358 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
1879. Perophora viridis Verrill, Preliminary Check-List of Marine Inverte- 
brata, p. 27. 
1889. Perophora viridis McDonald, Rep. U. S. Comm. Fish and Fisheries 
for 1886, p. 858. 
1891. Perophora viridis Herdman, Journ. Linn. Soc. London, Zool., vol. 23, 
p. 602. 
1898. Perophora viridis Lefevre, Journ. Morphology, vol. 14, p. 367. 
1898. Perophora Davenport, Science, new ser., vol. 8, p. 687. 
1900. Perophora viridis Metcalf, Zool. Jahrbi'icher, Anat., vol. 13, p. 508, 
pi. 34, fig. 14 (ganglion, neural gland, etc.). 
1900. Perophora viridis Wilson, Amer. Naturalist, vol. 24, p. 354. 
1902. Perophora viridis Van Name, Trans. Connecticut Acad. Sci., vol. 11, 
p. 337. 
1905. Perophora viridis Seeliger, Bronn's Tier-reich, vol. 3, suppl., pp. 979 
ff (budding). 
1909. Perophora viridis Hartmeyer, Bronn's Tier-reich, vol. 3, suppl., p. 1410. 
The colony compri.ses a varving but very often considerable number 
of distinct and sometimes quite widely separated zooids, each sur- 
rounded by a rather thin layer of transparent colorless test substance, 
which does not unite with that of adjacent zooids to form a common 
mass, but is continuous at the posterior end of the zooid with that 
covering the stolon. The stolon is slender and tubular, its outer layer 
consisting of test substance like that of the zooids, and it grows like a 
vine over the surface to which the colony is attached, giving off numer- 
ous branches which in large and prospering colonies may thickly cover 
parts of that surface. The zooids are generally nearly sessile on the 
branches of the stolon. The buds from which the zooids develop are 
mostly produced on the actively growing terminal portions of the 
branching stolons, so that in general the zooids are younger and smaller 
as the terminal parts are approached. 
The zooids are, when fully grown, from 2.5 mm. to 3.5 mm. in length 
or height, but colonies contain many smaller individuals, either imma- 
ture or undersized from other causes. In a dorso-ventral direction the 
zooids measure somewhat less than they do in length, while in lateral 
diameter (from right to left) they are not tisually more than one half 
or two thirds of the length, the larger and older zooids being generally 
more flattened laterally than the younger ones. The yellowish or 
yellowish green color of the zooids, which gives the species its name, is 
chiefly due to corpuscles of that color, which are contained in numerous 
anastomosing vessels forming a network in the mantle. 
The mantle is thin and quite transparent except for the above 
