280 MAZATLAN UNIVALVES 
T’pool Col.—|C. ?P hepatica: Benguela and Loander, very 
common and variable, Tams: Tafel Bay and Natal, Krauss. | 
Tablet 1388 contains 3 sp. very young.—1389, 4 sp. different 
ages, finely grown.—1390, 2 sp. form approaching C. incurva; 
one very dark.—1391, 1 sp. with irregular ridges, passing to 
the form Lessonii.—1392, 1 sp. twisted, apex lateral.—1393, the 
largest specimen.—1394, 1 sp. light coloured, slightly rayed 
with darker.—1395, 1 sp. very light coloured, beginning con- 
vex, suddenly becoming fiat and shghtly rayed in the middle. 
Tablet 1396 contains 2 young sp. var. Lessonii, probably 
belonging to this species, but perhaps to C. nivea. 
341. CREPIDULA NIVEA, C. B. Ad. 
Cr. t. ellipticd, subrotundatd, seu maxime elongata; tenu, 
seu tucrassatd ; intus nived, lineis castaneis radiantibus sepe 
ornatdé ; sublevi, seu irregulariter concentrice plus minusve 
yugosd, seu lamellis extantibus varie instructé ; limbo acuto, 
seu maxime planato, lamelloso ; epidermide copiosd irregulari- 
ter lamellosa& ; superficie seu striulis coneentricis seu (sub lente) 
rugulis radiantibus varie calaté ; habitu incrementi vie spirali ; 
vertice nucleoso, minimo, Velutine simili, apicem monstrante, 
castaneo, rare albo, rugis concentricis conspicuis instructo, satis 
prominente, spiraliter subito augente, dextrorsum deflecto, & mar- 
gine vix remota, sepe ad marginem vecto et detrito ; septo plus 
minusve in medio angulato seu sinuato, ad sinistram partem 
plus minusve profundé, ad dextram parum sinuato, tenui, lineas 
ancrementi, haud lineam centralem monstrante. 
C. B. Ad. Pan. Shells, 1852, pp. 234, 320, no. 351: diagn. 
auct.—(Crypta n.) H. & A. Ad. Gen. i. 369. 
+ Calyptreea (Crepidula) Squama, Brod. Proc. Zool. Soc. 1834, 
p. 40:—Zrans. Zool. Soc. vol. i. p. 205, pl. 29, f. 10.— Mild. 
Syn. Nov. Test. Viv. p. 151.—(Crepidulas.) Lam. An. s. Vert. 
vol. vil. p. 648, no. 16.—C. B. Ad. Pan. Shells, no. 649, 
p. 229.—(Ianacus s.) H. & A. Ad. Gen. 1. 370.—? = Crepidula 
Goreensis, Whe. Zeit. f. Mal. 1851, p. 36, no. 124. 
+ Crepidula striolata, Whe. Zeit. f. Mal. 1851, p. 35, no. 123. 
+ Calyptreea (Crepidula) Lessonii, Brod. Ryroc. Zool. Soc. 1834, 
p. 39 :—Trans. Zool. Soc. vol.i. p. 204, pl. 29, f. 5.— Mill. 
Syn. Nov. Test. Viv. p. 149.—(Crepidula L.) Lam. An. s. Vert. 
vol. vii. p. 649, no. 20.—(Ianacus L.) H. & A. Ad. Gen. 1, 
p. 370. ' 
