'94 SIR C. ELIOT ON NUDIBRANCHS [May 17, 



lation of the jaw varies with age. Of the six species, M. jyellucidcc 

 seems distinct from the others, which are all nearly related to 

 M. arhorescens. M. levis is distinguished by being quite smooth 

 and not at all tuberculate. M. ramosa is closely alhed to M. arho- 

 rescens, and differs chiefly in having unusually large branchife and 

 appendages. M. viridescens and albo-tuherculata differ from these 

 last two forms in having branched processes on the velum, and 

 are closely allied one to another in structure, though by no means 

 similar in external appearance. 



It is noticeable that in none of these forms is the interior of the 

 buccal cavity black, and that most of them have only one fully- 

 developed row of denticles on the jaw. 



Marionia pellucida, sp. n. 



One specimen dredged in 10 fathoms near Wasin, East Africa. 



The living animal showed very little colour but for the pink 

 liver which shone through the transparent integuments. The back 

 was sparsely reticulated with vermilion, turnmg to deep crimson 

 near the bases of the branchise, and also bore some opaque white 

 raised spots. The sides of the body were white and the edge of 

 the velum sandy- coloured. The velum was not bifid, and bore 12 

 processes, of which 8 were 3-branched. The branchiae were 13, of 

 moderate size, directed backwards. The finer branches very 

 delicate and transparent. 



The alcoholic specimen is yellow, with small tubercles of a 

 lighter colour on the back and sides. It is 15 millimetres long, 

 5 broad at most, and 4 high. The 13 branchiae are rather far 

 apart from each othei' ; none are large, and the first pair as well 

 as the last three are minute. The dorsal margin is not very 

 prominent. The rhinophores are large. The velum as described 

 above, but though the outermost processes probably represent the 

 tentacles, they do not seem to be grooved as usual. The long- 

 narrow jaws bear three or four rows of denticles on the edge. 

 The radula is at most 22 + 1.1.1 + 22 X 25, but many of the rows 

 are much shorter. The central tooth is not very wide and tri- 

 cuspid, the side cusps being as high as that in the middle. The 

 stomach has a circular band of about 70 small yellowish plates, all 

 of much the same size and usual triangular shape. 



Marionia levis, sp. n. (Plate TV. fig. 4.) 



Six specimens from Chuaka, East Coast of Zanzibar, and Wasin, 

 East Africa. Two were dissected. 



The living animals were high and narrow in shape, with a flat 

 back. The sides were described as white, mottled with tiunslucent 

 patches. The ground-colour of the back was a light purplish 

 brown, with stripes of the same colour but darker and others of 

 white. The bi'anchise and rhinophores were pink with dark red 

 blotches. 



An iminjured alcoholic specimen is 26 millimetres long, 10 high. 



