Maryland Geological Survey 303 



Description. — Form extremoly elongate-conical, slender, becoming more 

 nearly cylindrical on approaching the mouth. The apical portion is 

 extremely attenuate Math regular and closely arranged acute annulations, 

 which near the apex are visible only under a strong lens, and the extreme 

 portion is apparently smooth, the distance between the annulations in- 

 creases toward the mouth and fine transverse, lamellose striae develop in 

 the interspaces. The usual length is from 15 to 22 mm., and the largest 

 individuals have a diameter at the mouth of nearly 3 mm. This species 

 is distinguished from T. attenuahis by its larger size and regularity in 

 distance of the annulations. 



Specimens longer than the preceding species with annulations at about 

 a uniform distance apart, decreasing from the mouth toward the apex, 

 the broader interspaces marked by fine transverse striae, are referred to 

 this species. 



Length, about 14 mm. : width, toward mouth, 114 mm. 



Occurrence. — RoMNEY FoRirATiON, Hamilton Member. McCoys 

 Ferry ; west of iron bridge over Town Creek northeast of Oldtown ; on 

 road abont half way between Eomney and Hanging Rock, W. Va. 



Collections. — Maryland Geological Survey; American Museum of Xat- 

 ural History. 



Tentaculites bellulus var. potomacensis n. var. 

 Plate XXXYIII. Figs. 1-3 



Description. — External impreesions which are more robust and longer 

 than the normal forms of T. hcUuIns. The annulations are not so acute 

 and have a steep posterior slope with a more gradual anterior one, while 

 there is a larger number of transverse striae on the interspaces and slopes 

 of the annulations. The size and number of striae apparently distinguish 

 it from the normal specimens of this species. 



The specimen from McCoys Ferry was submitted to Dr. Grabau who 

 wrote as follows : " I should be inclined to call it a variety of T. helhdus 

 with some characters of T. scaJariformis. Xote the steeper posterior slopes 

 of the annulations." 



