130 Transactions. 
findet und ausserdem in patagonische und antarctische Altertertiar wieder- 
kehrt" (О. Wilckens, Cen. f. Min., &c., Jahrg. 1920, No. 15 и, 16, p. 264). 
The specimen was too imperfect for Woods to write any description of it, 
but its form in the figure he gives is certainly different from that of the 
present species. 
Lahillia neozelanica n. sp. (Plate 16, figs. 1—3.) 
Mactra crassa Marshall non Hutton, Trans. N.Z. Inst., vol. 49, 
pl. xxxvii, fig. 49 (figure only). 
Shell of moderate size; height 72 mm., length 78 mm; another specimen, 
height 37 mm., length (imperfect) 33mm. Shell thick, rather swollen, umbo 
curved forward, beak median, posterior margin regularly curved, descending 
rapidly, the ventral margin gently rounded, anterior margin in front of 
the beak somewhat concave, descending less rapidly than the posterior, 
the anterior end broken off. Surface nearly smooth, marked with a large 
number of concentric lines in larger and smaller series, the latter from six 
to ten between each pair of the larger lines, on the posterior margin they 
are sharply raised and closely crowded together. Hinge of right valve with 
a large, deep, and very marked pit below the beak, slightly oblique and the 
posterior margin longest, outside of this a narrow groove followed by a long 
somewhat narrow tooth coalescent above; anterior to the pit the hinge- 
plate is large, thick, and somewhat curved, with no distinct tooth-like pro- 
jection ; the whole hinge, however, is corroded. 
Specimens have been found at Wangaloa only. 
Type to be presented to the Wanganui Museum. 
The specimen originally figured by Marshall as Mactra crassa is not at 
present available, and the larger measurements given are taken from the 
figure of that specimen. The above description has been drawn from а 
smaller right valve (imperfect), and the interior filled with hard matrix, 
while the hinge is that of a fragment of a hl ‘cht: тае Аш 
the beak eroded. gm much larger rig 
species approaches Lahillia luisae Wilckens, from the Upper 
early Tertiary. It 
fauna contains species of Heleroterma and Perissolax which are very closely 
allied to species from the Tejon fauna of California. 
