98 ARTICTJLATA. 



No. 373. Asaphns gigas, Dalmann. 



This large Trilobite, the Isotelus 

 gigas of De Kay and Isotelus megistos of 

 Locke, has an oval form and convex 

 surface ; the head and tail nearly equal 

 and both subtriangular ; well devel- 

 oped eyes ; eight body-segments ; and no 

 glabella, nor any ribs on the tail. This 

 cast is a restoration by Professor Locke 

 from fragments discovered in the Tren- 

 ton limestone (Lower Silurian), in Ad- 

 ams Co., Ohio. It is well adapted for 

 lecture-purposes, exhibiting on a large 

 scale the prominent parts of these an- 

 cient Crustaceans. 



Size, 22x14. Price, $3.75. 



No. 374. Asaphns gigas, Dalm. 



A large specimen from the Hudson River Group (Lower Silurian), Cincinnati, 

 Ohio. Size, 10 x 7. Price, $2.00. 



No. 375. Asaphus gigas, Dalm. 



From the same locality as the preceding. 



Size, 10 x 6. Price, $1.75. 



No. 376. Asaphus gigas, Dalm. 



This specimen shows well the long posterior processes of the cephalic shield. 

 It is from the same locality as the preceding. Price, $0.60. 



No. 377. Asaphus gigas, Dalm. 



Hypostoma with a portion of the cephalic shield, and showing its position 

 beneath the same. From the same locality as the preceding. Price, $0.30. 



No. 378. Asaphus gigas, Dalni. 



Hypostoma. From the Utica Slate (Lower Silurian), Mohawk Valley, N. Y. 



Price, $0.30. 

 No. 379. Asaphus expaxisus, Dalm. 



From the Lower Silurian at Motala, Sweden. (Coiled.) Price, $0.20. 



No. 380. Asaphus expansus, Dalm. 

 From the same locality as the preceding. 



Size, 10 x 7. Price, $1.75. 



No. 381. Asaphus ingens, Barrande. 



From the Lower Silurian slate of Beraun, Bohemia. 



Size, 12 x 7. Price, $1.25. 



