flattened valves of I. pictus and a few molds of a small ammonite, possibly Eucalyoceras, and, in one locality, excellently preserved pedunculate cirripeds of the genus Stramentum, comprise nearly the entire fauna in the middle part of the Lincoln. Over much of central Kansas, Lincoln deposition terminated with accumulation of a zone of skeletal limestone lenses composed chiefly of remains of Inoceramus and probably representing a brief return to depths shallow enough to permit occasional reworking of bottom deposits by wave action. Concentration of debris originally scattered widely through the sediment resulted from this renewed turbulence. Hartland Shale Member.- The term shale, in the usual sense of fissile clayey rock, is inappropriate for the Hartland which consists dominantly of laminated olive-black chalk with scattered beds of lighter colored chalky limestone as much as 0.9 foot thick and a few beds of bentonite. Some of the chalky limestone beds are demonstrably time parallel because they maintain a uniform relationship to marker bentonites. The member is 29 to 32 feet thick in the immediate vicinity of the field trip. During Hartland deposition environmental con- ditions were generally inhospitable to benthonic forms of life, possibly owing to the smothering effect of fine-grained sediment, or to poor circulation, or to both of these fac- tors. The chalky limestone beds are believed to have resulted either from periods of better circulation, perhaps during storms, or from periods of slower sedimentation. Such beds are generally more richly fossiliferous than the intervening chalk units and commonly contain numerous burrow structures. Inoceramus pictus dominated the sea floor through much of Hartland deposition, although Inoceramus labiatus (Schlotheim) characterizes the uppermost part of the member. A lime- stone bed lying near the middle of the member contains Cerithiopsis sp. and Pteria sp. Otherwise, the Hartland macroinvertebrate fauna consists entirely of cephalopods including Kanabicer as kanabense (Stanton) (sparse), baculitids [including a few specimens identified as Sciponoceras gracile (Shumard)], Worthoceras vermiculum (Shumard) (sparse), Allocrioceras pariense (White), and Metoicoceras whitei Hyatt. Jetmore Chalk Member.- The Jetmore Chalk is 20 to 21 feet thick in the field-trip area and is similar lithologically to the Hartland but contains more numerous, more closely spaced, mostly thicker and more prominent beds of chalky limestone. The chalky limestone beds are dark olive gray where fresh but commonly are weathered to some shade of orange. The chalky limestone beds appear to be time parallel because of uniform position with respect to marker bentonites and appear to have originated in essentially the same manner as those in the Hartland. As in the Hartland, the limestone beds are generally more fossiliferous than the intervening shaly chalk beds. The conspicuously burrowed character of nearly all of these limestones suggests periods of better circulation which favored development of the extensive mobile infauna that produced the numerous burrow structures. The upper half of the member contains a profusion of Inoceramus labiatus valves which seemingly reflect optimum 15