314 
toes?; and this was a strong one in Aptornis, with a pulley to match. The base of the 
perforated process equals half the transverse diameter of the proximal end of the meta- 
tarsus, outstanding a little to the outer side of the middle of the hind part of that 
surface, slightly deflected at the end. ‘The inner wall has a longer base of origin than 
the outer one. ‘There is a feeble indication of the parts of the canal respectively 
traversed by the ‘ perforans” and “‘ perforatus”’ tendons, but no outside grooves; and 
the difference from the gallinaceous metatarsus is shown by the non-continuation of the 
entocalcaneal plate with the postinternal crest on the.shaft of the bone, giving attach- 
ment to one of the divisions of the sheath-forming insertional tendon of the “ gastro- 
cnemius externus””. 
The beginning of the postinternal crest is separated from the entocalcaneal process by 
a canal about 14 line wide, into which opens the antero-posterior (interosseous) canal 
between the inner and middle metatarsal elements. The surface on the inner side of 
the postinternal crest for the origin of the “ flexor brevis pollicis” is extensive and well 
marked, according with the size of the digit indicated by the hallucial articular surface 
(Pl. LXXXVIL. fig. 5,1). The anterior surface of the metatarsus is impressed, near 
the tibial articulation, with a deep fossa, into which open the two “ interosseous ” tubular 
canals; beneath these are surfaces for the origins of the “extensor pollicis brevis” and 
“ adductor digiti externi;”’ and the inner side of the fossa is produced into a short ridge, 
into which the tendon of the “ tibialis anticus”* is in part inserted, Midway down the 
fore part of the shaft begins the groove for the “ adductor digiti externi,” the tendon of 
which glides through the canal above the interval between the middle and outer trochlear 
condyles, which canal is present in the Votornis and Coots, though by no means peculiar 
to them. It is one of the well-marked distinctions between the metatarsus of Aptornis 
and of Apteryx, this latter bird agreeing with Dinornis in the absence of the intertro- 
chlear canal. 
The surface below the postinternal crest indicates a strong and large back toe (hallux, 
Pl. LI. fig. 7,1); but Notornis and the Coots have this in common with the Rasores. 
The trochlez of the digits 1 & Iv descend almost to the same level; Iv is, perhaps, 
rather the lowest ; in Notornis and the Coots it is more decidedly so. The mid condyle 
ismore advanced and more produced in Aptornis, as is usual in Gralle and Galline, and 
as it is, indeed, in Apteryx and Dinornis. The interval between the toes ur & rv in 
Aptornis is wider and deeper than that between 11 & u. The grooved or trochlear 
character of each condyle is well marked. 
On the whole, the inference seems legitimate that we have in the metatarsus of 
Aptornis a bone extremely modified for “rasorial” functions upon a porphyrian or 
* yalline ” type. 
1 & Myology of Apteryx,” pp. 41-70, Pls, XII., XIV., 1,3, 4, 5,6. 2 Pl, XLV. R***, 8 Tb. 8. 
