2(', PAL.EONTOLOGY. 



seen in tninsvense sections, subti-igonal or subrlionibic, and sei)arated by 

 walls etiualing their smaller diameter in thickness; apparently not very 

 obliqne at their terminations to the general sni-face, and showing (at least 

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

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

 anil 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. valloruni), 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 ti-ansverse 

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

 these ))arts not having been seen in that coral. 



T'ompared with European species, it seems to be in some respects 

 allietl to A. suhorhicularis, Lamarck, from the Devonian i-ocks of France, 

 and A. retkulatiis, Steiningei-, fi-om rocks of the same age in France and 

 (iennany. 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 tabulre are much more numerous and more 

 crowded. Its calices are a size larger than tluwc of A. rcHciilatits, and sepa- 

 rated l)y thinner Avails, thev also seem to be less obli(ine. 



LocaV.ti) ami position. — Argyle Hill, White Pine District, Nevada; 



Dev..uian. 



Alvkomtks (iiiidt. s]).) 



From near the same localitv, there is, in the collection, fi'om the Devo- 



