SIXTH REPORT OF THE DIRECTOR I9O9 



199 



0(19.1.1 ). The last is new to the species. The faces, with the 

 exception of those of o(iii), are sharp and brilHant. The planes of 

 the new trapezohedron 0(19.1.1) show a slight tendency to de- 

 velop unsymmetrically in opposite pairs with respect to the axes 

 of tetragonal symmetry. In several instances reddish violet spots 

 of cubic outline were noted in the center of the hexoctahedral 

 crystals. The following measurements served to identify the forms 

 v(73i) and 0(19.1.1) : 



LETTER 



ANGLE 



NUMBER OF 

 READINGS 



MEASURED 



CALCULATED 



v : V 



V : V 



V : V 



a :0 



731 : 713 

 731 : 731 

 731 : 371 

 100 : 19.1.1 



4 

 5 



4 

 4 



/ 



20 39 



15 6 



42 53 



4 13 



/ 



21 13 



14 57 



43 12J 



4 15 



Magnetite 



Split Rock, Essex co. 

 Among the specimens collected in the summer of 1907 by Prof. 

 James F. Kemp of Columbia University, was one from the Split 



Fig. 3 Magnetite, Split Rock 



Rock iron mine which proved to be of special interest. Through 

 the courtesy of Professor Kemp this specimen has been placed at 



