OF DENISON UNIVERSITY. 7 



notes on the osteology appended. Before preceding to these the fol- 

 lowing description will suffice to make the bird recognizable. 



Sp. char. Bill, yellowish green, dusky at base ; anterior half of body dusky 

 yellowish olive, shading into yellow to the rump above, and the under tail coverts 

 below. Outer scapulars, a broad frontal band continued on each side over the 

 eye, axillaries, and middle of under wing coverts, yellow. Feathers along the ex- 

 treme base of bill, the crown, tibiae, wings, upper tail coverts, and tail, black ; in- 

 ner g'-eater wing-coverts and tertiaries, white. Length, 7.30, wing, 4.30, tail, 2.7;;. 

 In the female the head and back is dull olivaceous brown. Below, the body is 

 pale yellowish ash. There is an obscure black line on either side the chin. There 

 is more white upon the wings and tail. (See plate, which is intended to give 

 simply the tout ensctnhk without strict accuracy as to color.) 



Osteology of Hesperiphona vespertina. 



The anatomy of the Evening Grosbeak is of more than usual inter- 

 est, not only on account of the rarity of the bird and the air of mystery 

 which has associated itself wnth it, but because it stands at the head of 

 American Friiigillidae , by virtue of possessing the extreme develop- 

 ment of the finch type of structure. Our observations are based on 

 the study of three more or less perfect skeleta, which, so far as we 

 know, are the first which have been studied. 



The skull. The most striking peculiarities of the skull are those 

 which are corelated with the extraordinary development of the beak. 

 The angle, for instance, formed by the quadratojugal-jugal bony pillar 

 with the lower margin of the maxilla is greater than usual, chiefly on 

 account of the great size of the quadrate bone. In this way a firm 

 support is afforded to the upper jaw. But we pass to a detailed de- 

 scription. As seen/;w;^ above, the skull is, in outline, a perfect trian- 

 gle, with a narrow rounded base. The apex of the triangle is formed 

 by the remarkably large and strong (though correspondingly very light) 

 beak. The bones entering the beak are cancellated within, forming a 

 firm bat light organ. These bones are, first, the premaxiUa, which 

 makes up the bulk of the bony frame-work of the beak and is early 

 anchylosed with the maxillaries in the family under consideration. 

 Although we can not separate the parts, we may distinguish in the tiiax- 

 illary bone a superior or nasal process which separates the opening of 

 the nares and unites with the nasal bones, two lateral or maxillary pro- 

 cesses, and two palatine processes which are within the mouth-opening- 

 The distance from the apex of the beak to the subcircular nares is .6 

 inches, the distance between them, .10. The nasals are inseparably 



