585 



on a pair of large hind limbs, the weight thereupon being transferred 

 by a larger proportion of the vertebral column than in the prone 

 crawling crocodiles and lizards of the present day. 



The author, from certain associated fossils, deduces a probability 

 of the triassic age of the sandstones including the above-described 

 South African Reptilia, and remarks that it is in a sandstone of triassic 

 age in Shropshire where fossil remains occur of a reptile which, in 

 biting with trenchant edentulous jaws, also pierced its prey by a 

 pair of produced weapons analogous to the tusks of Dicynodon. Of 

 this reptile, the Rhynchosaurus articeps, Ow., the author describes 

 the skull, vertebrae, and some other bones, which have been lately 

 discovered in the New Red Sandstone of Grinsill, Shrewsbury. The 

 remains of the limb -bones in this specimen bespeak a reptile capable 

 of progression on dry land, as well as of swimming in the sea of one 

 that might leave impressions of its foot-prints on a tidal shore. 



This paper is illustrated by numerous drawings. 



February 27, 1862. 



Major-General SABINE, President, in the Chair. 

 The following communications were read : 



I. " Notices of some Conclusions derived from the Photographic 

 Records of the Kew Declinometer, in the years 1858, 1859, 

 1860, and 1861." By Major-General EDWARD SABINE, 

 P.R.S. Received February 6, 1862. 



The discussion of the magnetic observations which have been 

 made in different parts of the globe may now be considered to have 

 established the three following important conclusions in regard to 

 the magnetic disturbances : viz., 1 . That these phenomena, whether 

 of the declination, inclination, or total force, are subject in their 

 mean effects to periodical laws, which determine their relative fre- 

 quency and amount at different hours of the day and night. 2. That 

 the disturbances which occasion westerly and those which occasion 

 easterly deflections of the compass-needle, those which increase 

 and those which decrease the inclination, and those which increase 

 and those which decrease the magnetic force have all distinct and 

 generally different periodical laws. 3. That there exists a periodical 



