262 A. J. Hoses — JV'ew Mercury Minerals from Texas. 



The name Montr oydite. — The name Montroydite is sug- 

 gested in honor of Mr. Montroyd Sharpe, one of the owners of 



the mines at Terhngua. 



4. Crystallized Calomel, 



One of the specimens from the cavity which yielded the 

 minerals just described consisted of tabular crystals of calomel 

 not suitable for measurement. Some specimens obtained by 

 Mr. W. P. Jenney, from the district but not from the cavity 

 however, yielded measurable crystals of two types .: 



1. Square prismatic crystals, iig. 5, sometimes 4 to 5™™ in 

 length by 1 to \\ in breadth. 



2. Tabular crystals flattened parallel to one of the faces of 

 a {010|. Fig. 6 shows/ in orthographic projection, two such 

 individual crystals in parallel position with the a |113| planes 

 relatively large. 



The forms are the same in both types and consist of : 

 c 1 001 1 somewhat rough; a |010[ slightly curved ; r jlllj 

 dull ; a |113[ bright and z |013| minute. 



Between the two individuals, as shown in fig. 6, and in the pris- 







6 





'^ 





v/ 



^ 



\ 



> 



/ 







7>\ 



/> 



r\ 



/- 



matic zone a single reflection was obtained corresponding very 

 closely to a face of anew form !120(. 



The essential measured and calculated angles were 





Measured. 



Calculated 



cr 



67" 50' 



67° 41' 



Co. 



38 45 



39 05 



cz 



30 14 



29 52 



