NEW AGELACRINITES ' 197 



well defined. In young stages the oral surface is much con- 

 tracted, the marginal rim proportionally broader, and the rays 

 are straight^ passing directly to the elevated inner 



edge of the rim. - — 



Nine of these individuals have been found at- 

 tached to a fragment of a shell of Ptychopteria. ' 



Geologic horizon and localities. Specimens of va- 

 rious sizes have been found on the southwest slope 

 of Mt Moriah about 1| miles south of Russell sta- 

 tion, Cattaraugus co. The horizon is regarded m nrtu;Iis1ze^\"we; 

 above the range of the true Chemung fauna. It is Carbonic, warren 

 about 100 to 150 feet above the Wolf creek con- 

 glomerate, lying between the latter and the Mt Hermon sand- 

 stone. 



In the succession of faunas from below upward in this section, 

 a marked change occurs at the Wolf creek conglomerate, notable 

 both for the introduction of species having a postdevonic 

 aspect and for the extinction of typical Chemung forms. Thus 

 appears here a species of Oehlertella closely similar to O. 

 pleurites, of the Ohio Waverly; all the Productellas have 

 disappeared ; Leptodesma potens, mortoni, sociale 

 do not pass above this horizon; L. curvatum, maclurei, 

 mytiliforme, orodes, etc. appear only above it. Likewise 

 the Pararcas (3 species), the Ptychopterias for the most part 

 (8 species), the Palanatinas (2 species) lie above it; the dictyo- 

 sponges all lie below it. 



A close analysis of the new elements introduced here shows 

 various early Carbonic affinities, and none perhaps more emphati- 

 cally, than this species itself, A. b u 1 1 s i . The expression of 

 this fossil is primitive throughout and indicates the senile mani- 

 festations of race exhaustion. The species has also been found 

 by Prof. Beecher at about the same horizon in the section at 

 Warren Pa. Of similar structure and diminutive form are cer- 

 tain other agelacrinites described from the lower Carbonic, A. 

 legrandensis Miller & Gurley, Kinderhook, A . b 1 a i r i 

 Miller, etc, 



