220 Geological Society. 



10 inches wide. It is split so as to expose a portion of the skull, 

 the vertebral column and ribs as far as the pelvis, the scapula, part 

 of the humerus, the fomur, and parts of the tibia and tibula. The 

 tail and left hind-limb, and apparently part of the right fore-limb, are 

 lost, owing to the jointed condition of the rock. The bones have 

 decomposed, and are represented by natural moulds from which a 

 beautiful cast was obtained by means of a jelly mould in the Geo- 

 logical Department of the Natural History Museum, before the speci- 

 men was returned to Grahamstown. The remains indicate an animal 

 about 2 feet long, exclusive of the tail, and standing probably about 

 8 inches high ; it was not more than 6 inches wide in the fore part 

 of the body. The animal w^as of great mobility, capable of easily 

 bending the body, and, by straightening the limbs, of occasionally 

 raising its height to 10 inches or more. It is a new type of 

 Theriodout reptile, contributing important facts to the osteology of 

 the group, and especially in regard to the natural association of the 

 bones. It is possibly to be included in the Cyuodontia, from which 

 it differs in characters of the ilium, scapula, and skull. 



2. ' Fossils in the Oxford University Museum. — IV : Notes on 

 some Undescribed Trilobites.' By H. H. Thomas, Esq., B.A., F.G.S. 



Two new species of Dahnania from the Wenlock Shales and one 

 of Olenus from the Shineton Shales of Shropshire are described in 

 this paper. The specimens on which the first species of Dahnania 

 is founded were collected by the late Dr. Grindrod at Malvern 

 Tunnel. The species has a strong resemblance to certain varieties 

 of D. caudatas, especially those more nearly approaching D. longi- 

 caudatus ; its nearest ally seems to be D. ne.viUs. Among its 

 characters are spines round the head, the height of the head-shield, 

 and the distance between the eyes. The type-specimen of the 

 second species came from tb£ Wenlock Shale of Builth. The 

 Shineton specimen was presented to the Oxford Museum by the 

 Right Rev. Bishop Mitchinson. 



3. ' On Radiolaria from the Upper Chalk at Coulsdou (Surrey).' 

 By W. Murton Holmes, Esq. 



The radiolaria described in this paper were contained in the 

 cavities of two small Hints which were thrown out of the new 

 cutting between Coulsdon Station and the a^w Merstham Tunnel on 

 the L. B. k S. C. Railway. They were prooably derived from the 

 zone of Uolaster planus. After treatment with hydrochloric acid, 

 the material yielded silicified casts of foraminifera as well as radio- 

 laria. The surface of the radiolaria is so much altered by corrosion 

 that specific identification is in most cases impossible. Twenty 

 genera have been recognized, and the organisms appear to belong to 

 torty-one species of these genera. A list of the radiolaria is given, 

 accompanied by a short description of each form, and four new 

 species are described. The Discoidea appear to have the predomin- 

 ance, and the species of Dictyomitra come next in numerical order. 



