row boat, and pulled ihicjugh th^- water at a distance of 16 

 or 20 feel from the boat itself, filtered the inrushing tide, 

 which also kept it inflated and gathered a film of algae 

 (oscillatori?e) in its pores, which in turn entrapped and re- 

 tained associated forms. This film was washed oflP into a 

 saucepan, and the washings^poured into settling bottles, from 

 whose sediment the material for microscopic examination 

 was obtained. Dredging was resorteti to upon Harlem 

 Lake (the upper Iske). but it did not reveal any molluscous 

 life, though the silt drawn up contained numerous diatoms. 



Our examination has not revealed as many varied forms 

 of life as we had expected, and among the algse we have 

 failed to detect forms considered as more or less prevalent 

 in the C rot on water. A noticeable absence of desmids and 

 rhizopods was something of a surprise, as also the deficient 

 representation of algae. One form of osciilatoria (Ochlo- 

 rina), however, filled the waters of the lower lake at every 

 point, and its waving and crowded filaments produced a 

 turbid and flocculent appearance thatis curiously deceptive, 

 resembling clouds of some impalpable precipitate in the 

 water. Among the threads of the osciilatoria were scat- 

 tered chains of auabtena and nostoc. Spirogyra in limited 

 and depauperate colonies were found near Ihe shore, and 

 braids and collections of a stigeoclonium-like algae else- 

 where. 



Desmids are strikingly absent in our collections, but these 

 may be discovered by later examinations. It seems pro- 

 bable that the staiinant. offensive state of the water naay 

 exercise an injuri(ms influence on the multiplication of 

 these objects, and the deficiency of fresh water hasten their 

 death and decomposition when introduced. The diatoms 

 are comparatively numerous, and found in numbers among 

 the clusters and' knots of algae moving and disseminated 

 through the surface waters, and entombed in the mud of 

 the bottom. The infusoria in numbers exceeded all other 

 objects, though the species enumerated are not many. 

 These will be extended in future examinations. These 

 puzzling creatures have gi^eu us great entertainment, and 

 representing the nucleus of that ill-defined and chaotic 

 assortment of objects known as ardinalrula will have in 

 later and fuller lists more attention paid to them, as their 

 identification has been rendered more possible by the ex- 

 tended treatise of Saville Kent. 



The Crustacea; were strikingly few in species, though in 

 some spots abundant in numbers; cy clops, cypris, daphnia, 

 being prevalent and widespread. 



Rotifers were frequent: vermes were found on sticks and 

 through the algae, and the species of larva indicated was 

 seen associated with a new species (?) of spongilla to which 

 in the list we havi- appended a note. Among micrococci, 



