32 SIRENOID AND CROSSOPTERYGIAN GANOIDS. 



[C. Phillipsii, A<?.] PI. V, figs. 13, 14. 



The following is Agassiz's account : 



" This is the smallest species of tooth of this genus which I know ; it was communi- 

 cated to me by Professor Phillips, and comes from the Oolite of Stonesfield. The internal 

 edge is straight ; the tooth is particularly distinguished by its very prominent denticles, 

 sharply cut, much compressed, and separated by deep grooves, which extend far upon the 

 surface of the crown, the flat part of which projects very little beyond them. The posterior 

 [anterior] denticle is transverse, truncate at its extremity, and shorter than the lateral 

 denticles ; the anterior [posterior] denticle is a mere prolonged thickening of the internal 

 border ; the three lateral denticles are successively longer and more prominent up to the 

 third, which is the largest of all." 1 There are shown in the figure five denticles, of which 

 the second, counting from the front, is the largest. 



Another example, of what may be the same species and from the same locality is 

 preserved in the British Museum. The locality and formation are not authenticated. 2 

 It cannot be decided on the basis of these two fossils, one of which is now lost, whether 

 the species {Phillipsii) is distinct, and whether both examples are referable to it. The 

 drawings (PI. V, figs. 13, 14) seem to differ conspicuously, but in this variable genus it 

 is useless to reason from scanty data. 



[C. LvEVISSIMUS.] PI. V, fig. 2. 



Another doubtful form is C. lavissimus, from the Upper Keuper Sandstone of Glover's 

 Hill cutting, Ripple, Worcestershire. The original, shown in PI. V, fig. 2, is now in the 

 British Museum. I cannot ascertain who is responsible for the naming of the species, 

 which seems to be undescribed. 



This appears to be the only British example from the Trias proper. It cannot be 

 satisfactorily discussed, so long as we have only a single fragmentary specimen to deal 

 with. It seems to me to resemble not polymorplms or parvus, but the group including 

 Gulielmi, palmatus, and Weissmanni of the German Trias. These species (I cannot say 

 how far they are separable from one another) agree with the present tooth in their con- 

 siderable breadth, nearly central internal angle, obtusely sinuous external margin, and 

 tolerably defined but blunt ridges. 



1 ' Poissons Fossiles,' t. iii, p. 135. 

 3 Ante, p. 26. 



