1902.'] KUDIBRAXCnS FROM ZAXZIBAR. 63 



a little below the tip. Above the movith are two .short, slender, 

 ei-ect tentacles. Behind them ai-e the rhinophores, which ai-e 

 considerably longer and more slender than the cerata : they 

 bear about eight bracket-like semicircles, which alternate with 

 one another, so that there is not a complete circle round the 

 I'liinophore ; at the base of each I'hinophoi'e is a black eye-spot. 

 The foot is rounded in front and the cornei'S are not produced 

 in tentacle-like expansions (PI. VI. fig. 13). 



The body is ti-anslucent and coloui-less (the viscera being white) 

 with a few blotches foi'med of opaque white dots. The cerata 

 are also translucent, except at the rings, wdiich are opaque white ; 

 they beai' a few oi'ange .spots or sti-eaks. Tliei'e is a long orange 

 sti-eak on each rhiuophoi'e. 



The jaws are .sniidl and the masticatory edge is finely denti- 

 culate. The iTidula is shoi't and uniseriate. Each tooth is shaped 

 like a horse-shoe and bears on its antei'ior margin one large 

 denticle with six small ones on each side (PL YI. fig. 12). No 

 trace of armature was discoverable in the reproductive organs. 



In many characters, in the disposition of the cei'ata, the 

 rounded anterior margin of the foot, and the buccal parts, 

 the animal appears allied to Cratena ; but it diflfei'S in two points, 

 the rudimentaiy pei-foliation of the rhinophores and the rings 

 round the cerata. The latter peculiarity is, so fai- as I am awai-e, 

 unrecorded among the ^'Eolids, but it almost entirely disappears 

 in specimens preserved in alcohol, and it is therefoi-e possible that 

 it jiiay really exist in other genera which have been desciibed 

 fi-om such specimens. 



DuNGA NODULOSA, gen. et sp. nov. 



This animal is fairly common on colonies of Sertalaria. The 

 body and tail are both long. The cerata ai-e easily detached and 

 have then some power of independent movement. They are 

 cai'i'ied very erect in the living animal and are set in transverse 

 rows varying from four to six in number. Behind the last 

 transverse row is a clump of smaller ceiata, also of varying 

 number. Probably the caducous character of the appendages 

 has something to do with these valuations. Each transverse i"ow 

 consists of ten cerata, gradually inci-easing in size fi-om the 

 outside to the centre, the two middle ones being much larger 

 than the others. The outer cerata are of the ordinary cylindiical 

 shape ; the middle ones are swollen and ovate, but terminate in a 

 fine point. At the top of the broad part and at the base of this 

 point ai'e eight knobs. The rhinophores are very long and simple. 

 The tentacles are modeiutely long, and the anterior angles of the 

 foot are produced into processes of about the same length. The 

 foot "is narrow and without mai-kings. The length varies from '5 

 to 1"2 cm. 



Tlie coloration is very vaiiable and ranges from clear light 

 yellow to purplish brown. These differences may be partly due 

 to two different colours of the liver diverticula seen in the 



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