360 CALIFORNIA ACADEMY OF SCIENCES. 



roughened that trustworthy measurements could not be obtained 

 from them. lies plainly in the zone k : n, which with the ap- 

 proximate angle k : ( l> = 162° 58' would determine the symbol 

 of to be — y- P - 1 /-. An attempt to determine other zonal rela- 

 tions with the goniometer was not very satisfactory. It seemed 

 as though ( P might be in the zone k (to the right) : t (to the left) 

 which with the well marked zone k : n would make <P = — 7 P 7. 

 Which of these two symbols is correct can be settled only by 

 observation on a better developed crystal. I have provisionally 

 entered the trace of <P in the linear projection PI. Ill, as 

 — 7 P7. 



D (Pig. 4) is in the zone k ( — 3 P 3) : s (oo P), and a very care- 

 ful adjustment on the goniometer shows that it is probably also 

 in the zone k (to the right) : t (to the right). These two zones 

 lead to D = — 7P|. This also needs confirmation however. 



About the minute face p, nothiug definite, nor even approxi- 

 mate can be recorded, except that it lies in neither of the zones 

 s : <I> and kit. It is a — m P n with both m and n very large. 



From the Death Valley locality, I have had an opportunity for 

 studying seven specimens. All were from crystal cavities, the 

 walls of which were thickly lined with crystals resting on mas- 

 sive Colemanite. Three distinct habits are represented: a short 

 columnar with very complex terminal development (Figs. 5 and 

 5 a ), short columnar with pronounced rhombic terminal develop- 

 ment (Figs. 6 and 6 a ), and thin to very delicate tabular (Figs. 7 

 and 7 a ). 



Fig. 5 represents en profil the most highly modified crystal 

 thus far observed, presenting no fewer than twenty-three forms, 

 viz: s (oo P), y (P), d (2 P 2), o (2 P), c (P oo), a (2 P oo), 

 6(— P), 7i(2P oo), i(x> P2), 2(xP2), «,(— 3 P 3), U (6 Poo), 

 o(2P2), g(oP), r(fPf), x (3 P 3), '/-(4Poo), Q (4 P 2), 

 a (— 3 P), e (3 P |), e (— i P 2), and m (oo P oo). m is so mi- 

 nute as to be scarcely discernible on the acute orthodiagonal ex- 

 tremity. (I have omitted it from the figure.) e ( — 2 P 2) is a 

 new form, observed only on the crystals of this specimen, some- 

 times on the edge b ( — Pj : co ( — 3 P 3) and sometimes on c 

 (P oo) : s (co P). The zones of these two edges determine its 



