232 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
stone. We found here, August 29, seemingly in consequence of this fact, an extra 
ordinary abundance of mollusks; large Limnceee in the grass at the margin, a small 
Planorbis , Pisidium , Sphcerium, etc. Gammarus occurred here under stones, and 
numbers of Allorchestes dentatus were taken in the weeds. 
The insects collected were species of Rydaticus and Rydroporus , Notonecta and 
Corisa , caseworms, and Chironomus larvae. A few water-spiders (hydrachnids) were 
taken among the weeds, and on the stones were great numbers of the cocoons of the 
large leech, Nephelis maculata. Young of this leech were numerous, and an occasional 
adult was seen, with specimens of Glepsine ornata and other species of the genus. 
The most abundant entomostraca were Daphnia schcedleri and Diaptomus sicilis, var., 
frequent specimens of 1). shoshone occurring with the latter. That this large species, 
previously found only in the larger lakes, should replace here in this shallow pond the 
Diaptomus lintoni elsewhere characteristic of shallow water, was another of the sur- 
prises of distribution and association of which these mountain lakes are fruitful. The 
other small Crustacea noted were Cyclops , Eurycercus , Alona , and several species of 
Cypris. The occurrence of Spongilla here is also worthy of mention. 
Gardiner Lakelet. — Similar to the foregoing in geological situation, but smaller, 
deeper, and surrounded by deep and broken hills, is a little pond formed in the course 
of a swift and rocky stream to the west of Gardiner River, between Mammoth Hot 
Spi'ings and the town of Gardiner. It is about 250 yards long by three-fourths as 
wide, and 20 feet deep in the interior, with its marginal waters filled with a strong 
growth of rushes and other vegetation. It was full of entomostraca, gammarids, and 
insects. On the stones were great numbers of the egg capsules of the common large 
leech, Nephelis maculata , and many young of this species were crawling about, but 
the time for the adults had apparently gone by. The assemblage of entomostraca 
was again peculiar, the most abundant form being a Ceriodaphnia, and the next 
commonest a medium-sized Diaptomus (mostly immature), described on page 253 as 
a new species under the name of />. piscince. There were also many specimens of 
Cyclops , an occasional Daphnia pulex , and several of Chydorus , in a collection obtained 
by drawing the surface net through the open water. Chironomus larvae were, of course, 
abundant; and worms of various kinds, small flat planariaus, larvae of Agrion and 
Dytiseidce , species of Haliplus , Corisa , and Notonecta , larvae oi Libellulce and epliemerids, 
species of Clepsine and of Physa , were represented in our collections. 
Small ponds. — Occasional roadside collections made from small standing pools 
will be of interest chiefly because of the locality and altitude. The ordinary contents 
of such waters at the time of our visit may be learned from the following lists: 
Weedy pool between Norris Basin and Grand 
Chironomus larv:c (a few). 
Corethra larva (one). 
Corisa larva; (three). 
Diaptomus lintoni (many). 
Cyclops (a few). 
Polyphemus pediculus (a few). 
Daphnia pulex (many, with ephippia). 
Canon, August 21, 1890: 
Daphnia schcedleri (a few). 
Scapholeberis mucronatus (very many). 
Ceriodaphnia reticulata (many). 
Chydorus sphuericus (very many). 
Macrothrix sp. (one). 
Acroperus leucocephalus (one). 
