1886.] 339 [Davis. 



Professor W. T. Sedgwick spoke of the excretory contractile 

 vacuoles of Paramoecium. Pay Lankester's figures descriptive of 

 the progress of diastole and systole are quite faulty and their true 

 character was shown by drawings and diagrams. 



General Meeting, Dec. 15, 1886. 



The President, Mr. S. H. Scudder, in the chair. 

 Dr. E. G. Gardiner sketched the history of our knowledge of the 

 pineal eye in lizards, and reviewed a recent paper on the subject 

 by Mr. W. Baldwin Spencer, in the Quart. Journal Micr. Sc.,Oct., 



1886. 



Prof. W. M. Davis presented the results of a study on the mechan- 

 ical origin of the Triassic monoclinal in the Connecticut Valley. 

 The present attitude of the Triassic formation in the Connecticut 

 valley may be described as a faulted monoclinal ; the dip is nearly 

 always eastward, fifteen to thirty degrees, but the continuity of the 

 strata is interrupted by the occurrence of numerous faults, running 

 nearly parallel with the strike of the beds, and with upthrow of vari- 

 able amount on the east. The formation is thus divided into long, 

 relatively narrow blocks trending from west of south to east of 

 north, the strata in all the blocks being canted to the east. The 

 repetition of beds, caused by the upthrow of the faults, is always 

 on the side of the direction of the dip, and thus allows a mod- 

 erate thickness of strata to cover a broad surface, greatly simplifies 

 the scheme of eruptive action by correlating many different trap 

 ridges as the outcropping edges of only four or five trap sheets, 

 and gives a systematic structural interpretation to a complicated 

 topographic form. 



The mechanical origin of the faulted monoclinal offers an inter- 

 esting problem for investigation. It cannot be referred to original 

 oblique deposition, because heavy conglomerates occur on the east- 

 ern margin of the formation, dipping toward the ledges from which 

 they were derived. A disturbance contemporaneous with the pro- 

 cess of deposition is excluded by the occurrence of faults, which 

 require continuity of their corresponding members across broad 

 areas before the disturbance took place. The monoclinal attitude 



