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bulletin: museum of comparative zoology. 



plication of structure may progress with growth, in a Medusa the Hfe- 

 history of which is unknown. But the large size of Agassiz's speci- 

 mens (20-25 mm. high) argues against it. And the specimens of <S. 

 atra which I have myself studied (1909a) suggest that the simplicity 

 of gonads and lip is permanent, for in all of them, irrespective of size 

 (6-14 mm. high), the sexual folds are simple, or at most bifid, with no 

 trace of the pinnation so characteristic of S. pterophylla. And the 

 margin of the lip is perfectly simple, without crenulations, or folds of 

 any sort. In short, they agree perfectly, in these respects, with the 

 still larger specimens described by A. Agassiz (1865). 



Thus the evidence at hand points to the existence of two species of 

 Stomotoca, atra and pterophylla, closely allied to each other it is true, 

 but sufficiently separated by the simplicity of lip and gonads in the 

 former, contrasted with their complexity in the latter. 



Stomotoca pterophylla Haeckel. 



Stomotoca 'pterophylla Haeckel, 1879, p. 52, taf. 4, fig. 10; Mayer, 1910, p. 113, 



pi. 29, fig. 3-5, pi. 30, fig. 7; Bigelow, 1917, p. 306. 

 Stomotoca divisa Maas, 1897, p. 11, taf. 1, fig. 1-9; Bigelow, 1909a, p. 203, pi. 7, 



fig. 9; pi. 43, fig. 6-7. 

 Stomotoca atra (partim) Vanhoffen, 1913a, p. 14; {non Stomotoca atra A. Agassiz, 



1865; Mayer, 1910; Hartlaub, 1913). 



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These specimens agree so closely, in general appearance, with 

 earlier descriptions (Bigelow, 1909a; Mayer, 1910), that no further 

 account, beyond what has been given above, is needed. 



Pandea Lesson, 1843. 



Hartlaub (1913), in his recent revision of the Pandeidae admits to 

 this genus only one species, P. conica, of the five grouped there by 

 Mayer (1910), adding thereto P. rubra Bigelow (1913). This reduc- 

 tion results partly from the fact that at least one of Mayer's Pandeas 



