Vol. X~| Recent Literature. 345 



as to what the climate may have been in those times. ... To speak 

 again of the climate, it might well be compared with the present climate 

 of Florida and the lower part of Louisiana, with the vegetation fully as 

 luxuriant as it is now in those parts and with the palms more abundantly 

 represented." 



Dr. Shufeldt's memoir is thus a very interesting and important contri- 

 bution to the early history of bird life in North America. Although he 

 has fortunately had a comparatively large amount of material for exami- 

 nation, the field is obviously not exhausted, so that much may be hoped 

 from further exploration of even this same region. — J. A. A. 



Shufeldt on Ichthyornis, and on the Classification of the Longipennes. 

 — In a paper entitled 'Comparative Osteological Notes on the Extinct 

 Bird Ichthyomis' 1 Dr. Shufeldt reaches the conclusion that this type, 

 while resembling in many points the Gulls and Terns, shared more 

 characters in common with the Skimmers. Much of the paper is, in fact, 

 given up to a discussion of the relationship of the Skimmers (Rhyncho- 

 pidffi) to the Laridre, reaching the conclusion that while the Gulls and 

 Terns gradually approach each other, through such forms as Xema, 

 Creagrus, and Gelockelidon, as long since stated by Cones, the Skimmers 

 are sharply separated from either, and are well entitled to the rank of a 

 distinct family, as placed in the A. O. U. Check-List. In a later paper 2 

 he returns to the subject, and after reviewing various previous classifica- 

 tions of the group, proposes that already adopted in the A. O. U. Check- 

 List as best agreeing with his extended osteological studies of the North 

 American forms. — J. A. A. 



The Affinities of Hummingbirds and Swifts.— The pros and cons of 

 the relationship of Hummingbirds and Swifts have recently been pre- 

 sented in various more or less controversial papers on the subject by Dr. 

 Shufeldt 3 and Messrs. Ridgway 4 and Lucas. 5 As is well known. Dr. 



1 Journ. Anat. and Phys., XXVII, pp. 32> 6 ^3A°- 



2 On the Classification of the Longipennes. By R. W. Shufeldt. Am. Nat., March, 

 1893, pp. 233-237. 



3 Ridgvvay on the Anatomy of Hummingbirds and Swifts. By R. W. Shufeldt. 

 Am. Nat., April, 1892, pp. 869, 870. 



Ridgway on the Anatomy of the Hummingbirds and Swifts.— A Rejoinder. By 

 R. W. Shufeldt. Am. Nat., April, 1893, pp. 367-371. 



Comparative Notes on the Swifts and Hummingbirds. By R. W. Shufeldt. 

 Ibis, Jan., 1893, pp. 84-100. 



••Shufeldt on the Anatomy of the Hummingbirds and Swifts. By Robert Ridgway. 

 Am. Nat., Dec., 1892, pp. 1040, 1041. 



5 Swifts and Hummingbirds. By Frederic A. Lucas. Ibis, July, 1893, pp. 364-371 

 (with nine cuts in the text). 

 44 



