PROFESSOR OWEN ON THE GENUS DINORNIS. 145 



But this ridge commences nearly three inches below the back part of the proximal 

 end of the bone, nearer the outer side than in the D. struthioides : it is interrupted by 

 an oblique smooth tract at the point indicated in the admeasurement, where the 

 medullary artery penetrates the bone ; it then reappears about an inch and a half below 

 the interruption, and soon gradually subsides. This second lower part of a fibular 

 ridge is better marked than in the Din. struthioides. The relative size and position of 

 the procnemial, p, and ectocnemial, e, ridges are much the same as in the tibia of the 

 Din. struthioides and Din. dromioides. 



Metatarsus (PI. XLI. fig. 3). 



The difference between the Din. struthioides and the Din. gracilis is more obvious at 

 first glance in a comparison of their metatarsi than in that of the above-described bones ; 

 especially to an eye accustomed to the comparison of the metatarsi of the different 

 species. The superior length and slenderness of that bone in the Din. gracilis would at 

 once prevent its being confounded with the metatarsus of the Din. struthioides. 



The following are the chief dimensions of the bone in question : those of the extre- 

 mities being approximative by reason of their worn margins : — 



Length of the tarso-metatarsus . . . 

 Circumference at the middle of the shaft 

 Transverse breadth of proximal end 

 Transverse breadth of the distal end 

 Breadth of the middle of the shaft . 

 Thickness or antero-posterior diameter of ditto 



The depressed surface for the back toe is better marked than in the Din. struthioides. 



Subjoined is the " Note on the locality" affording the femur of the Dinornis gracilis, 

 kindly contributed by W. E. Cormack, Esq. ; with a sketch of the section of the strata, 

 of which a woodcut is here given. 



" The bone "(PI. XLI. fig. 1)" of the Dinornis now presented to Professor Owen was 

 found in the north part of the North Island of New Zealand, in the month of January 

 1849. Its locality was in a small bay called ' Opito,' at the east extremity of the pro- 

 jecting land between Mercury Bay and Wangapoua, on the east coast, in about the lati- 

 tude of 36° 40' S., and fifty miles east from Auckland. The bay is about a mile in length, 

 northerly and southerly, by about half a mile in depth, with high bluff heads or rocky 

 cliffs projecting at each extremity ; the semicircular sandy beach inside forming the 

 bay. An irregular strip of low land Hes inside of the beach, in some parts fertile, in 

 other parts consisting of downs, and is overlooked in the rear by round hills of from 

 100 to 300 feet in height. The hills are composed of yellow- white and red burnt earth; 

 very barren, producing stunted fern, and a solitary bush or scrubby tree here and there. 



