30 PROCEEDINGS OF THE ACADEMY OF 



smaller than the preceding ; length between 14 and 15 inches, wing barely 7, 

 bill along rictus 1'60, its depth at base, exclusive of height of horn, -65. 



Young. (No. 23,392, Mus. Smiths., Straits of Fuca). — This specimen is just 

 not quite fully feathered, patches of down adhering here and there. The bill 

 is small and weak, hardly more than half the size of that of the adult; its 

 general shape, however, is nearly attained. The base of the upper mandible 

 is covered with a soft skin, about as far as the end of the nostrils. That part 

 of the culmen formed hj the ridge of this skin is sunken below the level of the 

 rest. Unmistakable indications of the future horn are present, in a small knob 

 on the ridge of this skin. In the present dried state this knob is shrunken, 

 presenting the appearance represented in the plate. In life it was probably 

 a small full rounded protuberance, rising a little above the level of the culmen. 

 Between the mandibular rami, at the symphysis, there is a slight fold or ridge 

 of skin, evidently the matrix of the future accessory corneous element. The 

 upper mandible is mostly blackish ; the lower dull obscured reddish. The legs 

 and feet appear to have been colored much like thoseof the adult. The colors 

 of the plumage are precisely those of the specimen last described ; the patches 

 of down are smoky brown. There is no trace of white about the head. 



Nestling, about 5J inches long. (Farralone Islands. Mus. Acad. Phila.) 

 All over smoky brown, lighter and more grayish below. 



The horn of this bird, always present in the adult, and always indicated, 

 even in the scarcely feathered young, as we have just seen, varies a great deal 

 in the details of its size and shape. It is usually nearly upright, but fre- 

 quently projects a little obliqely forward. Its average height is between 

 four and five-tenths of an inch, measuring from the level of the culmen at 

 the anterior edge of the root of the horn. The real roots of the horn begin a 

 little above the nasal aperture ; the nostril opening just beneath the lower 

 edge. The horn is thus bifurcated, as it were, at the base, and saddled on the 

 base of the upper mandible. The anterior outline is usually straight, or 

 slightly curved, the apex rounded, and the posterior border irregular in out- 

 line. The figure represents what is perhaps an average horn. It would be 

 impossible to indicate all the variation in detail; scarcely two horns are pre- 

 cisely alike. 



The frontal feathers ascend a very little way up the back of the horn in 

 the majority of instances ; sometimes, however, they end abruptly at its base. 

 From their foremost point they sweep downwards and backwards along the 

 side of the upper mandible with a gentle regular curve, to the rictal angle, 

 leaving the tomial edges of the upper mandible bare. The chin feathers begin 

 at the accessory symphyseal piece, rise quickly on the sides of the under man- 

 dible, and reach its tomial edge in advance of the rictal angle. 



The symphyseal piece, which is developed from the skin at the apex of the 

 interramal space, is, when fully formed, as hard as the rest of the bill. Anteri- 

 orly it is directly continuous with the mandibular symphysis. On its sides, a 

 groove indicates its line of cohesion with the mandibular rami. The horn, 

 when mature, is perfectly corneous and hard to its extreme base ; there being 

 no soft skin even about the nostrils. Its main shaft is hollow ; a tube is dis- 

 closed when the top is worn off or broken off. 



The white feathers on the side of tlie head differ from those of other Phaleri- 

 dines (except S. Suckleyi) in not being very slender, filamentous and wavy. 

 They are straight, short, acutely pointed, stiffish, standing discreet from each 

 other, like so many narrow spear-points. 



The very large series of this bird examined warrant the belief that the horn 

 is always present, accidents of course not considered ; that it begins to be ap- 

 ])arent even before the bird is fully fledged, as a slight knob. That, in like 

 manner, the accessory symphyseal piece is always developed ; and that its be- 

 ginning may be detected at a very early age. These facts must be borne in 

 mind in discussing the unusually interesting points connected with Sagmator- 

 rhina as compared with the present genus. The opinion relative to the season- 



[Jan. 



