26 THE MEDUSAE. 



entire endodermal system is described as densely pigmented. The fact that 

 the two forms, P. dodecubostrycha and P. hjacintUna, have both often been taken 

 not only at the same locality, but even in the same haul, is a farther, even 

 if indirect, argument in favor of the view that they represent nothing more 

 than different stages in the growth of but one species. If this be the case, 

 the older name, P. hyacinthina Steenstrup, '37, must be retained. 



As to the validity of P. regim Haeckel, which both Maas ('97, : 04*=) and 

 Vanhoffen (:02^) retain as a good species, I am not able to form any final 

 opinion, since I have at hand only a single rather fragmentary alcoholic 

 specimen from the Gulf Stream, which can be referred to this species. The 

 fact, however, that in this form the gonads do not appear until a size of 

 some 70 mm. in diameter is attained (Vanhoffen, .•02") argues strongly for 

 the view that it is a distinct species. There appears, also, to be a definite 

 difference in its color from that of the other species, although this difference 

 is not shown in Vanhoffen's figure. 



Periphylla hyacinthina Steenstrup. 



Periphylla hyacinthina Steenstrup, '37 ; Haeckel, '80, p. 419 ; Vanhoffen, : 02% p. 23, 



taf. 2, tig. 9; Maas, : 04s p. 47, pi. 5, fig. S6, pi. 6, figs. ^5, 46. 

 ? Charybdea bicolor Quoy et Gaimard, '33, p. 293, pi. 25, figs. IS. 

 Quoyia bicolor L. Agassiz, '62, p. 173. 

 Charybdea periphyUa Peron et Lesueur, : 09, p. 332 ; Blainville, '34, p. 275, pi. 31, fig. 1; 



L. Agassiz, '62, p. 173. 

 PeriphyUa peronii Haeckel, '80, p. 420. 



If we accept the view that P. h//acinthina and P. dodeccibostryclia are in 

 reality but one species, the following synonyms must also be included : — 



? Chrysaora (dodecabostrycha ?) dubia Brandt, '38, p. 387, taf. 29, 30. 

 Dodecabostrycha dubia L. Agassiz, '62, p. 173. 

 Cassiopia dubia Lesson, '43, p. 408. 



Periphylla dodecabostrycha Haeckel, '80, p. 421 ; Vanhoffen, '92, p. 10, taf. 2, fig. 1; : 02% 

 p. 23 ; Maas, '97, p. 63, taf. 9 ; : 04-=, p. 47, pi. 5, figs. S6, S7. 



Plate 1, Fig. S; Plate 9, Fig. 2. 



Station 4652; 200 fathoms to surface; one specimen, very fragmentary, 

 15-20 mm. in diameter. , 



Station 4669 ; 300 fathoms to surface ; two specimens ; diameter about 

 10 mm. ; fair condition. 



Station 4707 ; 300 fathoms to surface ; one specimen, 80 mm. in diameter 

 by 90 mm. high. 



Also twenty-three other specimens ranging from 20 mm. to 40 mm. in 



