22 
MOLLUSCAN COLLECTIONS AND DETERMINATIONS. 
The Station collections of mollusks, made mostly by Mr. Hart, con= 
tain about 11,000 specimens, 600 of which are clams (Unionide). All this | 
material except that most recently brought in has been examined and deter- 
mined by various American specialists. About eighty-five names of aquatie | 
or semi-aquatie mollusks have thus been obtained and their distribution and 
life history have received special attention. The Unionide have been studied 
with reference to characters derived from the entire animal and much inter 
esting information has been accumulated concerning their relationships, life. 
histories, and parasites. | 
FRESH WATER WORMS. 
The greater part of the time of Professor Smith available for State Labora- 
tory work has been devoted to a study of the oligocheete worms (earthworms 
and their allies) found in and about the Illinois River and other waters near 
Havana. Most of this work has necessarily been of a systematic character, 
although progress has been made along other lines. The importance of sys- 
tematie work on this order is shown by the fact that with the exception of de- 
scriptions of two species published in Vol. III of the Bulletin of the State 
Laboratory,* almost nothing has been known of the representatives of the 
group in the Mississippi Valley and but little, indeed, for all the eastern part 
of the United States. 
Collections have been made from all the regular substations and at various 
places in the bottom-lands and along the shores of the river to a point two. 
miles south of Havana. Many of the worms obtained were studied while liv- 
ing, and for further study about seventy bottles of specimens have been pre- 
pared and preserved in alcohol or formaline. For a successful study of most 
of these worms serial sections are indispensable and thus far about four 
hundred microscopical slides of such sections have been made and used. 
The work of identification is now nearly completed and probably nearly all 
of the different species occurring in the region are represented on our lists.) 
Of the thirteen families of Oligocheta recognized by Beddard, nine are repre 
sented at Havana by thirty species belonging to sixteen genera. Less than 
one half of these species occur in Europe and the remainder, with few excep=| 
tions, are known only from the United States. Two new genera and at least. 
seven new species have thus far been found by us. 
“a 
Numerous experiments have been made in rearing naidiform worms and 
considerable new information has thus been acquired concerning their asex- 
ual reproduction. 
Identification and description of the planarian worms of the Station collee- 
tions has been kindly undertaken for us by Professor W. M. Woodworth, of 
i 
Art. IV. “On the Anatomy and Histology of a New Earthworm (Diplocardia communis), 
gen. et sp. nov., by H. Garman; and Art. VII, ““On an American Earthworm of the Family 
Phreoryctide,” by S. A. Forbes. i 
