12 SIR CHARLES ELIOT. 
BATHYDORIS (Brrex). 
(Bergh, Chall. Report Nudibr. (1884), p. 109; id., Ingolf Exp. Nudibr. (19—), p. 7 ) 
Tats remarkable genus is in many ways a link between the Tritoniide and Doridide. 
The shape is spherical, and the back bears deciduous papilla. The head parts are much 
as in the Doridide; the rhinophores perfoliate and non-retractile. The branchize 
consist of separate non-retractile tufts, set in a circle on the posterior part of the back. 
The powerful jaws and radula are much as in the Tritoniide. The hermaphrodite 
gland is separate from the liver. In the nervous system the cerebral and pleural 
ganglia are distinct and not fused. 
Only four specimens of this genus are recorded, constituting as many species :— 
1. B. abyssorum Bergh, obtained by the ‘ Challenger’ near New South Wales, in a 
depth of 2,425 fathoms. 
2. B. ingoljiana Bergh, from Davis Strait, in 1870 fathoms. 
3. B. hodgsoni spec. nov., from the Antarctic, in 100 fathoms. 
4. B. inflata spec. nov., from the Antarctic, depth not stated. 
It is noticeable that this genus, which is only recorded from great depths in 
northern and temperate seas, is in the Antarctic regions found in comparatively shallow 
water. 
The Antarctic forms agree with those described by Dr. Bergh in most points, but 
differ in several details, among which may be mentioned the presence of numerous 
papillze along the dorsal margin and over the mouth. Unfortunately it is difficult to 
give a complete and satisfactory description of either, for B. hodgsoni, though well 
preserved internally, has probably been somewhat distorted externally, while B. inflata 
appears to be excellently preserved externally, but has no internal organs in a 
recognisable condition except the teeth and jaws. The two appear to be specifically 
distinct, as the radule are different and, as it would seem, the tentacles and branchiz as 
well. £. hodgsoni is best characterised as having an armature of small black spines in 
the stomach and large solid tentacles at the side of the head. B. inflata has smaller, 
grooved tentacles, very small, easily detachable branchiz, and comparatively few dorsal 
papillee. 
Dr. Bergh gives as a generic character rhinophoria retractilia. This is possibly a 
slip, for neither his descriptions nor his figures are quite decisive on the point. But 
there can be no doubt that in both of these species, and also in B. abyssorwm (the 
specimen of which preserved in the British Museum I have examined) the rhinophores 
are not retractile, that is to say, there are no pockets into which they can be with- 
drawn. 
4. BarHyboris Hopesont (Figs. E-G). 
ONE specimen captured in 100 fathoms off Coulman Island on January 13th, 1902, 
As preserved the colour is orange yellow of varying shades. Though the animal is not 
