PLATE XCII. 
Orthoceras Bebrtx, var. Cayuga. 
Page 276. 
See Plates 89, 86, 91. 
Fig - . 1. A compressed chamber of habitation, covered with numerous portions of a'branching, parasitic 
Bryozoan. 
Fig. 2. A fragment similar to the preceding, with several attached air-chambers, showing surface-markings. 
' The lamellose, transverse striae form a broad, retral curve over the chamber of habitation and 
the air-chambers. 
Fig. 3. A chambered fragment, showing the effects of compression in a fracture along the centre. 
Fig. 4. A portion of an individual retaining its normal form and dimensions, showing the depth of the air- 
chambers, the concavity of the septa, with straight and horizontal suture lines. 
Fig. 5. A septum of the preceding, showing the excentric position of the siphuncle -and the circular, trans¬ 
verse section of the tube. 
These specimens are from the lower portion of the Chemung group, in the University quari'ies 
at Ithaca, IV. F. 
