402 CARBONIFEROUS FORMATIONS AND FAUNAS OF COLORADO. 



On the other hand Davidson" while describing tiic surface of «Sp. octopUcata 

 Sow. ;is pustulose, refers it to Sj). criMafa in a varietal relation. Supposing that 

 Davidson knew the characters of the real crlsfaf.a, one would from this be led to infer 

 that the latter was also of the pustulose division of the genus. SimilarW the form 

 identified h\ King* as Sp. cristata in his monograph on the Permian fossils of Eng- 

 land, seems to be at least a coarsely punctate, and possibly a pustulose species. Some 

 of his expressions undoubtedly refer to the punctate structure of the shell, but others 

 perhaps involve the surface ornamentation. Furthermore he states: *" "Having 

 examined in Mr. J. de C. Sowerby's collection the oi'iginals (from Derbyshire) of 

 the figures in the 'Mineral Conchology' [of Sp. octoplicata\ the only difference 1 could 

 perceive is that they are wider than any examples which have occurred to me of the 

 present species." Since King noticed characters so minute as the punctate shell 

 structure, it seems probable that the less microscopic surface ornamentation would 

 not have escaped his observation, and as Davidson, who also examined the original 

 specimens of Sp. octopJleata, describes that species in such terms as to leave no doubt 

 that it belonged to the spinose type of spiriferinas, as just noted, it would appear 

 that the shells which King believed to be identical with Schlotheim's species wei'e also 

 of the same character. 



If 82). cristata belongs to the spinose section of the genus, there can be no doubt 

 that 8p. hentuchyensis is specifically distinct. If, on the other hand, it is of the 

 type of Sp. kenttickyensis^ I still believe Shumard's species to be worthy of at least 

 varietal position. A comparison of well-characterized specimens of Sp. kentucky- 

 ensis with our European material, which is premised to truthfully T'epresent 

 Schlotheim's species, reveals seven'al points of difference. The most constant and 

 important of these seem to be the following: Sp. cristata is typically rounded at the 

 hinge extremities and appears rarelj% if ever, to have the cardinal diameter pro- 

 longed into mucronate points, as is frequently the case in the American species. Its 

 plications are sharper and higher, and the furrows dividing them deeper than in our 

 own form, while the concentric imbricating strise are never, even when most closely 

 set, as evenly disposed and as thickly crowded. 



While Spiriferina kentuckyensis is perhaps no more than varietally distinct from 

 the material from Posneck identified as Sp. cristata, because I am still somewhat in 

 doubt, for reasons given above, as to what the surface ornamentation of typical Sp. 

 cristata really is, Shumard's name is provisionally retained in full specific import. 



Locality and Iwrizori. — San Juan region (stations 2220, 2322); middle portion of 

 Hermosa foi'mation. Crested Butte district (station 2295) ; Maroon formation. Uinta 



a British Fossil BracMopoda, vol. 2, 1858-63, p. 38. 

 6 Monograph Permian Foss. England, 1850, p. 127. 

 oLoc. cit., p. 128. 



