PLATE XXXV— Continued. 



SpIKIFEK CONSOBRINU8, (I'Oibigiiy. 



See Plate 34. 



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



ridge in the bottom of the valve. 



Hamilton grroup. Western New York. 



Genus SPIRIFERINA, d'OrbiGxNy. 



PsKe 51. 



Spiriferina transversa, McChesney. 



Fig. 19. An entire si>ecimen ; showing the general form and proportions, and the lamellose exterior. 

 Fig. 20. The interior of a poi-tion of the pedicle valve ; showing the median septum. 



Chester limestone. Buzzardfi' Rooitt, Alabama. 

 Pig. 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 cai-dinal process, dental sockets and low median ridge. 

 X2. 



Carboniferous limestone. Itaituba, Brazil. 

 (Figs. 23-2.5 ai-e from specimens figured by Dbrby, Bulletin of the Cornell University, vol. i, pi. ii, 

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



Spiriferina subelliptica. McChesney. 



Kg. 21. The interior of a portion of the pedicle-valve ; showing median septum and muscular scars. 

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

 cular ridges and low median ridge. X 2. 



Keokuk group. New Providence, Indiana. 



Spiriferina spinosa, Norwood and Pratton. 



Figa 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. 

 Pig. 29. An enlargement of the external surface ; showing the bases of the spinules and the punctte of the 



shell. 



Chester limestone. Chenter, Illinois. 



