Family Buccinulidae nov.
This seems necessary to cover the Austral genera Buccinulum Swainson, 1837 (= Evarne H. & A.Ad., 1853), Dennantia Tate 1888, Euthrena Iredale, 1918, Tasmeuthria Iredale, 1925, Evarnula Finlay, 1926, and Chathamina nov. (v.i.). As a subfamily may be ranked Siphonalinae nov., covering Siphonalia A.Ad., 1863, Austrosipho Cossmann, 1906, Verconella Iredale, 1914, Berylsma Iredale, 1924, Glaphyrina Finlay, 1926, Aeneator Finlay, 1926, Pomahakia Finlay, 1927, Pittella Marwick, 1928, and Ellicea Finlay, 1928 (in Marwick, 1928), proposed for Siphonalia orbita Hutton, 1885 (T.N.Z.I., vol. 17, p. 326); Marwick has recently (T.N.Z.I., vol. 56, p. 321, 1926) referred this species and Streptopelma henchmani Marwick to Streptopelma Cossmann, judging by the resemblance of figures; this likeness is purely superficial, and actual specimens show so many differences that I doubt their inclusion in the same Family. The Family Neptuniidae covers a large suite of Boreal forms; to this, under the name Chrysodomidae, Cossmann and Suter have referred the Neozelanic forms, but it seems better to select a distinct family name for the large number of southern genera, rather similar inter se that centre around the New Zealand Buccinulum. “Euthrias” have been referred to several families, and in any case Buccinulum has long priority over Euthria Gray, 1850.
In regard to the New Zealand members, it would be out of place here to give a full account, with keys for separation of genera and species, but I have prepared this, and hope to give it elsewhere at an early date. Therefore I merely deal briefly in the present paper, with the means for separating the Chatham “Euthrias.”
Euthrena may be always separated from Buccinulum and its allies, Chathamina and Evarnula, by its protoconch, which is small, with a minute smooth portion, early weakly axially ribbed, with a conspicuous brephic stage of coarse reticulation; if this is lost or worn, the next best feature is the inner lip callus, which is vertical for less than half of its length. The three other genera have a large embryo, of several smooth whorls, showing more or less axial acceleration, but never a reticulate stage; and the inner lip callus is vertical for usually much more than half of its length. As Chathamina is now first proposed, a comparative diagnosis of these three groups is necessary.
Buccinulum Swainson (= Evarne H. & A.Ad.):—Includes linea (Martyn), pallidum n. sp., and sufflatum Finlay (1926, p. 416). Axials small and numerous, confined to first three whorls.
Chathamina n. subgen. of Buccinulum:— Type: Tritonidea fusco-zonata Suter, 1908. Includes also characteristica n. sp., and the fossil T. compacta * and its allied new species. Generally more squat than Buccinulum, wider and more solid; outer lip especially very thick, and with a heavy varix just before it; axials rather stout and prominent, generally persistent over all whorls; pillar more suddenly bent; teeth of outer lip inclined to be stouter, shorter, and fewer.
Evarnula Finlay:—Includes the fossil striata (Hutton), a new Recent deep water species, and marwicki n. sp. Spire rather elate; outer lip thin and sharp, rapidly thickening internally, but without a distinct varix; axials moderately prominent and numerous, persistent up to, and often also on, last whorl; teeth of outer lip not prominent, usually only subobsolete lirae; aperture less heavily armed with denticles than in the last two groups, there being rarely more than 2-3 at inflection of canal, but the lowest always very prominent, almost as in Dennantia; canal much more strongly flexed to left, and with a much stronger fasciole; strong spiral sculpture predominant; whorls more medially convex and better separated than in Buccinulum and Chathamina.
[Footnote] * N.Z. Geol. Surv. Pal. Bull., No. 5, p. 35, 1917.