A VIC. 



68 



Avicula demissa. (Conrad, Journal Acad. Nat. 8ci. Phil. 

 Ill' ^m^^^7¥jmmmmm^^^^^^ ^^i- S, 1842, Hudson river forma- 



% ^^^^iy^^mmim^B ^i^^-) Emmons' Kept. p. 404, fig. 



113, 2. American Geol. I, ii, p. 

 175, plate 13, fig. 10 ; Characterises 

 Loraine (Hudson river) shales, 

 and is found in S. W. Virginia. — 

 Illh. Note. — Emmons gives on 

 page 233, the same plate 13, fig. 

 10, 11, as D'Orbigny's Lyonsia 

 mytiloidea. But Lyonsia is now 



BmmcinsJK^ 



Z Sedgwickia ; and S, compressa^ 



Meek ; S. divaricata^ Hall and Whit. ; S. fragilis^ Meek ; S, 

 neglecta^ Meek, are all from the Cincinnati (Loraine) formation. 

 S. A. Miller's Am. Pal. Foss. 1877.— 7/75. 



Avicula desquamata. See Obolella crassa. J7. Cambrian, 

 Avicula elliptica. (Hall, Palaeontology of N. Y., Vol. I, 

 1847, Trenton group.) Emmons' American 

 Geol. Vol. I, part 2, page 175, plate 13, fig. 

 27, a cast of a somewhat elliptical shape, 

 hence called by Emmons suielliptica. — Tren- 

 ton formation. — Hall gives its figure in pi. 

 36, fig. 3, and compares it to Sowerby's A. 

 oUiqua, Sil. syst. p. 635; adding that it may 

 13 be an AmionycJiia. — II c. 



Avicula emacerata. Hall, page 108, fig. 38, 4. (Conrad, 



^ V h 



CotlT^ 



Jour. Acad. Nat. Sci. Phil. VIII, 241, plate 12, fig. 15.) Niagara 

 formation^ V h. — In Pennsylvania it seems to occur earlier. 

 See 00, Pal. Coll. p. 233,— specimens 501-1, 8, 18, 19 (an im- 

 pression), 24 (two in good condition on a slab), 25 ; by Hale & 

 Hall, 1875, in Ferguson Valley, Mifflin Co., Pa.— Spec. 504-13, 

 from near Orbisonia.— Spec. 505-4, at McKee's ore bank, 

 ]y[ifflin —Spec. 507-5, 12,Fellows & Hall,Matildafurnace,MifHin. 

 All from Clinton shale, V a.— It is reported by Claypole from 



