PARALLELOPORA DARTINGTONENSIS. 199 



now under consideration and that described by Bargatzky as P. Goldfussii, I was 

 formerly disposed to think (General Introduction, p. 104) that we had to deal with 

 a single species only, for which the specific name given by Goldfuss should be 

 retained ; but I am now satisfied that the two are really distinct. This being the 

 case, it will be best to retain Bargatzky's name for the species to which he 

 originally gave it, and to apply provisionally to the present species the title given 

 by Goldfuss. I was also formerly disposed to think (loc. cit.) that this species 

 might be referred to the genus Idiostroma, Winch. ; but a further and more 

 complete investigation has shown that the large and irregular tabulate tubes by 

 which the coenosteum is traversed are really of the nature of astrorhizal canals, 

 and that the proper place of the species is in the genus Parallelopora. 



In the general form of the coenosteum, the characters of the surface, the 

 general structure of the skeletal tissue, the irregular development of the astrorhizae, 

 and the common presence of scattered lenticular or globular vesicles (ampullae ?) 

 of large size, the present species very closely resembles P. Ooldfussii, Barg. It 

 is, however, distinguished from the latter by the very much coarser nature of the 

 ccenosteal tissue ; so that even with the aid of a pocket lens only it is usually easy 

 to separate examples belonging to these two types. All the specimens of 

 P. capitata which I have investigated are more or less highly mineralised ; and in 

 most cases the minute structure of the skeleton-fibre has been largely or wholly 

 destroyed. It is, therefore, rarely possible to fully determine the characters of the 

 skeleton-fibre ; but so far as these can be made out they agree essentially with 

 those distinctive of P. Goldfussii. From P. dartingtonensis, Cart, sp., the present 

 form is at once distinguished by its greatly more robust fibre and the irregular 

 development of the astrorhiza?. 



Distribution. — P. capitata, Goldf. sp., occurs commonly in the Middle Devonian 

 Limestone of Hebborn (Paffrath district), in association with P. Goldfussii, Barg. ; 

 but it appears to be wholly absent at Steinbreche (Refrath), where the latter 

 species is very abundant. The species also occurs, though by no means plentifully, 

 in the Devonian pebbles in the Triassic breccias of South Devon. 



3. Parallelopora dartingtonensis, Garter sp. PI. IV, fig. 1 ; PI. XXIV, figs. 13 



—15 ; and PI. XXV, figs. 1—3. 



Stkomatopoea elegans, Carter. Ann. and Mag. Nat. Hist., ser. 5, vol. iv, p. 263, 



1879 (non Stromatopora elegans, Rosen). 

 daetingtonensis, Carter. Ibid., vol. vi, p. 316, pi. xviii, figs. 1 — 5, 

 1880 (fig. 1 of the plate is doubt- 

 fully referable to this species, and 

 perhaps belongs to Stromatoporella 

 eifeliensis, Nich.). 



27 



