FOSSILS OF THE LOWER SILURIAN. 



87 



4. Endoceras multitubulatum Hall? (Pal.N. Y., vol.i, p. 59, 1847). 



Several elongate tubes filled in with smaller tubes, as in E. multitubula- 

 tum, occur in the upper beds of the Fish Creek Mountain Pogonip, and simi- 

 lar specimens were observed a little lower in the group at White Mountain. 

 They belong to the same group of species as E. multitubulatum, but in the 

 fragmentary condition of the specimens it is impossible to state that they 

 are specifically identical with the Trenton species. 



5. Orthoceras sp. ? plate xii, fig. 1 b. 



This is a transverse section of a tube showing a peculiar siphuncle and 

 inner tube. As the figure on the plate does not give the desired repre- 

 sentation, figures are here introduced that show a slightly oblique section at 

 each end of a tube 10 mm in length. 



The inner tube (s) is subcentral with a broad extension (e) from one 

 side nearly to the side of the tube next outside of it (#), 

 and on the opposite side a thin septum (c) projects towards 

 the side of the tube. A longitudinal view of the tube (s) 

 shows it to be straight and without annulations. Viewing 

 the specimen as complete with the tubes (s) and (#), we 

 find it to be closely allied to a section given of Orthoceras 

 bonum by Barrande, 7 but if the outer shell (0) belongs to the 

 Nevada shell and is not a fragment into which the tube (x) was drifted, 

 then the peculiar section is not explained by any described species known 

 to me, as it would be much as is represented by the fig. 1 b of plate xii, and 

 be formed of three tubes, one within the other. 



Future exploration and the discovery of more material will undoubt- 

 edly afford the paleontologist the means of identifying this and several 

 other species now recognized by fragments too imperfect for description but 

 still specifically distinct from each other and the species we have mentioned. 

 The fragmentary remains now before us, however, with the associated 

 Brachiopods, Lamellibranchs, and Gasteropods serve the present purpose of 

 the geologist, as they indicate the passage from the Pogonip (Quebec) to 

 the Trenton fauna. 



FIG. 2. 



7 Syst. Sil. Boh&me, vol. ii, pi. ccxlvii, fig. 11. 



