TRACHYMEDUSAE 49 



The number of marginal clubs is 16 in adult specimens, two in each octant, and they are arranged 

 in a characteristic way, which is in accordance with Vanhoffen's figure. One of them is always placed 

 near a radial canal separated from it by one tentacle, usually to the right when seen from the ex- 

 umbrellar side, exceptionally to the left; the other marginal club is a little to the left of the middle 

 point of the octant. Young specimens up to 7 mm. in diameter have only one marginal club in each 

 octant, always the one developed nearest to a radial canal ; the club near the middle of the octant 

 appears later. In all stages of development the tentacles are of different sizes, but of the same 

 structure ; they may be about as long as the diameter of the umbrella, but as a rule all or most of them 

 are broken off near their base. 



The majority of the specimens were taken in hauls through the intermediate water-layers, mainly in 

 hauls of 500-250 m. and 750-500 m., a few in 250-100 m., very few in vertical hauls from very great 

 depths, and these may have been taken at higher levels during hauling because the nets failed to close. 

 Distribution. Mediterranean (Kramp 1924, p. 29; Ranson 1936, p. 171); several localities between 

 the Canary Islands and the Azores (Ranson 1936); off the west coast of Africa between Cape Verde 

 and the Cape of Good Hope (the Discovery collections); South Atlantic between South Africa and 

 South America (Thiel 1936); subantarctic and antarctic parts of the Atlantic area (Vanhoffen 19026, 

 Thiel 1936, Kramp 1948 b, p. 6, and the present collection) ; west of Graham Land in the Pacific sector of 

 the Antarctic (Discovery); also found in the Indian Ocean sector of the Antarctic, near the Gauss 

 Station (Vanhoffen 1912 a). 



Haliscera racovitzae Maas 1906 



19066 Homoeonema {Haliscera) racovitzae Maas, p. 10. PI. i, figs. 3, 4; PI. 2, fig. 13. 



1909 Homoeonema racovitzae Bigelow, p. 144. 



19 10 Halicreas racovitzae Mayer, p. 393. Fig. 246. 

 193 1 Halicreas racovitzae Thiel, p. 328. 



1936 ^Halicreas album Thiel, p. 37, in part. 

 1947 Haliscera racovitzae Kramp, p. 6. 



Occurrence: St. 355. 9. ii. 30. 54° 13' 3°" S, 34° 18' 30" W to 54° 10' 30" S, 34° 16' 30" W. East of South 

 Georgia. Net: N 70 V 750-500 m. i specimen. 



The specimen, which is well preserved, is 7-5 mm. in diameter and 4 mm. in height. The exumbrella 

 is evenly rounded, with no indication of a conical apex, the gelatinous substance being fairly thin and 

 flaccid. Diameter of stomach 3-5 mm., mouth 2 mm. The gonads, male, are broadly egg-shaped, thick 

 (not flat), in the proximal two-fifths of the radial canals close to the stomach. The distal part of the 

 radial canals and the ring-canal are fairly narrow. In each octant there are 6 tentacles, of different 

 sizes, with conical basal bulbs, and two marginal clubs, one separated by one tentacle from the 

 adjacent radial canal to the right (when seen from the exumbrellar side), the other similarly separated 

 from the radial canal to the left by two tentacles. Velum very broad. 



This specimen is a perfect image of Maas's beautiful figures, except that it is almost colourless. The 

 species differs distinctly from H. conica in the shape of the umbrella, the shape and position of the 

 gonads, the number of tentacles, and their narrow conical bases. I have not the slightest doubt that 

 it is a distinct species. It is not easy to comprehend how Thiel could identify it with H. alha Van- 

 hoffen, which has elongated, flat gonads and a much larger number of tentacles. Two specimens from 

 the tropical East Pacific, off Callao, Peru, were referred to H. racovitzae by Bigelow (1909) though 

 with some doubt, and it also seems to me the safest course to regard this record as dubious. 



Vanhoffen (19120, PI. 25, fig. 4. Text-fig. 17) has described and figured a medusa taken in the 

 South Atlantic, at about 35° S, and he referred it to Haliscera racovitzae, but it cannot possibly belong 

 to this species, nor can it with certainty be referred to any other known species. It was about 10 mm. 



