MAZATLAN UNIVALVES 265 



vol. x. pi. 168, f. 16267 iDilliv. Eec. Shells, p. 1018, 

 no. 6: =Calyptrsea (Trochatella) t. B. M. Cat. D'Orb. 

 Moll. p. 48, no 411 : + Patella trochoides, Dillw. loc. cit. no. 

 7: + Calyptraea Araucana, Less, (teste D'Orb. Cat.) 

 PJun. = Calyptrea dilatata, Sow. Gen. f. 9, (non Crepidula 

 d., f. 5.) Calyptrsea radians, (max,) Vol. Voy. Ven. pi. 14, 

 f. 3 5 pi. 15, f. 4. 



Of this beautiful species, besides the specimen here des- 

 cribed, I have seen only one other, in the collection of T. 

 Nuttall, Esq., from an unknown locality. It differs from the 

 S. American T. radians, (also quoted from Benguela and St. 

 Vincent, Guinea, on the authority of Dr. Tarns ; and of which, 

 a remarkably conical variety is figured in Beechey's Voyage ;) 

 and also from the Gulf species, T. spirata, in the great con- 

 vexity of the whirls, which are so produced at the shoulder 

 that the sides of the suture form nearly a right angle. It ap- 

 proaches most nearly to a fossil species from Dax, which 

 however has the base still more concave. The Infundibulum 

 Californicum, H. Ad., (Proc. Zool. Soc. 1851, p. 153,) which 

 from its name might be supposed to have some connection, is 

 a species of Poly donta, (Trochinse.) Diam. '74, alt. '64, (eujus 

 anf. ult. '48,) div. 110. 



Hob. Mazatlan ; one fresh sp. ; IS pool Col. 

 Tablet 1316 contains the specimen. 



GENUS GALEBUS, Gray. 



Galerus, Humph. 1797: Gray, Proc. Zool. Soc. 1847, p. 157, 



no. 269 :Phil. Handb. Conch, p. 187 : H. fy A. Ad. Gen. 



vol. i. p. 367. 

 Trochita (pars,) Schum. 1817. Calyptrsea (pars,) Lam. 1822. 



Siphopatella (pars,) Brod. 1834. Infundibulum, pars, J. 



Sow. TrochateUa, pars, D'Orb. 

 Mitrula, Gray, 1821. Trochilea, Swains. 1837. 



This genus is intermediate between Crepidula or Crucibulum, 

 and Trochita. The shell is conical, slightly spiral, with a 

 rapidly ascending spiral lamina, doubled in upon itself. Unfor- 

 tunately, no very young shells were found of this section. The 

 plane of the vertex is parallel to the base in all observed species. 



| 332. GALEEUS CONIGUS, Brod. 



Calyptraea (Siphopatella) conica, Brod. Proc. Zool. Soc. 1834, 

 'p. 38: Trans. Zool. Sac. voL i. p. 202, .pi, 27, f. 7.MML 

 July 1856. * 



