Dinfoiiis, 



Amphipleura sp V 

 Actinocyclus niagar.i- 

 Cocconeis sp? 

 Cyclotclla rotula. 



" astra>a. 



Cymbella affiuis. 

 Bacillaiia paradoxa. 

 Fragillaria capuciiia. 



acuta. 

 Licmophoia flabellata. 

 Naviculasp? 



" rhynchocepbalus. 



" placentula. 



Protozf 



Navicula rhomboides. 

 inflata. 

 cuspidata. 

 Melosira crenulata. 



crotoaensis. 

 Nitzscbia longissima. 



" sigmoida. 



Pleurosigma spenceri. 

 Stepbanodiscus niagartie. 

 SynediM capitata. 



ubia. 

 Goiupbonema constrictum. 

 acuminatum, 

 oans, etc. 



Vibrio bacilhis. 

 " spiralis. 



Schizomycete><. 



I Bacterium terrao' 



Amoeba proteus. 

 Actinopbrys sol. 



RJiizopoda. 



I Cocbliopodium bilimbosum. 

 ! Difflugia urceolata. 



^pongida. 



Spongilla fragibs? The specimen wbicb was identified as 

 tbis sponge was gathered upon tbe surface of rocks in a 

 stream of artificially supplied water, tributary to tbe Harlem 

 Lake. It was sent to Prof. E. Potts, of Philadelphia, who 

 kindly acknowledged it, and said that tbe weight of evidence 

 was in favor of Spongilla fragilis, but the absence of stato- 

 blasts prevented any entirely satisfactory identification. 



Spongilla? sp? This specimen, which caused us consider- 

 able perplexity, and which may be quite wrongly classified, 

 was found attached to sticks of rubti.s, floating in the water, 

 in the form of low spine-like projections in groups, which 

 under tbe microscope were seen to be composed of hollow 

 needles irre^gularly blotched with brown patches, and quite 

 densely hispid with hairs of various lengtbs, wbicb seemed 

 fascicled. These needles or tubes were irregularly lobose 

 and swollen at points, and seemed striated. Tbe slender 

 ends were terminated by long flagellum-like hairs. Among 

 these moved a vermiform larva with a mop-like head of re- 

 curved hooks at one extremity. 



