Text-fig. 4. 



m% m^'^^ 





@,C5:^ 



^r 



^"^'' ^^Ki 







c 



B 





I 



'77",.-- • -^v 



'^/ 



'.'■I 



\f N 



.'i^A, 





f\/7 



I" o 





v^*;-' 



H 



