292 AMPniPODA NORM A LI A. 



rior iintonnic one-fourth longer ; inferior apex of basal portion 

 acute. JJiusa of tliree posteiior pairs of pereiopodu obtuse at 

 apex ; dactyla less than half the carpi in length : third pair of 

 perciopoda longer than the fourth or fifth. 

 " Length 2 lines. 



" Hah. Atlantic, in latitude 1° S., longitude 17° to 18° W. Collected 

 on November 3rd and 5th, 1838." — Dana. 



2. HYPERIA. 



Hyperia, LatreiUc, Dcsmarest, Consul, sur ks Crust, p. 258, 1825. 



Edmtrds, Ann. dcs Se. Nat. xx. p. 387 ; Hist, des Crust, iii. p. 74. 



Dana, U. S. Explor. Expcd. p. 086. 

 Metoechus, Krinjcr. Grind . Anifip. p. 60. 



Edicards, Hist, des Crast. iii. p. 78. 

 Tauria, Dana, U. S. Explor. Exped. p. 988. 



Cephalon large, dcei)er than broad. Eyes large, occup}-ing most of 

 the lateral, and encroaching considerably upon the fi'ontal walls of 

 the cephalon. Antenna3 subequal, short. Gnathopoda subuni- 

 forra, complexly subchelate, having the carpi produced inferiorly, 

 and forming a process to antagonize with the extremities of the 

 daetyla. Pereiopoda subequal and moderately robust. Three 

 posterior paii-s of pleopoda biramous. Telson squamiform. 



The separation of Hyperia from Lestrigoims is veiy doubtful, and 

 depends only upon the length of the flagella of the antennae ; in each 

 genus this is so variable, that it is difficidt to say M'here Lestrigonus 

 ends and Hyperia commences. In both genera the first articulus 

 consists of several articuli, coalesced together. I have a strong 

 suspicion that they A^dll be found to be sexually rather than generi- 

 cally distinct. They ai-e frequently met with associated ; and I am 

 not aware that a single female of Lestrigonus has been recorded, 

 while all the specimens of which I have been able to detect the sex 

 in Hijperia have been females. 



The distinction between Tauria and Hyperia depends upon the 

 opposite extreme of the development of the eaipi of the gnathopoda 

 as compared with that of Kroyer's genus Metoechus, offering, to my 

 mind, nothing more than a specific difference, — namely, in the latter 

 the great, and in the former the small amount of development of the 

 produced angles of the carpi of the gnathopoda. 



1. Hyperia galba. (Plate XLVIII. fig. 9.) B.M. 



Hyperia giilba, ^Lmtaijii, Linn. Trans, xi. p. 4. pi. 2. f. 2. 

 Edicards, Hist, des Crust, iii. p. 77. 



jr. Thompson, Ann. Nat. Hist. xx. p. 244. 



White, Cot. Crust. B. M. 1847 & 1850 ; Hist. Brit. Crust, p. 206. 



Gosse, Marine Zool. p. 139. 



Spenct, Bate, Synopsis, ^-c, Ann. Nat. Hist. Feb. 1857. 



