A/^ ^ i^rff^n^OF CONCHOLOGY T^ ■ 1^^ 16T 



DESCRIPTION OF A TTE'W SPECIES OF MONOCSROS, 

 FROM CALIFORNIA, W^ITH REMARKS ON THE DISTRI- 

 BUTION OF THE NORTH AMERICAN SPECIES. 



BY KOBERT E. C. STEARNS. 



M. PAUCILIRATA, Stearns. PI. 14, fig.)6. 

 • M. 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 wdiorl 

 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 costre 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 

 3Ionoce.ros lugubre, Sby., shows the former to be a connecting 

 link between the upper Californian and more southern forms. 

 M. laguhre r'eaches northerly nearly to San Diego, being found 



