18 ON CERTAIN SERIES OF SECTIONS OF THE 



(A) {A ) ,{B) (7i ),{C) {C ),{D) {D ), 



i^lX^M'^r ^^il^-^^r;)' ^^',l.(^c;)' ^^lU^.^' 



(^) (.4 ) ' ,{B) (B ),{C) {C ),{D) {D ), 



{A(i){A^X^^^^, {Bci)^{B^), iC'u)^{C^), {I)u)^{D^), 

 {Ay){A^\^_. {ByHB'^X (0(2)' (C^^ (^/3H^,> 



■(^'^^l^^.V.' (^^l(^.)' (^^^l(^.)' ^^^)/^c)' 



{A' ) (ûsV), (i^' ) (iS'V) , (<^'' ) (iSr') , {B' ) (jo/) , 

 {A' ) (/ê), {B' ) {(i'S) , (6" ) (Sy) , {!)' ) {yf) 



t8) 



{A'J^iBc,), iA\J^{Bu), 

 {A''Jpu), iA''J^^(Cu), 



{B\nC(2), {B\){B(2l 

 {B'\){D^), {B\,){A(2)^^_^^, 

 {B' )(A(2) (B'UCfi),' 



D II (I'll n n 



(C'^liBy), {C'^iBy), 

 {C ) (Dy), (6" ) {Ay) , 

 (C ) {Ay) ,{C' ) {By), 



^ Dii ' (20) Un ' 



{D' ) {Bè) ,(/J' ) {(Je) , 



^ A II (2X) ^ A II i2(i) 



(T)' ') {Ce) ,{D' ) (./J) , 



II ir ^(25) ^ Bii (1) 



{D ) {Aê) , {B' ) {Bè) , 



^ cii ^ Uco ^ a II ^2!i) 



{A' )u,{B' ) /3 , {C ^y ,{D' ) è 



^ ll'f 1 ^ A ' l' 1 ^ .1 If' 1 ^ .1 'f 1 (24) 



{A' ) ct,{B' ) /3,(6" ) 7,(2)' )h 

 {Â ) u.,{B' ) (i ,{C' )y ,{D' ) è . 



^ U'f 1 l> ! 1 l> I ' I ^ C/f 1 (9) 



Diagram VI. 



^ ,B,C,B, 



1(1) 1 1 1 



{/0){AfiU,.,U(J) (AS) 



(( " ( 5 ) 



(/i)),,(-/r)„,,('^'^)„('^/3)„»,. 



