30 



of Ohio. We have also seen a number of specimens 

 from that state, which could not be distinguished 

 from the Dudley trilobite. Our model was taken 

 from a specimen found at Trenton Falls, in the state 

 of New York. 



The three following species found in the United 

 States, will no doubt be considered by many as mere 

 varieties of the C. Blumenbachii; we have ventured, 

 however, to call them by distinct names. 



CALYMENE CALLICEPHALA.* Green. Cast No. 2. 



Clypeo antice attenuato, figura liliiformi in fronte 

 depictaj oculis minimis; abdomine quatuordecim ar- 

 ticulis; corpore piano. 



The buckler is subtriangular; on the front there is 

 a figure in high relief, somewhat resembling a fleur 

 de liSj or perhaps more, the capital of a Corinthian 

 column. The oculiferous tubercles are rather lower 

 down on the cheeks than usual. The articulations 

 of the abdomen and the tail cannot well be distin- 

 guished from each, other; fourteen in all may be 

 easily counted. The middle lobe of the abdomen is 

 nearly equal in breadth throughout. The ribs, or 

 costal arches, are not grooved or bifurcated at their 

 extremities. Length nearly two inches and a half. 



This beautiful species is in the Philadelphia Mu- 

 seum, where it is labelled as being found in " Hamp- 

 shire, Virginia." It is mineralized by a dark yellow- 



From two Greek words, which signify " beautiful head." 



