Oeological Society. 233 



snurus, as belonging to a distinct suborder of Repttlia, 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 Theriodonts. 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 re- 

 sembles that of a mammal. 



The dentition is so much better presei'ved 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, ia 

 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 Cijnolraco. The incisors 

 are eight in number in both upper and lower jaws, four in each 

 premaxillary, opposed or partially interlocking with the same 

 number in each mandibular 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 corresponding 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 

 proportions ; but the Author shows how they differ from those of 

 mammalian carnivores and Galesaurus. A similar character and 

 disposition of destructive canines is shown by the fossil jaws of the 

 oolitic great extinct carnivorous Saurians, e. g. Mer/alosaurus. In 

 the Triassic Labyrinthodonts the destructive and prehensile lauiaries 

 would by position rank as incisors rather than canines. In exist- 

 ing Lizards the dental series has more uniformity, and the cement- 

 clad roots contract bony union with the jaw-bone. In Galesaurus 

 the teeth, besides being distinguished, as in Mammals, by their 

 differential characters, are implanted freely in sockets, the cold- 

 blooded character being chiefly manifested in the greater number 

 of teeth following the canines, and in their want of distinction. 



Lastly the Author remarked on the earlier reptilian character shown 

 by the oolitic Mammal Amphltherium, and also by the existing 

 Australian Myrmecohms. He speculated on the degree of resem- 

 blance manifested by the teeth of the old Triassic lleptile of South 

 Africa with the exceptional characters of some of the low Australian 

 forms of Mammals. 



Ann. & Mag. N. HisL Ser. 5. Vol. xix. 16 



