156 LlTTORlNIDiE. 



ulate tentacles bearing the eyes on biilgings at their 

 external bases. Foot rather short, oblong, rounded at 

 both ends ; opereuligerous lobe with rudimentary lateral 

 wings, and furnished posteriorly with an obscure rudimen- 

 tary cirrhus. 



This genus was established by Dr. Fleming for the 

 Helix clepressa of Montagu, and some apparently allied 

 shells, and was dedicated by him to the memory of Dr. 

 Skene, of Aberdeen, a Scottish naturalist of eminence in 

 the time of Linnreus. It is synonymous with the Delphi- 

 noiclea of Brown. The Skenea may be said to be discoid 

 Rissoee. The only one of the following shells which un- 

 questionably should retain this generic appellation is the 

 S. planorbis, type of the genus. All the remainder are 

 doubtfully, and in the absence of information respecting 

 their animals, placed here. Indeed, thei*e is good reason 

 to surmise that they do not even belong to this family, but 

 are rather likely to prove Trochidrr, and some of them, at 

 least, are, in all probability either belonging or nearly allied 

 to Adeorhis. At present, however, we prefer describing 

 them under the genus the shell of which they most re- 

 semble. Philippi has i)laced some allied forms in Del- 

 phinula with a query. That genus is very nearly allied 

 by both animal and shell to Troclms. 



S. PLAN0K15IS, 0. Fabricius. 



Pale olivaceous or brown, devoid of sculpture, not lustrous, 

 suture subcanaliculatcd ; umbilicus not ribbed ; aperture almost 

 circular. 



Plate LXXIV. fig. 1, •_>, 3 ; and (Animal) Plate O. (i. fig. 1. 



Turbo planorbis^ 0. Fabr. Fauna Groenland, p. 394, from which Gmki,. Syst. 

 Nat. p. 3C02. 



