Hydmmedusce of Torres Straits, Australia. 201 



tentacle bulbs are simple and are not flanked by cirri, and their entodermal cores 

 do not project inward into the gelatinous substance of the bell. The hydroid 

 is Campanulina Van Beneden. 



Phialidium pacificum Maas. 



(Plate 2, Fig. 3.) 

 Phialidium pacificum, MAAS, 1906, Revue Suisse de Zool., tome 14, p. 91, plate 2, fig. 7. 



Specimens of this medusa were fairly common in surface tows taken off the 

 Murray Islands, Torres Straits, Australia, in September and October. When 

 mature the bell was flatter than a hemisphere, thin-walled, and about 4.25 to 

 5 mm. in diameter. In an average mature female there were 43 tentacles, all 

 similar each to each and about half as long as the bell-radius. There were 26 

 small spherical lithocysts, each with a single concretion. The manubrium was 

 small and with 4 simple lips, and the 4 swollen gonads occupied somewhat more 

 than the middle thirds of the 4 slender radial-canals. The entoderm of the 

 manubrium, gonads, and ring-canal was dull green to light grass-green. In 

 some medusae the entodermal lamella of the bell was green, but in others it was 

 transparent and colorless. 



A comparison between the figures of this medusa from Torres Straits and 

 one from the Mediterranean shown in figure 143, page 268 of Mayer's "Medusae 

 of the World," will show that the two are identical in all essential respects. 

 Moreover, it will be recalled that Calkins (1899, Proc. Boston Soc. Nat. Hist., 

 vol. 28, p. 349) described a hydroid from Puget Sound, Pacific coast of North 

 America, which appears to be identical with the hydroid of Phialidium hemi- 

 sphcericu?n of the Atlantic, and Murbach and Shearer record a medusa from 

 Puget Sound which may be derived from this hydroid. In fact were our 

 Murray Island medusa found in the Mediterranean or off the coasts of Europe, 

 we would at once call it Phialidium hemisphcericum; if off the American coast, 

 P. languidum, and if in the Tropical Pacific, P. pacificum. These names 

 merely express the doubt that still exists respecting the specific identity of 

 the hydroids of these medusae, for no differences can be detected between the 

 mature medusae themselves. 



When young, this Torres Straits medusa passes through a stage wherein there 

 are 16 short, equally developed tentacles, 32 lithocysts, and 4 small gonads 

 near the ring-canal. 



Genus EUTIMA McCrady, 1857. 



Eutima, McCRADT, 1857, Gym. Charleston Harbor, p. 87. 



GENERIC CHARACTERS. 



Eucopiidae with 8 lithocysts, 2 in each quadrant, and with 4 or more well- 

 developed tentacles, and numerous rudimentary tentacles, marginal cirri, or 

 both. Stomach mounted upon a well-developed gelatinous peduncle. The 

 4 or 8 linear gonads are developed upon the 4 radial-canals. The hydroid 

 is Campanopsis. 



Eutima australis nor. sp. 



(Plate 3, Fig. 5.) 



This medusa was common in surface tows off the Murray Islands, Torres 

 Straits, Australia, in September and October 1913. The bell is flatter than a 

 hemisphere and the gelatinous substance is thin and tenuous. There are 4 

 perradial tentacles each about as long as the bell-radius and with laterally 



