Maryland Geological Survey 697 



the associate goniatites in these rocks by the ahnost complete obscuration 

 of the inner whorls. 



In the New York succession the species entered the region during the 

 Hamilton stage and surviving the inroad of the Naples fauna attained 

 therewith its most abundant development, at the same time being wholly 

 restricted to the Naples suliprovince while in the Chautauqua subprovince 

 the genus is represented in equal abundance by the species T. bicostatum 

 Hall. 



Diameter 26 mm.; diameter of volution 17 mm. 



Occurrence. — Jennings Formation, Genesee Member. Corrigan- 

 ville and in the vicinity of Cumberland. 



Collection. — Maryland Geological Survey. 



Suborder GLOSSOCAMPYLI 

 Family PHARCICERATIDAE 



Genus SANDBERGEROCERAS Hyatt 



Sandbergekoceras chemungensis (Vanuxem) 



Plate LXXII, Fig. 7 



Goniatites chemungensis Vanuxem, 1842, Geol. Survey N. Y., Rept. 3d Dist., 

 p. 182, fig. 1. 



Goniatites chemungensis Hall, 1S7G, Illustrations Devonian Foss., Cephalo- 

 poda, pi. Ixix, fig. 9. 



Goniatites chemungensis Hall, 1879, Pal. of N. Y., vol. v, pt. ii, p. 467, pi. 

 Ixix, fig. 9; pi. Ixxiv, flg. 6. 



Sandbergeroceras chemungensis Clarke, 1903, Bull. N. Y. State Mus. No. 65, 

 p. 649. 



Description. — " Shell discoid, expanded. Inferring from the condition 

 of the compressed specimen, the transverse section of the tube has not 

 exceeded one-fourth that of its lateral diameter. Volutions gradually 

 expanding, about four (or five?) ; all exposed in the wide, shallow um- 

 bilicus; the inner ones partially embraced in the outer. The transverse 

 section is broadly oval, and a little sinuate, or somewhat expanded in 

 the middle of the sides of the outer one; rounded upon the periphery. 



