SHUMARD — NEW PALEOZOIC FOSSILS. 109 



Goniatites Texanus, n. sp. 



Shell large, discoidal, strongly rounded on the dorsum, 

 gently convex on the sides ; umbilicus deeply excavated, ex- 

 hibiting the inner volutions, and having a diameter equal to 

 two-thirds the greatest width of the last volution ; margin 

 subangulated ; transverse section of last volution semiellip- 

 tical ; its dorso-ventral diameter about equal to, or a little 

 greater than, the width from side to side. 



A small fragment only of the shell is preserved in one of 

 the specimens in the Texas State Collection. It is extremely 

 thin and the surface is marked with numerous parallel re- 

 volving lines, crossed with flexuous transverse lines, present- 

 ing a neat cancellated appearance. There are also faint 

 indications of transverse costae perceptible near the margin 

 of the umbilicus. Septce deeply sinuous; dorsal lobe cleft 

 by a profound linguseform sinus with a broad base, into two 

 narrow, elongated branches, which are not as wide as the 

 sinus between, and which are gently expanded in the middle 

 and narrowed to an acute point at their extremities by an 

 oblique truncature of their inner margins; dorsal saddle lin- 

 guseform, longer than wide and larger than the branches of 

 the dorsal lobe ; superior lateral lobe having nearly the same 

 form as the branches of the lateral lobe, but larger. 



Diameter, 3.35 inches. 



Bluffs of Wallace creek, San Saba county, Texas, in dark 

 Carboniferous (Coal Measures?) Limestone. 



Texas State Collection. 



Goniatites Choctawensis, n. sp. 



Shell discoidal, broadly and strongly rounded on the dor- 

 sum and flattened laterally, inner volutions entirely concealed 

 by the outer one ; umbilicus small, its diameter scarcely equal 

 to one sixth the breadth of the volution ; transverse diame- 

 ter of volution about equal to the breadth from dorsal to 

 ventral side ; aperture lunate, much wider than high ; surface 

 marked with fine, distinct revolving lines, less than the width 

 of the intervals between, crossed by extremely fine, crowded, 

 transverse striae. Septce having but one lateral lobe on either 

 side ; dorsal lobe as wide as long, divided into two lanceolate 

 branches by an accessory saddle, which is truncated and bifid 

 at tip and extends almost to the middle of the lobe ; dorsal 

 saddle of the same form, but wider and double the length of 

 the branches of the dorsal lobe ; superior lateral lobe wider 

 than the dorsal saddle, and contracted at extremity to an 

 acute point. 



This shell resembles the G. striatus (Sowerby) both in the 

 form and number of the lobes of the septse and its surface 



