Sertularella simplex (Hutton). (Fig. 7.) Sertularia simplex Hutton, 1872, p. 257: Coughtrey, 1874, p. 283 (in part). Sertularella simplex Coughtrey, 1875, p. 300 (in part); 1876, p. 27. Sertularella fusiformis Hincks var. nana Hartlaub, 1901, p. 372. Hydrocaulus simple (or rarely branched—Hutton), twisted at base, about 8 mm. in height, divided by narrow twisted joints into internodes, each bearing a hydrotheca on upper part. Hydrothecae adnate a little less than half their height, divergent and directed somewhat forward, smooth, narrowed upwards and contracted near aperture, margin slightly everted, with four teeth; three internal compressed vertical teeth, two of which are within the two upper emarginations of border, and the third below inferior marginal tooth. Gonangia about 3½–4 times length of hydrothecae, borne on lower portion of hydrocaulus, ovate, with a few distinct coarse rugae on upper part, and tubular neck; summit with about four conical teeth. Loc.—Lyall Bay (Hutton): Sumner (Hartlaub). I have formerly ranked S. simplex as a synonym of S. polyzonias, as also has Farquhar, but examination of one of Hutton's specimens from the Dunedin Museum shows this to be erroneous. They agree with Coughtrey's figure of the type (1874, fig. 8); the internal teeth, however, are not shown. Fig. 10 is no doubt a different species, and probably fig. 9 also. though Hartlaub includes it with the type. The species is analogous to the Australian S. indivisa, but the hydrothecae are smooth and have four emarginations of the border instead of three; they are also larger, and have the lip rather more everted. The gonangia are of the same type, but larger, with neck more pronounced and the circular rugae fewer and less sharp. Hartlaub's reference of this form to S. fusiformis Hincks seems to me doubtful. Sertularella robusta Coughtrey. Sertularia simplex Coughtrey (in part), 1874, p. 283. Sertularella simplex Coughtrey (in part), 1875, p. 300; 1876, p. 27. Sertularella robusta Coughtrey, 1875, p. 300; 1876, p. 27: Farquhar, 1896, p. 464. ? Sertularella sp. Thompson, 1879, p. 101. Sertularella tenella Hartlaub, 1901, p. 370. This form, originally described by Coughtrey as one of the varieties of S. simplex Hutton, was figured by him in 1874 (pl. xx, fig. 10), but afterwards described as a distinct species. Hartlaub refers it, along with several other species, to the S. tenella of Alder (Hincks, 1868, p. 242). He only cites Coughtrey's original description, and seems to have overlooked the later references (1875 and 1876), in which Coughtrey named the form S. robusta. I cannot agree with Hartlaub's reference of the present species, with S. microgona von Lendenfeld and S. angulosa Bale, to S. tenella, as these forms all possess three distinct internal teeth in the hydrothecae, which in S. tenella are wanting. Hartlaub's specimens were from French Pass. Sertularella crassiuscula n. sp. (Fig. 8.) Sertularella solidula Hartlaub, 1900, p. 71; 1901, p. 371. Not S. solidula Bale, 1881, p. 24; 1884, p. 106. Hydrocaulus simple, twisted at base, about 10–12 mm. in height, divided by twisted joints into internodes, each bearing a hydrotheca on upper part.