98 Dr. F. Baron Nopcsa on Kerunia. 



some more spines are developed. Internally both fossils are 

 furnished witli the bent cone-like chamber whicli in Belosepia 

 lias a mucli shorter ventral side than characterizes Kerunia-, 

 tlierefore in this latter genus tlie cone appears to be much 

 more complete and more involute than in Belosepia. Thus, 

 though the Lateral horns of Kerunia are absent in Belosepia, 

 still the similarity is striking. Moreover the bilobate opening 

 q{ Kerunia (PI. III. fig. 1) is fairly safe evidence that the 

 internal chamber of this organism was inhabited by a Belosepia- 

 like animal. The growth of Kerunia occurred by thin layers 

 of calcareous matter superimposed one above the other over the 

 whole body, so that at the same time the oral opening was 

 shifted forwards and the different spines augmented in height 

 and length. No new layers were formed on the inside wall 

 of the chamber, except close by the mouth, where sometimes 

 a constriction resulted. That the formation of new layers 

 was influenced by the animal living in the cone-like chamber 

 is clearly shown by the fact that in the same degree as the 

 oral aperture was shifted forward new spines were developed 

 in the median line, one in front of the other. In some cases, 

 however, double spines were developed, that is, one or two 

 on each side of the median line (tig. 4), 



As the new layers which augmented the size of Kerunia 

 showed different thicknesses, the first small dorsal spines 

 slowly got covered up, and it is thus explainable that the 

 hindermost free spine of the dorsal row (the one nearest to 

 the ventral lip) is always the strongest, while the more 

 jjosterior spines form a breast-like projection. In large or 

 old specimens the lateral spines show branch-like protu- 

 berances or outgrowths (fig. 5), and as the number of these 

 outgrowths augments an irregular body is formed resembling 

 somewhat the horns of an elk with its pointed ends turned 

 upwards (fig. 6). On such occasions it also happens that 

 the basal region of the lateral branches in medium-aged 

 specimens (fig. 1), which exhibit a certain amount of flat- 

 tening, becomes perfectly flat and united w^ith the breast-like 

 projection (fig. 7). Then it is that remarkable asymmetry 

 occurs, the dorsal spines branch off in quite a posterior 

 direction high above their base, and frequently again become 

 irregularly united (fig. 8). 



Taking all these facts into consideration, I am unable to 

 acknowledge Kerunia as a Hydractinian : first, because of its 

 regular shape; secondly, on account of its external resem- 

 blance to Belosepia ; and, thirdly, from its regular growth on 

 the plan of a Belosepia-\\kt organism. 



The regular shape of Kerunia and its external resemblance 



