136 MOLLUSCA. 



No- 595. Phragmoceras maximum, Conrad. 



In this genus the shell is more tightly coiled than in any of the preceding 

 Orthoceratidce. This species — the largest one known — is from the Hamilton Group 

 (Devonian) of Madison Co., N. Y. Diameter, 14. Price, $2.25. 



No. 596. Phragmoceras nestor, Hall. 



From the Niagara Group (Upper Silurian), Wauwatosa, Wis. Price, $0.50. 



No. 597. Phragmoceras SUbvenitriC0S1im,D'Archiac and DeVerneuil. 



From the Middle Devonian of the Eifel, Shine Valley. Original in the Ward 



Museum of the University of Rochester. Price, $0.75. 



No. 598. Cyrtoceras macro stomum, Hall. 



This slightly incurved shell is from the Trenton 

 limestone (Lower Silurian), Mineral Point, Wisconsin. 



Price. $0.40. 



No. 599. Cyrtoceras COrbulatum, Barrande. 



• Two specimens. A form with singularly plaited and abundant septa from 

 the Upper Silurian of Bohemia. Original in the Ward Museum of the Univer- 

 sity of Rochester. Price, $0.60. 



No. 600. Cyrtoceras elongatum. Barrande. 



An elegant form from the Upper Silurian of Beraun, Bohemia. The origi- 

 nal is in the Ward Museum of the University of Rochester. Price, $0.50. 



No. 601. Cyrtoceras eugenium, Hall. 



This perfect specimen is from the Schoharie Grit (Devonian), Schoharie Co., 

 New York. Size, 7x2. Price, $0.65. 



No. 602, G-yroceras trivolvis, Conrad. 



From the Upper Helderberg (Devonian) of Scho- 

 harie Co., N. Y. Diameter, 6. Price, $1.50. 



No. 603. G-yroceras Burlingtonense, Owen. 



In this, the most Nautiloid form of the Orthoceratidce, the whorls of the shell 

 nearly touch. From the Lower Carboniferous Limestone of Burlington, Iowa. 



Diameter, 15. Price, $2.25. 



No. 604. G-yroceras expariSUm, Ssemann. 



From the Hamilton Group (Devonian), Cazenovia, New York. Price, $0.35. 



