180 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
enriched by the introduction of non-indigenous species, some of which are now among 
the best food and game fishes of the region. The acclimatized species, numbering 
about 10, are mostly members of the bass family and are indicated in the list. About 
30 species are of economic importance, of which the principal are the shad, hickory 
shad, alewives, striped bass (better known locally as rock or rockfish), white perch, 
black basses, yellow perch, eel, sturgeon, suckers, carp, and catfishes. Some years ago 
the value of the fishes caught for market in that part of the Potomac under District 
jurisdiction was about $12,000, about half of which sum was credited to the shad. A 
recent act of Congress has prohibited all forms of net fishing in the District waters, 
which thus become an important nursery where such valuable species as the shad, 
the lierriTig, the striped bass, and the black basses may spawn unmolested. 
Four species recognized as distinct by recent authorities have been described 
from District waters; two of these are minnows (N'otropis), one is a silverside 
(Menidia), and one is a darter [Boleosoma). From the Potomac have also come the 
types of a number of other species which are now regarded as identical with previously 
described forms. 
An interesting feature of the fish fauna is the regular or occasional appearance 
in our waters of typical salt- water fishes. These are usually observed during dry 
weather, when there is an extension upstream of the zone of brackish water, which is 
normally about 40 miles below Washington; but a few, such as the silver gar, make 
deliberate visits to the fresh waters. The salt water fishes which have thus far been 
detected within our limits number about 12; others may be looked for in spring and 
summer between Alexandria and Mount Vernon. 
The following list includes all species of fishes known to occur in the vicinity of 
Washington, and is largely based on collections of the United States Fish Commission 
and United States National Museum. Those species of which specimens are preserved 
are indicated by an asterisk (*) after the scientific name. The common names of the 
fishes are given in all cases; those in local use are distinguished by quotation marks. 
This list is only preliminary, as the available specimens and information do not 
Avarrant a full discussion of the District fish fauna at this time. It is contemplated 
to issue a second list, Avith illustrations of all the species and detailed notes on their 
habits, distribution, and abundance, as soon as the material can be collected. To this 
end the cooperation of anglers, commercial fishermen, fish-dealers, and students is 
asked in furnishing specimens and notes, for which full credit will be given. 
PBTROMYZONIDiE. The Lampreys. 
1. Petromyzoii marinus Linnseus.* ^‘Lamprey”; “Lamper Eel”; ‘‘■Sucker”; Sea Lamprey. 
Not common. Comes from salt water in spring and runs np streams to spawn. Shail are 
sometimes taken witli lampreys 6 to 14 inches long hanging on their sides. Large ones, 11 to 3 feet 
long, ascend small streams Avitli the hranch herring. Fishermen make it a point to kill the lamprey 
Avhene\mr there is an opportunity, as it is of no economic value and is regarded as destructiAm to 
other fish. 
GALEIDiE. The Requiem Sharks. 
2. Carcharhinus obscurus (LeSueur).* Duelaj Shark. 
Occasionally observed in the Potomac between Fort Washington and Alexandria during dry 
weather when the water becomes brackish. An example 5 feet long, taken at Glymont in August, 
1894, was examined by us in Center Market, where a cast of the specimen is now oxhildted. Other 
sharks have also been taken in sturgeon nets at Glymont during dry weather, and many years ago one 
was captured at Fort AVashington. 
