62 BULLETIN OF THE BUREAU OF FISHERIES. 
GASTROPODA: PISCES: 
Anachis avara (common, living and shells). Myoxocephalus eneus. 
Astyris lunata. Pears. 
Cochlodesma leanum (1 shell). PHAOPHYCES: 
Crepidula convexa (1 living). Desmarestia aculeata (many). 
Crepidula fornicata (many shells). Leathesia difformis (1 drift). 
Crepidula plana (few). RHODOPHYCE: 
Eupleura caudata (several shells). Callithamnion roseum (2). 
Littorina litorea (1 shell). Corallina officinalis (1 drift). 
Polynices triseriata (common, living and Cystoclonium purpurascens var. cirrhosum 
shells). (many). 
Tritia trivittata (many living). Phyllophora Brodizi (many). 
Urosalpinx cinereus (few shells). Phyllophora membranifolia (many). 
Vermicularia spirata (several shells). Polyides rotundus (many). 
TUNICATA: Polysiphonia nigrescens (many). 
Didemnum lutarium (several masses). Polysiphonia urceolata (1). 
Molgula manhattensis (2). Rhodomela subfusca (1). 
2. THE DISTRIBUTION CHARTS. 
We have deemed it advisable to publish a large number of charts portraying the 
distribution of species as revealed by the station records. It is not likely that the 
lists of station numbers given in the text for each species will often be translated by 
the reader into definite localities; while, on the other hand, the generalized statements 
of the authors are necessarily incomplete and at best do not take the place of graphic 
representations such as the charts. Some explanation is necessary for a proper under- 
standing of these last. With a few exceptions, they are based upon the records of the 
regular dredging stations only, i. e., those for the years 1903, 1904, and 1905. No data 
derived from outside information, however reliable, have been included here, nor even 
data from our own shore collecting, or (exceptions aside) from our supplementary dredg- 
ings and repetitions of earlier stations, though, of course, such additional data have 
been incorporated in the text. The exceptions mentioned include the “bis” stations 
as a whole (see p. 55), the records from which have been plotted for all species. 
In the case of the Foraminifera, hydroids, and Bryozoa, many records derived from 
supplementary dredgings (repeated stations) during the summers of 1906-1909 have 
been plotted upon the charts. This has been considered advisable owing to the probable 
imperfection of the original records for all of these organisms. 
Such procedure is open to two objections. In the first place, the repeated stations 
are at best rather rough approximations to the original ones whose numbers have been 
given them. Even with the greatest care, it is impossible to lower a dredge at precisely 
the same point as on a previous occasion, and in the case of most of our repetitions, lack 
of time prevented the maneuvering necessary to a very exact location of the spot origin- 
ally charted. In the second place, the repeated stations were not distributed with any 
regularity throughout the region dredged, and unless due caution is exercised the results 
of these are likely to be misleading. Moreover, since the records from these have been 
plotted only for certain groups, undue emphasis has in some cases probably been thrown 
upon the latter. Despite these objections, however, we believe that the distributions 
a Including the completion of the western shore of Buzzards Bay in 1907. 
