of laevigata Sowerby for the Sydney and Calloundra shells. In describing his Venus laevigata (Thes. Conch., vol. 2, p. 103) Sowerby gave three figures, 156, 157, and 158. Figure 156 represents the exterior of a left valve 27 mm. × 19 mm. with a long, straight, relatively high posterior dorsal margin and a straight, steep, anterior dorsal margin. In shape it is thus not at all like the Sydney shells allotted to N. disrupta which have a strongly convex posterior dorsal margin and a strongly concave anterior dorsal margin. The colour pattern of Sowerby's figure 156, namely, rays formed of black zig-zags on a yellowish ground, is not that of Notocallista but of Eumarcia nitida (Q. and G.), which, moreover, has a high, straight dorsal margin, though, to be sure, the anterior end projects more. Sowerby's figures 157 and 158 are of a left valve measuring 39 mm. × 25 mm. They show a hinge with three equally diverging cardinal teeth and no trace of an anterior lateral, exactly, indeed, as in Eumarcia nitida and quite unlike Notocallista. Moreover, the interior colour, a pale salmon band along the pallial line and filling the sinus, added to the hinge evidence, leaves no doubt whatever that the shell is a Eumarcia. Accordingly, laevigata is not available for any groups of Notocallista.

It seems possible that a form of the southern diemenensis has been identified by authors as disrupta. Thus Iredale mentioned “disrupta from Tasmania,” yet May in his Check List recorded only kingi and diemenensis (as Macrocallista). Also Pritchard and Gatliff in their Catalogue of the Marine Shells of Victoria recorded Meretrix disrupta from Port Phillips Heads, with the remark: “We agree with Mr. Hedley in regarding this as distinct from planatella (= diemenensis), though very closely related.”

Now Sowerby's figure 20 of disrupta shows a shell 47 mm. × 35 mm. which he described as “laevigata … concentrice tenuiter striata … lunula excavata,” emphasising in his notes the excavated lunule. Calloundra shells agree in size, shape, and excavated lunule, and the Sydney shells differ from these only in being more elongate, though both have a much less conspicuous colour pattern than Sowerby's figure. N. diemenensis, on the other hand, measures about 32 mm × 24 mm., often much less, is concentrically ridged and has an almost straight lunular margin. It is unlikely that there would be any hesitation such as suggested by Pritchard and Gatliff about separating shells like the Calloundra and Sydney ones from diemenensis. Moreover, the southern shells lack the several deep growth-furrows that so characterize Sydney and Queensland ones.

However, the sorting out of the true disrupta and its regional relatives cannot be carried out with the material available in New Zealand. All that can be done in this paper is to remove the Calloundra and Sydney shells from laevigata and provisionally place them back under disrupta. It is suggested that the true disrupta is a brightly patterned shell having the form of the Calloundra ones, but being somewhat less inflated. The Sydney ones, being consistently more elongate, represent a distinct subspecies.

For careful copies of Sowerby's figures of disrupta and laevigata I am indebted, through the kind agency of Mr. F. S. Colliver, to Mr. A. C. Frostick of Melbourne.

Notocallista (Striacallista) submultistriata (Tate). Plate 12, figs. 9—11, 13.

1887.Cytherea submultistriata Tate, Trans. Roy. Soc. Sth. Aust., vol. 9, p. 160, pl. 18, figs. 6, 8.

1924. Notocallista submultisriata (Tate); Iredale, Proc. Lin. Soc. N.S.W., vol. 49, p. 210.

Pliocene (Kalimnan): Upper beds Muddy Creek (type). Jimmy's Point (F. A. Singleton). Forsyth's Grange Burn. Kalimna.

Two different shapes are common in this species, one a fairly regularly inflated form with erect umbones, the other, generally smaller, is more inflated, has a flattened escutcheon bounded by a rounded ridge, more forward-curved umbones and a narrower posterior end, making the outline more subtrigonal. Both forms were figured by Tate, and of the eight specimens examined during the present revision six belong to the second subtrigonal variety. Whether the differences merit systematic recognition should not be decided without examining the field occurrences of a large number of specimens.

From the Recent disrupta the Pliocene multistriata is readily distinguished by its different shape, being always relatively shorter in front and having a much less excavated lunule. Further, the left posterior cardinal ofsubmultistriata is considerably longer and stronger than that of disrupta. However, submultistrata appears undoubtedly to be directly ancestral to the Recent shell.

Notocallista (Striacallista) lutea n.sp. Plate 13, figs. 5, 6.

Shell small, moderately inflated, thin, elongate, beaks not very prominent. Surface shining, with very fine concentric grooves, many persisting across the disk. Left posterior cardinal joined to the nymph without a separating groove. Hinge-plate lightly built. Ligament not deeply set, the walls low, the posterior dorsal marginal ridge meeting them at about half height. Pedal retractor separated from the adductor by a very short line. Pallial sinus ascending, roundly truncated.

Holotype in Auckland Museum (ex Finlay collection).

Length, 13.8 mm.; height, 10 mm; inflation (1 valve), 3.5 mm.

Oligocene-Miocene: Lower beds (Balcombian) Muddy Creek, Vic.

This shell has been indentified as N. eburnea (Tate), which it resembles in size and general appearance. It can readily be separated, however, by its shallow ligament and more elongate shape. It further-differs from eburnea in the narrower, subtruncate sinus, separated pedal retractor, more persistent and finer sculpture and less inflation. The differences are more accentuated in juveniles, especially because of the marked inflation of eburnea.

Notocallista (Striacallista) cudmorei n.sp. Plate 13. figs. 1, 2.

Shell rather small elongate oval, beaks inconspicuous. Sculpture of fine concentric grooves, 6 to 8 per mm., becoming weak and irregular and some obsolete medially. Hinge very like that of