PEOFESSOE OWEN ON THE GENUS DINOENIS. 363 



A comparison of these dimensions with those of the two species of Dinornis to which 

 the present comes nearest, in the Tahle of Admeasurements, p. 371, will exemplify the 

 chief metatarsal characteristics of Dinornis gravis. 



In general configuration, as in robustness of proportion, though exceeding in the 

 latter respect, the present metatarsus most resembles that of Dinornis crassus. I note 

 the following differences, which are repeated in specimens of the metatarsus from two 

 individuals of Din. gravis from remote localities in the South Island of New Zealand. 

 The intercondylar rising (PL LVIII. figs. 1, 3, c) is but slightly developed anteriorly 

 in any Dinornis, but it has more claims to be considered a " process " in Din. gravis 

 than in Din. crassus ; the entometatarsal tuberosity (ib. figs. 1 & 3, e) is more pro- 

 minent, and is longer. 



In the antinterosseal depression (ib. fig. 1, i) the upper common anterior orifice (ib. n) 

 of the interosseal canals is less speedily divided into the entinterosseal (ib. fig. 2, I) and 

 ectinterosseal (ib. m) canals than in Dinornis crassus; the rough depression below for 

 the tibialis anticits (ib. fig. 1, o) is deeper and better-defined for its size in Dinornis 

 gravis. 



The calcaneal groove (ib. figs. 2, 3, u) is narrower and deeper in Din. gravis ; and the 

 entocalcaneal process (ib. ib. r) is rather less prominent. The outer depression on the 

 ectocalcaneal process (ib. s) is better marked, and in one metatarsal specimen of Din. 

 gravis appears as a shallow longitudinal groove. 



The posterior orifice of the entinterosseal canal {I) does not open into a depression of 

 the bone; that into which the ectinterosseal canal (m) opens, is wide and shallow. 

 The interval between these two orifices in one of the specimens is greater in Din. 

 gravis than in the longer metatarsus of Dinornis crassus ; in the other it is as great. 



As in Dinornis crassus, the places of insertion of the strong ligamentous aponeurosis 

 formed by the confluence of the tendons of the gastrocnemius internus and gastro- 

 cnemius externus are less longitudinally extended, less ridge-like, and are more concen- 

 trated, broader, and better marked than in Apteryx australis^. 



The entogastrocnemial surface (PI. LVIII. fig. 2, g) begins behind the entometatarsal 

 tuberosity, and runs downward and backward to near the mid length of the bone ; it 

 becomes more defined as it descends, retaining a breadth of about 3 lines, before it 

 suddenly expands into a rough tract of a semioval shape, about 2 inches long by 6 or 7 

 lines in extreme breadth. This surface terminates about an inch and a half above the 

 hind end of the articular surface of the inner condyle (ii). The lower part of this 

 surface indicates the position (ib. fig. 2, i) of the ligaments which would attach the 

 metatarsal rudiment of a back toe to the main bone, if such toe existed in Dinornis 

 gravis. 



The ectogastrocnemial tract (PI. LVIII. fig. 2, x) is at the outer part of the hind 

 surface, and on the lower or distal half of the shaft, of the metatarsal. It is of a semi- 

 ' Trans. Zool. Soc. vol. iii. p. 277, plates 31 & 32, R. 



3f2 



