OWEN PXJRBECK FOSSILS. 



431 



1854.] 



Fig. 12. — Portion of the right ramus of the lower jaw, with teeth, 

 of the Spalacotherium tricuspidens, Owen. (Nat. size, and 

 magnified.) 



(I. Two molars, without the middle 

 and hind cusps ; magnified. 



l>. Canine tooth ? 

 c. First premolar ? 



In the same block of Purbeck " dirt-bed " are imbedded part of a 

 vertebra, a fragment of the jaw with a few teeth of the Macellodus, 

 and three of the small subquadrate and externally pitted dermal 

 scutes. There is also a beautifully clear impression of the dentary 

 bone, with six or seven of the anterior minute teeth, and a row ot 

 fine vascular pits or foramina, of the Macellodus. 



In regard to the Spalacotherium, sufficient evidence, it seems to 

 me, is afforded by Mr. Brodie's fossils, described in the foregoing 

 pages, to satisfy the most scrupulous palaeontologist as to the mam- 

 malian and insectivorous character of the species. The portions of the 

 jaws and teeth on which the genus and species are founded, show 

 precisely the same dark charred colour as the reptilian fossils with 

 which they are associated ; and there can be no doubt of the mamma- 

 lian and lacertian remains being of the same date, included, as they 

 often are, in the same block of matrix. There is no satisfactory 

 evidence of the marsupial character of the jaws of the Spalacothe- 

 rium : from the great number of the tricuspidate molars, one might 

 be inclined to infer its affinity with the recent Myrmecobius ; but, 

 although the molar teeth are not so numerous in any placental Insec- 

 tivore, they manifest so much variety in number and shape, in the 

 existing species, that a further deviation from the common type in 

 regard to number would not be a very violent departure from the 

 characters of the true Insectivorous order. The'Straight vminflected 

 angle of the lower jaw of the Thylacotherium has led me to view 

 that genus as more nearly allied to the placental than to the marsu- 

 pial Insectivora ; and the Spalacotherium has closer affinities with 

 the Thylacotherium than with any known existing Insectivora. In a 

 comparison with these, the Spalacothere most closely resembles, as to 

 the shape of its teeth, the iridescent Cape ^io\e {Chrysochlor a aiirea) : 



