340 



DISCOVERY REPORTS 



longing to this genus. In spite of the relatively small size and feeble development of the 

 gonads in most of the specimens, which certainly are not yet fully developed, the 

 principal characteristics are distinctly to be seen: the more or less cylindrical form, the 

 mesogloea not thickened at the apex, the feebly formed pillars, the large wide stomach, 

 the transparent, well-developed, crescent-shaped mesenteries, and the gastric filament 

 arranged in vertical interradial rows along the sides of the stomach. The gonads, however, 

 which are absent in four specimens, are developed in two specimens as broad, unfolded, 

 plainly bordered leaves, running al- 

 most from the apex to the velarium, 

 and have more the shape usually de- 

 scribed in Charybdea . As previously 

 mentioned, however (1930, p. 9), I 

 believe that the grade of folding of the 

 border of the gonads depends very 

 much on the age of the specimens. 

 The description given by Mayer ( 1 9 1 o , 

 p. 513) is better than his figures (pi. 57, 

 figs. 2, 2'). I therefore give in Figs. 

 I a-c somewhat schematic sketches of 

 the whole medusa, of the velarium 

 and the sensory pit, and believe it 

 convenient to add some details con- 

 cerning the present specimens. 



The FORM OF THE BELL is Cylindrical 

 with a widening in the middle part 

 (Fig. I a). 



The EXUMBRELLA of the medusa is, 

 in the upper parts, thickly covered 

 with small or larger, oval or round, 

 wart-like, colourless clusters of ne- 

 matocysts. Towards the proximal part 

 of the umbrella they diminish in size. The velarium and the pedalia are absolutely free 

 from nematocysts; Mayer writes that both are covered with large white wart-like 

 clusters. 



The CORNER PILLARS are very feebly protruding. 



The PEDALIA are very variable both in length and breadth (see Table I). The up- 

 wardly directed diverticulum of the canal in the pedalia on the outer side of the base, 

 described by Uchida in Tarnoya alata from Japan (1929), is present in our species. 



The VELARIUM (Fig. i c) is broad and stout. The number of velar canals is about 10; 

 they are strongly branched dendritically and terminate in numerous non-anastomosing 

 branches. Miiller's (1859) fig. 12, pi. i, agrees much better than the figure of Mayer, 

 pi. Ivii, fig. 2'. 



Fig. I. Tarnoya haplonema, F. Miiller. 



«, side view, >; 2/3. b, sensory pit, x 3. c, part of the 



velarium with dendritic velar canals, x 4. 



