MIDDLESEX ELORA. 137 



A. Boottii, Tuck. (A. spinulosum, var. Boottii, Man.) 

 Maiden, Medford, Lowell, Ashby, et al. Not very common. 



A. acrostichoides, Swartz. Christmas Fern. 

 Common. The var. incisum, Gray, at Medford (Mrs. P. D. 

 Eichards). 



Ctstopteris, Bernh. Bladder Fern. 



C. fragilis, Bernh. 



Xot uucoinmon. 



Onoclea, L. 



O. sensibilis, L. Sensitive Fern. 



Very common. The form known as var. obtusilobata is 



occasionally found. 

 O. Struthiopteris, Hoftm. (Struthiopteris Germanica, Willd., 



Man.) Ostrich Fern. 



Maiden (F. W. Morandi), but now probably extinct in this station; 



Lincoln (G. E. Davenport) ; Bedford (L. L. Dame). Rare. 



WOODSIA, R. Br. 

 W. Ilvensis, R. Br. 



Not uncommon. 

 W. obtusa, Torr. 

 Maiden and Melrose (F. S. Collins) ; Medford (L. L. Dame) ; 

 Chelmsford (Dr. C. W. Swan). Xot very common. 



DiCKSONiA, L'Her. 



D. pilosiuscula, Willd. (D. punctilobula, Kunze, Man.) 

 Common. 



Ltgodium, Swartz. 



L. palmatum, Swartz. Climbing Fern. 

 Concord (G. E. Davenport) ; West Newton (Severance Burrage) ; 

 Dracut (Dr. C. W. Swan) ; Groton (C. W. Jenks). Rare. 



OSMUNDA, L. 



O. regalis, L. Flovtering Fern. Royal Fern. 



Common. 

 O. Claytoniana, L. 



Common. 

 O. cinnamomea, L. Cinnamon Fern. 



Common. The state called var. fronclosa at Newton (F. S. 



Plympton) ; Medford (G. E. Davenport). 



Ophioglossum, L. 



O. vulgatum, L. Adder's Tongue. 



Maiden, Melrose and Concord (F. S. Collins) ; Newton (F. S. 

 Plympton) ; Chelmsford (Dr. C. W. Swan). Not common. 



