200 NEW YORK STATE MUSEUM 



ones on either side; linear interspaces; sharply defined fold of 

 brachial valve, with plications almost obsolete. 



Found only in the Manlius limestone of North Buffalo and Will- 

 iamsville. Not common. 



Spirifer (Delthyris) sulcatus Hall (Fig. 120) (1852. Pal. N. Y.. 



2:261, pi. 54) 



Distinguishing characters. Near- 

 ly equal valves; deep mesial 

 sinus; four or more plications on 

 either side, with wide inter- 

 spaces; fine radiating striae 

 crossing plications and inter- 

 Fig. 120 spirifer (Deithyns) suicatus with striae spaces ; very coarse, lamellose,. 

 enlarged subcqually Spaced concentric 



growth lines which interrupt the radiating striae. 



Found rarely in the Clinton lenses and the lower Rochester shale ,*^ 

 more common in the Bryozoa beds at Niagara. Also at Lockport 

 and elsewhere (Hall). 



Genus homoeospira Hall & Clarke 



[Ety. : ofjMco?, like; (j-eTpa, spire] 



(1893. Pal N. Y. V. 8, pt 2, p. 112) 



Shell rostrate, radially plicate, and with a short curved hinge line; 

 apex truncated by a circular pedicle opening. Spirals spiriferoid, 

 with from six to nine volutions and a V-shaped jugum. A linear 

 cardinal process separates the crural plates. 



Homoeospira apriniformis Hall (Fig. 121). ,^^ 

 A try pa aprinis Hall (1852. Pal. N. Y. [ 



2:280, pi. S7) IT- ,01TT 



'A ^' ^ Fig. 121 Homoeospira aprini- 



Distingiiishing characters. Small, roundish, ^^^^^ 

 oval, scarcely longer than wide; nearly equally convex valves; non- 

 sinuate front, numerous simple rounded plications; fine concentric 

 striae. 



Found in the Rochester shale at Lockport (Hall). Probably also 

 at Niagara. 



i 



