1907] Terry,— Partial List of Connecticut Diatoms 181 
this is a colony of large and very active Bacillaria paradoxa (Gmel.) 
Grun. Another colony of this species in Morris Creek marsh, although 
in constant motion, was covered with a parasitic growth of Lepto- 
thrix, and was accompanied by numerous rapidly revolving filaments 
of Spirulina. 
In fresh water the most abundant genus is Pinnularia W. Sm.; it 
is found in quantities almost everywhere. Next to this in numbers 
is the genus Sfauroneis, then Cymbella, Surirella, Navicula, and 
numerous filamentous forms. Although these genera are represented 
in nearly every pond, yet each pond shows a combination characteristic 
of itself, and types of the same species vary greatly in the different 
ponds. In several ponds in Bristol Surirella elegans is very large and 
sometimes much elongated; in Plymouth it is smaller and much 
shorter in proportion; in Highland Lake, Winsted, beautifully typical 
specimens of S. nobilis W. Sm. are abundant, and in several ponds in 
Connecticut Navicula  peripunctata Brun abounds; Prof. Brun 
founded the species on specimens in mud from Crane Pond, Grove- 
land, Massachusetts, but it is more plentiful in Bristol and in Leete’s 
Island. Van Heurck states that Achnanthidium flexellum (Kiitz.) 
Bréb. is rare; it is abundant in two of the Bristol fossil deposits. He 
also gives Fragilaria Harrisonii Grun as very rare; this grows abun- 
dantly in Bristol. Dr. Ward found a new diatom in one of my slides 
from the Connecticut shore, which Cleve named Caloneis Ward. 
Mr. O. E. Shaffer sent a find of Nitzschia to Europe from Port Town- 
send, Puget Sound, and Cleve named this N. Shafferi; I had previously 
found this nearly twenty vears ago at Morris Creek, and reported it 
at the time in the Amer. Micr. Journal as N. curvula. I find Isthmia 
nervosa Kütz. in nearly évery deep water sounding from off the Con- 
necticut shore, but do not believe that it grows here; it is probably 
brought in by ocean currents from warmer waters. 
List or SPECIES. 
The arrangement of this list is that of De Toni, Sylloge Algarum, 
and the nomenclature for the most part follows that work. Names 
given as synonyms are those that have been used by the writer either 
in published notes or with material distributed. Species marked 
with a star were founded on Connecticut material. 
Navicula nobilis (Ehrenb.) Kütz. Common. 
