1889.] MR. W. K. PARKER ON STEATORNIS CARIPENSIS. 179 



length of the ulna, whilst the manus is more than three and a half 

 times as long as the humerus. 



In Steatornis, on the contrary, the humerus (h.) is seven eighths 

 the length of the manus, whilst the former is only two thirds the 

 length of the ulna, and the manus less than four fifths. 



Caprimulyus is intermediate between these two extremes ; its wing- 

 regions increase in size in a regular manner (from above down- 

 wards) ; it is a sub-typical " Macrochire." 



Buceros is tlie most remarkable in one respect ; its manus is only 

 four-sevenths the length of its ulna. 



In the two good instances of birds with a light buoyant flio'ht, the 

 White Owl and the White Gull, the greater length 'of the°ulna as 

 compared with the humerus is similar in both birds ; but the 

 Gull has its ulna and manus of tlie same length, whereas in the Owl 

 the latter is only six sevenths the length of the ulna or cubitus. 



All these birds have to be considered separately in their various 

 modifications, and no inference as to their genesis made rashly from 

 some one or more similarities in their adapted structures. 



I might have included Podargus humeralis amongst the birds 

 whose wings were measured ; but it gives me Httle help iu seekino- to 

 find the afiinities oi Steatornis. Podargus iip])ea.TS to me to be more 

 allied to Eui-ystomus ; its sternum and pelvis differ greatly from 

 those of this Neotropical bird, and its wings are more normal iu 

 the relative length of the three regions. Thus the humerus in 

 Podargus is 74 millim. long, the ulna 88 millim., and the manus 68 

 millim. 



The relations of Podargus must be sought for in the Australian 

 Region and the Eastern Notogaea, generally; those oi Steatornis in the 

 Neotropical Region ; whilst the true Goatsuckers, or Capri mulo-idae, 

 must find their ancestors where they can. I cannot see my way to 

 "father them" on either Steatornis or Podargus; yet both of 

 these types may possibly be not unlike the birds that, during time, 

 have been specialized into the true Goatsuckers. 



I can only find a pneumatic foramen in the humerus (k.) ; that 

 bone is quite normal ; its upper crest for the insertion of the great 

 pectoral muscle is large, and the dilatation below is hooked inwards, 

 hollowed out and perforated to let in the air. The distal condyle is 

 well developed, and there is above it, on the flexor side, a semi-oval 

 hollow for the origin of the flexor muscles \ 



The long, slender, gently sigmoid radius (r.) and arcuate ulna (u.) 

 are quite normal ; the latter is marked very slightly for the secondary 

 quills. The radiale and the ulnare are also well developed and per- 

 fectly normal ; I see no " sesamoids " attached to them. The top of 

 the manus has the large 2nd distal carpal (^.c") over the laro-e 

 middle metacarpal, the lesser 3rd distal carpal (rf.c.^) on the outer 

 side of the top, and the 1st distal carpal (Plate XX. fig. 2, d.c.^) is 

 seen as a knob looking towards the 1st metacarpal, but ankvlosed to 

 the 2nd. ^ 



1 Mr. Frederic A. Lucas liuds au "os humero-capsulare " iu this bird Csee 

 Plate XX. fig. 1, o.kc). ^ 



