LEPTOMF.nUS.E — KTICOPE. 235 



GENERIC CHARACTERS. 



Eucopidae with 8 adradial lithocysts and 4 sac-like gonads, one on each of the 4 simple 

 radial-canals. Without marginal cirri. Manubrium without a peduncle. With 2 or more ten- 

 tacles which lack basal projections extending into the gelatinous substance of the bell. No 

 marginal eye-spots. The hydroid is Campanulina Van Beneden. 



The medusae of Eucope are readily distinguished from Obelia bv the fact that in Eucope 

 the tentacle-bases are simple and hollow, and the entodermal cores of the tentacles do not 

 project inward into the gelatinous substance of the bell as in Obelia. 



As the number of tentacles varies greatly in the different species which are otherwise closely 

 related, it seems convenient to group them all under the generic name of Eucope. Haeckel, 

 however, proposes the designation Saphenella for medusae with 2 diametrically opposed per- 

 radial tentacles; and Eucopium for medusae with 4 tentacles; while his Eucope applies to 

 medusae with 8 or more tentacles. Inasmuch as the number of tentacles probably increases 

 with age it affords a poor criterion for the separation of genera and may better be regarded 

 as of specific rather than of generic value. I have therefore included Haeckel's three genera 

 under the oldest name "Eucope." 



The medusae described by Gegenbaur under the generic designation Eucope are probably 

 young stages of Clytia, and mature ones of Obelia, and stages in the growth of Plualidium. 

 Thus Gegenbaur's "Eucope" campanulata and E. affinis appear to be young stages of Clytia 

 volubihs. His E. thaumantiodes is probably a young Plualidium and his E. polystyla is an 

 Obelia. 



The oldest described Eucope, in the present sense of the definition of the genus, is E. 

 globosa=T haumantias quadrat a, etc., Forbes, from the British coasts. 



Eucope globosa. 



Thaumantias quadrata, Forbes (young medusa), 1848, British Naked-eyed Medusa', p. 43, plate 9, fig. 2; Ibid., T. aronautica, 

 p. 44, plate 9, fig. 3; T. octona, p. 44, plate 8, fig. 4; T. maculata, p. 45, plate 9, fig. 4; T. globosa (mature medusa), p. 46, 

 plate 10, fig. 4. 



Thaumantias cymbaloides, Van Beneden, 1866, Mem. Acad. Royal Belgique, tome 36, p. 88. 



Campanulina repens (hydroid and young medusa), Hincks, 1868, Hist. British Hydroid Zoophytes, p. 189, plate 38, figs. I, la. 



Tetranema aeronauticum = Phialidium variabile (in part), Haeckel, 1879, Syst. der Medusen, pp. 125, 186. 



Thaumantias globosa, Haddun, 1887, Sci. Proc. Royal Dublin Soc, p. 476, plate 1 1, fig. I (medusa infected with parasitic Hal- 

 campa). 



Phialidium cvmbaloideum, Browne, 1896, Proc. Zool. Soc. London, p. 491, plate 17, figs. i-2a; 1905, Proc. Roy. Soc. Edin- 

 burgh, vol. 25, p. 771. 



Forbes, 1848, described this medusa under several names, the first name applied to it 

 being Thaumantias quadrata to indicate its young, 4-tentacled stage. The name applied by 

 Forbes to the adult was T. globosa. "Quadrata" takes precedence over this, being mentioned 

 on page 43, while "globosa" occurs on page 46, but the specific name must be globosa, this 

 being the first one applied to the adult medusa. 



Browne shows that the following described by Forbes are probably only stages in the 

 growth of this medusa: Thaumantias quadrata, having 4 tentacles; T. aionautica, 4 tenta- 

 cles; T. octona, 8 tentacles; T. maculata, 16 tentacles; T. globosa, 32 tentacles. 



The adult medusa may be described as follows: Bell thick-walled, fuller and slightly 

 higher than a hemisphere. About 13 mm. wide. 32 or more short tentacles, not half as long 

 as bell-diameter. 8 adradial lithocysts, each with 3 to 8 concretions. No cirri. 4 short, 

 linear gonads, beyond middle points of the 4 straight, slender radial-canals. Manubrium 

 short, with 4 simple recurved lips. No peduncle. Manubrium and gonads yellowish to 

 reddish-brown. Common off the British coasts and the coast of Holland. 



Browne described the early stages of this medusa. When 1.5 mm. high and 1 mm. wide, 

 there are 4 perradial tentacles, 4 interradial tentacle-bulbs, and 8 adradial lithocysts each with 

 2 or 3 concretions. The 4 gonads appear as 4 small oval swellings at middle points of the 4 

 radial-canals. 



Hydroid. — Browne discovered the hydroid of this species at Plymouth, England. It was 

 described by Hincks, 1868, as Campanulina re pens. The stems arise from a creeping hydro- 

 rhiza and are ringed throughout; they branch sparingly and somewhat irregularly in a more or 

 less alternate manner; several branches sometimes arise from the stem close together. The 



