332 



DE. 31. W. SHTJFELDT's MOEPHOLOGICAL 



Next, passing to the consideration of the tihia^ we find its 

 shaft to be nearly straight, being but slightly convex forwards; 

 while for the greater portion of its midcontinuity it is of a sub- 

 cylindrical form, changing only as it approaches its enlarged 

 extremities. At the proximal end of the bone the pro- and 

 ectocnemial ridges on its anterior aspect are considerably sup- 

 pressed, and soon merge into the shaft below ; they are nearly 

 of equal size, and the cnemial crest above them does not rise 

 above the tibial summit. 



Although the condyles at the distal end of the bone are very 

 similar to these protuberances as they are commonly fouud in 

 the majority of small birds, they are yet peculiar in having 

 between them, below and behind, a mid- and well-marked longi- 

 tudinal ridge, constituting a feature that at this moment I do not 

 remember to have noticed among the tibiae of the class. 



On the anterior aspect of this tibia, just above the condyles, 

 we notice the usual longitudinal tendinal groove, spanned at its 

 lower part by an osseous bridgelet thrown directly across it. 



The tar so-met at arsus has a length equal to rather more than half 

 the length of the tibia, while the calibre of its shaft is about one 

 third less than that of the latter bone. This tar^o- metatarsal 

 shaft presents three plane and iftigrooved surfaces, an anterior 

 one and two lateral, or rather postero-lateral, ones. The summit 

 of the bone is moulded in the usual manner for articulation with 

 the tibial condyles. Behind the proximal extremity of the bone 

 we find a fairly well-developed hypotarsus, vertically pierced by 

 two tendinal canals placed side by side. 



Passing to the distal end of the tarso-metatarsus, we find the 

 trochlese so disposed as to accommodate themselves to the zygo- 

 dactyle condition of the j^odal digits, which consists, as we know, 

 in Trogons of a permanent reversion of the second toe. 



These digits have their bony phalanges arranged upon the 

 most usual plan as we find it in the vast majority of living birds, 

 i. e. 2, 3, 4, and 5 joints for the first, second, third, and fourth 

 toes respectively. 



Considered as a whole, although the skeleton of the foot of 

 this bird is in due proportion with the rest of the limb, it never- 

 theless strikes us as being rather a delicately formed structure. 

 The accessory metatarsal possesses a shape usually assumed by 

 it among birds, but in the present instance makes a very close 



