21 



Explanation of Plate VI. 



(Portage Gastropoda, Cephalopoda, Pteropoda.) 



Fig. 



26-27. Bellerophon ithacensis. Rare, at Ithaca. 



28. Platyceras sp. Middle Portage and Chemung. 



29. Macrocheilus (sp. probably macrostomus distorted). Middle 



Portage. 



30. Loxonema (sp. probably delphicola, eroded). Middle Port- 



age, but generally a Hamilton species. 



31. Pleurotomaria capillaria. Middle Portage and Chemung. 



Also in Hamilton beds below. 



32. (romphoceras titmidum. Middle Portage. 



33. Orthoceras bebryx var. cayuga (about 2 /z nat. size). Middle 



Portage. Common. 



34. Orthoceras demus. Middle Portage. Ithaca. 



35. Tornoceras peracutum. Outline showing sigmoidal suture 



lines. From middle Portage at Ithaca. In Ma?itico- 

 ccras patersoni, a characteristic west Portage Cephalo- 

 pod, the suture lines run as indicated by a — a. 



36. Bactrites acicula. Middle Portage and eastern Chemung. 



37. Tentaculites spiculns. Middle Portage. Rare. 



Explanation of Plate VII. 

 (Portage Brachiopoda.) 



Fig. 



38. Spirifer levis. Lower Portage sandstone, eastward. About 



2 /z nat. size. 



39. Spirifer mesastrialis. Middle Portage and Chemung, east- 



ward. 



40. Spirifer mesacostalis. 

 41-2. Camaroteechia eximia. 



ward. 

 43. Pugnax pug nus. 

 ward. 



