V. Researches on the structure, organization, and classification of the fossil reptilia.—III. On parts of the skeleton of a mammal from Triassic rocks of Klipfontein, Fraserberg, South Africa (theriodesmus phylarchus, seeley), illustrating the reptilian inheritance in the mammalian hand

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Abstract
Among specimens collected from various localities in Cape Colony by Mr. Thomas Bain, and deposited in 1878 in the British Museum of Natural History, is a small counterpart slab, 8 inches long by 5½ inches wide, now registered under the number 49,392. It was labelled by its discoverer “The hand of a Saurian, from Klipfontein, Fraserberg, South Africa” ; and this determination escaped question. Its exact geological horizon is unfortunately unknown, but is probably the same as that of the Dicynodont Reptiles collected with it, which are on many grounds regarded as Triassic. This slab is a natural mould of the bones of the fore-limb of one of the smaller Mammalia characterised by five digits. It also shows, in less satisfactory preservation, remains of the tibia and fibula, which are relatively longer than the corresponding bones of the fore-limb. The animal thus indicated was considerably larger than the Otter, and approximated to the dimensions of the Wolverine. In their general shape and elongation, the limb bones, as a whole, approximate to the smaller Carnivora, but are distinguished by many differences of detail. Thus, the bones of the fore-arm are more nearly equal in size, though the difference is one of degree rather than type ; and the same is true of the bones of the fore-leg. But, except the tibia, and possibly the humerus, none of the bones give evidence of having terminated in epiphyses, and the forms of the distal ends of the ulna and radius are unlike those found in Carnivora. The carpus also shows some new points, though the bones are displaced, in giving evidence of a third row of carpal bones. The phalangeal bones of the digits, also, vary from the usual Mammalian type, and possibly, in one digit, give evidence of renewal after the digit had been lost, as among Amphibians. The vertebral column is only indicated by a portion of a single caudal vertebra. None of the differences, however, which the specimen shows from the skeletons of existing Mammals can be regarded as making an approximation towards lower Vertebrates in the plan of the skeleton, or as throwing a doubt on the interpretation of the animal as a typical Mammal ; but as evidences of inheritance, the carpus, metacarpus, and digits are singularly suggestive. I would express my thanks to Dr. Henry Woodward for permission to study and describe this remarkable fossil, and for his assistance in pre­paring the beautiful cast from the slab which was made by Mr. Hall, the mason, after the specimen had been cleared from some fragments of the original bone which adhered to the natural mould.

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