494 ' ^'EW YORK STATE MUSEUM 



Gonioceras chaziense sp. nov. 



Plate 36, figure 3, 4 



On account of the great interest attaching to the appearance of 

 this genus in the Chazy beds and in the Appalachian basin, we de- 

 scribe here this species, though we possess but two specimens which 

 are retained as natural sections upon weathered rock surfaces. 

 Another large specimen was observed by the writer in an early 

 reconnoitering trip near Chazy village and in the same horizon as 

 those described and figured here but could not be located again 

 when the proper tools for collecting were at hand. 



The natural section exposes the septa, which are closely arranged, 

 there being lo of them counted within the space of 20 mm ; each 

 septum rises within the body of the shell to about the hight of five 

 cameras, forming broad and low saddles in the lateral flanges, and 

 becoming slightly deflected backward towards the outer margin of 

 the flanges. Their central portions are much thickened by secondary 

 deposits. The outer conch, which according to Hall is also in the 

 other species of Gonioceras excessively thin, is not preserved ; the 

 greatest width of the phragmocone, as indicated by the septa, is a 

 little over 70 mm. The phragmocone appears to have been at least 

 as rapidly expanding as that of G. anceps. The siphuncle is 

 very large (its diameter 7 mm), strongly nummuloidal, filled with 

 organic deposits which leave open but a narrow endosiphotube. 

 From the latter radiate horizontal tubuli as in the other congeners. 

 We have not been able to ascertain the transverse section of the 

 conch and the surface is unknown. 



Position and locality. The specimens were obtaiiied from the 

 middle Chazy beds (Bg) near Chazy village, N. Y. 



Observations. This species is, according to the character of 

 the saddles in the lateral flanges, more closely related to G . 

 anceps than to G . o c c i d e n t a 1 e , which seems but natural 

 since also in time of appearance it is nearer to that form, a Black 

 river species, than to the later G. occidentale. 



Subdivision ACTINOSIPHONATA 

 Family oocer^^tidae 



The Beekmantown and Chazy beds have furnished a small group 

 of five cyrtoceraconic species, three of which can be positivelv placed 

 with the Actinosiphonata by the internal structure of their siphuncles, 

 while the other two though not showing this structure belong, ac- 



