142 MEDUS.E OF THE WOULD. 



bell. There are 8 stiff marginal tentacles with large basal bulbs. These tentacles are carried 

 curled upward from the bell-margin. The 4 radially situated, marginal tentacles are about 

 two-thirds as long as the bell-height, but the 4 interradial ones are only about halt of this 

 length. The basal bulbs of all of the tentacles are large, swollen, and hollow, with their 

 entoderm deeply pigmented. The velum is broad. There are 4 simple, straight radial-canals 

 and a simple circular vessel. The stomach is mounted upon a short, wide, solid peduncle. 

 The stomach and mouth-parts are together only about half as long as the depth of the bell- 

 cavity. The mouth is a simple, round opening without prominent lips and is surrounded by 

 8 unbranched, oral tentacles, each of which terminates in a knob-like bristle of nematocysts. 

 4 of these oral tentacles are radial and 4 interradial in position. Their entodermal cells are 

 chordate, and the nematocyst-capsules upon their free ends are spindle-shaped. Medusa- 

 buds develop upon the 4 interradial sides of the stomach. When set free each medusa has 

 only 4 short, equally developed, marginal tentacles. The 4 interradial, marginal tentacles 

 do not develop until the medusa is about half-grown and after it has acquired 8 oral tentacles. 

 The entoderm of the manubrium is usually red in color, although often the inner core is red or 

 pink and the outer annulus of entoderm is green. Each tentacle-bulb is provided with a 

 dense mass of red, entodermal pigment, which in the case of the radial tentacle-bulbs extends 

 a considerable distance up the radial-canals. This medusa was quite common on the surface 

 at Tortugas, Florida, in June, 1899 and 1907. 



This species and P. octostyla Haeckel are the only forms of Podocoryne having rrfore 

 than 4 oral tentacles. The remarkably late development of the 4 interradial, marginal ten- 

 tacles and the presence of more than 4 oral tentacles indicate the close relationship between 

 C,\ticis and Podocoryne. In Cyttns more than 4 oral tentacles are the rule. Although the 

 medusa appears to begin life with but 4, later it acquires 8 or more, Cyta-is vulgans having 32 

 tentacles. 



Podocoryne humilis Hartlauh. 



Podocor\ne liutnilis, HARTLAUB, 1905, Zoolog. Jahrbuchern, Suppl. 6, p. 523, fig. K. 



( ?) D\stnorphosa tenuis (medusa), BROWNE, 1902, Annal. and Mag. Nat. Hist., ser. 7, vol. 9, p. 277. 



Hartlaub describes this hydioid from Terra del Fuego, and states that it may prove 

 to be the stock of Podocoryne tenuis, which was briefly described by Browne, 1902, from the 

 Falkland Islands. 



The polypites arise in groups from the hydrorhiza. The feeding polypites are about i 

 mm. long, club-shaped, with narrow bases, and a short, conical hypostome, which is encircled 

 by a single zone of about 12 filiform tentacles about half as long as the body of the polypite. 



The reproductive polypites are swollen, with only about 5 well-developed tentacles 

 with a cylindrical proboscis, and with 3 to 4 large medusa-buds upon the basal half of the 

 polypite below the zone of tentacles. These medusa-buds are mounted upon short pedicles, 

 and when set free the medusae have no sexual products. The hydrorhiza forms an open net- 

 work of thin branches bearing short, smooth, thorn-like processes. There are no spiral 

 zooids or tentacular filaments. Color ( ?) Number of tentacles possessed by the medusa 

 when set free ? 



Puerto Bridges, southern Terra del Fuego, January, 1893; from a depth of 7 fathoms. 



This species appears to me to be closely allied to, if not identical with, the Podocoryne 

 of the coast of New England. The number of the tentacles is very variable in our New England 

 Podocoryne, especially in the reproductive polypites, and the colonies range considerably in 

 size, apparently being influenced in this respect by conditions of nutrition. There is nothing 

 in Hartlaub's description to prevent our considering the species from the southern end of 

 South America to be identical with P. cornea of the coast of New England. 



Podocoryne denhami Thornely. 

 Podocoryne denhami, THORNELV, 1905, Roy. Soc. Report Ceylon Pearl Oyster Fisheries, vol. 2, p. no, plate I, fig. 6. 



Basal crust beset with numerous tall, stout, linear, reddish spines. Hydranths white, 

 with about 24 tentacles on the barren ones, and only 4 or 5 on those bearing gonophores; and 

 these latter are considerably swollen. A pair of large globule (medusiform ?) gonophores on 

 each reproductive hydranth. Medusa unknown. Size ( ?) 



Growing on a shell of Murc\ in Polk Strait, Ceylon. 



