30 Mr. II. M. Bernai-a on the 



primitive protothecal walls, recognized by Miss Ogilvie as 

 equivalent to epitlieca, have been hitherto called eutheca. 

 But proto- is a more appropriate affix to express primitive 

 simplicity than eu-, which better denotes some special excel- 

 lence. Hence I propose, once more, that eutheca be applied 

 to those \valls which have been thickened, ornamented outside, 

 and cemented firmly to the substratum in the way described 

 above (p. 22) and illustrated in diagrams figs. 13 h, 14, 

 and 15. 



We now come to the term " pseudotheca " of Heider. This 

 is applied to cases in which the septa are so crowded together 

 that they fuse along lines which together constitute a fairly 

 symmetrical solid thecal ring. The parts of the septa within 

 this ring are septa proper and tlie parts without are costte. 

 Now I cannot help doubting whether this differs in any 

 respect from the eutheca, for it is obvious that a eutheca, as 

 here understood, over which the septa ran close together, 

 would give exactly the same result. 



The suggestion that this wall is built wholly of fused septa 

 does not take the possibility of a ring-fold into account. But 

 from the review of coral morphology here set out it would 

 appear that the ring-fold was a more primitive structure than 

 the radial septa. I'urther, it is really impossible in a matter 

 of such complicated folds to say how much at their points of 

 crossing belongs to the radial and how much to the con- 

 centric elements. 



That the concentric element plays a part we gather from 

 the fact that dissepiments frequently slope up the intcrseptal 

 loculi just as if, had there been space enough, they would 

 mount over the walls. This giving off of dissepiments 

 means that the basal floor shares in the formation of the wall. 

 What is usually called pseudotheca, then, is to my mind 

 simply a modification of the eutheca as here understood, and 

 the word, if retained at all, should have a new significance. 

 My own proposal is to apply it in the sense of Ortmann's 

 *' athecalia " *. This term was suggested by that author for 

 the Perforata in which the protothecal cup, being entirely 

 flattened out, a new secondary theca rises up formed entirely 

 out of septa with their synapticular junctions. Now it is 

 obvious that no part of the old protothecal rim is found in 

 this new septate thecal wall, and to mark the total distinction 

 between this and all the wall-formations made by folds of 

 the true lip of the prototheca, it might well be called pseudo- 

 theca. 



* Zool. Jahrb. (Syst. Abth.) iv. 1889, p. 493. 



