ANTHO.MKDCS.E ZANCI.KA. 



well figured by McCrady. I have frequently taken Corynitis in Charleston Harbor, South 

 Carolina, where McCrady discovered it, and it is wholly different from any "Geniniaria" or 

 Zanclea. (See also Hargitt, 1908.) 



The common '/aticli-a ot the southern coast of New England, in America, may become 

 mature with only 2 tentacles, and with poorly developed lips. On the other hand, a vcrv 

 similar medusa is occasionally found in the same waters with 4 tentacles and with 4 well- 

 developed lips. I am inclined to believe that these conditions represent developmental staues. 

 or starved and well-fed states of one and the same medusa. 



Zanclea costata Gegenbaur. 

 Plate 8, figs, z, 3, 6, and 7. 



Zanclea conaia, GEGENBAUR, 1856, Zeit. fur wisscn. Zool., Bd. 8, p. 229, taf. 8, figs. 4-7. HAECKEL, 1879, Syst. dcr Mcdu sen 



p. 103. 

 Hydroid ( ?), MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. 35, plate 41, figs. 137, 138. 



Gegenbaur found many specimens of this medusa in the Mediterranean. His fully 



developed medusae had 4 long, equally developed tentacles. For details see tabular description 



of the medusae of Zanclea. 



I have found a medusa at Tortugas, Florida, which accords well with 7, ancle a costata, 



excepting that it has but 2 tentacles. 



Medusa from Tortugas, Florida. Bell 6 mm. high and ellipsoidal, with bluntly-rounded 



apex. Without an apical projection. Bell-walls of uniform thickness everywhere. There are 



2 long, spindle-shaped, rough-looking tentacles somewhat longer 

 than the bell-height. These are thickly covered with papillae and 

 beset on their outer sides with a row of filaments, each of which 

 ends in a spherical knob, the surface of which is covered with 

 blunt papillae. Each of these knobs contains a cluster of nemato- 

 cysts (plate 8). Basal bulbs of tentacles are elongate, spindle- 

 shaped, and hollow. No traces of tentacle-bulbs 90 away from 

 the 2 long tentacles. 4 swollen lines ot nematocysts extend upuaul 

 over the exumbrella from the bases of the 4 radial-canals and 

 nearly meet near the apex of the bell. Velum well developed. 4 

 radial-canals, and the circular vessel straight and narrow. Manu- 

 brium flask-shaped, with 4 simple lips. Entoderm of the manu- 

 brium and tentacles milky white, There were 4 interradial 

 gonads. A single specimen was found in a surface-tow at Tor- 

 tugas, Florida, on May 15, 1906. 



This species is distinguished by its ellipsoidal, high, rounded 

 bell, without a sharp-pointed apex, the 4 very long meridional lines 

 of nematocysts over the exumbrella, and the spherical nematooyst- 

 capsules at the ends ot the tentacular filaments. 



The Tortugas medusa differs from //uiclea cost<ita,as described 

 by Gegenbaur, in having but 2 tentacles. It is well known, hu\v- 



Flc. 41. Zanclea costata, from the 

 Mediterranean, after Gegen- 

 baur, in Zeit. fiir wissen. 

 Zool., Bd. 8. 



ever, that in Zanclea some individuals ot the same species develop 4 while others become 

 mature with but 2 tentacles. 



Gegenbaur states that the female gonads are red (pink '). In the Tortugas specimen the 

 male gonads were milky-yellowish white. 



Hydroid (plate 8, fig. 2). That which is probably the hydroid stock of this species was 

 tound by Mayer, 1900, at Tortugas, Florida, and erroneously ascribed to '/.anclea gctntnosa; 

 but Murbach, 1899 (Quart. Journ. Micros. Sci., New Series, vol. 42, p. 354), describes and 

 figures the hydroid ot '/.anclea genniiosa, and it is now evident that the form described In 

 Mayer is specifically distinct from Z. gemmosa and is probably Zanclea costata, the medusa 

 of which occurs at Tortugas. 



Hydroid of Zanclea costata (?). The hydrorhiza is creeping, tubular, and net-like, and 

 gives rise at irregular intervals to short, more or less twisted hydrocauli. Both the hydrorhiza 

 and hydrocauli are covered with a horny, chitmous pensarc, which is annulatcd in the hydro- 



