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Show 384 SIR C. ELIOT ON NUD1BRANCHS [Dec. 1, The teeth are simply hamate; the innermost are smaller; the outermost smaller and imperfect in shape, bifid or irregularly serrulate. The stomach is large, muscular, and free from the liver. No armature was visible in the reproductive apparatus, and the genital orifices were unusually small and inconspicuous. On the right side of the liver was found a parasite (PL X X X I Y. fig. 4), extending from the fore end halfway down, the head being bent downwards round the fore end of the liver. The impression of the parasite on the liver was very distinct. This form has not the hard feeling characteristic of Sclerodoris, but as the back is leathery, reticulate, and granulate, I hardly think it advisable to create a new genus for its reception. 30. ASTERONOTUS HEMPRICHI Ehr. (Plate XXXIY. figs. 5 & 6.) [Ehrenberg, Symbolae Physicae, Animalia Evertebrata, 1831.] This large animal is common under rocks at Zanzibar and in all parts of British East Africa, between tides. It has a characteristic feeling like leather or india-rubber, and not hard or rough like Platydoris. The ground-colour varies from black to olive or chocolate-brown. The skin is quite smooth, but bears a number of irregular lumps, resembling blisters in appearance. Towards the edges of the mantle they are smaller and somewhat confluent. Down the centre of the back runs a more or less elevated ridge, varying much in different specimens. All these protuberances are of a much lighter tint than the rest of the body. In some specimens there are small white lines round the lumps. The large branchiae are white or pinkish. The underside of the mantle is light yellow, with a row of chocolate blotches forming a line round the margin of the mantle and another round the foot. The coloration shown in the figure (Plate X X X I Y. fig. 5), though an accurate representation of some specimens, is not the commonest. The greater number of individuals are more distinctly green. The animals are sluggish and show little inclination to move. The branchiae are comparatively insensitive. Though completely retractile, they are not hidden when the teeth close over the pocket, but can be clearly seen at the bottom of the cavity (PL X X I Y . fig. 6). The largest alcoholic specimen measures 8'3 cm. in length by 6, and is 2-4 cm. high. The foot is 6 in length by P 5 ; the anterior margin is deeply notched and grooved, the upper flap being very ample. The tentacles are large and in two specimens show a rudimentary foliation resembling that of Hexabranchus. This may be due to artificial compression, but I a m not sure. The lips are also ample and protruding, so as to look like a second pair of tentacles. The rhinophore-pockets are somewhat raised and smooth, sometimes distinctly bilabiate. The branchiae are six, ample, and quadripinnate. The margin of the pocket is produced into six lobes, which partially close over it. The radula consists of about 32 rows, each containing about 45 large yellow teeth on either side of the wide, naked rhachis. The teeth are simply hamate : the outermost two or three are smaller, and the inner- |