276 MAZATLAN TTNIVALVES 



the colour lighter than in C. incurva, and disposed to break up 

 into spots ; shaped like Emargiuula rosea, with a very recurv- 

 ed, distant and projecting vertex, a short, deeply sunk and 

 slanting dock, and a hole above it passing up the spire. The 

 characters are like some of the forms of Cr. incurva intensified ; 

 and are subject to considerable variation. The mode of growth 

 is as in that species ; but the planorbiform vertical whirls 

 are even smaller, (about "01 across) with the apex deeply 

 sunken. The smallest specimen is "15 in length ; the largest 

 found measures long. '84i, lat. '62, alf.'4f3. 



Aflatsp. „ '62, „ -48, „ "18. 



The shortest-decked specimen measures "16 from deck margin 

 to the posterior, '39 to the anterior end, with an apical projec- 

 tion of ■ 14. 



Sa7}. — Bodegas, California ; attached to dead and Hving shells 

 and to each other, 6-10 fm. ; Sinds. — Straits of De Fuca, 

 Qould. — Sta Barbara, Col. Jeicett. — Panama, extremely rare, 

 C. B. Ad. — Mazatlan ; extremely rare ; L'pool Col. 



Tabtet 1357 contains 2 sp. very young. 1358, 1 sp. flat, 

 margin extended. — 1359, 1 sp. corfipressed, dark brown. — ISGT', 

 the largest sp., twisted growth, slightly ribbed and corruga- 

 ted. — 1361, 1 sp. pale flesh colour. 



339. Ceepidula incxjeva, Brod. 



Calyptrtea (Crepidula) incurva, Brod. Proc. Zool. Sac. 1834 



p. 40 ■.— Tran.s. Zool. Soc. vol. i. pi. 29, f. Q—Miill. Syn. Noi 



Test. Viv. p. 150. 

 Crepidula incurva, B. M. Cat. D'Orb. Moll. p. 49, no. 421.- 



C. B. Ad. Pan. Shells, p. 228, no. 347.— (Crypta i.) R. ^ A 



Ad. Gen. i. 369. 

 = Crepidula hepatica, Menhe, (non Desk, nee C. B. Ad. ne 



Xrauss,) Zeit.f. Mai. 1847, p. 184, no. 33. 



This species is known normally by the sharp longitudint 

 ridges on the back, which are not dependent on the attachmem 

 being regular in growtli, and conspicuous when adherent o 

 smooth shells. It is much smaller than C. onyx, of a deepe 

 chocolate brown colour, convex, with the beak very prominen 

 smooth and black as in C. rugosa, Nutt. The epidermis i 

 rather thin and deciduous. There are however so many spec 

 mens in which one or other of these characters pass away, ths 



