30 T. STERRY HUNT ON THE GENETIC 
§ 53. The late J. B. Perry at the same time and place’ announced a similar conclu- 
sion, to which he had arrived, namely, that these limestones in eastern Massachusetts, as 
well as others elsewhere in New England and in northern New York, though possessing 
“the form of dikes,” “have a vein-like structure, and should be regarded as true vein- 
stones.” He farther says of these deposits: “The foliated structure, with its accompany- 
ing series of mineral substances, each occurring in a determinate order, evinces that the 
process of deposition was gradual and probably long continued.” Thus these observers, 
in 1871, had, although without acknowledgment, confirmed my observations and adopted 
my conclusions of 1866 as to these endogenous calcareous masses of the ancient gneissic 
series. J. W. Dawson had in 1869 recognized ÆEozoon Canadense in a serpentinic lime- 
stone from Chelmsford, and both Burbank and Perry maintained that all of the limestone 
masses of the region were vein-stones, as an argument against the organic nature of 
Hozoon. 
§ 54. The mineralogy of these endogenous, more or less calcareous, masses has been 
the subject of much study. While sometimes having the aspect of a coarsely crystalline 
limestone, and nearly pure, they may include apatite, fluorite, chondrodite, wollastonite, 
amphibole, pyroxene, danburite, serpentine, phlogopite, gieseckite, orthoclase, scapolites, 
brown tourmaline, idocrase, prehnite, epidote, allanite, garnet (sometimes chromiferous), 
titanite, zircon, rutile, spinel, volcknerite, corundum, menaccanite, magnetite, hematite, 
pyrite, and, more rarely, pyrrhotite, chalcopyrite, sphalerite, molybdenite, and galenite. 
To these must be added stilbite, chabazite, and barite. All of these species have been 
met with in the deposits studied in Canada and New York, while in the similar cal- 
careous masses in eastern Massachusetts chrysolite and petalite occur. Exceptionally, as 
in Franklin and Stirling, New Jersey, there are found in this connection zinciferous and 
manganiferous minerals, as willemite, tephroite, spartalite and franklinite. ° 
The various associations of apatite in these aggregates are worthy of notice. Crystals 
of this species have been observed by the writer directly imbedded in the quartzo-felds- 
pathic vein-stone, in vitreous quartz, in calcite and dolomite, in pyroxene, in crystals of 
phlogopite, in pyrite, in magnetite, in spinel, and in foliated graphite, as well as in a 
massive granular apatite, which sometimes surrounds large and well defined crystals of 
the same species. Dr. Harrington has farther noted its inclusion in amphibole, in ortho- 
clase, in scapolite, in steatite, and in fluorite. On the other hand, apatite crystals have 
been found to enclose quartz, calcite, fluorite, phlogopite, pyroxene, zircon, titanite, and 
pyrite. The apatite of these deposits, so far as known, is essentially a fluor-apatite, con- 
taining in one case, by the writer’s analysis, 0.5 hundredths of chlorine. From these 
facts it is evident that the succession of species in these veins is by no means inyariable. 
Mention should here be made of the apatite occurring in disseminated grains in the great 
deposit of magnetite so extensively mined at Mount Moriah, near Port Henry, New York. 
The banded arrangement of the crystalline apatite, generally reddish in color, and in thin 

5 
1 Perry. Proc. Amer. Assoc. Ady. Science, 1871, pp. 270-276. 
2 For farther and more detailed accounts of the occurrence of the mineral species already mentioned, and 
many others which are found with the calcarous masses of the Laurentian rocks, see Report Geol. Survey of Canada, 
1863-66, pp. 181-229, which were reprinted, with the exception of the last six pages, in the Report of the Regents of 
the University of New York, for 1867, Appendix E. See also, in abstract, Chem. and Geol. Essays, pp. 208-217, and 
farther the reports of Dr. Harrington and Mr. J. Fraser Torrance, cited in the note § 45. 
