8 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.73 



NATICA ALAZANA, new species 



Plate 2, Figures 1, Ic, 1& 



Shell small, thick; whorls four and one-half, smooth except for 

 deep grooves that extend forward from the suture almost to the 

 periphery; suture well marked; aperture asymmetrically semilunate, 

 wider in front than behind; inner lip contiguous to the whorl for 

 half its length; umbilicus with one strong rib. Length, 6 mm.; 

 breadth, 5 mm. 



Natica alazana closely resembles Natica " canrena " from the 

 Chipola formation of Florida, but its whorls are more convex than 

 those of the Florida species. 



Occurrence. — Oligocene, Alazan clay, Rio Buena Vista west of 

 Alazan, Mexico. (M. 49 V.) 



Type.—Q^i. No. 352704, U.S.N.M. 



POLYNICES (LUNATIA) LACRIMANS, new species 



Plate 2, Figures 2, 2a, 2& 



Shell small, globular, spire moderately high; whorls rounded, 

 smooth except for antesutural corrugations which become obsolete on 

 the body whorl; aperture large, semilunate; callus half filling the 

 umbilicus, set with a medial bump resembling a teardrop and sepa- 

 rated from the rest of the callus by shallow depressions. Length, 8.5 

 mm. ; breadth, 7.2 mm. 



OccwtTence. — Oligocene, Alazan clay, Rio Buena Vista west of 

 Alazan, Mexico. Abundant. (M. 47, 48, 49 V.) 



Type.— C^t. No. 352705, U.S.N.M. 



POLYNICES (EUSPIRA) BYRAMENSIS, new species 



Plate 2, Figures 3, 3o, 3& 

 Lunatia sp. g., Cooke, U. S. Geological Survey Prof. Paper 129, p. 84, 1922. 



Spire rather low, sides flattened; whorls, five, constricted in front 

 of the suture; body whorl large; aperture semilunate; umbilicus 

 large, with a broad, low, rounded, spirally striated rib continuous 

 with the callus of the inner lip and bordered anteriorly by a shallow 

 sulcus ; callus of inner lip thin. Length, 13.4 mm. ; breadth, 12.7 mm. 



The umbilical rib is very inconspicuous in all the specimens ex- 

 amined except the type. 



This species is rather rare at Vicksburg and Byram, Miss. The 

 specimens from Mexico are small and broken, but seem to have no i 

 specific differences from the Mississippi forms. 



Occurrence. — Oligocene, Byram marl, Vicksburg, Miss, (type, sta- 

 tion 3722) and Byram, Miss, (station 6454) ; Alazan clay, Rio Buena 

 Vista west of Alazan, Mexico. (M. 49 V.) 



Type.— Cdit. No. 352706, U.S.N.M. 



