Peculiar Fossils from the Chemung Hocks. 21' 



VII. — Descriptions of some peculiar screw-like Fossils from 

 the Chemung Rocks. 



BY J. S. NEWBEKRY. 

 Read Dec. 10th. 1883. 



In the sandstones of the Chemung Group in Northern Penn- 

 sylvania and Southern New York, have been found a number of 

 cylindrical or fusiform bodies, traversed by spiral raised ridges, 

 which have been something of a puzzle to those who have col- 

 lected them. At first sight, they would seem to bear a close re- 

 lationship to some species of Spirangium, particularly Sp. 

 Quenstedti, Sch. (Palceoxyris. Quenstedt, Handbuch d. Petrefac- 

 ten, Tab. lxxxit. Fig. 9), and Sp. Gilewii, Romanowski, (Geol. 

 Turkestan, p. 135, Taf. 23, Fig. 3). 



But in these, as in all the other species of Spirangium de- 

 scribed, the fusiform body is traversed by six or more spiral 

 raised lines, instead of two as in the specimens under considera- 

 tion. 



The geological horizons of these fossils are also different, Spi- 

 rangium ranging from the Coal-measures to the Wealden, while 

 our screw-like casts, to which the name Spiraxis is now given, 

 are confined, so far as yet known, to the Chemung. 



The resemblance between some of the species of Spiraxis and 

 the species of Spirangium enumerated above, is so striking that 

 it is difficult to resist the conviction that they are of similar char- 

 acter and somewhat closely related. Spirangium has been gen- 

 erally considered as a fruit of some kind, and the first species 

 noted was described by Brongniart under the name of Palwoxy- 

 ris regularis, (Ann. Sc. Nat, Ire Ser., Vol. XV, p. 456) from 

 a conviction that it was the fruit of a plant allied to Xyris. 

 Ettingshausen has also suggested that Spirangium is the fruit 

 of an extinct plant related to the living Bromelia, and so In s 

 called it Palwobromelia, (Abhandl. d. K. K. Geol. Reichsan- 



