254 MAZATLAN UNIVALVES 
thority. The differences in the Mazatlan shells appear too 
trifling to found specific distinction upon them. The characters 
of the shell can only be seen in the young state; in its ordinary 
form, it has the external aspect of the British Osilinus (Troc- 
hocochiea) lineatus; from which the umbilicated axis and 
nodulous columella at once distinguish it. Long. 1°17, lat. 1°08, 
div. 70°. 
#iab.— China, Mus. Cuming. [?]— Mazatlan ; very rare; 
L’pool Col. 
Tablet 1130 contains the largest and smallest specimen.— 
1131, 1 sp. lip tinged with orange. 
292. OMPHALIUS ViRIDULUS, Gmel. 
Trochus viriduius, Gimel. p. 3574. — Schreib. Conch. vol. i. 
p. 245.—Dillw. Deser. Cat. p. 777, no. 42.— Wood Ind. Test. 
no. 42, pl. 28, p. 136. 
Omphalius viridulus, H. & A. Ad. Gen. i. 429. 
Globulus ex viridi et rubro variegatus, Chemn. vol. v. p. 114, 
pl. 171, f. 1677:—(non Trochus variegatus, Chemn. p. 104, 
f. 1661-2 :—Dillw. p. 774, no. 35:— =T. Capensis, Gmel. 
p. 3973: Hab. ‘Cape of Good Hope.’) 
Phorcus variegatus, A. Ad. in Proc. Zool. Soc. 1851, p. 156. 
=Trochus Brazilianus, Whe. teste A. Ad. loc. cit. 
+Trochus Byronianus, Wood Suppl. p. 16, pl. 5, no. 17. 
(Hab. ‘Sandwich Is.’) 
Var.=Trochus reticulatus, Gould, ms. Cat. 
Comp. O. cruciatus, Gmel. (non Linn. teste Phil., Brazils) :— 
=Q. Brazilianus, 1//e.=O. Byronensis, teste Mus. Cum. 
The single specimen which Mr. Cuming assigns to this very 
variable species, differs from all forms of O. ligulatus in the‘ 
following particulars. Spiral lire, both above and below, much 
fewer, with broad interspaces. Umbilicus somewhat cork- 
serew shaped, the parietal callosity being further off from 
the centre, while the spiral ridge is nearer to it. It appears 
also to want the seminodulous callous ridge at the base of 
the labrum. Colour dull red, slightly spotted with orange. 
Long. 64, lat. °76, div. 90°. 
Hab.—Mazatlan, Col. Jewett—Do.; 1 dead sp. ; L’pool Col.— 
San Diego; very red variety ; Lieut. Webb. 
Tablet 1132 contains the specimen. 
