406 



MEDUSA OF THE WORLD. 



Found near the surface in the Maldive Islands, Indian Ocean (Miladummadulu Atoll), 

 and off the west coast of Sumatra. Browne gives a good series of figures of this medusa. 

 Bigelow, 1909, found 6 specimens of this medusa in Acapulco Harbor, Pacific coast ot 

 Mexico, on February 28. The largest specimen was 6 mm. wide, with somewhat conical 

 bell and thin, but rigid, gelatinous substance. About 64 tentacles. When young there are 

 4 small, alternating with 4 large, gonads, but in later life all gonads become of one and the 

 same size. Bigelow found upon sectioning his medusae that all of the gonads in any one 

 medusa were of one and the same sex, thus casting doubt upon Browne's conclusion. 



Genus STATJRAGLAURA Haeckel, 1879. 



Stauraglaura, Haeckel, 1879, Syst. der Medusen, p. 277.— Maas, 1906, Fauna Arctica, Bd. 4, Lfg. 3, p. 496. 



The only known species is Stauraglaura tetragonima Haeckel, from the coast of Australia. 



GENERIC CHARACTERS. 



Aglaurinae with 4 gonads upon every alternate one of the 8 radial-canals, leaving every 

 alternate radial-canal sterile. This genus resembles Tetrorchis Bigelow, but is distinguished 

 by having a gelatinous peduncle above the stomach. 



Stauraglaura tetragonima Haeckel. 



Stauraglaura tetragonima, Haeckel, 1879, Syst. der Medusen, p. 277, taf. 

 16, fign. 10, II. 



12 mm. high, 8 mm. broad, bell-shaped with 

 octangular sides and small conical apex. 60 to 80 ten- 

 tacles, 4 lithocyst-clubs apparently in the radii of the lips. 

 Velum very wide. Peduncle slender and cylindrical, half 

 as long as bell-height. Stomach small, bell-shaped, 

 hardly one-fourth as long as peduncle, 4 very short, wide, 

 triangular lips. 4 spherical gonads, each about twice 

 as large as stomach, upon the peduncle adjacent to 

 stomach. Haeckel studied two preserved specimens and 

 states that there are 8 radial-canals on the subumbrella, 

 but apparently only 4 along the peduncle. The 4 

 peduncular canals may, therefore, bifurcate, but of this 

 he is not certain. At any rate, there are only 4 gonads. 

 Coast of Australia. Exact arrangement of the gonads, 

 lips, sense-clubs, and radial-canals ( ?) 



Genus PERSA McCrady, 1857. 



Fig. 258. — Stauraglaura tetragonima, after 

 Haeckel, in Syst. der Medusen. 



Persa, McCrady, 1857, Oymn. Charleston Harbor, p. 104.— L. Aoassiz, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 278.- 

 1879, Syst, der Medusen, p. 278.— Maas, 1906, Fauna Arctica, Bd. 4, Lfg. 3, p. 496. 



The type species is Persa 

 States. 



-Haeckel, 



olorata McCrady, of the southern Atlantic coast of the United 



GENERIC CHARACTERS. 



Aglaurinae in which only 2 of the 8 radial-canals bear gonads. The 2 gonads are 180° 

 apart and are situated upon the subumbrella portions of the radial-canals. 



Haeckel enumerates three "species," but the differences between them are so slight that 

 it seems probable that there is but one true species and this should be called P. incolorata. A 

 synopsis of these forms is given in the following table. 



Haeckel's so-called lantern-shape of the bell is due to contraction, yet he attempts to dis- 

 tinguish two "species" upon the presence or absence ot this character. 



On December 11, 1907, I found an immature Persa in the Bay of Naples, Italy. The bell 

 was 1 mm. high and oval, with a solid dome-like apex. There were 46 tentacles all broken off 

 short. The 16 radial and interradial tentacles had each a brilliant ruby-red spot in the ento- 



