MUSSEL, FAUNA OF MAUMEE KIVER. 61 



ferent. One of the examples of L. ligarrhentinus taken in the 

 Auglaize, however, contained many very minute cylindrical objects 

 with rounded ends, which were probably bacteria. 



The stomach contents of the mussels found in the reservoir of the 

 feeder canal, a shallow pondlike body of water, bore considerable con- 

 trast to that of the river. This reservoir was well populated with 

 small green monads and similar organisms, and during the last days 

 of our observation became covered over with a green scum. It was 

 " puddle plankton " rather than that which is characteristic of either 

 lakes or rivers. The stomach contents of the mussels were greenish 

 in mass, and were found to consist of various organisms, mostly green 

 in color and actively moving. 



The main mass consisted of small globular and thick celled, green 

 or brownish flagellates, probably Trachelemonas lagenella. Among 

 other organisms were species of Phacus^ several species of Scene- 

 desm/iis, Pediastnim pertusum^ Gomphonema., several species of 

 Navicula^ a little Botryococcus hrmini^ Anurma cochlearis^ Cos- 

 mariuTn, small fragments of a Conferim-VikQ alga two or three cells 

 long, fragments of the test of Geratium Mrundinella^ and the brown 

 objects resembling fungus spores. There were numerous narrow 

 curved objects which Avere probably loricas of Trachelemonas. 



PARASITES OF THE MAUMEE MUSSELS. 



During the progress of the Maumee River investigations the para- 

 sites encountered were noted and examples saved for further study. 



Generally speaking, Anodontas and other thin-shelled mussels are 

 more heavily parasitized than the species having thick shells, and 

 parasites are more abundant in shallow, warm, and quiet pools than 

 in rivers. 



The mussels of the feeder canal reservoir Avere more heavily para- 

 sitized than those of the main streams. The following parasites were 

 observed : 



1. Cotylasjyis insigiiis Leidy, a small organism, which to the naked 

 eye resembles a pale leech. The body is trumpet shaped, and the 

 ventral surface has a large ovate disk cut up by partitions. By this 

 disk the animal adheres to its host, and it usually inhabits the axils 

 of the inner gills. It was most common in Anodonta grandis and 

 occurred occasionally in most other species of mussels examined. An 

 example of Lmnpsilu rectus obtained at the riffles contained the sur- 

 prisingly large number of 67 of these parasites. So far as could be 

 ascertained, this parasite produces no marked physiological effect 

 upon the host and appears to do no particular harm. 



2. Aspidogaster conchicola Von Baer bears a close general resem- 

 blance to the above, but is considerably larger, and the adhering 



9275°— 13 10 



