EXPLANATION OF PLATE XXVIII. 



All the figures in this plate are reproduced from Dr. Joseph Leidy's " Parasites of the 

 Termites," contained in the 'Journal of the Academy of Natural Sciences of 

 Philadelphia,' vol. viii., 1881. 

 FIG. 



1-15. TRICHONYMPHA AGILIS, Leidy, vol. ii. p. 552. i and 2, Bilaterally symmetrical 

 animalcules as seen immediately after escaping from the intestine of their 

 host, X 450 ; at i ingested food-particles ; 3-5, symmetrical examples, that 

 at 3 having the anterior or distal region of the body spirally involute, 

 those at 4 and 5 with the entire body contorted into respectively shorter 

 and longer helicoidal contours, x 450 ; 6, bilaterally symmetrical example in 

 a condition of fullest extension, x 450 ; 7-12, supposed immature examples of 

 the same species, those at 7, 10, n, and 12, x 666, those at 8 and 9, 

 X 450, the example at Fig. 7 containing numerous spore-like bodies ; 

 13-15, youngest observed examples, x 666 (Leidy). 



16-20. PYRSONYMPHA VERTENS, Leidy, vol. ii. p. 554. 16 and 17, distinctly ciliated 

 animalcules, that at 16 containing at i numerous ingested particles of wood 

 fibre, ch undulating cord-like structure, x 666; 18-20, examples in which 

 no cilia are visible, the periphery of the body presenting a more or less jagged 

 and membranous aspect, x 666 ; Fig. 19 containing at z numerous ingested 

 food-particles (Leidy). 



21-24. DINENYMPHA GRACILIS, Leidy, vol. ii. p. 555. Various more or less contorted 

 examples, Fig. 21 containing a row of spore-like bodies, and 23 and 24 at z'z" 

 ingested food-particles, x 666 (Leidy). 



