8G The A iiiericd II Geoluijist. July, 1895 
H., but (Icscribed them simply as diabase, oli vine-diabase and 
diorite. I apprehend it was to material from this localit}'^ 
that Rosenbuseh first applied the term camptonite, as tlie 
iKime implies. Subsequently similar rocks found in the vi- 
einit}' of Montreal were described by B. J. Harrington. In 
188S J. F. Kemp* discovered other occurrences in Orange 
county, N. Y. In 1889 the same writerjj described another 
camptonite dike from Kennebunki)ort, Maine, and in the 
same j^ear (as joint authc)r with the present writer) published 
a short description of identical intrusives from Whitehall,! 
N. Y. and Proctor, Vt. In 1890-91 a much larger number of 
cam])tonite dikes were discovered along the sliores of lake 
C'hamplain b}-^ the same writers.^ An additional occurrence 
some thirt}' miles east of Fairhaven has been noted l>y Mr. F. 
L. Nason.** But few occurrences liave been noted in other 
countries. E. Gollerf f describes very similar rocks from the 
Black forest; CathreinJ]; and Doeltergg make mention of one 
from the Southern Tyrol, and Brogger|||| of others from 
Norwa}'. 
MONCHIQLITE DiKES. 
In dike No. 16 the feldspar disappears — pyroxene and am- 
phibole become very prominent, making at least 80 per cent, 
of the rock. Olivine and its decomposition products play an 
important role. The importance of the individual constitu- 
ents based upon relative amoiints composing the rock is as 
follows: Augite (second generation), augite (first genera- 
tion), basaltic hornblende, olivine, magnetite, 
*.I. F. Kemp: Diorite dike from tlic Forest of Di'aii. Oraimi' Co., X. Y. 
A. ,1. S.. (8), vol. XXXV, p. 331 . 
N^J. F. Kemp: Trap Dikes near Kfnncbimkijorl, Me. Am. liEOi,., Mar., 
]8!)0, 1). 127. 
||.l. F. Kemp and V. F. Maksteus: Camptonite Dikes near "Wliiteiuill, 
Wasliington Co., N. Y. and Proctor, Vt. Am. Geoi.., 1889, p. !>7. 
•|.I.F. Kemp and V. F. Maksters: The Trap Dikes of the Lake Cham- 
plain Refrion. Hull. U. S. G. S. No. 107, 18!):5. 
**F. L. Nason: On a new locality for the Camptonite (if Dawes ;ind 
Rosenbusch. A. .1. S., (3), vol. xxxviii, p. 22!). lS8it. 
ffF. Golleh: Die Lamprophyrjrans-e des siullicheii Vosiiersart. Neues 
Juhrbuch, vol.A'i, Beil. Hand 1S88, p. 485. 
iftA. Catiirein: Zoitsc-hr. f. Krystal., vol. x, 1881. p. 221, 
J^^C. Doelter: Tscher. .Min. und Petrog-. Millh., 187.1, pp. 1 7!t, 188 
and' 304. 
||||\V. C. Hrogger: Zeitschr. f. Krystal,, vol. xvi, 1890, p. 23. 
