ASSIMINEA. 99 



subgenus of Rissoa. Nor can I agree with Prof. E. 

 von Martens in referring to Assiminea the Melania 

 Charreyi of Morelet, which seems to me scarcely a 

 variety of Hydrobia ulvce. The A. gallica of Dr. 

 Paladilhe is likewise H. ulva, and will be noticed in the 

 Supplement. It is to be regretted that this writer did 

 not ascertain the genus, as well as that he changed the 

 specific name without any reason. 



1. ASSIMINEA GRATA' NA*, Leach. 



Assiminea Grayana, Flem. Brit. An. p. 275. Assiminia Grayana, F. & 

 H. iii. p. 70, pi. Ixxi. f. 3, 4, and (animal) pi. HH. f. 6. 



BODY dark grey, with close transverse streaks of a purplish 

 hue : mantle open behind : snout broad and thick, corrugated 

 or wrinkled across, more or less cloven in front : mouth forming 

 a perpendicular slit intersected below by a narrower trans- 

 verse slit : tentacles cylindrical, thick, rather short, divergent ; 

 they are not double, nor are any eye-stalks united with them : 

 eyes large, black, and lustrous, placed at the extremities or 

 tips of the tentacles : foot yellowish-white, or sometimes nearly 

 white, forming a short oval, squarish and broader in front 

 (this part being plain or single-edged), and rounded behind; 

 sole light grey, minutely speckled with white : respiratory 

 orifice oblong, large, on the right-hand or outer side of the 

 animal ; the pouch is distinctly visible through it, lined with 

 reticulated vascular tissue ; there is no gill or branchial plume 

 [faeces elliptical, as in Cyclostoma (Berkeley)]. 



SHELL forming a short cone, rather solid, when adult nearly 

 opaque, glossy: sculpture, slight and indistinct but close-set 

 spiral striae, the periphery (especially in immature specimens) 

 being more or less angulated : colour Brownish-yellow, with 

 now and then a broad rufous band encircling the periphery : 

 spire bluntly pointed : whorls 7, compressed and almost flat, 

 gradually enlarging ; the last occupies one-half of the shell : 

 suture slight, although well-defined and narrowly excavated : 

 mouth representing a short oval, and rather small ; its length 

 is two-fifths of that of the whole shell : outer lip contracted 

 and somewhat incurved above, expanded and bluntly angular 



* Named in honour of the distinguished naturalist Dr. J. E. Gray. 



