Lip U. S. BUREAU OF FISHERIES. 
Therefore, for several years the Bureau has had a skilled assistant 
devote exclusive attention to the whitefishes and related species. 
This investigation, pursued by Walter Koelz, scientific assistant, is 
not all that is required, but it will surely provide a fund of informa- 
tion for more intelligent guidance in future. 
The investigation ‘of the systematic relationships and habits of the 
coregonines was conducted in the year 1920 on Lake Michigan. 
Forms allied to those which the investigations of the previous year 
disclosed in Lake Huron, and in addition two. undescribed species, of 
which at least one is now known to occur also in Huron, were ob- 
tained. Diagnoses of the species have been prepared from over 2,000 
preserved specimens. Data have been collected bearing on the dis- 
tribution in the lake and on the spawning habits of the various forms. 
To avoid dissemination of premature conclusions a report will not 
be published until work is done upon other lakes. 
These studies have been supplemented by microscopic examination 
of the scales and systematic investigation of the food, conducted, 
respectively, by J ohn Van Oosten and Carl L. Hubbs, temporary in- 
vestigators, under the direction of Prof. Jacob Reighar d. 
Mr. Van Oosten first determined that the scale characters of the 
lake herring (Coregonus artedi) are so well defined as to permit the 
determination from them of the age of individuals and the rate of 
growth of the species. The variations in the scales of individuals 
were found to be within specific limits. But scales from different 
parts of the body of an individual are so unlike that for comparison 
of individuals or species it is necessary to use scales from the same 
body region. 
The scales of 10 specimens of each of the 10 Lake Huron forms 
recognized by Koelz were next compared, and it was found that 8 
of them (including the two races) are discriminable. Further study 
will probably enable discrimination of the two other forms. It 
appeared that in one of these forms (Coregonus artedi) there are 
probably two geographic races which differ in rate of growth, but 
the matter needs further study. 
Through the courtesy of Dr..C. H. Townsend, director of the New 
York Aquarium, it was possible to secure specimens of whitefish 
(Coregonus clupeaformis) hatched and reared at the aquarium and 
therefore of known age (7 years). The 10 specimens studied show 
that there is one annulus for each year of age. This, so far as known, 
is the first demonstration of this fact and enables the determination 
of the age of coregonine fish from scale characters to be undertaken. 
with confidence. Two individuals of the 7- -year-old whitefish were 
segregated at the New York Aquarium and kept living, while scales 
were removed at intervals of a month. <A study of these scales shows 
that the annuli are formed in winter, fixes the time of formation, and ~ 
indicates temperature change as one of the factors. It is believed 
that a continuation of these studies will add mater lally to our knowl- 
edge of age and rate of growth of coregonine fishes, aid in their 
systematic grouping, and lead to the discovery of local races in some 
of the forms. 
The food of the whitefish, lake herring, and allied species of Lake 
Huron coregonines in the ‘Koelz collection was inv estigated by a 
volumetric method by Carl L. Hubbs, of the Museum of Zoology, 
