PLATE XXVIII. 



ECHINOCARIS PUNCTATA. 

 Page 166. 

 See Plates 27 and 29. 

 Fig. 1. The left valve of a specimen of average size, showing the normal outline and proportions, pre- 

 serving the nodes and ridges of the surface in perfection, and retaining the faint, elevated 

 lines radiating from the lower edge of the carina. The specimen is preserved as an internal 

 cast and consequently shows a finely punctate surface. 

 Fig. 2. The right valve of the same individual. 



Hamilton group. In the sandy shales at Faluns, Onondaga county. 

 Fig. 3. A nearly entire individual, slightly distorted about the cephalothorax ; showing the six abdominal 

 somites, the spine-bases on their posterior margins, the caudal plate and portions of the caudal 

 spines. These spines are restored in outline to their proper length. 

 Hamilton group. Pratt's Falls, Onondaga county. 

 Fig. 4. Ventral aspect of a very large individual, showing the lower edge of the right valve of the 

 cephalothorax, the large mandibles in nearly their normal position, the fourth, fifth, sixth and 

 a portion of the third abdominal somites, and the caudal plate with its spines. The posterior 

 margin of the somites is so broken as to show only the lateral spinules, and the caudal spines 

 appear to be somewhat shorter than is usual. 



Hamilton group. Mi nteth's Point, Canandaigna Lake. 

 Fig. 5. The ventral surface of a small, quite imperfectly preserved specimen, showing the mandibles in 



place. 



Hamilton group. Pratt's Falls, Onondaga county. 



Fig. ti. Dorsal aspect of the posterior port ion of a large individual, preserving the fifth, sixth and a portion 

 of the fourth somites, with the caudal plate and spines nearly entire. The spinules upon the 

 somites are in part restored in the figure, but their character is well shown. 

 ■Fig. 7. Ventral aspect of the same specimen, showing the absence of spinules upon the posterior margins 

 of the somites, and the character of the articulation between the last somite and the caudal 

 plate is well shown. 



Hamilton group. Menteth's Point, Canandaigiia Lake. 



