274 On the FresJnrotcr Medusa of Lake Tamjanyika. 



wall ot" tlic manubrium. I liopc, liowever, to be able to 

 supply further details of this interesting ])roces3 of bud- 

 formation in a subsequcjit paper. 



As the Tanganyika Medusa is still without a generic name, 

 I propose that of Limnocntda for it, with the following cha- 

 racters : — 



LiMNOCNiDA, gen. nov. 



Umbrella flat, almost disk-like, about four times as broad 

 as high, with a lens-shaped thickening in the middle. Ten- 

 tacles very numerous, hollow, with bases partly imbedded in 

 and adnate to the umbrella margin. Marginal sense-organs 

 situate along line of attachment of velum, composed of a 

 multicellular mass of refringent cells enclosed in a roundish 

 capsule. Mouth round, two thirds the diameter of animal. 

 Manubrium very short. Stomach shallow, of same diameter 

 as mouth. Radial canals four. Reproduction by budding. 

 Sexual organs situated on the manubrium. 



Limnocnida tanganjiae (Bohm). 



Size : diameter of umbrella | inch. 

 Loc. Lake Tanganyika. 



As ray knowledge of the significance of several points 

 observed in the general anatomy of this freshwater Medusa is 

 as 3-et very imperfect, I must reserve a more detailed account 

 of these, as well as all discussion of the probable afiinities and 

 systematic position of Limnocnida, for another paper. If a 

 place has to be found for Limnocnida in Ha?cke]'s System of 

 Medusa^ we are beset with almost the same difficulties as those 

 which presented themselves in ihacti^toi Limnocodium. The 

 same battle will have to be fought over again, only the Held 

 is changed. Those who considered Limnocodium to be one 

 of the Lcptomedusa3 will refer Limnocnida to the Antho- 

 medusa?, while those Avho regarded Limnocodium as one of 

 the Trachomedusae will have to place Limnocnida among the 

 Narcomedusge. 



EXPLANATION OF THE TL VTES. 

 Plate XIII. 



Fifj. 1. Side view oi LinmocnifJn tnmjanjica^ X 4. 



Fi(/.2. VpiUial view of ditto, X 3. 



Fig. 3. Ventral view of a portion of the periphery of the di.-^k, x 0. 



