14 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. 
ence. Aneel and some killifishes (Fundulus), neither of particular 
food value, were identified, and the fish eggs eaten probably also 
were those of killifishes. Another item of animal food worthy of 
mention is marine worms of the genus Nereis. These were found 
in 17 stomachs, no fewer than 25 in one. These worms prey to some 
extent upon oysters and other shellfish. 
Elements of the animal food of the black duck credibly reported 
by other observers * but not found during the present investigation 
are: angle-worms, the sand flea Gammarus ornatus, the isopod Idotea 
marina, and the snail Campeloma decisa. 
Foop OF THE YOUNG. ~ 
Having gizzards from representatives of three different broods of 
black ducks allows brief discussion of the food habits of the young. 
As is the case with a majority of birds, the percentage of animal food 
taken by the young is much higher than by the adults. For the three 
broods examined it ranges from 40 to 79.25 per cent. The constitu- 
ents of this part of the food are practically the same as those taken 
by adults with the exception of fish eggs. All of a 6-day-old brood 
of five black mallards taken on Wallops Island, Va., May 18, 1910, had 
eaten eggs of fishes, probably of the little lallifishes SO abundant in 
salt marshes. The ‘tood of a brood from James Bay, Canada, taken 
July 13, 1914, consisted on the average of 96 per cent caddis larve. 
The eceuslela food of the young showed no peculiarities, except that 
possibly more odds and ends, rare items in the dietary, were picked 
up than would be by an equal number of adults. Such were seeds of 
marsh mallow (Hibiscus), cleavers (Galium), Hypericum, lamb’s- 
quarters (Chenopodium), amaranth, Lippia modiflora, and rose. The 
Wallops Island brood mentioned sine dle on the average 47 per cent of 
its food of alge. 
SOUTHERN BLACK DUCK. 
(Anas fulvigula.) 
The southern black duck inhabits peninsular Florida and a narrow 
strip of marsh and swamp land bordering the Gulf of Mexico from 
Florida to Texas. Usually it is considered to consist of two subspe- 
cies, the Florida duck (Anas fulvigula fulvigula), and the mottled 
duck (A. f. maculosa), the latter living in Louisiana and Texas. 
However, these are treated together here as the southern black duck. 
This is a smaller and lighter-colored bird than its northern relative 
and may be recognized by the plain creamy buff throat and foreneck. 
In the northern black duck these parts are streaked with dusky. 
1 This does not include the generalization of Audubon. 
