﻿50 



Cincinnati Society of Natural History. 



the right, sometimes to the left, so that they seem to be part of a 

 system. These branches run parallel with one another, sometimes 

 approaching, but never branching further. The greater number are 

 lost among the clusters of plants, horse-tails, and cat-tail flags, which 

 crowd the pond ; but others running between, begin clearly and 

 end abruptly. 



(M. Zeiller here refers to some figures of some of the fragments 

 of these tracks) which I have preserved by taking away the soil, 

 that, in drying, separated in small pieces, .oiom (4-10 of an inch) 

 thick, from the edges, and which, while yet soft and damp, easily 

 left the layer beneath, to which they had scarcely adhered. 



Their extent, their strong relief, and the regularity of the points 

 with which these tracks are covered, suggests a comparison with 

 Phymato derma, especially with P. liasicum; at the same time it is 

 difficult to forget the analogy which they present to certain impres- 

 sions of Conifers of the genus Brachyphyllum, notably B. Desnoyersi 

 (Brgt.), of the oolitic of Mamers and d'Etrochey. 



I do not, however, in making this comparison, dream of ques- 

 tioning the vegetable nature of Brae hyp hy Hum, though the case 

 admits of a doubt. Nevertheless, I believe, that if we found in a 

 fossil state, an impression bearing a resemblance to the tracks that 

 I have just described, without a good idea of their nature, their 

 resemblance to plants would cause us to place them, according to 

 their greater or less clearness, either with the Coniferae, closely 

 allied to Brae hyp hy lluui, or else with the Algae, closely allied to 

 Phymato derma . 



I have explored in vain, the galleries which cover the bottom of 

 the pond, to discover the animal that has made these hollows ; but 

 while the search has so far been fruitless, I have succeeded, by ex- 

 amining the tracks which bear a close resemblance to them, in 

 determining their author with certainty. 



These tracks present certain characteristics. The floors of the 

 galleries are composed of transverse ridges, all grouped by fours, 

 to the depth of about .001m (1-40 of an inch) ; these ridges are 

 like those that would be produced by a comb with four small teeth ; 

 are as large at the bottom as they are high, and are sharp pointed 

 at. the summit. On the ceilings of these galleries we observe a 



