PLATE XXXV— Cimtiimed. 



Spibifek consobrinus, (I'Oibigiiy. 



See Plate 34. 

 Fig. 18. The interior of an imperfect pedicle-valve ; showing- the median septum, which appears as a h)w 

 riiige in the bottom of the valve. 



Hamilton group. Western New Tork. 



Genus SPIRIFERINA, d'Orbigny. 



Page .51. 



Spiriferina transversa, McChesney. 



Fig. 19. An entire specimen ; showing the general form and proportions, and the lainellose exterior. 

 Fig. 20. The interior of a portion of the pedicle valve ; showing the median septum. 



Chester limestone. Bmzard.t' Rooat, Alabama. 

 Fig. 23. A cardinal view of an individual with a high area. 



Fig. 24. Oblique view of the interior of a pedicle-valve ; showing the median septum 



Fig. 25. The interior of a brachial valve; showing cardinal process, dental sockets and low median ridge. 

 X2. 



Carboniferous limestone. Itaituba, Brazil. 

 (Figs. 23-2.') are fi'om specimens figured by Derby, Bulletin of the Cornell University, vol. i, i)l. ii, 

 fig. 6 ; pi. iii, fig. 12 ; pi. v, fig. 4. 1874.) 



Spiriferina subelliptica. McChesney. 



Fig. 21. The interior of a portion of the pedicle-valve; showing median septum and musculai' scars. 

 Fig. 22. The interior of a portion of the brachial valve ; showing the articulating apjjaratus, elevated mus- 

 cular ridges and low median I'idge. X 2. 



Keokuk group. New Prmiidenee, Indiana. 



'Spiriferina spinosa, Norwood miil Pratlt'ii. 



Figs. 26, 27. Views of an entire example ; showing the exterior characters. 



Fig. 28. A longitudinal median section through conjoined valves ; showing the height of the median 



septum. 

 Fig. 23. An enl.argement of the external surface ; showing the bases of the spinules and the punctie of the 



shell. 



Chester limestone. CheMet; llHiiois. 



