BIOLOGICAL SURVEY OF WOODS HOLE AND VICINITY. 143 
degree this is due to the small number actually present in our local waters and to what 
degree it is due to an insufficient search can not be stated. 
The ranges of our two commoner species, as stated by Wilson, are: 
Tanystylum orbiculare......... From off Marthas Vineyard to Virginia. 
Anoplodactylus lentus......... Long Island Sound; Woods Hole; Eastport, Me. (x record). @ 
Thus the former appears to be a predominantly southern form, while for the latter 
the data are insufficient to warrant us in assigning to it a range. 
One pycnogonid, which was taken upon the gulfweed on a number of occasions, 
is Endeis spinosus Montagu. ‘This, like the gulfweed fauna in general, is doubtless an 
exotic species which comes to us from southern waters. Its presence on the weed is 
rather unexpected, considering the ordinary habitat of this species in European waters. 
XI. INSECTA AND ARACHNIDA. 
There are, of course, very few strictly marine insects in existence, and it is doubt- 
ful whether any of our local species can be so regarded. The thysanuran species 
Anurida maritima is, however, perhaps as nearly marine as are certain of our littoral 
Crustacea. Verrill and Smith record having taken in the vicinity of Woods Hole a 
number of insect larve, which appear to have been living in sea water. One of these was 
described by Packard as a new species. Most of the insects listed in that report were, 
however, beach-dwelling species, which seldom or never enter the water. 
The list prepared by the writers comprises for the greater part species taken in 
brackish ponds in the neighborhood. Many of these were larve, and about half of 
them have not been determined specifically. In many, if not most, cases these insects 
are ones which are known to dwell in fresh-water ponds as well as brackish ones. It 
has been thought worth while to include them here, however, since no list has ever 
been published of our local brackish-water insects. 
The single arachnid here listed (Chernes oblongus) is scarcely to be regarded as 
marine, though it has been taken under stones along shore, near low-water mark. 
9. MOLLUSCA. 
Mollusks, or their shells, have commonly constituted by far the most conspicuous 
feature of the organic contents of the dredge. In respect to the number of species 
likewise, the mollusks have generally preponderated, there frequently being more rep- 
resentatives of this group contained in a given dredge haul than of all the other phyla 
combined. Likewise the total number of molluscan species recorded in the course of 
our dredging operations is considerably greater than that of even the Crustacea, though 
the latter group preponderates as regards the number recorded for the region as a whole. 
It must be stated, however, that the vast majority of specimens taken were merely 
dead shells, and that many species were rarely or never taken in a living condition. 
This preponderance of molluscan remains in our dredging records is obviously due to the 
enduring character of the exoskeleton of these animals, which insures the accumulation 
of shells, even in the case of the less common species. Another fact which results 
directly from the one just mentioned is the relatively great frequency with which most 
of the molluscan species were dredged. Of the 127 species which appear in our dredg- 
ing records, 68, or more than half, are recorded from more than 10 stations each, while 
@ This is to be regarded as a doubtful record. 
