12 BULLETIN 1196, U. S. DEPARTMENT OF AGRICULTURE. 
This was noticeable in particular in specimens secured on the Pacific 
coast and in those from Okanogan Lake, British Columbia. Among 
these, fresh-water sculpins (Cottus) occurred six times. A peculiar 
marine sculpin (Chitonotus pugetensis) was eaten once, while another 
member of this family, eaten by one grebe, could not be defi- 
nitely identified. Fragments of vertebrae or scales of bony fishes that 
could not be named were found in 30 stomachs, and eggs of fishes 
were identified in 3. One bird had eaten a fish belonging to the 
group of perches. This and the eel and carp mentioned above 
formed the only fishes of any particular commercial value encoun- 
tered in studying the food of the horned grebe. On the whole, val- 
uable fishes form a small, almost insignificant item in the food. 
Crustaceans, found in 29 stomachs, are another important source 
from which the horned grebe draws a supply of food. Crawrfishes, 
encountered in 8 instances, amount to 10.4 per cent of the. total. In 
2 cases these belonged to the eastern group of crawfishes (Cam- 
barus), which in many places are injurious to various crops. Craw- 
fishes were taken during the months from January to May, inclusive, 
and in September and October. They are doubtless eaten rather 
extensively during the summer months also, but the material -avail- 
able is too scanty to show this. 
Other crustaceans, eaten by 21 birds, form 7.5 per cent of the total 
food. The common shrimp, or prawn (Palaemonetes vulgaris), a 
species valuable chiefly as food for various predatory animals, was 
identified 5 times. The Brazilian prawn (Penaeus brasiliensis), 
a species which in contradiction of its name ranges on our eastern 
coast north to Cape Cod, was found once, and the sand shrimp 
(Crago septemspinosus) once. <A bird from the Pacific coast had 
eaten another form of shrimp, Crago franciscorum, a species common 
from San Francisco Bay northward, and still another had taken a 
shrimp of the same genus, but not specifically identified. Shrimps 
of the last forms are captured in nets and sold in the markets for 
human consumption. 
Following these, isopods, small flattened crustaceans that could 
not be determined, were found twice, and a sowbug (Mancasellus) 
belonging to the same group, once. <A curious form (JMichtheimysis 
stenolepis) belonging to the opossum shrimps was eaten once. 
Though found at times on the surface of the water, these shrimps 
are more abundant below and may have been secured by diving. 
The great group known as the amphipods form a valuable source 
of food for the horned grebe, as they do also for fishes and other 
predatory aquatic animals. One species taken (Chironestmus multi- 
articulatus) belongs to a family whose forms are abundantly repre- 
sented in Arctic waters, where they play the part of scavenger. 
Any dead animal floating i in the water is rapidly eaten up by swarms 
of these crustaceans. 
Other families—Mefopidae, Pontogeniidae, and Calliopiidae— 
usually found floating on the surface of the ocean, were also repre- 
sented in these grebe stomachs. Sand-fleas (Gammarus) and 
another related species (family Gammaridae) were each taken once. 
Amphipod remains that were not identified occurred once, and mis- 
cellaneous fragments of indeterminate crustaceans six times. Crus- 
taceans other than crawfishes were eaten most commonly in winter, 
