(2) Cordylophora whiteleggei, v. Lendenfeld (1887).
Zool. Jahrb. ii, p. 97 (1887).
A species or race of much feebler growth; as yet imperfectly known and only recorded from fresh water in Australia.
Cordylophora is a normal genus of the class Hydrozoa and the order Gymnoblastea; the next four genera are certainly Hydrozoa, but their affinities are very doubtful.
(3) Microhydra ryderi, Potts (1885).
Potts, Q. J. Micr. Sci. London, l, p. 623, pls. xxxv, xxxvi; Browne, ibid. p. 635, pl. xxxvii (1906).
This animal, which has been found in N. America and in Germany, possesses both an asexual hydroid and a sexual medusoid generation. The former reproduces its species by direct budding as well as by giving rise, also by a form of budding, to medusæ that become sexually mature. The hydroid has no tentacles.
(4) Limnocodium sowerbii, Lankester (1880).
Lankester, Q. J. Micr. Sci. London, xx, p. 351, pls. xxx, xxxi (1880); Fowler, ibid. xxx, p. 507, pl. xxxii (1890).
There is some doubt as to the different stages in the life-cycle of this species. The medusa has been found in tanks in hot-houses in England, France and Germany, and a minute hydroid closely resembling that of Microhydra ryderi has been associated with it provisionally.