272 OAKHONlFKKon^ FORMATIONS AND KAUNAS OV OOLOKADO. 



J/c/i(>j->/ii///iiiii (ilrichi.uiiini, iiuiv lie de.sc'ribcd ;i.s follows: Coriiiluin .simple;, lur- 

 binate, small, rapidly expanding, and rather strongly curved. Marked by numerous 

 irregularities of growth, resulting in concentric expansions and coiistrictioiis. The 

 principal septa are thin and about 4-8 in number. There are smaller secondary septa 

 alternating witli them, which are, however, not to be observed below the calice. 

 The septa below the calyce are so thickened with stereoplasma as to form a nearly 

 solid mass, and the constituent rays on this account can there scarcely be counted. 

 Dissepimental tissue and tsibuliv appear to be entirely wanting. The principal 

 fossette is large and joins the convex side of the corallum. The secondaiy fossuhc 

 a-re much smaller, but the tripartite arrangement of the septa is a distinctly marked 

 chai'acter. There are 13 principal septa in the divisions on either side of the 

 principal fossette and 22 in the division directly opposite it. The numbers here 

 given, as well as the total number cited above, are derived from the calycinal cast 

 figured on Plate I. In other examples of no greater size the numbei' of septa 

 developed, both primary and secondarj', is fully one-fourth greater than in this 

 example. There seems to have been a solid (?), elevated, concentric platform in 

 the center of the calice into which the principal fossula was- deeply and strongly 

 excavated. The corallum walls on the inside between the septa seem to have had a 

 finely and regularly pitted surface, as is seen from the pustulose edges of a siliceous 

 internal cast (fig. 2) of the calice of a specimen belonging to this species. 



M. uhfichanum is smaller than M. esacavaUmi, more rapidly expanding and more 

 strongly curved. It also differs in the much greater number of its principal septa. 



Simpson has recentlj' described two genera of Zaphrentoid corals which appear 

 to be closely allied to Meiiophyllum. I refer to ^feniscopkyllwm and Trijjlojthyllwni . 

 The resemblance is so strong, in fact, as to suggest that the latter, if not the former, 

 is a synonym for Edwards and Haime's genus. 



I avail myself of this opportunity' to rectif j^ an error into which I fell in the 

 course of describing the Devonian fauna of the Ouraj' limestone, the only one which 

 it was at that time known to contain. 



Corals were obtained from the Ouray limestone at two stations. At one of 

 these in the Crested Butte quadrangle (Gunnison 145a) they were found associated 

 with the characteristic Ouray fauna. The other station was in the Durango quad- 

 rangle and the horizon occurred at the top of the Oura}^ limestone. In this case 

 these fossils were found taj- themselves, uuassociated with other species. Not kno^^■- 

 ing at that time that the upper portion of the Ouray limestone, locally at least, repre- 

 sented Mississippian time and contained a characteristic fauna of that age, I included 

 these fossils in the Ouray fauna. 1 furthermore included those from both localities 

 under a single heading as Streptelasmas^^.^fiCiYm^ to observe diderences which are 

 clearly seen on reexamination. The specimens from the top of the Ouray from the 



