2 BULLETIN 50, L^NITED STATES NATIONAL MUSEUM. 



has ever been drawn between the two groups, and there is much reason 

 for doubting: whether their separation can be maintained. The only 

 other groups to which the Turdidae are intimately related are the 

 Mimidse (Mocking Thrushes) and Cinclidas (Dippers). The former 

 have often been included with the Turdidaj as a subfamily (Miminse) ; 

 but their more or less distinctly scutellate acrotarsium, relatively 

 larger hallux, more rounded wing, with relatively longer outermost 

 (tenth) primary, and weaker or fewer rictal bristles, will serve to 

 separate them as a fairly well-defined family group.'* The Cinclida' 

 are much too different to need close comparison with the Turdidfe, 

 and ma}', therefore, be dismissed without further notice.^ 



The folk)wing osteological characters are said to be diagnostic of 

 the Turdidse as distinguished from the Mimidse: — 



Ante-orbital region wide; descending process of nasal w^ide, the 

 angle formed by this process and the pars jtlana acute; maxillo- 

 palatines of a modified claviform shape; costal process of sternum 

 large, blunt, rhomboidal in outline; coracoid with a wide flange run- 

 ning halfway up the shaft; pelvis broad, flattened.'^ 



Authors have varied greatly in the limits which they have assigned 

 the family Turdidse, as they have respectively defined it. Mr. Henry 

 Seebohm, author of that volume of the ''Catalogue of the Birds in the 

 British Museum" '^ which contains the group includes in his "Family 

 Turdidse," besides the true thrushes, the w^arblers (Sylviidse) as a 

 "subfamily Sylviinse," but excludes the "Myadestinse," the Mimidse, 

 and the genus Pratincola. In a later special paper on the group* 

 Doctor Stejneger has recast the limits of the family by adding to it the 

 " Myadestinae " (as suggested by Professor Baird in his "Review of 

 American birds," 1866, p. 417), and the genus Pratincola (in accord- 

 ance with the views of many previous authors), and removing the Syl- 

 viidse. The family Turdidae, therefore, as defined by Doctor Stejneger, 

 whose views are here adopted, is equivalent to Mr. Seebohm's "Sub- 



o- It is true that not all the characters mentioned above as diagnostic of the Mimidse 

 invariably occur in the same genus; but one or another of them at least is always 

 present to determine which of the two groups a given form should be referred to. 



b See the present work, Part III, 1904, 675. 



c Lucas, Proc. U. S. Nat. Mus., xi, 1888, 179. For osteological characters of Mi- 

 midse and Troglodytidse as compared with those of Turdidee, see p. 181. 



<^ Catalogue [ of the | Passeriforms, | or | Perching Birds, | in the | Collection | of 



the 1 British Museum. | | Cichlomorphee: Part II. | Containing the family | 



Turdidai ] (Warblers and Thrushes). | By | Henry Seebohm. | London: | Printed by 

 order of the Trustees. ] 1881. | 



(Constituting Volume V of the Catalogue of the Birds in the British Museum. Pp. 

 xvi-|-426, pis. (hand colored) 18.) 



« Remarks on the Systematic Arrangement of the American Turdidee. By Leon- 

 hard Stejneger. Proc. U. S. Nat. Mus., 1882, (February 13, 1883), 449-483, with 

 n\imerous cuts. 



