S YRING OPORID^E. 



211 



more or less conspicuously infundibuliform, and they become 

 connected with one an- 

 other in such a manner as 

 to give rise to a central 

 cylindrical tube, occupy- 

 ing the axis of the vis- 

 ceral chamber. Whether 

 or not this tube is present 

 in all the species of the 

 genus is a point for future 

 determination; but its ex- 

 istence is clearly recog- 

 nised by Goldfuss (Petref. 

 Germ., PI. XXV., figs. 

 6 b, 7 b), and I have re- 

 cognised its existence in 

 all the forms which I have 

 . as yet examined micro- 

 scopically. In its general 

 form and structure it is 

 precisely similar to the 

 axial tube which is form- 

 ed by the tabulae in the 

 corallites of Syringolites, 

 Hinde ; and the continu- 

 ity of its internal cavity 

 seems to be interrupted 

 (as in Syringolites] by the 

 occasional extension of a 

 tabula across it. Some 

 forms of Syringopora are 

 stated to possess horizon- 

 tal tabulae, but the true 

 structure and position of these will require to be more fully 

 worked out before this can be finally admitted. 1 



1 Ludwig (Pal. des Urals, p. 10, 1862) has endeavoured to revive the genus 

 Harmodites, Fisch., as distinct from Syringopora, Goldf., upon the ground that 



Fig. 30. A, Part of a longitudinal section of Sy- 

 ringopora reticulata, Goldf., from the Carbonifer- 

 ous Limestone of Kendal, Westmorland, enlarged 

 five times, showing the spiniform septa and the 

 funnel-shaped tabulae with their central tube. 

 Owing to the flexures of the corallites, the section _ 

 cuts the tubes in different parts, sometimes passing 

 close to the wall and showing the cut ends of the 

 spiniform septa, sometimes passing through the 

 axis of the visceral chamber and bisecting the 

 axial tube, and sometimes cutting the axial tube 

 and its enveloping tabulae in an oblique manner. 

 B, Part of a transverse section of the same speci- 

 men, enlarged five times, showing the spiniform 

 septa, and the cut edges of the tabulae surrounding 

 the central tube. 



