314 



PALEONTOLOGY OF NEW YORK. 



Genus OLDHAMINA, Waagen. 1883. 



1863. Bdlerophon, de Koninck. Quart. Jour. Geol. Soc. London, vol. xix, p. 8. 



1880. Thecidea, ZuiiMAYER. Untei'S. iibei' rhat. Brachiopoileii ; Beitr. /iir Palaout. Oesten-eich- 



Unjrarn, I, p. 22. 

 1883. Oldhamina, Waaobn. Productus-limestone Fossils; Brachiopoda, pp. 403-409, pi. xxxi, iigs. 1-9. 



Shells highly concavo-convex. 



Pedicle- valve subhemispherical ; apex incurved, at maturity covered by a 

 callosity, as in Bellerophon ; attached by cementation in early growth. Hinge- 

 line short and straight, not interrupted in the middle ; below it lie well- 

 developed teeth. Interior surface of the valve covered with diverging lateral 

 ridges. 



f 



Via. 216. 



Fig, 245. 



riG. 217. 



Oldhamina decipiens, de Koninck. 

 Fig. 245. The exterior of a pedicle-valve with Ihe sliell partly exfoliated. 



Fig. 246. Posterior view ol' the brachial valve; showing elevation and lobation of the cardinal process. 

 Fig. 247. The interior of a pedicle-valve; showing the median and lateral ridges. (Waagen.) 



Brachial valve concave. Cardinal process inconspicuous, quadripartite at the 

 summit ; continuous with a median ridge extending the entire length of the 

 valve. Internal surface covered with divergent grooves corresponding to the 

 ridges of the opposite valve. 



Exterior smooth or with numerous concentric lines of growth. 



Type, Oldhamina decipiens, de Koninck. Carboniferous. India and China. 



Dr. Waagen has described the structure of these genera at great length, and 

 i'rom his investigations infers that the shells are not distantly related to 



