CRUSTACEA. 



101 



No. 398. Ceraurus pleurexanthemus, Green. 



This genus is closely allied to the Acidas- 

 pis of Murchison. In this species the buckler 

 is crescent form ; the eyes small, distant, and 

 granulated ; the glabella deeply farrowed on 

 each side ; the thorax has eleven articulations, 

 and the caudal shield four. This specimen is 

 a restoration by adjustment of fragments from 

 different individuals discovered in the Trenton 

 Limestone and Hudson River Group (Lower 

 Silurian). Price, $1.25. 



No. 899. Ceraurus pleurexanthemus, Green. 



This specimen, showing the hypostoma on the lower side, was found in the 

 Trenton Limestone (Lower Silurian) near Ottawa River, Canada. Price, $ 0.80. 



No 400. Chirurus Claviger, Beyrich. 



Two specimens. These loosely built Trilobites resemble Phacops. The 

 number of body-rings is eleven. The fragments of this species were discovered 

 in the Lower Silurian at Wesela, Bohemia. Original of the glabella in the Ward 

 Museum of the University of Rochester. Price, $0.60. 



No. 401. Conocephalus Sulzeri, Schioth. 



This Trilobite has a cephalic shield not unlike a half-moon, very small eyes, 

 a glabella separated by deep furrows from the lateral lobes, and fourteen joints. 

 The specimen is from the Lower Silurian at Ginetz, Bohemia. Price, §0.40. 



No. 402. Cychaspis Chrystyi, Hall. 



This Trilobite was found in the Niagara Group (Upper Silurian) at Waldron, 

 Indiana. Price, $0.20. 



No. 403. Dalmania ( Cryphaeus ) Boothii, Green. 



This genus is distinguished by an ovate oblong body, convex and trilobed ; a 

 buckler with two reticulated tubercles ; aad a long, lobate tail. The head and 

 upper part of the body closely resemble those of Calymene. This specimen is 

 from the Devonian at Huntingdon, Pennsylvania. Price, $0.25. 



No. 404. Dalmania ( Cryphaeus ) Boothii, Green. 



Showing the under-side of the tail. From the Hamilton Group (Devonian), 

 Ontario Co., N. Y. Price, $0.25. 



No. 405. Dalmania (Cryphaeus) calliteles, Green. 



Pygidium, showing the lobes more deeply cleft than in the 

 preceding species. From the Hamilton Group, York, N. Y. 



Price, $0.25. 



