GASTEROPODA. 183 
It was found in the greatest abundance under stones above low- 
water mark in the harbour of Valparaiso, and also at San Lorenzo, 
but smaller. Nearly all the shells found at the former locality were 
also found at the latter; but it is remarkable that those found at San 
Lorenzo were invariably much smaller than the Chilian specimens, 
though the climate is so much warmer. [. P. c.] 
Figure 213, shell, with the animal, as in motion. 
Trocuus Mastus (Jonas), in Menke’s Zeitsch. fiir Malak., 1844, 113. 
The variety of this species is so remarkable on account of its less 
elevated form, and its peculiar circle of sutural scales, that a figure of 
it is deemed advisable. In its more essential characters it accords with 
ty pe specimens. 
Figure 214, profile view of the shell. 
TRocHUS COLUBRINUS (Gould). 
Testa depressa, conico-globosa, imperforata, olivacea maculis subquad- 
ratis hepaticis tessellata, sulcis inequalibus minimé profundis cincta: 
sptra anfractibus quinque, planiusculis, ultimo ad peripheriam obtusé 
angulato: basis convexiuscula, regione centrali absque colorem: aper- 
tura semi-circularts ; columella acuta, anticé truncata et dentem men- 
tiente ; labro acuto, viridi ; fauce submargaritaced. 
Trochus (Monodonta) colubrinus, Gouin ; Proceed. Boston Soc. Nat. 
Hist., 11. 107. April 1849. Expedition Shells, 58. 
Anima. Foot broad, narrowed behind, faintly channeled along the 
middle beneath, aud coloured olive-green, with ramifications of deeper 
green; above dark green mottled with brown; head distinct, flattened, 
mottled with black ; tentacles very long and slender, pale-brown, with 
transverse black lines; eyes on long, detached pedicles: lateral mem- 
brane incised for only a short space on each side of the head, furnished 
on each side with three long annulated cirrhi. Neck rose-coloured. 
