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Show 1 9 0 4 .] FROM EAST AFRICA AND ZANZIBAR. 2 8 1 predominates, a variety is formed which seems to have five or seven longitudinal rows. As I have mentioned elsewhere, my observations do not confirm the statements of the older naturalists as to the torpidity and immobility of the Phyllidiadse, which seem in this respect much like the average Dorid. Ph. varicosa is the most active and crawls quite rapidly ; Ph. nobilis when in captivity crawled continually but slowly; Phyllidiopsis cardinalis was sluggish but not motionless. The Phyllidiadse are common in the Indo-Pacific, but appear not to he littoral. They are generally found in a few fathoms or in spring-tides at extreme low water. P h y l l id ia varicosa Lam. [Bergh, Bidr. til en Monogr. p. 500 f.] This large, handsome animal is common on the coasts of Zanzibar and the mainland of East Africa. My largest specimen is 73 mm. long and 32 broad, and specimens measuring 50 or 60 mm. are not infrequent. The colour in life is glossy black, with slate-blue ridges on which are bright orange-coloured projections. The rhinophores are bright light yellow. The tubercles are more or less confluent. Down the middle of the back run three ridges bearing 12-16 tubercles. From the sides of the mantle there run inwards about 30 ridges, less uniformly continuous than those in the centre and bearing each two or three tubercles. The openings for the rhinophores and anal papilla are small and placed in tubercles, not on the smooth surface of the back. The tentacles are digitiform and yellowish. The buccal mass is large, yellow*, and, as Bergh says, " magnopere compositus." The foot is broad, and bears in the middle a distinct black line 1 ‘5 mm. wide in large specimens. There are sometimes black mottlings at the side of the line. "Variations from the typical form are frequent. In one specimen the three longitudinal ridges are all fused together to form a central dorsal prominence, whose tripartite nature is only obscurely visible. In another the three unite in the posterior third of the body, though before it they are separate. In one very fine specimen the three ridges are very distinct behind, but in the anterior third of the body form a group of tubercles like those found in Ph. nobilis. The most distinct variety, however, is one which perhaps corresponds to Bergh's Ph. fasciolata*, which also comes from East Africa (Comoro Islands), and which he appears to regard as not specifically distinct. It is characterised by having from five to seven ridges on the back, in which the tubercles are more distinct and the connecting-lines less developed than in the typical form. The lateral ridges are almost entirely absent. The rhinophores vary from yellow to grey. The bulbus pharyngeus * Bidr. til en Mon. af. Phyllidierne, p. 507. " Ph. varicosae et eleganti forma et charactere dorsi affinis, sed rhinophoriis nigerrimis, varicositatibus dorsalibus (7) sat /tuberculosis." |