ACTINOSTROMA ASTROITES. 143 



(Plate XIV, fig. 2) show that they are formed of laminae which are strongly bent 

 upwards or towards the surface, and which are somewhat wider apart than usual. 

 On the other hand, the intervals between the cylinders are occupied by laminae, 

 which are sharply bent in the reverse direction, and are closer together than else- 

 where. The centres of the cylinders commonly correspond with the axial canals 

 of the astrorhizal systems, and the surface (which I have not seen) would doubtless 

 exhibit prominent " mamelons " corresponding with these. The astrorhizae are 

 small, with few radiating branches, and have their centres placed 5 — C mm. apart. 

 Intermediate forms between these and the preceding group exist, in which the- 

 undulations of the laminae are sufficiently sharp to produce a system of parallel 

 cylinders, but these are small and close together. The forms of this group are 

 the commonest examples of the species in Devonshire, but I have not yet seen any 

 from the Eifel. 



As regards the synonymy of the species I am unable to identify it with 

 certainty with any of the forms described by Bargatzky, or, indeed, with any 

 previously described species except the one which Dr. Maurer (loc. cit. supra) 

 regarded as being Stromatopora concentrica, Goldf. Dr. Maurer was good enough 

 to send me a fragment of the type-specimen of this, and from a macroscopic 

 examination of this I came to the conclusion that it was probably referable to 

 Actino stroma vcrrucosum, Goldf. sp. (" Introduction," p. 26). I have, however,, 

 prepared thin sections and I now find it to belong really to the present species. 



Distribution. — Actinostroma stellulatum appears to be confined to the Devonian 

 formation and is at present only known as occurring in the Middle Devonian. In 

 Devonshire it is by no means a rare species, occurring abundantly at Dartington 

 and Lummaton, and more rarely in the pebbles from the Triassic conglomerates 

 of Teignmouth. In the Eifel it is exceedingly common in the neighbourhood of 

 Gerolstein, and it occurs also at Sotenich, but I have not hitherto recognised it 

 in the Paffrath district. 



7. Actinosteoma astroites, Rosen sp. PL XVII, figs. 1 — 7. 



Stromatopoea asteoites, Rosen. Ueber die Natur der Strotnatoporen, p. 62, 



pi. ii, figs. G aud 7, 1867. (Non Stromatopora 

 astroites, Barg.) 



Actinosteoma ? asteoites, Nich. Ann. Nat. Hist., ser. 5, vol. xvii, p. 229, pi. vi, 



figs. 6—7 a, 1886. 



The coenosteum in this species is massive, or in the form of a thick laminar 

 expansion, and grows in successive strata, or "latilaminae," of varying thickness. 



