386 MAZATLAN UNIVALVES 
specific or only of sectional value (as will be learnt by induction 
from more numerous specimens,) it bears the honoured name 
of the author of the Synopsis of this genus in the Proc. Zool. 
Soc. 1843, pp. 159 et seq. Long. 1°24, long. spir. °98, lat. *27, 
div. 18°, 
Hab.—Mazatlan ; 6 specimens, dead; LZ’pool Col. 
Tablet 1836 contains 2 specimens, with extremes of sculpture. 
452. MYURELLA SUBNODOSA, ?2. s. 
M.t. “ M. albocincte” forma et indole simili ; sed rufo-fuscda, 
albido tincté ; sublevi, lirulis radiantibus et striulis extantibus 
paucis spiralibus vix ornata; superficie haud striata; peri- 
pheria subangulatd, subnodosi ; columellé carind vix extante, 
haud plicata. 
Two specimens were found, agreeing in shape exactly with 
T. albocincta, but with the faint spiral sculpture raised instead 
of indented, the surface destitute of microscopic striule, the 
periphery subnodulous, and the keel surmounting the canal 
very faint. Long. 1°22, long. spir.1°, lat. ‘36, div. 18°. 
Hab.—Mazatlan ; extremely rare; L’pool Col. 
Tablet 1837 contains the large specimen, with the spire bent 
through fracture. ‘ 
453. MyYURELLA RUFOCINEREA, /n. 8. 
M.t.“M. Hinds” forma et indole simili ; sed omnino rufo- 
cinered, haud maculata ; cingulo latiore, pallidiore, margine im- 
presso, tuberculos confertiores angustos, magis elongatos gerente ; 
costis radiantibus acutis expressis, tuberculis lineis vie undatis 
convenientibus ; fascia circa peripheriam valde rotundatam 
pallidiore ; columella & carind super canalem plicata ; anfrac- 
tibus subconvexis, lineis spiralibus, haud sculpturd microscopica, 
ornaiis. 
In shape agreeing with M. Hindsii ; but with markings more 
like those of M. albocincta, yet destitute of minute sculpture ; 
with the coste much more developed, and the sublinear tuber- 
cles in a less waved line of junction. The cincture is marked 
off by a deep suture. This, and the more rapid rounding of 
the base, give the whirls a slightly convex appearance. One 
fresh, beautifully tinted specimen was found; and a spiral 
