﻿DEANE ON THE SANDSTONE FOSSILS OF CONNECTICUT RIVER. 177 



Fig. e exhibits the trail of the body, with lateral feet. 



These extraordinary fossils occur upon surfaces as smooth as polished marble ; no 

 other would receive, much less retain such delicate impressions with such fidelity. 

 To explain their obscure meaning I have sought the assistance of several gentlemen 

 distinguished for their scientific attainments, and it gives me pleasure to subjoin their 

 opinions to these meagre descriptions of my own. 



Prof. Leidy considers the impressions 7c, d, i, f, c, and b, to be the tracks of insects 

 and Crustacea ; g and e those of worms ; and a, from its remarkable uniformity, to be 

 rather a vegetable than an animal impression. 



Prof. Gray is of opinion that fig. a represents leaf scars of some plant like a tree 

 fern. 



Prof. Wyman is of opinion that fig. a is a vegetable impression, and that the other 

 impressions upon this plate are due to articulate animals, insects or Crustaceans. 



Prof. W. B. Rogers is of a similar opinion as regards fig. a, yet he remarks that this 

 is but conjecture, and that we are without any guide as to what might be esteemed 

 a probable interpretation of this mysterious inscription. 



Prof. Dana can refer fig. a to nothing but a plant, the prominence being the traces 

 of leaves, probably coniferous ; still it is not like any known coniferous plant, ancient 

 or modern. Upon the remaining figures of pi. 19 he offers the following valuable re- 

 marks : " The delicate linear tracks must be made by an articulate animal. They 

 can hardly have been made by annelids (excepting e and g of which there is doubt), 

 and may have been made by Crustaceans or insects, perhaps water insects. I should 

 incline to say Crustaceans. Among the tribe of this class they may have been either 

 Entomostracans, Isopods, Macrourans, or small species of Anomourans. Isopods have 

 too small legs and pointed claws to make so large a track as 7i, and they would not 

 make the two distinct series of this figure, or a track with three impressions as in c. 

 The legs spread from the longitudinal axis, and do not point forward as in I. Still 

 it is possible that d and k might have been made by an Isopod, the bent form of the 

 track in this case being due to the fact that three joints of the leg, pressed on the mud 

 in the progress of the animal. There is a small tribe of Crustaceans near the Isopods, 

 which I have called Anisopods, in which the two anterior feet often have large claws, 

 and are projected forward in front of the head, and such an animal might make marks 

 with these claws like I, but I should think they would be likely to be less regularly, 

 or even continuous lines." 



" The Entomostracans may have been tracking the mud ; but so small species of that 

 group have usually very thin or slender feet, commonly more or less foliaceous for 

 swimming." 



" I should therefore be inclined to refer the triple and quadruple track to small 

 Anomourans. The two more central tracks, where there are four, being made by the 



