BIGELOW: MEDUSAE FKOM THE MALDIVK ISLANDS. 259 



Muyer (Bull. Mus. Comp. Zool., vol. 30, p. 166, plate 9). lilaycr's figure 

 appL-ars tu be taken from an iiuniature imlivuUuil, and in liis description be 

 makes no mention of tlie i'orm of the gonads, so it is possible that the two 

 species may prove to be identical. Both are closely allied to Liriope scutigera 

 McCrady (Proc. Eliott Soc. Nat. Hist., vol. 1, p. 208, 18.59), from Charleston 

 Harbor, South Carolina. 



Liriope hemisphericus, sp. nov. 



Plate 4, Figs. 15, 10. 



The bell is nearly hemispherical, with rather thick walls. It is eight mm. 

 in diameter and slightly more than half as high as broad. The bell cavity 

 is flatter than a hemisphere. There are two kinds of chyniiferous tubes. 

 There are four radial canals, and alternating with these are four broad, arrow- 

 shaped canals which arise from the ring canal and end blindly in the bell wall 

 at about one half the height of the cavity. Corresponding to these two kinds 

 of canals are two kinds of tentacles. The four opposite the radial canals are 

 hollow, flexible, about as long as the bell is high, and ringed with nettle cells 

 throughout their length. Alternating with these, and opposite the blind 

 canals, are four others which are only slightly shorter, but are solid, stiff, and 

 carried curved sharply outward. Instead of being ringed, they bear a series of 

 clusters of nettle cells on their centripetal surfaces (Plate 4, Fig. 16). The 

 cylindrical peduncle, which is very flexible, is nearly as long as the diameter 

 of the bell, and so hangs far below the opening. Its distal end is prolonged 

 into a pointed stomatostyle. The stomach is nearly cylindrical and the mouth 

 bears four simple lanceolate lips which are usually recui'ved. The gonads are 

 heart-sliaped, rather narrow, and occupy the proximal half of the radial canals. 

 They occupy hardly more than one eighth of the surface of the subumbrella. 

 The eight otocysts, whicli are all similar, are arranged radially and interra- 

 dially, the radials being at one side of the tentacles, the interradials directly 

 above their bases (Plate 4, Fig. 16). This Medusa is colorless, except that the 

 gonads are opaque whitish, and the nettle cells on the short tentacles Vandyke 

 brown. 



Three specimens, December 26, Male atoll, near Male island, surface. This 

 species differs in important particulars from all known members of that divi- 

 sion of the genus Liriope whose adult members normally possess centripetal 

 canals, in having only one of the latter to each quadrant, — a condition charac- 

 teristic of the young of other species. In general appearance it most resembles 

 Liriope tenuirostris Agassiz, from the Atlantic coast of North America. A 

 striking characteristic of the species is the large size of the interradial canals. 



Although our specimens were sexually mature, it is by no means certain that 

 the number of blind canals had reached its maximum. Studies on a species of 

 Olindias from Bermuda have shown a condition in which the number of these 

 canals and of the tentacles nearly doubles with the increase in size of the Me- 



VOL. XXXIX. NO. 9 2 



