MAZATLAN UNIVALVES 505 
earimated. The shape of this is like Anachis, &c.; but in all 
the Columbelloid shells examined, the nucleus is regular. 
Hab.—Mazatlan; 1 young sp. off Spondylus ; L’pool Col. 
Gents COMINELLA, Gray. 
H. & A. Ad. Gen. vol.i. p. 110. Shell Buccinoid. Operculum 
Muricoid. 
644. PCoMINELLA ————, sp. ind. 
Tablet 2417 contains a small smooth yellow shell, of regular 
form. The first four whirls have a different shade of colour 
and may be nuclear. 
Hab.—Mazatlan ; 1 young sp. off Spondylus; L’pool Col. 
Genus ANACHIS, H. & A. Ad. 
Gen. vol. i. p. 184: (as Subgenus of Columbella.) 
Testa Columbelle similis, spird elevata, anfractibus liratis ; 
apertura subquadrata ; labro intus dentato, labio crenato. 
Operculo elongato, unguiformi, nucleo terminali. 
Columbella, pars, auct. 
These shells, which form avery natural group of the old 
genus Columbella, are distinguished essentially by the opercu- 
jum, which has closer analogies with Pisania. The operculum 
of Columbella fulgurans, which is a smooth species with a 
twisted mouth, is figured by Messrs. Adams, pl. 19, f. 73, ¢, 
as resembling that of Anachis. The opercula of Columbelloid 
shells have hitherto received so little attention that Dr. Gould 
in his great work on the U.S. Expl. Exp. Shells, p. 270, states 
that they have none. 
645. ANACHIS SCALARINA, Sow. 
Columbella scalarina, Sow. in Proc. Zool. Soc. 1832, p. 116 :— 
Thes. Conch. p. 130, no. 55, pl. 39, f. 118 —Desh. in Lam. 
An. s. Vert. vol. x. p. 288, no. 40.—Chénu Conch. Lil. pl. 25, 
f. 34, (malé.) 
(Columbella) Anachis scalarina, H. f° A. Ad. Gen. i. 184. 
Two young shells and one adult specimen are referred to 
this species by Mr. Cuming. Being in perfect condition, the 
» April, 1857. VU 
