RHIZOSTOM^ — CRAMBIONE, MASTIGIAS. G77 



The 4 intenadial gonads form a cross following the lines of the cruciform stomach of the 

 medusa but interior to the border. The adjacent gonads lie so close one to another that the 

 genital cross is extremely narrow and elongate. There is a unitary, subgenital poiticus or 

 chamber which serves as a brood-sac for the planula larvre. There is a well-developed, 

 peripheral ring-muscle in the subumbrella, and this is not broken by radial muscle-strands, 

 such as are found in Mastigias. 



The gelatinous substance is translucent and milky. The frilled mouths are whitish and 

 the clubs reddish. The gonads are flesh-colored, pinkish, or reddish. 



This medusa is found at Amboina and at other places among the islands of the Malay 

 Archipelago. It is described and figured in detail b\' Maas, 1903. 



Crambione cookii, sp. nov. 



Plate 74, fig. 2. 



Bell hemispherical, no mm. wide, gelatinous substance tough. Exumbrella smooth in 

 the flexible zone above the margin, but the inflexible central pait of the dome is reticulated 

 by a network of deep furrows trending more or less radially outward from the apex. 8 rho- 

 palia. 88 large, pointed, marginal lappets, equal in size each to each. Mouth-arms 1.5 times 

 as long as bell-radius. The lower two-thirds of each arm is 3-winged and the outer edges of 

 these lamellae are complexly folded and bear the mouths. 4 slender, uniform filaments, as 

 long as the bell-radius, arise from the arm-disk. There are about 2 to 6 trlobular, gelatinous 

 appendages on the outer sides of each mouth-arm. These are about 6 mm. long. 



The gelatinous substance of the bell is opaque, horny, milky-yellow. The marginal 

 ring-muscles of the subumbrella are brown and the valleys of the exumbrella furrows are of 

 a lighter shade of the same color. Mouth-arms and vesicles translucent milky-blue. Mouth- 

 frills brown. 



Found by me on the surface along Great Barrier Reef, off Cooktown, Queensland, Australia, 

 May 4, 1896, during Dr. Alexander .\gassiz's exploration of the reefs. Named in honor of 

 the distinguished navigator. Captain James Cook, whose voyage first made the Queensland 

 coast known to the world, and whose ship, the Endeavour, met with misfortune in June, 1770, 

 near the place wherein this medusa was found. 



Genus MASTIGIAS L. Agassiz, 1862. 



Mastigias, Agassiz, L., 1S62, Cont. Nat. Hist. U. S., vol. 4, p. 152. — Cl-^us, 1883, Organisation und Entwick. der Medusen, 

 p. 61. — VON LzNDENFELD, 1884, Proc. Linnean -Soc. New South Wales, vol. 9, p. 300. — Kishinouye, 1895, Zoological 

 Mag. Tokyo, vol. 7, No. 78. — Chun, 1896, Mittheil, Nat. Mus. in Hamburg, Jahrg. 13, p. 13. — Maas, 1909, .Abhandl. 

 Akad. Wissen., Munchen, Suppl. Bd. I, Abhandl. 8, p. 46. 



Mastigias + Eucrambessa, Haeckel, 1880, Syst. der Medusen, pp. 622, 624. 



Mastigias + Desmostoma, Vanhoffen, 1888, Bibliotheca Zoologica, Bd. I, Heft. 3, pp. 33, 35, 44, 45. — Maas, 1903, Scyphome- 

 dusen der Siboga Exped., Monog. 11, pp. 62, 66, 81. 



Mastygias, Vanhoffen, 1902, Wissen. Ergeb. deutsch. Tiefsee Exped., Valdivia, Bd. 3, Lfg. 1, p. 46. 



The type species is the widely distributed M. papiia of the Indo-Pacific region. It was 

 first described as Ccphea papiia by Lesson, 1829. 



GENERIC CHARACTERS. 



Rhizoslomata tripfera with 3-winged mouth-arms which terminate in a naked, club- 

 shaped extremity. There are also sinaller clubs and filaments between the frilled mouths. 

 The mouths are developed not only along the edges ot the 3 leat-like wings ot the lower pans 

 of the mouth-arms, but also over parts of their flat, expanded sides. The central stomach 

 gives rise to 8 rhopalar canals and numerous, interocular radial-canals all ot which anastomose 

 and finally connect with the ring-canal. The rhopalar canals extend straight to the sense- 

 clubs, but (the inter-rhopalar canals end in the ring-canal. On its outer side the ring-canal 

 gives off a network of vessels which extend into the lappet-zone and fuse with the outer ends 

 of the rhopalar canals. The ring-muscles of the subumbrella are interrupted in the 8 rhopalar 

 radii. A unitary subgenital porticus. No furrows in the exumbrella sensory pits. 



The genus Desmostoma of Vanhoffen, 1888, conforms in all respects to Agassiz's Mastigias 

 except that there are clusters of filaments upon its arm-disk at the bases of the mouth-arms, 

 whereas the other species of Mastigias lack filaments and have only small clubs on the sides 



