1889-] Life- History of Chorophilus triscriatns. 773 
reason to think it does, we shall have then a sort of pharyngeal 
respiration such as Profs. Gage have observed in Aspidonectes 
and CryptobrancJius, and myself in three species of Amblystoma. 
This mode of respiration in the frogs named, if it really is such, 
differs from that in Amblystoma in that in the latter the water 
enters by the nasal passages and leaves by the mouth. 
It may be proper here to describe the labial dentary apparatus 
of Chorophilus as compared with that of Acris, as we find it in 
maturer tadpoles of both. In Acris there seem to be but four 
rows of denticles, two on the upper and two on the lower lip ; 
while, as already said, in Chorophilus there is a short third row 
on the lower lip. In the former species the teeth are not notched 
at their tips ; in the latter each tooth is notched at the tip so as 
to present about eight little points. The teeth are also more 
numerous in Chorophilus than in Acris. This may be most, 
briefly presented as follows : 
Chorophih 
. outer, or upper, row of upper lip . 
By the 26th of May the tadpoles had attained a length, in 
some cases, of 27 mm., 16 of which is tail. Many of them 
about this time succeeded in releasing their fore limbs from the 
skin which bound them down. There was so much difference 
in size among them that I was quite convinced that tadpoles of 
other species had invaded the pool ; but this proved not to be the 
case. The difference was principally in size and plumpness; but 
it was evident that as soon as the fore-legs were released, and 
even before, there was a reduction in the animal's bulk. 
These four-legged tadpoles were very lively and very timid, 
and darted about in great alarm when disturbed. They would 
also crawl out of the water on stones in the aquarium, and sit 
there in great contentment. They were also perfectly ready to 
leap out upon the table or the floor. It was easy to see even at 
