ÖPVERSTGT AF K. VETENSK.-AKAl). FÖRHANDLINGAR 1895, N:0 J). 629 



character, which can be applied only to the Acervularia in tig. 

 VIII. As bis tiist description in Cor. baltica chiefly aims at 

 tbe Acervularia fig. IX, I think it best to keep for that the 

 narae which LiNN^us first gave it or to call it Acervularia 

 ananas. Fig. VIII then represents what has generally been 

 called Acervularia luxurians EiCHWALD p. p. which is distin- 

 guished by its total want of septa within the interiör circle of 

 the calicle, as shown in Fougt's figure. It is probable that the 

 speciraen delineated in figure N:o 2 belongs to a third species, 

 Wahlenberg's Madrepora (^Acervularia) truncata, which is quite 

 another species than Madrepora truucata of LlNN^us. As to 

 the figure IX it is so badly drawn that it is only possible to 

 identify it by means of the description. It very much resembles 

 certain specimens of Syringophyllura. 



I cannot now enter into all the details, accorapanied by 

 the figures necessary to denionstrate that there are at least four 

 quite distinct silurian species of Acervularia in Gotland. 



P. 22, N:o IV. Madrepora composita corp)oribus proliferis 

 e disco plurihus margine coadunatis; stellis fruiicatis, centro 

 cylindraceo-concavis fig. X, n. 3. ^) 



1749 » » Am. Ac. I, p. 93. 



1758 Madrepora truncata S. N. ed. X, 795. 



1761 '' » » F. Su. ed. II, 536. 



1767 » » S. N. ed. XII, p. 1277. 



1768 Madreporus (Helmintholitus) truncata S. N. ed. XII, 



vol. III, p. 167. 

 1820 Strombodes truncatus Schweigger Ilandb. 448. 

 1837 Caryophyllia explanata Hising. Leth. Suecica p. 101, 



pl. 28 f. 13. 

 1851 Cyathophyllum truncatum E. H. Pol. pal. 379. 

 1865 üiplophyllum Ngesianum Kjerulf Veiviser p. 31, f. 



40 (ceteris exclusis). 



') Figure »n. 3» has been reproduced by Dana, Zoopbytes U. S. Exploring Ex- 

 pedition p. 80 and by Quenstedt Petrefaktenkunde Deutschlands, pl. 156, 

 fig. 7. 



