294 SIR C. ELIOT ON NUDIBRANCHS [NoV. 29, 



larly a large folliculate mass which covers the sides and part of the 

 centre. 



The largest specimen is 20' 5 mm. long and 11 broad across the 

 hack. The genei^al construction of the head-parts is as in Phyllo- 

 hranchus, with the dividing line running down and forming- 

 lappets by the mouth, grooved oral tentacles, and grooved bifid 

 rhinophores about 4 mm. lojig. At the base of these latter can 

 be seen the large black eyes. The genital openings are as in 

 Phyllohranchus, but the intestine terminates dorsally in a cylin- 

 drical tube set in front of the pericardium and slightly to the 

 right of the median line. The foot is in two divisions, of which 

 the anterior is the wider, being 17'5 mm. broad by 7*5 in the 

 longitudinal direction of the body, whereas the posterior portion is 

 12 mm. long by 9"5 at its broadest part. Except for this division, 

 the foot is as in Phyllohranchus 2Jrasinus, but the corners of the 

 anterior margin are not much produced. Nearly all the papillse 

 have fallen off, but it appears that they were arranged at the sides 

 of the back, leaving the centre bare. The largest are about 5 mm. 

 high and 3"5 broad. Though they taper towards the base, they have 

 not a distinct stalk. On their margins are 8-10 yellowish spots. 

 The anatomy of this species, like that of Phyll. jyrasinus, has been 

 elaborately investigated by Bergh {I. c), but the structure of the 

 hepatic system is obscure. In my specimens most of the papillse 

 are quite transparent, and it seems clear that they contain no 

 hepatic branches, and when they are held out from the body 

 the folliculate mass, which I take to be the liver and which is 

 distinctly visible, is not seen to send any prolongations into their 

 transparent bases. On the other hand, the folliculate mass 

 adheres to the sides of the body- wall in the neighbourhood of the 

 papillse, which it does not do elsewhere, and must be in immediate 

 contact with the openings at their bases. Within the papillse are 

 round bodies which look like minute bubbles, and in some cases it 

 seemed that these bubbles were connected by a system of colourless 

 canals. I have unfortunately no means here (East Africa) of 

 preparing sections for microscopic examination. 



The radula consists of elongated teeth as figured by Bergh (l. c. 

 pi. XV. figs. 5-11), each bearing 12-17 denticles, but the number 

 of teeth seemed less, and was 14-1-9 in one specimen and 17-f 10 

 in another. The second figure in these expressions represents the 

 teeth which have fallen down into an irregular heap, and this 

 heap was much smaller than that described and figured by Bergh, 

 possibly in consequence of the youth of the specimens. 



Elysiad^. 



Placobranchus ocellatus Van Hass. = PL. argus B. (Plate 

 XVII. figs. 13 & 13 a.) 



[B. in S. R. iii. pp. 147-165, and id. Danish Exp. to Siam, 

 Opisth. pp. 180-181.] 



Two specimens from Prison Island, Zanzibar Harbour, The 

 larger measured 30 mm. in length, and 15 in breadth when the 



