168 BRITISH STROMATOPOROIDS. 



Nich. The species described by Lonsdale (' Sil. Syst.,' p. 680, pi. xv, fig. 31, 

 1839) as S. concentrica is really Clathrodictyon striatellum, D'Orb. sp. The form 

 described under this name by Phillips (' Pal. Foss. of Cornwall, &c.,' p. 18, pi. x, 

 fig. 28, 1841) appears to be an example of a hitherto undescribed Stromato- 

 poroid which occurs commonly in the Devonian Limestones of Devonshire, and 

 which will, I think, prove to be referable to the genus Hermatostroma. At any 

 rate, the 8. concentrica of Phillips is certainly quite distinct from the form which 

 rightly bears this name. The fossil noted by M'Coy from the Carboniferous 

 Limestone of Ireland (' Synopsis of the Carb. Foss. of Ireland,' p. 193, 1844), 

 under the name of 8. concentrica, Lonsd., is described with extreme brevity and is 

 not figured, so that its true nature is wholly doubtful, though it may be taken 

 for certain that it is not the present species. On the other hand, the fossil 

 described by M'Coy from the Devonian Limestones of Devonshire as 8. concentrica, 

 Goldf. (' Brit. Pal. Foss,' p. 65, 1851), is clearly an Actinostroma, and is probably 

 identical with A. clathratum, Nich. The S. concentrica of Bargatzky (' Die 

 Stromatoporen des rheinischen Devons, p. 54, 1881) is unquestionably the form 

 which I have described under the name of Actinostroma clathratum, and has no 

 relationship with the 8. concentrica of Goldfuss. Under the name of S. concentrica, 

 Goldf., Prof. Ferd. Roemer (' Leth. Pal.,' p. 538, 1883) includes a number of dis- 

 tinct species of Stromatoporoids of Devonian age, and it is not possible to deter- 

 mine how far his descriptive remarks really apply to the true S. conceyitrica of 

 Goldfuss. The figures which accompany his description (loc. cit., Atlas, Taf. 

 xxvi, figs. 3a, 36) would seem to be probably referable to Actinostroma stellu- 

 latunt, Nich. The form identified as 8. concentrica, Goldf., by Dr. Maurer ('Die 

 Fauna der Kalke von Waldgirmes,' p. 108, Taf. ii, figs. 12, 13, 1885) is referable 

 in reality to Actinostroma stellulatum, Nich., but is very badly preserved. Lastly, 

 the form described as 8. concentrica, Goldf., by Freeh ("Die Korallenfauna des 

 Oberdevons," ' Zeitschr. d. deutschen geol. Gesellschaft,' p. 116, Jahrg., 1885) is 

 also an Actinostroma, and is apparently partly referable to A. clathratum, Nich., 

 and partly based on A. verrucosus, Goldf. sp. 



Distribution. — Stromatopora concentrica, Goldf., so far as at present known, is 

 a purely European species, and is entirely confined to the Devonian Rocks. The 

 normal form of the species occurs, not uncommonly, in the Middle Devonian 

 Limestones in the neighbourhood of Gerolstein, and occurs also at Sotenich, but 

 seems to be absent from the limestones of the Paffrath area. In Britain, the 

 typical form of the species occurs in the Middle Devonian Limestones of 

 Lummaton, in Devonshire, in strictly characteristic examples. It is also found 

 in the Devonian pebbles of the Triassic conglomerates at Teignmouth ; but 

 it is always a rare form. The form which I have called 8. concentrica, var. 

 colliculata, is common at Gerolstein, commoner, in fact, than the normal form of 



