52 



University of California Publications in Geology [Vol. 10 



medial ribs reflected interiorly on the outer lip by ridges and grooves. 

 Shell longitudinally sculptured only by numerous fine incremental 

 lines. Aperture oval, although somewhat constricted toward the canal- 

 end ; sutural notch deep ; outer lip thin ; inner lip smooth, and fairly 

 heavily incrusted. Umbilicus excavated, but imperforate ; columella 

 light and straight ; canal short and pronouncedly recurved. 



Dimensions. — Longitude, 78 mm. ; latitude, 47.3 mm. 



This species agrees in its broad features with Thais kettlemanensis 

 Arnold described from the Jacalitos, but is readily distinguished by 

 the greater height of spire, more acute apical angle, greater inclination 

 of the spiral sculpture to the columellar axis, deeper sutural notch, 

 sharper recurving of the canal and by the pronounced rounding groove 

 above the sharp angle. It is quite distinct in outline and sculpture 

 from the recent Siphonalia kelletti, but its aperture and canal char- 

 acters place it in the same genus. 



Two reasonably well preserved specimens were found. 



CIIEYSODOMUS DIRUS MERIDIEI, var. nov. 

 Plate 1, Figures 9a, 9b 

 Univ. Calif. Coll. Invert. Palaeont., no. 11078. Type locality, Fourth and 

 Broadway, Los Angeles. 



Shell medium-sized, short, fusiform. The elevated spire is made 

 up of six or seven rounded whorls ornamented with about ten trans- 

 verse rounding nodes which die out toward the sutures and are nearly 

 obsolete on the body-whorl. The body-whorl possesses a tendency 

 toward tabulation due to a faint angulation in the middle portion 

 of its upper half. The shell is ornamented by seventeen strong, 

 squarish, equally spaced ribs, the interspaces being three-fourths the 

 width of the rib. The suture is strongly appressed and, due to the 

 enlargement of the last spiral rib and to the excavated subsutural area, 

 appears to bear a collar. Aperture subquadrate ; inner lip incrusted; 

 outer lip heavily thickened ; umbilicus imperforate ; canal short and 

 strongly recurved. 



Dimensions. — Longitude, 44.1 mm.; latitude, 21.6 mm. 



Comparison with C. dims shows that, while probably belonging 

 to the same species, this form possesses characters sufficiently marked 

 to give distinction to the variety. Among the more important differ- 

 ences are the presence of the angulation, the sharply curved canal, and 

 the heavy thickening of the outer lip of the Los Angeles form. The 



