ANTHOMEDUS.E STEENSTRUPIA. 31 



The hydroid generation is Corymorpha Sars, i$3$ = Halatractus of Allman, 1871. 



Haeckel, 1879, restricts Steenstrupia to describe medusae having characters as above, 

 but with an apical projection upon the bell, and with an axial canal extending upward into 

 this projection from the stomach. Euphysa he would restrict to include forms which lack an 

 apical projection and an axial canal. As Vanhoffen, 1891, rightly states, an apical projection 

 is always lacking in young medusae and is highly variable in its development even in mature 

 individuals of the same species. The same is true of an axial canal. Moreover, among 

 species discovered since Haeckel wrote his "System der Medusen," Euphysa tetrtibrachin, 

 Bigelow, 1904 (Bull. Mus. Comp. Zool. at Harvard Coll., vol. 39, p. 251, plate I, fig. i), has 

 a well-developed apical projection, and no axial canal, and would therefore have no place in 

 Haeckel's system. 



Maas, 1905, would institute a genus Euphysora to describe Codonidae having I large, 

 and 3 well-developed but still considerably smaller tentacles. Here again, however, we meet 

 with a condition of degree only. When, for example, are the 3 small tentacles large enough 

 to be Euphysara or small enough to be Steenstrupia ? In order to avoid confusion, it appears 

 best to combine all of these forms under one generic name. Vanhb'ffen, 1891, suggests Euphysa 

 as the proper generic name to include all of these forms, but Steenstrupia takes precedence 

 over Euphysa, for it was used by Forbes in 1846, while Euphysa was first used by him in 1848. 



Bigelow finds that the eggs of S. tetrabrachia are arranged in 8 adradial longitudinal lines 

 in the ectoderm of the stomach, and Maas states that in S. bigelou'i the gonads are interradial 

 and separated by very narrow linear interspaces in the 4 principal radii. These conditions 

 are interesting, for they foreshadow those characteristic of the Oceanidae where the gonads 

 are interradial or adradial, and are often quite widely separated in the principal radii. 



Hartlaub, 1907, defines Heterostephanus (Allman, 1871) as a Steenstruf>ia-\\ke medusa-bud, 

 not known to be set free from its Coryrnorpha-\\\ie hydroid. Medusa with a single tentacle, 

 ringed at its base, and terminating distally in a knob. The only known species is H . annuli- 

 cornis, Allman, l^l=Hybocodon annulicornis Haeckel. This was first described by M. 

 Sars, 1859; as Corymorpha ? annulicornis. 



Steenstrupia rubra Forbes. 



Plate I, fig. 7. 



Corymorpha nutans (hvdroid), SARS, M., 1835, Beskriv. og Jagtt., p. 6, plate i, fig. 3; SARS, O., 1877, Fauna Littor. Norveg., 



tome 3, p. 2, taf. 2, figs. 25-28. 



Corymorpha nutans (hvdroid), BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 63 (literature to 1850). 

 Corymorpha nutans (hydroid and medusa), HARTLATB, 1907, Nordisches Plankton, Nr. 12, p. 76, figs. 72-75 (complete li 



authors, localities, and best modern description of hydroid and medusa). 

 Corymorpha nutans, HINCKS, 1868, Hist. British Hvdroid Zoophytes, p. 127, plate 22. AI.LMAN, 1871, Monog. Tubularian 



Hydroids, p. 388, plate 19. 

 Corymorpha nuians = S. galanthus (Haeckel)=.S. faveola, Forbes = S. rubra, Forbes, BROWNE, 1896, Proc. Zool. Soc. London, 



pp. 463, 464, plate 16, fig. i (review of literature). 

 Steenstrupia galanthus, BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 148 (literature to 1850). HAECKEL, 1879, Syst. ilrr 



Medusen, p. 31. Hybocodon ntttans, Ibid., p. 34. MULLER, 1908, Zeit. fur wissen. Zool., Bd. 89, p. 52, taf. 5, figs. 20-24 



(origin and structure of the eggs). 

 Steenstrupia rubra, HARTLAUB, 1904, Wissen. Meeresuntersuch. Kommiss. Meerc Kiel, Abth. Helgoland, Neue Folgc, Bd. 5, 



p. 105, fig. 3. 



Steenstrupia rubra (Forbes), BROWNE, 1895, Trans. Liverpool Biol. Soc., vol. 9, p. 247. 



Steenstrupia rubra (medusa)+S. faveola, FORBES, 1848, British Naked-eyed Medusa, pp. 73, 74, plate 13, figs, i, 2. 

 Steenstrupia cranoides, HAECKEL, 1879, Syst. dcr Medusen, p. 30, taf. 2, figs. 10-14. 

 Steenstrupia gracilts, BROOKS, 1882, Studies Johns Hopkins Vniv. Biul. Laboratory, vol. 2, p. 144. MAYER, 1900, Bull. Mus. 



Comp. Zoo!, at Harvard Coll., vol. 37, p. 29, plate 16, figs. 36, 37. 

 Steenstrupia lintata, LEUCKART, 1856, Archiv. fur Naturgesch., Bd. 22, p. 29, taf. 2, fig. 6. SPACNOLINI, 1876, Catali-i:" \ 



Mediterraneo, p. 17, taf. I, figs. 1-4. HAECKEL, 1879, Syst. der Medusen, p. 30. DU PLESSIS, 1888, Recueil /.<.!. s,n re, 



tome 4, p. 543. 



This medusa is found on the coasts of Europe from Norway southward to the Mediter- 

 ranean. S. cranoides Haeckel = .V. lineata Leuckart, from the Mediterranean, appears to be 

 identical with S. rubra. S. gracilis Brooks, of the Atlantic coast of the United States south 

 of Virginia, is probably identical with S. rubra of Europe, but the hydroid of the American 

 form remains unknown. I believe that 5. Un<-ntn, S. rrtinoiJfs, and .V. i>r/ii-ilis are identical, and 

 that they are probably identical with .V. ruhrn Forbes. 



For description of i'. rubra of Europe, see synoptic table of species of Steenstrupia. 

 3 



