720 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Adult male (?) — Length (skin), 210; wing, 160; tail, 90.5; culmen, 

 from cere, 12.5.*^ 



Adult female.— I j&Vigih (skins), 206-219 (212.5); wing, 157.5-160 

 (158.7); tail, 81.5-82.5 (82); culmen, from cere, 13.5.^ 



Yucatan (Chichen-Itza ; Tizimln). 



Scops guatemalse (not of Sharpe) Salvin and Godman, Biol. Ceutr.-Am., Aves, 



iii, 1897, 20, part (Tizimln, Yucatan). 

 Otus choliha thompsoni Cole, Bull. Mus. Comp. Zool., 1, no. 5, Nov., 1906, 123 



(Chichen-Itza, Yucatan; coll. Mus. Comp. Zool.). 



OTUS CASSINI (Ridgway). 



CASSIN'S SCREECH OWL. 



Resembling 0. Tiastatus Tiastatus and 0. li. tliompsoni in coloration 

 but much darker and decidedly smaller; also resembling, super- 

 ficially, the grayish brown phase of 0. tricliopsis, but at once to be 

 distinguished by much longer wing and tail and perfectly naked toes; 

 slightly resemblmg 0. harbarus, but feet conspicuously larger (tarsus 

 more than 30, middle toe piore than 20 mm.). 



Brown phase. 



Adults {sexes alike). — Pileum sooty black, broken by small spots 

 of light brown, larger and paler anteriorly, the posterior part of the 

 crown with an imperfect band, or transverse patch, of much larger 

 spots of pale wood-brown or pale brownish buff; ear-tufts with large 

 black spots, connected along the shaft, and separated by large spots 

 of light brown on outer webs and of pale brownish buff on inner webs; 

 a broad and conspicuous nuchal band of pale brownish buff, mixed 

 with dull grayish white, and varied with blackish bars, spots, and 

 mottlings; hindneck warm-sepia brown indistinctly mottled with 

 dusky, and minutely spotted with paler, each feather with an irregular 

 and not sharply defined mesial spot of blackish; a broad collar across 

 lower hindneck and upper back of pale dull buff, broken by dusky 

 bars and mesial streaks, the buff often in the form of large roundish 

 or transversely oblong spots; general color of remaming upper parts 

 grayish brown, freckled and vermiculated with dusky and further 

 variegated by irregular mesial streaks and occasional dull buffy spots 

 and pale grayish buffy bars; outer webs of exterior row of scapulars 

 chiefly white, very broadly tipped and more narrowly margined with 

 black; exterior middle wing-coverts with exposed portion of outer 

 webs white, margined internally by a broad mesial streak of black; 

 exterior greater coverts with a large terminal or subterminal spot of 



o One specimen; sex determined as male by the collector, but probably female. 

 b Two specimens. 



