262 THE ZOOLOGIST. 
by the fungus at once takes us a step nearer the origin of the mysterious 
disease. The presence of bacteria at once accounts for the luxuriant growth 
of the Saprolegnia, which has had such a fatal effect on the Salmon. The 
spores of this fungus are always present, ready to germinate into active life 
when a proper nidus—such as the skin of a sickly or wounded fish—comes 
into contact with them. It remains to be ascertained what impairs the 
constitution of Salmon and other fish so as to permit of animaleul@ living 
in their flesh. He thought it, in some measure, due to the absence of 
Otters. The Otter is the natural enemy of the Salmon in fresh water ; 
but they have been hunted, trapped, and shot till not one remains where 
formerly there were dozens. The Otter, like the Peregrine, he thought, _ 
takes the prey most easily captured, thus removing the weakly, the sick, 
and all those which, from whatever cause, would cause a degeneration of 
the breed. If there had been Otters in the district in the numbers in 
which they once were, he thought those wretched-looking Salmon to be 
seen along the sides of the Nith would all have been dragged out and eaten 
by them. He felt confident that if the Otters, just for a change, were 
protected for a year or two, the disease would be checked. 
Tue Eacie Ray orr Prymoura.—A very perfect, but rather small, 
specimen of that rare fish, the Eagle Ray, Myliobatis aquila, caught off 
Plymouth, was purchased on May Ist by Mr. Brooking Rowe, and is now 
in process of preservation. Its measurements, as nearly as could be ascer- 
tained, were as follows: —'The whole length of body, not including the long 
cord-like tail, about 9 inches; breadth across the pectoral fins, 18 inches ; 
length of tail, 20 inches, furnished with a dart or spine having reversed 
serrated teeth at the sides, and placed within a few inches of its base. The 
back is raised and sloping towards the snout, and also towards the tail, which 
is very long and slender, ending in a point, about twice the length of the 
body. Colour above of a dark purplish brown, shading to dark slate on the 
back ; under parts nearly pure white. Head, eyes and mouth very toad-like 
in appearance ; hence it is sometimes called ‘“ Toad-fish."—Joun GarcomBE 
(55, Durnford Street, Stonehouse, Plymouth). 
UnusuaL ASSEMBLAGE or THE Maskep Crasp.—On May Ist my 
trammel, of forty fathoms in length, was shot east and west on a rocky 
bottom in about three fathoms water at two hundred fathoms south of our 
pier-head, and throughout it—not in any particular place, but scattered— 
I took twenty-eight male and seventeen female (altogether forty-five) speci- 
mens of the Masked Crab, Corystes cassivelaunus. This crab is not an 
uncommon oue, but I have never before taken it except in single specimens, 
and never, that I can recollect, on a rocky bottom. It is essentially a sand 
crab,— THomAs CornisH (Penzance). 
ue a 
