URODELA. 307 



rnatozoa which have been introduced in the previous July and stored 

 until the young of the previous year are born ; S. atra Laur. alpine 

 salamander, black, viviparous, produces only two young at a birth,* 

 which are born fully developed, the uterine yoiing have external 

 gills which absorb nutriment and oxygen, they nourish themselves 

 on other embryos which break down, they are able to live in water 

 if removed before development is completed f ; S. caucasica Waja, 

 Chioglossa Bocage, Spain, Portugal. Triton Laur. (Molge Merrem), 

 aquatic salamanders, newts, with laterally compressed tail, Eur., 

 Asia, N. Amer., pair in water, in the pairing the males of some species 

 develop a crest, oviparous, eggs glued singly to stones or water plants, 

 may attain sexual maturity if prevented from metamorphosing 

 (v. Siebold, Z. /. w. Z. 28, 1877) ; T. cristatus Laur., the crested newt, 

 Gt. Britain, Eur., said to be in rare cases viviparous (Balfour, Comp. 

 Embryology, vol. 2), T. vulgaris L. (taeniatus], Gt. Britain, Eur. 

 Salamandrina Fit z. with 4 toes, Italy; Tylototriton Anders., Yunnan, 

 Himalayas ; Pachytriton Blgr. China. 



Fam. 3. Proteidae. Three pairs of external gills and two gill-open- 

 ings (hyobranchial and last branchial closed) persist throughout life ; 

 maxillaries absent ; premaxillaries, vomer, and mandible toothed, amphi- 

 coelous vertebrae, no eyelids, fore and hind limbs present. Necturus 



FIG. 174. Necturus maculatus (Regne animal) from Claus. 



Raf. (Menobranchus] 4 fingers, 4 toes, eyes exposed, N. Amer. ; N. 

 tnaculatus (M. lateralis) (Fig. 174), 1 foot, spawn Apr. and May; Proteus 

 Laur., the olm, 3 fingers, 2 toes, eyes hidden, Carniola subterranean 

 waters, white turning black if exposed to light, spawn Apr., eggs fastened 

 singly to stones ; Typhlomolge, waters of an artesian well in Texas. 



Fam. 4. Sirenidae. External gills (3 pairs) and gill openings (3 

 pairs, hyobranchial being closed) through life, maxillaries absent, pre- 

 maxillaries and mandibles toothless but with horny beaks, amphicoelous 

 vertebrae, no eyelids, hind limbs absent, fore limbs 3 or 4 toes, S.E. Un. 

 States, young larvae unknown, in the youngest known the gills are small 

 and covered by the skin and the respiration is said to be aerial (Cope, 

 Amer. Nat. 19, 1885, p. 1226), later the gills increase in size. Siren L. 

 3 gill clefts on each side, 4 fingers, S. lacertina Gray, mud-eel, Pseudo- 

 branchus Gray, 1 gill cleft on each side, 3 fingers. 



Order 3. ANURA.J BATRACHIA. 



Scaleless Amphibia without tail, external gills or gill-slits in the 

 adult state ; with four limbs. 



* Schwalbe, Zeitsch. Biol., (2), 16, 1897, p. 340. 



t v. Chauvin Z. /. w. Z, 27, 1876. 



J Roesel v. Rosenhof " Historic, naturalis ranarum nostratium" Niirn- 



