EUCOPE. 



83 



Eucope diaphana of the fourth vohime (not that of the Memoirs of the 

 American Academy) is probably identical with the English Eu(0])e 

 genicnlata of Wright, not that of Gosse, and it may hereafter be de.sif- 

 nated as Eucope alternata. 



EUCOPE Gegenb. 



Eucope Gegenb. Vcrsuch eincs System ; Zeit. f. Wiss. Zool., p. 241. 1856. 

 Eucope AiiASS. Cont. i^at. liist. U. S., IV. p. 351. 18G4. 



Eucope diaphana Agass. 



Eucope dhipliana Agass. {ex p.). Cont. Nat. Hist. U. S., IV. PL 33, Fig. 2. Ilydrarium. 1862. 

 Tluiwiwnlinx dinphtiim A<i.\s.s. Mem. Am. Acad., IV. p. 300, Figs. 1, 2. 

 Eucope iliopliaiui A. Agass. Pi-oc. Bust. Soe. Nat. Hist., IX. p. 92, Figs. 7-9. 

 I'liuumanlias diaphana Muncu ; in Beskriv. af Gronlaud, p. 96. 1857. 



This is by far the most common of our Jelly-fishes ; it does not grow 



to a large size, adult specimens not measuring 



more than a quarter of an inch across the disk. 



On escaping from the reproductive calycle, the 



little medusa has but twenty-four tentacles, and is 



constantly swimming with the disk turned inside 



out, as in Fig. 115 ; at the base of two of the ten- 

 tacles [t', t', Fig. 116), situated on both sides of the mid- 

 dle tentacle, between the chj-miferous tubes, are found 

 large spherical capsules ; there are no traces of ovaries 

 to be found in this early stage, it is not till the second 

 set of tentacles begin to develop (2, Fig. 117) that they 

 niiike their appearance. Young tentacles do not pos- 

 ' sess the root-like projection at their 



this is only developed in older tentacles 



of more advanced Medusa;. (See Fig. 120.) With 



advancing age the Medusae lose the habit of 



swimming with the pro))oscis uppermost, and grad- 

 ually assume the usual mode of swimming of Jelly- 

 fishes. The young Eucope of Fig. 117 develops 



rapidly additional tentacles, the ovaries increase in 



size, and we soon have an adult Medusa, with large bag-like ovaries, a 



Fig. ll.j. A Ei-.eope diajilKina just after its escape from the rciirodiictive calyeic, seen in 

 profde. 



Fig. 116. One ipiarter of tlie disk of the same, seen from above, t, tentacle opposite chyniif- 

 crous tul)e ; t', t', tentacles with capsules. 



Fig. 1 1 7. A more advance(l Eucope, in which the second set of tentacles (2) is developing 

 between the original tentacles (1). 



base ; 



