PLATE XXXVII. 



Orthooeras inoptatum. 



Page 267. 

 See Plate 113. 

 Fisr. 1. A fragment, retaiuing a large part of the chamber of habitation, and showing the regular frequency 

 of the septa. From the Upper HeUlerberg limestone. Wett-em New York. 



Orthoceras budiocla. 



Page 268. •' 



See Plate 112. 

 Fig. 2. A septate fragment, showing the rapid expansion of the tube, and the increase in the depth of the 

 wr-chambers from the apex toward the chamber of habitation. Stafford, N. Y. 



Orthooeras Pelops. 



Pago 233. 

 See Plates 3.5. 35 A, 78 B. 

 Fig. 3. A septum, preserving the natui-al fiireulai- form of the transverse section. 



Pig. 4. A 8*!ptum, showing an elliptical form, due to compression. Schoharie grit. Schoharie and _the 

 Hdderberg mountains. 



Orthooeras viator. 



Pago 270. 

 Fig. 5. A fragment, preserving the chamber of habitation nearly entire, and portion of two of the air-cham- 

 bei-s, partially showing the double constriction of the tube toward the aperture. Upper Hel- 

 derberg limestone. Clarence Hollow, N. Y. 



Orthooeras (Edipus. 



Page 29i. 

 See Plate 82. 

 Fig. 6. A fragment, probably of the outer chamber, showing the surface ornaments Hamilton group. 

 Oeneseo, N. Y. 



Orthooeras proptjndtjm. 



Page 271. 

 Fig. 7. A cast of the chamber of habitation, preserving its normal form arfd retaining the imprint of the 



surface-markings from the interior of the test. WiUiavuiville, N. Y. 

 Fig. 8. A fragment of the test of the grand chamber, showing the surface ornamentation. Black Sock, N. Y. 

 Fig. 9. A partial cast of the chamber of habitation, preserving a portion of the shell. M'ilUainsville, N. Y. 

 The specimens of this si>ecies are all from the limestone of the Upjter Helderberg. 



