PTILOGONATIN^. 409 



It may be considered that the presence or absence of scutellae 

 on the tarsus is a matter of comparatively slight importance, since 

 in some Thrushes having normally smooth tarsi, we occasionally find 

 individual specimens exhibitiug scutellse, and the Mocking Birds 

 differ from the true Thrushes in having such scutellse. Yet when 

 to this we add the tendency in Ptilogonys and Phsenopepla to 

 division of the whole length of the lateral plates, and even occasional 

 indications of a supplementary series on the posterior edge of tarsus, 

 the difference from the smooth tarsi of Myiadestes and its allies, is 

 one of essential moment. Add to this the peculiarities of marking 

 in young birds, and the difference of vocal powers, and the grounds 

 for separation would seem well established, and the assignment of 

 the Myiadestinee, as a subfamily, to a place near the Saxicolidae and 

 Turdidse (perhaps better under the latter), well founded, as all the 

 characters referred to above apply to the Turdinse. Since, however, 

 other authors may not agree with me in this view, and as the Tur- 

 didse have already been discussed, I propose to present the llyia- 

 destinse in the present article after the Ptilogonatinae, and to leave 

 the final decision of their true position to a future period. 



TJie comparative diagnoses of Myiadestinee and Turdinae may be 

 expressed as follows : — • 



Common Characters. — Tarsi without regular transverse scutellse, except at 

 lower end. Wings acute, pointed, as long as or longer than tail, which is 

 but slightly graduated. First primary rarely half 2d, which exceeds the 

 secondaries. Base of qnills bufty yellow, as are inner edges. Tail spotted 

 or varied at the end. Young birds with many light spots. Very melodious 

 singers. 



Myindestinx. Bill short, much depressed ; mouth deeply cleft ; width 

 at base about equal to the distance from nostril to tip, or greater; 

 commissure more than twice distance from nostrils to tip of bill, and 

 nearly two and a half times length of gonys. Legs weak ; tarsi 

 rather longer than middle toe and claw. Tail feathers tapering 

 slightly from base to near tip, giving a slightly cuneate appearance 

 to the tail. 

 Turdinae. Bill stouter, more lengthened ; narrow at base and more 

 compressed; width at base less than distance from nostril to tip; 

 commissure not more than twice distance from nostrils to tip of bill, 

 and about twice length of gonys. Tarsi stouter, longer than middle 

 toe and claw. Tail feathers widening slightly from base to near tip, 

 giving a parallel sided or slightly fan-shaped appearance to the tail. 



The Miminse differ from both in the strongly scutellate tarsi ; 

 shorter, more rounded wings, the 1st primary generally half the 2d ; 

 the tail usually much graduated, etc. 



