1865. ] GENERA AND SPECIES OF CYPSELIDZ. 595 
large irregular medial foramina, one on each side. The same fora- 
mina are present in some of the weaker forms of Cypselus, as already 
noticed by Mr. Gosse* in the case of his Tachornis phenicobia. 
Collocaliat presents us with a sternum (figs. 5 & 6), which may be 
described as a miniature of that of Chetura. Besides the irregular 
Fig. 5. 
Figs. 5 and 6. Sternum of Collocalia francica. 
lateral foramina in the face of the sternum noticed in the latter genus, 
there are likewise two small openings perforating the lower part of the 
carina, as is mentioned by Gosse in the case of his Tachornis (I. c.). 
These are not shown in the figure. 
Dendrochelidon, as already remarked by M. Blanchard, is, as re- 
gards its sternum, somewhat divergent from the typical form of 
Fig. 8. 
Figs. 7 and 8. Sternum of Dendrochelidon wallacii. 
Oypselus. The whole sternal apparatus is much broader in propor- 
tion. The posterior margin of the sternal plate is slightly concave 
instead of being convex. The two medial foramina are large and 
well-defined, and two posterior foramina are likewise present, although 
the posterior margin of the sternal plate is entire and strongly ossi- 
fied. The general character of the sternum, however, is strongly 
Cypseloid, and, putting aside the other points of its structure, leaves 
* Birds of Jamaica, p. 59. 
+ Of the Osteology of Collocalia Dr. Bernstein has written a very complete ac- 
count in the twenty-sixth volume of the ‘Acta Academiz Leopoldino-Carolinz 
(p-15). Dr. Bernstein gives figures of the breast-bones of the two Javan species 
(C. esculenta and C. nidifica), and shows conclusively that this genus is in every 
point of view truly Cypseloid and is most nearly allied to Dendrochelidon. 
