Cushman : New England Saccodermae 351 



3. Mesotaenium 



Cells imbedded in mucilaginous masses. 



9. M. macrococcum. 



Cells large, often curved, 2^-3 times as long as wide, 



diameter 20 // or more. 8. M. DeGreyi, 



Cells small, cylindrical, twice as long as wide, diameter 

 16-18//. 



Cells small, cylindrical, 2-2^ times as long as wide, 



diameter 11-12//. 10. M. chlamydosporum \ 



Cells minute, cylindrical, 3 times as long as wide, 



diameter 4-5 ju. II. M. minimum. 



Cells free-swimming, about 3 times as long as wide, the 

 breadth 8-10 /z. 



12. M. Endlicherianum. 



4. Cylindrocystis 



Cells unconstricted. 



Cells cylindrical, 2^-3 times as long as wide. 13. C, Brebissonii, 



Cells oblong-cylindrical, IJ^-2 times as long as wide. 14. C. crassa. 



Cells very slightly constricted. 



Cells slightly dilated toward the apices, which are 



truncately rounded. 15. C. dipiospora. 



Cells not dilated toward the apices, which are broadly 



rounded. 



16. C. americana. 



5. Netrium 



Cells with 2 chloroplasts, the edges notched. 



Cells elliptical-oblong, large, 3-4 times as long as wide, 



- diameter usually more than 40//. 17. N. Digitus 



Cells oblong-lanceolate, of medium size, 4-5 times as 



long as wide, diameter usually about 30//. 18. N. Naegelii. 



Cells oblong-cylindrical, of medium size, 3~3}4 times 



as long as wide, diameter usually about 30 //. 19. N. oblottgum 



Cells with 4 chloroplasts, the edges entire ; ends of cells 



rapidly attenuated. 



Boston Society of Natural History. 



20. N. interruptum. 



