292 Dr. G. J. Hinde — On Solenopora garwoodi, sp. nov. 



the text of the paper. In Fig. 4 of the same plate a dark line is 

 also shown in the longitudinal walls of a Canadian specimen, but 

 it is much thicker and less definite than in Fig. 7. It happens that 

 Fig. 7 was drawn from a section still in my possession, and the dark 

 line shown in this cannot, in my opinion, be interpreted as representing 

 a median partition in the cell-wall, and it is not referred to as such 

 by the authors ' of the paper. 



The second reference is by Professor Rothpletz,* who, in describing 

 a specimen of S. compacta, states that the walls show a distinct, 

 dark, median line, which also marks the exact boundary between 

 two contiguous cells. It reminded him of the dark line in corals ! 

 It is further stated not to be continuous, but perforated at intervals 

 by very fine pores. I strongly suspect that the dark median line 

 mentioned by Rothpletz is of the same character as that in my 

 specimen figured by Professor Nicholson. 



The characters of this species from the Lower Carboniferous fully 

 support the conclusion of Dr. A. Brown ^ that Solenopora is one of the 

 calcareous Algae, and this view is also supported by Professor Seward,* 

 who places the genus in the Corallinacese. 



Distribution. 



S. garwoodi was first discovered by Professor Garwood in limestone 

 rocks of Lower Carboniferous age, which, in his elaborate memoir on 

 "The Lower Carboniferous Succession in the North-West of England ",^ 

 he has grouped together as a separate subzone, with the present 

 species as the index-fossil, and given it the name of the ' Solenopora^ 

 subzone. The fossils are met with at the Abbey Cliff, Shap District ; 

 Stonegill in the Ravenstonedale District ; and Low Meathop in the 

 Arnside District ; and also at other localities in Westmorland. 



EXPLANATION OF PLATE X. 

 Solenopora garwoodi, Hinde. 



Fig. 1. A horizontal section of a nearly complete specimen showing concentric 



bands of growth. x 2 diams. 

 ,, 2. A radial section of a specimen from Shap Abbey, showing the close 



arrangement of the cell-rows, x 50. 

 ,, 3. A similar section from Meathop. x 50. 

 ,, 4. A transverse section of a specimen from Meathop, showing the 



cells. X 50. 

 ,, 5. A transverse section of a specimen from Stonegill. x 50. 

 ,, 6. A radial section of a specimen from Shap Abbey, showing the structure 



of the cell-walls, x 150. 

 ,, 7. A transverse section of a specimen from the same locality, showing the 



structure of the cell-walls. x 150. 

 All the specimens are from the Solenopora subzone of the Lower 



Carboniferous. 



^ Geol. Mag., 1885, p. 533. 



* Svenska Vetensk. Akad. Handl., Bd. xhii. No. 5 (1908), p. 12, pi. 3, 

 figs. 1-6. 



^ Geol. Mag., 1894, p. 203. 



^ Fossil Plants, vol. i, p. 190, 1898. 



* Quart. Journ. Geol. Soc, vol. Ixviii, pp. 449-586, 1912. 



