Maryland Geological Survey 177 



mens in the office of the New York State Paleontologist labeled Lio- 

 rhynchus limitare from the fissile Mareellus shales of Western New York. 

 The size, form, strength of plications and concentric striae are about 

 identical. Specimens were submitted to Prof. Charles Schuchert, who 

 wrote as follows : " It is very difficult to be certain of these crushed 

 specimens, but they are usually called L. limitare when from the Mareellus, 

 and these are." There is not a very marked difference between young 

 specimens of L. laura and L. limitare, but the smaller size and finer plica- 

 tions of these specimens refer them to the latter species. It is also to 

 be noted that these specimens in size, shape and strength of plications are 

 similar to L. dubium Hall of the Mareellus shale. 



Length, 8-13 mm. ; width, 8-14 mm. 



Occurrence. — Romney Formation, Marcellus Member. B. & 0. 

 R. E. cut at 21st Bridge; W. Va. Cent. E. E. cut at 21st Bridge; Wil- 

 liams Boad, 3i miles southeast of Cumberland. 



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



LiORHYNCHUS LAURA (Billings) 

 Plate XV, Figs. 9-12 



Rhynchonella (?) laura Billings, May, 1860, Canadian Jour., vol. v, p. 273, 



figs. 26-28. 

 Leiorhynchus viulticosta Hall, December, 1860, Thirteenth Rep. N. Y. State 



Cab. Nat. Hist., p. 85, figs. 14, 15 on p. 94. 

 Leiorhynchus muUicosta Hall, 1867, Pal. N. Y., vol. iv, p. 358, pi. Ivi, figs. 



26-40. 

 Liorhynchus miilticosta and lauraHaU and Clarke, 1893, Pal. N. Y., vol. viii, 



pt. il, p. 194, pi. lix, figs. 8-10, 13-17. 

 Leiorhynchus laura Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 237. 

 Leiorhynchus laura Shinier and Graban, 1902, Bull. Geol. Soc. Amer., vol. 13, 



pp. 168-170. 

 Liorhynchus muUicostum Clarke, 1903, N. Y. State Mus., Bull. 65, p. 253. 

 Leiorhynchus laura Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 289, fig. 357c. 



Description. — Shell ovate, with the length and greatest width nearly 

 equal, in compressed specimens the width is often greater than the length. 

 Ventral valve gibbous on the umbo, curving to the sides, becoming grad- 

 ually depressed in the center and forming a sinus which is broad and 

 12 



