162 
BUDLEIIlNr OF THE BUEEAU OF FISHERIES 
where it is almost impossible to distinguish them from the sand. None were 
taken in the smiace collections of 1922; in fact, they are recorded only twice by 
Edwards in 15 years. In 1899 a few were taken on July 11 and again on July 12. 
In 1904 several appeared on August 9. On August 14, 1923, a single specimen was 
taken. As these are the only times that they have been seen here, it is probable 
that they are usually absent in surface collections except after northeast storms, 
when specimens may be transported from Buzzards Bay. The specimen taken in 
1923 appeared after a hard northeast wind. 
CHORDATA 
After a storm on July 16, 1922, a postlarval Balanoglossus aurantiacus (Girard) 
was taken. On September 9 and 1 1 of the same year a single acidian larva, 1 mm. 
in length, appeared. They were the only representatives of this phylum seen during 
the year, excepting the Appendicularia, which at times appeared in great abimdance. 
There were two species of the latter, one occurring during the summer and fall and 
Fig. 63.— Occurrence of Appendicularia in surface collections from June, 1922, to December, 1923. 
distribution in 1922; , distribution in 1923 
the other in winter, the seasons almost overlapping. Both belong to the genus 
Oikopleura. On several days in the latter part of July, 1922, single specimens 
were noted. In August the number increased until they became very abtmdant. 
Throughout September, October, and November they grew scarcer, rapidly disap- 
pearing in December (see fig. 63). 
During October and November the "Haus," characteristic of Oikopleura, was 
taken. At times the tow contained hundreds of these pink "Hauser," each filled 
with copepods. One, on October 24, 5 mm. in length, was found to contain exactly 
100 copepods; 97 of these were Acartia tonsa, 2 were Centropages liematus, and 1 
was Labidocera sestiva. The contents of all had been removed, leaving only the outer 
transparent shell. Lohmann found that this "Haus" was often so deUcate that the 
most minute organisms, which normally pass through the finest nets, were captured. 
In some forms the mesh gradually becomes finer toward one end. Undoubtedly 
those taken in my collections were not complete, for the wall mesh was compara- 
