THE MEDUSAE OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 239 



species of Halicreas will be ultimately found to possess this character. I cannot call 

 to mind any other kind of medusa possessing tubercles in a similar position, and they 

 are certainly a most useful aid in the identification of specimens in bad condition. 



Botrynema, novum genus. 



Generic Character. — Trachomedusse with sixteen groups of tentacles (two groups 

 containing many tentacles in a single row in each octant) and eight solitary perradial 

 tentacles (without perradial tubercles or outgrowths of jelly near the margin of the ex- 

 umbrella) . 



The characteristic feature of this new genus is the arrangement of the tentacles into 

 distinct groups or clusters ; hence the generic name. 1 think less confusion will be 

 produced by introducing a new genus based upon the above character, than by trying 

 to emend an old genus and regarding this character as a specific one. The placing of 

 the new genus Botrynema in the family Halicreidse, as emended by Maas, is 

 provisional. Until better specimens showing the shape of the tentacles and the 

 structure of the sense-organs can be obtained, the position of this genus among the 

 Trachomedusse must remain doubtful. 



Botrynema brucei, nova species. (Plate I. figs. 8-9 ; Plate II. fig. 1.) 



Station 301, lat. 64° 48' S., long. 44° 26' W. Trawl, 0-2485 fathoms. 13th 

 March 1903. 



The collection contains only one specimen which is in fairly good condition, except 

 for the margin of the umbrella. 



Description. — The umbrella is very thick, about as broad as high, 25 rnm., with a 

 conspicuous conical projection on its summit. The velum is very broad. The stomach 

 is circular, about 9 mm. in diameter, and its centre is partly filled with a semi-globular 

 projecting mass of jelly. The mouth is large and circular, owing to the thin wall of 

 stomach being contracted back. There are eight broad radial canals, and a very broad 

 circular canal. The gonads are shield-shaped and occupy the central part of all the 

 radial canals. They are in rather a macerated and torn condition, and have the 

 appearance of immature male gonads. 



The tentacles (fig. 1) have all been broken off close to the margin of the umbrella, 

 but their basal ends remain partly embedded in the ex-umbrella. There are eight 

 percanal (perradial) solitary tentacles and sixteen groups of tentacles. The eight 

 solitary percanal tentacles are in a deep groove or furrow, which extends about 2 mm. 

 over the margin of the umbrella. These tentacles are probably directed upwards, and 

 those in the groups directed downwards. Halicreas papillosum has eight percanal 

 tentacles which are very much larger (though similar in structure) than the tentacles 

 which line the margin of the umbrella between the radial canals. 



