262 MEDUSA OF THE WORLD. 



The type species is Clytia volubilis Lamouroux, 1812, previously described by Ellis and 

 Solander, 1786, as Sertularia volubilis. 



Alder, 1858, renamed this species Clytia johnstoni in order to disitnguish it from Campan- 

 ularia volubilis. It is a widely-distributed form and is found along the Atlantic coasts of 

 Europe as well as in the Mediterranean. Clytia bicophora Agassiz, of America, is apparently 

 identical with the European C. volubilis; and Eucope campanulata and E. affinis of Gegen- 

 baur are apparently only stages in the growth of the medusa of C. volubilis. 



Calkins, 1899, finds a hydroid from Puget Sound, Pacific coast of America, which is 

 apparently identical with C. bicophora = C. volubilis; and if this be true, C. volubilis is probably 

 widely distributed over the temperate coasts of the northern hemisphere. 



GENERIC CHARACTERS. 



Eucopida? with 16 tentacles alternating with 16 vesicular, closed lithocysts. 4 sac-like 

 gonads upon the 4 simple radial-canals. No well-developed peduncle. No cirri. The 

 hydroid is Clytia, closely related to Cam panul aria, but distinguished by its free-swimming 

 medusae. 



When set free from the reproductive calycle of the hydroid, the medusa has 8 adradial 

 lithocysts and a high, dome-like bell. As growth proceeds the lithocysts become 16 in num- 

 ber and the bell becomes flatter than a hemisphere. 



There are a number of closely related species of Clytia which produce medusae, but the 

 free-swimming or adult medusa is not known and therefore no description ot them appears 

 in this text. Such species are: 



Clytia gemculata Thornely, 1905, Roy. Soc. London, Report Ceylon Pearl Oyster 

 Fisheries, vol. 2, p. 112, plate 3, figs. 4, \a; from near Ceylon. 



Clytia fragilis Congdon, 1907, Proc. American Acad. Arts and Sci., vol. 42, p. \fo, 

 fig. 13. Bermuda Islands. 



Clytia simplex Congdon, Ibid., p. 471, figs. 14, 15. Bermuda. 



For Clytia bakeri Torrey see Eucheilota bakeri in the appendix. 



Clytia volubilis Lamouroux. 



Plate 32, figs. 1-7. 



European Synonyms. 



Sertularia volubilis, Ellis and Solander, 1786, Nat. Hist. Zooph., p. 51, No. 22, plate 4, figs, e, f, E, f. 



Clytia (Sertularia) volubilis, Lamouroux, 1812, Nouv. Bullet. Sci. par la Soc. philomantique, tome 3, p. 181. 



Clytia volubilis, Lamouroux, 1816, Hist, des Polypiers Zooph., Caen, p. 202; 1821, Exposition method.que genres Polypiers, 

 p. 13, plate 4, figs, e, f, E, r (after Ellis and Solander); 1824, Encyclopedic methodique, tome 2, p. 202, Fans.-BEDOT, 

 1 001, Revue Suisse de Zool., tome 9, p. 436; Ibid., tome 13, p. 60 (literature, 1786-1850). 



Campanular.a volubilis, Johnston, 1832, Trans. Nat. Hist. Soc, Northumberland, Durham, and Newcastle-upon-Tyne, vol. 2, 

 p. 255; 1838, Hist. British Zoophytes, p. 154, fig. i 7 .-Van Beneden, 1847, Bull. Acad. Sci. Belgique, tome 14, p. 457, 

 fie. 7 (medusa). „ ,- 



Campanula johnstoni, Alder, .848, Trans. Tynes. Nat. F. Club, .858, vol. 5, p. .26, plate 2, fig. 8.-Allman, .87,, Monog. 

 Tubularian Hydroids, part 1, p. 23, fig. 2. 



Clytia johnstoni, H.ncks, .868, Hist. British Hydroid Zooph., vol. ., p. 143. I^te 24, fig. 1 (lvydro.d and medusa).-Ri.FroRD, 

 1902, Notes on British Zoophytes, p. 53, fig. u (edited by E. Connold). 



Europe campanuIata+E. affinis, Gegenbaur, 1857, Zeit. fur wissen. Zool., Bd. 8, pp. 243, 244. 

 Eucope affinis, M etschnikoff, 1880, Zool. Anzeiger, Jahrg. 3, p. 261 (digest.ve cells are amceboid). 



American Synonyms. 



Chlia bicophora, Agassiz, L., 1862, Cont. Nat. Hist. V. S., vol. 4, pp. 304. 354, plate 29, figs. 6- 9 .-Agassiz, A., 1865, North 

 Amer. Acalepha-, p. 78, figs. 108-1 11 .-Nutting, 1901, Bull. U. S. Fish Commission, vol. 19, p. 343, ng. 21 (hydroid;. 



Clytia johmtonii= C. bicophora^ C. unifora, Verr.ll, 1873, Report Commis. Fish and Fisheries for 1871-72, P- 7^- 



Clytia cylindrica, Agassiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 307, fig. 41. 



Clytia johnstoni, Clarke, 1876, Exploration of Alaska, vol. 1, p. 8, plate 3, fig. 12 (from Alaska). 



Etenthesis bicophora, Haf.ckel, 1879, Syst. der Medusen, p. 184. 



Epenthesh jolleata, Fewkes, .882, Bull. Mus. Comp. Zool. at Harvard College, vol. 9, No. 8, p. 298, plate 1 figs. 10-14. . 



Campanularia johnstoni, Calkins, 1899, Proc. Boston Soc. Nat. Hist., vol. 28, p. 348, plate 1, figs. 6-6r; plate 6, fig. 6d (hydroid 

 from Puget Sound, Pacific coast). 



I can not detect any specific difference between the European Clytia volubilis Lamouroux 

 and the American Clytia bicophora Agassiz. The following description is based upon a study 

 of the American medusa and its hydroid. 



