NATURAL SCIENCES OF PHILADELPHIA. 8t 



the vicinity of our city, tliere was one especially remarkable for 

 the comparatively enormous quantity of quartzose sand wliich it 

 swallowed with its food. The animal might be viewed as a bag 

 of sand ! It is a sluggish creature, and when at rest appears as 

 an opaque white, spherical ball, ranging from |^ to | of a line in 

 diameter. The animal moves slowly, first assuming an oval and 

 then a clavate form. In the oval form one measured f of a line 

 long by I of a line broad, and when it became clavate it was f of 

 a line long b}' |^ of a line broad at the. advanced thick end. An- 

 other, in the clavate form, measured | of a line long by ^ of a 

 line wide at the thick end. The creature rolls or extends in ad- 

 vance while it contracts behind. Unless under pressure it puts 

 forth no pseudopods, and the granular entosarc usuallj^ follows 

 closely on the limits of the extending ectosarc. Generally the 

 animal drags after it a quantity of adherent dirt attached to a 

 papillated or villous discoid projection of the body. 



The contents of the animal besides the granular matter and 

 many globules of the entosarc, consists of diatomes, desmids, 

 and confervas, together with a larger proportion of angular particles 

 of transparent and mostly colorless quartz. Treated with strong 

 mineral acids so as to destroy all the soft parts, the animal leaves 

 behind more than half its bulk of quartzose sand. 



The species may be named Amceba sabulosa, and is probably 

 a member of the genus Felomyxa, of Dr. Greef (Archiv f. Mik. 

 Anat.,:s., 1873, 51). 



The animal was first found on the muddy bottom of a pond, on 

 Dr. George Smith's place, in Upper Darby, Delaware County, but 

 has been found also in ponds in New Jersey. 



When the animal was first noticed with its multitude of sand 

 particles, it suggested the probability that it might pertain to a 

 stage of life of Difflugia^ and that by the fixation of the quartz 

 particles in the exterior, the case of the latter would be formed. 

 This is conjectural and not confirmed b}-^ any observation. 



A minute amoeboid animal found, on Sjnrogyra, in a ditch at 

 Cooper's Point, opposite Philadelphia, is of interesting character. 

 The body is hemispherical, yellowish, and consists of a granular 

 entosarc with a number of scattered and well-defined globules, 

 besides a large contractile vesicle. From the body there extends 

 a broad zone, which is colorless and so exceedingly delicate that 

 it requires a power of 600 diameters to see it favorabl3% B}'' this 

 zone the animal glides over the surface. As delicate as it is, it 

 evidently possesses a regular structure, though it was not re- 

 solved under the best powers of the microscope. The structure 

 probably consists of globular granules of uniform size alternating 

 with one another, so that the disk at times appears crossed by 

 delicate lines, and at others as if finely and regularly punctated. 

 The body of the animal measures from ^\ to g^^ of a line in dia- 

 meter, and the zone is from ^ J^ to 5^^ of a line wide. The species 

 may be named Amoeba zonalis. 



