MuRiE. — On Hybridism of Fowl and WoodJien. 3i9 



inner toe slightly longer than outer toe ; mid-toe about one- 

 third longer than either ; claw-bones relatively wide. 



Of the leg-bones in Ocydromus the following obtains : The 

 trochanter is depressed ; the external condyle barely descends 

 beyond the internal one ; the cnemial process towards the 

 inside of the bone is short, but relatively and absolutely more 

 prominent than in the larger pseudo-hybrid skeleton ; the 

 outer tibial knuckle is the largest one ; fibula two-thirds the 

 length of shaft of tibia ; the upper post-tarsal projection only 

 extends down one-fourth the length of the tarso-metatarse, is 

 furrowed, but has no foramen. Hind-toe bones shorter than 

 the first phalanx of mid-toe ; outer and inner toe subequal in 

 length; mid-toe one-fourth longer than either adjoining; 

 claw-bones laterally compressed. 



With regard to the vertebral column, costoe, and cavity of 

 the chest in this quasi-hybrid, these in the main coincided 

 with what Darwin records of the fowl in the volume already 

 quoted. Thus, we reckon as present 14 cervical,* 7 dorsal 

 with ribs, 15 lumbo-sacral, more or less ankylosed, and, lastly, 

 6 or 7 caudal vertebral elements. It is worthy of notice that 

 the 6th cervical presented the bridge of bone said by Darwdn 

 to exist in the Cochin fowl. The llth cervical did not bear 

 ribs. The ribs extant were 7 in number and proportionally 

 strong and broad. 



In the skeleton of Oc//dronius used for comparison the 

 cervicals were 14, dorsals 8 freely-separated vertebras, 14 

 more or less coalesced lumbo-sacral, and 11 caudal vertebral 

 bodies, all free and movable on each other. The entire spinal 

 column and its related parts show a delicacy of mould, and 

 this is very notable in the tail-elements, which organ, be it 

 remarked, has in the rail tribe only short soft feathers cloth- 

 ing it. There are ten ribs, seven of which are very long, and 

 all are attenuate bony rods ; six have mid-costal processes. 

 The last cervical and first ilio-sacral vertebra have each a pair 

 of short free ribs. The chest cavity is unusually deep and 

 narrow, as contradistinguished from that of the doubtful 

 hybrid or that of the common fowl. 



From the foregoing data it will readily be conceded that in 

 all the exterior as well as interior organization of the bird 

 under examination scant ground is left for support of its being 

 a hybrid between the fowl and weka rail. Assuming no 

 detailed anatomical investigation had been undertaken, the 



* Darwin, in a footnote, loc. cit., p. 2G6, accuses himself of not correctly 

 assigning the vertebral group-numbers, referring to Prof. W. K. Parker's 

 opinion thereon. I prefer to follow his own notation and statements, as 

 more readily allowing comparisons, while not involving any theoretical 

 question as to what constitutes vertebral regions in birds — a subject, more- 

 over, by no means yet settled among osteologists. 



