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 fth of an inch in diameter,) but some had partly shed it ; one of 

 the former was in total weight 9^ oz. the roe alone weighing 2£ oz. 

 In the others, the proportion of roe was similar. On the 11th 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 i. 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| lbs. 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 lesser 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. ClCINDELIDiE. 



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. 



