92 SIR C. ELIOT OX NUDIURAXCnS [M^^V 17,. 



perfoliations. As in the last species, the gills are very thick, 

 strong, and mnscular, apparently five, but in this case, too, the 

 lateral pairs sometimes coalesce, so that the whole number may be 

 counted as three or four. They are bipinnate. The oral tentacles 

 appear as large, distinct tubercles on each side of the mouth, and 

 were doubtless fairly long in life. The foot is rather broad, with 

 a shallow groove in front ; the upper lamina is connected with the 

 sides of the mouth under the tentacles. 



The internal oi-gans are mostly of a greyish yellow, not deep 

 black as in the last species. Though the labial cuticle contained 

 a few scattered yellowish rods, no connected armature is visible. 

 The radula much resembles that of iV. cristata, and has for 

 formula about 2 7 X 1 + 1 . 1 . 1 + 1 or occasionally 1 1 + 1 . 1 . 1 + H , 

 but the median plate is broader, with five distinct denticulations 

 which do not vaiy in number. The first lateral has a groove near 

 the end of the hook, and the next two or three teeth have a rudi- 

 mentary hamate shape. The liver is large. The upper wall of 

 the pericardium is very thick and strong. The verge resembles 

 the figures in Bergh's plates of Nembrotha niyerrima, the glans 

 being armed with a profuse mass of hamate teeth. Tliose on the 

 top seemed rather larger and more curved than in his figures. 



This species is closely allied to N. nigerrima, but appeaivs to 

 be sufficiently distinguished by (a) its coloration, (b) the only 

 slightly projecting edges of the rhinophoi-e-pockets, (c) the absence 

 of a labial armature, (d) slight difierences in the radula, (e) another 

 form of tentacles. 



Nembrotha affixis, sp. n. (Plate IV , figs. 3 a-3 d.) 



\Gi. N. gratiosaTiQVgh., Nudibr. of 'Blake' Expedition, pp. 172- 

 175.] 



One specimen caught in a trawl in Chuaka Bay on the East 

 Coast of Zanzibar. Very long and narrow, being 5 centimetres 

 in length and 1 in height. 



The living animal was extremely soft, dull violet-black in 

 colour, with dull yellow stripes on the sides and somewhat brighter 

 ones of the same colour on the back. The stems and bases of the 

 gills were light green, and the same colour occurred between the 

 rhinophores and round the edges of their pockets. The pinme 

 of the gills looked black, but when seen by transmitted light were 

 of a fine purple. The foot was very narrow, and the animal could 

 not adhere strongly to anything. 



The alcoholic specimen is flabby, 28 millimetres long, 5 broad, 

 and 10 high. As the result of this reduction in size, the yellow 

 parts look wider and the black parts narrower, so that the animal 

 appears to be yellow with black stripes, rather than black with 

 yellow stripes as in Mr. Crossland's figure. No doubt, however, 

 the latter is correct ; it represents four lateral yellow stripes and 

 one medio-dorsal. The stripes are interrupted in places, particu- 

 larly on the tail, and there ai-e some long yellow spots between 

 them. The branchise are distinctly only three in number, smaller 

 [10] 



