2676 NEWTS, SALAMANDERS, AND CCECILIANS 



when the subterranean waters are at their greatest height that the olms are cap- 

 tured by the peasants, by whom they are placed in glass jars, half filled with water 

 and sold to tourists. In confinement, where they have been known to survive from 

 six to eight years, they lie sluggishly all day at the bottom of their tank, only mov- 

 ing if a ray of light impels them to seek a darker corner. When in small vessels, 

 where the water is not often renewed, they will frequently come to the surface to 

 breathe, opening their mouths, and letting air pass through their gill openings; but 

 in deeper, or frequently changed water, they breathe entirely by means of their 

 gills. Many experiments have been made, with the view of ascertaining whether 

 the olm will, under any circumstances, lose its gills, but hitherto without result. In 

 captivity the food of these amphibians consists of mollusks, worms, and the 

 minute creatures to be found among the leaves of water plants. In spite of having 

 been kept for many years in captivity, it was not ascertained till 1875 that the olm 

 lays eggs; and it was thirteen years later before any tadpoles were hatched in cap- 

 tivity. In April 1888, upward of seventy-six eggs were laid by a single female; 

 and after a period of three months developed into tadpoles. These were very simi- 

 lar to the adult, but the tail fin extended three-quarters down the back; the eye 

 was larger, and apparently more susceptible to light; and the hind-limbs were in the 

 form of small knobs. 



A very different looking animal is the furrowed salamander (Nec- 



~ turns maculatus} of Eastern North America and Canada, which takes 

 amander 



its name from the strongly-marked fold of skin on the throat. In ad- 

 dition to its shorter and more lizard-like form, and relatively-longer limbs, it differs 

 from the olm by having well-developed eyes, and four toes to each foot. The 

 tongue is large, with the front border free; and the palatal teeth are large and form 

 a single series. In color the smooth skin is brown, with more or less well-defined 

 circular blackish spots, and lighter on the under parts than on the back. The total 

 length is about a foot. An allied species (N. pundatus) inhabits the rice fields of 

 the Southern States. The food is similar to that of the allied forms, and in winter 

 these salamanders seek protection from frost by burrowing deep in the mud. They 

 come at times to the surface to breathe, and will even venture on land; but they 

 chiefty respire by means of their gills, and if the latter become entangled, they are 

 carefully rearranged by means of the fore-foot. 



TWO-LEGGED SALAMANDERS 

 Family SlRENID^E 



The sole representatives of this, the last family of the Tailed Amphibians, are 

 the two-legged salamanders of North America, of which there are two species, ar- 

 ranged under as many genera (Siren and Pseudobranchus} . While agreeing with 

 the preceding family in the permanent retention of external gills, they are dis- 

 tinguished by the total loss of the hind-limbs, and likewise by the absence of 

 teeth in the margins of the jaws. The siren salamander (Siren lacertina), which 



