1903.] FROM EAST AFRICA AND ZANZIBAR, 257 



having been distinguished by any difference or intensity of colour. 

 It exactly resembled a piece of the racemose seaweed {Caulerpa) 

 on which it was found. 



The length of the alcoholic specimens is 2 centim. ; the extreme 

 breadth of the back with cerata 8 millim,, and of the foot 2' 3 millim. 

 The rhinophores are long and distinctly canaliculate. There ai'e 

 no oral tentacles, but two lobes over the mouth. Behind the 

 rhinophores are two very distinct black eyes. The cerata are 

 club-shaped as in Galvina, of varying size, the largest inside. On 

 each side of the back are four clumps of about nine cerata each, 

 and there is a thick bunch on the tail, which, however, projects a 

 considerable distance behind the last cerata. Down the centre of 

 the back is a broad bare space, in the anterior portion of which 

 is the very lai'ge, elongated (not oval) pericardial prominence. In 

 front of this and fused with it is the vent, a large and conspicuous 

 tube. The foot is rounded in front. 



I dissected one specimen, but was unable to obtain a clear view 

 of either the central nervous system or the reproductive organs. 

 The latter, as usual in this family, were extremely complicated, 

 both the prostate and albumen-gland appearing to be extensively 

 ramified. The verge was armed with a small spine. The hepatic 

 diverticula in the cerata, being colourless, were not easy to dis- 

 tinguish, but appear not to be much ramified and to i-esemble the 

 figure of those in Ercolaida siottii in Trinchese, pi. ix. fig. 2. 



The mouth-parts, buccal muscles, radula, &c. are of the usual 

 ascoglossan type. The teeth are not unlike those of Ercolania 

 viridis (v. Bergh, I. c. pi. xii. figs. 3 & 4), but the dorsal surface 

 is a simple curve and does not show any depression. The upper 

 portion of the radula contains 6 teeth, the lower 27, the last 

 members being arranged in a spiral like that depicted in Trinchese's 

 plate of U. siottii (pi. x A. fig. 1 ), from which it may be concluded 

 that the individual is young. 



As the specimen presents all the characters of the genus Erco- 

 lania, I describe it under that name, but I feel very doubtful if 

 the genus is valid. The only characters which differentiate it 

 from /Stiliger, viz. that the rhinophores are canaliculate and the 

 pericardial prominence elongate and not oval, ai'e surely very 

 slight. Vayssi^re {I. c. p. 122) referred to the genus a species 

 (funerea) with entire rhinophoi-es, which is probably in any case 

 a Stiliger. 



The animal is not likely to be specifically identical with 

 E. viridis Bei'gh, for the coloration is not really the same, the size 

 is much larger, and the shape of the teeth somewhat different. 



17* 



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