MUSSEL FAUNA OF THE KANKAKEE BASIN. 



33 



feet in the river. These make this part of the river unnavigable. 

 Accordingly, the boat and outfit Avere shipped from Kankakee, and 

 the remaining portion of the river was worked from the railroad. 



From Wilmington, the nearest station, we drove to the house of 

 Mr. Jesse Fairchild, on the north bank of the river. He kindly lent 

 us his boat and told us where to find a mussel bed, which he said 

 was the only one for some distance up and down the river. 



It lay along the edge of a riffle where the water was about 2 feet 

 deep and the current 5 or 6 miles an hour. The bottom was entirely 

 covered with stones of all sizes and shapes, mostly well rounded, and 

 thrown together with small pockets between them. These pockets 

 were filled with sand or fine gravel, and in them the mussels were 

 found. The stones, the gravel or sand, and the mussels were all 

 covered with a dense coating of dark green algse. 



All the mussel specimens obtained were small, for large ones can 

 not crowd in among the rocks, and many of the females were gravid. 

 L. ligamentinus was the most common species, and every specimen 

 showed clearly the radiating rays on the external surface. 



Marginal cysts were found in some of the S. edentulus and L. liga- 

 mentinus^ and a few Atax in one L. ventrieosus, but as a whole this 

 lot of mussels was remarkably free from parasites. The number of 

 species at this station was only equalled by those which were obtained 

 from the 15 tons collected at Momence by the mussel fishermen. 



Statio7h 32. Wilmington^ III. — This station was just below the 

 road bridge across the Kankakee Eiver, between the second and 

 third dams. The river here has a rocky bottom and is practically 

 one continuous riffle with a very swift current. There was a large 

 outcrop of limestone on the shore and more appeared in the bed of 

 the river. 



The collecting was very difficult, but the few live mussels found 

 were supplemented by a large pile of freshly cleaned shells on the 

 shore, probably left by a pearler. All the shells were large and well 

 developed, particularly the L. ligamentimts and S. costata. The L. 

 \ ventricosus and rectus had an exceptionally good luster and were of 

 excellent quality ; the other species were about average. 



Station 33. Forked Creek^ Wilmington^ III. — Tl^^s is a rather small 

 creek that runs into the Kankakee from the north, and is made up 

 of alternating pools and riffles. In the riffles the bottom is rocky, 

 with many gravel and sand bars; in the pools there is more or less 

 mud. The main vegetation is water willows, with occasional yellow 

 water lilies and Philotria^ and everywhere an abundance of tough 

 algae. Most of the shells were dead and seemed to have been killed by 

 muskrats. The live specimens of A. calceola^ S. edentulus and L. 

 ellipsiformis were all gravid. The L. ventricosus and ligamentinus 

 and the Q. undulata were all small in size, but otherwise normal. 



