350 Some JSew Species of Fossils from the Cincinnati Group. 



in front just back of the front marginal furrow and is projected poster- 

 iorly over the middle lobe of the thorax in a strong curving tubercu- 

 lated spine of equal or greater length than the spines projecting from 

 the cheeks. There are two lateral lobes on each side of the middle one ; 

 the anterior ones are somewliat circular with about ten or twelve tu- 

 bercles on each ; the posterior ones are subelliptical, bear from twelve 

 to twenty tubercles and extend back between the anterior parts of the 

 eye tubercles and the middle lobe. A curved row of tubercles start- 

 ing from the inner lateral side of each eye terminate even with the 

 anterior lateral lobe of the glabella (in some specimens thei-e are two 

 rows) and another curved row starting from the anterior part of the eye 

 and running parallel with the former terminates with the expanded 

 front of the middle lobe just forward of the anterior lateral lobe. 



Thorax unknown. 



Pygidium known only from a view of the under surface as shown by 

 the figure. It appears to be more than twice as wide, as long and to 

 bear two strong diverging slightly curving spines, which take their rise 

 from the sides of the last segment in the mesial lobe. These spines are 

 covered with tubercles. Between these spines there are six prominent 

 tubercles, four of which seem to have borne very short spines, and to 

 be visible from the opposite side, the other two placed at the lower 

 part of the base of the spines, and on each side of the strong curving 

 spines there are three short spines. 



The figures are drawn natural size, but it is not an uncommon occur- 

 ence to find the glabella, ■with its produced spine, much longer than it 

 is in the specimen figured. The specimens figured are from the same 

 slab, collected by me, in Judge Collin's quarry, at an elevation of 

 about 340 feet. I have found tolerably good specimens of the glabella 

 on the top of the hill in Mt. Auburn, at an elevation of about 400 feet, 

 above low water mark. 



Beyrichia Cmcinnatiensis (n. sp.) 

 CD 



Fig. 25. Beyrichia Cincinnatiensis. 



This is the smallest Beyrichia, known to me, in the Cincinnati rocks. 

 It belongs to the unisulcate group of "simplices,"' and is very closely 

 related to the Leperditia. General form, elliptical, with a straight dor- 

 sal edge. Surface of the valves smooth, convex, with a single depres- 

 sion extending from the middle of the dorsal margin across about or a 



