1904.] FROM EAST AFRICA AND ZANZIBAR. 291 



Stiliger irregularis, sp. n. (Plate XYII. fig. 12.) 



Two specimens from Chuaka on the East Coast of Zanzibar, 

 found among Sertularians. The animal had a somewhat peculiar 

 appearance owing to the hinder cerata being about twice as long 

 as those in front and spreading out in a fan-like shape. One speci- 

 men was of a translucent white, but the liver, extending in two 

 lines down the side of the body and giving ofi' branches to the 

 cerata, was green, and created an impression that the whole 

 animal was of that colour. In the other specimen the branches 

 of the liver in the cerata were of a dirty yellow, and there was 

 some reddish-grey pigment in the integuments of the body, so 

 that the longitudinal liver-tiibes were not easily discernible. Near 

 the head, however, they were distinct and green. The cerata in 

 this specimen had white spots. The animals were less than 

 2 mm. long. 



Only one specimen has been preserved, and its very small 

 dimensions rendered examination i-ather difficult. In the hinder 

 part of the body there are two longitudinal lines of cerata 

 arranged in five transverse rows on each side, of which the inner 

 are two or three times as long as the outer. In the front part 

 there is a single line of five small cerata, and there are no signs 

 of others having been detached. The cerata are cylindrical, much 

 like those of Hermcea dendritica, and not inflated or ovate. 

 Though the surface of the liver-branches is irregular, they do not 

 appear to have distinct secondary ramifications within the cerata. 

 ISTo pericardial prominence is visible. The rhinophores are short 

 and simple ; behind them are two very distinct black eyes. The 

 oral veil is circular and not notched. The foot is truncate in 

 front ; there were no signs of a groove or tentacular prolongations 

 of the corners. 



The radula consists of four teeth in the ascending portion, six 

 in the descending, and a small heap. The teeth are mvich like 

 those of S. varians, but the outline is somewhat simpler and less 

 wavy (PI. XVII. fig. 12). 



Phyllobranchid^. 



[Bergh, in S. R. ii. k, xvi. ; id. Beitrage zur Kennt. d. Aeoli- 

 diaden, ix. ; A. & H., OoU. of Nudibr. Moll, made in India, p. 145 ; 

 Trinchese, Aeolididse del Porto di Genova, 1881 ; Pelseneer, Re- 

 cherches sur divers Opisthobranches, 1894, pp. 50-52.] 



This remarkable family, which is characterised by its flat leaf- 

 like dorsal papillae, consists of three genera, Phyllobranchus, 

 Cyerce, and Ccdiphylla, of which the fixst two are recorded from 

 the Indo- Pacific (but Ph. viridis from the West Indies), and the 

 last from the Mediterranean. They all agree in having flat 

 leaf-like cerata, an ascoglossan radula and a buccal crop, compli- 

 cated reproductive oi'gans, and (except Galijohylla) oral tentacles 

 as well as rhinophores. Chjerce, though vei-v like Phyllohranchus 



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