54 



THE ANTHOZOA 



lateral mesenteries which correspond with the long axis of the 

 colony are very long, and are the only mesenteries which bear 

 gonads. They are conveniently distinguished as the reproductive 

 mesenteries. The development of the Antipathidea is unknown, 

 and it is therefore impossible to say what is the sequence of the 

 mesenteries ; but it seems probable, from a comparative study 

 of the existing genera, that the sequence conforms to the 

 Edwardsio-Actinian type. The tentacles are placed over the sulcar 



FIG. XXVI. 



1. Portion of a colony of Antipathes dichotoma. 



2. Transverse section through the oral cone of Antipathella subpinnata. s, sulcus si, 

 sulculus ; g, gonads. 



3. Transverse section through the upper part of the oral cone of A ntipatlieUa minor. The 

 numerals indicate the probable order of succession of the mesenteries. 



4. A section somewhat lower down from the same specimen. Only three pairs of mesen- 

 teries are present. 



5. Section through the oral cone of Leiopathes glaberrima. Six pairs of mesenteries are 

 present, their probable order of succession being indicated by the numerals. 



and sulcular chambers, and over the four chambers adjacent to the 

 reproductive mesenteries. In Antipathella minor ten mesenteries 

 are present in the oral cone, but lower down four of them disappear, 

 leaving six mesenteries only, which, as Fig. XXVI. 3 and 4 show, 

 are the sulcar and sulcular pairs and the reproductive mesenteries. 

 Assuming that the more persistent mesenteries are the oldest, 

 and that the great reproductive mesenteries correspond in order of 

 appearance, as they do in position, to the mesenteries 1, 1, in the 

 Actinian larva, we may number the two remaining pairs 2, 2, 



