Geological Society of London. 379 



proximal end resembles many Triassic gjenera ; and in its distal end 

 is well distinguished from Massospondylus by its mode of union 

 with the astragalus. The claw-phalanges are convexly rounded, 

 being wider than is usual in Megalosauroids. The lower jaw from 

 the Kraai Eiver gives the characters of the articular bone, and the 

 articulation, as well as of the dentary region and teeth. The 

 cervical vertebra is imperfect, but is remarkable for the shortness 

 of the centrum, being slaorter than in Megalosauriis. 



In Part 8 an account is given of Hortalotarsus skirtopodus from 

 Barkly East, preserved in the Albany Museum. It is an Euskele- 

 sanrian, and exhibits the tibia and fibula, and tarsus. There is a 

 separate ossification for the intermedium, which does not form an 

 ascending process ; and the astragalus is distinct from the calcaneum. 

 The metatarsals are elongated, and the phalanges somewhat similar 

 to those of Dimodosaurus. 



Part 9, in conclusion, briefly examines the relations of the Saur- 

 ischian types with each other, and indicates ways in which they 

 approximate towards the Ornithosauria. It is urged that the Ornitho- 

 sauria are as closely related to the Saurischia as are the Aves to the 

 Ornithischia ; and that both divisions of the Saurischia approximate 

 in Staganolepis and Belodon. Finally, a tabular statement is given 

 of the distribution in space and time of the 25 Old-World genera 

 which are regarded as probably well established. Eight of these are 

 referred to the Cetiosauria, thirteen to the Megalosauria, and four to 

 the Aristosuchia or Compsognatha. 



2. " Mesosauria from South Africa." By Professor H. G. Seeley, 

 F.R.S., F.G.S. 



The author gives an account of specimens of Mesosaurus pleuro- 

 gaster (Seeley) obtained from the shales at the Kimberley diamond- 

 mine. They are of small size, and show generic identity with the 

 Paris type, but indicate an animal with a long tail, with the hind 

 limbs well developed. The centra of the vertebrae are barrel- 

 shaped, contracting to the articular faces, which are conically 

 cupped. The dorsal ribs have the usual subcylindrical character 

 and development ; but the abdominal armour is more like that of a 

 Plesiosaur, only the sternal ribs are thin and flat. The vertebrse 

 appear to give attachment to the dorsal ribs in an unusual way, 

 which suggests the condition in the Theriodontia, but without 

 distinct tubercles or facets ; so that the slender head of the rib 

 lies in the depression between two centrums. In the early caudal 

 vertebra the transverse processes are stronger, the neural spines 

 long and compressed, and chevron bones well developed. Details 

 are given of the structure of the tarsus and hind limb. 



A new example of Mesosaurus tenuidens from Albania, preserved 

 in the South African Museum, shows many details of structure 

 more perfectly than in the type-specimen ; and the author describes 

 the skull, cervical and dorsal vertebra, shoulder-girdle, ribs, and 

 fore limbs. The forms of the cervical ribs are determined, and the 

 composite structure of the scapular arch shown to have characters 

 in common with that of Dactylosaurus, StereG sternum, and Plesio- 



