176 SHOULDER-GIRDLE AND BREAST-BONE. 



a sub-triangular, square-ended middle plate. The costal processes are high, sharp, and recurved ; 

 there are four pairs of condyles. There is no rostrum, but the ento-sternum retains a shallow 

 (primordial) notch, both above and below the distinct coracoid grooves. The keel is very deep, 

 veiy arcuate in its lower outline, and elegantly concave in its front margin ; the angle is less pro- 

 duced than in Cuculus canorus, and the inter-clavicle is attached to it by a larger ligament. 



In Nyctibius jamaicensis (op. cit., fig. 7) the coracoids are relatively longer ; the furcular rami 

 are much more pointed and curved at their tips ; the prae-coracoid enlargement is indistinct ; and 

 there is no inter-clavicle. The Sternum is nearly square, the outer xiphoids bulging but little ; 

 there are four rather shallow notches, and the intermediate bars are nearly as large as the outer, the 

 middle process equalling the two together. Podargus plumiferus (op. cit., fig. 8) agrees morpho- 

 logically with Nyctibius, but the Sternum is longer ; its increased length being due to the large, sub- 

 arcuate outer xiphoid bars, which reach some distance behind the middle plate, and are obliquely 

 pedate. The intermediate bars are very small, and are differentiated from the truncated wedge- 

 like middle plate by a small notch ; they do not reach so far backwards as the middle part. 



In Podargus humeralis (Hunt. Mus., No. 1528) the furcula is narrower, and the meso- 

 coracoid processes are very much curled, the sternal notches are deeper, and the outer and inter- 

 mediate processes are longer and narrower, whilst the middle plate is rather oblong than 

 wedge-shaped much wider than that of P. plumiferus. 



In Professor Owen's valuable paper on the Dodo ('Trans. Zool. Soc.,' 1867, pi. 24, 

 fig. 4) there is the lower view of a Sternum, said to be that of Podargus humeralis. This would 

 appear to be rather a young one, or not belonging to the true P. humeralis ; or if it belong to 

 that species, it is a very curious individual variety. The whole xiphoid region is much feebler 

 than in the specimen in the Hunterian Museum ; the outer processes are incurved instead of 

 spreading outwards ; the right inner notch is absent ; and the middle plate is wedge-shaped, nar- 

 rower than in P. plumiferus, and very unlike that in the specimen of P. humeralis above referred 

 to. In jtEgothcles cristatus (Hunt. Mus., Nos. 1526, 1527) the Shoulder- and Breast-bones are 

 feebler than in Caprimulgus, the coracoids are shorter, the furcula feebler, but having the same 

 prae-coracoid shoulder and inter-clavicular plate. The Sternum is much narrower in front, but 

 wider behind, and in the old bird there are four very large angular " fenestraa," the inner being 

 the largest. These were once " notches" (see ' Ost. Catal.,' Hunt. Mus., vol. i, p. 291, No. 1527), 

 for in the younger specimen two of these spaces are open. In the older bird all the five bars are 

 bound together by periosteal growths, so as to form an arcuate and sinuous posterior margin with 

 projecting and rounded angles. 



Family" CYPSELINvE." 



Example. Cypselus apus, Linn. 



The Swifts have their whole osseous structure correlated to the most perfect organs of flight 

 in the whole Class ; they form a connecting link between the Caprimulginge, the Hirundina?, and 

 the Trochilinse, but are much nearer akin to the first two Families. I am fortunate (with my 

 limited space) in being able to refer to a very valuable paper on this Family by Dr. Sclater 



