NAPLES FAUNA IN WESTERN NEW YORK, PART 2 343 



Tentaculites tenuicinctus F. A. Roemer 



Plate 20, fig. 20, 21 



Tentaculites tenuicinctus F. A. Roemer, Beitr. 1 zur geol. Kenntniss d. 



nordw. Harzgebirges. 1850. p. 28, pi. 4, fig. 19 

 Tentaculites tenuicinctus Sandberger, Verstein. des rhein. Schichtensyst. 

 in Nassau. 1850-56. p. 250, pi. 21. fig. 13 



Very slender and delicate, elongate, gradually tapering tubes closely 

 and regularly annulated by concentric, narrow, elevated rings with narrower 

 interspaces. The rings run almost to the tip of the shell, and in the later 

 growth of the tubes there are about 20 in the length of 1 mm, the length 

 of an average shell being 4-5 mm and the diameter at the larger end about 

 .3 mm. No longitudinal lines are visible. ' 



This species is smaller and much more slender than any American 

 species known to me, T. s p i c u 1 u s expanding more rapidly and having 

 more distant rounded annulations with concentric lines on the intervals. It 

 is without distinguishing characters from the German species which was 

 described from the Intumescens horizon at Riibeland in the Hartz moun- 

 tains and occurs at various localities of this fauna. 



Habitat. Genesee province ; Naples subprovince. In sandy concre- 

 tions at Naples. 



