MAGILUS. 217 



M. COSTATUS, Sowerby. PI. 69, fig. 421. 



The revolving eosta 1 are perhaps simply a pronounced form of 

 the somewhat evanescent lines or stria* which frequently occur 



on M. (inli<jnu$. The costje continue on the tube. 



Hob. f 



M. Cumingii. 11. and A. Adams, described as from California, 

 is evidently the same species, and probably described from the 

 same specimen. The name had already been used by Deshayes, 

 I therefore prefer to retain Mr. Sowerby 's later name costa-tu*. 



M. RUPPELLII, Deshayes. PL 68, fig 412; PI. 69, figs. 414, 418. 



I unite with this form M. Cumingii (fig-. 418), and M. globulosus 

 (fig. 414), Desh. 



The spire is sometimes depressed so as to make the distinction 

 from M. antiquus arbitrary, and the body-whorl is narrowed 

 below, and somewhat produced in some specimens so as to suggest 

 a passage into the next form. 



Idle o 



Mr. Sowerby's fig. 1 /;., in the Conch. Icon. (fig. 413), appears 

 to me to represent this form, although I do not dispute his deter- 

 mination of it as M. antiquus. 



M. MAILLAEDI, Deshayes. PL 69, tigs. 416, 415, 417. 



The type is a depauperate shell, somewhat distorted, the normal 

 growth being better shown in M. Lamarck ii, Desh. (fig. 415), 

 and M. solidiuscula, Pease (fig. 417). I have before me a series 

 connecting these species. I have already suggested their rela- 

 tionship through M. Ruppellii with M. antiquus; on the other 

 hand some transition forms to M. fimbriatus are not wanting. 



Isle of Bo ID-IK HI. 

 M. FIMBRIATUS, A. Ad. PL 69, tigs. 419, 420, 422, 423. 



The fimbriated, ribbed surface, in the type, the great expansion 

 of the body-whorl and large aperture suggest the genus Con- 

 cholepaSj and Mr. Adams originally made a subgenus Coralliobia 

 under Concholepds, for his species ; afterwards H. and A. Adams 

 made Coralliobia a subgenus of Leptoconchus. The shell is very 

 like Coralliophila madreporarum, which 1 have placed in the 

 subgenus Galeropsis, Hupe, but differs in the surface and in 

 color. The expansion of the lip does not appear to be uniform ; 

 28 



