606 



MEDUSA OF THE WOULD. 



lappets. 24 (8X3) hollow tentacles 2 to 3 times as long as the bcU-dianietei. Throat-tube 

 1.5 times as long as the bell-radius and as the 4 complexly folded, leaf-shaped lips. The 

 central stomach gives rise to 16 unbranched radial-canals which are joined one to another by 

 a marginal ring-canal. 4 interradial crescentic gonads with their con\exities outward. 

 These project from the floor of the subumbrella. There are no subgenital pits. The gonads 

 are lined on their inner, concave sides by a row of gastric cirri. Color ( ?) Found at New 

 Caledonia, New Guinea, and the Cocos Islands in the tropical Pacific and Indian Oceans. 

 Another specimen called ''Flo.uuhi pnndora" by Ilaeckel, 1880 (p. 643), is from the tropical 

 Pacific. The bell is 50 mm. wide, without a star-like marking upon the exumbreila, and with 

 a short throat-tube hardly one-fourth as long as the long, narrow mouth-arms. Tentacles as 

 long'as the bell-radius. Lappets oval, sharp pointed, 1.5 times as long as broad. 

 ^.»- These medusx- appear to be immature, although Haeckel states that the gonads contained 

 ripe eggs, bur he studied only preserved specimens and cut lu) sections. 



TWA , 



(b m 



'''rw4^^^^ 





Fic. 385. — ^^Floscula promethea.^ 



Fig. 386. — **Florfsra pmlhenin.^ 



.After Haeckel, in Das Syst. der Medusen. 



Genus DISCOMEDUSA Claus, 1877. 



Diicomeduia, Ci.Ai:s, 1877, Dcnkschrift, Wicn. .-Xcad., Bii. 38, p. 42. 

 Ulmaris+ Vmbroia, Hafckfl, 1880, Syst. dcr Medusen, p. 545. 

 Umbrosa, Maas, 1908, Expi'dition Antarctiijue Franjaisc, Meduscs, p. 9. 



The type species is DiscomcJiisa lohata Claus, 1877, of the Mediterranean. This may 

 prove to be an arrested variety of Haeckel's Undosa uruiulata of the west coast of tropical 

 Africa. In Undosa, however, there arc 40 tentacles and 48 lappets, whereas in Ducomrdtisa 

 there are 24 tentacles and 32 lappets. 



GENERIC CHARACTERS. 



Ulmaridae with 24 (3X8) tentacles, 32 (4X8) lappets, and 8 sense-organs. The ten- 

 tacles arise from the clefts between the marginal lappets. There are 8 simple, unbranched 

 adradial canals, 8 branched, perradial and interradial canals, and a marginal ring-canal. 



Haeckel's genus Ulmaris is apparently onl\- the young of Di.uonudusti in a stage wherein 

 there are onl\- 8 tentacles and 16 lappets. His genus Undosa hears the same relation to Disco- 

 medusa that Dactylanictra does to Clirysaora, the tentacKs and i;i|ipets having increased from 



