1904.] FROM EAST AFKICA AND ZANZIBAR. 85 



consist of about 27 small tufts, pinnate, bipinnate, or tripinnate 

 according to their size, and spread over three areas corresponding 

 to the valves. Possibly each area represents a separate axis, and 

 the gills should be described as three tripinnate or quadripinnate 

 plumes. But this arrangement cannot be demonstrated with 

 certainty in the preserved specimen, and the living animal never 

 raised the valves at all. The rhinophores are thick, conical, and 

 without a ti-ace of perfoliations ; they are retracted into simple 

 holes, provided with neither valves nor raised edges. No oral 

 tentacles and no groove in the anterior margin of the foot could 

 be discovered (fig. 1 e). 



There is no trace of armature on the labial cuticle. The radula 

 consists of 33 rows, the largest of which contain a,bout 25 teeth 

 on each side of the rhachis. The teeth are transparent and 

 crowded : the innermost ai-e smaller and close over the rhachis ; 

 the outermost are longer and show no trace of irregularity. The 

 shape of all is much the same, hamate with a rudimentary denticle 

 under the tip of the hook. They much resemble the teeth of 

 Notodoris cltrina (Bergh, I. c. pi. ix. figs. 39, 40), but are somewhat 

 more erect and hardly ever show indications of more than one 

 denticle (fig. 1 g). The glans penis spreads out somewhat as in 

 Nembrotha, and appears to be trifid. The lower part is armed 

 with a thick mass of minute blunt spines (fig. 1/). 



Trevelyana Kelaart. 



[Kelaart, in Ann. Mag. Nat. Hist. 3rd ser. vol. i. p. 257, 1858 ; 

 Bergh, in Semper's Reisen, Heft xi. p. 441, k xvi. 2, p. 850.] 



This genus is recorded only from the Indo- Pacific, where it 

 seems to be the commonest representative of the Polyceradse, 

 being frequent under stones between tides. The animals are 

 limaciform, but some specimens at any rate show indications 

 of a division between the back and sides. The body is smooth, 

 bears no appendages, and is usually of a light bright colour 

 varying from red to white. The branchiae are rarely less than 

 ten, often numerous, and generally small. There is no labial 

 armature or central tooth. The radula is fairly wide, and com- 

 posed of hamate or awl-shaped teeth, which are often irregular. 

 The hermaphrodite gland, instead of being spread over the liver, 

 is collected into two globular masses. 



Several of the species, e. g. the T. ceylonica and T. hicolor given 

 below, are very imperfectly described by the original authorities, 

 and hence identification is uncertain. It is clear that the whitish 

 forms with yellow lines and spots show considerable variety, but 

 it is hard to say how many of these varieties are specific. 



Trevelyana coccinea, sp. n. (Plate III. figs. 2 a-2f.) 



One specimen, dredged between Shimoni and Wasin at 6-8 

 fathoms. 



The notes on the living animal describe it as the largest species 



