98 



CCELENTERATA 



Fig. 158 



Stomotoca 



apicata 

 (Hargitt). 



3. Stomotoca Agassiz. Trophosome like Perigonimus. Gonosome: 

 medusa more or less conical with an apical projection ; with 2 long mar- 

 ginal tentacles and a squarish manubrium and 4 oral lobes 

 and the often very large gonads on the side: 6 species. 



S. apicata (McCrady) (Fig. 158). Hydroid form 

 unknown; entoderm of manubrium greenish in color in the 

 male and brownish in the female; base of the tentacles 

 purplish or yellowish ; size 4 mm. by 3 mm. : Florida to 

 Vineyard Sound; Europe. 



S. rugosa Mayer. Similar to preceding, but with 14 

 rudimentary marginal tentacles together with the 2 long 

 ones; base of the tentacles and manubrium brick red; 

 5 mm. high : common at Newport, R. I., and southwards. 



4. Rathkea Brandt {Lizzia 

 Forbes). Trophosome unknown. 

 Gonosome: medusa subconical with 

 marginal tentacles in 8 clusters of 3 

 to 5 each; young with only 4 ten- 

 tacles; manubrium buds off young 

 medusae; 4 branching oral tentacles; 

 no ocelli: 8 species. 



R. grata A. Agassiz (Fig. 159). 



Medusa 3 to 6 mm. high, transparent: Massachusetts 

 Bay to NeAvport, R. I.; often common. 



5. Nemopsis Agassiz, Trophosome like Bou- 

 gainvillia except that the medusae arise from the 

 hydranths. Gonosome: medusa like Bougainvillia 

 but with a pair of short-knobbed tentacles directed 

 upwards from each group of long tentacles and with 

 gonads extending on to the subumbrella: 2 species. 



N. bachei Ag. (Fig. 160). Medusa 6 to 10 mm. 

 high: Florida to Vineyard Sound; common. 



Fig. 159 — Rathkea grata (Hargitt). 



Fig. IGO 



"Nemopsis hachei 

 (Mayer). 



Family 4. EUDENRIIDAE. 



Trophosome: colony branching, rising from a reticulated hydro- 

 rhiza; perisarc distinct and variously annulated; hydranth with trumpet- 

 shaped hypostome (Fig. 150) and a single whorl of filiform tentacles. 

 Gonosome: no free medusae; male sporosacs in a whorl just beneath, 

 and the female sporosacs usually just above the tentacles and occasion- 

 ally on the hydrocaulus: 1 genus. 



Ettdendritjm Ehrenberg. With the characters of the family : about 

 8 American species. 



