OCR Text |
Show 1896.] SKULLS OE A L E M U R A N D ORANG. 997 they were not uncommon in the genus Lemur, especially in young individuals, although their existence had apparently not been recorded. The bones in the specimen examined by me are triangular in form and, as will be realized from the sketch (fig. 1), occupy Fig. 1. Skull of Lemur, from above. Fr. Frontals. x. Supernumerary bones. L. Lachrymals. N. Nasals. M. Maxillae. a position corresponding with the prefrontals in a Lizard The suture which marks their limits is very clearly defined. It is interesting to note -that corresponding bones have been recognized in the genus Hippopotamus. In a memoirl contributed to tome xvi., 1894, of the ' Annales des Sciences Naturelles' by M M . Grandidier and Filhol, for a reference to which I am indebted to Sir W . Flower and Dr. Forsyth Major, these bones are described and figured both in tbe case of an extinct species, H. lemerlei, from Madagascar and of young individuals of existing Hippopotami from Senegal. On examination of our only specimen of the skull of a Hippopotamus in the Museum of Queen's College, Belfast, I find the same bones (regarded by M M . Grandidier and Filhol as representing prefrontals) distinctly indicated, though the suture separating them posteriorly from the frontals is to a considerable extent obliterated. In Sir W . Flower's admirable ' Introduction to the Osteology of the Mammalia' (3rd edition), the following statement occurs (p. 162) with respect to tbe squamosal in Monkeys : "The squamosal in the higher forms is developed much as in Man, but in the lower forms it is more reduced and takes a smaller share in the formation of the side-wall of the cranium. It generally comes in contact at 1 " Ossements d'Hippopotames." |