344 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
details of the structure could be made out as well as one could hope to 
do with freshly preserved material, unless enough of it were available 
to preserve many different lots. 
In concluding these preliminary remarks, the writer Avishes to ex- 
press his thanks to Professor Verrill for the use of the collections 
as well as for much advice and information which have been of service 
in preparing this paper, and to Miss Katherine J. Bush, Ph.D., of 
the Peabody Museum, for assistance in looking up the specimens in 
the large and incompletely catalogued collections. 
Geographical Distribution. 
The region with which this paper deals extends from the Gulf of 
St. Lawrence and Banks of Newfoundland southward to, and including. 
Long Island Sound. A brief .synopsis of the distribution of the several 
forms in area and in depth is here given. The species are arranged in 
families, and in the order in which they are described in the systematic 
part of this paper, the classification adopted being substantially that 
of Hartmeyer (1909). In order to diminish as much as possible the 
inconvenience which the changes in nomenclature must cause for a 
time, Verrill's names are again repeated, following those adopted in 
this paper. 
Family Botryllidae Verrill, 1871. 
1. Botnjllus schlosseri (Pallas). [B. gouldii Verrill.] 
Coasts of Massachusetts, Rhode Island, Connecticut, and Long Island; 
Mediterranean and Atlantic coasts of Europe. 
Confined to very shallow situations. 
2. Botrylloides aureum Sars. [Botrijllus sp., Verrill.] 
Gulf of St. Lawrence; off Newfoundland; Gulf of Maine; Maine coast; 
northern waters of Europe. 
Shallow water to 250 meters. 
Family Perophoridae Giard, 1872. 
3. Perophora viridis Verrill. 
Southern Massachusetts, Rhode Island, Connecticut and North Caro- 
lina coasts; Bermuda. 
Low-water mark to 12 fathoms. 
