PART Il. 
HYDROMEDUSA OF TORRES STRAITS, AUSTRALIA. 
DESCRIPTION OF SPECIES. 
Genus STOMOTOCA L. Agassiz, 1862. 
Stomotoca, Acassiz, L., 1862, Cont. Nat. Hist. U.S., vol. 4, p. 347.—Maybr, 1910, Meduse of 
the World, vol. 1, p. 108 
GENERIC CHARACTERS. 
Stomotocini with 2 long diametrically opposed perradial tentacles with 
hollow basal-bulbs. With or without other smaller tentacles or cirri, and 
with or without abaxial, ectodermal ocelli at the bases of the tentacles or cirri. 
The interradial or adradial gonads are complexly folded and may migrate 
outwards more or less along the 4 radial-canals. These radial-canals are 
broad and flat and there is a well-developed circular canal. The hydroid 
appears to be Perigonimus. 
Stomotoca turrida (Mayer). 
(Plate 1, Fig. 1.) 
Dissonema turrida, Mayer, 1900, Mem. Mus. Comparative Zool. at Harvard Coll., vol. 37, p. 44, 
plate 2; also, 1910, Medusz of the World, pp. 116, 490, plate 10, fig. 1; plate 22, fig. 1. 
Amphinema turrida, BiazLow, H. B., 1909, Mem. Mus. Comparative Zool. at Harvard College, 
vol. 37, p. 200, plates 7, 40, 43, and 44. 
This medusa was fairly common at the Murray Islands, Torres Straits, 
Queensland, Australia, late in September 1913. H. B. Bigelow found it in 
Acapulco Harbor, Pacific coast of Mexico, and it is common at Tortugas, 
Florida. The largest of the Murray Island specimens was still immature, the 
bell being only 4 mm. in height, whereas at Tortugas, Florida, the bells of 
mature medusz are usually about 6 mm. high. It differs from the Tortugas 
meduse in its duller color, the green being absent, and there are no ocelli on the 
abaxial sides of the 2 main tentacles. The marginal cirri are only beginning 
to develop and the adradial gonads are beginning to migrate outward along 
the radial-canals. The absence of ocelli at the bases of the 2 long ten- 
tacles may be due to the immaturity of the specimen, for they are sometimes 
absent from the tentacle bases of small meduse at Tortugas, Florida. Alto- 
gether the differences between the tropical Pacific and the tropical Atlantic 
meduse appear to be too slight to warrant their specific separation. This 
species is closely related to Stomotoca octedra, but differs in having numerous 
marginal cirri each with an abaxial, ectodermal, basal ocellus. 
Genus CYTAIS Eschscholtz, 1829. 
Cyteis, EscHscHOLTz, 1829, System der Acalephen, p. 104. 
GENERIC CHARACTERS. 
Cytezidx with 4 simple, radially placed, marginal tentacles, and with 4 or 
more simple, unbranched, oral tentacles. 
199 
