 depth of the coxae of the foui* anterior pairs of legs. The fii'st pair" 

 of gnathopoda are, generally, short and strong, the second long 

 (induced by the great develojiment of the ischium and cai^pus) and 

 feeble : an exception exists in CaUisoma, where the first are feeble 

 and the second strong. It is one of the most nat^iral of the sub- 

 families. The genera may be ari'anged thus : — 



a. Those that have the second pair of gnathopoda feeble and 

 imperfectly cheliform, and the first strong. 



h. Those that have the second pair of gnathopoda robust and 

 cheliform, and the fii-st feeble. 



a. Second pair of gtiathopoda feeble and im])erfedly cheliform, ami 



the first strong. 



6. LYSIANASSA. 



Lysianassa, Edwards, Ann. Sc. Ned. t. xx. ; Hist, des Crust, iii. p. 20. 

 Bana, U.S. Explor. Exped. p. 908. 



Superior antennae pyiiform, very short, stouter than the inferior, 

 and furnished with a secondary appendage. Mandibles having an 

 appendage ; the incisive edge not fiu-nished with teeth ; armed 

 upon the anterior margin -with a stout tubercle ; secondary or 

 moveable plate wanting. Maxillipeds with large squamiform 

 processes attached to the third and fom-th joints. Fii'st pair of 

 gnathopoda not subchelate. The secon^ pair subchelate, imper- 

 fectly developed, long, and membranous. Ischium and carpus 

 long. Dactylos rudimentary. Coxae of the gnathopoda and the 



