~>1S MEDUSA OF THE WORLD. 



Atorella. The peripheral canal-system resembles that of Periphylla. The central stomach 

 opens into a wide ring-sinus by 4 perradial ostia separated by 4 interradial septa. The ring- 

 sinus is about 10 mm. broad and is at the zone of the gonads. On its outer side it gives off 24 

 broad, spoke-like radial-canals in the radii of the rhopalia and tentacles, and these canals are 

 connected one with another by a festoon ring-canal at the margin, extending in loops around the 

 lappet margins. There are 8 oval gonads, adradial in position and equidistant one from 

 another. The mouth parts were lost in both Vanhoffen's and Bigelow's specimens, but there 

 are about 80 to 100 simple gastric cirri arranged in a single linear row. There are 4 inter- 

 radial ostia in the subumbrella. The entire entodermal system is chocolate-red. 



The Valdivia specimen was dredged from between 1,200 fathoms and the surface in the 

 Indian Ocean between New Amsterdam and Cocos Islands, and the Albatross specimen which 

 was studied, while yet alive, by Bigelow was obtained in the Humboldt current off the coast of 

 Peru between 400 fathoms and the surface. 



Genus (?) NAUPHANTOPSIS Fewkes, 1885. 



Nauphanlopsis, FEWKES, 1885, Report Commiss. Fish and Fisheries U. S. A. for 1883, p. ^96; 1886, Report Comrniss. Fish and 

 Fisheries U. S. A. for 1884, p. 944. VANHOFFEN, 1892, Ergeb. der Plankton Expedition, p. zi; 1902, Wissen. Ergeb. 

 deutsch. Tiefsee F.xpeJ. t'aldivia, Bd. 3, Lfg. I, p. 51. HARGITT, 1904, Bulletin I'. S. Bureau of Fisheries, vol. Z4, p. 66. 

 MAAS, 1907, Ergeb. und Fortschritte der Zool., Bd. I, p. 199. 



GENERIC CHARACTERS. 



Coronatae with 32 marginal lappets, 4 interradial sense-organs, and 28 tentacles. With 

 an annular furrow and 32 radial ridges (or pedalia) upon the exumbrella in the radii of the 

 tentacles and sense-organs. 



O 



Owing to the incompleteness of our knowledge of the only known species of this genus it 

 must remain problematical. 



Nauphantopsis diomedeae Fewkes. 



Nauphanlopsis diomedfee, FEWKF.S, 1885, Report Commiss. Fish and Fisheries U. S. A. for 1883, p. 596; 1886, Report Commiss. 

 Fish and Fisheries U. S. A. for 1884, p. 946, plate 6, figs, i, 2; 1888, Amer. Journ. Sci., ser. 3, vol. 35, p. 173; Ann. and 

 Mag. Nat. Hist., ser. 6, vol. i, p. 255. HARCITT, C. W., 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 66. 



Fewkes gives an unsatisfactory account of this medusa owing to the poor preservation 

 of his material. We are uncertain whether there are 4 or 8 marginal sense-organs. 



Disk quite flat, 70 mm. in diameter. Central part of exumbrella flat and surrounded 

 by an annular furrow; diameter of this region about 35 mm. Centrifugally from the annular 

 furrow there is a zone about 10 mm. wide consisting of 32 radial elevations separated by 32 

 deep radial furrows; these elevations lie in the radii of the tentacles and sense-organs and 

 alternate with the lappets. Each elevated ridge is bifurcated at its outer end by a deep median 

 cleft. The 32 lappets are long and rectangular with rounded outer edges. They are each 

 about 10 mm. long and 8 mm. wide. There are 4 or 8 ( ?) marginal sense-organs and 24 ( ?) 

 or 28 tentacles. The sense-organs were not observed in the specimen studied by Fewkes. 

 Tentacles slender and flexible and about 80 mm. in length. Subumbrella (?) Mouth (?) 

 Gonads (?) Color (?) 



A single specimen was dredged from a depth of 2,033 fathoms in N. lat. 38 30', W. long. 

 69 8'. 



Family PARAPHYLLINIDvE Maas, 1903. 

 Paraphyllinidtc, MAAS, 1903, Scyphomedusen der Siboga Expedition, Monog. n, p. 6. 



FAMILY CHARACTERS. 



Medusa Coronates with 4 perradial rhopalia and 4 or more tentacles. 



This family differs from the Periphyllidas only in having the marginal sense-organs 

 perradial instead of interradial. 



There is only one known genus among existing medusje, this being Paraphyllina; but 

 this is very closely related, if not identical, with Paraphyllites, a fossil medusa of the litho- 

 graphic slate of Kelheim. 



Maas records a Paraphyllina from the Malay Archipelago, and another specimen was 

 taken by the Krupp yacht Puritan at a depth of 500 fathoms, near Capri, Bay of Naples. 



