SULCATOR ARENARIUS. 
189 
A MPHIP OB A . PH OXIDES. 
NATATORIA. 
Specific character. Body not compressed, three posterior segments of the 
pleon bent under and enclosed beneath the third. Antennae subequal. Coxae 
of the pereiopoda largely developed. Basal joint of the three posterior pairs 
also largely developed ; dactyla wanting, or only represented by stiff spines. 
Length, n inch (not including the inflected portion of the pleon). 
Sulcator arenarius. Spence Bate, Ann. Nat. Hist. vol. xiii. p. 504 (1854) 
vol. xix. p. 140, 1857. Rep. Brit. Assoc. 1855, p. 58. 
Trans. Tyneside Nat. Field Club, vol. iv. p. 15, 
pi. ii. fig. 2, 1858. Cat. Amph. Brit. Mus. p. 112, 
pi. xviii. Gosse, Marine Zool. p. 142, f. 264. 
White, Hist. Brit. Crust, p. 174. 
Bellia arenaria. Spence Bate, Ann. Nat. Hist. vol. vii. p. 318, 1851. 
Dana, United States’ Explor. Exped. Crust, p. 912. 
The upper portion of tlie head is projected anteriorly 
as a flat hood, hut has an excavation on each side, cor- 
responding to the superior pair of antennae, while the 
centre terminates in a blunt point. Between the antennae 
the integument also extends into a point, though not so 
