8 



In certain cases »the fibro-crystal- 

 line deposit is radially symmetrical 

 around ideal trabecular axes in the me- 

 dian septal plane«. As examples, the 

 markings perpendicular to the spiniform- 

 toothed edge of the 3Iussa septum are 

 quoted , and reference is made to the 

 striae of the Galaxea septa, the ridges 

 on the septa oî Fiingia , etc. (1. c. p. 11). 



»Häufig finden sich auch Streifen 

 normal zu den vorigen (sie entsprechen 

 den Zacken des Randes), und bei man- 

 chen Gattungen, Mussa, den Fungien, 

 Siderastraea und anderen können diese 

 letzteren so individualisiert sein, daß 

 man an ihnen eigene Krystallisations- 

 centren und Trennungslinien gegen ein- 

 ander unterscheiden kann« (1. c. p. 256). 



Prof. V. Koch then goes on to derive the »durchbrochene« and 

 »kammförmige« varieties of septa from the simple »plattenförmige« 

 septa, and this practically completes his contribution to the subject of 

 septal structure. Septal varieties and their systematic importance form 

 a large part of my paper presented to the Eoyal Society in July 1895, 

 and are features shortly indicated in the published »Abstract«. 



With regard to the question of [»true« and »false« synapticulae, 

 Prof. V. Koch does not go beyond the distinction originally dravt^n by 

 Herr Pratz. But the important fact is that his research upholds this 

 distinction even while he declares it to be of small value ; whereas 

 several authors have in recent years declared it quite untenable. 

 In this Prof. v. Koch's actual observations again agree with, and 

 were anticipated by, mine; this is also the case in his statement that 

 both kinds of synapticulae occur alongside one another in the genus 

 Fungici. A few farther quotations may be compared concerning other 

 parts of the skeleton. 



„Abstract" O gii vie 1895. 



»The microscopic structure of dis- 

 sepiments and tabulae is demonstrated by 

 the author to be the same. Both are com- 

 posed of a series of calcareous growth- 

 lamellae laid down from one surface only 

 of the aboral body-wall of the polyp. The 

 fibro-crystalline deposit is therefore per- 

 pendicular to the plane of contact be- 

 tween polyp and skeleton« (1. c. p. 13). 



»Cases occur in both those families 

 where the only peripheral support is af- 

 forded by the epitheca. The author is 

 inclined to think this was the primitive 

 form of the Madreporarian Calyx, and to 

 look upon both theca and pseudotheca 



„Das Skelet der Steinkorallen " 



V. Koch 1896. 



»Diese Schraffen (Linien von der 

 Anordnung der Krystalle abhängig) sind 

 immer nahezu senkrecht zur Fläche des 

 Dissepiments gestellt, oft zeigt sich auch 

 noch eine ganz zarte Streifung parallel 

 zu dieser, und gleichen sie also hierin 

 sehr dem Stereoplasma der Septen« . . . 

 (1. c. p. 260). 



»Eine Tabula ist ganz dasselbe wie 

 die Summe aller in einer Ebene liegenden 

 Dissepimente« (1. c. p. 262). 



»So werden wir mit großer Wahr- 

 scheinlichkeit annehmen können: das 

 ursprüngliche Skelet der Steinkorallen 

 bestand aus einer lamellären Abschei- 

 dung von Kalk durch das Ectoderm: 

 Basis und Epithek, die eine schützende 



