222 Cincinnati Society of Natural History. 



sibly, have been made by the Cephalopoda. It consists of a wide trail, 

 composed of numerous transversely- elongated depressions, arranged 

 apparently without definite order, but equivalent to three or more in- 

 terlocking rows. 



Petalichnus multipartitus, n. sp. (Plate XIV., fig. 2, natural size.) 

 This species consists of a wide trail, formed by four or five irregu- 

 larly-arranged, transversely-elongated tracks, following each other with- 

 out definite order. One track so interlocks with another \)y an alter- 

 nate arrangement that the trail is not susceptible of division into 

 definite rows. A single track is a simple elongated depression, trans- 

 verse to the course of the trail. 



Collected by C. B. Dyer, Esq., in rocks of the age of the Utica Slate, 

 on Walker Mill POad, in Cincinn.ati, at an elevation of less than 100 

 feet above low-water mark of the Ohio river. 



Ormathichnus, n. gen. 



[Eti/.—Ormathos, a string of beads ; ichnos, a track.] 



This genus is proposed for the reception of trails which I suppose 

 may have been made by a Gasteropod. It consists of a single, con- 

 tinuous, beaded track or trail. 



Ormathichnus moniliformis, n. sp. (PL XIV., figs. 4 and 5, 

 natural size.) 



This species consists of a simple beaded trail, resembling somewhat 

 the impression made b}^ a small column of Heterocrinus sim2)lex^ 

 though longer beaded. Fig. 4 illustrates it. I have also referred fig. 

 5 to the same species, though it has a longitudinal furrow in the 

 middle, and I am at a loss to account for the furrow if made by the 

 same species. Collected by C. B. Dyer, Esq., in rocks of the age of the 

 Utica Slate, on the Walker INIill Road in Cincinnati. 



In 1852, Prof. Hall illustrated a number of tracks and trails (Pahe- 

 ontology of N. Y., vol. 2) from the Clinton Group of Herkimer and 

 Oneida counties, New York. Those, which he suggested might have 

 been made by some of the Gasteropoda, bear little or no resemblance 

 to any of the species described in this article; but some of those which 

 he thought might have been made bj- Crustacea or fishes may be com- 

 pared with those here described and supposed to have been made by 

 Cephalopoda. He was inclined to believe that many of the tracks he 

 illustrated were made while the bed was exposed above water and 

 most of the others in very shallow water, while I have expressed the 

 opinion that the tracks here described were made on the bottom of the 

 sea at considerable depth. 



