240 ON THE ORGANIZATION OF THE GENUS GREGARINA OF DUFOUR. 



EXPLANATION OF THE FIGURES. (PLATES 11, 12.) 



The figures are all magnified and viewed by transmitted light. 



Figs. 1 to 20. — Gregarina Juli marginati. 



Fig. 1. — An ordinary form in a state of rest; length 1.25th in.; breadth 1.160th in. 



Figs. 2 to 8. — Exhibit various movements of the animal. To the posterior part of figure 8 is observable an 

 attached shred of epithelium. 



Figs. 9 to 12. — Represent younger animals in movement; fig. 9 1.80th of an inch long; fig. 10 1.107th in.; 

 fig. 11 1.160th in.; fig. 12 1.57th in. 



Fig. 13. — An individual, highly magnified, exhibiting the appearance of the contained granular masses, and also 

 presenting to view two globular, nucleated, corpuscles. 



Fig. 14. — The posterior extremity of the same individual more highly magnified. The larger granules at the 

 bottom exhibited very lively molecular movements. 



Fig. 15. — A similar individual with the two sacs burst from pressure, and the contained matters escaping. 

 The longitudinal markings of the inner tunic of the posterior sac are represented. 



Fig. 16. — Posterior extremity of the same individual, with the contents removed, exhibiting the arrangement 

 of the longitudinal lines. 



Fig. 17. — Anterior extremity highly magnified. An apparent canal or opening is represented as existing in the 

 papillary thickening of the integument. 



Fig. 18. — Exhibits the relation of the longitudinally lined tunic of the posterior sac to the cephalic sac. 



Figs. 19, 20. — The two globular nucleated corpuscles of the posterior sac. 



Fig. 21. — Gregarina Juli pusilli. Length 1.250th in. 



Fig. 22. — A younger individual. Length 1.1500th in. 



Figs. 23 to 29. — Various forms and ages of Gregarina Polydesmi virginiensis. 



Fig. 30. — An attached pair of Gregarina Passali cornuti. 



Fig. 31. — A single individual of Gregarina Passali cornuti, in outline, representing the longitudinal lines of 

 the posterior sac. 



Fig. 32. — Gregarina Achetac abbreviate. 



Fig. 33. — A young individual of Gregarina Achetac abbreviatgp. 



Fig. 34. — A young individual of Gregarina Achetae abbreviatae, with a proboscidiform appendage. 



Figs. 35, 36. — Gregarina Locustac Carolina?. 



Fig. 37. — Another individual of Gregarina Locustas Carolina?, with a remarkable proboscidiform appendage. 



Fig. 38. — Corpuscle of the posterior sac of the same individual, with numerous nuclei. 



Figs. 39 to 41. — Three forms of Gregarina Blattae orientalis. 



