202 Papers from the Department of Marine Biology. 



flattened, hollow, basal bulbs which are not flanked by cirri. The basal bulbs 

 extend upward over the exumbrella in the manner described by Browne for 

 Eutima curva. There are about 64 short, blunt excretory papillae upon the bell- 

 margin and about one-quarter of these are flanked by one or occasionally two 

 short coiled cirri. A dense black pigment collects in these excretory papillse 

 but is discharged if the medusa be left for several days in an aquarium without 

 food. There are 8 adradial lithocysts, each with 7 to 9 spherical concretions. 

 The gelatinous peduncle is about 1.25 times as long as the bell-diameter, and 

 is conical above, and slender, 4-sided, and prismatic below. The stomach is 

 about one-fifth as long as the peduncle, and there are 4 recurved and com- 

 plexly crumpled lips. The 8 gonads are developed upon those parts of the 

 radial-canals which lie over the subumbrella and the peduncle, but appear to 

 reach maturity only over the peduncle. The gonads, stomach, and tentacle 

 bulbs are dull milky in color, all other parts being transparent. 



The nearest ally of this medusa is Eutima elephas of the North Sea and 

 Tropical Atlantic, but in this form there are no cirri upon the bell-margin. It 

 is also closely related to Eutima mira, but the laterally flattened tentacle bulbs 

 which extend part way up the sides of the exumbrella appear to distinguish it 

 from this common Atlantic Eutima. 



Genus RHOPALONEMA Gegenbaur, 1856. 



Rhopalonema (in part), GEGENBAUR, 1856, Zeit. fur Wissen. Zool., Bd. , p. 245. 



GENERIC CHARACTERS. 



Trachymedusce with 8 well-developed tentacles in the radii of the 8 radial- 

 canals, and with 8 or more club-shaped or cirrus-like tentacles. All tentacles 

 arise from the bell-margin in a single row. The 8 gonads are developed upon 

 the 8 radial-canals. 4 lips. Stomach without a peduncle. Lithocyst clubs 

 in inclosed cavities on the bell-margin. 



Rhopalonema velatum Gegenbaur. 



(Plate 2, Fig. 4.) 



Rhopalonema velatum, GEGENBAUR, 1856, Zeit. fur Wissen. Zool., Bd. 8, p. 251, figs. 1-5. MAYER, 

 1910, Medusa; of the World, vol. 2, p. 378, figs. 214-219. 



Specimens of this widely distributed medusa were found off the Murray 

 Islands, Queensland, Australia, in September and October 1913. The bell 

 was nearly hemispherical, thin-walled, and about 8 mm. in diameter. There 

 were 16 tentacles and 16 lithocysts following the tentacles in clockwise rotation 

 around the edge of the bell. The linear gonads occupied the middle thirds of 

 the 8 radial-canals. The manubrium had 4 lips, and the velum was well 

 developed. The entodermal lamella of the bell was bottle green, all other 

 parts being colorless. 



