CONTRIBUTIONS TO THE BIOLOGY OF THE GREAT LAKES. 



HIRUDINEA AND OLIGOCHiETA COLLECTED IN THE GREAT LAKES REGION. 



J. PERCY MOORE, Ph. D. 



HIRUDINEA. 



The operations of the tieUl parties directed by Prof. Jacob Reighard in connec- 

 tion with the biological survey of the Great Lakes \'ielded a large number of 

 carefullj' preserved and labeled leeches, the detailed study and identification of which 

 have required considerable time and furnished interesting data on variation that can 

 be more profitably utilized elsewhere than in this report. The bulk of the collection 

 comes from the western end of the lake, where a few specimens were collected in 

 the vicinity of Put-in Bay during the .summer of 1898, and a great many at the same 

 place, at other points about the Bass I.slands, at Sandusky, and along the Canadian and 

 Ohio shores during the following summer; in the latter sea.son also smaller collections 

 were taken at Erie, Pa., and other places in eastern Lake Erie. As no systematic 

 collecting seems to have been done in the small lakes, ponds, and creeks in which the 

 large, jawed leeches abound, no representatives of the family Hirudinidte are included; 

 nor was tiny attempt made to gather the fish leeches, and the single vial containing 

 Ichthyobdellidai unfortunately met with an accident that prevents the determination 

 of its contents." On the other hand, the shore collecting was very thorough, and the 

 families Glossiphonida; and Herpobdellidte are probably represented by every species 

 found in such situations in Lake Erie, and in most cases by many beautifully pre- 

 served specimens. Several carefully executed water-color sketches from life, 

 prepared by Mrs. H. S. Jennings, which are herewith published, and some notes on 

 the living colors accompany the collection and furnish valuable data. The determi- 

 nation of .some of the .species of Glossiphonidaj is especially difficult and requires 

 the most minute study of both internal and external features of their organization 

 in all stages of growth and development, at different seasons, and under different 

 nutritive conditions. 



While this and other large collections studied in recent years have materially 

 advanced the writer's knowledge in this direction, nuich yet remains to be done 

 before the limits of variation and the correlations of characters can be finalh' defined 



<i A later systematic examinatum ol the food tishes of Lake Erie shows that they are remarkably free from leeches. 

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