54>8 Zoological Society. 



source, arising from a branch of natural history to which in particular 

 I have devoted my attention ; but from the general nature of the de- 

 scription, I was obliged to defer my desire of identifying the fish till 

 some future opportunity should enable me to do so. Quite unex- 

 pectedly, however, a few days ago, the last overland despatch brought 

 me a letter from my valued friend Mr. McClelland, a Corresponding 

 Member of this Society, an extract of which, bearing upon the point 

 in question, I lose no time in laying before the Society : — ' .... I 

 have now to mention what is of far greater importance in another 

 point of view, namely, that the Suleah Fish described in a recent 

 number of Parbury's Oriental Herald is the Polynemus Sele of Ha- 

 milton. I have examined that species, and found an individual of 

 two pounds weight to yield sixty-five grains of pure isinglass, an ar- 

 ticle which here sells at sixteen rupees (\l. \2s.) per lb. Refer to 

 your dissections of Polynemi ; mark those with large air-vessels to be 

 isinglass, requiring no other preparation than merely removing the 

 vascular membrane that covers them, washing with lime-water, and 

 drying in the sun. You know the size these fishes attain, and the 

 number in which they abound in the Sunderbuns ; you also know 

 the method of taking them, and can therefore state to what extent 

 isinglass may be obtained in India. I have sent a paper on the sub- 

 ject to the Journal of the Asiatic Society, which I will send you by 

 the next overland despatch.' 



" Perceiving by this that the subject has been taken up by a na- 

 turalist of Mr. McClelland's rank, and that we ere long may expect 

 his observations embodied in a paper from his hand, I think it suf- 

 ficient to confine myself to a few general remarks upon those species 

 of Polynemus which have come under my actual examination while 

 I was attached as surgeon to the Hon. Company's survey of the 

 sea-face of the Gangetic Delta. 



" The species best known is the Polynemus risua, Hamilton ; Pol. 

 longifilis, Cuvier; the Tupsee or Mango Fish of the Anglo-Indians ; 

 this inhabits the Bay of Bengal and the estuaries of the Ganges, 

 but enters the mouths of the rivers, even higher up than Calcutta, 

 during the breeding- season (April and May), when the fish is con- 

 sidered in its highest perfection, and is greedily sought as a great 

 delicacy. This species is the smallest, for its length seldom exceeds 

 eight or nine inches, and one and a half to two inches in depth. 

 Polynemus aureus and Topsui, Hamilton, are species closely allied to 

 this. 



" Polynemus sele, Hamilton, P.plebeius, Broussonnais, P. lineatus, 

 Lacepede, is the Suleah Fish mentioned in Parbury's Oriental Herald, 

 the same which Mr. McClelland submitted to examination. This 

 species, as well as another closely allied to P. quadrifilis, Cuvier, 

 which I have dissected, figured, and described, under the name of 

 P. Salliah (Saccolih), appears equally plentiful, in shoals, all the 

 year round in the estuaries of the Ganges, and is appreciated by 

 Europeans and natives for its excellent flavour. Both species at- 

 tain a size from three to four feet in length, and eight to ten inches 

 in depth. 



