BATRACIIIA. 285 



pedicles of their lower JHW,wliich is extremely dilatable ; all their body-scales are equal, of small size, and disposed 

 liexa;;-onally. To these subf^eriera I have added that of 

 Cieni/drus,— the head and body of which are equally covered with small scales. 



THE THIRD FAMILY OF OPHIDIAN'S,— 

 The Naked Serpents, — 

 Comprises but one very singular genus, \Yliich several naturalists have deemed to belong rather to the 

 r.atrachians, although we are not aware that it undergoes any metamorphosis. It is tliat of 



The CceciLiANS {Ccecilia, Lin.), — 

 So named on account of their excessively minute eyes, which arc nearly hidden by the skin, and are 

 sometimes absent altogether. The skin is smooth, viscous, and annularly wrinkled, appearing naked, 

 although, upon dissection, some perfect though minute scales are discernible, wdiich are regularly 

 disposed in several transverse ranges between the wrinkles of the skin, and which we have detected, 

 with certainty, in more than two species. The head is flattened, the anus round and nearly at the 

 extremity of the body, the ribs much too short to encircle the tiunk, the articulations of the vcrtebrffi 

 together are by eonically hollow facets filled up with gelatinous cartilage, the same as in the Fishes 

 and some of the lower Batrachians, and, in a slight degree, in the Auiphisba;ncs only, among the other 

 Ophidians ; their maxillary bones cover the orbits, which are pierced by only a very small foramen, and 

 the temporal bones extend over the fossa, so that the skull presents a continuous bony buckler above ; 

 their hyoid bone, composed of three pairs of arcs, induces the supposition that it originally supported 

 gills. The maxillary and palate teeth are arranged in two concentric lines, the same as in the 

 Proteans, but are often sharp and curved backward, as in the Snakes properly so called ; the nostrils 

 open behind the palate, and the lower jaw has no moveable pedicle, the tympanic bone being encased, 

 together with the other bones, in the buckler formed by the skull. 



The auricle of the heart of these animals is not divided so deeply as to be considered double, but 

 their second Inng is as small as in Ihe other Serpents ; the liver is divided into a great number of 

 transverse laminae. In their intestines have been found vegetable matter, together with soil and sand. 

 Their ear has merely a small plate ujion the oral orifice, the same as in the Salamanders. 



Some of them have an obtuse muzzle, lax skin, very deep wrinkles, and two small ciliae near the nostrils; as 

 C. aninilata of Brazil, which is found in marshy places several feet under g'round, C gluCmosa of Ceylon, &c. ; 

 while others have the folds of the skin nearly obsolete, a very long slender body, and projectinj^ nuizzle. One of 

 these is totally blind, the C luinbiiioides, Daudin ; it is of a blackish colour, two feet lon^', and no thicker than a 

 goose-quill. 



THE FOURTH ORDER OF REPTILES,— 



THE BATRACIIL'VNS,— 



Have but one auricle and one ventricle to tlie heart, [an assertion disproved by Professor Owen]. 

 Their two lungs are always eciiial, and wdicii young tliey conjoin to these, pills, wdiich give tlieni 

 a relationship with the class of Fishes, and which are borne on the sides of the neck, upon the 

 ctirtilagiiions arches which sn]iport the hyoid bone. The greater number lose these gills, 

 together with the supporting a])iiaratus of them, u])on tittaining the perfect state : three genera 

 only, the Syrens, Protei, and Menobrauehi, retaining them at all ages. 



During the period of the retention of the gills, the aorta, on proceeding from the heart, 

 divides into a number of branches njion each side, correspoiuling to that of the sills ; the 

 blood from the gills returning through veins which unite together towards the back, into a 

 single arterial trunk, as in Fishes ; this trunk, or the veins which form it more directly, supplies 

 the greater number of arteries which nourish the body, and even the vessels which conduct the 

 Ijiooil for respiration into the lungs. Rut in the species which shed their gills, the vascular 

 ramifications that communicate with them become obliterated, excepting two, wliieh unite 

 together to form a dorsal artery, each giving off a small branch to the lung of its jjarticidar 

 side, so that the circulation of a Fish becomes thus converted into that of a Reptile. 



