OCR Text |
Show 268 PROF. HUXLEY ON THE CRANIAL AND [Apr. 6, magellanicus; but, so far as the measurements of his figures of the teeth permit me to form a judgment, G. griseus differs in no respect from some specimens of C. cancrivorus. With a shorter skull, Bur-meister's specimen of C. magellanicus has larger sectorial teeth than either of the specimens I have seen. In the lower jaws of two specimens of C. cancrivorus, and in one of C. magellanicus, in the British Museum, there is a well-formed though small fourth molar; and in a third specimen of C. cancrivorus there is a curious abnormal structure, consisting of a bunch of five minute crowns of teeth (whether united by their roots or not cannot be made out without injuring the specimen) in the place of the fourth lower molar on the right side. Fig. 15. Side view of the skull of Icticyon venaticus: f nat. size. Van der Hoeven * has described and figured a skull with a third upper molar on both sides, which he ascribes to C. azaree, but which, according to Burmeister, belongs to G. cancrivorus. In C. cancrivorus, therefore, the persistence of - - seems to be a common occurrence, while ^ ^ is found occasionally. Thus it would appear that we have under our eyes, in this species, another stage in the modification of the primitive dentition of the Canidae, which, as 1 "Over het geschlacht Icticyon van Lund," Verhandelingender Koninklijke Akademie van Wetenschappen, Amsterdam, iii. 1856. |