PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 41 



until in the later years especially English ornithologists (Saunders, 

 Dresser) have tried to vindicate the name ]}arasiticus for the long- 

 tailed species. 



In the 10th edition of Linn^ei Systema we find nothing which justifies 

 the change of the generally adopted appellation. Mr, Saunders (Pr. 

 Zool. Soc. Lond. 187G, p. 327) thinks, however, that the short diagnosis, 

 viz, '■'■ rectricihus duabus intennedus longissimis,^^ is snflBcient to prove 

 the contrary, and exclaims, "Nothing could well be clearer!" This 

 might perhaps have been right, if Linn^us had had before him more 

 than one species, of which one or more were supplied with rectricihus 

 longiSj and the parasiticus then was given as having rectrices longissimi ; 

 but as he knew but one species, his expression would be quite correct 

 if the middle pair of rectrices in his parasiticus had been still shorter 

 than they are in " Kichardson's Jaeger." The phrase "i^ec^rices iuter- 

 medii longissimi" indicates only that the middle pair was longer than 

 the other, or it may also siguify that it in this "iar?(s" was very long 

 compared with the other Lari described by him, which all had a square 

 tail. Mr. Sundevall (Tent. Meth. Av. Disp. p. 130) uses the same 

 phrase exactly in the same meaning, when he characterizes the whole 

 genus in the words, " Cauda suhaquali, pennis 2 mediis lougissimis," and 

 nobody will cousider this to be incorrect, although he, in the genus thus 

 cliaracterized, includes the Cataracta sJcua Brunn. Besides, the quo- 

 tations and the habits of the bird, as they are given in the lOtli edition, 

 agree better with the common Jaeger than with the long-tailed species. 

 The authors who take this edition for their starting point in nomencla- 

 ture have not the slightest reason for changing the name. 



Saunders, Dresser, and most English writers, however, found 

 their nomenclature on the 12th edition of 1766. In this the diagnosis 

 from the 10th edition is reprinted verbatim. Besides, there is nothing 

 new which can justify the change ; it might then be that Linn^us here 

 cites as synonymous the longicaudatus of Brisson, but as he does not 

 adopt the other sj^ecies of the same author, the " Stercorrarius^^^ the erro- 

 neous citation is of no importance, as it only shows that he did not 

 recognize more than one species. Thus the 12th edition does not furnish 

 any reason supporting the change. But — and this is the main point — 

 this edition contains a phrase which corroborates the opinion here de- 

 feuded, and which appears to have been overlooked by Mr. Saunders, 

 viz, '■^ Rachis remigum rectricumque, imprimis subtus, nivea." From this 

 quotation it seems to be evident that Linn^us means the biM which 

 has the shafts of all the primaries white, and that his parasiticus of 1766 

 belongs less to the long-tailed species than even the parasiticus of 1758. 

 If it is so that both editions of the Systema jSTaturalis entitle the common 

 Jaeger to bear the name parasiticus Lin., it will be of no importance 

 that the description in Fauna Svecica (1761) — the diagnosis is the same 

 as in S. K. — is perhaps made from a specimen of the long-tailed species 

 which Linnaeus himself confounded with the common Jaeger. It will 



