360 Systematic Paleontology 



Description. — " Shell longitudinally oval or ovate: dorsal valve convex; 

 beak slightly incurved ; cardinal margin excavated on each side of the beak 

 for the reception of the broad dental laminse of the other valve : ventral 

 valve depressed convex, most elevated in the umbonal region, flattened 

 towards the lateral margins and depressed in front, forming a faint broad 

 and undefined sinus. Surface ornamented by about seventy-five angular 

 plications, vphich occasionally bifurcate." Hall, 1857. 



Hall considered this form related to C. pleiopUura, but it clearly holds 

 the same relation to C. harrandii that G. ramsayi does to C. speciosa. 

 Both are variations in which the lateral margins are not incurved an- 

 gularly and make plane sides. The only difference noticeable between 

 C. filchana and C. ramsayi is that the latter is only half the size of the 

 former, but as no intergradmg specimens have been seen, both names are 

 for the present retained. 



Length about 5 cm. ; width about 6 cm. 



Occurrence. — Oriskany Formation, Kidgely Member. Cumberland. 



Collections. — U. S. National Museum, American Museum of Xatural 

 History. 



Camarotceciiia (Plethorhyncha) PLEiorLEURA (Conrad) 

 Plate LXIV, Fig. 6. 



Atrypa pleiopleura Conrad, 1841, Fifth Ann. Rept. GeoL Surv. N. Y., p. 55. 

 Rhynchonella pleiopleura Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. 



Hist., p. 86, figs. 1-4. 

 Rhynchonella oblata Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. Hist, 



p. 86. 

 Rhynchonella multistriata Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. 



Hist, p. 85. 

 Rhynchonella pleiopleura Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 440, 



pi. cii, figs. 3a-3c, 4a-4c, 1861. 

 Rhynchonella oblata Hall, 1859, Nat. Hist N. Y., Pal., vol. iii, p. 439, pi. cii, 



figs. 1, 2a-2d, 1861. 

 Rhynchonella multistriata Hall, 1859, Nat. Hist N. Y., Pal., vol. iii, p. 440, 



pi. cii, fig. 3 (? pi. cvi, fig. 3). 

 Plethorhyncha pliopleura Hall and Clarke, 1893, Nat Hist. N. Y., Pal., vol. 



viii, pt. ii, p. 191. 

 Camarotocchia oblata Clarke, 1900, Mem. N. Y. State Mus., vol. iii. No. 3, p. 41, 



pi. V, fig. 22. 



