NARCOMEDUS/E — SOLMUNDELLA. 



457 



I am inclined to consider this as identical with the somewhat larger S. bitentaculata, or at 

 most only an ill-defined variety of the latter. 



S. mediterranea, however, becomes mature when the bell is only 3 to 6 mm. wide, whereas, 

 according to Maas (1905, p. 75), S. bitentaculata shows no trace of gonads even when 8 mm. 

 wide. The largest S. mediterranea are not more than 6 mm. wide, whereas S. bitentaculata 

 becomes 12 to 15 mm. wide. Moreover, according to Maas, 1893, 1905, the apex of the bell 

 in S. bitentaculata is sharp-edged and keel-like, being laterally flattened and elongated in the 

 axis of the 2 long tentacles. The apex of the bell of S. mediterranea is, on the other hand, 

 simply dome-like and rounded. According to Maas, 1893, 1905, the outline of the bell-margin 

 of S. bitentaculata is elliptical and elongated in the tentacular axis, whereas the outline of the 

 margin of S. mediterranea is circular. In S. bitentaculata the intertentacular peronial strands 



301. 



Fin. 301. — Solmundella bitentaculata, Tortugas, Florida, 1907, 

 from life, by the author. 



Fig. 302. — Solmundella bitentaculata var. mediterranea, oral view. 

 From life, by the author, Naples Zoological Station, Febru- 

 ary 1, 1008. 



are buried in the gelatinous substance of the bell, and this is also true of S. mediterranea; but 

 in some specimens of S. mediterranea they are at the bottom of open or partially open furrows, 

 as are the tentacular peronia in both species. There are as many as 32 marginal sense-clubs in 

 S. bitentaculata, but apparently never more than 16 in S. mediterranea. 



There are occasionally a few very small vestigial tentacles on the bell-margin of S. mediter- 

 ranea. These are merely minute projections and may be at the margin in the radii of the inter- 

 tentacular furrows or in one or more of the 4 interradii. They are often entirely absent and 

 are usually irregular in development and position when present. 



