AMPHINEMIDAE. 197 



Color. — The base of the manubrium and the tentacular bulbs in the 

 Acapulco specimens varied from yellowish green to ochre yellow ; they are 

 described by Agassiz and Mayer as rosin yellow (: 02, p. 145). The tentacles 

 are milky ; the bell is transparent. 



This species is widely distributed over the Tropical Pacific Ocean and 

 the Malaysian region. 



Amphinemidae Haeckel, 1879. 



sens. em. Vanhoffen, '89. 



Anthomedusae with interradial gonads and with hollow tentacles ; with 

 only two developed tentacles, although there may also be numerous rudi- 

 mentary tentacles. 



This family was included by Haeckel ('79) in the Tiaridae as a subfamily, 

 but we may well follow Vanhoffen ('89) in classing it as a separate family, 

 for, although it is more closely allied to the Tiaridae, from which it is to be 

 distinguished only by the restricted number of tentacles, than it is to any 

 other family of Anthomedusae, its members form an extremely homogeneous 

 group. This classification is likewise accepted by Maas. 



Vanhoffen has united the three genera of Amphinemidae which Haeckel 

 distinguished under the oldest name, Stomotoca, believing that the 

 differences in the extent and form of the gonads which formed Haeckel's 

 basis for separating Amphinema from Codonorchis are merely the expression 

 of different stages in development, and that the presence of a gelatinous 

 peduncle which serves to characterize Stomotoca is at most of specific, not 

 of generic, importance. With the union of Amphinema with Codonorchis 

 I entirely agree. According to Haeckel the gonads of the former are 

 restricted to the walls of the manubrium, while in the latter they extend 

 from the manubrium over the surface of the subumbrella ; but since in at 

 least one species in the present collection, A. turrida Mayer, moderate-sized 

 individuals show the former, larger ones the latter condition, it is evident 

 that the difference represents nothing more than successive stages in devel- 

 opment, and therefore should not be given generic significance. It may be, 

 however, a specific character, should it prove that the simpler condition is the 

 final one in any species of the genus. The ground for Vanhoffen's com- 

 bination of Amphinema with Stomocota is less certain. A peduncle, when it 

 occurs, is a very constant character; and, inasmuch as it distinguishes several 



