MAZATLAN UNIVALVES 453 
or less closed. The largest (which is very thin) is probably 
N. ovum, Mihe.—2058, 6 sp. normal form, open umbilicus.— 
2059, 4 do. umbilicus more or less closed:—2060, 4 sp. acumin- 
ated form, umbilicus open.—2061, 5 do, umbilicus more or less 
closed.—One sp. has a second umbilical groove. 
Famiry LAMELLARIAD A. 
Genus LAMELLARIA, Mont. 
Lamellaria, Mont. Linn. Trans. 1825, vol. xi. p. 184 (pars).— 
H. & A. Ad. Gen. vol. i. p. 201. 
Marsenia, Leach.— Phil. Handb. Conch. p. 163. 
577. LAMELLARIA ————, sp. ind. (a.) 
Tablet 2062 contains a minute white shell, measuring *065 by 
°047, having one whirl and a half, with coarse strize of growth, 
and reflected labium. 
Hab.—Mazatlan ; 1 sp. off Chama; L’pool Col. 
578. P LAMELLARIA ——-——, sp. ind. (b.) 
Tablet 2063 contains a fragment which may belong to Lamel- 
laria or even to an Atlantid. It possesses a stout globular nucleus 
of two rounded whirls, white and glossy, large (as compared 
with Vitrinella) and rapidly increasing ; with a portion of a 
flat expanding outer whirl, the texture of which may have 
been, when fresh, somewhat gelatinous, and in its dried state 
is transparent and very finely wrinkled. 
Hab.—Mazatlan ; 1 broken specimen off Spondylus ; LZ’ pool Col. 
* 
Famity FICULIDA. 
Genus FICULA, Swans. 
Sycotypus, (Browne,) H. & A. Ad. Gen. vol. i. p. 198. 
Pyrula, pars, Lam. 
(579. FicuLa VENTRICOsA, Sow. 
Pyrula ventricosa, Sow. Tank. Cat. no. 1614, App. p. 16, 1825.— 
Kien. Icon. Conch. p. 27, pl. 12, f. 2—Lam. An. s. Vert. 
