KO.2207. WEST AMERICAN MELANELLW MOLLVSKS—BARTSCH. 315 



thick within, thin at tho odgo, somewhat protracted in the middle; 

 inner hp short, stout, reflected over and approssod to the base an- 

 teriorly; parietal wall covered with a thick callus. 



The type and another specimen (Cat. No. 322299, U.S.N.M.), come 

 from San Hipolito Point, Lower California. The type has nine and 

 a half post-nuclear whorls and measures — length, 5.1 mm.; diameter, 

 2 mm. 



MELANELLA (MELANELLA) MEXICANA. new species. 



Plate 37, fig. 5. • 



Shell elongate-conic, straight, polished, marked by exceedingly 

 fine hues of growth and scarcely perceptible microscopic spiral 

 striations; bluish-white. Whorls flattened, separated by an ill- 

 defined suture. The basal portion of tho preceding whorl, shining 

 through tho succeeding turn, gives to this an appearance of having 

 a false suture. Periphery well rounded. Base rather short, well 

 rounded. Aperture moderately long, oval; posterior angle acute; 

 outer lip thin, decidedly protracted halfway between the posterior 

 angle and the base; inner lip oblique, slightly curved, reflected over 

 and appressed to tho base; parietal wall covered with a moderately 

 thick callus. 



The type (Cat. No. 267304, U.S.N.M.) comes from the Gulf Coast 

 of Lower California. It has 12 whorls and measures — length, 6.4 

 mm.; diameter, 2 mm. 



The present species is much smaller than M. compacta and has a 

 much shorter aperture than that species. 



Tho following specimens have been examined : 



« Type. 

 MELANELLA (MELANELLA) ABREOJOSENSIS. new species. 



Plate 40, fig. 4. 



Shell small, acicular, bluish-white, semitranslucent. Whorls 

 rather high between the sutures, well rounded, separated by a con- 

 stricted suture. Marked by extremely fine incremental lines and 

 irregularly spaced varices. Periphery well rounded. Base rather 

 protracted, well rounded. Aperture moderately large; posterior 



