108 NEW YORK STATE MUSEUM 



BALMANITBS Emtllrich. 1 845 



Dalmanites sp. 

 A fragment consisting of some thoracic somites and part of the pygid- 

 ium insufficient however to determine the species was found at Rochester. 

 The surface of both parts is more coarsely granulose than in D. 1 i m u - 

 1 u r u s Green, and a row of coarse tubercles upon the segments indicates 

 relationship toD. verrucosus Hall. The segmentation of the pygidium 

 however is unlike either and the specimen may represent an unknown form. 



fboetus Steininger. 1830 

 Proetus sp. 



Plate 21, fig. 13-16 



At Rochester was obtained a single internal impression of a cranidium 

 of Proetus with tapering glabella, quite narrow and convex but not pro- 

 tuberant in front, eyes small and closely appressed to the glabella, anterior 

 border thickened and separated from the glabella by a narrow sulcus. This 

 form may prove to be the species referred to by Hall as Asaph us 

 stoke si Murchison 1 but that is believed to have the anterior end of the 

 glabella more remote from the border as it is described as having " the 

 space between it [border] and the cheeks and glabella depressed in a broad, 

 shallow groove." Proetus corycaeus Conrad is of a somewhat differ- 

 ent type of glabellar structure. 



The material from Shelby has afforded besides a glabella several small 

 pygidia of a Proetus with highly elevated strongly annulate axis and 

 deeply sloping pleurae with three or four obscure duplicating ribs. These 

 are also features ascribed to P. s t o k e s i Hall. 



The relatively frequent occurrence of the specimens of this genus in 

 the eastern Guelph is interesting in view of the fact that no species of 

 Proetus has been elsewhere reported from this fauna. 



'Pal. N. Y. 1852. 2:316. 



