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MANUAL OF THE INFUSORIA.

VOLUME III. PLATES.

" Our little systems have their day,

They have their day and cease to be ;
They are but broken lights of Thee,
And Thou, O Lord, art more than they."

TENNYSON, In Memoriam.

JXONTISPIECE

A COLLARED MONAD. _. MONOSIGA GRACILIS, S. K.

Artificially fed. with Carmine , The- Arrows denote the direction, of the current', educed
by the. rotatory- motion, of the, Flag Mum-, and the course -taken, by the Food- particles on-

striking against anil adheruig to the extended Colla-r . c.l. Collar, ft. _Flaqf/ l:iin .

$9- F°<* •- " Eiu.lvpla.st orS-iiclrns. c.v. Contractile ve

MANUAL OF THE INFUSORIA:

INCLUDING A DESCRIPTION OF ALL KNOWN

BRITISH AND FOREIGN,

AND AN ACCOUNT OF THE

OKGANIZATION AND AFFINITIES OF THE SPONGES.

W. SAVILLE KENT, F.L.S., F.Z.S., F.R.M.S.,

FORMERLY ASSISTANT IN THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH ML'SBUM.

VOLUME III. PLATES.

LONDON:

DAVID BOGUE, 3 ST. MARTIN'S PLACE,

TRAFALGAR SQUARE, W.C.

1880-1882.

PLATE I.

The following abbreviations retain the same significance throughout the present and
succeeding Plates : —

n. Nucleus or endoplast.
c v. Contractile vesicle.
f. Flagellum.

cl. Collar.
o. Oral aperture.
an. Anal aperture.

Where the figures are borrowed from another authority, the name of such authority is
bracketed ; where no bracketed name appears the figures are derived from the author's
original investigation.

EXPLANATION OF PLATE I.
FIG.

i, 2. TRYPANOSOMA SANGUINIS, Grube, x 600 (Ray Lankester).
3-6. TRYPANOSOMA EBERTHI, S. K., x 1200 (Eberth).
7, 8. ACTINOMONAS PUSILLA, S. K. — 7, Zooid attached by a single stalk-like filament ;

8, zooid attached by a number of its ray-like pseudopodia, x 800.
9-11. ACTINOPHRYS SOL, Ehr. — Successive developmental phases out of a primary

monadiform germ, as observed by the author, x 600.

12-17. MAGOSPH^ERA PLANULA, Hkl. — 12, Adult spheroidal colony-stock, x 240; 13,
ideal optical section of the same ; 14, a single isolated zooid derived from the
disintegration of the social colony-stock ; 15, a similar zooid having assumed
an amoeboid phase ; 16 and 17, encysted zooids, the one at 17 having divided
by segmentation into four spheroidal sporular bodies (Haeckel).
18. ACTINOMONAS MIRABILIS, S. K., x 800.
19, 20. MASTIGAMCEBA RAMULOSA, S. K., extended and contracted conditions, x 400.

21. MASTIGAMCEBA ASPERA, Sclz., x 170 (Schulze).
22, 23. MASTIGAMCEBA MONOCILIATA, Carter sp., dimensions unrecorded (Carter).

24. EUCHITONIA VIRCHOWII, Hkl., x 370 (Haeckel).

25. SPONGOCYCLIA CHARYBDEA, Hkl., x 72 (Haeckel).

26, 27. RHIZOMONAS VERRUCOSA, S. K. — 26, Animalcule enclosed within granular
gelatinous sheath, X 750 ; 27, example devoid of such covering.

28, 29. PODOSTOMA FILIGERUM, C. & L. — 28, Animalcule with flagelliferous pseudo-
podia extended ; 29, example with appendages entirely retracted, x 250
(Clap, and Lach.).

30. MASTIGAMCEBA SIMPLEX, S. K. — Having attached by a posteriorly extended
thread of sarcode the frustule of a diatom, probably ejected from its body,
X 800.

31-33. REPTOMONAS CAUDATA, S. K. — 31, Normal animalcule, profile view, x 800;

32, Dorsal view of example with short posterior pseudopodal extensions ;

33, a similar example in the act of ingesting food by the peripheral exten-
sion of its body-sarcode.

34-44. NOCTILUCA MILIARIS, Suriray. — 34, Normal adult animalcule, X 40; 35 and
36, peripheral regions of two animalcules having variously developed masses
of germinal bodies, x 50 (Cienkowski) ; 37, a similar germinal patch more
highly magnified, and showing its composition of uniflagellate monadiform
elements (Cienk.) ; 38-40, isolated monadiform germs in different aspects and
phases of development, X 500 (Cienk.) ; 41, more abnormal zoospore-like
germ, x 500 (Cienk.) ; 42, entire adult animalcule, dorsal view, showing
median groove, stylate rod, and tooth-like process (Huxley) ; 43, latero-
inferior view, showing oral cavity with tooth-like process and contained
cilium (Huxley) ; 44, conjugation of two animalcules (Cienk.).

45. Encysted condition of Noctiluca, figured by Wyville Thomson as a new diatom,
Pyrocystis pseudo-noctiluca, x 30 (Wyv. Thorn.).

46-53. LEPTODISCUS MEDUSOIDES, Hwg. (Hertwig) — 46 and 47, Two animalcules with
edges variously folded, nat. size ; 48, animalcule extended, x 40 ; 49,
zooid in vertical section, showing the thicker central and more attenuate
peripheral regions ; 50, segment of a similar section more highly magnified,
showing oblique tubular oral fossa, superiorly attached flagellum, and at
a a a superficial oil-like globules; 51, endoplast or nucleus of adult animal-
cule, x 100; 52 and 53, supposed developmental phases of Leptodiscus,
with, in the former instance, one-half of the cyst-like body-wall contracted.
54. PYROCYSTIS FUSIFORMIS, Wyv. Thomson.— Probably the encysted condition
of Leptodiscus, X 35 (Wyv. Thorn.).

PLATE 1.

PLATE II.

EXPLANATION OF PLATE II.

FIG.

i, 2. CODOSIGA ALLOIDES, S. K. — i, Umbellate adult colony-stock, or zoodendrium,

bearing numerous terminal clusters of associated collared zooids, x 650;

2, a single zooid or animalcule with its body spherically, and collar conically

contracted, x 800.
3. MONOSIGA GRACILIS, S. K., X I2OO.

4-6. MONOSIGA GLOBULARIS, S. K. — 4, Adult zooid, x 1500; 5, free-swimming
monadiform germ ; 6, subsequent attached condition of free-swimming germ,
the characteristic collar and pedicle being as yet undeveloped.
7-9. MONOSIGA BREVIPES, S. K. — Exhibiting diverse protean contours, x 1200.

10, ii. CODOSIGA GROSSULARIA, S. K. — 10, Normal adult colony-stock, x 1000 ;
1 1, smaller colony of three zooids only, having their collars conically con-
tracted, and protruding numerous lateral, digitiform, pseudopodic processes.

12, 13. ASTROSIGA DISJUNCTA, From. sp. — 12, Free-floating colony as imperfectly
delineated by De Fromentel, the lateral margins of the collars and bases of
the enclosed flagella only being represented, x 600; 13, the same colony
further enlarged, the details missing in the preceding figure being added by
the author.
14. CODOSIGA PYRIFORMIS, S. K., x 1200.

15-19. CODOSIGA FURCATA, S. K. — 15, Colony of two zooids as observed by the author,
x 1200; 16-19, imperfectly observed colony-stocks of various dimensions,
as figured by Stein in the year 1854 ('Die Infusionsthiere,' Taf. iii. figs. 42
and 43), as probable young conditions of Epistylis digitalis or Zootham-
nium Jxzrasila, x 450.

20, 21. CODOSIGA STEINII, S. K., figured by Stein (Wiegmann's 'Archives,' 1849), as
probable young conditions of Epistylis (Opercularicf) nutans, x 300.

22-29. CODOSIGA (EPISTYLIS) BOTRYTIS, Ehr. sp. (C. pulcherrima, Jas.-Clk.). —

22, Colony-stock with pendulous zooids diagrammatically outlined, x 1000;

23, smaller colony with three erect zooids; 24, single zooid dividing by
longitudinal fission, the process having already extended through the body
and the proximal region of the contracted collar ; 25, two zooids assuming
an amoeboid condition, their collars and flagella being entirely retracted
and digitiform pseudopodia protruded from all parts of their periphery;
26, a single zooid emitting similar but more slender pseudopodic processes,
the collar and flagellum remaining extended, x 2000 ; 27, sporocyst with
contained spores derived from the encystment and segmentation of a single
zooid ; 28, earliest illustration of the species in which the existence of the
characteristic membranous collars is clearly indicated, as given by Fresenius
in the year 1858 ; 29, associated colony-stocks crowded upon a confervoid
filament, x 120.

30. DESMARELLA MONILIFORMIS, S. K. — A free-floating colony-stock of eight

laterally united zooids, x 1 200.
31, 32! MONOSIGA ANGUSTATA, S. K. — 31, Normal adult zooid, x 2500; 32, immature

or larval condition with the collar as yet undeveloped.
33-35. MONOSIGA OVATA, S. K. — 33 and 34, Typical zooids, x 1200; 3$ zooid

abnormally prolonged preparatory to dividing by transverse fission.

PLATE E.

KM* del,

PLATE III.

EXPLANATION OF PLATE III.
FIG.

1. SALPINGCECA or MONOSIGA sp.— Figured in Mr. Carter's MS. note-book with-

out description, Bombay, Aug. 1855.

2. SALPINGCECA or MONOSIGA sp.— Figured by R. Greeff (Wiegmann's 'Archiv,'

Heft vi., 1870) as minute Flagellata attached to pedicle of Epistylis
flavicans.

3-7. CODOSIGA CYMOSA, S. K. — 3 and 4, Fully developed colony-stocks, or " zooden-
dria," x 1250; 5, branchlet with three zooids, the one at a being of abnormal
size ; 6, branchlet with two zooids, the one at a having encysted and
separated by segmentation into two equal halves ; 7, apparent abnormal
colonial growth of the same species ?
8, 9. CODOSIGA CANDELABRUM, S. K., x 800.

10-12. SALPINGCECA MINUTA, S. K. — 10, Two adult zooids and a single undeveloped
germ (a) attached to an empty lorica of Dinobryon sertularia, X 1000 ;
n, a single zooid further enlarged ; 12, a zooid with collar withdrawn pre-
senting a semi-amoeboid condition.

13-15. SALPINGCECA MARINA, J.-Clk.— 13, Early and naked condition ; 14 and 15,

adult zooids with loricae developed, x 1 800.
1 6. SALPINGCECA PYXIDIUM, S. K., x 1000.

17-21. SALPINGCECA AMPULLA, S. K. — 17, Adult zooid with fully developed lorica,
X 1250 ; 1 8, empty lorica ; 19, zooid with lorica imperfectly developed and as
yet mucilaginous in consistence, at a, a monoflagellate collarless germ attached
to the exterior of the lorica; 20, a germ which has become attached and
commenced to develop its collar and protective lorica; 21, a more
advanced growth of the same zooid.

22-24. Minute flagellate and apparently collar-bearing loricate monads (Salpingceca),
attached to pedicle of Epistylis flavicans, as delineated by Greeff, x 300.

25. LAGENCECA CUSPIDATA, S. K., x 1500.

26. SALPINGCECA PETIOLATA, S. K., x 1250.

27, 28. POLYNCECA DICHOTOMA, S. K. — Two social colony-stocks or polythecia,
x 1000.

PLATE HI.

W Small. Kmt d:

PLATE

EXPLANATION OF PLATE IV.

FIG.

1-5. CoDOSIGA UMBELLATA, Tatem sp. — i, More normal and adult colony-stock
with compound pedicle or zoodendrium, tripartitely branched, x 625 ; 2, a
single zooid, X 1250; 3, a simpler growth of the same fundamental formula;
4, an example with the pedicle quadripartitely branched (Tatem) ; 5, an ab-
normal type with five primary subdivisions of the supporting pedicle (Stein).
6-10. CODOSIGA (EPISTYLIS) BOTRYTIS, Ehr. sp. (Stein). — 6, An abnormally luxuriant
colony with a spheroidal cluster of associated zooids, at a one of the latter
detached from the parent stock, x 650 ; 7, a colony-stock in which at a a
larger zooid is dividing by longitudinal fission, the group of four smaller ones
at b having been derived from similar repeated subdivision of an original
single zooid ; 8, a free-swimming zooid detached from a sedentary colony ;
9, coalescence or conjugation of a similar free swimming zooid with a normal
sedentary form ; 10, a zooid emitting minute pseudopodic processes which
present the aspect of adherent Bacteria.

11. SALPINGCECA CAMPANULA, S. K., x 1250.

12. MONOSIGA STEINII, S. K. — Five zooids attached to a stalk of Vorticella con-

vallaria, x 650 (Stein).

13-16. SALPINGCECA CONVALLARIA, Stein (Stein).— 13, Three normal zooids attached to
stem of an Epistylis, x 650 ; 14, a zooid dividing by longitudinal fission ;
15, zooid with lorica of an irregular and abnormal form; 16, a detached
and free-swimming zooid.

17. MONOSIGA FUSIFORMIS, S. K. — A social group, x 1800.

1 8. MONOSIGA LONGICOLLIS, S. K., x 1800.

19-21. MONOSIGA SOCIALIS, S. K. — 19, A group showing at « a zooid with collar and
flagellum withdrawn about to enter upon an encysted state, and to the
extreme right an example with a short pedicle, x I5°o> 2O and 21, zooids
with collars and flagella retracted and assuming a vacuolar amoeboid phase.

PLATE IV

PLATE V.

EXPLANATION OF PLATE V.
FIG.

1-9. SALPINGCECA AMPHORIDIUM, J.-Clark. — i, Social colony attached to confervoid
filament, x 625 ; 2, a separate and normal zooid with collar fully expanded,
x 1250 ; 3, a zooid with collar contracted, and with lorica supported on a
rudimentary pedicle; 4, zooid encysted within its lorica; 5, zooid with collar
entirely retracted, the flagellum remaining, but much thickened at its base,
and the body-sarcode protruding in a lobose form ; 6, anterior region of
zooid, showing its protrusion from the lorica in the form of a fascicle of
filamentous pseudopodia ; 7, a zooid in which the protruded sarcode has
assumed a branched, pinnatifid, contour ; 8, the protruded sarcode of the
same zooid having become detached, and resembling a stellate floating
amoeba, x 1250; 9, a more minute stellate amceba-like body found floating
in the same vicinity, and probably possessing a similar derivation.

10-12. SALPINGCECA STEINII, S. K. — 10, two rosette-shaped colonies, and four more
isolated zooids attached to the pedicle of Epistylis anastatica, x 300 (Stein) ;
1 1, a single zooid (Stein); 12, a colony, as found by the author, attached
to the pedicle of Vorticella campanula, x 1000.
13. SALPINGCECA AMPHORA, S. K., x 1500.

14-16. SALPINGCECA URCEOLATA, S. K. ; 14 and 15, z6*oids with collar extended and
contracted; 16, empty lorica, x 1500.

17, 1 8. SALPINGCECA RINGENS, S. K.— At 1 8 an example encysted, x 1500.

19. SALPINGCECA CURVIPES, S. K., x 2000.

20. POLYNCECA DICHOTOMA, S. K., X 1500.

21, 22. SALPINGCECA TINTINNABULUM, S. K. — 22, Encysted state, x 2000.

23, 24. SALPINGCECA (?) WALLICHI, S. K. — 23, Remains of lories at a a a embedded

within shell substance of a Globigerina ; 24, a single isolated lorica, highly

magnified.
25, 26. SALPINGCECA NAPIFORMIS, S. K. — 25, A social colony in vegetable fibre, x 800 ;

26, a single zooid more highly magnified.
27-31. SALPINGCECA FUSIFORMIS, S. K. — 27, A normal, fully expanded zooid, x 1500 ;

28, a zooid with collar and flagellum retracted, assuming an amoeboid state ;

29, an encysted zooid ; 30, similar encystment, with body broken up into
numerous spore-like bodies; 31, spore-like bodies further developed, and
being discharged from the lorica as monoflagellate germs.

32. A form of SALPINGCECA, apparently near S. FUSIFORMIS, dividing by transverse

fission (after Biitschli).

33. A probable variety of SALPINGCECA AMPHORIDIUM, the lorica having a flattened

base, the collar imperfectly delineated (after Biitschli).

34. SALPINGCECA MARINA, J.-Clk. — An example with the collar and flagellum with-

drawn, emitting ray-like pseudopodia, x 1 800.

PLATE V.

PLATE VL

EXPLANATION OF PLATE VI.

FIG.

1-6. SALPINGCECA INQUILLATA, S. K. — i, Zooid in its normal and fully extended
state, x 1250; 2-5, showing various phases accompanying the process of
transverse fission ; 6, a recently attached collarless zooid commencing to
excrete its protective lorica.

7. SALPINGCECA LONGIPES, S. K. — Two zooids, x 1250.

8-16. SALPINGCECA INFUSIONUM, S. K. — 8, Normal adult zooid, x 800 ; 9, zooid
dividing by transverse fission ; 10, distal separated half of the same zooid
presenting the form of a simple uniflagellate monad ; u, the same monadi-
form zooid attached by its posterior extremity, and having already developed
a short pedicle ; 1 2 and 1 3, further progressive phases, showing in the latter
instance the zooid fully developed, but as yet wanting a lorica; 14, the same
zooid, with collar and flagellum retracted, secreting its lorica; 15 and 16,
sporocyst and liberated monadiform germ of the same species.

17-19. SALPINGCECA CLARKII, Stein (after Stein). — 17, A social colony attached to the
anterior extremity of a Rotifer (Philodina htrsuta), x 650; 18 and 19,
larger examples obtained from the roots of duckweed, the zooid in the latter
instance with collar and flagella retracted and assuming an amceboid
phase, x 650.

20-23. SALPINGCECA OBLONGA, Stein (after Stein). — 20 and 21, Normal zooids, x 650;
22, exhibiting an apparent conjugative process between a normal sedentary
and a naked free-swimming zooid ; 23, an encysted zooid.

24. SALPINGCECA VAGINICOLA, Stein. — Apparently an intermediate variety of
S.gracilis, J.-Clk. (after Stein), x 650.

25-32. SALPINGCECA GRACILIS, J.-Clk. — 25, Early condition of short-stalked variety
(after Stein) ; 26 and 27, adult long-stalked varieties, x 1250 ; 28, zooid
dividing by transverse fission within posteriorly pointed but non-pedi-
cellate lorica ; 29, another phase of transverse fission, the original collar and
flagellum being retracted ; 30, anterior half of the same zooid liberated as
a free-swimming monadiform germ; 31, a zooid encysted within its lorica,
and marked by a transverse divisional line ; 32, a cluster of zooids having
sessile and posteriorly rounded loricas, X 1250.

33-36. SALPINGCECA CORNUTUM, S. K. — 33, Normal adult form, the zooid adherent to
the side of its lorica by several pseudopodic posterior processes, x 1000 ;
34, an abnormal variety, in which the second zooid derived by fission has
remained closely associated with the parent one, and produced a pseudo-
compound lorica; 35, an isolated zooid, having an attenuate vermicular
contour ; 36, a zooid attached to the wall of its lorica by a simple pedicle-
like posterior prolongation.
SALPINGCECA CYLINDRICA, S. K., x 2000.
SALPINGCECA TUBA, S. K. — A social colony, x 1500.

SALPINGCECA CARTERI, S. K. — Monad with so-called " ear - like points," as
originally figured and described by Mr. Carter, x 1500.

PLATE VI.

PLATE VII.

EXPLANATION OF PLATE VII.

FIG.

1. HALISARCA LOBULARIS, Duj., a spiculc-less sponge, in vertical section, after

F. E. Schulze, x 75. — a/, apertures of afferent canals or pores leading to the
spheroidal monad-lined chambers or ampullaceous sacs, amp.\ ef, debouch-
ment of efferent canal conducting from the ampullaceous sacs to the deeper
interstitial canal-systems, which finally open upon the larger excurrent
orifices or oscula ; a, b, c, d, e, f, progressive phases of development by
segmentation of swarm-gemmules in the deeper substance of the sponge,
these occupying the positions previously filled by the ampullaceous sacs,
and from which, by metamorphosis, they are obviously derived ; g, younger
and more rudimentary phase of these bodies, embedded in the cytoblastema
adjacent to the ampullaceous sacs.

2. ESPERIA sp., a siliceous-spiculed sponge, in vertical section, showing grape-like

arrangement of the ampullaceous sacs round a single afferent or pore
system, x 500. — af, entrance of afferent canal or pore, the arrows denoting
the course followed by the incurrent stream of water ; s. cyt., superficial
cytoblastematous layer, bounding the sponge -periphery and extended
canopy-wise over the distal extremities of the spicula ; sp., acerate spicula ;
amp., ampullaceous sacs ; c, amoebiform cytoblasts ; a b, imperfectly deve-
loped ampullaceous sacs in the deeper substance of the cytoblastema;
2 a, minute bihamate spicula from the structureless cytoblastema, x 800.
3, 4. GRANTIA COMPRESSA, Bowerbank, a calcareous-spiculed sponge. — 3, Segment
of an entire transverse section, x 300, showing at a central cavity or cloaca
receiving currents passed through the surrounding ciliated or monad-lined
chambers b, b ; c, c, two such monad-lined chambers containing respectively
one and two ciliated swarm-gemmules; </, external fringe of recurvate-clavate
defensive spicula. 4, One entire, and a portion of a second monad-lined
chamber, x 600 ; af, afferent canal or pore by which currents are received
from the external water ; ef, efferent canal conducting to the central cloacal
chamber; m, collar-bearing monads; d, external defensive spicula; /, in-
ternally projecting triradiate spicula ; g, swarm-gemmule in its earlier amoeboid
and non-segmented phase of development.

PLATE VH.

PLATE VIII.

EXPLANATION OF PLATE VIII.

FIG.

1-17. GRANTIA COMPRESSA, Bowerbank, a calcareous-spiculed sponge. — i, Small
intraspjcular area, showing pavement or.tesselated arrangement of collared
monads;/,/, pore apertures, x 800 ; 2-8, various polymorphic forms assumed
by the collared monads, X 1600 ; 9-12, small isolated groups of collared
monads from the same sponge, exhibiting various conditions of metamor-
phosis, some of them with simply the collars withdrawn and flagella remaining
extended, others with both these organs retracted and the body sarcode pro-
duced in form of pseudopodia, and in consequence presenting an amoebiform
contour ; at 9, the monads' bodies filled with ingested carmine particles ; 1 3,
an isolated monad with collar and flagellum retained in combination with
a long, bifurcated, posteriorly produced pseudopodium ; 15 and 16, amoebi-
form phases of collared monads of the same sponge ; 17, a metamorphosed
collared monad, with radiating pseudopodia, presenting an Actinophrys-like
aspect.

18-31. HALICHONDRIA PANICEA, Johnston, a siliceous-spiculed sponge. — 18, Group of
collared monads attached to a slender acerate spicule, x 1000; 19-23,
groups of collared monads attached to spicula, and in most instances
partially immersed within a thin stratum of structureless cytoblastema, ex-
hibiting various phases of metamorphosis ; 24, a group of metamorphosed
collared monads presenting an amoeboid aspect ; 25, very young, simply
monoflagellate, collared monads attached to a spiculum, x 1000 ; 26-31,
isolated amoebiform phases of collared monads of the same species, those in
the last three instances having capitate pseudopodia, and presenting an
Acineta-like contour.

32-40. ASCETTA PRIMORDIALIS, Hkl, a calcareous-spiculed sponge (after Haeckel). —
32-38, Metamorphosed collared monads, x 700 ; 39 and 40, amoebiform
zooids or cytoblasts, from the cytoblastema, the example in the latter instance
possessing two nuclei or endoplasts, and representing either two recently
coalesced zooids, or one about to divide by fission, x 700.

41. LEUCOSOLENIA CORIACEA, Bwbk. — Portions of transparent cytoblastema sur-

rounding a poral aperture, and containing amoebiform cytoblasts enclosing
ingested carmine particles, X 800.

42. Portion of cytoblastema of HALICHONDRIA PANICEA, containing amcebiform

cytoblasts in various stages of development, those of the smallest order
originating from sporular bodies, x 1500.

• 43. APLYSILLA SULFUREA, F. E. Sclz. — Associated cytoblasts, with attenuate and
interconnecting pseudopodia, x 400 (after F. E. Schulze).

PLATE

WScwufcKmtii WBheuvs

PLA TE IX.

EXPLANATION.

FIG.

1-12. HALISARCA DUJARDINII, Johnston sp. — i, Spheroidal monad-chamber or
ampullaceous sac, as seen in optical section without intersecting an afferent
or efferent aperture, x 800 ; the introversion of this monad-chamber is alone
required to produce a rosette-gemmule or ordinary swarm-gemmule as
delineated at Figs. 20, 24, and 25 ; 2, six laterally attached collared monads
from an ampullaceous sac of the same sponge, these corresponding remark-
ably in their isolated condition with the moniliform colonies of the collared
monad Desmarella moniliformis represented at PL II. Fig. 30, x 1000 ;
3, ampullaceous sac of the same type as seen in optical section, and inter-
secting, where indicated by the arrows, an afferent and efferent aperture ;
4-11, progressive phases of development of an ampullaceous sac by segmen-
tation from a primitive amoeboid body, x 400 ; at 10 the segmented products
present the aspect of simple amoebiform corpuscles possessing no flagellate
appendages, and held together by intervening hyaline cytoblastema ; at 12
the same elements closely approximated have developed internally-projecting
flagella, but still want the characteristic collars ; 12, profile view of matured
ampullaceous sac, with surrounding cytoblastema ; at c, enclosed cytoblasts.

13-17. HALISARCA LOBULOSA. — 13 and 14, Detached ampullaceous sac, x 400 (after
Metschnikoff) ; 15-17, subspheroidal, freely detached cell-aggregations, with
externally-projecting flagella, as figured and described by Metschnikoff under
the title of " rosette-cells," x 400 (Metsch.).

18-21. HALISARCA DUJARDINII. — 18-20, Spheroidal cell-combinations, or rosette-gem-
mules, more fully developed, as observed by the author, and shown to consist
of various numerical aggregations of typical collared monads, x 800; 21,
portion of the same sponge with, at a, earlier and undetached condition of a
similar rosette-gernmule, the externally projecting units possessing flagellate
appendages, but as yet no collars ; at b, portion of an adjacent ampullaceous
sac ; c, c, cytoblasts immersed within surrounding cytoblastema, x 800.

22-29. GRANTIA COMPRESSA, Bwbk. Swarm-gemmules or so-called ciliated larvae,
exhibiting various phases and modifications of development, as observed by
the author. — 22 and 23, simple " planuloid " variety of such swarm-gemmule,
as viewed superficially and in longitudinal optical section, and shown in the
latter instance to be composed of similar closely apposed, conical, uniflagellate
elements, x 350 ; 24, portion of longitudinal section of a more advanced
swarm-gemmule, each constituent uniflagellate element being characterized
bj the possession of a distally developed rudimentary collar, which embraces

EXPLANATION OF PLATE IX. (continued).

FIG.

22-29 the base of the projecting flagellum ; through the enlargement and expansion

(continued), outwards of these constituent units the common body now possesses a dis-
tinctly developed central cavity; 25, more matured developmental phase of the
same planuloid type of gemmule, in which the common body is shown to be
;,. composed of a symmetrically ovate aggregation of typical collared monads or

; spongozoa, x 600 ; 26-29, diverse varieties and phases of development of the

" amphiblastuloid " type of swarm-gemmule from the same sponge, produced
through the uneven growth of the constituent collared monads or spongozoa in
the neighbouring halves of the common body ; in 27, 28, and 29, the collared
monads of the posterior region have developed so much in advance of those
of the opposite extremity as to have withdrawn their collars and flagella,
assumed an amoeboid condition, and coalesced more or less completely with
one another, x 600.

30. GRANTIA (SYCON) CILIATUM, Bwbk. — Variety of "amphiblastuloid" type of
swarm-gemmule, as represented by Barrois, in which an equatorial ring of
metamorphosed spongozoa presents an intermediate condition of development
as compared with the series above and below it.

31,32. GRANTIA COMPRESSA. — Irregularly developed " amphiblastuloid " swarm gem-
mules. At 31 (after O. Schmidt) the more matured amoeboid units have
become invaginated within the primitive central cavity of the common
body.

33-35. SYCANDRA RAPHANUS, HkL— 33 and 34, " Amphiblastuloid " swarm-gemniules,
as represented by F. E. Schulze ; in the first of these the amoeboid units are
invaginated within the uniflagellate, or so-called ectodermal elements, while
in the second one an entire opposite process, or the invagination of the
so-called ectodermal elements, is in course of progress ; 35, irregularly
developed amphiblastuloid swarm-gemmule (after O. Schmidt).

36-39. ASCETTA PRIMORDIALIS, Hkl.— 36, " Planuloid " swarm-gemmule as seen in
optical section, with internally contained cell-spherules ; 37 and 38, portions
of lateral wall of a swarm-gemmule of the same sponge, showing at a a
cell-spherules derived by metamorphosis from the constituent uniflagellate
elements ; these assuming an amoeboid condition and apparently coalescing
with one or more neighbouring units, creep into and occupy the common
central cavity, as shown in the preceding figure; 39, one such cell-spherule
further enlarged, subdivided by segmentation into spore-like elements (Oscar
Schmidt).

40,41. HALISARCA LOBULARIS, Duj. — 40, Optical transverse section of "planuloid"
swarm-gemmule, showing enclosed closely corresponding and similarly
derived cell-spherules, which are identified by Metschnikoff with the primi-
tive condition of the rosette-gemmules represented at Figs. 15-17 ; 41, one
such cell-spherule further enlarged (Metschnikoff).

PLATE DC

* amp

P LA TE X .

EXPLANATION.

FIG.

1-9. LEUCOSOLENIA CORIACEA, Bwbk. — i, Group of collared monads or spongozoa,
certain of them at a a having withdrawn their collars and flagella and assumed
a quiescent state, and others at b b become divided by segmentation into
innumerable sporular elements, x 800 ; 2, small area of the same sponge
magnified 2500 diameters, as viewed by the author with a -y^-inch objective ;
«, ordinary collared monads ; b, one such monad with collar and flagellum
withdrawn, having entered upon a quiescent or encysted state; c, spore-
spheres, produced by the segmentation of the metamorphosed collared
monads ; d d, spores derived from the disintegration of the spore-spheres,
and scattered irregularly through the common mucilaginous cytoblastema,
cyt ; sp. triradiate spicule ; 3-7, spores in aggregate and isolated conditions
liberated from the investing cytoblastema, and in most instances possessing
single terminal flagella, x 2500 ; 8 and 9, spore-masses figured as entoderm
cells by Metschnikoff, x 400.

10. ASCORTIS FRAGILIS, Hkl., showing at a a collared monads, and at b a group of

sporular elements with flagellate appendages (figured by Haeckel as sperma-
tozoa), x 400.

1 1. ASCETTA PRIMORDIALIS, Hkl. — A portion of the inner or lining wall ; a a, pore-

apertures circumscribed by flagelliferous monads ; b b, spore-groups derived
by metamorphosis from the ordinary collared monads, interpreted by Haeckel
as sperm-cells ; c c, large amoeboid bodies derived from the metamorphosis
and coalescence of similar collared cells, which develop later into the charac-
teristic ciliated swarm-gemmules, x 350 (Haeckel).

1 2. Spore-like bodies, found by the author associated with a species of Halichondria,

x 600.

1 3. Spore-like mass from the interstitial substance of a species of Hymeniacidon, x 500.

14, 15. LEUCOSOLENIA BOTRYOIDES, Bwbk. — 14, An intraspicular area, consisting of a
film-like expansion of transparent and structureless cytoblastema in which are
immersed collared monads in an encysted state, those at a a having become
divided by segmentation into sporular elements ; at b b, similar spore-masses
disintegrated and dispersed within the substance of the cytoblastema ; c, a
minute triradiate spiculum, developed within the cytoblastema, x 600 ; 15,
an isolated sporocyst with contained spores from the same sponge, x 1200.

16-18. Sporocysts of a species of Halichondria, that at Fig. 1 8 burst and discharging
minute granular spores, x 600.

EXPLANATION OF PLATE X. (continued).
FIG.

19. ASCETTA PRIMORDIALIS, Hkl. — Three uniflagellate spores, or so-called sperma-
tozoa, as figured by Ernst Haeckel, x 1600.

20-30. PROTOSPONGIA H^ECKELI, S. K. — A collared monad which excretes and socially
inhabits a common gelatinous matrix or " zoocytium " resembling the cyto-
blastema of an ordinary sponge ; 20, a social colony of about forty monads,
x 800 ; at a a, zooids which, withdrawing their collars and flagella, have
assumed an aspect corresponding with the amcebiform cytoblasts of a sponge-
body ; b b, examples with collars and flagella retracted, dividing by transverse
fission ; cc, normal zooids, with their collars contracted ; s, spore-mass ; z z,
hyaline- mucilaginous zoocytium; 21, smaller colony of eleven zooids only,
those at a a a exhibiting an amcebiform aspect, and in one instance extending
slender pseudopodia ; 22, small social colony, including at a four spore-like
bodies produced by the subdivision of a metamorphosed collared zooid, and
at b b two minute, monadiform germs ; 23, small symmetrical colony-stock of
sixteen zooids, derived from the even and continued segmentation of a single
primary unit ; 24 and 25, still younger colonies of two and four zooids only ;
26, solitary attached monadiform germ, having as yet developed neither a
collar nor investing zoocytium, x 1000 ; 27, more advanced phase of the
same zooid, having a well-developed collar and mucilaginous investing sheath,
and corresponding at this stage with the earlier phases of Salping aeca ampulla,
S. K., represented at Plate III. Figs. 19 and 20 ; 28, metamorphosed collared
zooid, projecting a lobose extension of its anterior border beyond the margin
of the zoocytium ; 29, spore-mass, as at 21 s, x 1000 ; 30, social colony viewed
in longitudinal optical section.

PLATE X.

^94

PL A TE XI.

EXPLANATION.

Figs. 1-19, ILLUSTRATING DEPOSIT AND DEVELOPMENT OF INFUSORIAL GERMS ON

HAY-FIBRE, AS DESCRIBED AT CHAPTER IV. PAGE 136 et sea.
FIG.

1. Fragment of hay-fibre examined after six hours' maceration, showing at a a

encysted Vorticellce, and at b b b masses of microspores of Heteromita lens,
x 800.

2. Fragment of hay-fibre, wetted and immediately examined ; at a a a, microspores

of Heteromita lens ; at b, four macrospores of Oikomonas mutabilis ; at c,
macrospores of Heteronema caudata; and at d, macrospores of an unde-
termined type, x 800.

3. Fragment of hay-fibre, showing at a a mass of microspores of Heteromita lens

lodged in crevice formed by the serration of its surface, x 800.

4. Fragment of hay-fibre encrusted with spore -masses of the single type Heteromita

lens.

5. Fragment of hay-fibre examined after two weeks' maceration, showing bacterial

film and monad spores depending in grape-like clusters from its lower surface.
Minute monads developed from these spores, mixed with vibrios and Bacteria,
swimming beneath, x 8000.

6-17. HETEROMITA LENS, Mull. sp. — 6, 7, Two isolated patches of microspores, x 800 ;
8, 9, free-swimming monadiform germs developed from the patches of
microspores, x 800; 12-15, similar monadiform germs in their primarily
attached and variously aggregated free-swimming states, as seen with a
i-Vinch objective, x 2500; 16 and 17, succeeding biflagellate condition of
the same germs, x 800.

1 8. HETERONEMA CAUDATA, Duj. sp., developed from the mass of the macrospores

delineated at Fig. 2 c, x 800.

19. HETEROMITA LENS.— Adult monad, x 800.

Figs. 20-46, ILLUSTRATING THE PROTOZOIC NATURE OF THE MYXOMYCETES OR
MYCETOZOA, AS DISCUSSED AT CHAPTER II. PAGE 41 et seq. (Fics. 32-35 AND

45-47 AFTER ClENKOWSKI, THE REMAINDER AFTER A. DE BARY).

20. ARCYRIA INCARNATA, Pers. — Two sporocysts or sporangia ; the one at a burst

and protruding its sporiferous rete or capillitium, x 15.

21. PHYSARUM PLUMBEUM, Fries. — Numerous associated sporangia, slightly

enlarged.

EXPLANATION OF PLATE XI. (continued).

FIG.

22. ARCYRIA CINEREA, Fries. — A single sporangium, completely filled with half-

matured spores, x 25.

23. PHLEBOMORPHA RUFA, de Bary. — Portion of horny rete or capillitium, with

enclosed spores, x 390.

24. DIDYMIUM SERPULA, Fries. — Section of sporangium, showing contained

spores.

25-28. LYCOGALA EPIDENDRON, Fries. — 25, Two isolated spores ; the one at a bursting
and liberating its monadiform germ, x 390 ; 26, three fully developed, free-
swimming, highly polymorphic monadiform zooids, developed from the
spores represented in the preceding figure, x 390; 27, amoaboid condition
assumed by the same monadiform zooids, representing the first step towards
the development of the compound plasmodium ; 28, Young repent amcebi-
form plasmodium formed by the coalescence of several of the smaller
amoeboid particles.
29. yETHALiUM SEPTICUM, Fries. — Young repent plasmodium, x 200.

30, 31. DIDYMIUM FARINACEUM, Fries. — 30, Fragment of peridium or indurated outer
wall of sporangium, containing substellate calcareous spicula, x 390 ; 31, an
isolated spicule from the same peridium further enlarged.

32-35. DIDYMIUM SERPULA, Fries. — 32, 34, Polymorphic monadiform zooids, the
example at 32 with ingested food-particles ; «, nucleus or endoplast ; c v, con-
tractile vesicle, x 350 ; 35, amcebiform condition of a similar monadiform
zooid, x 350.

36-38. TRICHIA VARIA, Pers.— 36, Isolated spore, x 390 ; 37 and 38, the same spore
with its wall ruptured, and giving exit to a free-swimming monadiform
zooid.

39. DIDYMIUM LIBERTIANUM, Fres. — Minute subaqueously developed sporangium,
with nine or ten contained spores, x 390.

40-44. STEMONITIS OBTUSATA, Fries. — Successive phases of multiplication by fission
of a monadiform zooid, X 390.

45-47. DIDYMIUM LEUCOPUS, Fres. — Young repent amcebiform plasmodia, containing
(c v, -v c] numerous contractile vesicles, the plasmodia at 45 and 46 being
in a contracted, and at 47 in a fully extended state, x 350.

ELATE XI.

W Swill.Koit aAWBbjhi sculp

PLATE XII.

EXPLANATION OF PLATE XII.

FIG.

1-4. PHALANSTERIUM DIGITATUM, St. (after Stein). — i, Adult branching mucila-
ginous zoocytium, x 450 ; 2-3, early conditions of a similar zoocytium ;
4, a single animalcule, X 1 200 ; d, rudimentary collar.

5-9. PHALANSTERIUM CONSOCIATUM, Cienk. — 5, Adult discoidal colony, x 650 (after
Stein) ; 6, an isolated animalcule further enlarged ; 7 and 8, encysted zooids
(after Cienkowski), the one at Fig. 8 having developed a hard tricarinate
capsule ; 9, an animalcule dividing by longitudinal fission.
10. SPONGOMONAS DISCUS, St., x 650 (after Stein).

11-14. SPONGOMONAS INTESTINUM, Cienk. sp. — 11, Filamentous adult colony, natural
size (Cienk.) ; 12, extremity of similar colony enlarged, showing disposition
of contained animalcules ; 13, an isolated monad, x 650 ; 14, fragment of
gelatinous granular zoocytium, showing at a normal zooid ; S, two zooids
derived from the longitudinal fission of such as a ; c, a retracted and encysted
zooid ; d, e, f, various multiplicative phases by which a primary quiescent
or encysted zooid has become divided into two, four, or eight spore-like
bodies, X 650 (12-13 after Stein).

15, 16. SPONGOMONAS UVELLA, St. (Stein).— 15, An adult colony, x 650; 16, initial
condition of such a colony as founded by a single animalcule.

17-23. SPONGOMONAS SACCULUS, S. K. — 17, Adult colony, x 10; 18 and 19, showing
proportionate growth of same colony in three days as observed by the author,
natural size ; 20, fragment of granular zoocytium, containing two normal
biflagellate and a single encysted subdividing zooid, x 1200 ; 21 and 22,
isolated zooids, x 1200 ; 23, encysted zooid dividing by transverse fission.

PLATE XII.

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PL A TE XIII.

EXPLANATION.
FIG.

1-9. MONAS DALLINGERI, S. K. (after Dallinger and Drysdale).— i, Normal adult
form, x 2000 ; 2, monad preparing to assume an encysted state ; 3, 4, 5,
progressive phases following upon encystment, and resulting in the produc-
tion of a spherular aggregation of elongate vermicular macrospores ; 6, the
same macrospores liberated as simple monads resembling the parent, but of
smaller size ; 7, conjugation of larger and smaller monads j 8, encystment
resulting from such conjugation ; 9, the compound cyst bursting and
liberating infinitesimally minute microspores.

10-18. MONAS FLUIDA, Duj. — 10, Typical adult monad, x 1000 ; 11-16, metamorphic
forms of similar adult monads; 17, congregation of two zooids ; 18, their
encystment.
19. MONAS IRREGULARIS, Pty. (Cienkowski), x 350.

20, 21. MONAS OBESA, Stein sp., x 650 (Stein).

22-24. MONAS RAMULOSA, Stein sp. x 600 (Stein).

25, 26. LEPTOMONAS BUTSCHLII, S. K. (Biitsch.). — 25, A group attached by their
posterior extremities, x 600 ; 26, a free-swimming monad, x 1 500.

27, 28. OPHIDOMONAS JENENSIS, Ehr., x 600 (Ehr.).

29-34. HERPETOMONAS MUSCLE-DOM ESTICLE, Burnet sp. (Stein).— 29-32, Polymorphic
phases of the adult monads, x 650 ; 33 and 34, monads dividing by longi-
tudinal fission.

35-40. HERPETOMONAS LEWISII, S. K. (Lewis). — 35-38, Various contours of the adult
organism, x 800 ; 39, two red and forty-one colourless corpuscles of the rat's
blood which they inhabited, equally magnified to show proportionate size.

41, 42. SCYTOMONAS PUSILLA, St., X 650 (Stein).

43, 44. PLEUROMONAS JACULANS, Pty., x 500 (Perty).

45. MEROTRICHA BACILLATA, Meresch. (Dimensions unrecorded) (Mereschkowski).

46, 47. CYATHOMONAS ELONGATA, From. — 47, Dividing by longitudinal fission, 600

(De Fromentel).
48. CYATHOMONAS TURBINATA, From., x 400 (De Fromentel).

49-53. ANCYROMONAS SIGMOIDES, S. K. — 49, Free-swimming animalcule, x 1500; 50,
animalcule fixed by distal termination of the single flagellum, the dotted
outline indicating the position alternately assumed by the body with relation
to the flagellum in the course of its rapid oscillations, x 2500 ; 51-53, showing
the several progressive phases of oblique fission.

EXPLANATION OF PLATE XIII. (continued).
FIG.

54. PLATYTHECA MICROPORA, St. — Three loricae with their contained animalcules
attached to a joint of conferva ; at a two zooids, the result of fission,
occupy the same lorica, x 650 (Stein).

55-64. OIKOMONAS MUTABILIS, S. K. — 55, A group of four monads attached to vegetable
fibre, showing at a and b normal sedentary forms, at c an example ingesting
food-matter at its lateral periphery, and at d a young and recently adherent
example, not having yet developed a filiform pedicle, x 800 ; 56, an adult
monad about to exchange its sedentary for a free-swimming condition ;
57, the same monad detached and free-swimming, still retaining an attenua-
tion of its posterior and previously fixed extremity ; 58, typical free-swimming
zooid ; 59 and 60, more aberrant forms ; 61, a motile zooid dividing by
longitudinal fission ; 62 and 63, spore-masses produced by segmentation of
encysted animalcules ; 64, a young monad developed from a spore.

65-70. OIKOMONAS STEINII (S. K.) — 65, A group of monads attached to a spheroidal
bacterial mass, X 650 ; 66, four monads similarly attached, exhibiting a
considerable irregularity of contour ; 67, a free-swimming animalcule with
branched posterior extremity ; 68, a free-swimming animalcule dividing by
transverse fission ; 69 and 70, young free-swimming monads (Stein).

71. OIKOMONAS QUADRATUM, S. K. — A group of five monads ; at a and b, zooids

ingesting food at opposite regions of the periphery, x 800.

72. OIKOMONAS OBLIQUUS, S. K., filled with artificially administered carmine-

particles, a portion of which it is discharging from its posterior extremity,
x 2500.

73-77- OIKOMONAS ROSTRATUM, S. K.— 73, A group of monads attached to a vegetable-
fibre, x 800 ; 74 and 75, two attached monads, the one with and the other
without a posteriorly developed pedicle, x 1000 ; 76, an example with an
abnormally long pedicle ; 77, a free-swimming monad with pedicle retracted.

78-80. OIKOMONAS TERMO, J.-Clark sp.— 78, A group attached to vegetable fibre,
showing at a a zooid dividing by longitudinal fission, at b an example ingesting
food-matter, and at c a young, recently attached and almost stalkless zooid,
x loco ; 79, a free-swimming monad ; 80, a free-swimming zooid dividing by
fission.

PLATE

W.Scrailelfcnt isl, WHbou 5

,

PLATE XIV.

EXPLANATION OF PLATE XIV.

FIG.

1-3. BODO JULIDIS, Leidy, x 750 (Leidy).

4-6. BODO MAXIMUS, Schmarda, x 300 (Schm.).

7-8. BODO URINARIUS, Hassall, x 400 (Hass.).

g-ii. BODO LYMNjEi, Stiebel sp. — 9 and 10, motile zooids, x 600 ; u, Sporocyst with

escaping germs, x 250 (Ecker).

12, 13. BODO (CRYPTOBIA) HELICIS, Leidy, x 400 (Leidy).

14. BODO INTESTINALIS, Ehr., X 400.

15, 1 6. CERCOMONAS CRASSICAUDA, St. — At 16, with posterior irregular pseudopodic
extensions, x 600 (Stein).

17-20. CERCOMONAS LONGICAUDA, Duj. — 17 lateral, 18 dorsal view; 19 and 20,

progressive stages of longitudinal fission, x 600 (Stein).
21. CERCOMONAS CYLINDRICA, Duj., x 1200 (Dujardin).

22-30. CERCOMONAS TYPICUS, S. K. (Dallinger and Drysdale). — 22, normal adult
monad, X 1750 ; 23 and 24, amoeboid phases of matured monads ; 25 and 26,
successive results of coalescence of two amceboid monads ; 27, sporocyst
ultimately derived from foregoing coalescence ; 28, sporocyst burst and
liberating minute spores ; 29 and 30, progressive phases of transverse fission.

31-33. GONIOMONAS TRUNCATUS, Fres. sp. — At a, eye-like pigment-band, x 600 (Stein).

34-36. SPUMELLA VIVIPARA, Ehr. sp. (Stein). — 34 attached, 35 and 36 free-swimming
conditions ; at a, eye-like pigment-band or supposed oral aperture, x 6oy.

37-45. PHYSOMONAS SOCIALIS, S. K. — 37, A group of five monads attached to vegetable
fibre, showing at a and b examples incepting food-matter at opposite regions
of their periphery, x 1000 ; 38, a free-swimming monad; 39 and 40, illus-
trating the alternating systole and diastole of the two medianly located con-
tractile vesicles ; 41 and 42, phases of longitudinal fission ; 43, an encysted
group, showing at a a stalked and at b a stalkless cyst ; at c, two stalks con-
nected with a single and larger cyst, indicating its derivation from the conju-
gation or coalescence of two zooids, x 1500 ; 44, a sporocyst with ripe spores,
x 2000 ; 45, monadiform germs released from the same sporocyst, x 2500.

46-52. SPUMELLA GUTTULA, Ehr. sp. (Stein), x 600. — 46, normal attached monad ;
47 and 48, free-swimming monads ; 49 and 50, illustrating conjugative process
of larger and smaller monads ; 51 and 52, successive phases of longitudinal
fission.

53. CODONCECA COSTATA, J.-Clk., x looo (J. -Clark).

54. CODONCECA OBLIQUA, S. K., x 800.

55-59. AMPHIMONAS GLOBOSA, S.K. — 55, a group of four monads, one, at a, incepting
food on its lateral periphery, x 800 ; 56-59, successive phenomena observed
during the inception of a large Bacillus, and in the preliminary phases of
which process (Figs. 56 and 57) a film-like expansion of sarcode was extended
over the captured prey.

60-65. DELTOMONAS CYCLOPUM, S. K.— 60, a social group attached to hair of a species
of Cyclops j at a, a free-swimming animalcule, and at b a young non-flagellate
germ, x 1500 ; 61, a single monad, x 3000 ; 62, a group of four monads
united by their posterior extremities ; 63, longitudinal fission ; 64 and 65,
sporocysts with spores.
66. AMPHIMONAS DIVARICANS, S. K., x 2500.

PLATE XIV.

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PLATE XV.

EXPLANATION OF PLATE XV.

FIG.

1-17. HETEROMITA LENS, Mull. sp. — i and 2, normal adult monad in the fixed and free-
swimming conditions, x 800 ; 3 and 4, irregular-shaped amoebiform conditions ;
5 and 6, two monads attached close to each other and about to coalesce ;
7, coalescence or conjugation ; 8 and 9, phases succeeding conjugation, pro-
ductive in the last instance of a spheroidal sporocyst ; 10, sporocyst, with
contents consisting of innumerable microspores ; 11-14, minute, uniflagellate,
monadiform germs, developed from such microspores, and either single or
adherent in diverse combinations, x 2500; 15, two sporocysts, containing
eight or sixteen macrospores ; 15, a sporocyst with four macrospores only;
17, the same sporocyst burst open and giving birth to four biflagellate germs
differing only in size from the parent animalcule, x 1000.

18-28. HETEROMITA ROSTRATA, S. K. (Dallinger and Drysdale).— 18, attached condition
of adult monad, the outlines at a and b indicating the positions to which the
body is projected by the uncoiling and extension of the posterior and adherent
flagellum, x 1500; 19 and 20, successive phases of longitudinal fission; 21
and 22, conjugation of two monads ; 23, triangular sporocyst resulting from
such conjugation ; 24, the same sporocyst bursting at its angles and releasing
the enclosed microspores, x 2000 ; 25 and 26, development at phases of the
released microspores, liberated from the triangular sporocyst, x 2500 ; 27 and
28, further progressive stages towards the attainment of the parent form at
the end of eight and ten hours, x 2500.

29-41. HETEROMITA UNCINATA, S. K. (Dall. and Drysd.). — Normal adult monad,
x 1500 ; 30, irregular semi-amoeboid phase, preceding fission ; 31, fission ; 32,
conjugation of two monads of diverse size ; 33, conjugation of four monads ;
34-39, sporocyst resulting from conjugation with successive phases of segmen-
tation of its contents, producing finally a mass of minute microspores ; 40,
bursting of sporocyst and release of contents as minute uniflagellate germs ;
41, one such germ a few hours later, having nearly attained the parent form.

42, 43. PSEUDOSPORA VOLVOCIS, Cienk., X 400. — Natatory and repent conditions of

the same zooid (Cienkowski).
44. HETEROMITA ADUNCA, Meresch., x 1500 (Meresch).

45, 46. COLPONEMA LOXODES, St. — 45, dorsal, and 46, ventral aspect, x 600 (Stein).

47, 48. PHYLLOMITUS UNDULANS, St., x 600 (Stein).

49-60. SPIROMONAS ANGUSTATA, Duj. sp. — 49-52, Free-swimming monads, with their
bodies in all cases, excepting 52, variously contorted, x 1500 ; 53, an
adherent monad; 54, amoebiform condition; 55, two amoebiform monads
conjugating ; 56-59, successive phases of encystment and spore-production ;
60, free-swimming monad, as represented by Dujardin.

61-64. HETEROMITA GLOBOSUS, St. sp. (Stein).— 61-63, Normal adult monads, x 600 ;
64, a number of monads tenanting the cell of an QEdogonium, and feeding on
its contents.

65, 66. HETEROMITA OVATA, Duj. — Dorsal and lateral aspects, x 600 (Stein).

67-78. POLYTOMA UVELLA, Mull. sp. — 67-6.7, Animalcules showing loop-like flexure
of the basal region of the flagella, the example in the first instance being
attached by this loop-like coil, as observed by the author, x 800 ; 70 and
71, examples with supposed basal inflations of the flagella, or independent
knobbed appendages, as represented by Messrs. Dallinger and Drysdale ;
72-74, successive phases of multiplication by complete segmentation of
the internal contents (Dallinger and Drysdale) ; 75, multiplication by the
breaking up of the endoplasm of the posterior region only into minute
angular germs (D. and D.) ; ;6, the same angular germs, more highly magni-
fied (D. and D.) ; 7 , conjugation of two animalcules (D. and D.) ; 78, rupture
of sporocyst resulting from such conjugation, and release of microspores,
x 800 (D. and D.).

PLATE XV.

"Mir-tem. Bro? isaj.

PLATE XVI.

EXPLANATION OF PLATE XVI.

FIG. ^

1-3. RHIPIDODENDRON SPLENDIDUM, St. (Stein). — Flabellifbrm compound colony-
stock or zoothecium, consisting of several hundred closely-united tubules,
the entire structure representing the product by repeated subdivision and
excretion of a primarily single monadiform animalcule, x 400 ; 2, young
zoothecium, constructed up to the point of bifurcation by a single monad,
which then dividing by longitudinal fission, has produced two parallel tubes
x 600 ; 3, an isolated monad, x 1150.

4-8. RHIPIDODENDR^N HUXLEYI, S. K.— 4, Detached ramiscule from an adult
branching zoothecium, x 170; 5, portion of branchlet, showing quadruple
tubular construction, x 300 ; 6, distal termination still more magnified,
showing contained monads, x 800 ; 7, diagrammatic illustration of mode in
which the characteristic branching zoothecium is produced, the four primary
monads, as at a, dividing by longitudinal fission, the right and left halves of
such total product then parting, as at b, and forming their respective tubules
at divergent angles ; 8, symmetrically developed adult zoothecium, x 5 ;
9, an adult zoothecium, natural size.

PLATE XVI.

W. Savill. E«nt tt. WBkan.liaL

PLATE XVII.

EXPLANATION OF PLATE XVII.
FIG.

1-4. DENDROMONAS VIRGARIA, Weisse sp., vol. i. p. 266.—!, Adult colony-stock
or zoodendrium, x 800 ; 2, younger and less ramified zoodendrium, as
figured by Stein, ' Wiegmann's Archives,' 1849, as a probable young condition
of Epistylis anastatica ; 3, an isolated monad, x 2000 ; 4, colony of two
monads in process of division by longitudinal fission.

5-7. CLADONEMA LAXA, S. K., vol. i. p. 265. — 5, adult colony, x 1000; 6, a monad
dividing by longitudinal fission ; 7, a single monad ingesting a food-particle
towards the posterior region of its periphery, x 3000.

8. DENDROMONAS PUSILLA, Schmard. sp., vol. i. p. 266, x 250.

9-11. ANTHOPHYSA SOCIALIS, From., vol. i. p. 272. — 9 and 10, Colony-stocks, after
De Fromentel, x 350; n, head of colony-stock, including centrally an
encysted monad, x 1500, after Biitschli.

12. CEPHALOTHAMNIUM CUNEATUM, S. K., vol. i. p. 273, x 1250.

13-26. ANTHOPHYSA VEGETANS, Mull, sp., vol. i. p. 267. — 13-15, Branching colony-
stocks and detached monad clusters, or coenobia, as originally delineated
by O. F. Miiller, x 50; 16, a typical, erect, shortly branching colony-
stock, with four terminal monad-clusters or coenobia, x 400 ; 17, a portion
of common stem, showing its compound or fibrous nature ; 18 and 19,
two colonies in which the monads, being fed with carmine, have after
passing it through their bodies, incorporated the pigment from the points a,
into the substance of the common stem, x 800 ; 20-22, sporocyst, showing
progressive phases resulting in the liberation of the contents in the form of
simple monadiform germs, x 800 ; 23, the empty sporocyst, showing its
composition of an outer firmer and inner more delicate and elastic mem-
brane ; 24, monadiform germs liberated from sporocyst, x 2000 ; 25, subse-
quent resting condition of the same germs ; 26, branching zoodendria
derived from these resting spores, the monad clusters having become de-
tached.

27-32. CEPHALOTHAMNIUM OESPITOSA, S. K., vol. i. p. 272. — 27 and 28, Adult com-
pound colony-stocks, x 1200 ; 29-31, single stalked monads, those in the last
two figures emitting pseudopodia from within the distal region only, or from
the entire surface of their periphery, x 1800 ; 32, a zooid dividing by trans-
verse fission. — The size of the zooids in the descriptive account of this
species has been accidentally set down as 1-5000", instead of 1-3000."

PLATE

.

PLATE XVI I I.

EXPLANATION OF PLATE XVIII.
FIG.

i-io. ANTHOPHYSA VEGETANS, Miill., vol. i. p. 267 (Stein). — i, Prolific colony-stock,
with lax homogeneously-granulate branching stem, x 500 ; 2, detached
monad cluster, or " coenobium," seen from below ; 3, ccenobium, showing its
relationship to supporting pedicle, as seen in vertical optic section, x 1000 ;
4 and 5, free-swimming coenobia, composed of a small number of monads
only ; 6, disintegrated ccenobium, the monads with tail-like posterior pro-
longations, x 1000 ; 7 and 8, independently motile monads, with pseudopodic
processes, derived from breaking up of the adult ccenobium ; 9, one such
motile zooid, fixed by a posterior pseudopod-like extension ; 10, early con-
dition of sedentary colony-stock, bearing a single ccenobium of eight
monads only.

ir, 12. CLADOMONAS FRUTICULOSA, vol. i. p. 284 (Stein). — 1 1, Adult tubular colony-stock
or zoothecium, showing at a a detached monad, and at b two monads, the
result of longitudinal fission, temporarily inhabiting the same tube, x 650 ;
12, terminal branchlet of variety having dark-coloured band-like internodes.

13-19. BlCOSCECA LACUSTRIS, vol. i. p. 275, J.-Clk. — 13, Adult monad in lorica, x 1250 ;
14 and 15, successive phases of transverse fission; 16, distally separated,
free-swimming integer of fissive process, presenting a Heteromita-like
aspect ; 17, monad with spirally-coiled flagella, retracted within its lorica ;
1 8, lorica with sporular contents ; 19, adult monad in lateral aspect, showing
eccentric development of thread-like footstalk, and lip-like prolongation of
the anterior region, x 1250.

20. BlCOSCECA CURVIPES, S. K. — Contained monad dividing by longitudinal fission
or conjugating with an externally derived zooid, x 1500.

21, 22. BlCOSCECA GRACILLIPES, J.-Clk., vol. i. p. 276. — 21, normal form ; 22, example
with shorter pedicle and more exsert zooid, x 1250.

23. BICOSCECA TENUIS, S. K., vol. i. p. 276, x 1500.

24. HEDRJEOPHYSA BULLA, S. K., vol. i. p. 274, x 1500.

25-29. BlCOSCECA POCILUJM, S. K., vol. i. p. 277. — 25, Typical adult form, x 1000 ; 26,
monad dividing by transverse fission ; 27 and 28, obtusely and acuminately
pointed free-swimming monads derived from the fissive process ; 29, a
similarly derived monad adherent by its posterior extremity, but as yet
wanting the characteristic protective lorica.

30, 31. DIPLOMITA SOCIALIS, S, K., vol. i. p. 289.— 30, Social group attached to a
confervoid filament ,-31, two monads within their stalked loricae, x 1500,
at e eye-like pigment-spots.
32. STYLOBRYON EPISTYLOIDES, S. K., vol. i. p. 279, x 1 500.

33-35- CEPHALOTHAMNIUM CJESPITOSA, S. K., vol. i. p. 272 (Stein). — 33, Adult colony-
stock, x 1000 ; 34 and 35, free-swimming and attached isolated monads.

PLATE XVffl

•,-.: <Ul V,' Stem scolp *

ffc.terr. Bro? imp.

PLATE XTX.

EXPLANATION OF PLATE XIX.

FIG.

1-14. TREPOMONAS AGILIS, Duj., vol. i. p. 300. — 1-8, Animalcule from various points
of view, and with the body straight or twisted upon itself, as represented by
Stein, at 7 an example dividing by longitudinal fission, x 650 ; 9, character-
istic aspect as given by Perty; 10-12, other phases, as delineated by O. F.
Biitschli, the arrows in the last instance indicating the course followed by
the circulatory motion of the endoplasm ; 13 and 14, young animalcules
after Stein.

15. CHLORASTER AGILIS, S. K., vol. i. p. 317, x 1250.

16-19. CALLODICTYON TRICILIATUM, Carter, vol. i. p. 307. — 17, an animalcule en-
veloping a vegetable filament, x 400 (Carter).

20. CHLORASTER TETRARHYNCHUS, Schm., vol. i. p. 316, x 350 (Stein).
21, 22. CHLORASTER GYRANS, Ehr., vol. i. p. 316, x 250 (Stein).

23-25. TRIMASTIX MARINA, S. K., vol. i. p. 312. — 23 and 24, lateral, 25, oblique view,
x 1250.

26, 27. TETRAMITUS SULCATUS, St., vol. i. p. 314, x 430 (Stein).

28, 29. TETRASELMIS CORDIFORMIS, Carter sp., vol. i. p. 315, x 450 (Stein).

30-32. TRICHOMONAS BATRACHORUM, Pty., vol. i. p. 308, x 650 (Stein).

33, 34. TRICHOMONAS VAGINALIS, Duj., vol. i. p. 309, x 1000 (Dujardin).

35-41. DALLINGERIA DRYSDALI, S. K., vol. i. p. 310 (Dallinger and Drysdale) ; 35,
animalcule fixed by two posterior flagella, and showing at a and b respective
positions occupied by the body during the alternate extensions and spiral
contractions of these appendages, x 2000 ; 36, free-swimming animalcule,
seen from above ; 37, example dividing by longitudinal fission ; 38,
animalcule with posterior flagella retracted and about to enter upon an
encysted state ; 39, encystment ; 40, sporocyst bursting and liberating clouds
of microspores, x 2000 ; 41, triflagellate monads developed from the liberated
microspores.

42-48. TETRAMITUS ROSTRATUS, Pty., vol. i. p. 313 (43, 47, and 48 after Stein, the
remainder after Dallinger and Drysdale). — 42, Normal free-swimming
animalcule, x 1000 ; 43, ventral view, showing groove-like channel ; 44 and
45, successive phases of longitudinal fission, accompanied by the assumption
of an irregular amcebiform contour ; 46, biflagellate animalcule derived by
fission with flagella in process of further subdivision, so as to reproduce the
normal number ; 47 and 48, young animalcules, X 650.

49, 50. TETRAMITUS DESCISSUS, Pty., vol. i. p. 314, x 1500 (Biitschli).
51. LOPHOMONAS STRIATA, Biitschli, vol. i. p. 322, x 800 (Biitschli).

52-54. LOPHOMONAS BLATTARUM, St., vol. i. p. 321.— 52 after Biitschli, 53 and 54,
after Stein, x 650.

55. HEXAMITA ROSTRATA, St., vol i. p. 320, x 650.

56-59. HEXAMITA INFLATA, Duj., vol. i. p. 319 (56-58 after Stein). — 56, normal adult
animalcule, x 650 ; 57, animalcule about to divide by longitudinal fission ;
58, example with posterior flagella entangled in floccose matter ; 59, animal-
cule fixed by the extremities of its posterior flagella, and gyrating upon the
same, as observed by the author, x 1000.

60-62. HEXAMITA INTESTINALIS, Duj., vol. i. p. 318. — 60, free- swimming animalcule,
x loco ; 61, example anchored by the posterior flagella, and actively vibrating
the four anterior ones ; 62, an example with toothed antero-lateral borders
and pseudopodic posterior prolongations (Stein).

PLATE XIX.

PL A TE XX.

EXPLANATION.

FIG.

1. PARAMONAS GLOBOSA, From, sp., vol. i. p. 370, x 400 (Fromentel).

2. PARAMONAS STELLATA, From, sp., vol. i. p. 370, x 400 (Fromentel).

3. PETALOMONAS MEDIOCANELLATA, St., vol. i. p. 371, x 350 (Stein).

4. PETALOMONAS SINUATA, St., vol. i. p. 372, x 400 (Stein).

5,6. PETALOMONAS ABSCISSA, Duj. sp., vol. i. p. 371, dorsal and ventral views,
x 500 (Stein).

7. PETALOMONAS ERVILIA, St., vol. i. p. 372, x 400 (Stein).
8,9. PETALOMONAS IRREGULARIS, St., vol. i. p. 372, x 1250.

10-12. ATRACTONEMA TERES, St., vol. i. p. 373. — 11, Animalcule dividing by longi-
tudinal fission ; 1 2, example without flagellum, and with the endoplast
enlarged and broken up into* germinal elements, x 640.

13, 14. PHIALONEMA CYCLOSTOMUM, St., vol. i. p. 373, x 500. — 14, Variety with spirally
ribbed cuticle (Stein).

15, 16. MENOIDIUM PELLUCIDUM, Pty., vol. i. p. 374.— 15, As observed by the author;
1 6, after Stein, x 600.

17-21. ASTASIA TRICHOPHORA, Ehr. sp., vol. i. p. 376. — 17, Typical adult zooid, after
Biitschli, x 600; 18, example with internal germ-like bodies, after Carter ;
19-21, various polymorphic forms.

22. COLPODELLA PUGNAX, Cienk., vol. i. p. 378.— Three animalcules parasitically

attached to a cell of Protococctts, x 500 (Cienkowski).

23. SPIROMONAS DISTORTUM, Duj. sp., vol. i. p. 298, x 600 (Dujardin).
24-25. EUGLENA ACUS, Ehr., vol. i. p. 383. — 25 and 26, after Stein, x 300.

26. EUGLENA OXYURIS, Schm., vol. i. p. 383, x 200 (Stein).

27, 28. EUGLENA SPIROGYRA, Ehr., vol. i. p. 382. — 27, Normal extended animalcule, as
observed by the author, at a a, amylaceous corpuscles, x 240 ; 28, con-
tracted phase (Stein).

29-51. EUGLENA VIRIDIS, Ehr., vol. i. p. 381. — 29, Animalcule with a bulbous distal
termination to the flagella, after W. H. Robson ; 30-33, polymorphic con-
tours assumed at will by the same animalcule, x 200; 34, typical form,
x 600 ; 35, anterior extremity, with of, funicular oral fossa, c v, contractile
vesicle, and e, eye-like pigment-spot ; 36, animalcule with large ovate inter-
nally developed germs ; 37, an example with enclosed irregularly shaped
amrebiform germinal bodies ; 38 and 39, transparent varieties (E. hyalina,

EXPLANATION OF PLATE XX. (continued).
FIG.

29-51 Ehr.) containing large central modified endoplasts or germ-spheres (after

(continued). Stein) ; 40 and 41, similar animalcules giving exit by rupture of their germ-
spheres to swarms of minute monadiform germs (Stein) ; 43, an animalcule
emerging from a temporary encystment (Stein) ; 43, an example of fission as
accomplished during the encysted state (Stein) ; 44-48, various phases of
encystment accompanied with the production of internal germ-spheres,
(Stein) ; 49 and 50, examples of encystment observed by the author, in which
the entire endoplasmic contents have become divided into spheroidal spore-
like bodies, at 50 a double sporocyst formed apparently by the conjugation
of two animalcules; 51, repent amcebiform germs developed from the
preceding sporocysts, x 600.

52, 53. EUGLENA DESES, Ehr., vol. i. p. 383, x 500. — At 53, a young non-flagellate
zooid (Stein).

54-56. EUGLENA TUBA, Carter, vol. i. p. 385. — 54, Normal free-swimming animalcule,
X 300; 55, flask- shaped encystments associated in mucous reticulation;
56, a single flask-shaped body, more highly magnified (Carter).

57. EUGLENA VIRIDIS dividing by longitudinal fission, x 300 (Carter).

58. EUGLENA ZONALIS, Carter, vol. i. p. 388, x 300 (Carter).

59. CCELOMONAS GRANDis, Ehr. sp., vol. i. p. 393, x 400 (Stein).

60-62. RAPHIDOMONAS SEMEN, Ehr. sp., vol. i. p. 392. — At 61, example with hair-like
trichocysts extended, x 400 (Stein).

63. AMBLYOPHIS VIRIDIS, Ehr., vol. i. p. 386, x 200 (Ehrenberg).

64. EUGLENA AGILIS, Carter, vol. i. p. 384. — Encysted animalcule, having by the

abnormal process of serial subdivision become separated into four lineally
disposed, equal-sized segment masses, x 300 (Carter).

PLATE XX

« Ktsut dr.

PLATE XXI.

EXPLANATION.
FIG.

i. PHACUS TRIQUETER, Ehr. sp., vol. i. p. 387. — a a, Amylaceous corpuscles; e,
eye-like pigment-spot, x 600 (Stein).

2-5. PHACUS PLEURONECTES, Ehr. sp., vol. i. p. 386 (Stein). — 2, Normal animalcule,
x 600 ; 3, example with the nucleus or endoplast divided into four frag-
ments, those at g g being further separated into germinal elements, consti-
tuting the so-called " germ-sacs " or " germ-spheres " of Professor Stein ; 4,
an instance of transverse fission ; 5, indurated membrane or carapace left
after the decay of the enclosed body-substance.

6, 7. PHACUS LONGICAUDUS, Ehr. sp., vol. i. p. 387 (Stein). — 6, More normal form ;
7, spirally twisted non-flagellate example, x 300.

8,9. CHLOROPELTIS HISPIDULA, Eichwald, vol. i. p. 388.— 8, Lateral, 9, ventral
aspect, x 600 (Stein).

10. PHACUS PYRUM, Ehr. sp., vol. i. p. 387, x 600 (Stein).

1 1-13. CHLOROPELTIS OVUM, Ehr., vol. i. p. 388. — a a, Amylaceous corpuscles ; 13,
subcylindrical variety, x 600 (Stein).

14-16. TRACHELOMONAS VOLVOCINA, Ehr., vol. i. p. 389 (Stein). — 14, Normal type,
x 500; 15, animalcule with flagellum retracted, emerging from its lorica;
1 6, example bursting and liberating monadiform germs.

17. TRACHELOMONAS RUGULOSA, St., vol. i. p. 389, x 500 (Stein).

18, 19. TRACHELOMONAS LAGENELLA, Ehr. sp., vol. i. p. 389 (Stein). — 19, Encysted
example with body divided by transverse fission, x 500.

20. TRACHELOMONAS CYLINDRICA, Ehr., vol. i. p. 390, x 600 (Stein).

21-23. TRACHELOMONAS HISPIDA, Pty. sp., vol. i. p. 390 (Stein).— 21, Necked variety,
X 500 ; 22, neckless variety, with animalcule emerging from its lorica ; 23,
example with lorica invested with an outer mucilaginous covering.

24. TRACHELOMONAS CAUDATA, Ehr. sp., vol. i. p. 391, x 500 (Stein).

25. TRACHELOMONAS ARMATA, Ehr. sp., vol. i. p. 390, x 500 (Stein).

26. TRACHELOMONAS ACUMINATA, Schmarda, vol. i. p. 391, x 450 (Stein).

27. TRACHELOMONAS EURYSTOMA, St., vol. i. p. 390, x 500 (Stein).

28, 29. ASCOGLENA VAGINICOLA, St., vol. i. p. 393 (Stein). — 28, Normal form, x 500 ;
29, example divided by transverse fission, the anterior segment emerging
from the parent lorica.

EXPLANATION OF PLATE XXI. (continued).
FIG.

30-32. COLACIUM CALVUM, St., vol. i. p. 395 (Stein). — 30, Social colony-stock, x 400 ;
31 and 32, detached, free-swimming animalcules in extended and contracted
states.

33. COLACIUM ARBUSCULA, St., vol. i. p. 394. — Tree-like colony-stock, x 500 (Stein).

34-38. COLACIUM VESICULOSUM, Ehr.. vol. i. p. 395 (Stein). — 34, Sedentary colony-stock,
X 600 ; 35, detached, free-swimming animalcule ; 36-38, successive de-
velopmental phases following on the attachment of a motile zooid, and
resulting, through further subdivision, in the building up of a more or less
extensive sedentary stock.

39-41. COLACIUM STEINII, S. K., vol. i. p. 395. — 39, Erect colony-stock, x 350;
40, arborescent stock, x 700, showing variety of contracted or contorted
forms assumed at will by the component animalcules ; 41, animalcule in an
encysted state, with the body-contents divided into sporular elements.

42. CRYPTOGLENA CONICA, Ehr., vol. i. p. 419, x 500 (Ehrenberg).

43-45. CRYPTOGLENA ANGULOSA, Carter, vol. i. p. 420 (Carter). — 43, Normal aspect ;

44, example enclosing four endogenously developed germinal bodies ;

45, lateral aspect, x 500.

46-51. DISTIGMA PROTEUS, Ehr., vol. i. p. 418 (Stein). — 46, Normal biflagellate ani-
malcule, x 500 ; 47 and 48, old, non-flagellate, and repent zooids (Proteus
tenax, O. F. Miiller ?) ; 49 and 50, young free-swimming animalcules; 51,
still younger monoflagellate example (Monas punctum, Ehr.).

52, 53. ZYGOSELMIS NEBULOSA, Duj., vol. i. p. 417 (Stein), x 1000.— 53, Example with
body distended by ingested diatoms.

54-59. EUTREPTIA VIRIDIS, Pty., vol. i. p. 416. — 54 and 55, Normal free-swimming
animalcules, X 250 ; 56, repent example ; 57, sporocyst burst and liberating
green amcebiform germs, x 400 ; 58, amcebiform germs more highly mag-
nified ; 59, young monoflagellate zooids, x 250.

PLATE .XXI.

PL A TE XXII,

EXPLANATION OF PLATE XXII.
FIG.

i, 2. CHLOROMONAS PIGRA, Ehr. sp., vol. i. p. 401. — Vertical and profile aspects,
X 1500 (Stein).

3-7. CHRYSOMONAS OCHRACEA, Ehr. sp., vol. i. p. 402 (Stein).— 3 and 4, Normal
free-swimming animalcules, x 600; 5-7, resting or encysted conditions,
accompanied by multiplication by segmentation into two, four, or eight
spore-like daughter-cells.

8,9. CHRYSOMONAS FLAVICANS, Ehr. sp., vol. i. p. 402 (Stein).— 8, Normal free-
swimming animalcule, x 600 ; 9, resting or encysted reproductive phase.

10. MICROGLENA PUNCTIFERA, Ehr., vol. i. p. 403, x 6oo (Stein).
11-13. NEPHROSELMIS OLIVACEA, St., vol. i. p. 405, x 600 (Stein).
14-15. HYMENOMONAS ROSEOLA, St., vol. i. p. 408, x 600 (Stein).

16-18. CRYPTOMONAS OVATA, Ehr., vol. i. p. 404 (Stein). — 16 and 17, Adult animalcules,
x 600 ; 1 8, young example.

19-21. CRYPTOMONAS EROSA, Ehr., vol. i. p. 404 (Stein). — 19, Adult animalcule
enclosing large ovate germ-mass, x 600; 20, encysted animalcules; 21,
example dividing by longitudinal fission.

22.. STYLOCHRYSALIS PARASITA, St., vol. i. p. 405. — Social group attached to the
cell-wall of a Eudorina, one example at a dividing by transverse fission,
x 500 (Stein).

23. DINOBRYON JUNIPERINUM, Eichw., vol. i. p. 411, dimensions unrecorded
(Eichwald).

24-26. UVELLA VIRESCENS, Ehr., vol. i. p. 406 (Butschli). — 24, Socially united cluster
of five zooids, x 1200 ; 25, example treated with acetic acid, showing central
spl^roidal nucleus or endoplast, and two laterally developed pigment -bands ;
26, an animalcule dividing by longitudinal fission.

27. SYNURA (RHODESSA) GRIMSELINA, Pty. sp., vol. i. p. 412, x 300 (Perty).

28, 29. CHRYSOPYXIS BIPES, St., vol. i. p. 408 (Stein). — 28, Colony fixed to a node of
Mougeotia, x 600 ; 29, isolated example showing the two spine-like
posterior prolongations of the lorica, by which adhesion to the confervoid
algal is secured.

30-33. EPIPYXIS UTRICULUS, Ehr., vol. i. p. 409 (Stein). — 30, Social colony, x 600,
at a lorica with network-like markings, probably indicating the presence or
previous existence of sporular elements ; 31, a more abnormal and closely
aggregated colony ; 32, an isolated animalcule with its protective lorica
more highly magnified ; 33, an example dividing by oblique fission, as
observed by the author.

34-40. DINOBRYON SERTULARIA, Ehr., vol. i. p. 409. — 34, Compound detached poly-
thecium, x 250 ; 35, a similar but smaller colonial aggregation, x 1000,
at a an animalcule derived by recent fission, attached to the margin of the
parent lorica, and constructing for itself by exudation a new protective
sheath ; 36, an isolated animalcule with its investing lorica, x 2500 ; e,
coloured eye-like pigment-spot ; am, amylaceous corpuscle ; st, thread-like
contractile pedicle or footstalk ; n, nucleus or endoplast ; c v, contractile
vesicle ; 37, example dividing by transverse fission (Butschli) ; 38, encysted
example (Butschli) ; 39 and 40, examples of encystment, after Stein.

41. DINOBRYON STIPITATUM, St., vol. i. p. 410, x 500 (Stein).

PLATE XXE.

V.'. Small. K«»t4d.VfHh«inl!fiu

PL A TE XXI I L

EXPLANATION OF PLATE XXIII.
FIG.

1-2. SYNURA UVELLA, Ehr., vol. i. p. 412 (Stein). — i, Adult spheroidal colony-stock,
composed of animalcules possessing no eye -like pigment-specks, x 350 ;
2, smaller colony of variety having two anterior eye-like pigment-specks.

3. SYNCRYPTA VOLVOX, Ehr., vol. i. p. 413, x 200 (Stein).

4-15. UROGLENA VOLVOX, Ehr., vol. i. p. 414. — 4, Subspheroidal colony-stock, x 150 ;
5, segment of a similar colony, more highly magnified, containing sporular
elements in various phases of development ; 6, a single animalcule ; e, eye-
like pigment-speck ; c v, contractile vesicle ; am, refringent amylaceous
corpuscle ; 7 and 8, isolated spores, x 1200 ; encysted zooid, with body-
mass divided by segmentation into four sporular elements; 10 and u,
sporocysts fractured by artificial pressure, and liberating their contained
sporular elements, x 400 ; 12, animalcule as represented by Stein ; 13, three
zooids of the same species, after Biitschli ; 14-15, examples treated with
acetic acid and carmine, after Biitschli and Stein.

16. SYNURA (UVELLA) FIMBRIATA, From, sp., x 400 (De Fromentel).

17-30. STYLOBRYON PETIOLATUM, Duj. sp., vol. i. p. 278.— 17, Colony-stock of six
zooids, as observed by the author, having very long, slender pedicles to their
loricae, x 400 ; 18, colony-stock, in which the pedicles of the distal series
are rudimentarily developed ; 19 and 20, animalcules in dorsal and profile
view, as examined in living state, x 800; 21-23, example from another
colony preserved with osmic acid, the longer flagellum being variously
convoluted ; 24 and 25, examples with entire body-substance separated into
sporular elements ; 26, isolated spores, x 1 200 ; 27 and 28, colony-stocks
of the same type, after Stein ; 29 and 30, colony-stock and isolated animalcule
of the same species, as figured and described by De Fromentel under the
title of Stylobryon insignis.

PLATE XXm.

PLATE XXIV.

EXPLANATION.
FIG.

i-io. DIPLOMASTIX CAUDATA, Duj. sp., vol. i. p. 432. — i, Typical adult form, x 800 ;
2 and 3, examples with prolonged posterior extremities ; 4, conjugation of
two animalcules ; 5, spore-groups, imbedded in decaying hay-fibre, at a a
two uniflagellate, monadiform germs, produced from the same, x loco ; 6,
sporocyst with four rounded macrospores, x 1000 ; 7, group of elongate
spores, with cyst-wall dissolved, x 1000 ; 8, sporocyst with germ emerging,
after Stein ; 9 and 10, animalcule ingestjng and having ingested a bacillus
filament, after Stein.

ii, 12. DIPLOMASTIX SALTANS. Ehr. sp., vol. i. p. 433, x 800 (Stein).

13. DIPLOMASTIX AFFINIS, S. K., vol. i. p. 433, x 800.

14, 15. HETERONEMA ACUS, Ehr. sp., vol. i. p. 430, x 400 (Stein).

16, 17. HETERONEMA GLOBULIFERUM, Ehr. sp., vol. i. p. 430, x 400 (Stein).

18-20. SPHENOMONAS OCTOCOSTATUS, St., vol. i. p. 438 (Stein). — 18 and 19, Lateral
and ventral aspects, x 400 ; 20, quiescent or encysted phase.

21-23. SPHENOMONAS QUADRANGULARIS, St., vol. i. p. 438 (Stein). — 21, Normal adult
type, x 400 ; 22, the same viewed vertically to its long axis ; 23, zooid
dividing by longitudinal fission.

24,25. ANISONEMA TRUNCATUM, St., v >'. i. p. 435 (Stein).— 24, Dorsal, 25, ventral,
aspects, x 450.

26-30. ANISONEMA GRANDE, Ehr. sp., vol. i. p. 434.— 26, Axial, and 27, dorsal, aspects,
x 400, the four flagella present in the ast figure indicates approaching fission
(after Jas.-Clark) ; 28 and 29, dorsal and ventral aspects, the zooid in the
first instance containing two germinal masses, x 450, after Stein ; 30, zooid
after O. Butschli.

31-34. ENTOSIPHON SULCATUM, Duj. sp., vol. i. p. 437 (Stein), x 400.— 31, Zooid
enclosing ovate germ-mass ; 32, living, and 34, dead examples, with their
horny pharyngeal tubes protruding.

35,36. ANISONEMA LUDIBUNDUM, S. K., vol. i. p. 435, x 1200.— 35, Animalcule in
lateral view discharging faecal matter from its posterior extremity ; 36,
dorsal aspect, showing the two anteriorly located contractile vesicles.

37-39. ANISONEMA INTERMEDIUM, S. K., vol. i. p. 436.— 37 and 39, dorsal and lateral
aspects, x 1 200 ; 28, two young animalcules, possessing as yet only a single
posterior anchoring flagellum, or gubernaculum, x 1 200.

40-42. STERROMONAS FORMICINA, S. K., vol. i. p. 420. — 40 and 41, Dorsal and lateral
aspects, x 1 200 ; 42, encysted state.

EXPLANATION OF PLATE XXIV. (continued).
FIG.

43-45. DlNOMONAS TUBERCULATUS, S. K. vol. i. p. 422. — 43, Animalcule with prolonged
caudal extremity, x 1800; 44, an animalcule devouring a smaller monad;
45, an example with ingested Bacillus.

46-48. DlNOMONAS VORAX, S. K., vol. i. p. 422. — 46, Normal adult type, x 1200 ; 47,
more attenuate early condition ; 48, example in the act of devouring a
smaller monad.

49. CHILOMONAS AMYGDALUM, S. K., vol. i. p. 426, x 1800.

50. CHILOMONAS CYLINDRICA, Ehr. sp., vol. i. p. 425, x 500 (Butschli).

51,52. CHILOMONAS PARAMECIUM, Ehr., vol. i. p. 424 (Butschli).— 51, Normal adult
form, x 650; 52, example dividing by longitudinal fission.

53-61. OXYRRHIS MARINA, Duj., vol. i. p. 427. — 53, A reproduction of Dujardin's
original figure ; 54-56, right and left side aspects,, as observed by the author,
x 800; 57, an example of transverse fission ; 58 and 59, empty membran-
ous carapaces ; 60 and 61, delineations of the same animalcule as given by
Cohn.

62-64. ASTHMATOS CILIARIS, Sals., X 400 (Salisbury).

65, 66. TRICHONEMA HIRSUTA, From., x 400 (Fromentel).

67, 68. MITOPHORA DUBIA, Pty., x 350 (Perty).

69. STEPHANOMONAS LOCELLUS, From, sp., x 400 (Fromentel).

70, 71. HETEROMASTIX PROTEIFORMIS. J.-Clk. — 70, extended, and 71, contracted,
phases, x 500 (J as.- Clark).

72,73. MALLOMONAS PLOSSLII, Pty., x 800.
74. MALLOMONAS FRESENII, S. K., x 350.

PLATE XXIV:

PLATE XXV.

EXPLANATION OF PLATE XXV.
FIG.

1-5. PERIDINIUM TABULATUM, Ehr., vol. i. p. 448. — i, Variety with rounded poles or
apices and no eye-like pigment-spot, ventral aspect, x 350 (Claparede and
Lachmann) ; 2, variety with pointed apices, dorsal aspect (Ehr.) ; 3,
separate reticulated plate from cuirass, x 600; 4, encysted example, with
eye-like pigment-spot (C. & L.) ; 5, example with four pigment-spots, its
cuirass cast off (C. & L.).

6, 7. PERIDINIUM APICULATUM, Ehr. sp., vol. i. p. 449, x 400 (Ehr.).
8-13. CERATIUM DIVERGENS, C. & L., vol. i. p. 453. — 8 and 9, Empty cuirass, dorsal and
ventral aspects, showing form and disposition of its component plates,
x 500 (C. & L.); 10, encysted animalcule (C. & L.) ; n, example with
carapace cast off (C. & L.) ; 12 and 13, the same species as figured by Bailey
under the title of Peridinium depressum.

14. PERIDINIUM JEQUAHS, S. K., vol. i. p. 45 1. — Dimensions unrecorded (WiU.-Suhm).
15, 1 6. PERIDINIUM SPINIFERUM, C. & L., vol. i. p. 449, x 400 (C. & L.).
17, 18. GYMNODINIUM FUSCUM, Ehr., vol. i. p. 443, x 300 (Ehr.).— 18, Example of con-
jugation or longitudinal fission.

19, 20. GYMNODINIUM PULVISCULUS, Ehr. sp., vol. i. p. 443, x 500 (Ehr.).
21, 22. GLENODINIUM ACUMINATUM, Ehr., vol. i. p. 446, x 250 (Ehr.).

23. CERATIUM MICHAELIS, Ehr. sp., vol. i. p. 453, x 300 (Ehr.).

24. CERATIUM TRIPOS, Miill. sp., var. MACROCEROS, vol. i. p. 454, x 250 (C. & L.).

25. CERATIUM KUMAONENSE, Carter, vol. i. p. 458, x 190 (Carter).

26. CERATIUM LONGICORNE, Perty, vol. i. p. 457, x 300 (Carter).

27, 28. GLENODINIUM CINCTUM, Ehr. sp., vol. i. p. 446, x 400 (Ehr.). — 28, An example

of longitudinal fission or conjugation.

29, 30. PERIDINIUM sp., encysted examples, vol. i. p. 447, x 250 (C. & L.).
31,32. CERATIUM FURCA, Ehr. sp., vol. i.p. 445, x 350. — 32, Central region, showing

more minute structure of the cuirass, x 600 (C. & L.).

33. CERATIUM TRIPOS, Miill. sp., normal short-armed type, x 250 (C. & L.).
34, 35. MELODINIUM UBERRIMUM, Allman sp., vol. i. p. 445. — 34, Normal animalcule,

x 3°° > 35> example dividing by transverse fission (Allman).
36. CERATIUM TRIPOS, Miill. sp., var. ARCTICUM, vol. i. p. 454, x 300.
37-39- PROROCENTRUM MICANS, Ehr., vol. i. p. 461.— 37 and 38, Lateral and dorsal

aspects ; 39, empty cuirass, x 303 (C. & L.).

40. CERATIUM FUSUS, Ehr. sp., vol. i. p. 456, x 300 (C. & L.).

41. PERIDINIUM RETICULATUM, C. & L., vol. i. p. 449, x 300 (C. & L.).

42. DlNOPHYSIS VENTRICOSA, C. & L., vol. i. p. 459, X 3$O (C. & L.).

43. DlNOPHYSIS ACUMINATA, C. & L., vol. i. p. 459, X 3OO (C. & L.).

44. DlNOPHYSIS OVATA, C. & L., vol. i. p. 460, ventral aspect, x 350 (C. & L.).
45, 46. AMPHIDINIUM OPERCULATUM, C. & L., vol. i. p. 461, x 300 (C. & L.).

47-50. PERIDINIA sp., encystments, vol. i. p. 448, with contents variously divided, that
at 49 with the contained protoplasmic mass separated into eight minute
naked Peridinia, x 300 (after Claparede and Lachmann).

51, 52. DIMASTIGOAULAX CORNUTUM, Ehr. sp., vol. i. p. 462, front and lateral aspects,
x 300.

53. GYMNODINIUM ROSEOLUM, Schmarda sp., vol. i. p. 444, x 350 (Schmarda).

54. GYMNODINIUM INERME, Schmarda sp., vol. i. p. 44/1, x 600 (Schmarda).
55-57- PERIDINIUM TABULATUM, Ehr., vol. i. p. 448, brown variety with cleft anterior

border, x 300. — 55, Ventral, 56, dorsal, 57, lateral aspects, the example at

56 enclosing a recurved band-like endoplast.
58, 59. GYMNODINIUM LACHMANNI, S. K., vol. i. p. 444.— At 58 an example dividing

by longitudinal fission, x 300 (C. & L.).
60, 61. GYMNODINIUM MARINUM, S. K., vol. i. p. 444, x 600. — At 61 an example

devouring a smaller monad.
62. CERATIUM BICORNE, Schmarda sp., vol. i. p. 453, x 400 (Schmarda).

PLATE XXV!

PLATE XXVI.

EXPLANATION.

FIG.

1-9. OPALINA RANARUM, Purkinge, vol. ii. p. 559. — i, Adult animalcule, x 100 ; 2-5,
successive phases of segmentation terminating in the production of minute
ovate zooids possessing but a few nuclei or endoplasts, x 100; 6, succeeding
encysted condition of No. 5, x 200 ; 7 and 8, successive developmental phases
of zooid that has re-emerged from the encysted state, the one at 7 possessing
but a single endoplast, and that at 8 three such structures, the lowermost
of which, at a, is in the act of subdividing ; 9, a young zooid with ragged
pseudopodium-like lateral extensions (1-8 after Ernst Zeller, 9 after T. W.
Engelmann).

10-11. OPALINA OBTRIGONA, Stein, vol. ii. p. 562. — 10, Adult zooid, x 100; n, minute
encystment, x 200 (Ernst Zeller).

12. ANOPLOPHRYA NAIDOS, Duj. sp., vol. ii. p. 563. — Adult zooid, x 200 (Ray

Lankester).

13. ANOPLOPHRYA FILUM, C. & L., vol. ii. p. 567, x 120 (Claparede & Lachmann).

14. ANOPLOPHRYA PROLIFERA, C. & L., vol. ii. p. 564.— Adult example with five

incompletely separated posterior segments, x 120 (Clap. & Lach.).

15. HOPLITOPHRYA LUMBRICI, Duj. sp., vol. ii. p. 571. — Adult zooid in the act of

dividing by transverse fission, at u, u, horny uncini, x 200 (Stein).

16-18. OPALINA DIMIDIATA, Stein, vol. ii. p. 561. — 16, Adult animalcule, x 100; 17,
minute zooid, produced through successive fission of adult unit, commencing
to subdivide again in a longitudinal direction; 18, elongate zooid, containing
but a single endoplast, recently emerged from a minute encystment (Ernst
Zeller).

19. OPALINA INTESTINALIS, Ehr. sp., vol. ii. p. 562, x 100 (Ernst Zeller).

20. OPALINA RANARUM, Purk., vol. ii. p. 559. — Fragment of cuticular fibrillae treated

with acetic acid, x 200 (Zeller).

21. ANOPLOPHRYA CLAV ATA, Leidy sp., vol. ii. p. 566, x 150 (Leidy).

22. HOPLITOPHRYA RECURVA, C. & L. sp., vol. ii. p. 573, x 130 (Clap. & Lach.).
23, 24. OPALINA CAUDATA, Zeller, vol. ii. p. 563. — Dorsal and lateral aspects, x 120

(Zeller).

25. ANOPLOPHRYA COCHLEARIFORMIS, Leidy sp., vol. ii. p. 566, x 150 (Leidy).
26, 27. ANOPLOPHRYA MYTILI, Quenn. sp., vol. ii. p. 565. — Lateral and dorsal aspects,

x 250 (Quennerstedt).

28-30. PARAM^ECIUM AURELIA, Miiller, vol. ii. p. 483.— 28 and 29, Lateral and ventral
aspects, x 200 ; 30, two conjugating zooids.

EXPLANATION OF PLATE XXVI. (continued).

FIG.

31-32. PARAM^ECIUM BURSARIA, Ehr. sp., vol. ii. p. 486.— Dorsal and ventral aspects
X 250. The arrows in each case indicate the direction of the endoplasmic
current or cyclosis.

33. CONCHOPHTHIRUS ANODONTjE, Ehr. sp., vol. ii. p. 490, x 2oo (Engelmann).
34, 35. CONCHOPHTHIRUS STEENSTRUPII, Stein, vol. ii. p. 490. — Ventral and lateral
aspects, x 200 (Quennerstedt).

36. PRORODON NIVEUS, Ehr., vol. ii. p. 492, x 75 (Ehrenberg).

37. CYRTOSTOMUM LEUCAS, Ehr. sp., vol. ii. p. 497, x 150 (Ehrenberg).

38. ISOTRICHA MICROSTOMUM, C. & L. sp., vol. ii. p. 498, X 250 (Clap. & Lach.).

39, 40. PLACUS STRIATUS, Cohn, vol. ii. p. 490. — Ventral and lateral aspects, x 450
(Cohn).

41. NASSULA AMBIGUA, Stein, vol. ii. p. 495, x 200 (Stein).

42. NASSULA ORNATA, Ehr., vol. ii. p. 494, x 100 (Ehrenberg).

43. PRORODON EDENTATUS, C. & L., vol. ii. p. 493, x 260 (Clap. & Lach.).

44. PRORODON MARGARITIFER, C. & L., vol. ii. p. 493, x 120 (Clap. & Lach.).

45. HOLOPHRYA OVUM, Ehr., vol. ii. p. 498, x 200 (Clap. & Lach.).

46. HOLOPHRYA LATERALIS, S. K., vol. ii. p 500, x 100 (Carter).

47. LOXOCEPHALUS GRANULOSUS, S. K., vol. ii. p. 489, X 300.

48. CHASMATOSTOMA RENIFORME, Eng., vol. ii. p. 540, x 200 (Engelmann).

49. PRORODON NIVEUS, Ehr., vol. ii. p. 492. — Pharyngeal rod-fascicle, x 120

(Ehrenberg).

50. NASSULA ORNATA, vol. ii. p. 494. — Pharyngeal rod-fascicle, x 200 (Ehrenberg).

51-53. ENCHELYODON FARCTUS, C. & L., vol. ii. p. 503. — 51, Extended, 52, contracted
states, x 120; 53, contractile vesicle at full diastole, with its lateral sinuses
and at a central pore-like opening (Wrzesniowski).

54. HELICOSTOMA OBLONGA, Cohn., vol. ii. p. 501, x 150 (Cohn).

55-58. OTOSTOMA CARTERI, S. K., vol. ii. p. 500.— 55 and 56, Adult animalcules, that at

56 showing the band-like endoplast and stellate contractile vesicles, x 100;

57 and 58, successive phases of subdivision into sporular elements (Carter).

59, 60. HOLOPHRYA TARDA, Quenn., vol. ii. p. 499. — Extended and contracted states,

x 200 (Quennerstedt).
61, 62. TRACHELOPHYLLUM APICULATUM, Perty sp., vol. ii. p. 502. — Extended and

contracted states, x 200 (Wrzesniowski).

63, 64. OPHRYOGLENA ATRA, Ehr., vol. ii. p. 532. — Lateral and ventral views, x 200
(Ehrenberg).

65, 66. PANOPHRYS FLAVICANS, Ehr. sp., vol. ii. p. 534. — Ventral and lateral views,
x 150 (Ehrenberg).

67, 68. CYCLOTRICHA CITREUM, C. & L. sp., vol. ii. p. 535. — Lateral and ventral
aspects, x 230 (Clap. & Lach.).

69. PLAGIOPYLA (?) CARTERI, S. K., vol. ii. p. 538, x 100.

70. PLAGIOPYLA (?) FUSCA, Quenn. sp., vol. ii. p. 539, x 150 (Quennerstedt).

PLATE XXVI.

PLATE XXVII.

EXPLANATION.
FIG.

1. UROTRICHA LAGENULA, Ehr. sp., vol. ii. p. 505, x 300.

2. UROTRICHA FARCTA, C. & L., vol. ii. p. 505, x 350 (Claparede & Lachmann).

3, 4. COLEPS HIRTUS, Ehr., vol. ii. p. 506. — 3, Adult animalcule, x 400 ; 4, example
dividing by transverse fission.

5. CQLEPS FUSUS, C. & L., vol. ii. p. 507, x 350 (Clap. & Lach.).

6. COLEPS UNCINATUS, C. & L., vol. ii. p. 507, x 350 (Clap. & Lach.).

7. PLAGIOPOGON COLEPS, Ehr. sp., vol. ii. p. 508, x 250 (Perty).

8-10. POLYKRIKOS SCHWARTZII, Biitschli, vol. ii. p. 508.— 8, Adult example, x 200 ;
9 and 10, supposed trichocysts with thread-like filament in the retracted and
extended states, x 600 (Biitschli).

11-13. METACYSTIS TRUNCATA, Cohn, vol. ii. p. 511. — ii and 12. — Adult examples, x
400 ; young zooids as yet devoid of transverse annulation (Cohn).

14. ENCHELYS ARCUATA, C. & L., vol. ii. p. 5 10, x 300 (Clap. & Lach.).

15. ENCHELYS FARCIMEN, Ehr., voL ii. p. 510, x 600.

1 6, 17. ANOPHRYS SARCOPHAGA, Cohn, vol. ii. p. 512, x 400 (Cohn).

18. PERISPIRA OVUM (?) Stein, vol. ii. p. 511. — Dimensions unrecorded (Carter).

19-23. COLPODA CUCULLUS, Ehr., vol. ii. p. 512. — 19, Adult animalcule, x 200; 20-23,
mucous phases of encystment and sporular mode of multiplication (Stein).

24. COLPODA PIGERRIMA, Cohn, vol. ii. p. 513, x 600 (Cohn).

25-27. LACRYMARIA COHNII, S. K., voL ii. p. 518. — At 25 example with the body
contorted into a screw-like form, x 250 ; at 27 an animalcule spherically
contracted (Cohn).

28. LACRYMARIA CORONATA, C. & L., vol. ii. p. 518. — The distal extremity only
showing the double ciliary wreath, x 350 (Clap. & Lach.).

29-31. TRACHELOCERCA OLOR, Miiller sp., yol. ii. p. 515. — 29 and 31, Adult animalcules,
x 300; 30, distal extremity more highly magnified, displaying oral
structure.

32. TRACHELOCERCA PHCENICOPTERUS, Cohn, vol. ii. p. 516, x 300 (Cohn).

33. TRACHELOCERCA VERSATILIS, Mull, sp., vol. ii. p. 516, x 200.

34. LACRYMARIA LAGENULA, C. & L., vol. ii. p. 517, x 350 (Clap. & Lach.).

35. LAGYNUS ELEGANS, Eng. sp., vol. ii. p. 521, x 300 (Engehrunn).

EXPLANATION OF PLATE XXVII. (continued).
FIG.

36. PHIALINA VERMICULARIS, Ehr., vol. ii. p. 519, x 200 (Ehrenberg).

37. PHIALINA VIRIDIS, Ehr., vol. ii. p. 519, x 200 (Ehrenberg).

38. TRACHELIUS OVUM, Ehr., vol. ii. p. 522, x 80.

39,40. AMPHILEPTUS ANSER, Ehr., vol. ii. p. 525, x 120 (Ehrenberg).

41-44. CHCENIA TERES, Duj. sp., vol. ii. p. 521. — 41, 42, Animalcule in a contracted
and extended condition as observed by author, X 200 ; 43, 44, oral region
in its expanded and contracted states as delineated by Quennerstedt ; i in
Fig. 44 represents an ingested food-particle.

45, 46. AMPHILEPTUS MELEAGRIS, Ehr. sp., vol. ii. p. 526. — 45, Adult animalcule,
x 100 (Ehrenberg) ; 46, showing at a an example which has affixed itself to
and become encysted upon the branching pedicle of a Zoothamnium, the
former occupant of which it has first devoured (after D'Udekem).

.47. TRICHODA PURA, Ehr., vol. ii. p. 535, x 700.

48. MENISCOSTOMUM STOMOPTYCHA, Ehr. sp., vol. ii. p.'$39, x 200 (Eckhard).

49. COLPIDIUM CUCULLUS, Schrank sp., vol. ii. p. 537, X 200.

50, 51. PLAGIOPYLA NASUTA (?) Stein, vol. ii. p. 538. — Lateral and ventral aspects,
x 200 (Quennerstedt).

52. LOXOPHYLLUM MELEAGRIS, Ehr. sp., vol. ii. p. 528, x no (Wrzesniowski).

53. LOXOPHYLLUM ARMATUM, C. & L., vol. ii. p. 529, x 150 (Clap. & Lach.)

54. LEMBADION BULLINUM, Perty, vol. ii. p. 537, x 200. — m, Undulating membrane

(Clap. & Lach.).

55. PLEURONEMA CHRYSALIS, Ehr. sp., vol. ii. p. 543, x 250.

56. PLEURONEMA CORONATA, S. K., vol. ii. p. 544, x 200.

57,58. CYCLIDIUM GLAUCOMA, Ehr., vol. ii. p. 544. — 57, Normal zooid, x 600; 58,
immature example, being as yet deficient of the oral membrane that dis-
tinguishes the adult type.

59, CYCLIDIUM CITRELLUS, Cohn. sp., vol. ii. p. 545 x 300 (Cohn).

i. URONEMA MARINA, Duj., vol. ii. p. 546.— 60, Adult, and 61, immature examples,

x 600.
62, «. j. LEMBUS VELIFER, Cohn, vol. ii. p. 547. — 62, Adult, and 63, immature example,

x 400 (Cohn).
64. BjEONlDlUM REMIGENS, Perty, vol. ii. p. 546, x 350 (Fresenius).

65, 650. PROBOSCELLA VERMINA, Mull, sp., vol. ii. p. 549. — 65, Example as observed

and delineated by the author, x 500 ; 6$a, illustration of apparently the
same species as given in Miiller's 'Animalcula Infusoria,' tab. viii. fig. i,
1786.

66, 67. LEMBUS SUBULATUS, S. K., vol. ii. p. 548, x 700.

68. AMPHILEPTUS GIGAS, C. & L., vol. ii. p. 526. — Attenuate variety, having the
contractile vesicles disposed in linear order along the dorsal border,
X loo ; tr, trichocysts (Wrzesniowski).

PLATE XXVE.

sr~

1

*

PLATE XXVIII.

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).

PLATE XXVm.

PLATE XXIX.

EXPLANATION OF PLATE XXIX.
FIG.

1-2. BURSARIA TRUNCATELLA, Muller. — i, Adult animalcule, x 50; 2, supposed
young condition, x 200 (Stein).

3. BALANTIDIUM ENTOZOON, Ehr. sp., x 100 (Stein).

4. NYCTOTHERUS CORDIFORMIS, Stein, x 150. — an, anal aperture (Stein).

5. NYCTOTHERUS VELOX, Leidy, x 200 (Leidy).

6-9. METOPUS SIGMOIDES, Clap. & Lach.— 6 and 8, Extended, 7 and 9, spirally
contorted animalcules, x 200 (Stein).

10. PLAGIOTOMA LUMBRICI, Duj., x 200 (Stein).

11. CONDYLOSTOMA STAGNALIS, Wrz., x 150. — u, Undulating membrane (Wrzes-

niowski).

12. CONDYLOSTOMA PATENS, Miill. sp., x 150 (Stein).

13, 14. SPIROSTOMUM AMBIGUUM, Ehr. — 13, An extended, 14, a spirally contorted
zooid, x 1 50 (Stein).

15. BLEPHARISMA UNDULANS, Stein, x 150. — u, Undulating membrane (Stein).

16, 17. BALANTIDIUM COLI, Malmsten sp., x 200. — At 17 an example preparing to
divide by transverse fission, and having already developed at p 2 a second
peristome (Stein).

1 8. LEUCOPHRYS VIRENS, Ehr. sp., x 150.—^, pharyngeal passage (Stein).

19, 20. FOLLICULINA STYLIFER, St. Wrght. sp. — In each instance the anterior region of
the lorica is alone represented, the peristome lobes of the contained animal-
cule in Fig. I9«being fully expended, while in Fig. 20 they are entirely with-
drawn, leaving the stylate appendage only projecting beyond the orifice of
the lorica. Dimensions unrecorded (Strethill Wright)

21-28. FOLLICULINA AMPULLA, Muller sp. — 21 and 22, Entire animalcule and distal
region of peristome of var. ACULEATA, Clap, and Lach. ; at 24 numerous
examples crowded on a shell of Spirorbis nautiloides, x 20 ; 25-27,
examples showing the diverse plans of ornamentation of the lorica; 28,
normal type in its fully extended state, x 200 (Stein).

29-32. FOLLICULINA PRODUCTA, St. Wrght. sp. — 29, Adult animalcule in its full;
extended state, x 200 ; 30-32, embryonic condition (Strethill Wright).

33-35. FOLLICULINA ELEGANS, Clap. & Lach. sp. — 33 and 34, Adult animalcules,
ventral and lateral aspects, x 200 (Stein) ; 35, empty lorica showing at v
valvular elements (Clap. & Lach.).

36. FOLLICULINA BOLTONI, S. K., x 200.

37, 38. CH^ETOSPIRA MUELLERI, Lachmann, extended and partially retracted states as
observed by the author, x 300.

39. FOLLICULINA HIRUNDO, S. K., x 200.

40. FOLLICULINA AMPULLA, Muller sp., var. VIRIDIS, St. Wrght., x 1 50 (Strethill

Wright).

PLATE XXK.

WSawlkKsnt ii.WSiaililitk

Minterr. :

PLATE XXX.

EXPLANATION OF PLATE XXX.
FIG.

1-4. STENTOR IGNEUS, Ehr.— i, Attached, fully extended animalcule, x 70 ; 2 and 3,
free-swimming conditions ; 4, embryo released by the disintegration of the
parent zooid.

5. STENTOR PEDICULATUS, From., x 250 (De Fromentel).
6, 7. STENTOR AURICULA, S. K., ventral and dorsal aspects, x 120.
8, 9. STENTOR MULTIFORMIS, Stein, x 200 (Stein).

10-20. STENTOR POLYMORPHUS, Miiller sp. — 10, Attached, fully extended animalcule,
x 120; II, a social colony, colourless variety, attached to a rootlet of
Anacharis, which has built up through excretion a common mucilaginous
basis, x 15; 12, examples conjugating with their neighbours, as delineated
by Balbiani ; 13, free-swimming zooid with attenuated posterior region;
14, example with, at/r, a laterally developed membranous crest, representing
the initial condition of the peristomal ciliary circlet of a future zooid
(Ehrenberg) ; 15, an encysted example (Stein); 16, an animalcule dis-
charging faecal matter, as observed by the author; 17 and 18, groups of the
green variety, natural size, and x 50, after Ehrenberg; 19 and 20, portion
of the nucleus or endoplast, showing in the former instance the union of the
component granular nodules by an interconnecting cord or funiculus ; at 20 an
isolated nodule with an enclosed elongate vacuolar structure, x 300 (Stein).

21. STENTOR BARETTII, Barrett. — Fully extended animalcule, x 100.

22-23. STENTOR ROESELII, Ehr. — 22, Fully extended example affixed within its excreted
mucilaginous sheath, x 80 ; at pr, initial condition of a second peristome
(Clap. & Lach.) ; 23, basal or pedal region with pseudopodic peripheral
extensions (after Simroth) ; 24, clavate free-swimming zooid with at pr
secondary peristome in progress of development (Stein); 25, more advanced
condition of fissure, the second peristome, pr, having attained a contour and
proportions that correspond closely with those of the primary one (Clap,
and Lach.) ; 26, last phase of fissive process, the anterior moiety being
now almost completely separated from the posterior one (from a MS.
drawing by H. E. Forrest); 27-30, progressive developmental phases, after
Claparede and Lachmann ; 31, supposed germ-sphere as delineated by Stein ;
32, foot or basal region with tuft of longer setose cilia, after Stein ; 33, free-
swimming semi-contracted animalcule (Stein).

PLATE XXX.

'^p IE
r

PLATE XXXI.

EXPLANATION.
FIG.

1,2. TINTINNUS EHRENBERGII, C. & L., extended and contracted states, x 150
(Claparede & Lachmann).

3. TINTINNUS URNULA, C. & L., x 150. — Atpr, a second peristome in process of

development (Clap. & Lach.).

4. TINTINNUS Ussowi, Meresch., empty lorica, x 400 (Mereschkowsky).

5. TINTINNUS SUBULATUS, Ehr., x 250 (Ehrenberg).

6, 7. TINTINNIDIUM SEMICILIATUS, Sterki sp.— At 7 an animalcule isolated from its
lorica, viewed in optical section, and showing at m outer wreath of furcately
branched cirrose cilia or membranellas, and at i inner circlet of ordinary
vibratile cilia, x 200 (Sterki).

8. TINTINNIDIUM FLUVIATILIS, Stein sp., x 200.

9. TINTINNIDIUM MARINUM S. K., x 200 (Ehrenberg).

10. TINTINNUS CINCTUS, C. & L., empty lorica, x 250 (Clap. & Lach.).

11. TINTINNUS CAMPANULA, Ehr., x 150. — At/r, a second peristome is in course of

development, x 150 (Clap. & Lach.).

12. TINTINNUS AMPHORA, C.& L., x 150 (Clap. & Lach.).

13. TINTINNUS QUADRILINEATUS, C. & L., empty lorica, x 150 (Clap. & Lach.).

14. TINTINNUS ACUMINATUS, C. & L., empty lorica, x 200 (Clap. & Lach.),

15. TINTINNUS INQUILINUS, Ehr., x 300 (Clap. & Lach.).

1 6. TINTINNUS MUCICOLA, C. & L., x 150 (Clap. & Lach.).

17. TINTINNUS sp. — Empty lorica, x 250 (Clap, and Lach.).

18, 19. TINTINNUS DENTICULATUS, Ehr. — 18, Empty lorica, x 150; 19, portion of the

same, x 800 (Clap. & Lach.).

20. TINTINNUS STEENSTRUPII, C. & L., x 200 (Clap. & Lach.).
21,22. TINTINNUS LAGENULA, C. & L. — 21, normal example, x 300; 22, lorica con-
taining two zooids (Clap. & Lach.).

23. TINTINNUS sp., C. & L., x 150 (Clap. & Lach.).

24. TINTINNUS HELIX, C. & L., empty lorica, x 150 (Clap. & Lach.).

25. TINTINNUS ANNULATUS, C. & L., empty lorica, x 150 (Clap. & Lach.).

26. TINTINNUS OBLIQUUS, C. & L., x 300 (Clap. & Lach.).

EXPLANATION OF PLATE XXXI. (continued).

FIG.

27, 28. VASICOLA CILIATA, Tatem.— 27, Animalcule contained within its lorica, x 150 ;
28, free-swimming zooid (Tatem).

29. STROMBIDINOPSIS GYRANS, S. K., x 200.

30. TINTINNUS sp., C. & L., empty lorica, x 150 (Clap. & Lach.).

31. TINTINNUS VENTRICOSUS, C. & L., empty lorica, x 200 (Clap. & Lach.).

32, 33. CODONELLA GALEA, Hkl. — 32, Animalcule fully extended beyond the orifice of
its lorica, x 200 ; 33, empty lorica, showing its tesselated character
(Haeckel),

34-37. CODONELLA CAMPANELLA, Hkl. — 34, Fully extended animalcule enclosing cen-
trally numerous ovate germs, x 200 ; 35, empty lorica ; 36, ovate germ, with
contained endoplast and contractile vesicle ; 37, earlier spore-like condition
(Haeckel).

38. CODONELLA ORTHOCERAS, Hkl., x 180 (Haeckel).

39-43. TRICHODINOPSIS PARADOXA, C. & L. — 39, Adult animalcule, profile view,
x 200 ; 40, ventral acetabulum with plicate horny ring, x 300 ; 41-43,
internally developed corneous elements (Clap. & Lach.).

44. TRICHODINA MITRA, Stein sp., x 300 (Clap. & Lach.).

45. TRICHODINA STEINII, C. & L.— Acetabulum with denticulate ring, x 250

(Clap. & Lach.).

46, 47. TRICHODINA SCORP^ENA, Robin, lateral and ventral views, x 400 (Robin).

48-52. TRICHODINA PEDICULUS, Ehr. — 48, Examples adherent in various positions to
the portion of a tentacle of a Hydra ; 49, two animalcules in lateral view,
x 150; 50, depressed free-swimming zooid; 51, conically contracted
animalcule showing at or oral aperture, as delineated by Busch ; 52, apparent
example of conjugation between a large and small zooid, a, after Busch.

53. TRlCHODiNA-like larva, or Trochosphere of Polyzoon, Alcyonidium
gelatinosum, as delineated in note-book placed at the author's disposal by
H. E. Forrest.

54, 55. SCYPHIDIA PHYSARUM, C. & L., expanded and contracted zooids, x 200
(Quennerstedt).

PLATE XXXI

Mmtem Bro

PLATE XXXII.

EXPLANATION OF PLATE XXXII.

FIG.

1-8. ICHTHYOPHTHIRIUS MULTIFILIIS, Fouquet. — i, Adult animalcule, x 120 ; 2-5,
successive phases of segmentation following upon encystment, and resulting
in the subdivision of the entire body-mass into a swarm of minute ciliated
germs ; 6, ciliated germ, x 350 ; undeveloped germ with twisted thread-like
cuticular extensions of the opposite poles ; 8, oral apparatus viewed from
above (Fouquet).

9. PARAMJECIUM MARINUM, S. K., x 250.

10. LEMBUS ELONGATUM, C. & L. sp., x 300 (Clapardde & Lachmann).
11, 12. MARYNA SOCIALIS, Gruber. — n, Social colony within branched granular

zoothecium, x 60 ; 12, isolated animalcule, x 120 (Gruber).
13. TILLINA MAGNA, Gruber, x 190 (Gruber).

14, 15. HAPTOPHRYA GIGANTEA, Maupas — 14, Adult animalcule, ventral aspect, x 33
15, acetabulum, x 50 (Certes).

1 6. LOXOCEPHALUS LURIDUS, Eberhard, x 100 (Eberhard).

17. ENCHELYODON ELONGATUS, C. & L., x 150 (Clap. & Lach.).

1 8. METOPIDES CONTORT A, Quenn., x 275 (Quennerstedt).

19. OPALINA RAN ARUM, Purk. — Showing temporarily assumed parallel disposition

of the cilia as observed by the author, x 100.
20, 21. NYCTOTHERUS GYCERYANUS, Stein.— Ventral and lateral aspects, x 200 (Stein).

22. BALANTIDIUM MEDUSARUM, Meresch., x 600 (Mereschkowsky).
23, 24. CALCEOLUS CYPRIPEDIUM, J.-Clk. sp.— Ventral and lateral aspects, x 200

(Jas.- Clark).
25, 26. DICTYOCYSTA MITRA, Hkl.— 26, Empty lorica, x 230 (Haeckel).

27. DICTYOCYSTA TEMPLUM, Hkl.— Empty lorica, x 400 (Haeckel).

28. DICTYOCYSTA TIARA, Hkl. — Empty lorica, x 400 (Haeckel). _,

29-31. DICTYOCYSTA CASSIS, Hkl. — 29, Empty lorica, showing cribrate structure, x 165 ;
30, extended animalcule, containing germinal bodies g, depending from its
lorica, x 165 ; 31, isolated germ, x 300 (Haeckel).

32-34. TORQUATELLA TYPICA, Lankester. — 32, Animalcule with oral membrane con-
tracted ; 33 and 34, examples, viewed laterally and from above, with this
structure variously expanded. Dimensions unrecorded (Ray Lankester).

35-38. HALTERIA GRANDINELLA, Miill. sp. — 35 and 36, Lateral and ventral aspects, x
600 ; 37, animalcule dividing by transverse fission ; 38, example with its
springing-setae deflected in the act of leaping.

39. HALTERIA VOLVOX, Eichwald, x 250 (Claparede & Lachmann).

40. MESODINIUM ACARUS, Stein, x 400, as observed by the author.

41. ARACHNIDIUM CONVOLUTUS, S. K., x 400.

42, 43. ARACHNIDIUM BIPARTITA, From. sp. — 42, Ambulatory, and 43, free-swimming
examples, x 400 (De Fromentel).

44. MESODINIUM PULEX, C. & L. sp., x 350 (Clap. & Lach.).

45. ACARELLA SIRO, Cohn, x 250 (Cohn).

46. STROMBIDIUM CLAPAREDII, S. K., x 200.

47. STROMBIDIUM SULCATA, C. & L., x 200 (Clap. & Lach.).

48, 49. ARACHNIDIUM GLOBOSUS, S. K. — Examples with tentacles extended and con-
tracted, x 1 200.

50-57. DlDINlUM NASUTUM, Miill. sp.— 50, Normal aspect of natatory animalcule, as
observed by the author, x 200; 51 and 52, illustrating the seizure and
engulfment of a Paramacium as delineated by Balbiani ; 53 and 54, aspects
antecedent to and attending transverse fission (Balbiani); 55, example of
abnormal multiple subdivision as delineated by Eberhard; 56 and 57,
embryonic conditions, after Balbiani.

PLATE XXXII

PLATE XXXIII.

EXPLANATION.
FIG.

1-6. GYROCORIS OXYURA, Stein, vol. ii. p. 640. — i, Adult, and 2, 3, undeveloped zooids,
x 300 (after Tatem) ; 4-6, adult animalcules as delineated by Eberhard.

7-10. UROCENTRUM TURBO, Miiller sp., vol. ii. p. 641. — 7 and 8, Free-swimming and
posteriorly adherent zooids, X 300; 9, an example dividing by transverse
fission ; 10, a-f, showing consecutive contours exhibited by the contractile
vesicle.

11-13. TELOTROCHIDIUM CRATERIFORME, Mull, sp., vol. ii. p. 643. — it, Normal ex-
ample, x 200 ; 12, zooid with abruptly truncate posterior border ; 13,
example dividing by longitudinal fission.

14-18. TRICHODINA PEDICULUS, Ehr., vol. ii. p. 646. — 14-16, Lateral and ventral aspects
x 300 (after Stein) ; 17, denticles of adherent disc (after Quennerstedt) ;
1 8, the same structures as interpreted by the author; ex. external, and
in. internal elements, x 800.

19-21. TRICHODINA BALTICA, Quenn., vol. ii. p. 649. — 19 and 20, Lateral and ventral
views, x 350; 21, denticles of adherent apparatus more highly magnified
(Quenn.).

22. URCEOLARIA MITRA, Stein, vol. ii. p. 650, x 600 (Stein).

23, 24. CYCLOCH^ETA SPONGILUE, Jackson, vol. ii. p. 650. — 23, Adult animalcule in
profile view, x 400 ; 24, portion of denticulated ring of acetabulum more
highly magnified.
25. LICNOPHORA COHNII, Claparede, vol. ii. p. 652, x 400 (Cohn).

26-28. COZNOMORPHA MEDUSULA, Petty, vol. ii. p. 641, x i jo (Perty).

29. ASTYLOZOON FALLAX, Eng., vol. ii. p. 654, x 250 (Engelmann).

30. LICNOPHORA AUERBACHII, Clap., vol. ii. p. 651, x 500 (Cohn).

31. SCYPHIDIA PHYSARUM, C. & L., vol. ii. p. 658, x 300 (Claparede & Lachmann).

32. SCYPHIDIA LIMACINA, Lach., vol. ii. p. 658, x 300 (Lachmann).

33. SCYPHIDIA RUGOSA, Duj., vol. ii. p. 659. — Expanded and contracted examples,

x 280 (Dujardin).

34, 35. GERDA FIXA, D'Udk., vol. ii. p. 657. — 34, Expanded zooid almost completely
divided by longitudinal fission ; 35, contracted example, dimensions un-
recorded (D'Udekem).

36-38. GERDA CLANS, C. & L., vol. ii. p. 657. — 37, An adherent zooid; 38, a free-
swimming example with adventitious posterior ciliary circlet, x 150 (Clap.
& Lach.).

EXPLANATION OF PLATE XXXIII.— continued.
FIG.

39-42. SPIROCHONA TINTINNABULUM, S. K., vol. ii. p. 661. — 39 and 40, Adult fully
extended zooids, x 600; 41, example with subcentral ciliary circlet preparing
to divide by transverse fission ; 42, posterior moiety of subdivided zooid, the
membranous funnel being as yet imperfectly developed ; h, hyaline triangular
interspace.

43-49. SPIROCHONA GEMMIPARA, Stein, vol. ii. p. 660. — 43, Adult fully extended zooid
with at g a single germinal bud, x 350 ; 44, example with two laterally
attached germs ; 45 and 46, detached germs in lateral ventral aspect, showing
rudimentary stellate acetabulum and hypotrichous plan of ciliation ; 47 and
48, acetabuliform adherent apparatus of adult zooid ; 49, endoplast and
nucleus (43 and 44, after Stein ; 45-49, after Hertwig).

50-52. SPIROCHONA SCHEUTENII, Stein, vol. ii. p. 661. — 50 and 51, Spirit-preserved
zooids, x 300 (after Stein) ; 52, colony attached to branched hair of Gam-
marus marinus (after Westwood & Bates).

53. SCYPHIDIA FROMENTELLII, S. K., vol. ii. p. 659, x 200 (De Fromentel).

54, 55. STYLOCHONA CORONATA, S. K., vol. ii. p. 663. — 54, Two adult fully extended
zooids, x 600; 55, adult and imperfectly developed zooids attached to
branched hair of Gammarus sp.

56, 57. STYLOCHONA NEBALINA, S. K., vol. ii. p. 662. — 56, a, Adult, and b, immature
zooid, x 500 ; 57, distal region of spirit-preserved example with membranous
funnel unrolled.

PLATE XXXin.

C <=(> e>e

^ 29

I®
7

•

'

-. I ]-.:

•.',l\-^^a

•

PLATE XXXIV.

EXPLANATION OF PLATE XXXIV.
FIG.

1. RHABDOSTYLA RINGENS, From, sp., vol. ii. p. 666, x 150 (De Fromentel).

2. SCYPHIDIA INCLINANS, D'Udk. sp., vol. ii. p. 659. — a, Extended, and b, con-

tracted zooid, dimensions unrecorded (D'Udekem).

3, 4. RHABDOSTYLA SERTULARIUM, S. K., vol. ii. p. 665. — 3, Short-stalked, and 4, long-
stalked varieties, 3 x 300.

5, 6. RHABDOSTYLA OVUM, S. K., vol. ii. p. 664. — Expanded and contracted zooids,
x 250.

7. PYXIDIUM COTHURNOIDES, S. K., vol. ii. p. 667, x 350.

8. RHABDOSTYLA BREVIPES, C. & L. sp., vol. ii. p. 665, x 300 (Claparede & Lach-

mann.

9. PYXIDIUM INCLINANS, Mull, sp., vol. ii. p. 667.— a, Expanded, and b, contracted

zooids, x 250 (De Fromentel).

10. RHABDOSTYLA SPH/EROIDES, From., vol. ii. p. 666, x 200 (De Fromentel).

11,12. RHABDOSTYLA NEBULIFERA, From., vol. ii. p. 665. — 12, Example dividing by
longitudinal fission, x 100 (De Fromentel).

13, 14. VORTICELLA BREVISTYLA, D'Udk., vol. ii. p. 675. — 13, a, Expanded, and d, con-
tracted zooid, x 200 ; 14, encysted example (D'Udekem).

15-19. VORTICELLA STRIATA, Duj., vol. ii. p. 684. — 15, Two zooids, the one with a
lateral gemmulethe product of longitudinal fission, X 300; 16-19, successive
phases of detached germ, resulting in the last instance in the attachment and
development of a pedicle.

20, 21. VORTICELLA NEBULIFERA, Ehr., vol. ii. p. 673.— 20, Social group, showing at
a and b successive phases of longitudinal fission, and at c contracted zooid
with conjugating germ, x 200; 21, free-swimming zooid the product of longi-
tudinal fission (D'Udekem).

22. VORTICELLA CRATERA, S. K., vol. ii. p. 679.— Expanded and contracted zooid,
x 250 (D'Udekem).

23, 24. VORTICELLA PUTRINUM, Mull., vol. ii. p. 684. — 23, Expanded and contracted
zooid, the latter at a, two basally attached migrant zooids, the product of
repeated longitudinal fission, x 300 ; 24, free-swimming migrant zooid (fine
cross-striation of the cuticle accidentally omitted by the artist).

25,26. VORTICELLA CRASSICAULIS, S. K., vol. ii. p. 676. — a a, Extended, and bb, con-
tracted zooids, x 300.

27. VORTICELLA HAMATA, Ehr., vol. ii. p. 687. — a, Expanded, and b, contracted

zooids, x 300.

28. VORTICELLA NUTANS, Mull., vol. ii. p. 679, x 300.

29. RHABDOSTYLA LONGIPES, S. K., vol. ii. p. 666. — At b fully contracted zooid, x 200.

30. VORTICELLA LONGIFILUM, S. K., vol. ii. p. 677, x 200.

31,32. VORTICELLA TELESCOPICA, S. K., vol. ii. p. 677.— 31, Extended, and 32, con-
tracted zooid,- x 250.

33. VORTICELLA ALBA, From., vol. ii. p. 676. — At a example with rudimentary

pedicle, b contracted zooid, x 200.

34. VORTICELLA QUADRANGULARIS, S. K., vol. ii. p. 685.— At b contracted zooid,

x. 125.

35. VORTICELLA SPECTABILIS, S. K., vol. ii. p. 687.— Social group, x 100.

36. VORTICELLA CAMPANULA, Ehr., vol. ii. p. 678. — At a expanded example, with

the cuticle irregularly puckered, at b contracted zooid, x 100.

PLATE XXXIV

W 5 «.-<fllt K«it del -W. Rhnn

PLATE XXXV.

PLATE XXXV.

EXPLANATION OF PLATE XXXV.
FIG.

1-8. VORTICELLA MARINA, Greeff, vol. ii. p. 685.— 1-3, Successive phases of longi-
tudinal fission resulting in the production of the free-swimming zooids,
Figs. 4 and 5 ; 6-8, successive phases illustrative of the conjugation of a
free-swimming microzooid with a normal sedentary animalcule, x 200 (Greeff).

9-24. VORTICELLA MICROSTOMA, Ehr., vol. ii. p. 683.— 9-11, Showing production of
microzooid by uneven longitudinal fission ; 12 and 13, conjugation of micro-
zooid with normal animalcule resulting in the disintegration of the endoplast
or nucleus (after Greeff) j 14-16, encysted zooids apparently developing, in
the two latter instances, endoparasitic organisms (Stein) ; 17, normal de-
tached sedentary animalcule as observed by the author ; 18, encysted zooid ;
19, example of production of eight microzooids through repeated fission of
primarily segmented moiety (after D'Udekem) ; 20, zooid with two basally
attached microzooids ; 21, zooid encysted upon its contracted pedicle (after
Stein) ; 22-24, conjugating adult zooids, x 300 (after Claparede & Lachmann).

25. VORTICELLA ELONGATA, From., vol. ii. p. 686, x 200.

26. VORTICELLA PATELLINA, Mull, vol. ii. p. 679, x 170.

27, 28. VORTICELLA MONILATA, Tatem, vol. i. p. 688. — At b contracted zooid ; 28, de-
tached free-swimming animalcule, x 300.

29. VORTICELLA CITRINA, Ehr., vol. ii. p. 678, x 150.

30, 31. CARCHESIUM POLYPINUM, Linn, sp., vol. ii. p. 690. — 30, Hinder portion of body
that to the left viewed in perspective, that to the right in optic section ;
cl, temporarily developed posterior ciliary girdle ; b, obliquely striated band
that gives' origin to these cilia ; mm, fibrillae of muscular or myophan layer,
c, cuticulum ; ^contracted ectoplasm; 31, obliquely striated band, b of
preceding figure, X 2000, showing its granular consistence (after T. W.
Engelmann, from a specimen prepared with a one-half per cent, solution of
osmic acid).

32-47. VORTICELLA NEBULIFERA, Ehr., vol. ii. p. 673. — 32, Body of adult zooid, showing
at m outline of myophan layer continuous with the contractile fibrilla of
the pedicle, x 400 ; 33~35, successive phases following upon detachment
and encystment resulting in the subdivision of the endoplast or nucleus into
nodular fragments ; 39-46, successive phases illustrating the development
of a nodular endoplastic fragment through a Strombidium-Xfas, condition
(Figs. 38-41) into an ordinarily attached zooid, the example at 40 dividing by
transverse fission ; 47, lenticular protective encystment (after Everts).

48-50. EPISTYLIS FLAVICANS, Ehr., vol. ii. p. 702. — 48, Terminal branchlet with two
zooids ; v, vestibulum ; ph, pharynx ; ce, oesophagus ; /, food-mass passing
through the tubular oesophagus ; /', food-globules discharged into the internal
parenchyma or endoplasm ; an, anal aperture, X 200 ; 49, alimentary tract
isolated and further enlarged ; or, oral aperture ; b, bulbous enlargement of
oesophagus ; s, vestibular seta ; /, flap-like developments of pharyngeal walls ;
other lettering as in preceding figure ; 50, basal region of body, showing
radiating muscular fibrillae and concentric striae of the cuticulum, x 300
(after R. Greeff).

51. CARCHESIUM POLYPINUM, Linn, sp., vol. ii. p. 690. — Diagrammatic outline of
peristome and oral system ; p, peristome ; c I, ciliary wreath ; v, vestibulum ;
s, vestibular seta ; cv, contractile vesicle ; an, anal aperture (R. Greeff).

PLATE XXXV.

PLATE XXXVI.

EXPLANATION OF PLATE XXXVI.

CARCHESIUM POLYPINUM, Linn, sp., vol. ii. p. 690. — i, Adult colony-stock,
X 100 ; 2, a similar stock completely retracted ; 3, three colony-stocks
attached to a rootlet of Lemna, natural size, as delineated by Schaffer (1754) ;
4, termination of branchlet showing unilateral plan of disposition of the
zooids, X 150 ; 5, terminal branchlet with three zooids, showing independent
relationship of the contractile element of their respective pedicles, x 350
(after Stein) ; 6, fragment of pedicle, showing apparent transverse striation of
the central muscular cord, as delineated by H. E. Forrest ; 7 and 8, succes-
sive phases of longitudinal fission.

9. ZOOTHAMNIUM NUTANS, C. & L., vol. ii. p. 698, x 2oo (Claparede & Lachmann).

10. CARCHESIUM ASELLI, Eng., vol. ii. p. 693, x 125 (Engelmann).

11. ZOOTHAMNIUM MARINUM, Meresch., vol. ii. p. 700, x 125 (Mereschkowsky).

12-14. CARCHESIUM EPISTYLIDIS, C. & L.,vol. ii. p. 692. — 12, Small colony-stock (after
Clap. & Lach.), x 300 ; 13 and 14, large colony-stock and terminal branchlet
of the same, as delineated by H. E. Forrest.

15. ZOOTHAMNIUM NUTANS, C. & L., vol. ii. p. 698. — Isolated zooid during contrac-

tion, x 200 (Clap. & Lach.).

1 6. ZOOTHAMNIUM AFFINE, Stein, vol. ii. p. 698, x 150 (Stein).

17-20. ZOOTHAMNIUM SIMPLEX, S. K., vol. ii. p. 700. — 17, Adult colony-stock, x 150;
1 8, retracted condition ; 19, isolated zooid, x 300 ; 20, conjugation of
migrant microzooid a with an ordinary sedentary animalcule.

2i. CARCHESIUM LACHMANNI, S. K., vol. ii. p. 691, x 200 (Clap. & Lach.)

22, 23. ZOOTHAMNIUM ALTERNANS, C. & L., vol. ii. p. 695. — 22, Colony-stock with at
aaa subcylindrical microzooids, as observed by the author; 23, isolated
microzooid, X 400.

24, 25. ZOOTHAMNIUM GLENISCUM, C. & L., vol. ii. p. 697.— Expanded and contracted
zooids, x 200 (Clap. & Lach.).

26. CARCHESIUM SPECTABILE, Ehr., vol. ii. p. 691.— Colony-stock, as figured by Roscl
(1755), dimensions unrecorded.

PLATE XXXVI.

PLATE XXXVII.

EXPLANATION OF PLATED XXXVII.
FIG.

1-8. ZOOTHAMNIUM ARBUSCULA, Ehr., vol. ii. p. 694. — i, Fully extended adult colony-
stock with at a a large subspheroidal reproductive zooids, x 100 ; 2, a similar
colony-stock, natural size ; 3, colony-stock in a semi-contracted state ; 4,
isolated conical zooid, X 350 ; 5, spheroidal reproductive zooid, as delineated
by H. E. Forrest ; 6 and 7, successive phases of growth of a reattached repro-
ductive zooid ; 8, ordinary conical zooid with the anterior border plicately
contracted.

9-12. ZOOTHAMNIUM DICHOTOMUM, Wright, vol. ii. p. 697.— 9, Adult colony-stock,
x 50; 10, an isolated zooid, x 200; n, colony-stock in semi-contracted
state ; 12, scarcer reproductive zooids, x 200.

13, 14. ZOOTHAMNIUM NIVEUM, Ehr., vol. ii. p. 694. — 13, Adult colony-stock, x 50;
14, isolated zooid, x 200.

15. ZOOTHAMNIUM CIENKOWSKII, Wrz., vol. ii. p. 696, x 400 (Wrzesniowski).

16. ZOOTHAMNIUM PARASITA, Stein, vol. ii. p. 698, x 100 (Stein).

17-19. ZOOTHAMNIUM CARCINI, S. K., vol. ii. p. 700.— 17, Adult colony-stock, x 80 ;
1 8 and 19, expanded and contracted zooids, x 200.

20-24. ZOOTHAMNIUM ALTERNANS, C. & L., vol. ii. p. 695. — 20, Adult colony-stock with
various sized zooids, as delineated by Greeff, x 125 ; 21, attenuate undeveloped
colony-stock, as observed by the author ; 22 and 23, larger reproductive zooids
with subcentrally developed supplementary ciliary girdles ; 24, portion of
pedicle with finely striate central cord, as observed by the author ; 25, a
portion of the same structure, as delineated by H. E. Forrest.

PLATE XXXVH.

SiffleK.

PLATE XXX VI II.

EXPLANATION OF PLATE XXXVIII.

Fio.

1-5. EPISTYLIS FLAVICANS, Ehr., vol. ii. p. 702. — Adult erect colony-stock, with at
rr rosette-like groups of microzooids produced through the repeated seg-
mentation of the ordinary animalcules ; at k k detached microzooids laterally
adherent to and conjugating with ordinary sedentary animalcules, x 100, after
Greeff (as originally delineated by Greeff, the right-hand half of the colony is
alone portrayed, the left one has been filled by the author, in keeping- with
the same, for the purpose of symmetry) ; 2, decumbent colony-stock ; 3, zooid
after death, the cilia having fallen away, but showing concentric lines of ciliary
circlets ; 4 and 5, trichocyst-like bodies, as delineated by Greeff, x 600.

6-8. EPISTYLIS PLICATILIS, Ehr., vol. ii. p. 701.— 6, Adult colony-stock, x 150;
at a a commensally attached Flagellata, Monosiga; 7 and 8, contracted
zooids, x 200.

9. EPISTYLIS UMBILICATA, C. & L., vol. ii. p. 706, x 250 (D'Udekem).

10, ii. EPISTYLIS COARCTATA, C. & L., vol. ii. p. 706. — 10, Colony-stock, as delineated
by Claparede & Lachmann, x 150 ; ii, more luxuriant colony, as figured by
H. J. Slack ; at a an apparently encysted zooid.

12-16. EPISTYLIS DIGITALIS, Ehr., vol. ii. p. 704. — 12, Adult colony-stock, x 150; 13,
isolated zooid, x 300; 14, contracted zooid; 15 and 16, migrant zooids de-
tached from the parent stock, that at 16 progressing on the ground after the
manner of a Trichodina.

17. EPISTYLIS STEINII, Wrz., vol. ii. p. 708, x 3oo'(Wrzesniowski).

18. EPISTYLIS NYMPHARUM, Eng., vol. ii. p. 708.— Isolated zooid, x 160 (Engelmann).

19-22. EPISTYLIS ANASTATICA, Linn, sp., vol. ii. p. '701. — 19, Colony-stocks attached to
limbs of Cyclops, x 100 ; 20, isolated zooid, X 300; 21, contracted animal-
cule. Cyclops with numerous colony-stocks attached, x 10.

PLATE XXXYUI.

"M'lr.terr. Brc» :

PLATE XXXIX.

EXPLANATION OF PLATE XXXIX.
FIG.

i, 2. EPISTYLIS BRANCHIOPYLA, Perty, vol. ii. p. 705.—!, Fragment of colony-stock,
X 200 ; 2, encysted zooid, x 200 (Stein).

3. EPISTYLIS ARTICULATA, From., vol. ii. p. 707, x 200 (De Fromentel).

4. EPISTYLIS LEUCOA, Ehr., vol. ii. p. 704, x 100 (Ehrenberg).

5. EPISTYLIS BALANORUM, Meresch., vol. ii. p. 709. — Isolated zooid, x 240 (Meresch-

kowsky).

6. EPISTYLIS GALEA, Ehr., vol. ii. p. 701. — Terminal branch with two zooids, x 120

(Ehrenberg).

7, 8. EPISTYLIS TUBIFICIS, D'Udk., vol. ii. p. 707. — 7, Adult colony-stock, x 120 ;
8, zooid with irregularly developed posterior prolongations (D'Udekem).

9-1,1. OPERCULARIA HOSPES, From., vol. ii. p. 714. — 9, Expanded, 10 and n, con-
tracted zooids, x 200 (De Fromentel).

12-15. EPISTYLIS PLICATILIS, Ehr., vol. ii. p. 701. — 12, Three zooids containing ciliated
embryos derived through the disrupture of the endoplast, x 200 ; at a a a,
spout-like apertures whence similar embryos have made their escape ; 13,
fragment of endoplast enclosing three embryos ; 14 and 15, isolated embryos
more highly magnified (Claparede & Lachmann).

16. OPERCULARIA MICROSTOMA, Stein, vol. ii. p. 713, x 200 (Stein).

17. OPERCULARIA STENOSTOMA, Stein, vol. ii. p. 712, x 200 (D'Udekem).

18. EPISTYLIS INVAGINATA, C. & L., vol. ii. p. 706. — Isolated zooid, x 200 (Clap. &

Lach.)

19. EPISTYLIS CRASSICOLLIS, Stein, vol. ii. p. 705. — Fragment of branch with two

zooids, x 200 (Stein).

20. OPERCULARIA LICHTENSTEINII, Stein, vol. ii. p. 712, x 200 (Stein).

21. OPERCULARIA CYLINDRATA, Wrz., vol. ii. p. 713. — Terminal branchlet with two

zooids, x 300 (Wrzesniowski).

22, 23. OPERCULARIA NUTANS, Ehr. sp., vol. ii. p. 710. — 22, Adult colony-stock, x 300 ;
23, isolated animalcule with at a a conjugating migrant zooid, as delineated
by Ehrenberg.

24-26. OPERCULARIA ARTICULATA, Ehr. sp., vol. ii. p. 711. — 24, Portion of adult colony-
stock, x 150; 25, isolated zooid; 26, distal extremity showing membranous
collar c, and stalked ciliary disc more highly magnified ; e e, kidney-shaped
corpuscles of undetermined nature (after Stein).

27. OPERCULARIA BERBERINA, Linn, sp., vol. ii. p. 711, x 200 (Stein).

28, 29. VORTICELLA ANNULARIS, MiiU., vol. ii. p. 689.— 28, Group, natural size, attached
to a small Planorbis j 29, isolated zooid, x 10 (O. F. Miiller).

30. ZOOTHAMNIUM MACROSTYLUM, D'Udk., vol. ii. p. 699.— Dimensions unrecorded
(D'Udekem).

31, 32. OPERCULARIA sp., apparently allied to O. stenostoma, vol. ii. p. 712. — 31, Frag-
ment of colony-stock; 32, isolated zooid, as figured by Henry Baker,
' Employment for the Microscope,' 1785, pi. xiii. figs. 13 and 14, dimensions
unrecorded.

PLATE XXXDC

Mintnrn. Bros imp.

PLATE XL.

EXPLANATION.

FIG.

1. VAGINICOLA CRYSTALLINA, Ehr., vol. ii. p. 715.— Lorica containing two zooids,

x 200.

2. STYLOCOLA STRIATA, From., vol. ii. p. 730, x 300 (De Fromentel).

3. VAGINICOLA GLOBOSA, D'Udk., vol. ii. p. 716, dimensions unrecorded (D'Udekem).
4, 5. THURICOLA VALVATA, Wright sp., vol. ii. p. 718.— Loricse with two zooids in an

expanded and contracted state ; z/, valvular structure, x 200 (Str. Wright).

6-8. THURICOLA FOLLICULATA, Mull, sp., vol. ii. p. 718. — 6, Fully extended zooid
with at -vv lateral edges of pectinate valve, x 2005 7 and 8, distal region
' of lorica showing pectinate structure of valve, x 400.

9, 10. COTHURNIA IMBERBIS, Ehr., vol. ii. p. 720. — 9, Lorica containing two zooids,
that at a in a contracted condition, having developed a subcentral ciliary
girdle preparatory to migration, x 200; 10, detached migratory zooid (Greeff).

11. COTHURNIA PONTICA, Meresch., vol. ii. p. 725.— Empty lorica, x i5o(Meresch-

kowsky).

12. COTHURNIA GRACILIS, S. K., vol. ii. p. 724.— Zooid contracted, x 250.

13-15. THURICOLA OPERCULATA, Gruber sp., vol. ii. p. 719. — 13 and 14, Expanded zooids,
showing at op valve-like operculum, and at / retractile ligament that connects
the same with the body at the bottom of the lorica ; 15, basal region with the
operculum and retractile ligament diagrammatically represented (Gruber).

16. PYXICOLA SOCIALIS, Gruber sp., vol. ii. p. 728. — Distal region of expanded zooid
with at m collar-like membrane, dimensions unrecorded (Gruber).

17, 1 8. COTHURNIA COMPRESSA, C. & L., vol. ii. p. 722. — Front and lateral aspects,

x 170 (Claparede & Lachmann).
19. COTHURNIA HAVNIENSIS, Ehr., vol. ii. p. 720, x 100 (Ehrenberg).

20, 21. COTHURNIA PATULA, From., vol. ii. p. 722. — Lorica with two zooids in their
expanded and contracted states, X 200 (De Fromentel).

22. COTHURNIA COHNII, S. K., vol. ii. p. 723, x 400 (Cohn).

23. COTHURNIA PUPA, Eichw., vol. ii. p. 724, dimensions unrecorded (Eichwald).

24, 25. COTHURNIA SIEBOLDII, Stein, vol. ii. p. 720. — Ventral and lateral aspects, x 150
(Stein).

26. COTHURNIA ASTACI, Stein, vol. ii. p. 721, x 150 (Stein).

27. COTHURNIA CURVA, Stein, vol. ii. p. 721, x 300 (Stein).

EXPLANATION OF PLATE XL.— continued.
FIG.

28, 29. PYXICOLA AFFINIS, S. K., vol. ii. p. 727. — Expanded and contracted zooids ; op,
operculum, x 250.

30,31. PYXICOLA SOCIALIS, Gruber sp., vol. ii. p. 728. — 30, Social group, x 90; 31,
isolated zooid, x 250 ; op, operculum (Gruber).

32. PACHYTROCHA COTHURNOIDES, S. K., vol. ii. p. 729. — Extended zooid with at
op fleshy operculum, x 500.

33, 34. PLATYCOLA DECUMBENS, Ehr. sp., vol. ii. p. 731.— Dorsal and lateral aspects,
the lorica at 33 containing two zooids, x 280.

35. PLATYCOLA LONGICOLLIS, S. K., vol. ii. p. 732, x 300 (De Fromentel).

36-38. LAGENOPHRYS VAGINICOLA, Stein, vol. ii. p. 733. — 36, Two zooids attached to a
branched hair of Canthocamptus minutus, x 350 ; 37, example with at
g posteriorly separated germ ; 38, membranous valve of oral region.

39. PYXICOLA OPERCULIGERA, S. K., vol. ii. p. 725. — Extended zooid with at op

discoidal operculum, x 250.

40. PYXICOLA CARTERI, S. K., vol. ii. p. 729, x 400. — op, Operculum.

41. PYXICOLA PYXIDIFORMIS, D'Udk. sp., vol. ii. p. 726. — Extended zooid with at

op lid-like operculum, x 150 (D'Udekem). „

42. PLATYCOLA STRIATA, From., vol. ii. p. 732, x 300 (De Fromentel).

43. PLATYCOLA DILATATA, From., vol. ii. p. 731, x 300 (De Fromentel).

44-46. LAGENOPHRYS AMPULLA, Stein, vol. ii. p. 733. — 44, Extended zooid with at gg
detached ciliated germs, x 300 ; 45 and 46, detached germs more highly
magnified, showing hypotrichous plan of ciliation (Stein).

47. LAGENOPHRYS NASSA, Stein, vol. ii. p. 733.— Retracted zooid, x 300 (Stein).

PLATE XL.

PL A TE XLL

EXPLANATION OF PLATE XLI.

FIG.

1-9. OPHRYDIUM VERSATILE, Mull, sp., vol. ii. p. 735. — i and 2, Colony-stocks, natural
size (after Ehrenberg) ; 3, portion of a similar colony-stock, as seen in optical
section slightly magnified ; 4, fragment of a colony-stock with fully extended
zooids, showing at a a the thread-like branching pedicle with its surrounding
common gelatinous matrix or zoocytium z, x 100 (after Wrzesniowski) ;
5 and 6, extended and contracted zooids, x 200 (after Stein) ; 7, basal
region of three zooids of a variety in which the relatively short pedicles are
distinctly annulate at their distal ends (Wrzesniowski) ; 8, fragments of a
colony-stock treated with haematoxylin and osmic acid, showing at a the
urceolate cavities in the zoocytium into which the zooids retreat ; d, a re-
tracted zooid ; and c, the pedicle ; the lines at d indicate the boundaries of
the zoocytial element exuded by the individual zooids, x 150 (Wrzesniowski) ;
9, a detached free-swimming zooid having a posteriorly developed supple-
mentary girdle of cilia.

10-17. OPHRYDIUM EICHORNII, Ehr., vol. ii. p. 737. — 10, a moderate-sized colony-stock
with fully extended zooids, as observed by the author, x 50 ; ii, a fragment
of the same stock with, a.ta,l>, contracted zooids, X 150; 12, a zooid with
posteriorly developed ciliary girdle preparing to enter upon the free-swimming
state ; 13, a zooid exhibiting the rare phenomenon of subdivision by trans-
verse fission, the line at tr indicating the region of separation ; 14, a detached
free-swimming zooid; 15 and 16, whole and portion of a normal zooid
X 400 (as delineated by Wrzesniowski) ; or, oral entrance ; z/, vestibular
fossa; pk, pharynx; as, cesophageal tube; 17 and 18, outlines of the
contractile vesicle.

19-21. OPHRYDIUM SESSILE, S.K., vol. ii. p. 738. — 19, colony-stock attached to vegetable
filament, natural size; 20, a colony-stock with fully extended zooids,
x 100; 21, a similar stock with the zooids retracted within their common
gelatinous zoocytium.

22, 23. OPHIONELLA PICT A, S.K., vol. ii. p. 734. — 22, extended, and 23, contracted zooid,
x 300.

PLATE XLI

EXPLANATION.

FIG.

1-3. LOXODES ROSTRUM, Ehr., vol. ii. p. 748. — i, zooid as viewed superficially, showing
cuticular striae, marginal setae, and endoplastular spherules ; ph, sickle-
shaped pharyngeal tube, x 200 ; 2, a similar zooid more deeply focussed>
showing the reticulate or cancellate structure of the internal parenchyma ;
•v, vacuolar spaces ; r, refringent corpuscles ; 3, indurated pharynx, x 300
(after Wrzesniowski).

4. LITONOTUS VARSAVIENSIS, Wrz., vol. ii. p. 744, x 500.— tr, trichocysts
(Wrzesniowski).

5-11. LITONOTUS FASCIOLA, Ehr. sp., vol. ii. p. 743. — 5, lateral view, and 6, ventral
aspect, x 500 (Wrzesniowski) ; 7, example abnormally dilated with ingested
food ; 8-1 r, successive developmental phases of a single zooid (as observed
by the author).

12, 13. LITONOTUS WRZESNIOWSKTI, S. K., vol. ii. p. 742.— 12, Lateral, and 13, ventral
aspects, x 400 ; tr, trichocysts.

14, 15. PHASCOLODON VORTICELLA, Stein, vol. ii. p. 746. — Ventral and lateral aspects,
x 250 (Stein).

16-22. CHILODON CUCULLULUS, Mull, sp., vol. ii. p. 746. — 16 and 17, Ventral and
lateral aspects, x 200 (Stein) ; 18, example dividing by transverse fission ;
19, conjugation of two independent zooids (Stein) ; 20, zooid with abnormally
developed pharyngeal tube, drawn from a preserved example supplied to the
author by Mr. Charles Stewart ; 21 and 22, pharyngeal rod-fascicles,
showing extended and contracted conditions during theingestion of a' diatom
frustule.

23. OPISTHODON NIEMECCENSIS, Stein, vol. ii. p. 750. — Ventral aspect, x 150

(Stein).

24-26. IDUNA SULCATA, C. & L., vol. ii. p. 752. — Dextral, sinistral, and ventral aspects,
x 175 (Claparede & Lachmann).

27-30. DYSTERIA ARMATA, Huxley, vol. ii. p. 752. — 27, Sinistral aspect, x 250;
28-30, corneous elements of pharyngeal apparatus further enlarged (after
Huxley).

31-33. CVPRIDIUM LANCEOLATUM, C. & Lv sp., vol. ii. p. 754.— 31 and 32, Dextral and
sinistral aspects, X 350 ; 33, ventral view of posterior region, showing the
union of the lateral valves, and at st caudal style (Claparede £
Lachmann).

EXPLANATION OF PLATE XLII. (continued).
FIG.

34. CYPRIDIUM SPINIGERUM, C. & L., vol. ii. p. 754. — Dorsal aspect, x 300 (Claparede
& Lachmann).

35, 36. ^EGYRIA MONOSTYLA, Ehr. sp., vol. ii. p. 755. — Dextral and sinistral views,
X 200 (Stein).

37, 38. HUXLEYA CRASSA, C. & L., vol. ii. p. 758, x 300 (Claparede & Lachmann).

39, 40. ^GYRIA 'ANGUSTATA, C. & L., vol. ii. p. 755. — Dextral and ventral aspects,
X 300 (Claparede & Lachmann).

41, 42. CHLAMYDODON MNEMOSYNE, Ehr., vol. ii. p. 750.— Ventral and lateral aspects,
x 250 (Stein).

43,44. ^EGYRIA OLIVA, C. & L., vol. ii. p. 756. — Dextral and sinistral aspects, x 250 ;
<?, eye-like pigment-speck (Claparede & Lachmann).

45. CYPRIDIUM ACULEATUM, C. & L. sp., vol. ii. p. 754.— Sinislral aspect, x 250

(Claparede & Lachmann).

46. TRICHOPUS DYSTERIA, C. & L.^ vol. ii. p. 758, x 200 (Claparede &

Lachmann).

47,48. TROCHILIA SIGMOIDES, Duj., vol. ii. p. 757.-*— 47, as figured by Claparede &
Lachmann, under the title of Huxley a sulcata, x 500 ; 48, after Dujardin.

49, 50. SCAPHIDIODON NAVICULA, Stein, vol. ii. p. 750. — Ventral and dorsal aspects,
x 240 (Stein).

5 1, 52. TROCHILIA PALUSTRIS, Stein, vol. ii. p. 757. — Dorsal and ventral aspects, x 400
(Stein).

PLATE XLH.

PLA TE XLTII.

EXPLANATION OF PLATE XLIII.

FIG.

1-3. PsiLOTRlCHA ACUMINATA, Stein, vol. ii. p. 762. — i, Ventral, 2, dorsal, and 3,
lateral aspects, x 300 (Stein).

4-5. KERONA POLYPORUM, Ehr., vol. ii. p. 763. — Ventral and dorsal aspects, x 200
(Stein).

6-8. UROSTYLA GRANDIS, Ehr., vol. ii. p. 765. — 6, Elongate example in ventral aspect ;
7, shorter zooid, dorsal view, x 100 ; 8, encysted zooid (Stein).

9-10. UROLEPTUS MOBILIS, Eng., vol. ii. p. 781. — Extended and contracted examples,
x 150 (Engelmann).

11. HOLOSTICHA MYSTACEA, Stein sp., vol. ii. p. 769. — Ventral aspect, x 150 (Stein).

12. AMPHISIA PERNIX, Wrz. sp., vol. ii. p. 768. — Ventral aspect, x 300 (Wrzesniowski).

13. ONYCHODROMUS GRANDIS, Stein, vol. ii. p. 766. — Ventral aspect, x 150 (Stein).

14. UROLEPTUS MUSCULUS, Mull, sp., vol. ii. p. 779. — Ventral aspect, x 150 (Stein).

15. AMPHISIA GIBBA, Mull, sp., vol. ii. p. 767. — Ventral aspect, x 200 (Stein).

16. GASTROSTYLA STEINII, Eng., vol. ii. p. 784. — Ventral aspect, x 200 (Engelmann).

17. HOLOSTICHA RUBRA, Ehr. sp., vol. ii. p. 770. — Ventral view, x 300 (Cohn).

1 8. UROLEPTUS VIOLACEUS, Stein, vol. ii. p. 781. — Ventral aspect, x 200 (Stein).

19, 20. HOLOSTICHA FLAVA, Cohn sp., vol. ii. p. 769. — 19, Lateral, and 20, ventral aspects,
x 250 (Cohn).

21. UROLEPTUS PISCIS, Mull, sp., vol. ii. p. 780. — Ventral aspect, x 100 (Stein).

22. PLEUROTRICHA KCHINATA, C. & L. sp., vol. ii. p. 783.— Ventral aspect, x 300

(Claparede & Lachmann).

23, 24. EPICLINTES RETRACTILIS, C. & L. sp., vol. ii. p. 774. — 23, Extended, and 24, con-
tracted conditions, ventral view, x 500 (Claparede & Lachmann).

25. PLAGIOTRICHA AFFINIS, Stein sp., vol. ii. p. 772. — Ventral aspect, x 300 (Stein).

26, 27. PLEUROTRICHA LANCEOLATA, Ehr. sp., vol. ii. p. 783.— Ventral aspect, x 150;
27, encysted zooid (Stein).

28-30. EPICLINTES AURICULARIS, C. & L. sp., vol. ii. p. 773. — 28, Ventral view ; 29,
repent animalcule in lateral aspect, x 200 (after Claparede & Lachmann ;
30, anterior region more highly magnified, as delineated by Mereschkowsky.

31, 32. EPICLINTES RADIOSA, Quenn. sp., vol. ii. p. 774. — 31, Dorsal, and 32, lateral
aspects, X 300 (Quennerstedt).

33. UROLEPTUS RATTULUS, Stein, vol. ii. p. 780. — Ventral aspect, x 150 (Stein).

34. PLAGIOTRICHA STRENUA, Eng. sp., vol. ii. p. 772. — Ventral view, x 180

(Engelmann).

35, 36. OPISTHOTRICHA PARALLELA, Eng. sp., vol. ii. p. 785.— 35, Dorsal, and 36,
ventral aspects, x 150 (Engelmann).

PLATE XLffl.

PLA TE XLIV.

EXPLANATION OF PLATE XLIV.

FIG.

i, 2. STICHOTRICHA SECUNDA, Perty, vol. ii. p. 776. — i, Zooid projecting from its

mucilaginous sheath ; 2, isolated animalcule in ventral aspect, x 250

(Stein).

3. STICHOTRICHA ACULEATA, Wrz., vol. ii. p. 777.— Ventral aspect x 500 (Wrzes-
niowski).

4-8. SCHIZOSIPHON SOCIALIS, Gruber sp., vol. ii. p. 778. — 4, pendent dichotomously
branching colony-stock or zoothecium with terminally enclosed zooids, x 60 ;
5, an isolated animalcule, x 240 ; 6, an example dividing by transverse fission
within its tube ; 7, termination of tube temporarily occupied by two zooids ;
8, a colony-stock, natural size (Gruber).

9, 10. STICHOTRICHA REMEX, Hudson, vol. ii. p. 777. — 9, Animalcules projecting in
various positions frdm their cylindrical sheaths, X 40 ; 10, an isolated zooid,
x 150 (C. S. Hudson).

11. STICHOTRICHA CORNUTA, C. & L., vol. ii. p. 776. — Zooid in ventral aspect, x

400 (Claparede & Lachmann).

12. OXYTRICHA TUBICOLA, Gruber, vol. ii. p. 789.— Zooid enclosed within its tube,

x 200 (Gruber).

13, 14. STICHOCH^ETA PEDICULIFORMIS, Cohn, vol. ii. p. 775. — 13, Ventral, and 14,
lateral aspects, x 500 (Cohn).

1 5, 16. AMPHIBIA GIBBA var. CRASSA, C & L. sp., vol. ii. p. 768.— Ventral, and lateral
aspects, x 200 (Claparede & Lachmann).

17, 18. OXYTRICHA SCUTELLUM, Cohn, vol. ii. p. 788.— Extended and contracted zooids,
x 360 (Cohn).

19, 20. OXYTRICHA VERUGINOSA, Wrz., vol. ii. p. 787. — 19, Ventral and 20, lateral
aspects, x 150 (Wrzesniowski).

21. HOLOSTICHA OCULATA, Meresch. sp., vol. ii. p. 770. — Ventral aspect, dimensions

unrecorded (Mereschkowsky).

22. EUPLOTES HARPA, Stein, vol. ii. p. 799. — Ventral aspect, x 150 (Stein).

23-25. EUPLOTES PATELLA, Ehr., vol. ii. p. 798.— 23, Dorsal, and 24, ventral aspects, x
200 (after Stein) ; 25, lateral aspect (Dujardin).

26-29. EUPLOTES CHARON, Miill. sp., vol. ii. p. 799. — 26, Ventral view, x 300 ; 27,
example dividing by transverse fission ; 28, encysted zooid (Stein).

30, 31. STYLOPLOTES APPENDICULARIS, Ehr. sp., vol. ii. p. 800.— Dorsal and ventral
aspects, x 300 (Stein).

PLATE XLIV

PLATE XLV.

EXPLANATION OF PLATE XLV.

STYLONYCHIA MYTILUS, Ehr., vol. ii. p. 790. — Diagrammatic plan of oral ciliary
system : ad, adoral cilia or membranette; prcs, prasoral, and en, endoral
cilia ; «, undulating membrane ; fr, frontal style (Sterki).

2. GASTROSTYLA, sp. (Sterki). — Diagrammatic optic section showing disposition of
the several ciliary systems ; d, dorsal, and m, marginal setae ; par, paroral
cilium ; the other lettering as in the preceding figure.

3-5. OXYTRICHA PELLIONELLA, Mull, sp., vol. ii. p. 786. — 3, Ventral aspect, x 400 ;
4, diagrammatic longitudinal section : ad, adoral, fr, frontal, v, ventral, an,
anal, and d, dorsal cilia or setae (after Sterki) ; 5, ventral aspect (after Stein).

6. ACTINOTRICHA SALTANS, Cohn, vol. ii. p. 790, x 360 (Cohn).

7. OXYTRICHA FALLAX, Stein, vol. ii. p. 787.— Ventral aspect, x 170 (Stein).

8, 9. OXYTRICHA PLATYSTOMA, Ehr. sp., vol. ii. p. 787. — Ventral and dorsal aspects
X 300 (Stein).

10-12. HISTRIO sp. (Sterki). — 10, diagrammatic outline of zooid antecedent to sub-
division by transverse fission, showing at j, and sz the newly-growing
ventral ciliary series, at prz, the second peristomal fringe, and at m\, mt,
the new elements of the first and second marginal series ; 1 1 and 12, showing
disposition and numerical order of development of the newly developing
frontal, ventral, and anal series (after Sterki).

13, 14. HISTRIO STEINII, Miill. sp., vol. ii. p. 789. — 13, Ventral aspect, x 200 ; 14,
example dividing by transverse fission, with at prz and pr3 newly
developing secondary and tertiary peristomal ciliary systems (Stein).

15-17. STYLONYCHIA PUSTULATA, Ehr., vol. ii. p. 791. — 17, Ventral aspect, x 150 ; 15,
zooid disintegrating by difnuence ; 16, encysted animalcule (Stein).

18-21. STYLONYCHIA MYTILUS, Ehr., vol. ii. p. 790. — 18 and 19, ventral and lateral aspects,
X 1 50 ; 20, zooid preparing to divide by transverse fission, the rudimentary
second peristomal fringe pr^ being already developed ; 21, variety having
the frontal, ventral, and anal styles and setae distinctly fimbriated (Stein).

22. STYLONYCHIA FISSISETA, C. & L., vol. ii. p. 791. — Ventral aspect, x 300

(Claparede & Lachmann).
23, 24. ASPIDISCA LYNCASTER, Stein, vol. ii. p. 793-— 23, Ventral and, 24, dorsal aspects,

x 250 (Stein).
25-29. ASPIDISCA COSTATA, Duj. sp., vol. ii. p. 794. — 25 and 26, ventral and dorsal

aspects, x 300 (Stein) ; 27-29, developmental phases as observed by the

author and described at p. 794.

30. GLAUCOMA MARGARITACEUM, Ehr. sp., vol. ii. p. 796, x 150 (Clap. & Lach.)
31-33. ASPIDISCA TURRITA, C. & L., vol. ii. p. 793.— Ventral, dorsal, and lateral aspects,

x 209 (Stein).

34-36. URONYCHIA TRANSFUGA, Mull, sp., vol. ii. p. 797. — 34 and 35, Dorsal and ventral
aspects ; 36, example with fimbriated anal uncini, x 250 (Stein).

37. MICROTHORAX SULCATUS, Eng., vol. ii. p. 796, x 22o (Engelmann).

38-40, GLAUCOMA SCINTILLANS, Ehr., vol. ii. p. 795. — 38 and 39, Ventral aspect, with at
39, vibratile membrane extended, x 150 ; 40, encysted zooid dividing by
oblique fission (Stein).

PLATE JCLV

37.

PLATE XLVL

EXPLANATION.
FIG.

1,2. RHYNCHETA CYCLOPUM, Zenker, vol. ii. p. 806. — i, Adult animalcule, x 150;
2, extremity of single tubular sucker, x 600 (Zenker).

3-5. SPH^EROPHRYA UROSTYUE, Maupas, vol. ii. p. 809. — 3, Normal adult zooid ; 4,
example dividing by transverse fission, the anterior moiety with temporarily
developed cilia ; 5, a zooid elongated and with cilia developed preparatory to
subdivision, X 200 (Stein).

6. SPH^EROPHYRA PUSILLA, C. & L., vol. ii. p. 808, x 150 (Claparede & Lach-

mann).
7-9. SPH^EROPHRYA STENTOREA, Maupas, vol. ii. p. 808, x 2oo (Stein).

10, ii. TRICHOPHRYA DIGITATA, Stein sp., vol. ii. p. 812. — 10, Adult animalcule, x 300 ;
n, non-tentaculate germ (Stein).

12, 13. TRICHOPHRYA EPISTYLIDIS, C. & L., vol. ii. p. 811. — 12, Dorsal; 13, lateral
aspects, X 150 (Clap. & Lach.).

14-17. PODOPHRYA ASTACI, C. & L., vol. ii. p. 819. — 14, Adult animalcule, X 200 ;
15 and 1 6, ciliated embryos ; 17, earliest phase of fixed condition (Stein).

1 8. PODOPHRYA QUADRIPARTITA, C. & L., vol. ii. p. 820. — Two examples attached
to stalk of Epistylis plicatilis, x 150 (Stein).

19-22. PODOPHRYA FERRUM-EQUINUM, Ehr. sp., vol. ii. p. 813. — 19 and 20, Front and
profile views showing compressed form of body and proportionate size of
pedicle, x 100 (after Clap. & Lach.) ; 21, ciliated embryo ; 22, earliest fixed
condition possessing only a single tentacle as represented by Zenker.

23. PODOPHRYA CYCLOPUM, C. & L., vol. ii. p. 818, x 150.

24-30. PODOPHRYA Fix A, Miill. sp., vol. ii. p. 813. — 24, Adult animalcule containing at
a a ciliated embryo, X 200; 25, an example dividing by transverse fission;
26, conjugation of two adjacent animalcules ; 27, animalcule forming a
membranous encystment (Stein) ; 28, encystment as found within body of
Stylonychia mytilus (Engelmann) ; 29 and 30, ciliated embryos.

.31. PODOPHRYA WRZESNIOWSKII, S. K., Stein sp., vol. ii. p. 817, x 150 (Wrzes-

niowski).

32-35. ACINETA STELLATA, S. K., vol. ii. p. 838.— 32, Adult animalcule, x 1000; 33 and
34, encysted examples, the body contents in the first instance divided into
two equal halves ; 35, free-swimming Sphaerophrya-like embryo.

36-39. ACINETA LINGUIFERA, C. & L., vol. ii. p. 831. — 36 and 37, Adult zooids, front
and profile views, x 150; 38, empty lorica ; 39, ciliated embryo (Stein).

EXPLANATION OF PLATE XLVI. (continued).
FIG.

40-43. ACINETA MYSTACINA, Ehr., vol. ii. p. 834. — 40 and 41, Long and short pedicled
varieties, the former with, at a, a germinal bud x 150 ; 42, lorica with
contained animalcule seen from above ; 43, a germinal bud with contained
ciliated embryo further enlarged.

44. ACINETA NOTONECTVE, C. & L., vol. ii. p. 833, x 150 (Clap. & Lach.).

45-47. ACINETA PATULA, C. & L., vol. ii. p. 835. — 45 and 46, Animalcules with tentacles
extended and contracted, x 100 ; 47, example with elongate lorica giving
birth to a ciliated embryo (Clap. & Lach.).

48-51. HEMIOPHRYA GEMMIPARA, Hertwig sp., vol. ii. p. 823.— 48, Distal extremity of
pedicle bearing animalcule with extended tentacles of two orders, suctorial
and prehensile, x 150; 49, prehensile rib tentacles more highly magnified,
showing spirally disposed granular external sheath ; 50, example with six
terminal buds, into each of which is produced a prolongation of the
branching endoplast, the tentacles not represented ; 51, an hypotrichously
ciliated embryo, x 400 (Hertwig).

52. SOLENOPHRYA CRASSA, C. & L., vol. ii. p. 828, x 150 (Clap. & Lach.).

53-56. PODOPHRYA MOLLIS, S. K., vol. ii. p. 821. — 53 and 54, Adult animalcules, X 150 ;
55 and 56, successive phases of transverse fission of the samezooid, first mani-
fested by the extension and fixture of two ordinary suctorial tentacles to a
more remote point, these two ultimately fusing together and joining the
pedicle of the newly produced animalcule.

57. ACINETA MYSTACINA, vol. ii. p. 834.— Ciliated embryo, x 300 (Stein).

58, 59. PODOPHRYA STEINII, C. & L.,vol. ii.p. 815.— 58, Adult zooid, x 150 (Stein) ; 59,
ciliated embryo, x 300 (Stein).

PLATE XLVI.

PLATE XL VII.

EXPLANATION OF PLATE XLVII.

FIG.

1-5. PODOCYATHUS DIADEMA, S. K., vol. ii. p. 827.— i, Adult zooid, with tentacles
fully extended, x 300 ; 2, zooid with tentacles retracted ; 3, zooid of abnor-
mally minute size as compared with that of the lorica, being probably the
relict of a recent fissive process ; 4 and 5, successive developmental forms.

6, 7. SPHJEROPHRYA SOL, Mecz., vol. ii. p. 810. — 6, Normal zooid, x 250 ; 7, elongate
- shape assumed preparatory to division by transverse fission (Mecznikow.).

8. HEMIOPHRYA CRUSTACEORUM, Haller sp., vol. ii. p. 826. — Zooid with numerous
ovate gemmules and distal end of pedicle, x 300 (Haller).

9-14. HEMIOPHRYA GEMMIPARA, Htwg. sp., vol. ii. p. 823. — 9 and 10, Distal end of
pedicle, with zooid at 9 bearing as many as eight elongate ciliated gemmules,
and at 10 with two subsphasroidal tentaculiferous embryos, x 200 ; 11-14,
phases of development from a free-swimming hypotrichously ciliated embryo
towards the parent form (Robin).

15. HEMIOPHRYA BENEDENI, Fraip. sp., vol. ii. p. 824. — Zooid with extended
tentacles and distal region of pedicle, x 200 (Fraipont).

16-22. DENDROSOMA RADIANS, Ehr., vol. ii. p. 841. — 16, Erect, slender zoocaulon of
young colony-stock, having but three tentaculiferous ramuscules, as delineated
by Mr. Thomas Bolton, x 150 ; 17, luxuriantly developed colony-stock as
supplied to the author by Mr. Bolton, the decumbent stolon, st, giving origin
to numerous erect, variously branching zoocaula, some of these, as at a,
enclosing internally developed ciliated embryos, and others, as at b b, with
more minute externally developed reproductive capsules, x 50; 18, distal
region of zoocaula with exogenous germs, that at a having short capitate
tentacles, x 150; 19, portion of zoocaulon with enclosed ciliated embryo et
and a portion of the cord-like endoplast, x 400 ; 20, free-swimming ciliated
embryo, x 600 ; 21, earliest adherent condition of embryo, the cilia being
absorbed and short capitate tentacles developed in their place ; 22,
more advanced growth of the same embryo, a single short tentaculiferous
prolongation being developed at one extremity, x 600.

PLATE XLVH.

PLATE XLVIIL

EXPLANATION.

FIG.

1-4. URNULA EPISTYLIDIS, C. & L., vol. ii. p. 807. — i, Normal zooid with extended
tentacula, x 200 ; 2, zooid in a resting or encysted state, its body-substance
having subdivided into four germinal fragments ; 3, example with contained
ciliated embryo ; 4, isolated ciliated embryo, x 300 (Clap. & Lach.).

5. PODOPHRYA LIMBATA, Maupas, vol. ii. p. 816. — Typical zooid with peripheral
gelatinous film, x 200 (Maupas).

6, 7. SPH^EROPHRYA MAGNA, Maupas, vol. ii. p. 808. — 6, Zooid having seized and in
the act of devouring by suction half a dozen examples of Colpoda parvifrons,
x 300 ; 7, two tentacles, that at a with a central hyaline vacuosity, and that
at b having the substance of its terminal sucker lacerated through the
temporary adhesion and subsequent escape of a ciliated infusorium, x 1 280
(Maupas).

8-1 10. ACINETA DIVISA, Fraipont, vol. ii. p. 836. — 8, Normal zooid with, at a. a single
anteriorly developed, pyriform germ-capsule, from which a ciliated embryo
is in the act of emerging, x 300 ; 9, germ-capsule with, at op, operculum-
like differentiation through which the embryo ultimately emerges ; 10,
ciliated embryo, X 600; n, abnormally elongated zooid with central band-
like endoplast ; i \a, empty lorica with, at s, platform-like horizontal septum
upon which the body of the animalcule ordinarily reposes (Fraipont).

12. ACINETA LIVADIANA, Meresch., vol. ii. p. 828. — Adult zooid, x 250, as observed
by the author.

13-17. ACINETA FCETIDA, Maupas, vol. ii. p. 832. — 13, Normal adult animalcule, x 580 ;
14, lorica with tentacular fascicles as seen from above; 15 and 16, ciliated
embryos ; 17, young zooid with imperfectly developed lorica (Maupas).

18. ACINETA EMACIATA, Maupas, vol. ii. p. 837, x 300 (Maupas).

19. HEMIOPHRYA THOULETI, Maupas, vol. ii. p. 826, x 200 (Maupas).

20. PODOPHRYA CYLINDRICA, Perty, vol. ii. p. 814, x 250 (Mereschkowsky).

21, 22. PODOPHRYA ELONGATA, C. & L., vol. ii. p. 820. — 21, Normal zooid, with at a a a
tentacles partially retracted and exhibiting a spirally convolute aspect ;
x 150; 22, one such tentacle as observed by the author, x 800, showing
that the spiral aspect is due to the presence of a superficial spirally developed
granular crest or film.

23. PODOPHRYA CARCHESII, C. & L., vol. ii. p. 818, x 200.

EXPLANATION OF PLATE XLVIII. (continued).
FIG.

24. ACINETA GRANDIS, S. K., vol. ii. p. 831. — Adult zooid, x 100 ; affixed near the
base of this species, see letter a, is delineated an ordinary example of Acineta
lemnarum found associated with it, under a similar magnification, for the
purpose of indicating the relative proportions of these two forms.

25-28. ACINETA TUBEROSA, Ehr., vol. ii. p. 829. — 25, Long-stalked variety, x 400;

26, example as seen in horizontal optical section showing the four points of
attachment of the body to the lorica and the bases of the tentacular fascicles ;

27, a similar body as seen in vertical section ; 28, horizontal optical section
immediately above the junction of the pedicle with the lorica (Fraipont).

29. ACINETA SAIFUL^E, Meresch., vol. ii. p. 836. — Spirit-preserved example, x 200
( M er es chko wsky ).

30, 31. HEMIOPHRYA BENEDENI, Fraipont, vol. ii. p. 824. — 30, Zooid, x 70; 31, portion
of pedicle, x 300, showing quadrangular contour and transversely striated
central core.

32, 33. ACINETA CRENATA, Fraipont, vol. ii. p. 837. — Zooid with elongate lorica, x 600 ;
33, shorter lorica, with distal region onlyof the pedicle (Fraipont).

34, 35. ACINETA JOLYI, Maupas, vol. ii. p. 835. — 34, Front and, 35, lateral view, x 200
(Maupas).

36, 37. OPHRYODENDRON BELGICUM, Fraipont, vol. ii. p. 853.— 36, Vermiform and, 37,
proboscidiform zooids, x 400 (Fraipont).

38-46. OPHRYODENDRON SERTULARI^;, Str. Wright sp., vol. ii. p. 851. — 38, Ordinary
proboscidiform zooid in lateral view, bearing at v a single vermiform germ,
x 200; 39, proboscidiform zooid from above, showing, after treatment by the
author with osmic acid, orbicular contour of body and enclosed branching
endoplast ; 40, detached vermiform zooid more highly magnified, showing
acetabular character of the basal region.

42. ACINETA VORTICELLOIDES, Fraipont, vol. ii. p. 837. — Distal region showing
rudimentary development of the lorica, x 300 (Fraipont).

43-45. AciNETOPSlS RARA, Robin, vol. ii. p. 855. — 43, zooid with extended tentacle,
X 200 ; 44 and 45, tentacle in various states of contraction more highly mag-
nified and showing externally developed spiral fibrilla (Robin).

46. HEMIOPHRYA TRUNCATA, Fraip., vol. ii. p. 825.— Adult zooid, x 250 (Fraipont).

PLATE XLVn.

W SowilU Krait dtfWBVwitt :

Mir.tem Bro* imp.

PLATE XLVIIlA.

EXPLANATION OF PLATE XLVIIU.

FIG.

1-^3. EPHELOTA CORONATA, Str. Wright, vol. ii. p. 846. — i, 2, Animalcules with
tentacles extended, at m m captured monads, x 200 ; 3, tentacles retracted.

4. PODOPHRYA CONIPES, Meresch., vol. ii. p. 815, x 250 (Mereschkowsky).

5. EPHELOTA TROLD, C. & L., vol. ii. p. 847, x 175 (Claparede & Lachmann).

6. ACTINOCYATHUS CIDARIS, S. K., vol. ii. p. 848, X 300.

7. ACINETA TUBEROSA, Ehr., vol. ii. p. 829. — Two zooids with tentacles in a fully

extended and partially retracted state, x 200.

8-12. DENDROCOMETES PARADOXUS, Stein, vol. ii. p. 839. — 8, Adult animalcule, x 400,
one of the branched tentacles at a grasping a captured monad ; 9, the same
tentacle, x 1200, and showing the tubular perforations of the distal ter-
minations ; 10, a young recently attached animalcule; n, animalcule
enclosing a ciliated embryo ; 12, a detached ciliated embryo (Wrzesniowski).

13-15. OPHRYODENDRON ABIETINUM, C. & L., vol. ii. p. 850. — 13, Proboscidiform zooid
with proboscis retracted and with vermiform zooid attached to one side,
x 100; 14, proboscidiform zooid with proboscis extended; 15, ciliated
embryo, x 200 (Clap. & Lach.).

16-19. OPHRYODENDRON PEDICELLATUM, Hincks, vol. ii. p. 852.— 16 and 17, Proboscidi-
form zooids with proboscis extended and retracted ; 18 and 19, two vermiform
zooids, the one in the latter instance having a second example sessilely
attached to its body, dimensions unrecorded.

20-25. OPHRYODENDRON PORCELLANUM, S. K., vol. ii. p. 852. — 20, Zooid with probos-
cidiform appendage extended and recurved, x 200 ; 21, the same appendage
more completely extended in a rectilinear direction ; 22, a zooid bearing
both a proboscidiform and vermiform appendages ; 23, an example having
only a vermiform appendage ; 24, distal extremity of proboscis highly
magnified, x 800; 25, distal region of shaft of the proboscis, x 1200, show-
ing its transverse corrugation.

26-31. OPHRYODENDRON MULTICAPITATUM, S. K., vol. ii. p. 854. — 26, Sessile zooid
bearing four proboscidiform organs, x 300 ; 27, sessile example with four
proboscidiform organs pr, and three ovate gemmules s ; 28, stalked example
with two proboscidiform organs, two gemmules, and one vermiform appen-
dage; 29-31, young pedicellate zooids ; 30 and 31, bearing each a single pro-
boscidiform organ only, this structure in the latter instance being retracted ;
29, representing a still younger zooid entirely destitute of appendages, and,
except for the presence of a pedicle, corresponding with the gemmular bodies
represented in figures 27 and 28.

32. OPHRYODENDRON ABIETINUM, C. & L., vol. ii. p. 850.— Vermiform larva with
basal chitinous rod, x 400 (after Robin).

PLATE

VI Seville Kenl U.

PLATE XLIX.

EXPLANATION OF PLATE XLIX.

Constituting a key to the numerous species of the genus Vorticella, each specific form
being represented in diagrammatic outline at its most typical condition of extension
and in accordance with the scheme suggested in vol. ii. p. 672. To facilitate
identification the specific name is appended to each type.

PLATE XLIX.

2. V pi-cto,.

4: V. bre.vistylot,.

5. V.

6. V.

7. V.

11. V. teles

12.V. campanula*.

13. V. citriria-.

/4. V. craterou.

15.

16. V. n,u,tcuns .

17-. V. afierta,.

18. V.procvunbens

19. V cOloutoubou.

20. V. fouscienlcuta,

21. V.

Z2.V qlobuLana,.

24- V.marcjaritifer.

25. V. mcunudLata

Z6.V. constricta,.

27. V. microstoma,

29. V. strlatoL.

32.V elongate-.

34- V convcdlaria,.

35. V.

J36. V. spectabtiis .

»iieroscopica<.

38.V.

39. V. mondouta/.

4-O.V cyathina,.

4-1. V. hicuns.

4-2.V.luxiari£.

PLATE L.

Illustrating the more important modifications of the nucleus or endoplast and nucleolus or
endoplastule as developed among the Infusoria.

EXPLANATION.
FIG.

1. Simple spheroidal nucleus or endoplast, with enclosed nucleolus or endoplastule, of

a collared monad, Codostga, the same type being distinctive of the majority
of the Flagellata.

2. A single germinal fragment or spore, with contained endoplast and endoplastule,

of Dictyocysta cassis, x 1000 (Haeckel).
3-5. Modifications of the endoplast of Euglena viridis. — 3, representing the normal

form ; 4 and 5, progressive phases resulting in the subdivision of its entire

mass into sporular elements x 600 (Stein).
- 6. Fusiform endoplast, with centrally enclosed endoplastule, of Chilodon cuculhtllus,

X 480 (Wrzesniowski).
7-9. Various modifications of the endoplast of Leptodiscus medusoides (Hertwig).

10. Ovate endoplast having a reticulate granular consistence, with laterally attached

endoplastule, of A cineta foetida, x 1280 (Maupas).

1 1. Subspheroidal endoplast, with numerous enclosed endoplastules, of A cineta Jolyi,

x 900 (Maupas).

12. Spheroidal granular endoplast of Rhizopod Pelomyxa villosa, x 1000 (Leidy).

13. Twin endoplasts, with connecting cord or funiculus, of Litonotus fasciola, x 480

(Wrezsniowski).

14. Endoplastic system of Loxodes rostrum, consisting of numerous spheroidal endo-

plasts with both enclosed and externally developed endoplastules connected
together by a thread-like funiculus. In some instances, a a, the external
endoplastules are attached to the funiculus, x 600, and treated with acetic
acid and iodine (Wrzesniowski).

15. Twin endoplasts with connecting funiculus vi Litonotus diaphanus after treatment

with acetic acid and iodine, x 600 (Wrzesniowski).

1 6. Endoplast of Chilodon cucullulhis with both an internally developed and laterally

attached endoplastule, x 400 (Wrzesniowski).

17. Twin endoplasts, with laterally attached endoplastules, of Stichotricha aculeata,

X 600, + acetic acid (Wrzesniowski).

1 8. Endoplastule of Pleuronema chrysalis after treatment with acetic acid (Biitschli).
19, 20. Modifications of the endoplast of Nyctotherus cordiformis. — 19, normal form,

with laterally attached endoplastule ; 20, endoplast become greatly enlarged
and metamorphosed into an elaborately convoluted coil (Stein).

21. Band-like endoplast with a, investing membrane and b, b, contained endoplas-
tules of Vorticella microstoma, x 450 (Stein).

22, 23. Band-like endoplasts of Carchesium polypinum, subsequent to conjugation ; at
22, earlier phase with numerous enclosed endoplastules ; at 23, more
advanced stage in which the internal substance has become separated into
as many as ten germinal masses which are held together only by the delicate
bounding membrane of the originally continuous and homogeneous endo-
plast, x looo (Greef).

EXPLANATION OF PLATE L. (continued).

FIG.

24. Conjoint endoplasts of Amphileptus anas after treatment with acetic acid, their
substance being thus shown to be divided up into numerous polygonal frag-
ments, each with a minute central refringent corpuscle, x 600 (Biitschli).

25-28. Endoplastules or nucleoli of Paramcecium putrinum ; 25 and 26, normal forms,
x 2000 + acetic acid ; 27 and 28, successive phases during the process of
subdivision or fission (Biitschli).

29-31. Endoplastules of Carchesium polypinumj 29, living condition ; and 30, after
treatment with acetic acid, x 1500; 31, example elongated preparatory to
subdivision (Biitschli).

32. Endoplast of Paramacium bursaria, during process of subdivision, the normal,

single, laterally attached endoplastule having already separated into two, x
800 (Biitschli).

33. Twin endoplasts of Stylonychia mytilus j aspect exhibited at the commencement

of the fissive process, the endoplastules in the vicinity of each endoplast also
commencing to subdivide, x 600 (Biitschli).

34. Twin endoplasts of Stylonchia mytilus in a more advanced stage of subdivision,

the endoplasts having already separated into four, both these and the endo-
plasts presenting a striated aspect, X 500 (Biitschli).

35-37. Variously branched endoplast of Ophrydendron belgicum; 35 and 36 derived
from proboscidiform, and 37 from a vermiform zooid, x 800 (Fraipont).

38. Ramifying endoplast from an erect main trunk of Dendrosoma radians, as

observed by the author, x 800.

39. Endoplastic system of Loxophyllum meleagris, consisting of numerous irregu-

larly ovate nodular endoplasts, united to each other by a delicate thread-
like funiculus, x 600, + acetic acid, iodine, and picrocarmine (Biitschli).

40. Irregular nodular endoplast of Hemiophrya Thouleti, x 500 (Fraipont).

41, 42. Moniliform endoplast of Stentor polymorphus j 41, the entire structure, x 200;
42, a fragment more highly magnified showing internal refringent corpuscles
and connecting funiculus (Stein).

43. Anterior region of undulating band-like endoplast of Stentor Rceselii, from the

extremity of which one germ-sphere or embryo, with a central endoplastule
(the future endoplast) and incipient contractile vesicle, has become already
constricted off, a second similar germ-sphere being in an advanced state of
development, x 500 (Claparede and Lachmann).

44. Twin endoplasts of Stylonychia mytilus, normal aspect, showing a distinct

investing membrane, connecting funiculus, and laterally attached endoplas-
tules, x 600 (Biitschli).

45, 46. Single endoplastic elements, with attached endoplastules, of Stylonyc hia mytilus.
— 45, Showing distinct differentiation of the anterior and posterior moieties ;
46, exhibiting at one extremity the delicate investing membrane, x 400
(Stein).

47. More abnormal elongated endoplast of Stylonychia mytilus showing distinct

bounding membrane and three striated laterally located endoplastules, x 400
(Stein).

48. Single endoplast, with striated laterally attached endoplastule, of Kerona poly-

porum, x 300 (Stein).

49. Single endoplast of Oxytricha sp., whose substance has divided up into numerous

polygonal germs, x 600 (Biitschli).

50. Single endoplast, with contained germ-spheres, of Urostyla grandis, x 600

(Biitschli).

51. Compound racemose endoplast of Plagiotoma lumbrici, x 400 (Stein).

52. Branching endoplast of young zooid of Dendrosoma radians as observed by the

author, x 800, + osmic acid and picrocarmine.
53, 54. Branching, convoluted endoplast of Acineta mystacina, x 600 (Fraipont).

PLATE L.

VT. Sowffle Kout dd-W.Eheiji «o.

PLATE LI.

EXPLANATION.

FIG.

1-5. Illustrating the apparatus employed by Messrs. Dallinger and Drysdale during
their prolonged investigation of the life-histories of various monads referred
to at vol. i. p. 116, originally figured and described in the ' Monthly Micro-
scopical Journal for March 1874. — i, a a, glass plate adapted to fit the stage
of the microscope ; b, circular aperture cut in the plate, a thin piece of glass
c , d, e,f being cemented over it to permit the near approach of the achro-
matic condenser ; g g g, brass socket with ring attached which is fixed with
marine glue to the projecting arm of the glass plate a, and supports a cylin-
drical reservoir of water, Fig. 4 ; hhhh, outline of position of bibulous paper
having central aperture and tongue-like projection which dips down into the
reservoir fitted to the socket g ; 2, bibulous paper cut to fit the glass stage,
the portion b c leading into the reservoir g of Fig. i ; 3, moist chamber con-
sisting of a short piece of glass tubing a, having the bottom edge e carefully
ground, the top having over it a thin elastic film with a minute central per-
foration c, and securely fastened to the sides at the groove d ; 4, cylindrical
glass reservoir fitting into the socket^ of Fig. i, and into which the project-
ing arm of the bibulous paper dips ; 5, the entire apparatus in working order,
the object glass g being racked down through the central perforation of the
elastic film/ of the moist chamber ch ; a a section of glass stage ; b, aperture
in the same ; c, the glass cemented over the aperture ; d, covering glass over
object examined ; e, walls of moist chamber.

6. Chamber invented by Professor Tyndall, referred to at vol. i. p. 130, originally
figured and described in the 'Transactions of the Royal Society,' 1877,
for the perfect isolation and cultivation of organic infusions and equally
suited for a similar culture of Infusoria, c, central box or chamber, the
front being removed showing the windows w , TV, for the admission of light ;
/, six test-tubes fitting with an air-tight packing into the floor of the chamber ;
a, b, sinuous glass tubing permitting the access of air but not of germs to
the chamber ; p, pipette with stuffed funnel, fitting into a pin-hole perfora-
tion in a piece of indiarubber and stuffing-box containing cotton-wool
moistened with glycerine, and thus permitting its insertion and withdrawal
without the introduction of adventitious germs.

EXPLANATION OF PLATE LI. (continued).

FIG.

7, 8. Illustrating the arrangement of the microscope and lamp employed by the author
for obtaining the most satisfactory illumination and definition of minute
flagellate organisms, when working with object-glasses of i-i6th to i-joth
inch nominal focal distance, for which he is chiefly indebted to a most kind
and painstaking demonstration by Mr. E. M. Nelson, F.R.M.S. The mirror
m being turned to one side, the microscope and lamp are so disposed that
the central ray of light ax from the narrow edge of the lamp flame passes
through the optical axis of the achromatic condenser a c, and is then focussed
upon the field of view, by means of the substage rackwork, in such a manner
that employing a i-inch object-glass, a sharply defined image of the lamp-
flame, edge on, is projected upon the centre of the field in company with the
objects under examination as shown at Fig. 8. If the i-inch object-glass is
now detached, and a i-i6th, i-asth or i~5oth substituted, and focussed into
place, a slight readjustment of the centering of the achromatic condenser
being perhaps required, it will be found that the entire field is brilliantly
illuminated, and the most minute objects defined with an amount of sharp-
ness rarely obtained under other conditions. In addition to the ordinary
graduating diaphragm placed immediately beneath the lenses of the achro-
matic condenser as at d1 in Fig. 7, the author has derived considerable
advantage from the interposition of a second diaphragm at dz, or the lowest
point in the substage arrangement.

9, 10. Trichocysts of Bursaria (Panophrys) leucas (see vol. i. p. 82), as interpreted by
Professor G. J. Allman ; Fig. 9, trichocysts, tr, in sittt, disposed in an even
vertical layer immediately beneath the cuticle and locomotive cilia c, x 1000.
Fig. 10, the same trichocysts projected irregularly from the entire peri-
phery as hairlike filaments or setae with recurved distal ends, on the appli-
cation of acetic acid or forcible compression (after Allman, ' Quarterly
Journal of Microscopical Science,' vol. iii., 1855).

PLATE LI.

/^\

a t> c

0

Fig. 2.

' imp.

EXPLANATION OF PLATE LI. (continued).

FIG.

7, 8. Illustrating the arrangement of the microscope and lamp employed by the author
for obtaining the most satisfactory illumination and definition of minute
flagellate organisms, when working with object-glasses of i-i6th to i-5oth
inch nominal focal distance, for which he is chiefly indebted to a most kind
and painstaking demonstration by Mr. E. M. Nelson, F.R.M.S. The mirror
m being turned to one side, the microscope and lamp are so disposed that
the central ray of light ax from the narrow edge of the lamp flame passes
through the optical axis of the achromatic condenser a c, and is then focussed
upon the field of view, by means of the substage rackwork, in such a manner
that employing a i-inch object-glass, a sharply defined image of the lamp-
flame, edge on, is projected upon the centre of the field in company with the
objects under examination as shown at Fig. 8. If the i-inch object-glass is
now detached, and a i-i6th, i-25th or i-5oth substituted, and focussed into
place, a slight readjustment of the centering of the achromatic condenser
being perhaps required, it will be found that the entire field is brilliantly
illuminated, and the most minute objects defined with an amount of sharp-
ness rarely obtained under other conditions. In addition to the ordinary
graduating diaphragm placed immediately beneath the lenses of the achro-
matic condenser as at d1 in Fig. 7, the author has derived considerable
advantage from the interposition of a second diaphragm at dz, or the lowest
point in the substage arrangement.

9, 10. Trichocysts of Bursaria (Panophrys) leucas (see vol. i. p. 82), as interpreted by
Professor G. J. Allman ; Fig. 9, trichocysts, tr, in sitti, disposed in an even
vertical layer immediately beneath the cuticle and locomotive cilia c, x loco.
Fig. 10, the same trichocysts projected irregularly from the entire peri-
phery as hairlike filaments or setae with recurved distal ends, on the appli-
cation of acetic acid or forcible compression (after Allman, ' Quarterly
Journal of Microscopical Science,' vol. iii., 1855).

PLATE LI.