30 M. Jules de Guerne on a 



Dr. Tautain, a distinguished anthropologist and an excellent 

 observer, who is well-known on account of his travels in the 

 French Soudan and in Beledougou, and who was formerly 

 medical officer to the Galli^ni Expedition, and is now colonial 

 administrator of one of the most distant archipelagos of the 

 Pacific. 



The following are the principal passages in Dr. Tautain's 

 communication, written from Taiohae (Nouka-Hiva Island), 

 30th September, 1893 :— 



" In the issue of ' La Nature ' for June 24, 1893, I observe, 

 under the signature of M. Jules de Guerne, an article on the 

 subject of freshwater Medusa?, with reference to the Medusa 

 of Lake Tanganyika. 



" It is stated by M. de Guerne that this species is the 

 third freshwater Medusa that has been recorded. I believe 

 that I am acquainted with another. 



" In the month of January in the year 1888, at low water, 

 I found in the Niger near Bamakou, in the still water at the 

 edge of the river above the rocks of Sotuba, a Medusa which 

 appears to me to be different from that of Lake Tanganyika. 

 If my memory serves me, the diameter of this Medusa is 

 from 20 to 25 millim. 



" On the day when I noticed it I busied myself in collecting 

 a certain number of individuals, and in a short time I had 

 some fifty specimens of it in a bottle. 



" On my return to Bamakou I endeavoured to preserve 

 these Medusas, in order to bring them back to France ; but 

 the various methods which I employed, the only ones that I 

 had at my disposal, miscarried, and after the lapse of a certain 

 time, varying according to the different methods, I had 

 nothing left. It was my fixed intention to return to Sotuba 

 to make a fresh collection and attempt other systems or 

 combinations of systems of preservation, but I was unable 

 to do so. 



" The distance between the habitat of the Medusa of the 

 Niger and the sea is considerable, and it must be remarked 

 that the number of rapids (besides those of Sotuba) between 

 Timbuctu and Boussa renders communication with the ocean 

 very difficult for a creature of the nature of a Medusa." 



It is a matter for regret that Dr. Tautain did not think of 

 at once making a sketch of the animal in question. Its 

 dimensions would certainly have enabled him to recognize 

 with a simple lens, or even to see with the naked eye, certain 

 details of structure, according to which it would have been 

 possible to form a correct idea of the organism. 



The animal is, in all probability, a Hydromedusa of a 



