No. 3.] BUDDING IN PEROPHORA. 369 
I take much pleasure in acknowledging my indebtedness to 
Professor Brooks for the kindly interest with which he has fol- 
lowed my work, and for valuable assistance given me. I also 
desire to express in this place my great appreciation of the 
many courtesies extended to me by the late Colonel Marshall 
MacDonald at the station of the United States Fish Commis- 
sion at Woods Holl.} 
Perophora viridis Verrill. 
This ascidian, which is the only species of Perophora known 
to occur on the Atlantic coast of North America, was first 
found in Vineyard Sound by Verrill (34), and described by him 
in 1871. A new species, P. annectens, has recently been 
reported from the coast of California by Ritter (23). 
Perophora viridis grows luxuriantly below low-water mark 
on the wharf piles in Little Harbor, Woods Holand Vine- 
yard Haven, Martha's Vineyard. I also found it to be 
equally abundant during the summer months in the harbor of 
Beaufort, N.C. The colonies form large, thick clusters of a 
beautiful greenish-yellow color, and usually occur together with 
other ascidians and with hydroids, bryozoa, sponges, and bar- 
nacles, the delicate stolons creeping over and covering the 
surfaces of everything within reach. 
The Rudiment of the Bud. 
Budding in Perophora was first studied by Kowalewsky (12), 
whose careful work on this form laid the foundation for all 
subsequent investigation of the process of budding in the 
ascidians. 
Metschnikoff (18) had already discovered in Botryllus that 
the bud-rudiment consists of two vesicles, one within the other, 
the outer being derived from the ectoderm and the inner from 
the peribranchial wall of the parent. He also observed the 
splitting up of the inner vesicle to form the median branchial 
sac and the lateral peribranchial spaces, but neither Metschni- 
1A preliminary account of some of my results was published in the Johns 
Hopkins University Circulars, No. 119, June, 1895. 
