382 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 42. 



The fo^o^villg species are published to ilkistrate the paleontology 

 of the Eastport quadrangle of Wasliington County in the southeast 

 corner of Maine, the field work on which has already been completed 

 by a party of the United States Geological Survey in charge of Edson 

 S. Bastin, who has in course of preparation the folio maps of the 

 Eastport quadrangle. 



EURYMYELLA, new genus. 



Shell thin, subtriangular in outline, compressed, high and subalate 

 posteriorly, narrowed anteriorly, the front curving regularly from the 

 cardinal angle into the base. Beaks small and low. Umbonal ridge 

 moderately elevated, rounded or subangular. No mesial sulcus. 

 The surface forward and downward from the umbonal ridge is slightly 

 convex or flattened, not concave. Hinge line straight, narrow, 

 slightly thickened at edge, generally v/ithout distinct teeth. A small 

 obscure thickening of the hinge is seen in an occasional specimen 

 under the beak of the right valve, with a broader thickening in the 

 same position in the left valve, and in a single specimen a linear 

 thickening of the inner edge of the hinge margin is evident near its 

 posterior end. Ligament linear, external. 



Anterior adductor impression distinct, situated close imder the 

 hinge, subovate, sharply defined on the inner side by a strong, short 

 ridge coming down from the hinge border. Posterior muscular scar 

 too indistinct for description. Paliial line simple. Umbonal and 

 pedal muscular pits present on the sides of the umbonal cavity and 

 behind the anterior muscular scar in some specimens. 



Type-species. — Eurym,ycUa shaleri, new species. 



RExMARKS ON THE GENUS EURYMYELLA. 



The genus Eurymyella is erected for a group of fossil Pelec^^poda 

 found abundantly in the shales of Moose Island, Eastport, Maine. 

 The fossils were noted by N. S. Shaler in a paper on the Geologj^ of 

 the Cobscook Bay District, Me.,^ as ''Modiomorpha, allied to M. subu- 

 lata," and the particular localities named by Shaler are 'SShackford 

 Head," a promontory on the west side, and ''Princess Cove," on the 

 south end of ]\Ioose Island. The rocks containing them constitute 

 the upper formation of the Silurian series called by Shaler the "Cobs- 

 cook Bay series." They are immediately overlain, unconformably, 

 by the Perry formation, the flora of which is fully described by David 

 White and assigned to the Devonian age.^ 



By " Modiomorpha suhulata" is probably intended Cypricardites 

 subalata. Conrad,^ described by Conrad as from the "shales near 



» Amer. Journ. Sci., ser. 3, vol. 23, ISSC, p. 58. 



2 Smith and White, Geology of the Perry Basin in Southeastern Maine. U. S. Geol. Surv., Prof. Paper 

 No. 35, 1905. 

 8 5th Ann. Kept. Geol. Surv., New York, 1841, p. 53. 



