220 Cincinnati Society of Natural History. 



tracks or impressions in each series are corapoimd, or, in other words, 

 they are composed of four or five parts, which present a beaded ap- 

 pearance. The arrangement of the compound or beaded track is either 

 transverse to the course of the trail, or inclined forward from the inner 

 to the outer side. The tracks are as close together in each series as 

 they can well be placed without commingling, and in some specimens 

 form almost a continuous trail. Figures 2 and 3 represent the casts 

 from the impressions made by the moving animal, but figure 4 shows 

 the trail itself in the rock. This trail is, we may presume, just as the 

 animal made it. It is as distinct as if made l)ut 3'esterday. 



It is not unusual to find trails crossing each other, as may be seen 

 in the lower part of figure 2. In this case the animal that made T. 

 permultus, crawled along on the mud first, and afterward the animal 

 that made 2\ numerosus, crossed its trail, obliterating T. permultus, 

 or throwing the tracks into confusion where they came in contact, but 

 leaving them between the series uninjured. (Tiie illustration does not 

 show this peculiarity as distinctly as the specimen does.) 



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

 Walker Mill Road, in the City of Cincinnati. 



Trachomatichnus permultus, n. sp. (Plate XIII., fig. 5.) 



This species consists of impressions arranged in two rows, w4iich 

 are separated by a space that is wider than a row of tracks. The 

 tracks are subtriangular, wider than long, and indicate a slight dragg- 

 ing of the feet at the central posterior part. 



It is distinguished from T. mimerosus, because the tracks are not 

 so numerous, they are destitute of the beaded appearance, they are 

 subtriangular instead of somewhat uniforml3^ rounded, and the rows 

 are proportionall}^ farther apart. 



The lower part of fig. 5 shows some extra markings upon the left 

 side, which may indicate that some other part of the bod^- occasional- 

 ly touched the bottom of the sea, or they may belong to another trail 

 which is nearly obliterated. 



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

 Walker Mill Road, in the City of Cincinnati. 



Trachomatichnus cincinnatensis, n. sp. (Plate XIY., fig. 3.) 



This species consists of numerous simple impressions, arranged in 

 two series, which are widely separated from each other. The impres- 

 sions are small, and possess no well detined characters. The species is 

 distinguished from T. permultus by the smaller and more ill-defined 



