230 SOLARIID^. 



Another relic of the glacial epoch is N. Smithii of 

 Brown, a specimen of which was found by the late 

 Duchess of Argyll at Ardincaple near Helensburgh. 

 This is the N. flava of Gould and N. aperta of Loven, 

 as well as probably N. fragilis of Leach and N. glacialis 

 of Danielssen — an arctic species. Finmark, in 40-60 f., 

 is its most southern known habitat. 



The following species of Natica and allied genera 

 have been wrongly introduced into the British fauna : — 



1. Nerita nitida, 'Doiio\£in.= Nalicina lactea, Guilding; 

 West Indies. 



2. Nerita intricata, Don. = Natica Valenciennesii, 

 Payr. ; Mediterranean. 



3. Nerita tuber osisshna, Mont. ; West Indies. 



4. Nerita virginea, Linn.; West Indies. This is 

 perhaps also the Nerita glabrissima (horresco referens !) 

 of Brown = Nerita sulcata of Turton, not of Born = 

 Natica Browniana of Leach. 



Family XXI. SOLARI'ID/E, Chenu. 



Genus ADEOR'BIS"^, Searles Wood. PI. III. f. 5. 



Animal unknown. 



Shell small, trochiform with a flattened base, porcellanous, 

 few-whorled, deeply umbilicate: spire depressed: mouth ob- 

 liquely rhombic, angulated above and slightly notched or 

 emarginate below: operculum horny, having an excentric or 

 lateral spire. 



The position of this family and genus is unsatisfactory; 

 we want more information as to both. The animal of 

 the typical genus, Solarium, is thus described by Reeve 



* Approaching a circle. 



