Descriptions of Exotic Coleopterous Insects. 251 
animation were 13 inches in length, and all on dissection proved 
to be females. Most of them were in full roe, (the ova from ^th 
to Jth of an inch in diameter,) but some had partly shed it ; one of 
the former was in total weight 9J oz. the roe alone weighing 2f oz. 
In the others, the proportion of roe was similar. On the llth of the 
same month, several male specimens of full size that I procured, 
and which contained milt most prominently developed, measured 
but 11^ inches. Thus showing, that in maturity the female fish ex- 
ceeds the male in length, in the proportion of 13 to 1 1 ^. Its average 
weight when in season is about 6 oz. One specimen, mentioned to me 
as the largest taken within the last ten years, weighed 2^ Ibs. The 
only food that I have, without resorting to the microscope, detect- 
ed in the stomach of the pollan was a full grown specimen of the 
bivalve shell Pisidium pulchellum. A pebble of equal size was also 
found along with it. In one which I had the pleasure of sending 
to Mr Yarrell, he met with a species of Gammarus. * (Yarr. Brit. 
Fishes, Vol. ii. p. 88.) 
The Buddagh, or great lake trout, is occasionally taken in night 
lines baited with the Pollan ; for which purpose the perch, divest- 
ed of its spinous dorsal fin, is also used. The lessef black -backed 
gull (Larusfuscus, Linn,) which frequents the lake in considerable 
numbers, is, in consequence of being believed to subsist on this 
fish, called there commonly by the name of Pollan Gull. 
As yet the Pollan is known to me only as inhabiting Lough Neagh. 
In Harris's " Down" (p. 238.) it is stated, " that Lough Earn, in the 
county of Fermanagh, has the same sort of fish, though not in so 
great plenty." This is probably correct, as Lough Erne is of very 
considerable extent, ranking amongst the lakes of Ireland as the 
second in size ; being inferior only to Lough Neagh. 
IV. Descriptions of some new species of Exotic Coleopterous Insects 
from the Collection of Sir Patrick Walker. By J. O. WESTWOOD, 
F.L.S., &c. Plate VII. 
Order COLEOPTERA. 
Section PENTAMERA, (GEODEPHAGA ADEPHAGA.) 
Fam. CICINDELIDJE. 
DISTIPSIDERA, genus novum. 
Corpus elongatum, abdomen capite cum oculis vix latius : caput 
* June 10, 1836. On opening the stomachs of six pollans, I found them 
all filled with food, consisting chiefly of mature individuals of Gammarus aqua- 
ticus, and the larvae of various acquatic insects ; some shells of the genus Pisidi- 
um, one of the fry of the three-spined stickleback (Gasterosteus,) and a few 
fragments of stone also occurred W. T. 
