SEMAEOSTOME^ — FLORESCA. (')()5 



The niedusie ot this family arc closely related to the Cyaneida.-, but differ in that their 

 radial-canals are placed in interconimiiiiication b)- means of a marginal circular canal; 

 moreover, th radial-canals anastomose m some ot the genera, and this is never the case in 

 the Cyaneidae. 



The genera ot the Ulmaridae are as follows: 



1. Subfamily Umbrosin.^. 



The tentacles arise singly from the margin in the clefts between the lappets. 4 cvaginated, sac-like gonads without subgenital 



pits. 8 or 16 marginal sense-organs. 4 unbranched mouth-arms. 

 ( .') Floresca (immatme ?)= FIoscula+ Floresca Haeckel, 1880. 8 rhopalia, 24 tentacles, 32 lappets 16 simple unbranched 



radial-canals. 

 Diicornedusa, Cl.'Mjs, 1877= L'lwiiris+ I'mhrosii Haeckel, 1880. 8 rhopalia, 24 tentacles, 32 lappets. The 8 perradial and 



interradial canals are branched, the 8 adradial canals are simple. 4 gonads. 

 Paruwhroici, KlsHlNOuYE, 1910. Similar to Discomedusa but with 64 instead of 32 lappets. (See Ajipendix to this 



volume.) 

 Vndosa Haeckel, 1880. 8 rhopalia, 40 tentacles, 48 lappets. Radial-canals as in Discomedusa. 

 Dtplulmaris, Maas, 1908= L7m(3rj3/)5/j, Vanhoffen, 1908. 16 rhopalia, 16 tentacles, 64 lappets, 32 radial-canals arise from 



stomach. The 16 rhopalar canals branch and the 16 tentacular canals are simple. All canals are merged in a marginal 



network of anastomosing vessels. 



2. Subfamily Sthenonin.^. 



Tentacles arise from floor of subumbrcUa. Evaginated, sac-like gonads without subgenital pits. 8 to 16 marginal sense- 

 organs. 4 unbranched mouth-arms. 



Stkenonia, f.scHScHOi.TZ, 1829. 8 marginal sense-organs. 8 adradial linear clusters of tentacles. Perradial and interradial 

 canals branched, .\dradial canals some simple and some branched. 



Phacellophora, Brandt, 1835. 16 marginal sense-organs alternating with 16 clusters of tentacles. Radial-canals in the 

 rhopalar radii are branched, in the tentacular radii simple. 4 gonads. 



Poralia, Vanhoffen, 1902, Numerous straight, unbranched radial-canals. Numerous gonads in a ring around the 

 stomach-margin. 



3. SueFA'MILY Aurelin^e. 



The tentacles and lappets arise from the sides of the disk above the margin. Invaginated gonads with external subgenital 

 pits. 8 marginal sense-organs. 4 simple or bifurcated mouth-arms. Numerous tentacles and lappets. 



Aurellia, Peron and Lesueur, 1809. 4 simple non-bifurcated mouth-arms. Some or all of the radial-canals give rise to 

 anastomosing branches. 4 gonads. 



Aurosa, Haeckel, 1880. Similar to Aurellia but with 4 bifurcated mouth-arms. 



Subfamily UMBROSINiE. 

 SUBFAMILY CHARACTERS. 



The tentacles arise singly from the bell-margin in clefts between lappets. 4 protrusive, 

 bag-like gonads without subgenital pits. 4 unbranched mouth-arms. 



(?) Genus FLORESCA Haeckel, 1880, sens. ampl. 



Fioscula 4- Floresca, H-aeckel, 1880, Syst. der Medusen, p. 537, 1^38, 643. 



GENERIC CHARACTERS. 



Haeckel's genera Fioscula and Floresca may possibly be the young stages of some medusae 

 of the Ulmaridae. In these forms we find that the central stomach gives rise to simple radial- 

 canals which connect with one another by means of a marginal ring-canal. The tentacles 

 arise from the clefts between the lappets, not from the floor of the subumbrella. We must 

 bear in mind, however, that in the young of Cyanea the tentacles first appear in the clefts 

 between the lappets and later the margin grows outward, leaving them to project from the 

 subumbrella. Indeed all tentacles in Scyphomedusae are structures of the subumbrella. 



Fioscula has 8 tentacles and 16 marginal lappets; Floresca has 24 tentacles and 32 

 marginal lappets. Indeed Floresca presents every appearance of being immature and only 

 an advanced stage of "Fioscula," both being one and the same species. Both come from 

 the tropical Indian and Pacific Oceans. 



A brief description of these medusas may be of service should the)- prove to be mature 

 forms. Haeckel is the only naturalist who has seen them. 



"Floresca parthenia" Haeckel. 



Floresca parihenia+ F . pallada, Haeckel, 1880, Syst. der Medusen, pp. 538, 539, taf. 32, fign. 5-8. 

 Fioscula promerhea (younger stage), Haeckel, loc. cit., p. 537, taf. 32, fign. 1-4. F. pandora. Ibid., p. 643. 



Bell rounded, 50 mm. wide, 30 high, with a i6-rayed pigmented star-like marking in 

 the perradii, interradii, and adradii of the exumbrelhi. 8 rhopalia, (8X4) 32 tongue-shaped 



