1 825.] Mr. Gray on the Genera of Reptiles, 193 



of carbon, as Mr. Brande conjectures, or, what is perhaps more 

 likely, as a gaseous compound, containing a less proportion of 

 sulphur than exists in that liquid. 



- 'In whatever state of combination the sulphur may be, it does 

 not affect the salts of lead like sulphuretted hydrogen ; nor does 

 it act so readily, if at all, on polished silver and gold. Hence 

 the gas which contains only this impurity, will be less injurious, 

 when any of it escapes unburnt, than such as contains sulphur- 

 etted hydrogen ; but since it uniformly yields acid vapours 

 during its combustidn, '§flfe pisirt of thef objection remains in full 

 f^rce. -u-MiH'io nm t^^.-> . . : - ..-■ ^ ■ ' 



• 'These various objections, whatever wfeight they may have, 

 jigply to coal gas only. ^ y 



' -D'sq.gj 'iUi'k) ja jihjin'i ji^ij a j>;i^H# , „^ , nf>ffy i ^- aimu-j ni ' Jj;>U^. 

 j'5M| h huU j:>una?H'y'^loil* f l>i.%b' ''vlbTB^FA^ ip^»lto 4di \,W^igii 



A Si/nopsis of the Genera of Reptiles and Amphibia, imlh a 

 Description of spmeneiv Species f By. John Edward Gray, Esq. 



'-■FGS. &c, ^i ,.imiwimf 'eqi^r)^^ M V 



(To the Editors of the Annals of Fhilosophy.) jf^lp^' 



GENTLEMEN, ^ British Museum, July U, 1825. 



The reptiles have 'beeri comparatively neglected by recent 

 zoologists, perhaps on account of the popular prejudices against 

 this interesting and curious class of animals which Linneeus 

 designates " Animalia pessima tetra nuda." It is only necessary 

 to overcome these prejudices, and to examine them even 

 superficially, and we cannot but be struck with the beauty of 

 their colours, the wonderful nature of their structure, and the 

 pecuHarities of their habits and manners. Indeed I do not 

 know any class of animals better calculated to excite the wonder 

 and astonishment of a student of nature. 



With the hopes of inducing some inquiry into, and exd;- 

 mination of, this department of natural history, I have 

 attempted to bring together into the form of a synopsis, the 

 labour of the preceding writers on this class, and have also 

 thrown into it my own notes formed on an examination of the 

 specimens at present under arrangement in the British Museum, 

 which are exceedingly interesting to me in several points o^ 

 view, first, as containing several undescribed species, and sp6^ 

 ci'mens of interesting or obscure genera; and secondly, the 

 old^r specimens having been examined, and most carefully 

 named by my late uncle, who paid great attention to this 

 department of zoology, and several of whose manuscript species 

 still remain unpublished. ^ '•' ' . . : •: i ■ 



I need not dwell on the distinctness of the two classesof rep- 

 "iiem Series J vol, x. o 



