CRUSTACEA. 



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No. 441. Phacops bnfo ( var. rana), Green. 



Trilobites of the genus Phacops have very large, prominent, 

 granulated eyes, forming a segment of a cone, distinct trilo- 

 bation, and eleven body-rings. This species, the Calymene 

 macrophthalma of Brongniart, and perhaps identical also with 

 the Phacops latifrons of Bronn, has a very convex head, occu- 

 pying one-third of the whole length, a tuberculated glabella, 

 and the eleven pleurae bent down at the extremities. There 

 are 66 lenses in each eye. This specimen (coiled) is from the 

 Hamilton Group (Devonian), Ontario Co., N. Y. 



No. 442. Phacops cephalotes, Corda. 



From the Upper Silurian Limestone at Tetin, Bohemia. 



Price, $0.40. 

 Price, $0.60. 



No. 443. Phacops Logani, Hall. 



From the shaly limestone of the Lower Helderberg Group (Upper Silurian), 

 New York. Price, $0.60. 



No. 444. Placoparia Zippei, Bock. 



From the Lower Silurian, Bokycan, Bohemia. Price, $0.30. 



No. 445. Prcetus longicaudus, Hail. 



In this genus, the eyes are of moderate size, very prom- 

 inent, smooth, and joined rather closely to the glabella; 

 and the body has ten segments. This specimen (coiled) is 

 from the Hamilton Group (Devonian), Iowa. Price, $0.25. 



No. 446. Stanrocephalus Murchisoni, Barr. 



In this genus, the head is almost globular, glabella large ; eyes minutely 

 facetted ; thorax of eleven joints, and tail of three segments. This species, 

 which occurs in both hemispheres, was found in the Upper Silurian at Listice, 

 Bohemia. Price, $0.25. 



No. 447. Sphserexochus minis, Beyr. 



Two specimens. This curious Trilobite has a globular head, 

 projecting eyes, and ten pointed body-rings. It is from the 



Upper Silurian, Beraun, Bohemia. 



Price, $0.75. 



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