(ilBBEKI LA. 41 



M. GUANCHA, d'Orb. PI. 11, fig. 42. 



Whitish; columella four-plaited. Length, 1 '5 mill. 



Canary Islands. 

 Narrower than M. clandestina, and compressed at the ends. 



M. OVULIFORMIS, d'Orb. PI. 11, fig. 43. 



White, columella with three plaits'. Length, 1*5 mill. 



West Indie*. 

 Possibly an immature shell. 



M. MARGARITULA, Carpenter. 



White, columella with four plaits , very like M. ovuliformis, 



Length, -032-'0f3 inch. 



Mazatlan, W. Coast of Mexico. 

 I have no specimens of this unfigured, very minute species. 



M. PYRIFORMIS, Carpenter. PI. 13, fig. 38. 



Like M. margaritula, but sometimes tinged with light orange; 

 longer and narrower in front; lip (not always) very minutely 

 denticulated ; columellnr plaits rather acute. Length, 2 mill. 



Monterey to San Diego, Cal. 



M. LEFEVREI, Bernardi. PI. 11, fig. 44. 



White or slightly yellowish. Length, 13 mill. 



Habitat unknown. 

 Section Gibberula, Swainson. 



Shell suboval ; spire slightly prominent ; outer lip posteriorly 

 dilated and gibbous, not denticulated. A group of small species 

 differing from Persicula in the spire being slightly prominent 

 instead of sunken. 



M. MONILIS, Linn. PI. 11, figs. 45, 46. 



Ivory-white ; columella four-plaited ; above the plaits are 

 additional denticulations. Length, 10-12 mill. 



West Africa; Red Sea; L of Socotra. 



The African tribes form necklaces of these shells. For the 

 purpose of stringing them a hole is made through the upper 

 part of the body-whorl, apparently by rubbing. M. Petit, finding 

 the figures of this species in Sowerby's Thesaurus to have a spire 

 more projecting than is warranted by Linnaeus' description, and 

 the locality of the latter being given as China, separates Sowerby's 

 shells as M. Sowerbyana ; no subsequent authors have recognized 

 6 



