MUSSEL FAUNA OF THE KANKAKEE BASIN. 17 



drained into them is limited. In general, they are surrounded by 

 high banks of clay with only a little sand and gravel. They are 

 fed largely by springs, nearly the whole shore line being marshy, 

 with only a few bits of sandy beach. 



Three of the lakes, Lorance, Meyer's, and Cook, were carefully 

 examined for mussels; nothing was found in the one first mentioned; 

 the other two yielded returns as follows: 



East Lake (Meyer's) is considerably the shallower and warmer 

 of the two; the bottom is a firm sandy marl, with scattered patches 

 of Chara and Pofarnogeton, while the shores were fringed with pick- 

 erel weed, water lilies, reeds, bulrushes, and similar vegetation. The 

 mussels were rather widely scattered, but formed beds where they 

 did occur. Only tAvo species were found, Anodonta grandis and 

 Lam})s'dis suht'ostratus, the former in far greater abundance than the 

 latter. The subrostratus yielded no parasites at all, the grandis 

 were fairly loaded vvath them, every specimen yielding large numbers. 

 They included Atax. of several species, prominent among which was 

 a rather small, deep-red one, Cotylaspis^ marginal cysts, and the 

 distomid of Osborn. The cysts of the marginal distomid were 

 especially abundant and number hundreds in many of the specimens, 

 while one must have had fully a thousand. The distomid of Osborn 

 formed great pink patches under the umbo and tinged nearly all 

 the shells with a reddish salmon color. 



Northwest Lake (Cook) is deeper and the water was clearer and 

 colder. Like East Lake the bottom is a firm sandy marl, covered 

 in many places with Chara. The shallow water along the shore 

 was one solid mass of reeds, bulrushes, and lil}'- pads. The mussels 

 were widel}^ scattered and the same two species were found as in 

 East Lake, with the addition of L. liUeolus. As before, grandis was 

 much the more common ; the older examples were found with their 

 shells high out of the sand, just enough being buried to hold them 

 in place. The younger examples were more deeply buried. Many 

 small fishes were seen upon the mussel beds ; they included Notropis 

 hlennius, Fundulus dispar^ and the young of Lepomis pallidus and 

 Erimyzon sucetta. 



Samples of plankton were secured from the clear water in the 

 center of the lake at a depth of 8 feet. There were found five 

 species of copepods, most of them covered with VorticeUa^ small 

 pink water mites, Daphnia^ a few nauplii, Lyjighija, minute Spiro- 

 gyra^ Anurasa cocKLeans., Ceratium, krrudinella^ Fragillaria croton- 

 ensis, and Anahcena. This was the richest plankton obtained during 

 the summer, and yet the water appeared perfectly clear. 



On examining the mussels they were found to be as badly in- 

 fested with parasites as those of East Lake, but here the Atax and 

 Cotylaspis were far more numerous, and there were not as many 



