PLATE m. 



Fig. 1. 301. 2. Ceraurus pleurexanthemus. (Pag. 242.) 



1 a. A fragment of a large individual, preserving the buckler and eight articulations of the thorax. The sur- 

 face is beautifully and evenly granulated or papillose, with larger tubercles upon the cephalic shield, 

 and mamillary tubercles upon the articulations ; these are enlarged in the figures 1 b, c, d. 



1 e. Front view of the specimen 1 a, showing the elevation of the oculiferous tubercles. 



1 f. One of these tubercles magnified. When magnified to this degree, they exhibit only rounded granulations. 



1 g. The cephalic shield represented in 1 a, showing the separation of the maxillffi J y sX the facial sutures. 



1 //. The right maxilla, separated from the cephalic shield. (Tliis figure on the plate is without a number.) 



Fig. 2. 297. 2. Calymene beckii. ( Pag. 250.) 



2 a. An entire specimen, with the exception of the maxillary shields, which are separated at llie facial suture, 



leaving the cephalic shield in the usual form. 

 '2 b. An imperfect specimen, with the maxillary portions partially preserved, but separated at the suture, and 



pressed downwards. 

 2 c. The thorax and caudal shield, preserving the crust, with the tubercles upon the middle lobe, in a. very 



perfect manner. 

 2 d. The cephalic shield, with the maxillary portions separated at the facial suture. 

 2 e. Tlie cephalic shield entire, but so much compressed that the eyes are obliterated. The posterior angles 



are too much rounded in the figure ; in other respects, the true form of the buclder is represented. 

 2/. The cephalic shield preserved in compact calcareous stone. 



2 g. A larger specimen, in compact limestone, preserving a more convex form in all its parts. 

 2 h. A small individual, preserving the thorax and the maxillary portions of the buckler, the glabella being 



separated. 

 2 i. Tlie maxillary shields, as they frequently occur in the slate, separated from any other part of the fossil. 



The lower figure is the labrum. 

 2 k. A single maxillary shield of this species. 



Fig. 3. 308. 4. CALYHEtiE (Species undetermimd). (Pag. 253.) 



3 a. A part of the thorax, preserving eight or nine articulations. 

 :i 4, Tlie caudal shield, with a few segments of the thorax. 



Fio-. 4. 309. 5. AsAPHtTS? latimarginata. (Pag. 253.) 



4 a. The caudal shield of a small individual. 



4 6. A fragment of the lateral lobe of the caudal shield of a larger individual 



Fig. 5. 43. 1. IsoTELus oiras. (Pag. 254.) 



The hihnitn or epist(jroa of a very large indiviilual. 



