430 Systematic Paleontology 



Length 1.8 cm. ; width 2 cm. 



Occurrence. — Helderberg Formation, New Scotland Member. 

 Dawson, Corriganville, Cumberland, 21st Bridge. 

 Collection. — U. S. National Museum. 



Trematospira equistriata Hall and Clarke 



Plate LXXIII, Figs. 8, 9 



Trematospira equistriata Hall and Clarke, 1893, Nat. Hist. N. Y., Pal., vol. 

 vlii, pt. ii, pi. xlix, fig. 47. 



Description.— l^hh species has not been described by Hall and Clarke. 

 It differs from T. multistriata in being more equally biconvex, with a very 

 much smaller sinus and no dorsal fold, and the plications are finer, simple, 

 regular, and never fasciculate as in that species. Further, the anterior 

 margin is emarginate and the outline diamond-shaped with the lateral ends 

 rounded. There are six plications in the sinus with twenty-three on each 

 side. 



This species is distinguished from T. deweyi in being more transverse, 

 less gibbous, with the ventral beak more incurved. It may turn out to be 

 but a variety of T. deweyi. 



Length 1.9 cm. ; width 2.7 cm. 



OccwTence. — Helderberg Formation, New Scotland Member. 

 Dawson, Corriganville, 21st Bridge, Maryland; Keyser, Cherry Eun, West 

 Virginia. 



Collection. — U. S. National Museum. 



Genus NUCLEOSPIRA Hall 



Nucleospira ventricosa (Hall) 

 Plate LXXIII, Figs. 10-13 



Spirifer ventricosa Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. Hist., 



p. 57. 

 Nucleospira ventricosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 220, pi. 



xiv, fig. 1; pi. xxviiib, figs. 2-9, 14, 1861. 



Description. — " Shell globose ; valves almost equally convex : ventral 

 valve having a narrow sinus extending down the center from beak to base ; 

 beak projecting above the other, strongly incurved and pointed (in many 



