GEOLOGICAL AND MINERALOGICAL NOTES. 



197 



the minerals are only to be seen with the aid of the Com- 

 pound microscope, although abundant in the rocks. The 

 arrangement of the minerals follows thetext book of Prof . 

 E. S. Dana, tenth revised edition. In studying the rock 

 formations morethan six hundred thin sections weremade 

 for microscopic study and these may be seen by persons 

 engaged in the study of the minerals by applying to me 

 at the office on the lower floor of the museum building. In 

 connection with the minerals will be found collections il- 

 lustrating the rocks of the county and the geological for- 

 mations, including photographs of the more interesting 

 features. All of the specimens are clearly labelled and 

 can readily be found by anyone who may care to examine 

 them in connection with this list. 



INDEX 



f the mineral 





The references are to 



the numbers o 



5 in the list. 



Acmite, . 





54 



Actinolite, 











60, 61 



Actinolitic Quartz, 











42 



iEgirine, 











55 



Ainigmatite, 











63 



Alkali Hornblende, 











62 



Allanite, 











76 



Albite, 











97 



Almanclite Garnet, 











70 



Amazon Stone, . 











99 



Andalusite, 











118, 119 



Anker ite, 











138 



Annite, . 











87 



Anorthite, 











95 



Anorthoclase, 











103 



Antimony, Gray, 











3 



Apatite, 











. 129, 130 



Arfvedsonite. 











62 



Arsenopyrite, 











13 



Asbestus, 











61 



Astrophyllite, 











38 



ESSEX INST. BULLE' 



'IN YOI 



,. XXV] 



22* 







