26 PALEONTOLOGY. 



seen in transverse sections, subtrigonal or subrhombic, and separated by 

 walls equaling their smaller diameter in thickness ; apparently not very 

 oblique at their terminations to the general surface, and showing (at least 

 in sections) a small tooth-like projection at the middle of the outer wall. 

 Longitudinal sections showing the tabulae to be numerous, extremely thin, 

 and not always exactly transverse or parallel to each other, but nearly so, 

 and arranged somewhat regularly at intervals of only one-hundredth of 

 an inch apart. Mural pores comparatively rather large, and regularly 

 arranged, so that six of them may be counted in a space of one-tenth of 

 an inch. 



In the size and form of its calices, as well as in its massive growth, 

 this species is nearly allied to a coral described by the writer (under the 

 name A. vallorum), found by Mr. Kennicott at "the Ramparts" on Macken- 

 zie River, near Fort Good Hope, Arctic America (see Trans. Chicago 

 Acad. Sci., I, 86, pi. xi, fig. 9). It differs, however, in having its calices 

 slightly larger, and not ranging near so obliquely to the general surface ; 

 the tubes formed by their continuous growth being much straighter, and 

 more nearly parallel with each other, or only slightly radiating, instead of 

 being very oblique and curving about in all directions. Whether or not it 

 agrees with the Arctic species in the arrangement of its numerous transverse 

 septa or diaphragms and its mural pores, I have been unable to determine ; 

 these parts npt having been seen in that coral. 



Compared with European species, it seems to be in some respects 

 allied to A. suhorhicularis, Lamarck, from the Devonian rocks of France, 

 and A. reticulatus, Steininger, from rocks of the same age in France and 

 Germany. From the first, it differs in its massive instead of encrusting 

 mode of growth, as well as in its thicker walls between the calices, which 

 latter are also smaller ; while its tabulae are much more numerous and more 

 crowded. Its calices are a size larger than those of A. reticulatus, and sepa- 

 rated by thinner walls, they also seem to be less oblique. 



Locality and position. — Argyle Hill, White Pine District, Nevada ; 



Devonian. 



Alveolites (nndt, sp.) 



From near the same locality, there is, in the collection, from the Devo- 



