242 REPTILES AND BATRACHIANS 



In all three genera the eyelids and tympanum are absent ; 

 the toes are very broadly webbed and pointed. The 

 processes of the sacral vertebrae are much dilated. 



They are perfectly aquatic animals, never leaving the 

 water, even for feeding purposes. 



The African Clawed Frog, Xenopus Icevis, of South 

 Africa, so called owing to the tips of its three inner toes 

 being capped in horny, claw-like sheaths, has the perfectly 

 smooth skin studded with tube-like sensory canals, as in 

 larval frogs and toads. The upper jaw is toothed. The 

 toes are remarkably broadly webbed, and when fully 

 expanded resemble half-opened umbrellas. The head is 

 small and the nostrils and lidless eyes are, as in most strictly 

 aquatic animals, situated on the top of the head ; a very 

 short, fleshy tentacle is situated below the eye. The 

 coloration is dark brown or olive above, whitish beneath, 

 immaculate or with brown spots. Females may be dis- 

 tinguished in having three fleshy flaps closing the vent. 



When at rest Xenopus nearly always assumes an upright 

 position, and scarcely ever a sitting posture. It feeds on 

 insects, fishes, and even the young and larvae of its own 

 kind. Pairing takes place in South Africa in August, 

 when about lOO eggs are laid singly, and attached to aquatic 

 plants. The tadpoles, which have no beak or horny teeth, H 

 are remarkable in possessing long tentacles, situated on each 

 side of the head, at the angles of the jaws just above the 

 mouth ; these appear about a week after hatching, and, 

 when fully developed, attain a length equalling that of the 

 head and body. 



According to Bles, who has published a long and detailed 

 account of the life history of this frog in the Transactions 

 of the Royal Society of Edinburgh^ it may be fairly easily 



