175 



§2. 



Lašt ivhorl not strongly produced. Sculpture a fevo strong, and 

 many fine carince. 



"VViLKiNSONyEA Tappaniana, Chitty. See Stoastoma Tnppania- 

 num, Ad. Cont. Conch. p. 149 ; Cat. Phan. p. 233. 



Hab. Peace River, Manchester. 



WiLKiNSON^A HoLLANDiANA, Chitty. See Stoastoma Hol- 

 landianum, Ad. Cont. Conch. p. 149 ; Cat. Phan. p. 234. 



Hab. The back woods of Manchester. 



WiLKiNSON^A Dysoniana, Chitty. 



Hab. John Crow Hill, Portland. 



Farm, subdiscoidal or very depressed conic. Colour, very pale 

 yellow. Sculpture, beautiful, — 6 very highly raised sharp spirai 

 carinse, with about 11 very fine highly microscopic carinae inter- 

 vening in the first space below the suture, 9 on the second space, 

 7 on the third, fewer on the fourth and fifth, and very numerous 

 beyond the sixth strong carina round the umbilicus. On the upper 

 whorls, one strong carina in the middle, and one close above the 

 suture, with a proportionate number of very fine intervening. Spire, 

 slightly elevated, with very convex outlines. ^^ea:, sharp. TFhorls, 

 4į, scarcely rounded, with very light suture ; lašt whorl scarcely 

 produced from the body-whorl. Aperture, very slightly constricted 

 at the fauces, not expanded, except very slightly below. Labrtim, 

 pectinated and very slightly scolloped by the six strong carinse, thin 

 and sharp. Labium, detached from the penult whorl ; on a plane 

 with the labrum, very slightly rounded above, much below to the 

 right. Umbilicus, very deep and suddenly narrowed. Labral lamella, 

 very strongly produced close to the labrum above, less prominent 

 round the umbilicus. Operculum, slightly concave in the middle, 

 with a deep broad margin all round, very fine granulations in the 

 hollow, with (?) four very fine distant carinse crossing diagonally 

 from right above to left below. 



Height 0-04, greatest breadth 0'066, least breadth 0-053, 



Named in compliment to the memory of the late Mr. David Dyson 

 of Salford, so well known for his zoological researches in Central 

 America, Venezuela, &c. 



WiLKiNSON^A Hanleyana, Chitty. 



Kab. Pool's Rock, Hanover. 



Form, subdiscoidal, or very depressed conic. Colour, pale horn. 

 Sculpture, lines of growth, wide apart : 3 strong spirai carinse ; 

 4th, stronger ; 3 strong ; 8th, stronger ; 3 strong ; 12th, stronger ; 

 3 strong; 16th, stronger; 2 strong; 19th, stronger; and 4 strong 

 round the umbilicus. On the upper whorls, 3 strong ; 1 stronger ; 

 and 3 strong. Spire, slightly elevated, with straight or very slightly 



