184 THE AMERICAN MUSEUM JOURNAL 
TOADS AND FROGS. 
Order Salientia. 
The Toads and Frogs are the most familiar forms of the 
batrachians. Eleven species occur in the local fauna, repre- 
senting four families. All of the local species deposit their eggs 
in the water and the young pass through a tadpole stage before 
acquiring the form of the adult. The duration of this larval 
stage varies considerably with the different species. In some 
it is limited to a few weeks, others require considerably more 
than a year to complete their metamorphosis. The growth in 
the water is much influenced by light and temperature. 
For a short time after hatching, the tadpoles of most species 
are provided on the under surface of the head with two suckers. 
These organs enable the fragile creatures to cling to the leaves of 
aquatic plants instead of lying upon the muddy bottom, where 
they would be exposed to the attacks of many enemies in the 
shape of the carnivorous larve of aquatic insects. At the time 
of hatching, the young creatures are leech-like in appearance. 
Development is rapid. Within three days they present the 
complete form of the tadpole, with fin-like tail. Within a few 
hours after hatching the mouth-parts begin to develop, and a 
few days later the little creature feeds upon delicate aquatic 
vegetation. They then swim readily in search of food, and the 
suckers become aborted and quickly disappear. 
For a few hours after leaving the egg, the frog tadpole possesses 
branching gills. These soon shrivel and their bases are covered 
with folds of skin (the “operculum’’). Under this fold the fore 
limbs soon begin their growth. This is the first pair of limbs to 
acquire full growth, but they are not visible until after the hind 
pair has appeared. From external appearances the frog tad- 
pole thus seems to acquire the posterior pair of limbs first. 
Somewhat later the front pair suddenly are thrust through the 
