:-'G4 NOTES ON SOME r.KITlSll NTiPir.TtANCHS. 



Amj)horina under the Galvinid.ne, which hardly form a natural sub- 

 family, the only character common to the component genera being that 

 the cerata arc more or less inflated. In Am,i)horina this feature is 

 not very marked, and its other characters ally it to Cratcna. The 

 tropical genera Zatteria, Myja, and Ennoia are also probably allied, but 

 need not be considered here. 



With regard to nomenclature, Bergh appears to have proved that the 

 names Cavulina and Montagua must be rejected. 



The animals which compose the four genera Craiena, Cuthona, 

 Cidhonclla, and Amphorina are small and inconspicuous, though often 

 beautifully coloured. The rhinophores are not perfoliate, the corners 

 of the foot are not developed into tentacular processes, and the radula 

 is uniseriate. There is an absence of any very striking characteristics 

 either internal or external. The most distinct genus is Am2)horina. It 

 lias slightly inflated cerata, a style on the penis, and a long tapering 

 radula containing from fifty to eighty teeth, which gradually increase in 

 size. The denticles on the teeth, particularly the median cusp, arise far 

 back, and hence have a peculiar elevated appearance. To this genus at 

 least the following species must, in my opinion, be referred : — 

 1. Amijhorina alhcrti, Quatrefages. 



{2. A. cccrulca (Mtg.). 



1 3. A. molios, Herdman.* 



4. A. aurantiaca (A. & H.) = Cuthona aurantiaca. 



5, A. olivacea (A. & H.) = Cratcna olivacea. 



Perhaps Cratena viridis will prove to be an Amphorina, as may also 

 E. f/lottensis. In separating the other genera Bergh makes use of the 

 structure of the auditory capsule, which he says contains a single 

 otolith in Cuthona, but several otoconia in CuthoncUa and Cratena. 

 Beaumont, however, denies this, and reports the existence of single 

 otoliths in species classified by Bergh under Cratena (e.g. Cr. amcena). 

 In any case, the character is so minute and so dilUcult to determine 

 in preserved specimens that it seems undesirable to use it, unless 

 absolutely necessary. Setting aside possible differences in the auditory 

 capsule, it would appear that the only clear distinction between Cuthona 

 and Cratena formulated by Bergh is that the head is broad in the 

 former, but not in tiie latter. This character seems to be clear and 

 conspicuous, though, as it is merely a question of degree and develop- 

 ment, one may doubt if it is really of generic value. If it is accepted, 

 it would appear tliat the following are referable to Cuthona: — 



1. Cuthona nana, A. & H, 



2. C. jmmilio, Bergh (Sargasso Sea). 



* I agree with Mr. Beaumont (I.e.) in thinking that the specific distinctness of this 

 species from A. cceruha is donhtful. 



