178 Papers from the Department of Marine Biology. 



Atolla bairdii forma valdiviae Vanhb'ffen. 



Atolla valdivice, VANHOFFEN, 1902, Wissen. Ergeb. deutsch. Tiefsee Expedition, Dampfer Valdivia, 

 Bd. 3, Lief. 1, p. 13, Taf. 1, Fig. 3; Taf. 6, Fign. 41-46. MAAS, 1903, Scyphomedusen der 

 Siboga Expedition, Monog. 11, p. 17, Taf. 1, Fign. 3, 4; Taf. 3, Fig. 23; Taf. 12, Fig. 108. 

 MATER, 1910, Medusa of the World, vol. 3, p. 565, fig. 358. 



This form is very closely related to A. bairdii but the central disk is only 

 half as wide as the medusa, and the 4 septal nodes are wider than in A . bairdii. 



The Albatross obtained three specimens of this medusa in the Philippine 

 Islands on April 10, 1908, at dredging station No. 5202, in Sogod Bay, depth 

 502 fathoms, bottom green mud. The characters and dimensions of these 

 specimens are given in Mayer's "Medusae of the World," vol. 3, p. 565. 



Genus PELAGIA Peron and Lesueur, 1809. 



Pelagia, PERON ET LESUEUR, 1809 Annal. du Mus. Hist. Nat. Paris, tome 14, p. 349. 



GENERIC CHARACTERS. 



Semseostomata of the family Pelagidse, in which the central stomach gives 

 rise to 16 completely separated radiating pouches, 8 in the radii of the tentacles 

 and 8 in the radii of the sense-organs. There are 8 adradial tentacles, 8 

 rhopalia, and 16 partially cleft marginal lappets. Each of the 16 stomach 

 pouches is cleft at its distal end, where it enters the marginal lappets. There 

 is no ring-canal. 



Pelagia panopyra Peron and Lesueur. 



Pelagia panopyra, PEKON ET LESUEUR, 1807, Voyage aux terres Australes, planche 31, fig. 2. 



This widely distributed tropical Pacific species is distinguished by its small, 

 low, rounded exumbrella warts, which are elliptical in outline and have a 

 longitudinal furrow with cross-foldings. The bell becomes about 50 mm. wide, 

 and the oesophagus is about as long as the bell-diameter, the mouth-arms 

 being somewhat longer. In common with the species of Pelagia, the color 

 is highly variable, but the bell is usually rose-colored or violet, and the nettling- 

 warts are violet. The gonads are usually purple and the mouth-arms violet. 



There are 21 specimens of this medusa in the collection of the Albatross in 

 the Philippines; 10 are from Station 5422, March 30, 1909, from a tow made at 

 a depth of 15 feet below the surface, about 10 miles off Lusaran Point Light, 

 between Panay and Guimaras; the largest specimen is 33 mm. wide and with 

 large gonads, while another 28 mm. wide has only small gonads. 11 young 

 specimens were obtained at Station D5220, April 24, 1908, on the surface 

 between Luzon and Marinduque at 12 h 57 m p. m. These are all small and 

 about 10 mm. in diameter, evidently being taken from a swarm of immature 

 individuals. 



Genus CHRYSAORA Peron and Lesueur, 1809. 



Chrysaora, PERON ET LESUEUR, 1809, Annal du Mus. Hist. Nat., Paris, tome 14, p. 364. 



GENERIC CHARACTERS. 



Pelagidae with 8 marginal sense-organs, 3X8 tentacles, and typically 4X8 

 marginal lappets; although in C. melanaster the lobes may still further divide, 

 giving 6X8 marginal lappets. 



