1895.] NATUHAL. SCIENCES OF PHILADELPHIA. 79 



the posterior canal extends nearly or quite to the apex of the spire, 

 and recurving descends to near the body whorl. The only orna- 

 mentation is the spiral striation at the base of the body whorl, and 

 sometimes faint costa? near the apex. 



Localities. — Two miles east of Alto, Cherokee Co. ; near McBee 

 School-house, Cherokee Co.; Collier's Ferry, Brazos River; 2 miles 

 west of Alto, Cherokee Co. ; Sulphur Springs, Rusk Co. ; Robbing' 

 well, Houston Co., Tex. 



Geological horizon, — Lower Claiborne Eocene. 



Type. — Texas State Museum. 



Genus CERITHIUM. 

 Cerithium webbi now sp. PI. 9, fig. 3. 



Specific characterization. — General form of young specimens as 

 shown in the figure; whorls about 9 ; spiral ones marked by two 

 submedial approximate spiral rows of crenules or nodes above which, 

 and just below the suture, is a third row with smaller crenulations ; 

 suture deep and broad; body whorl marked somewhat as those above 



though the lower submedial row of crenules is faint, and below it to 



- • 



the end of the beak occur spiral raised lines of varying strength; the 

 entire surface is apparently covered with minute revolving lines ; 

 lines of growth on the body whorl start at right angles to the suture 

 above, pass downward to the middle of the whorl, curve gradually 

 forward and, after reaching the base of the whorl, slowly again curve 

 backward and pass downward on the canal. 



Locality. — Rio Grande, 13 miles by river below Laredo, or 9 by 

 river above the Webb-Zapata County line, Texas side. 



Geological horizon. — Lower Claiborne Eocene. 



Type. — Texas State Museum. 



Cerithium penrosei nov. sp. PI. 9, fig. 4. 



Specific characterization. — Whorls at least 15, gradually tapering, 

 ornamented as follows: by (1) about seven laterally compressed, 

 oblique subcentral or basal nodes, or costa± on each whorl, those on 

 the smaller whorls of the spire not so distinctly defined as represented 

 by the figure; by (2) spiral lines or stria?, about five of which are 

 strong and occupy the lower one-third of each whorl, three or four 

 more are finer and occupy a narrow, irregular central zone, while 

 four or five more occupy the upper or non-costate portion of the 

 whorls. 



