MUSEUM OF COMPAKATIVE ZOOLOGY. 83 



of the Southington plain is obtained ; it is broadly drift-covered. No 

 interruption in the ridge is discovered for a mile and a half ; then near 

 the outlet of. Southington reservoir (2) two small notches are found, in- 

 dicating dislocations vpith heave of seventy and eighty feet; these are 

 probably connected with the indentations in the main ridge to the 

 northeast, which bear about N. 50° E. from the notches. Another mile 

 •without interruption brings us to the Shuttle Meadow fault, Fig. 3 be- 

 ing repeated in Fig. 13; the bluff of the northern member of the an- 

 terior should be followed around its edge into the fault valley in order 

 to appreciate the regularity of its curve. Three small dislocations ap- 

 pear in the North High Rock block, next beyond : and near the third one, 

 fragments of vesicular trap are found in the shaly beds in the road (3). 

 Advancing a little farther, an oblique valley (4) between North and 

 South High Rocks is disclosed ; if it is located on a fault, and if the 

 fault belong to the prevailing system, a dislocation in the anterior ridge 

 should be found when we have gone far enough southward to give the 

 oblique valley a bearing of about N. 60° E., and the dislocation should 

 be of the Shuttle Meadow pattern. At the expected point, the anterior 

 bluff curves around and ends in a ravine (5), across which another bluff 

 of the same form begins at a little higher level, indicating an uplift of 

 say a hundred feet. The oblique valley between the High Rocks cannot 

 be distinguished until the ravine is followed up towards the road ; then 

 its bearing is found to be closely parallel to that of the faults near by. 

 The impure limestone that is fQund at a number of points in the region 

 on the back of the anterior is exposed in an old quarry close by on the 

 roadside. 



If the vague conception of the Triassic structure with which Shuttle 

 Meadow was entered on the second day's walk be now recalled and com- 

 pared with the definite conception that has slowly grown up as the to- 

 pography has been deciphered and the structure interpreted from it, the 

 student will find that the alternative hypothesis of repeated sequences 

 of deposition has no longer any claim on his attention. The hypothesis 

 of repetition by faulting has found continued confirmation since it was 

 first tested at Shuttle Meadow. Every method devised for testing the 

 occurrence of faults has been applied, and no doubt whatever can re- 

 main of their occurrence. The members of the repeated sequence are 

 sufficient in number to make a good case, and succeed one another too 

 arbitrarily to be regarded as products of a single process ; repetition is 

 frequent, and when once perceived it becomes a prominent characteristic 

 of the region ; the faults by which the repetition is produced are strik- 



