PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 467 



Diodes, Reichenb., Av. Syst. Nat. 1S50, pi. 66, fig. (type, D. pyrrholwma, Reichenb., 

 = Tyrannus carolinensis f; no description!). 



Satellus, Reichenb., 1. c. (type, Tyrannus vociferans, Swains.?; no description). 



^>Laphyctes, Reichenb., 1. c. — Cabax. & Heixe, Mns. Hein. II, 1659, 76 (includes T. 

 melancholicus, T. " satrapa", T. apolites, T. vociferans, and T. verticalis). 



^> Mclittarchus, Cabax., J. f. O., Nov. 1655, 477 (type, Tyrannus magnirostris, D'Orb. : in- 

 cludes also T. crassirostris and T. do m in ice n sis). — Cabax. & Heixe, Mus. Hein. 

 II, 1659, 60. 



Gen. Ch. — Tyrant-birds of large, medium, or rather small size, ^vitli 

 strong*, conical bills, strongly bristled rictus, even, emarginated, or 

 slightly rounded tail, and the ends of the outer primaries abruptly nar- 

 rowed (except in T. luggeri). Crown with a concealed colored crest (red, 

 orange, or yellow) : plumage without streaks or bars. 



The above brief diagnosis, although imperfect, will suffice to distin- 

 guish the members of Tyrannus from those of allied genera. Milvulus 

 agrees in the attenuation of the outer primaries, the colored crest, and 

 many other features, but the tail is excessively forked, the lateral 

 feathers twice or more as long as the middle pair. Pitangus is also quite 

 similar in many respects, but has the bill more elongated, less depressed, 

 the outlines straighter, while there are various other differences. Upon 

 the whole, the genus may be considered quite a natural group. 



The species vary -among themselves not only in colors, but in other 

 respects also, each one (with a single exception so far as I know*) hav- 

 ing its own peculiarities of external form, so that were all identical in 

 coloration they could even then be readily distinguished. Attempts 

 have been made to subdivide the genus, but all have proved unsatisfac- 

 tory. There is, truly, a vast difference in size and form between the ro- 

 bust, almost gigantic, T. magnirostris, and the little T. aurantio-atrocris- 

 tatus; but other species are variously intermediate, so that it seems best 

 to consider the variations of form and size in this genus as of mere spe- 

 cific importance. 



Conspectus Tyrannorum. 



A. White beneath, the chest shaded with pale grayish (very faint in T. magnirostris). 

 a. Tail distinctly emarginate at end. Bill very large, much longer than tarsus (measur- 

 ing from nostril to tip). ' Tail not sharply tipped with white (= Mel it larch m f 

 Cabanis, part). 



L Wing, 5.20-5.30; tail, 4.00-4.25; bill, from nostril, 1.00-1.05, its depth at 

 base .42-46, width .60-.64 ; tarsus, .66; middle toe, .72. Grayish brown 

 above, the head blackish snuff-brown. Hah. — Cuba ; Bahamas. 



T. MAGXIROSTKIS. 



2. Wing, 4.70-4.75; tail, 3.85-4.20; bilV, from nostril, .92- 95, its depth 



.34-. 40, width .58-. 60; tarsus, .70; middle toe, .58-.02. Hnmbeous-gray 

 above, the head similar. I£ab. — Guiana, Trinidad, Isth. Panama (?), and 

 Lesser Antilles T. ROSTBATUS, 



3. Wing, 4.45-4.80 ; tail, 3.50-4.05; bill, from nostril, .75-. 82, depth .30-. 3ti, 



width .47-55; tarsus, .70-.75; middle toe, .52-.60. Colors of roat rains, 

 but somewhat lighter plumbeous above. Hah. — West Indies and adja- 

 cent coasts T. DOMIXICENSIfl. 



*T. ro8tratii8 and T. dominicensis are alike in the details of structure. 



