Geological Society. t1 



the liberty to ask the possessors of such collections who may be 

 interested in this matter to favour me with such specimens as may 

 seem to them calculated to give to this series of observations the 

 greatest possible extension. 



GEOLOGICAL SOCIETY. 

 April 20, 1859.— Major-General Portlock, V.P., in the Chair. 



•* On some Reptilian Remains from South Africa." By Prof. 

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



Fam. Crocodilia. Galesaurus planiceps, the Flat-headed Gale- 

 saur (from yaXi], polecat, aavfws, lizard), a genus and species founded 

 on an entire cranium and lower jaw. The skull in length less 

 than twice the breadth, much depressed, and flat above. Occipital 

 region sloping from above backward, divided by a high and sharp 

 ridge from the temporal fossae ; these are wide and rhomboidal ; orbits 

 small ; nostril single and terminal. Dentition, i. ^, c.y^, wi. j^^ ; 

 all the teeth close- set, except the intervals for the crowns of the 

 long canines when the mouth is closed. Canines of the shape and 

 proportions of those in Mustela and Viverra, without trace of pre- 

 paration of successors in the sockets ; of quite mammalian character. 

 Incisors longish and slender, molars subcompressed ; both with simple 

 pointed crowns, of equal length, and undivided roots. Original 

 transmitted to the British Museum by Governor Sir George Grey, 

 K.C.B. From the sandstone rocks, Rhenosterberg. 



Cynochampsa laniarius, the Dog-toothed Gavial (from kvmv, dog, 

 and ■ya.fx-^lja.i, Egyptian name for Crocodiles, applied by Wagner to 

 the Indian Gavial). This genus and species is founded on the 

 rostral end of the upper and lower jaws of a Crocodilian Reptile, 

 with a single terminal nostril, situated and shaped as in Teleosaurus, 

 and indicating similarly long and slender jaws. Only the incisive 

 and canine parts of the dentition are preserved ; but these closely 

 correspond with the same parts in Galesaurus, the incisors being 

 equal and close-set, of simple conical form, and the canines suddenly 

 contrasted by their large size. In shape they resemble closely the 

 ^completely formed canines in Carnivorous Mammals. There is no 

 trace of successional teeth. Original transmitted to the British 

 Museum by Governor Sir George Grey, K.C.B. , from Rhenoster- 

 berg, South Africa. 



Fam. DicYNODONTiA. Subgenus Ptychognathus, Ow. (tttvx^h, 

 ridge, yvaQos, jaw). — This subgenus is founded on four more or less 

 entire skulls, two retaining the lower jaw, referable to two species. 



Ptychognathus declivis, Ow. — Plane of occiput meeting the upper 

 (fronto-parietal) plane at an acute angle, rising from below upward 

 and backward, as in the feline mammals ; fronto-parietal plane 

 bounded by an anterior ridge, extending from one superorbital 

 process to the other ; from this ridge the facial part of the skull 

 slopes downward in a straight line, slightly diverging from the 

 parallel of the occipital plane; superoccipital ridge much pro- 



