1904.] FROM EAST AFRICA AND ZANZIBAR. 281 



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 i-espect much 

 like the average Dorid. Ph. varicosa is the most active and 

 crawls quite rapidly ; Ph. nohilis when in captivity crawled con- 

 tinually but slowly ; Phyllidiopsis cardinalis was sluggish bvit not 

 motionless. 



The Phyllidiadfe are common in the Indo-Pacific, but appear 

 not to be littoral. They are generally found in a few fathoms or 

 in spring-tides at exti-eme low water. 



Phyllidia VARICOSA Lam. 



[Bergh, Bidr. til en Monogr. p. 500 f.] 



This lai-ge, 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 measuiing 50 or 

 60 mm. ai-e not infrequent. The colour in life is glossy black, 

 with slate-blue i-idges on which are bright orange-coloured pro- 

 jections. The rhinophores are bright light yellow. The tubercles 

 are more oi- less confluent. Down the middle of the back run 

 three ridges bearing 12-16 tubercles. From the sides of the 

 mantle there run inwai-ds about 30 i-idges, less unifoi-mly con- 

 tinuous 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 tubei'cles, 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 beai-s in the middle a distinct black line 

 r5 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 fiised together to form a central doi'sal 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 tubei'cles like those found in Ph. nohilis. 



The most distinct variety, however, is one which perhaps 

 corresponds to Bergh's Ph. fasciolata* , which also comes from 

 East Africa (Comoi'o 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 gi'ey. The bulbus pharyngeus 



* Bidr. til en Mon. af. Phyllidieriie, p. 507. "Ph. varicosae et eleganti forma et 

 charactere dorsi affinis, sed rhinophoriis nigerrimis, varicositatibus dorsalibus (7) sat 

 tuberculosis." 



