Marylakd Geological Suuvev 197 



mucronate liingc-line. This species is generally readil}' distinguished In- 

 the high, inclined cardinal area and extended hinge-line. The dorsal 

 valve resembles quite closely some forms of <?. mucronaius, hut the high 

 cardinal area of the ventral valve readily separates them. Young speci- 

 mens resemble »S^. audaculus, while the mucronate extensions of the hinge- 

 line are rarely preserved in internal impressions so that it is apparently 

 shorter than in other specimens. 



Length, 12-15 mm.; width, 50-56 mm. 



Occurrence. — Eomney Formation, Hamilton Member. McCoys 

 Ferry (?) ; east side Warrior Mt. east of Eush; east bank Evitts Creek 

 below Wolfe Mill ( ?) ; B. & 0. R. E. cut at 21st Bridge. 



Collections. — Maryland Geological Survey; New York State Museum; 

 American Museum of Natural History. 



Spirifer (Eetioularia) fimbriatus (Conrad) 

 Plate XIX, Figs. 10-12 



Delthyris fimbriatus Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii. p. 



263. 

 Spirifer f.mhriat^is Hall, 1858, Ceol. Surv. Iowa, vol. i, pt. ii, p. 505, pi. iv, 



fig. 5. 

 Spirifera fimhriata Hall, 18G7, Pal. N. Y., vol. iv, p. 214, pi. xxxili, figs. 1-21. 

 Spirifera conradana Miller, 1883, Amer. Pal. Foss., 2d ed., p. 372. 

 Spirifera conradana Keyes, 1891, Jobns Hopkins Univ. Circ, vol. xi, p. 29. 

 Spirifer fimbriatus Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, pp. 17, 



20, 21, 33, "37, pi. xxxvi, figs. 17-22; pi. xxxviii, figs. 9, 10. 

 Reticularia fimbriata Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 342. 

 Spirifer fimbriatus Clarke, N. Y. State Mus., Bull. 65, p. 316. 

 Reticularia fimbriata Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 338, figs. 431a, b. 



Description. — Outline transversely subelliptical ; hinge-line less than the 

 width of the shell ; cardinal angles rounded ; valves gibbous and regularly 

 convex. Ventral valve has well defined sinus, usually shallow and 

 rounded, sometimes deep and ang-ular; beak small and incurved over the 

 cardinal area which is high and concave, extending about one-half the 

 width of the shell. Dorsal valve slighly flattened at the cardinal angles; 

 mesial fold abruptly elevated in the lower part, low and frequently but 

 imperfectly defined toward the beak. Surface of each valve marked by 



