WHITLOCK. — CRYSTAL FORMS OF CALCITE. 323 



O: (4-16-20-9) = (11 -7-9.). This scalenohedron was noted by 

 Sansoni 90 on crystals associated with the pink apophyllite of pyra- 

 midal habit from Andreasberg. The measured angles as recorded 

 by Sansoni agree well with theory. Further, the form which falls in 

 normal series _Ns marks the intersection of the zones [7189 : 0441] 

 and [0001 : 1450] both of which are well marked. The form is quite 

 probable. 



3): (4 • 12 -16- 7) = (957). This scalenohedron was recorded by 

 Cesaro 91 on two crystals from Rhisnes, Belgium. The faces measured 

 by Cesaro were small and ill defined. The form however falls in 

 normal series N5 and marks the intersections of the zones [4047 : OlIO] 

 and [5167 :0881]. It is somewhat less probable than the preceding 

 form. 



&: (12- 8- 20 -7) = (13-1-7). This scalenohedron was noted by 

 Hessenberg 92 on crystals from Matlock, Derbyshire. The form was 

 included in Irby's list without comment. Although falling in a high 

 normal series it marks the intersection of several fairly well marked 

 zones. It is fairly probable. 



In the zone fragment between (20T) and (113) only two scaleno- 

 hedrons have been recorded. 



Referred to No this zone fragment lacks the term \ but contains no 

 extra forms. 



Zone 6 = Z 6 Scalenohedrons of the Zone [4041: 1120] = [113: 101] 



—j — (Miller) = 2. Symbol - 

 A: k 



The principal zone intersection in this section of Zone 6 is the pole 

 of the relatively common scalenohedron (6281) = (513). Splitting 



90 Sansoni, F., R. Acad. d. Line, 19, Plate III, Fig. 29 (1884). 



91 Cesaro, G., loc. cit., Fig. 34. 



92 Hessenberg, F., Min. Not., 4 (1863). 



