TERTIARY INVERTEBRATE FOSSILS. 



(continued.) 



MURICIDEA, Swains. 

 M. (? Phyllonotus) paucivaricata, n. s. 



PI. 14. Pig. 1. 



Shell moderate in size, robust, fusiform, spire nearly as long 

 as the aperture; whorls seven, subangulated, sloping above and 

 bearing eight or nine large longitudinal ribs which develop into 

 prominent nodes on the angle; on the body whorl these ribs dis- 

 appear on the middle or towards the anterior part of the shell. 

 Aperture subovate above, narrowed anteriorly, canal slightly de- 

 flected and often closed by a union of the two lips; labrum 

 thickened behind, acute on the margin, coarsely dentate inter- 

 nally, and bearing a small compressed tooth a little below the 

 middle, inner lip incrusted by a smooth plate; umbilicus subper- 

 forate. Surface marked by two or three varices, acute on the 

 margins, never prominent, and not infrequently entirely obsolete; 

 these varices are usually coincident with the longitudinal ribs; 

 crossing them are from five to seven revolving ribs, between 

 each pair of which are six to eight smaller rounded ribs with 

 acute interspaces, giving the whole shell a closely costate surface; 

 in well-preserved specimens the revolving ribs are crossed by 

 small squamose plates, the remains of the lines of growth. 



Length 1.8 inch, width 1.05 inch, length of aperture 1.1 inch. 

 Locality: Post-Pliocene; Santa Barbara, San Pedro, and San Diego. Not known 

 in a recent state. 



( 43 ) 



