64 Royal Society ; — 



points out the characters indicative of its carnivorous hahits and of 

 its affinities to the marsupial order. 



The large size of the temporal fossse, meeting to form a low crest 

 on the parietal bone, and bounded behind by a strong occipital crest ; 

 together with large carnassial teeth in both upper and lower jaws, 

 evince the carnivorous habits of the extinct species. Its marsupial 

 nature is, in the author's opinion, demonstrated by the following 

 cranial structures : — A large vacuity in the bony palate ; a propor- 

 tionally large lacrymal bone extending upon the face and perforated 

 by the lacrymal canal, anterior and external to the orbit ; three ex- 

 ternal precondyloid foramina ; the perforation of the basisphenoid by 

 the entocarotid canal ; the great interval between the foramen ovale 

 and foramen rotundum ; the separation of the tympanic from the 

 petrous bone ; and the development of the ' bulla auditoria ' in the 

 alisphenoid ; the position of the outlet for a vein from the lateral 

 sinus behind and above the root of the zygoma ; finally, the low and 

 broad occiput, and the very small relative capacity of the brain-case. 



In the marsupial order, the present large extinct Carnivore, for 

 which the author proposes the name of ' Thylacoteo * carnifex,' 

 is most nearly allied to the Basyurus (Sarcojihilus) ursinus ; but is 

 very different in its dentition from that and all existing Carnivora. 



The fossils described were discovered by "William Adency, Esq., in 

 a calcareous conglomerate stratum in a bank of a lake situated 80 

 miles south-west of Melbourne, Australia. 



January 13, 1859. — Sir Benjamin C. Brodie, Bart., President, in 

 the Chair. 



" On the Embryology of Comatula rosacea (Linck)." By Prof. 

 Wyville Thomson. 



The author briefly described the male and female reproductive 

 organs of Comatula. When the ova are mature, and before impreg- 

 nation, they are protruded and remain hanging from the ovarian 

 orifice, entangled in the areolar tissue of the everted ovary. In 

 this position impregnation appears usually to take place. 



After segmentation of the yelk, a solid nucleus is formed in the 

 centre of the mulberry yelk-mass. This nucleus becomes invested 

 in a special membrane ; and into this embryonic mass the remainder 

 of the yelk is gradually absorbed. Ciliary motion is observed at 

 various points on the surface of the enclosed embryo, which finally 

 assumes its characteristic form. The young larva, on escaping from 

 the egg, consists of a homogeneous mass of pale-yellow granular 

 matter, with scattered nuclei, cells, and oil-globules. It is barrel- 

 shaped, and girded at intervals with about five broad ciliated bands. 



As development proceeds, one of these belts becomes depressed at 

 a certain point ; and within the loop thus formed, an inversion of the 

 integument indicates the position of the rudimentary mouth. 



A distinct oesophagus and stomach are rapidly differentiated, and 

 a short intestine, ending in a large anal orifice, near the posterior 

 * From OvXanos, a pouch; \euv, a lion. 



