LEPTOMEDUS^E — ^EQUOREA. 325 



from the meristic standpoint, some individuals having the tentacles more and others less 

 numerous than the radial-canals. Moreover, the shape of the stomach changes from a simple 

 4-lipped manubrium to one having 50 or 100 lips, widely gaping, and with curtain- like, folded 

 margins Gonads develop at various times upon the radial-canals. Indeed the greatest 

 confusion has been introduced into the synonymy through the description of developmental 

 stages of /Equorea under various generic names. 

 For example, Haeckel distinguishes: 



(1) Rhegmatoies, with simple funnel-shaped stomach and closed, narrow-necked mouth. 



(2) Polycanna, with elongate stomach with large throat-tube and closed mouth with folded lips. 

 (7) /Equorea, with wide, short stomach and widely gaping mouth with simple lips. 



(4) Mesonema, with wide, short stomach and widely gaping mouth with complexly folded lips. 



Claus 188 1, 1883, shows that the common /Equorea forskalea of the Atlantic and Mediter- 

 ranean passes from the "Rhegmatoies" condition through all four stages, ending with the 

 "Mesonema" stage, and there can be no doubt but that Haeckel has described this medusa in 

 its various stages under different generic names. Indeed, as Browne, 1903, and Bigelow, 1909, 

 have shown, when an /Equorea (Haeckel) contracts its stomach-wall so as to tend to close its 

 mouth and cause its lips to fold complexly, it becomes a "Polycanna" or a "Mesonema. 



When young the lips are commonly closed, but when old the mouth is often found to be 

 gaping open; while in an intermediate condition of life the mouth is open when relaxed and 

 closed when contracted. It is evidently impossible to separate genera upon intergrading char- 

 acters such as these, and we have no alternative but to include all jEquondae with numerous 

 simple radial-canals, numerous lips, and smooth subumbrella under the genus /Equorea, 

 allowing the relative numbers of radial-canals and lips, or of canals and tentacles, to serve 

 as specific distinctions. . . 



The following species appear to me to be too vaguely described for recognition, and 1 



have therefore failed to consider them: 



/Equorea ciliata Eschscholtz, 1829, Syst. der Acad., p. 109, taf. 9, fig. 1. From Pacific 



coast of America between 41 to 50° N. lat. 

 Mesonema abbreviata Eschscholtz, 1829, he. cit., p. 113, taf. 11, fig. 3. From tne Straits 



of Sunda. 

 Mesonema dubium Brandt, 1838, Mem. Acad. Imp. Sci. St. Petersbourg, ser. 6, tome 4, 



p. 361, plate 26. From off the coast of Japan. 

 /Equorea cubana = Zygoiactyla cubana Mayer, 1900, Bull. Mus. Comp. Zool. at Harvard 



College, vol. $J, p. 60, plate 25, figs. 84, 85. (Too immature for determination.) 



From Tortugas, Florida. 



JEquorea forskalea Pe'ron and Lesueur. 

 Plate 42, figs. 1 to 6; plate 43, fig. 8. 



SYNONYMS OF THE EUROPEAN MEDUSA. 



Medusa .equorea, Forskal, 1775, Descriptiones animalium, Hauniae, p. 110; 1776, Icones rerum naturalium, plate 32. 



Medusa patina, Modeer, 1791, Nova Acta Phys. Med. Acad. Caes. Leop. Carol., tome 8, Append.*, p. 3*- 



Equorea forskalea, Peron et Lesueur, 1809, Ann. Mus. Hist. Nat., tome 14, P- 336.-Dj.lleCh.aje, S ,841, An.ma . 

 senza Vert., tome 7, tav. 148, fig. V, also, M. rissoana, tav. 139.— Forbes, .85., ^Proc. Zool. Soc. London, p. 272, 

 plate 4 ,-Kru K enrerc, ,880, Vergleichend. physiolog. Studien Z u Turns etc Abth. 3, p .24 (reactions to curare 

 and s.rvchnine).-CLAUS, .88., Arbeit. Zool. Inst. Wien, Bd. 3, p. 283; Ib.d., Bd 4, P- 9°S >»•*. Z °°>- Ar f' f r > Bd " 5> 

 p. 284 (development of the egg); .883, Untersuch. iiber Organisation und Entw.ck. der Medusen, p. 6., taf. .6-20, fign. 

 ,,2-157 (variations and development).-HAEC K ER, .892, Archiv. Mikr. Anat.,Bd. 40, p. 243 taf. .3, .4, 5 fign.(deve op- 

 ment of the egg); .895, Ibid., Bd. 45, P- 2O0.-Hartlaub, .894, Wissen. Meeresuntersuch Xomm. Meere Kiel, Helgo- 

 land, Neue Folge, Bd. I, p. l 9 6= Pohcanna germaniea, of Haeckel.-B.DOT, ,90., Revue Su.sse de Zool tome 9, p. 482; 

 Ibid., .905, tonTe ,3, p. .30 (citation of references to ,8 5 o).-Maas, .904, Result. Camp. So. Prince de Monaco, fasc. 28, 

 p. 24, planche 2, figs. .2-14 (states of contraction of the stomach walls). 



Mquorea risso, Lamouroux, Bory de St. Vincent et Desloncchamps, ,824, Hist. Nat. Zoophs., Pans, p. 372. 



/Equorea rissoana, Risso, 1826, Hist. Nat. Nice et Alpes maritimes, p. 294, planche 7, figs. 37, 38. 



/Equorea violacea, M.lne-Edwards, 1841, Annal. des Sci. Nat., Zool., ser. 2, tome .6, p. .95, planche I. 



.■Equorea vilrina, Gosse, 1 8 <; 3 , Naturalist's Rambles Devonshire Coast, p. 340, plate 23. 



Zwdacf/la vilrina (hydroid), Hincks, 1868, Hist. British Hydroid Zooph., p. 192, plate 38, figs. 2-26. 



Zyiodaciyla rosea, Metschnikofe, E., 1871, Verhandl. Gesell. Freunde Nat. Moskau, Bd. 8, p. 353, taf. 5, fign. 7, 8 



Ocmanna oc,one,„a (young medusa O+^orea discus + M. forska!ea + M. vioiacea+ Mesonema eurysto,na+ Polycanna fung,a + 

 P. germanica + P. italica+P. vilrina, Haeckel, 1879, Syst. der Medusen, pp. 2.3 2.9, 220, 227, 229-23.. 



