46 J. D. Dana on the Homeomorphism 
The following are notices of other species in Table I: 
Chondrodite has for the summit angle of 12, in = three types, 68° 32, 
64° 54’, 70° 29’, giving as the mean 67° 58’, from which the mean for 
3, eae as 12 in the table) is 106° 52’, and ‘the ites 103° 28’ and 
° 26’. The angle for 17 in the New w Jersey chondrodite is 68°. 
t 
vertical axis is twice that given in the table, or 148352. ; In Chryso- 
lite, also, we have as good reason for doubling the vertical axis, in 
dome has the angle 70° 57’, and taking this as a unit dome, ¢ axis a= 
1-53136. 
The relations of Polianite to Gothite and Diaspore appear to sustain 
the conclusion of Volger, cited in the American Journal of Science, 
vol. xvil, e 213. 
<ients has the same relation to the species of Section II, that 
Antimony Glance has to those of Section I. It has very nearly the 
angles o 
Wohlerite has pe recenity been ct by the able crystallographer 
of Paris, M. Descloizeaux.* He gives for the vertical prism, the ang 
108° 56. But tees oapueiion the sang 
of angles with those of the above spe- 
cies, it appears that its true relations are 
zeaux. This gives for the vertical prism, 
the angle 90° 54’, and for the unit domes, 
the angles 108° 2’ and 108° 56’, very 
near Andalusite. It appears to be 

for the prisms of two axes, angles (meas- 

Piniasaiet is near Wohlerite in its crystallization. With the funda- 
mental form adopted, the known octahedron is 23 om and the occur- 
ring prisms are 12 =109° 46’, 2i= 70° 50’, 4;—39° 9 
Polycrase affords angles in three directions near 90°, whichever po- 
sition be taken. In the figure annexed, the position and lettering cor- 
* Ann. de Chim. et de Phys., vol. xl, 3d series, 
