MUSEUM OF COMPARATIVE ZOOLOGY. Ill 



and irregular texture near its upper surface ; stratification of sandstone 

 conformable to irregularities in the upper surface. Intimate mixture 

 of sand grains and trap fragments along and above line of junction ; 

 surfiice fissures and vesicles filled from above with sand grains, distinctly 

 stratified parallel with the sandstone bed above. The hardness of the 

 overlying sandstone is due to induration by infiltrated calcite, etc., and 

 presents no evidence of being derived from baking by heat. See special 

 account. 



Localities 15, 16. Section numbers, 5-17, 77. Totoket Mountain, inside south and 

 north hooks. Percival's Report, pp. 336-338. Percival's notation, E. II. 



Totoket }kIountaiu is a well formed crescent, next north of Saltoustall 

 Mountain. Exposures of the upper contact with the sandstone were 

 found in a stream, locality 15 (Fig. 2), half a mile northwest of North 

 Branford, in the southern hook of the crescent ; and again in a stream- 

 bed inside of the northern hook, locality 16 (Fig. 3). Another stream, a 

 mile southwest of the last, locality 16', cuts a channel in what seems to 

 be a bed of clinkers. 



The trap is porphyritic, and originally possessed a glassy base ; upper 

 surfoce very vesicular and irregular ; sandstone lamination conformable 

 to uneven contours of surface ; intimate mixture of rounded (water- 

 worn) trap grains and sands at contact ; occasional trap fragments in 

 sandstone for a few feet above ; clastic grains of trap, quartz, etc., fill 

 vesicles, with lines of deposition parallel to the stratification of the sand- 

 stone above ; sand in vesicles is connected with the sandstone above by 

 narrow necks. The overlying sandstone, locality 16, is indurated by 

 cementation, and shows no signs of baking. 



Locality 17. Section numbers, 204-207. Higby Mountain. Percival's Report, p. 351. 



Percival's notation, E. III. [i]. 



The eastern base of Higby Mountain, south of the road from IMeriden 

 to Middlefield, is followed by the upper course of Fall Brook, which at 

 a point about a quarter of a mile south of the road lays bare a valuable 

 exposure of sandstone lying on the trap, locality 17 (Fig. 4). A second 

 exposure is found a little farther south, locality 17'. Numerous frag- 

 ments of vesicular trap enclosed in sandstone are found in the stream 

 for some distance northward. 



The trap is porphyritic, and originally glassy ; upper surface very ve- 

 sicular, much decomposed, and uneven ; not excessively fine-grained at 



