70 THE VOYAGE OF H.M.S. CHALLENGER. 



in form to certain Antipathidse. In both families an elongation in the transverse axis 

 is often marked. In Amphianthidse, however, the stomodseum is usually elongated in the 

 transverse axis, so that the siphonoglyphes, supported by the directive mesenteries, 

 almost touch one another. In Antipathidse the elongation in the stomodseum, when such 

 occurs, usually takes place in the sagittal axis. It appears probable that the elongation 

 in the transverse axis, characteristic of the Amphianthidse, and also found though not 

 always well marked in Antipathidse, does not afford a character of phylogenetic value. 



In Dendrobrachia fallax we have a form with branched tentacles, thus showing that 

 the type of the tentacle once thought to be characteristic of Alcyonaria may occur also 

 in Antipatharia as well as in Actiniaria. 



