III.—DESCRIPTION OF SOME OF THE APPARATUS USED BY THE 
UNITED STATES COMMISSION OF FISH AND FISHERIES IN 
DREDGING OFF THE NEW ENGLAND COAST. 
By A. E. VERRILL. 
[Prepared by request of Professor S. F. Baird, Commissioner of Fish and Fisheries. ] 
Since the organization of the United States Fish Commission, in 1871, 
dredging has been carried on extensively by it every summer, except 
that of 1876, in connection with the investigation of.the marine fisheries. 
In addition to the ordinary form of the naturalists’s dredge, which has, 
with minor modifications, been in constant use, several other forms of 
apparatus, some of them novel, have been used. The ‘“ beam-trawl” 
and “ otter-trawl” have proved very efficient in this work, wherever the 
character of the bottom would admit of their use. By their use fishes 
in large numbers are always secured, and also very large quantities of 
crustacea, echinoderms, sponges, &c. For use on rough and stony bot- 
toms, an improved form of ‘ tangles,” to be used without the dredge, was 
devised by the writer as early as 1571, and has done good service. In 
order to secure those creatures which burrow so deeply beneath the mud 
or sand as to be beyond the reach of the common dredge, which usually 
merely scrapes over the surface of the mud, or penetrates it but slightly, 
a “rake dredge” was constructed in 1871. This has proved very use- 
ful indeed for securing certain bivalve-shells, rare holothurians, and 
many annelids, &e., that might not have been obtained by the ordinary 
dredges. Owing to the enormous quantity of material brought up, es- 
pecially by the trawls and rake-dredges, it became necessary to devise 
new forms of sieves, by means of which large quantities of mud or sand 
could be washed out rapidly, and the specimens properly cared for at 
once, without incumbering the deck. This necessity led to the inven- 
tion of the “cradle sieve” in 1872, and subsequently, in 1878, of the large 
“table-sieve.” The latter has proved to be one of the greatest improve- 
ments yet devised, giving great satisfaction to the officers and crew of 
the steamer, as well as to the naturalists, for it keeps a large proportion 
of the mud off the deck, and wonderfully facilitates the work of assort- 
ing and preserving a large haul of specimens. 
Some other pieces of apparatus will also be mentioned below. 
. THE DREDGE. 
a Figure 1. 
The common dredges used by the Fish Commission are mostly of two 
sizes. The larger size is the one ordinarily used on the steamer; the 
[1] S. Mis. 29 5 65 
