Lytocarpus phoeniceus, except that the branches are alternate instead of opposite. Secondary branches sometimes occur. The two hydrothecae on gonocladium do not differ appreciably from the others, but those on corbula are smaller, more cylindrical, with intrathecal fold more oblique, marginal teeth smaller, and anterior one without superior point. Only male corbulae present. Hemicarpus banksi (Gray). (Fig. 17, a.) Plumularia banksii Gray, 1843, p. 294: Coughtrey, 1874, p. 289. Aglaophenia banksii Bale, 1886, p. 103: Farquhar, 1896, p. 467. Ever since Gray's time this has remained an unidentifiable species, Hutton's reference to it of a hydroid found by him at Lyall Bay being pronounced by Coughtrey to be erroneous. By the aid of a fragment of Gray's specimen received from British Museum I am enabled to give Fig. 17.—a, Hemicarpus banksi (Gray), from Sir Joseph Banks's specimen; b, Lytocarpus secundus Allman, from one of Allman's specimens. × 80. an account of it sufficient to render its identification possible. Though its gonosome is not present, its close similarity to Hemicarpus secundus (Aglaophenia secunda Kirchenpauer, Lytocarpus secundus Allman), which Bedot unites with the Sertularia pennaria of Linné, leaves no doubt as to the affinity of the two forms, and in fact it is not certain that they are even specifically distinct. Gray mentions that the stem is compound and branched; his description of branchlets as opposite is, however, not in accordance with the specimens, which, Captain Totton informs me, have the branches alternate, pinnately arranged, pinnae being at distances of from 5 mm. to 8 mm. apart, and both series directed strongly to front (Gray describes them as unilateral). The specimens, which are fragmentary, measure about 38 mm. and 35 mm. respectively.