Thomson. — (jreology of Middle Waipara and Weha Pass Dist7-ict . 369 



Hemithyris nigricans (Sow,). 



A mutation of this well-known Recent species is found in the uppermost 

 Mount Brown limestone (E). It differs from Recent specimens only in its 

 slightly smaller size and slightly more imbricated growth-lines. A similar 

 mutation is found in Park's upper Hutchinsonian of Target Gully, Oamaru 

 district, the lowest horizon from which any specimens referable to this 

 species have been found. 



Terebratulidae. 



Terebratulina suessi (Hutt.). 



Three specimens only of this species have been fovmd, in the top of the 

 main Mount Brown limestone (D). They agree well with the type from 

 the Curiosity Shop. 



Terebratulina sp. cf. cancellata Koch. (Plate XXIV, figs. 14, 15.) 



A single, not very well preserved specimen from the uppermost Mount 

 Brown limestone (E) seems referable to the Terebratulidae from its epithyrid 

 beak characters and labiate foramen, while a fine dichotomous striation 

 suggests Terebratuliyia. These characters are combined only in the Recent 

 Australian species Terebrahdina cancellata Koch, which, however, on account 

 of its beak characters, will doubtless be made the type of a new genus. 

 The specimen under consideration is larger than the average specimen 

 of T. cancellata, but does not show the dorsal bipli6ation characteristic of 

 adults of that species. Its dimensions are : Length, 38 mm. ; breadth, 

 30 mm. ; thickness, 21 mm. 



No terebratulids other than the above have been obtaiijed, and the 

 absence of Liothyrella is worthy of remark. 



TeREBR ATELLIDA E . 



Bouchardia minima Thomson. 



Geol. Mag., dec. 6, vol. 5, 1918, pp. 260-61, fig. ], a, h, c. 



This species occurs locally in abundance in the main Mount Brown 

 limestone (D). 



Magadina browni Thomson. 

 Magadina waiparensis Thomson. 



Trans. N.Z. InsL, vol. 47, 1915, pp, 399, 400, 402, 403, figs. 7, a-d, 8, a, b. 



M. waiparensis has been found only in the third Mount Brown lime- 

 stone (C) in the cliffs overlooking the Waipara River, and near Mount 

 Donald. M. browni is extraordinarily abundant in places in the main 

 limestone (D), and can be found in most exposures. It occurs rarely in 

 the sandstones imder the uppermost limestone (E), It is strange that 

 Magadina should be so abundant in the Waipara district and be absent or 

 very rare from the Oamaru district. There are two specimens in the 

 Geological Survey collection from locality 308, Oamaru formation, Oamaru, 

 Hector, 1876. One is a specimen of M. browni, and the other a new species 

 of Magadina. The locality record gives little information, and must be 

 accepted with caution in view of the absence of similar specimens in the 

 extensive collections made by Uttley, Park, and myself. 



