I 



The Saint Peter Sandstone. 77 



CEPHALOPADA. 



Genus Orthoceras. 



Orthoctras minnesotense n. sp. 

 Plate III, figures 11 and 12. 



The only specimen is a fragment of the septate portion of the shell. In 

 the length of about 30 mm. the dorsal and ventral sides converge from 3(> 

 mm. to 23, and in that length there are included eight septa. The trans- 

 verse section is oval, probably broadest above. And the siphuncle, which 

 is about five mm. in diameter, is placed five or six millimeters above the 

 lower surface. The septa were strongly convex, and on the cast the sutures 

 are seen to have been curved backw^ard on the sides as shown in the figure. 

 The surface was smooth and the shell very thin. 



Found at South Saint Paul. 



Orthoceras (?) sp. undet. 

 Plate III, figure 10. 

 Compare O. montrealense Billings, Canadaian Naturalist, vol. iv, p. 361. 

 A fragment of the shell showing numerous septa and fine longitudinal 

 stria and enough only to show what the circumference probably was is all 

 that has been found of this species. 

 Highland Park. 



Orthoceras sp. undet. 

 Plate III. figures 13 and 14. 

 This is a fragment probably of the siphuncle of an Orthoceras which 

 shows no diminution in size at either end. The under side is the exact re- 

 verse of the side figured. It has probably suffered from compression since 

 becoming fossilized. 



From Highland Bark, Saint Paul, Minn. 



BRACHIOPODA. 



Genus Crania. 



1 Crania re versa n. sp. 

 Plate III, figures 6 and 7. 

 A single cast of a shell marked only by very indistinct concentric lines, 

 with a nearly conical outline and centrally placed apex, has been found. 

 Besides the general outline of a Crania it has what are probably a pair of 

 large muscle scars, 1.5 mm. in diameter at halfway between the apex and 

 the posterior margin and about one mm. apart. Other characters can not 

 be observed, but this appears to be the ventral valve of a Crania. 

 Found at Highland Park. 



Genus Lingula. 



Lingula tnorsii N. H. Winchell. 

 Plate ly, figures 2 and 3. 

 Lingulepis morsensis N. H. Winchell, Fourth Annual Report of the Geo- 

 logical and Natural History Survey of Minnesota|1876),p.4-l,fig. 6,a,b,c. 



