8 PRESIDENT S ADDRESS. 



whilst those of the Frog, especially the hinder pair, are immensely 

 increased in dimensions and take upon themselves the whole 

 locomotive functions. The skin of Amphibia plays a very 

 important part in the aeration of the blood. 



The Order Urodela is spoken of collectively as the Tailed 

 Amphibians because the tail in its larval-state is retained 

 in the adult stage. The Urodela is characterised by its naked 

 skin and no exo-skeleton. The bones of the fore-arm (ulna 

 and radius), and of the hind leg (tibia and fibula) are not 

 anchylosed. In one of the sections of this Order, Perenni- 

 branchiata, the larva-gills are retained through life in the form 

 of three plume-like appendages on each side of the neck. 

 Another section, Derotremata, comprises Amphiuma and 

 Menopoma, in which the larva-gills disappear, and the gill-slits 

 are retained by the adult. In a third section, represented by 

 the Salamandnda, having no branchiae or branchial clefts, 

 furnished with movable eye-lids, the perfect adult is destitute 

 both of gills and gill-slits. 



Among the Perennibranchiata the Sirens or Mud-Eels are 

 remarkable for the total absence of hind limbs and pelvic arches ; 

 fore-legs are weak. Siren lacerlina inhabits the swamps of 

 the Southern United States. Another remarkable form is 

 Proteus anguineus, which inhabits the subterranean waters of 

 Carniola and Carinthia ; it is furnished with both pairs of limbs, 

 the anterior have three toes, the posterior two only ; the eyes are 

 extremely weak. Some of the tailed Batrachia present a 

 simplification of organisation, many of them being retrograde. 

 The maxillo-jugal arch is incomplete ; none of them are 

 pentadactyle in both limbs ; ten species out of six genera are 

 without lungs ; respiration is buccal or pharyngeal. Among 

 these recently-discovered Reptilian troglodytes three are from 

 America. Spelerpes lives in the valley of the Mississippi, the eyes 

 of Typhlotriton during growth undergo an easily detected degener- 

 ation, Typhlomolge was discovered in 1896 in the underground 

 waters of Texas. It is quite blind, possessed of functionless 

 eyes. The animal is of special interest as furnishing the American 



