338 PROCEEDINGS OF THE ACADEMY OF [1880. 



1. Length 0.072; breadth 0.072; neck 0.003 long: breadth of mouth 0.009. 



2. " 0.072; " 0.078; " 0.003 " ; " " 0.009. 



3. " 0.678: " 0.078; " 0.0015 " ; " " 0.009. 



4. " 0.084; '' 0.078; " 0.003 " ; " " 0.012. 

 Shell with minute elliptical caucelli. 



DiFFLUGiA CONSTRICTA. — Rare. Only a few specimens seen. 

 Small forms, with shell of minute sand grains and yellowish dirt. 

 Pyriform viewed from the front or back. 



1. Length 0.06 ; breadth 0.048 



2. " 0.078; '• 0.048; breadth of mouth 0.024. 



3. " 0.108; " 0.102; breadth opposite moulh 0.078. 



DiFFLUGiA PYRiFORMis. — Rare. Shell of dirt and fine sand. 

 1. Length 0.084 ; breadth 0.048; breadth of neck and mouth 0.024. 



DiFFLUGiA ARCULA. — Rare. Shell yellowish, incorporated with 

 more or less brownish dirt and sand. Form hemispherical ; mouth 



trilobed. 



1. Breadth 0.132; height 0.09. 



Centropyxis aculeata. — Rare. Shell of pale brown chitinoid 

 membrane incorporated with more or less dirt and sand ; with 

 coarser grains of the latter along the course of the usually six 

 spines. Mouth oval, with a more or less sinuous border. 



1. Length 0.096 ; breadth 084 ; breadth of mouth 024. 



2. " 0.12 ; '• 0.096; mouth 0.03 by 0.024. 



Heleopera petricola Occasional ; shell incorporated with 



more or less dirt and sand, and of a purplish brown tint, 



1. Length 0.09 ; breadth 0.078; breadth of mouth 0.042. 



2. " 0.108; " 0.09 ; " " 0.036. 



EuGLYPHA AREOLATA, Ehr. — Small compressed forms, without 

 spines or other appendages. Abundant. Apparently from six to 

 fifteen teeth to the mouth of the shell. Mostly emptj^ shells. 

 Often living specimens. 



