334 Oeological Society. 



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

 the skull, cervical and dorsal vertebrae, 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, Stereosternum, and Plesio- 

 saurus. The humerus closely resembles that of the edentate 

 Megalonyx before its epiphyses are ossified. There are four bones in 

 the distal row of the carpus, and three bones in the proximal row. 

 The characters of the dorsal surface are given from a specimen 

 preserved in the Albany Museum. 



The Author then discusses the relation of Mesosaurus to Stereo- 

 sternum, as preserved in the British Museum, arriving at the 

 conclusion that the two genera are distinct, defined by characters 

 drawn from all parts of the skeleton. Stereosternum has four sacral 

 vertebrae, with the ilium extended far in front of the acetabulum. 

 The coracoids are regarded as meeting in the median line, and not 

 by overlap as in the thin ossification of Mesosaurus. In both genera 

 there are five bones in the distal row of the tarsus. 



The Author concludes that these types are closely allied to 

 Neusticosaurus, which he would separate from the Nothosauria and 

 unite with the Mesosauria. That group is subdivided into two 

 divisions — the Proganosauria of Baur, and the JS^eusticosauria ; the 

 former being known from South Africa and South America, and 

 the latter from Europe only. 



2. " On a new Reptile from Welte Vreden, Eunotosaurus africanus 

 (Seeley)." By Prof. H. G. Seeley, F.R.S., F.G.S. 



The Author obtained the specimen described at Welte Vreden, 

 near Beaufort West, Cape Colony, where it was found by Mr. L. 

 Pienaar in beds of Middle Karoo age. It indicates a small 

 animal, and shows the dorsal ribs, vertebrae, and part of the pelvis. 

 The centrums are more slender than in any known South African 

 fossil, and conically cupped at the ends as in Mesosaurus, &c. There 

 is no indication of great transverse widening of the neural arch. The 

 neural spine is compressed. The ribs appear to have been attached 

 much as in Chelonians, though the articulation is not seen. They 

 are remarkably massive, long, wide, compressed above, and sub- 

 triangular m transverse section. There may be some sternal ribs. 

 The OS pubis is thin and flattened, with a notch on the outer hinder 

 border like that seen in Mesosauria. The genus is probably 

 referable to that group, but distinguished from all known genera by 

 the forms of the vertebrae and ribs. 



3. " On the Structure of the American Pteraspidian, Palceaspis 

 (Claypole), with Remarks on the Family." By Prof. E. W. Clay- 

 pole, B.A., D.Sc, F.G.S. 



After reviewing the discovery of PaUvMspis and noticing cases 

 where Scaphaspid plates had been referred to ventral plates of 

 Pteraspidian fish, the Author describes two specimens of his genus 

 Paloiaspis from the Onondaga group (referred to the Lower Ludlow) 



