572 Reports and Proceedings — Geological Society of London. 

 BEPORTS .AJCsTID ZPIROCIEIEIDIICsrO-S. 



I. —November 3, 1886.— Prof. J. W. Judd, F.E.S., President, 

 in the Chair. 



The President noticed the presentation, on the part of Dr. Hector, 

 of a preliminary report of the late eruptions in New Zealand, and 

 stated that Dr. Hector hoped shortly to communicate a paper to the 

 Society on the subject; papers had also been sent or promised on the 

 same subject by other New Zealand geologists, and it was hoped that 

 before long the Society would be in possession of very full accounts of 

 these remarkable volcanic outbursts. 



The following communications were read : — 



1. "On the Skull and Dentition of a Triassic Saurian, Galesaurus 

 planiceps, Ow." By Sir Richard Owen, K.C.B., F.R.S., P.G.S., etc. 



The author referred to a fossil skull from the Triassic sandstone of 

 South Africa, which combined dental characters resembling those of 

 a carnivorous Mammal with the cranial structure of a Saurian. The 

 structure was described and figured in Owen's ' Catalogue of the Possil 

 Eeptilia of South Africa,' under the generic title of Galesaurus, as 

 belonging to a distinct suborder of Eeptilia, termed Theriodontia. 



The characters of the skull and teeth of the original specimen of 

 Galesaurus have been brought to light by further development. 



In both the type specimen and that lately received the reptilian 

 nature of the fossil is indicated by the single occipital condyle and 

 other features. The chief difference from a mature male of a placental 

 or marsupial carnivore is the evidence of a primordial "gullet-tract." 

 Further details as to the structure of the skull were given, more 

 especially with reference to the orbits and nasals. The palatal region 

 repeats the same general characters as in previously described Theco- 

 donts. The angle of the jaw is not produced, as in the Crocodile, 

 beyond the articular element. In general shape and bony strength the 

 mandible of Galesaurus resembles that of a mammal. 



The dentition is so much better preserved in the new specimen than 

 in the type Galesaur as to call for description; and illustration. In 

 four of the upper molars the entire crown is preserved ; it shows less 

 length and greater breadth than appears in the previous restoration, is 

 moderately curved externally, and triangular ; the base is flanked by a 

 short cusp before and behind, and the corresponding margins are finely 

 crenulate, as in the molars of Cynodracon. The incisors are eight in 

 number in both upper and lower jaws, four in each preni axillary, 

 opposed or partially interlocking with the same number in each mandi- 

 bular ramus ; they have longish, slender, simple-pointed crowns. The 

 canines, one on each side of both upper and lower jaws, have the same 

 laniariform shape and size of crown as in the original fossil. In the 

 right maxillary bone the long deeply planted root is exposed ; the cor- 

 responding part of the lower canine is similarly exposed in the left 

 mandibular ramus. No trace of successional teeth, as in ordinary 

 Saurians, has been found. 



Both Crocodiles and Alligators have two or more teeth of canine pro- 

 portions ; but the author shows how they differ from those of mammalian 



