110 



MB. C. W. AITOEBWS ON EBMAINS OF JEPTOEIHS [Feb. 6, 



1 cm., but the summit is broken away. This projection occupies 

 just the position of attachment of the hallux in such birds as 

 possess one, and it maj represent the ligament by which the hind 

 toe was attached ossiBed from age. 



The trochlese are large and are arranged along a slightly curved 

 line. The middle one is broadest and projects beyond the others ; 

 its sides are deeply concave and its articular groove only very 

 slightly oblique to the long axis of the bone. Of the other two, 

 the inner is the smaller, but projects slightly beyond the outer. 

 There are no projections at the lower end of the channel for the 

 tendon of the adductor of the outer digit, such as are figured in 

 the tarso-metatarsus of uE. hildebrandti. 



In both the present specimen and in that described by 

 Burckhardt (2) the width of the distal end is greater, in proportion 

 to the least circumference of the shaft, than it is in the tarso- 

 metatarsi from the coast. 



The fibio-farsus is complete except the postcondylar processes, 

 which are broken away. The bone on the whole resembles that of 

 ^. hildebmndti, but differs from it in size and in some other 

 respects. The dimensions are : — 



Length 



Width of distal end 



Width of shaft at narrowest 

 point 



Circumference of shaft at the 

 same point 



M, sp. 



cm. 

 57-5 



100 



50 



14-0 



^. maximus. 



M. hildebrandti. 



cm. 

 64-0 



13-5 



15-5 



cm. 

 48-0 



8-2 



11-0 



It wall be seen from the above table that the tibio-tarsus, hke 

 the tarso-metatarsus, is intermediate in size between the corre- 

 spoudiug bones of JE. maximus and ^. hildebrandti, and it is also 

 rather longer in proportion to the tarso-metatarsus than is the 

 case in ^. hildebrandti. The antero-posterior flattening and the 

 curvature of the shaft, which are characteristic of the genus, are 

 well marked. The distal articulation fits exactly into the proximal 

 one of the tarso-metatarsus above described, and there is no doubt 

 that the two bones belong to the same species, if not to the same 

 individual. The median ridge between the condyles figured in the 

 tibio-tarsus of ^. hildebrandti (2) is here wanting. The cnemial 

 crest is moderately developed and rises a little above the proximal 

 articular surface. On the upper outer surface of the ectocnemial 

 crest is a foramen, probably pneumatic, the exact size of which 

 cannot be determined, its edges being broken away owing to the 

 thinness of the bone at that point. 



