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Show 436 PROF. P. M. DUNCAN ON DEEP-SEA [May 16, As the form has no endotheca, is simple, and without pali, it comes within the Turbinolinee, in the neighbourhood of Desmophyllum, Smilotrochus, and Discotrochus ; but it differs from all. Like the two well-known Japanese simple corals, the corallum has its base surrounding a shell; but in this instance the small Ditrupa-hke annelid does not always interfere with the symmetry of the base. Genus B R A C H Y T R O C H U S. The corallum is very short, free, or incrusting annelid-shells. The calice is circular, and deep centrally; there is no columella. The septa are exsert and papillose; the costse are well developed, except on the rounded centre of the base, where they merge into a granular structure. B R A C H Y T R O C H U S S I M P L E X , sp. n. (Plate X X X I X . figs. 7-10.) The calice is widely open, and the floor of the fossa is visible. The septa are in six systems, and there are four perfect cycles in each ; the primaries are the largest, the most exsert, and project the most internally and externally ; the secondaries are slightly smaller than the primaries, and larger than those of the third order. The fourth and fifth orders are the smallest, and rather approach the tertiaries. All have large and wide papillae internally ; and those of the third and higher orders of septa reach furthest from the axis. The septa are rounded faintly and are thin and exsert. The costse are profusely granular. The inner granulations, or papillae of the septa, radiate, as it were, from where the columella might have been. Height ^ inch. Breadth T 4 0 inch. Locality. Gaspar Straits, 12 fathoms. From the Liverpool Museum. Family OCULINID^E, Ed. & H. O C U L I N A CUBAENSIS, sp. n. (Plate X L . figs. 1, 2.) The corallum incrusts dead Polyzoa and Serpula, and rises also in the form of irregular stems which branch and often coalesce. Gemmation sometimes lateral and alternate, at other times in spiral series, and without order. The calices are not very prominent, and are moderately deep. The columella is extremely small and trabecular; the septa are alternately large and small; and the primaries and secondaries are exsert, arched, and finely spinulose at their margin. There are rarely three complete cycles. The pali are before all the septa except the last, are long, rather papillose at the surface, tall, and their inner end meets the almost rudimentary columella. The costse are often well seen over the sides and running between the corallites; at other times they are wanting. They are often unequal, a large one being followed by a very small one. All are minutely granular, so that they feel as if spiny. Fissiparity is rare. |