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Show 1885.] TROCHILID^E, CAPRIMULGID.E, AND CYPSELID^. 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 m y 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 accomplished 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 morphology 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 alexandri 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 external 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 Numenius longirostris, though in them the osseous outgrowth a referred to, is not developed 1. 1 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 k. |
