154 
MALACOPTERYGII. 
blue, very dark silvery colour on lower half, upper half clouded with brown. 
This is different from the colour of any eye in the species of this genus 
that I have remarked, they are generally whitish silvery. It proved a 
female on inspection, and containing ova (?) of every size, from three lines 
in diameter downwards to very minute, and these were loose, apparently 
as if part had been shed. I never before saw this variation in the size of 
ova in any fish ; the very largest size in this were clear, and all the smaller 
opaque, of a dull stem-colour, and exhibiting blood-vessels in them. The 
stomach contained the remains of small Crustacea, an insect larva, &c. 
The Gillaroo Trout. 
The coats of the stomach of other species of Salmones than S. Fario (of 
which only the Gillaroo is set down as a variety) become muscular from 
the same cause. I have seen S. ferox, from different localities, with a 
muscular stomach, and these examples were called Gillaroo trout, by 
persons who distinguish them from the ordinary state of the fish, believing 
them to be a distinct species. 
1838. — Dr. Drummond sent me the contents of the stomach of a trout, 
about eight inches long, from Lough Neagh. They consisted oiLimneus 
pereyer of small size, and Valvata obtusa , but more of the former ; they 
also contained a few Cyclas cornea. I reckoned fifty of these shells, and 
divided the remainder into parcels of a similar number, and found that 
the whole amounted to a thousand. 
The stomach of another trout from Lough Neagh, examined by me, 
was half filled with Limneas pereger ; the other half of the contents com- 
prised flies and coleoptera, which it must have taken on or above the 
surface ; and of sub-aquatic insects of various kinds. The stomach also 
contained Gammari. 
The Gillaroo Trout. 
December 1st, 1849. W. It. Wilde, Esq. , tells me that in September last 
he caught a number of these in Lough Bofin, within four miles of Ough- 
terard, between that and Clifden. The first which was caught was pointed 
out to him as a Gillaroo by his boatman, who knew it from the markings, 
without feeling the stomach. He said he recognised it by the “ invisible 
marks ” above the ventral profile. These marks Mr. Wilde describes as 
resembling dirty finger-marks. The boatman examined a number of these 
trout, and found they were Gillaroos, with hard stomachs and shell-fish 
in them. All the fish were of a very small size. 
Gillaroo trout are found in the Shannon, in Lough Corrib, and Lough 
Mask. NewenhawHs View of Ireland, 1809. 
Nimmo has taken Gillaroos in the Galway lakes, with shells in them, 
from April to August. With a fly he has caught those with thick 
stomachs containing shells. 
Mr. It. M‘Garry informs me, that in Lough Neagh it sometimes 
attains 12 lbs. weight; he has never seen one under 1 lb; he says it is 
very partial to flies, with which he has seen the mouths of those taken 
filled ; he has never known it to be caught with any bait excepting the 
fly, though all the other species of trout are so taken. 
The fishermen distinguish them at every age by form, markings, and by 
the hardness of the stomach or gizzard as they term it. It is partial to a 
rocky bottom, takes a worm-bait, but may also be captured with artifi- 
cial fly. 
