RHIZOSTOM.E CATOSTYLUS. 667 



A gelatinous papilla is found upon the subumbrella on the outer side of the opening of each 

 subgenital ostium. The 8 mouth-arms are about 1.5 times as long as bell-radius. The laterally 

 compressed, simple, upper part of each arm is only about one-sixth as long as the j-winged, 

 tapering lower part. The 3 expanded membranous lamellae of the lower parts of the arms are 

 1 20 apart, and their free, outer edges branch profusely and bear the frilled mouths. The 

 mouth-arms taper to a pointed end below. No clubs, filaments, or other appendages. The 

 mouths are bordered by small knobbed tentacles, which wave incessantly. 16 radial-canals 

 leave the cruciform central stomach and are connected by a ring-canal which gives oh\ both 

 on its outer and inner sides, an anastomosing network of vessels which fuse with the radial- 

 canals, but do not extend inward to the margin of the stomach. 



This medusa is normally cobalt-blue, but in Port Jackson, New South Wales, Australia, 

 it is infested with plant cells (Zooxanthellee), which give it a uniform creamy or brownish- 

 yellow color except along the upper edges of the wing-like folds of the mouth-arms, where 

 the deep blue color appears. In Brisbane Harbor and at Melbourne, Australia, the medusa 

 is not commonly infested with plant cells and is deep cobalt in color. 



C. mosaicus occurs in vast swarms in the harbors and estuaries of the Australian coast 

 from Brisbane to Melbourne during the Australian summer and autumn. 



It swims by an incessant series of pulsations of its bell-rim and tends to oppose the current. 

 It is the most abundant medusa along the Australian coast, and is often cast up on the beaches 

 in long wind-rows during storms. 



A small fish, Trichinurus Jeclivis, is often seen living commensally with the medusa. 



Catostylus cruciatus. 



Rliizostoma cruciala, LESSON, 1829, Voyage de la Coquille, Zooph., p. 121, planche ll, fig. I. 

 Rharopilus cruciatus, AGASSIZ, L., 1862, Cunt. Nat. Hist. U. S., vol. 4, p. 153. 

 (!) Riiacopilui cyanolobalus, AGASSIZ, L., Ibid., p. 152. After mss. of Couthouy. 

 Crambeua cruciata, HAECKEL, 1880, Syst. dcr Medusen, p. 620. 



Bell hemispherical, 120 to 150 mm. in diameter. 8 marginal sense-organs and 48 lappets. 

 4 large triangular velar and 2 very small ocular lappets in each octant. There are about 32 

 deep, radial furrows in the exumbrella. Arm-disk as wide as bell-radius. The 8 mouth-arms 

 are 1.5 times as long as bell-radius. The simple, cylindrical, upper part of each arm is short, 

 while the lower part is about 4 times as long and tapers to a point. These lower parts of the 

 mouth-arms are 3-winged in cross-section and thickly covered with frilled mouths. 



The medusa is yellowish-white with rose-red gonads and ring-canal, according to Lesson; 

 but according to Agassiz's note from Couthouy's manuscript, the bell is bluish-white with 

 deep-blue marginal lappets and with carmine mouths upon the arms. It should be borne in 

 mind that Crunihfssa mosaica of Australia is sometimes yellowish-white while other individuals 

 are deep cobalt-blue. This yellowish-white is caused by unicellular, commensal plant cells 

 which sometimes infest the medusa. 



Found at Santa Catharina Island and at Rio de Janeiro, Brazil. 



Catostylus palmipes. 



Crambeua palmipes, HAECKEL, 1880, Syst. der Medusen, p. 620. LI'NEL, 1883, Annals and Mag. Nat. Hist., scr. 5, vol. 12, 

 p. 268. SCHULTZ, L. S., 1898, Denkschr. Med. Nat. Gcsell., Jena, Bd. 8, p. 453, taf. 33, fig. i; taf. 34, fig. n. 



Bell 64 mm. wide, hemispherical. Exumbrella covered with fine granulations. 64 

 marginal lappets. In each octant 6 quadratic, truncated velar lappets, flanked by 2 oval 

 ocular lappets only halt as large as the velar ones. Mouth-arms thick, somewhat shorter than 

 the bell-radius. The cylindrical, upper shaft of the arm is only about one-sixth as long as the 

 pointed, ^-winged, lower part. These short, upper shafts of the 8 arms are bound one to 

 another along their sides by 8 membranes, leaving only the pyramidal lower parts of the arms 

 free. Neither clubs nor filaments. Subgenital ostia 3 to 4 times as wide as the columns between 

 them. Color (?) Found from northern Australia to Amboina, Malay Archipelago. Most 

 fully described by Schultze. 



Lunel, 1893, observes that this medusa is often found commensal with a fish Carncx 

 melampygus. 



