SMITH : ON MALLUVIUM. 



123 



If difference of sculpture be sufficient to constitute a new subgenus, 

 we might propose one for Capulus irregularis. Smith, which is neither 

 smooth nor radiately ridged or striated, but only concentrically 

 laraellated. It also possesses one of the other features characteristic 

 of Malhwium, namely, colour-rays. To sum up — (1) We have at 

 present no knowledge of the soft parts of this mollusc (C lissus), so 

 that it is impossible to say whether it will show greater affinity with 

 Capulus or Amalthea} (2) Conchologically it differs only from 

 Aiiialthea in being smooth instead of radiately ridged or striated, 

 a feature even variable in degree among the known species, for 

 A. australis (Lamk.), the type of the genus, is very strongly radiately 

 costate, whereas A. antiquata (Linn.) is conspicuously concentrically 

 lamellated with only very faint delicate striae. I think, therefore, 

 that Malluvium, at all events, may be regarded as premature, if not 

 unnecessary. 



In conclusion, I may point out that the genus Eipponix {sic) was 

 described by Defrance in the Journ. de Physique, 1819, vol. Ixxxviii, 

 p. 215, and not in the Bull. Soc. Philom., 1819, p. 9, which is only 

 a notice of it by Blainville. 



Since this was written the radulas, extracted from some dried-up specimens, have 

 been very kindlj- examined by Professor H. M. Gwatkin. He is of opinion that, 

 among the genera known to him, the odontophore of C. lissus is certainly 

 nearest that of Anialthea. 



