] 904.] FROM MADAGASCAR AND EGYPT. ] 67 



reception of the so-called middle trochlea of the tibia. The upper 

 part of the anterior face of the shaft is deeply concave owing to the 

 posterior position of the upper end of the middle metatarsal ; this 

 concavity runs about three-quarters of the way down the shaft, 

 and even below this the anterior face is slightly grooved for the 

 adductor tendons. The inter-osseous foramina open at the same 

 level anteriorly, and immediately beneath them is the single large 

 tuberosity for the insertion of the tendon of the tibialis anticus. 

 On the posterior surface of the bone, the upper end of the thii-d 

 metatarsal forms the biilk of the large talon, consisting of a pro- 

 minent ridge on the outer side and a small tuberosity on the inner, 

 separated by a shallow groove for the tendons. The main ridge 

 of the talon is continued down the upper three-fourths of the 

 trihedral shaft, of which it forms the posterior angle. In section, 

 the middle portion of the shaft is triangular, the sides of the 

 triangle being concave and the concavity of the anterior face being 

 the deepest. A little above the distal articulation the shaft is 

 convex in front and slightly concave behind. The middle trochlea 

 is much the largest of the three and extends considerably beyond 

 the inner one, which in size and form closely resembles the outer, 

 much more nearl}'-, indeed, than is the case in yEpyomis. Just 

 above the notch between the outer and middle trochlere, the 

 bone is perforated by two foramina, one above the other but close 

 together : of these the upper one (add.) pierces the bone and opens 

 on the palmar aspect at the posterior end of the channel between 

 the two trochlete, the other opens in the middle of the same 

 channel ; the upper or posterior of these perforations probably 

 tx^ansmitted the tendon of the adductor digiti externi, but the 

 function of the other is unknown to me. 



In a note on some remains of jEpyornis in the Tring Museum 

 published some years ago*, I ventured to suggest that Midlerornis 

 rudis, the metatarsal of which is said to be perforated by the 

 tendon of the adductor digiti externi, should on that account be 

 referred to a new genus, Flacourtia. If the presence of this 

 character were really of generic value taken alone, the present 

 species should likewise be referred to Flacourtia ; but since the 

 presence or absence of this perforation seems to be of very A-ariable 

 occurrence, it will be better to refer all the small, lightly built 

 yEpyornithidfe at present known to one genus, Mullerornis, at 

 least till some more valid distinctions are found, which may very 

 well happen when the skulls and skeletons of the various species 

 are known. 



So far as can be seen, the thickening of the bones (pachyostosis), 

 though of course much less in degree than in yEpyornis, is of 

 precisely the same kind as that described by Burckhardt in 

 the case of uEjyyoi^nis hildehrandti, and differs from the type found 

 in the Dinornithid^e, in which the bones are much more solid and 

 heavier. 



* Novitates Zoologicoe, vol. ii. p. 25. Tring, 1895, 



