334 



MEDUSAE OF THE WORLD. 



The bell-cavity is very shallow, so that the disk has almost the shape of a thick plano- 

 convex lens, 50 to 100 mm. wide. There are 10 to 16 short, tapering, hollow tentacles, about 

 one-fourth as long as the bell-radius. The basal bulbs of these tentacles have a wide lateral 

 extension along the margin of the disk. There are no excretory papillae, but only simple 

 pores. Each tentacle is at the foot of a radial-canal and two rows of nematocysts extend 

 down the sides of the tentacle. There are a very large number of permanently undeveloped, 

 rudimentary tentacle-bulbs upon the margin, these being between 2 and 3 times as numerous 

 as the radial-canals. The marginal lithocysts are 2 to 4 times as numerous as the tentacular 

 rudiments. They are small and each one contains 2 spherical concretions. Velum is very 

 narrow. 100 to 250 straight, narrow radial-canals and a slender, marginal ring-canal. The 

 stomach is one-half to two-thirds as wide as diameter of disk. Its side walls are short and 

 rudimentary and only about 2 to 4 mm. in length, so that the mouth can not be closed but is a 

 wide circular opening, almost as wide as the stomach itself. The lips are as numerous as the 

 radial-canals, elongate, pointed, and provided with an external, gelatinous, axial rib. Gonads 

 linear and developed upon all of the radial-canals extending nearly from periphery of stomach 

 to the circular vessel. 



The entoderm of the stomach, tentacle-bulbs, and radial-canals is milky to slaty-blue in 

 color; the stomach may be pink; all other parts colorless. 



Widely distributed over the Red Sea, tropical Indian Ocean, and the Pacific, but not 

 found in the Mediterranean. 



The best descriptions have been given by Browne and Maas, and the following table, 

 showing the range of variability, etc., is mainly derived from their works: 



^quorea parva Browne. 



Mquorea parva, Browne, 1905, Report Pearl Oyster Fisheries, Gulf of Manaar, Supplementary Report No. 27, Roy. Soc. London, 

 p. 146, plate 2, figs. 5-7. 



Bell is 6 mm. wide, 4 mm. high. Plano-convex, lenticular, with very thick gelatinous 

 substance. 4 to 8 tentacles, with large basal bulbs. 50 to 100 marginal bulbs and 50 to 100 

 lithocysts, each with 2 concretions. Velum quite wide. 13 to 16 simple radial-canals. Stomach 

 flat, with circular periphery; about one-third as wide as the bell. 13 to 16 lips. Gonads 

 sac-like upon the central thirds of the radial-canals. Galle Bay, Ceylon, June. Three speci- 

 mens studied by Browne. 



jEquorea conica Browne. 



JEquorea conica, Browne, 1905, Report Pearl Oyster Fisheries, Gulf of Manaar, Suppl. Report No. 27, Roy. Soc. London, p. 

 145, plate 1, fig. 2; plate 2, figs. 16-18. 



Bell 7 mm. wide, 8 mm. high. Cone-shaped, with a bluntly-rounded apex and very thick 

 walls. 26 to 30 small, slender tentacles, with conical basal bulbs which are said to lack 

 excretory pores. These tentacles are about as long as the bell-diameter. 26 to 30 minute 

 marginal bulbs alternate with the tentacles. 52 to 60 lithocysts, each with 2 concretions, 

 between the marginal bulbs and tentacles. Velum narrow. About 16 radial-canals. Stomach 



