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Ce gt R EE ae) ENA EE AO S TE ee ETEEN EE E ea E ET E 
PRT OR E C EIA V EER P E S PIOR E EEO E E ERT E AE E S EN Ae AEM SLEE PERSE ~ 
1883.] Notes on the Chetonotus larus. 1217 
thus become leaves and the homologues of the other floral or- 
gans. It is most likely that the branch which runs up each car- 
pellary wall corresponds to the midrib of the leaf. If so, in this 
case one midrib produces an ovule, while the other does not, nor 
do the margins of the carpellary leaves. 
To sum up, in conclusion, the testimony of the dandelion: 
I. The inferior ovary is produced by an arrest in the develop- 
ment of the floral axis, the rising in a peripheral ring of the floral 
organs, and the gradual arching over of the cavity thus produced, 
by the carpellary leaves. 
1. The syngenesious anthers are united by contact and pres- 
sure, but in no sense structurally. 
ut. The ovule is not produced directly from the axis, but is an 
outgrowth from the surface (probably the midrib) of a carpellary 
leaf. 
:0: 
NOTES ON THE CHAZETONOTUS LARUS. 
BY PROFESSOR C. H. FERNALD. 
B the year 1874, I spent'some time in the study of microscopic 
forms occurring in the fresh-water streams and ponds in and 
about Orono, Me. Among the animals observed was one which 
occurs here in considerable abundance, which I suppose to be 
Chetonotus larus Ehr. 
The descriptions and figures of this animal given by Ehren- 
berg, Dujardin and in the third edition of the Micrographic Dic- 
tionary, are superficial and unsatisfactory. To gain a more com- 
Plete insight into the structure of this organism, I spent some 
time in the study of its anatomy and habits. ee 
Chetonotus larus Ehr., is very common in the fine debris over 
the bottom of ponds, streams and springs, as well as in decom 
Posing vegetable matters in watering troughs, and in cisterns 
which have no filters. I have found it at all seasons of the year, 
even in midwinter in springs which were frozen over. 
Tkig animals are aoui 3, of an inch long, one 
i nd armed on 
Ove, somewhat enlarged posteriorly, and a ari pat 
d without spines, 
