OF CONCHOLOQY 



16T 



DESCRIPTION OF A NEW SPECIES OF MONOCEROS, 

 FROM CALIFORNIA, WITH REMARKS ON THE DISTRI- 

 BUTION OF THE NORTH AMERICAN SPECIES. 



BY ROBERT E. C. STEARNS. 



M. paucilirata, Stearns. PI. 14, fig. 6. 



31. paucilirata, Stearns, Prel. Descr. May 18, 1871. 



Description. Shell small, ovate, spire moderately elevated, 

 subacute ; whorls four to six ; body whorl four-fifths the length 

 of the shell ; upper portion of same angulated, and excavated 

 between the angle and the suture, and anteriorly broadly but 

 not deeply grooved ; upper whorls rudely cancellated except the 

 apex, which is nearly smooth ; aperture ovate, purplish-brown ; 

 columella flattened, enameled, purple, brown, or blackish, some- 

 times showing all of these colors; outer lip simple, acute, inter- 

 nally denticulated, whitish or yellowish near the edge, with a 

 single prominent tooth at its anterior margin ; canal short, 

 slightly recurved ; umbilicus nearly concealed ; body whorl 

 traversed spirally by four to five narrow ribs placed nearly equi- 

 distant, and longitudinally marked by irregular varix and fine 

 incremental lines; shell yellow or yellowish-white, with large 

 angular spots of black ; the transverse costas and the more pro- 

 minent of the longitudinal lines are of the lighter color, and the 

 largest specimen exhibits faint transverse sculpture between the 

 prominent ribs. 



Length of largest specimen, -55. Width *33 inch. 



Habitat, Coronado Islands, off San Diego, California. 



Three specimens of this well-marked species, quite distinct 

 from others of the genus, were collected by Mr. Hemphill. 



A comparison of the above shell with immature specimens of 

 Monoceros lugubre, Sby., shows the former to be a connecting 

 link between the upper Californian and more southern forms. 

 31. lugubre reaches northerly nearly to San Diego, being found 



