1 CO Lucas on the Affinities of C/i(^fnra. [October 



shorter in Chcettwa than in Trochihis. In shape it is intermedi- 

 ate between Trochilus and Chordeiles^ Trochilus being inter- 

 mediate between Chordeilcs and CheUdon. The first phalanx 

 of the thii-d digit of Trochilvs^ although long and slender, does 

 not begin to equal in these respects the corresponding phalanx of 

 Aptenodvtcs^ and is approximated even by C/ioj'deilcs^ so that 

 mere length can hardly be adjudged a good distinctive character. 

 In the manner in which the second and third digits articulate with 

 the metacarpus T)'ochilus^ Chcetiira and CJiordciles agree very 

 well among themselves, showing little of the 'breaking joints' found 

 in CheUdon and other Passerines. In the proportional length of 

 the outer phalanx of the second digit CJnvtura falls a little short 

 of Ti'ochilus, although vastly exceeding CheUdon. 



The most remarkable feature in the pelvis of Trochi/us is the 

 o-reat length of the slender, incurved pubes, which almost touch 

 one another. This is also the case with Chcvtitra., although to a 

 much less degree. In CheUdo?z, on the contrary, the pubes are 

 of but moderate length and but slightly incurved, so that they are 

 verv far removed from one another at their extremities, as in the 

 hi<''her Passerines. Chordeiles^ in this as in other particulars, 

 lies between CheUdon and Chcvtiira. 



A slighter character is found in the varying development of 

 the ilio-neural grooves. These are practically obsolete in Tro- 

 chiUiS and nearly so in Chcvtura ^ shallow in Chordciles^ and 

 deeply excavated in CheUdon., AnipeUs, Merula^ and others. 

 The region immediately over the true sacrals is strongly tumose in 

 both Trochilus and Chcctura., but not at all in CheUdon., or even 

 Chordeilcs. 



Passing by the femora, which present few salient characters, we 

 find that Trochilus and Chcctura have the cnemial ridges of the 

 tibia but poorly defined, while in CheUdon they stand forth as 

 boldly as in Merula., Chordeilcs again holding a median position. 

 In Trochilus the fibula is one-fourth the length of the tibia, in 

 ChcetJira less than one third, in CheUdon over one-half. 



Both Trochilus and Chcctura have a deep groove on the front 

 of the 'tarsus,' at the lower end of w4iich is a comparatively large 

 foramen. Not only CheUdon but Chordeilcs also has the shallow 

 tarsal groove and minute perforation of the higher Passerines. 

 Trochihis is peculiar in having a deep notch or emargination on 

 the iniiej' side of the 'tarsus' near its proximal extremity. 



