PLATE XCII. 



Orthooeras Bebrtx, var. Catdga. 



Page 276. 



See Plates S9, 86, 91. 



Pig. 1. A compressed chamber of habitation, covered with numerous portions of a branching, parasitic 



Bryozoan. 

 Fig. 2. A frag^ment similar to the preceding, with several attached air-chambers, showing surface-markings. 

 The lamellose, transverse strise form a broad, retral curve over the chamber of habitation and 

 the air-chambers. 

 Fig. 3. A chamberel 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 quarries 

 at Ithaca, N. T. 



