L. DOLLO. - 1.A PALÉONTOLOGIE ÉTHOLOGIQUE. 



419 



nécessaire, vu les exemples choisis plus haut, nous avons distingué, en 

 ce qui concerne les Organismes marins : 



1. Zone littorale, 1. Région euphotiqiie, 



2. Zone pélagique, 2. Région dysphotique, 



3. Zone abyssale. 3. Région aphotique. 



1. Vie nectique, 1. Vie gastronectique, 1. Vie euphotique, 



2. Vie planctique, 2. Vie notonectique, 2. Vie dysphotique, 

 8. Vie benthique. 3. Vie pleuronectique (i), 3. Vie aphotique. 



4. Vie hypsonectique (2). 



5. — Après quoi, nous avons reconnu, comme un Cas de Convergence 

 entre les Ostracodermes (Poissons), les Mérostomates (Arachnides) et 

 les Trilobites (Crustacés) : 



1. — Les Yeux marginaux et la Queue en palette ^ adaptation à la 

 Vie nectique ; 



2. — Les Yeux centraux et la Queue en pointe, adaptation à la Vie 

 benthique. 



(1) Pleuronectidœ : « Fiat-fishes when adult live aiways on the bottom, and swim 

 vvith an undulating motion of their body. » 



A. GuNTHER. An Introduction ta the Stiidy of Fisfies. Édimbourg, 1880; p. 554. 



(2) Natation avec l'axe cérébro-spinal vertical : 

 Hippocampus, Amphisile, Acantkarchus, têtard de Megalopfirijs. 



A. WiLLEY. Zoological Results based on material from Mew Britain, New Guinea, 

 Loyaltij Islands and elsewkere. Gambridge, 1902; pp. 718 et 719. 



« The only olher attitude which I désire to mention is the vertical attitude assumed 

 by some fishes. Some years ago 1 described and pubiished an idéal picture of the 

 vertical swimming attitude of Amphisile strigata (Zoological Results, etc., p. 719). 

 More recently the late M. VV. Saville Kent told me that he had seen the same thing, 

 and had kept the hsli in an aquarium, whereas I had only seen it from a boat, swim- 

 ming in a small shoal in the sea. I was glad of the confirmation of the vertical 

 attitude; but upon showing my figure to M. Saville Kent, he pointed out to me that 

 the head is not directed upwards, as there represented, but downwards, as if to feed 

 from the bottom, What I saw were swimming in mid-water, and as the body has a 

 pronounced amphioxine form, it was impossible to be certain which end was upper- 

 most. This uncommon vertical attitude, with head directed downwards is not 

 without parallel amongst hshes, having been observed by Dr. Abbott in the case 

 of the » mud sunfish « {Acantkarchus pomotis) in 1884. » 



A. WiLLEY. Forms, Markings, and Attitudes in Animal and Plant Life. ^ATmxE. 

 Londres, 1909. Vol. LXXX, p. 247. 



« One of the most extraordinary kinds of tadpoles is that of Megalophrys montana. 

 Mr. Annandale (Skeat Expédition» found it at Bukit Besar, Malay Peninsula, from 2000 

 to 3000 feet above the level of the sea. The tadpoles were found in the beginning of 

 the month of May 1899 in sandy streams and in pools of rain-water; they tloated 

 in a vertical position, the peculiar membranous funnel -shaped expansion ot the 

 lips acting as surface-tloats. The inside of the funnel is beset with radiating séries of 

 little hoi-ny teeth, and the whole apparatus is possibly used for scraping the under- 

 surface of the leaves of water-plants in search of food. Total length of the tadpoles 

 1 inch. « 



H. Gadow. Amphibia and Reptiles. Cambridge Natural History. Londres, 1901. 

 Vol. VIII, p. 59. 



4909. MÈM. 28 



