FRESH WATER DIATOMS. 
301 
Diatoms from Docks in St. John Harbor. 
The following species were obtained from the wharves of the 
Eastern Steamship Co., and the Balla.st wharf in St. John. 
These are directly washed by the waters of the Bay of Fundy 
and represent essentially marine conditions, yet must be subject 
to the influence of the powerful fresh water currents which at 
times traverse St. John Harbor. The collections made in this 
vicinity are as yet very imperfect : 
Melosira nummuloides Ktz. 
Melosira varians Ag. 
Melosira Jurghensii. 
Melosira subflexilis Ktz. 
Coscinodiscus radiatus Ehr. 
Coscinodiscus minor Ehr. 
Grammatophora marina Kutz. 
Cocconeis scutellum Ehr. 
Cocconeis pediculus Ehr. 
Doryphora Boeckii W. Sm. 
Doryphora amphiceros Kutz. 
Actinoptychus undulatus. 
Amphiprora alata Kutz. 
Amphiprora ornata. 
Cyclotella striata Thw. 
Cocconema Cistula Ehr. 
Mastogloia Smithii Thw. 
Acnanthes subsessilis Ktz. 
Acnanthes longipes Ag. 
Rhabdonema minutum. 
Stauroneis. 
Gomphonema marinum W. Sm. 
Gomphonema geminatum Ag. 
Tryblionella gracilis W. Sm. 
Navicula didyma Kutz. 
Navicula Smithii var. ovalis. 
Navicula maculata Bail. 
Navicula infiata Kutz. 
Pleurosigma Aestuarii? W. Sm. 
Pleurosigma obscurum W. Sm. 
Pleurosigma fasciola W. Sm. 
Pleurosigma Balticum W. Sm. 
Pleurosigma hippocampus W. S. 
Pinnularia distans W. Sm. 
Pinnularia. 
Bacillaria paradoxa Gmel. 
Biddulphia aurita Breb. 
Nitschia sigmoidea \V. Sm. 
Nitschia fasciola. 
Nitschia closterium W. Sm. 
Nitschia vermicularis. 
Cyclotella Kutzingiana Thw. 
Stephanodiscus Niagara Ehr. 
Orthosira marina. 
Triceratium alternans Bail. 
Surirella gemma Ehr. 
Surirella minuta Breb. 
Amphiprora. 
Epithemia ventricosa Kutz. 
Synedra ulna Ehr. 
From scrapings of old wharves in Courteney Bay specimens 
of the following were obtained : 
Nitschia closterium W. Sm. Cocconeis. 
Melosira. * Nitschia sigma? 
From a comparison of the forms which have now been 
enumerated (a very incomplete list) with those given from 
