20. Geology, &c. of the Connecticut. 
Glandulous Gneiss. 
This is very abundant, especially in the gneiss east of 
Connecticut river. Indeed, a considerable proportion of 
that range is occasionally glandulous, presenting numerous 
oval masses, chiefly of felspar. The layers of this variety 
of gneiss are usually very distinct, and it contains a large 
proportion of mica, which is usually of a blackish colour; 
and thus it is easily distinguished from the porphyritic gran- 
_ ite above described. 
3. Hornpuenps —— CLRAVELAND. 
Coloured Vermillion, Red, and clouded with India Ink. 
This is an anomalous and perplexing rock. It is not 
generally well characterised in this region: but I have put 
it down, because a rock approaching nearer the characters 
of this than of any other, occurs 
along the Connecticut. I have no eae pie however that 
I have given in all cases its exact situation or extent. Yet 
I believe that wherever this stratum is coloured on the map, 
the. rocks may be found i in the vicinity. Thus in the range 
d, Ct.a person willgen- 
erally find this rock more or less abundant in crossing from the 
secondary rocks to the gneiss: but sometimes he may thus 
cross and miss of it, unless he make an excursion to the right 
or left; and sometimes he must cross a portion of the gneiss 
before "he reaches it, ‘The continuity of the strata of this 
rock seems to be much less perfect than in the gneiss or 
mica slate, and the direction of the strata if often oblique to 
that of other rocks :—a remarkable instance of which occurs 
in the south east corner of Halifax, Vt. The dip of the 
strata varies from 45° to 90°, and the schistose structure in 
the purest specimens is very perfect, the layers varying in 
thickness from half an inch to three inches. 
But there is another difficulty in ascertaining the limits of 
this rock. It is no easy matter to draw the line between it 
and gneiss, all, or at least, two of the ingredients of the lat- 
ter rocks being sometimes present, while more than half of 
the rock is hornblende. Indeed, I have sometimes been dis- 
