258 Mr. J. W. Fewkes on Deep-sea Medusce. 



Abandoning for the present as insufficient any evidence 

 which might be adduced from the structure of the Medusae 

 themselves, and passing to the recorded facts in relation to 

 batliymetrical distribution, we find no more satisfaction from 

 this consideration. It would appear that the strongest argu- 

 ments for the existence of nomadic deep-sea MedusiB of the 

 Acraspeda are found by Ha?ckel in the following genera *. 

 The names in brackets are authorities for distribution. 



1. PectantMs. — Surface (Hoeckel). 



2. Pec<?/^Z/5.— 200-600 fath. (Hajckel). 



3. Pectis.—12&0 fath. (Hasckel). 



4. Cunarcha. — " Possibly captured in drawing up the 



lead" (Hfp.ckel). 



5. ^ginura. — " 2150 fath. apparently " (Hasckel). 



6. Periphylla. — Surface (Fewkes). 



7. Periphema. — 1975 fath. (Hackel). 



8. Tesscrantlia.—2\Q0 fath. (Hajckel). 



9. AtoUa.—20A0 fath. (H*ckel) ; surface (Fewkes). 

 10. Nauphanta. — 1425 fath. (Hasckel) ; surface (Fewkes). 



Of the above genera the * Albatross ' has collected many 

 specimens of Periphylla and Atolla from the surface of the 

 ocean. Greely collected a species of Nauphanta from the 

 icy waters of the surface of Lady Franklin Bay ; Periphema 

 is so closely allied to Periphylla that we may well hesitate to 

 accept its limitation to the great depth at which it is recorded 

 (1975 fath.) ; Pechjllis is recorded from 200 to 600 fath. 

 In the present use of the word deep-sea this genus can hardly 

 be regarded as preeminently a deep-sea Medusa. There 

 remain t Pedis (1260 fath.) and 7'esserantha (2160 fath.) as 



that they are aacestrah They are in reality seeondaiily modified, for the 

 ancestral method of development is direct, without an attached young, in 

 Acraspeda as in Craspedota. 



While the primitive structure and relationship of Atolla, Nai(phmUa, 

 and Nauphantopsis would seem to ally them closely toEphyra, and stamp 

 them as less modified than such genera as Cyanea, in certain anatomical 

 details they might he regarded as higher even than the last mentioned. 

 We cannot consequently draw from their simple relationship to an em- 

 bryonic form the conclusion that they have retained that likeness on 

 account of the simpler conditions of deep-water habitat. Nor is the 

 argument drawn from the supposed abortion of the sense-body conclusive 

 as far as these Meduste are concerned, although it looks plausible. 



* Op. cit. Introduction, p. ii. 



t Cunarcha was " possibly captured in drawing up the lead,'" and ^(ji- 

 nura, 2150 fath., " apparently." 



As a bit of positive evidence that Atulla is a deep-sea Medusa, Mr. 



