[WILLIAMS] FOSSIL FAUNAS OF THE ST. HELEN'S BRECCIAS 2 1 



the St. Helen's limestone rests upon paheoiitological evidence alone^ it 

 has seemed to me worth while to give tlie fanna a very close scrutiny and 

 'state the reasons for applying the names selected in making up the lists. 

 In the following notes are recorded my personal impressions upon critical 

 study of the specimens. 



The species will be discussed in the natural association in whicli 

 they were found, on the supposition that the species of each of tlie three 

 lots belong together and must be regarded as representing single horizons. 



The specimens obtained from Lot 1 (252.1) are listed under twenty- 

 five specific names on the supposition that they ail belong to a single 

 fauna. The fauna is called the Spirifer arenosus fauna from the species 

 among them which appears most sharply diagnostic of a particular geo- 

 logic horizon. 



The Spirifek arenosus fauna. 



1. Favosites {Chœtens) .spiwricits. Hall. 



This species is represented by several fragments showing an original 

 mass of uncertain shape, but the columns were at least 10 mm. long. 

 They are angular and closely massed together, about .35 mm. in diameter 

 and nearly uniform in size and form. The species was originally de- 

 scribed as Chgetetes spherica by Hall.^ Later the species was described 

 as.ravosit.es, and in the illustrations of the species Hall- figured mural 

 pores (fig. 9) and in another figure (fig. 10) corrugations and in still 

 another specimen the columns are figured with smooth wall (fig. 8). 

 All three of these characters are represented on the specimens from St. 

 Helen's, so that whatever genus we refer the species to the identity of 

 our species with the form of the Xew Scotland beds of Clarkesville and 

 Schoharie is established. It is interesting to know that Favosites helder- 

 bergise and this species occur together in the New Scotland beds as 

 shown by the two appearing on the same specimen (figured as figure 8 

 on plate VIII of the work above referred to). This is sufiicient to estab- 

 lish a faunal connection between lots 1 and 3. 



I cite the species as Ch^tetes in parenthesis recognizing Schucherf's 

 reference,^ without attempting to discuss the merits of the case. 



2,. S'mall Crinoid Stehis, 



These are listed to indicate the presence of erinoid's in the fauna, 

 tho' the discs alone are insufficient to establish generic or specific iden- 

 tity with any known species. 



iHall, James, 26th Rept. X. Y. State Mns. Nat. Hist, 1.S74, p. ]11. 



2 Hall. James. Pal. N. Y., VI, 1S87, PI. VIT. Fi?. 9 and 10. p. . 



3 Schuchert, C, Lower Devonic Aspect of the Lower Helderbera; and Oriskany 

 formation, p. 280. 



Sec. IV., 1909. 1."^. 



