PLATE LXXXVI. 



^\j., OUTilOCEEAS SUBDLATtrap^JCf 

 Page 283. 

 .K;j See Plates 38, M.oBTflO 

 Pig. 1. The chamber of habitation nearly entire, and pi-eservdng a poi'tion of the test. Hamilton 'group. 



Pratt's Falls, N. Y. 

 Fig. 2. A septum of the precediog, showing the central position of the siph uncle. > t « 



.'i .Vi. ,yi\ U .Roiaa'Snqmoa mtr^l 



OaTHOCERAS Bebrtx, var. Catcqa. 



See Plate 39, 91, 92. 



Fig. 3. A fragment of the chambered portion, showing the siphuncle exposed. The specimen has been 

 compressed and the siphuncle displaced, and lying against the interior surface of the cham- 

 ber walls. Chemung group. Itliaca, iV. Y. 



Fig. 4. A compressed septate fragment, showing the oblique sutures, as produced by compression. Che- 

 mung group. Ithaca, iV. T. 



Fig. 5. A poi'tion of a smaller individual of the same species (?), showing a gentle constriction of the cham- 

 ber of habitation and traces of the lamellose surface markings. 



