NUDIBRANCHIATE GASTEROPODA. 23 



the Tritoniae, and does not show the tentacles, peculiar to those. The rhiuophores are of a 

 quite different structure. The back is not, as in the Tritoniae, without appendages, but has several 

 series of such; the somewhat projecting dorsal edge appears to have a series of low branchial tufts, 

 resembling those in the Tritoniae. The anus, the renal pore, and the foot are as in the Tritoniae. 



The bnlbus pharyngeus is very strong as in the Tritoniae, and as in those the mandibles 

 are lying on the fore end of the bulbus, and are covered by a thick muscular plate; but they have 

 no masticatory continuation, and the masticatory edge is smooth. The tongue is broad, and the 

 radula bears a rather large number of series of teeth, and these series contain many tooth-plates. 

 The median teeth are quite different from those in the Tritoniae, longish, with a protracted denticu- 

 lated hook; also the lateral teeth are of a somewhat other shape, the innermost one with a denticu- 

 lated hook. — Also with regard to the liver, and the relation between this and the hermaphrodite 

 gland, there seems to be essential differences between the Atthilidae and the Tritoniadae, while both 

 families otherwise seem to agree with regard to the genitalia. 



The Atthilidae seem (as the Tritoniadae) to be rather voracious beasts of prey. 



Hitherto the family comprises only the one genus 



Atthila, Bgh. N. gen. 

 with the one species 



Atthila Ingolfiana, Bgh. n. sp. 

 PI. Ill, figs.' 10— 26. 



At station 40 i. e. on 62 00 Lat. N., 21° 36' Long. W. one single specimen was fished from a 

 depth of 845 faths, where the temperature was 3°3. 



It is stated to have been, when living, pink or of a pale flesh-colour. Preserved in 70 % 

 alcohol it was upon the whole of a whitish or slightly yellowish white colour. Its length was 3-2 cm by a 

 breadth of up to i'7 cm ; the breadth of the frontal veil was io ram , the height of the sheaths of the rhinophores 

 3 ram ; the length of the foot was 27""" by a breadth of up to io mm , the breadth of the foot-brim was 

 3 mm . — The specimen was somewhat curved and contracted, the back with its edges somewhat 

 rubbed. 



The form was somewdiat longish, broader before, evenly narrowing and sloping backward, 

 upon the whole rather like the form in the Tritoniae. The frontal veil (fig. 10) was broad with 

 smooth edges, and its rounded, somewhat tentacle-like lateral ends projected 2-5 rom , while its free upper 

 margin was 3 nim broad. Behind the frontal veil, adjoining the fore end of the dorsal margin, the 

 rhinophores were seen; their sheath stood out with a two-lipped edge (fig. n), the hinder lip low 

 and convex, the former one seen as a somewhat tapering lobe, 2 - 5 mm long; in the depth between both 

 the point of the club was distinguished; this latter was reddish gray, (highly contracted) 2-5 mm high, 

 rather short-stalked, with about 30 broad leaves (on either side), containing a number of highly re- 

 tractive bag-glands, of a length of up to o-o4 n,m . The back evenly convex, covered with small, whitish 

 papillae; as far as I was able to discern, 3 series of such papillae were found, a median one with 5, 

 and on either side a lateral one with 4 — 5 papillae; only a single one was quite preserved, and was 



