222 THE DEVONIAN OF MISSOURI. 



Subclass Hexacoralla 



Suborder Tabulata 



Family Favositidae 



Genus Favosites 



Favosites cf. helderbergiae Hall 



Plate 57, figure 8. 



1874. Favosites helderbergiae Hall, N. Y. State Mus., 26th Ann. Rept., p. 111. 

 1887. Favosites helderbergiae Hall, .Nat. Hist. N. Y. Pal., vol. 6, p. 8, pi. 4; figs. 1 ; 2; 



pi. 5, figs. 1-3; pi. 6, figs. 1-8. 

 1913. Favosites helderbergiae Swartz, Geol. Surv. Md. Low. Dev., p. 208, pi. 22, fig. 1, 



Description — "Corallum consisting of large, lenticular, depressed, convex or hemis- 

 pherical masses; base covered by a strongly wrinkled epitheca. Cell tubes polygonal; 

 their inner surface showing evidence of a few strong longitudinal striae. Septa frequent, 

 from 10 to 15 in the space of 10 mm.; thickness equal to that of the cell walls. Mural 

 pores in one or two ranges, comparatively large, circular, with margins distinctly elevated. 

 Cell walls thin, but frequently much thickened near the surface by silicification, and 

 sometimes granulose or spinose on the inner face. On some specimens the cells, at the 

 surface, are nearly equal, having a diameter of about 1.5 mm.; on other specimens the 

 diameter varies from .66 to 1.5 mm. On many of the specimens some of the cell tubes 

 are larger and less angular than those surrounding them, being a little more than 2 mm. 

 in diameter.— "Hall, 1887. 



Remarks — A few specimens have been observed in the Little Saline limestone which 

 are doubtfully referred to this species. The specimens are fragmentary and in no case 

 show the hemispherical outline which characterizes the corallum of the species. The 

 corralites are prismatic, polygonal, more rarely hexagonal. The mural pores are irregu- 

 larly disposed, at least two rows being present. Longitudinal striae not observed. The 

 diameter of the cell tubes varies considerably*,' some of them being as large as 2.5 mm. 

 in diameter. 



Horizon. — Lower beds. 



Figured specimen No. 27554 Walker Museum. 



Favosites sp. undet. 

 Plate 57, figures 9, 10 



There are present in the collection studied, several impressions of the epitheca of 

 the concave bases of the Favosites. They do not exhibit any diagnostic characters, and 

 are recorded only to show the presence of this type of coral in the Little Saline limestone 

 A tentative comparison may be suggested with Favosites foerstei as figured by Dunbar, 

 from the Tennessee beds, with this difference, that Favc sites foerstei is characterized by 

 convex bases, while the Little Saline form is concave. 

 Horizon — Lower beds. 



Figured specimen No. 27551 Walker Museum. 



