PLATE A 66. 



Fig. 1. 663. 1. Cybele i-uNCTATA. (Pag. 297.) 



1 a. An individual nearly entire, showing the proportion of parts. 



1 b, c. The glabella and base of buckler of two individuals of different size. 



1 d. The check separated at the facial suture. 



1 e. Profile (if glalx'lla, showing the strong indentations at the base. 



1 /. An enlarged portion, sliowing the jironiiiient tul)ercles. 



1 g, h. Tlie caudal shields (imperfect at the extremities) of two individuals. 



1 i. A small individual. 



1 k. An enlargement of several articulations of the caudal shield. 



1 /. The surface magnified, showing pustules of diflcrcnt size. 



Fig. 2. 665. 3. Aciuaspis (Species xtndetermined). (Pag. 299.) 



Fig. 3. 666. 3. Phacops trisulcatcs. (Pag. 300.) 



3 a. The individual of the natural size. 



3 b. Enlargement of the buckler, several ribs of the body, and the caudal shield. 



Fig. 4. 667. 5. Ceraurus i.xsiaNis. ( Pag. 300.) 



Fig. 5. 664. 5. Calymene clintoni. (Pag. 298.) 



6 a. An individual having the cliceks parti.iUy separated at the sutures, and crushed. 



5 6. A profile view of the same. 



5 c. A cheek of a larger individual separated from the buckler. 



5 d. A caudal shield of a large individual in the iron ore. 



Fig. 6. 293. 2. Calymene BLUMENBACiiir, var.? senaria. (Pag. 299.) 



6 a. Kw individual of large size, much expanded laterally. 



(j b. Tlie caudal extremity of the same, of remarkably Large dimensions. 



C c. The glabella of the same. G d, e. The caudal extremities of two individuals. 



Fi". 7. Fragments of Homalonotus delphinoccphahcs. ( P^g- 299.) 



Fig. 8. Fragments of Phacops li-mulunis. ( P^g. 299.) 



Fig. 9. 669. ]. BuMAsTis baheiensis. ( Pag. 299.) 



9 a. The central j)ortion of the cephalic shield, from shaly limestone of the Clinton group. 

 9 6. Front view of tlie same, showing tlie elevation. 



9 c. The caudal shield of another individual. 9 d. View showing the convexity of the same. 



9 e. Section of a fragment of limestone, which is mainly composed of the cephalic and caudal shields of this 

 trilobite. 



9 /. .Magnified view of a weathered portion of one of these shields. 



Fig. 10. 663. 1. Bevrichia lata. (Pag. 301.) 



10 a. A fragment of ferruginous slate, covered with the separate valves of this fossil. 

 10 i. A valve having a subcentral deprc.<sion. 



10 c. .V valve with a subcentral lobe or nucleus. 



10 d, c. Tlic interior of the shell, or impression made by the cast. 



#«l 



