324 NOTES — FISHES. 



Dame Nature, than against her most conscientious and painstaking 

 interpreter. 



The third volume of the British Coleoptera deals with the 

 Clavicornia — a somewhat artificial and unsatisfactory division, as at 

 present understood and constituted. The most familiar insects 

 described in this volume are the Ladybirds and the Carrion-beetles, 

 but many of the groups are obscure and difficult, from the minute size 

 of the insects. The Trichopterygidce can only be worked with the 

 microscope. This volume appears, nevertheless, to be characterised 

 by the same painstaking work as its predecessors, and there can be 

 no doubt that the completion of the whole book will inaugurate 

 a new era in the study of the British Coleoptera. — W. C. Hey. 



NO TES— FISHES. 



Anchovies at Whitby. — On the 9th instant, two fishes, caught off Whitby 

 in the herring nets, were shown to me for identification, which I have no 

 hesitation in stating were Anchovies (Engraulis eticrasicholus). Unfortunately, 

 they had not been taken proper care of, and the scales and skin were much 

 abraded ; nevertheless, I am quite satisfied from the head, lower jaw, etc., that 

 they are what I have pronounced them to be. The fisherman (Freeman) who 

 caught them, said he had taken above a dozen this season. — Thos. Stephenson, 

 Whitby, October nth, 1889. 



Destruction of young Trout in the river Costa. — On the 29th of April 

 Mr. Chadwick, of Malton, sent through Mr. Roebuck a large bottle labelled 

 ' Brown dust from the River Costa ; it kills the young Trout wholesale by clogging 

 the gills — J. W. Wheldon.' In his letter he wrote that Mr. Wheldon, who is a 

 pisciculturist at Pickering, said that at that time of year and later it kills all the 

 young trout, but that afterwards the larger fish feed upon it. It is also fed upon 

 by Limncea and other mollusks. 



On examining the sample of water from the river Costa, with the muddy ' deposit,' 

 I found nothing but what one would expect, viz., crustacean and infusorial debris, 

 fragments of the pseudo-mucoroids (Leptothrix, Hyplncothrix, etc. ), and of Conferva: 

 and Monostroma. I met with nothing in Mr. Wheldon's sample like a Saprolegnia, 

 or other vegetable, which I could imagine as ' killing the young trout wholesale by 

 clogging the gills,' as described by Mr. Wheldon. Absence led me to neglect the 

 sample for some days, but it was protected from dust, and preserved in a shallow 

 glass dish exposed to the direct sunlight. On my return I found it covered on the 

 surface with a thick pellicle of what turned out to be simply ferric oxide (Fe„O.T), 

 with flakes of the same in large quantity lying upon the muddy sediment. I much 

 regret not having estimated the quantity of the oxide in the given bulk ; but it is 

 very large, and proves the water to be highly charged with iron. Of animal 

 physiology I know little, but I know that lung- (and gill-) action in animals exerts 

 a ' reducing action,' chemically speaking. This being so, and iron in soluble con- 

 dition existent in the water, I would ask — Is it not possible that the gill-action in 

 the little trout might reduce the iron from the soluble form to that of insoluble 

 oxide, and thus clog the delicate membranes of the gills ? Might not the gill-cilia, 

 or blades, well developed in an old fish, be so weak in the juvenile trout as to be 

 unable to throw off the accumulation? The first stage of the action would 

 probably be the reduction of soluble ferric carbonate to simple oxide ; the second 

 change would convert the FeO into Fe. 2 3 by the oxidising action of the gills. 

 Mr. Wheldon speaks of ' brown dust,' surely this may be the ferric oxide alluded 

 to. It is quite possible that one of the little known semi-mucoroid Algre (Fungi?) 

 may have been the cause, but I am inclined to think my theory as to the iron is 

 correct. — W. Barweli, Turner, Leeds. 



Naturalist, 



