1865.] ON THE GENERA AND SPECIES OF CYPSELIDA. 593 
9. Nores oN THE GENERA AND SPECIES OF CyPSELIDZ. By 
P. L. Scuater, M.A., Pu.D., F.R.S., SECRETARY TO THE 
Society. 
(Plates XXXTIL., XXXIV.) 
In offering to the Society some notes on the Cypselid@, which 
have been put together during the time that I have devoted to this 
group with the object of working out the American species, I may 
begin by stating that my views as to the correct position of this family 
in the Natural System coincide with those of L’ Herminier*, Nitzsch, 
and Burmeister. There can be no doubt, I think, if osteological and 
pterylographical characters are to have any weight in our classifici- 
tion, that we must place the three families Trochilide, Cypselide, 
and Caprimulgide next to one another. It need scarcely be added, 
therefore, that I consider that the Swifts have no relationship what- 
ever with the Swallows (Hirundinide), with which, in spite of the 
frequent protests of scientific ornithologists, they are confounded 
even to the present day by certain systematists who attend only to 
the most superficial external characters. 
Without going into the general anatomy and osteology of the 
Swifts, which offer so many peculiarities, I may say a few words con- 
cerning two points—the form of the sternum, and the number of the 
phalanges of the toes—concerning which I have some new facts to 
communicate. 
The general form of the sternum in the genus Cypselus has been 
well described by M. E. Blanchard in his admirable article upon the 
osteological characters of the sternum of birds in the ‘ Annales des 
Sciences Naturelles’+. As a typical form of the group, M. Blanchard 
describes and figures the sternum of the Common Swift (Cypselus 
apus). We cannot do better than follow his description of the more 
noticeable points in the structure of this organ, which is represented 
in the accompanying woodcuts (figs. 1 & 2). 
The body of the sternum of Cypselus apus is much produced, and 
gradually widened towards its posterior extremity, the lateral mar- 
gins curving gradually outwards, and meeting the posterior margin 
nearly at right angles. The posterior margin (see fig. 1) is convex, 
forming a segment of a circle ; it is continuous throughout, and pre- 
sents no traces of posterior fissures. The keel (see fig. 2) springs at 
once from the posterior margin, and rises high and rapidly, attaining 
an enormous development. It projects far in front over the anterior 
margin of the body of the sternum, and terminates in a rounded 
point, descending thence to the anterior margin of the body in a 
concave curve. ‘There is scarcely a trace of the manubrial process 
* As long ago as the year 1827, in his ‘ Recherches sur ]’appareil sternal des 
oiseaux,’ M, l’Herminier well described the sternal apparatus of the Swifts, and 
constituted them the seventh family of his “‘ Normal Birds,” placing them between 
the Colibris (Trochilus) and the Engoulevents (Caprimulgus). 
+ Recherches sur les caractéres ostéolugiques des Oiseaux, &c. (Ann. d. Sc. Nat. 
ser. 4, Zool. vol. xi. p. 11). 
Proc. Zoou. Soc.—i865, No. XX XIX. 
