BIGELOW: MEDUSAE AND SIPHONOPHORAE. 389 



the apical thickening, or top-knot, which is intact in all, serve to iden- 

 tify them as R. velatum. Vanhoffen (1902) and I (1909a) have already 

 given reasons for the belief that this is likewise true of all Rhopalone- 

 mas, except the recently discovered R. fiincrarium of the mid-depths. 

 Browne (1916), on the contrary, believes that the specimens described 

 by him (1906) from the Bay of Biscay, as R. coeruleum, represent a 

 separate species, a view, based on the length of the gonads, which 

 occupy the middle \ of the radial canals, the specimens agreeing in all 

 other respects with R. velahivi. But this difference does not seem 

 sufficient to separate them from R. velatum for there is considerable 

 variation in the length of the gonads in the latter, the condition de- 

 scribed by Browne falling well within the extremes. 



Geryonidae Eschscholtz. 

 LiRioPE Lesson, 1843. 



The few imperfect specimens listed below do not add anything to 

 my previous discussions of the genus (1909a, 1913). The shape of the 

 gonads is now generally accepted as the most important character in 

 Liriope (Vanhoffen, 1902, Maas, 1905, 1909, Bigelow, 1909a, Browne, 

 1916); and the form with primarily triangular gonads is usually 

 designated as L. tctraphylla. The various races with oval gonads are. 

 in such urgent need of revision, that I (1909a, p. 115) have hesitated 

 to identify such specimens; Browne (1916) does likewise. 



Liriope tetraphylla (Chamisso and Eysenhardt). 



Geryonia tetraphylla Chamisso & Eysenhard, 1821, p. 357, pi. 27, fig. 2. 

 (For synonymy, see Bigelow, 1909a, p. 112; 1913, p. 55). 



Station 



10,200 75-0 meters 1 specimen 8 mm. in diameter 



10,207 100-0 " 1 " 10 mm. " " 



Both specimens are fragmentary; but their gonads are already 

 triangular, though small. 



Liriope scutigera McCrady? 



Liriope scutigera McCrady, 1857, p. 106. 



(For synonymy, see Mayer, 1910, p. 421). 



Five small fragmentary specimens of Liriope, 6-10 mm. in diameter, 

 and obviously immature, with small oval gonads, were taken at Sta- 



