532 Transactions. 
Two New Species of Magadina. 
Ву Н. J. Frxrav, M.Sc., Edmond Fellow of Otago University. 
[Read before the Otago I nstetute, 11th December, 1923 ; received by Editor, 31st December, 
1923 ; issued separately, 30th July, 1924.| 
Thomson and M. waiparaensis Thomson—but the locality is much farther 
south. Thomson (loc. cit., vol. 52, p. 369, 1920) has indicated the existence 
of a third species, and this may possibly belong to one of the present forms. 
the only two other New Zealand species have been obtained—viz., M. brown 
Magadina clifdenensis n. sp. (Fig. 1.) — | 
Shell small, sub-shield-shaped, longer than wide, greatest breadth just 
below hinge-line ; sides at first gently curved, but curve rapidly increasing 
anteriorly and then diminishing quickly, giving rise to-a marked taper; 
hinge-line still straighter than in M. browni; dorsal valve very lightly 
convex, with a long, narrow, and increasingly pronounced anterior sinus, 
having the appearance of a shallow trough traversing half the shell ; ventral : 
valve highly raised, very strongly but bluntly carinate, the ridge being of 
regular prominence from inception at beaks to termination at valve-margin, 
and not noticeably widening over its whole extent ; commissures with very 
strong, narrow, and sudden fold, dorsal valve being much bent inwards 
in a narrow tongue; beaks short, not in- 
rim is not rounded and slightly thickened 
as in M. browni, but thin and sharp, forming 
(more than in M. browni) is occupied by 
a lightly concave pseudo-deltidium. Tn- 
ternally valves agree with M. browni, except 
M. т 1 
type of Magadiniform loop than has M. clifdenensis. Outline of loops, t00, 
is less cireular, an i 
, 
m 
shell. In ventral valve hinge 
