484 



Mr. S. Stutchbury on Pachyodon, 



6. Pachyodon abductus, Plate X. fig. 9, 10. 



Shell triangular ; umbones produced anteriorly; lines of growth 

 nearly smooth ; lunula cordate; height 1'3, length 1 "7, thickness 0' 7. 

 Inferior oolite, Dundry Hill, Somersetshire. 

 Lias, near Cheltenham. 



Unio abductus, Phillips, Geol. of Yorkshire, tab. II. fig. 42. 

 Museum of Bristol Institution. 



7. Pachyodon cuneatus, n. s., Plate X. fig. 11, 12. 



Shell cuneiform ; anterior portion but slightly produced beyond the 

 umbo ; lunule deep and heart-shaped; height 0'7, length 1'2, thick- 

 ness 0'4. 



Lias, Frethern, Gloucestershire. 



Museum of Bristol Institution. 



8. Pachyodon lanceolata, n. s. 



Shell lanceolate ; anterior portion ^th of the length, posterior 

 portion acutely produced ; hinge-line straight ; lunule small ; base 

 curi'ed ; height \'4, length 3-4, thickness 0"9. 



Robin Hood's Bay, Yorkshire. 



Mus. W. Bean, Esq., Scarborough. 



This singular species has been kindly sent me for exami- 

 nation by Mr. Beau of Scarborough, who has for some time 

 distinguished it by the specific name of lanceolata. 



It approaches most closely to P. attenuatus, but differs in 

 being more acute posteriorly, by the straightness of the hinge- 

 line, as also by its greater thickness upon the basal margin. 

 I regret that this species did not come to hand in time to al- 

 low of its being included in the Plates. 



