THE POLLAN. 
171 
herrings, were go! in Lough Derg [a mere expansion of the river Shannon] very 
near this, about four years ago in the eel-nets, but none since, at least in this 
quarter.” So far only is the history of the species known to me : that the 
ichite fish were this Coregonus I think hardly admits of doubt. 
On examining the specimen, the nearest approximation I find to it is the 
Salmo clupeoides of Pallas,* * * § and Cor. clupeoides of Nilsson, f who with a query 
marked Pallas’s as synonymous with his species. 
Although there is a tolerable general agreement, yet a want of accordance in 
some characters between my specimen and the description in the Zoographia 
renders it doubtful whether they be the same fish. Between it and Nilsson’s C. 
clupeoides I perceive no specific (though a considerable individual) difference, 
and consider them identical, if the phrase “ tereti-compresso,” applied to the 
body in his specific characters, be taken singly, and be translated, roundly com- 
pressed ; but if “ tenue,” J applied again to the body in the detailed descrip- 
tion, mean that it is thin or compressed, the species cannot be the same, the in- 
dividual under consideration being very thick for one of the Coregoni. 
Nilsson is altogether silent on the history of this species, stating merely that 
it was sent him with other fishes from Lake Wettern. As this lake communi- 
cates with the Baltic, it is to be regretted that we are not informed whether the 
Coregonus be stationary in it, or migrate to the sea, as the Shannon species is be- 
lieved to do. 
Desc. — General form, gracefully elongated, sloping equally from the centre 
of back to the head and tail, the anterior and posterior portions of the ventral 
profile also corresponding to each other, but rather more convex than the dorsal ; 
rounded in the back (like Atherina presbyter) ; considerable thickness main- 
tained throughout.§ Length 4^ inches ; depth where greatest, at origin of 
dorsal fin, 9 lines, or compared with the entire length as 1 to 5| ; thickness 
more than half the depth, just behind the head 5 lines, the same at the middle, 
and \ of an inch before the base of the caudal fin 2 lines ; lateral line for ~ of 
an inch from its origin sloping downwards, thence to its termination straight, 
and except at the tail, where it is equidistant from each, placed rather nearer 
the dorsal than the ventral profile ; head 1 1 lines long, or about as 1 to in 
the entire length ; eye large, placed at the distance of its own diameter from the 
snout, and occupying \ the length of head ; upper jaw truncated, lower round- 
ish-oval, and when the mouth is closed projecting § a line beyond the snout (in 
this respect exceeding that of the vendace, Cor. Willughbei , Jard.). The only 
teeth apparent with the aid of a lens are a few placed regularly on both upper 
and under jaws, none apparent on the tongue or the vomer ; pre-opercle nearly 
describing the segment of a circle, opercle from the posterior base gradually 
narrowing upwards. Fins ; dorsal originating half-way between extremity of 
lower jaw and base of caudal ; pectorals pointed, nearly ~ the length of head, 
these and the ventrals of about equal length ; the latter commencing in a line 
with the first quarter of dorsal ; when laid close to the body, the dorsal ap- 
proaches the tail more nearly than the ventral ; anal distant its own length from 
the first short ray of caudal ; adipose ending nearly on the same line as the anal. 
D. 15 (1st very short) ; P. 15 ; || Y. 1 + 11 ; A. 16 or 17 ; C. 20{|=Br. 7. 
Scales (judging merely from their impressions', they having been rubbed off) 
* Zoographia Russo-Asiatica, iii. pp. 410, 411. To this -work I have not had 
access, but am indebted to my friend Mr. Ogilby for transcribing from it the full 
description, and sending it me from London, 
f Prodromus Ichthyologise Scandinavicse, p. 18. 
X The commencement of the specific characters is “ C. corpore elongato, 
tereti-compresso; ” the detailed description “Corpus elongatum, tenue.” 
§ It is so formed, especially the anterior half, that like the Coregonus qucidri- 
lateralis of the Fauna Boreali-Americana (pi. 89, fig. 1), it might be called 
“ four-sided with the angles rounded off.” 
|| This number appears in both fins; which are somewhat injured. 
