MELAMPUS. 



Subfamily MELAMPIN^. 



Animal amphibious, or living in brackish water. Shell with 

 the inner lip plicate ; outer lip straight and acute. 



MELAMPUS, MoNTF. 



Foot bifid posteriorly. Shell ovate-conical; spire short, oli- 

 tuse ; aperture narrow, linear ; inner lip with several transverse 

 folds ; outer lip acute, internally plicate. 



Jaw — ? 



Lingual membrane — ? 



Numerous species of this genus have been met with, widely 

 distributed over the world. 



9Ielampus olivaceiis, Cpr. — Shell small, rather smooth, coni- 

 cal ; spire depressed, obtusely angulated below the suture, which does not 

 distinctly separate the whirls ; color dirty white, with irregular patches 

 or revolving lines of dark red or purplish ; epidermis olive- 

 colored ; on young or very fresh specimens there are some- Fig. 10. 

 times microscopic revolving Hues near the base of the shell, 

 and on the spire, which cross the delicate lines of growth so as 

 to present under the microscope a granulated surface ; whirls 

 seven to nine, the upper ones distinguished only by means of 

 the lens, and flattened ; aperture long, equalling j ^ of the 

 shell, edge variegated in color by the termination of the reddish 

 bands on the white ground of the shell, within white ; the 

 outer lip is furnished with numerous sharp, white laminae, in 

 the specimens before me varying from 1 to 9 ; the parietal wall of the 

 aperture is covered with an almost imperceptible shining, callus ; there 

 is one constant, prominent, elevated white tooth-like lamina revolving 

 within the shell, which is usually placed within two smaller shorter ones ; 

 on the columella there is also a stouter lamina entering into the aperture, 

 and passing outwards and curving downwards so as to join the termination 

 of the labium. Length 13, diam. 18 mill. 



Melampus olivacetis, Carpenter, in Reigen Cat. of British Museum, 178 

 (1856).— W. G. BiNUEY, T. M. U. S. IV, 27, pi. Ixxix, f. 8. 



San Diego to Mazatlan (Reigen Cat.). 



This is the first species of the family Auriculacea found on the 

 Pacific coast of North America. There were numerous specimens 

 found by M. Reigen, which Mr. Carpenter describes as dis- 



