146 EEPORT 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 has 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 

 Unibata, (Plate XI, fig. 51,) mostly males, which occurred both in the 

 evening and day-time ; Nectonereis megalops, (Plate XII, figs. 62, 63,) 

 Which was quite common in the evening; Autolytm cornutm, (Plate 

 XIII, figs. 65, 66,) the males, females, and asexual forms; Podarke 

 obscurq, (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 oft Gay Head, among Satyw, September 8- 

 It is a very small and 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 rnucro. 



Many of the Mollusca swim free by means of vibrating cilia, for a 

 short time in the larval stages of growth, but as such larvae 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. 105,) 

 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. The color 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 



