Genus TRUNCATULINA D'Orbigny.
A group of extremely variable foraminifera in which the shell is rotaline; i. e., involute on the lower side and revolute on the upper (Brady). The shell is calcareous and coarsely porous in older forms. The characters are very inconstant, and Brady gives up the attempt to distinguish the group by precise and constant characters.
Truncatulina lobatula Walker & Jacob.
Synonyms: See Brady '84 for a long list.
"It is impossible to define by any precise characters the morphological range of the present species. Its variations are infinite." (Brady, p. 660.)
This very common form, which occurs in all latitudes, was found frequently among the algæ at Woods Hole. Its characters are so difficult to define that for the present I shall limit my record to this brief notice. Size of shell 230µ by 270µ.