Geological Society of London. 377 



II. — Geological Society of London. 



June 22nd, 1892.— W. H. Hudleston, Esq., M.A., F.E.S., President, 

 in the Cbair. — The following communications were read : 



1. " Contributions to a knowledge of the Saurischia of Europe and 

 Africa." By Prof. H. G. Seeley, E.E.S., F.G.S. 



The Saurischia are defined as terrestrial unguiculate Ornitho- 

 morpha, with pubic bones directed downward, inward, and forward 

 to meet in a ventral union. The forms of the pelvic bones vary 

 with the length of the limbs, the acetabulum becoming perforate, 

 the ilium more extended, the pubis and ischium more slender, and 

 the sacrum narrower as the limb bones elongate. The order is re- 

 garded as including the Cetiosauria, Megalosauria, and Aristosuchia 

 or Compsognatha. 



The Cetiosaurian pelvis has been figured in the Quart. Journ. 

 Geol. Soc. ; and a restoration is now given of the pelvis in Megalo- 

 saurus, StreptospondyJus, and Compsognatlius. 



The characters of the skull are evidenced by description of the 

 hinder part of the skull in Megalosaurus found at Kirtlington, and 

 preserved in the Oxford University Museum. In form and propor- 

 tions it closely resembles Ceratosavrus, and the corresponding region 

 of the head in Jurassic Ornithosauria. The brain-cavity and cranial 

 nerves are described, and contrasted with those of Ceratosaurus. 



The skull in Cetiosauria, known from the American type Diplo- 

 docus, is identified in the European genus Belodon, which is re- 

 garded as a primitive Cetiosaurian. 



Part 2 discusses the pelvis of Belodon, restored from specimens in 

 the British Museum, and regarded as Cetiosaurian. A restoration 

 of the shoulder-girdle is made, and found to resemble that in Ichthyo- 

 saurs, Anomodonts, and Dinosauria. The vertebrae in form and 

 articulation of the ribs are Saurischian, the capitular and tubercular 

 facets being vertical in the dorsal region, and not horizontal as in 

 Crocodiles. The humerus shows some characters in common with 

 that of StereoracMs dominans in the epicondylar groove. In general 

 character the limb-bones are more Crocodilian than the axial skeleton. 

 The interclavicle is described, and regarded as a family characteristic 

 of the Belodontid^e. 



In the 3rd part an account is given of Staganolepis, which is 

 regarded as showing a similar relation with the Megalosauria, to 

 that of Belodon with the Cetiosauria. This interpretation is based 

 chiefly upon the identification of the pubic bone in Staganolepis, 

 which has the proximal end notched as in Zanclodon and Strepto- 

 spondylus ; and the inner ridge at the proximal end is developed into 

 an internal plate. A note follows on the pelvis of Aetosaurus which 

 is also referred to the Saurischia on evidence of its pelvic characters, 

 approximating to the Cetiosaurian sub-order. 



Part 4 treates of Zanclodon which is regarded as closely allied 

 to Massospondylus, Euskelesaurus, and Streptospondylus. It is 

 founded chiefly on specimens in the Royal Museum at Stuttgart, 

 and in the University Museum at Tiibingen. The latter are regarded 

 as possibly referable to Teratosaurus, but are mentioned as Zanclodon 



