4 PALEONTOLOGY OF NEW-YORK. 
This shell is somewhat variable in form, as represented in the figures ; but the apex is. 
uniformly acute, and the surface of the shell marked by concentric striz. It approaches in 
form to the L. acuminata of Conrap; and I am unable to 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 obscure, it would not be difficult to indicate two 
distinct species. 
a. The usual form of this fossil. 
b. A broader specimen, with apex wanting. 
0g" 09" 08 
eo Go Ww 
3 c. A very broad somewhat rounded specimen, a view of the interior of the shell, the inner lamine 
wanting, and the concentric elevated lines showing in relief: 
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 commonly received notions, we here find, 
as the earliest representative of the animal race, species of a still existing genus, showing 
that the conditions of that 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 the common and numerous forms of the present day, still, since 
some similar forms do occur during all this time, we are justified in supposing that the 
conditions then existing were not very dissimilar from those at the present time, where such 
forms now flourish. 
The form of these Lingule 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 habit, like the little shells which flourished in the earliest 
era of life upon this globe ; a period so incalculably lost in the past, that we can have no 
conception of the time that has elapsed between. 
* Prof. H. D. Rocers has informed me tha! he believes he has obtained a species of Orbicula from this rock,. thus 
adding a third species, all belonging to genera which flourished in nearly every subsequent period, and of which 
species still exist. Mr. Lyexn also remarks that he obtained at Keeseville a placunoid fossil associated with the 
Lingula (Travels, p. 132). 
