PLATE XXIT 



STAGES OF GROWTH IN SILURIAN BRACHIOPODA 

 (Pagk :i1i') 



Series of the shells of Dalimindla eleijantuln, Orlholhetes suhplanus, Rliijn- 

 clu>tri:la cuiieala, and Ilutriuox/iini ei-iix, from the youngest form observed 

 lip to the adult or senile condition. The jilate was drawn on stone 

 from a photograph, and serves to show, not the details of structure, but 

 tlie character and completeness of tliu niatei'ial which has served as the 

 basis of this work. 



