MAGTLUS. 217 



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



The revolving costa? are perhaps simph~ a pronounced form of 

 the somewhat evanescent lines or strife which frequently occur 

 on M. a-nh'quus. The cost*? continue on the tube. 



Hob. ? 



M. Cumingii. H. 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, 

 J therefore prefer to retain Mr. Sowerby 's later name costatus. 



M. RUPPELLII, Deshayes. PI. <;8, fig 412 ; PI. 69, figs. 414, 418. 



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

 (fig. 414), Desh. 



The spire is sometimes depressed so as to make the distinction 

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

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



a passage into the next form. 



Me of Bourbon. 



Mr. Sow^rby's fig. 1 6., 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. 



M. MAILLARDI. De>hay<^. PL H9, figs. 416, 415. 417. 



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

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

 and J/. soli <li 11*1:1.1 la, Pease (fig. 417). I have before me a series 

 connecting these species. I have already suggested their rela- 

 tionship through M. /,'"p/'//ii with M. 0,'nfii/im^ : on the other 

 hand some transition forms to 31. tirnhriotu* are not wanting. 



1*1 1 <>f I >o iii-bo n. 



M. PIMBRIATUS. A. Ad. PL r,9. figs. 4111. 420. 4'2'2. 423. 



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

 of the body-whorl and largr aperture suggest the genus ('<>,,- 

 ckolepas, and Mr. Adams originally made a . subgenus Coralliobia 

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

 made Coralliobia a subgenus of Leptoconchus. The shell'is very 

 like Coralliophila madreporaram^ which I 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 



