236 THE ZOOLOGIST. 
as Mr. Cornish’s example and 13 ft. longer, the first investigation I made 
was naturally into the size of its teeth, and the longest in either jaw was 
0:09 of an inch, or merely {ths of the length of those in the smaller Penzance 
specimen. These teeth also were not in rows parallel to the edge of the 
jaw, but passing obliquely over that bone. An excellent figure of a single 
tooth will be found in Prof. Turner’s paper in the ‘ Journal of Anatomy and 
Physiology’ for April, 1880. It is evident that this species of Shark has 
no teeth anything like “half an inch long.” Its stomach was gorged with 
‘red stuff like bruised crabs or the roe of the sea-urchin,” as described by 
Low and others, and which on being placed under the microscope was 
seen to consist principally of Amphipoda and Copepoda, among which was a 
small piece of sea-weed, possibly swallowed inadvertently. Two quarts of 
food then practically consisted of small sessile-eyed Crustacea, and no 
vegetable substance. The Penzance fish was possibly a Porbeagle, Lamna 
cornubica, a fierce and destructive species, by no means rare off the coast of 
Cornwall. The Basking Shark may be killed for its intrinsic value as an 
oil-giver, or for the damage it does in disturbing fisheries, or for consuming 
the minute crustaceans on which some of our best table-fish subsist; but 
I submit that we have no evidence of its devouring any fishes, especially 
such as are suitable for the market, while its teeth conclusively demonstrate 
that they are not adapted for such a purpose.—F'rancis Day (Cheltenham). 
Food of Sea Fishes.—For a period of more than twenty years I have 
noted that the surface of the sea off the coast of Cornwall in spring assumes 
at certain times a deep olive colour, which in favourable seasons extends 
full twenty miles from land. Our fishermen call it ‘‘ cowshiny water,” no 
doubt on account of the similarity which it presents to the excrement of the 
cow when diluted. On looking carefully into the sea I found it full of 
olive-coloured jelly-like forms, which for some time I thought were small 
Meduse, but under the glass they were found to be globules of olive matter, 
varying in size from ordinary gunshot to that of small garden peas. They 
permeated the water for many yards in depth; their numbers were as 
incalculable as the sands on the shore. On further observation it was noted 
that all our surface-feeding fishes were exceedingly fond of them as food, 
and that the stomachs of Mackerel, Herring, and Pilchard were often 
quite distended with them. Moreover, the success of the inshore Mackerel- 
fishery on this coast, in the months of March and April, seems to depend 
much on the quantity of this food which may then exist. Further 
investigation showed that the existence of these globules in the sea depends 
entirely on the occurrence of showers during the months above mentioned. 
If there is no rain there will certainly be no olive-colouring in the sea and 
no olive globules. The earliest date at which I have noticed them was 
about March 10th, and the latest about May 20th. By those professionally 
interested in our fisheries the first change of sea from blue to olive is more 
