366 



DR. E. SHTJFELDT's MORPHOLOaiCAL 



present drawings of tlie same here to illustrate my meaning. 

 A glance at the contour of Micropus will be sufficient to con- 

 vince us that in general outline it is strikingly, indeed actually, 

 far more like any one of our Swallows, as JProgne for instance. 

 And, apart from the resemblance which its short antibrachium 

 gives it to Trocliilus (PI. XXIV. fig. 39), it has no other character 

 upon this aspect of its body to support the view that any true 

 relationship exists between it and the latter bird. For the 

 rest, to my mind, shortness of the antibrachium amounts to 

 nothing as an indication of affinity unless correlated with actual 

 similarity of form in its details. Clicntura having a deeper 

 carina to its sternum than has the other Swift, Micropus^ it bears 

 a somewhat more general resemblance to the body of a Humming- 

 bird (fig. 39) than it otherwise would do, or as does Micropus ; 

 but some of the smaller Petrels might hold an equal claim to 

 affinity wdth Trochilus were it based upon such data as this. 



Coming to a few of the true characters, we find the bill, the 

 position of the commissure of the gape, the feet, and some other 

 points widely different in a Swift from what the corresponding 

 characters are in a Humming-bird ; and when Micropus is the 

 Swift chosen for the comparison, the entire contour of its tody 

 differs from that of Trochilus in all important particulars. 



Let us next examine the pterylography of these three birds, 

 and see what it indicates in regard to their affinity. 



Nitzsch has presented us with fairly good figures of the 

 pterylography of Oypselus apiis and Trochilus moschitus (Pterylog., 

 ed. Sclater, pi. iii. figs. 16-19) ; but there are several points 

 requiring elaboration in his account, while in other particulars 

 his comparisons are deficient. 



Taking his figures and descriptions just as they stand, how- 

 ever, and bringing into the discussion his figure 14 on the same 

 plate, of Hirundo urhica, we find that the pteryloses of the Swift 

 and Swallow, so far as their heads are concerned, agree, with the 

 exception that the Swift possesses those peculiar crescent-shaped 

 apteria, one over each eye ; these are absent both in the Swallow 

 and Humming-bird. 



But the Humming-birds have a median naked space of a 

 spindle-shaped outline on the crown, situated longitudinally, and 

 between the eyes and the base of the superior mandible. This 

 is well marked in all species which I have thus far examined, 

 and it was overlooked by Nitzsch ; moreover, it is absent in 

 the Swifts and Swallows. 



