352 ANNUAL OF SCIENTIFIC DISCOVERT. 



This island, situated about one hundred and thirty miles east of Porto Rico, 

 N about two and one-half miles long, one-half to three fourths of a mile 

 wide, and rises from twenty to forty feet above the level of the ocean. It 

 is a barren rock, formerly avoided by navigators, and appears to be entirely 

 composed of the rich phosphatic mineral. Analyses of the substance. In- 

 competent chemists, indicate it to bear a resemblance in composition to 

 bones deprived of their cartilage, and otherwise altered, as we might sup- 

 pose bones to be, exposed to the influence of the ocean water. It contains 

 about the same proportion of phosphate of lime as calcined bones; and it 

 is this circumstance which has directed the attention of merchants and 

 agriculturists to its value as a manure. 



From this, the Sombrero material deserves to be distinguished by a new 

 name ; and perhaps the easy one of Osite, from its resemblance in composition 

 to bones, and its probable origin, would not be inappropriate. But are we 

 to ascribe the immense mass forming the Sombrero rock to animal origin? 

 Many reefs and shores of vast extent are known positively to have had 

 their origin in the testaceous coverings of the lower animals, but Sombrero 

 appears to be the first instance of an extensive island formed alone of the 

 remains of the higher animals. The composition of the Sombrero sub- 

 stance, with its included bones, ieads us to suspect that the island was once 

 a shoal swarming with turtles and other vertebral animals, whose accumu- 

 lated remains of ages have been cemented together, and gradually elevated 

 above the ocean level to the present position of the island. 



GIGANTIC AUSTRALIAN LIZARD. 







Professor R. Owen has communicated to the Royal Society the description 

 of some remains of a gigantic Land Lizard from Australia. A collection 

 of fossil remains now in the British Museum, demonstrates the former exist- 

 ence in Australia of a land lizard far surpassing in bulk the largest species 

 now known. The characters are derived from vertebras, partially fossilized, 

 equalling in size the largest known crocodiles. They .are of the proccdian 

 type, presenting lacertian modifications, .and agreeing closely with those of 

 the existing lace-lizard of Australia. A generic distinction is indicated by 

 the comparatively contracted area of the neural canal, and by the inferior 

 development of the neural spine of this fossil vertebra, which, from the 

 proportions of the body, must have belonged to an animal not less than 

 twenty feet in length. For this probably extinct lizard the name of Mega- 

 laneaprisca is proposed. 



Prof. Owen also has communicated to the Geological Society, " Notes on 

 some Outline-drawings and Photographs of the Skull of Zygomatnms trilo- 

 bus, Macleay, from Australia," received by him from Sir R. Murchison, be- 

 ing seven photographs, three of which are stereoscopic, of perhaps the 

 most extraordinary mammalian fossil yet discovered in Australia. This 

 unique and extraordinary skull of a probably extinct mammal, together 

 with other bones, but without its lower jaw, were found at King's Creek, 

 Darling Downs, the same locality whence the entire skull and other re- 

 mains of the Dfprotodon have been obtained. Mr. Macleay has described 

 the fossil under notice as belonging to a marsupial animal, probably as 

 large as an ox, bearing a near approach to, but differing generically from, 

 THprotodon. He has named it Zygomatums trilobus. The skull has trans- 

 versely ridged molars, and a long process descending from, the zygomatic 



