52 



MEDUS.E OF THE WORLD. 



Sarsia tubulosa Lesson. 



Syncorvna sarsii (hydroid), LOVEN, 1835, K. Vet. Acad. Handl. for Ar., p. 275, plate 8, figs. 7-10. 



Oceania tubulosa (medusa), SARS, M., 1835, Beskriv og Jagtt., p. 25, plate 5, fig. 1 1 . Also: Syncorine sarsii, 1846, Fauna littor. 

 Noveg., part. 2, p. 2, tab. i, figs. 1-6. 



Syncoryne sarsii, LOVEN, 1837, Archiv. fur Naturgesch., Jahrg. 3, p. 321, taf. 6, fig. 25. WEISMANN, 1883, Entsteh. Sexuabellen 

 bei Hydromedusen, Jena, pp. 56, 216. GARSTANG, 1894, Journal Oxford Club, vol. 2, No. 30, p. 7. CITRON, 1902, 

 Archiv. Naturges., Jahrg. 68, pp. I, 26, taf. i, 2 (sensory cells of tentacles). HINCKS, 1868, British Hydroid Zoophytes, 

 p. 52, plate 7, fig. 3. ALLMAN, 1872, Monog. Tubularian Hydroids, p. 275. 



Syncoryne sarsi and Sarsia tubulosa, BEDOT, 1905, Revue Suisse de Zool., tome 13, pp. 120, 147 (all literature 1835-1850). 



Sarsia tubulosa, LESSON, 1843, Hist. Zooph. Acalephes, p. 333. SCHI'LZE, 1873, Ueber den Bau von Syncoryne Sarsii, p. 14, 

 taf. 3. ROMANES, 1885, Jellyfish, Star-fish, and Sea Urchins, etc., International Scientific Series, vol. 49 (reactions to 

 stimuli). LINKO, 1905, Zool. Anzeiger, Bd. 28, p. 212. HARTLALIB, 1907, Nordisches Plankton, Nr. 12, p. 19, figs. 10-16. 

 BROWNE, 1903, Bergens Museums Aarbog, No. 4, p. 9; 1895, Proc. and Trans. Liverpool Biol. Soc., vol. 9, p. 246. 



Sarsia tubulosa, SARS, i$$$=Sarsia macrorhyncha, BUSCH, 1851; BROWNE, E. T., 1905, Proc. Royal Soc. Edinburgh, vol. 25, 

 p. 758. 



Syncoryne gravata, HINCKS, 1868, Hist. British Hydroid Zooph., p. 53. 



Sarsia tubuhsa+S. macrorhyncha, HAECKEL, 1879, Syst. der Medusen, pp. 16, 19. 



Sarsia tubulosa + S. pulchella, FORBES, 1848, British Naked-eyed Medusa-, pp. 55, 57, plate 6, figs. ^, 3. 



Corynt pusilla, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 340. 



(!) Syncoryne Sarsii, HARTLAUB, 1905, Zoolog. Jahrbiichern, Suppl. 6, p. 525, fig. F (hydroid from Terra del Fuego). 



Sarsia macrorhyncha, BUSCH, 1851, Beobach. wirbell. Seeth., p. lo, taf. 3, figs. 7-10; taf. 4, figs. I, 2. 



FIG. 13. "Sarsia litorea," after Hartlaub, in Nordisches Plankton. 



FIG. 14. "Sarsia decipiens," after Hartlaub, in Nordisches Plankton. 



FIG. 15. "Syncoryne gravata," after Hincks, in British Hydroid Zoophytes probably hydroid of Sarsia 



T^l- ' . _J ' r 1 _T^l__ TT 1' t_ . - _1 ' ^1_ - ! L..^ :^ J' _ 



mirabilis 



This medusa is found off the English coast early in the spring, but it disappears before 

 August. It is evidently an Arctic species, is abundant off the northern coasts of Europe, 

 and is found off Iceland. It is very closely related to, if not identical with, the American 

 S. mirabilis, but may possibly be distinguished by its more slender and higher bell, its very 

 long manubrium, and its somewhat shorter tentacles. All of these characters are, however, 

 very variable in Sarsia mirabilis, and I have become convinced that the American and 

 European forms are at most only varieties, one of the other. For details see the tabular 

 description of medusae of Sarsia. 



Romanes, 1885, carried out many interesting physiological experiments upon this 

 species, and showed that its ocelli are organs for the perception of light. The medusa is 

 sensitive only to rays between the red and violet, and is strongly attracted by the light. The 

 smallest part of the bell-margin is capable of initiating and maintaining the rhythm of the 

 bell, but if the margin be entirely removed all pulsations of the bell instantly cease, while 

 the cut-off margin continues to pulsate. Stimulation of the subumbrella of the bell causes 

 contraction of the manubrium (proboscis), and indeed the bell, when deprived of its margin, 

 still responds by contractions to all sorts of stimuli, chemical, thermal, electrical, or mechan- 

 ical, although sustained rhythmical pulsation is never resumed. 



The hydroid is Syncoryne sarsii, which is common in shallow water along the coasts from 

 England to Norway. The polypites are spindle-shaped and elongate and have about 12 to 



