CEPHALOPODA. 



135 



No. 586. Orthoceras crebram, Ssemann. 



From the Middle Devonian, Eifel, Rhine Valley, and now in the private Geo- 

 logical Cabinet of Mr. Ward, Rochester. Price, $0.40. 



No. 587. Orthoceras inequale, Barr. 



This species of a very niuch attenuated form is from the Upper Silurian, 

 Butowitz, Bohemia, and now in the private Geological Cabinet of Mr. Ward, 

 Rochester. ' Size, 13x3. Price, $1.25. 



No. 588. Orthoceras pseudo-calamiteum, Barr. 



This is a neat, ornamental form, in which the outer shell with its peculiar 

 markings is preserved. From the Upper Silurian, Kronieprus, Bohemia, and now 

 in the private Geological Cabinet of Mr. Ward, Rochester. Price, $0.25. 



No. 589. Ormoceras temiifilum, Hail. 



Two specimens. This sub-genus of Orthoceras includes those 

 forms which have the siphuncular beads constricted in the mid- 

 dle. These specimens are sections showing septa. From the 

 Black River limestone (Lower Silurian), Watertown, NewYork. 



Size, 6x3. Price, $1.00. 



No. 590. Endoceras proteiforme, Hall. 



This sub-genus has a large siphuncle, mostly lateral or eccentric, marked or 

 ridged on the outer surface by the septa. Within the siphuncle are one or more 

 very elongated conical tubes, often one within another, as shown in the present 

 specimen. From the Trenton limestone (Lower Silurian), Middleville, N. Y. 



Size, 12 x 3. Price, $1.50. 



No. 591. G-onioceras anceps, Hail. 



This specimen is a section showing wavy lines of septa. From the Black 

 River limestone (Lower Silurian), Watertown, N. Y. Size, 6x4. Price, $0.75. 



No. 592. G-omphoceras inflatum, Quenst. 



This genus is characterized by an abrupt tapering or contraction of the last 

 chamber towards the mouth ; which latter is frequently of a very sinuate and 

 irregular form. This specimen, which shows the septa and the last chamber, is 

 from the Middle Devonian of the Eifel, Rhine Valley, and is now in the Ward 

 Museum of the University of Rochester. Pi ice, $0.50. 



No. 593. G-omphoceras seriniurn, Hall. 



From the Niagara Group (Upper Silurian), near Chicago, 111. 



Pike, $0.30. 



No. 594. Oncoceras orcas, Hall. 



This genus is distinguished by its curved, club-shaped form ; the siphuncle 

 is dorsal, and the aperture of the shell small. From the Niagara limestone (Upper 

 Silurian), Racine, Wisconsin. Size, 6x2. Price, $0.60. 



