Mussel fauna of the kankak:ee bastn. 



23 



at the end of long tracks that looped and turned upon themselves. 

 Some OsciUatoria was found growing on the quieter shells. 



Three or four miles farther down the river the old channel crossed 

 the ditch again. Here in the deeper parts of the pools the mussels 

 fairly touched one another. A pearler had been working on these 

 mussels and had left a couple of large piles of freshly killed shells 

 on the bank. 



Along this stretch of river we obtained the first good evidence that 

 the mussels are reestablishing themselves in the dredged channels. 

 Living specimens were fairly common near the shore. 



This part of the river was once the bottom of English Lake, a 

 marshy overflow from the Kankakee, 10 or 12 miles long, 2 or 3 in 

 width, and of shallow depth. It was filled with algse of all kinds, 

 reeds, rushes, water lilies, and an abundance of wild rice, and formed 

 a natural breeding ground for thousands of waterfowl. It must 

 have fairly swarmed with mussels, to judge from the dead shells of 

 those thrown out by the dredge and the large numbers still found 

 alive in every portion of the old channel that contains water. The 

 dredging has entirely drained the lake and it is now a straight cross- 

 country ditch, with the mussels gradually repopulating it. The con- 

 ditions here are much more favorable than in the Yellow River, and 

 a little artificial restocking would restore the mussel fauna in a few 

 years. 



On cleaning the mussel shells we found them an interesting lot. 

 The L. luteolus were all more or less blistered and steel-colored at 

 the tips of the valves, and frequently the whole shell was curiously 

 roughened. They yielded many small pearls, all located near the 

 tip of the mantle in the region of the siphons. And they usually 

 had a number of young Atax crowded around the exhalent orifice. 

 So far as our experience goes this is a rather unusual position for 

 young Atax. Their ordinary situation is along the lips of the in- 

 halent aperture. Q. pustulosa also contained many Atax^ but they 

 were not as numerous as at station 15. Four of the Q. coccinea had 

 white nacre and all the L. rectus were pink instead of the deep 

 purple of those farther up the river. Parasites were also found 

 occasionally in L. ventricosus^ L. ligamentinus^ and Q. undulata. A 

 few of the ventricosus and luteolus were gravid or beginning to 

 become so. 



Station F. Bass Lake^ Starke County^ Ind. — This lake is fourth 

 in size among the Indiana lakes and covers an area of 2J square miles. 

 It lies in the southeastern part of the county, about 6 miles south of 

 Knox. It is somewhat boot-shaped, the leg portion elongated 

 northeast and southwest, the foot portion at right angles to this. It 

 I occupies a shallow basin on the top of a morainic ridge and more 

 I than half of its area is 5 feet or under in depth; the maximum 



