THE AMERICAN MIDLAND NATURALIST. 

 NAVICULOIDEAE. 



Amphipleura sp. On Zostera Inner Harbor. — C.S.H. ; N.M.G. 

 Amphora oralis (Breb.) Kuetz. Frequent. — Jelliffe. 

 Gomphonema constrictum Ehrb. Common in second lake. — 



C. S. H.; D. S. J. 



Navicula virdis Kuetz. Frequent throughout island. — Jelliffe. 



Pleurosigma angulatum (Quek) CI. Mud, pebbles, etc. — C. S. 

 H.;D. S.J. 



Neidium affine (Ehr.) Pfitzer. Common in second lake. — C. 

 S. H.;D. S.J. 



Naricida cuspidata Kuetz. Common throughout island. — Jel- 

 liffe. 



Navicula grerillei (Ag.) CI. On Zostera Inner Harbor. — C. 

 S. H.; N. M. G. 



Naricida Kennedy i W. Sm. On Zostera Inner Harbor. — C. S. 

 H.;H. H. Y. 



Naricida. Lyra Ehrb. Not infrequent around coast. — Jelliffe. 



Navicula major Kuetz. Common in second Lake. — C. S. H. ; 



D. S. J. 



Gyrosigma Balticum (Ehr.) CI. Not infrequent in salt marsh- 

 es, throughout island. — Jelliffe. 



Pleurosigma distortion W. Sm. Mud, pebbles, etc. — C. S. H.; 

 D. S. J. 



SURIRELLOIDEAE 



Siirirella elegans Ehrb. Not infrequent throughout island. — 

 Jelliffe. 



* Revised according to Van Huerck's "Treatise on the Diatomaceae" 

 with some reference to "The Diatomaceae of Philadelphia and Vicinity." 

 — C. S. Boyer, Philadelphia, 1916. J. B. Lippincott Company. 



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