322 CARBONIFEROUS FORMATIONS AND FAUNAS OF COLORADO. 



and possibl}' 2329b belong to the group with 21 septa. To th(! other belong .speci- 

 mens furnished by stations 2202, 2204, 2233, 2241, 22S5, and 2299. I am in doubt 

 about the bearing which more extensive collections would have in the matter of the 

 validity of tiie two groups which my material indicates, whether it would establish 

 them as distinct species or varieties, or demonstrate that the}' are only nuitations of 

 a single radical. I have placed all with the well-known Z. prqfmidimi, but it is with 

 a feeling of dissatisfaction at this disposition. 



LocaVdy and horizon. — San Juan region (stations 2202, 2204, 2222, 22o3, 2241); 

 middle and upper portions of the Hermosa formation. Dolores Kiver region, Sin- 

 bads Valley (station 2285); Hermosa formation. Crested Butte district (stations 

 2299?, 2302, 2319); Maroon formation. Grand River region, Glenwood Springs 

 (station 2329b?). Uinta Mountain region, overlooking Yampa River (station 2191). 



AMPLEXUS Sowerby, 1814. 

 Amplfxus sp. 



Only two specimens of this species have yet been found, both from the San Juan 

 region, but each from a different locality. One, from the mouth of Hermosa Creek 

 (station 2242), is nearly indeterminable, but it jarobably belongs to the same species 

 as the other, which was found near Deadwood Gulch in the Rico quadrangle (station 

 2222). 



The latter is small, conical, and wnere the diameter measures 7 mm. has 18 septa 

 which reach about halfway to the centei'. There is no dissepimental tissue, the 

 remaining cavitj^ being dissected by tabulse. 



The characters shown by this material indicate that it belongs -svith the genus 

 Amplexus rather than with Zaphreiitis or Canvpophyllum. The onlj' known species 

 of Amplexus from the Upper Carboniferous of America is A. saphrentifonnis White, 

 young specimens of which, when sectioned at the same stage, differ materially from 

 the form under consideration. The septa are somewhat more numerous, reach quite 

 to the center, and inclose a large, well-marked fossula. I would scarcely be justified, 

 therefore, in regarding these fossils as representatives of White's species. 



This coral quite strikingly resembles, in some particulars, the* species which 

 Beede described as Anijylexios 'westi," but that form, as Beede has since shown,* is 

 clearly a member of the genus Zophophyllum. 



Locality and horizon. — San Juan region (stations 2222, 2241); middle and upper 

 portions of the Hermosa formation. Crested Butt district (station 2316); Weber 

 limestone. 



a Kansas tJniv. Quart., vol. 7, 1898, p. 17. 



fcOniv. Geol. Surv. Kansas, Kept., vol. 6, 1900, p. IS. 



