FOSSIL FISH. 429 



it is in the chalk, and the shell or crag limestone, (calcaire 

 grassier, of the French,) that some begin to appear; and, as 

 we proceed upwards, they increase in greater and greater pro- 

 portions. 



Though a very great number of these fossil teeth are found 

 and of very different forms, yet we must not suppose that they 

 proceed from an equally great number of species; in fact, a 

 very moderate study of the teeth of Squali is sufficient to prove 

 that, in the same species, there are sometimes not two on the 

 same side exactly similar, and yet their differences are so 

 marked, and so constant in their recurrence, that the Squali 

 are easily characterized by the consideration of this part of 

 their organization alone. 



The fossil teeth seen by M. de Blainville, either in their 

 natural state or figured, are by him referred to the following 

 species : — 



1. Squalus cornubicus. To this animal are referred a great 

 number of teeth from Sicily, Brussels and its environs, and the 

 neighbourhood of Montpellier, &c. All the fossil teeth named 

 by oryctographers suhulatij cuspidati suhulati, ophioglossce, 

 glottid(B, ophiodont(JB, &c., and by Lluid, ornithoglosscB recur- 

 virostres, must certainly belong to this species. They are, in 

 general, slender, narrow, elongated, and pointed, with entire 

 edges, somewhat trenchant, flat within, and a little convex 

 without. This kind of fossil teeth appears to be by far the 

 most common, since they are found in all parts of the earth, 

 and at all depths ; accordingly we find this species of shark 

 very common in all our European seas. 



2. Squalus ferox. Teeth, more or less broad, sometimes 

 rather elongated, altogether straight, or but little curved back- 

 wards, and which, without denticulations on their edges, are 

 accompanied at their base by a very evident point on each side, 

 belong to this large species of shark, which exists in the Medi- 

 terranean. They are found at Boutonnet, near Montpellier, 

 and in different parts of England. 



