138 
BULLETIN OF THE BUREAU OF FISHERIES 
s wimm ing stage and. were carried into the nets by the strong currents. No oyster 
larvae were noted during the summer of 1922. 
Of the Amphineura one species (Chaetopleura apiculata Carpenter) was taken 
on September 23, 1922. The larva was at that time in a late stage of development, 
the shell measuring 1.2 mm. in length. However, the free-swimming period had not 
ceased, for the little animal continued to float about in a watch glass for several 
hours. 
Throughout the latter part of May and June the eggs of Loligo pealii Le Sueur 
are found in great abundance. Scattering young forms appeared on June 2, 1922, 
and increased rapidly until July 11, when the largest number was taken. On clear, 
calm days small schools of these little cephalopods could be seen swimming at the 
surface in much the same manner as the adults. Such schools were particularly 
common about the fish traps, where large numbers of adults are frequently captured. 
Fig. 36.— Occurrence of larval forms ot Loligo Fig. 37.— Occurrence of Phyllopoda in surface col- 
pealii in surface collections of 1922 and 1923. lections from May to December, 1922. . , 
, distribution in 1922; , dis- Podon intermedius; , Evadne nord- 
tribution in 1923 manni; , E. tergestina 
In August there was a decrease in the abimdance. Tliis continued throughout that 
month and early September. Two specimens were taken in October and one on 
November 20. The last occurrence is rather surprising, because no young forms 
had been seen since October 18, and then only one specimen was found. In 1899 
the last specimen was taken on October 24. In 1923 the season lasted from June 26 » 
until October 16 (fig. 36). 
ECHINODERMATA 
Practically all of the echinoderms of the Woods Hole region have a free-swim- 
ming stage. A few holothurians and one starfish (Henricia sanguino lenta (Miiller)), 
are viviparous, but these are imcommon forms. In certain years great numbers 
of the larvse of Asterias have been taken in surface towings. None were found in 
collections of 1898-99 nor during 1922, although Asterias is known to breed through- 
out the summer months in this region. In 1923 a single brachiolaria of Asterias 
