184 PALEONTOLOGY OF NEW-YORK. 



578. 3. TENTACULITES DISTANS (?t. sjB.). 



Pl. a XLI. Fig. 9 a, b, c. 



Tubes strong, rather rapidly enlarging from the apex, annulated by sharp elevated rings ; 

 annulations distant, apparently extending to the apex, four to five in the eighth of an inch ; 

 intermediate spaces striated longitudinally ; strite sharp, with spaces between equal to their 

 width. 



This species is readily distinguished from the last, and indeed from any of the others, by the 

 great distance of its annulations, which are sharp, while the spaces between are marked by 

 longitudinal strise : the tube is likewise stronger, and more rapidly enlarging from the apex 

 than the species in the lower silurian strata. 



Position and locality. This species has thus far been found only in the thin layers of lime- 

 stone in the lower part of the group at Flamborough Head, Canada West, near the head of 

 Lake Ontario. It probably occurs at Loekport and Reynale's Basin, since the associated fossils 

 are precisely similar. 



The following are, in a few words, some distinctive characters of the species as they have 

 fallen under my observation : 



T.Jlexuosus. Annulations sharp, nine in i of an inch, with intermediate spaces striated longitu- 

 dinally. 



T. minutus. Annulations obtuse or rounded, seventeen in \ of an inch ; intermediate spaces 

 smooth or transversely striated. 



T. distans. Annulations sharp, distant, four to five in i of an inch ; intermediate spaces striated 

 longitudinally. 



T. of Niagara group. Annulations rounded, eight or nine in | of an inch ; intermediate 



spaces marked by transverse rounded striae. 



T. of Tentaculite limestone. Annulations rounded, unequally distant, from six to twelve in 



the space of | of an inch ; intermediate spaces transversely striated with rounded 

 strife. The tube is very long and slender, and the annulations frequently do not 

 extend to the apex, leaving that portion smooth for the distance of an eighth of 

 an inch : this feature, however, is variable. 



These characters constitute reliable means of distinction, and, if properly observed, will enable 

 any one to distinguish them. I am the more solicitous to show these in conjunction, since some 

 persons have been disposed to doubt the distinctions between these small bodies in the succes- 

 sive groups. I need not here, perhaps, point out the very marked distinction between these and 

 the other species known in a higher position. 



