436 
BULLETIN OF THE BUREAU OF FISHERIES 
this series was taken in about 40 meters, near the center of the basin and approxi- 
mately one-half mile from the mouth of the river. The second sample was taken 
about one-fourth mile from the mouth of the river in 38 meters, and an attempt was 
then made to get a sample from a point approximately 100 yards from the mouth of 
the river in about 20 meters. This last was not successful, however, on account of 
twigs and other debris which prevented the dredge from closing. After several 
trials the attempt was abandoned and a sample taken in 17 meters near what is 
known as Island Point on the western side of Thumb Bay and about three-fourths 
mile from the mouth of the river. 
Following is a list of the species of diatoms found in the collections as a whole: 
Amphipleura pellucida 
K. 
Amphora Lybica E. 
Amphora ovalis K. 
Ceratoneis arcus K. 
Cocconeis Placentula E. 
Cyclotella Bodanica Eul. 
Cyclotella antiqua W. S. 
Cymatopleura Solea 
(Breb.) W. S. 
Cymbella cxspitosa (K.) 
Cl. 
Cymbella cistula (Hemp.) 
Kirch. 
Cymbella cuspidata K. 
Cymbella Ehrenbergii K. 
Cymbella gastroides K. 
Cymbella Helvetica K. 
(not W. S.) 
Cymbella Mexicana var. 
Kamtschatica Grun. 
Cymbella ventricosa K. 
(not Ag.) 
Denticula tenuis K., 
var. 
Diatoma anceps (E.) 
Grun. 
Epithemia turgida (E.) 
K. 
Epithemia Zebra (E.) 
K. 
Eunotia bidens (E.) W. 
S. 
Eunotia lunaris (E.) 
Grun. 
Eunotia prxrupta E. 
Fragilaria construens 
(E.) Grun. 
Fragilaria Harrisonii 
(W. S.) Grun. 
Frustulia rhomboides 
(E:) De T. 
Gomphonema constric- 
tum E. and varieties. 
Gomphonema gemina- 
tum (Lyng.) Ag. 
Gomphonema herculea- 
num E. 
Gomphonema subclava- 
tum Grun. 
Hantzschia amphioxys 
(E.) Grun. 
Melosira arenaria 
Moore. 
Melosira crenulata var. 
tenuis (K.) Grun. 
Melosira Italica (E). 
K. 
Melosira Rxsxna Rab. 
Melosira varians Ag. 
Meridion circu'are Ag. 
Navicula amphirhyn- 
chus E. 
Navicula borealis (E.) 
K. 
Navicula commutata 
Grun. 
Navicula elliptica K. 
Navicula Gastrum (E.) 
Donk. 
Navicula Iridis var. dil- 
atata (E.) 
Navicula lata W. S. 
Navicula limosa K. 
Navicula major (K.) 
Grun., char, emend. 
Navicula mesolepta E. 
Navicula Placentula 
(E.) K. 
Navicula rupestris 
(Hantz.) A. S. 
Navicula tenella Breb. 
Navicula transversa A. 
S. 
Navicula viridis (W. S.) 
A. S., char, amend. 
Nitzschia Brebissonii 
W. S. 
Nitzschia palea (K.) 
W. S. 
Pleurosigma acumina- 
tum (K.) Grun. 
Rhoicosphenia curvata 
Grun. 
Rhopalodia gibba (E.) 
Muell. 
Stauroneis Phoenicen- 
teron E., and varie- 
ties. 
Stephanodiscus Nia- 
gara E. 
Surirella amphioxys W. 
S. 
Surirella bifrons E. 
Surirella biseriala (E.) 
Breb. 
Surirella elegans E. 
Surirella robusta E. 
Synedra delicatissima 
W. S. 
Synedra subxqualis 
Grun. 
Tabellaria flocculosa 
(Roth) K. 
The scarcity of members of the genus Pleurosigma in all the samples is note- 
worthy; for it is a semisaprophytic genus and the unusually high percentage of decay- 
ing organic matter in all of the gatherings would presuppose an abundance of Pleuro- 
sigma. A possible explanation of this scantiness is that the genus as a whole thrives 
best in temperate and subtropical waters. 
LITERATURE CITED 
Black, C. S. 
1929. Chemical analyses of lake deposits. Transactions, Wisconsin Academy of Sciences, 
Arts and Letters, vol. 24, pp. 127-133. Madison. 
Gilbert, Charles H., and Willis H. Rich. 
1927. Investigations concerning red-salmon runs to the Karluk River, Alaska. Bulletin, 
United States Bureau of Fisheries, Vol. XLIII, Part II, 1927 (1929), pp. 1-69, 34 figs. 
Washington. 
