145 
2091 Helix (Arionta). Magdalenensis 
Type locality:—-Magdalena, Son., Mexico (V. Bailey), among 
rocks on top of a mountain 1000 ft. above the sea. 
2092 MHolospira semisculpta 
Type locality: —San Carlos, Chih., Mexico (T. W. Stanton). 
2093 Melania acutifilosa 
“Shell slender, elongated; whorls rounded, convex; sutures 
much impressed. Spire eroded above the 4th whorl. Surface 
sculptured with strong thread-like revolving keels alternating 
with broad channels; of these Keels there are usually 6 on the 
body whorl, sometimes more, and generally 3 only on the pre- 
ceding whorls, of which the upper 2 are rather the most promi- 
nent and are usually interrupted and regularly broken up, pro- 
ducing an evenly crenulated chain. Following the wind of the 
shell and just below the sutures, the whorls broadly slope to the 
succeeding keel, which gives the shell a turrited outline. Sur- 
face of shell a very dark horn color, blackish; aperture smail, 
ovate, inside lighter colored than the surface, the substance of 
the shell being thin and partially translucent, the keels showing 
through on the inside of the mouth, when held up to the light. 
Dimensions of the largest: longitudinal 16.5, latitudinal 7.5 mm.” 
—-Stearns, U. S. Natl Mus pr 13:211, t 15 f 9. 
Type locality: —Hagle Lake, Cal. (Henry W. Henshaw). 
2094 Mitra nodocancellata 
Type locality: —Gulf of Cal. (W. J. Fisher). 
2095 Venericardia barbarensis 
“Shell rounded, inequilateral, variable in outline, more or 
less oblique, moderately convex. Beaks small, slightly elevated 
and turned forward. Surface orhamented with 19-20 radiating 
ribs usually somewhat granulose, and generally obscure on the 
extreme anterior and posterior margins of the valves. Epidermis 
a dingy yellowish brown, thicker towards the ventral margin and 
sides of the valves; thin and commonly eroded at or towards the 
umbos. Lunule small, slightly sunken, faintly defined. Hinge’ 
line small, not thick; hinge composed of, in the left valve, a sin- 
gle strong cardinal sloping posteriorly and a smaller tooth often 
obscure, slanting anteriorly; a 3d tooth-like process is generally 
present, situated under and apparently a projection of the edge 
of the lunule. This latter varies much in prominence in different 
specimens, and is often but barely perceptible. The hinge in the 
right valve is characterized by a single strong cardinal tooth with 
a slanting, somewhat sinuous groove above, and a slight notch 
and tooth-like point below the upper part of the lunule; this latter 
character is frequently inconspicuous and feeble. The valves are 
rather thin and somewhat translucent, bluish white on the insidé 
and showing the ribs when held up to the light. Dimensions. from 
umbones or beaks to opposite edge 15, from anterior to posterior 
edges 15 mm, varying the fraction of a millimeter in either or 
both of these dimensions in different individuals.’’—Stearns, U. S. 
Nat. Mus pr 13:214, t 16 f 3, 4. 
Type locality: off Santa Barbara Islands, Cal., in 276 fms. 
2096 Verericardia borealis 
Stearns, l. c., t 16 f 8, which see for range and synonymy. 
2097 Lucina zquizonata 
“Shell moderately convex, dull white chalky where eroded; 
