6 University of California Publications in Zoology [ Vou. 14 
entire contents, weighing a ton or more, were lost. To remedy this 
difficulty the simple expedient was adopted of attaching a broad 
ce 
wooden ‘‘shoe’’ to each of the trawl runners. These ‘‘shoes’’ were 
of oak plank, eleven inches wide and about one inch thick, and were 
bent upward at the fore end after the manner of Norwegian snow- 
shoes or skis. This device was found to serve the purpose admirably. 
Surface organisms were scraped from bottoms of soft mud, often 
throughout a course of half a mile or more, while little or none of the 
mud remained in the bag. 
(3) The ordinary dredge, of the type said to have been originated 
by O. F. Miiller (referred to in our records under the familiar name 
of ‘‘boat dredge’’). This was commonly provided with an inner bag 
of fine fish netting, tied at the bottom, and an outer sheathing of 
canvas. The latter was commonly left open at the end to permit the 
passage of water, though it was sometimes tied up in order to retain 
the bottom material. Sometimes the dredge net was dispensed with, 
the canvas bag (‘‘mud bag’’) alone being used. In operations with 
the ‘‘ Albatross’? the dredge most commonly used had a width of 19 
inches (48 em.) and was generally fastened to the end of the trawl 
net. When dredging was conducted with the launch, a smaller pat- 
tern was employed, and it was used independently of any other form 
of apparatus. 
(4) A very heavily built iron dredge (plate 9), which, except for 
the strength of the materials used, followed the pattern of a com- 
mercial oyster dredge. The design for this was adapted from the 
figure given by the Massachusetts Commissioners of Fisheries and 
Game (1909). The length of the toothed bar was 3 feet 6 inches 
(1.07 meters), while the distance from this to the attachment of the 
cable was 4 feet 7 inches (1.4 meters). Most of the iron used had a 
section of 1 by 2 inches, while the teeth were three-quarter inch square. 
The bag was about 3 feet deep and consisted of steel rings 2 inches 
in diameter and of one-quarter inch materials. When in use this 
chain bag was commonly lined with a bag of fish netting, in order 
that the finer bottom materials and the smaller organisms might be 
retained. 
It is rather surprising how little thought seems to have been de- 
voted by those engaged in devising oceanic collecting apparatus to 
types of dredges suitable for use upon very rough bottoms. The one 
here figured has repeatedly brought up hundreds of pounds of stones, 
some of them a foot or more in diameter, from bottoms upon which 
a beam trawl would speedily have come to grief. The only accident 
