formational status and is, therefore, inappropriately ranked as a member (Hattin, 1962, p. 20). The Fairport ranges from 90 to 118 feet in thickness in the area of this field trip. The Fairport consists chiefly of olive-gray to dark-olive-gray chalk with beds of chalky limestone in the lower part and beds of marly chalk in the upper part. Lenses of skeletal limestone are scattered throughout the middle and upper parts. Terrigenous detritus con-stitutes as little as 15 percent of the shaly chalk, increasing to as much as 50 percent of the rock in the uppermost part of the member. As in the Greenhorn Limestone, many of the widespread layers of chalky limestone and marly chalk of the Fairport have a uniform relationship to marker bentonites across the west-central Kansas outcrop and are thus believed to be essentially time parallel. Occasional but widespread wave agitation of lime mud on the sea floor has been suggested by Hattin (1962, p. 102) as a mechanism underlying the production of widespread limestone beds. Stronger wave or current action produced lag con-centrates of skeletal debris that are now skeletal limestone lenses in the middle and upper parts of the formation. Shaly chalk beds containing remains of few benthonic organisms other than Inoceramus probably represent deposition in quiet, poorly circulated water. Macroinvertebrate fossils in Fairport rocks are little more diversified than in the Greenhorn Limestone, which is of similar thickness and lithology. A largely undescribed group of epizoans occurs widely in the Fairport and is best developed in parts of the section containing skeletal limestone. These fossils, attached to Inoceramus or to one another, in-clude Serpula tenuicarinata Meek and Hayden, Membranipora sp., Proboscina n. sp., Ostrea con-gesta, Stramentum n. sp., and Exogyra sp. (rare). The extensive development of this epifauna in those parts of the section containing skeletal limestone lenses reflects in part the better circulation of bottom waters during formation of the lenses. Slower sedimentation rate is suggested by occurrence of several generations of epizoans on Inoceramus in some localities. Fairport cephalopods include Scaphites patulus Cobban, Actinocamax manitobensis (Whiteaves) (rare), and Collignonicer as wool lgari (Mantell). Inoceramus labiatus (broad form) occurs in the lowest part of the Fairport and grades upward into I. latus Sowerby which occurs throughout the remainder of the member. A new species of sulcate inoceramid resembling I. latus occurs near the top of the Fairport. Abundance of cephalopods, planktonic foraminifers, and carbonate rocks suggests that waters were of normal salinity during deposition of the Greenhorn and Fairport sediments. Blue Hill Shale Member.- The Blue Hill Shale Member ranges in thickness from 168 to 185 feet in the field-trip area. The member consists chiefly of dark-gray silty shale that weathers flaky and is sandy near the top. Zones of septarian concretions characterize most of the member and clay-ironstone concretions occur in two zones in the lower half of the unit. Fine-grained noncalcareous sediment in the Blue Hill represents influx of terrigenous detritus 17