188 PHYLLOBRANCHIA. TURBONIDZE. 
tumid, spirally and slightly sculptured with elevated strice ; the 
epidermis grey, greenish, reddish, pale fuscous or dark brown, 
and is sometimes banded. Height one inch. 
Animal yellowish. Tentacles of a dark yellow. 
Inhabits the sea, Whitstable ; north coast of Somersetshire ; 
Plymouth ; Devon; and in Dublin Bay. 
4. TuRBO TENEBROSUS. 
T. testa elevaté, glabra; sutura profundi; anfractibus sex, 
tumidis ; epidermide rugulosa, grisea aut ferruginea. 
Turbo tenebrosus, Mont. Test. Brit. ii. 303.—Suppl. t. xx. 
f.4; Pult. Cat. Dorset. t. xviii. f. 15; M. & R. Trans. 
Linn. Soc. viii. 160; Turt. Conch. Dict. 197 ; Flem. Edinb. 
Encycl. vii. ; Dill. Dese. Cat. 783. 
Habitat in mari Danmoniensi, Cornubiensi, Cambriensi et Hi- 
bernico Australi sat frequens. 
Shell elevated, smooth ; suture deep, with six tumid whorls ; 
the epidermis roughish, grey or ferrugmous. Height half an 
inch. 
5. TuRBO PETRICOLA. 
T. testa moderatim elevata; sutura profunda, crenulata; an- 
fractibus quinque, planiusculis; epidermide profundé pur- 
pureo-brunnea, nonnunquam lineis aut maculis ornata. 
Turbo petreeus, Mont. Test. Brit. u. 403 ; Pult. Cat. Dorset. 
t. xvill. f. 13; M. & R. Trans. Linn. Soc. viii. 160; Turt. 
Conch. Dict. 198; Flem. Edinb. Encycel. vi. ; Dill. Desc. 
Cat. 783. 
Habitat in mari Britannico in scopulos ubiqué. Alt. 2 une. 
Shell moderately elevated ; suture deep; epidermis deep 
purple brown, sometimes ornamented with white lines or spots. 
Height three-eighths of an inch. 
Inhabits all the shores of Great Britain on the rocks. 
I have taken the liberty of changing the name of this species : 
petreus signifies, according to Pliny, any substance that grows 
upon a rock, such as alum, nitras, &c., which seems to me to 
be inapplicable to an animal that only lives on rocks. 
