RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 1 67 



7. The same as No. 6, with lateral red V-like marks. 



Among these more marked varieties others were noticed which 

 were more or less of an intermediate character. The most common 

 variety was that which was least distinguishable in color from the 

 animal's location, the tobacco leaf, so that it was especially favored 

 in its preservation. 



Prof. Leidy further remarked that the past season had appeared 

 to be favorable to many of the Lepidoptera. Our shade-trees had 

 been greatly ravaged by the Orgyia, many of the poplars had suf- 

 fered from the Clostera inclusa, and he had observed an unusual 

 quantit}^ of the Ailanthus silk-worm, Attaciis cynt/iia, upon the 

 Ailanthus trees. The latter was introduced here in 1861 by Dr. 

 Thomas Stewardson. 



[October, 1882. No 500 See Bibliography] 



ROTIFERA WITHOUT ROTARY ORGANS. 



The Rotifera or Wheel-animalcules form a small class, abundant 

 in kind and found almost everywhere in association with Algse, 

 and with Infusorians, to which they were formerly considered to 

 belong. Later they have been recognized as not having the simple 

 cell structure of the latter, and for a time were regarded as pertain- 

 ing to the Crustacea. They are now commonly looked upon as 

 belonging to the group of worms, but their relative position cannot 

 yet be considered as positively determined. They generally po.ssess 

 a chitinous integument, with a more or less annulate disposition or 

 tendency to articulate division, but they are destitute of limbs. 

 Some are provided with a carapace, and recall crustacean forms, 

 but in other points they exhibit but little likeness to them. Their 

 usually striking characteristic, the rotary disks, from which they 

 are named, is not possessed by any well-marked Crustacean. Among 

 the Rotifera, however, there appear to be some which do not possess 

 the rotary organs, at least in the mature condition, and yet in all 

 other respects the animals conform in structure with ordinary forms. 



>1< ;|< ;i; * * * * 



[The above is extracted from the original paper for reference. 

 The whole paper is not included.] 



[October, 1882 No. 501. See Bibliography.] 



A iVnc Infusorian Belonging to the Genus Pyxicola. — Prof. Leidy 

 exhibited drawings of an infusorian, a species of Pyxicola, which 



