' Lower Helderberg Fauna. 297 



large and conspicuous. The nucleus of an astrorhizal system is 

 sometimes represented by an axial tube, and the laminaB at that 

 point are often elevated into a low monticule. Skeletal tissue 

 finely fibrous, but a little coarser than in S. centrotum. 



This species is characterized by the infundibuliform cpncentric 

 growth and the flat base without an epitheca (?). Without the 

 aid of thin sections, the outer surface of the type specimen ap- 

 pears dense, fine-grained and structureless, except for latilaminae 

 which separate in unusually thin sheets. Sections near the sur- 

 face are without monticules, astrorhizse, and axial tubes, exhibit- 

 ing only the uniform, porous skeleton and fibrous structure. 

 The same surface characters are presented by the basal portion 

 and suggest an epithecate condition, but it has not the polished 

 surface and concentric wrinkles characteristic of the epitheca in 

 Fayosites. The flat base of the specimen is attached to a branch- 

 ing form of DiPLOPHYLLUM. Syringostroma JBarretti is the com- 

 mon species at the Indian Ladder. 



Horizon. — Lower Pentamerus limestone. 



Locality. — The Indian Ladder, IST. Y. 



Syringostroma oonsimile, sp. nov. 

 Plate VII, figures 3, 4. 



Coenosteum massive, large, and subspherical. Latilaminate 

 structure shown by sections or on weathered surfaces. The lam- 

 in se are disposed in pointed, wave-like folds, which are not super- 

 imposed. Skeleton-fiber finely porous; tissue reticulate; astro- 

 rhizee few and very large, sometimes provided with a tubular 

 axis. 



This species is similar to S. Barretti, but the material examined 

 can be separated with little difficulty by the character of the 

 laminae, which, in the latter, are gently curved, proximate, and 

 parallel, but in S. coiisimile are angular and independent in their 

 flexures. Thus, S. consimile generally lacks the superimposed 

 monticules of the kindred form. The reticulations of the skele- 

 ton-fiber are somewhat coarser than in S. Barretti, and very 

 much coarser than in S. centrotum^ while the thinness of the 

 laminae is also characteristic. The figure which presents a ver- 

 tical section of this species is drawn to slightly too large a scale, 

 making the columno-lamellose structure of the cut more open 



