34 MICHIGAN ACADEMY OF SCIENCE. 



4. DRYOPTERIS, Adans. Shield Ferns. 



0. Thelypteiis (Lin.) A. Gray. More or less frequent on Belle Isle. 



7. simulata, Davenport. More or less frequent on Belle Isle. 



8. marginalis (Lin.) A. Gray. In woods at Linden Park. Rare. 



5. ADIAXTU:^!, Lin. Maidenhair Fern. 



9. pedatum, Lin. 



Thickets on Belle Isle, more or less frequent. 



Order 2. Equisetales. 



FAMILY 4. EQUISETACE.E. Horsetail Family. 



6. EQUISETUM, Lin. Horsetails. 



10. arvense, Lin. Belle Isle, also main land. Common. 



11. pratense, Ehrh. Thickets on Belle Isle. Rare. 



12. fluviatile, Lin. Belle Isle, also main land. Common. 



13. variegatum, Schleich. Sandy shores of Belle Isle. Not common. 



SUBKINGDOM 2. SPERMATOPHYTA. 



CLASS ANGIOSPERMAE. 

 SUBCLASS 1. MONOCOTYLEDONES. 



Order 1. Pandanales. 



FAJVIILY 1. TYPHACE.E. Cat-tail Family. . 



1. TYPHA, Lin. 



1. latifolia, Lin. Cat-tail. Sandy grounds on Belle Isle. Rare. 



FAAIILY 2. SPARGANIACE.^. Bur-reed Family. 



2. SPARGANIUM, Lin. 



2. eurycarpum, Engelm. Marshy grounds on Belle Isle. Common. 



Order 2. Naiadales. 



FAMILY 3. POTAMOGETONACE.E. Pondweed Family. 



3. POTAMOGETON, Lin. 



3. natans, Lin. Detroit River. Common. 



4. var. prolixus, Koch. Detroit River. Rare. 



5. alpinus, Balbis. Detroit River. Not common. 

 G. gramineus, Lin. 



P. gramineus L. var. graminifoUus Fries. 

 Detroit River. The common form. 



7. var. heterophyllus (Schreb.) Fries. 



Detroit River, canals on Belle Isle. Not as common as the type. 



8. var. longipedunculatus (Merat.) 



P. heterophyllus var. longipedunculatus (Merat.) Morong, Mem. Tor. 

 Bot. Club, 3, Pt. 2, 24^: 1893. Detroit River. Common. 



9. perfoliatus, Lin. Detroit River. Common. 



10. var. Richardsonii, A. Bennett. Detroit River. Rare. 



11. compressus, Lin. 



7*. zosteru'folius Schum. Detroit River. Common. 



12. mucronatus, Schrad. Detroit River: in shallow places near shore of 



main land. Common. 



13. filiformis, Pers. Sanely shores of Belle Isle, in shallow water. Rare. 



14. pectinatus, Lin. With the last, but common. 



