CORONATE — ATOLLA. 567 



I am iiuliiied to believe that A. wyvillei, A. verrillii, A. alcxandri, and A . nclullts are only 

 varieties of one and the same species. " A . alcxandri" is a form of A. tuyvtllei with indistinct 

 notches in the margin of its central lens. 



A specimen was dredged hy x\\q Albatross on April lo, 1908, dredging station No. 5201, 

 off the south end of Le\i Island, Philippine Islands, from a depth of 554 fathoms. A side 

 view is shown in hg. ^(u. There were zi, pedalia and tentacles, and 22 radial furrows in the 

 margin of the central disk. J he dimensions in millimeters are as follows: 



Diameter of bell 55 Width of tentacular pedalia 6 Width of ring-muscic 3 



Thickness of bell 26 Length of pedalia of lappets 6.5 Diameter across zone of gonads. . 28.5 



Diameter of central lens 40 Width of pedalia of lappets 5 Diameter of manubrium 2r 



Deptli of coronal fujrow ^ Length of tentacles 13 Length of manubrium 22 



Length of tentacular pedalia. .. . 6.5 Diameter to outer edge of ring- Gonads 7 long in the circumferential dinc- 



muRclc 48 lion, 5 wide in the radial direction. 



Atolla wyvillei forma verrillii Verrill. 



Atolla verrilliif Vkrrii.l, 1885, Report Commiss. Fish and Fisheries U. S. A. for 1883, p. 594. — Fkwkes, 1885, Report Commiss. 

 Fish and Fisheries U. S. A. for 1883, p. 596; Ibid., 1886, Report for 1884, p. 939, plates 4, 5, 4 figs.; Ihid., 1889, Report 

 for 1886, p. 530; 1888, American Journ. .Sci., ser. 3, vol. 35, p. 172; 1888, Ann. Mag. Nat. Hist., ser. 6, vol. i, p. 253. — 

 Maas, 1897, .Mem. Mviseum Comp. Zool. at Harvard College, vol. 23, p. 79. — Vanhoffen, 1902, Wissen. Ergrb. dcutsch. 

 Tiefsee Exped., Valdivia, Bd. 3, Lief, i, p. 10, taf. 5, fig. 23; taf. 6, fig. 39; taf. 7; 1908, deutsche Siidpolar Expedi- 

 tion, Bd. 10, Zool. 2, p. 36. 



This form is distinguished from the typical Atolla halrdii and resembles A . ivyvillet by the 

 absence ot a projectmg annular ridge on the outer side ot the ring-furrow, the numerous, 

 fine, radial furrows of its central dome, the long, narrow pedalia of the sense-organs, and the 

 smallness of its marginal lappets. The medusa Ijecomes 95 mm. wide and has between 14 to 28, 

 usually 22, tentacles and marginal sense-organs and 28 to 56 small lappets. Central lens of 

 e.xumbrella wider than in A . hatrdii. It is found in deep water in the Atlantic, Indian, and 

 Pacific Oceans. Most of the specimens have been obtained in open nets dragged from depths 

 of 373 to 2,369 fathoms; but several have been found upon the surface. It is probably only 

 a variety of A. wyvillei. 



Family ATORELLIDiE Vanhoffen, 1902. 



Atordlidw, Vanhoffen, 1902, Wissen. Ergeb. deuLsch. Tiefsee Expedition Valdivia, Bd. 3, Lfg. i, p. 51. — Bigei.ow, H. B., 1909, 

 Mem. Museum Comp. Zool. at Harvard College, vol. 37, pp. 21, 30. 



FAMILY CHARACTERS. 



Coronatae with 6 rhopalia. 



There is but a single known genus, this being Atorella. 



The relationship between the Atorellidse and other Coronatae is unknown; for in the 

 Periphyllidae, Paraph)llinid2e, and Eph\opsids there are 4 or 8 rhopalia, and in the Collaspidae 

 a large fmore than 8) but indefinite number of these organs; and it is impossible at present to 

 determine how the number 6 may have been derived in the Atorellidae. It is probable, how- 

 ever, that its affinities are much closer to Atolla than to the other Coronatae. 



Genus ATORELLA Vanhoffen, 1902. 



Alorella, Vanhoffen, 1902, Wissen. Ergeb. deutsch. Tiefsee Expedition, Dampfer Valdivia, Bd. 3, Lfg. i, p. 33. — Maas, 1903, 

 Scyphomedusen der Siboga Expedition, Monog. 1 1, p. 10. — Bigelow, H. B., 1909, Mem. Museum Comp. Zool. at Harvard 

 College, vol. 37, p. 30. 



The type species is Atorella subglobosa VanhoflPen, of Dar es Salaam, Africa, and from 

 the Alalay Archipelago. 



GENERIC CHARACTERS. 



Coronatae with 6 marginal sense-organs, 6 tentacles, 12 margmal lappets, and 12 pedalia. 

 A coronal furrow is present, and the 12 pedalia alternate with the lappets. There is a poorly 

 developed ring-muscle in the subumbrella. 4 lips, 4 interradial gonads. 



