EXCEPTIONAL MIGRATION PHENOMENA 123 



rock amounts to fifteen, all of which, however, with the exception 

 of two, are represented by only one example each. These are : 

 Turdus swainsoni ; pallasi, fuscescens, niigratorius, lividus and 

 rufus ; Sylvia virens ; Anthus ludovicianus, one old and one young 

 example ; Dolichonix oryzivora, twice, though one of the examples 

 bears marks of having been in captivity at some time or other pre- 

 viously ; Charadrius virginicus ; Totanus macularius ; Tringa 

 rufescens ; Larus bonapartei, sabinii and rossii. Of the last 

 species but one, two examples are in my collection, and it has been 

 seen on two other occasions besides. Finally, a fine old male of 

 the Surf Scoter (Anas perspicillata) has also been shot here once. 

 Three-fourths of the birds above enumerated were old individuals. 

 As one might expect from the facts just mentioned, England, also, 

 has been visited by considerable numbers of American birds. The 

 number of instances cited by Harting (Handbook of British Birds) 

 amounts, up to the date of 1872, to two hundred and fifty-two 

 individuals, belonging to forty-six species ; in the most recent con- 

 sideration of this subject (J. J. Dalgleish, in the Bulletin of the Nuttall 

 Ornithological Club) the number given is a still larger one. Even 

 after excluding all doubtful cases, such as Anthus ludovicianus, the 

 numerous instances of the occurrence of the Greenland Falcon, 

 which is out of the question here, and leaving out of consideration 

 the Petrels and West Indian and South Sea Terns, which are not 

 pertinent to the present inquiry, there remain, even after a careful 

 sifting like this, still two hundred and twenty-three instances for 

 us to record. Strange to say, among the fifteen species observed 

 in Heligoland, nine are not included in the above lists, and it is 



O ' 



still more remarkable that, with the. exception of the one example 

 of the Migratory Thrush, caught at Dover in 1877, not one other 

 occurrence of any American thrush has been observed in England. 

 Ought one, perhaps, to conclude from this that the American 

 species which have visited Heligoland did not reach this island 

 via England, but landed farther south on the coast of France? 

 The fact that many American thrushes have occurred on the Con- 

 tinent in close proximity to this island lends support to this view. 

 It stands to reason that if all the thrushes of this kind which have 

 been observed in Heligoland and Germany had touched upon the 

 shores of Ireland and England, some of them at least could not fail 

 to have been remarked among the great bulk of other American 

 birds observed in that country, especially when we take into con- 

 sideration that, besides the individual actually killed, a considerably 

 larger number must have crossed over from America without 

 having come under observation. 



The occurrence of so many American species on European soil 

 involuntarily suggests the question as to the possible route by 



