318 REPORTS ON THE STATE OF SCIENCE. 
No. 4004 was selected because it was collected from a point only a 
few yards from where a specimen, collected by Mr. Barrow when visiting 
the district with the Secretary in 1899, showed klastic structure. This 
rock is banded. 
It is possible that in 2154 and 1004 the alkalies are too high, and we 
hope to revise those figures. 
No, 215a. 
7TS.W.* Old Quarry’ Ynys Fawr. 
: I II. 
SiO, : : é . 60°36 59 79 
SLO SRN Seeie rt 18°16 
KeEole se: : ; =) G768 6 23 
FeO : ; 1:88 
CaO 389 
MgO 2:27 
K,0 | ~.9x : 
Na,O J 29 718 
H, 0-17 
100-21 99°57 
No. 100. 
17 S.1W. 530 feet B.N.E. Llanfaelog Church. 
1 INE 
Si eustwteged Buns tee 58°76 
RL OSs i bat) Sedeotad & OP 18:63 
NC Se ea a Sar 65) 
FeO : : é - os 3°39 
CaO “ : 1 23 
MgO : ; 2 
K,O “9. / 
or (At SR aeeae 9-01 
co, : 2 i . 043 0-42 
H,0 ; : C31 
100°79 100-41 
No. 400a. 
17 S.W. Coast, at Bone y Bedd. 
I. Il. 
SiO, ; : ; . 74:02 73°82 
Mss be! at ating reas 
Pao ¢ wis witelieot en gOey 
FeO ; - ; eee iy 
CaO , : . pemree Wi(0) 
MgO . : , Abie a Bee) 
K,O ; : ; (a) 2°44 (b) 2°42 (c) 1:26 (d) 1:44 
Na,0°* 3 : 2» B28 3°22 3:24 3:12 
H,O0 : ; P op ood! 
In above rock SiO, (determination II.) is by Miss C. Pearson, B.Sc., 
and alkalies (c) and (d) by Dr. Orton. ‘ 
No. 112a is from the flaggy mica schists into which the hornfels passes 
on its south-east side—that is, the side away from the granite. The 
rocks into which these schists pass in their turn, still further away, have 
yet to he analysed. 
