1921] NATURAL SCIENCES OF PHILADELPHIA. 167 



23. An animalcule swelling up to construct the capsule. 



24. a to g, a young individual, resting on the mucilaginous substratum, 

 then straightening, pushing down a pedicle and beginning the con- 

 struction of the capsule. 



25. a, unequal division; b, the small flagellate which comes from the un- 

 equal division. 



26. Encystment; the cyst is complete, except at the anterior extremity, 

 where the protoplasmic collar and the flagellum are seen expanded. 



27. Another cyst, entirely closed. 



28. Another form of encystment, in a balloon-like capsule. 



Plate VI. — Figs. 29-33. — Salpiiigoeca lepidula. 



29. Typical form. 



30. Division; the young animalcule sliding down the old capsule. 



31. The same animalcule, J^ minute later; nearly reaching the substratum. 



32. A young animalcule attaching. 



33. Construction of the capsule; above to the left is shown a large microbe 

 which fell upon the neck, then slowly glided along the ectoplasm and 

 stopped opposite the contractile vacuole. 



Plate VII. — Figs. 34-40. — Salpingoeca lepidula. 



34. Swimming form of the animalcule, after abandoning the capsule. 



35. An individual completing the eon.st ruction of the capsule; the primi- 

 tive fixation thread is still to be seen. 



36. An animalcule, whose ectoplasm is expanding in filamentous pseudo- 

 podia. 



37. Thickening of the protoplasmic collar, by means of intruding ecto- 

 plasmic material. 



38. The same, a few minutes later. 



39. Another specimen, with ectoplasmic material climbing up along both 

 the collar and the flagellum. 



40. An individual with a sheet of ectoplasm, climbing up along the inner 

 surface of the collar. 



Figs. 41-44.- — Chrysavioeba radians. 



41. The Amoeba state. 



42. A flagellate, about to revert to the Amoeba state. 



43. Flagellate state. 



44. Division. In a, the division is as yet but little advanced; the two 

 V-shaped chromatophores, together forming a TI', are seen in the middle; 

 to the left, a large mass of leucosine. In b, the body has lengthened; 

 in c, it begins to be distinctly narrower in the middle; the leucosine 

 mass has lengthened; the large vacuole is larger still; in c, the leucosine 

 body is already rod-like in form; in d, the large vacuole has burst. 

 In c, the separation is nearly effected; half of the leucosine body passes 

 to each of the new individuals. In /, the new individuals are sepa- 

 rated. 



Figs. 45-49. — Chrysopyxis bipes. 



45. Normal appearance. 



46. Special form, without tubular opening; the body is in process of di- 

 vision ; one pseudopod only, down which microbes are gliding. 



47. An animalcule about to leave the capsule. 



48. The same, swimming about after leaving the capsule. 



49. No tubular opening. At the base of the psudopodia, an accumula- 

 tion of microbes, about to disappear into the common trunk. 



Plate VIII. — Figs. 50-54. — Hyalobryon ramosum. 



50. Normal aspect of the animalcule, with its caudal adhesive filament 

 (which is represented too short, as well as the enveloping tube also). 



51. A bunch of empty tubes, straight. 



52. A bunch of empty tubes, contorted. 



53. Tubes in a fascicle, attached to a diatom. 



54. Several tubes inserted one within the other. 



