Occasional Papers of the Museum of Zoology 47 



B7. Common along the western escarpment (203 specimens). Simi- 

 lar to Bl, but considerably heavier; the peristomal callus is especially- 

 well developed. Usually more bleached than the other lots, but one speci- 

 men is solid orange and another dark purplish-brown. 



Bb3. Frequent (55 specimens). Darker and more strikingly colored. 

 Growth threads finer, and practically all of the shells markedly cancellate. 



Bb7. Quite infrequent, even in the richest portions (38 specimens). 

 Similar to Bl; some specimens are so smooth as to show a polish. 



Table V. Dimension of Tudora aurantia, T. rupis and T. mus'kusi^'' 



37 Males in upper horizontal row under each heading; females in lower. 



