302 gammaridj:. 



amp bipod a. gammarides. 



NATATORIA. 



Genus— BATHYPOREIA. 



Bathyporcia. Lindstkom. Bidrag Ostersjons, Invert. Faun, in Ofvers. 



Kongl. Vet. Akad. Forhandl. 1855, p. 59. Nat. Hist. 



Review, Jan. 1857, p. 43. White, Hist. Brit. Crust. 



p. 187. 

 Thersites. Spence Bate, Rep. Brit. Assoc. 1855. p. 59. Ann. Nat. 



Hist. 2 ser. xix. p. 146. 



Generic character. Superior antennae short ; having the first 

 joint of the peduncle large and tumid ; the second articulating 

 on the infero-distal extremity of the first, and furnished with a 

 secondary appendage. Inferior autennse slender ; twice as 

 long as the superior ; mandibles with a tri-articulate appendage. 

 First pair of gnathopoda subchelate ; second having the dactylos 

 wanting. Posterior pair of pleopoda biramous, the longer 

 branch being bi-articulate. Telson double. 



The superior antennae in this genus are much shorter 

 than the inferior, having the basal joint greatly swollen, 

 and its extremity oblique ; hence the peculiar position 

 which the second joint of the peduncle holds to the first, 

 the articulation, instead of being at the extremity of the 

 joint, being at the distal end of the inferior margin ; 

 thus the second articulates with the first joint almost 

 at a right angle: the other tw^o joints are generally 

 short, and the flagellum is never long, and is furnished 

 at its base with a secondary appendage. The inferior 

 antennae are much longer than the superior, and 

 more slender. The mandibles are furnished with an 

 appendage. The first pair of legs are subchelate. The 



