1885.] TROCHILID,E, CAPRIMULGID.C, AND CYPSELTD.*:. 90o 



against the coracoids, their apices extending backwards to touch 

 either scapuhi. In Nuttall's Whippoorwill an outer ledge is deve- 

 loped on either clavicular head to abut against the corresponding 

 coracoid in front, a feature which is still better displayed on the 

 part of the Ci/pse/idrf: ( Plate LX. fig. 2, z). 



A scapula in the Night-hawk has the typical blade-like portion, 

 which is more inclined to be truncated in PhalcEonoptilus. Both 

 birds have its head broad transversely, and somewhiit flattened from 

 above downwards. Wlien articulated it rests upon rather a meagre 

 scapular process of the coracoid, with its inner angle extended tor- 

 wards to meet the clavicle, as already defined above. 



The elements of the pectoral arch seem to be non-pneumatic bones 

 throuujhout the CaprimuU/ulte. 



Of the remainder of the Cypseline Axial Skeleton. — We find in 

 the cervical region of the column of P niyptila saxatUis twelve 

 vertebrae before meeting that one in wl)ich the pleurapophyses have 

 become liberated as ribs. These latter are here of the most rudi- 

 mientary character; for in a specimen before me, on one side the rib 

 is merely represented by a minute rod of bone suspended from 

 beneath the transverse process, while on the opposite side the head 

 of the bone is found, and the whole is rather more advanced. The 

 atlas is more than usually delicately constructed, while the axis is 

 very narrow in the antero-posterior direction. 



A shallow carotid canal seems to be confined to the fourth and 

 fifth vertebrae, the usual process taking its place after that. All 

 these vertebrae, as a rule, are notably short, with well-developed pre- 

 and post-zygapophyses. 



Beneath, the parapophyses are as long as the centra, and are 

 placed rather close together on each vertebra. 



The articulations are of the heterocoelous type, and the lateral 

 canals are very short. One very interesting feature is seen in this 

 part of the spinal column of the White-throated Rock-Swift, and 

 that is the ossification of the interspinous ligaments among the 

 ultimate segments. The neural spines of the tenth, eleventh, twelfth, 

 and thirteenth vertebrEe are low and inconspicuous, and the fine 

 thread-like hgament that joins these processes has become thoroughly 

 ossified, the minute osseous rods thus formed articulating, at eitiier 

 end, with the neural spines of the vertebrae in question. These 

 vertebrae, in Panyptila, are essentially very different from the corre- 

 sponding bones in Trochilus. 



The fourteenth vertebra possesses a pair of free ribs, which may 

 or may not have uniform appendages near their lower extremities ; 

 and this segment has likewise many of the characteristics of the 

 dorsal series that follow. 



Below it develops a tricornuate hypapophysis, this process being 

 markedly prominent on all the succeeding vertebrae, occurring also 

 upon the first two in the sacrum, an unusual thing. The presence 

 of this formidable series of hypapophyses is accounted for by the 

 same law that demands their presence in Colymbus, the sole differ- 

 ence being that, while the latter, by the aid of his strong wings, passes 



