stem, each taking the place of a hydrocladium. Hydrocladia close, alternate, at about 45°, one on each internode, both series directed a little forward. Hydrothecae at an angle of about 40°, deep, widened upward from base; a very narrow interathecal ridge near base on adcauline side, with a fold from it crossing hydrotheca and curving slightly forward; aperture with short anterior tooth, above which the front is produced into a somewhat longer point; lateral teeth 4 on each side, the first and fourth very minute, often obsolete, second and third nearly triangular, shallow: back adnate. Internode with short septal ridges opposite the intrathecal ridge and the bases of the lateral sarcothecae. Mesial sarcotheca a little shorter than calycle, and mainly rising from it, tapering, canaliculate. Lateral sarcothecae tubular, adnate to hydrotheca nearly to margin and then bent forward, canaliculate. Cauline sarcothecae canaliculate, two at base of each hydrocladium, the lower projecting forward, the other larger, projecting outward. Fig. 16.—Thecocarpus chiltoni n. sp. × 80. Gonangial pinna replacing a hydrocladium, with the first two internodes bearing hydrothecae. Corbula curved, rather short, consisting of about 8 pairs of alternate ribs, originating as narrow pinnules but expanding above into broad leaflets, which unite to form corbula; distal margin of each leaflet bordered with about 5–7 tubular, closely-set sarcothecae; a stout spur springing from distal side of each leaflet, just above base, bluntly pointed or with alternate sarcothecae, and bearing a small modified hydrotheca with lateral sarcothecae. Loc.—Cape Maria van Diemen, ten miles north-west, 50 fathoms (Chilton). The specimen has two main stems, reaching about 8 in. in length, and about 8 mm. in diameter at base, clothed almost down to base with branches, which reach about 3 in. in length, and are alternate, the average distance between successive branches on the same side being about ¼ in. Being all in one plane, the colony somewhat resembles that of