36 C. S. PROSSER — PERMO-CARBONIFEROUS AND PERMIAN ROCKS. 



4. ITustedia mormonii {Mar con), 1^. Sind C (rr) 



5. Froductus longispinus, Sowerby. {rr) 



6. Cladodus mortifer, Newberry and Worthen. (rr) 



7. Orthoceras ^ sp. {rr) 



This fossiliferous shale undoubtedly represents bed 34 of Meek and 

 Hayden. Below this horizon and near the base of the quarry on mount 

 Prospect is a yellowish calcareous shale, probably in bed 37 of Meek and 

 Hayden, which contains Spirifer {Martinia) piano convexus, Shum. ; Pro- 

 ductus cora, d'Orbigny; Athyris suhtilita (Hall), Newberry, and other 

 species. 



BASE OF SWALLOW'S PERMIAN. 



Bed 27 of Meek and Hayden. — The lowest prominent terrace of the 

 bluffs in the vicinity of Manhattan is composed of the drab, hard lime- 

 stone which is mentioned as forming the top of number 3 of my section. 

 It is well shown at the northern end of mount Prospect, as well as on Blue 

 mount. This stratum is probably number 27 of Meek and Hayden's 

 section, which is described as a " gray limestone, often fragmentary, with 

 much clay above; lower part hard and more or less cellular in middle," 

 exposed near Ogden Ferry and Manhattan ; and, taking into considera- 

 tion the thickness which they give for the intervening beds, about 58 feet 

 above the Rhynchonella uta (Marcou), Meek, zone.f 



"Z)r2/ Bone Limestone^^ of Swallow. — This stratum is an important one in 

 Professor Swallow's section, as it forms the base of the rocks which he 

 called the lower Permian. The beds of this part of his section are well 

 described and may be readily identified in the region about Manhattan. 

 This drab limestone was called the " Dry bone limestone, brown, con- 

 cretionary and cancellated limestone, 5 feet, Synocladia biserialis, Spirifer 

 planoconvexa,^^ etcetera, at Manhattan and Mill creek. Next above this 

 stratum Swallow gave one foot of bluish brown marls, and then bed 

 number 82 : 



"Cotton rock, 5 feet; a light cream-colored argillo-magnesian limestone; some- 

 times in thin beds, with shale partings." t 



This stratum is well exposed at numerous places near Manhattan, as 

 at the northern end of mount Prospect, along the Manhattan-Ogden 

 road west of Wild Cat creek, etcetera, and is quarried to some extent for 



*This specimen is somewhat similar to figure 5, plate 30, vol. 5, Geo!. Surv. of Illinois, which is 

 not identified specifically. 



t My barometric section of mount Prospect gave me about 45 feet; but, on account of the rapid 

 changes in the barometer that day, I am not confident of the approximate accuracy of this read- 

 ing Consequently I am quite willing to admit the thickness of these beds to be greater than 45 

 feet, although I fancy 58 feet is an overestimate of their actual thicl^ness as shown in the vertical 

 section near the top of mount Prospect. 



X Pre!. Rep. Geol. Survey Kansas, p. 16. 



