4 PALEONTOLOGY OF NEW-YORK. 



This shell is somewhat variable in form, as represented in the figures ; but the apex ia 

 uniformly acute, and the surface of the shell marked by concentric strife. It approaches in 

 form to tiie L. acuminata of Conrad ; and I am unable lo point out the difference, having 

 only a drawing of that shell. In many cases, this shell, in the Potsdam sandstone, is almost 

 wholly absorbed, a mere film remaining, showing the form of the shell. By taking extreme 

 forms of this species, since the shell is so obsciue, it would not be difficult to indicate two^ 

 distinct species. 



Fig. 3 a. The usual form of this fossil. 



Fig. 3 A. A broader specimen, with apex wanting. 



Fig. 3 c. A very broad somewhat rounded spfcimen, a viewof the interior of the shell, the inner laminae- 



waniing, and the concentric elevated lines showing in rehef. 

 Fig. 3 d. An elongated specimen, somewhat compressed laterally. 

 Fig. 3 e. An enlarged portion of 3 c. 



Position and locality. In the grey friable variety of this rock in the town of Hammond,, 

 St. Lawrence county, and near Alexandria landing in Jefferson county. (State Collection.) 



We look upon these minute fossils with no ordinary degree of interest, as having been,. 

 for a long period, almost the only representatives of animal life, at least upon this portion 

 of our globe.* We find other species of the same genus in nearly every group in the New- 

 York system, while others have flourished in every geological period, and many are still 

 living in our present seas. In opposition to very conmionly received notions, we here find, 

 as the earliest representative of the animal race, species of a still existing genus, showing 

 that the conditions of tliat primeval ocean were in many respects similar to our own. We 

 see, so far as the evidence goes, that external conditions were then as favorable to this form 

 of life as at present ; and though subsequently immense numbers of forms were called into 

 existence, differing from I he common and numerous forms of the present day, still, since 

 some similar forms do occur during all this time, we arc justified in supposing that the 

 conditions iheii existing were not very dissimilar from those at the present lime, where such 

 forms now flourish. 



The form of these Lingidcc scarcely differs from that of some of the modern or existing 

 species, showing that through all this time nature has worked upon the same principle in 

 the production of her works ; and the little shell of modern seas is produced, in form and 

 appearance, and in action and h;d)it, like tlie little shells which flourished in the earliest 

 era of life upon this globe ; a period so incalculably lost in the [jasl, that we can have no 

 conception of the time that has elapsed between. 



* Prof. H. D. Rogers has informed inc tlui' he bclipvcs he ha.s obtained a species of Orbkuhi from this rock, thu.i 

 adding a third species, all belonging to genera whicli flourished in nearly eveiy subseijucnt period, and of which 

 species still exist. Mr. Lyell also remarks that he obtained at Kecseville a placunoid fossil associated with the 

 IJngttla {Travels, p. 132). 



