( 80 ) 



an OeyrlromtiS in wliicli the bone is aliout tlie same length as in tlie fossil, the siialt 

 is mncli more slender; and in Cahnlus sylvcstris and C. dutfenhachii, in which, 

 however, the bone is much smaller, its proportions differ from the fossil in the same 

 way. 



The ulna is similar in structure to that of Ocyilromufi, but is consideralilv shorter 

 and thicker; there is a deep depression for the hmcliiaJis anlicun, him] the points 

 of insertion of the secondaries are well marked. 



The radius is also shorter and thicker than in Ocydromus. 



The metacarpus is extremely short and stout, and the proximal end is dispro- 

 portionately large. The second metacarpal is very much thicker than the third 

 which is laterally compressed. The first metacarpal is less prominent than in 

 Ocydrovius and Cabaius, and forms a rectangular prominence. .\t the post-axial 

 end of the pnlleylike surface for the carpals there is, on the outer side, a very large 

 deep pit into which the outer end of the " cuneiform " fits when the mauus is flexed 

 upon the forearm. 



The 1>i;xgth in .Millimetres or the Puinctpal Boxes oe the Wi.no. 



In a skeleton of Binphorapteryx in which all the wing-bones probably belonged to one individual 

 the respective lengths of humerus, ulna, radius, and metacarpus are fi5, 44, 10, 27 niiu. 



Except that it is considerably broader in proportion to its length, the pelvis 

 is very like that of Ocyilroiiius. The obturator notch is, however, more rounded, 

 and the ischiadic foramen somewhat different in form. The supra-acetabular crest 

 of the ilium is more strongly developed than in Ocydromus, Erythromackus, 

 and Cabaius, but behind the acetabulum the ridge is smaller than in those 

 birds, and is not ])roduced outwards into a pointed process overhanging the surface 

 for the ischio-femoral muscle. In the preacetabular region the lower borders of 

 the ilia are less concave than in Ocydromus; the upper borders unite above the 

 neural spines to form a crest strongly convex from before backwards. In some 

 specimens the ilio-neural canals remain open posteriorly ; in others they close. 

 As in Ocydromus and Cabaius sylvestris, the upper sm-face of the sacrum behind 

 the iliac crest is somewhat depressed and concave from side to side ; there is a 

 number of irregularly placed interosseous foramina. The pectineal processes are 

 \ery small. 



The fir.st of the fused vertelirae which constitute the "sacrum" has its neural 

 spine almo.st comjiletely overlapped by the ilia; it bears capitular and luliercular 

 facets for articulation with a free rib, and really belongs to the thoracic region. The 

 succeeding five vertebrae (lumbar) are united with the ilia by their transverse 

 processes, which increase in size from before backwards; in Ei-ythromachus and 



