482 Mr. C. T. Regan on the British and 



along the fold; the sexual pencil of long hairs pale buff 

 tipped with grey. 



Expanse 32 mm. 



Bab. Makala-Beni, Congo Free State, July 1906. 



In the Powell-Cotton collection. 



LXII. — A Revision of the British and Irish Fishes of the 

 Genus Coregonus. By C. Tate Regan, M..A . 



FOUR species of Coregonus have usually been recognized as 

 pertaining to the British fauna, viz. : C. o.ryrhynchus, Linn., 

 the migratory Routing, which is common on the coasts and in 

 the rivers of continental Europe from Scandinavia to Holland, 

 and is occasionally captured in our southern and eastern 

 counties ; G. clupeoidcs, Lacep., the Powan of Loch Lomond, 

 Schelly of Ullswater and Haweswater, and Gwyniad of Bala 

 Lake; G. pollan, Thomps., the Pollan of Ireland; and 

 G. vandesius, Richards., the Vendace of Lochmaben. 



Two years ago I described the Vendace of Derwentwater 

 and Bassonthwaite as a new species, C. gracilior, differing 

 from the Lochmaben Vendace in the more elongate body and 

 more slender caudal peduncle, smaller head, shorter paired 

 and lower unpaired fins, and in usually having a ray more in 

 the dorsal fin. My description was based on five specimens ; 

 eight more are now in the British Museum collection, and 

 agree well enough with the types, but the differences from 

 G. vandesius are so slight that it may be best to recognize 

 G. gracilior as a subspecies only. 



A fine series of tlie Pollan of Lough Erne show that, as 

 observed by Yarrell, this fish has usually a deeper body than 

 the Lough Neagh Pollan ; also, as a rule, there i3 a scale 

 more between the lateral line and the base of the pelvic fin. 

 These and other slight differences are here recognized by 

 describing the Lough Erne fish as a new subspecies of 

 ( '. y ollan under the name G. altior. The Pollan of the lakes 

 of the Shannon system has already received the name 

 G. elegans from Thompson ; it is here regarded as a second 

 subspecies, differing from the typical C. Julian in the shorter 

 maxillary and also in having the scales usually more nume- 

 rous, especially when counted in a transverse series or round 

 the caudal peduncle. 



I have examined two spirit-specimens of the Loch Lomond 



