CATALOGUE OF PLANTS. 423 



X. asteptum, Nordst. 

 In quiet waters. 



X. fasciculatum (Ehrb.), Ralfs. 

 In ponds; frequent. 



X. antilopseum (Breb.), Kiitz. 

 Same habitat. 



X. tetracentrotum, Wolle. 

 Sussex : In a pond. 



ARTHRODBSMUS, Ehrb. 



A. converg-ens (Ehrb.), Kalfs. 

 In ponds ; common. 



A. fragile, Wolle. 



Atlantic : Hammonton Pond and elsewhere. 



A. Rauii, Wolle. 



Gloucester : In a pond near Newfield E. A. Rau. 



A. subulatus, Kiitz. 



In ponds ; rather rare. 



A. Incus (Ehrb.), Hass. 



Atlantic : Hammonton. 



A. octocornis, Ehrb. 

 Same locality. 



EUASTRUM, Ehrb. 



E. crassum (Breb.), Kiitz. 

 E. oblongum (Grev.), Ralfs. 

 E. pinnatum, Ralfs. 

 E. humerosum, Ralfs. 

 E. ansatum (Ehrb.), Ralfs. 

 E. Didelta (Turp.), Ralfs. 

 E. ampullaceum, Ralfs. 

 E. affine, Ralfs. 



All frequent in ponds. 



