ADEORBIS. 231 



in his ' Elements of Conchology : ^ — '' disk small, oval, 

 elevated on a short pedicle, and furnished at its hinder 

 extremity with a small horny operculum ; head flattened, 

 and prolonged into two tentacles, at the base of each of 

 which is a short pedicle, supporting the eyes ; the mantle 

 is reflected into a collar around the aperture/' And he 

 remarks that it differs from Turbo and Trochus in the 

 head not being snout-shaped, '^ but prolonged, some- 

 what after the manner of Buccinum and Purpuraj into 

 two elongated tentacles/' The family is called Archi- 

 tectonicidce by Messrs. Adams, and Architectomidce by 

 Dr. Gray ; the former place it near Eulimidce. S carles 

 Wood was anticipated in giving a name to the present 

 genus. In an '' Enumeration of Marine Shells '' found 

 on the South Devon coast, published in 1829 (a copy 

 of which was presented to me by Dr. Turton ''^from 

 the author''), the genus Tornus, signifying a turner's 

 wheel or lathe, was characterized as follows : — " Shell 

 orbicular, depressed, aperture oval or roundish ; pillar 

 none. Operculum horny. Includes Helix subcarinataJ' 

 This publication was anonymous, a circumstance which 

 may deprive the author of the right of precedence 

 according to the laws of scientific nomenclature. I 

 therefore retain Adeorbis, although the other name is 

 preferable. Perhaps this genus should merge in Sola- 

 rium. Many species assigned to it by Mr. S. Wood and 

 others must be removed from it, and placed in different 

 genera. 



Adeorbis subcarina'tus^, Montagu. 



Helix subcari7iata, Mont. Test. Br. p. 438, t 7. f. 9. A. subcarinata, P. 

 & H. ii. p. 541, pi. Ixviii. f. 6-8. 



Shell nearly circular, solid, semitransparent when fresh, 



* Somewhat keeled. 



