610 



MEDUSA OF THE WORLD. 



but later the bell-margin becomes cleft so that the tentacles project from the clefts. Diplul- 

 mans resembles the genus Phacellophora in having 16 rhopalia. 



VanhofFen, 1908, describes this medusa under the name Ulmaropsis drygahkii. Some 

 of his specimens were more advanced than those seen by Maas, and they had 64 marginal 

 lappets instead of only 32, as in those of Maas. 



Diplulmaris Antarctica Maas. 



Dip/ulmaris antarctica, MAAS, 1908, Exped. Antarctique Francaise, Meduses, p. 12, i taf. 



Ulmaropsis drygahkii, VANHOFFEN, 1908, Deutsche Sudpolar Expedition, 1901-03, Bd. lo, Zool. 2, p. 45, fign. 10-12. 



Ulmaropsis antartica, VANHOFFEN, 1909, Ibid., Bd. 10, Zoo]. 2, p. vi. 



FIG. 390. Diplulmaris antarctica, young medusa, after Maas, in Meduses Expedition Antarctique Francaise. 



The largest specimen is described by VanhofFen, whose publication appeared only a few 

 weeks after that of Maas. and is as follows: 



Bell 42 mm. wide, 16 marginal sense-organs alternating with 16 simple, hollow tentacles. 

 The sense-organs and tentacles are flanked by 64 slender, pointed lappets, the 32 lappets 

 flanking the sense-organs being wider and longer than those flanking the tentacles. 32 radial- 

 canals arise from the central stomach these being in the tentacular and ocular radii. The 

 tentacular canals are simple and unbranched, but each of the ocular canals gives off 2 pairs 



