Journal of the 



N. Y. Microscopical Society 



^Urr^r:.^At 



Plate No. 27. 

 x\pril, 1891. 





35 





<? 



T. F. SMITH ON THE STRUCTUPxE 



OF THE 



PLEUROSTGMA VAT.VF. 



42 



?44 



30 



