120 BRITISH FRESHWATER FISHES 



scales more numerous in a transverse series. The 

 characters in which the two forms are not identical 

 may be compared thus — 



Lough Erne Pollan 



{Corego?itis altior) 



Depth of body contained 

 three and one-third to four 

 times in the length of the fish ; 

 caudal peduncle once and one- 

 fourth to once and two-thirds 

 as long as deep. Maxillary 

 extending to below anterior 

 one fourth or one-third of eye. 

 Eight and one-half to ten 

 scales between lateral line and 

 base of pelvic fin, twenty-one 

 to twenty-four round the caudal 

 peduncle. 



Lough Neagh Pollan 



( Coregoniis pollan) 



Depth of body contained 

 three and three-fourths to four 

 and one-half times in the length 

 of the fish ; caudal peduncle 

 once and one-half to twice and 

 one-fourth as long as deep. 

 Maxillary extending to below 

 anterior one-third of eye or 

 beyond. Seven and one-half 

 to nine scales between lateral 

 line and base of pelvic fin, 

 nineteen to twenty-two round 

 the caudal peduncle. 



This form is not so abundant as the Lough Neagh 

 Pollan, but still occurs in sufficient numbers to be 

 occasionally netted for the market, fetching 8d. 

 per lb. in Belfast and lod. per lb. in England; in 

 size it averages somewhat larger than the Neagh 

 fish ; the example figured (PI. XVI), nearly a foot 

 long, is one of a fine series of Lough Erne Pollan 

 kindly sent to me by Major H. Trevelyan. 



The Shannon Pollan {Corego7ius elcgans) 

 inhabits the lakes of the Shannon system, especially 

 Loughs Ree and Derg. It has the elongate body 

 of the Neagh Pollan combined with the shorter 

 caudal peduncle of the Erne fish ; the mouth is 

 smaller than in either, the maxillary extending only 

 a little beyond the vertical from the anterior margin 

 of the eye ; the scales number seventy-eight to 



141 



