imjperfecily -known Species of Stromatoporoids. 237 



sitically with the curious coral which has been described by 

 Prof. Ferd. Roemer under the name of Ghcetetes stromato- 

 ■poroides. 



Stromatoporella damnoniensis^ Nich. 

 (PL Vlir. figs. 3 and 4.) 



Coenosteum massive, or in thick laminse (?). Surface un- 

 known. Astrorhizai undoubtedly present, and furnislied with 

 vertical canals from which they spring, but apparently much 

 less developed than in 8. eifeliensis. Skeletal tissue exceed- 

 ingly thick and minutely tubulated. Concentric laminjB very 

 thick and with correspondingly narrow interlaminar spaces. 

 About three concentric laminaj and two interlaminar spaces 

 may occupy the vertical space of 1 millim., the laminae and 

 intervening spaces being of approximately equal thickness. 

 Radial pillars confined to their respective interlaminar spaces. 

 Irregular, tabulate zoijidal tubes, usually extending only from 

 one interlaminar sj^ace to the next above, are present. 



Ohs. This species is closely allied to 8. eifeliensis^ but 

 seems to be sufficiently distinct to deserve a special name. 

 Its special cliaracteristics, as compared with the latter, are its 

 extraordinarily thick skeleton- fibre, its possession of irregular 

 tabulate zooidal tubes, and the smaller development of the 

 astrorhizge. 



Formation and Locality, Middle Devonian, Devonshire 

 (Teignmouth). Also in the Middle Devonian of the Eifel 

 (Sotenich). 



Stromatoporella arachnoidea, Nich. 

 (PI. VIII. figs. 1 and 2.) 



Coenosteum thin and laminar, the specimens examined 

 apparently having a basal epitheca, and being about 1 centim. 

 in thickness. Well-developed astrorhizaj are present, with 

 " astrorhizal tabulse," and having axial vertical canals, which 

 open on the surface by prominent conical eminences. 

 General structure of the skeleton as in Stromatoporella eifeli- 

 ensis^ the skeleton-fibre not being excessively thickened, the 

 radial pillars being confined to their respective interlaminar 

 spaces, and definite zooidal tubes being very imperfectly 

 developed or wholly absent. The " concentric laminoe " are 

 very well marked, and are placed about \ millim. apart. The 

 interlaminar spaces are crossed in every direction by numerous 

 delicate curved vesicular " tabula " or calcareous partitions. 



Ohs. This species presents externally nothing special to 

 separate it from 8. eifeliensis^ except that the specimens I 

 have seen have much more irregular astrorhiz® than the 



Ann. & Mag. N. Hist. Ser. 5. Vol. xvii. 17 



