38 



MEDUS.E OF THE WORLD. 



Haeckel, 1874, instituted the genus Amphicodon to include medusae with 3 rudimentary 

 tentacles, and a cluster of 2 or more long tentacles at the foot of the longest radial-canal. 

 Vanhoffen, 1891, Browne, 1896, and Hargitt, 1901, have pointed out, however, that the 

 young medusae commonly have but I long tentacle, and that others appear, and develop from 

 the side of the basal bulbs of this original tentacle; thus the genus "Amphicodon" is only 

 a mature Hybocodon. These secondary tentacles may appear before or after the medusa- 

 buds begin to develop upon the tentacle-bulbs. According to Hargitt, 1902, 1904, Perkins, 

 1904, and Linko, 1905, the sexual products of the manubrium become mature while 

 medusa-buds are still being produced upon the tentacle-bulbs. 



Synopsis of the Species of Hybocodon.* 



*For description of H. chilensis Hartlaub, H. chrislinf Hartlaub, H. pu/cher Hartlaub, and H. (?) januarii, see text. 



Hybocodon prolifer L. Agassiz. 

 Plate 2, fig. i; plate 3, fig. 3. 



(?) Corymorpha fritillaria, STEF.NSTRUP, 1842, Generations-wecksel., p. 20, taf. I, figs. 41-46 (the medusa only may be identical 



with //. prolifer; the hydroid appears to be an Amaltheea or Diplura). 

 ( ? ) Stcenstrupia globosa, SARS, 1859, Christiania Vidensk. Selsk. Forhandl., p. 101. KOREN and DAWELSSEN, 1877, in Sars's 



Fauna Littoralis Novegiie, tome 3, p. 20, taf. i, figs. 1-6. 

 (?) Corymorpha annulicornis (young medusa), KOREN and DANIELSSEN, 1877, Ibid., p. 8, taf. i, figs. 7-13. 



