MUSEl'-M OF COMPARATIVE ZOOLOGY. 115 



Locality 24. Section numbers, 120-123. Highl.i'ml Lake. Pcrcim!'.<i Report, pp. 336- 

 3C3. Fercicid's notation, P. 4, E. III. (5). 



The rid;^'o posterior to Chauucy Peak is cut near its southern end 

 by the Mcriilcri, Watcrbury, and Connecticut Kiver Raih-oad, a quarter 

 of a mile east of Hi-hland station (Fig. 4). x\.n excellent exposure. 

 Under contact not shown. Trap generally dense ; originally glassy and 

 porphyritic ; not locally close-grained at upper contact ; upper portion 

 extremely vesicular; sand grains filling vesicles and fissures, their lines 

 of deposit conforming to the irregularities of the trap surface (Fig. 14) ; 

 these deposits connected with the sandstone above by necks ; inequali- 

 ties in upper surface of trap covered by conformably stratified sandstone. 

 Numerous angular, vesicular, large and small fragments of trap lying 

 above the sheet ; spaces between these filled wifh n-regularly bvit con- 

 formably stratified sandstone ; vesicles in fragments filled with sand ; 

 some of the vesicles only partly filled, and in such cases the upper sur- 

 face of the filling is parallel to the dip of the Triassic monocline. 



Localiti/ 25. Section numbers, 12J-1-"1. IlartforJ Ave. and N. Stanley St., New Brit- 

 ain. Percival's Re/jort, pp. 3S1, 3S4. Percivuf's notation, P. (e), E. IV. I. (7). 



The overlapping ends of the small trap ridges on the northeastern 

 border of New Britain are regarded as faulted portions of a single pos- 

 terior sheet ; a small stream flows between them. The eastern ridge is 

 quarried, and discloses the base of the sheet ; the upper contact is found 

 where the stream runs on the back of the western ridge. 



Trap generally dense, but containing local amygdaloidal areas, sur- 

 rounded by dense trap, as if produced by intermittent flowing; very 

 vesicular at upper surface, and originally possessing a glassy base ; sand- 

 stone immediately above contains water-worn grains and fragments of 

 much decomposed trap. 



Locality 2(3. Section 7iumbcrs, 152-1-50. Near Trinity College, Hartford. Percival's 

 Report, pp. 385, 3SC. Percival's notation, 1\ (i"), E. IV. I. (9). 



This ridge is of doubtfttl relationship : it may be a second posterior 

 sheet, and therefore not directly comparable with the previous examples. 

 Its middle portion and base are well exposed in large quarries. The 

 trap is generally dense; triangular areas between the feldspars contain 

 a little glass ; the lower portion is brecciated and extremely scoriaceous ; 

 obsidian-like grains of trap in shale immediately under trap ; upper 

 portion vesicular, but overlying sandstones not seen. See special 

 account. 



