Chap. I. 



REPRODUCTION OF CORYNE MIRABILIS. 



201 



about one eighth of an inch in diameter (wood-cuts 20, 21, and 22) ; after this 

 they died, owing, no doubt, to their excessive tenderness, and the difficulty of keeping 

 the water sufficiently aerated. However, this did not preclude the possibility of 

 examining them in all stages of growth, from the youngest to the full-grown con- 

 dition, inasmuch as the water of Boston Harbor was filled with the same medusae, 

 of all ages. By comparing specimens found in the open ocean, with those of the 

 same size, just born in confinement,^ it was impossible to see any difference, and 

 so it was with those collected at the same time, and placed by the side of the 

 largest which Avere reared. These facts being established to a certainty, no one 

 could fiiil to see that the series of specimens, of five different sizes, from one 

 sixteenth to one fifth of an inch 

 in diameter (wood-cuts 20, 21, 22, 

 23, and 24), all collected on the 

 same day, belonged to one and the 

 same species of Medusa, in various 

 stages of growth. These comparisons were made in two different years; March 26, 

 1855, and March 29, 1858. Nearly a month after the first-mentioned date, on the 

 21st of Api'il, specimens, some about two thirds of the size of full-grown ones, were 

 obtained (wood-cut 28, p. 211), measuring one third of an inch in diameter, and by 



Fig. 20. 



Fig. 21. 



Fig. 23. 



Fig. 22. 



A 



Young Coryne (Sarsia) mibabilis. 



Fig. 24. 



» Wood-cuts 20, 21, 22, 23, and 24 represent a 

 scries of young medusae of Corync mirabilis, drawn 

 from nature by H. J. Clark. The specimen repre- 

 sented by wood-cut 20 was seen to drop from the 

 parent stem ; that of wood-cut 21 was found in 

 Boston Harbor, and was as large as that of wood- 

 cut 20 when three days old ; that of wood-cut 22 

 was found with that of wood-cut 21, and was as 

 large as that of wood-cut 20 when six days old ; 

 those of .wood-cuts 23 and 24 were also found 

 with the preceding, but their precise age could not 

 be ascertained. In order to facilitate the com- 

 parisons between our Sarsia and tlie European 

 species, during their development, I submit here 

 references to the different descriptions thus far 

 published of the young Sarsia of Europe, with the 

 dates of the observations. 



Coryne ramosa, Gosse, Devon. Coast, p. 190. 

 Simple sac (Medusa), with eggs, July, 1852. 



Coryne gravala, Wright, Edinb. New Phil. Jour., 

 1858, Vol. VII. Aborting Medusa attached, with 

 spermatozoa. Spring. 



VOL. IV. 26 



Coryne glandulosa, Wright, Ed. Ph. Jour., July, 

 1857. Simple sac, with eggs. 



Coryne (Syncoryna) ramosa, Loven, Wieg. Arch., 

 1837. Aborting medusa with eggs. June. 



Coryne (Syncoryna) Sarsii, Loven, Wieg. Arch., 

 1837. Nearly perfect medusa (aborting), June. 

 Compare PI. XVII. Figs. 14, 15, and 16. 



Coryne (Syncoryna) Sarsii, Sars, Faun. Litt., 

 PI. I., 1846. Perfect and free medusa. May and 

 June, 1838. 



Coryne (Syncoryna) decipiens, Dujardin, An. 

 Sc. Nat., 1845, IV. Perfect free medusa, Sthenyo 

 (Sarsia). December, 1842. 



Coryne (Syncoryna) pusilla, VanBeneden, Acad. 

 Brux., 1843. Simple sac, with four-armed hydroids ! 

 Summer,? 1843. 



Coryne (Stipula) ramosa, Sars, Bidrag, 1829, 

 and Isis, 1833, Tab. X. Fig. 1. Simple sac with 

 eggs. ? July. 



Desor's paper, Ann. Sc. Nat., 1849, Vol. XII., 

 represents the American Coryne mirabilis. 



