18 PAPERS ON ZOOLOGY OF MICHIGAN. 



formed a conspicuous green growth on the submerged branches of a 

 tree that had fallen into the water. This tree can be seen in Plate V. 



Macrobdella decora. — A few were seen and collected. 



Two species of fish were found, Catostonius catostomus (one small 

 specimen) and Micropterus salmoides (small specimens, less than two 

 inches long), the latter being common. 



Station 7. Sparganium (Plate VI), growing in patches in one to two 

 feet of water, covered much of the bottom of the shoal called Station 

 7. Except for many long slender leaves floating on the surface, the 

 plants were submerged at the time studied. Beyond this growth, to- 

 ward deep water, was a zone of pond weeds {Potomogeton NuttalUi 

 and perhaps other species of the genus), followed Ijy a zone of 

 water lilies, which occupied the deepest part of the shoal and extended 

 out to the beginning of deep water. A small, sandy delta at the mouth 

 of a little creek entering the lake at this point broke the Sparganium 

 zone. 



The follosving fish were caught on the shoal, but a representative 

 collection could not be made on account of the denseness of the vegeta- 

 tion: Se?notilus atromaculatus, Rhinichthys atronasus lunatus, Lepomis 

 cyanellus, Micropterus salmoides. Only a few small specimens of each of 

 the listed species were taken. Ten of the small Semotilus caught were 

 infested with a protozoan parasite, Mijxoholus. Many small fishes were 

 seen. 



Station ^6. The shoal with the greatest amount of plant life of am' 

 visited is on the west side of the lake and just north of a small point of 

 land. This is called Station 46. No attempt will be made to describe 

 the complex association of plants found in this habitat, but an idea of 

 its general character may be had from Plate VII. The water is mostly 

 three or four feet deep and the sand is covered by several inches of 

 humus. 



As at Station 7, the abundance of vegetation did not permit careful 

 seining. Many fish, including some large Semotilus atromaculatus 100- 

 120 mm. long, were seen, showing that this was a favorite fish habitat, 

 and even from the small amount of data obtained it was evidently the 

 type most favored b}' shoal fish. A noteworthy feature was the great 

 abundance of red-bellied leeches, Macrobdella decora, which, while 

 found at other stations in some numbers, were nowhere so abundant 

 as on this shoal. 



The following fish were found at this station: 



Semotilus atromaculatus. — Many seen, none taken. 



Leuciscus neogeus. — Three small specimens collected. 



Micropterus salmoides. — Many small bass were seen l)ut none Avere 



