,'flb 10 



lOa 



31 



12 



140, 





17a 



-\ 



20 



18 18a 



16 a 



22. 



23 



24a 



27 



28a 



25 25a 



A A 



26 26a 



/A 



21 a 



STAGES OF GROWTH IN SILURIAN BRACIIIOPODA 



