6 THE NAUTILUS. 
Anodonte occurred with their usual abundance and _ perplexing 
variety so characteristic of the inland lakes of Michigan. Possibly, 
owing to the unprotected character of the shore near Charlevoix, 
but few were found in Lake Michigan. A. footiana Lea, however, 
was found at Fisherman’s Island near Charlevoix and also at St. 
James’ Harbor, Beaver Island, where A. subcylindracea Lea and 
ferussaciana Lea also occurred. But it was among the Corbiculidae 
that the most interesting finds of the expedition were made. Both 
species and individuals were exceedingly abundant. Indeed, there 
can be no doubt that the smaller Pisidia form one of the most im- 
portant portions of the food of the whitefish. The Sphaeria were 
most abundant in the inland waters where S. simile Say and stria- 
tinum Lam. were found in profusion nearly everywhere. S. rhom- 
boidewm Say and the beautiful little S. rosaceum Pme. also occurred 
in one of the smaller lakes. A fine, new species, about the size of 
S. occidentale Pme. was dredged from 25 metres off Grand Traverse 
Bay. A larger form not yet satisfactorily determined was brought 
up from a lesser depth off the south end of Beaver Island. The 
Pisidia are now in the hands of Dr. V. Sterki, who has kindly con- 
sented to examine and determine them, so that the entire list ecan- 
not be yet given. But I am enabled to state that there are, at least, 
twelve species represented, of which seven are new to the State, in- 
cluding four species new to science. At High Island Pisidia were 
particularly abundant. A fine triangular form, as large as P. vir- 
ginicum Bgt., proves to be the P. idahoense Roper. At the same 
place, Dr. Sterki’s recently-described species, P. punctatum, also 
occurred. A most interesting find was that of a form which Dr. 
Sterki informs me cannot be distinguished from the P. milium Held., 
of Europe. This, I believe, is the first instance in which a species 
of this family has been proved to be an inhabitant of both conti- 
nents. The other species found were P. variabile Pme., abditum 
Hald., compressum Pme., rotundatum Pme.and ventricosum Pme. In 
all, ninety-three species of mollusca were obtained, of which eleven 
species and three varieties were new to the fauna of the State, one 
species new to this country, and five species new to science. 
ISAAC LEA DEPARTMENT. 
[Conducted in the interest of the Isaac Lea Conchological Chapter of the Agassiz 
Association by its General Secretary, Mrs. M. Burton Williamson.] 
The Isaac Lea Conchological Chapter of the Agassiz Association is 
