358 



referred. Tliey have the form of crinoidal columns, but are not jointed. 



No structure can be made out in thin slices under the microscope. 



2. Rliabdaria fiircata. — A single specimen of this species only has 

 been collected. The principal stem is three lines in thickness, and it 

 sends off a number of branches at angles varying from 15° to 30°. The 

 branches seem to be connected in one place by lateral processes as in 

 Syringopora. 



CaLATHIUM ? PAKADOXICUM. (N. Sp.) 



Fig. 345. 



Fig. 345. — CtdatHum? paradoxicum. Side view of the upper extremity of a large 

 specimen. 



Description. — The specimen above figured is a fragment of the upper 

 extremity of an individual which, when perfect, was probably six inches or 

 more in length, and three inches across at the top. It is perfectly sepa- 

 rated from the matrix, but split in two longitudinally, giving a vertical 

 section on the side opposite that figured, but showing no structure except 

 an obscure concentric lamellar arrangement near the outside. It is com- 

 posed of compact chert or quartz. The lower half is cylindrical, slightly 

 tapering. The upper half suddenly expands, and has two projecting lobes 

 at a and 6, each of which appears to be the base of a branch. On the 

 surface of the lower half there are a number of somewhat prominent 

 rounded longitudinal ridges. 



