414 Mr. WHEWELL on the Classification 
SQUARE-PYRAMIDAL COMBINATIONS. 
Remarks. Class. Combinations. 
Example and Figure. 
Class I. 
Included in 4 by Mohs. Sq. Pyr'. Tin-ore Qr, ©Q PQ, ~Qr 
Mohs II. 102. s 1 or pQr, ~Q 
Sq. Pyr. Tin-ore ©Q, ©Qr oQ, Qr 
T1025 78 g 
Class IT. PQ gGQn 
So also or pQr, pQzr 
Sq. Pyr'. Garnet Q, Q2 
Il. 96:. cs Sq. Pyr'. Garnet Q, Q3,Q4| No. 1. PQ, pQn 
Q2 is marked (P—1)° in II. 96. ¢ s a |MohsII.1. 
Mohs, being derived from 
Qr, by 3. 
Sq. Pyr': Garnet Qr, £Q3| No. 2. P 
TH. 96.,iulo" tia MohsII. 1. PQr, n—1 a7 
n—1qQr, gQn 
No. 3. 0Q, gQu 
MohsII.2. 
Sq. Pyr’. Zircon @Q, Q3 No. 4. ~Q, gQn 
II. 99. “4 «x |MohsII.3. 
If we have also qQ, the | Sq. Pyr'. Zircon ©Qr, Q3 No. 5. eQr, gQn 
sides of the rhombs are II. 99. s 2 |.MohsII.3. 
parallel to the terminal 
edges of gQ. 
