Branchioi in the young Caeciliae. 355 



being the only specimen, could not be dissected, measured 4|^ 

 inches in length ; whilst a full-grown specimen of the same 

 species, that exhibited no vestige of these apertures, was more 

 than a foot long. 



" It is therefore now ascertained, that the Caecilice, which 

 have so many anatomical resemblances with the naked Am- 

 phibians, really belong to them, and that they undergo meta- 

 morphosis. They likewise resemble in external structure the 

 Amphiumde, which, with a vermiform shape of the body, re- 

 tain their gill-apertures during life, without the branchiae re- 

 maining. The division of the Batrachians is too confined and 

 defective. All the scaled or shielded Amphibians (the Croco- 

 diles, Lizards, Serpents and Tortoises) have as common cha- 

 racters — one distinct penis or tvvo, a double cloaca, two ori- 

 fices in the organ of hearing, and a cochlea. These must 

 constitute one division. All the naked Amphibians, on the 

 contrary, have no penis, a single cloaca, only one orifice, and 

 no cochlea in the ear. All the Amphibia nuda possess either 

 early gills, later lungs, or both during the whole of life. The 

 orders of the Amphibia nuda are as follow : — 



"I. Gymnophidia seu Ccecillce. Without feet, branchial 

 apertures in the young state. 



"II. Derotremata, from heprj, neck, and rprffia, aperture. 

 Four rudimentary feet. Apertures in the neck through- 

 out life without branchiae. Here belong the Amphiuma 

 and Menopoma, 



"III. Proteidea. Gills and lungs through the whole of life. 

 Proteus, Axolotl, Menobranchus, Siren. 



" IV. Salamandrina. 



" V. Batrachia. 



" Messrs. Schlegel and Van der Hoeven will gladly testify 

 the accuracy of the before-mentioned assertion concerning the 

 branchial apertures of the young Ccecilia. This animal re- 

 mains preserved in the Museum at Ley den. The anatomy of 

 the Ccecilia lumbricalis, and many of the doubtful or anomalous 

 Serpents, I have described in a separate paper that appeared 

 in Meckel's ^ Archives.' I will communicate in a supplement 

 thereto, a drawing of the young Ccecilia hypocyanea with its 

 gill-apertures. I have there also endeavoured to place the 

 distribution of the anomalous and true Serpents upon anato- 

 mical grounds ; and the arrangement of the naked Amphibians, 

 except the second principal division of the Amphibia in the 

 five orders above given, is accurately made from full anato- 

 mical examinations. These orders of the Amphibia nuda are 



2 A 2 



