part 3] jurassic bocks of new zeal.vnd. 275 



typical specimens of Inoceramus haasti at Kohai Point in being 

 more elongate and narrower, and having much more acute beaks 

 and more numerous concentric ribs, which are about equal in 

 width to the furrows between them. 



The form now described occurs on a lower horizon than I. haasti, 

 of which it may be an ancestor. There are two specimens in my 

 collection, and one from Kerrs belonging to Prof. Marshall. They 

 bear a close resemblance to Bcehm's figures (pi. ix, fig. 12 & 

 pi. x, fig. 1). His description of the species was drawn up from 

 115 specimens which he collected on the Wai Galo, where he 

 describes the river-bed as being paved with them, specimens of 

 various sizes occurring in clay-limestone nodules. 



He remarks that the species is reminiscent of I. retrorsus 

 Keyserling ; but he makes no mention of any resemblance to the 

 New Zealand shell I. haasti. He figures two other species : 

 namely, /. taliahuticits Bcehm and I. sularum Bcehm, from the 

 same locality ; but in both of these the angle between the hinge 

 and the anterior margin is much greater than it is in either 

 I. galoi or I. haasti. Bcehm's figure of I. galoi (pi. ix, fig. 14), 

 in the width of its shell and the wide spacing of the sharp con- 

 centric ribs, is very reminiscent of a small specimen of I. haasti. 



Istoceeamtjs haasti Hochstetter. (PL XV, fig. 8.) 



K. A. von Zittel, ' Palaontologie von Neu-Seeland ' 1864, p. 33 & pi. viii, 

 figs. 5 a- 5 c. 



Description. — Outline sub triangular, the hinder and lower 

 margins well rounded, the anterior margin rather concave. The 

 beaks are pointed, slightly rolled, and the shell in the neigh- 

 bourhood of the beaks is well inflated. The ornamentation consists 

 of seven or eight coarse concentric ribs, rather irregularly spaced, 

 especially towards the margins, the interspaces being strongly 

 hollowed out. On the young shell the ribs are low and rounded, 

 and not at all sharp or prominent, but increase after the shell has 

 attained a length of about 25 mm. 



Dimensions. — Length = about 100 mm.; greatest width = 

 about 62 mm. 



Locality. — Kohai Point, Kawhia, with Aucellce of the group 

 represented in PI. XVII, figs. 4-8, called A. plicata Bcehm. 



Remarks. — Zittel, whose specimens are recorded from Takatahi, 

 east of Kohai Point, says that only very incompletely preserved 

 casts were at hand, and therefore no determination could be made 

 with certainty. The whole surface was ornamented with very 

 strong concentric folds which spring rather strongly forwards. 

 The shape reminded him very much of I. crippsi and other related 

 forms from the European Cretaceous. Bcehm, who had 22 

 specimens which were collected for him by the late Mr. H. Suter 

 at Kohai Point and southwards, and between Captain King and 

 Totara Point, remarks that the form is triangular, and therefore 

 can bear no relation to I. crippsi. His largest specimen was from 



