536 



MEDUSAE OF THE WORLD. 



Haliclystus antarcticus Pfeffer. 



Haliclystus antarcticus, PFEFFER, 1889, Mitthci]. Naturhist. Museum Hamburg, Jahrg. 6, p. 16. 



Bell flat, 17 mm. wide to bases and 27.5 mm. wide to ends of arms. Height 11.5 mm. to 

 subumbrella disk and I? mm. to ends of arms. The stalk is 8 mm. long, flexible, and when 



-* O' 



expanded it is about two-thirds as long as bell-height. It has 4 mterradial, longitudinal 

 muscles and is 4-sided in cross-section, the longitudinal muscles being in the 4 flat or grooved 

 sides. The attached end ot the stalk is swollen. There are 8 adradial arms 45 apart with 

 the 8 clefts all of equal depth, and each arm has more than 100 tentacles; 8 large biscuit- 

 shaped, marginal anchors about as long as width of stalk; 8 wide, lancet-shaped gonads, 

 widely separated one from another and extending to ends of arms. The number of sacs in 

 the gonads is not clearly defined in PfefFer's specimens, but there appear to be at least 100 to 

 150 in 6 to 8 longitudinal rows. Stalk single-chambered thus illustrating the close relation- 

 ship between Haliclystus and Lucernana. 



The medusa is a beautiful blue-violet in color, with lighter, somewhat reddish anchors 

 and tentacles. Found at South Georgia, Antarctic Ocean. 



Haliclystus kerguelensis VanhOffen. 

 Haliclystus kerguelensis, VANHOFFEN, 1908, Deutsche Sudpolar-ExpeJition, 1901-1903, Bd. 10, Zool. 2, p. 31, taf. 2, fig. I. 



Bell 27 mm. wide across the outstretched arms exclusive of the tentacles, and 10 mm. 

 high. Arms 45 apart, the concavities between them all similar each to each as in H. antarc- 

 ticus. Peduncle prismatic, 20 mm. long and 3 mm. wide. Not quite 50 tentacles in each 

 adradial cluster. Marginal anchors only one-third as wide as the peduncle in its expanded 

 state. 8 wide, lancet-shaped gonads. 



^^ 



s^ 340. 



FIG. 340. Ha/iclystus stejnegeri, after Kishinouye, in Proc. U. S. Nat. Mus. 



Fie. 341. Hallclvstus kergurltnsh, after VanhuHen in Deutsch. SuJpolar Expedition. 



peduncle sandy-brown with a play of green over the surface. 



Bell and peduncle sandy-brown with a play of green over the surface. Gonads dark 

 olive-brown and plainly visible through the walls of the lighter colored bell. Terminal knobs 

 of the tentacles rose-red. 



Found at Observatory Bay, Kerguelen Island, Antarctic Ocean; in July, growing on 

 the stems of Al/icrocystis. 



This form is closely related to H. untnrctictis, but has fewer tentacles, smaller anchors, 

 and apparently a longer peduncle, although the stalk of H. antni-ctn-iis was probably con- 

 tracted in PfefFer's preserved specimens. There are also color differences between the two 

 forms. 



Genus HALIMOCYATHUS Clark, 1863. 



Halimocyathus, CLARK, 1863, Journ. Boston Soc. Nat. Hist., vol. 7, p. 536. AGASSIZ, A., 1865, North Amer. Acal., p. 61. 



Halicvathus, HAF.CKEL, 1880, Syst. der Medusen, p. 393. 



.\fanania, CLARK, 1863, Journ. Boston Soc. Nat. Hist., vol. 7, p. 541. 



The type species of this genus is H. platypus Clark, from Massachusetts Bay. 



