54- Mr. Gray's Si/noj)sis of the Genera of Saurian Reptiles. 



observations of pendulum experiments, or of measurements of 

 arcs from the equator to tlie pole, by which the relative ex- 

 cesses and defects may exactly counteract each other, when 

 all those both placed in favourable or in unfavourable cir- 

 cumstances are grouped together ; and that in consequence of 

 which, the ellipticity derived from the measurements of de- 

 grees considerably distant from each other, is more likely to 

 be accurate than that obtained from the method of the least 

 squares from arcs under such circumstances. 



P.S. If £ = 0"00325, then from an application of formula 

 (2) to the degrees of France and India, the radius of the equa- 

 tor or t, the semitrans verse axis of the ellipse will be 20921178 



feet Also - being equal to 0-00.'}25, e = 0-00325 t. Taking 



the value of t in feet, then e = 67993*8 feet, or 12*878 miles. 

 Hence also the semiconjugate or polar semiaxis, designated 

 by c, = 20853184 feet. The radius of curvature at 45° be- 

 ing represented by t 1- will be 20887181 feet = 3955*905 



miles. Whence the mean diameter of the earth is 7911*81 

 miles, and the mean circuniference 24855*686 miles. 

 I am, &c. 

 Edinburgh, May 7, 1827. Wm. Galbraith. 



XI. A Synopsis of the Genera of Saurian Reptiles, in 'which 

 some new Genera are indicated^ and the others reviewed by 

 actual Examination. By J. E. Gray, Esq. F.G.S. S,-c.* 



I 



N the Annals of Philosophy, (N. S. vol. x. p. 193.) I col- 

 lected together the genera of Reptiles ; but since that time 

 several new ones having been established, and having lately 

 been enabled to examine most of them, as well as several others, 

 especially some from India, collected by General Hardwicke, 

 of the Bengal Artillery, whose fine collection of drawings il- 

 lustrative of the Natural History of India is well known, I am 

 enabled to add several new and very curious genera which 

 have not hitherto been published. 



A. Tongue long, end deeply two-cut. Teeth denticulated ; on 

 the inner side of the jaw. Saurae. 



Fam. I. UARANID^. 



Tongue retractile; head and body scaly, femoral pores none; 

 palate toothless. — Only found in the Old World. 



* Coniimuiicatcd hy the Author. 



L'AUANUS 



