CLINTON GROUP. 77 
7. Lingula elliptica. — Shell oval, nearly equal in width at each extremity, marked by 
concentric lines or slight folds, which are scarcely elevated. 
8. Lingula oblata. — Shell very wide in proportion to the length ; surface marked by con¬ 
centric lines or slight folds, which are stronger and more prominent on the margins ; the whole 
surface covered with exceedingly fine concentric stria;. This shell differs from the last in its 
proportions, and in having two series of concentric markings which do not appear in the first. 
9. Lingula acutirostra. — This shell is readily distinguished from the other two by its 
form, and also from any described Lingula of the New-York rocks. The shell is broad be¬ 
low, tending abruptly to an acute point at the apex; surface marked with a single series of 
rather coarse striae. It is larger than the L. acuminata , and the surface more strongly marked 
by the concentric striae, as well as more abruptly acute. 
The three species here described are all found in a single locality, the two last quite nu¬ 
merous. This circumstance is somewhat unusual; the shells of this genus, though often 
abundant, rarely exhibit more than a single species in a rock or at a locality. 
All the forms presented above, with several others, may be obtained in the shale at the 
Wolcott ore bed, and those of the previous illustration at Sodus point and Rochester; while 
Medina and Reynolds’s basin will afford a rich harvest in the other forms, as well as some 
not described. 
The following woodcut is an illustration of the characteristic fossils of this group in the 
Third District, and is from Mr. Vanuxem’s Report. 
19. 
1. Fucoides biloba. 3. Crinoidal joint. 5. Strophomena depressa.. 
2. Tail of Hemicrypturus. 4. Lingula oblonga. 
The Strophomena depressa , and tail of Hemicnjpturus , are the only fossils of this illustra¬ 
tion which are found in this group in the Fourth District, and they are by no means common. 
