No. 405.] DEVELOPMENT AMONG ANURA. 707 
embryo was folded around a large yolk-mass in the same way 
as Hylodes martinicensis. The tail was entirely wanting in the 
more advanced specimens. No traces of gills were found, but 
on each side of the body were several transverse folds of skin 
that were thought to be respiratory organs. The legs were 
well developed ; the anterior were shorter than the posterior. 
The tip of the upper lip was furnished with a small conical 
protuberance, which in one case projected through the envelope 
of the egg, suggesting that its function is to perforate the 
egg-membrane. 
The South African frog Dactylethra capensis, like Pipa ameri- 
cana, the other representative of the Aglossa, lives entirely in 
water; the tadpoles of the two forms agree in having the 
fore limbs free from the operculum and in having two 
spiraculae. 
Leslie (90) writes of Dactylethra (called by him Xeno- 
pus): “Its habits are essentially aquatic, the animal never 
leaving the water except in search of places where food or 
shelter is better supplied. Unlike other frogs, it feeds in the 
water, on insects, small fishes, or even young and larve of its 
own kind, and is apparently unable to feed out of that ele- 
ment. The mode of eating is by forcing the prey into the 
mouth by means of the hands, which act as a pair of claspers; 
the deglutition always takes place under water. Locomotion 
on land is by difficult and awkward crawling and leaping. But 
Xenopus is a most admirable swimmer, and remarkable for the 
manner in which it remains poised for a long time immediately 
under the surface of the water, with the nostrils only exposed. 
The whole structure of the animal denotes its thoroughly 
aquatic habits — the broadly webbed toes, the smooth, slimy 
skin with its symmetrically disposed muciferous tubules ; there 
are no eyelids proper, but merely the transparent nictitating 
membrane, moving up and down ; and the nostrils have a disk- 
like internal valve. When at rest, Xenopus never assumes a 
sitting posture like other frogs and toads, and the back never 
appears humped." 
The €ggs (measuring about one-sixteenth inch in diameter) 
are laid singly and attached to water-plants or stones, each 
