THE 



JOURNAL OF MALACOLOGY. 



No. 8. December ist, 1900. Vol. VII. 



NOTES ON SOME FURTHER MALFORMED 

 SPECIMENS OF ANODONTA OYGNEA, L. 



By H. H. bloomer. 



SiNXE my paper appeared in the June number of this JournaP des- 

 cribing certain malformations in the animal and shell of Anodonta 

 ciiiinea, L., I have received from Mr. S. P. Bolton two more specimens, 

 which, while exhibiting some similar malformations present others of 

 an interesting character. 



In the first specimen the left valve is fractured just below the 

 umbo, and from here an indentation extends nearly to the ventral 

 edge, while opposite to it, the right valve though not showing any 

 sign of fracture is also slightly indentated, but in this case the inden- 

 tation extends for about only half the distance. 



On examining the animal I found that both the right and left 

 mantle lobes were thickened along the part adjacent to the injury, the 

 left lobe more so than the right one. The gills on the right side are 

 normal, but those on the left have both received considerable injury, 

 curious to say the inner one more than the outer one. A transverse 

 section of the animal in the region of the injury (tig. i), shows a fusion 

 of the outer side of the left outer gill with the left mantle lobe, and 

 a slight fusion of the outer side of the left inner gill with the inner 



I Journ. of Malac, igoo, vol. vii, pp. 136 — 138, pi. vii. 

 JouRN. OF Malac, 1900, vol. vii, No. 8. 



