DEXAMINE SPINOSA. 
237 
AMP HIP OB A. GA MM A RIDES. 
NAT ATOM A. 
DEXAMINE SPINOSA. 
Specific character. Each of the four anterior segments of the pleon ele- 
vated into a large posteriorly-directed tooth ; first joint of the peduncle of 
the upper antenna with a blunt tooth. 
Length \ inch. 
Cancer (Gammarus) spinosus. 
Dexamine spinosa. 
Amphithoe Marionis . 
Acanthonotus ? spinosus. 
Amphitoe spinosa. 
Montagu, Linn. Trans, vol. xi. t. ii. fig. 1. 
Leach, Edin. Encyc. vii. p. 433. Zool. Misc. 
ii. p. 23. Linn. Trans, xi. p. 359. Enc. 
Brit. Suppl. i. 425. Samouelle, Ent. 
Comp. p. 102. Thompson, Nat. Hist. 
Ireland, iv. p. 395. Desmarest, Consid. 
sur les Crust, p. 263, pi. xlv. fig. 6. 
White, Cat. Brit. Crust. (1849), p. 49. 
Hist. Brit. Crust, p. 178, pi. x. fig. 7. 
Spence Bate, Brit. Assoc. Rep. 1855, p. 58. 
Ann. Nat. Hist. 2 ser. xix. p. 141, 1857. 
Cat. Amph. Brit.Mus. p. 130, pi. 24, fig. 1. 
Milne-Edwards, Ann. des Sci. Nat. xx. 
p. 375. Hist, des Crust, t. iii. p. 40. Cuv. 
Regne Anim. Edit. Crochard, pi. 60, fig. 6. 
Milne-Edwards, Hist, des Crust, iii. p. 25. 
GIosse, Mar. Zool. p. 141, f. 266. 
The head has the anterior margin produced in the 
centre into a little flat rostrum. The body of the ani- 
