1880.] NATURAL SCIENCES OF PHILADELPHIA. 335 



Nebela coLLARis. — Occasional. Flask-like forms, with the 

 usual variations in the condition of the cancellated structure of the 

 shell ; sometimes finelj^ punctate, but mostly with distinct circular 

 oancelli, more or lesg uniform or greatly var3'ing in proportionate 

 size. In several specimens the cancelli of the shell appeared to be 

 like minute lenses or spheres, and to present an external con- 

 ACxity. Individual specimens measured were as follows : 



" 0.015. 



" 0.018. 



" 0.015. 



" " 0.018. 



" " 0.018. 



" 0.018. 



" " 0.024. 



Hyalosphenia tincta ? — One specimen onl3^ Sarcode encysted 

 as a ball 0.048 diameter, containing much brownish food and 

 bright yellow oil-like globules. Shell structureless, pale yellowish, 

 with a pair of pores piercing the body above the junction of the 

 neck. The specimen looked like a Nehela fiabellulum, but the yV 

 inch magnif3'iug power showed no structure to the shell. 



Length 0.060, breadth 0.072, breadth of m lutU 0,024, length of neck 0.0045. 



DiFFLUGiA GLOBULOSA. — Rare. Small forms with shells of fine 

 sand and dirt. From hemispherical to globular and with circular 

 mouth. 



1. Breadth of shell 0.06, height 0.042, brei.lth of mouth, O.OIS. 



2. '• " 0.06, " 0.018, " '• 0.024. 



DiFFLUGiA CONSTRICTA. — Rare. Shell of yellowish dirt and. 

 sand. 



Length 0.072, breadth 0.072. 



DiFFLUGiA ARCULA. — Rare. Shell hemispherical, brownish, in- 

 eorporated with dirt and fine sand ; mouth trilobate. 



Breadth 0.132, height 0.09, breadth of mouth 0.048. 



Heleopera petricola. — Occasional. Purplish brown, with 

 variable proportions of incorporated sand. 



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



2. " 0.096, " 0.078, " " 0.036. 



