Well&r — Kinderhook Faunal Studies. 203 



Bellerophon panneus White. 



PI. XX. f. 17-18. 



Original description. " Shell subglobose, gradually ex- 

 panding, except at the lateral margins, where it expands 

 abruptly ; transverse section of the volution opposite the 

 aperture an irregular ellipse ; umbilici narrow and deep, which, 

 when not filled with the imbedding material, display the 

 rounded sides of the volutions, which are three or four in 

 number. The back of the shell is somewhat flattened, and 

 has a central longitudinal elevation, which becomes a distinct 

 carina at the front; surface marked by strong, irregular, 

 undulating lines of growth, becoming very rough towards the 

 front margin." 



The dimensions of the type specimen are: greatest diameter 

 of shell 37 mm., and width of aperture 35 mm. 



Remarks. The accompanying illustrations of this species 

 represent two views of the best preserved of the type speci- 

 mens in the University of Michigan collection. The illustra- 

 tion published by Keyes * as a representative of this species 

 is something entirely different and probably represents an 

 undescribed species. His illustration f designated as B. bila 

 bialus is more nearly like B. panneus, being entirely distinct 

 from the true B. bilabiatus from the Chonopectus sandstone. 



CORRELATION. 



The number of species in the faunas of beds No. 3. and No. 4 

 is so limited that the correlation of these beds will be depend- 

 ent in large part upon the correlation of the subjacent and 

 superjacent strata with their more prolific faunas. The 

 presence of Chonopectus jischeri throughout these two beds, 

 however, and the absence of any forms which especially ally 

 the faunas to those immediately above them in the Burlington 

 section, would seem to indicate that these two beds should be 

 associated with the underlying Chonopectus sandstone rather 

 than with the overlying strata. These two beds, and these 

 alone in the Burlington section, contain specimens of the 

 typical form of Pugnax slriaticostata , the specimens from 



* Mo. Geol. Surv. 5. pi. 50. f. 6. 

 t Loc. cit. pi. 50. f. 3. 



