38 DEVONIAN FAUNA. 



Suh-genus — Coleolus, Hall, 1879. 



Shell tubularly conical or slightly curved, very elongate; walls rather thick, 

 smooth interiorly, annulated with transverse or oblique striae or rings externally. 



It is very doubtful whether there is any reason for separating this group from 

 Tentaculites proper, on account of its smooth, simple interior, thicker walls, &c. 



2. Tentaculites (Coleolus?) tentacularis, Phillqjs, sp. Plate IV, fig. 15. 



1841. Obthoceeas tentaculaee, Phillips. Pal. Foss., p. 112, pi. xliii, figs. 



210 a— e. 

 ? 1845. Tentaculites tenuis, Keyserling. Wissensch. Beob. Petschora-Land, 



pp. 272, 273. 

 ? 1850. — TENUiciNCTUS, F. A. Romer (pars ?). Beitr. Harzgeb., 



pt. 1, p. 28, pi. iv, figs. 19 a ?, b. 

 ? 1853. — — Sandberger. Verst. Eheiu. Nassau, p. 250, 



pi. xxi, fig. 13. 

 ? 1887. — — Tschernyschetv. Mem. Com. Geo)., vol. iii, 



No. 3, p. 42, pi. vii, fig. 14. 



Description. — Test very elongate, conical, circular in section, increasing at the 

 rate of about 1 : 20, internally smooth, externally banded by very numerous, 

 regular, elevated, rather distant annuli, about five or seven in a space equal to 

 width, and with a few finer irregular strise. Structure rather thick. 



Size. — An imperfect specimen is 15 mm. long and 2 mm. in diameter. 



Localities. — A slab in the Porter Collection contains six imperfect specimens 

 from Pilton. Phillips quotes it from Baggy Point and from Meadfoot (near 

 Torquay). 



BemarJcs. — These specimens are evidently identical with Phillips's North 

 Devon shell, though the annuli are generally closer. He regards it as an 

 Orthoceras, because he considered that he saw septa in some of the specimens. 

 He remarks, however, " that they are not satisfactory in regard to the siphunclc 

 and septa," and he does not state whether it was in the North or the South 

 Devon specimens that he observed these appearances. I should have very great 

 difficulty in regarding those fossils which I have examined as Cephalopods, both 

 on account of the thickness of their walls and the smooth simple casts of their 

 interior, which show no signs of septa. The lines indicating septa in Phillips's 

 figure might, I think, easily be accounted for by the shrinkage of sediment in a 

 long tube. Septa, however, exist near the apical end of T. attenuatus, Hall.^ 



1 1889, Nicholson and Lydekker, 'Manual Palseont-.,' vol. i, p. 809, fig. 725. 



