MEDUSA. 51 
16 mm. in diameter, has one long slender tentacle and four to six minute tentacles or 
tentacular buds in each group. A specimen 25 mm. in diameter has in each group 
three to six tentacles, one of which is very long and slender, and about six tentacular 
buds (‘Scotia ’ Report, Pl. IL, fig. 2). It is clear that the young stages of Desmonema 
chierchianum have far more tentacles in each group than Vanhiffen’s Medora stage, 
though the latter is larger in size. There is also a difference in the shape of the 
tentacular lobes. 
Detached Tentacles taken in Nets—The ‘Scotia’ when in lat. 72° 31’ S., and 
long. 19° W., on 5th March, 1904, found in a drift net at 1 to 100 fms. some long, 
thick tentacles. The longest was over four feet in length and the maximum thickness 
measured was 7mm. These tentacles have been described and figured by Dr. Rennie 
(1905) and considered by him to be the tentacles of a Siphonophore. 
The ‘ Discovery’ obtained isolated tentacles in McMurdo Sound, and these were 
also examined by Dr. Rennie (1907), who considered them to be the tentacles of 
another Siphonophore. ‘‘ These tentacles differ from those of the Scottish Expedition, 
both in colour and consistency, the latter being brownish and of a markedly gelatinous 
nature even in their badly preserved parts. They appear to belong to a distinct and 
otherwise unknown form.” 
Dr. Vanhéffen (1908) has proved, beyond all doubt, the tentacles of Rennie’s 
Siphonophore to be the tentacles of a Desmonema. The ‘Gauss’ obtained similar 
large tentacles at her winter quarters off the Antarctic Continent. 
I obtained from the British Museum a piece of one of the tentacles found by 
Mr. Hodgson in McMurdo Sound and cut some sections of it. The sections clearly 
show that Dr. Vanhéffen was right when he said that the tentacles belonged to a 
Desmonema and not to a Siphonophore. The structure of the tentacles of Dr. Rennie’s 
Siphonophore is similar to that of Desmonema gaudichaudi in the ‘Southern Cross’ 
collection. 
The tentacles of Desmonema chierchianum and D. gaudichaudi are similar in 
structure, but the muscle bands of D. chierchianum are smaller in size and more 
slender than those of D. gaudichaudi. As the tentacles of D. gaudichaudi are 
much thicker than those of D. chierchianum, so also are the muscle bands larger 
and thicker. 
Distribution. —Antarctic Ocean. Booth-Wandel Island, lat. 65° 8., long. 66° W. 
(Paris) (Maas, 1908, ‘Francais’ Expedition); lat. 69° 59’ S., long. 82° 39’ W. 
(Maas, 1906, ‘Belgica’ Expedition); lat. 66° 8, long. 89° HK. (Vanhéffen, 1908, 
‘Gauss’ Expedition) ; Cape Adare, lat. 70° 18’8., long. 170° 9' E. (‘Southern Cross’ 
Expedition); lat. 72° 31’ 8., long. 19° 00’ W. (Rennie, 1905, ‘Scotia’ Expedition) ; 
McMurdo Sound. Lat. 78° 48’ 8, long. 166° 20’ 8. (Rennie, 1907, ‘Discovery’ 
Expedition). 
VOL. V. 20 
