1885.] TROCHTLID^, CAPRIMULGID^, AND CYPSELIDiE. 887 



seemed to me, as it no doubt has to others, that the grouping 

 together of the Humming-birds, Goatsuckers, and Swifts, is an 

 evident confession of weakness on our part, besides being on the face 

 of it a very decided violence done to natural taxonomy and the science 

 of ornithology. As I look over the material before me, the discussion 

 of which will make up the body of the present paper, the fact is 

 strongly impressed upon my mind that the result of the study will 

 prove to be more of a contribution to the differences to be found 

 among the skeletons of the Macrochires, than it will afford sufficient 

 data to place any of the forms in question in their proper places in 

 the system ; though I hope it may, in the end, prove to be a step in 

 that direction also. 



I am confident that this latter will not be satisfactorily accom- 

 plished in the case of the Picarian birds until we not only have 

 a pretty thorough knowledge and understanding of their structure 

 in its entirety, but an equally complete comprehension of the mor- 

 phology of a number of the groups that are known to approach them 

 in one particular or another. 



To review the characters presented in the Trochilidine skeleton — 

 for many of the important ones are already known to us — Trochilus 

 (dexandri affords a very good type. I have at hand a perfect 

 skeleton of this Humming-bird, collected and prepared by myself for 

 the purpose. 



Of the Skull of Trochilus (Plate LVIII. figs. 1, 2, 3).— Viewing 

 this part of the skeleton from above, we find that the superior 

 mandible has a length of something less than two thirds of the 

 medio-longitudinal axis (fig. 1). It is nearly flat in its anterior 

 moiety, being much compressed from above downwards, narrow, 

 rounded at the apex, and of nearly equal width throughout, and 

 slightly decurved, for this part of its extent. The posterior half of 

 the superior mandible is broad at the base, and gradually tapers 

 forwards to merge into the portion just described ; sutured traces 

 among the bones here have all been completely absorbed ; the ex- 

 ternal narial apertures are very capacious, though an attempt on the 

 part of the nasal processes of the premaxillary to diminish their size 

 is evidently made. This effort is to be detected in the horizontal 

 osseous outgrowth on either side from these parts, which if it had 

 been more extensive and produced, as it is in some birds, would have 

 succeeded in creating narial openings, as in the majority of the class. 

 As it is, however, in this Humming-bird a knife-blade may be carried 

 from the foot of the nasal on the upper side of the maxillary and 

 dentary process of the premaxillary, in contact with them to near 

 the tip of the latter, without coming in contact with the bone above, 

 if the knife be properly inclined at a right angle (figs. 1, 2, 3a). 

 This is well seen in some Limicoline birds, as in Nmnenius longirostris, 

 though in tbem the osseous outgrowth a referred to, is not developed \ 



^ See author's osteology of N. longirostris, &c., in the Journal of Anatomy 

 and Physiology for Oct. 1884, plate iv. fig. 3, and his meaning will be clear. 

 Here, however, the bones simply rest against each other, though they would 

 allow the passage of a knife-blade from i to h. 



