958 DESCEIPTION OF THE ENGEAVIXGS. 



21. An encysted specimen ; 22. A ruptured and empty cyst ; 23. Probably the act of 

 fission. The large circular body lying between the two halves is an encysted Oxytricha 

 which has been taken up by the Amoeba. 24-27. Cypliidium aureolum. 28, 29. Grega- 

 rina Sipuncidi ; 29. A double being, the resvdt of fission. 30-32. Progi'essive develop- 

 ment of the contents of a Gregarina from an Annelid (Coeniu-us variegata) into pseudo- 

 navicellse,— in other terms, three pseudo-navicella capsules. 33. G. clavata, 34. G. 

 Sieboldii, full-grown, 35, 36. G. Terebellie ; 36 exliibits longitudinal costse. 37. A 

 group of Psorospermia, from a cyst in the eye of a Cyprinus Tinea. 38 a, h, c. Full- 

 grown Psorospermia : a, viewed in front, X 900 ; b, seen from above ; c, on one side. From 

 the vesicula of Gadus lota. 39. PsorosjDermia from a cutaneous cyst on a Gasterosteus 

 (Stickleback), x580. 40. Psorospermia from a cyst of Gosterosteus aculeatus; a group 

 showing the different stages of development. 41. Psorospermia burst by pressm-e from 

 Cyprinus Brama ; b, the contained amoebiform body isolated, X 900. 42. Epipyxis 

 Utricvdus. 44, 45. Microtheca octoceros. 46. Opalina Lumbrici. 47. O. armata, 

 transverse fission. 48, 49. Dinobryon Sertularia. 



PLATE XXIII. (Protozoa). 



Figures 1, 2. Actinophrys, figured as one phase in the development of Yorticella 

 microstoma by Stein : a, external coat; b, nucleus; c, vesicle. In 2 a ciliated embryo 

 appears within a distinct sac. 3-5. Podophrya fixa (?), represented by Stein as another 

 phase, besides figs. 1 and 2, in the development of Vorticella microstoma. A ciliated germ 

 is seen in 4, which in 5 is about to escape. 6-8. Other forms of Podoph^-ean AcinctjB as 

 figured by Stein : 6, 7. As treated with acetic acid ; the development of an embryo from 

 the nucleus is shown in figs. 7 and 8. 9-14. Vorticella-cysts, after Stein's figures. In 9 

 the nucleus is resolved into monadiform germs ; 10, 11. Development of cyst-contents into 

 secondary cysts, which are further seen in figs. 12 and 13 as become fusiform and protruded 

 through the wall of parent cyst, so as to discharge their monadiform germs without, as seen 

 in fig. 14. 15, 16. Acineta diademiformis, with its embryo. 17-20. A. linguifera, or 

 Acineta with the tongue-like process attributed to Opercularia berberina ; 20 shows an 

 empty capsule. 21. A. digitata, or Acineta with the finger -like processes. 22,23. Acineta 

 attributed by Stein to Opercularia Lichtensteinii ; 23. A specimen acted on by acetic acid. 

 24, 25. Actinoplnys oculata ; 25 represents three individuals in the act of conjugation, 

 treated with acetic acid. The contents of two have intermingled ; a large vacuole with food- 

 particles lies between them. Tlie individual on the other side is simply coherent. (1-26, 

 Stein.) 26, 27. Acineta ferrum-equinum ; 27 shows the escape of the ciliated embryo. 

 The horseshoe-shaped nucleus appears as a clear space. 28. Actinopln-ys Sol. 29, 30. A. 

 Eiclihornii ; 30. A highly magnified section to show the reticiilated structure. 31, 32. A. 

 Sol: 31. In the act of self-division (conjugation ?) ; 32 shows three vesicular expansions 

 concerned in the introduction of food, and an encysted animalcide just brought to the 

 surface. 33-35. Podophrya fixa ; 34. In act of fission ; 35. Segment becoming one inde- 

 pendent and about to separate. 36, 37. Encysted Podoplu-yae. 38, 39. Stages of Podo- 

 plnya towards encysting. 40, 41. Aciuetee with embryos. 42, 43. Transformation of 

 the embryo into an Acineta, figured as commencing in 43, and as completed in 42. 



PLATE XXIV. (Protozoa). 



Figures 274, 275. Lacrymaria Proteus. 276, 277. Leucopln-ys patula. 278. L. 

 Spathula. 279, 280. L. sanguinea. 281. Holophrya Ovum. 282, 283. Prorodon teres. 

 284-286. Coleps liirtus. 287, 287* 288, 289. Trachelius Anas. 290. T. Ovum. 

 291-293. Loxodes Rostrum. 294. Bursaria Yorticella. 295. B. leucas. 296. B. Pupa. 

 296*. Spirostomima vu-ens. 297, 298. S. ambiguum. 299. Phiahna viridis. 300- 

 302. Glaucoma scintillans. 303-309. Chilodon Cucullulus. 310, 311. Nassula elegans. 

 312, 313. Ampliileptus Anser. 314-316. A. Fasciola. 317-319. Trachelocerca Olor. 

 320. T. biceps. 



PLATE XXV. (Protozoa). 



Figures 321-323. Aspidisca denticulata. 324-328. Kolpoda Cucullus. 329-332. 

 Paramecium AureKa. 333. Uroleptus Musculus. 334, 335. Ophryoglena acuminata. 

 336, 337. Oxytricha gibba. 338, 339. Ceratidium cimeatum. 340, 341. Kerona 

 polyjjorum. 342. Urostyla grandis. 343, 344. Stylonychia lanceolata. 345, 346. 

 Discocephalus rotatoriiis. 347, 348. Himantophorus Charon. 349. Clilamidodon 

 Mnemosyne. 350-353. Euplotes Charon. 354, 355. Ptygura Melicerta. 356. Ich- 



