TRACHYMEDUS.E — AGLAURA. 



397 



pushed outward by its growth so as to appear at its margin in the developed medusa. The 

 ectodermal ithocyst-clubs are evidently not homologous with the ectoderma , vesiculai lith- 

 "yst saTs of Lept'omedusa,. In common with other Trachymedus* the Aglaumur may be 



rega Th d e £££%£ devlH upon some or upon all of the radial-canals and they may be 

 linear or Susage shaped and suspended. In the genus Amphogpna the medusa may be her- 

 maphrodiuc 4 of the" gonads being male and the 4 on every alternate canal be.ng female. 

 Tn all other genera the sexes are separate. . 



The 8 rail-canals of the Aglaurin* are perradial and mterrad.al. not adrad.al m refer- 

 ence to the lips, as is claimed to be the case by Haeckel, 1879. 



The Ag a P u ina,, owing to their direct development and independence of coasts are widely 

 distribu ed over the world' and are among the most characteristic Trachyhna medusae of the 

 oc an far from land. The genus Aglantha is characteristic of cold waters while Aglaura 

 is P abundant in warm seas. A synopsis of the genera ot the Aglaunn* follows. 



the tum.ng-poii.ts of the 8 radial canals **£«£ P qr h g ridiilxam i, nea r the bell-marg.n. 



03Z2Z2?2^& :&?£££ « one of the 8 radial-canals, the 4 other canals being 

 PersTucC,^, .8J7. With , gonads on , of the radial-canals ,8o° apart. The 6 other radial-canals are sterile. 



Genus AGLAURA Perron and Lesueur, 1809. 

 Ailaura, Peron et Lesueur, .809, Annal. Mus. Hist Nat. Paris, tome .4, p. 351. 

 Unonia, Evooux et Souleyet, .84., Voyage de la Bonn, tome 2, Pj^- Naturgesch., Jahrg. », 



low; H. B, .909, Mem. Mus. Comp. Zool. at Harvard College, vol. 37, p. I 17. 



The following table will illustrate the differences between the several varieties oi Aglaura 



hemistoma. . . 



Synopsis of the Described Varieties 0} Aglaura hemistoma. 



A. "nausicaa' 

 Haeckel. 



A. "prismatica" 

 Maas. 



Size in mm. 

 Shape of bell. 



Length of pedun 

 cle in terms of 

 bell-radius(r). 



Color of stomach 



Shape of gonads. 



Number of ten- 

 tacles. 

 Where found. 



2 to 3 wide, 4 



high. 

 Egg-shaped, 



oval. 



Very short, 0.1 r. 



Colorless. 



Club-shaped, 

 widest at outer 

 ends. 



.6 to 31 



Adriatic Sea, 

 March. 



A. hemistoma 

 Peron and 

 Lesueur. 



3 to 4 wide, 3 to 4 

 high. 



Cubical to pris- 

 matic, with low 

 apex. 



Short, 0.5 



Delicate rose, 

 orange-brown or 

 brownish-red. 



Sac-shaped to sau- 

 sage-shaped. 



50 to 60 



Gulf of Panama to 

 tropical Pacific 

 (Fiji, Maldive). 



A. "radiata* 

 Haeckel. 



3 to 4 wide, 4 to 6 

 high. 



Cylindrical or pris 

 matic with rela- 

 tively flat top. 



Short, r. 



Reddish-yellow to 

 brownish-yellow. 



Egg-shaped to sau- 

 sage-shaped. 



50 to 60 



Mediterranean, 

 Atlantic, Pacific, 

 Indian Oceans. 



A. "laterna. 



4 wide, 8 high. 



Cylindrical or 

 prismatic with 

 32 "ribs" (= 

 Ducklings of el 

 umbrella due to 

 contraction). 



Fairly long, r± 



(?) 



Club-shaped as 

 in A. nausicaa. 



3 2 



South Pacific. 

 (Is this not a 

 contracted A. 

 prismatica ?) 



A. "octagona" 

 Bigelow. 



6 wide, 8 high. 



Octagonal pris- 

 matic below 

 with pyramidal 

 truncated top. 



Long, 1.5 r. 



Purplish-red. 



Spherical or 

 oval. 



16 to 32 



Canary Islands, 

 in January. 



1.5 wide, 3 high. 



Octagonal pyra- 

 midal above 

 with truncated 

 top. Sides 

 vertical. 



Long, 1 .5 r+ . 



Colorless. 

 Egg-shaped. 



3 2 



Kolumandulu 

 Atoll, Maldive 

 Islands, Indian 

 Ocean, Decem- 

 ber. 



