36<t Prof. J. van der Hoeven on the Genus Menobranchus 



also a genus left by Cuvicr among tbe Ophidians, but the 

 Batrachiau affinities of which had not escaped that illustrious 

 naturalist, and had been remarked already at the commencement 

 of our century by his friend and collaborateur Prof. C. Dumeril. 

 This genus, that of the CcEcilia, was placed by Oppel* and 

 Merrem in the subclass which wc are dealing with at present. 

 The important discovery of two branchial apertures, one on each 

 side, in a small specimen of Cacilia hypocyanea, made by Miiller 

 in 1831, effectually confirmed this view of their affinities, and 

 now consigns the genus to the vicinity of Amphiuma and Siren, 

 whose movements are effected by dragging the body along the 

 bottom of the waters which they inhabit, and whose very small 

 feet could not be of any assistance for walking. 



The Batrachians furnished with extremities have been divided 

 by Dumeril into Anoura and Urodela. The first, of which the 

 frogs and toads of our fauna may serve as examples, will not 

 detain us at present. Suffice it to observe that the external form 

 of these Anoura (Batrachians properly so called) departs entirely 

 from that of the Urodela (that, for example, of the aquatic 

 Salamanders), and that this difference shows us the slight value 

 due to external form in regard to primary groups in the natural 

 classification of the animal kingdom. We are now far from the 

 time when Linnseus united the salamanders with the crocodiles 

 in his undigested genus Lacerta-, but it is possible that the 

 vulgar eye and judgment unassisted by science will find this 

 union less strange than that of our. actual systems. The frog, 

 with its enormous head, its stunted trunk, and long claws, pre- 

 sents no resemblance whatever to the salamander, and less still 

 to the Froteus, while these latter genera would seem to be inti- 

 mately allied to the lizards, and, above all, to the scincoids. 



The scalpel forces us, however, to alter our judgment; and the 

 transitional forms of the frogs during their development prove 

 indisputably that such appearances are deceptive, and that we 

 may not give credence to them without strict examination. 



Amongst the Urodela it is well to make a principal division. 

 There are two groups or families of these Batrachians. One 

 comprehends the genus Salamandra, i. e. the terrestrial sala- 

 manders and the numerous subgenera of the aquatic salamanders 

 or tritons. The other might borrow its name from the genus 

 Proteus : such is the family of the Proteidse or Ichthyoidse. 

 At the commencement of our century Cuvier published a me- 

 moir on some reptiles of this division, which is inserted in the 



* Die Ordnungen, Familjen und Gattungen der Reptilien, von M. Oppel, 

 (Miinchen, 1811, 4to) p. 7G- These naked serpents are indicated by the 

 authors above named under the title of Batrachia apoda. 



