INVERTEBRATE ANIMALS OP VINEYARD SOUND, ETC. 449 



tliose tliatliave been actually taken at the surface will be here included. 

 Quite a number of the species were not observed by us, but have been 

 recorded by Mr. A. Agassiz, but in some cases he has given neither the 

 time uor date of capture. 



A fine large specimen of the beautiful jelly-fish, Tima fonuosa, has 

 been sent to me by Mr. V. jST. Edwards, who captured it at Wood's 

 Hole, April 30. He states that the same species was very abundant in 

 February, 1872. It has not been previously recorded as found south of 

 Cape Cod. The specimen received differs* from the description given 

 by Mr. A. Agassiz, in having thirty-six tentacles instead of thirty-two. 



Among the most common of the larger species in summer were Mnem- 

 iopsis LeUlyi, which occurred in abundance at nearly all hours of the 

 day and evening, and was very phosphorescent at night; Cijanea arc- 

 ilea, which ocurred chiefly in the day-time, and was here seldom more 

 than a foot in diameter; Aurelia Jiavidula, (Plate XXXYI, fig. 271,) 

 which was not nnfrequently seen in the day-time; Bactylometra quinque- 

 cirra, (Plate XXXVI, fig. 272,) which was quite common both by night 

 and day in August and September ; and Zi/godactyla Grmilandica^ (Plate 

 XXXVII, fig. 275,) which was common in July, both in the day and 

 evening, but was seldom seen later in the season. 



The two species last named, and also the Cyanea arctica, were fre- 

 quently found to be accompanied by several small fishes, of different 

 sizes up to three inches long, which proved to be young "butter-fishes,' 

 Foronotiis triacanthns. These fishes swim beneath the broad disk of 

 these jelly-fishes, surrounded on all sides by the numerous tentacles, 

 which probably serve as a protection from larger fishes that are their 

 enemies, for the tentacles of the jelly-fishes are capable of severely sting- 

 ing the mouths of most fishes, evidently causing them great pain. As 

 many as ten or twelve of these fishes were often found under a single jelly- 

 fish, and in one case twenty-three were found under a Cyanea about ten 

 inches in diameter. They do not appear to suffer at all from contact with 

 the stinging-organs of the tentacles, and are, perhaps, protected from them 

 by the thick coating of tenacious mucus which constantly covers the skin, 

 and gives them their common English name. Mr. A. Agassiz states* 

 that he constantly observed a " Clupeoid" fish under the Dactylometra 

 in this region, which had essentially the same habits, according to his 

 account, as the species observed by us, though, if a Clupeoid, it must 

 have been a very diiferent fish. 



He says, however, that the fishes observed by him were occasionally 

 devoured by the jelh'-fish : *^'It is strange that the fish should go there 

 for shelter, for ever}' once in a while one of them pays the penalty by 

 being swallowed, without this disturbing the others in the least ; they 

 in their turn find food in the lobes of the actinostome, and even eat the 

 folds themselves, until their turn comes to be used as food. I have 

 seen in this way three fishes eaten during the course of as many days. 



* Catalogue of North Auiericau Acalephte, p. 49. 



S. Mis.- 61 29 



