522 BULLETIN 50, UNITED. STATES NATIONAL MUSEUM. 



etc.); tertials very slightly to decidedly produced. Tail two-thirds to 

 five-sevenths as long as wing, two and a half times or more longer 

 than tarsus, half or more hidden by upper coverts, emarginated or 

 double-rounded, the rectrices rather narrow, but not pointed. Tarsus 

 less than twice as long as exposed culmen, its scutella indistinct or 

 obsolete on outer side; middle toe, with claw, as long as or longer than 

 tarsus; lateral toes relatively short, their claws not reaching beyond, 

 sometimes falling short of, base of middle claw; hallux about equal 

 in length to outer toe, its claw variable as to relative length, some- 

 times decidedly longer, sometimes shorter tban the digit. 



Coloration. — Above more or less yellowish, the back usually streaked 

 with dusky; beneath 3'ellow, or largely so. 



Range. — Tropical South America; one species in southern Mexico 

 and Guatemala and one in Jamaica. 



Although regarded by Dr. Sharpe as closely related to Serinus 

 Koch, the resemblance seems to me to be a purely superficial one, not 

 involving structural characters, which are so different that the two 

 genera scarcely need comparison. The supposed structural dif- 

 ferences given on page 169, vol. xii, of the "Catalogue of Birds 

 contained in the British Museum,"^ 1 am unable to appreciate, the 

 tomia being in reality quite as much deflected basallj' in Slcalis as in 

 St-rinus, though there is^ slight difference, that of Serinus commenc- 

 ing a little farther forward. Seisin us, however, has a well-developed 

 fringe of antrorse plumules quite concealing the nostrils, and also a 

 rictal fringe nearly hiding the deflected portion of the commissure, as 

 in Sjyinus, Carj)odacus, and other true "Finches;" has the bill much 

 broader in proportion to its depth, and the tail proportionally longer 

 and more deeply emarginated. In Sicalis the nostrils are fully 

 exposed, the coccothraustine nasal and rictal fringes of Serinus being 

 quite wanting, as in other so-called "Buntings." 



The resemblance in coloration between some of the species of Sicalis 

 and a species of the Old World genus Serinus (S. canarius) is, how- 

 ever, remai'kable; so much so, in fact, that were it not for the differences 

 in structural details it would be very difficult to distinguish them. 



Although at one time I considered the smaller, conspicuously streaked 

 species of Sicalis as generically distinct and proposed to place them 

 in a separate genus (Serinopsis), I now believe that they can not 

 be separated, certain species being quite intermediate in structural 

 characters. 



KEY TO THE SPECIES OF SICALIS. 



ci. Inner webs of primaries edged with yellow; wing more than 65.00. (Jamaica.) 



Sicalis jamaicBB (p. 528.) 



Oft. Inner webs of primaries edged with pale brownish gray; wing less than 65.00. 



(Southern Mexico and Guatemala. ) Sicalis chrysops (p. 528.) 



' c'. Tomium deflected toward the gape 41. Serixi's. 



d°. Tomium straight for its whole length. 42. Sycalis. 



