MAZATLAN UNIVALVES A413 
SuseEenus AURICULINA, Gray. 
H. & A. Gen. vol. i. p. 233. 
In this group are deposited some shells, having the general 
aspect of Odostomic, but presenting no vestige of a plait, and 
with the vertex scarcely bent. They are not sufficiently well 
characterized for description. 
494, AURICULINA —, sp. md. (a.) 
Tablet 1959 contains 3 imperfect specimens, having the 
general aspect of O. gravida, Gould, (Cal. & Mex. Shells, p. 11, 
pl. 14, f. 14, Sta Barbara.) 
Hab.—Mazatlan ; extremely rare, off Spondylus and Chama ; 
LP’pool Col. 
495. AURICULINA ————, sp. ind. (b.) 
Tablet 1960 contains 2 imperfect specimens, white, differing 
from the last in being much narrower in proportion. 
Hab.— Mazatlan ; extremely rare, off Chama; D’pool Col. 
496. AURICULINA ————, sp. ind. (c.) 
Tablet 1961 contains a fragment, like the last, but of a rich 
orange colour, with a conspicuously sinistral vertex. 
Hab.—Mazatlan ; 1 sp. off Spondylus ; L’pool Col. 
Suscenus PARTHENIA, Lowe. 
Parthenia, H. § A. Ad. Gen. i. 238. 
Parthenia (pars), Lowe. 
Shell with the surface somewhat strongly sculptured ; colu- 
mella plaited. 
Section A. Shell thin, turrited, transversely ribbed. 
497. PARTHENIA SCALARIFORMIS, 7. s. 
P.t. turrita, solutd, albé ; vertice nucleoso parvo, verticaliter 
sito, pane immerso ; anfr. normalibus vy. elongatis, postice 
acutius angulatis, liris acutis, in adulté ix., in guniore pluribus, 
