•iSS Systematic Paleontology 



secondaries intercalated; interspiral areas linear; sutures quite deeply 

 impressed, the posterior slope of the sutural channel steeper than the 

 anterior; periphery of body whorl obtusely carinate; sculpture of base 

 similar in strength and character to that upon the sides of the whorl. 



Dimensions. — Altitude 13.5 mm., maximum diameter 4.5 mm. 



In the casts the earlier whorls are broadly rounded and quite distant, 

 but the later volutions are obtusely angulated and proximate. 



The species is very abundant at the type locality, and was at first mis- 

 taken for T. encrinoides juvenis. The spirals are much more uniform in 

 size, however, and the whorls more obscurely angulated in the casts. 



Occurrence. — Matawan Formation. Post 105, Chesapeake and Dela- 

 ware Canal. 



Collection. — Maryland Geological Survey. 



TUEEITELLA PAEAVEETEBKOIDES n. Sp. 



Plate XVII, Fig. 1 



Description. — Shell elongate-turrited, the whorls flattened, probably 

 fourteen or fifteen in number, regularly increasing in size, converging at 

 an angle of approximately 20° ; axial sculpture not developed ; spiral 

 sculpture uniform in character over the entire surface of the shell, pri- 

 maries normally five in number, though occasionally one more or less, well 

 rounded moderately elevated cords, subequal in size and spacing at least 

 upon the anterior half of the whorl, often more distant and less prominent 

 upon the posterior; inter-spiral areas flattened; entire surface overrun 

 with microscopically fine crowded striae, six to eleven in number on each 

 of the inter-spiral areas of the later whorls ; suture line impressed, placed 

 nearer the posterior spiral than the anterior of the preceding turn; the 

 posterior slope of the sutural channel steeper than the anterior; body 

 whorl obtusely carinated at the periphery ; the base flattened and micro- 

 scopically striate. 



This species, like most of the group, shows a wide range in variation. 

 There is quite a little difference in the relative strength of the spirals, 

 although they never approach in sharpness the primaries of the true 



