1862.] DR. A. GTJNTHER ON THE BRITISH CHARRS. 53 



simple ; the fifth branched ; the last is split to the base, two-fifths 

 as long as the fourth. 



Caudal fin forked, one of the middle rays not being quite half as 

 long as the outer ones, the length of which is one-fifth of the total. 

 Lobes pointed. 



The base of the pectoral is entirely free, and not overlapped by the 

 gill-cover apparatus. It is as long as, or even longer than, the head, 

 and extends to, or slightly beyond, the vertical from the origin of 

 the dorsal, terminating at a short distance from the ventral. 



The ventral is inserted below the ninth, tenth, and eleventh dorsal 

 rays, its length being three-quarters of that of the pectoral ; it ter- 

 minates at no great distance from the vent. In smaller specimens than 

 the one described the two outer rays are somewhat less lengthened. 



The scales are very conspicuous, comparatively much larger than 

 in the other British species. Those between the dorsal fin and lateral 

 line are nearly square, with the hind margin rounded. Those of the 

 lateral line are not larger than the others ; and their number, there- 

 fore, nearly coincides with the number of the transverse series. The 

 scales on the back are the smallest, yet very distinct. 



Sides and belly silvery ; the scales on the side of the back have a 

 silvery centre and a blackish margin ; the back iiself bluish black ; 

 belly with a reddish shade; sides with scattered light orange-coloured 

 dots ; fins blackish ; the dorsal lighter superiorly, and Avith a few 

 light dots at the base; ventral with a narrow whitish margin. Head 

 silvery, black above. 



This account of the " Freshwater Herring" is very incomplete, and 

 can be considered only as the first step towards a satisfactory know- 

 ledge of this species. We are not yet acquainted with the immature 

 state, or with variations which may occur, and with the female fish 

 only by a short notice of Mr. W. Thompson. I have before me two 

 other male specimens of nearly the same size as the one described, 

 but without any indication of the locality, and preserved in spirits for 

 a long time ; and six other specimens given to Prof. W. Thomson, of 

 Belfast, as being perhaps from Lough Melvin, and kindly lent to me 

 for examination. Those eight specimens agree with the Freshwater 

 Herring in the small size of their teeth, by which character these 

 Irish fishes may be at once distinguished from the other allied Eu- 

 ropean species — in the shortness of their head, in the length of their 

 pectoral, and in the shape of the fins ; but they differ from the 

 typical specimens in several not unimportant points, which I shall 

 point out when a further supply of specimens shall enable me to form 

 a definite opinion about the value of those differences. I may, how- 

 ever, mention that the females of one of those Irish fishes have fully 

 developed eggs of the size of a pea, when only 5 inches long ! With- 

 out full material, and with the uncertainty as to locality, it would be 

 as dangerous to establish new species on differences which may, after 

 all, turn out to be dependent on age, as unwise to refer them to the 

 "Freshwater Herring" of Lough Melvin, thereby destroying a defi-^ 

 nition of its specific characters. 



The typical specimens were taken in the beginning of November, 



