272 VV. II. SHERZER — THE GENUS CHONOPHYLLUM. 



ure, surrounded by successive routings of the carbonate. The silica must 

 have been deposited from infiltrating water 'previous to the deposition of 

 the calcium carbonate. 



5. Thin sections, under polarized light, show a uniform mass of fine, 

 interweaving crystals, many of which have their axes turned in the same 

 direction, so that upon revolving the microscope stage the field extin- 

 guishes in large irregular patches. Sections of Strombodes alpt -m nsis are 

 identical in appearance, while those from the Acervularia above mentioned 

 differ only by being more coarsely crystalline. 



6. Portions of specimens, especially through the center, have been 

 t'i >und from which the deposit is absent. It is not improbable that diligent 

 search may bring out specimens from which it is entirely so. 



This species is separated from all others by its more irregular growth, 

 by more numerous septa, which are decidedly twisted at the center, and 

 by the solid deposits of calcium carbonate. 



8. Chonophyllum sedaliense, White. 



Chonophyllum sedaliense, White. Cont. to Paleontology* 1880, Nos. 2-8, 



]>. 157. pi. 39, fig. la. 



The original description of this species reads thus : 



"Corallum moderately large, approximately straight, the angle of divergence of 

 its Bides being quite small; calyx apparently rather shallow; rays numerous; sur- 

 face rough by the presence of numerous projecting successive calyx-borders, and by 

 coarse, irregular longitudinal strige. Only one example has been obtained, and thai 

 lias been broken off at the lower end, and also somewhat crushed. Its full length 

 was probably about 130 millimeters, and the diameter of the calyx about 30 milli- 

 meters. 



"Position and locality. Near the top of the Chouteau limestone (Kinderhook 

 division of the Subcarboniferous series), Sedalia, Mo., where is was obtained by 

 Professor G. C. Broadhead." 



The figure given bears some general resemblance to that of Chonophyllum 

 elongatum, E. and H. 



Some half dozen specimens of this form, kindly sent by Professor 

 Broadhead, are now before me. They have a conico-cylindrical growth. 

 strongly curved near the base, and are all more or less compressed. The 

 specimen in which the structures are best preserved had an exceptionally 

 long cylindrical growth, this fragment being 14.5 cm in length and as 

 broad at one end as at the other (3.5 to 4 cm). A polished cross-section 

 shows 17<» very thin, alternating septa, the primaries reaching the center, 



* Extracted from the 12th Ann nil Reporl ol the U.S. Geol. and Geog. Survey of tin- Territories for 

 the year 1878. 



