450 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The specimens measured about au inch in length." The fishes found 

 by us were from a quarter of an inch to three inches long, and we 

 never saw them swallowed, and never found them in the stomachs of 

 any among the several dozen jelly-fishes, of the different kinds that we 

 found accompanied by the fishes, although we found young squids and 

 other kinds of marine animals in a half-digested condition. It is pos- 

 sible that the observation of Mr. Agassiz was made on them when 

 kept in confinement, and that the fishes devoured were not in a perfectly 

 healthy and natural condition, so as to resist the stings of the nettl- 

 ing organs. But if his fish belonged to a family different from ours, the 

 difference may be peculiar to the respective fishes. Yet our observa- 

 tions afford only negative evidence, and it may be that this is one of 

 the peculiarities of this remarkable companionship ; though, if so, we 

 should suppose that the race of Poronotus would soon become extinct, 

 for we never observed the young under any other circumstances. The 

 adult fishes of this species, when five or six inches long, were often taken 

 in the pounds in considerable numbers. 



Among the mouth-folds and lobes of the ovaries, beneath the disk of 

 Cyanea, we very often found large numbers of living specimens of a 

 delicate little jelly-fish, nearly globular in form, the Margelis Garolinen- 

 sis, which we also frequently took in the towing-nets in the evening. 



In the winter season the Mnemiopsis Leidyi is often abundant in Long- 

 Island Sound, and I have also observed it in New York harbor in Feb- 

 ruary, in large numbers. At Wood's Hole Mr. V. IS". Edwards found 

 the PleurobracMa rhododactyla, both young and nearly full-grown, very 

 abundant in February and March ; at Watch Hill, April 13, I found 

 both adult specimens and young ones not more than an eighth of an 

 inch in diameter. It probably occurs through the entire year, for we 

 frequently met with it in mid-summer in Yineyard Sound. Mr. S. I. 

 Smith also found it very abundant at Fire Island, on the south side of 

 Long Island, in September. 



In July and August we obtained several large and perfect specimens 

 of the curious " Portuguese man-of-war," Physalia Arethusa. This species 

 occurs as far west as Watch Hill, Ehode Island, where it was observed 

 by Profevssor D. 0. Eaton. The boatmen at that place state that it is 

 frequent there in summer. The float of this species was generally deep, 

 rich crimson or purple, and the hydroids beneath it were commonly 

 bright blue in the specimens observed by us. The float or air-bag is, 

 however, sometimes blue and sometimes rose-color. 



According to Professor Agassiz, (Contributions, vol. IV, p. 335,) the 

 floating bag in windy weather always presents the same side to the 

 wind, and it is upon the windward side that the bunches of very long 

 locomotive hydroids of the lower surface are situated, and these at such 

 times are stretched out to an enormous length, and thus act as anchors 

 to retard the motion by friction in passing through the water. The 

 smaller locomotive hydroids, the feeding hydroids, and the reproductive 

 hydroids, are on the lee side. 



