268 THE ZOOLOGIST. 



The Heligoland Laridce are, as might be expected, very similar 

 to those of the British Islands. Larus glaucus, L. leucopterus, 

 L. marinus, L. fuscus, L. argentatus, L. canus, L. tridactylus, 

 L. ridibundus, L. minutus, Sterna cantiaca, S. arctica, S. hirundo, 

 S. nigra, Stercorarius richardsoni, S. buffoni, and S. pomarinus, 

 bear somewhat the same relation to each other so far as numbers 

 go in both areas, and the same may be said of the accidental 

 visitors Larus ichthaetus, L. bonapartii, L. sabinii, L. rossi, L. 

 eburneus, Sterna caspia, S. anglica, and S. dougalli. Stercorarius 

 catarrhactes is a very rare visitor to Heligoland ; Sterna fuliginosa, 

 S. leucoptera and S. hybrida are not recorded from the little rocky 

 island, but the absence of these southern species is compensated 

 for by the occurrence of two examples of the Arctic species 

 Larus affinis. 



The Heligoland Alcidce are the same as those in the British 

 list, except that no record has been kept of the probable visits of 

 Alca impennis during the last century, and there is an example of 

 one of the allies of Alca grylle which remains undetermined in 

 Gatke's collection for want of material with which to compare it. 



Only two Gallince have occurred on Heligoland, Perdix cinerea 

 and Coturnix communis, leaving Tetrao mutus, T. scoticus, T. 

 tetrix, T. urogallus, Phasianus colchicus and Perdix rufa to the 

 credit of the British list. 



There is not nearly so much difference in the respective 

 Grallce. The following are found in both lists : — Pterocles para- 

 doxus, Otis tetrax, Grus cinerea, G. virgo, Rallus aquaticus, Crex 

 pratensis, C. porzana, C. bailloni, C. parva, Gallinula chloropus, 

 and Fulica atra, leaving Otis tarda and 0. macqueeni to the credit 

 of the British list. 



The Pygopodes are represented in both lists by Colymbus gla- 

 cialis, C. arcticus, C. septentrionalis, Podiceps cristatus, P. rubri- 

 collis, P. cornutus, P. nigricollis, and P. minor, but P. adamsi 

 appears hitherto to have escaped detection on Heligoland. 



There can be' little doubt that many more species remain to 

 be discovered as more or less accidental visitors to Heligoland. 

 The ornithological world is profoundly indebted to the inhabitants 

 of Heligoland, especially to the untiring zeal of the Brothers 

 Aenckens, for having detected so many rarities, and to the 

 veteran Gatke for his careful records of observations extending 

 over nearly half a century. 



