1897.] NEW YORK ACADEMY OF SCIENCES. 269 



Bellerophon sublaevis Hall, 

 PI. XXI., fig. 10. 



1856. Bellerophon sublaevis, Hall, Trans. Albany Inst., Vol. 4, 



p. 32. 

 1858. Bellerojjhon sublaevis, Hall, Geol. Iowa, Vol. 1, pt. 2, p. 



666, PL 23, fig. 5. 

 1882. Bellerophon sublaevis, Whitfield, Bull. Am. Mus. Nat. 



Hist., Vol. 1, p. 89, PI. 8, figs. 6-7. 



1882. Bellerophon sublaevis. White, 11th Rep. Geol. Surv. Ind., 

 p. 359, PI. 40, figs. 5-7. 



1883. Bellerophon sublaevis. Hall, 12th Rep. Geol. Surv. Ind., p. 

 371, PI. 31, figs. 6-7. 



1891. Bellerophon sublaevis, Whitfield, Ann. N. Y. Acad. Sci., 



Vol. 5, p. 592, PI. 14, figs. 20-21. 

 1894. Bellerophon sublaevis, Keyes, Mo. Geol. Surv. Vol. 5, p. 

 148. 



The Arkansas specimens of this shell are all imperfectly pre- 

 served and in the form of internal casts. There seems to be no 

 doubt, however, as to the accurac}^ of their identification. But 

 little can be said in the way of description of the specimens, ex- 

 cept that they are sub-globular in form with a smooth surface. 



All the specimens of this species in the Walker Museum col- 

 lection are so much crushed and distorted as to be unfit for il- 

 lustration. The figure on plate 3 is from a specimen in the U. S. 

 G. S. collection loaned for illustration by Professor Williams. 



Bellerophon branneri sp. nov. 



PI. XXI., fig. 9. 



Inner volutions of the shell small, closely coiled. Outer 

 volution broadly expanding toward the aperture, subangulate 

 along the dorsum. Aperture large, sub-circular in outline, with 

 a slightly sinuate dorsal margin. Shell ornamented with rather 

 remote transverse undulations. 



This species is represented in the collection by a single im- 

 perfect example, but it is so distinct from every other Car- 

 boniferous species that it is given a specific designation. The 

 figure is drawn from a wax cast of the mould of the speci- 

 men in the sandstone. It is similar to the Devonian species B. 

 natator. Hall,* but diflfers from it in having a shallower and less 

 sharply sinuate dorsal margin in the aperture, and in having a 

 less angular dorsum. The transverse undulations are also more 

 remote in the Arkansas species. 



*Pal. N. v., Vol. 5, pt. 2, p. 108, PI. 24, fig. 1. 



