﻿208 



BRITISH STROMATOPOROIDS. 



respective interlaminar spaces. Irregular tabulate zooidal tubes, usually extend- 

 ing from one interlaminar space to the next above only, may be present. Tan- 

 gential sections (Plate XXVII, fig. 8) show an irregular and imperfect reticula- 

 tion, the more complete tracts of which (where the section is most completely 

 coincident with the plane of a concentric lamina) exhibit the rounded apertures 

 of the irregularly divided zooidal tubes. 



Obs. — This species is most nearly related to 8. solitaria, Nich., from which it 

 is distinguished more particularly by the markedly greater thickness of the 

 skeleton-fibre, and the greater density of the coenosteal network thence resulting. 

 The astrorhizal system is also not so highly developed in 8. damnoniensis as it is 

 in 8. solitaria. From 8. eifeliensis, Nich., the present species is distinguished by 

 its wholly different mode of growth, by the much more rudimentary condition of 

 the astrorhizal system, and by the more solid character of the skeleton-fibre. 

 There are no other species of the genus Stromatoporella, as yet described, with 

 which 8. damnoniensis could well be confounded. 



The external characters of 8. damnoniensis are imperfectly known, as all the 

 British examples hitherto recognised have been derived from the Triassic con- 

 glomerates of Devonshire, and the few German specimens which I have collected 

 are in a state of poor preservation. 



Distribution. — Rare in the pebbles of Devonian Limestone in the Triassic 

 conglomerates of Teignmouth. Also in the Middle Devonian Limestones of 

 Sotenich, in the Eifel. 



5. Stromatopokella. eifeliensis, Nicholson. PI. IV, fig. 2 ; PI. VII, fig. 3 {non 



fig. 4); PI. XI, figs. 1 and 2; 

 PI. XXVII, figs. 1—3. 



Stromatopobella eifeliensis, Nicholson. Mori. Brit. Strom., part 1, 1886 



(named and figured, but not 

 described). 



— — — (pars). Ann. and Mag. Nat. Hist., 



ser. 5, vol. xvii, p. 235, pi. viii, 

 fig. 5 (non figs. 6 and 7), 1866. 



The coenosteum in this species is encrusting and parasitic, and is attached by 

 the whole of the lower surface to some foreign body, the thickness of the crust 

 varying from one millimetre up to 1^ centimetres. The laminse are straight or 

 gently curved, and the surface is therefore smooth and destitute of " mamelons." 

 The astrorhiza? are exceedingly well developed, greatly ramified (Plate XXVII, 

 tig. 1, and Plate IV, fig. 2), and often of remarkably large size, their centres 



