212 BULLETIN OF THE 



regions really are.* It can hardly be supposed that different physical 

 conditions and environment, as far as the coast line itself is concerned, 

 could have brought about such a great difference and such a restriction 

 in these floating pelagic animals. The great influence in t-heir limitation 

 must be the temperature of the water, and its difference in the two 

 localities. 



As strictly related to this line of inquiry is a suggestion in regard to 

 the possible medusan fauna of a region contiguous to the Bay of Fundy. 

 It is a well-known fact tliat the southern part of the Gulf of St. Law- 

 rence, near Prince Edward's Island, presents us an assemblage of south- 

 ern genera of Mollusca, surrounded by strictly boreal forms. It would 

 be very interesting to discover what the character of the hydroid and 

 medusan life of this warm area is, and to see if we have, as in the case 

 of the Mollusca, a colony of southern genera protected in their northern 

 home by the higher temperature of the water. I liave been unable to 

 visit this locality for study, but I commend the problem to those who 

 engage in marine work on this coast. Unfortunately we know next 

 to nothing of the acalephian fauna of this region of the Gulf of St. 

 Lawrence. 



CTENOPHORA. 



Mertensia ovum, Morch. 



The common tentaculated Ctenophore at Grand Manan resembles M. ovum. 

 It is not rare near Eastport, where I found it in the summer of 1885 iu con- 

 siderable numbers. It was taken in some abundance at Grand Menau in 

 1886.t 



* Tabular lists of medusEe from the Bay of Funrly region and from that of 

 Narragansett Bay are given by A. Agassiz in the " North American AcalepliEe." 

 The well-marked contrast which one can easily see in these lists appears even 

 more ^.triking when we add to those of the Bay of Fundy some of the charac- 

 teristic boreal genera here mentioned. 



t Ova of a Ctenophore were found in great abundance at Grand Manan in July 

 and August, 1886. These were traced into young Mertensiae, and are possibly of 

 this species. They look unlike the eggs of Plcurobrachia found at Newport. The 

 fact that Pleurohrachia rhndodadyla, recorded by other observers from Eastport, 

 was not seen by me does not mean that it is not thought to exist there. I have 

 only spoken of jelly-fishes observed, and do not wish this paper to be regarded as 

 a list of medusae which live iu the Bay of Fundy. 



