129 



the general surface and open at the bottom of an expanded polygonal cup, 

 showing rudimental septal ridges on the bottom of the calices ; further in 

 Striatopora, the corallites are oblique to the surface of the corallum. The dis- 

 tinction of Striatopora from Favositcs {Pachypora) is by no means easy, when 

 the specimens at hand are worn on the surface ; in thin section, Sti-iatopora 

 cristata is t-asily liable to be confounded with F. reticulata. 



Striatopora eristat i (Blum.) Gurich. 



PI. XII., Fig. 3 ; PI. XIX., Fig. II. 



1S96. Striatopora cristata (Blum.) Gurich : Das Palaeozoicum im Polni- 



schen Mittelgebirge, p. 137. 

 KJ09. 5'. cristata (Blum.) Gurich : Leitfossilien, Devon, p. 105, pL 



XXXIL, figs. 3, 3a. 

 = Favosites or PacJiypora cristata of many authors. 



Two small pieces of ramose coralla are assigned to the genus, on account 

 of their c rillites being set very obliquely to the surface, though another 

 essential feature of the genus — the cup shaped calices with septal striae on 

 the floor — ^is not seen on either of these specimens. The larger specimen of 

 the iwo s 7 mm. broad, and compared with F. reticulatus of the same dia- 

 meter, i' possesses corallites somewhat l irger in diameter and appearing less 

 crowded ; i is in these features that the present examples approach Striato- 

 pora cristata rather than Pachypora reticulata. 



PI. XIX, Fig. II, shows a ramose corallum in cross section from the 

 piece ot h same rock in which the o her two are lound ; it is very probable 

 that the former belongs also to the same species as the latter, though there are 

 no charac eristics by which it is distinguished from P. reticulata in thin sec- 

 tion of :hi same orientation. 



Striaopora cristata, as defined by Gurich, occurs in the Middle Devonian 

 deposiis of Rheinland and Poland ; it is not clear that all or any of the fossils 

 previon.^l- called by the name Pachypora or Favositcs cristata really repre- 

 sent til's sp--cies ; the fossils bearing tliis name are known from Devonian and 

 Gotlandiaii ' ocks of various parts of the world. ' 



