is greatly more thin and delicate than that of U. latissima. The
form of both plants is too variable to find a place among the distinctive
characters. U. latissima is found at all seasons and
on every shore ; but TJ. lactuca is seldom seen except in spring
or early summer.
Fig, 1. U lv a l a c t u c a , young and old :— tIte natural size. 2.
portion of the membrane:—magnified.
Small
;i 5
•i i;
