628 



MEDUSAE OF THE WORLD. 



mere ridge or ledge-like mass of tissue covering the concavity in which lies the sense-club. 

 The dorsal sensory-pit in Aurellia solida is a deep triangular funnel with a long, narrow mouth, 

 and is quite unlike the shallow exumbrella sensory-pit of Aurellia aurita. 



The bell is 80 mm. wide and 40 mm. high. Canal-system similar to that of Aurellia 

 aurita, but the 4 circular, subgenital ostia are each only 2 mm. in diameter, whereas in A. aurita 

 they are usually much larger. The oral arms are not quite as long as the radius of the 

 umbrella. The genital radius is about 0.4 that of the umbrella. 



Maldive Islands, Indian Ocean, and 15 west of Madeira in the North Atlantic. 



Aurellia labiata Chamisso and Eysenhardt. 



Aur,-lia labiata, CHAMISSO UND EYSENHARDT, 1820, Nova Acta phys. med. Leop. Car., tome 10, p. 358, planche 28, figs. I A, B . 

 Aurellia labiata, DE BLAINVILLE, 1834, Manuel d'Actinologie, p. 294, planche 42, figs. I, 2. FEWKES, 1889, American 



Naturalist., vol. 23, p. ^92, fig. 2; Bull. Essex. Institute, Salem, vol. 21, No. 7, p. 122, plate 5, fig. 2. 

 Diplocraspedon limbata, BRANDT, 1838, Mem. Acad. Sci. St. Petersbourg, Sci. Nat., ser. 6, tome 4, p. 372, taf. 10. 

 Aurelia flausa (young medusa), LESSON, 1829, Voyage de la Coqitille, Zool., p. 119. 

 Aurelia labiata + A. clausa+A. limbata, HAFCKEL, 1880, Syst. der Medusen, pp. 557, 558. 

 Aurelia limbata, GOTTE, 1886, Sitzungsber. Akad. Wissen. Berlin, Jahrg. 1886, p. 836. VANHOFFEN, 1906, Nordisches Plankton, 



Nr. II, p. 61, fig. 32. KISHINOUVE, 1910, Journal College of Sci. Tokyo, vol. 27, art. 9, p. 22. 



B 



FIG. 398. Aurellia labiata. Drawn by the author, from specimens collected by the U. S. Bureau of 

 Fisheries steamer Albatross at Masbate Anchorage, Philippine Islands, April 21, 1908. 



A, oral view of medusa with one mouth-arm cut off. B, bell-margin seen from exumbrella side showing 

 dorsalward migration of lappets and tentacles. C, section of bell-margin, the areas cut across 

 being dotted, c, circular vessel; ex, exumbrella; /, marginal lappet; re, radial-canal; su f sub- 

 umbrella; z>, velum-like bell-margin of bell; /, tentacle. 



This species is distinguished by having 16 velar lobes separated by deep median clefts 

 instead of 8 simple lobes as in A. aurita. The canal-system is similar to that of Aurellia aurita, 

 but there is probably a greater tendency for fusions to occur between the adradial and other 

 canals than in A . aurita. The bell-margin projects downward from the subumbrella side as 



