‘ON THE REPRODUCTIVE SYSTEM IN THE HYDROIDA. 367 
lopment which it attains in any adelocodonic gonophore, if we except the 
peculiar body described below under the name of “ meconidium.” It is per- 
forated at its summit, and the perforation is surrounded by a distinct circular 
Fig. 6.—Types of Gonophores. 
A, Clava multicornis. B, Garveia nutans. C, Tubularia indivisa. D, Syncoryne 
 eximia. 
a, ectotheca; b, mesotheca; c, endotheca; d, spadix; d', manubrium; e, radiating 
gastrovascular canals; f, circular gastrovascular canal; g, marginal tentacles; h, ocelli; 
0, ova; p, ovarian plasma in Tubularia. 
canal which receives four radiating canals, which open into it by small bulbous 
expansions (fig. 6 C). We thus find almost entirely the condition of a medusa— 
a medusa, however, which never becomes free, the mesotheca never disen- 
gaging itself from the ectotheca, the spadix remaining as a simple cecal di- 
yerticulum, and the codonostome being reduced to a mere perforation of the 
mesotheca, while this last exhibits but the faintest traces of contractility, 
and is quite incapable of acting as a locomotive umbrella. 
From the sporosac of Tubularia indivisa it is thus but a single step to the 
true phanerocodonic gonophore, such as we find in Corymorpha nutans, 
Campanularia Johnstoni, or Syncoryne (Coryne) eximia, where the mesotheca 
assumes the condition of a contractile locomotive umbrella, with a well- 
