116 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. II. 



struthious birds ; for in the specimens alluded to, the division 

 of the original three metatarsals is strongly marked, and 

 one of the bones has, unfortunately, cracked by drying, along 

 the line of separation of the primitive ossicles ; and yet 

 these bones appear to have belonged to a mature individual. 



The longest tarso-metatarsal bones I have seen are eighteen 

 inches and a half in length, the circumference of the shaft 

 being five inches and a half. 1 



Phalangeal Bones. The bones of the feet bear a closer re- 

 semblance to those of the largest species of Apteryx, Ap. Aus- 

 tralis, than to any of the other existing struthious birds. The 

 phalanges present the ordinary numerical progressive increase, 

 viz. the inner toe is composed of three bones, the middle of 

 four, and the outer of five. The proximal articular surface of 

 the first phalangeal of the middle toe is symmetrically divided 

 by a slight ridge, as in the Cassowary ; but in the inner and 

 outer toes the corresponding bone has the proximal end 

 deeply notched, and the inner half greatly produced to em- 

 brace the corresponding trochlear surface of the metatarsal. 2 



The ungueal or claw-bones are large and strong, of a sub- 

 trihedral form, and gently arched. 



In his last visit to Waikouaiti, my son dug up the entire 

 series of phalangeals with the corresponding metatarsal of a 

 smaller species of Dinorriis ; but whether referable to D. 

 dromioides or D. rheides, or to a distinct species, is uncertain, 

 for the metatarsal corresponds with that assigned to the for- 

 mer in Zool. Trans, vol. iv. Plate III. fig. 1, while the 

 series of phalangeals are unquestionably of the same species 

 as those figured in PL II., and ascribed to D. dromioides. 3 

 In the reconstruction of the foot of the Dinornis robustus, my 

 son's specimens have afforded a certain guide. 



Several phalangeals were discovered, in which the trochlear 

 articulation of the proximal bone of the middle toe is as un- 

 equally divided as in the Ostrich ; a character which seems to 

 indicate that a didactyle, or two-toed wingless bird, may have 



1 These specimens are figured as the frontispiece of the " Pictorial 

 Atlas of Organic Remains." 



2 See figs. 1 & 3 of the same plate. 



3 As the restoration of these parts is based on detached specimens, it 

 is probable the metatarsal does not belong to the series of phalanges 

 with which it is associated. 



