540 REPORT—1883. 
4. On two new Dredging Machines. 
By Professor Mitnes Marsuatt, M.D., D.Sc. 
The machines in question, named respectively dredging harrow and dredging 
plough, are examples of apparatus devised for the capture of special organisms and 
not for general purposes. 
The harrow was designed for capturing Funiculina, a giant Pennatulid attain- 
ing a length of five feet or more. ‘The machine consists of a horizontal bar, four 
feet long, supported at a height of fifteen inches above the ground by runners ; to 
the bar are attached a number of cords, weighted at their distal ends and bearing a 
number of triple fish-hooks without barbs. ‘To obviate the danger of the machine 
falling on the bottom wrong way up, the runners are made in the form of wheels, 
so that it is immaterial which way up the machine reaches the bottom. The 
instrument was tried at Oban, and proved very successful. 
The plough was intended to dig up Virgularia, which owing to its brittleness 
and length of stalk is usually cut off level with the sea-bottom by the ordinary 
dredge. It consists of four digging blades attached to a horizontal bar, which, like 
that of the plough, is furnished with a wheel runner at each end. The machine, 
like the plough, is made reversible, so that it is immaterial which side reaches 
the ground first, and special provisions are made to prevent risk of damage from 
contact with rocks on the sea-bottom. 
The plough, which was designed for and used by the Birmingham Natural His- 
tory Society, worked well, though no opportunity has yet occurred of testing it for 
the capture of Virgularia. It was followed by a large bag to collect the specimens 
dug up. 
5. On the Influence of Wave-Currents on the Marine Fauna of shallow seas. 
By A. R. Hunt, ILA., F.G.8,. 
After showing that the action of alternate wave-currents on the sea-bottom 
down to a depth of some fifty fathoms could not be safely disregarded by natu- 
ralists, owing to the great length of storm-waves, which occasionally attain to and 
exceed the length of one hundred fathoms (600 feet), the author proceeded to dis- 
cuss the action of wave-currents on the marine fauna of shallow seas, under the 
following heads, viz. :— 
(1) The influence of wave-currents on animals living on rocks between tide- 
marks. 
(2) The influence of wave-currents on animals living in sand between tide- 
marks, 
(3) The influence of wave-currents on animals living in, or on, sand or mud, 
below low-water mark. 
Asa general rule, those animals belonging to the first class referred to above 
evade the attacks of waves by their powers of adherence to rocks, or by taking 
refuge in crevices; those of the second class do so by rapidly penetrating the shift- 
ing sand in which they live; those of the third class depend for safety on their 
powers of burrowing and mooring themselves in the sand or mud (being assisted 
therein by many apecial adaptations of form and structure), on their powers of 
attaching themselves to fixed objects, and on their powers of overcoming the 
wave-currents on the surface of the bottom by virtue of peculiar forms whereby a 
slighter wave-current suffices to restore them to their normal positions than suffices 
to overset them. 
6. On Green Oysters. By Professor E. Ray Lanxester, F.2.S. 
7. The Egg-capsules of the Dog-whelk and their contents. 
By Dr. Carpenter, O.B., F.R.S. 
