"1 



Stokes.] ' ^ [April 13, 



Measurements. 



[' m c 32 mm. 



I first phalanx 15 " 



3d digit. .. J second " 15 " 



third " 9 " 



fourth " 4 " 



, m. c 31 " 



) first phalanx 14 " 



4th digit.. < second „ u « 



1 third " \ " 



sin. c 33 " 



_,,,.. J first phalanx 14 " 



5th digit. . < „. ., 



6 J second " 10 " 



^ third " 1 " 



Length of femur 15 " 



" tibia 16 " 



" foot 13 " 



" tail 25 " 



" free portion of tail 3J " 



Notices of New Fresh-water Infusoria. 



By Alfred G. Stokes, 31. D. 



(Bead before the American Philosophical Society, April IS, 1S90.) 



Mastigamaiba reptans, sp. nov. Figs. 1-5. — Body constantly amoeboid, 

 at its apparently greatest extension ovate, depressed, about two and one- 

 half times as long as broad, the pseuclopodia few, scattered, lobate, short 

 and uubranched, progression being chiefly by the amoeboid expansions of 

 the body ; flagellutn apical, about three times as long as the extended 

 zooid, only the tip usually vibrating ; nucleus not observed ; contractile 

 vesicles several, small, scattered ; motion commonly very slow, occasion- 

 ally rapidly and irregularly vibratory. Length of the extended body TJ \^ 

 inch. Hab. — Pond water with decaying vegetation. 



Heteromitafasiformis, sp. nov. Figs. 6 and 7.— Body elongate fusiform, 

 from three to four times as long as broad, widest centrally, tapering 

 thence to both extremities ; soft and changeable in shape, having the 

 ability to protrude filamentous pseudopodic prolongations of the body 

 substance, the extremities of these extensions not rarely becoming amoe- 

 boid and producing a reticulation by the interlacing of the minute 

 branches or by the formation of minute vacuoles; fligella diverse in length, 

 originating close together at the frontal extremity, the anterior one 

 vibratile, less than twice as long as the body, the other trailing and more 

 than twice the body in length ; contractile vesicle small, apparently 



