146 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [440] 
for owing to the great changes they undergo, this is often impossible, 
unless the specimens can be raised, or at least connected with the 
adults by a large series of specimens. For a few this bas been done. 
Several species also swim at the surface in the adult state, especially in 
the evening. With some this seems to be a habit peculiar to the 
breeding season, and sometimes only the males are met with. 
Among the species most frequently taken in the adult state at the 
surface, are Nereis virens, (Plate XI, figs. 47-50,) chiefly males; Nereis 
limbata, (Plate XI, fig. 51,) mostly males, which occurred both in the 
evening and day-time; Nectonereis megalops, (Plate Xil, figs. 62, 63,) 
which was quite common in the evening; Autolytus cornutus, (Plate 
XIII, figs. 65, 66,) the males, females, and asexual forms; Podarke 
obscura, (Plate XII, fig. 61,) which was extremely abundant in the eve- 
ning; and several other species. The Sagitta elegans was taken at 
Wood’s Hole, July 1, and off Gay Head, among Salpw, September 8. 
Itis a very small aud delicate species, and so transparent as to be 
nearly invisible in water. .A larger and stouter species of Sagitta was 
taken in large numbers at Wood’s Hole, by Mr. V. N. Edwards, January 
30, Febuary 10, and February 27, and at Savin Rock, near New Haven, 
May 5. This species has a longer caudal portion, with a small terminal 
fin ; some of the specimens were nearly an inch long and many con- 
tained in the cavity of the body, posteriorly, a parasitic nematode 
worm, about half as long as the body. This parasite is round, not 
very slender; the head has three prominent angles; tail with a small, 
acute, terminal mucro. 
Many of the Mollusca swim free by means of vibrating cilia, for a 
short time in the larval stages of growth, bat as such larve are very 
minute and the period often quite short, these young are not often taken 
in the nets. 
The Cephalopods of this region are all free-swimming species, from 
the time when they leave the eggs through life, though they may rest 
upon the bottom when depositing their spawn.. Numerous specimens 
of the “squid,” Loligo Pealii, (Plate XX, figs. 102-104, embryos and 
young,) were thus taken by the trawl in July, together with large 
clusters of their eggs. Later in the season the free-swimming young of 
this species, from a quarter of an inch to an inch in length, (fig. 103,) 
were often taken at the surface and were also found in the stomach of 
the red jelly-fish, Cyanea arctica, in considerable numbers. The adults 
were frequently taken during the whole summer in the pounds. Some 
of these were over a foot in length, but most of them were not more 
than five or six inches long. Thecolor when living is very changeable, 
owing to the alternate contractions of the color-vesicles or spots, but 
the spots of different colors are much crowded, especially on the back, 
and the red and brown predominate, so as to give a general reddish or 
purplish brown color, and this is usually the color of preserved speci- 
mens. The clusters of gelatinous egg-capsules of this species were 
