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Show 1904.] FROM EAST AFRICA AND ZANZIBAR. 393 outside and white inside, as had also the foot. In the middle of the back were two longitudinal white lines uniting behind the branchiae; on the tail, which projected well behind the mantle, was one white line. The gills and rhinophores were yellow, and the slightly raised pockets of both were fringed with the same colour. The creeping-surface of the foot was narrow. The sides of the body were black with a white stripe between the mantle and the foot. The alcoholic specimens are high and stout, with the colours fairly well preserved. The largest is 26 m m . long, 13 broad, and 10 high. The mantle-margin is fairly ample, measuring about 3 mm. at the sides and head, 5 mm. over the tail. Of the branchial plumes there is only one which can be called simply pinnate in the strict sense, all the rest being more or less bipinnate. Some are merely bifid, and some bear four or five branches. It is rather difficult to say what is the number, as when a small plume springs up at the base of a large one it may be counted either as an accessory branch or as a separate branchia, but they may perhaps be described as 10, set in a semicircle. The foot is grooved and notched in front; the tentacles are close together above the mouth, conical and larger than usual in the genus. The labial armature is greyish and formed of a thick mass of bent rods, some bifid but most simple. The formula of the radula is in one specimen 94 x 90.0.90 and in the other 90 x 75.0.75. The innermost teeth bear three denticles on both sides ; the remainder 3-4 minute denticulations on the outer side only, and some are quite smooth and simply hamate. I think these specimens may be referred to Bergh's Chr. eliza-bethina (S. R. xi. pp. 466-473). The difference in appearance, though striking, is due to the relative preponderance of black in one and of white in the other variety. The dentition and the tendency to bipinnate branchiae are strong points of resemblance. On the other hand, the differences found in both the African specimens are sufficient to constitute a well-marked variety. (1) Whereas the specimens from the Philippines are whitish with black stripes, these are black with white and yellow stripes. (2) The denticles on the teeth of the African specimens are fewer and finer and many of the teeth are smooth. 9. CHROMODORIS RUNCINATA B. [Bergh, in S. R. xi. pp. 479-481.] One specimen from Chuaka on the East Coast of Zanzibar. The general colour of the living animal was light blue with many spots, some dark blue and some whitish yellow, on the back, tail, and sides, but not on the foot. Some of the yellow spots were arranged so as to form a rather irregular border at the sides of the mantle and a line down the middle of the back. The rhinophores and axes of the gills were a bright, light red. The gills were kept in motion, |