VAX NAME: COMPOUXD ASCIDIAXS. 361 
lisfcri Forbes and Hanley, 18 IS, and to P. banijulcnsis Lahille, 1887, 
of the Mediterranean, but not having had an opportunity to study 
these species, the writer cannot say how great and how constant the 
distinctions between them are. It is stated that the production of 
buds on the older parts of the stolon is more frequent in P. listen than 
in P. viridi^, resuhing in a somewhat different habit of the colony, 
that the zooids are practically colorless (they sometimes are so in P. 
viridis also) and further that there are more oral tentacles and that the 
incomplete longitudinal bars are wanting in P. listen. These latter 
differences might be due solely to differences in the age of the indi- 
viduals. Xor can the writer express an opinion as to how far the 
differences in the accounts of the budding in P. listen by Kowalevsky 
(1874) and P. viridis by Lefevre (1898) are due to different interpreta- 
tions of the obscure phenomena of this process, though a difference in 
the orientation of the young buds in relation to the stolon seems to exist 
between the two species. Lahille's species seems to be still more like 
P. viridis, and Herdman (1891, p. 602; 1906, p. 298) has suggested 
that it may not be distinct from the American form. 
P. viridis can be found abundantly in summer at Wood's Hole and 
Vineyard Haven, Mass., on the piles of wharves, at or below low-water 
mark, usually growing in company with or upon other ascidians, 
simple or compound. Verrill gives it as common on algae and ascidians 
in Vineyard Sound, Mass., 2 to 12 fathoms. It has been recorded from 
Newport, R. I., and Xoank, Conn., Cold Spring Harbor, L. I. (Daven- 
port, 1898), and Beaufort, X. C. (Lefevre, Wilson). Lefevre found 
it as abundant in summer at Beaufort as at Wood's Hole. This 
species occurs also about the Bermuda Islands, where the writer has 
collected it at various points, attached to stones in shallow water, 
usually, as on the Massachusetts coast, growing in company with 
other ascidians. In the spring (May) the colonies were not very 
abundant, nor so large and flourishing as those found at Wood's Hole 
in summer, but this may be due more to the season than to the locality. 
Hartmeyer (1908a) in his preliminary report on the ascidians of the 
Tortugas mentions the occurrence of this genus in that region without 
indicating the species. 
