OF THE COLD-BLOODED VEETEBllATA. 225 



do uot hesitate to associate them with the true E-eptiles. It is 

 still disputed whether the Perennibranchians should be separated 

 from tlie other tailed forms, to constitute an additional order*. 

 On the whole it seems best to follow Agassiz, Dumeril and 

 Bibronf, Stannius, and Van der Hoeven|, in regarding Anura, 

 Sosuraov SaurobatracMa^, and Ophiomorpha or CcecilicE'^ as three 

 well-marked orders of recent Amphihia. Lastly, a sixth order 

 may be reserved for Lepidosiren. 



For Pishes, no doubt can exist as to the propriety of adopting 

 the classification of J. Miiller, his subclass Dipnoi being of course 

 excluded, if Lepidosiren be placed with the Ampliibia. The recent 

 recommendation of Professor Agassiz, to divide Fishes into four 

 separate classes, advocates changes of too radical a nature to be 

 hastily adopted. 



Class EEPTILIA. 

 One occipital condyle. No gills. An amnion and allantois. Two 

 auricles. Proximal ends of liyoidean and mandibular arches 

 distinct from one another . 



("With post-orb itals and supra-temporals, Limbs natatory, 

 with more than five digits Ord. Ichthyopteiiygii. 

 No post-orbitals, and supra-tcmporals 2. 



' Limbs absent or very imperfect. Vertebrae veiy numerous, 

 procoelian, with a single transverse process on each side. 



No sacrimi. Eyelid immobile Ord. Ophidia^. 



Limbs present 3. 



2^ 



* This has been done by MUne-Edwards, Van Bcneden and Gervais, and 

 Prmce Bonaparte. Mihie-Edwards recognizes four orders oi Amphibia, namely, 

 Amt/ra, Urodela, PerennihrancJuata, and Ccecilia ; with which the Batrachla, 

 Salamandria, Pseudo-salamandrla, and Ccecilia of Van Beneden and Grervais 

 are, respectively, equivalent. Pi-mce Bonaparte, however, has placed the two 

 first of these divisions in a single ordinal group, Ranee. 



t Erpetologie generale, ou Histoire naturolle complete des EeptUes. Paris, 

 1834-1855. 



X See the English translation of his Ilandbook of Zoology, by tlie Rev. Prof. 

 Clark. London, 1858. 



§ Caudata of Vogt ; Urodela of Dumeril and Bibron, also of Stannius, who 

 divides this group into tlu-ee suborders — Ferennibranchiata, Derotremaia 

 (Amphiuma, Menoponia), and Myciodera (Triton, Salamandra). The Urodela 

 of Milne-Edwards uiclude only the second and thhd of these divisions. 



II Peromela, Dumeril and Bibron ; Batrachophidii, Bonaparte ; G-ymuo- 

 phiona, Miiller and Stannius ; Apoda, Vogt, 



1[ Serpents which pi'esent traces of limbs and sternum may be distinguished 

 from Sauriaus by theii* immobile eyelid and want of tympanic cavity. Thus 



