CONCHY LI A— BITHYRA. 39. 173 



of this species. But the specimen he presented to us was of 

 such minuteness as to elude our powers of detection, without an 

 examination of intermediate sizes. 



Pectunculus iestd orhictilari subdepressd tequilaterali, mactilis ""'la''"*- 



transversim wndatis. 

 Shell orbicular rather flat and equilateral, with the colored 

 marks disposed in transverse undulate bands. 

 Tab. nost. 12, fig. 3, 4. 

 Area undata. Linn. Syst. Nat. p. 1 1-^2. 



Gmelin, Syst. p. 3312. 

 Tnrton, Linn. Syst. iv. p. 255. 

 Dillvoyn, Descript. Catal. p. 241. 

 Chemnitx, vii. p. 224, tab. 57, fig. 560. 

 Mus. nost. British Channel and Guernsea. 



Shell an inch and a half in diameter, and differs only from the 

 last, in the colored marks being disposed in transverse undulate 

 bands of deep red or morone. 



Pectonculus testa orbiculari depressd decussatd, macuhs "lecussatus 



nebulosis. 

 Shell orbicular flat decussate, with clouded colored marks. 



Tab. nost. 12, fig. 5. 

 Area decussata. Linn. Syst. Nat. p. 1142. 

 Gmelin, Syst. p. 3310. 

 Tnrton, Linn. Syst. iv. p. 253. 

 Dillwyn, Descript. Catal. p. 239. 

 Chemnits, vii p. 226, tab. 57, fig. 561. 



