Dr. F. Baron Nopcsa on Kermiia. 99 



to Belosepia, as well as the continuous development of new- 

 spines near the shifting oral opening, are characters which 

 prevent us from assuming that it is the result of a Ilydrac- 

 tinian covering some Gastropod or other animal in the 

 manner quoted by H. J. Carter and others, because in such 

 cases irregular masses are the only result. 



(B) Kerunia a Hydractinian. 



Tiiough it was rather easy to prove in the previous remarks 

 that Kerunia could not be a simple Hyclractinian, it is 

 jMobably easier to demonstrate that this organism could have 

 been notliing else. The internal structure of Kerunia 

 throughout tlie entire fossilized body, as shown by ditFerent 

 sections, is everywhere exactly the same and without any 

 sign whatever of a shell-like centre. Agreeing altogether 

 with liydrozoan structure and perfectly unlike the dense shell 

 oi Belosepia* J Kerunia is built up of concentric layers, showing 

 a tubular structure {^g. 11). The tubulae of the different 

 layers are always direct(;d so as to point vertically towards 

 the external surface of the more internal layer, and through 

 irregular tubes of similar size they are in communication 

 with each other. The outermost layer is capable of covering 

 Balanids and other animals that adhere to its surface, forming 

 another fact which forcibly reminds us of Hydractinian 

 affinities. 



As already remarked by (Jppenheim, there can be distin- 

 guished on the external surface of Kerunia low spine-like 

 defences, pits for the single individuals, and small channels 

 corresponding to the sarcorhiza. The tubercle-like defences 

 show clearly small convergent liblets, and are mostly accumu- 

 lated on the bottom or more flattened surface, the pits are 

 more numerous on the top, while the dense network formed 

 by the sarcorhiza seems equally spread out over the whole 

 body ; but none of these elements appear to be present in 

 the cone-like chamber. Since Oppenheim's sketch gives but 

 a poor representation of the delicate surface-sculpture of our 

 animal, it is considered necessary to introduce a micrr*- 

 drawing of a portion of the surface of /lugrMwia (fig. 12), where 

 a great resemblance will be observed to Vinasso de Kegny's 

 illustration of the external structure of Cyclactinia f incrus- 

 tans. At the same time it should be observed that Cyclactinia 

 incrustans is the single Hydractinian species giving off 

 KeruniaAWit ramifications. 



* Beloptera seems to bo less dense in its shell-striictui-L'. 



t This genus, according tu Oppeulieiiu, belongs to ILidractinia. 



