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THE BOTIFEKA.

VOLUME II.

PRINTED BY

SPOTTISWOODE AND CO., NEW-STREET SQUARE

LONDON

^ THE EOTIFEHA;

OR

WHEEL-ANIMALCULES

BY

C. T. HUDSON, LL.D. Cantab.

ASSISTED BY

P. H. GOSSE, F.E.S.

IN TWO VOLUMES VOLUME II.

WITH ILLUSTRATIONS.

LONDON :

LONGMANS, GREEN, AND CO

1886.

All rights reserved.

Those viewless beings,
Whose mansion is the smallest particle
Of the impassive atmosphere,

Enjoy and live like man :
And the minutest throb,
That through their frame diffuses
The slightest, faintest motion,
Is fixed, and indispensable,
As the majestic laws
That rule yon rolling orbs.

Shelley.

Qui curiosus postidat totum sua;
Patere menti, ferre qui non sufficit
Mediocritatis conscientiam suae,
Judex iniquus, sestimator est mains
Suique naturaeque ; nam rerum parens,
Libanda tantum qua? venit mortalibus,
Nos scire pauca, multa mirari jubet.

Grotius.

THE L I B R A R ▼ _,

CONTENTS

OF

rn

THE SECOND VOL U M E

ooj^oo-

CHAPTER IX.

PACK

ploima (il-loricata — continued) ...... 1

CHAPTER X.

PLODIA (LORICATA) ........ 57

CHAPTER XI.

SCIRTOPODA . . . . . . . . . .129

ADDENDA . . . . . . . , . .134

APPENDIX : THE VASCULAR SYSTEM ...... 133

,, THE SETIGEROUS SENSE-ORCUNS .... 139

IHDLIOGRAPHY OF THE ROTIFERA ...... 140

INDEX ..... ..... 143

CHAPTER IX.

PLOIMA

IL-LORICATA— continued.)

VOL. II

Les actions des betes sont peut-etre un des plus profonds abimes su:.
quoi notre raison se puisse exercer; et je suis surpris que si peu de gens
s'en aper<;oivent. — Bayle.

Their good is good entire, unmixed, unmarred ;

They find a paradise in every field,

On boughs forbidden where no curses hang :

Their ill, no more than sti-ikes the sense, unstretched

By previous dread, or murmur in the rear ;

When the worst comes, it comes unfeared ; one stroke

Begins and ends their woe. — Young.

I

■ .
m.VX

UriAA^CLhMjhXX^ CuArJjlSUXs .( /fo-O-cl ■ IQ.J

CHAPTER IX.

Family VIII. TRIARTHRAD.E.

Body furnished with shipping appendages ; corona transverse; ciliary wreath single,
marginal ; foot absent.

The four genera which form this family resemble each other in one striking particular.
Each bears spines, or moveable appendages, by means of which the creature can leap
through the water. These spines have no connection with the body-cavity, though they
are moved indirectly by the usual longitudinal muscles ; which, in sharply withdrawing
the head, throw the spines forward. In one genus, Ptcroessa, which is known only by
its lorica, the spines are very numerous, and are of two distinct patterns ; in another,
Polyarthra, they are clusters of blades borne upon the shoulders ; in the remaining two,
Triarthra and Pedetes, there is only one simple spine on each shoulder, but Triarthra
carries also a similar spine on the posterior ventral surface. All the genera are more or
less loricated. In Pedetes the skin bears hard knobs for the attachment of the spines,
while Triarthra has it stiffened chiefly round the edge below the neck. Polyarthra is
semi-loricated ; the dorsal surface is very tough and there is a still harder shield
on each side between the dorsal and ventral surfaces. The ventral surface, however,
is soft and membranous. In all, the longitudinal muscles are highly developed, and
coarsely striated.

The genera differ in their trophi. Triarthra has the malleo-ramate tropin of
Melicerta ring ens ;. in Pedetes the trophi have not been clearly defined; while Poly-
arthra, widely unlike either, has a mastax and trophi closely resembling those of
Synchceta. Polyarthra, moreover, is still further separated from Pedetes and Triarthra
by having one occipital eye, instead of two frontal.

Genus POLYARTHRA, Ehrenberg.

GEN. CH. Spines in clusters on the shoulders ; eye single, occipital ; mastax
very large and pear-shaped ; trophi forcipate.

It is not easy to decide in which family the genus Polyarthra should be placed. Its
mastax and trophi are almost exactly those of Synchtzta ; its corona bears styligerous
prominences similar to those of S. pectinata ; its ciliary wreath is marginal and single,
though not broken up into curves ; and, like Synchceta, it possesses but one occipital eye.
On the other hand its skipping spines naturally place it with Triarthra and Pedetes,
which genera it further resembles by its lack of foot, by its habit of carrying its eggs,
and by the partial stiffening of its skin into an imperfect lorica.

P. platypteea, Ehrenberg.
(PI. XIII. fig. 5.)

Polyarthra platyptera '

Ehrenberg, Die Infus. 1838, p. 441, Taf. liv. fig. 3.
Leydig, Ueb. d. Ban d. Rdderth. 1854, p. 42, Taf. i. fig. 10.
Gosse, Phil. Trans. 1856, p. 435, pi. xvii. figs. 44-49.

„ 1857, p. 320, pi. xv. figs. 27-29.
Plate, Jenaisch. Zeits.f. Natur. 1885, p. 16, Taf. i. fi£> 4.

Ehrenberg's P. trigla is possibly P. platyptera with the blades seen edgewise.

r. 2

4 THE ROTIFERA.

SP. CH. Spines twelve broad blades with serrate edges.

When gliding along under the action of its ciliary wreath Polyarthra seems to have
a triangular outline ; for the body, though itself truncated both in front and rear,
carries four clusters of serrated blades fastened to the shoulders ; and these trail behind
so as nearly to meet in a point, at some distance from the animal's body. Every now
and then the blades are jerked vigorously forward, and the creature is tossed out of its
path, several times its own length. The trunk is partially loricated. There is a kind
of chitinous shield running down each side of the body, pointed at its hinder end, and
bent at the sides so as to encroach a little on the tough dorsal and membranous ventral
surfaces. The edge of the dorsal lorica (if it may be so termed) is plainly visible run-
ning across from one cluster of blades to the other. A pair of powerful striated muscles,
forming a letter V, is fastened to the lower pointed end of the shield, and to the inner
surface of the soft tissues, to which, at the upper end on each side, six of the blades are
attached. The contraction of these V-shaped muscles drags the soft tissues sharply
down over the hard edge of the shield, and makes the blades fly out with great swift-
ness. The blades are curiously like a bird's feather in general outline (fig. 5d), having
a midrib (fig. 5e) and being distinctly serrated on both edges. The corona is slightly
convex and bears, towards the dorsal surface, two prominences like those of SyncJiceta
pectinata, each carrying a brush of styles. There are also two long styles facing these,
and springing from the corona towards the ventral surface. Mr. Gosse has, moreover,
noticed, besides these tactile organs, a small occipital pimple armed with bristles. The
very large mastax points obliquely downward to the ventral surface. Both it, and its
tropin, closely resemble those of Synchceta pectinata. The contractile vesicle can be easily
seen, but neither lateral canal nor vibratile tags have been recorded. Nothing else in
its internal structure requires notice.1 The animal carries the great female egg singly,
and transversely, between the points of the two side shields ; but the small male eggs in
clusters of half-a-dozen or more at a time (fig. 5b). The male was discovered by Mr.
Gosse in 1850, and described and figured by him in the " Phil. Trans." for 1856. [Its
length is only z^ inch. The head is very large (fig. 5h) and the body tapers quickly to
the posterior part, but both extremities are truncate. The front bears two warts between
which the rotatory cilia are placed, but the cilia are longer (perhaps setae) on the warts.
The hinder part is bifid, the smaller division being the caudal extremity or toe-less foot,
and the latter a protrusile truncate penis ciliated at the tip. No internal organization
was discoverable. — P.H.G.] Dr. Plate's figure (loc. cit.) shows the sperm-sac.

Length. Female's body, ^^ inch. Habitat. Pools and ponds : common.

Genus PTEROESSA, Gosse.

[GEN. CH. Lorica entire, save for a large oval opening behind; beset with arti-
culate pinnate styles, and simple setae : foot wanting.

P. surda, Gosse, sp. nov.
(PI. XIII. fig. 9.)

SP. CH. The only known species. Horny yelloic ; pinnae twenty -four, in six longi-
tudinal rows.

The form of this remarkable species is that of an ancient amphora ; a long oval
tapering to an obtuse point, with no foot, forming a constricted neck, in front, and thence

1 An observation of Mr. Gosse's leads him to think that the rectum is turned far forward as in the
Rhieota ; and thai it is capable of consi.krablc protrusion, though ordinarily invisible.

TRIARTHRADyE. 6

expanding to a broad truncate margin. Behind there is a great ovate opening, as if a
slice had been cut off the entire breadth from the middle to the extreme point. Doubt-
less this, in life, is covered with membrane, and its edge is thickened. From the upper
margin rise two short setae, jointed to knobs ; while from the breast, exactly opposite,
there issues another, similarly jointed but of great length, descending far behind the
extremity of the body.

But the chief peculiarity of the creature is that four-and-twenty styles, regularly
arranged, are affixed to the lorica, giving a most unique aspect to it. For every one is a
feather in appearance ; the shaft, moderately long and stout, being beset, on its two
opposite sides, with regular pinnules like those of a fern (Polyjwdium, for instance), in
considerable number, length, and regularity (fig. 9c). These pinna3 are arranged in
six longitudinal rows, three on each side, on the ventral aspect, the middle pair of
rows consisting of six each, the next pair four, and the outmost two, each. The shaft of
each is evidently articulated on a knob of chitine, which is itself a tubercle on a some-
what larger round knob, set in a commensurate orifice in the lorica, — apparently moving
freely in it, a true " ball and socket " joint, worked doubtless by proper muscles within.
Thus, adding the three simple styles, which are similarly based, we have here a wonderful
array of exterior articulate members, which well illustrate the claim of the Rotifeka to
a place among the ARTHROPODA. The pinnules vary much in their number, their
length, and the angle of their expansion. The body ends in a blunt point, with no foot,
nor other appendage. The anterior extremity, beyond the marked neck, is short, some-
what inclined toward the back, truncate, with an orifice as wide as the widest part of
the trunk. Through this, of course, the head is protruded during life ; but of this, and
of the whole internal organization, I can give no information. The specimen which
came under my observation was an empty lorica, in good preservation, as if recently
dead, which I was enabled to revolve under the microscope, and so to examine in several
aspects. The whole lorica was of a dark yellow-brown hue, with a dull translucency
like that of a smoky horn lantern : but whether this is specific, or only accidental, I
cannot tell.

This most curious form occurred in the sediment of a bottle of water, examined on
October 20, 1885, but which had been standing on my table since September 23, when
I had received it from Mr. Hood with a colony of Scaridium eudactylotum. From the
condition of the lorica I have little doubt that it had come to me alive ; but being occupied
with the new Scaridium I did not search closely. — P.H.G.]

Length. Of lorica, T}s inch ; to tips of pinnae, ^3 inch ; from brow of lorica to tip of
ventral seta, T\ inch. Habitat. Loch near Dundee (P.H.G.).

Genus TRIARTHRA, Ehrenberg.

GEN. CH. Spines single, two lateral, one ventral; eyes two frontal ; mastax of
moderate size ; trophi malleo-ramate.

There are three known species of this genus, and they resemble each other very
closely ; the main points of difference being the length of the leaping-spines, the distance
between the eyes, and the length of the oesophagus. The first of these characters is
one that cannot be much relied on except in the case of T. breviseta ; for the length of
the spines varies very much in the same species. Ehrenberg makes a further point of
difference, in the presence or absence of any well marked separation between the stomach
and intestine, asserting that T. longiseta possesses this separation and that T. mystacina
lacks it. This, however, is a character of small value, for the same animal will show at
one time an undivided alimentary canal ; and, at another, one sharply divided into in-
testine and stomach.

THE ROTIFERA,

T. longiseta, Ehrcnbcrg.
(PL XIII. fig. 6.)

Triarthra longistia . . . Ehrenberg, Die Infus. 1838, p. 447, Taf. Iv. fig. 7.
„ „ ... Hudson, Mon. Micr. J. vol. i. 18G9, p. 176, pi. vi.

... Grenadier, Sieb. u. Koll. Zeits. Bd. xix. 1869, p. 491, Taf.
xxxvii. fig. 3.

SP. CH. Body oval; buccal orifice prominent but not beaked, cup-shaped ; spines
more than twice the length of the body ; eyes wide apart ; oesophagus long.

The habit of this interesting creature is to swim slowly forward while turning round

its longer axis, and every now and then to dart out of its course by jerking forwards the

three long spines which usually trail behind it. The corona is oval, and bears in its

centre one broad, low prominence, with a smaller one on either side of it ; and just within

each of these latter is placed a red eye. The buccal orifice is cup-shaped and has its

inner surface lined with cilia. The buccal funnel slopes backwards and upwards towards

the dorsal surface to meet the mastax, whose tropin are almost identical with those of

Melicerta ring ens. The oesophagus is long and narrow, and the stomach and intestine

are usually separated by a deep constriction. The gastric glands (fig. 6a) are curiously

shaped, and frequently studded with what appear to be oil-globules. The vascular

system is delicately transparent, and difficult to be seen. I have traced the lateral canals

on each side, for some distance down the trunk, from a plexus of tubes in the neck, and

have detected just there a vibratile tag. I failed to discover the contractile vesicle, but

Dr. Grenadier (loc. cit.) has seen it, in its usual position, close to the cloaca. There is a

large ovary ; and the newly laid eggs remain attached to the parent by a thread for some

time after their exclusion. The ephippial eggs (fig. 6/) are as curious in shape as the

gastric glands, and are protected by a thick layer of yellowish transparent cells. By

bringing into focus the central inner portion of the head, seen sidewise, a bluish and

roughly rhomboidal mass may be observed ; this is the nervous ganglion, and above it

are the eyes, and from it threads extend to a setigerous fossa in the neck, as well as to

rocket-headed antennae, one on each side (fig. tie) just under the surface. Each eye

(fig. 6b) is a clear, colourless, refracting sphere -g-o'cnj hich in diameter, resting on, and

partly imbedded in, a flat plate of red pigment. The longitudinal muscles are very

powerful, and are strongly striated ; the striae not being straight transverse lines, but

irregular obliquely transverse curves (fig. tic). Indeed they appeared to me to alter both

in direction and in size as I looked at them, giving me the impression that I was looking

at illusory stria), produced possibly by looking through separated sheets of striated fibre,

lying over each other. There is an unusually powerful muscular collar running round

the neck. The spines are stiff quill -like appendages, broadest at their attached bases,

and tapering at their free ends. The bases (fig. 6d) are like quills that have been

obliquely cut across, and it is by these cut surfaces that they are attached, one on each

side of the corona, just above the neck ; and one on the ventral surface, at the spot from

which the foot springs, in those Rotifera that possess one. The spines are notched here

and there (fig. 6d), and finely imbricated towards their tips. On looking at fig. 6, it will

be evident that if the muscular collar round the neck be suddenly contracted, and the

head withdrawn, the spines will be first dragged across the stiff edge of the trunk,

below the collar, and then jerked forward by the downward pull of the head.

How the third spine is moved is not so clear. Dr. Grenadier suggests that it is
dragged forward by the other two, which are often crossed beneath it ; but adds that
this is a forced explanation. It is probable, I think, that this spine is driven forward
by the sadden jerk downwards on its base, when the longitudinal muscles sharply com-
press the stiff ventral cuticle. Fine muscular fibres surround the trunk at regular

TRIARTHRAD/E. 7

intervals, and unite with the broad band round the neck in driving out the retracted
head, and restoring the spines to their usual position.

Length. Without the spines, Ti^ inch. Habitat. Fresh-water ponds and ditches :
common.

T. mystacina, Ehrenberg.
(PL XIII. fig. 8.)
Triarthra mystacina . . . Ehrenberg, Die Infus. 1838, p. 417, Taf. Iv. fig. 8.

[SP. CH. Body oval; buccal orifice taking the form of a beak projecting from the
face ; spines not twice the length of the body ; eyes approximate ; oesophagus invisible.

In July 1849, from the ditch at Dalston Causeway, near London, I took several of
the Whiskered Three-beard. The moderate length of the leaping spines, the approxi-
mate eyes, and the absence of any manifest oesophagus — the stomach coming into contact
with the mastax — marked the species as Ehrenberg's mystacina. The absence of the
oesophagus is doubtless only apparent, this duct, as is the case with Polyarthra (see
PI. XIII. 5c) and many other Rotifera, issuing from behind the mastax, near its summit.
One adult had an egg attached to the hind extremity, which somewhat retarded its
motions, as compared with those of its fellows. After a while the spontaneous move-
ment of the embryo became more and more vigorous, and the ciliary rotation energetic ;
and a clear globule, as of air, was seen within, while yet the egg remained adherent.

The front is formed of a ring of six or seven sub-globose masses, in mutual contact,
each of which is crowned by a cluster of divergent cilia. The chin descends in a promi-
nent hook, like a parrot's beak, which appears stiff, and projects between the bases of
the two pectoral spines. The two eyes are nearly frontal, small, bright red, and
approximate. The mastax appears formed on the plan seen in the Bdelloida. The
stomach is large and saccate, and is supplemented by a distinct intestine. The animals
are very subject to be infested by two species of Colacium, which are seen in fig. 8.
They cling to its spines as well as its trunk, and appear to give it uneasiness. I have
counted sixty-five of these parasites on one individual, and nearly fifty on another.

The animal seems to have no power of affixing itself, or of resting. It swims con-
stantly ; interrupted only by its spasmodic jerks or leaps, performed by the sudden
throwing out of the elastic spines, chiefly, I think, the pectoral pair. These are
articulated to shelly knobs, which imply a solidifying of the integument around their
bases, to supply the necessary resistance. In the act of springing, these two are often
shot forward so forcibly as to be projected in front, reminding us of the anal bristles in
Podura. This is done with a rapidity that the eye cannot follow ; and this, through so
dense a fluid as water, requires the exertion of great muscular power. — P.H.G.]

Length. To tips of setae, 3^ inch. Habitat. Around London : ditches and orna-
mental waters (P.H.G.).

T. BEEVISETA, GoSSe.
Triarthra breviseta .... Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200.

[SP. CH. Body cylindrical; breast projecting, but not beaked; spines not one-
fourth as long as the body.

This species is more regularly cylindrical than the others ; it is diminished toward
the front, which is truncate ; the hinder end is ventricose, and extends much beyond the
base of its spine ; the belly is deeply sulcate, with thick collops of the skin between ;
the breast forms a great rounded projection, but not a beak. Just beneath this is a
constriction, where the very short spines are set, each not more than half the body's
width in length, very slender. The whole head can be retracted as far as this, by which
involution of the skin the spines point straight forward, reverting to their normal direc-

8 THE ROTIFERA.

tion as the head emerges. The animal has no power of springing by means of the
spines, or of using them in any appreciable manner. The hind spine is similar, and
similarly set in a deep sulcus of the lower belly. All are dilated at their bases.

At the very front are two minute but distinct red eyes, side by side, seated on a small
brain-mass, which tapers into a thread that passes to the occiput, probably to an antenna,
not detected. The mastax was obscure, but seemed of the Bdelloid pattern. A very
slender but long oesophagus leads to a vast sacculate alimentary canal, and this to a
cloaca at the very point of the body, behind the spine ; which hence, Herr Grenadier's
judgment notwithstanding, I conclude to represent the foot. A momentary action, like
that of a contractile vesicle, I perceived, but could not define one ; and lateral canals
run down each side. Several muscles are discernible.

The animal is vivacious, swimming freely and swiftly ; I did not see it attempt to
spring, nor to crawl ; the foot-spine was not whisked about. I first met with the species
in a pond in Holly Walk, Leamington, in July 1850 ; and again lately in water from
Keeper's Pool, Birmingham, sent me by Mr. Bolton. — P.H.G.]

Length, TJ-j to T\z inch. Habitat. Warwickshire pools : rare (P.H.G.).

Genus PEDETES, Gosse.

[GEN. CH. Body ovate, tailed; toes absent ; eyes tivo frontal ; two leaping styles
articulated to the breast.

P. saltator, Gosse, sp. nov.
(PI. XIII. fig. 10.)

SP. CH. Leaping styles thrice the length of the body.

This genus has a very close relation to Triarthra. It may, indeed, be described
as a Triarthra with the posterior style wanting. The body, though apparently soft
and flexible, must be considered as enveloped in a lorica, since the knobs to which the
styles are articulated, are hard, immoveable, and doubtless chitinous. Its form, viewed
dorsally, is ovate, obtusely pointed behind and broadly truncate in front. Viewed
laterally (fig. 10a), it is flat on the ventral, and strongly arched on the dorsal surface.
The dorsum rises to a marked conical elevation which is a true tail, for the cloaca opens
between it and the foot. The latter (or what represents it) is a small ovate terminal
member, within which, close to the tip, is a minute vesicle, possibly the contractile
bladder. The rotatory cilia are seated on a number of small projecting eminences, with
which the front is beset. On each side of what for convenience sake we call the breast,
but rather high up, is a large round shelly knob, apparently hard and immoveable.
Dr. Hudson (" M. M. J.") long ago explained the action of the pectoral styles in the
parallel case of Triarthra (see T. longiseta, p. 6). We may conclude the mechanism
to be the same in both cases ; but I am inclined certainly to see more than mere
mechanical action in these shelly knobs, viz. special muscles for the forcible and definite
motion of the styles, by means of a true (perhaps ball and socket) joint. Each style is
a highly elastic rod, thick at its origin and for a considerable distance, then gradually
tapering to a great attenuation, about thrice as long as the body. On the tips of these,
which must therefore possess remarkable firmness, the animal, now and then, suddenly
jerks itself away, as on a leaping-pole, with great force ; so that they are in an instant
seen stretching out at a right angle, or even more, forward. These leaping-poles are
composed of transparent refractive material (chitine), resembling glass in appearance.
The brain has not been defined ; but two eyes, of a translucent red hue, near together,
are conspicuous at the very front. The mastax, far down in the body, with vigorously
working mallei, was visible near the middle ; and below this a great globose, sac-like

aentary canal, without visible division. The only specimen I have seen occurred in

HYDATINAD.E. 9

a tube, rich in Rotifera, sent me by Mr. Bolton in the autumn of 1884. It had become,
in the live -box, accidentally entangled in a small mass of tenacious mucus, which
evidently annoyed it, and from which it made vigorous but ineffectual efforts to become
free. I have never met with the form since. — P.H.G.]

Length of body (without styles), about T^ inch. Habitat. A pool near Birmingham
(P.H.G.).

Family IX. HYDATINAD^E.

Corona truncate with styligerous prominences ; ciliary wreath, two parallel curves,
the one marginal fringing the corona and buccal orifice, and the other lying within the
first, the styligerous prominences being betiveen the two ; trophi malleate ; foot furcate.

Ehrenberg's very extensive family of the Hydatincea, under the name of Hydatinadce,
is here restricted to three genera, viz. Hydatina, Notops, and Ehinops. They are all
alike in their corona, ciliary wreaths, and trophi, but differ from each other in their
shape, eyes, and foot.

The head is truncate with a deep cup-like cavity as it were scooped out of it. This
cavity lies more towards the ventral surface than the dorsal, so that a transverse slice
would be horseshoe-shaped, the bend of the horseshoe being to the dorsal surface.
The principal wreath fringes the outer edge of the cup's wall, and the secondary wreath
borders the inner ; both wreaths are continued down into the buccal orifice, which lies
just within a deep notch in the wall of the cup on the ventral surface.

Styligerous prominences rise in the space between the two wreaths, except in the
case of Bhinops ; and in this genus the dorsal side of the corona bears a thick proboscis,
around the edges of which the principal wreath is continued.

In their habits they in the main resemble each other ; for all but Rhinojis tolerate
even very dirty water, provided that it contains an abundance of the minute organisms
on which they feed.

Genus HYDATINA, Ehrenberg.

GEN. CH. Body conical, tapering towards the foot; foot short, and confluent with
the trunk ; eye absent.

H. senta, Ehrenberg .
(PI. XIV. fig. 1.)

Hydatina senta . . . . Ehrenberg, Die Infus. 1838, p. 413, Taf. xlvii. fig. 2.

„ „ Cohn, Sieb. u. Koll. Zeits. Bd. vii. 1856, p. 436, Taf. xxiii.

„ „ . . . . Leydig, IfrtZZer's Archiv, 1857, p. 404, Taf. xvi.

,, „ . . . . Hudson, Hon. Micr. J. vol. ii. 1869, p. 22, pi. xix.

H. senta is one of the largest of the Rotifera, and its flashing styles, ruddy teeth, and
yellow stomach, often stuffed with brilliantly green Englence, make it a charming object
for dark-field illumination. Its shape is conical, the corona being the base, and the
toes the apex. When seen, however, from the side (fig. lb), especially if a little arched,
the separation of the head and foot from the trunk is distinctly visible. The styligerous
prominences are semi-globular cushions crowned with long and rapidly vibrating styles,
set fan-fashion. It is difficult to say how many cushions there are, owing to Hydatina' s
incessant restlessness ; but there are probably ten or eleven. Two are on the median
line ; one on the dorsal edge, and one between the first and the cavity of the head. The
rest are arranged round the cavity in a sort of quincunx fashion ; mainly on the dorsal
half of the corona. The great hollow in the corona is not only ciliated on its edge but

10 THE EOTIFEEA.

also on its whole surface, and may fairly be considered to be the buccal funnel. At its
base, close to the ventral surface, lies the mastax, containing malleate reddish tropin
with unci of four arrow-like teeth (fig. le). I have often seen these hand-like unci pro-
truded into the funnel to grasp some desired morsel. The thick cellular walls of the
stomach, are well seen in the young specimen (fig. la), in which a thin line of green food
marks the hollow of the nearly empty stomach. The secreting and vascular systems
are obvious and normal. A rectangular nervous ganglion (fig. 1) below the corona,
and just under the dorsal surface, sends off a pair of nerve-threads at each corner. The
upper pairs possibly ramify to the styligerous prominences which are very sensitive ;
and which Mr. Gosse has seen individually depressed below their usual position by mus-
cular threads rising up to them from the depth of the head. One of the lower pairs
supplies the two lateral antennae (fig. la, lb), and the other two nerve-threads pass to
the dorsal antenna (fig. lb). The ovary in the half-grown animal (fig. la) is very
transparent, and the oviduct is then conspicuous ; as are also the fibres that tie the
ovary to the body-walls.

Tbe male was described by Ehrenberg under the name Enteroplcea hydatina, as
he was not aware of its sex. It is often to be met with among the swarms of females
that haunt dirty farmyard ponds and neglected water-butts. Its general appearance is
that* of a young female, but it can be recognised at a glance by the absence of the
mastax. Its internal structure is precisely like that of the male of Asplanchna pri-
odonta, and is sufficiently shown in fig. In.

Disease. — I once found a few specimens of II. senta (fig. Ira) with what appeared to
be the mycelium of a fungus growing in the perivisceral fluid, and loosely surrounding
the various organs. The infected creatures, however, seemed as vigorous as the healthy
ones. H. senta, too, suffers from an internal parasite. It is of a narrow oval form,
about 3^ inch in length, and swims up and down its host's stomach by jerking the
contents of its body constantly backwards and forwards (figs. Ill, Ik). There are curious
bodies inside the parasite itself something like the globe of a lamp in shape (fig. 11).

Length. From ^ inch to -^ inch. Habitat. In water swarming with Euglence,
&c. : common.

Genus RHINOPS, Hudson.

GEN. CH. Body conical, tapering to the foot ; a long dorsal proboscis on the corona ;
foot short, and confluent with the trunk, with tioo minute toes clesely pressed together ;
eyes two, at the end of the proboscis.

E. vitrea, Hudson.
(PI. XIV. fig. 2.)

Rhinops vitrea .... Hudson, Ann. Nat. Hist. 4 Ser. vol. iii. 1869, p. 27, pi. ii.
„ „ .... Plate, Jenaisch. Zeits. f. Natur. Bd. xix. 1885, p. 46.

Rhinops vitrea appears to have escaped notice till 1869, when I found it in a pond in
Losely Park, near Guildford ; so I suppose it must be rare : and yet I have often taken
it in the neighbourhood of Clifton, and at times even in abundance. Though not a
large Eotiferon, it is easily recognized with a hand-lens by its slow, deliberate way of
swimming ; a peculiarity which first attracted my attention to it. Its shape is striking.
It is a Hydatina without any styligerous lobes on the corona ; but bearing, in lieu of
them, a unique prolongation of the dorsal surface into a sort of proboscis. Two splendid
ruby eyes are placed on the extremity of this proboscis, and its under surface is furred
with cilia like the prone face of Adineta. The outer ciliary wreath is carried up each
side of the proboscis ; but the tip between the eyes is free from cilia, and seems to act

HYDATINADJE. 11

as an organ of touch. The inner ciliary wreath consists of larger cilia which are some-
times held erect. The oesophagus is long and narrow, and the gastric glands so irre-
gularly conical, that they generally appear unlike ; probably owing to their being seldom
presented to the eye from similar points of view. The nervous ganglion has an unusual
position. It lies near the end of the proboscis, and gives off, above, four parallel nerve-
threads ; the two outer of which pass to the eyes, and the two inner to the sensitive
bare spot on the tip of the proboscis (fig. 2c). The rest of the internal structure is
both obvious and normal. The young animal quits the egg while yet in the body of
the parent, and may often be seen filling up a large portion of the body-cavity. The
ephippial eggs closely resemble those of Conochilus volvox.

Khinops vitrea usually swims at a moderate pace, rolling gentlj round its longer
axis as it goes, and every now and then bending back its proboscis, or turning somersaults
as Synchceta pectinata does, only in a much more leisurely manner. Occasionally it
darts forward ; and, at each time that it has done so, I fancied I could see the atom
which it wished to secure. Then it glides over the stems of Alga, using its long pro-
boscis just as Adi?ieta vaga does its ciliated face ; and, when a larger atom than usual
has been drawn into the coronal cavity, it compresses the broad flaps of the corona,
and rounds the whole front of the body into a long ciliated tube.1

Length, -^ inch. Habitat. Clifton (C.T.H.) : not common.

Genus NOTOPS, Hudson.

GEN. CH. Body not conical ; foot long and symmetrically placed with respect to
the trunk, or short and wholly retractile within the ventral surface ; eye single, occi-
pital.

Of the three remarkable species contained in this genus, two, N. Brachionus and
N. clavulatus, are strikingly alike each other, especially in the head and its ciliated
protuberances, and also in the tropin. They are, however, curiously unlike in their
outline, and in the relative length of the foot. The third species, N. hyptopus, resembles
N. clavulatus in the short foot, and in the odd position in which it is placed ; but differs
widely from all the Hydatinadce. in the corona and tropin. Feeble, however, as are its
affinities with the two other species of the genus, they are stronger than those it has
with any other ; so it has been placed here as the best makeshift that could be devised.

N. brachionus, Ehrcnberg.
(PL XV. fig. 1.)

Notcmmata brachionus . . . Ehrenberg, Die Infus. 1838, p. 433, Taf. 1. fig. 3.
„ Leydig, Ueb. d. Bau d. Raderth., 1854, p. 99.

„ „ . . . Hudson, Mon. Micr. J. vol. xiii. 1875, p. 46, pi. xci. figs. 1-4.

SP. CH. Trunk square; foot one-third of total length, placed in continuation of
the body's longer axis, not wholly retractile; trophi malleate.

I found this handsome creature in a small rain-pool in Leigh woods. The summer
heat frequently dried the pool up, but a heavy shower or two soon filled it again ; and,
two or three days after the downfall, I always found N. brachionus there in abundance :
no doubt hatched out from eggs deposited on the rotting leaves which formed the
bottom of the pool. These strange habitats of the Kotifera are probably due to their
eggs being wafted by winds, or carried by birds ; so that it is no wonder that this species
should have been captured by Schmarda in a spring near the top of Adam's Peak in

1 Dr. Plate (loc. cit.) says that It. vitrea has but one toe. I thought so myself, till I saw the
creature, of its own accord, separate the apparently single toe, into two.

12 THE ROTIFERA.

Ceylon. It is a remarkable Rotiferon, surpassing almost every other in the number and
variety of its styles, setaa, and cilia. In general shape it is something like a Brachionus,
but its head is that of a Hydatina. There are only three styligerous prominences in
the corona between the two usual wreaths, and these bear styles arranged fan-fashion
and thickened at the base, as if each style passed through a short sheath ; a form of
style strikingly visible in the young animal, when the styles are short. The whole of
the cavity leading to the buccal funnel is ciliated, and at its base is a ring of large
curved styles, pointing upwards. On each side of the wedge-shaped opening, at the
entrance to the buccal funnel, are large setae set horizontally above one another in short
sheaths, and fringed at their bases with minute vertical setae (fig. lc). The trophi are
malleate, and Mr. Gosse says that they are the exact repetition of those of N. clavtdatus
(Notommata clavulata) as figured by him in " Phil. Trans." 185G, PI. xvi. fig. 23. The
rest of the nutritive system, as well as of the secreting and vascular systems, is obvious
and normal. The ovary is horseshoe-shaped, with its germs set in a single line.
There is a nervous ganglion just below the dorsal surface of the head, somewhat rect-
angular in outline like that of Hydatina senta ; and, like it, giving off nerve-threads at
its corners, two of which doubtless pass to the large dorso-lateral antennae shown at the
lower corners of the trunk in fig. 1. Mr. Gosse, in a side view, has seen that the
nervous ganglion is a truncated pyramid, bearing the red eye on its summit.

The Male. — N. brachionus carries its egg for some time after exclusion, so that it is
possible to identify the male with certainty. The male is very unlike its mother in
shape and size, and a side view (fig. lb) shows that the head slopes back to a hump, on the
apex of which is a bunch of tactile setae. A nerve-thread from the nervous ganglion
passes to these, and lies between two fine muscular fibres. A moderately sized sperm-
sac ends in a ciliated penis just above the foot, which contains two large club-shaped
glands. Close to the sac is a small contractile vesicle, the lateral canals of which can
be readily traced on either side of the ventral surface.1

Length, ^0 inch. Habitat. Ponds and pools ; Clifton (C.T.H.) ; Kingswood (P.H.G.,
T.B.) : not common.

N. clavulatus, Ehrenberg.
(PL XV. fig. 3.)
Notommata clavulata . . . Ehrenberg, Die Infus. 1838, p. 432, Taf. 1. fig. 5.

SP. CH. Body sac-shaped ; foot one-ninth of total length, wholly retractile within
the ventral surface ; trophi malleate.

At the first glance one would say that this animal was an Asplanchna, which genus
it greatly resembles in general shape, in brilliant transparency, and in the comparative
emptiness of the trunk. But a little examination shows that the two are widely unlike
in corona, trophi, and alimentary canal. On comparing, however, the apparently dis-
similar creatures N. brachionus and N. clavulatus, it will be found that they are, in
many important points of their structure, exact counterparts of each other. The coronae,
for instance, are closely alike, although N. clavulatus has a greater number of styligerous
lobes, and lacks the ring of curved styles that lie round the base of the cavity of the
corona in N. brachionus (fig. 1). The trophi are identical. The muscular and vascular
systems are much alike; the latter, indeed, curiously so, for the sharp bend at right angles
in the lateral canals, which is rendered necessary by the shape of N. brachionus, is
repeated (needlessly, as it were) by N. clavulatus. The contractile vesicle in the latter,
however, has much thicker walls, and is sluggish in action. The eye is seated on the

1 Ehrenberg found a female with a cluster of male eggs ; and, misled by their size and number,
supposed that the issuing young were those of a Notommata which he named N. granularis, and
which he credited with laying its eggs on the backs of Brachionus pala and Notops brachionus.
Leydig explained the error [lor. rit.).

HYDATINAM. 13

ventral side of the nervous ganglion in N. clavulatus, and on the dorsal side in
N. brachionus ; but in other respects the nervous systems are alike ; the side view
(fig. 3a) of the female of the former showing precisely the same nerve-threads to a
dorsal antenna which are exhibited by the male of the latter (fig. lb). The ovaries in
both species are flat horseshoe-shaped ribbons bearing a single row of germs. The
chief points in which N. clavulatus differs from N. brachionus, besides those of the
general shape, and of the size and position of the foot, are as follows. The gastric glands
are long and cylindrical, and below them there are two pairs of short casca attached to
the dorsal surface of the stomach. The stomach often appears as a long conical tube
tapering to a cloaca above the foot, colourless when empty, or tinged above with a faint
yellow tint when filling with food. Frequently, however, there is a deep constriction
above its lower portion, thus forming an intestine ; and on one occasion I saw this con-
striction suddenly disappear, and the contents of the intestine at the same time drawn
up into the stomach. Mr. Gosse noticed that the body had its surface marked with
minute oblong points, which were scarcely visible except at the edge. He observed
also that the discharged egg was carried behind the cloaca, and that its development
was extremely slow ; no sensible maturation having appeared even several days after its
exclusion. The male is unknown.

Length, -Bls inch. Habitat. Hampstead (P.H.G.) ; Clifton (C.T.H.) : not common.

N. hyptopus, Ehrenberg.
(PL XV. fig. 2.)

Notommata hyptopus . . . Ehrenberg, Die Infus. 1838, p. 426, Taf. 1. fig. 6.

SP. CH. Corona without setigerous prominences; ciliary wreath single; foot
about one-fifth of the total length, arising from the ventral surface and capable of being
wholly withdrawn within it ; trophi forcipate. Partially loricated.

This must be a rare animal ; for, since Ehrenberg found two specimens in 1835, no
one but Dujardin and Perty records having seen it. I have myself only seen it twice ;
but on one of these occasions I fortunately had many specimens, and so I was able to
add something to Ehrenberg's rather meagre details. The first thing that strikes the
observer is the creature's odd, wabbling way of swimmmg. This is due, no doubt, to its
unusual shape ; for it is greatly compressed, having a narrow dorsal surface, but a broad
lateral one. The skin can hardly be termed a lorica, yet there are several places where
it is much stiffened. The two curved edges down the dorsal surface (figs. 2, 2a), the
undulating edge of the trunk beneath the neck, and the rim of the aperture into which
the foot can be withdrawn, are all thick and unyielding. The corona is truncate, but
bulges forward towards the centre. The marginal ciliary wreath is interrupted on each
side by a long vibratile style. A grape-shaped mastax, with feeble forcipate trophi, lies
close to the buccal orifice. Ehrenberg says that there is neither oesophagus nor
intestine ; and if his two specimens had their alimentary canals much distended with
food, these organs would have appeared to be wanting. But in front of the true
stomach, with thick cellular walls, there is a very thin transparent chamber (fig. 2a)
often empty, and constantly puffed in and out, in ever-varying shapes.

This, I think, is an oesophagus similar to those in Asplanchna and Synchcsta ; and,
like them, capable of being distended with food, so as to be confluent with the stomach,
or of collapsing to form a narrow tube. The apparent absence of intestine is also a
temporary condition of the alimentary canal : my specimens had all a most well-marked
intestine. The gastric glands are large and plainly nucleated ; and the walls of the
stomach are studded with unusually large oil-globules. The contractile vesicle is high
on the ventral surface owing to the whole animal being tucked up, as it were, towards
that surface. The lateral canals are unusually large and distinct ; and lie, with their
floccose ribbons, close to the skin : they are well shown in fig. 26. The same figure

U THE ROTIFEEA.

shows the chief longitudinal muscles. The ovary (fig. 2a) is very large, and has largo
germs: a maturing ovum is visible in fig. 2. A large nervous ganglion of Notommatan
type stretches back from the corona to the dorsal surface and bears a large red eye. 1
failed to find any antennae. The male is unknown.

Length, 7\ inch. Habitat. Near Birmingham (T.B.) : rare.

Family X. NOTOMMATAM.

[Corona obliquely transverse ; ciliary wreath of interrupted curves and clusters,
usually with a marginal wreath surrounding the buccal orifice ; trophi forcipate ; foot
furcate.

The Eotifera associated in this family may be considered the most typical repre-
sentatives of the whole class. They are permanently free, never affixed to other objects,
never to each other in clusters. Their bodies are not inclosed in tubes ; their integu-
ment is more or less flexible, never hardened into a shelly mail. The body is generally
cylindrical, with a length twice or thrice the diameter : the front does not expand into a
flower-like disk, but is usually convex, often with a flat versatile face, inclined down-
wards (supposing the animal to be crawling), beset with strong vibrating cilia, so arranged
that their combined action produces two vortices, one on each side of the head. The
posterior extremity bears a foot of several diminishing joints, capable, in a slight degree,
of telescopic inversion ; and the last of these bears two diverging toes, chitinous in
structure, used for support and locomotion.

The trophi are well developed, all the seven constituent elements — the labrum, the
two mallei, the two inciis-rami, the fulcrum and the labium— corresponding homo-
logically to the labrum, the mandibles, the maxilla and the labium, of insects,1 being
present, in relative proportions. The mastax is so placed that the jaws can be freely
protruded from the buccal orifice, as has been seen in most of the genera, and used,
forceps-like, to slit the cells of Algae, to nibble the flocculent matter which grows on
vegetable stems, or to seize, retain, and devour active animalcules.

Some of the genera possess a singular apparatus for suddenly augmenting locomotion,
in the form of a pair of organs (auricles), ordinarily concealed, which can be thrust out
in an instant, by eversion of the skin. The surface which is then external is clothed
with cilia, dense, vigorous, and capable of producing ample vortices in the water.

The Noto?nmatadce are the most highly organised of all Rotifera ; the most sudden,
varied, and energetic in their motions ; most highly endowed with external sense-
organs ; most predatory ; most nearly approaching to the Articulate classes, not only in
their manducatory organs, but also in their skin usually firm, elastic, capable of being
thrown into transverse folds, or sub-articulations, more or less permanent. If not the
most beautiful, they may claim to be the most interesting ; best repaying investigation,
while they present the greatest difficulties to the student. As this must be considered
the central or typical family, without adopting all the fancies of the Circular theories,
we may suggest that the relation between the genus Furcularia and the Loricata,
through Diaschiza, is very close : that Proales, with its long prone face, leads to the
Bdelloida through Adineta : that the skipping species of Furcularia, as longiseta and
cequalis, look towards the Scirtopoda : and that in the mucous investiture common in
the genus Copeus, we perceive a reflection of the excreted tubes of the Bhizota. —
P.H.G.]

1 Sec my mem. " On Maud. Organs," Phil. Trans. 18;35 p. 419.

NOTOMMATADiE.

Genus ALBERTIA, Dujardin.

[GEN. CH. Body vermiform, lengthened ; ciliated face sub-prone ; eyes wanting ;
jaws minute, forcipate ; foot small, one-toed. Entozoically parasitic in Annellida. —
P.H.G.]

A. intrusoe, Gosse, sp. nov.
(PL XVII. fig. 13.)

[SP. CH. Body greatly lengthened, nearly cylindric, but swollen behind ; foot of
one joint, besides the toe, which is a small cone ; viscera divided by annular constric-
tions, within the straight (unconstricted) integument.

This species seems distinct from the A. vermiculus of M. Dujardin, if I may
judge from his figures (Infus. PI. 22. 1a, b). The general form of that is uniformly
cylindrical, slightly tapering to a great conical foot ; of this, cylindrical, gradually swelling
to the ventricose hind parts, where a very minute conical toe terminates a small one-
jointed foot. The mastax and jaws of that species are moderately large ; of this,
excessively minute. That species is parasitic within earthworms and slugs ; this, within
water- worms (Nats). The discovery of the following species makes it almost certain
that these differences are specific.

The body is greatly elongated, slender in front, thickening behind the middle, so
that the diameter of the hind part is just double that of the fore. As, however, a great
ovate egg was mature in the ovary, at the very extremity of the visceral cavity, of the
specimen figured, the body may have been more than usually swollen. The ciliated
face is broad and oblique ; the mastax minute, displaying a forcipate incus, with broad
blades, resembling those of Diglena, to which are attached slender simple mallei, with
long straight arms indexed at their extremities. All the tropin are frequently pro-
truded fully half-way from the ciliated front, and vigorously snapped. A very slender
oesophagus leads to a long alimentary canal, which is constricted at short intervals
throughout, but appears to be simple. No gastric, or biliary (?) glands were seen. The
ovary is long, and occupies the greater part of the abdomen. In all the specimens that I
examined, there were seven or eight amorphous nuclei, and one large well-matured ovum
filling up the posterior end ; its substance minutely granular, with a vitelline globule
near the anterior end. Between this ovum and the intestine was a small contractile
vesicle. A minute point projects from the front, which may possibly be a sense-organ,
but I perceived no setae on it. A long pointed occipital sac descends far below the
mastax, but is destitute of any eye-speck. The whole animal is slightly tinged with
yellow ; and this is the only trace of colour in it, as the abdomen contains no coloured
food, owing to its peculiar economy. For the animal lives as a parasite in the visceral
cavity of Nats proboscidea. I was examining a specimen of this aquatic worm (in
October 1854), when a slight pressure of the compressorium caused it to separate into
If j parts. I had looked over it with a lens, but had no suspicion that my Nats was
any other than a single integer, and unfortunately it was not in focus when the separa-
tion took place, so that I did not actually watch the process. The next moment, how-
ever, I found that I had two perfect Naides ; the one which had been the tail differing
only by being a little smaller, but with a head, eyes, and proboscis, as perfect as the
other. The one which must be called the parent had the hind extremity less distinct
than the daughter, and there was a slight trace of jaggedness visible. But my attention
was arrested by a vermiform animal snooting swiftly through the water ; and presently
another. They were evidently Rotiferous, and as I was sure that they had not been in
the live-box before, I conjectured that they had been discharged from the body of the
Nats, at the moment of division. This was immediately confirmed : for, on examining
the Nais, I found, within the alimentary canal of the parent, near the dividing point,
three or more of the parasites snugly nestled, and actively writhing about. All the

16 THE ROTIFERA.

specimens agreed accurately with each other, as described above. In the open water
they swam swiftly ; and it was difficult to confine them even with the compressor; for
they soon managed, by contraction and elongation, to wriggle themselves out of the
field of view. The Nats was from a pool at Walthamstow. Examining another Na'is
from the same phial, I found a single Albcrtia in the intestine; in another, an egg of the
parasite was within the intestine, attached to a pellet of faecal matter, which pushed it
along. The opacity of the bowel prevented my seeing whether any matured parasites
were present or not in this case. — P.H.G.]

Length, TJ0 inch ; diameter, 5^,j to TJ6U inch. Habitat. Walthamstow (P.H.G.) :
entozoic.

A. na'idis, Buusfield, sp. nov.
(PI. XVII. fig. 14.)

[SP. CH. Body moderately long, the cervical and pectoral parts the thickest,
diminishing to the hind part ; toe minute, soft, papilliform ; integument slightly con-
stricted in the hinder half.

This species was discovered by Mr. Edward C. Bousfield, who has kindly communi-
cated to me his own careful drawings and descriptive MS. notes. He has " several times
observed it in situ, in Na'is barbata, living free within the cavity of the stomach of its
host."

"Body cylindrical, soft, hyaline, vermicular, extremely flexible and telescopic, espe-
cially the hinder part. Anterior extremity truncate. Trochal disc small, oblique, on
dorsal aspect of body. [One drawing shows that it is invertile, the cilia being depicted
far down the buccal funnel. — P.H.G. ] Jaws very minute, protrusile, snapping. Ali-
mentary canal conical, extending through the body, opening at the junction of the last
two segments. Gastric gland semi-ovoid. Ovary straight, slender, cylindro- conical ;
the ova developed serially. A minute contractile vesicle.

"Caudal appendage [ = foot, P.H.G.] papilliform, composed of two joints [of which
the terminal is] soft, resembling in its action the finger of an elephant's trunk."

"Habitat. Vicinity of London. Anterior portion of stomach of Nais, in which it
moves freely. Egg about one-third of length of parent's body. LeDgth, 2}^ inch." '
—P.H.G.]

Genus TAPHROCAMPA, Gosse.

[GEN. CH. Body fusiform or cylindrical, annulose, furnished with tivo furcate toes;
trophi forcipatc ; rotatory cilia wanting or very limited.

T. annulosa, Gosse.
(PI. XVII. fig. 12.)
Taphrocampa anmdosa . . . Gosse, Ann. Nat. Hist. 2 Ser. 1851, p. 199.

SP. CH. Body cylindrical, short and thick, marked throughout with distinct articu-
lations ; brain opaque; alimentary canal simple, wide, cylindrical; terminal fork
thick, conical, acute.

This animal is very larva-like ; the body consists of many well-marked rings or
segments which are set within the clear cylindrical integument, apparently touching
tins only at the points. Each of these, if viewed through the longitudinal line, would
be of a sub-square outline, with four projecting angles, as seen at fig. 12&. In general
no vortices are seen, nor any trace of vibratile cilia, so that I long concluded

1 Thus the three recorded species differ notably in their respective dimensions : — A. vermiculus
being „',-, inch to S'B inch (Duj.) ; A. intrusor, I(},; in. (P.H.G.) ; A. na'idis, x^ in. (Bousfield).

NOTOMMATADjE. 17

rotatory organs to be wanting. Yet, lately I saw one on whose front a strong ciliary
action was conspicuous : it seemed as if the ciliate surface were on the prone side of the
front. The species, moreover, is furnished with protrusile auricles for augmented loco-
motion, like Notommata proper. I have not myself seen these, indeed ; but the fact rests
on ample evidence. Dr. Hudson was assured by Mr. Brayley, the Secretary of the Bristol
Microscopical Society, that he had seen a Taphrocarnpci " put out very small auricles
from the head, and swim with a slight vermiform movement." He had made a pen-and-
ink sketch of the creature in both conditions ; which sketch is in my possession, and
represents indubitably T. annulosa. Miss Saunders, too, a careful observer, writes me
under date of June 10 : " Watching your Taphrocampa annulosa a long time, I saw it
thrust out an ear-like lobe on each side, and swim frantically about in a most headlong
fashion ; but only one of three did this. The processes were not very prominent, but
were quite distinct." This fact affords an interesting link with the present family.

The form of the mastax and trophi, too, though not yet quite satisfactorily defined,
is evidently Notommatous , and seems to resemble the pattern seen in some of the Fur-
adaria, and some of the Rattulidce also, consisting of an incus with a long fulcrum and
a pair of long incurved mallei. The animal can bring the tips of the jaws to the very
front, and nibbles floccose matters with them. An alimentary canal, broad and straight,
with no accessory glands, and with no constriction, runs through the cavity to the cloaca
close to the forked toes. It is usually empty and colourless. At the occiput, behind the
mastax, and almost invariably sharing its motions in contraction and elongation, is a
moderate- sized mass of opaque matter, white by reflected light, and probably chalky.
Like a similar mass in many Notornmatce, with which it is another link, it lies at the
bottom of a wide and deep sac. I had vainly searched for any trace of red pigment in
this mass which might indicate an eye. On one occasion recently, however, I was
examining a specimen under direct sun-light, when there suddenly flashed out from the
opaque mass a spark of radiance, as if from an eye-lens, though I could not discern any
red hue. What represents the ordinary foot and toes is peculiar. It would seem rather
to be a forked tail ; for I have seen, now and then, projecting beneath this, a very
delicate rounded lobe, which is possibly the foot, the cloaca opening between these. Or,
rather, it is the optical expression of the lower half of the cylindrical rectum, of which
the middle of the crescentic fork forms the upper part or ceiling. The intestine can be
traced down to this orifice beneath the fork. The fork, or, if this explanation is correct,
the tail, is formed of two incurved taper, chitinous, clear, sharp spines, together making
a semicircle ; but not separated into toes, nor articulated with the segment that carries
them, and so having no power of motion independent of one another, or of their
segment. True toes would have both.

The animal contracts strongly and continually, like a Notommata ; but the sphere of
the contraction is the space occupied by the alimentary canal, the parts both before and
behind this viscus remaining unaffected, while the parts included contract forcibly, and
both ways, but chiefly from behind forward. In most of its movements it resembles
Chatonotus, crawling sluggishly about the glass, and the masses of sediment.1— P. H.G.]

Length. About ^ inch. Habitat. Pools and ditches : common (P.H.G.).

1 There are two very distinct varieties of the above, well-marked and constant; yet with hardly
sufficient dissimilarity to warrant our separating them as species. The one smaller, with the articula-
tion strong, the lateral projections of dark tissue into each segment clearly seen, the caudal points
short, stout, and straight. This was the form first recognized, is the form above described, and is by
far the more common. The other much larger, the articulation and the interior projections both in-
distinct, often imperceptible; the caudal points long, slender, crescentic, wider at their bases, and
making together a regular semicircle. In this variety, an excellent observation which I obtained
showed the mastax, mallei, and incus, almost exactly of the same familiar pattern as in Notommata
aurita (Phil. Trans. 1856, pi. xvi. figs. 16-21).

1

VOL. II.

18 THE ROTIFERA.

T. SAUNDEBSI2E, GoSSC, Sp. 110V.

(PL XVII. fig. 11.)

Taphrocampa Sawidersice . . Hudson, J. Roy. Micr. Soc. 2 Ser. vol. v. 1885, p. 614, pi. xii.

[SP. CH. Body lengthened, fusiform, annulate; brain clear; a decurved frontal
hood; two eyes (?) ; a distinct tail; foot and furcate toes of normal form.

Many examples of this form occurred to my observation in the floccose sediment of
water, very rich in Rotiferous life, which was sent me by Miss Saunders of Cheltenham,
in May 1885, dipped from a tank which she had used as a preserve of living Rotifer a.
But Dr. Hudson had observed the same species in water from Birmingham, in July
1884 ; and had prepared a notice of it for the " Journ. Roy. Mic. Soc." The publication
was delayed, however, through press of matter, till the following spring. It is a very
distinct species, less abnormal than T. annulosa, more manifestly Notommatous in its
affinities.

The body is divided into well-marked rings, about seven or eight, not so numerous
as in annulosa ; each of which rises to what seems a sharp edge ; but momentary
glimpses, which one has as it turns around the weeds, show a number (not only four) of
conical points (perhaps about eight in the dorsal half) in the transverse section (as at
fig. 116), the expression of as many series of conical elevations running down the whole
(possibly dorsal and lateral) surface. The head is rather large, and sub-globose (fig. 11),
and seems permanent in outline ; as the restless animal twists and turns itself about con-
stantly, causing much change of diameter, the head remaining undiminished, the neck
(so to speak) becomes conspicuously slender, to be filled up by the next contraction, in
an instant. Very frequent retractation of the hind parts towards the head occurs. There
is a marked diminution in these parts, the ultimate segment bearing two moderately
short diverging toes ; the penult or antepenult segment sending forth a distinct conical
projection, which follows the general direction of the body, and may be called a tail,
with more breadth than depth, much as in Notomm. tripus, N. pilarius, and others
(fig. 11a). The front of the head bears a projection, which, on a lateral view (fig. 11a),
looks like a proboscis, and often like a sharp hook, bent forward and downward ; yet I
think it has considerable width, and Dr. Hudson has found it to be a broad arched
hood. Just behind this organ, and so on the very front of the globose head, are a
pair of minute colourless globules, quite conspicuous in all aspects, wbich may be
eye-spots. The mastax consists of two stout, curved, pointed teeth, capable of being
widely expanded and closed, like the blades of scissors (fig. 11) ; these appear based on
an oblong transparent body, probably the muscular bulb requisite for motion. The
points can be brought to the edge of the front.1 The front is oblique ; it is composed
of several fleshy eminences, each bearing a crown of cilia, whose vibrations I have
distinctly seen, though they do not appear to constitute a disk or rota. The animal's
motion in the free water, a smooth and rather swift gliding, is doubtless produced by
these frontal cilia. Accurate observation, with the high powers required by its minute-
ness, is very difficult from its incessant restlessness ; as it glides througb the open, it
is constantly contracting and extending the body ; at the nearest atom of sediment it
pauses, but instantly throws itself into rapid contortions. A long stomach, capable of
much width where it proceeds from the mastax, reaches to the cloaca under the tail,
while a large ovary occupies the ventral region. The body is transparent, more or
less tinged with yellow. The stomach usually contains particles of dark food, sufficient
sometimes to impart a blackish hue to the body ; while the entire venter may be filled
with a dark egg.

I have honoured this species with the name of Miss Saunders of Cheltenbam — from

1 These seem to be the blades of an incus (of the pattern Fig. 21 of my memoir in Phil. Trans.
185R, pi. xvi.) ; flip mallei appnrently quite aborted.

1 —

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NOTOMMATAD/E. 10

whom I have received many specimens — a lady, who, for many years, has given intelli-
gent attention to this class of animals, and who has aided me very effectively in my
researches. — P.H.G.] l

Length, T^ to ^ inch. Habitat. Pools near Birmingham (C.T.H.) ; Cheltenham
(P.H.G.): not rare.

Genus PLEUROTROCHA, Ehrenberg.

GEN. CH. "No eyes; mallei one-toothed; foot furcate" (Ehr.).

[There seems nothing very obvious to distinguish this genus from Notommata, but
the lack of eyes, both cervical and frontal ; and characters that are merely negative are
always somewhat unsatisfactory. The form seems scarcely to have attracted attention
in Britain. In the close, almost daily, study of the class, which I pursued some thirty
years ago, it never occurred to my notice ; no example of it appears in Dr. Collins's
richly-stored book of drawings ; Dr. Hudson has no record of it ; and in my recent resump-
tion of the study, extending over the last year and more, I have met with but three
examples ; which, with more or less certainty, I identify with the three recorded species
of Prof. Ehrenberg. Doubtless, by us all, it may possibly have been confounded with
the obscurer species of Notommatadce, and have been overlooked. But yet the common
difficulty of discerning the eye in a restless animalcule is more likely to cause a Notom-
mata to be taken for a Pleurotrocha, than a Pleurotrocha for a Notommata. — P.H.G.]

P. consteicta, (?) Ehrenberg.
(PI. XVIII. fig. 3.)

[SP. CH. Toes moderately long, acute, straight

If this is identical with P. constricta, the singular and almost unprecedented illustra-
tion which Prof. Ehrenberg has given us on the testimony of his own eyes, of its preda-
tory instincts, I may cite as adding to it the greatest interest. He has figured the ap-
parently weak and unarmed Pleurotrocha as watching a specimen of the swift and vigorous
Notommata lacinulata ; then, as having seized it ; then, as sucking out its juices ; and
then, as having dropped away the now empty skin. Well may he give it the secondary
title of The Eobber.

I have seen nothing of this in the little delicate creature which I here represent. It
occurred to me in the spring of 1885, and then for so brief a period that I had but just
time to make a drawing of it, which is here reproduced. It is indubitably rare. Ehren-
berg appears to have seen but two examples, one of which was the above warrior of now
historic renown. I had no time for measuring mine, but his length of T^ inch would
well enough agree with my estimate. But, a few months later, I met with a specimen
in water from Dundee represented in fig. 3, which I conclude to be specifically identical
with the above, though there are some slight differences. The front is broader ; and,
though I could not say that auricles were actually protruded, their presence seemed
indicated. (I incline to think the existence of these aids to locomotion more usual in the
class than is generally accredited.) The toes also are more slender and more acute.
It was active and moderately swift, gliding through the clear water ; now and then
suddenly darting a little right or left of its course, and apparently seizing some invisible
prey. The manner of the action could not be mistaken ; it was manifestly predatory.

The mastax was large and conspicuous ; but I could not obtain a look at it suffici-
ently steady to define it. The intestinal canal was ample and filled with dark bistre-

1 In one specimen I observed, on a side view, a long egg-shaped contractile vesicle lying between
the hind end of the stomach and the ventral surface, and terminating in a delicate tube entering the
cloaca. The vesicle filled and emptied every 2A seconds.— C.T.H.

C 2

20 THE ROTIFERA.

brown granular food. The toes are usually held close appressed when the animal
is gliding ; but often expanded. It was lost before I could complete my observation.

This individual was found in Monk Mire Loch near Dundee, in August 1885,
among slender filamentous weed crowded with minute diatoms, making dense masses
of impalpable floccose. The former was from Woolston Pond, Hants. — P.H.G.]

Length, -^¥ inch (?). Habitat. Woolston ; Birmingham ; Dundee (P.H.G.).

P. leptuea (?), Ehrenberg.
(PL XVIII. fig. 4.)

[SP. CH. Toes moderately long, slender, acute, slightly decurved ; face oblique.

This species is of equal rarity, in my experience, with its two congeners ; a single
solitary example alone having occurred to me, and that at about the same time.

The ciliated front is much more prone than I observed in the others, and the mastax
was at one time so thrust forward that the trophi were brought to the very face, as we
see with many of the Notommatce. The outline is gracefully swelling, and tapering be-
hind; and the form and curve of the slender toes are elegant. — P.H.G.]

Length. About TJ-0 inch. Habitat. Woolston Pond (P.H.G.).

P. gibba (?), Ehrenberg.
(PI. XVIII. fig. 5.)

[SP. CH. Short and thick in proportion to its length ; toes moderately long and
broad, nearly straight.

It is with great hesitation that I attach Ehrenberg's name of gibba to this little
species. The general shortness and stoutness of form agree, and, though the lumbar
parts of the body want the plumpness whence he has selected an appellation, this
may be a variable character dependent on repletion of the alimentary canal. My figure
was drawn from life ; but the example was lost before I had completed my observations.
It was in the early spring of 1885 ; but I made no record of the source whence it was
obtained.— P.H.G.]

Length. About 3^ inch : whereas Ehrenberg gives ?\^ inch as the average of his.

Genus NOTOMMATA, Gosse [nee Ehr.).

[GEN. CH. Body not annulose, cylindrical, furnished behind with a projecting
tail ; special organs (auricles) on the head for locomotion, evertile and protrusile ;
brain large, containing opaque chalk-masses ; trophi virgate. There are species in
which one or more of these characters may not be found.

The genus Notommata of Ehrenberg, even as it left his pen, was a heterogenous
mass of dissimilar species. Many naturalists have indicated the need of dividing and
redistributing the unwieldy group ; but none have yet ventured upon the task. I propose
to break it up into three distinct genera. The family AsplanchnoAa. having been already
formed, some species of large size, sacciform body, and hyaline transparency, migrate
thither ; while others of similar appearance may be associated with the Hydatinadce.
These being eliminated, there comes the curious species N. copeus, which Ehrenberg
distinguished by large dimensions, a fusiform body, a distinct tail, and organs of special
sense, projecting from the lumbar regions, as well as from the head. As a number
of others, allied to this form, have been discovei-ed, I form them into a separate group
with the generic appellation of Copeus. Then there is a group of conspicuous species,
marked by auricles, by a more or less distinct tail, and by the brain being unusually

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NOTOMMATADyE. 21

developed, and opaque with chalk deposits. This genus may retain the name of Notom-
viata. There still remain a multitude of species, mostly of small, none of large, size, with
characters mainly negative, yet having much in common with each other, a community
more easily recognized than described ; but having the ciliate face more or less obliquely
prone. These make the genus Proales. The second of these three is characterized above,
and shall still prolong the time-honoured title. It is even now a populous tribe, as
usual with typical groups : yet not unnaturally associated. Its constituent species are
easy of recognition, by three prominent characters, all fairly constant — 1, the tail ; 2, the
auricles ; 3, the opaque brain. The first is moderately conspicuous, and readily dis-
tinguished by being always on the dorsal side of the cloaca, while the foot and toes are
always on the ventral. The second is not always available, being often inactive and
invisible ; but if seen, seen without doubt. The third is the best mark : the opaque
brain-mass, like a vast well-defined black cloud, striking the eye at the first glance,
unmistakably.

The genus is widely distributed in our fresh waters. — P.H.G.]

N. aurita, Ehrenberg.
(PI. XVII. fig. 6.)

Notommata aurita .... Ehrenberg, Die Infus. 1838, p. 430, Taf. Hi. fig. iii.

,, „ . . . . Gosse, Trans. Micr. Soc. Lond. 1852, p. 93, pis. xii. xv.

[SP. CH. Body sub-cylindric, ventricose ; brain opaque ; head toide, furnished with
evertile auricles ; tail minxtie.

Of this moderately large species, of elaborate organization, and of frequent occur-
rence, the anatomy has been given with so much detail, by myself (loc. cit. supra), that
only a very succinct account is needful here. Its opaque brain-mass, looking like a great
black ball in the neck, connected by a tube with the front, renders it conspicuous as
soon as it is seen ; and when it glides through the clear water, the sudden quickening of
its speed, as it everts the great ciliate hemispheres from its two cheeks is hardly less
notable.1 The foot consists of two very short and small joints, telescopically infolded ;
bearing two furcate toes, acute cones, also short and small. — P.H.G.]

Length, ^v to T^ inch. Habitat. Fresh waters. Common everywhere (P.H.G.).

N. ansata, Ehrenberg.
(PI. XVII. fig. 3.)

[SP. CH. Closely resembling N. aurita inform and structure, bat smaller ; the brain
not opaque ; the toes long.

The examples of this species that I have observed I could distinguish from the pre-
ceding only by the points mentioned above. Perhaps it is slightly more slender, more
cylindrical. Ehrenberg gives no appreciable diagnosis between the two forms ; nor can
his figures be distinguished, save by the lack of opacity on the brain of ansata. The
length of the toes is, however, a good mark, and readily observed.

A few specimens have occurred to me in water sent me by Dr. Collins from Berkshire,
containing aquatic moss. They moved in the clear, with great impetuosity, driving
round and round, and turning on their course, with no apparent aim. One made its
way just within the edge of a moss-leaf, where it worked for itself a little hollow, in
which it remained several hours, incessantly turning round and round, or to and fro, as
fast as it could move, without a moment's intermission. In this example the alimen-

1 Herr Eckstein (Sieb. u. KOll. Zeits. 1883, p. 361) describes in this, as in many other Rotifera,
specks of crimson pigment near the front, each in connection with a setigerous sense-organ. He con-
cludes these to be secondary eyes. I have myself never detected them ; neither has Dr. Hudson, nor

Dr. Plate.

22 THE ROTIFERA.

tary canal was large, not visibly separated, and filled with food of a rich dark-brown
hue. The toes are long, slender, acute, and slightly decurved. The auricles, which
were freely protruded, are rather small. — P.H.G.]

Length, ^^ inch. Habitat. Sandhurst, Berks ; Epping Forest ; Woolston, Hants
(P.H.G.) ; pools : rare.

N. cyrtopus, Gosse, sp. nov.
(PL XVII. fig. 7.)

[SP. CH. In form resembling N. aurita, but very much smaller, and more slender
in proportion ; brain intensely opaque ; no visible auricles; toes long, decurved.

This little species I had known from a single specimen just dead, in August 1851,
which I found in water from Widcombe Pond, Bath. 1 had never met with it again
till June 1885, when I found a second in water from Woolston, and subsequently many,
from many localities. It much resembles N. aurita ; but is smaller ; and the toes are
slender and decurved. A pair of colourless specks, like air-globules, are in its front,
which may be eyes, and a large brain, which carries at its hinder end an aggregation of
opaque matter forming a collection of round cells. This, by refracted light, is intensely
black, as in aurita, and renders the species very conspicuous, reaching far down into the
body-cavity. The mastax is normal ; the alimentary canal also large, not visibly
divided ; ovary and contractile vesicle as ordinary.

In manners it is particularly sluggish, scarcely changing its place, though in con-
stant motion. It roots and nibbles among the floccose sediment, and affects conceal-
ment, seeking the shelter of the thin integument of decaying Nitella, and such-like
plants, under which it hides ; and, if it creep out for an instant, presently betaking
itself to its refuge again, where it twists and turns restlessly on its centre. — P.H.G.]

Length. About TiTT inch. Habitat. Bath ; Woolston ; Sandhurst, Berks ; Epping
Forest; Cheltenham (P.H.G.) ; pools: not common.

N. tkipus, Ehrenberg (nee Leydig.)
(PI. XVII. fig. 4.)

[SP. CH. Body thick, arched dorsally, diminished behind to a conspicuous tail,
and furcate toes; tail equal in length to the toes; brain opaque; auricles small,
slender.

I know this animal by a single specimen, which I found among Myriophyllum in a
tank in my own garden, near London, in 1854. It has never occurred to me again ;
and I do not feel quite certain that it is the tripus of Ehrenberg. The body is marked
by several strong folds of the skin. Viewed from the side it is arched, and the ventral
outline is concave ; but the ovary was undeveloped, which fact might modify the form.
The frontal cilia are set on a large ovate area looking ventrally (fig. 4), so that
ordinarily the front appears rounded and free from cilia. Occasionally, however, the
front is elevated and expanded somewhat angularly, and an auricle is thrust out on
each side, of somewhat serpentine outline, set on its anterior edge with vibratile cilia,
whose effect is manifest in accelerated motion. The brain runs down to a long obtuse
point in the occiput, whose extremity, in my example, was occupied (fig. 4a) with some
irregular granules of opaque matter ; seated on the end of which was a large pear-
Bhaped red eye. The posterior extremity of the trunk runs out into a prominent tail, a
tapering cone, with alternate constrictions and swellings. Beneath this are the furcate
toes ; and as the tail is of the same length as these, and diverges at a like angle, forming
three angles of a triangle, the animal well deserves its specific name. — P.H.G.]

Length, Tf5 inch. Habitat. A garden pan, near London (P.H.G.).

NOTOMMATADiE. 23

N. pilarius, Gosse, sp. nov.

(PL XVII. fig. 5.)

Nutommata tripus .... Leytlig, Ucb. d. Bau d. Rdderth. p. 37. Taf. iii. fig. 28.

[SP. CH. Body {viewed dor sally) rhomboidal in outline, sub-truncate at both ends ;
head broad, with great globose auricles ; brain pointed, filled to a greater or less extent
with opaque matter ; tail and toes as in N. tripus.

This little creature has much likeness to the preceding, from which, however, it
sufficiently differs in the trapeziform outline, tapering from the middle to the foot ; in
the size and form of the auricles, which are very large, hyaline, and round, more than
a semi-globe being exposed ; in the conspicuous eye ; in the singular overarching of the
edges of the dorsal region, like the carapace of an Oniscus. Mr. Perty mentions this
peculiarity in his N. onisciformis ; yet a glance at his figure proves that the two species
are not identical. The singular effect produced when the little creature suddenly pushes
out, and as suddenly withdraws, its frontal balls of glass, reminded me of the ancient
pilarii, or jugglers with balls, and suggested a specific name.

The great transverse diameter of the body is remarkable. The rhomboidal outline
has much of the appearance of a lorica ; for it is constant, and the viscera within take
the form of great sacculate lobes, varying, and more or less receding, from this outline.
The brain is a large, perfectly defined opaque mass stretching almost wholly across the
head.1 There seems to be a very minute crimson eye-speck in the centre of the front,
discernible with difficulty. The contractile vesicle is very large ; its period of discharge
was just two minutes. The globular auricles are exserted only at uncertain intervals,
as when the animal wishes to swim swiftly. We may watch one by the hour, creeping
up and down the stems, nibbling ever as it goes, or even now and then slowly gliding
through the clear water ; yet not once see the crystal balls thrust out by the little
juggler. Yet is he unmistakable, in whatever condition, when once familiarly known ;
and a very pretty, attractive little fellow he is.

I first became cognizant of it in February 1855, when examining a tangle of conferva
and Nitella in one of my window-reservoirs at Torquay. But I have since met with it
on many occasions and in many waters. It is moderately lively, actively grubbing
about the vegetation and sediment, now and then swimming across the open spaces,
generally with little speed or energy, till the great glassy globes are set to work. The
interior structure calls for no special notice. — P.H.G.]

Length, ^ inch; breadth, ^ inch. Habitat. Woolston Pond : common (P.H.G.).

N. foecipata, Ehrenberg.
(PI. XVIII. fig. 1.)

Notommata forcipata . . . Ehrenberg, Die Infus. 1838, p. 428, Taf. li. fig. 5.

[SP. CH. Form lengthened, saccate, large in front, tapering to a small foot, and
very minute furcate toes; occipital end of \iT&m semi-opaque, a small inverted pyramid ;
eye a broad transverse lens.

This is an active, graceful, attractive animal, somewhat sack- or purse-like, slender
behind, but enlarged towards the head, which is in constant contraction. The front is
obtuse in the dorsal and lateral aspects ; the face is slightly prone. Behind a large
mastax of normal jaws, very protrusile, an ample brain descends into the occiput,
whose pyramidal tip, for a small space, is occupied by a well-defined granulation of clear
brown tissue, not white by reflected light, and so not cretaceous ; on the frontal end of
which is seated a broad, somewhat square eye of pigment darkly red. Two' small ciliate

1 From this transverse development of the opaque chalk-masses, I infer that Dv. Le.jdig's tripus is
this species. .

24 THE ROTIFERA.

auricles can, at will, be protruded from the head, and I believe there is a small appressed
antenna. The cloaca is very manifest, overhung by a minute wart-like projection. Then
the foot tapers rapidly, ending in small, sometimes very minute, furcate toes, which
about mid-length lessen abruptly, leaving a marked shoulder (fig. lb).

I am indebted to Mr. Bolton for many specimens on repeated occasions. — P.H.G.]
Length, ^ inch. Habitat. A ditch in Sutton Park, Birmingham (P.H.G.).

N. beachyota, Ehrenberg.
(PL XVII. fig. 1.)
Notommata brachyota . . . Ehrenberg, Die Infus. 1838, p. 435, Taf. li. fig. 3.

[SP. CH. Brain clear ; body fusiform ; auricles small; foot invisible; toes minute;
no tail.

Outline rounded and plump, stout in the middle, tapering to each end. The face is
obliquely prone ; a pair of very small auricles are thrust out from the sides of the head,
occasionally, when pushing between stalks of Nitella, and not only wdien swimming.
Fore and hind extremities hyaline, but corrugated longitudinally. Mastax large and
round ; mallei strong, of several teeth, on a long-stalked incus, much on the pattern seen
in N. aurita, which worked vigorously and perseveringly, boring its way into a Nitella
stalk, and nibbling till it had cleared a great space of its green pulp-cells. The eye-spot
is moderately large, of full crimson. This, in an instant's good view, I discerned to be
a regular globe, of which only the hinder half was red, the anterior half being quite
colourless ; the two halves being distinctly divided by a clean line (fig. lb). The clear
half was doubtless a crystalline lens of very perfect form and of powerful magnification.
This eye is seated near the end of a long occipital brain. I could detect no dark spot,
on each side of the eye, as figured by Ehrenberg ; but have little doubt of the species.
A great sacculate stomach comes up, as a brown granular mass, to the mastax, furnished
with the usual pair of ear-like gastric glands. It reaches, without any manifest division,
nearly to the clear space around the base of the foot ; a contractile vesicle intervening.
The foot is scarcely distinguishable, the pair of very minute conical toes apparently
emerging from the rounded end of the body. No projection could be called a tail. It
was not till I had watched the creature a considerable time, actively engaged, that I
suspected the head to be other than simple in outline. Then, as it was swimming
smoothly, I noticed its motion suddenly augmented ; and at the same instant I saw that
two minute clear semi-globes were extruded, but only for a few moments ; then with-
drawn, and no trace left. The absence of these organs, therefore, must not confidently be
inferred from the non-observation of them, particularly in species inadequately observed.
The plump body seems very soft, compressible, and flexible ; the integument thin,
elastic, and yielding. The animal is eager, impatient, persevering, pushing everywhere.
It really seemed to have some sense of locality, which its perfectly -formed eye might
assist. For though it often strayed to a considerable distance, beyond many stalks, it
invariably returned, and sought out its feeding-ground within the Nitella. I was called
away ; but, after nearly two hours, there he was, pegging away at the very same hole ! —
P.H.G.]

Length, T^ inch. Habitat. Woolston Pond : rare (P.H.G.).

N. saccigera, Ehrenberg.
(PI. XVII. fig. 2.)
Notommata saccigera . . . Ehrenberg, Die In/us. 1838, p. 434, Taf. 1. fig. 8.

[SP. CH. Slender, obtusely pointed at both ends ; face prone, greatly lengthened,
ending with a prominent chin; foot and toes small.

The form is unneually thin from side to Bide, oom pared with the length, widening

NOTOMMATADiE. 25

sensibly at three -fourths from the head, and thence, more or less abruptly, diminish-
ing. It is rather deeper (viewed laterally, fig. 2a), the dorsal outline rising to about
the middle, thence falling to the tail. The ventral line is nearly straight, only that the
ciliated face, almost quite prone, extends fully one-third of the length, and there forms
a sort of projecting chin. The outline of this part is, however, very flexible and
versatile. The dorsum terminates in a minute conical tubercle, beneath which the
cloaca opens ; so that it is a true tail. Below this is a very short and inconspicuous foot,
and two minute furcate conical toes. The front is rounded, and can evolve two small
hemispherical auricles, very observable, because they are freely protruded, even when
the animal is not swimming, but pushing its way among the tangled algas. The mastax
is ample, and the trophi of the normal pattern ; behind, the brain descends low into the
occiput, and carries a dark red eye near the middle of the sac. I have not seen this
sac so pyriform as Prof. Ehrenberg has figured it. It is, in general, turbid toward the
lower part, and sometimes quite opaque with angular chalk-masses. A large stomach,
and intestine, with gastric glands ; a wide ovary ; indications of a vascular or branchial
system, and a small contractile vesicle, are all normal, and require no remark. The
animal is usually tinged with an olive-brown hue, especially in the abdominal viscera.

Both the form and manners of this species strike the observer, at once, as unusual.
It swims almost constantly ; and affects the surface when in freedom. It makes a
smooth rapid course, devious, and apparently objectless ; probably, however, governed
by aims which we cannot appreciate. For it frequently makes little darts and jumps
as it goes, with a sensible snap of the jaws, as if it took invisible prey. A number of
examples occurred in water collected by Mr. Bolton from a ditch in Sutton Park,
Birmingham, and specially marked " surface."

I presume this to be the N. saccigera of Ehrenberg, from the general form, the long
pointed head, the long prone ciliated face, the short toes and shorter foot. Yet he has
not noticed the auricles, nor the opacity of the brain. The former, however, are re-
tractile ; and the latter varies much. — P.H.G.]

Length, -^ to y^ inch. Habitat. Birmingham (P.H.G.).

N. naias, Ehrenberg.
(PI. XVIH. fig. 2.)
Notommata najas .... Ehrenberg, Die In/us. p. 429, Taf. Hi. fig. 2.

[SP. CH. Of large size, fusiform; brain clear; head broad, obscurely auricled ;
foot long ; toes short, pointed.

This is a large and imposing form, evidently approaching the genus Copeus, yet
showing no visible sense-organs projecting from the trunk. Its claim to a place in the
present genus is slight, for the brain has no opacity, there is no tail, and the auricles,
if present, are small, and appear to be permanent, as globose ciliated knobs, not evertile.
Yet there is no prone face, and the general appearance and structure show affinity with
these higher forms. The body is nearly cylindric, somewhat ventricose ; the head nearly
of the same width, divided into several broad but shallow lobes, the cilia on which make
independent whorls. The mastax is ample, the jaws of the normal pattern. A brain
descending into the occiput, and carrying a transversely ovate dark-red eye near its
middle,1 is flanked by a shorter sac on each side ;— another point of resemblance to
Copeus. A small antenna projects from the occiput. Several annular folds of the skin
— false joints — encircle the body, three in the anterior half, and one distinguishing the
trunk from the foot. The latter consists of three well-marked joints rapidly diminishing,
terminated by two forked acute toes which are rather short. Two pyriform mucus-
glands run through the foot from the toes. The branchial system is well displayed :

1 Eckstein figures two tentacular brushes of setae on the front, -with a crimson eye-speck at the
kae6 of each.

26 THE EOTIFEKA.

a rather thick ribbon, slack, but scarcely convolute, passes down each side, apparently
lost in (perhaps beneath) the lateral brain-sac, bearing sundry vibratile tags, and merging
into a small contractile vesicle. The alimentary canal and the ovary were both amply
sacculate in such specimens as I have examined.

I first met with this fine species on the dichotomous leaves of the Water Crowfoot,
growing in a sunken pan in my own garden near London, in the summer of 1849. It
was vigorous and active, swimming rapidly through the water, with a headlong, pushing
violence, or fixing itself slightly by its toes, and thrusting about its head in all directions.
It seemed fierce and voracious ; for, though I did not actually see it swallow food, it
several times munched with apparent greediness the side of a large Rotifer, returning
to the attack, and seeming to bite ferociously. The Rotifer, if not materially injured,
was thoroughly alarmed. I have since met with the species, but very rarely.- — P.H.G.]

Length, .',, inch. Habitat. Near London (P.H.G.) ; Sandhurst, Berks (Dr. Collins).

N. tuba, Ehrenberg.
(PI. XVII. fig. 8.)
Notommata tuba .... Ehrenberg, Die Infus. 1838, p. 433, Taf. xlix. fig. 3.

[HP. CH. Body trumpet-shaped; brain clear; a cervical eye ; toes furcate, conical,
minute.

My right to mention this species rests on a pencil-sketch which I made from life,
many years ago, and which I still possess, but without sufficient detail to warrant de-
scription, and of which I have preserved no accompanying notes. In Dr. Collins's Note-
book, which is kindly entrusted to me, there is a pencil-drawing to which he has
attached this name ; but this also is unaccompanied by any note, except the date 18GG.

From Ehrenberg's figs. I conjecture that its affinities are with Hydatina, the
cervical eye notwithstanding. — P.H.G.]

N. lacinulata, Ehrenberg.
(PI. XVII. fig. 9.)
Notommata lacinulata . . . Ehrenberg, Die Infus. p. -128, Taf. li. fig. 4.

[SP. CH. Small; body cylindrical, thick, broadly truncate; brain clear; foot
short; toes long ; trophi forcipate; incus much developed, hemispheric ; mallei very
small.

This tiny, sprightly atom is of pleasing form ; vertically viewed, it is a very regular
oval in outline, the head dilated, archedly truncate, and of a width, when the hemi-
spheric auricles are out, equal to that of the body ; while at the other end the acute
divergent toes, set on a very short foot, make an elegant finish to the form. Laterally
viewed, the diameter is nearly the same, the fore and hind extremities nearly perpen-
dicular and nearly equal, the dorsal line arched, the ventral straight, the foot and toes
set-on at the end of the latter.

The mastax is very large and the trophi peculiar. The incus is remarkably developed,
the fulcrum stout and long, the rami forming, when closed, a transparent hemisphere,
" so as to resemble, when viewed obliquely from above, a globe of glass standing on a
pedestal." (See my mem. " On Manduc. Org." in " Phil. Trans." 1855, p. 432, pi. xvii.
figs. 32-34.) The tips of the rami are habitually projected in greater or less degree
from the front, so that there is no buccal funnel proper. Behind the mastax there is
a large dilated pale-red eye, seated near the middle of a moderate brain, which carries
no opaque chalk-granules.1 The alimentary canal is ample, usually filled with food of a
rich yellow-brown hue, which adds much to the attractiveness of the animal.

1 Eckstein finds his usual two red specks at the ciliate front, in addition to the large red cy« at
the bottom of the brain ; but he doee not associate them here with tentacular seta.

NOTOMMATAD.E. 27

I first found this species in various waters around London in 18-49 ; and have been
familiar with it ever since. Wherever filamentous sub-aquatic vegetation grows, it is
sure to be abundant. A restless little creature, it ranges among the leaves with
incessant activity, now pushing its way through some narrow aperture, using its toes as
points of resistance ; now pausing to nibble among the decaying algaa ; now scuttling off,
by means of its ciliary paddles, to another quarter. The toes, when used as a rest, are
often stretched asunder as wide as they will bear. In general a free rover through its
tiny ocean, it yet occasionally, though rarely, anchors by the mucous excretion from its
toes.1 These moorings it cannot always loosen when it wishes again to leave port. I
have been amused to see one swiftly pursuing its course, dragging after it, at some half
dozen times its own length, a bit of floccose sediment attached by an invisible thread.
It seemed as it were pursued by an eager persevering enemy through all its windings,
which enemy at length proved to be nothing but a bit of inanimate dirt. — P.H.G.]

Length, -^^ inch ; of toes alone, T^ys hich ; of egg, Ti^ inch. Habitat. Every-
where in still fresh waters of aquatic vegetation : abundant (P.H.G. ; C.T.H.).

N. collaris (?), Ehrenberg.
(PI. XVI. fig. 6.)

Nolommata collaris . . . Ehrenberg, Die Infus. 1838, p. 428, Taf. lii. fig. 1.

SP. CH. Body cylindrical, tapering to both extremities ; ciliated face very long
and oblique, projecting far out from the ventral surface just below the mastax ; head
tvith small evertile auricles ; neck large and swollen ; nervous ganglion tri-partitc,
semi-opaque at the free border ; tail distinct; toes minute.

This Motif eron (probably Ehrenberg's N. collaris) resembles Gopeus Cerberus ; and,
like it, might almost be placed either in the genus Gopeus or Notommata. I have only
seen one specimen, which from its size (two-thirds of that given by Ehrenberg) was, I
think, a young one. It can at once be distinguished from Gopeus Cerberus by its singular
ciliated face (which, on a side view [fig. 6a], gives the head quite a triangular outline),
and by its swollen neck. My impression, when I drew fig. 6, was that this swollen
condition of the neck was due to the presence of two unusually large and clear gastric
glands, which inclosed the mastax between them, on one side, and pushed out the
surface of the body on the other. But on referring to Ehrenberg's figure (loc. cit.), I
found that he had drawn the gastric glands as small round bodies, decidedly below the
neck. Unfortunately I lost my specimen before I had an opportunity of revising my
sketch. The front of the head carries two low ciliated projections, one above each
auricle ; the auricles themselves are decidedly larger than those of Gopeus Cerberus.

The nervous ganglion consists of three distinct parts : a broad upper portion filling
up the head ; a narrower truncate part, projecting downwards to the top of the mastax ;
and a long flask- shaped body, the lower end of which, at times, reaches almost to the
bottom of the mastax. There is a splendid crimson eye, and a very well developed
vascular system. The rest of the internal structure requires no notice.

It is a sluggish creature, loving to creep among the algae ; but at times it will pro-
trude its auricles and swim off into the open, giving one, as it turns, a good view of the
peaked gutter, in which the ciliated face projects in front of the mastax, just as in
Copeus spicatus and C. labiatus. Although mine was but a young specimen, still it was
a handsome Eotiferon ; and a full-grown one of ^ inch (Ehr. loc. cit.) would certainly
be one of the largest and most striking of the Notommata. I am indebted to Mr.
Thomas Bolton for this rare animal.

Length. My specimen, ^ inch (Ehrenberg's, -^ inch). Habitat. In water from
Sutton Park (T.B.) : rare.

1 I once saw half a dozen of these lively creatures, all in a row, attached by their toes to a delicate
green filament, and whirling round it like gymnasts on the horizontal bar.— C.T.H.

28 THE ROTIFERA.

Genus COPEUS, Gosse.

[GEN. CH. Usually of large size, ventricose behind the middle, furnished with
organs of sense ' in tlie lumbar regions ; brain usually threefold ; body tailed.

The type of this natural group is, as already observed, Notommata copeus, of Prof.
Ehrenberg, which I propose to honour with his own name, Copeus Ehrenbergii. As I
have myself found several other species closely allied to this, yet quite distinct, in a very
brief period, and in one locality, it is probable that future research may considerably
augment their number.

The feature which peculiarly marks the genus is the existence of organs, doubtless of
some unknown sense, not only in the vicinity of the great brain (where their presence
is quite normal), but in the lumbar region of the trunk, far from the brain, where it seems
strange to find them, and where the form and conditions of the surrounding parts
seem to preclude their advantageous exercise. This, however, is but the expression of
our ignorance.

In many cases there is some extraordinary development of the ciliary system, in the
shape of wide expansions of the face, or remarkable forms of the auricles, lately
described; and sometimes the tail takes unusual shape and size. The skin, in several
cases, has the power of secreting a dense mucus, insoluble in water, so as to constitute
a thick coherent mantle for the animal, in which extraneous matters are entangled ; and
the production and retention of this seem to be subject to the animal's will.

It is perhaps in harmony with this specialty of sense-development that the brain itself
is generally of great size, and of complex form ; for there is often, in addition to the central
sac, which is sometimes pyriform with a tubular stalk, a secondary sac on each side.

The species are for the most part of large dimensions, heavy and unwieldy in motion,
and vegetable feeders. — P.H.G.]

C. labiatus, Gosse, sp. nov.
(PL XVI. fig. 1.)

Noionwiata centrum . . . Leydig, Ueb. d. Ban d. Riiderth. p. 33. Taf. iii. fig. 21.

[SP. CH. Lumbar regions furnished on each side with a stout seta (apparently
single) projecting horizontally ; tail pointed; chin projected into a long, horizontal,
channelled, ciliated process, very versatile ; brain threefold.

This noble species I at first thought to be the N. copeus of Ehrenberg. Yet the
dissimilar structure of the head presently showed that it is quite distinct.2 There is no
trace of the great lateral telegraph-like arms which project from the head in C. Ehren-
bergii ; what answer to the auricles being small ciliate channels, bent-over at their ends,
into which the front is produced on each side. These cilia are continued along the frontal
margin : while from the lower part of the face projects horizontally forward a very
moveable lip in the form of a great fold of transparent flesh, of which the two sides,
sloping outward, make a channel as long as the width of the head, deep at the base, but
coming to a point, its edges, which fold over toward the hollow (see fig. la), being fringed
with locomotive cilia. From the occiput projects, pointing outward and forward, a stout
antenna, of outline swelling to about seven-eighths of its height, then diminishing with
an angle, to a truncate end, whence issues a brush of divergent setae, evidently connected
by internal nerve-threads with the brain beneath. The ciliation of the face reaches far
below the lip on the ventral surface. The longitudinal muscles are very numerous and
conspicuous. Immediately behind the front is a row of (at least) four oval translucent
masses, which may be compared with the globose masses in the head of Hydatina

1 An account of these " sense-organs," " antennae," or " tentacles," in the whole Class, will be given
at the end of Part VI.— C.T.H.

2 Dr. Leydig, who (loc. cit.) has well described and figured this species, assumes that it is the
N. centrura of Ehrenberg. But so practised an observer could not have overlooked the great lip, if
lalialui had indeed been before him.

NOTOMMATAD/E. 29

senta and Euchlanis dejlexa ; these appear to be quite independent of the great brain
proper. This is here triple ; the middle lobe is pear-shaped, depending considerably
below the mastax, with a long slender neck, quite pellucid, having a great red eye
seated near its mid-length ; on each side is a similar but shorter lobe. The trophi are
of the pattern in N. aurita : each uncus is somewhat slender, and seems to comprise but
two fingers ; but, from the opacity of the parts, I am not certain. Under pressure,
there seemed to be five, blade-shaped, and closely parallel. A very long oesophagus
leads to a wide and ample alimentary canal, divided by a sensible constriction into
stomach and intestine, even when there is no diminution in their common outline. But
this condition I saw rather suddenly much altered ; so that the constriction was made
as manifest as if a cord had been drawn tightly round. Both stomach and intestine
were, in all specimens that I have seen, moderately full of dark yellow-brown granular
food, interspersed with orange-coloured oil-globules, brilliantly refractive, most thickly
at the pyloric end. The alimentary canal, when moderately filled with food, has a very
peculiar appearance, as if divided by constrictions, both transverse and longitudinal,
into squares. This is not accidental, but characteristic, being seen in every example
that has occurred to me, and distinguishing the species from all its congeners. A pair
of ovate, colourless gastric glands are seated on the two shoulders of the stomach.
The contractile vesicle is large ; the branchiae take the form of two very long, and very
slender bags, transparent, but much corrugated, rather than of convoluted cords. I
counted three vibratile tags, which happened to be all on the same side : one level
with the eye, one with the lumbar seta, and one intermediate. The ovary appeared
normal. The fusiform body ends in a well-marked tail, stiff, transparent, tapering to
a point, but diminishing abruptly in the middle, forming a distinct shoulder there.
Through it runs a pair of chain-like glands, resembling those in the toes, supposed to
be mucous. A foot of two joints carries a pair of straight, short, conical acute toes.

The manners of this striking creature were rather sluggish, though it moved and
turned and twisted about restlessly. I did not see it swim. I had an interesting
observation of the character of its food, and of its mode of feeding. The water was
much stocked with the finer desmids and diatoms, — great Closteriums, Euastrums,
Cosmariums, and the like. I caught my Copeus eating a great Epithemia turgida. He
had evidently only just seized it with his protruded jaws, and had drawn one end of the
desmid into his mouth, and was vigorously biting it. After a while, the frustule was
pierced, as was seen by the cloud of dark granules that rushed down the mastax. All
the contents were quickly sucked-in, till the shell was as empty and clear as a glass
vessel ; to the manifest increase of the dark contents of the alimentary canal. Then it
was contemptuously thrown away. Another had partly gnawed through a slender fila-
ment of conferva, and had extracted, and was still extracting, the green granules from
its interior, just at that part. Afterward I saw it devouring a small crescentic
Closterium. This it ate up bodily ; and it occupied considerable time, even after the
desmid was within the buccal funnel, and the end within its jaws. Thus it appears
that this large species is a true vegetarian in diet. I have seen several more, all from
a ditch in Sutton Park, Birmingham. All agree in these characteristic details. Each
one has been quite clean, and totally devoid of any gelatinous covering.— P.H.G.]
Length, ?V inch ; width, T4g- inch. Hab.tat. Birmingham (T.B.).

C. spicatus, Hudson.
(PL XVI. fig. 2.)
Notommata spicata . Hudson, J. Roy. Micr. Soc. 2 Ser. vol. v. 1885, p. 612, pi. xii. fig. 5.

[SP, CH. Lumbar regions furnished with tubules, setigerous at their extremities ;
two occipital antennse ; brain threefold; tail saccate.

In this species we see two pairs of what we may call tentacles, of consiniilar

00 THE ROTIFEEA.

structure : the one pair (the ordinary antenna) seated on the occiput, the other on the
hinder part of the trunk, one on each side. Each tentacle consists of a tubular column,
which has a thickened extremity, whence issues, in the anterior pair, a brush of
divergent setae ; in the posterior, a single seta ; all of great length and tenuity. The
lumbar tubules are much more slender than the occipital, but are twice as long ; and
the increase to the terminal knob is much more gradual.

The general form is sub-cylindrical, becoming more ventricose at the hinder part,
then abruptly diminishing. But this form is subject to constant alteration, as the
animal is ever lengthening or shortening, swelling one point, and contracting another.
A very curious appearance is presented by the two sides at intervals. There is, near
the middle of each side, a portion of the outline, which is now and then thrown into
folds, — not constrictions of a rounded saccate body, as usual, but presenting the exact
appearance of a single thin tissue, the edge of which is thrown into sharp, minute, and
close-set wrinkles, like those of a frill of crimped muslin. The appearance is very fre-
quent, seldom lasting more than a minute or two : not peculiar to one individual, but
common and characteristic. I cannot explain it. The body is contracted into a true
tail, which is of a thick sub-cubical form, corrugated with strong folds of the skin, like
that of C. pachyurus, presently to be described, but smaller. Below this is a small foot,
bearing a pair of furcate toes, short, taper, and drawn out to excessively slender points,
often slightly incurved, the flexure varying in different examples. The frontal cilia ap-
pear to be seated on slight eminences. The face projects into a channelled protrusile
lip, whose edges are ciliated ; agreeing both in shape and structure with the like organ
in C. labiatus, but not nearly so large (figs. 2a, 2b). The brain is 3-lobed, composed of
three pyriform ovate sacs ; the outer two clear, the middle one shorter, and turbid or
almost opaque, with a broad red eye lying transversely across its upper part, in shape
like a shallow lens. The trophi are large and distinct, of the form seen in Notovi.
aurita. A long oesophagus leads to an ample alimentary canal, on which are seated a
pair of kidney-shaped gastric glands. In the specimen which I have delineated (and I
have observed it in others), the alimentai'y canal formed a great bag, one side of which
was smooth and expanded, a most delicate transparent tissue, enclosing many small
diatoms and other alga? ; while the other half was thrown into close longitudinal
wrinkles. Within it were four or five oil-globules of brilliant orange-hue, varying in
size, the light refracted through which made very attractively beautiful objects, as the
focus was ever and anon changed. The ovary takes the form of a long and slender
band, full of clear embryonic vesicles, passing in a sigmoid curve from near the gastric
glands to the bottom of the cavity. At its hinder extremity was an ephippial egg, covered
with transparent spines, broad-based, much curved, much like the prickles of a rose, of
whose development Dr. Hudson has given an interesting account [loc. cit.). Just above
this was another smaller egg, maturing and already opaque. The undeveloped portion
of the ovary is speckled all over with minute light-refracting dots. The branchiae take
the ordinary form of slender, somewhat twisted cords, probably tubular throughout,
beginning apparently at the front face, by many attenuate ramified channels, with
doubtless open ends, to receive the influent water for respiration ; and terminating each
on one side of a large contractile vesicle, occupying the hinder end of the visceral cavity.
Each branchia has attached to it by a slender stem a pear-shaped bag, which hangs
free in the cavity, at about mid-body ; and, a little below this, an ovate enlargement,
which is sessile by its whole side. The contractile vesicle takes a globose form when
full ; when it is seen to have a number of very minute clear glands (?) scattered over
its surface. I found the period of filling, between one contraction and the next, to be
just three minutes. At the point where the pear-shaped bag is given off, each branchial
cord adheres firmly to the epithelial lining of the skin ; but is free above and below that
point. I searched carefully, but vainly, for any vibratile tags in the course of either
branchia. But, in one I saw, in a very slender offshoot, close to the attachment of the
pear-shaped bag, which yet was not a " tag," a vibration exactly similar to that of a

NOTOMMATAD/E. 31

" tag." From each toe runs up a thread, which in the foot dilates into an ovate gland,
studded with minute vacuoles. Probably these are mucous glands : but no mucus-
strings were visible from the foot, nor any gelatinous envelope of the body, in all the
specimens (nearly a score) that I have examined. The brush of each occipital tentacle
(antenna) consists apparently of three, or at most four, setae ; each lumbar tentacle
carries but a single seta. Through all, lines are seen running down from the setae to
the base. From the base of each lumbar tentacle the thread which descends from the
seta is distinctly seen to pass for some distance up the visceral cavity toward the brain,
till it can be no longer distinguished among the multitude of lines. On the other
hand, the thread issuing from the base of each antenna may be traced to the very
summit of the brain.

This is, perhaps, the largest of all known Rotifera. Some among the Rhizota may
exceed it in length, a great part of which is occupied by the foot of almost linear tenuity.
But, bulk for bulk, Copeus spicatus far exceeds them all. It is a noble, as well as a
very interesting, member of its class. Viewed on the stage of the microscope, we forget
that we are contemplating a speck, such as a lady's cambric needle might prick in a sheet
of paper, and are struck with what we are ready to call its gigantic dimensions. For,
with a half- inch objective, it almost crosses the round field of view, and with a quarter,
such as is needful to interpret the organization of the Rotifera, we are obliged to
examine it piecemeal ; for a large portion of the creature is necessarily beyond our vision.
Its great size, slow movement, and brilliant transparency make it a subject very favour-
able for observation. Perhaps this is the finest addition made to our knowledge of the
Rotifera since Ehrenberg's magnum ojnis. And we owe our acquaintance with it to Dr.
Hudson, who named, described, and figured it in the " Journ. Roy. Micr. Soc." for
May 1885. It was discovered by Mr. Bolton, who sent him specimens, as he has lately
sent to me also, obtained from Sutton Park, Birmingham. — P.H.G.] '

length (moderately extended), ^inch; width, T \ -$ inch. Habitat. Birmingham:
Coleshill (T.B.) ; Sandhurst (Dr. Collins).

C. pachyukus, Gossc, sp. nov.
(PL XVI. fig. 4.)

[SP. CH. Front furnished with a pair of long and thick auricles projectile and
retractile ; lumbar regions tvith tubules, destitute of setce ; tail saccate.

The general accuracy of Prof. Ehrenberg's details, where he gives them, makes me
distinguish this species from his N. copeus ; though it comes very close to that fine
species, perhaps even closer than does Dr. Hudson's N. spicata, or any other. It is, in-
deed, less than half the size of Copeus ( = Ehrenbcrgii), my specimen measuring fs inch
in length, when moderately extended ; I could not be sure that the brain had more than
one lobe ; the lumbar tentacles are placed far back, as in spicatus, and differ in
apparent structure from those of either ; and finally the tail is neither a minute conical
tubercle nor a long stiff point, but a wide sub-globose sac (as in spicatus, but far
larger), whose walls are thrown into stiff sharp folds, as if composed of a firm leathery
skin.

Yet the general aspect is that of Ehrenbcrgii ; the auricles have the same form and
direction, and the same comparatively large dimensions. Ordinarily they are quite un-

1 A side view of this fine Eotiferon has been accidentally omitted from pi. xvi. ; but will be given
in pi. xxx. It shows that the two occipital antennae are connected by a transverse ridge crossing from
the base of the one, to that of the other. My solitary specimen had a semi-transparent gelatinous
covering, out of which peeped the ends of the four tentacles. The ephippial egg, when I first saw it,
was quite smooth, and separated by a clear space from its outmost covering. I saw its prickles begin
to grow, and watched them slowly stretching across to the outer shell. Two hours elapsed before they
had accomplished the distance. — C.T.H.

82 THE ROTIFERA.

suspected, being absolutely concealed witbin the rounded outline of the head ; but, at the
will of the animal, are suddenly pushed out horizontally, by eversion of the skin, to
a length more than half the diameter of the head. They then form oblique cones,
which are truncate at their tips ; but the skin there, which seems in some sort double,
is at every instant drawn in a little, as if very sensitive. The outer upper corner of each
is richly ciliated ; and the ciliary action, at this point of each, makes a strong vortex, into
which floating atoms are drawn, and whirled round as in those of the Bdelloids. The
auricles are often extruded when the animal is not swimming, but grubbing among the
sediment ; and they do not sensibly augment the speed, then ; but if extruded during
the swimming, they do so notably. Each can be thrust out in varying degrees ;
and very often one is out while the other remains concealed : they are manifestly
very flexible. No antenna from the occiput is visible ; and the tentacles on the
lumbar regions are very minute tubules projecting through the internal skin, and con-
nected with a visible basal area on the exterior of a vascular membrane which sur-
rounds the abdominal viscera. I can discern, even with a high power, no setas at the
tips of these tubules : but possibly these may be retractile. Indeed, the tubes them-
selves are not always apparent. After death, the ventral surface being in view, a thread
was distinctly seen on each side proceeding from the base of the lumbar tentacle,
dividing into two branches at about mid-length, and going up to the sides of the brain.
Each thread, both before and after the division, had a sensible diameter, and showed
a double outline. No under lip breaks the uniform rotundity of the frontal outline.
But, in a ventral view, when it was still and contracted in dying, I have observed an
ovate line, as of a minute orifice, just within the edge (fig. 46), which may possibly
have marked the place where a lip had protruded.

The general figure of the animal much resembles that of N. aurita ; but is more
variable, as if the integument were softer and more flexible. A momentary glance
while it was turning left the impression that a segment would be as at fig. 4a; as if the
ventral surface were dilated and flat. The skin was free from gelatinous envelope.

A stout foot of three joints carries two toes of the blade-form, stout, of uniform
width, somewhat long, straight, and pointed. Behind them, separated from them by
the cloaca, and from the gibbosity of the trunk by a strong constriction, there is a large
bladder-like inflation of the skin, thrown into strong folds or creases, which must be
taken to represent the tail. It is colourless, and appears quite empty ; it is constantly
changing its outline, but ever falls into the same folds. It is slightly bilobed, and
seems somewhat dilatable. This great fat ventricose tail is a conspicuous character, by
which this species may in a moment be recognised. The internal economy is, in most
examples, sufficiently clear. A three-fold brain is seen : the mid-lobe pear-shaped with
a long slender neck, the bulb reaching far below the mastax ; the side-lobes compara-
tively short. I have seen the mid-lobe filled with granular matter, not quite opaque,
but darkly turbid. A deep-red eye, large, oblong-square or ovate, is seated on the neck
of the mid-lobe. An ample mastax, with normal trophi, nearly fills the breadth of the
pectoral region; followed by a vast stomach, in most examples, densely filled with dark-
brown conglobate rolls of food ; sometimes with no glands visible, at others with two
small glands, dark, with a large oil-globule within each, of deep orange hue, whose rich
refraction of light has a very striking effect, like a pair of coloured carriage-lamps.
The ovary often has a great egg, nearly mature. Lateral canals, one on each side, are
more or less clearly discerned, on one of which I have seen one vibratile tag ; but I
have not been able to detect a contractile vesicle.

In manner of life this, like its congeners, is dull and slothful, rolling stupidly and
aimlessly about, and ever altering its form, but not much given to locomotion. Now
and then, however, it seeks a new locality; and then it shoots away in a straight line,
with considerable swiftness and grace, cleaving its path, with dilated front, through the
water. I was so fortunate as to be present at the dinner of this species, as I had been at
that of C. labiatns. Several large alga? were strewn around, among them a Closterium,

NOTOMMATADyE. 33

dark green, very slender, nearly straight, and longer than the Copeus (perhaps C. line-
atum). The animal attacked two of these in succession, taking hold transversely, yet
not attempting access there. But feeling its way, it worked, very cleverly, and with
manifest intelligence, till its jaws reached the tip. At this, then, they worked eagerly,
drawing it in, so that it stretched out lengthwise from the head. No impression, how-
ever, was made on the flinty frustule, and it was presently relinquished, to attack
another, equally in vain. After some hours, I perceived that it was essaying food
again ; and again one of the same long Closteriams, which now was drawn far down
the buccal funnel ; while the mastax in its usual position had already eaten a good deal
of the desmid, chewing it away, as one would eat a radish. The great auricles (in this
very example) were reluctantly and charily put out. They would not be suspected at
other times. During several hours' observation I saw them extruded only on one occa-
sion, when the creature was gliding through clear water. And then, it thrust out first
one and then the other, timidly and tentatively, as it were, and drawing each back
before it was nearly out ; then again protruding it ; till, by this time, some impediment
was reached, and I saw neither any more. Such was very much my experience of others
also. The first specimen that I saw occurred in water sent me, in June, by Dr. Collins
from his " happy hunting-ground " at Sandhurst. But more recently Mr. Bolton has
sent me examples from the prolific ditch in Sutton Park, near Birmingham, where it
revels in company with labiatus and spicatus. — P.H.G.]

Length, -^ inch. Habitat. Pools and ditches where the larger Diatomacece abound.
Sandhurst ; Birmingham (P.H.G.).

C. caudatus, Collins.
(PI. XVI. fig. 5.)

[SP. CH. Form slender, swelling in the middle ; auricles wanting ; one occipital
antenna, and one lumbar tentacle ; tail minute.

In " Science Gossip " for 1872, Dr. Collins described and figured this Notommata of
singular facies. I had long desired to examine it, having had my curiosity excited, not
only by the brief diagnosis of its discoverer, but by numerous pencilled sketches in his
well-filled note-books, committed to me from time to time by his courtesy. At length,
by his kindness in sending me samples of water from the original habitat, I have been
gratified by the sight of several specimens in healthy activity. It is a species much
more abnormal in appearance than in structure : an appearance which depends on the
seeming severance of the head from the body by a long interval. The head is large,
somewhat square in outline, and, owing to the definition of the brain with its eye, and
of the mastax, it catches the observation in a moment. Then follows a neck of unusual
length ; and though its thickness is scarcely less than usual, its extreme transparency
and colourlessness render it hardly visible till focussed ; and it contains no organs, save
on each side the twisted lateral canals, of such filmy mistiness as scarcely to be
perceptible when searched for ; and so there seems nothing at all, save the oesophagus,
a tube of great subtleness and slenderness running through the middle of its entire
length. We seem to see an oval abdomen filled with viscera, and a head tied to it at
the end of a long string. The head carries at each frontal corner a small globe refractive
of light, which I take to be an auricle, though I have not seen them retracted or pro-
truded, nor are they manifestly ancillary to speed, being visible uniformly in the animal's
twinings and crawlings. The frontal surface between these auricles bears vibratile setae,
as well as ordinary locomotive cilia. A large well-developed brain occupies the whole
width, and descends, sack-shaped, far down the occiput, bearing on its facial side a bril-
liant crimson globular eye, and in its rear, supplying a nerve-thread to the sensitive seta
which runs through an antennal tubule, projecting from the back of the head (figs. 5c, d).
A mastax of ordinary form in the family has the bent mallei of some thickness. It
is figured at 5b from some very good observations, though, from difficulties inseparable

VOL. II. D

31 THE ROTIFERA.

from the circumstances, I dare not vouch for the minute details, particularly of the
ts-rarmi. The respiratory organs, in the form of slender cords, loosely twisted
together, but, as I presume, tubular, can be traced to the very front of the head ; at
least to the point on each side where the proximity of the brain to the integument
allows them to be no longer discerned ; and thence backward without interruption, till
their ends ramify and are lost on the walls of the ample contractile vesicle that occupies
the termination of the abdominal cavity. It was an operation of much delicacy, but
with a ^-in. obj. I think I satisfactorily followed the entire course described. In the
ample abdomen the viscera are large. The alimentary canal is clearly separated into a
stomach and an intestine. In all the individuals examined, neither of these held any
visible food, but both were tinged with pale umber-brown. An ovary of embryonic
vesicles, and a great dark ripening ovum, were conspicuous in one. At the expansion
of the long oesophagus into the stomach are the pair of ovate colourless glands, which
possibly are biliary, and may impart the prevalent yellow-brown tinge to the digestive
canal. The dorsum, just before the point where it contracts into the foot, rises into an
angular prominence ; which must be regarded as a true tail, because beneath and behind
it is the common excrementary outlet, whether for matters urinary or faecal — the cloaca.
The anterior side of the orifice is crowned with a bristled tubercle (fig. 5d), very closely
resembling that projecting from the hind head. It seems a tubular wart with a thick-
ened rim, bearing a rather short seta on the summit. From the base of this are
discerned, clearly running down through the transparent tube, two fine lines, which
probably are the optical expression of a nervous cord, bending forward to some sensible
distance up the body, till lost behind the viscera. I searched (vainly) for some ganglion
in the vicinity, with which this thread may communicate. But I rather presume that
it runs through the body, and communicates with the great brain at the very front. It
seemed to me that each of these tentacular warts, both that on the head and that on
the tail, is susceptible of sensible elongation, and of occasional withdrawal, partial or
perfect. The foot is slender and colourless, like the anterior parts, and is terminated by
two minute and delicate toes ; from which two long, club-shaped muscles pass forward
nearly to the cloaca.

The species was discovered by Dr. Collins in 1865, in a small pool near Sandhurst
Military College, whence he has recently sent me a supply. There seemed here the
exercise of a sense of companionship, at least in captivity. After some days this species
became rather numerous in the bottle of water-moss, and I have had, perhaps, a dozen
in my live-box at once, of various ages. I noticed, much too often to be merely
fortuitous, that they were in the habit of associating in couples, two being generally in
close contiguity, and now and then coming into actual contact ; the one crawling, in
their lithe embracing manner, over the foreparts of the other ; separating, however,
immediately after. It was not sexual. In young individuals, not more than half as
long as the adult, all the characters are developed ; except the great length and almost
invisibility of the neck, which are not so manifest. — P.H.G.]

Length, -,.}„■ inch. Habitat. Sandhurst, Berks (Collins) ; Dundee (P.H.G.).

C. Cerberus, Gosse, sp. nov.
(PI. XVI. fig. 3.)
Notommata ccnlrura . Gosse (ncc Ehr.), Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200.

[SP. CIT. Tentacles wholly wanting (or unobserved) ; auricles small; brain three-
lohed ; tail a minute tubercle.

This species approaches the ordinary Notommatce, in form and in the absence of
those projected organs of sense which characterise the other species of this genus.
Yet the general aspect, the sluggish manners, and the three-lobed brain, seem to war-

NOTOMMATAD^E. 35

rant me in placing it in this genus. Indeed, when, five-and-thirty years ago, I first met
with it, I concluded that it was identical with Ehrenberg's N. centrum. But I have
lately seen several more examples, which have convinced me that it is still an un-
described species.

The form is rudely cylindrical, with many irregular constrictions, and the abdominal
regions somewhat swollen. The front is rondo-truncate, with a minute auricle on each
side. These seem scarcely protrusile, though the oval space in which ciliary action is
seen appears in each. The ciliated face is prone, and reaches far down ; no lip appears.
At the hinder extremity there is a distinct tail, small, saccate, almost amorphous,
beneath which the cloaca opens, as I saw by the actual emptying of the rectum. A
very short foot carries two minute, conical, pointed toes. The brain consists of three
sacs, of which the central hangs low, being seen behind the rnastax, and as usual forms
a long tube at the origin, in which is the eye of lenticular form, and brilliant crimson
hue. The lateral sacs are moderately short. All three are more or less occupied with
opaque granular matter ; but in the central sac this is generally (not always) so much
diluted as to be pellucid. The central sac, too, is occasionally seen truncate at its lower
end, exhibiting very distinctly at its margin the separate cells of which it is composed.
The trophi are normal : the mallei apparently four-fingered. The alimentary canal is
large, saccate, furnished above with small globose gastric glands, and not sensibly
divided ; its central longitudinal cavity may usually be traced, full of digesting food of a
dark umber-hue, while the thick surrounding walls are tinged with the same. The vo-
luminous ovary, forming a wide horseshoe across the ventral region, its horns directed
backwards, is full of clear embryonic vesicles, and often carries a dark maturing egg
which I have seen discharged. The branchial system has the usual form of a rather
thick cord (probably tubular), not twisted, but hanging so loose as to be thrown into
many curves, with at least three vibratile tags on each, and the usual contractile vesicle
of moderate size occupying the hind mid-ventral region. Muscles, both longitudinal and
transverse, agree with those that I long ago demonstrated in Not. aurita.1 The whole
head is usually tinted with buff, and the mastax-front with red-brown.

My first example of this species was found in June 1850, in a phial dipped on Hamp-
stead Heath three weeks before. The more recent were in the sediment of a phial sent
me by the kindness of Dr. Collins, from the historic pool in Sandhurst Wood. The
creature, like its congeners, is slow and deliberate in manners, burrowing and rooting
in its floccose surroundings. Its motions are much like those of the water-bears ; in-
deed, on first catching a glimpse of my subject among the half-hiding sediment, I have
repeatedly been doubtful whether I was looking at a Tardigrade or one of these massive
Notommatadce. — P.H.G.]

A specimen of Mr. Gosse's Cogens Cerberus, which I found in some water from
Sutton Park, Birmingham, enabled me on one occasion to obtain an excellent view of
the mastax and tropin ; for it every now and then slowly turned its head back, so as to
bring its ciliated face up to the cover-glass, and thus to rotate the mastax, for me, with
all its parts in their natural position. I could distinctly see the massive malleate trophi
unusually thick and broad ; the short, wide, yet graduated teeth of each uncus opposing
each other at the top of the mastax, like the fingers of the two hands brought just to touch
at their tips. Immediately above them were two very prominent lips, like a parrot's
beak, and evidently of a much harder substance than the rest of the mastax : they were
seated upon it, on each side of the opening between the buccal funnel and the teeth.
These I saw repeatedly open and shut as food passed down the funnel to the trophi.

Length, A inch. Habitat. Hampstead Heath; Sandhurst, Berks (P.H.G.).

1 Trans. Micr. Soc. Lond. vol. iii. p. 101, pi. xv.

SO THE ROTIFERA.

Genua proales, Gosse.

GEN. CH. Of moderate or small size ; body generally cylindric, or larviform ;
ciliated face more or less prone ; brain clear ; auricles and tail wanting.

This again is an extensive group, containing many species, some of them of familiar
occurrence, often obscure, of indefinite character, and hard to be distinguished. Some
are entozoically parasitic on other creatures. The vibratile cilia are disposed on a face,
along that side of the head which is more or less in the ventral plane. Their bodies are
usually lithe, soft, and versatile ; their motions rapid and various.

P. decipiens, Ehrenberg.

(PI. XVIII. fig. 6.)

Notommata decipiens . . . Ehrenberg, Die Infus. 1838, p. 431, Taf. lii. fig. 6.
„ vermicularis . . Dnjardin, Hist. Nat. Zooph. p. 648, pi. xxi. fig. 7.

[SP. CH. Body cylindric, slender, worm-like ; foot undeveloped ; toes minute.

This much resembles a dipterous larva ; having a soft, flexuose, slender body, with
a rounded front, and two minute, conical toes, without any sensible foot. A large, oc-
cipital brain carries a red eye, distinct, though small ; a crystalline lens is conspicuous,
seated on, and partly imbedded in, the pigment-globule ; the latter much the larger.
(See Duj. loc. cit.) Near the front are two clear colourless granules, usually distinct in
the many examples that I have met with. These may be readily mistaken for eyes
when the animal is in motion. A mastax with tropin of normal form leads by a very
long and slender oesophagus to a cylindric alimentary canal, with usual accompaniments.

I first found this in 1849, in waters near London both north and south. Since then
it has occurred repeatedly in various localities. When I saw my first example, it was
spinning round on its long axis. After a while it became less impatient, but still very
lively. It frequently bent itself up double, in the manner of a caterpillar, and occasion-
ally shrank up into a wrinkled, shapeless ball, remaining thus awhile quiet. Gliding
through the water by means of its rotatory cilia, its motion was not particularly rapid.
Though I have called the tropin normal, there is, in the form of the rami, a manifest
approach to these organs in Diglena. — P.H.G.]

Length, -j-^ to yl^ inch. Habitat. Near London ; Epping Forest ; Birmingham ;
Stapleton Park, Yorkshire; Dundee (P.H.G.) : pools : not common.

P. felis, Ehrenberg.
(PI. XVIII. fig. 17.)
Kotomniata felis .... Ehrenberg, Die Infus. p. 431, Taf. lii. fig. 7.

[SP. CH. Body cylindric, slender ; a large decurved fleshy proboscis ; eye very
large; trophi D i glenoid ; foot stout ; toes slender, pointed.

Of this little species, the slender trunk is strongly fluted longitudinally. The curious
projection which Ehrenberg calls a horn, is a thick soft lobe of translucent flesh, which
curves down before the head, perhaps a tentative organ, and recals what we see in some
of the Diglena. So also do the pincer-shaped rami ; and, as in that genus, they are
capable of being rapidly and forcibly thrust forth, with a snapping action. The brain is
broad, and descends far ; it bears on its round extremity an eye so large that it occupies
fully half the diameter of the body. Yet it is seldom seen ; being a lens seated
transversely, and edgewise to the observer. The stomach too, with high lateral
shoulders, usually densely filled, hinders the observation, not only of the eye, but of all

NOTOMMATADiE. 87

the viscera.' Its manners are lively and restless ; rarely swimming, but incessantly
boring and pushing through the yellow sediment in which it chooses to dwell ; and that
so pertinaciously, that when it comes to the edge of a mass, it will not (or very rarely)
go on into the clear, but turns back, and bores its path anew. If it does sail out for an
instant, it presently stops short, turns tail, and hurries back to its cover. I have seen
the pincer-jaws rapidly protruded almost to their full length. I have seen many speci-
mens, in water and sediment from the ditch in Sutton Park, Birmingham, which Mr.
Bolton has so successfully explored.

The new Rotifera Pleurotrocha mustela lately described and figured by Mr. W. Milne
("Trans. Phil. Soc. Glasgow," 1885), is very like the present species. He has represented
the male, which closely resembles the female, but is smaller, and devoid of digestive
system. The memoir is of high value. — P.H.G.]

Length. About ^z inch. Habitat. A ditch near Birmingham (P.H.G.) ; Glasgow
(Mr. Milne).

P. gibba, Ehrenberg.
(PI. XVIII. fig. 8.)
Notommata gibba . . . . Ehrenberg, Die Infus. 1838, p. 430, Taf. lii. fig. 4.

[SP. CH. Body compressed ; back much arched, deeply incised above the stout
foot ; toes slender, pointed, slightly decurved.

The fore parts are separated from the trunk by a marked infolding, as well as the
foot ; this latter constriction, when viewed sidewise, forms a deep sinus. The first
example that I met with was in November 1849, in a pond at Battersea Rise. I
afterwards found other specimens. The front is prominent and round ; over it pro-
jects a semi-ovate plate apparently slightly bent downward, on each side of which
is a fine seta. Perhaps the more natural place of this species would be in the (restricted)
genus Notommata, near lacinulata. But the ciliated face is prone. The brain descends
bag-like, into the occiput, and bears a wart-shaped red eye on its very end. The taper
rectum terminates in a cloaca, in the deep posterior infolding. A minute contractile
vesicle is in almost incessant contraction. The foot, with its curved toes, is often
thrown forcibly back, in the manner of Rattulus.

The animal is lively, actively swimming, and contracting strongly as it goes, and
throwing the toes backward and forward.— P. H.G.]

Length, ^^ to ^^ inch. Habitat. Battersea ; Stapleton, Yorkshire ; my domestic
aquarium (P.H.G.) : rare.

P. sobdida, Gossc, sp. nov.
(PI. XVIII. fig. 7.)

[SP. CH. Body nearly cylindrical ; head broad, truncate ; foot very broad, with a
depression through the median line ; toes minute, conical.

This is a somewhat clumsy, ungraceful, unattractive species. The whole integument
is flexible, and thrown into transverse folds, though seemingly stiff. The corona is
broadly truncate, formed by numerous ill-defined globose masses, on which the cilia are
grouped. The whole front is capable of little expansion or change, and the motion
consequent, not very swift. The mastax is ample, of the Notommatous pattern ; behind
which a brain, moderately developed, carries a red eye, on its side. The eye is often
invisible ; then suddenly appears as a minute speck (or, as I once saw, two red specks,
apparently in contact), or, often, as a well-defined considerable mass of rich colour. I

1 Herr Eckstein (Sieb. u. Koll. Zeits. 1883, p. 363, fig. 29) describes and figures a pair of minute
dark-red points one on each side of the front, whence a brush of setae springs. These I have not seen,
but cannot doubt that they are of the nature of antennae, and that the red speck is imaginary. He
describes the proper eye besides, and notices the distinct refracting lens, by which it is embraced.

38 THE KOTIFEKA.

have seen the saccate brain at its hinder end, densely opaque in a great ball, just as in
N. aurita, while all the remainder was clear. In every other respect the specimen was
a normal sordida. The most observable characteristic of this species, by which it may
without fail be identified (for it is quite constant), is the condition of the foot. The
hinder half of the trunk, viewed dorsally, insensibly diminishes to a width about one-
third that of the widest part, where it is abruptly truncate ; the hind half of this is
separated by a slight fold, and appears to constitute the foot-proper. Yet there are no
visible joints in it, and its outline, as I have said, simply continues the gradual tapering.
Down the middle of this foot there runs what seems a shallow depression, crossed by
two similarly depressed transverse lines, and the whole ends in two small conical toes.
When once this peculiarity has been noticed, there is no mistaking it.

I first found the species in a tube sent me by Mr. Hood from Dundee, and since
then in water from Miss Saunders of Cheltenham, and abundantly from Woolston,
sent by Miss Davies. Some of these last were hyaline, and more active. — P.H.G.]

Length, -, J ff to ^^ inch. Habitat. Many localities in England and Scotland :
common in pools (P.H.G.).

P. TIGEIDIA, Gosse, Sp. 110V.

(PI. XVIII. fig. 10.)

[SP. CH. Body cylindric or fusiform, curved in the manner of Rattulus; foot
and toes both long, and bent in a sigmoid curve.

This animal, I do not doubt, has been confounded by observers, as it was by myself,
with the N. tigris of Ehrenberg, but this latter I now relegate to another genus, in the
Sub-order Loricata. The present is certainly il-loricate, and its long ciliate face,
almost absolutely prone, shows its affinities to be here, though it is certainly osculant
with Battulus. Its trophi, too, are symmetrical, and of the Notommatous pattern.
The cilia of the face seem set on minute eminences ; and there are longer seta3 among
them. The belly line bends upward and then downward to include the base of the deep
foot, which again bends upward (i.e. backward) to the toes, and these bend downward
at their tips. So that the whole line from the face to the toe-tips forms a double
sigmoid curve of much elegance. In June 1885 I first became cognizant of this interesting
form. It was haunting the decaying whorls of Nitella, in water from Woolston Pond, sent
me by the kind courtesy of Miss Saunders. It has occurred also in other waters.

It is an energetic animal, given to sudden and rapid changes of motion, shooting
through the free water with great celerity, the toes stretching behind straight and
parallel ; now abruptly turning on itself to pursue another course, now arrested by a
cloud of floccose, to dig into the decaying vegetation with apparent determination and
vigorous perseverance. The digestive canal is almost invariably dark with granular
food, of a deep rich-brown hue. A contractile vesicle is usually conspicuous. — P. H.G.]

Length, -j\s inch. Habitat. South and Midland England; pools (P.H.G.) : rare.

P. petromyzon, Ehrenberg.
(PI. XVIII. fig. 9.)
Notommatu petromyzon .... Ehrenberg, Die Infus. p. 427, Taf. 1. fig. 7.

[SP. CH. Body orate; foot long, stout, and very distinct ; toes minute.

The form is gibbous-ovate, truncate at each extremity, when contracted ; the head is
rounded, protrusile ; the foot apparently of one joint, very large and long, but abruptly
less in width than the truncate body whence it issues ; the two toes are very minute
cones. The character of the foot makes the species particularly easy of recognition.

The simplicity of the trophi makes them very instructive. The incus-fulyum is

NOTOMMATADvE. 89

thin and blade-like, straight but slightly incurved at the free end, deeply truncate above
where the rami are jointed, which are long triangular blades arching backwards. The
mallei are slender rods, each with a process, and an uncus of two fingers.1

Ehrenberg describes the species as parasitic on the branching Bell-vorticels Epistylis
and Carchesium, among whose twigs it lays its eggs ; and also in Volvox. I have seen
it always free, though repeatedly in close association with both these Infusoria. I have
been acquainted with it from many localities since 1850. It is lively in its motions ;
yet frequently adhering to the glass, and moving by a feeble crawling ; it can, however,
swim rapidly. Its contractions are almost perpetual, and very vigorous. — P.H.G.]

Length, when . extended, T\^ inch. Habitat. Around London ; Walthamstow ;
Leamington Canal ; Cheltenham ; Woolston ; Birmingham : pools and garden reser-
voirs (P.H.G.).

P. parasita, Ehrenberg.

(PI. XVIII. fig. 11.)

Notommata parasita . . . Ehrenberg, Die Infus. 1838, p. 426, Taf . 1. fig. 1.
Hertiuigia volvocicola . . . Plate, Jeimisch. Zeits. f. Nattir. 1885, p. 26, figs. 7, 8.

[SP. CH. Body cylindric or gibbous, rounded at each end ; foot and toes toanting.
Parasitic in Volvox.

To the characters just given may be added that the jaws are long, slender, protrusile,
and asymmetric : the mallei being dissimilar in length and curvature ; thus recalling
the Battulidce. A brilliant crimson eye, wart-shaped, sits on the dorsal corner of a
large occipital brain; from the front of which projects a club-shaped antenna, some-
times drooping, sometimes erect. The prominent round head is clothed with fine
cilia, and surrounded by a wreath of stronger vibration ; when this is retracted the
margin is thrown into puckers.

The habits of this inconspicuous species are curious ; for it is parasitic within the
spheres of Volvox globator. Examining this elegant creature, we may, even with a
pocket-lens, discern which are tenanted, by a spot differing from the young clusters in
form and colour. Such a spot proves to be the Proales, snugly ensconced within the
globe, in whose spacious area it lives at ease, and swims to and fro like a goldfish in a
glass vase. For the most part it affects the inner surface, engaged in devouring the
green Monads that stud the gelatinous expanse, or else eating away the embryo clusters.
Sometimes laid eggs are present, with the Proales ; sometimes eggs alone. The young
seems always hatched in a Volvox, and, entering an embryo cluster, is expelled with it.
Often they eat their way out, and swim at freedom. Observing in a globe one large egg,
I opened the globe with a needle, and freed the Proales, placing it in water, and adding
several Volvoces, all untenanted. But it did not enter one, during several hours' obser-
vation. During this period it discharged, loose in the water, an ephippial egg, covered
with prickles. I have seen a prickly egg and a smooth one, transparent, with eye and
jaws visible, in the same sphere. One of the latter I saw hatched, the young just like
the adult. The Volvox appears to suffer little from the depredations of its ungrateful
guest. The Proales is lively and energetic in freedom. It glides wildly about, often
in a zigzag course, turning from side to side, as it dashes rapidly along. Sometimes it
rotates on its axis as it goas ; or, becoming stationary, it turns on its blunt extremity, as
on a pivot. It is perpetually contracting and elongating, and throwing itself into angular
folds and contortions. — P.H.G.]

This is one of the partially loricated Eotifera. The soft front of the head, seen dor-
sally, is truncate, and much like that of Notops hyptopus. The edge of the trunk, within
which the head can be withdrawn, is chitinous, and scolloped in regular curves, just like
the edge of a lorica. At the hind end of the trunk, and on the median line of the dorsal

1 See Phil. Trans. 1855, p. 432, pi. xvii. figs. 27-3L

40 THE ROTIFERA.

surface, is a forked projecting pucker of the hardened skin, so greatly resembling the
notch in the lorica of a Brachionus, that I thought at first that the structures were
identical. Ehrenberg (loc. cit.) says that the creature has a minute, and slightly project-
ing foot ; which, as Mr. Gosse has stated above, it certainly has not : but it is clear,
from Ehrenberg's description and figure, that he has mistaken the forked pucker which
I have just described for a pair of small toes; a mistake easily made when the dorsal
surface is presented to the line of sight from a certain point of view. The animal's dor-
sal outline reminds one of Notops hyptopus ; which Rotiferon is also partially loricated.

I have often seen one of these little creatures ineffectively nibbling at the gonidia of the
Volvox which it inhabited ; but once I watched one bite its way into what was, I sup-
pose, a softer place than usual ; and a moment after I saw a long stream of bright green
globules course swiftly through the mastax, down the oesophagus, and into the stomach.1

Length, ^.^ to , ,l(T inch. Habitat. Wherever Volvox is numerous : London,
Birmingham, Leamington, Dundee (P.H.G.) ; Clifton (C.T.H.).

Genus FURCULAEIA, Ehrenberg.

[GEN. CH. Body generally larviform, cylindrical, with a tendency to enlargement
in the lumbar region; usually compressed ; front conical, broad, and deep ; eye single,
frontal, sometimes wanting ; incus forcipate, much developed, protrusile ; toes two fur-
cate, usually conspicuous.

It is not easy to attach to this genus such a definite character as shall be really use-
ful to the student for identification and diagnosis. Ehrenberg is very vague. He gives
but two distinctive points, — the frontal eye, and the forked toes. The latter is worth-
less, as being indistinctive ; and the former is unfortunately not constant, or not always
available. Eckstein's character for the genus is really but the character of one species,
inapplicable to others. Yet it is a good genus (as used by Ehrenberg, not by Dujardin),
and easily recognized in almost all its members, by one who is personally familiar with
them. Possessing much resemblance to the species of the extensive genus Proales, the
FurcularicB have an aspect, as well as habits, of their own. Both aspect and habits are
more easily detected than described. The front, more or less a low cone of wide base,
in vertical aspect, with a minute but usually conspicuous crimson eye set at the very
point, with no lateral developments — this is doubtless highly characteristic. So also
are the toes, in general strongly marked, very active, and often thrown spasmodically
backward, above the body-plane. There is one feature in their habits which is markedly
prevalent : the predilection which many of them show for darkling retreats, and the
tenacity with which they cling to them. No hare flees to cover more eagerly. Examples
will be given in detail presently.

The species are vivacious, energetic, restless, eager, predatory. The strongly deve-
loped rami of the powerful incus, moved by proper muscles, are capable of protrusion
from the face of the front, with a fierce snapping action, in which, however, they arc
rivalled by other kindred genera, such as Diglena and Distemma in particular. The
recognized species are not numerous. Ehrenberg admitted four. To these I have
added five others, including the F. marina of M. Dujardin (if, indeed, mine is identical
with his) ; but one of Prof. Ehrenberg's has not been yet met with in Britain. They
are wide-spread, and are not very uncommon, in the sediment of pools and ditches.
Two species which Ehrenberg placed in his great genus Isotommata, I prefer to place
here.— P.H.G.]

1 Dr. Plate (loc. cit.) has described P. parasila (Notommata parasita, Ehr.), male and female, as a
new species under the name Hcrtwicjia volvocicola, on account of its having no toes. Dr. Cohn gave
nn excellent figure of the male in Sicb. u. Kbll. Zeits. 1858, but drew the female with two minute toes.

■J

I .' , ._. .

■

NOTOMMATADiE. 41

F. forficula, Ehrenberg.

(PI. XX. fig. 1.)

Furcularia forficula . . . Ehrenberg, Die Infxis. 1838, p. 421, Taf. xlviii. fig. 5.
,, „ ... Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 199.

... Lord, Micr. News, 1884, p. 235, fig. 27.

[SP. CH. Body stout, straight, nearly cylindrical; broadest at the head, which
comes to a frontal point, ivhere is a single red eye ; toes two, furcate, blade- shaped,
acute, decurved, the ventral edge of each notched with ttvo strong teeth.

The deep sickle-shaped toes, having their under-edges notched near the base, readily
identify this.1 Its form is nearly cylindrical, slightly thicker in front ; the back is
sometimes gibbous, viewed laterally. The head forms a short regular cone, whose base
is the width of the head, at the apex of which is placed the small but distinct red eye.
The whole front appears set with cilia, which cause two vortices : a turbid occipital
brain is visible, carrying the eye at its anterior extremity. In contact with this as
usual, is an ample sub-globose mastax, with characteristic tropin. A long oesophagus
leads to the alimentary canal, which has thick granular walls, and bears two large
gastric glands. At times the dorsal portion of the stomach is inflated into a large
clear bladder, which displaces the granular walls around it. As this often appears and
vanishes rather suddenly, it has a singular effect. Towards the hinder part the granu-
lation becomes less opaque ; but whether there is any division between stomach and
intestine has not been clearly seen. A small contractile vesicle lies around the base of
the foot, and I have sometimes been able to trace the lateral canals and vibratile
tags. A small oblong or cord-like ovary generally occupies the venter, sometimes
dilated into a maturing granulate ovum. Many longitudinal muscles are visible, but
the contractions and contortions of the animal are so incessant as to render it almost
impossible to define them. By these contortions the firm skin is thrown into various
irregular angular folds. The foot seems composed of two joints, of which the basal is
by much the stouter, each enclosing a gland. The curved broad blade-like toes bend
downward at their sharp points ; each is cut into a strong projecting sharp tooth at
its base, and its foot joint immediately preceding has two teeth exactly similar.

Ehrenberg alludes to this animal as very rare. I have been familiar with it for more
than five-and-thirty years, and I consider it by no means uncommon. I used to meet
with it in the waters around London, and have since found it in very many localities,
often among conferva, and in the floccose sediment of ditches. In confinement it is
often most restless, constantly swimming about with a swift gliding shooting motion,
and throwing itself into frequent folds and twistings. The body is nearly colourless,
but for the opacity of the granulate viscera, which appear white by reflected light.

On repeated occasions I have observed, in this species, the curious habits already
referred to of inhabiting tubes, for some unimaginable purpose, of its own ingenious
manufacture. I cite the following note from my Journal, jotted down while under my
eye. " A fine specimen I found tenanting a long curved passage, in the yellow-brown
floccose from the ditch in Sutton Park. This was just wide enough to allow it to move
freely, and to turn its soft flexible body, when needed. It was about twenty times the
animal's length, outwardly undefined, being but a cavity formed in the irregular mass
of accumulated floccose. Within this, semi-transparent in parts, the Furcularia was
diligently pushing its way from end to end, turning back on itself the instant the end was
reached, not showing its nose out in the clear for a moment, and returning on its course ;
moving with considerable rapidity, never deviating and never resting. But after doing
this a long while, perhaps an hour or two, it began to pause here and there, and to move

1 Ehrenberg describes and figures a species, Distemvia forficula, of which I know nothing more,
with toes closely resembling the above. Only, to judge from his figs., the toes are recurved instead of
decurved, and the notching is on the dorsal instead of the ventral edge.

42 THE KOTIFERA.

more slowly. I at last picked the sheltering material to pieces with needles in order to
be quite sure of the species : for I had not yet had one satisfactory view of it at this
time. Yet even then it kept obstinately under the floccose, refusing to come out into
the open, even when its tube was torn up." On another occasion, lately, a striking
illustration of the fierce appetite of this carnivorous creature occurred to me. One in
the live-box was driving to and fro in its eager headlong way, when its course was
suddenly arrested. A Nats worm had been wounded, probably by the pliers in taking
up the milfoil from the phial, and a cloud of the pale flesh-granules had oozed, and was
still oozing, out of its side. The Furcularia, aimlessly swimming, had come to the out-
side of this cloud, and its whole manner was changed instantly. It darted at the mass,
snapped and snapped again, turning hither and thither, but not leaving the vicinity.
The sharp rapid momentary projections of the head and of the jaws showed how
heartily it was enjoying its unexpected meal. This went on for some time ; but I was
called away, and was compelled to leave my hungry little friend at his dinner. — P.H.G.]
Length, {Kt inch to -,-^y inch. Habitat. Around London, Dundee, Birmingham,
Hants, Devonshire, and elsewhere (P.H.G) : by no means rare.

F. gracilis, Ehrenberg.
(PI. XIX. fig. 14.)
Furcularia gracilis .... Ehrenberg, Die Infus. 1838, p. 421, Taf. xlviii. fig. 6.

[SP. CH. Body slender, compressed, the ventral line making a prominent angle;
front rounded ; face oblique; toes slender, straight, acute.

This well-marked little species is of slender form, as its name imports, nearly equal-
sided, somewhat compressed, occasionally gibbous at the hind-back, the outline of the
belly concave, with a salient angle about two-thirds from the head, whence it abruptly
recedes to the short conical foot. The front is rather small, rounded ; the face
obliquely prone, ample, clothed throughout with cilia. The joints of the foot are
not readily separable ; the toes, furcate, slender, acute rods, almost straight, are about
one-fourth as long as the body, and are usually carried parallel. The eye is small, but
conspicuous, of a vivid crimson, situate as usual in the middle of the very front, at the
anterior extremity of the brain. A little wart-like projection is seen on the occiput,
which is probably an antenna. The mastax is long and pear-shaped, containing a
strongly forcipate incus, of which the fulcrum is evanescent, with a pair of long incurved
mallei. The rami seem to reach over in a long descending pair of points, probably
accessory to, but distinct from, the glassy rami themselves. The latter are frequently
protruded from the oblique face, to bite the flocculent matter, adhering to the moss,
and to seize atoms with a short snapping action.

I obtained this species in some abundance, near London, in my early researches,
among the stems and bracts of a submerged moss. Since that time, it has occurred in
widely separated localities, never with any notable variation. Its manners are active,
writhing nimbly along with the toes stretched out behind, but now and then, for an
instant, widely expanded. — P.H.G.]

Length, T>/)ff inch to ^\Ti inch. Habitat. Pools, wide-spread; London; Stapleton
Park, Yorkshire ; Woolston ; Caversham ; Cheltenham; Dundee; Oban (P.H.G. ).

F. oeca, Gosse.
(PI. XX. fig. 4.)
Furcularia cccca Gosse, Ann. Nat. Hist. vol. viii. 1851.

[SP. ('II. Body cylindrical, the ventral line straight ; front round ; head separated
by a strong constriction ; eye wanting or invisible ; toes slender, slightly recurved,
obtuse.

NOTOMMATAD.E. 43

This species is much like the preceding : yet it seems sufficiently distinct. The
figure is truly cylindrical, with a hemispherical head, and a short conical foot, each
divided-off by a strong fold. Both the folds are bounded body-wards by a distinct
tliick-:ned ring, the anterior by far the stronger ; there is a third fainter transverse fold
just behind the mastax. The face is prone ; but its plane is curved, not flat as in
gracilis. The great obtuse cone which forms the foot has but two separable joints, of
which the hinder is notched behind, and carries two furcate slender rod-shaped toes, one-
third the length of the body, very slightly recurved at the tips, which are rounded.
This last character, which may seem unimportant, is, I think, constant.

The whole visible head, in vertical aspect a perfect hemisphere, appears clothed
with short cilia, which extend also over the prone face, as far as the great constriction.
No eye was discernible. The toes are commonly held in mutual contact, the tips often
slightly crossed.

The manners were much like those of the other smaller Furcularia ; it both crawled
and swam, but not swiftly. It was found in July 1850, in the sediment of a phial
which had been dipped five days before, from Oldham's Pond, Leamington. A few
weeks afterward, I met with another in the same phial, which well sustained my judg-
ment of the distinctness of the species ; while it gave me a few additional details.
It had an occipital brain, but again no trace of eye. The alimentary canal has a pair
of minute gastric glands ; it was traced clearly to the cloaca, which appeared on the
dorsal surface of the foot as a minute notch. The oesophagus, a long slender and
somewhat sinuous duct, leads from the back of the mastax to the stomach. These
two examples have furnished all the information that I possess of it.1 — P.H.G.]

Length, of body, T\s inch ; of toes, -g^ inch ; total, extended, Tl^ inch. Habitat.
Leamington (P.H.G.) ; Sandhurst (?) (Dr. Collins).

F. gibba, Ehrenbcrg.
(PI. XIX. fig. 13.)
Furcularia gibba Ehrenberg, Die Infus. 1838, p. 420, Taf. xlviii. fig. 3.

[SP. CH. Body oblong, slightly compressed, convex on the back, flat on the belly ;
the gibbosity of the back abruptly falling off steep to the foot ; toes furcate, style-
shaped, straight acute, nearly half the body-length.

For more than thirty years I had assumed that this species was well known to me ;
when at length I discovered that what I had supposed F. gibba was really a loricate
form, with a cleft dorsum, presently to be introduced under the name of Diaschiza
semiaperta. Lately, however, I have met with an animal precisely agreeing with Ehren-
berg's description and figure. Yet I judge it highly probable that other observers have,
like myself, confounded the common Diaschiza with the rare Furcularia.

As I have se6n but a single example of the real Simon Pure, I can add nothing to
the published descriptions, except what may be gathered from the figure.— P. H.G.]

F. ensifeea, Gosse, sp. nov.
(PL XX. fig. 3.)

[SP. CH. Body gibbous; toes simple, blade-shaped, wider vertically than laterally ;
foot-joints tvanting ; eye wanting.

I first observed this rather attractive species in July 1885, in water taken from one
of my window jars, where aquatic mosses had been growing for several months. The

1 Except that Dr. Collins, in his Note-book kindly communicated to me, has pencil sketches of
what he supposes to be this species, taken at Sandhurst, Berks. Its form, however, is much more
gibbous behind than that of mine.

44 THE ROTIFERA.

mosses originally came from one of the Scottish lochs, and the ancestors of these Rotifera
may have been then introduced. But I constantly rinse out my live-boxes, after an
examination, in one or other of my reservoirs ; and as I have received samples of water,
animals and plants, from many kind friends in various parts, it is impossible to trace the
original habitat of any species which either of them may now contain.

In form the present species much resembles cceca or gracilis ; it is, however, larger
than either, nearly, if not quite, equalling forficula in dimensions. The gibbosity of
the back, its abrupt descent to the cloaca, and the peculiar mode of carrying the toes
behind, more easily seen than described, are all characteristically Furcularian.

A remarkable peculiarity, that strikes the eye at the first glance in the vertical
aspect, is that the toes seem to be articulated direct to the trunk, without the interven-
tion of the usual foot-joints. This is not an accidental malformation, but is evidently
proper to the species, all the specimens being alike. The toes, too, are wide apart at
their bases, the interval being sometimes straight, sometimes running up into an angle
(fig. 3). They are in general carried nearly parallel ; but tbey are often stretched so
wide apart as to be horizontal, or, on the other hand, crossed. I could detect no eye,
nor any brain, nor even turbidity, though I sought diligently. All the examples were
brilliantly transparent, but most were tinged with a very delicate shade of canary-
yellow, the stomach and intestine usually gorged with food of a warmer hue. The front
and face are of a pale orange-tint.

The manners of this species are exactly those of its fellows. In the live-box half-a-
dozen congregated under a single leaf of the moss, neglecting other leaves, though there
were plenty more, apparently as eligible ; and there they kept restlessly moving to and
fro, twining and twisting on themselves, suo more, beneath the translucent green leaf.
The freedom and facility with which they turn round within their own length and
breadth is remarkable. It is effected with marvellous rapidity, and with no change of
place, but only of position. You are looking with a high power at the head or mastax —
a twinkle, a dimness — and in an instant you see the toes in the very spot ! The creature
has turned itself quite round, and is off on its steps.— P.H.G.]

Length, ^.^ inch; of which the toes make about one-fourth. Habitat. The leaves
of aquatic moss in a tank (P.H.G.).

F. marina, Dujardin.

(PI. XIX. fig. 15.)

Furadaria marina . . . Dujardin, Hist. Nat. Zooph. 1841, p. 649, pi. 22, fig. 4.

[SP. CH. Body long, cylindrical; toes blade-shaped, simple, decurved, pointed,
minute; eye wanting. Marine.

The great length and uniform thickness of tln3 species, truncate at each end, obliquely
in front, transversely behind, distinguish it readily from its fellows. There is a lobu-
late, pointed glandular brain in the occipital region, on which no eye-speck can be
detected by either transmitted or reflected light. Behind this are some minute, seem-
ingly isolated bodies, which may be connected with the branchial system. The points of
the jaws are frequently pushed out from the oblique front to a considerable distance
(fig. 15a), and retracted rapidly and repeatedly, with a snapping action. A minute
protrusile antenna (?), ciliated at the tip, is seen behind the buccal funnel (fig. 15a).

It was in August 1854 that I became acquainted with this interesting species, already
made known by M. Dujardin in 1841. I had been keeping a small marine aquarium
ever since February ; but during a two months' absence from home in the summer,
most of the creatures had died, and were decomposed on my return. The water, how-
ever, remained fairly pure ; and I therefore merely removed a good deal of the decayed
mutter from the bottom, and restocked it, mainly with Actinia. On the sides of the
tank, and in the sea-water, I found this pretty Furcularia by thousands, associated with

NOTOMMATADiE. 45

a species of Euplotes, and a few of a Colurus. I have since found it repeatedly in sea-
water from the Tay Estuary. It is active and sprightly in its manners, browsing among
the floccose ; frequently elongating and contracting its body, and occasionally swimming
in the open water. — P.H.G.]

Length, ^-g- to ^ inch. Habitat. A marine aquarium ; tide-pools in the Firth of
Tay (P.H.G.).

F. Boltoni, Gosse, sp. now
(PI. XX. fig. 2.)

[SP. CH. Front rondo-truncate; body fusiform ; foot-joints small; toes conical,
about half as long as the foot ; eye small. Lacustrine.

This species I at first supposed to be Ehrenberg's F. Reinhardti, which has not yet
occurred to British research ; but, on mature consideration, there seem important
differences, which warrant my raising this to specific rank. Reinhardti is stated to be
Tfo inch in length, which is not so large as F. forficula and F. gibba ; whereas this is
^2- inch in length, and so is a very giant among Furcularics. Then the foot in
Reinhardti is half the length of the body : in Boltoni about one-fourth ; the toes in the
former are minute, one-fifth to one-sixth the length of the foot : in the latter rather
long and slender, full half the length of the whole foot and toes. Ehrenberg speaks of
" the great eye " as an attractive feature in his species ; but in this, the eye is, as usual,
minute and inconspicuous. Lastly, his species is marine, living parasitically on the
branching stems of the well-known polype, Laomedia geniculata ; whereas mine oc-
curred in a pool in the heart of England. Thus I venture to pronounce it new ; and
honour it with the name of that energetic microscopist, Mr. Thomas Bolton, who sent it to
me. It has evidently very close relation with i*1. Reinhardti, as is shown by the general
form, and especially the spindle-shaped trunk, and abruptly tapered foot. It is a true
Furcularia, as to its trophi, of which I had a very favourable observation ; the mallei
being slight and feeble, while the incus is strongly developed with wide, glassy, arched
rami, produced into long decurved points.

The front, in life, is probably conical, as usual ; but in the condition in which alone
I have seen the species, the cone was so low that its outline was nearly straight, with a
minute but clear red eye-speck occupying the very centre of its edge. The mastax is of
the usual large dimensions, followed by a slender oesophagus, an ample stomach with
small oval glands, a separate intestine full of dark granulate food, an ovary with a great
opaque maturing egg, and what I took for a contractile vesicle. The trunk is thickest
at the lumbar region, and that whether viewed laterally or dorsally. Thence it
diminishes rapidly to a width less than that of the head, and carries a foot of three
joints, of which the first is contained within the trunk- walls, and the others are very
small and slender, followed by a pair of furcate toes, which are of a long conical shape,
acute, and nearly as long as the three foot-joints together. The whole foot is sometimes
thrown up towards the belly.

I first became cognizant of this species in October 1885, a specimen having occurred
in sediment collected from a ditch in Sutton Park (a locality most prolific in rotiferous
and other microscopic life) by Mr. Bolton and sent to me. The animal was dead, but
recently ; so that the form was little altered, and the organs were all in situ, and readily
identified. I subsequently found a second rather smaller example in the same tube of
water, also dead; which afforded me the advantage, always to be prized, of an additional
study. A sight of the living animal is still a desideratum. — P.H.G.]

Length, ^ inch to ^0 inch. Habitat. A ditch near Birmingham (T.B.).

46 THE ROTIFERA.

F. mickopus, Gosse, sp. nov.
(PI. XIX. fig. 12.)

[SP. CH. Foot inconspicuous ; toes minute, conical. No eye visible.

This small species, known only by a single example, is much like F. forficula in
form, but the toes are very small in proportion, being cones whose length little exceeds
the breadth of their base. The animal is clear and colourless ; very soft and flexible ;
constantly contracting and lengthening. The anterior parts are somewhat thick,
gradually attenuating to the foot, where the width, both transverse and vertical, is less
than half that of the head. An occasional glimpse of the side (fig. 12a) showed that the
face was truncate, and obliquely prone ; whereas the front viewed dorsally was obtusely
conical in outline. But the extreme changeability of form, especially in the fore parts,
and the flexibility, were notable. No brain could be defined, nor any trace of an eye.
Though, according to Ehrenberg's arrangement, this should be a Pleurotrocha, if the
eye is really wanting, yet the whole habit and form of this creature showed its affinities
to be with Furcularia. I found the specimen described in water sent me by Mr. Bolton
in December 1884, obtained from a boggy ditch in Sutton Park. — P.H.G.]

Length, ^}lJS inch. Habitat. A ditch near Birmingham (P.H.G.).

F. longiseta, Ehrenberg.
(PI. XVIII. fig. 16.)
Nolommata longiseta . . . Ehrenberg, Die Infus. 1838, p. 432, Taf. liii. fig. 2.

[SP. CH. Body cylindric, round at each end ; foot thick, one-jointed ; toes twice as
long as the body, unequal.

The cylindric body is slightly arched, but retains an uniform thickness. The whole
rounded front is ciliate, with a semi-prone face. The toes, jointed on a thick cylindric
foot, seem made of spun glass, thick at the base, but tapering to great tenuity, though
not very acute. The right is about one-fourth longer than the left. The mastax and
its tropin, in situ, closely resemble those of Furcularia gracilis ; but I have not resolved
them satisfactorily. A great brain carries an opaque terminal mass at its point. The
front, viewed dorsally, has the outline of a low cone, with a single minute red eye at the
very point ; and now and then I have seen pushed out what seemed minute lateral
auricles ; yet with no perceptible acceleration of motion. The contractile vesicle is
very large. There is a prominent angle on the occiput, which may indicate a protrusile
antenna ; but I have not seen it exserted.

I had this pleasing species in 1851, from a dyke near Stratford, and presently after-
ward from Maidenhead. Recently it has occurred in water from Snaresbrook sent me
by Mr. H. Davis, and from Woolston, by Miss Davies. It swims slowly, often turning
to one side ; occasionally throwing apart the long toes, and springing when alarmed,
so as to fling the body more than its own length in an uncertain direction, the sound made
by the toes striking the glass on such occasions being distinctly audible. — P.H.G.]

Length, to tips of toes, ?]0 to ,!,0 inch. Habitat. Pools in the southern half of
England (P.H.G.).

F. .equalis, Ehrenberg.
(PI. XVIII. fig. 15.)

Kulommata ccqualis . . . Ehrenberg, Die Infus. 1838, p. 432, Taf. liii. fig. 3.

[SP. CH. Indistinguishable from the preceding, save that the toes are equal.
Though the resemblance between these two species is very close, Ehrenberg was

NOTOMMATAD.E. 47

certainly right in distinguishing them. Quite accidentally I have had the two in sight
at once, side by side, yet without the slightest mutual recognition, and thus had facilities
for comparison. JEqualis has the body longer and slenderer, more taper, where
longiseta is gibbous, less divided into apparent joints by constriction, especially at the
foot, besides the co-equality of the toes in this. Yet, on the other hand, the gibbosity
of the former nearly disappears when extended in swimming, and then they are much
alike.

I first saw this species together with F. longiseta, and both in some plenty, in water
from Woolston, in September 1885. Though the species showed no association, their
manners were exactly the same. The springs made by both and by Scaridium, with
which they have apparent affinity, depend, doubtless, on the length and elasticity of the
toes : and suggest a certain relation to the Triarthradce, and even to the order Scirtopoda,
in which, toes being wholly wanting, the same function is performed by special limbs,
long, taper, and elastic. — P.H.G.]

Total length, about T£u inch. Habitat. Woolston (P.H.G.).

Genus EOSPHOEA, Ehrenberg.

[GEN. CH. Body oblong; head dilated and furnished with protrusile auricles ;
foot very distinct, tvith telescopic joints, and furcate toes ; eyes three, viz. one large, cer-
vical, two minute, frontal.

Of the four species which Ehrenberg includes under this genus I know but the one
which he has not catalogued in its proper place, but which he subsequently mentioned
under the head of Diglena anrita. His words are : " Dr. Werneck sent me a drawing
of a new Eosphora, very like the Diglena of Berlin. I found, soon after, in the Berlin
animal, a pale red point on the opaque sac in the neck, which makes this an Eosphora,
if it prove to be an eye " (" Die Inf." p. 444).

Judging by this species, there is little to distinguish Eosphora from Notommata
(proper), except the two minute frontal eyes ; ' and this distinction is evanescent, when
we remember in how many species of Notommata Herr Eckstein bas seen frontal pig-
ment-specks. Yet, looking at the form of the tropin, I consider it intermediate between
Notommata and Diglena. — P.H.G.]

E. aurita, Ehrenberg.
(PI. XVII. fig. 14.)

Diglena aurita . . . Ehrenberg, Die Infus. 1838, p. 444, Taf. lv. fig. 2.

Eospliora aunta . . . ) B' J ' * 6

,, „ Gosse, Pop. Sci. Rev. 1863, vol. ii. p. 475, pi. xx.

[SP. CH. Body cylindric ; head separated by a neck ; front slightly convex ; brain
an opaque globe at the end of a long slender tube; trophi forcipate ; foot slender,
cylindric ; toes slender, acute, furcate.

This is an attractive species: its form is elegant and symmetrical, particularly when
the auricles are everted above the neck ; the slender foot and toes well finish the body
bebind ; and the prevalent depletion of the viscera with bright pellucid green food, add
brilliancy of colour to the clear glassy vase. To the naturalist, too, it is specially
interesting. Far down in the body is a transparent ball, filled with opaque matter,
whence a slender tube extends right up the very front : this tube is more or less turbid
with like matter. On the ball just where it contracts to the tube is a broad and thick

1 The frontal specks Dr. Leyclig denies to be eyes, in the species aurita ; but I have no hesitation
in pronouncing them to be strictly analogous with what we call eyes throughout the class.

48 THE ROTIFERA.

lens of crimson pigment, and at the frontal end of the tube, one on each side of it, are
two small crimson globules.1 All three are beautifully rich and distinct, even by trans-
mitted light. It is indubitably Werneck's Eosphora aurita. The jaws are quite of the
Diglena type, but the mallei are stouter, as in Notommata : the points are often pro-
truded. A curious feature is that the capacious stomach juts up in two long horns, as
high as the top of the mastax, distinct from the gastric glands. An ovary and a con-
tractile bladder, both ample, help to fill the cavity ; and the body terminates dorsally in
a broad triangular tail, which projects far above the foot, with the cloaca between. On
the occipital edge is a minute antennal tube and a bristled wart on each side of it.
This triple arrangement is peculiar. The manners are usually sluggish.2 — P.H.G.]

Length, T^s to yj^ inch. Habitat. Greenwich Park ; Hampstead Heath ; Birming-
ham : pools ; not rare (P.H.G.).

Genus DIGLENA, Ehrenberg.

[GEN. CH. Body sub-cylindric, but very versatile in outline, often sioelling behind
and tapering to the liead ; eyes two, minute, situated near the edge of the front ; foot
furcate; trophi forcipate, generally very protrusile.

This genus, while Notommatoid in form, has a certain aspect of vigour and intensity
of function peculiar to it. Though one or two assigned species are massive, the majority
are slender, lithe and energetic ; the taper and elongate anterior parts habitually thrown
above the general line of progression, in the manner of some lepidopterous and dipterous
larvae, as if eagerly exploring. The form of the trophi, though on the Notommatous
pattern, is very predaceous ; and the sharp, formidably- armed rami of the incus can be,
and frequently are, thrust far beyond the limits of the head, and forcibly snapped.
The front, hi most of the species, is furnished with a hooked proboscis. The furcate
toes are, in general, long and sharp, sometimes sickle-shaped.

Of the eight species included in the genus by Prof. Ehrenberg, lacustris, conura,
and capitata have not been recognised in Britain ; aurita is an Eosjyhora, and has been
just described. To the remaining four, seven species are now added. — P.H.G.]

D. gkandis, Ehrenberg.
(PI. XIX. fig. G.)

[SP. CH. Body ?nassive, sub-cylindric ; head ro7cnded, with a frontal proboscis ;
face nearly prone ; a tubcrculiform tail; foot large, bulbous ; toes straight, parallel-
edged, abruptly pointed.

Of this imposing species my knowledge for many years was limited to a specimen
which I found in September 1851, already dead, in a dyke at Maidenhead. The trophi
were beautifully distinct. Their structure was nearly the same as in D. forcipata, but
the bristle-like teeth that line each side of the incus were much more conspicuous, and
apparently larger ; arranged in double rows. In August 1885, examining an aquatic
moss growing in a glass reservoir in my study, I found, first one, and then another,
of the same species, alive and active. The agreement in detail with my dead original
was exact. Two very minute eyes, nearly close together, are at the front, whence pro-
jects a small hooked proboscis ; and below this the ciliate face is very prone. The

1 Eckstein says that these are connected with the great cervical eye by nerve-threads.

2 Eyferth (On the Lowest Forms of Life, 1878) says that Triophthabnus of Ehrenberg is but the
young condition of Eosphora ; and that, even in the egg, are seen two dark specks, near the eye, which
subsequently disappear. But Eckstein (Slab. u. Kiill. 188.'$) holds this conclusion doubtful, till the
entire development from the egg has been watched. lie confronts the points of consimilarity with
those of dissimilarity in two instructive tables.

PLATE XVI.

1. Copeus labiatus .

. dorsal view .

. G

la

edges of lip .

. G

2. Copeus spicatus .

dorsal view ....

. G

2a, 26. .. „

side views of head

. G

3. Copeus Cerberus .

dorsal view . . . . .

. G

3a. .. ....

side view .

. G

4. Copeus pachyurus

dorsal view ....

. G

4a. .. ....

transverse section

. G

46

head, showing buccal orifice

. G

5. Copeus caudatus .

dorsal view ....

. G

5a. .. .. . .

side view ....

. G

56

mastax and tropin

. G

5c. .. ...

. occipital antenna

. G

5a\ .. ....

hind dorsal tentacle

. G

6. Notommata collaris (?)

dorsal view ....

. H

6a. ,,

. side view ....

. H

ABIATUS. 2C.SPICATU.- RBERU! J.PACHYURUS.

5.C.0/

PLATE XVII.

1. Notomixuita brachyota

. dorsal view

. G

1«. „

. side view

. G

16. „ „

. end of brain, with eye ; side view

. G

2. Notommata saccigera

. dorsal view .....

. G

2a

. side view .....

. G

3. Notommata ausata

. dorsal view .....

. G

'6a. ,, ,,

. side view .....

. G

4. Notommata tripus

. dorsal view .....

. G

4a. „ „

. side view (smaller scale)

. G

46. „ „

. head, showing auricles

. G

*c. ,, )|

. tropin ......

. G

5. Notommata pilarius

. dorsal view .....

. G

5(7. ,, „

. side view .....

. G

56. „ „

. transverse section

. G

(i. Notommata aurita

. dorsal view .....

. G

Cxi. „ „

. side view .....

. G

66. „ „

. central lobe of brain, with eye .

. G

7. Notommata cyrtopus

. dorsal view .....

. G

la. „

. side view .....

. G

76. „ „

. tropin ......

. G

8. Notommata tuba .

. dorsal view .....

. G

9. Notommata lacinulata

. dorsal view

. G

•'"• )i >>

. side view .....

. G

96.

. tropin, ventral view .

. G

JC. ,, )|

. tropin, side view

. G

10. Eosphora aurita .

. dorsal view

. G

10a. „ „

. side view .....

. G

11. Taphrocampa Saundersi

ae . dorsal view .....

. G

Ha. „ „

. side view .....

. G

116. „ ,,

. transverse section

. G

12. Taphrocampa annulosa

. dorsal view .....

. G

12a. „ „

. side view .....

. G

126. „ „

. transverse section

. G

12c. ,, .. .

. trophi, side view ....

. G

Vld.

. trophi, ventral view .

. G

12c. „ „

. tail (var.)

. G

13. Albertia intrusor .

. ventral view ....

. G

13a. „ „

. side view

. G

L36. „ „

. trophi, ventral view .

. G

14. Albertia naiadis

. side view . . (after Mr. E. C. ]

3ousficld)

.

PLATE XVIII.

1. Notommata forcipata
■la. ,, ii
16. ,, ii

2. Notommata naias .
2a. ,, ,,
Zo. || ||

3. Pleurotrocha constricta.
3a. i, ,,
36. ,, n

OC. || ,,

4. Pleurotrocha leptura
4a. „ „

5. Pleurotrocha gibba
5a. „ „
G. Proales decipiens
6a. „ „

7. Proales sordida
7a, 76. „

8. Proales gibba

9. Proales petroniyzon
Jet. ,, ,,

JO. ,, ||

yc. ,, ,,

Jrf. ii ||

10. Proales tigridia
10a. „ „

11. Proales parasita .
11a. „ „

12. Distemma labiatum
12a.

13. Distemma Collinsii

14. Triophthalinus dorsualis (?) .
14a.

15. Furcularia aequalis
15a. „ „

16. Furcularia longiseta
16a. „ „

17. Proales felis .
17a. „ „ . .
176. ,

dorsal view .

side view

toes

ventral view

head ; dorsal view

mastax and tropin

dorsal view .

side view

head ; ventral view

foot and toes

dorsal view .

side view

dorsal view .

side view

dorsal view .

side view .

dorsal view .

side views .

tropin .

side view

ventral view

side view ; extended

side view ; contracted

head, side view ; enlarged

eye .

dorsal view .

side view .

side view .

mastax and trophi

dorsal view .

side view .

side view .

dorsal view .

side view .

dorsal view .

6ide view .

dorsal view .

side view

dorsal view .

side view .

trophi .

G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G

G

G
G

G

.

'

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PLATE XIX.

1. Distemma raptor
la.

16

If

Id

le. .. „

2. Diglena forcipata
2a.

26.
2c.

3. Diglena biraphis
3a.

4. Diglena circinator
4a. „

46. „ „

5. Diglena clastopis
•r)a. „

6. Diglena grandis .
6a. ., „

7. Diglena gibber .
6. Diglena caudata

9. Diglena giraffa .
9a. „

10. Diglena catellina
10a. „ „

11. Diglena pennollis

12. Furcnlaria micropus
1-2". „

13. Furcularia gibba
1"". „

136

loc. ,, ,.

14. Furcularia gracilis
14a.

1"). Furcularia niarina

15a.

156.

dorsal view G

side view G

trophi G

foot and toes . . . . " . . . G

contracted ; dorsal view . . . . G

„ side view G

dorsal view G

side view G

trophi, expanded G

trophi, shut G

dorsal view G

side view . G

dorsal view G

side view G

fore parts, in contraction . G

dorsal view G

side view G

dorsal view G

side view G

side view G

dorsal view ....... G

side view G

head, dorsal view . . . . . . G

dorsal view G

side view G

dorsal view ....... G

dorsal view G

side view ....... G

side view ....... G

mastax and trophi, obliquely ventral view . G

trophi, expanded ...... G

trophi, shut ....... G

dorsal view ....... G

side view G

side view ....... G

protruded trophi, and antenna . . . G

trophi G

as se ad ■.-..■ del

■

DISTIMMAi BIGlLlSNAs ¥ UWX ULAE:

LniSRAPTiJ ORGIPATA 5.DIG:BIRAPHIS.4.DIG: CH .TOPIS 6DIG: GRAND!

:ATELLINA.11.DIG;PERM0LLIS L4,F GRACILIS 15 F.Mf

PLATE XX.

1. Furcularia forficiila .

dorsal view ... . G

la. „ „ .

. side view

. G

16. „ „

toe ...

. G

2. Furcularia Boltoni

. dorsal view .

. G

2a.

side view

. G

3. Furcularia ensifera

dorsal view .

. G

oa. ,, ,,

side view

. G

4. Furcularia caeca

dorsal view .

. G

4a. „

side view

. G

5. Mastigocerca bicornis .

dorsal view .

. G

oa. ,, „ . .

side view

. G

5b. „ „

muscles

. G

6. Mastigocerca stylata .

side view

. G

6a. ,, „

mastax and tropin

. G

06. „

muscles

. G

7. Mastigocerca carinata

side view

. G

7a.

insertion of toe

. G

8. Mastigocerca elongata

side view

. G

9. Mastigocerca rattus .

. dorsal view .

. G

9a.

. side view

. G

10. Mastigocerca lophoessa

. side view

. G

10a,

empty lorica .

. G

11. Mastigocerca scipio .

. side view

. G

12. Mastigocerca inacera .

side view ; dead .

. G

IB. Eattulus tigris .

side view

. G

13a. ,, ,, . .

. mastax and trophi

. G

136, 13c

foot and toes

. G

14. Eattulus cimolius

dorsal view .

. G

14a. „ „

side view

. G

146, 14c.

mastax and trophi

. G

15. Eattulus sejunctipes .

dorsal view .

. G

15a.

side view

. G

16. Eattulus calyptue

side view

. G

17. Eattulus hehninthoides

obliquely ventral view

. G

17a.

side view

. G

18, 18a. Coelopus porcellus

side views

. G

186. „

front of lorica

. G

18c.

transverse muscles ; and toe

5, apart

. G

18d. „ „

toes, one within the other

. G

19. Ccelopus tenuior .

dorsal view .

. G

19a. „ „ . .

side view

. G

20. Coelopus minutus

dorsal view .

. G

20a. „ .

side view

. G

21. Ccelopus brachyurus .

side view

. G

22. Coelopus cavia

side view

. G

3b

Hinha/'t u»[.

-

-

3RACHY!

NOTOMMATAD^E. 49

brain hag a turbid yellowish appearance, at times clearly defined. The alimentary canal
is very large, darkly granulate, composed of many sacs ; and a slender rectum clearly
opens into a cloaca below the tubercular tail. Convoluted lateral canals run down each
side ; but no contractile vesicle could be discerned.

The manners are sluggish ; it twists and wriggles much, with little change of place.
It is a fine large species, not devoid of elegance when extended ; but it often contracts
into very uncouth shapes. — P.H.G.]

Length, ^ inch. Habitat. Maidenhead; an aquarium at Torquay (P.H.G.) : rare.

D. gibbek, Gosse, sp. nov.
(PI. XIX. fig. 7.)

[SP. CH. Body encased m a transparent leathery sheath, hunch-backed; face
prone ; frontal proboscis small ; toes long, decurvcd.

In sediment from one of my window-reservoirs, I found this large Diglena. About
the size of D. grandis, it much resembles that fine species in general appearance. Its
form is that of a cylinder, flattened along the belly ; the entire soft parts are encased in
what we might call a lorica, only that it is manifestly flexible : a difference, perhaps,
merely in degree. This sheath, of a glassy transparency, is almost unchangeable in
shape ; yet it has marked creases here and there, which are permanent, serving for
needful flexibility. At what might be called the shoulders, it rises to a conspicuous
conical hump, diminishing thence by a gradual slope to the hinder parts. The internal
organs do not rise above the cylindrical body- wall, leaving thus an ample cavity within
the sheath all down the back ; quite empty, save that a very delicate conglobate gland,
attached by a thread to the hinder extremity, works up and down within it, by the con-
tractions and contortions of the animal. What seemed the trochal front was, through
the inclination of the head, nearly on the level of, and continuous with, the ventral sur-
face, and was covered with vibratile cilia. Behind, the body-sheath is cut off obliquely,
with a well-marked edge, for the emission of a stout foot, which carries two long curved
blade-like toes, often thrown widely apart. On each toe, at about one-fourth of its
length, there is an abrupt decrease of diameter on its superior edge, with the appearance
of a joint ; and a delicate line crosses each near its point.

This individual appears to have been subjected to the remarkable accident of the
protrusion of the entire mastax, with all its accessories, from the frontal face, so that it
was totally unable to retract it. Whether this was the result of over-eagerness in feed-
ing, producing unguarded muscular exertion, or of violence from some of its predatory
foes, I cannot guess. I could discern no mark of any pinch on the body. But there
was a great extruded mass of flesh, amorphous and motionless, yet bearing a manifest
resemblance in outline to a mastax : while in an occasional glance that I could get at
its front, I saw what looked exceedingly like a long incus and a hooked malleus on each
side, though only the bottoms of these organs could be shaped, and that very vaguely.
Besides, there was not a trace of mastax to be seen within the head, for I searched
carefully for it ; the protruded mass was just where it would be, if such a misfortune
had occurred ; there was a conspicuous constriction behind the mass, evidently pre-
venting retraction ; while the mass was apparently of definite and unyielding shape,
containing hard and lengthened organs. The frontal disk, both above the mass and
also to a small extent below it, was covered with cilia in rapid, but feeble vibration ;
no whorls were produced in the surrounding fioccose ; no swimming or crawling pro-
gress was made by the animal ; though it constantly contorted its body, and threw about
its toes. Its vital power was manifestly stricken, and even the movements gradually
grew feebler and feebler. I had not detected the slightest motion within the (supposed)
mastax ; its nerves had been probably paralysed at once. But fragments of the rloccose
sediment kept on adhering to the exposed parts, as if these were glutinous ; and this
was more manifest at first than after some time. From the summit of the front a
minute finger-like proboscis descends. — P.H.G.]

VOL. II. e

50 THE ROTIFERA.

Length. Of head and body, T,V„- inch ; of toes, ^^ inch ; total length, about ,?2 inch ;
vertical height at hunch, about ^ inch. Habitat. An aquarium (P.H.G.).

D. FORCirATA, Ehrcnbcrg.
(PI. XIX. fig. 2.)

Diglma forcipata . . • Ehrenberg, Die Infus. 1838, p. 443, Taf. 1 v. fig. 1.

[SP. CH. Body cylindric, rather stout, obtuse at each end; face long, prone;
trophi typically forcipate ; toes scythe-shaped.

This is one of the imposing species ; stout, though more larva-like than either of the
foregoing. The integument is again firm and thick, and forms tranverse folds, which are
constant. The bluntly-tapered head carries the usual decurved fleshy proboscis, whence
the ciliated face descends in the ventral plane to a length about one-third that of the
body. A turbid brain descends far down the occiput, and bears two minute eyes on the
very frontal edge. The mastax and jaws show a fine development of the form normal
in this genus,1 and perhaps they could nowhere be studied with greater advantage.
The digestive apparatus differs little from that of D. grandis, or other species, but
there is here no projection above the cloaca. The foot is large and bulbous, severed
from the body by one of the strong folds ; it bears two toes, which are stout, shaped
like the blade of a pocket-knife or scythe. A large contractile vesicle occupies the
lower abdomen, which appeared strangely divided into two by a strong constriction.
Small vibratile tags were seen on attenuate threads running down each side.

I made acquaintance with this species, crowding the edges of a jar of water dipped
from the " Black Sea " at Wandsworth, in Jaimary 1850. It was active, but little given
to locomotion. Its numerous cilia are in constant agitation, and appear pale blue
by reflected light ; while the minute ruby-like eyes sparkle on the colourless body, the
turbid parts of which are like whitish clouds. What I have called the proboscis may
possibly be a broad lip, for it is visible only from the side. The wide spread of the
toes is characteristic.2 — P.H.G.]

Length, ^ to 7V inch. Habitat. Domestic aquaria near London, and Torquay
(P.H.G.) ; Sandhurst, Berks (Collins).

D. cikcinator, Cosse, sp. nov.
(PI. XIX. fig. 4.)

[SP. CH. Body slender at each end, gibbous in the middle; proboscis acute;
mastax moderate; toes slender, strongly incurved.

The fore parts are slender and nearly cylindrical (but flattened on the oral surface),
swelling somewhat suddenly to a great ovate body, gibbous on the back, but flat on the
belly ; and as suddenly diminishing behind to a rather thick and short foot, which carries
a pair of toes, each one a very regular quadrant of a circle in outline, broad at the base,
running off to a very fine point. These toes are decurved, and also incurved towards
each other, like the legs of a pair of calliper-compasses ; and often thrown widely
apart. The skin is very flexible, and, as the animal is every moment lengthening and
contracting, and throwing itself into the most varied contortions, makes many irregular
folds ; yet the form delineated always recurs, and is evidently characteristic. The
under surface has a remarkable projection (fig. 4a), pointing obliquely backward, more
or less conspicuous, visible sometimes on each side in the dorsal aspect (fig. 4). This
seems the limit of the ciliated face. The very front is furnished with a hook, which is
capable of being thrown forward, as if hinged or jointed ; and apparently sidewise also,
for it is occasionally glimpsed for an instant, at either side of the head. This process is
not a bent finger, but a regularly curved hook, hard and sharp-pointed. After a while

1 They are described and figured in my Mem. " On the Mand. Org." (Phil. IV. 1850) 435, figs. 50,51.

2 The animal described and figured by Mr. J. E. Lord (Microsc. News, 1884, p. 140, figs. 23a, b, c)
IB, T lave little doubt, the present species.

NOTOMMATADiE. 51

the slender fore parts were retracted, and then from the gibbous body was seen project-
ing a curious little puckered bundle of transparent flesh and skin, as shown at fig. ib.

This species I first found in the sediment of one of my indoor tanks among decaying
conferva and milfoil : this was in June 1885. Afterwards it occurred again in a tube
sent from Dundee by Mr. Hood. All the features were exactly the same as before ; but
this was more impatiently restless. I thought I saw a pair of frontal eyes, but I could
not be quite positive. In a brief quiescence I made a careful study of the tropin, whose
points are in contact with the very skin of the front. — P.H.Gr.]

Length, -j-^ inch. Habitat. An aquarium at Torquay ; Dundee (P.H.G.).

D. gieafpa, Gosse, sp. nov.
(PI. XIX. fig. 9.)

[SP. CH. Body slender, necked; eyes distinct, fronted, protuberant; toes slender,
straight.

This form, having some resemblance to D. circinator, differs from it, not only in the
more marked neck, but in the toes being quite straight instead of circularly curved.
For, though this may seem an unimportant character, I think the form of the toes will
be found to present remarkable constancy in the same species. In circinator I could
not be certain of eyes, but in this species they are well-marked, though minute, of dark
hue, situate on the very front of the head, so close to the skin as to be prominent as
tiny black warts on the surface. The head is small, and its connection with the body
is by a sort of neck which can be greatly lengthened and attenuated, as the animal
makes its frequent explorations through the free water in all directions, feeling about,
very much as an earthworm does in the air. For this the skin is very flexible and
versatile. The abdomen is tumid ; but not so abruptly gibbous as in circinator. The
foot is taper, and the toes moderately long, straight in every direction, not blade-
shaped, but regularly diminished to great slenderness, and very fine points. There is
no tail. Beneath the eyes the front forms a well-marked proboscis, which takes the
shape of a decurved hook. At times this appears of equal thickness throughout, and
blunt, or even truncate ; then it is distinctly seen in the same individual much length-
ened, and tapering to a fine point. Can the terminal part be protrusile ? The ciliated
face is quite prone, and appears to run far back on the ventral surface, where a chin-like
prominence indicates the end of a ciliated furrow. (See Diglcna forcipata, fig. 2a.)
The skin, though flexible, seems very strong ; it is continually thrown into folds by the
unceasing contortions and contractions of the animal ; it looks leathery, but is perfectly
colourless and brilliantly transparent. It is a lively, vigorous, attractive creature ;
pushing among the sediment, occasionally swimming with a smooth gliding motion.

I found another specimen in the same water, exactly agreeing with the above. It
had the odd habit of forcibly contracting the foot, and throwing back the toes, as far as
the tapering outline of the body would allow ; and then protruding the foot with a jerk,
bringing the toes at the instant to a right-angle with each other, and therefore horizontal ;
immediately repeating the curious action ; and so for fifty times together. When
swimming glidingly, it will suddenly quicken its pace an instant, and make a sensible
snap, as if it seized something ; and this again and again ; though my eye could detect
no atom in the clear water. — P.H.G.]

Length, T^ inch. Habitat. Woolston (P.H.G.) : rare.

D. caudata, Ehrenberg.

(PL XIX. fig. 8.)
Diglena caudata . . . Ehrenberg, Die Infus. p. 445, Taf. lv. fig. 6.

[SP. CH. Body cylindric, long, slender ; front broadly truncate, with two frontal
colourless eyes ; foot short, very thick, with two long straight slender toes.

It is excessively versatile and variable in form, constantly contracting into inde-

E 2

52 THE EOTIFERA.

scribable shapes (of which fig. 8b may serve as an example), with various sharp folds and
angles. Yet it may be said to have a characteristic form, which is sub-parallel-sided
viewed dorsally ; but which, viewed laterally, is narrow for the anterior third, where it
rises abruptly to nearly double the height. This is generally maintained to the end of
the trunk, where it descends with even a sharper angle to give emission to a thick foot,
carrying two long, straight, slender, acute toes. The front is unusually wide and
truncate, viewed dorsally ; but laterally, it is seen to project into the usual fleshy hook,
which is probably sensitive, and used to collect and test food. The ciliated face is
f.hnost prone; behind this is an ample mastax with jaws of the normal pincer- form.
The viscera present nothing noteworthy. The whole animal is of crystalline clearness ;
and is devoid of colour, so far as I have seen. The eyes, too, if eyes they are, are two
colourless globules of considerable size and of somewhat irregular outline, placed wider
apart than in Ehrenberg's figure, at the very front. The toes are long, tapering regularly
to produced acute points, but slender throughout and quite straight, whereby they differ
from those of clastopis. They are frequently thrown forward suddenly to more than a
right-angle. (See fig. 8 and Ehrenberg's fig. 4.) The lumbar fold of skin is often strong
and shai'p ; but there is no projection really answering to a tail ; and the specific name
is a misnomer. I examined two specimens in September 1885, from water which had
stood on my table about four weeks, originally from Woolston Pond. — P.H.G.]

Length. About T}3 inch. Habitat. Woolston (P.H.G.) ; Sandhurst (Collins).

D. pekmollis, Gosse, sp. nov.
(PI. XIX. fig. 11.)

[SP, CH. Body extremely soft and versatile inform, swollen in the middle, broad
and truncate in front, tapering behind to a thick and long foot ; toes two furcate, slen-
der, acute.

I am conscious that the above is an unsatisfactory diagnosis of what I am sure is a
distinct form. In a tube dipped from a fresh-water loch by Mr. Hood, containing a few
leaves of milfoil thickly studded with Bhizota, I found a Notommatoid creature, cer-
tainly new to me, and apparently undescribed. Its most salient character was its exces-
sive softness, as if it had no skin at all, but were a lump of mere jelly, yet intensely active
and restless, swelling and contracting, lengthening and shortening, twisting and infold-
ing, without the slightest intermission, for more than two days while under observation.
All this made it quite unlike any other Rotiferon I had ever met with. The slender
toes, at the end of a rather large foot, are very mobile, ever thrown about to their ut-
most, or suddenly brought point to point with a snap ; in this specimen they had the
remarkable peculiarity of what looked like a minute terminal joint, like a separate claw,
which, however, was not apparent in other examples. The front is widely truncate,
composed of many globose transparent cells ; from the midst of which projects the usual
soft triangular proboscis. The ciliated face below this is prone, whence frequently the
tropin,— an incus with circularly forcipate rami, worked by long mallei, — are protruded
with energetic snaps and snatches. Below the mastax is a vast alimentary canal, con-
sisting of nucleate cells ; an ovary of embryonic vesicles occupying the venter. I could
not detect any eye-spots ; but a rather short brain filled the occiput.

I subsequently obtained other examples from the same quarter. In one was a largo
contractile vesicle which I saw discharged, but I could not time its period. The cor-
ners of the front, when rotating, have almost the appearance of auricles. — P.H.G.]

Length. About y^ inch. Habitat. A pool near Dundee (P.H.G.)

D. clastopis, Gosse, sp. nov.
(PI. XIX. fig. 5.)
[SP. CH. Body cylindric, long, slender ; front rounded, without visible hook; foot
h ng, slender, with two long decurved toes.

NOTOMMATADZE. 53

I am not quite clear whether I ought to name this form. But, assuming that the
cluster of unequal-sized and irregular- shaped red specks, resembling the fragments of
crushed rubies, at the very front of the head, represents two frontal eyes, I place it in
this genus, especially as the trophi appear to agree with those of the slenderer Diglena,
and there is much similarity to them in general contour and conformation.

Its shape is long, thin, and nearly parallel-sided, viewed dorsally (fig. 5), abruptly
narrowed to a very slender foot, and long, thin, acute, decurved toes. Laterally (fig. 5«),
the lumbar region is gibbous without any marked fold. The eyes, resembling broken
fragments, as said, are placed at the very front ; and are conspicuous, even in the swift
shootings of the animal. The front descends to a blunt angle, which may be the
anterior point of a prone ciliated face. I could discern no fleshy hook. I did not detect
the brain ; but behind the mastax were two opaque globules, which seemed not to be
eyes, but were possibly chalk-masses, smaller, and more shapely, than usual. A very
long alimentary canal reached far down the cavity, well filled with food of various tints,
accumulated in many dark nodules, which imparted to the animal in its movements a
very peculiar spotted appearance. Most of the internal structure is as yet undefined.

This is one sample of the very rich harvest of species that I reaped out of a small
bottle procured for me from Sandhurst Wood pool, by Dr. Collins, in June 1855.
Though I had the specimen under my eye for an hour or more, I could scarcely, in all
that time, find it still long enough to permit me to turn to the paper, in order to delineate
it ; and if I did, I was almost sure to lose it out of the field, to find it again with diffi-
culty. It is swift and headlong in its course, shooting through the free water rather
than swimming, and only now and then entering a cloud of floccose sediment, to push,
with persevering violence, a way through it.

Only this single example has been subjected to examination. — P.H.G.]

length, T}^ inch. Habitat. Sandhurst, Berks (P.H.G.).

D. catellina, Ehrenberg.
(PI. XIX. fig. 10.)
Diglcna catellina . . . Ehrenberg, Die Inftis. 1838, p. 444, Taf. lv. fig. 3.

[SP. CH. Body cylindric, short, abruptly truncate at each end; toes short, straight
acute, projected from the ventral side, at a right-angle to the body -axis.

This plump, sturdy little creature occurred among my earliest researches in the
summer of 18-49. It is a true Diglcna, yet is very dissimilar to its fellows, replacing
their long, lithe slenderness by a short thick body, having strong skin-folds, often quite
abruptly truncate before and behind. Now and then, indeed, a bluff rounded head is
pushed out, carrying two eye-points at its front, and a ciliated face, hardly prone.
From the broad square stern, a small foot projects at the lower margin, and two small,
slender, acute toes, pointing downward, serve the creature for support and for locomo-
tion. The internal organs are little noteworthy. There is a large occipital brain, and
an enormous mastax, of which the jaws are normal.

Ehrenberg describes this tiny species as both marine and lacustrine. I have found
many specimens from tide-pools in the Tay estuary, collected by Mr. Hood. — P.H.G.]

Length, ^^ to -pj- inch. Habitat. A garden near London ; a pond at Snaresbrook
(P.H.G.) ; Sandhurst (Dr. Collins) ; marine tide-pools in the Firth of Tay (P.H.G.).

DlGLENA (?) BTBAPHIS, GoSSC.

(PL XIX. fig. 3.)
Diglcna (?) biraphis . . . Gosse, Ann. Nat. Hist. vol. viii. 1851, p. 200.

[SP. CH. Body oblong, the head and abdomen gently swelling ; toes long, slender,
straight, and perfectly even in thickness; eyes placed close together frontally ; jaws

54 THE ROTIFERA.

protrusile ; alimentary canal very large, projected behind and above the mastax, always
filled with green matter.

This is an animal of no inconsiderable size, which has the technical characters of
Diglena, but has little affinity with that genus, in structure or manners. My first ac-
quaintance with it was in October 1849. A filamentous plant, growing in a pan sunk in
my own garden, was thickly covered with a floccose matter, inhabited by numbers of
Stentor polymorphic Among them were specimens of this Diglena (?). In January
1851, I again found it in the same water, and on a subsequent occasion; but I have
never met with it since.

The form is gracefully swelling and vase-like, not at all resembling a Diglena in
appearance ; it has much the aspect of being loricate, but it is not. Two eyes are placed
at the extreme front ; small, so close together as to be readily mistaken for one, brilliantly
crimson. The transparent mastax, in situ, shows a pair of incurved strong pincers,
whose approaching tips are two-toothed. These can be extended from the front for
half their length, and seem to be a formidable instrument for seizing prey. These are,
no doubt, the rami of an incus. What appears remarkable is that a great saccular lobe
of the stomach runs up behind the mastax into the occiput, and divides into two lobules.
The whole alimentary canal, with these lobes, was, in every example, uniformly filled
with round green granules, the exact similarity of which to the component granules of
the Stentor s and the Loxodes, which abounded in the same water (together with various
species of Euglena), suggested that the normal food of the Rotiferon may consist of the
juices of these Polygastrica, especially as its formidable forceps seems to indicate car-
nivorous propensities. The long straight rod-like toes are now and then turned up, so
as to incline over the back ; occasionally their tips are crossed. — P.H.G.]

Length, TJIJ inch. Habitat. A garden-pan near London (P.H.G.) : rare.

Genus DISTEMMA, Ehrenherg.

[GEN. CH. Body more or less cylindric, long, slender before, swollen behind, ver-
satile; tico cervical eyes; front furnished, with a fleshy proboscis; toes tioo, furcate.

This somewhat obscure genus Ehrenberg constitutes on four species. These, how-
ever, must be reduced to two : for D. setigerum clearly belongs to the family Rattulidce ;
and D. marinum is one of the Loricata. The others I have not met with. But I
enumerate three species, apparently undescribed, which seem to come into the genus.

In aspect and manners they closely resemble Diglena, especially in their long, lithe,
versatile forms, generally swollen behind ; in the presence of soft tentacular appendages
to the front ; in the forcipate form and protrusile character of their tropin ; and in their
fierce raptorial habits. The species inhabit the sea and fresh waters. — P.H.G.]

D. raptor, Gosse, sp. nov.
(PL XIX. fig. 1.)

[SP. CH. Body long, gibbous behind, very changeable ; front with a long projectile
lip; foot short; toes small, slender, decurved. Marine.

The lithe flexible form is usually lengthened, slender in the middle, becoming high
behind, its outline descending in an abrupt curve to the very small foot. This is armed
with two toes, whose thickness tapers abruptly at the middle (fig. le). It is near
D.forcipatum, but is distinguished by this peculiarity of the toes, and by their curvature.
And it is marine. The head is rounded, the front produced into three fleshy ciliate
points, and a conical projection on each side. The central point is probably the tip of a
curious fleshy process, which is now and then rapidly pushed out and in (figs. 1, la), quite
straight, thus differing from the proboscis of Diglena. The lateral projections, when this

NOTOMMATAD/E. 55

lip is retracted, close against each other, as in Dinocharis. The median line of the dorsum
makes a sharp roof-like angle, especially at the lumbar part, but does not rise to a ridge.
Eyes are sometimes clear and distinct, one on each side of the mastax, wide apart,
highly refractile, very pale red, but well denned ; but in some specimens they are quite
invisible. The trophi consist of an incus, with rami broad and circularly forcipate, on
which work slender bowed mallei (fig. lb). The mastax is often retracted below the
middle of the body ; then the animal will suddenly elongate, and the mastax will be
driven forward and backward, rapidly and far, the rami snapping fiercely. This snap-
ping snatching action is very observable. Sometimes the mastax is, fully half or more,
protruded from the front, and this again and again in rapid succession, the jaws giving
a short snap at each time. It is incessantly restless, sudden and rapid in its contrac-
tions and turnings, yet not very locomotive, remaining long anchored to the glass by the
toe-tips, swaying to and fro, much like a Monostyla, often stretching the toes apart.

I owe my acquaintance with this interesting form to Mr. John Hood, of Dundee,
who, lately, at my request, searched for marine Rotifera. He presently sent me con-
tributions of sea-water, from the estuary of the Tay, in which I found many species.
Among the stems of a conferva this new Distemma was pushing and snatching.

It seems tenacious of life. The individual first observed lived in a live-box, con-
taining a thin pellicle of water, for parts of three days, during which other Rotifera, its
associates, had one by one succumbed. Perhaps from hunger, this specimen roamed
incessantly through the clear water, snapping at every atom, now and then seizing a
small diatom, and drawing it into the buccal funnel, to reject it instantly. The jaws
were protruded and retracted every moment with lightning-like rapidity. Now and then
a tiny cloud of floccose would be dragged in and chewed eagerly, then forcibly ejected.
The force and energy displayed by so small an atom was remarkable. The sight seems
to have a very small range. This one seized and devoured many Monads and even
large Protozoa ; but it seemed to have no power of discerning them till they were close
to its head ; then the action was prompt enough.

The highest expression of animal life that I have observed among Rotifera is this
little obscure Distemma. As a fowl picks up minute atoms of food from the earth and
pebbles and rubbish with which it is mingled, showing sight, observation, discrimination,
selection, will, so does this Distemma manifestly snap up its food-atoms, often invisible
to our eyes, selecting them l with rapid precision from other surrounding atoms. The
jaws are thrust out and withdrawn, as I have said, with a quickness which we cannot
follow, and with stroke succeeding stroke, quite as rapidly as a hen's beak picks its
morsels, and evidently takes something at each. The way in which it pounces upon
animacules that we can discern, and the energetic vigour with which it seizes them, are
admirable, and quite unparalleled among Rotifera, so far as my experience goes ; and
there is hardly a species described in this work that has not come under my observa-
tion. If we could descend to his level, and form a personal acquaintance with him, I am
sure we should find this Distemma a person of great decision of character. — P.H.G.].

Length, (as in figs 1, la) T^ inch. Habitat. Tay-mouth : tide-pools (J.H.).

D. collinsii, Gosse, sp. now
(PI. XVIII. fig. 13.)

[SP. CH. Body cylindric, long ; head large ; foot stout ; toes two, furcate, long,
slender, unnotched, acute. Lacustrine.

This species is known to me only by a drawing in Dr. Collins's Note-book. It is re-
presented with a long body, a head of increased diameter, a stout foot, and two toes,

1 " The power of choice is the distinctive peculiarity of a mental being." "All activities that are
indicative of choice [except reflex actions] are indicative of consciousness. Wherever we see a living
organism apparently exerting intentional choice, we may infer that it is conscious choice ; and there-
fore that the organism has a mind."- Romanes, Merit. Evol. in Anim. pp. 47, 17.

66 THE ROTIFERA.

which are thick, decurved at the tips, and of a length equal to one third of the whole
animal when extended. The pencil-sketch has not many details of organisation.

The only note which the ohserver has added is the following : — " It has the power
of drawing-ill the first joint of the foot into the interior of the body ; and has a peculiar
manner of separating the pair of curved toes." — P.H.G.]

Length. Unrecorded. Habitat. Sandhurst, Berks (Dr. Collins).

D. (?) labiatum, Gosse, sp. 110V.
(PL XVIII. fig. 12.)

[SP. CH. Slender, long, gibborLS ; front furnished ivith a protrusile lip; foot long,
with two minute furcate, virgate toes.

Beyond what the mere outline suggests, as conveyed in the figures, I can give little
information concerning this species. With much doubt I place it in the present genus ;
and that only on the possibility that two obscure spots, dimly seen in the neck, may
have been eyes. They may have represented the trophi. In fact my knowledge of this
form rests on a single brief observation. I was examining an aquatic moss, which Dr.
Collins procured for me in June 1885, when this little creature glided out. I saw in a
moment it was new to me, but my attention was already occupied. There were in that
live-box, at that instant, three or four Rotifera unknown to me ; as many papers were
before me, on which I was labouring to reproduce the portrait of each, feature by feature,
as I could catch it. Here was one more. It was a complete embarras des richesses.
What could I do ? I hastily threw in the outlines here given, careful to secure correct-
ness in what was produced, but deferring minute examination in the hope of seeing it
again ; while I pursued the study of those already in hand. The present subject, how-
ever, found speedy concealment among the moss, and I could find it no more ; nor has
it ever reappeared. The form, particularly in the lateral aspect, recalls the outre shape
of Notommata caudata, with its long neck, elevated back, and slender foot ; but the re-
semblance is only superficial. Its chief peculiarities are — (1) a slender parallel-sided,
squarely- truncate proboscis or lip, projecting medially from the front, which is seen in
the side view to be somewhat low in position ; it seemed retractile to some extent ; (2)
a long, slender, and tapering foot-joint, furnished with a furcate pair of toes, very
minute, of equal thickness throughout, obtuse ; like tiny pegs.

I can find nothing in Ehrenberg with which satisfactorily to identify it. — P.H.G.]

Length. About -,4^ inch. Habitat. Sandhurst, Berks (P.H.G.).

[N.B. — In Dr. Collins's Note-book are pencil-sketches of an evidently large animal,
which may possibly be the Triophthalmus dorsualis of Ehrenberg. I have carefully
copied the sketches (PI. xviii. figs. 14, 14a) ; but the details are not suflicicnt for dia-
gnosis ; and there are no descriptive notes. I have not myself met with anything like it.
— P.H.G.]

CHAPTEK X.

PLOIMA

(LORICATA).

How much weariness has there been in the human race during the
last fifty years, because the human race cannot stop politically where it
was, and, finding no rest, is pushed to a strange future that the wisest
look forward to gravely, as certainly very dark, and probably very danger-
ous ! Meanwhile have the bees suffered any political uneasiness ? have
they doubted the use of royalty, or begrudged the cost of their Queen ?
Have those industrious republicans, the ants, gone about uneasily seeking
after a sovereign ? Has the eagle grown weary of his isolation, and
Bought strength in the practice of socialism ? Has the dog become too
enlightened to endure any longer his position as man's humble friend,
and contemplated a canine union for mutual protection against masters ?
No ! the great principles of these existences are superior to change ; and
that which man is perpetually seeking, a political order in perfect
harmony with his condition, the brute has inherited with his instincts.

P. G. Hamerton. Chapters on Animals.

Presumption is our natural and original disease. Man withdraws and
separates himself from the crowd of other creatures ; cuts out the shares
of the animals, his fellows and companions; and distributes to them
portions of faculties and force, as himself thinks fit. How does he know,
by the strength of his understanding, the secret and internal motions of
animals; ? — Montaigne.

CHAPTER X.

Sub-Order Lokioata.
Integument stiffened to a wholly, or partially , inclosing shell ; foot various.

Family XI. RATTULID.E.

[Body cylindric or fusiform, smooth, without plica or angles ; contained in a lorica
closed all round, but open at each end, often ridged; trophi long, asymmetric ; eye
single, cervical. Generally subject to abnormal conditions.

This family comes first in the Loricate sub-order, because the loricate structure is in
varied condition ; for, whereas in some species it is indubitable, in others, which yet can-
not be severed from these, the integument is still thin, flexible, and membranous.
Ehrenberg, indeed, while he assigned M. carinata to the Loricata, removed his genus
Monocerca far away to Il-loricata. Yet that carinata and rattus are congeneric cannot
be doubted by anyone who knows both; bicornis certainly goes with the latter. The
sausage-shaped species have many family affinities with these ; though subdivisible inter
se. The peculiar form of trophi represented in figs. GO-62 of my Memoir " On the Manduc.
Organs" runs with little variation through all.

The most curious peculiarity in the family is its tendency to asymmetry, which
appears in many organs. In the mastax the right malleus always differs from the left ;
when there is an elevated ridge on the dorsum, it is apt to be bent over on one side, and,
instead of running straight down the middle, to pass slantwise from right to left ; when
two antennaB are present they are unequal. The toes, sometimes normal, are often
reduced to a single style, with minute sub-styles grouped around its base. In other
cases they are modified in a most unprecedented manner, described under the genus
Cozlopus. On the whole, it is a group of very peculiar interest, both to the scient and to
the intelligent seeker for amusement. — P. H.G.J

Genus MASTIGOCERCA, Ehrenberg.

[GEN. CH. Body fusiform or irregularly thick, not lunate ; toe a single style, with
accessory stylets at its base ; lorica of ten furnished with a thin dorsal ridge.

The terminal style is by no means a tail, but a true toe, however modified. The
homology of the sub-styles is not clear. The surface of the body is usually smooth and
polished, often elegantly tapered ; nor does the thin elevated carina of the dorsum
materially interfere with this elegance, which the long taper toe admirably finishes.
This organ, though inflexible throughout, is capable of rapid and sudden motions, being
bent right and left, and whisked to and fro with great agility. The mastax is usually
pear-shaped and very long, but the oesophagus, a sinuate duct, leads from it almost at
its very summit occipitally, just where the mallei work upon the incus. Thus the great
length of the mastax does not intrench on the needful length of the stomach, since this
viscus begins far forward. The muscles, in many species, especially the transverse series,
have been well resolved. Muciparous glands are richly supplied. Surprise is often felt
that Rotifera with but a single style should be able to maintain so firm a hold upon

GO THE ROTIFERA.

glass as to resist the force with which the surrounding water is carried up into a pipette
by the pressure of the atmosphere. It is doubtless by the adhesive power of the clear
glue secreted and poured out by the oblong foot-glands. In Mastigocerca this may often
be seen running down the outside of the toe, its production seemingly subject to the
animal's will. When first put into the live-box, it is commonly poured forth abundantly,
so as to accumulate around the point, and to drag in a thick glairy stream behind it.
I have seen it surround the terminal half of the spine to a thickness four times as great
as that of the spine itself. Or it will run from the base downward, like a thick spiral
cord. Sometimes it is not perceptible. The male has not been detected in the family.
— P.H.G.]

M. carinata, Elirenbcrg.
(PI. XX. fig. 7.)
Mastigocerca carinata . . . Ehienberg, Die Infus. 1838, p. 4G0, Taf. lvii. fig. 7.

[SP. CH. Body long -oval ; lorica ridged; ridge high, arched, reaching to middle
of body ; toe straight, equal in length to body-and-head ; sub-styles very minute.

The height of the dorsal ridge is very characteristic in this familiar species, rising,
in the midst of its length, to fully half of the vertical thickness (i.e. from back to breast)
of the body. Its cessation, too, just beyond the middle of the back, gives a peculiar
humped outline to the forepart, viewed laterally. The belly-line is about equally curved
with that of the back. The ridge, as already observed, is not set-on straight down the
dorsal centre, but on a line that slants considerably to the left, while in its elevation it
leans over to the right. It is manifestly hollow along its base, for the viscera may often
be seen extending into it for a little way. It is marked on its basal part, through its
length, with close-set corrugations. The front is rounded, with many minute eminences,
on which the cilia, which make two distinct vortices, are set ; they increase in size
and height to the occiput, where an antenna projects, capable of being erected or inclined.
A long occipital brain carries a rather large bright-red eye, set like a wart at its interior
lower angle. The mastax, a pear-shaped bag, is enormous, reaching, from the front,
half the body-length. It contains an incus with a slender straight fulcrum, the rami of
which are obsolescent and the alulae very large, and two bent mallei, unequal in size
and form. There is a very small contractile vesicle, whose period is shorter than I
have observed in any other Rotiferon, twenty-five times a minute. The distension of
the viscera conceals the branchial vessels, but I have seen one vibratile tag.

The foot consists of an ovate bulb, to which is jointed the toe as a slender spine in the
midst of two or three bract-like accessory styles, one of which is slightly longer than the
others, distinctly moveable. The toe moves in all directions except backwards. — P.H.G.]

Length. Of lorica, ^^ inch ; of toe, ^ \ „ inch ; depth to summit of ridge, B^ inch.
Habitat. Pools ; generally distributed : common.

M. lophoessa, Gosse, sp. nov.
(PI. XX. fig. 10.)

[SP. CH. Body long-oval ; dorsal ridge reaching to the foot, nearly uniform in
height ; toe straight, two-thirds as long as body ; sub-styles one-third of toe-length.

This I think a well-defined species. The ridge attains nearly to as great a height as
in carinata, and is continued to the base of the foot. Its outline runs in several arches,
and descends rather abruptly at the end. It is marked with faint radiating corrugations.
The principal toe is a straight slender style, gradually tapering to a fine point, as in
carinata, but not quite so long in proportion ; and the accessory styles, of which I could
discern two, arc of unequal length, the longer equalling fully one-third of tho principal ;
whereas in carinata it is not more than about one-eighth, by very careful niicrometric
measurement. The rcastax and jaws seemed much shorter than usual, but of the common

^&X«...

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-Ou

t&fyjuk.-(#j

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'■■■ -\ ■■'■■■ J <

RATTULID/E. 61

form. I did not discern any eye, but do not doubt its presence in life. None of the
viscera showed any peculiarity.

This species I met with at the beginning of October 1885, among sediment furnished
mo by Mr. Bolton. It was just dead ; but afforded me a good observation. A week or
two later, the empty lorica of another example occurred from the same ditch ; and, a little
afterwards, in water from Bracebridge Pool, still from Mr. Bolton, I found it yet again.
And since, from Mr. Hood. The characters were constant in all. — P.H.G.]

Length, J§ to ^ inch ; lorica, ^^ inch ; depth at middle of ridge, T^- inch.
Habitat. Birmingham ; Dundee. Pools : rare (P.H.G.).

M. scipio, Gosse, sp. nov.
(PI. XX. fig. 11.)

[SP. CH. Eody sub-cylindrical, slightly larger in front, thick and round behind ;
the front of the lorica set with three spines ; a long low ridge considerably on the right
side; toe half the length of the lorica; sub-styles one-fourth the length of the toe.
Greatest width about one-eighth of total length.

This and the following two species have much in common ; yet are distinguished by
details of form and structure. The general outline differs in each, as shown in the
figures. The particulars detailed in the technical Spec. char, of each, though minute,
seem trustworthy. What appears distinctive of the present is that the front edge of the
lorica, otherwise smoothly truncate, carries three projecting spines, one occipital and
two lateral, each of which runs down the outside of the lorica for a short distance as a
sharp ridge. There is thus a certain resemblance to M. bicomis.

The general outline is that of a stout straight stick, thickened slightly near the head,
with both ends rounded abruptly. At the extremity a very low ridge is seen, which
runs up, considerably to the right of the medial dorsal line, almost imperceptibly at
length, to the very front. The foot, which is short and bulbous, is contained within the
rounded end of the trunk, but carries, attached to it by a very facile joint, a toe in
the form of a slender spine, about two-fifths as long as the lorica. The spine, as in
carinata, is not quite straight ; it bears at its base a short supplementary style on each
side, which moves on the basal joint with its own motions. Each is about one-fourth
as long as the toe. The mastax is of immense size, occupying much more than half the
body-length ; the tropin are often pushed to the very front. Vibrating cilia are disposed
on minute eminences, of which the central one is continually lengthened and shortened.
An ample brain runs down the occipital region, bearing a conspicuous crimson eye on its
extreme point. I saw no protruded antenna. Very characteristic (in all the specimens
observed) was a long clear blank space, wide at the foot-point, and tapering to near the
mid-venter : probably a contractile vesicle ; only that I could never see it contract. The
whole animal is transparent and colourless.

I first saw this species in the summer of 1885, on an aquatic moss, growing in one
of my window tanks. I subsequently saw other specimens ; one in particular, glued fast
to a filament by the toe, illustrating the abundance and tenacity of this excretion, which,
evidently, is not always under the control of the animal, so that, if usually it is a con-
venience, it may become a snare. This individual was not quite dead, yet the turbid
matter of the head was already forced out, together with many oil-globules. — P.H.G.].

Length. With the toe, ^^ inch. Habitat. On water-moss in pools (P.H.G. ).

M. maceka, Gosse, sp. nov.
(PI. XX. fig. 12.)

[SP. CH. Body fusiform, thickest behind the middle ; lorica smooth-edged in
front; without visible ridge ; toe half the length of the lorica; sub-styles one-fourth
the length of the toe.

62 THE ROTIFERA.

I can give little information about this species, which yet seems distinct. I have
seen but a single example, and that was moribund, if not actually dead. I met with it
in June 1885, in water from Woolston Pond, Hants, courteously supplied by Miss
Davies. Spontaneous motion had not ceased, particularly in the toe-spines, and the
structure of the abdominal viscera was still perfect ; yet all the foreparts were one mass
of dissolving flesh and air-bubbles, protruding from the front and spreading around. An
eye- spot could be detected in the mass ; but of the trophi not a trace.

The form recalls M. rattus ; but greatly produced in length, and without discernible
carina. I hesitate whether it should not be placed in the genus Coelopus ; for it appears
to have two unequal toe-spines, the smaller fitting beneath the other, and about one-
fourth of its length. But the longer is straight, the shorter curved. So that, in defect
of fuller observation, I assume that the shorter is but one of the supplementary styles
common in this family ; though I could detect other minuter spinelets at the base.

The specimen I unfortunately neglected to measure ; but the total length to the toe-
point was, approximately, rJ0- inch. — P.H.G.] Habitat. AVoolston (P.H.G.).

M. ELONGATA, GoSSC, Sp. 110V.

(PL XX. fig. 8.)

[SP. CH. Body nearly cylindric, slightly larger before than behind ; lorica smooth-
edged in front ; ridge long, low, medial; toe as long as the lorica; sub-styles oue-
liccutictJi the length of the toe.

This seems a very distinct species. Its smooth, hyaline, arched lorica, with a widely
truncate front edge, quite smooth, but tapering in a graceful curve to the hinder end,
where a small tubular orifice, also abruptly truncate, allows emission of the foot ; is very
distinctive from the preceding two species, to which, however, its remarkable length
allies it. It is nearer to M. carinata than they; yet sufficiently remote from this by
conspicuous characters ; in particular, by the dorsal ridge, which is low throughout, and,
as I believe, medial. The greatest depth of the lorica (viz. just behind the front edge)
is just one-fourth of its length. This front edge, destitute of points, is apparently
attenuated to thin membrane, thrown into minute transverse folds, inverted and everted
with the motions of the head-mass. The foot is of one minute joint, exterior to the
lorica. It bears one toe, a spine of great length and slenderness, almost quite straight,
nearly uniform in thickness to the fine point. Its length about equals that of the lorica.
Two accessory styles, very minute, are appressed to its base. The mastax is ample, and,
as in M. carinata, having two mallei, unequal and dissimilar.

I owe my acquaintance with this charming species to Mr. Hood of Dundee, whose
keen eye had already detected its specific distinctness. He sent me, in November 1885,
water from one of the pools near Dundee, containing a number of living specimens.
They are sprightly and active, swimming elegantly through the clear water, with a
smooth but swift gliding movement. — P.H.G.]

Lmgth. Total, ,1, inch ; of toe, T]T inch ; of sub-styles, ^7\tjy inch ; depth of lorica,
310 inch. Habitat. Loch near Dundee (J.H.) ; Birmingham (1M1.G.) : not rare.

M. hattus, Elvrcnbcrg.
(PL XX. fig. 9.)
Monocerca rattus . . . Ehrenbcrg, Die Iufus. 1838, p. 422, Taf. xlviii. fi;,. 7.

[SP. CH. Body ovate, truncate in front, pointed behind; ridge reaching to ttco-

tliirds, evenly arched; toe longer than body-and-head together ; sub-styles, very minute.

The lorica is elegantly ovate, subtruncate before, where a thiols head protrudes, with

a rounded front, on which numerous pimples are beset with bristle-like cilia, making

RATTULID^l. 63

a single vortex. Behind the head is a strong transverse fold, seen in retraction, but
obliterated in extension ; close to which projects horizontally backward a long antenna.
The whole structure bears a very close resemblance to tbat of M. carinata, from which,
however, it is distinguishable at a glance. The mastax and tropin are on the same
pattern ; but the right malleus is even still further reduced, only a slight vestige of it
remaining. The dorsal ridge is evident but very low, with an outline regularly and ele-
gantly curved. The foot is small and short ; the toe nearly straight, long, slender,
acute, closely embraced at its very base by several very short sub-styles. A copious
secretion of mucus is often seen running down like a cord, from the base, whose viscosity
is attested by the force with which the tip is moored to the glass.

This very elegant and sprightly animal is well nained, for its resemblance to a rat is
at once manifest, both in form and movement. It moves nimbly about among the
vegetation, now nibbling, now turning short, now scudding hither and thither by little
starts, whisking its long tail (toe) about in all directions. It swims gracefully and
rapidly, revolving often on its axis. The periodic evacuations of its small contractile
vesicle are thirteen in a minute. The species is often found in company of the finer De-
smidece, and from the alimentary canal being commonly distended with matter of a rich
golden-brown hue, I conjecture that some of these may form its ordinary food. In the
discharge of fasces, I have noticed such a quick closing contraction of the rectum at the
point where the intestine merges into it (yet ivithout constriction of the whole tube) as
suggests a sphincter there : and the distinction between the coloured contents of the
intestine and the perfect clearness of the rectum is well defined. — P.H.G.]

Length. Of body and head, -y^y inch; of toe, T^5 inch ; total, ^. Habitat. Pools,
widely dispersed, not uncommon (P.H.G.).

M. bicoknis, Ehreubcrg.
(PI. XX. fig. 5.)
Monocerca bicomis . . . Ehrenberg, Die Infus. 1838, p. 123, Ttif. xlviii. fig. 8.

[SP. CH. Body fusiform-ovate, with long thick head armed with two projecting
unequal spines; lorica not ridged; toe two- thirds as long as body-and-head, icith a
bulbous base, and no sub-styles.

The integument is truly a lorica, though more flexible than usual. It is truncate
at the neck, whence a thick cylindrical head protrudes, the anterior half of which can
contract by bringing the sides together in strong puckers. With much resemblance to
both rattus and carinata, there is a marked difference in aspect, from the greater
development of this head, and from the unequal spines which project over it ; of which
the left is medial, much the longer, and decurved. The absence, too, of any dorsal ridge
is noteworthy. The toe is slightly swollen at its base, but I cannot detect any sub-
styles, though Ehrenberg speaks of them ; it is slightly recurved. The right malleus
has here quite disappeared. The brain is of unusual length, even descending below the
long mastax, and the eye, of moderate size and a pale-red hue, is seated near its middle.
There are small gastric glands at the base of the stomach, and two similar vesicles
attached to the rectal end of the intestine. The contractile vesicle's periods are three
in a minute. In other points there seems little to distinguish the species from its
fellows. There are, however, two antennae, also unequal, which project, side by side,
beneath the chief frontal spine. I have seen an egg matured in the ovary, remarkable
for its small size : perhaps male. (Cf. Monoc. valga, Ehr.)

In ponds and lakes around London, I met with this species and the preceding, six-
and-thirty years ago ; I have occasionally found both since, the present the rarer. Yet
I have had this multiply in a phial ; so numerous and so large, as to be visible to the
naked eye. They glide slowly about, sometimes hanging to the glass, or playing around

64 THE KOTIFERA.

the floccosc attached to growing Nitclla. It forms a charming object under reflected
sunlight. The body is colourless, and sparkling as a vase of glass, as are some of the
viscera. An advanced egg is conspicuously white ; and so is the head of the mastax ;
the eye comes out like a ruby ; the stomach, full of food, is richly brown, or perhaps
grass-green ; and the rotating front is enveloped in a cloud of pale cobalt blue. Like
its neighbours, it is lively in movement. — P.H.G.]

Length. Of body, T} ^ inch ; of toe, T^ inch ; total, z\ inch. Habitat. Pools near
London ; Birmingham (P.H.G.).

M. STYLATA, GoSSe.

(PI. XX. fig. 6.)

Monocerca stylata . . . Gosse, Ann. and Mag. Nat. Hist. Sept. 1851, p. 199.

[SP. CH. Body irregularly oval ; head short; lorica flexible, jmckered in contrac-
tion, not ridged; toe less than half as long as body-and-head, simple, with no sub-
styles.

In several respects this nimble little species resembles the preceding ; the lorica
(even more flexible and skin-like) opens wide in front to emit the head, and closes with
many folds or puckers, converging to a blunt point. The form is more irregular than
in any other species, being plump and gibbous ; the skin, which is so flexible as scarcely
to be called a lorica, is often drawn in, or protruded in angles, which vary the shape.
Tlie foot-bulb is enormous, usually inclosed within the body ; to this is jointed the toe,
a taper acute spine, nearly straight, without a swollen base, and without sub-styles.

The brain is thick and moderately long, carrying a large eye on the middle of its
dorsal surface, protuberant as a wart. No antenna has been observed. The protruded
head is short, set with cilia, strong and bristle-like, around the margin. The jaws have
the asymmetric character already noticed ; the one malleus is very long and simply
bowed. As in bicornis, there is a long distinct rectum, to which are attached two
globular crcca, larger than the gastric glands above. There is a small contractile
vesicle. The cloaca is marked by a depression.

Under strong lateral pressure, a very complicated system of muscular bands is seen
(Gb), mostly transverse, but many irregularly diagonal. I copied them with great care.

I first obtained this species from a garden reservoir near London, in 1850. Its
minuteness and its figure, its short foot and great red eye, may cause it to be mistaken
for an Anurcea, which it resembles in its swift, headlong, obliquely-revolving motion.
Specimens in a phial may be detected with a pocket lens, rapidly urging their way,
generally in a perpendicular direction, upwards or downwards, always with this revolv-
ing action. When alarmed, they suddenly increase their speed, shooting across the field
of view with such a fleetness that it is difficult to keep them in sight. — P.H.G.]

Length. Of body, ._,!„- inch; including toe, 71(T inch. Habitat. South London;
liampstcad Heath ; Stapleton Park, Yorkshire ; Birmingham (P.H.G.).

Genus KATTULUS, Ehrcnberg.

[GEN. CII. Body cylindric, curved ; lorica smooth, (xcsually) ivithout a ridge; toes
two, decurved, symmetric.

The Notommata tigris of Ehrenbcrg, with its rounded body, thickest before, its
general curvature, and its two coequal toes, continuing the curve of the body, may be
considered the type of this genus, which manifestly, however, forms a connecting link
witli the NotommatadcB, through Proalcs tigridia. The genus is a very natural one,
inseparable, notwithstanding some diversities, with a common facies readily apparent to
the skilled observer. — P.H.G.]

KxwuJUaA) Arv<

«*W*>. ("UlEU^w.^.

RATTULUm G5

E. TiGiils, Midler.
(PL XX. fig. 13.)
Nolommata tigris . . . Ehrenberg, Die Infus. 1838, p. 431, pi. liii. fig. 1.

[SP. CH. Body subcylindric, largest in front ; foot thick ; toes two, stylate, long ;
sub-styles two pairs, very short ; brain clear.

The lorica, though subcylindric, a tube open at both ends, and bent, is wider in
front, where a great thick head is protruded, which is invested in an inflexible shelly
coat, running off both fron tally and mentally into hard sharp points. The face between
bears rotatory cilia set on minute eminences. Ehrenberg says " the outer skin appears
somewhat firm " ; and I have met with the empty dead shell, as evidently chitinous as
that of an Euchlanis. The whole animal is rounded, not only as a tube is round, but
the outline of the back is the segment of a circle, a form which is unchanged with all
the animal's motions. The foot appears to consist of one or two thick joints, and carries,
besides the two toes, which are long taper styles, evenly decurved, sub-styles one on each
side of each toe (fig. 13&), usually close appressed and minute. In death the toes are bent
up under the belly ; but in life they are usually carried straight behind, quite parallel,
or often thrown upward, without, however, changing the downward curvature of their
points. The ample mastax (fig. 13<x) is pear-shaped : the mallei straight, unequally de-
veloped. The large brain carries a clear pale-red wart-like eye, on its point. The
stomach is usually full of dark-brown food, coarsely granular.

Some points in Herr Eckstein's description of Diurella tigris make me doubtful
whether his species and mine are identical. Mine I have had repeated opportunities of
studying, both alive and dead. — P.H.G.]

Length, T\^ inch, of which the toes are ¥^ inch. Habitat. Sandhurst, Berks ;
Woolston, Hants : rare (P.H.G.).

R. HELMINTHODES, Gosse, Sp. 110V.

(PI. XX. fig. 17.)

[SP. CH. Body very slender, especially in front, the width less than one-fifth of the
length ; toes xvithout accessory styles at the base ; brain clear.

This obscure species approaches near to JR. tigris in form, and also in the slender-
ness and comparative length of the toes. It is, however, much more elongated (even
when all allowance is made for the protrusion of the parts in death) ; and the anterior
half is the slenderer, whereas in tigris it is the thicker. The lorica, if I am not mis-
taken, has a long low dorsal ridge, beginning insensibly near the mid-length, and end-
ing abruptly in an oblique angle (fig. 17) just above the foot. The short, stout, bulbous
foot carries two long furcate toes, which are simple styles, very slender, tapering to fine
points, decurved, closely resembling those of B. tigris. Yet I was not able to separate
any accessory styles at the base of each, such as are seen in that species. Something
was there ; if styles, very short and close appressed, but it seemed rather a swelling of
the basal part of each toe. It was only a dead lorica that came under my observation ;
from which the head-mass was extruded by decomposition, as an amorphous turbid
cloud. Yet the mastax and its jaws of the normal form were still distinct, and the
stomach and ovary were scarcely changed. I could not satisfactorily define a contractile
vesicle, nor branchial tubes. The toes were turned up close to the belly.

The lorica occurred in a tube sent me at the beginning of November 1885, by Mr.
Bolton, of water from Blackroot Pool, near Birmingham, in which Asplancha priodonta
had swarmed, all now dead. — P.H.G.]

Length. To tips of toes, ^1-$ inch ; of toes, ^4ff inch ; width (and depth) of body,
^-jj inch. Habitat. A pool near Birmingham (P.H.G.).

VOL. II. p

GO THE BOTIFEBA.

B. cimolius, Gosse, sp. nov.
(PI. XX. fig. 14.)

[SP. CH. Body arched, parallel-sided ; skin flexible ; brain opaque ; toes short,
blade-like, decurved ; no sub-styles.

The brain, descending far into the occiput, is furnished at the end with a large and
opaque chalk-mass. This I have signified in the specific name, from /a/AwAia = chalk.
Its component cells are very distinct at the lower margin, which is sub-truncate. When
the fore-parts are retracted forcibly, as is frequently the case, the conspicuous chalk-
mass will sometimes reach to two-thirds of the entire length, displacing the
viscera. A pair of small auricles are occasionally thrust out (fig. 14), without any
sensible augmentation of speed, while the animal pushes through sediment. I have
looked in vain for an eye, though it may have been concealed by the opaque cells. The tro-
pin (figs. 146, c) exhibit the virgate pattern common in the family. The toes are short
compared with those of tigris, decurved ; set side by side, and widely expanded (fig. 14).

This seems a quite distinct little species, there being no other with which it can be
confounded, on examination. The specimen described was in the bottle with which
Dr. Collins favoured me in June 1885. Its movements were by no means rapid, but
persevering, forcing its way incessantly through the leaves of water-moss and sedimentary
floccose. I have lately found a second in water from Mr Bolton. — P.H.G.]

Length, 3 J^ inch. Habitat. Sandhurst, Berks ; Kingswood Pool, Birmingham
(P.H.G.).

B. CALYrTus, Gosse, sp. nov.
(PI. XX. fig. 16.)

[SP. CH. Body and toes as in cimolius ; brain clear ; face furnished toith pendent
veil-Wee lobes of flesh. Marine.

This has much resemblance to B. civiolius, but it is larger, and the brain-sac is clear,
not opaque. No eye has been visible : the toes are of like dimensions, pattern, and de-
curvation. A remarkable peculiarity is that in the front a thick and broad veil of trans-
parent flesh hangs down, apparently bilobed, meeting another great lobe of like appearance
from below. The function of these lobes I do not know. The body is cylindric, with
no visible dorsal ridge. The mastax and tropin conspicuous, but ill-defined. An ample
brain descends with a point into the occiput, with neither chalk-deposits, nor eye. A
long and slender oesophagus leads to an ample alimentary canal. The ovary occupies
the ventral region of the cavity ; and a moderate contractile vesicle is behind all.

A single example of this charming little Battulus I found in October 1885, with many
other species of Rotifera, in sea-water, procured for me by Mr. Hood from the tide-pools
of the Firth of Tay. In manners it was sluggish, contracting and lengthening itself
with uniform persistence without changing its place. It was of hyaline transparency
and colourlessness. — P.H.G.]

Length, T^u inch. Habitat. Tide-pools on the Scottish coast (P.H.G.).

B. sEJUNCTir-ES, Gosse, sp. nov.
(PI. XX. fig. 15.)

[SP. CH. Body projecting much above and behind the foot ; toes two, coequal,
slender, decurved, set side by side, wide apart.

Of this remarkable species Dr. F. Collins has made several graphic sketches in his
Note-book. It is of the lunaris form, stout, plump, and curved ; the foot consists of a
great basal bulb, wholly internal, and a second joint, thick and short, to which are arti-
culated two toes ; these are acute slender styles, so curved as to continue the outline of
the body, mutually equal, set on the same plane, but (which is most unusual) wide a/pa rt.

fi*#""""4fcv

RATTULIDiE. 67

The hinder body is ventricose, greatly overhanging the foot. There is a great aggregation
of minute air-(or oil-)globules in the dorsal cavity. The trophi I supply conjecturally.

Dr. Collins has added to his figures the following note : " Head very large ; rotatory
organ compound ; a large eye ; peculiar ganglionic mass or brain lying on dorsal surface.
Two toes, which it sometimes crosses ; peculiar from being very wide apart, and de-
curved, as the toe of Battulus lunaris. Found in a pool near Wellington Military
College, Berks."— P.H.G.]

Length. Unrecorded. Habitat. As above.

Genus CCELOPUS, Gosse.

[GEN. CH. Body cylindrical, curved ; foot bulbous, inclosed; toes, one broad plate
with another laid upon it, in a different plane.

A very remarkable deviation from normal structure is found in the species thus asso-
ciated. Instead of two toes, consimilar and coequal, placed side by side right and left,
like the legs of a man ; here are two toes very unequal, hollow triangular plates of like
shape, but of diverse dimensions, the smaller lying within the hollow of the larger.
To use a homely comparison, let us suppose the bowl of a tablespoon, broadly truncate
at the top and drawn out to a long point ; then the bowl of a teaspoon of exactly the
same shape, laid smoothly in its hollow ; the two separately articulated to the foot-bulb,
so as to be capable of independent motion to a slight extent.

These organs are so anomalous that it is hard to describe them as " toes." If it could
be proved that the cloaca opens between them, we might say without hesitation that the
larger and upper represents a true tail, the smaller and lower a stylate toe. But I have
no knowledge on this point ; which could be settled only by a rare accident, — the observ-
ing of the act of evacuation at the moment when the animal was viewed laterally.

In general figure and organization, there is so close an agreement with the former
two genera, that the family affinity is indubitable. Several species I am able to asso-
ciate as manifesting this structure : and, what is very curious, I have found it exhibited
by a member of a remote genus, — one of the Coluri (q. v. infra).

It is possible that Ehrenberg's Battulus lunaris may represent my C. porcellus.
But the absence of any detailed diagnosis, in his text, leaves it doubtful ; while his
assigning of two eyes to his species is against the identification. The Diurclla rattulus,
Eyf., described and figured by Herr Eckstein, may possibly be the same thing. The delicate
lines that are drawn through the middle of the toe, in his engraving, may be either the
inner edges of two normal toes, or the outer edges of a single superposed toe ; and the
closest examination does not determine this. If the former, it is a species of my genus
Battuhis ; if the latter, a Cozlopus. His text also is ambiguous. " Two toes, long,
much bent bellyward, and slender," seem to point to Battuhis ; while " at their base they
do not stand close side by side, but lie with their points one on the other," appear to
indicate the peculiarity of Ccelopus, ill-understood. — P.H.G.]

C. poecellus, Gosse.
(PL XX. fig. 18.)
Monocerca porcellus .... Gosse, Ann. and Mag. Nat. Hint. Sept. 1851.

[SP. CH. Body cylindric, short and plump ; lorica ridged ; head with two pro-
jecting spines ; the longer toe equal in length to the depth of the body.

This neat, plump little creature always reminds me of a fat young pig. The general
form may be compared to that of a well-filled sausage, a little bent, as sausages often
are, and the varying shades of brown colour produced by the distended stomach and

v 2

G8 THE ROTIFER A.

ovary, add to the resemblance. The large head is bent downward ; the brow and the
chin project each in a sharp spine, between which the front is capable of a slight protru-
sion, ciliated, and furnished with a tubular antenna. Viewed dorsally, the front is ever
and anon closed by the rapid approach of two triangular pieces from the sides, which
recede immediately (cf. Dinocharis, &c). The movement has no connection with the
mastax. When the animal is confined by pressure, not sufficient to hurt it, it protrudes
the jaws ; and besides this a sort of veil is thrust forward, very thin and membranous,
seemingly stretched between the frontal and mental points, and from an intermediate
point (fig. 18b). The action, though frequent, is momentary, and the withdrawal is
complete. The lorica terminates anteriorly by a strong transverse fold, at its full width,
whence the mobile head is emitted, of much less apparent diameter. The difference, how-
ever, is mainly owing to a rather high dorsal ridge, which rises abruptly from the fold, and
continues nearly equal in height to three- fourths of the body's length ; or even, in some
cases, to the whole.1 The basal joint of the foot is a round transparent bulb of great
size, almost wholly enclosed within the body-walls. It must not be confounded with the
contractile vesicle, which is much smaller, and lies upon it. To this foot-bulb is so
articulated as to allow very free vertical motion the remarkable form of toe which has
been just described. It is usually bent forward toward the belly, but can be thrown out
behind, particularly in swimming. The tropin resemble those of Mastigocerca : the
fulcrum of the incus a long slender rod with the back elevated into a thin ridge ; no
trace of rami can be discerned, but their pendent divergent alulae, which are unequal.
The whole mastax is covered with fine transverse lines. A wide and long brain, of the
normal form and position, carries near its middle a great deep crimson eye. On killing
one by sudden pressure, the branchial vessels were severed from their connection with the
contractile vesicle, and forced out, displaying some details of their structure. They ap-
peared as a single tubule on each side, striate in parts with cross lines ; towards their
hinder parts are seen a number of transverse branchlets, whose ends have been torn oft",
suggesting not one but many communications with the contractile vesicle. There are
also very minute structures attached at intervals to them, one near the head, resembling
a twig of several leaves. These I cannot explain.

With this very attractive little creature I have been familiar since October 1849,
when I met with it at Clapton, near London. It has occurred in many localities since.
Its manners are sprightly and elegant. It is perpetually in motion, threading its way
through the tangled conferva wires, and swimming across the open spaces, with a rapid
gliding movement, turning on its long axis as it goes. The clear viscera, resembling
bladders of various shapes and sizes, some filled with richly-coloured food or faaces,
others granulate, or occupied with embryonic globules, all interspersed with orange-
coloured fat-bubbles, and all seen through the transparent skin, have a most charming
effect, as the animal thus revolves. It frequently arrests its roving course to examine
the plants, and now and then to nibble at them, when the mastax is brought to the very
front, and the jaws themselves are seen projecting from the head, and eagerly biting.
Sometimes it swims round and round, in a circle of which the curved outline of the back
forms an arc. — P.H.G.]

Length, 1\t, inch, of which the double toe forms about one-fifth. Habitat. Pools
and lakes : widespread through Middle and South England (P.H.G.).

C. tenuior, Gosse, sp. nov.
(PI. XX. fig. 19.)

[SP. CH. Body cyl in civic, decurved, slender ; lorica without sensible ridge; head
defended by tico or three projecting points ; toe xuith two sub-styles.

1 I am almost sure that the ridge is inclined ; its edge bending over towards the right. I have seen
it distinctly wrinkled along the base, as seen in M. carinata. — P.H.G.

RATTULID^. 69

Tins species lias manifest affinity with porcellus ; but it is much slenderer, and its
proportions are different. The width of the body to its length (exclusive of the foot) is
as 1 : 4 ; whereas in porcellus it is as 1 : 2^. The toe is here beset with a short sub-style
on each side (as in Mastigocerca) ; whereas in porcellus I can see no trace of these.
The lorica, moreover, is not elevated into any sensible dorsal ridge. In all other re-
spects it appears to agree with the preceding, except in being somewhat longer.

The species first occurred to my notice in water from Woolston Pond, sent me in
September by the courtesy of Miss Davies. Several examples occurred, but all dead.
A few days later I found it alive in water sent by Mr. Bolton from Birmingham, as well
as another dead.— P.H.G.]

Length, T^ff to T|¥ inch ; depth, -^ to ^ inch. Habitat. Weedy pools. Wool-
ston : Sutton Park and Coleshill, Birmingham (P.H.G.).

C. BRACHYURUS, GoSSe.

(PL XX. fig. 21.)

Monocerca brachyura . . . Gosse, Ann. and Mag. Nat. Hist. Sept. 1851.

[SP. CH. Body cylindric, short, plump, decurved ; lorica not ridged ; head without
spines ; toe-length less than the depth of the body.

This species I described in 1851 from a single example taken on Hampstead Heath.
It died before I had completed my observations ; but I have since seen it on repeated
occasions, from various localities, though always scarce. With much resemblance to
C. porcellus, it is notably smaller ; there is no trace of ridge ; the twofold toe, though
exactly similar, is proportionally shorter ; the front is obtusely truncate, seen dorsally
and laterally, and is destitute of projecting spines. When viewed endwise (as on many
occasions), the transverse outline appears quite circular, so far as the back and sides are
concerned. A long depending brain carries a great red eye at its tip. The singular
appearance of a second eye in the breast, mentioned in my original diagnosis, occurred
in no other specimen ; it must have been illusory, though unaccountable. The viscera
agree with those of porcellus ; the contractile vesicle very large. The toes are almost
always thrust up under the belly.

In manners this varies much from its lively predecessor, for though constantly in
motion it is singularly slow and sluggish, creeping to and fro on the leaves of the
milfoil, nibbling ever as it goes. — P.H.G.]

Length (without toe) , 1 \z inch ; toe, ^^j inch ; total, y^ inch. Habitat. Hampstead
Heath ; Sandhurst ; Woolston ; Caversham (P.H.G.) : pools : rare.

C. cavia, Gosse, sp. nov.
(PL XX. fig. 22.)

[SP. CH. Body elevated and globose, very protuberant behind the foot; lorica
without ridge or frontal spines.

In the summer of 1885 Mr. Henry Davis kindly collected water for me near Snares-
brook in Epping Forest. Among other treasures found therein I met with this pretty
little creature, which at first I was inclined to identify with C. brachyurus. It differs
from it in form, however ; the great elevation of its hinder quarters, and particularly the
development of its buttock into a great plump breech, gives it the aspect of a squatting
mouse or guinea-pig, and makes the double curved toe proceed (in appearance) from a
notch in the belly, far forward. The mastax agrees with that of its congeners, of
moderate size ; but the brain is very large, and so is the eye at its point. The stomach
was ample, filled with yellow food. Face truncate, slightly prone. The little thing was
rather swift at first, but not wild. — P.H.G.]

Length (without toe), ^^ inch. Habitat. Epping Forest (P.H.G.).

70 THE ROTIFEKA.

[I suspect the Distcmma sctigerum of Ehrenberg to belong to this genus. He himself
alludes to the liability of confounding it with Battidus, as well as to the difficulty of
resolving the very slender toe, which, at first sight, seems single ; and to his inability
to see any proper foot-joint. Yet he assigns to the species two eyes ; which does not
accord with any true species of Cozlopus known to me. — P.H.G.]

Ccelopus (?) minutus, Gosse, sp. nov.
(PI. XX. fig. 20.)

[SP. CH. Two eyes, wide apart; mastax and rotating cilia {apparently) wanting ;
body rotund, minute.

Little as I know of this tiny animal, enough is manifest to show that it is one of much
physiological interest. Though for convenience of reference, and because of certain
conspicuous resemblances, I place it with the Ccelopods, it must be considered a species
incertce sedis. The general figure, plump and round, recalls C. porcellus and cavia, and
so do the short, curved foot, thick at its base and tapering to a sharp point, and its
manner of articulation. Yet, whether the structure of this member is that peculiar to
Ccelopus, — a secondary spine lodged within the inferior concavity of the principal, — I
cannot certainly affirm. I strove hard to determine this point, but could not obtain
absolute certitude. It appeared single and indivisible.

But it is at the anterior extremity that the chief anomalies of the little creature are
found. Two cervical eyes are seen, tiny globelets, brilliant and distinct, set wide apart,
close within the outline on either side, in a dorsal aspect (fig. 20). I could find no
trace of mastax or tropin, in general so largely developed and so conspicuous in this
family ; but instead of it what seemed a simple slender duct or tube, formed by the union
of two short branches which communicate with the front, and open into a great sacculate
stomach; as if the oesophagus had been continued upward, — the mastax being atrophied,
— to the very front, or rather merged into the buccal funnel. Again, with the closest
scrutiny I could detect no cilia nor any ciliary action.

Only a solitary example has occurred to my observation, from the Black Loch, near
Dundee. It was alive but inert, and to a certain extent glued fast to the glass by an
excretion from the foot.— P.H.G.]

Length, zla inch. Habitat. Black Loch, near Dundee (P.H.G).

Family XII. DINOCHARIDiE.

Lorica entire, vase-shaped, or depressed ; sometimes facetted, often spinous ; head
distinct, with a ehitinous covering ; foot and toes often greatly developed; tropin
symmetrical.

Of the three genera, which together form the Dinocliaridce, two, viz. Dinocharis and
Scaridium, resemble each other in the great length of the foot and toes, and in their
conspicuous condyles. Both these genera are also completely loricated ; but whereas
in Scaridium tbe ehitinous cuticle is thin, somewhat flexible, smooth, and transparent,
in Dinocharis it attains a greater development than in any other genus of the Botifera.
For, not only is the trunk completely enclosed in a dense lorica shagreened with little
knobs, ornamented with ridged facets, or bristling with spines, but the head and foot
also aie similarly protected, and the lorica stretches down even to the base of the toes.
The third genus, Stc])hanops, resembles the first two in having a ehitinous covering for
the head, and in bearing stiff spines, which are not organs of locomotion, on various
parts of the trunk ; but its skin can hardly be termed a lorica, and its foot, though
well-jointed and often spinous, is never immoderately long. The head-gear in the

DINOCHARHLE. 71

three genera is also very different, and Stephanops has two eyes remote from the
mastax, while Dinocharis and Scandium have but one, closely applied to it. In all,
however, the trophi are symmetrical, the family differing widely in this respect from the

Battulidce.

Genus DINOCHARIS, Elircnberg.

GEN. CH. Lorica vase-shaped, dense, shagreened ; facetted, and with projecting
plates, or armed dorsally with sp>ines ; head retractile within a chitinous cap ; eye single,
apparently attached to the mastax ; foot and toes very long, the former bearing spines.

Two of the species of this genus, viz. D. pocillum and D. tetractis, resemble each
other very closely ; the main difference being that the former has, on the last joint of
the foot, a small spine between the two toes. But the third species, D. Collinsii, is
strikingly unlike the other two, in several respects. Their loricae are vase-shaped,
facetted and spineless ; whereas its lorica is quadrangular, much depressed, free from
facets, but notched round its edge and bearing long dorsal spines. The head-covering's
are also unlike. Those of the first two species consist each of quadrantal pieces that
can be brought close together so as to enclose completely the withdrawn corona ; but in
the latter species the head is protected on the dorsal surface by a notched shelly hood,
and is uncovered on the ventral surface.

D. pocillum, Ehrenbcrg.

(PL XXI. fig. 1.)

Dinocharis pocillum . . . Ehrenbcrg, Die Infus., 1838, p. 472, Taf. lix. fig. 1.
„ ,, ... Grenadier, Sieb. u. Kbll. Zcits. Bd. xix. 18G9, p. 497.

SP. CH. Lorica vase-shaped, sub-cylindrical, facetted, without spines ; foot and
toes very long, and together nearly ticice the length of the trunk ; spurs curved ; a short
spine between the toes.

The vase-shaped lorica of this species has a flat portion with scalloped edges down
the centre of its dorsal surface ; and a similar, but somewhat protuberant, portion on the
ventral surface. These two plates are connected by stippled concave surfaces, which
pass from a dorsal scallop to a ventral one and meet each other in stout transverse
ridges, which are very prominent in a side view ; and, when the creature is viewed
directly in front, so as to obtain transverse views of the trunk, it is evident that the
lorica, as shown in the elegant figure \c, is produced on either side into delicate wing-
like plates at right-angles to its surface. The head is protected by a complete cap, con-
sisting of two pieces, which can fit together closely so as to conceal the corona, or fall
back on each side into a fold in the neck in order to permit the head to protrude. The
loricated foot, which is as long as the trunk, has three joints ; on the last of which are
two slender toes, decurved, bent outwards, and as long as the foot itself. Between the
toes is a short chitinous spine. The first joint bears two stout spurs, usually about
as long as the joint that bears them, but occasionally more than double the length.
The front is rounded and set with small cilia : it is difficult to say what is the exact
structure of the corona, or the arrangement of the ciliary wreath. There are a large
mastax with sub-malleate trophi; two conical gastric glands; a broad cylindrical
stomach ; short intestine ; moderate ovary ; and very large contractile vesicle. This
latter lies athwart the body when distended, and in that condition fills up more than one-
third of the body-cavity: its time is four minutes. The lateral canals can be readily
seen on the ventral surface, but I detected only one vibratile tag. There is a large
crimson eye on the under surface of the nervous ganglion, which overlies the mastax so
that the eye seems attached to this latter. Dr. Grenadier (loc. cit.) has seen two lateral
rocket-headed antennae on each side of the lower third of the dorsal surface.

This is an elegant and curious creature. With its toes well apart like a pair of com

I

72 THE EOTIFEEA.

passes, and its foot either thrown into one long curve or oddly bent zigzag fashion, it
grubs among the sediment of the live-box ; and sometimes it glides gently away by the
action of the coronal wreath, with its long toes trailing gracefully behind it, just like
Scandium eudactylotum.

Length, ^ inch. Habitat. Clear ponds and ditches, Hampstead Heath ; Kew
Gardens ; Woolston (P.H.G.) ; Clifton, Birmingham (C.T.H.) : not very common.

D. tetractis, Ehrenberg.
(PI. XXI. fig. 2.)
Dinocharis tetractis . . . Ehrenberg, Die Infus. 1838, p. 473, Taf. lix. fig. 2.

SP. CH. Lorica vase-shaped, narrowing to the hind extremity, facetted, without

\ spines ; foot and toes very long, together more than tivice the length of the trunk ; spurs

curved; no spine between the toes.

\ This species is extremely like D. poc ilium, differing from it chiefly in having no spine

between the toes on the last joint of the foot. The trunk viewed dorsally has a some-
what triangular outline, the apex of the triangle being towards the foot, and is shorter
in proportion to the foot and toes than it is in the former species. Mr. Gosse has ob-
i^ served in this species that the lorica runs off at the hind end into three, thin, transparent,

and radiating plates, of which one is dorsal ; and that this latter is not continued so far
forward as the lateral plates, so that a transverse section shows no trace of the dorsal

*U radiating one, but rather a slight depression between two gibbous swellings. This is

well shown in fig. lc, a transverse section through D. pocillum. Mr. Gosse has also

y\» seen many specimens of D. tetractis, in which the spurs on the penultimate joint were

more or less deteriorated ; so that in some they were reduced to short tubercles, or even
effaced altogether. These latter specimens were precisely Ehrenberg's D. pauper, which
can no longer, therefore, be entitled to rank as a species.

Length. Up to ^s inch (P.H.G. ). Habitat. Clear ponds and ditches throughout
England and Scotland (P.H.G. ; C.T.H.j : common.

D. collinsii, Gosse.
(PI. XXI. fig. 3.)

Polychaitus subquadratw (?) . . Perty, Z. Kenntn. hi. Leb. 1852, p. 45. Taf. 1. fig. 6a.

Dinocharis Collinsii ..... Gosse, Litell. Observer, vol. x. 1866, p. 269.
Polychcetus spinulosus .... Archer, Quart. J. Micr. Sci. vol. viii. 1868, p. 72.

SP. CH . Lorica depressed, sub -quadrangular, with serrated edges and eight dorsal
spines; spurs straight ; foot and toes short, together as long as the trunk.

Though this Eotiferon is clearly a Dinocharis, it is a very singular one. The foot is
short, the toes small, the lorica depressed, and a chitinous dorsal hood protects the head.
The lorica is somewhat rectangular in shape, but broader in front than behind, with its
fore corners rounded off, and its lateral edges serrated. At each hind corner a sharp
spine projects, while six others rise from the dorsal surface. There is an outer pair
attached to the shoulders, pointing down the back ; and an inner pair, slightly decurved
at the tips, rising from the central highest point of the lorica, and pointing diagonally
outwards and upwards. A third pair, sharp and straight, rises from the hind end of the
lorica, one on each side of the foot, and pointing outwards and upwards; while the first
joint of the foot itself carries a pair of sharp chitinous spurs. The lorica is closed, much
arched dorsally, highest in front, and flat on the ventral surface. The dense lorica,
which is stippled in the central region, makes it difficult to define the internal structure;
but Mr. Gosse, from whose Memoir (loc. cit.) this account is taken, succeeded in ob-
serving a globose mastax, ample alimentary canal, and rich ruby eye.

DINOCHARIM. 73

This Dinocharis was discovered by Dr. F. Collins in 18G6, in a small pool in a wood
near Sandhurst. Dr. Collins sent it to Mr. Gosse, who figured and described it (loc. cit.)
in 1867. Dr. Max. Perty's Polychcetus stibquadratus may possibly, but not probably, be
the same creature ; if so, it is most inaccurately drawn and described. Mr. Archer's
Polychcetus spinulosus is undoubtedly D. Collinsii.

Mr. Gosse says of its habits that "it is rarely still, rooting among the sediment or
swimming with a smooth gliding motion of no great speed. If I may judge of its be-
haviour in freedom from what is seen while under our notice, it seems to be a specially
bottom-frequenting form."

Length, ^^ inch. Habitat. Sandhurst, Berks (Dr. F. Collins); Clifton (Mr.
Brayley) ; Carrig and Callery districts, Ireland (Mr. T. Archer) ; Dundee (P.H.G.) : rare.

Genus SCARIDIUM, Ehrenbcrg.

GEN. CH. Lorica vase-shaped and compressed ; or pear-shaped and depressed in
front ; very thin, transparent, smooth, without spines or projecting plates ; head with
a chitinous cuticle, except in front ; eye single, really or apparently attached to the
mastax ; foot without spurs ; toes very long.

In the genus Scaridium the foot and toes (especially the latter) are remarkable for
their great length, for the distinct condyles, which give them such free action, and for
the powerful striated muscles, which enable the animal to jerk its long toes widely
apart, and to strike the water violently with its foot, so as to make it an effective organ
of locomotion. In both species the lorica is a transparent, thin, stiff skin, which ap-
pears to be continued over the foot ; but its shape in the two species is very different :
for, while the lorica of S. longicaudum recalls that of Dinocharis pocillum, the lorica of
S. eudactylotum somewhat resembles in general outline that of a Brachionus. In each
species the eye appears to be attached to the mastax, instead of to the nervous ganglion ;
this would be a very unusual arrangement, but it is possible that the appearance is due
to the nervous ganglion's being closely applied to the mastax, and more than usually
transparent.1 The habits of the two creatures are similar. They swim quietly for a
time, trailing the foot and toes behind them in an elegant curve ; and then, with a
sudden leap, they dart off into a new course.

S. longicaudum, Ehrenberg.
(PI. XXI. fig. 5.)

Scaridium longicaudum . . . Ehrenberg, Die Infus. 1838, p. 440, Taf. liv. fig. 1.
„ „ .... Gosse, Phil. Trans. 1856, pi. xvii. figs. 64, 65.

[SP. CH. Body compressed ; front truncate; eye adherent to mastax ; body, foot,
and toes of about coequal length.

The most remarkable peculiarity of this species is the anomalous character of the
eye, — a large flattened capsule, with crimson pigment not quite filling it, permanently
attached to the surface of the mastax, and apparently not connected, as usual, with the
occipital brain, which, however, presses upon it from above and behind. The trophi,
too, are very abnormal. (See my Mem., loc. cit.) The animal, with its long unwieldy
foot and toes, reminds us, not less by its movements than by its form, of Dinocharis.
It is active, SAvimming with unequal, not very swift, action, with little movement of the
foot and toes. It has the habit of making sudden springs, using, apparently, for this
purpose, the fore parts, not the toes. — P. H.G.J

1 I suspect this to be the case in S. eudactylotum ; but in S. longicaudum Mr. Gosse is confident that
the eye is inseparably seated on the mastax.

74 THE ROTIFERA.

Length, ^ inch. Habitat. Stratford ; Maidenhead ; Cheltenham ; Birmingham ;
Starmont Loch, Dundee (P.H.G.) ; pools and dykes : rare.

S. eudactylotum, Gosse, sp. nov.
(PI. XXI. fig. 4.)

SP. CH. Lorica pear-shaped, depressed and narrowed in front ; toes as long as all
the rest of the animal.

[S. eudactylotum was discovered in September 1881 in a small loch in Perthshire,
by Mr. Hood, who sent me a tube of the water. This I found well peopled with this
charming species. It is much more globose than longicaudum, and much more trans-
lucent, looking like an oval bubble of clear glass. The head is small, formed of several
ciliated eminences. Among the turbid clouds, which are probably brain-matter, there
are one or two oval spots, which refract the light strongly ; but I cannot interpret them.
As a small red eye always moves to and fro with the movements of the mastax, I con-
clude that they are organically united as in longicaudum. The incus and mallei are
much more normal than in that species. The manubria, however, are tripartite, and
the middle joint is largely and somewhat irregularly looped. The apparatus is un-
usually minute, obscure, and difficult. The mastax is distinctly three-lobed. There
are a long oesophagus, wide stomach, intestine, and small ovary with nucleated
ovarian vesicles. In one example was a small maturing egg. The longitudinal
muscles are numerous, and unusually conspicuous, owing to the brilliant trans-
parency. But the most remarkable feature is the foot of three articulations, with
strongly marked condyles, and a pair of furcate toes of excessive length and tenuity.
They are usually straight, but are sometimes a little curved outward at their tips. It is
graceful and elegant in its motions. I have never seen one resting, but invariably swim-
ming with a smooth even gliding, not at all rapid, often varied by a sudden spring or
skip to one side, like its fellow S. longicaudum. The toes are very flexible, and highly
elastic ; sometimes when the animal suddenly turns, I have seen the toes bent almost
double, but recovering their straightness in a moment. That the integument is a proper
lorica, closed and vase-like, is undeniable ; yet it is so thin and flexible that the head
retracted every instant carries with it the in-turned delicate front edge, which is again
everted. At the moment of eversion I have repeatedly seen what I believe to be an an-
tennal seta of exceeding tenuity ; but certainly no tubule or pimple. — P. H.Gr.]

The lorica is tolerably flat on the ventral surface, but on the dorsal is distinctly
gibbous behind and depressed in front. Like that of Brachionus, it deepens down to the
hinder third of its length, and then suddenly drops with two abrupt curves. Viewed
dorsally (fig. 4), it can be seen that a central portion of the lower third is arched above
the general surface, and kept so bent by transverse muscular fibres. The head on the ven-
tral surface is scooped into a hollow above the buccal funnel, and the corona bears two
hemispherical ciliated prominences. On the long oesophagus, at a little distance from
the stomach, are two small stalked glands (fig. 4a) similar to those in Pterodina and
other Rotifera. The gastric glands are of unusual size and form. They are Y-shaped
(fig. 4), and each has its stem attached to the top of the stomach, and its outer branch
continued up to, and round, the inner dorsal surface of the lorica, to which it is attached.
Each inner branch hangs down, pointing inwards, towards the ventral surface, to which
it is probably tied by a fine fibre. These glands are distinctly, though delicately,
spotted with nuclei. The vascular system is best seen from the ventral surface (fig. 46),
where the lateral canals, surrounded by wide ribbons of delicate floccose matter, seem
to adhere to a considerable portion of the lorica, keeping chiefly toward the sides. The
contractile vesicle (fig. 46) looks as if it consisted of an oval central chamber, surrounded
by several smaller : an appearance probably due to the muscular fibres crossing it in a
somewhat regular pattern. It is rather large, and a side view (fig. 4a) shows that it
lies by itself at the hind end of the inner ventral surface, while the rest of the viscera

****"<+* f^^-Uy^U.C*

DINOCHARID^. 75

follow the arch of the dorsal. I detected four vibratile tags (fig. 46) on each side :
one near the top of the lorica one about the middle, and two on a plexus of tubes
lower down. The muscles that pass down the foot to move it and the toes are very
conspicuous and are coarsely striated ; and the condyles of the toes (fig. 4c) are remark-
able. The nervous ganglion (figs. 4, id) is so extremely transparent, that in can hardly
be detected except by a chain of dark spots round its lower edge, which betray its pres-
ence when it moves. It is very long, cylindrical, with a rounded free end, and lies
across the mastax and eye (fig. id). It may possibly be attached to both. Two rocket-
headed antennae can be seen, one on each side of the dorsal surface (fig. 4), and about
one-third of its length from its base. I am indebted to Mr. J. Hood for the numerous
specimens of this beautiful creature which enabled me to make drawings of it from
various points of view, and to supplement the details given by Mr. Gosse.
Length, ¥XT inch. Habitat. Pools near Blairgowrie (J.H.) : very rare.

Genus STEPHANOPS, Ehrenbcrg.

[Lorica cylindrical or pyriform, entire ; head bearing a permanent, wide, circular
shield ; toe (or toes) often surmounted by a toe-like tail.

The species which constitute this well-marked group are in general easily recognized
by the beautful glassy shield which protects the head, and which, seen dorsally, in-
stantly recalls the ring of glory which surrounds the heads of sacred persons in medieval
pictures. This differs from the frontal hood in the Coluridce, by being non-retractile,
and having no motion apart from the whole head. Several of the species have spines
affixed to the lorica or to the foot. The foot is habitually exserted, composed of joints
which are stout, long, and distinct. — P.H.G.]

S. lamellaeis, Ehrenbcrg .

(PL XXI. fig. 7.)

Stcirfianops lamellaris . . . Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 13.

[SP. CH. Lorica pyriform, having a narrow neck, and slightly prolonged behind
into three sub parallel slender acute spines ; foot furnished with a toe-like spine.

The form is swollen and vase-like, with a marked everted rim or neck, within which
the whole head has a slight motion, surmounted by its lovely round glory-shield, which
equals the lorica in breadth. Under its shelter is seen the conical front with its rotat-
ing cilia, its oblique points, and its two ruby eyes, very wide apart. Below the rim or
neck the trophi are conspicuous, formed on the pattern seen in Euchlanis. The viscera
are normal, including an ample transversely-ovate contractile vesicle. The hind part
of the lorica is deeply truncate, and the three spines are limited to the dorsal end. The
foot consists of three joints, long, and strongly marked, of which the last (save the toes)
carries a very slender spine seated on a tubercle on its dorsal side, not quite so long as
the two toes. The foot joints are permeated with two long chain-like glands. — P.H.G.]

Length, T^ inch. Habitat. A garden tub (P.H.G.) : rather scarce.

S. muticus, Ehrenberg.
(PI. XXI. fig. G.)
Stephanops muticus . . . Ehrenberg, Die Infus. 1838, p. 479, Taf. lix. fig. 14.

[SP. CH. Lorica cylindric, having a distinct thick neck, and prolonged behind into
a spoon-like shield, which is unarmed, as is also the foot.

What I identify with Ehrenberg's muticus agrees better with his description and
figures than with Eckstein's. Can the latter have made his drawing from two inclivi-

76 THE ROTIFERA.

duals, lamcllaris and muticus, which he supposed one and the same ? I confess I have
had suspicions that these are but one species. I have had specimens in my live-box of
what seemed lamcllaris, with the three caudal spines clear enough ; yet in a few
minutes I could find only specimens of muticus, with no spines at all to be discerned, to
my great bewilderment. It seemed as if the spines could at will disappear, but I cannot
conjecture how. This has happened repeatedly. Except the greater development of
the neck, there is little else to discriminate the two. — P.H.G.]

Length, yj-j- inch. Habitat. Fresh waters around London; an aquarium at Tor-
quay (P.H.G.) : scarce.

S. UNISETATUS, ColUllS.

(PI. XXI. fig. 8.)
Steplianops uniseta . . . Collins, Science Gossip, 1872, p. 11, figs. 9a, b.

[SP. CH. Lorica ovate, its hinder end without points, but bearing a dorsal spine,
very slender, straight, as long as the body ; foot tuith a slender tail and two toes.

The discoverer of this interesting form has furnished me with a number of examples
from its original habitat: all inhabiting the leaves of a subaquatic moss. In the " Jour.
Roy. Micr. Soc." 1885, Dr. Hudson has suggested the identity of Mr. Lord's species ' with
this ; but I think its thick fore-parts, the curvature of its spine, and several other pecu-
liarities, indicate their diversity. If so, we have five dorsal-spined species. The spine
here is so attenuate that it may well be called a seta. According to my observations, it
vibrates with the tremulous motions of the body, but has no proper separate motion.
Its base is attached to a shelly knob, level with the bottom of the mastax ; it is quite
straight, and its point reaches the tips of the toes. The hind edge of the lorica is
truncate and unarmed, as in muticus. There are two slender pointed toes, and a minute
spinous tail at right-angles from their base.

The species affects concealment, but occasionally comes out to swim with a smooth
gliding motion in the open interspaces ; often subject to a momentary vibration through-
out.—P.H.G.]

Length, 2£ff to T^ inch. Habitat. Sandhurst (Collins ; P.H.G.) : not rare.

S. chl^na, Gosse, sp. nov.
(PI. XXI. fig. 9.)

[SP. CH. Lorica cylindric, forming a semicircular occipital shield, without any
constriction ; toe single.

Ehrenberg's S. cirratus (not yet recognized with us) appears to lead to this, the sides
being straight without any neck. The face is oblique, wider than any other part, beset
with irregular fleshy lobes, with a retractile lobe forming a kind of chin. A great sac-
like brain carries one minute eye, very difficult to be seen. The lorica, without any
diminution in width, ends behind in three points, and resembles a short cloak reaching
to the loins. From this descends a thick and long foot, whose penultimate joint carries
an acute spine at a right-angle, which is a proper tail ; thence a stout taper pointed
toe, along whose middle a line may be dimly seen, suggesting two toes soldered into one.
The rectum may be traced to a cloaca between the tail and the toe. Its manners are
those of its fellows. In swimming, its movements, already rapid, are accelerated now
and then by sudden starts, probably predatory. — P.H.G.]

Length, -^ to y^ inch. Habitat. Sandhurst : Woolston (P.H.G. )2 ; pools : rare.

1 Micr. Neivs, vol. iv. 1884, p. 146, fig. 24. The figure of this Stcphanops has one dorsal spine, and
one short spine, or tail, sloping upwards, just above the toes.

2 There are differences in form and size between the Sandhurst and the Woolston specimens, so
considerable that possibly these may be distinct species : the former much larger, more slender, the
front not sensibly lobular ; the whole animal yellow-tinged. — P.H.G.

DINOCHARIDjE. 77

Mr. J. G. Tatem (" Quart. Journ. Micr. Sci." vol. vii. 18G7, p. 252, with figs.)
described and figured a Stcphanops (S. longispinatus) with one long dorsal spine, no
posterior spines, and two short straight spines (one on each side) on both the first and
second joints of the foot. Mr. T. Bolton (in 1884) published among his fly-leaves a
Stephanops (S. bifurcus) with one long dorsal spine, and one short posterior spine
slanting backwards and upwards, from the end of the lorica ; both spines on the median
line, and none on the foot. Mr. J. Hood in the same year sent me a drawing of yet
another species (S. armatus) with one long dorsal spine, and two short posterior spines,
one on each side of the end of the lorica slanting slightly upwards and outwards, and
somewhat convex to the lorica. This species also had no spines on the foot. Mr.
Hood's figure is given in pi. xii. of the " Journ. Roy. Micr. Soc." 1885.

Family XIII. SALPINADJE.

[Body more or less completely inclosed in a firm lorica, xvliich is open at each end, and
divided down the back by a fissure whose sides are united by membrane; tivo furcate
toes ahvays exposed.

We come now to forms which are indubitably and manifestly loricate, the integument
permeated by a peculiar chemical principle known as chitine, which imparts hardness
and stiffness to it without diminishing its transparency. This substance is unaffected by
alkalis, which immediately destroy all the flesh and membranous parts : a fact which is
often useful to the scient, as by the addition of a minute drop of caustic potash to the
cell containing a specimen to be examined, he can in an instant obtain the external
form unchanged, generally clear and bright, with all the internal organs, that had marred
distinct vision, dissolved away.

The animals we have now to consider are clothed in a coat-of-mail (lorica) more or
less complete, of which the edges are sharply marked. Thus they display an evident
analogy with the shelled MOLLUSC A, and one more close with the Entomostraca, with
which, in its bivalve tribe Ostracoda, the present family may be advantageously compared.

The lorica here consists of two lateral segments of an ovoid box, open in front and
behind, for the emission of the head and the foot, the two edges parallel and approximate
along the dorsal line, and either widely open along the belly, as in Diaschiza, or united
and soldered into one there, as in Salpina and Diplax. The front is composed of
ciliated prominences, not protected by an arching hood ; the foot is provided with two
furcate toes. — P.H.G.]

Genus DIASCHIZA, Gosse, gen. nov.

[GEN. CH. Body compressed ; the dorsal half of the trunk inclosed in a carapace,
which is split medially ; one eye present, usually cervical ; trophi virgate, not distin-
guishable from those of Furcularia ; toes long, blade-like, furcate.

This well-marked group, now consisting of seven species, was wholly unsuspected a
few months ago. One after another has occurred to my own observation, within the
past year, and I strongly suspect that other species will yet be discovered. The genus
forms a very striking link of connection between the Loricate and IMoricate sub-orders, as
will be shown, more in detail, under the remarkable species D. semiaperta. — P.H.G.]

D. valga, Gosse, sp. nov.
(PI. XXII. fig. 12.)

[SP. CH. Lorica decurved ; eye occipital, small ; toes long, slender, much decurved.

Among filaments of Myriopliyllum, growing in an aquarium, very thickly beset with

various Biatomacea, &c, appeared in March 1885 an active, restless, little creature,

78 THE ROTIFERA.

which, at first, I thought one of the common forms of the minuter Notommatce or
Furcularice. But I presently perceived that it had peculiarities of structure, which were
quite unfamiliar to me. Its figure is nearly that of a cylinder, somewhat bowed down-
ward at each end, and a little arched along the dorsal line. A small truncate foot carries
two slender toes, about two-thirds as long as the body, much decurved, so as to form a
segment of one-fourth of a circle ; tbese are usually carried wide apart. A large brain
bears a red eye-point considerably anterior to its extremity, visible only at intervals ;
in subsequent specimens, however, sufficiently conspicuous.

The whole form and manners of this animal indicate its affinity with species which
are il-loricate. The situation, dimensions, and structure of the manducatory apparatus
are indistinguishable from those of Notomm. lacinulata ; yet the dorsal parts are inclosed
in a semi-cylindrical shell of transparent chitine, reaching about half-way down each
side, with a straight edge ; and cleft throughout the dorsal line, into two parallel halves,
moderately separated (reminding us of a Salpina, or still more of my Diplax compressa),
reaching to the end of the body, where each terminates in a point slightly over-arching.
Anteriorly this bifid carapace terminates transversely at what may be called the neck,
allowing the soft tissues of the head to be partially retracted for an instant, when the
lateral angles of the lorica are seen as two unchanged blunt points. It is remarkable
that, in a lateral view, the very front itself appears as if the integument were so stiffened
with chitine as to project both above and below in slightly obtuse points (fig. 12a). I
soon after found two individuals among conferva in a ditch at Coffin's Well, near
Torquay ; and still later in waters from many widespread localities. I find little varia-
tion in them. The dorsal cleft is shallow, but always visible when the animal turns. —
P.H.G.]

Length. Of body, ^^ inch ; of toes, ^^ inch ; total, x-\4 inch. Habitat. Torquay;
Woolston ; Sandhurst ; Birmingham ; Cheltenham ; Oban (P.H.G.) : not rare.

D. exigua, Gosse, sp. nov.
(PL XXII. fig. 13.)

[SP. CH. Minute ; lorica flexible, constantly thrown into folds ; eye cervical ;
toes thick at their base, less than one fourth of total length.

On one or two occasions I had met with this little species in water sent me by Miss
Saunders, from a window tank in her residence at Cheltenham. I had marked differences
between it and D. valga, but yet set it down as that species, waiting for further light.
More than five months afterwards, I was examining some of the pale impalpable floccose
alga that grows thickly around the filaments of certain pond-weeds, originally from
Dundee, but which had been several weeks on my table, when I saw this little thing in
some number, and perceived that its peculiarities entitle it to specific rank. Though valga
is a small species, this is not half its size ; its proportions, too, are different. It is much
plumper and more gibbous behind ; the toes, instead of slender rods uniform in thickness,
are long cones, tapering to acute points ,and only one-third of the length of the head and
body. The investing integument is evidently very flexible, every contraction and every
turn throwing it into strong folds. Yet, thin as it is, it is a true lorica, reaching half-
way down each side, as in valga, and displaying the dorsal fissure quite distinctly, as
one views it from behind ; when it is seen to be very shallow. No other points in its
economy seem noteworthy. — P.H.G.]

Length, -^ to ^ff inch ; toes alone, rJw to r^g inch ; lorica, yj^ inch. Habitat.
Alga; in fresh-water aquaria (P.H.G.) : rare.

SALPINADiE. 79

D. Hoodii, Gosse, sp. nov.
(PI. XXII. fig. 15.)

[SP. CH. Body gibbous and ventricose behind ; dorsal cleft narroto, parallel-sided ;
eye cervical ; toes rather short, blade-shaped, acute, decurved, one-fifth of total length.

This little species comes near to D. valga, but is considerably larger, and more swollen
in the posterior half of the body, whether viewed dorsally or laterally. The toes afford
the most obvious discrimination between them. In both, each toe is a segment of a
circle : in valga it is a slender rod of about equal thickness throughout its length, which is
nearly equal to that of the lorica. In Hoodii it is shaped in one aspect like a carving-
knife, in another like the half of the moon when three days old. As I have observed the
forms of the toes in Rotifera generally to be very constant, I am disposed to rely much
on them in specific diagnosis.

Only one individual occurred ; and of this my observations were imperfect. I found
it in the pale floccose alga, which invests aquatic plants near Dundee. In memory
of this origin I honour the little Diaschiza with my respected correspondent's name.
A few weeks after this, I was so fortunate as to find another example, in water sent me
by Mr. Bolton, from Blackroot Pond, near Birmingham. In the former specimen I had
not perceived any eye ; but in this it was very conspicuous, of large size, and of some-
what pale rose-red hue, though brilliant, resembling D. pceta in colour, but in a less
marked degree. It is cervical, occupying the extremity of an ample brain. — P.H.G.]

Length. Not measured, but about one and a half that of D. valga. Habitat. Loch
near Dundee ; pool near Birmingham (P.H.G.) : rare.

D. p^ta, Gosse, sp. nov.
(PL XXII. fig. 11.)

[SP. CH. Body thick, widest in front ; lorica with the dorsal cleft very narroio, its
edges parallel and ridged ; eye cervical, very large, pale ; toes blade-like, recurved.

In June 1885, soon after I had discovered D. valga, a little water was sent me by
Miss Saunders, from Woolston, in which were a good many specimens of that species,
some much smaller than I have described. In the same water, however, I found one
much larger, which proved a second species of the same genus. Again was I deceived
into the supposition that I was dealing with a Notommata, or a Furcularia, such as
F. gibba, till I caught sight of the cleft down the back ; and particularly, when, as the
creature turned, I for a moment saw it from behind, and looked up along the furrow.

The lorica seems again to be a mere carapace, reaching no more than half-way down
the sides, and cleft in a straight line along the back. It has an elevated ridge through-
out ; so that the cleft forms a furrow between the low walls ; and these are much closer
together than in D. valga, so that the furrow is very narrow. The dorsal posterior
terminations do not run off into curved points, but make nearly right-angles. I judge
the lorica to be very thin and flexible. The toes are slender, pointed blades, somewhat
recurved, often carried parallel when the animal glides forward. The mastax is large,
and seems formed quite on the pattern seen in Furcularia. Behind this is an ample
brain, carrying at its sacculate extremity a very large globose eye, of extremely pale,
transparent, carneous hue ; this species differing thus from the former, in the position,
size, and colour of the eye, — itself a well-marked and conspicuous distinction. The
digestive canal is divided into stomach and intestine, both which are large and saccu-
late ; and there is a contractile vesicle. The forepart of the abdominal viscera was, in
this example, delicately tinged of a salmon-colour. At the cloaca, as if a minute portion
of the intestine, there was protruded a little clear globose vesicle ; perhaps accidental.

This species is in manners restless and recluse, seeking its food and shelter under

80 THE ROTIFERA.

the skins of decaying algae, and other aquatic plants. It seems reluctant to swim in
the open water ; but yet can glide along, smoothly and swiftly, when it pleases.

Three months had nearly passed, and I had met with no second example of this
beautiful species, though examples of valga and scmiaperta had been numerous. But
then, in water from the same fruitful pond at Woolston, a specimen occurred, which
seemed the counterpart of pceta, except that the great brain was destitute, so far as I
could discern, of the pink eye, which had been the most conspicuous distinction of the
species. Presently, however, another appeared ; and here the whole occiput was
instantly seen to be radiant with the soft, rose-red tint ; the eye, in fact, or at least its
pigment, occupying, just as in my first example, the whole lower part of the ample
cerebral sac. Hence I infer that the rosy hue, normally pale, may sometimes become
so dilute as to be practically undiscernible. — P.H.G.]

Length, T^«j inch. Habitat. Woolston Pond ; Sandhurst, Berks : rare (P.H.G.).

D. SEMIAPERTA, GOSSC, Sp. nOV.

(PL XXII. fig. 10.)

[SP. CH. Body compressed, highest behind ; lorica with the dorsal cleft closed in
front, gaping behind, the ventral edges apparentlij approximate ; eye frontal; toes long,
slender, recurved.

In describing Furcularia gibba (supra, ii. 43) I have spoken of the resemblance borne
to that species by the present, a resemblance which extends to other species.

D. semiaperta bears much likeness to D. pceta, but is still larger ; it is, too, higher
behind, and the brain has no pink colour. There is, indeed, a well-defined oval eye,
of deep red hue, but of moderate size, and situate near the front (fig. 105). The
brain is large, descending far down the back of the neck, quite clear, and strongly
defined in outline. The locomotive cilia appear set on minute eminences over the whole
rounded front, making no wheels, but visible as a simple fringe. The trophi are
unusually large (fig. 10<2 '). The lorica, though split all down the back, has the edges of
the fissure in contact at first, so that only the hinder half is open, and this but narrowly.
In a succession of fair views that I had of one which was dying, looking down the back
from the front of the head, not only was the gape of the lorica well seen to be but partial,
but it evidently appeared that the cleft part was not elevated into a ridge, as it is in
other species. The lorica-halves appear even to approach along the belly, as they do
along the back. But I am not certain of this. Each division terminates behind in
an obtuse, slightly-decurved point (fig. 10), often obliterate.

One individual of this species had two globose bladders protruding from the cloaca,
as I have described in D. pceta. It may indicate a prevalent form of disease in the
genus. In one specimen was a large dark egg, nearly matured. Another had the
alimentary canal greatly distended, and of a greyish-blue hue, an unusual colour in
Rotifera ; but the mystery was explained by the fact that a colony of the Blue Stentor
(S. ca,ruleus) was established on the same sprig of water-moss ; and it became evident
where the Diaschiza had obtained its dinner. — P.H.G.]

Length. Total, y^ to s's inch. Habitat. Cheltenham ; Woolston, numerous ;
Birmingham ; Stormont Loch, Scotland (P.H.G.) : pools, rather common.

' This drawing was made from a protracted and excellent observation of a recently dead specimen,
completed without any reference to my published figs. (Phil. Trans. 1886). Yet it is seen how exactly
the details agree with those figs. (35-40), and especially with 39 and 40 of the Memoir. In examining
many dead specimens of D. souuij'rrta, I have obtained accurately the appearance of fig. 37 ; the long
produced, decurved points of the incus explaining what had seemed so inexplicable in situ. I am,
however, almost sure that these arching points proceed from the fulcrum between the rami, and are not
prolongations of the wide glassy rami themselves.

SALPINAD.E. 81

D. tenuiob, Gosse, sp. nov.
(PL XXII. fig. 14.)

[SP. CH. Body sub-cylindrical ; dorsal cleft of lorica wide throughout ; toes
thick, nearly straight, obtusely pointed.

Here is a species which bears a relation to Furcularia gracilis^ similar to that
which D. semiaperta bears to F. gibba. In September, 1885, while I was examining
water, sent me by the courtesy of Miss Davies from Woolston Pond, my attention was
arrested by first one and presently another, of what appeared indubitable F. gracilis.
Each was either half-concealed, as it burrowed in the floccose matter, or in swift motion
as it glided through the clear water ; so that, while I could recognize the form and
general character as accurately agreeing with drawings which I had carefully made of
that species, many years before (except that these were of rather stouter build), I could
get no opportunity of testing the condition of the back. Presently, however, I was so
fortunate as to catch sight of the integument of a dead specimen of the same, perfect in
form, but empty and transparent, the mastax in situ. By imparting currents to the water
in the live-box, while the object was under my eye, I could turn it into various positions ;
among others, one in which I could look along the line of the back. It was distinctly
double-ridged, and rather wide-cleft. The gap is of nearly uniform width from the
occipital edge of the lorica to the hinder edge just over the foot. I have said that the
form was stouter tban of F. gracilis ; it appeared stouter now than in the two living
restless examples that had first attracted my attention. But I reflected that the dead
lorica would naturally be broader than in life, because, the tegumentary membrane of
the venter having been ruptured by decay, the elasticity of the dorsal shields would
naturally cause their lateral expansion.

Circumstances prevented my further study of the two living specimens ; and I can
give no further information of the anatomy than what was to be learned from the dead
body.2 The features, however, that were visible were, from the very stillness of death,
definable with precision. The toes, in particular, are diverse from those of any other
known species, being not sensibly recurved nor decurved, but straight, or nearly, not
blade-shaped, but round, rather thick, abruptly brought to a point. — P.H.G.]
Length. About T^ inch. Habitat. Woolston Pond ; Dundee (P.H.G.) : rare.

Genus DIPLAX, Gosse.
(Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201.)

[GEN. CH. As Salpina, but the eye is wanting, and the lorica is destitute of
spines in front and rear ; foot and toes long and slender.

The two species of this genus I found both in the same water, Oldham's Pond,
Leamington, and both on one day, July 13, 1850. Of the first, only one specimen
occurred ; the second was numerous. With a single exception of the latter, I have never
again met with either. They both approach very close to Salpina, but the absence of
spines is notable, and the toes are proportionally more attenuate and longer. The
head is seated in a flexible tube, cleft at the occiput, which is capable of entire involution
within the lorica. It seems an approach to the persistent neck-tube of Dinocharis, to
which genus the present is allied by the condyles of the foot, and by the length and
slenderness of the toes. — P.H.G.]

1 I strongly suspect that Herr Eckstein's delineation of F. gracilis (Sieb. u. Koll. 1883, pi. xxvi. fig.
43) has actually been drawn from a specimen of Diasch. tenuior.

2 Kecently (March 1886) I have found it, in an aquatic moss sent me by Mr. Hood. It was very
restless, but I saw that the trophi, viewed dorsally, were on the pattern of Notommata lacinulata. —
P.H.G.

VOL. II. G

82 THE POTIFERA.

D. compressa, Gosse.
(PI. XXII. fig. 8.)
Diplax compressa . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201.

[SP. CH. Body much compressed ; lateral outline of lorica nearly a 'parallelogram.

The lorica consists of two trapezoidal plates, of which the ventral is the longest side,
connected together a little within the dorsal edges, so as to leave a double ridge. The
plates are bowed outward, laterally, and seem to be conjoined below. The whole lorica
may be rudely compared to a cell made by two spoon-bowls soldered edge to edge. The
transparent dorsal ridges can approach and recede, and are probably connected merely
by elastic skin. The whole frontal region is occupied by the brain, which descends sac-
like into the occiput, but shows no trace of eye. The mastax is small, and the tropin
obscure. A digestive canal, very wide at its origin, almost opaque from granulation,
diminishes, with no apparent constriction, direct to the cloaca in a straight course.
The ovary was normal, and I saw an ample contractile vesicle of sluggish action.
No lateral vessels were traced, but one vibratile tag1 was seen. Along the line which,
in the lateral view (fig. 8), indicates the bottom of the dorsal cleft, there are seen three
oval scars, possibly insertions of muscles for closing the valves. The foot consists of
three lengthened joints, two of which are decidedly condyliform (as in Dinocharis),
habitually protruded; it carries two divergent toes, straight, rod-like, acute.

The manners of the single specimen found were much like those of Salpina, but it
swam more, rarely resting on its toes. It was found among the sediment in the phial,
after several days' keeping. — P.H.G.]

Length. Of lorica, -^^ inch ; total, when rotating, -j-f^ inch. Habitat. Leamington
(P.H.G.): rare.

D. trigona, Gosse.

(PI. XXII. fig. 9.)

Diplax trigona . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. Sept. 1851, p. 201.

[SP. CH. Body triangular in section ; lateral outline of lorica ovate.

There is much resemblance between this and the preceding ; but the ventral side is
flat, and about equal to each of the lateral sides; and the longitudinal outline of the back
forms one third of a circle. The pectoral edge, which in D. compressa is but slightly
notched, is in trigona indented with a broad and deep sinus (fig. 9). The neck-tube
which incloses the head is only so far retractile, that, when its sides are brought together,
they protrude between the lorica-edges, in form of a thin fold (fig. 9a). The frontal
cilia are strong and bristle-like, grouped on prominences ; behind which a very small
brain-sac descends, with no visible eye. The trophi, of the common Salpina pattern,
and the internal structure generally, are as in the preceding ; almost always obscured
by a vast aggregation of air-bubbles. A thick tortuous vessel runs down each side.
The toes are very slender, straight rods, in some examples much longer than here
figured. The surface of the lorica is delicately punctured. — P.H.G.]

Length. Of lorica, TJ^ inch ; total, v\ inch. Habitat. Leamington ; Stratford
(P.H.G.): rare.

Genus SALPINA, Ehrenberg.

[GEN. CH. Lorica an oblong box, furnished with spines, but widely open at each
end, sj)lit down the back; head and foot protrusile ; toes furcate, long, straight ; trophi
sub-malleate ; eye single, cervical.

A homely illustration of this common and well-marked genus may be obtained by
supposing a Notommata or Diglena of long straight toes inclosed in a transparent shell.
This shell, the lorica, may be compared to a pillow-case, open at the two ends, with one

SALPINAM. 83

long side (the dorsal) unsown, whose edges remain approximate, yet separate.1 Both
ends run off into projecting points, which are grouped into four series, occipital and
pectoral in front, lumbar and alvine behind ; and these terms may be convenient for
definition. The head can be retracted wholly Avithin the lorica ; but the foot only
partially, and the toes never. These are moderately long, blade-shaped, acute, straight,
divergent. The eye is usually conspicuous, single, rather large, placed on the occipital
end of an ample brain. The mastax is large, globose, the mallei and incus well-
developed, the former many-fingered. A bristle-bearing antenna is protruded between
the occipital spines. — P.H.GL]

S. mucronata, Ehrenberg.
(PI. XXII. fig. 1.)
Salpina mucronata . . . Ehrenberg, Die Infus. 1838, p. 469, Taf. lviii. fig. 4.

[SP. CH. Occipital spines two, procurved ; pectoral two, wide apart, separated by
a deep sinus ; lumbar single, short ; alvine two, recurved, separated by a wide and deep
simis ; dorsal parts of the lorica minutely stippled.

The lorica is somewhat three-sided, the back arched, and doubly ridged, with a narrow
but deep furrow ; the sides gracefully swelling ; the belly nearly flat. The two occipital
spines, antler-like, are bent forward and slightly approximate at their points, with a
deep sinus between their bases. From the two edges of this sinus spring the two dorsal
carinae, arching to the middle in an elegant curve, and meeting in the conical lumbar
spine. The two pectoral spines are short and nearly lateral, as are the two alvine ;
both pairs are mutually severed by a broad and deep excavation of the ventral surface
of the lorica, while a similar sinus, less deep, bounds each of these pairs on the right
and left. The flat ventral surface bulges out abruptly to form the pectoral spines. The
head is very large, and is composed of many globose lobes, each of which carries a
group of rotating cilia. An ample brain carries a small horizontal antenna, and a large
cervical crimson eye. The trophi are frequently seen to protrude obliquely from the front, to
nibble the floccose matters on which the animal feeds, which are, I think, exclusively vege-
table. The alimentary canal, large and very sacculate, following a short oesophagus, carries
two ovate clear glands, and leads (apparently without division) to the cloaca. In an
experiment, it readily received carmine. An ovary often shews embryonic vesicles ; and
sometimes a great maturing egg adds to the size and to the beauty of the animal. The
lorica is elastic ; in looking up along the cleft I have distinctly seen the ridges approach
and recede, sometimes nearly closing up and then gaping widely. The latter is coin-
cident with retraction of the head-parts, and at the same time some of the viscera are
forced up between the ridges, considerably above the level of their basal line (fig. 1).

Though active, it does not swim much. It chiefly courses up and down among the
roots of the duckweed, which it affects, examining each in detail. It is not very
sensitive to alarm, caring little for taps or jars upon the instrument. The toes are
often expanded and closed. It is nearly colourless. — P.H.G.]

Mr. E. C. Bousfield has seen a male Salpina attached by its penis to a female which
was probably S. mucronata. It seemed to him that the male organ pierced the ventral
surface of the foot at the base of the first joint. This appearance was doubtless due to
the male's adhering externally by the broad end of the retroverted penis. Dr. Plate 2
says that the male of Hydatina senta pierces the female, anywhere, with its penis. He
admits that he has never seen the organ within the female's body, and that he never
could find any aperture after the apparent penetration ; but suggests that the cilia of

1 The dorsal fissure is not of fixed width, but variable at the will of the animal. An example (not
quite mature) of S. brevispina, which was sitting quite still, end-on, so as to give me an excellent
sight, had its dorsal cleft rather wide open ; while I looked at it, it deliberately closed up the sides to
mutual contact.

2 Jenaisch. Zeits. /. Natur. 1885, p. 37.

g 2

84 THE EOTIFEKA.

the penis make very minute punctures in the skin, and that the rod-like spermatozoa
find their way through these. Such hypothesis scarcely requires serious notice ; but
I may mention that Mr. Brightwell, Mr. Gosse, Mr. Hood, and myself have all seen
coitus take place, in various Rotifera, at the cloaca.

Length. About , L- inch ; lorica, y^- inch. Habitat. Weedy pools ; duckweed ;
around London (P.H.G.) ; Sandhurst, Berks (Dr. Collins).

S. spinigeka, Ehreriberg.
(PL XXII. fig. 2.)

Salpina spinigera . . . Ehrenberg, Die Infus. 1838, p. 470, Taf. lviii. fig. 5.

[SP. CH. Occipital and pectoral spines scarcely diverse from the preceding ; lumbar
a long, slender, acute spine, slightly recurved ; alvine pair slightly divergent and
decurved ; sinuses separating the occipital from the pectoral, and the lumbar from the
alvine, with straight bottoms.

The species of this genus are so consimilar that little more is needful than an
enumeration of the points of technical difference. These will be better discerned from
the figures than from verbal description. Though minute, they are constant, and I
think, therefore, specific. The most marked, here, is the production of the lumbar point
into a true spine in which the ridges meet, and which takes a direction different from
their outline. The sides have oblique corrugations ; and the general surface is coarsely
stippled in various degrees. The eye is large and pale red. It is certainly a rare form ;
yet I have met with it on various occasions. — P.H.G.].

Length. Of lorica, y-^ inch. Habitat. Pools at Battersea Rise ; Hampstead Heath ;
Leamington ; on Ceratophyllum (P.H.G.).

S. brevispina, Ehrenberg.
(PI. XXII. fig. 4.)
Salpina brevispina . . . Ehrenberg, Die Infus. 1838, p. 470, Taf. lviii. fig. 8.

[SP CH. Occipital spines wlwlly wanting ; pectoral pair short and straight ;
lumbar and alvine as in mucronata.

The total lack of the pair of occipital spines to the lorica is a clear distinction of
this species, the anterior extremities of the dorsal carinas not sensibly projecting beyond
the level of its truncate front, which, however, is not quite a straight line. The dorsal
arch, and the lumbar joint which terminates it, are nearly as in mucronata, only the
point is much shorter, and the sinus between it and each alvine spine is circular. The
surface is delicately stippled or covered with impressed dots. The ventral plane of the
lorica has not that abrupt bulging, which marks both the preceding species ; the dorsal
is more strongly arched than in either.

This species is sufficiently common in the fine-leafed aquatic vegetation of ponds and
ditches. Its manners are precisely such as have been recently described. I do not
know how to distinguish between this and the S. redunca of the same author. — P.H.G.]

Length. About y^ inch. Habitat. Lakes and pools : very common (P.H.G.).

S. MACRACANTHA, GoSSC, Sp. nOV.

(PI. XXII. fig. 6.)

[SP. CH. Occipital spines wanting ; pectoral pair short, straight; lumbar spine
and alvine pair long, straight ; the latter much longer than the former ; the anterior
and posterior ends of the ventral side of the lorica deeply excised ; lorica- surface not
stippiled.

The lorica of this fine species is ventricose ; the dorsal cleft is widely gaping. The
lumbar union of the carina; farms a true spine comparatively long and slender, yet is

SALPINADjE. 85

much exceeded by the stout straight and long alvines. For many years I knew it only
by a single dead specimen found in a pool at Maidenhead in September 1851. But
recently (March, 1885) I met with a healthy example on Myriophyllum in one of my re-
servoirs at Torquay, which enabled me to complete my diagnosis and delineation.

The great head is sub-lobate, beset with brushes of cilia, stout in the middle, becom-
ing more slender on all sides. A great occipital brain carries a very large and brilliant
red eye, and a rounded antennal lobe, bearing a few setse. The great mastax, when
feeding, is protruded through the mental sinus. The abdominal viscera are normal,
except that the gastric glands seem wanting ; and there appear to be two contractile
vesicles, into which the two lateral canals open by a trumpet- shaped mouth.

The manners were similar to those of other Saljnncs, nibbling eagerly and persever-
ingly, as it crept, the vegetable surface of the milfoil, with its protruded trophi.

After it had remained in energy for several hours, I killed it, by mingling with the
water in the live-box a minute drop of sol. caust. pot., whereby all the soft parts were
instantly dissolved. There remained, however, uninjured, 1, the great red eye, which,
in one aspect, had a quadrate form : 2, the two toes : 3, the whole manducatory
apparatus. A few minute air-bubbles were scattered through the visceral 'cavity. I
could now discern that the surface of the lorica is not at all scabrous, by which (as well
as by the otber peculiarities already adduced) it may well be distinguished from Ehren-
berg's S. ventralis, to which it yet approximates. — P.H.G.]

Length. Of lorica, 7V inch ; breadth and depth, each ^^ ; length of toes, ^-^
Habitat. Maidenhead ; Torquay (P.H.G.).

S. eustala, Gosse, sp. nov.
(PI. XXII. fig. 5.)

[SP. CH. Occipital spines wanting ; pectoral pair short, incurved ; lumbar spine
conical, short, arched ; alvine pair very long, stout, and incurved ; dorsal cleft narroiu,
of equal width.

The lorica is gracefully ventricose, the back and sides being much arched, the belly
slightly. The great alvine spines strike attention, as a conspicuous feature in all aspects ;
they being long, thick at their bases, and incurved to the points, which are obtuse and
approach each other. The lumbar spine is the united termination of the two dorsal
ridges ; it is only half the length of the alvines, conical and sharp-pointed, slightly
arched on the dorsal edge. The dorsal cleft, narrow and of equal width throughout,
reaches to the very front edge, which then is nearly horizontal on each side, but on
reaching the pectoral side, after a deep sinus, rises to a short sharp spine. The whole
surface of the lorica, ventral as well as dorsal, appears stippled or punctured with
minute sunken dots. But, in some examples, this is hardly perceptible ; while, in
others, it is coarse and conspicuous. The head, viewed laterally, is about as deep as
the body ; the front is made up of an intricate series of eminences (carefully delineated
in fig. 5a) ; one large lobe, toward the mentuvi, is crowned with stout and long cilia,
which curve forward uniformly when in vigorous motion ; other lobes carry much finer,
shorter, and straighter cilia. There is a thick, obtuse, antennal lobe, bearing a brush
of fine setae near, but not at, its extremity ; and, within its walls, are seen curves and
lines connected interiorly with a great descending brain, near the point of which is a
round red eye. The internal structure is, in general, normal. But what appears peculiar
is that there are (if I have not greatly erred) two coequal and consimilar contractile
bladders symmetrically placed, large and conspicuous, each of which receives the dilated
end of a lateral vessel.1 And this does not seem to be a series of twisted cords, but a
long slender sac, dilated here and there, where globular vacuoles are seen within.

1 These vesicles were exactly alike, each subtrigonal, seated (optically) on each side of the circular
orifice for the outlet of the foot. Each was evidently the terminus of the respiratory apparatus of its
side, which, a rather wide ribbon or bag of clear tissue, containing several vacuoles, opens by a trumpet-

8G THE ROTIFERA.

This large and handsome species, one of the finest of the Salpinx, I was at first in-
clined to identify with S. redunca of Ehr. ; but it is more than double the size of that
species, and the great development of its alvine spines sufficiently distinguishes it. It
may be regarded as bearing the same relation to redunca as S. macracantha bears to
ventralis. I have seen several examples ; one from the Lake at The Grove, Stanmore,
the residence of my esteemed relative, Mrs. George Bright wen. — P.H.G.]

Length, J lT inch; horizontal width, j] z inch; depth, -^ inch. Habitat. "VVool-
ston ; Stanmore (P.H.G.) : rare.

S. SULCATA, GOSSC, Sp. 110V.

(PI. XXII. fig. 7.)

[SP. CH. Occipital spines two, slightly procurved ; pectoral two, straight, acute ;
lumbar single, short, with a widened base; alvines longer, straight; dorsal cleft very
wide, ivith outcurved edges.

The lorica is of the usual outline, but somewhat wide, both in the vertical and
lateral aspects. Of the anterior spines the pectoral are the shorter and straight, the
occipital incurved. In the rear, the alvine pair the longer, and recurved ; the lumbar
short, straight, acute, with an abruptly widened cuneate base. From this lumbar
point two dorsal ridges run up, curving outward to the occipital spines (figs. 7, lb), in-
closing a shallow depression, which appears covered with only membranous integument.
The lorica, on the ventral surface, is quite continuous and evenly rounded. I had some
protracted and satisfactory sights of the creature in various positions, particularly from
a point directly in the rear, and at different angles, by which I distinctly saw the dorsal
furrow. One of these views is carefully delineated at fig. lb.

I know this form only from a single specimen just dead (but with the soft parts not
yet decayed), which occurred, Sept 14, 1885, in water from Woolston Pond, sent me
just a month before. It seems to be undescribed, yet well-marked by its broad dorsal
farrow, widening forward. It has no relationship with Ehrenberg's S. bicarinata, from
which, however (to judge by his figures, — for of diagnosis he gives none), it is sufficiently
distinct. It is a small but interesting form. — P.H.G.]

Length. Of lorica, without toes, y^ inch ; transverse width, -j]^ inch. Habitat.
Woolston (P.H.G.) : rare.

[I am indebted for my knowledge of a very distinct species, S. mutica, to Dr. Collins's
Note-book of pencilled sketches, minute but carefully executed. I have enlarged his
figures (PI. xxii. fig. 3). He has added no note to this form ; but his delineations were
made from specimens procured from a secluded pool near Sandhurst Military College, in
December I860. He identifies the species with S. mutica of Herr Perty.

From these it appears that the lorica does not vary much from the normal form (as
in S. brevispina, for instance) ; save that the front is straightly truncate, without any
spines, that the dorsal fissure is narrow and shallow throughout, and that it slightly
widens behind, where its edges terminate in two very slightly prominent lumbar
points : alvines seem wholly wanting. This species looks toward the genus Diplax,
as sulcata looks toward Diplo'is, yet both appear to be true Salpinas. — P.H.G.]

Genus DIPLOJ'S, Gosse, gen. nov.

[GEN. CH. Lorica, more or less depressed, ovate in outline ; formed of two sub-
equal jilatcs, united by clastic membrane ; the dorsal plate arched, ridged, and split
down the middle ; the ventral flat ; toes straight, furcate ; eye single, cervical.

shaped expansion, into the upper obtuse point of the bladder. (See the description of the preceding
Bpeci )

SALPINAD/E. 87

Of the two noble species for which this genus is constituted, the general form and
aspect suggest their location in the next family, while the technical characters fix them
here. At the first glance at their elegant forms, like ample oval plates of the clearest
glass, evidently broader than deep, we hesitate not instantly to pronounce them normal
Euchlanes ; but a moment's observation reveals a fissure through the back, so charac-
teristic of the Salpinada. The affinity between Diplo'is propatula and Salpina sulcata
is very close.

The internal organization, so far as observed, agrees with that of Euchlanis.

It is possible that the E. bicarinata of Herr Perty and the E. Weissii of Dr. Leydig
may belong to this genus ; but I have seen no diagnosis, or figure, of either. — P.H.G.]

D. propatula, Gosse, sp. nov.
(PI. XXIV. fig. 2.)

[SP. CH. Dorsal cleft wide before, closed behind ; ventral plate considerably less in
outline, furnished tvith three spines behind ; toes very long, of uniform thickness.

This species is broadly ovate, sometimes nearly circular, in outline, the dorsal plate
strongly arched, and medially ridged ; the ridge cleft so widely that the lorica is oblit-
erated at its front in a vertical view, forming an acute point at each side. Each side of
the fissure, from the lateral point, approaches the other in a graceful curve, till, at the
hind-back, they unite at an acute angle. The posterior margin of the plate extends
beyond this, forming the uninterrupted segment of a circle. The ventral plate is of
similar outline, but very much smaller, and quite flat. It ends behind in three acute
spines, of which the laterals diverge and the middle one projects from the general level.
The foot, of strongly marked articulations, is protruded between the plates ; the toes, of
great length and tenuity, are straight, of uniform thickness throughout, with blunt
points. No setae have been detected on the foot-joints. The internal organization pre-
sents nothing distinctive, so far as it has been observed.1

The interspace between the lorica-plates is considerable ; and this, together with the
great width of the dorsal cleft, produces a curious effect, as the animal twists about,
making the triple character of the lorica, with its points and angles, very apparent.

This distinct and imposing form has but recently come under my personal observa-
tion. But it is figured by Dr. F. Collins in his Note-book, from specimens obtained
twenty years ago near Sandhurst Mil. Coll. Figs. 2 and 2a are carefully copied from
his pencil sketches.2 On two separate occasions I have found the species, at each time
in water sent from the original pool, which thus is its only recognised habitat. Its
motions are elegant and lively, and its appearance most attractive. — P.H.G.]

Length. Fully extended, about ^ inch. Habitat. Pool at Sandhurst, Berks (Dr.
Collins ; P.H.G.) : rare.

D. Daviesi^e, Gosse, sp. nov.
(PI. XXIV. fig. 3.)

[SP. CH. Dorsal cleft narrow, parallel-sided, open throughout ; ventral plate nearly
equal, with no posterior spines ; toes blade-shaped.

This species occurred in water dipped from Miller's Pond, Woolston, The lorica is
decidedly triquetrous, the dorsal plate rising with sides slightly bulging, to what would

1 It will be observed, however, that while in my own figure (2a) the gastric glands are of the ordinary
form, Dr. C. has represented a pair of large pyriform sacs, each containing a vacuole, with long and
slender ducts which lead from (or into) the oesophagus. These suggest the remarkable structure found
in Ptcrodina, to which I refer the reader.

2 The toes are here represented as out-curved ; whereas, in the living examples I have seen, these
organs were quite straight. Dr. Collins is a very accurate observer, and the length and curvature of
the toes ("slightly curved") are distinctly mentioned in his MS. notes. In his transverse section,
moreover, the lorica-plates are much closer together than I have seen them. Possibly, in both these
particulars, there is some individual variation.

88 THE ROTIFERA.

be a sharp medial line, but that it is split throughout, and so forms a narrow furrow
with low walls. Though the fissure can be distinctly traced to the occipital edge of the
lorica, I am not quite sure that the ridge, or tvall, begins to rise above the dorsum-level
quite so early ; perhaps not till the middle of the length, and then gradually. The two
strong sharp points at the hinder end of the dorsum, so conspicuous in many aspects of
the living animal, are but the optical expression of the ends of the dorsal ridges seen
vertically. The ventral plate is sensibly less in outline than the dorsal : it is ovate with
the pectoral edge truncate; flat, thin, and glassy; at each extremity it becomes delicately
membranous. The foot consists of three distinct joints, long, and regularly diminish-
ing ; they are habitually extruded between the plates, perhaps in a sinus of the ventral ;
but I am not sure of this. The toes are moderately long, slender, blade-shaped, being
(very slightly) dilated beyond the middle, and then rather abruptly pointed. No setaa are
visible. The condition of the dorsal cleft is not invariable. Sometimes it is seen to
extend not more than half-way up from the tip : or even to be closed nearly to the
points, expanding there rather suddenly. Possibly the lorica is elastic, and subject to
the animal's will ; for I have certainly seen the fissure wide throughout. The hyaline
transparency of the whole, while it enhances the beauty of the creature, increases the
difficulty of discerning all particulars of its structure, even those that are external ;
especially as, from the incessant movements and changes of axis in swimming, it is almost
impossible to focus any one part in any one position. The front consists of a number of
low prominences, each rising to an obtuse cone, and each crowned with a row of vibrating
cilia. The mastax, an oblate sphere, presents nothing noteworthy ; the brain descends sac-
like behind it, with a round deep-red eye near the middle of its internal side, distinctly
crowned with a refracting lens. The stomach and intestine, not separable, occupy a
large space in the body-cavity, usually filled with contents of an uniform rich deep-brown
hue. This greatly adds to the animal's beauty, as it constantly roves up and down the
narrow cells made by the crossing filamentous leaves of Myriophyllum in the live-box.

In general form and appearance this species very closely resembles the larger Eu-
chlanes, which all its manners and actions perfectly represent, and do not in the least
remind one of a Salpina. It is a fine addition to our Rotiferous fauna. Since it appears
new, I honour it with the name of Miss Davies, of Woolston, Hants : a lady who has
long made the Rotifera her special study, and to whose courtesy I am indebted for my
first knowledge of the species.

Specimens have come under my observation, not only from the extreme south of
England, but, on repeated occasions, from Scotland. It is, however, rare. — P.H.G.]

Length. Extended, -£$ inch. Habitat. Woolston; Dundee (P. H.G.).

Family XIV. EUCHLANIDtE.

Lorica of ttvo dissimilar plates, one dorsal, one ventral, united so as to form two
confluent cavities, of which the upper is much the larger ; foot jointed, furcate.

Genus EUCHLANIS, Ehrenberg.

GEN. CH. Dorsal plate with the medial portion arched ; ventral plate nearly flat,
usually with a flange on either side ; eye single, just above the mastax.

There are no more beautiful or perplexing Rotifera than those contained in the genus
Euchlanis. Their large size and brilliantly transparent loricas render £hem most attract-
ive objects for dark-field illumination ; and it is by this method of exhibiting them that
the true structure of their loricse can be best determined. The animal must have room
enough to swim at its ease, and there must be a few bits of alga? for it to creep on.
Then, as it turns while swimming, or as it works its way over and round the weeds, the
creature will display all the beauties of its glassy armour; which, invisible at ono
moment, will Hash out at another in broad plates and unsuspected surfaces.

EUCHLANID^. 89

To get a clear notion of the form of the lorica,1 suppose that the shell of a tortoise
has its flat base split longitudinally down the middle ; and then that half of each part,
on either side of the split, is bent down at right-angles to the flat base. Further suppose
that a second flat oval plate, smaller than the base, is cemented to the free edges of the
bent-down parts, and the resulting form will closely resemble the lorica of an Euchlanis.
It is obvious that a small box will thus be formed below the true base of the tortoise-
shell, and that its cavity will be continuous with that of the shell, and that its bottom
will project on either side as a flange. Moreover, on the outside of this box, on either
side of it, will be a long furrow, bounded by the oval plate above, the flange below, and
by the side of the box. In the actual lorica of Euchlanis the portion corresponding to
the small box, below the true shell, contains a considerable portion of the viscera ; while
the furrow (when the animal is viewed sidewise) often presents the edges of the two
bounding planes so as to look merely like two parallel lines running from front to
rear. If we further suppose that the altered tortoise-shell, with its attached second plate,
is made of glass, and that it is held up so as to have the lower plate fully exposed to
view, it is clear that we shall see three sets of edges. First the outside edge of the proper
base of the shell ; secondly, within the first and parallel to it, the smaller oval edge of
the lower attached plate ; and thirdly, within this latter oval, the edges of the bent
portions to which the lower oval plate is attached, and which connect the upper oval
plate to the lower one. All these lines can be plainly seen in the ventral surface of
E. dilatata (PI. xxiii. fig. 5) ; where a is the edge of the dorsal plate, b is the edge
of the ventral plate, and c the edge of the connecting portion at right-angles to both.
The position of the inner two of these three lines varies greatly with the different
species, according to the relative sizes of the upper and lower flat plates ; and so does
the distance between these plates, and consequently the breadth of the longitudinal side
furrows. These differences are great helps in distinguishing the species, which have
been much confounded. Another assistance is the presence or absence of a sharp notch.
(PI. xxiii. fig. 2b) in the occipital dorsal surface of the lorica. In some species there is
no such notch, but a wide gap (PI. xxiii. fig. 5a), and the dorsal portion of the lorica near
the head is membranous ; so that it has no constant outline when the head is retracted.

Mr. Gosse is of opinion that his two species, E, deflexa and E. pyriformis, as well as
a third lately discovered by him, have no ventral plate, but have a ventral membrane
instead of it. On this account, as well as on account of a peculiarity in the structure of
their rami, he would separate them from Exichlanis as a new genus, under the name
Dapidia. As, however, we do not agree on the first of these two points, we have
thought it better to leave the creatures, for the present, with their names unaltered.

Ehrenberg has made use of delicate setae, which are sometimes found on the foot,
in order to separate the species ; but neither Mr. Gosse nor myself thinks this a cha-
racter that can be trusted. For the setre are difficult to be seen, are liable to injury,
and are certainly not constant in their presence in the same species. The internal
structure of the various species is so closely alike that a description of it in one species
will very nearly serve for that in any other.

E. lyea, Hudson, sp. nov.
(PI. XXIII. fig. 1.)

SP. CH. Lorica long, narroiv, oval, depressed ; transverse section a loio circular
segment; dorsal occipital edge membranous; hind dorsal edge without a notch;
ventral plate with a very narroio flange, of ivavy outline, elliptical and broadest at the
hind end ; setae absent.

1 Ehrenberg quite misunderstood the lorica of Euchlanis, which he imagined to be open down the
ventral surface between the two inner lines c, c (pi. xxiii. fig. 5). This mistake, and the omission to
draw or account for the line 6, b, has led to endless confusion in determining the species. Dr. Cohn,
however (in Sieb. u. Koll. Zeits. ix. 1858, p. 2S9), fully explained the error about the lines c, c ; but
missed the flange of the ventral plate with its edges b, b.

90 THE KOTIFERA.

I found this large and beautiful new Euchlanis, in June 1885, in water sent to me
by Mr. Tbos. Bolton, from Sutton Park, Birmingham. It can be easily recognized by
its long oval dorsal plate, which has not a trace of a notch behind, and by the curiously
rounded end of the flange of its ventral plate, which, unlike that of any other Euchlanis,
is widest at the hind end, and elliptical there in outline. As in E. dilatata and
E. macrura, tbe dorsal plate is membranous near the head. The creature is very trans-
parent, and it has a way of jerking its toes apart and then keeping them open, which is
very characteristic. It has unusually large foot-glands, and shows the adhesive nature
of their secretion by slowly twirling round, first on one toe and then on the other, for
several minutes at a time. From the ventral surface it is easy to see the structure of
the corona. It is truncate, and gouged out, as it were, above the buccal orifice, some-
what in the fashion of Hydatina senta (PI. xiv. fig. lc). A fringe of small cilia surrounds
its outer and inner edges, and on the face of the corona itself are curves of larger cilia,
whose ground plan is shown in black lines in PI. C. fig. 10. Two papillae rise from the
same surface, very visible on a dorsal view, which seem to be tubular, but in which I
have never detected anything like a tactile organ. Dr. Plate1 figures the similar organs
in E. dilatata with a triradiate passage down their length. He says that they are
covered with a very delicate membrane, and suggests that they serve for respiration.
The trophi are sub-malleate with five teeth in each uncus. The stomach is tied on
either side by muscles, which are attached to the border of the lorica at one end and to
the middle of the alimentary canal at the other. From these latter points muscular
fibres pass diagonally upwards along the surface of the stomach, and by their perpetual
contractions throw it into ever-varying folds ; while at the same time the lateral muscles
twitch the stomach from one side to the other. Yellow oil-globules, often prettily
arranged in quincunx fashion, are imbedded in the thick stomach-walls ; and in the
intestine, which is usually most obvious, the furious motion of its lining cilia can be seen
with ease. The gastric glands are curiously lobed on the ventral side (fig. la) and
contain large nucleated cells. The foot-glands are very long, club-shaped, and bent
over almost to the edge of the lorica ; they are continued down the short three-jointed
foot, and end in each toe in what appear to be three very delicate, adhering, quill-shaped
vessels (fig. 16), with their pointed ends near the toe's extremity. The toes are two
short, stout, sword-like blades ; and, so far as I could see, without setae. The vascular
system is conspicuous. Two intertwined lateral canals, hanging in bold loops just on
a level with the mastax, and at the summits of the foot-glands, run down each side of
the lorica to a large and normally placed contractile vesicle. I have seen four vibratile
tags on each side : one close to the head, one at the upper loop, another at the lower,
and one midway between them ; doubtless there is a fifth. The ovary is a large
cushion-like mass stretching across the venter with unusually large germs : fig. la shows
a maturing ovum. The nervous ganglion (fig. 1) is very large, with nearly parallel
sides, a scalloped front edge, and a rounded hind end, which is distinctly cellular. It
stretches far below the mastax, in front of which, on its inner surface, it bears a dark-
red eye. Two small setigerous pimples rise from the corona behind the tubular papilla?
mentioned above. On the neck is another setigerous eminence, the dorsal antenna. I
have not succeeded in finding any dorso-lateral antenna?. There are two pairs of
longitudinal muscles for withdrawing the head, which are plainly striated ; the rest of the
muscular system is very similar to that already described (i. p. 8) in Bracliionus rubens.

Length, ^ inch. Habitat. A pond in Sutton Park (C.T.H.) : rare.

E. dilatata, Ehrcnberg.
(PI. XXIII. fig. 5.)

Euchlanis dilatata . . . Ehrenberg, Die Infus. 1838, p. 4G3, Taf. Iviii. fig. 2.

„ Cohn, Sicb. u. Kvll. Zcits. ix. 1858, p. 289, Taf. xiii. fig. 4.

1 Jenaisch. Zcits. f. Nalur. 1885, Taf. ii. fig. 18.

H

"TO

fflMPfWlM

EUCHLANID/E. 91

Euchlanis dilatata . . . Moxon, Trans. Linn. Soc. vol. xxiv. 1864, p. 459, with figs.
,, „ Eckstein, Sieb. u. Roll. Zeils. xxxix. 1883, p. 385, fig. 33.

SP. CH. Lorica a broad oval; dorsal plate depressed in front, arched behind;
transverse section (through the highest point) a low circular segment; dorsal occipital
edge with a broad gap, joined to the head by a membrane; hind dorsal edge notched;
ventral plate flat with a broad flange of oval outline; trophi with five teeth in each
uncus.

This species, like that which precedes and that which follows it, has no occipital
notch in the dorsal plate, but has a broad gap (fig. 5a), which is only visible when the
head is completely withdrawn. The edge of the gap is united to the head by a softer
continuation of the lorica, which effectually obliterates the gap when the head is
protruded. The lorica, though depressed, slopes upwards a little to a point not far
from the top of a posterior notch in it, and then drops abruptly as if pinched in on
either side of the notch. The ventral plate is nearly as wide as the dorsal, and a ventral
view shows the edge of its flange running parallel to the edge of the dorsal plate just
within it. A side view shows the two edges as two parallel lines near together, and
drawn along the animal's side from end to end. Ehrenberg says that there are no setae
on the foot, but both Dr. Moxon and Herr Eckstein draw a pair of pedal seta?, and I
have met with specimens bearing setae in no other respect differing from those that
lacked them. Dr. Colm (loc. cit.) gives a full description of the male. It is a reduced
copy of the female with a sperm-sac and penis taking the place of the alimentary canal
and mastax, which as usual are entirely wanting, Dr. Colm has seen the wand-like
spermatozoa " swarming " in the sperm-sac.

Length. Female, ^, male, -^ inch. Habitat. Clear ponds and ditches : common.

E. macrura, Ehrenberg.
(PL XXIII. fig. 6.)
Euchlanis macrura . . . Ehrenberg, Die Infus. 1838, p. 4G3, Taf. Iviii. fig. 1.

SP. CH. " Closely resembling E. dilatata; lorica a narroiocr oval ; toes somewhat
longer; trophi ivith seven teeth in each uncus ; a pair of recurved setae on the foot."

I have met with an Euchlanis, whose figure is given in fig. 6, which had all the
above characteristics given by Ehrenberg, but I doubt whether E. macrura is a good
species, as none of the corresponding characters seem constant in E. dilatata, except the
number of teeth in each uncus ; and, unfortunately, I found several specimens, of what
I should otherwise have termed E. macrura. with only five teeth in each uncus.

Length. About T\j inch. Habitat. Clear ponds and ditches : not uncommon.

E. triquetra, Ehrenberg.

(PI. XXIII. fig. 4.)

Euchlanis triquetra . . . Ehrenberg, Die Infus. 1838, p. 4G1, Taf. lvii. fig. 8.
,, ,, .... Hudson, Mon. Micr. J. viii. 1872, p. 97, pi. xxviii.

SP. CH. Lorica oval, with a high flat median plate at right-angles to the dorsal
surface; transverse section (through the highest point) triangular; dorsal occipital
edge notched ; hind dorsal edge notched ; ventral plate concave, and (toith its flange)
hvo-thirds of the width of the dorsal plate ; trophi with five teeth in each uncus.

This most beautiful species is often to be found among the confervoid growth on the
walls of old ponds. Its lorica rises in a high thin plate, and is not unlike a delicate glass
dish-cover set over an inverted glass dish somewhat narrower than itself. The vertical
plate, that thus rises like a crest from the dorsal surface, is very flexible and elastic, and
can be easily bent aside by the compressorium without injury. The ventral plate is
curved downwards all round its edge, so that the lateral furrow between the two plates is
wide ; and, as shown in fig. 4&, its flange stretches barely half-way across the base of

92 THE ROTIFERA.

the dorsal plate. The outline of the dorsal portion of the lorica, when seen directly
from the front or rear (fig. 4c), is triangular ; the section, so obtained, having a base
just twice its height. There is a well-marked occipital notch (fig. 4.b) in the dorsal
plate, through which a short, stout, dorsal antenna usually protrudes. Dr. Grenadier
has detected two dorso-lateral antennae close together "lying near the crest of the
lorica." Ehrenberg says that there are no setae on the foot ; but I have never failed to
find two when using dark-field illumination. The rest of the structure requires no
further notice, as it is a tolerably close repetition of that of E. lyra.

This is one of the choicest of microscopic objects, when shown in a dark field ;
especially when it is quietly gliding over and round a few tangled algoe. Its strange
armour is now invisible, and now blazes out as it catches the light ; while the ruby eye,
the daintily-tinted stomach studded with glittering drops on canary-coloured quiltings,
the ruddy intestine softened by the tremor of its ceaseless cilia, and the restless head
crowned with an ever-varying halo of flashing setae, form a picture that once seen can
never be forgotten.

There is a variety of E. triquetra, with a lower vertical plate, which I have met
with now and then ; and which, on several occasions appeared to have but one long seta
on the foot. Possibly this is Leydig's E. uniscta (PI. xxiii. fig. 3).

Length. Up to ^5 inch. Habitat. Clear ponds and ditches : not uncommon.

E. DEFLEXA, GOSSC

(PI. XXIV. fig. 1.)
Euchlanis dcflexa . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200.

[SP. CH. Outline of lorica ovate ; ventral gape wide, equal, with deep walls ;
toes broad, blade-shaped ; lateral horns of incus straight.

This is a large and very beautiful species. It is not to be distinguished at first sight
from a true Euchlanis, but the carapace, which is highly arched, turns in at the lateral
edges, and after proceeding for a space horizontally, i.e. across the ventral surface, is
bent down at a right-angle to a considerable width and then terminates, as if we might
suppose the ventral plate to have been originally flat and continuous ; then to have been
slit down the middle, and each side to have been bent down at a line midway between
the slit and the outer margin. Thus the abdominal cavity is enlarged, and the viscera
are protected only by the common integument which is stretched across from edge to
edge. This being flexible, a variation of contained space is allowed, for development of
eggs, for distension of the alimentary canal, &c, which, in Euchlanis, is obtained by the
flexibility of the skin that connects the two plates. The lorica is almost circular behind,
where a very minute central notch admits the two sides to overlap in the slightest pos-
sible degree. The foot issues, of course, from the ventral hiatus ; it bears two toes, which
are thin, flat, and wider in the middle part. The penultimate joint of the foot proper has
on its dorsal side a curved projection, which arches over a deep excavation. It carries two
pairs of long setae, one or both of which are sometimes wanting. Each toe has a cor-
rugated mucus-gland (?) running through it. The broad head is composed of many
(ten ?) transparent globate lobes ; the front is divided into several pairs of lobes, which
carry bundles of cilia. The three strong lines which (with the front) form a square,
reaching behind the mastax. are puzzling, but I believe they represent the wide, clear
brain. The sacculate stomach is enormous, with two gastric glands ; and two glands,
beside, are attached to the mastax : there is a small, distinct intestine in which the epi-
thelial cilia may occasionally be seen ; a great ovary, with embryonic vesicles, and
sometimes one (or more) dark ovum maturing. The branchial tubules, two or more,
contorted and very loosely twisted, carrying four vibratile tags on each side, open by
two distinct mouths on each side, into an ample contractile vesicle, just before the cloaca,
whose periods are very irregular, even in the same individual : now emptying once in
two minutes, then several tiinos per minute. Many muscles arc seen, some indubitably

EUCHLANIDyE. 93

striate. An eye-spot which appears to be unconnected with the brain, is situate nearer
the pectoral than the dorsal side.

I found this species in 1849 in ponds around London, and have seen it often since.
It has sometimes occurred so large that even with the naked eye I have had no difficulty
in distinguishing the head from the foot. — P.H.G.]

I once found among a number of specimens of E. deflexa a perfectly empty lorica,
belonging to this species, and fortunately standing up vertically, so that it turned
round and round on its pointed end, as on a pivot (PI. xxiv. fig. lc). I was thus
enabled to see with the utmost distinctness that it was closed everywhere except a large
opening in front, where the head had protruded, and a small one behind, that had given
a passage to the foot. The ventral plate (fig. lc ; v), as I term it — the ventral membrane
as Mr. Gosse considers it — had no flange, but seemed to me quite as stout and stiff as
(not to say stiffer than) the other ventral parts of the lorica. Whatever it was, whether
chitinous plate or membrane, it had remained with the rest of the lorica while the softer
tissues of the animal had disappeared.

Length, -^ to ¥V inch ; breadth, T^ inch. Habitat. Pools and lakes (P.H.G. :
C.T.H.) : widespread.

E. pyrifoemis, Gosse.
(PI. XXIII. fig. 2.)

Euchlanis pyriformis Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200.

[SP. CH. Outline of lorica constricted in the middle ; ventral gape narrow, widest
in front, with shallow ivalls ; toe3 narrow, rod-shaped ; lateral horns of incus over-
curved.

The peculiar narrowing of the edge which gives to this species a pear-shaped outline
is caused by the edge of the upper plate being curved right under on each side,
this edge being formed by two surfaces thinned off to great tenuity, so as practically to
become but one layer at some distance from the edge. The under sides then proceed
inwards till they nearly meet, when they are bent downwards into shallow walls, just as
in E. deflexa, which recede from either to form projecting lateral points at the front ;
while behind they merge into a shallow groove and small sinus, at the end of the upper
plate. Along this the foot is extruded, which usually has two setae, a prominence and
notch, as in the preceding, and two long toes, quite straight, slender, of equal width,
except that they are abruptly pointed. The brain and whole internal organization
scarcely differ from those just described ; but the four slender horns that stand up from
the sides of the incus are curiously bent over outwardly in the form of hooks. The
eye is small, as in the preceding. In both species the beauty is much enhanced by a
line of minute corrugations, running parallel with, and a little within, the margin of
the lorica, like the " milling " around the edge of a new coin. Muscles in much pro-
fusion, longitudinal, transverse, and oblique, are to be defined in this very fine species.

I obtained it first at Battersea Rise, only the day before my discovery of E. deflexa.
Few specimens occurred, and it has always been a rarity with me. It swims with
swiftness and grace ; is of sprightly manners ; is beautiful and attractive, and being
large and brilliantly transparent, is well suited for study. — P.H.G.]

The transverse section (fig. 2a), was obtained by viewing the animal, which I
have drawn in fig. 2, directly in front ; it is taken through the turned-in portions of the
dorsal plate. It shows that at these spots, the flange of the ventral plate (according to
my interpretation of the lorica), almost touches the dorsal edge. These curiously bent
portions varied somewhat in different specimens ; but all my examples had four setae on
the foot. The hind portion of the nervous ganglion was darker, denser, and more
obviously cellular than the fore-part, from which it was separated by a wavy outline.
Its front edge was also scalloped like that of E. lyra.

Length. Up to ^ inch ; of lorica, ■£$ inch ; of toes, T|^ inch. Habitat. Orna-
mental waters (P.H.G.) ; garden pond, Clifton (C.T.H.) : rare.

94 THE EOTIFEEA.

Family XV. CATHYPNAD^E.

[Body inclosed in a lorica, open at each end, of ttvo plates ; the dorsal more or less
elevated ; the ventral nearly flat, the two divided by a deep lateral longitudinal stdcus,
covered with flexible membrane ; toes tico, or one, alivays exposed.

This is a well-marked, easily recognised, and compactly coherent group, the two
divisions of the lorica, and their connection, readily identifying its members, notwith-
standing the diversity in toes. The appearance, viewed from behind, reminds one of a
pair of bellows, if we only imagine the upper board arched instead of flat ; the leathers
representing the lateral sulci. The toes, in two of the genera, are two, furcate ; in the
others there is but a single toe : yet the form, position, and use of these organs are so
exactly identical, and yet so peculiar, that the genera cannot be dissociated. An ample
brain, descending into the occiput, carries a single eye, usually conspicuous. The tropin
are large, the mallei much more developed than the incus, virgate.

All the genera are marked by a common habit, which is not found elsewhere. One
will rest on the tip of its toe (or toes), and having bent down the whole body, remain
motionless, and as if asleep, for a long interval, the whole fore-parts retracted. Then
it will seem to awake, and languidly swing round the body, first to the one side, and
then to the other, without letting go its moorings, and without protruding its head ; and
then, perhaps, go to sleep again. Or it may rouse itself into activity, and begin to
grope away among the floccose, or glide deliberately off, soon coming again to anchor.

Five species were known to Ehrenberg, who placed the two with furcate toes in the
genus Euchlanis, with which, however, they have no close affinity. — P.H.G.]

Genus CATHYPNA, Gosse, gen. now

[GEN. CH. Lorica sub-circular horizontally, usually much arched vertically ;
lateral inangulation wide and deep ; toes two, furcate.

The characters by which the species of this genus are distinguished are sometimes
minute, and even obscure, yet constant ; the shape assumed by the toes, and especially
by the extreme points of these organs, demanding attention. In one group they are
narrow, parallel-sided, like a carpenter's rule ; in another, much widened in the middle,
with the sides curving to the point : the former I call rod-shaped, the latter blade-shaped.
The former, too, do not taper gradually to the tip, but are abruptly narrowed with a
right- angle, so as to make a sensible shoulder, whence the point descends as a marked
claw. And this may be only on one edge, or on both edges ; the toe being one-shouldered
or two-shouldered. — P.H.G.]

C. luna, Ehrenberg.
(PI. XXIV. fig. 4.)

Euchlanis luna . . . Ehrenberg, Die In/as. 1838, p. 462, Taf. lvii., fig. 10.

[SP. CII. Dorsal and ventral plates of lorica sub-equal, occipital edge crescentic ;
toes rod-shaped, two-fifths as long as lorica, clawed ; the claw one- shouldered, one-fifth
as long as toe.

The lorica, broadly ovate in horizontal outline, ending in front by a crescentic exca-
vation, and in rear by a small sinus between two points, and the toes, very narrow,
parallel-edged, generally carried in contact, with short, sharp claw-tips, may easily serve
to identify this common species. The dorsal and ventral plates are of nearly the same
form and curvature ; high and deep behind, they come into contact in front, at least at
the lateral edges, which project in two acute points. During the long retractations of
the fore-parts, the lorica may be considered shut by this contact. When activity is
resumed, the plates separate, and a broad head protrudes, the front of which is truncate,

CATHYPNAM. 95

with two equidistant incisions, at each of which appears a bristle (fig. 4). The rotating
cilia are set along the edge. A mastax of very ample dimensions, with a pair of long
mallei, but rather small incus, is always conspicuous. Behind this the occipital brain
carries an eye, usually large and brilliant. A great saccate stomach, without sensible
oesophagus, with large gastric glands, and followed by a separate intestine, passes
obliquely across the dorsal region ; and the ovary, as usual, occupies the ventral.1 In
the adult, the surface of the lorica is smooth, and the whole animal is transparent and
colourless.

Though individuals swim actively now and then, yet the habitual sluggishness and
inertia of the species cannot fail to attract attention. As described, it will balance
itself, by the hour, on its united toe-tips, with an occasional lazy swaying to and fro ',
or even loosen this feeble hold, and allow its body to sprawl away at right- angles to the
food-surface, free in the water, the foot being bent up to the belly. — P.H.G.]

Length. Total, Tls inch ; of lorica, ^3- inch. Habitat. Fresh waters (P.H.G.j :
common everywhere.

C. kusticula, Gosse, sp. nov.
(PL XXIV. fig. 6.)

[SP. CH. Lorica regularly ovate, tuith the frontal opening very narrow ; dorsal
surface coarsely tesselated ; ventral plate nearly flat ; toes blade-shaved.

This fine species is very hyaline, notwithstanding that the broadly-oval and arched
surface is cut into facets. These are not very regular, nor very distinctly marked, having
the appearance of folds in leathery skin. They appear to be limited to the carapace.
This is turned-in along each side, with a sharp lateral angle meeting the edge of the
ventral plate, similarly turned-in, as is clearly seen when the creature is viewed from
behind (fig. 6b). The union is doubtless completed by a flexible and extensible membrane.

The head is included between firm plates, which, seen vertically (fig. 6), appear as
two lateral projecting points, between which the front, of many conical lobes that carry
vibratile cilia, works to and fro. The brain and its lozenge- shaped eye are normal ; and
so are the great tropin, the stomach with trigonal gastric glands and distmct intestine,
and the ovary. A contractile vesicle is sometimes conspicuous, but no details of the
respiratory nor of the muscular systems have been defined. A rather thick and short
foot, rounded laterally, bears the two toes, which are articulated with round condyles.
They are moderately thick blades of fusiform outline, when seen laterally, thinner
towards the base, and rather bluntly pointed.

I first met with this form, in July 1885, in the sediment of water in which aquatic
weeds had been sent from the north of London. Subsequently other examples occurred,
in water from Caver sham and Woolston, and from near Dundee, in December.

The earlier specimens were even more clumsy and sluggish than ordinary, moving
waywardly from side to side, as if not quite under control, adhering all the while by the
toes. Hence I called it rusticula. This, when too late, I would have changed ; for some
were much more attractive, transparently beautiful, with the eye large and of a lovely
rose-pink hue, and so sprightly in manners as to be worthy of a more courtly designa-
tion. In these, too, the digestive canal was distended with food of a clear rich orange-
brown hue. These were Woolston specimens. Scottish examples bred freely and in-
creased in my phials. — P.H.G.]

Length, y-i-g- inch. Habitat. Pools throughout England and Scotland (P.H.G.) :
common.

1 In one example the ovary was fastened, by two threads with swollen enlargements, to each side of
the lorica, near the middle ; and the gastric glands were also tied to the same points (fig. 4). Long
threads (muscular ?) with like enlargements were seen to pass from the foot-bulb to near the same
points, if not higher.

9G THE KOTIFEBA.

C. sulcata, Gosse, sp. nov.
(PI. XXIV. fig. 5.)

[SP. CH. Lorica broadly ovate, much elevated; anterior edges straight; ventral
plate much smaller in outline than dorsal, both strongly fluted ; toes blade-shaped.

The general form and appearance of tins species may cause it to be easily confounded
with luna, especially when viewed from the side. The arched carapace comes to a sharp
edge all round, bending far-in abruptly ; then bending outward again with a like angle,
and coming to a like edge, to form the ventral plate. This, when seen sidewise (fig. 5a),
seems to be of the same dimensions as the dorsal ; but when seen direct from below it is
much less all round (fig. 5c), except in front, where the pectoral edge is parallel with the
occipital, both being transversely straight, but bounded, as usual, by two small lateral
points. Both surfaces are coarsely and deeply fluted ; the incised lines of the dorsal
passing round and beyond the inbent edge. The bulbous foot projects slightly through
an excavation in the dorsal plate's thickness : it is kidney-shaped; in its hollow the toes
are articulated. The lorica is, by the graving of its surface, rendered so opaque that the
internal organs are not easily defined. There is, however, a small but conspicuous
crimson eye in the occiput, and, by inference, a brain. The mastax is so large that,
when the head is withdrawn, it occupies fully one-third of the visible area, at the
middle of the lorica. Below this appears the ample stomach, dark witli digesting food,
and (in the condition just named) pushed far up above the mastax on either side.

This well-marked species I obtained in a number of examples, both alive and dead,
haunting aquatic moss, in water sent me by Dr. Collins from his historic pool at Sand-
hurst. For awhile I thought I had got hold of the Euchl. lynceus of Ehrenbei'g, but
examination of his text and figures forbade the identification. It is of the usual manners.
It often swims smoothly and swiftly, continuing the exercise for long periods without
rest, the toes usually carried behind, in mutual contact ; yet at intervals anchoring, re-
tracting the head and foot, and assuming still repose, broken, now and then, to sway
wildly in all directions, on its glued toes, as on a pivot, more E. lunce. — P.H.G.]

Length.. Extended, -p^ inch; of lorica, ^^ inch; of toes, Yho inch; width of lorica,
?^j inch. Habitat. Pool at Sandhurst, Berks (P.H.G.) : uncommon.

Genus DISTYLA, Eckstein.

[GEN. CH. Lorica of the form of a long ellipse, open and membranous before, closed
behind, depressed, higher before than behind ; lateral inangulation feeble ; toes hvo ;
" selvage-like thickenings of the lorica around the foot."

Herr Eckstein has described and figured two species of this genus, whose toes bear
the same relation to each other as those of C. luna and rusticula. The genus is closely
linked with the preceding; yet the lengthened and flattened form, the habitual protrusion
of the head, and the more constant activity of the species distinguish it. Only one of Herr
Eckstein's species has occurred with us, but I add (doubtfully) another. — P.H.G.]

D. Gissensis, Eckstein.
(PI. XXIV. fig. 8.)
Distyla Gissensis . . . Eckstein, Sieb. u. Kiill. Zeits. xxxix. 1883, p. 383, pi. xxvii.

[SP. CH. Lorica round behind, broadly truncate in front, with short lateral
points ; toes rod-shaped, thick, obscurely two-shouldered, claws small ; brain simple.

The outline is that of a narrow ellipse abruptly cut-off a little before the middle, so
that the lorica, at its truncate front edge, is scarcely diminished in width. It becomes,

PLATE XXI.

1. Dinocharis pocillurn .

. dorsal view .

. .

. H

la. „ „

. side view

. • . .

. H

16. „ „

. ventral view .

• . . .

. H

If- ,,

. transverse section

. . . . .

. H

la". ,, »

. variety ; foot .

■ • . . .

. H

1€. ,, || ,

. trophi .

. . . •

. G

2. Dinocharis tetractis

. dorsal view .

• . • .

. G

2a. „

. side view

• . . •

. G

26.

. transverse section

. .

. G

"c- )> »

. head ; cap closed

.

. G

2d.

. head ; cap open

.

. G

3. Dinocharis Collinsii

. dorsal view, the armature omitted

. G

3a. „ „

. dorsal view, showing spines .

. G

36.

. side view .....

. G

oc. ,, ,,

. transverse section ....

. G

4. Scaridiuin eudactyloti

im . dorsal view .....

. H

4a. „ „

. side view .....

. H

46.

. ventral view .....

. H

4C. ,, ,,

. junction of foot and toes

. H

4a". „ „

. niastax and brain ....

. H

■*c || i)

. mastax, trophi, and eye

. G

5. Scandium longicaudu

m . dorsal view .....

. G

oa. ,, ,,

. side view .....

. G

56. „ „

. head, showing mastax, trophi, and eye

. G

6. Stephanops nauticus

. dorsal view ......

. G

Oa. „ „

. side view .....

. G

7. Stephanops lamcllaris

. dorsal view ......

. G

7a.

. side view .....

. G

8. Stephanops unisetatus

i . dorsal view

. G

8a. H „

. side view .....

. G

9. Stephanops chlaena

. dorsal view

. G

ja. ,, ,,

. side view

• . . .

. G

So

.LUM.2 D TE1

'.-*»

PLATE XXII.

1. Salpina rnucronata
la. „ „

16. ,» „

2. Salpina spinigera
2a.
26.

3. Salpina mutica
da. „ „

4. Salpina brevispina
4a. ,, ,,
46.

5. Salpina eustala
5a. ,, ,,

6. Salpina macracantha
6a. „ „

66. „ „

7. Salpina sulcata
la. „ „
76.

8. Diplax compressa
8a. „ „
86. „

9. Diplax trigona
Ja. ,, ,,
96. „

10. Diaschiza semiaperta
10a.

106.

10c. „ „

11. Diaschiza paeta
11a. „ „

12. Diaschiza valga
12a. „ „

13. Diaschiza exigua
13a. „ „

14. Diaschiza tenuior

1 !'■ ,, )>

15. Diaschiza Hoodii
15a. „ „

dorsal view

side view

lorica, oblique view

dorsal view

side view

transverse section, dorsal half

dorsal view

side view

side view

lorica, dorsal view

lorica, side view

dorsal view

side view

dorsal view

side view

tropin, side view

dorsal view

side view
rear view
side view
dorsal view
transverse section
dorsal view
side view
transverse section
side view
lorica, dorsal view
head and eye
trophi .
side view
dorsal view
dorsal view
side view
dorsal view
side view
dorsal view
side view
dorsal view
side view

G
G
G
G
G
G
G
G
G
G
G
G
G

G
G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

r h u-

iULCATAB

I'LATE XXIII.

1.

Euchlanis lyra .

la.

)i » •

16.

)> >> •

2.

Euchlanis pyriformis

la.

)) !)

26.

)» ))

'6.

Euchlanis uniseta (?)

4.

Euchlanis triquetra

4a.

>> i)

46.

» )>

4c.

)> t> ■

5.

Euchlanis dilatata

5a. „ „

56. „ „

6. Euchlanis macrura

dorsal view .

ventral view .

foot, and contained vessels

ventral view .

transverse section .

front-edges of lorica

side view

dorsal view .

side view

ventral view of lorica .

transverse section .

ventral view : a, edge of dorsal plate ; 6, edge
of the flange of ventral plate ; c, edge of
the portion connecting the dorsal and
ventral plates, and at right-angles to both .

dorsal front-edge of lorica ....

ventral front- edge of lorica ....

dorsal view .......

H
H
H
H
H
H
H
H
H
H
H

H
H
H
H

e r So

SEMACRl

PLATE XXIV.

1. Euchlanis deflexa

. ventral view

■

. G

la. i) »

. dorsal view

. G

16. „ „

. side view ....

. G

lc

. empty lorica, ventral view

. H

2. Diplois propatula

. dorsal view .

. G

2a. ,, ,,

. side view ....

. G

3. Diploiis Daviesiae

. dorsal view .

. G

3a. ,, ,,

. side view ....

. G

36. „ „

. transverse section

. G

3c „ „

. hind end of lorica, dorsal view

. G

o«. ,, „

. trophi .

. G

4. Cathypna luna .

. dorsal view, head extended

. G

4a. „ „ .

. dorsal view, head retracted

. G

46. „ „ .

. side view, head retracted .

. G

4c. „ „ .

. rear view .

. G

5. Cathypna sulcata

. dorsal view

. G

5a. „ „

. side view, head retracted

. G

56. „ „

. side view, head extended

. G

OC. ,, „ ,

. lorica, ventral view .

. G

5a*. „ „

. edge of lorica .

. G

6. Cathypna rusticula

. dorsal view

. G

6a. „ „

. side view .

. G

66. „ „

. rear view .

. G

7. Distyla flexilis .

. dorsal view

. G

7a. „ „ .

. side view .

. G

8. Distyla Gissensis

. dorsal view

. G

8a. „

. side view .

. G

I

.,ANHS> MPMK$jCAT1BIYPNA«M£'

"

PLATE XXV.

1. Monostyla cornuta

dorsal view .

.

(J

la. „ .,

. side view ■.

.

G

16.

. transverse section

■

G

2. Monostyla lunaris

. dorsal view .

,

G

2a, 26. „ „

. side view

.

G

2c.

. rear view

.

G

3. Monostyla quadridentata

. dorsal view .

,

G

4. Monostyla bulla .

. dorsal view .

,

G

4a. „ ,,

. side view

,

(.

46. ,, „

. rear view

, ,

G

4c. )| ))

. front of lorica

, #

G

5. Monostyla Lordii

. dorsal view .

,

G

6. Metopidia lepadella

. dorsal view .

. .

G

6a. ,, „

. side view

, .

G

66. „ „

. transverse section

,

G

7. Metopidia triptera

. dorsal view .

, .

G

"a. „ ,,

. side view

,

G

76. „ „

. front view

,

G

8. Metopidia oxysternon

. ventral view .

.

G

8a. ,. „

. side view

. .

G

86. „ „

. lorica ; ventral view

G

8o. ,, -,-, .

. lorica ; dorsal view

.

G

8a. ,, ,,

. transverse section

, .

G

He. ,, f,

. head ; side view .

, ,

G

8/. i> *»

. tropin .

.

G

8<7- .. n

. pectoral notch of lorica

. .

G

8/;. .. ,, .

. hind end of ventral plate, showing orifi

ce for

the foot .....

,

G

0. Metopidia acuminata .

. dorsal view .....

.

G

Ja. „ „

. side view .....

. ,

G

96.

. lorica ; ventral view

.

G

■ - ■ it ••

. transverse section ....

. .

G

10. Metopidia rhomboidee

. dorsal view .

.

G

10a. „ „

. side view .....

.

G

106.

. transverse section

,

G

11. Metopidia solidus

. dorsal view .....

.

G

Hot.

. ventral view, head retracted .

.

G

116

. side view ......

.

G

Lie

. rear view .....

.

G

lid

. front of lorica ....

.

G

lie.

. hind end of lorica ....

.

G

11/

stomach .....

. .

G

12. Colurus daetylotus

. dorsal view .....

.

G

12a.

. side view .....

.

G

13. Colurus pedal US

. side view

.

G

13a.

. foot and toes

, ,

G

CATHYPNAD.E. 97

however, very thin and flexible, so as to be subject to much inversion in retraction.
The head, very freely extruded, is thick and large, a truncate cone, with a slight
auricle, at each lateral angle, and a central bladder-like lobe, which is retractile. The
whole head, which is very mobile, projects between two pointed shelly shields. In
death, the head being abnormally extruded, these appear as stout oval (or lozenge-
shaped) shields, quite separate from the lorica. The foot, of one apparent joint, is
bulbous and kidney-shaped ; to it are jointed the toes, which are much stouter and
shorter than in Cathypna luna. They terminate in similar small acute claws, but the
shoulders are less sharply angular. It is very thin, viewed laterally (fig. 8a). The
dorsal plate comes down to a blunt edge on each side, with feeble duplication ; the
hinder ventral parts, inclosed in membrane, being small, and much overlapped by the
clear thin edge of the lorica. A very favourable sight of one, as it deliberately turned-
up endwise (so slowly, indeed, that I could carefully focus it as it moved), showed that
the ventral plate is co-extensive with the dorsal ; but is very thin at the edge, sloping
upward toward the middle half ; this forms a downward arch to contain the viscera.

Herr Eckstein describes the brain in D. Ludivigii, as divided into three long sacs,
like as in Copeus centrums and C. Cerberus. In the present species there seems to be
a broad base rather abruptly diminished in width, but forming only one sac, which
carries a great crimson ovate eye, at its very point.

I have received the species rather plentifully in water from Mr. Hood ; and more
sparsely from Mr. Bolton : the former averaging much larger size. Its manners are
much more sprightly than those of Cathypna. I have also found it (with lorica very
flexible and expansible) in spring, in a domestic aquarium of my own, which had re-
mained unchanged for more than a year. — P.H.G.]

Length, T^ to TJo inch ; width, T^ to -^ inch. Habitat. Bracebridge Pool,
Birmingham : rare. Starrnont Loch, Dundee : abundant (P.H.G.).

D. flexilis, Gosse, sp. nov.
(PI. XXIV. fig. 7.)

[SP. CH. Lorica narrow, nearly parallel- sided, corrugated, flexible, plicate.

I am not by any means sure that this is entitled to specific rank ; nor, if it is,
whether it ought to be placed in the genus Distyla. It may be but the immature con-
dition of some other species, such as C. sulcata. Yet the condition, at birth, of the
lorica of M. cornuta, appears to forbid the conclusion that flexibility and corrugation
are marks of immaturity in this family. A lorica is evidently present, soft and flexible,
covered with irregular wrinkles ; marked also with a series of longitudinal folds, scarcely
amounting to flutings. The eye is large, rectangular, bright rose-red, seated on the
inner side of the brain, close to its point. The other organs are normal.

Its manners are lively, often wild, searching the edges and surfaces of the water-
moss which it haunts, and often creeping within them. It sometimes anchors by its
toes, and appears to go to sleep, just like its brothers and cousins. — P.H.G.]

Length. Expanded, ¥^ inch. Habitat. Sandhurst, Berks (P.H.G.) : rare.

Genus MONOSTYLA, Ehrenberg.

[GEN. CH. As Cathypna, but that there is only a single toe.

This group, consisting of numerous species, is so exactly the counterpart of Cathypna,
except for the toe, that one can scarcely avoid the conclusion that this is, structurally, of
slight importance. The details of the form, the habits (as the use of the toe as a pivot,
aiid the frequent and long-continued inertia), and even the specific variations in the
shape of the toe, all are so accurately the reflection of what has been described as to

VOL. II. H

98 THE ROTIFERA.

suggest that Cathy pna is Monostyla with the toe cleft through the middle, or that
Monostyla is Cathy pna with its two parallel toes soldered into one. — P.H.G.]

M. lunaris, Ehrenberg.

(PL XXV. fig. 2.)

Monostyla lunaris .... Ehrenberg, Die Infus. 1888, p. 460, Taf. lvii., fig. 6.

[SP. CH. Lorica broadly ovate, the dorsal plate round and greatly elevated, the
ventral nearly flat ; both in front projected into wide, triangular, flattened points, be-
tween which the edge is deeply excavate ; toe straight, rod-shaped ; claw protruded
between two slender spines.

The gibbous lorica descends abruptly before it is produced into the wide clear
triangular lobes in front. And there seems no noticeable difference in outline, either of
the lobes or of the intervening sinus, between the dorsal and the ventral plates. For,
in retraction, these are very firmly appressed, with a common outline ; so that no
change of position, and no focusing, makes the eye cognizant of more than a single,
somewhat thickened, crescentic line. The general figure is so elevated that it is more
than half a sphere, if we neglect the inangulation of the lateral sulcus, which, in this
species, is not deep. The foot-bulb appears to lie in a hollow of the ventral plate ; it is
wide and kidney-shaped behind, where the straight-edged, rod-like toe is articulated.
This terminates in a slender acute claw, not with a rectangular shoulder ; but with
a pair of fine points, between which the claw is, as it were, imbedded. Herr Eck-
stein describes certain appearances, which he interprets of the thickened lorica-
structure, for strengthening the foot against the violent strains endured as the animal
throws itself to and fro. He also depicts certain pale-red specks and excessively fine
lines, going upwards from the claw, which he would connect with the nervous system,
as well as with the mucous glands. "The rotatory organ is simple, but almost retired,
so that only a slight elevation with a single seta projects out of the lorica. When it is
extended, we discern two great lobes, which overlap the lorica-edge on each side, over-
reaching each other dorsally, but ventrally running off into the buccal orifice " (Ibid.).

A specimen in my possession, anchored by the toe to the glass of the live-box, threw
itself vigorously into all possible positions, for twenty-four hours, without once removing ; *
all that time, so far as observed, active in this special way, but close shut-up. The
movements, indeed, though constant, were not incessant, but very forceful, spasmodic,
and sudden. In general the animal is clear and colourless : of this specimen, the whole
body was stained of a yellow-brown hue, like sherry wine, so deep, while yet clear, that
no definition of viscera was possible. Yet tbe red eye was now and then defined, and,
under direct sunlight, came out very rich, and of a deep crimson hue. The great tri-
angular lobes of the lorica, being very thin, were quite colourless and glass-like.— P.H.G.]

Length. When extended, T|iTJ to j-^ inch. Habitat. Woolston ; Sandhurst ;
Thames, near Reading ; Snaresbrook (P.H.G.) : mostly in pools : not uncommon.

M. cornuta, Ehrenberg.

(PI. XXV. fig. 1.)

Monostyla cornuta .... Ehrenberg, Die Infus. 1838, p. 459, Taf. lvii. fig. 4.

[SP. CH. Lorica ovate, moderately depressed, the front shallowly incurved ; toe
somewhat blade-shaped, the claw without a distinct shoulder.

This species is very much like M. lunaris, so as, when retracted, scarcely to be dis-
tinguished from it except that the anterior dorsal edge of the lorica is slightly less
incurved. It is smaller, and rather more oval in outline ; in the act of extruding tbe

1 During the latter part of the time, however, it became very sluggish, and less willing to move and
jerk about.

\y\Aryxc*JyJia, (OUAA^^yvi^Muk^ ■W^('J)

CATHYPNAM. 90

frontal disk, and when it is extruded, there is an appearance of two lateral, slender, incurved
horns, and between them two spots which look like a pair of ill-defined eyes ; neither of
which we see in lunaris. But these are not what they seem : the horns are the optical
effect of the somewhat thickened and stiffened edges of the extruded head-mass, which,
in the process of contracting and expanding, incline to each other, resembling conical
knobs ; and the spots are only the summits of certain fleshy eminences, which bear
vibratile cilia. There is a true eye-spot of large size and crescent form, and of pale-red
hue, seated on the inner side of the brain-mass, that hangs behind the mastax.

The ventral plate has its pectoral margin quite straight ; it is considerably less than
the dorsal along each side, while commensurate with it behind. There is a square
hollow in it for the reception of the foot-bulb, which is somewhat kidney- shaped. The
toe, viewed vertically, is more blade- than rod-shaped, for the outer margins bulge
outward hi a greater or less degree, the widest part generally (but not invariably) near
the point. This point has often the semblance of a claw ; but this is illusory, for there
is no true angled shoulder. The tropin are of the normal form, but of unusual length.
It is a very common species, and from its sluggish habits, combined with its minuteness,
the observer is apt to pass it by with contemptuous neglect. — P.H.G.]

Length. Of lorica, ^J^ inch ; total, extended, T^ inch. Habitat. Still waters
(P.H.G.) : common everywhere.

M. bulla, Gosse.

(PI. XXV. fig. 4.)

Monoityla bulla .... Gosse, Ann. Nat. Hist. 2 Ser. vol. viii., 1851, p. 200.

[SP. CH. Lorica a pointed oval ; dorsal and ventral plates both gibbous, and nearly
co-equal ; toe rod-shaped in vertical aspect, with a two-shouldered claw, but decurved and
gradually tapering in lateral aspect.

This species I found in a small pool on Hampstead Heath, in August 1850, and,
soon after, in the lake of Eichmond Park, abundant. Lately it has occurred in water
from Woolston, and from Caversham. The yellow hue is not, as I first supposed, in-
variable. Some are quite colourless, except for the digesting food. The great rotundity
of the ventral plate ; the regular decurvation of the tapered toe ; and the deep narrow
sinus in both the occipital and the pectoral fronts of the lorica, — these are the true dis-
tinctions. The oval outline is so acute in front that the sinuses are bounded only by
two obtuse points. The gibbous dorsum ends behind with an oblique retrocession,
showing laterally a great rounded foot-bulb. The head projects in two receding lobes,
ciliated on their inner surfaces, just as in cornuta. The mallei are certainly two-fingered.
The animal burrows among Charae, Confervae, &c. — P.H.G.]

Length. Expanded, T}5 inch ; of lorica, T}^ inch. Habitat. Pools (P.H.G.).

M. Lordii, Gosse, sp. nov.
(PI. XXV. fig. 5.)

[SP. CH. Dorsal plate of lorica tesselate, its hinder end excavate, the excavation
forming three sides of a square ; toe rod-shaped ; claw shouldered.

This is a rare species, bearing much the same relation as Gathypna rusticula does —
each to its congeners. Indeed, they are so much alike as to be easily confounded till
the foot is seen to be two-toed hi that case, one-toed in this. It in general resembles
M. cornuta, but is much more transparent. The single toe is more slender in propor-
tion to its length, and much longer in proportion to the whole animal ; it is a straight
parallel-sided rod, with a minute acute claw apparently forming a separate joint. If
this is the case, we should perhaps consider this joint as itself the toe, and the long rod
as the penultimate joint of the foot. The shoulder is double, viewed vertically, but
single and much rounded, viewed laterally. The outlines of the toe, however viewed,
are always a little uneven ; suggesting that the surface is irregularly pitted. The lorica

H 2

100 THE ROTIFERA.

is ovate, not so pyriform as in cornuta. The edges of the upper and lower plates come
closer together ; for the anterior two-thirds the edge of the dorsal plate is about level
with that of the ventral, but much exceeds it in length. The dorsal is straightly truncate
behind, with the margin on each side, following the ovate outline and descending much
farther, so as to form two points. The dorsal surface is somewhat coarsely tesselated,
like that of Cathypna rusticula, but with the pattern slightly different (PI. XXIV.,
fig. 6). The whole surface appears as if irregularly crumpled, interfering with distinct
definition in spite of the transparency. The head is a low truncate cone, produced into
a number of slight frontal eminences, on which the locomotive cilia are arranged in tufts
or bundles. These do not appear to create sensible vortices in the surrounding water.

This species is, I conjecture, the fig. 22 of Mr. J. E. Lord (" Microsc. News," June
1884, page 146), as M. cornuta is his fig. 21. I therefore distinguish it with his name.
I have met with it myself, on rare occasions recently, among decaying vegetation in the
water of Woolston Pond, and abundantly in water kindly sent me by Miss Saunders.

Length, ^^ to T^ inch. Habitat. Woolston ; Newbury ; Dundee (P.H.G.) : rare.

There is a form, — of which I am almost inclined to make a separate species, — in general
like Lordii, but remarkable for the excessive length and slenderness of the toe, which
almost equals the length of the lorica. It may be but an extreme var. of the present
form. Yet the lorica seems to lack the square excavation behind, and to be more pyri-
form in outline, running off in front into broader lobes, as in lunaris. This I have found
in water sent me by Mr. Bolton from Sutton Park. — P.H.G.]

M. quadridentata, Ehrenberg.
(PI. XXV. fig. 8.)
Monostyla quadridentata . . . Ehrenberg, Die Infus. 1838, p. 459, Taf. lvii., fig. 5.

[SP. CH. Lorica nearly circular, greatly depressed, especially behind ; front deeply
cleft, with hvo horn-like spines decurved and expanding at their tips.

The horns well distinguish this form. During retraction these are drawn together,
and made even to cross each other (fig. c). Besides these, and outside them, the
dorsal plate projects into a broad-based triangular point on each side; while the pectoral
margin forms a flexible membrane, very deeply cleft in the middle, and further deepened
at will. The hind part is exceedingly flattened, merging into the foot, of which the last
joint is cubical, with a central notch. Here is articulated the toe, rod-shaped, but that
the outline of each side, instead of being straight, is strongly waved : an appearance
which may possibly indicate the waves of a tenacious mucus. At one-fifth from the tip
a double shoulder, rounded rather than rectangular, leaves the usual acute claw. The
head protrudes (fig. b), much as described in cornuta. Of the trophi, the mallei (fig. d) are
remarkable for a conspicuous horn projecting upward from each angle. The gastric glands
are large ; there is a large separate intestine, and also an ample contractile vesicle.

Several examples have occurred to my observation. In one I was witness to a curious
phenomenon. A large shelled Infusory, Arcella vulgaris, was within the Monostyla,
though how it had managed to force its way in, I cannot imagine, for it almost filled the
cavity of the lorica. Its fleshy processes were protruding in front, and, by the death of
the Arcella, unable, I suppose, after it had devoured its host, to get out, these processes
gradually lengthened inordinately. It was a curious sight. — P.H.G.]

Length, rhj-to <}6 inch; of lorica, tt7^°t?i inch. Habitat. Barking; Stratford;
Maidenhead ; Ilampstead (P.II.G.) ; among duckweed, in pools and ditches : rare.

COLURIDiE. 101

Family XVI. COLURID^E.

[Body inclosed in a lorica, usually of firm consistence, variously compressed or de-
pressed, open at both ends, closed dorsally, usually open or iu anting ventrally ; head
surmounted by a chitinous arched plate or hood; toes two, rarely one, always exposed.

The arching hood over the front, looking, in a lateral view, like a thin hook, movable,
and so distinguished from the " glory-crown " of Stephanops, always conspicuous, is the
most notable mark of this family, in which I propose to unite the mostly flat Metopidice
with the high-backed Coluri. As no subdivision above species exists in nature, but all
(as Genera, Families, Orders, and Classes) are arbitrary collocations, made simply to
facilitate the study of the species, which alone is natural history ; it follows that the
more constant, and the more obvious, the characters on which we found our Divisions,
the better. Hence I would not choose the form of the tropin, the presence or position
of the eye-specks, or the distribution of the cilia, for distinction — if I could get others ;
because all these are found, in practice, so very difficult to determine. The existence of
eyes in some Coluri and Metopidice, for instance, is so very uncertain and indetermin-
able, that I incline to agree with Dujardin in rejecting some of Ehrenberg's genera. The
distinction between Lepadella, Metopidm, and Squamella, is more than doubtful ; while
in Metopidia and Colurus, individuals of indubitably the same species are found, some
displaying eye-specks, and others in which no search detects them. — P.H.G.]

Genus COLUEUS, Ehrcnberg.

[GEN. CH. Body subglobose, more or less compressed ; lorica of two lateral plates,
open in front, united on the back, gaping behind, and (in general) wholly so up the
belly ; frontal hood in form of a hook, not retractile ; foot permanently extruded, of
distinct joints, terminated by two furcate toes.

A very familiar group, of minute dimensions, agreeable form, and sprightly action,
the Coluri give the impression of being, while sub-circular in lateral outline, very thin
in transverse diameter. This, however, is an illusion, arising from their being most
frequently presented to the eye in the lateral aspect. When we do catch a glance at one
in turning or swimming, we see that the body is moderately broad, ventricose, and evan
globose in the middle. The lorica consists of two glassy shells, each a segment of a
hollow sphere, which are, normally, soldered edge to edge, at the fore-back, and begin to
gape at the loins, the cleft then passing round behind, usually widening for emission of
a stout foot, and passing up the belly to the front, by which time it has generally become
as wide as the body itself. So constructed it may be imagined to be highly expansile,
and in fact we observe that its width is constantly increasing and diminishing. The
fore edges of the two plates, in the retraction of the head, are appressed so close as to
seem but one lamina ; but separate for the protrusion of the head with its rotating cilia.
The hood, a decurved plate, often broad but sometimes narrow, of hyaline delicacy, is
not retractile, but is seen when the lorica is shut up, resembling a semi-crescentic hook.
The foot consists of three strongly marked joints bearing straight, acute, slender toes,
often thrown wide apart, but, in some cases, so uniformly adherent that it is difficult to see
whether they are two or one. The whole foot is often stretched behind ; but much more
commonly it is projected forward under the belly, through the ventral gape. The presence,
the position, and even the number of eyes, seem subject to much variation.

Most of the known species are lacustrine in habit, but some are exclusively marine.

It is a characteristic habit of the species of the genus, particularly of C. obttcsus, to
elevate themselves to the utmost on the toe-point as on a pivot, and then awkwardly
tumble over, as if they had not power to maintain their balance. The Monostylce per-
form in somewhat similar style, but though their posturings and gyrations are wild, they
seem to have better control over them.

102 THE ROTIFERA.

In general, the species cannot be discriminated, while in life and activity, without
extreme difficulty ; their differences are so very slight, their dimensions so minute, and
their restlessness so incessant. — P.H.G.]

C. deflexus, Ehrenberg.
(PI. XXVI. fig. 1.)
Colurns deflexus . . . Ehrenberg, Die Infus. 1838, p. 476, Taf. lix. fig. 9.

[SP. CH. Lorica, viewed dorsally, broadly ovate, bluntly pointed before, produced
behind into two acute spines, separated by a wide, deep sinus : viewed laterally, the
outline is the quadrant of an oval : the venter cleft from end to end ; foot robust, with
tivo short, slender, acute toes.

If I rightly identify the species, there is little difference of aspect between this and
bicicspidatus. In this the posterior spines are said to point slightly below, in the other
slightly above, the horizontal line. Yet as this depends on the angle at which the
animal is viewed, which is every instant varying, the distinction is evanescent, and, I
fear, worthless. Yet, on careful study, this, which is by much the more robust species, is
seen to have the two halves of the lorica severed all round, except in the middle of the
back. The fore edges of these halves, deeply truncate, but a little out-curved, are firmly
pressed together in retraction ; and the effect of this appression, when seen from above,
is the dividing line of the blunt cone, which is seen minutely opening and closing every
moment. A muscle-band passes, in relaxed curves, from the front of each of the appressed
sides to the surfaces of the retracted organs seen in a confused heap far down, evidently
for the purpose of pulling out the trochal apparatus when required.

A large pale crimson eye seated on an ample brain-sac ; a mastax of the Euchla-
nidan pattern; a cylindrical stomach succeeded by a wide intestine; an ovary often
containing a nearly developed egg ; and a small contractile vesicle ; are usually seen. But
in the middle of the back, just under the lorica, are two curious organs, each apparently
an agglomeration of minute, clear vesicles, perhaps of air, perhaps of oil, observed long
ago by Ehrenberg. He declared them inexplicable ; and I cannot supply the explanation.

When, after a self-inflicted imprisonment, it may be of hours, the Colurus opens its
closed cheek-plates, a trochal mass of conglobate lobes, fringed with wreaths of cilia, is
thrust out, by whose vibration the creature smoothly but rapidly shoots away. The
frontal hooked-plate, which, even in the inert state, has been discernible by the delicate,
thin, curved line of its edge, moves to and fro, and under very favourable circumstances
we may see that its inferior surface is fringed with vibratile cilia. I judge it to be an
organ of touch ; Herr Eckstein's opinion to the contrary notwithstanding. — P.H.G.]

Length. Of lorica, ^}.;jT inch ; from hook to toes, Tl^ inch. Habitat. Ponds and
ditches ; quite common (P.H.G.).

C. bicuspidatus, Ehrenberg.
(PI. XXVI. fig. 2.)

Colurus bicuspidatus . . Ehrenberg, Die Infus. 1838, p. 476, Taf. lix. fig. 7.

[SP. CH. Almost exactly those of C. deflexus, except that the lorica is not cleft
cither dorsally or ventrally ; but only excavate behind, slightly on the dorsal, deeply on
the ventral side.

I have seen only a few examples of this form, all from Sutton Park, Birmingham.
It is, I presume, Ehrenberg's bicuspidatus, his figures showing a lorica undivided
beneath. In examples long under examination, I became quite certain that neither the
dorsum nor the venter was cleft ; hut a narrow sinus, reaching to more than one-third
of the lorica in length was excavated up the ilat ventral plate, and a very slight one out
of the dorsal end. Through this orifice the foot is thrust, of rapidly diminishing joints,

COLURIM. 103

and what appears a single, slender, acute toe. At least I could not, with close watching,
detect any sign of its division. In the dorsal view the frontal hood (fig. 2) appears not
as the segment of a sphere, but somewhat indented in front. It ever moves backward
and forward, as protruded and retracted. The venter appears quite flat, the semi-globose
dorsal plate rising abruptly from it with a sharp angle. In one, as it turned slowly, I
saw distinctly the form. If we suppose one-third of an egg to be removed longitudinally,
and replaced by a flat plate, we shall gain a fair idea of the general outline.

This is certainly an uncommon form. My acquaintance with it is limited to a very
few examples, obtained from Woolston Pond, and Sutton Park, Birmingham. Its manners
are peculiar. It swims constantly, never resting to grope, as other species do, but sail-
ing deviously and deliberately about ; now and then quickening its pace ; almost con-
stantly with the venter at the glass of the cell ; so that whereas I obtained plenty of
ventral views, I got few dorsal, and scarcely one good lateral. — P. H.G.J

Length. Extended, -^ inch ; transverse width ^i^. Habitat. Woolston ; Birming-
ham (P.H.G.) ; very rare.

C. uncinatus, Ehrenberg.
Colurus uncinatus . . . Ehrenberg, Die In/us. 1838, p. 475, Taf. lix. fig. 6.

[SP. CH. Lorica, viewed dorsally, broadly ovate, truncate before, produced behind
into two short spines : vieioed laterally, the outline is rondo-triangular, high in the
middle of the back, the posterior spines short, blunt, and abruptly set-on ; venter ividcly
cleft throughout ; toes two, short, slender, acute. Lacustrine.

The lorica is turgid, the back not ridged but smoothly rounded ; its ventral gape
parallel-edged, the edges apparently bent downward (as in Euchlanis deflexa), making
an angle with the swell of the sides, the anterior portion lengthened into a short tubular
neck. The hook is narrow and spoon-shaped. The internal structure is obscure, partly
from its sphericity ; yet the xnastax, stomach, intestine and cloaca, the ovary and
the contractile vesicle, can be defined. It is usually of minute dimensions, and, though
widely spread, rather rare. I have known it since 1849. — P.H.G.]

Length. Lorica, from ^<j to ^v inch. Habitat. Clapton ; Battersea ; Bath ;
(P.H.G.).

C. obtusus, Gosse, sp. nov.
(PI. XXVI. fig. 3.)

[SP. CH. Lorica ovate in all aspects, the posterior ends rounded without any points,
ventrally cleft throughout, gradually expanding for the foot-orifice, the fissure reach-
ing round to the back, both before and behind ; foot small, with two minute slender, ex-
panding toes. Lacustrine.

This little unrecognised species, which I find not uncommon, is clearly marked by
the blunt ends of the lorica. The lateral plates are separate for above three-fourths of
their circumference, being soldered together with a sharp suture, only in the very middle
of the back, and generally much compressed. The foot and toes together are about one-
third as long as the lorica ; the toes, like setae for tenuity, with no shoulder, are often
separate. The internal economy is normal ; including the common bubbles in the back ;
two colourless refractile globules have been seen on the brain, which may be eyes. Its
manners are sluggish, swimming laboriously, with jerks. — P.H.G. ]

Length. Without foot, 3-^ to ^^ inch. Habitat. Near London ; Woolston ; Lea-
mington ; Dundee (P.H.G.) : not uncommon.

104 THE ROTIFERA.

C. caudatus, Ehrenberg.
(PI. XXVI. fig. 6.)
Colurus caudatus .... Ehrenberg, Die Infus. 1838, p. 47G, Taf. lix. fig. 8.

[SP. CH. Lorica, in dorsal aspect, pear-shaped, widest behind ; dorsal hind sinus
shalloiv, between very short terminal points, not at all produced ; ventral cleft close,
abruptly becoming a semi-circular foot-orifice ; toes slender, frequently expanded ; foot
and toes three-fourths as long as lorica; eyes two. Lacustrine.

There are several species which may, almost equally well, serve as the caudatus oi
Ehrenberg, to distinguish which requires minute examination. The above characters
are carefully noted from many observations, and need not be repeated. The free expan-
sion of the long toes, unusual in this group, is noteworthy. The frontal hook is normal,
and I have repeatedly seen two eyes just beneath it. On the ventral surface the abrupt
expansion of the fissure from a linear cleft to a broad round opening for the emission of
the wide basal foot-joint, should be noticed. — P.H.G.]

Length. Total ^^ inch. Habitat. Birmingham ; Woolston (P.H.G.) : weedy pools.

C. ambijYTElus, Gosse, sp. nov.
(PI. XXVI. fig. 5.)

[SP. CH. Lorica, in dorsal aspect, broadly ovate, the hind ends rounded, without
projecting points ; ventral cleft gaping, widening before and behind; toe single, long,
with a medial depression; foot and toe two-thirds as long as lorica; eyes cervical.
Marine.

This species also may be very readily confounded with C. caudatus, but the cha-
racters above given, though minute, seem to distinguish it satisfactorily and constantly.
The lorica is arched, so that its dorsal outline forms about one-fourth of a circle, split at
its occipital end, and also for a little way above the foot ; the two lateral extremities
being rounded. When the animal in its turnings shows the ventral side, even though
slightly, we seem to see sharp points to the lorica ; but this is an illusion, for the points
are but the ends of the curved plates seen edgewise ; another turn, and they at once become
again obtuse. On the ventral surface, which is nearly fiat, the edges of the two plates
are either wide apart or very closely approach each other, or may even overlap, but recede
on each side of the foot, so as to leave the orifice nearly circular. The single long slender
toe, running off to a fine point, has a medial mark throughout, as in those Metopidm,
&c, which keep the toes ordinarily appressed ; but I have never seen a separation,
and the most delicate focusing with high powers fails to divide the fine point. The
usual hood is displayed. The mastax and its tropin are normal. The brain, large and
turbid but undefined, occupies the occiput ; and two minute red eyes, rather close together,
are situate on it cervically. The other interior organs are as ordinary. One oil-globule
(sometimes two) occupies in general the middle of the back, and is conspicuous.

This species seems exclusively marine. I have found it somewhat numerous among
algae, collected by Mr. Hood from tide-pools at low-water at Taymouth, near Dundee,
and also in Torbay. It is very restless, ever roaming, yet mainly affecting the conferva,
at which it nibbles constantly ; when swimming it shoots along with smooth rapidity.
The form is plump and round, the blunt corners low-descending ; the body hyaline and
colourless, the taper toe stretching far behind.1 — P.H.G.]

1 I am very confident that other species of this long-toed group exist, in both our fresh and salt
waters. But though I have some drawings and notes, I have not as yet materials sufficient for satis-
factory diagnosis. — P.H.G.

COLURIM. 105

Length. From hood to ends of lorica, ^4ir mc^ '■> f°°t anc^ toe, ^^ inch ; total, T|3
inch. Habitat. Marine pools at low tide (P.H.G.).

C. DACTYLOTUS, GoSSC, Sp. 110V.

(PI. XXV. fig. 12.)

[SP. CH. Lorica mac in front, shalloivly tubular behind, without 'points ; foot very
short but wide ; toes thick, large, and curved. Marine.

A somewhat thickset form. The lorica is ovate, viewed dorsally, with a broad an-
terior gape, out of which what seems another shelly valve projects, connected by an
involute joint with the lorica (as seen in fig. 12a), a sort of hood, protecting the ciliate
front and answering to the usual hooked plate, but of very different form. The front
consists of several fleshy eminences (fig. 12) bearing vibratile cilia.

The lorica ends behind in a short truncate tube, through which the foot finds exit.
This is exceedingly short and inconspicuous, though broad ; the toes are furcate, thick
at their base, blunt-pointed, and slightly decurved, when seen laterally (fig. 12a).

I have seen but a single example, in sea-water from tide-pools near Taymouth. —
P.H.G.]

Length, yj- inch. Habitat. Marine pools (P.H.G.).

C. pedatus, Gosse, sp. nov.
(PI. XXV. fig. 13.)

[SP. CH. Lorica cleft behind, ending in two square points ; foot stout, long ; toes
minute, straight. Marine.

Two examples of this little insignificant species occurred in water sent by Mr. Hood,
from the Tay Firth marine pools. They were both in the same live-box as C. dactylotus.
The thick foot-joints and the very small toes forming a small cone, when closely appressed
as they usually are, will distinguish the species from all others. It is somewhat less than
its congener just named. I detected nothing in it worthy of record besides. — P.H.G.]

Length. About ^^ inch. Habitat. Marine tide-pools ; rare (P.H.G.b

C. casLOPiNus, Gosse, sp. nov.
(PI. XXVI. fig. 4.)

[SP. CH. Toe very long and slender, consisting of a narrow plate laid within a
similar, but wider plate, and closely appressed to it. Marine.

In the form of the toe we have here an example, quite unique in this genus, of the
structure which characterises the genus, hence named Caelojms, in the Rattulida?. The
toe consists first of an extremely long, tapering, hollow, thin plate of transparent chitine,
such as would be presented by the bowl of a glass spoon, if drawn out to excessive length
and tenuity. Tben suppose a similar plate of glass, but narrower throughout, to be laid
in the hollow of the former, fitted exactly to it, and reaching its taper point far before the
other. What is the relation of the one spine to the other, and of both to the body; what
their functions, what their movements, separately or conjointly, I know not. I have
met with but one example, and that a dead and nearly empty lorica. The occurrence of
such is often of great value. It is true that it may give little or no information of the
internal structure, and, of course, none of maimers. But of the external form and its
appendages, composed of undissolved chitine, we can often obtain views of beautiful
clearness, given with a minute precision that we can seldom hope for from a living
animal. For the object is perfectly still, and remains so as long as we choose, while it
is generally feasible to make it revolve in various directions by producing mechanical

10G THE ROTIFERA.

currents in the water, and so to examine its appearance in other aspects. Thus was this
creature delineated, and I vouch for its accuracy so far as the details are given.

The lorica seems (I can say no more) to be widely severed on the ventral aspect, and
to end in rectangular points behind. The frontal hook appears normal.— P. H.G.]

Length, to tip of spine, TJj inch ; of which the spine is about one-fourth. Habitat-
Among conferva? in tide-pools in the Firth of Tay (P.H.G.) ; rare.

Genus METOPIDIA, Ehrcnbcrg.

[GEN. CH. Lorica usually depressed, entire, with an opening at each end for the
emission of the head and foot ; frontal hood in form of a hook ; foot and toes as in
Colurus ; eyes usually two.

For reasons already given I include in this genus, not only the species so named by
Ehrenberg, but also his genera Lepadella and Squamella ; thus agreeing in principle
with Dujardin ("Infus." p. 632) while I cannot accept his details. They seem to fall
into the same natural family as Colurus ; for though the prevailing plate-like form seems
at first sight to differ greatly from the compressed Coluri, yet this form is not invariable,
M. oxystcmum and M. triptera presenting notable exceptions ; while in the arched
frontal hook there is a remarkably conspicuous feature in common. Some of the species
are among the most familiar of Rotifera. — P.H.G.]

M. lepadella, Ehrenberg.
(PI. XXV. fig. G.)

Mctopidia lepadella . . . Ehrenberg, Die Infus. 1838, p. 477, pi. lix. fig 10.

[SP. CH. Lorica oval, much depressed, evenly rounded above ; its ventral plate
shorter behind than the dorsal, and slightly excavate.

That Ehrenberg's Lepadella ovalis, Squamella bractea and S. oblong a, and Mctopidia
lepadella are but species of one genus, I cannot doubt, and even the specific differences
between them are very evanescent. The number, and even the visibility, of the eye-specks
vary in individuals, and cannot be trusted for diagnosis. The present is a common form
in most fresh waters. The lorica in its dorsal outline, both longitudinal and transverse, is
a segment of a circle, and the ventral is straight. Seen from above it is oval, pointed
at both ends, and yet truncate ; the ventral plate round behind, and so considerably shorter,
and slightly emarginate for the emission of the foot. The frontal hood agrees with
that in Colurus, slightly protrusile, and is used for raking the rubbish among which it
feeds. The ciliate face is almost prone, and the trophi can be brought to its surface.

I think I have seen the male ; a minute creature, in form a very long cone, tapering
to a point, with two slender toes; in front, quite truncate, with a sharp horn projecting
from its forehead. No organization was visible within, save two conspicuous clear vesicles,
side by side in the middle of the body, not at all like oil-globules, being irregularly
oblong : nor accidental, being found in each of a large number of individuals, seen at
different times. A pair of fine lines ran far down the two sides of the body, and in the
hinder part was a large angular web of thin yellowish tissue. Else the whole seemed
structureless and of hyaline clearness. It contracted into a shorter oval figure. — P.H.G.]

Length. Of lorica, 7Jff inch. Habitat. Fresh waters everywhere (P.H.G.).

M. solidus, Gosse.

(PI. XXV. fig. 11.)

Mctopidia solidus .... Gossc, Ann. Nat. Itist. 2 Ser. vol. viii. 1851, p. 201.

[SP. CH. Lorica nearly circular, depressed, ivith a low rounded ridge above ;
ventral plate commensurate with the dorsal behind, but deeply excavate ; dorsal having
a submarginal line of corrugation.

/■ •

'. I

\

SH

COLURID^;. 107

This charming species, though in technical characters very similar to the preceding,
is yet readily distinguished when once it is known. It is very much rarer, averages nearly
twice its size, while its outline, in retraction, far more nearly approaches a circle. This,
with its crystalline brilliance, recalls the lovely Pterodince, of which it is no unworthy
rival ; and its resemblance to them is much augmented by a delicate line of corrugations,
which run round just within the margin, like the "milling" within a shilling. It
was this feature that suggested the specific name, and no allusion to the adjective solidus.
The arch of the lorica is much lower than in lepadella, especially towards the edge,
while down the middle there runs a very low, rounded ridge. The fore and hind exca-
vations are nearly as in lepadella. Besides the frontal hood, there is another clear disk
which appears to protect the rotating cilia, and a transparent bulb is placed on each side
of this, within each of which is seen a minute red eye, so that tbese organs are widely
separated.

Some curious facts connected with digestion were illustrated by mixing a little car-
mine with the water. Particles were readily imbibed, and soon appeared as a red cloud
in the fore part of the stomach. Presently this pellet passed into the upbent viscus at
the bottom, which I supposed the intestine ; and a second pellet, swallowed at the same
instant, took the vacated place. After an hour, the whole alimentary canal had assumed
the appearance of fig. 11/, the supposed intestine being only a lobe or pocket of the
stomach. The pellet No. 1 now moved rapidly down to the cloacal extremity of the
twofold viscus, but, instead of being discharged, it swiftly passed up (as between the
dotted lines) to its first position at the base of the stomach ; then returned to the
cloacal end, and quickly again mounted ; repeating these movements several times, till
at length it coalesced with the second pellet. All the while the whole interiors of both
chambers were full of an incessant quivering from the action of epithelial cilia. From
all this, it really seems as if something analogous to rumination occurred in these minute
creatures. The gastric glands and the lateral canals are very abnormal ; and the con-
tractile vesicle is sometimes ample, sometimes totally wanting. — P.H.G.]

Length, T!(T inch. Habitat. Walthamstow ; Leamington; Birmingham; Woolston ;
Dundee (P.H.G.).

M. acuminata, Ehrenberg .
(PI. XXV. fig. 9.)

Mctopidia acuminata . . . Ehrenberg, Die Infus. p. 477, Taf. lix. fig. 11.

[SP. CH. Lorica ovate, ending behind in an acute point ; occipitally deeply notched
between projecting spines ; the edges very thin.

Besides the above peculiarities there is little to mark this obscure little species, which
yet is amply distinct. When seen sidewise it has much likeness to a Colurus, save that
its form is flatter ; and the decurved frontal hood is more conspicuous. It is an eager
and persevering feeder, raking with its hood-edge among the floccose. — P.H.Gr.]

Length. Of lorica, ^i^ to ^hs inc^- Habitat. North London ; Leamington ; Sand-
hurst (P.H.G.) ; very scarce.

M. OXYSTERNUM, GoSSC.

(PI. XXV. fig. 8.)
Metojndia oxysternon . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 201.

[SP. CH. Lorica an ovate box of tesselated surface ; with a thin ridge running
down the dorsum ; venter with a similar medial ridge terminating abruptly in mid-length.

This is a very curious form. It is a depressed rhomboid-oval, with a rather high and
thin arched ridge running down the back from the bottom of a deep frontal sinus. The
ventral surface is also ridged as far as the mid-length, where the ridge ends, like the
sternum of a bird. Then the surface is deeply excavated, and again projects, forming a
prominent sheath for the emission of the foot. The whole lorica is cut into facets, as

108 THE ROTIFERA.

in Noteus and in many Anurace, and all minutely shagreened. The head is deep, form-
ing three lobes, all ciliated. In retraction the two sides of the lorica close on each
other, leaving within a large clear space, exactly as in many Coluri, to which a further
resemblance is borne by the position and direction of the foot and toes ; the former in-
clined forward, and the latter bent abruptly backward. A rather small brain carries an
eye as large as half the mastax (possibly two suffused, since in some specimens two are
observed), pale but rich, transparent rose-red. In rotating a narrow, parallel-sided,
truncate lip is seen thrust out in front, as in M. triptera. The trophi are on the plan
common in the Euchlanidcs, and neighbouring families.

I first obtained the species in an ornamental water near London in 1849 ; recently
in a ditch at Coffinswell, near Torquay, and in water from the Black Loch, Dundee, in
company with CEcistes Stygis and QH. bracliiatus. It is of lively manners. — P.H.G.]

Length, -jJ-^ inch. Habitat. London ; South Devon ; Dundee (P.H.G.) : rare.

M. ehomboides, Gosse, sp. nov.
(PL XXV. fig. 10.)

[SP. CH. Lorica rhomboid-ovate in outline ; dorsal surface tectiform, lower behind,
ending in an obtuse point ; ventral surface flat.

This seems to come between oxy sternum and triptera. The oesophagus is long, and
often thrown into curves. The gastric glands are peculiar, being placed at the ends of
two long threads, probably tubular, which are seated on the corners of the stomach, the
globular glands themselves being affixed to the lining of the lorica. — P.H.G.]

Length, TJ^ inch. Habitat. North London (P.H.G.) : very rare.

M. triptera, Ehrenberg.
(PI. XXV. fig. 7.)
Mctopidia triptera .... Ehrenberg, Die Infus. 1838, p. 478, Taf. lix. fig. 12.

[SP. CH. Lorica nearly circular, as vieived dorsally, dilated into three wide, but
thin, wings, one dorsal and two lateral.

The aspect of this tiny living jewel, viewed dorsally, is almost exactly that of M.
lepadella, and so it is if viewed side wise. But an instant turn, or a slight change of
level, and the broad planes come into view, with an effect that surprises. Each of these
is, speaking loosely, a semi-oval, formed of two thin glassy plates, soldered into one for
about half their width, then diverging to constitute, with the like structure of the vertical
plate, a sub-cylindrical sheath, in which the organs and viscera are inclosed. The foot
finds its exit by a sinus excavated out of the lower part of the cylinder, whose fore end
is truncate for the extrusion of the head. This is surmounted by a broad chitinous
hood descending in front to a sharp edge (as usual hook-like in lateral perspective), quite
distinct from the tripterous lorica, within which its base is slightly retractile. It is con-
spicuous in all aspects. From above, the ciliate front, with its minute crimson eyes, one
at each extreme lateral joint, is clearly discerned through its transparency.

It is a most exquisite little creature, of crystal brilliance, and sprightly in manner,
without being swift. It swims little, but scrapes and pokes in the parasitic floccose.
Here, as it turns and twists deviously about, we see constantly changing aspects of the
three shining planes, whose surfaces and edges are ever crossing each other, all visible
through each other, from their perfect transluccncy. Thus, though the difficulty of
resolving the organic details of the active atom is augmented rather tantalisingly, one
cannot but be charmed by the beauty and variety displayed. I have seen one, slowly
gliding in a straight line, go on revolving on its axis, bringing the six surfaces into view
in quick succession, with a striking effect. On another occasion one came sidling up to
a noble Euchlanis. The contrast, and yet the resemblance, was curious ; the one could
have lain comfortably within the ample mastax of the other.— P.H.G.]

Length, .2]HS inch. Habitat. Sandhurst (Collins) ; Woolston; Dundee (P.H.G-.); rare.

COLURHLE. 109

M. beactea, Ehrenberg.
Squamella bractca . . . Ehrenberg, Die Infus. p. 480, Taf. lix. fig. 16.

[SP. CH. Lorica oval, much depressed, its front deeply excavated especially on the
pectoral side ; dorsal plate ending behind in two minute projections ; ventral deeply
excavate ; eyes four.

The differences perceptible between this and lepadella are exceedingly small ; the
four minute eyes, set in square, are very rarely discerned ; but I have seen them. One
deposited an ephippial egg", clothed with very long spines, while under my observation.
P.H.G.]

Length. Of lorica, ^^ inch. Habitat. Pools and infusions ; common (P.H.G.).

Genus MONUEA, Ehrenberg.

[GEN. CH. As Colurus, but the toe is a simp>le style.

It is mainly in deference to the great Prussian zoologist, that I retain the generic
distinction between this and the preceding group. With the recollection that in G. leptus
I can discern no trace of a medial depression in the toe, that in C. amblytelus there is
the depression, which I have never seen separated, that in C. caudatus there is the de-
pression apparently as inseparable, which, yet, on occasion, palpably opens and expands ;
to build a genus exclusively on this condition of the toe is most precarious. — P.H.G.]

M. colukus, Ehrenberg.
(PI. XXVI. fig. 7.)
Monura colurus .... Ehrenberg, Die Infus. 1838, p. 474, Taf. lix. fig. 4.

[SP. CH. Lorica ovate, much compressed, highest at the front, with the hind ends
rounded ; eyes two, approximate. Marine.

Viewed vertically this animal has the form of a mussel, gaping widely all along the
venter and around each extremity, with no sensible change of outline for the emission
of the foot, and hinged only along the middle of the dorsum. In a lateral view the
lorica forms the half of a very long ellipse, flattened ventrally, obtuse behind, thence
gradually rising till it is highest at the front, whence it descends in a bold curve to
rejoin the belly side. Thus the outline is markedly different from that which is charac-
teristic of Colurus, though the difference depends on minute peculiarities.

The round anteriors of the valves are, often and long, firmly appressed (fig. 7a), the
whole head and viscera being far withdrawn, and a wide hyaline space left, within
whose edge a very delicate corrugation marks the line of mutual contact. At intervals
the valves part, and a head is protruded, armed with long and coarse cilia, and over-
arched by a conspicuous frontal hood. This has the unusual appearance of a wide veil
of exceeding tenuity, strengthened by an acute taper hook of chitine running through its
medial line. Under the base of this organ are seen two brilliant crimson eyes,
moderately near each other. Slight indications of a manducatory apparatus are seen,
and occasionally the globose form of the mastax ; but all so evanescent as to defy defi-
nition. A large sacculate stomach, divided by constriction from a still ampler intestine ;
an ovary and a small contractile vesicle, with the cloaca at the dorsal base of the foot,
are all normal. The foot itself is prominent, moderately thick, of three long, well-
marked joints ; the toe, a single, long, acute style, thick at base, and suddenly diminish-
ing in its dorsal outline, has the remarkable peculiarity of being as flexible and elastic
as whalebone. The extruded foot and toe are two-thirds as long as the lorica.

I first met with this species, congregating in great numbers around my marine

110 THE ROTIFERA.

aquarium, in September 1854. Its manners agreed with those of the larger Coluri,
shutting itself within its valves, and that so stubbornly, as to die rather than open
them. Lately I have received specimens from Mr. Hood, found in marine tide-pools in
the Firth of Tay ; and have taken many in Torbay.

Length. Of lorica, ^\,T) inch ; of foot and toe, 5^ inch ; total extended, 2^ to 7>i-(T inch.
Habitat. Marine pools in Forfarshire and Devonshire ; domestic aquarium (P.H.G.).

Very recently specimens of what I suppose M. dulcis, Ehr., have been sent me,
from fresh water, by Mr. Lord of Rawtenstall. The lorica is acute, instead of obtuse,
behind.— P.H.G.]

Genus MYTILIA, Gossc, gen. now

[GEN. CH. Body ovate ; lorica as in Colurus, but the head and neck habitually
protruded, as tvcll as the ivhole foot ; no frontal hook. — P.H.G.]

M. tavina, Gossc, sp. nov.
(PI. XXVI. fig. 8.)

[SP. CH. Eyes hvo, frontal, wide apart. Marine.

The lorica is essentially similar to that of Colurus (though the facies of the animal
is quite different), being a shell of two lateral valves, like that of a mussel, unbroken
on the dorsum, descending on each side, and open all along the venter. Behind they
are patent, where the thick foot emerges ; but their edges approach, or even overlap, as
in Pterodina, at the pectoral front. A massive head, and an equally thick, distinct neck,
both about equal to that part of the trunk that adjoins them, are normally projected
from the lorica, and not, as in Colurus, concealed between the valves. As there is,
moreover, no trace of the hood, or hooked plate, that shields the face in kindred forms,
the difference of aspect is very marked, and one of the Illoricate forms is involuntarily
suggested.1 This is augmented by the circumstances, that the foot is long and thick,
especially at its base, that it tapers there gradually from the thickness of the trunk, and
that it is habitually carried in the line of the body. Whereas, in Colurus and Monura,
it is much smaller than the visible body, is usually projected at a sensible angle, and
appears to come out between the ventral edges of the valves. The lorica, too, is of
much less depth in proportion to its length ; for, whereas, in Colurus the depth to the
length may be about 2 : 3, in Mytilia it is about 2:5. It is obliquely truncate at the
hind margin, the lateral edges diverging thence till they meet at the pectus. The body,
which is arched on the dorsum, diminishes along the lumbar line, and forms a minute
conical projection, representing a true tail, behind which the cloaca opens, whence the
foot proceeds, in a similar ratio of diminution and in the same line, for a considerable
length, terminating in two stout pointed toes, often jerked widely apart. Each is per-
meated by the usual mucus-gland, long, thick, and clavate. The internal structure is
with difficulty defined. Tbe extreme restlessness of the creature, combined with its
minuteness, renders an examination during life almost impossible ; and, after death, the
outlines of the delicate organs become blurred, and soon obliterated. I believe I have
perceived, on repeated occasions, and in many specimens, two minute eye specks at the
front, rather wide apart. The mastax is comparatively large, and the tropin normal
(as in fig. 8c). But the whole interior is almost opaque from granulation, and so, very
difficult to penetrate.

It is a pretty little creature, sprightly and attractive, with much in its manners and
ways that reminds us of its kindred Coluri, one of which, C. amblytclus, is its constant

1 I cannot avoid a lurking suspicion that under Ehrcnberg's figure of Distemma marinum may have
lain Mytilia tavina, notwithstanding discrepancies.

COLURIDiE. Ill

associate. The species is another of the discoveries of Mr. Hood, of Dundee. He finds
it in sea-water, and lias sent me many specimens in vigorous health. — P.H.G.]

Length, r'o to T|-^ inch ; width and depth equal, about T^-j inch. Habitat. Tide-
pools at the mouth of the River Tay (J.H.) ; and in Torbay (P.H.G.).

Genus COCHLEARE, Gosse, gen. nov.

[GEN. CH. Lorica not half the length ; foot long , annulate ; toes two, furcate.

The two species which I include in this genus are minute and inconspicuous, but
peculiar. The lorica is quite a subordinate feature, the parts behind this greatly deve-
loped into what appears a very stout and long foot, of many annulose joints, terminated
by two minute toes, on which the creature usually elevates itself, and turns as on a pivot.
Both the species are lacustrine. — P.H.G.]

C. staphylinus, Gosse, sp. nov.
(PI. XXVI. fig. 9.)

[SP. CH. Lorica hemispheric.

The integument is wrinkled irregularly, and scarcely firm enough to be called a lorica.
It is nearly circular in outline, arched dorsally, and flat ventrally, abruptly attenuated to
the stout and long foot of four distinct joints, ending in what looks like two acute toes
soldered together, frequently turned up in a threatening manner. Eyes and internal
organs dim and uncertainly discerned. I have found but one specimen, in a dyke near
Stratford, in 1851.— P.H.G.]

Length, TJ5 inch ; width, 3|^ inch (P.H.G.).

C. tuebo, Gosse, sp. nov.
(PI. XXVI. fig. 10.)

[SP. CH. Lorica three-sided.

The form of the lorica may not be constant, yet the facies of this differed so much
from that of the preceding, that, until we have more knowledge, it is well to treat them
as distinct. The flexible lorica is nearly parallel-edged, but rises to a dorsal angle, like
a roof; yet each of the sloping lateral surfaces consists of two planes, very slightly in-
clined to each other. The head appears as if it had a broad hood like that of Stephanops
chlcena, but flexible, for sometimes a lobe of it flaps inward. The front is formed of
two half-cones, ciliated on their inner faces, which approach and recede at will, making
two vortices. A large occipital brain bears a red eye near its point. The toes are dis-
tinctly furcate. — P.H.G.]

Length, 5Jff inch ; width, -^^ inch. Habitat. Black Loch, near Dundee (P.H.G.).

Family XVII. PTERODINADiE.

Lorica entire, various ; corona and ciliary wreath those of the Philodinadae ; trophi
malleo-ramate ; foot wholly retractile, transversely wrinkled, jointless, toeless, ending in
a ciliated cup ; — or foot absent.

This is a singular group of Rotifera. Unlike all other loricate free-swimmers, Ptero-
dinadce possess a corona of a Bdelloidic, and trophi and foot of a Rhizotic type. The
corona is that of Philodinadce, the trophi are those of Melicerta, while the foot (when
present) would be very like that of GUcistcs serpentinus, but for its extremity. The two
genera of which the family consists differ in the shape of the lorica, and in the foot.

112 THE ROTIFERA.

In Pterodlna the lorica consists of two delicately thin, and nearly flat plates,
soldered together at their edges ; in Pompholyx it is continuous, flask-shaped, and
without edges. In the former the ventral plate is perforated for the emission of a long,
wrinkled, toeless foot ; the latter is footless.

Genus PTEEODINA, Ehrcnbcrg.

GEN. CH. Lorica entire, greatly depressed, of tioo oval, bid nearly circular plates
soldered together at their edges; foot w holly retractile, transversely wrinkled, jointlcss,
toeless, ending in a ciliated cup.

The species of this genus differ from each other chiefly in the flexibility, shape and
adorning of the lorica. In all, the corona consists of two circular lobes, whose ciliary
wreaths, seen from above, present as perfect an appearance of two revolving wheels as in
Philodina or Rotifer. The cylindrical foot is encircled by deep constrictions, which
cease abruptly at some distance from its free end, and is remarkable not only from its
being the foot of a fixed Rotiferon, but also from its ending in a richly-ciliated hemi-
spherical cup. There are, too, some other points common to all the species, that deserve
notice. The salivary (?) glands on the oesophagus are very numerous, and the gastric
glands are of unusual length and shape. They are attached to the junction of the
oesophagus and stomach by long tapering stalks ; and, crossing the lorica transversely,
are fastened to the dorsal surface by their broad ends. Between these attached ends
of the gastric glands, and the lowest portion of the head, lie curiously-scalloped folia-
tions (of a delicately blue-tinted substance) of which it is difficult to say whether they
are continuous with the gastric glands, or are expansions of the lobed masses investing
the base of the head, or are something analogous to the floccose ribbons which in so
many Rotifera surround the lateral canals. They are very conspicuous in P. patina,
but only faintly visible in P. valvata; and the upper portions of the lateral canals,
with the attached vibratile tags, lie across them.1 The contractile vesicle appears
to be absent. The longitudinal muscles are coarsely striated, and the two eyes are
distinct, colourless, transparent spheres resting on ruby pigment. I failed to find any
dorsal antenna, but the dorso-lateral antennae lie with their rocket-shaped heads close
to the surface of the lorica near its edge at about one-third of the semi-circumference
from the top.

P. patina, Ehrcnbcrg.

(PI. XXVI. fig. 11.)

Ptcivdina patina . . Ehrenberg, Die Infus. 1838, p. 517, Taf. lxiv. fig. 4.

„ . . Eckstein, Sieb. u. Eoll. Zeits. xxxix. 1883, p. 401, Taf. xxvii. fig. 59.

SP. CH. Lorica inflexible, nearly circular, stippled just within the edge, especially
on its upper third; bosses absent from the lorica ; gastric glands ivith broad, lobed ends.
Lateral foliations very consjneuous.

This is the common species ; but, though no rarity, Midler has rightly described
it as " Animalculum crystallinum, splendore nulli secundum " ; for it is a lovely crea-
ture. The dorsal and ventral plates are pressed close together into a glassy shield of
marvellous thinness. The former is more or less roughened round the edge ; and, about
the level of the mastax, this roughening spreads inwards to some distance. Occasionally,
too, I have met with specimens in which there were faint traces of bosses, at irregular
intervals, within the edge; but usually these are absent. A side view enables one to see
that the ventral plate bulges out along the longitudinal axis, so as to form half of a
hollow cone, whose broad end is forward, and whose point lies on the ventral surface at

' Mr. Gosse differs from me concerning the use of the " gastric glands " ; the presence of the
vibratile tags ; the structure of the foliations ; and, generally, concerning the Branchial System in
Ptcrodina. His account of this structure will be found in the Appendix.

PTERODINAD^E. 113

a distance of about one-third of the axis from the edge of the lorica. From the broad
front opening the head protrudes ; and here the cone is slit down a little, and the flaps
rounded off, to give the head a freer passage. When the head is withdrawn, the flaps
are drawn by muscles close together, up to the under side of the dorsal plate. Just
below the pointed end of the conical hollow, there is a circular opening in the ventral
plate, through which the foot can be protruded or withdrawn. The gastric glands are
very conspicuous. They are unusually long pear-shaped bodies, stretching from the top
of the stomach at right-angles to the animal's length, and having their broad headg
fastened to the inner lining of the lorica. Round these points of attachment spread out
wide foliations of a filmy substance, curiously and deeply scalloped, and passing upwards
towards the head, and outwards nearly to the edge of the shield. It is not easy to see
either the lateral canals or the vibratile tags, as they are often obscured by other organs.
Lately, however, I succeeded in holding a P. patina firmly down in a clean drop of
water, without hurting it ; and, as its head moved backwards and forwards, I could see
one of the thick, striped, longitudinal muscles bend aside, and permit a view of two
vibratile tags, as well as of the lateral canals to which they adhered. The former lay
about midway between the gastric gland and the bottom of the head ; while the latter
sloped upwards and inwards, towards the funnel in which the head moved, and were cut
off abruptly below by the edge of the gastric gland, at about its middle point : I could
see no trace of a contractile vesicle. Two pear-shaped glands are attached by long
stalks to the oesophagus just below the mastax, and lower down is a cluster of similar
glands crowding round the spot where the oesophagus enters the stomach. The
stomach and intestine lie usually side-by-side, and distinctly separate. The latter no
doubt discharges through a cloaca at the root of the foot, on its dorsal side, just where
it issues from the circular opening in the ventral plate.1

Length. Of lorica, -^ inch. Habitat. Clear ponds and ditches : tolerably common.

P. valvata, Hudson.
(PI. XXVI. fig. 13.)
Pterodina valvata .... Hudson, Mon. Micr. J. vol. v. 1871, p. 25, pi. lxxii.

SP. CH. Lorica capable of being folded down on each side, nearly circular, smooth ;
bosses skidding the edge at regular distances ; gastric glands very long, club-shaped,
with rounded ends. Lateral foliations inconspicuous.

I found P. valvata at Abbot's Pond, near Clifton, in the summer of 1871. It was in
great abundance, and in company with P. patina ; and in captivity it increased so
amazingly, that the glass sides of my aquarium were frosted with the adhering Rotifera.
The lorica is remarkably transparent, and is ornamented within its edge with ten bosses,
which add greatly to its beauty. When the two species are present together, the differ-
ence between them is recognized at a glance ; for, delicate as P. patina is, P. valvata
far surpasses it in filmy transparency. While watching some of the new Pterodince, I
was surprised to see one of them sailing by with its lorica folded down (fig. 13a) like the
flaps of a Pembroke table : 2 its outline was so altered that it scarcely seemed the same
animal. This curious infolding of the lorica is due to the contraction of two con-
spicuous transverse muscles, which do not necessarily act together ; as a friend, who was
watching with me, saw some specimens with only one side folded at a time.

The gastric glands have not such broad heads as those in patina, and are altogether

1 Herr Eckstein (loc. cit.) says that the foot is not an organ of prehension, but is the intestine, the
ciliated cup being the cloaca. He does not, however, state that he has ever seen the freces discharged
through the foot ; and, indeed, such a statement would seem incredible. Mr. Gosse, however, has
witnessed the faecal discharge, and says : " As well as I could see, it takes place at the upper side of the
orifice through which the foot protrudes, projected in a strong current, and not immediately diffused."

2 [As a rule the folding of the valves is somewhat rarely performed. I have observed, probably,
hundreds at various times, and I think I have not seen half-a-dozen folded. — P.H.G.]

VOL. II. I

114 THE ROTIFERA.

narrower. The foliations are so slight as to permit the lateral antennae with their
nerve-threads to be easily seen. Their rocket-shaped extremities lie close to the lorica,
not far from its edge, and between the first and second bosses on either side : they are
therefore, in an unusually forward position. The lateral canals can also be traced,
in many convolutions, from the lower part of the head, to the point where they are
abruptly cut off by the gastric glands. In young specimens, in which the ovary is a
small, transverse, pyriform sac, and so does not obscure the view, they are seen again
below the gastric glands on either side of the stomach ; and, passing behind it, appear to
end below it on either side, in small pear-shaped expansions. I could never find any
contractile vesicle ; but, under favourable conditions, I have seen three pairs of
vibratile tags : one a little above the heads of the gastric glands, one on a level with
the middle of the stomach, and one not far from the pear-shaped sacs in which the
lateral canals seem to end.

Length. Lorica, y^ inch. Habitat. Abbot's Pond, Clifton (C.T.H.) : not common.
Abundant near Torquay (P.H.G.).

I met once with an empty lorica (PI. XXVI. fig. 17) which I suppose to be that of
Ehrenberg's P. elliptica. It came from a pond hi Sutton Park, Birmingham.

P. MUCEONATA, GoSSC, Sp. nOV.

(PI. XXVI. fig. 15.)

[SP. CH. Lorica usually circular ; dorsal plate furnished with an acute mucro
'projecting from its front. Lacustrine.

In April 1885, associated with P. patina and P. valvata, which were swarming in
one of my window reservoirs, I first met with this very pretty form. It never became
very numerous ; but, in the course of a few weeks, during which I was paying special
attention to the genus, I met with more than thirty examples. The thought occurred
that it might be the young condition of one of its larger fellow-species ; and, if so, valvata
would be the more probable. Yet I have found the young of valvata no larger than
mucronata, but with no trace of the mucro : and I have seen a nearly mature egg in
mucronata, which, though not conclusive, augments the probability of adult condition.
On the other hand, slight unevenness of frontal outline is not rarely discernible in adult
specimens of both the larger species. The matter is still sub judice ; but for the present
mucronata seems worthy of specific rank.

The lorica has not only the intra-marginal granulation of its fellows, which gives
them so elegant a resemblance to a new silver coin, but is shagreened or studded with
close-set rugosities over the entire surface of the dorsal plate, so delicate, however,
that the hyaline transparency is not interrupted. What I consider the branchial organs
are small ; the efferent lobe, answering to the pyriform (gastric gland), is generally
inconspicuous, and the afferent tubes are clustered in form of a cone around the base of
the sub-horizontal muscle. I have not satisfactorily observed the existence of eyes.
The pair of diagonal muscles is unusually well-developed. The lorica has about two-
thirds of the diameter of valvata. — P.H.G.]
Length. About T^D inch. Habitat. A domestic aquarium (P.H.G.) : rare.

P. clypeata, Ehrenberg.
(PI. XXVI. fig. 14.)
Ptcrodina clypeata . . . Ehrenberg, Die In/us. 1838, p. 518, Taf. lxiv. fig. 6.

[SP. CH. Lorica elliptical, truncate at each end ; coronal disks widely separated.
Marine.

I first formed acquaintance with this attractive species in July 1850, in sea-water
from the Essex coast ; and lately it has been sent me in abundance by Mr. Hood from

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PTERODINAM. 115

the Firth of Tay. I have been able to preserve it in health for many weeks in phials of
sea-water. Its ovate outline well distinguishes it from lacustrine forms ; and this out-
line is subject to some variation by the action of a stout transverse muscle-band across
the venter, drawing together the two sides ; the medial length of the ventral plate being-
membranous and flexible, and the pectoral edge being cleft and overlapping. It is well
suited for illustrating the branchial system. The plexus of the anastomosing afferent
tubes is wide and particularly clear, and seems to be distributed on all sides of the great
funnel. And the union of these can be readily traced into a large sac, which (placed on
the ventral surface) presently bends dorsum-wards into a great pyriform vessel (as in
P. valvata) on each side, and so pours its deoxygenated water by a slender duct into the
oesophagus. The abdominal viscera are rather small. The long and flexible foot appears
to be furnished with a central piston which protrudes and retracts its ciliated end ; this
is endowed with considerable power of adhesion. — P.H.G.]

Length. Head and foot extended, Jg inch. Width, ^\z inch. Habitat. Among
conferva) in tide-pools ; mouth of the Naze, and of the Tay (P.H.G.) : not rare.

P. TRUNCATA, GoSSe, Sp. llOV.

(PL XXVI. fig. 16.)
Pterodina elliptica . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203.

[SP. CH. Lorica ovate, somewhat pointed behind, the occipital edge abruptly trun-
cate and slightly notched, the pectoral widely cleft. Lacustrine.

I know this from a single specimen only, which I took in the autumn of 1850, in
the expanse of water locally known as the Black Sea, at Wandsworth. My study of it
is imperfect ; for though it rotated freely, I was called away before my observation had
proceeded far, and when I returned it was retracted and soon died. The eyes are small,
remote, and almost colourless. The extrusile foot, the trophi, the digestive apparatus,
the pair of diagonal muscles, and (so far as seen) the plexus of branchial tubules on
each side, were all generally normal. — P.H.G.]

Length. Of lorica, T|7 inch. Habitat. A lake near London (P.H.G.) : very rare.

Genus POMPHOLYX, Gosse.

[GEN. CH. Lorica entire, bottle-like; foot wanting; two frontal eyes; corona
double behind, united before ; eggs attached after extrusion. Lacustrine.

Two species, so far as we know, compose this genus ; both small, obscure, and rarely
seen. The one was found by myself in 1850 ; the other by Mr. Bolton in 1884.— P.H. G.J

P. COMPLANATA, GoSSC
(PI. XXVII. fig. 1.)
Pompholyx complanata . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203.

[SP. CH. Lorica hvo-sided, nearly circular, with rounded edges ; occipital edge
obtusely pointed, pectoral edge notched.

The form is that of a round flat scent-bottle. The corona is composed of two disks,
resembling those of a Bdelloid, but united in front, with a deep occipital sulcus, wherein
an antenna protrudes. The eyes are placed one on each side of this sulcus, large,
globular, ruby-red, and highly refractile. The jaws and alimentary canal seem of the
Pterodina pattern, but the minuteness of the animal precludes definite observation.
The cloaca appears at the end of the lorica, as a round orifice, with a slightly raised
edge around it. Yet the great size of the egg suggests either that this orifice must be
expansible, or that there must be a separate duct.

In manners it resembles the Pterodina ; but it revolves as it goes like the Anurcece.

i 2

11G THE ROTIFERA.

It is somewhat slow of motion. The medial line of the venter is a salient angle ; and
this has a curious effect as the creature revolves. — P.H.G.]

Length. Of lorica, ^J^ inch. Habitat. Pond at Lower Clapton (P.H.G.).

P. sulcata, Hudson.
(PI. XXVII. fig. 2.)
PompJwlyx sulcata . . . Hudson, J. Boy. Micr. Soc. 1885, p. 613, pi. xii. figs. 7, 8.

SP. CH. Lorica entire, divided into four convex lobes, by four longitudinal
furrows.

The lorica of this species is very unlike that of Mr. Gosse's P. complanata. In the
latter the dorsal and ventral surfaces are so compressed that they are slightly concave,
while in the former both these surfaces are sharply convex, and so are the connecting
lateral surfaces. A transverse section, consequently, consists of four segments of circles,
as shown in fig. 2&. It is easy to obtain this view, as well as a good sight of the corona
with its two wheels and red eyes, for the animal is fond of swimming upright close to
the cover-glass, or of exploring the bottom of the live-box, head downwards. I had little
opportunity for studying the creature, but I noticed that the lorica had an aperture in
its lower, pointed, and somewhat curved extremity.

I am indebted to Mr. Bolton for this pretty little Eotiferon, which he discovered in
company with Conochilus dossuarius in the summer of 1884.

[A curious habit which this genus has in common with Brachionus is that of carrying
the eggs, after they are successively discharged, until the young burst the shell. These
are nearly circular (absolutely so as often presented to the eye), very large in propor-
tion to the animal, each connected by a highly elastic thread to the hindmost part of
the lorica, between its two terminal points. This thread can be lengthened or shortened
at the will of the animal, and this in a surprising manner ; for by very careful observa-
tion I perceived that, in elongating, the slender elastic thread was actually projected, the
egg of course being inert, and nothing pulling or even touching it. And to a surprising
extent ; for I have seen the thread to equal in length the longer diameter of the egg.

The front edge of the lorica rises to a rounded projection dorsally, and two of less
elevation laterally ; these latter appear to be separated by a shallow sinus pectorally.
The mastax is small, the trophi formed on the pattern seen in Pterodina, an incus with
small fulcrum and quadrantiform rami, and with obsolescent mallei. I have seen re-
traction of the anterior parts to such an extent that the foot of the incus was very
nearly at the bottom of the visceral cavity. — P.H.G.]

Length, ^ inch. Habitat. Near Birmingham (T.B.) : rare.

Family XVIII. BEACHIONID^l.

[Lorica box-like, open at each end, generally armed with anterior and posterior
spines ; foot long, excessively flexible, wholly retractile, ivrinkled, ending in two toes.

Genus BRACHIONUS, Ehrenbcrg.

GEN. CH. Lorica without elevated ridges, gibbous both dorsally and ventrally ;
foot very flexible, uniformly wrinkled, without articulation, toes very small. Lacustrine
and marine.

This genus contains Botifera mostly of large size and of showy appearance, being
inclosed in glassy shells of regular outline, adorned with symmetrical projections, and
always presenting a broad surface to observation. They have been favourites with
observers from the dawn of microscopy ; and they are still. Fortunately most of the
species are common and easily accessible. The form of the foot is peculiar ; it is a long

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BKACHIONID.E. 117

and thick muscular tube, very transparent, covered with minute and close wrinkles, full
of muscles, which admit of rapid protrusion and retraction, and of motion in all direc-
tions, with amazing flexibility (so that I have actually seen it tied in what, for the
moment, looked like a knot I). The toes, — so small and apparently feeble, — have con-
siderable power of grasping. They are sometimes used as a pivot on which the animal
revolves. The mutual relations of the sexes are very distinct ; as I have shown in detail
in my Memoir " On the Dioecious Character &c." (Phil. Trans. 1856). The female
carries the excluded eggs attached to her body till they are hatched.

The distinction of the species rests mainly on the number, dimensions, and relations
of the spines. Yet recent observations on B. pala throw doubt on the validity of such
characters. — P.H.Gr.]

B. pala, Ehrenberg.

(PI. XXVII. fig. 3 ; and PL XXVIII. fig. 3.)

Brachionus pala .... Ehrenberg, Die Infus. 1838, p. 511, Taf. lxiii. fig. 1.
„ amphiceros . . „ Die Infus. 1838, p. 511, Taf. lxiii. fig. 2.

,, polyacanthus . . Cohn, Sieb. u. Kbll. Zeits. Bd. xii. 1863, Taf. xxii. fig. 4.

„ amphiceros . . Plate, Jenaisch. Zeits. f.Natur. 1885, p. 65, Taf. ii. figs. 22-24.

SP. CH. Lorica thin, smooth, transparent ; with four, long, sharp, occipital spines.

B. pala has a colourless, smooth and transparent lorica, armed with four long spines
in front, but unarmed and rounded off behind. The lorica is flexible, and generally
dragged-in a little on either side, round the attachments of the long dorsal muscles.
The opening for the foot is a mere slit, through a pap-like protuberance at the end of
the lorica ; and its sides can be brought close together when the foot is withdrawn. The
animal's internal organization is very like that of B. rubens, which has already been so
fully described in Chapter I. that, beyond a reference to PL A, vol. L, and PL XXVII.
fig. 3, only a few points require notice. The mastax is very large ; and so are the trans-
parent vesicles which are seated on it on the ventral side, and may possibly be salivary
glands. By transmitted light they show only two curved lines (their outer bounding
walls) rising from the mastax to the head. The gastric glands are stalked, as in B.
rubens, but the stalks are generally hidden behind the broad triangular ends of the glands.1
The vascular system is very conspicuous, and the five tags on each side can be readily
found. I once obtained an admirable view of the top of a vibratile tag, which was
pointing up the microscope. It was not at all like that of Euchlanis dilatata given by
Dr. Plate, and taken from the same point of view. Dr. Plate figures the summit of the
tag as an oval with pointed ends. I found that of the lowest tag of B. pala to be a thin
straight edge, like that of a chisel. If there be an aperture there, it must be extremely
narrow. As the animal moved, the tag turned too, so as to present also the two charac-
teristic appearances given in PL XIII. fig. 3b.

Along with the undoubted specimens of B. pala were a good many of what appeared
to be Ehrenberg's B. amphiceros, with two short thorn-like spines on the lumbar
regions, and two others still smaller, one on each pap-like protuberance by the foot
(fig. 3c). Ehrenberg says that B. amphiceros differs from B. pala in its smaller size, in
having no coronal styles, in having four sharp posterior spines on the lorica, in lacking
side muscles in front, and in having four vibratile tags instead of three. Moreover he
says that he could not find a dorsal antenna. Now I carefully examined these speci-
mens with four posterior spines, and found them to be of the same size as B. pala, with
styles on the corona, with side muscles in front, and possessing a large dorsal antenna.
In fact they were the exact counterparts of pala. I may add, too, that both those which
had, and those which had not posterior spines, showed, under favourable circumstances,
five vibratile tags on each side. Nor is this all : for I found some specimens with two

1 The lower ends of these glands are tied to threads, which are attached to the lorica just above the
heads of the lateral antenna?, and at their other extremities to the stomach. Mr. Gosse discovered
and drew this arrangement, as well as the lateral antenna; themselves, in 1850.

118 THE ROTIFERA.

lumbar spines but none on the foot-paps (fig. 3d), and others with spines on the foot-
paps but none on the lumbar regions (fig. 3e) ; and, in all, the size and structure were
the same. From this I conclude that Ehrenberg's B. amphiceros is only a variety of
B.pala. [As is also, I have little doubt, my B. don ("Ann. and Mag. N. H." Sept.
1851. — P.H.G.] The lateral, or lumbar-spines are very variable, and occasionally reach
an extravagant length, as shown in PI. XXVIII. fig. 3, where they are nearly as long as
the body of the lorica. In this specimen the spines were hollow nearly to their ends, and
were, in fact, true prolongations of the body-cavity. They were, too, as flexible as the
lorica, so that they could be brought all four together at the tips, or even crossed.
Length. Lorica, T^ inch. Habitat. Ponds and ditches : common.

B. doecas, Gosse.
(PI. XXVIII. fig. 4.)

Brachionus dorcas . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203.
... „ Phil. Trans. 1857, pi. xv. figs. 15-19.

[SP. CH. As B. pala ; but the occipital spines longer and more slender ; and the
antlers curved forward ; pectoral edge undulate, toith a central notch.

This, too, may possibly prove only a variety of pala ; but the appearance of the
antlers struck me as unique ; particularly the elegant sinuous curvature, like that of the
horns of the Gazelle Antelopes, which suggested the specific name. I had ample
opportunities of studying it in both sexes, and in all ages, from Forest-school Pond at
"Walthamstow, in 1850 ; but I have not met with it since. The figures, in which I have
delineated its anatomy in detail, will render much description needless. I could find no
contractile vesicle in any specimen, but distinctly traced the lateral canals of each side
to a common termination at the cloaca. An excellent sight of one of the vibratile tags,
endwise, showed these organs to be attached by a very minute papilla, and to be flattened
on two opposite sides (as at fig. Ad). The parent carries her eggs after exclusion. —
P.H.G.]

Length. Of lorica, ^ inch; width, /g inch. Habitat. Walthamstow (P.H.G.) :
rare.

B. ueceolaeis, Ehrenberg.
(PI. XXVII. fig. 6.)
Brachionus urceolaris . . . Ehrenberg, Die Infus. 1838, p. 512, Taf. Ixiii. fig. 3.

[SP. CH. Lorica ivith six straight occipital spines and a deep sinus in the middle ;
the pectoral edge rising slightly to the middle, xvhichis slightly excavate : orifice for the
foot bounded by two papilla.

We have now species whose front is armed with six spines, usually low, but variable
in height. In the present each spine is the origin of a shelly ridge, which runs for some
distance down the lorica. Viewed dorsally, its outline is that of an elegant rounded
cup ; but, laterally, the occipital spines, and the gibbous dorsum descending below the
flatter venter, destroy the resemblance. A round, or sub-square, orifice gives emission to
the very agile wrinkled foot, as rapidly retracted. The lorica is somewhat scabrous.
The internal organization is that common to the genus. The lateral canals begin at the
highest point of the head-funnel, at the bases of the lateral spines. Tbey pass down
into close contact with the gastric glands, each of which is of great size and of retort-
shape,1 and each canal has at that contact a dilatation into an oblique plexus. Before
it reaches its end, it is tied to the lorica, and makes an abrupt angle, to join the con-
tractile vesicle at the very neck of its discharge.

Females carry, attached to the base of the foot, many small eggs which produce
males, or lew large eggs which produce females. (1'hil. Trans. 1850, pi. xv. figs. 3-5 ;

1 In one specimen the gastric glands evidently merged into the substance of the lateral canals.

BRACHIONIM. 119

where the species is named rubens.) The eye consists of three cells of ruby crimson,
from the edges of each of which, under sunlight, brilliant reflection is seen. — P.H.G.].
Length. Of lorica, ¥'s inch ; total, foot and head extruded, ^ inch. Width T} ■-$ inch.
Habitat. Ponds and ornamental waters near London ; Birmingham (P.H.G.) : rather
uncommon.

B. kubens, Ehrenberg,
(PI. XXVII. , fig. 5 ; and PI. A.)

Brachionus rubens . . . Ehrenberg, Die Infus. 1838, p. 513, Taf. lxiii. fig. 4.

[SP. CH. Nearly as the preceding, but the occipital spines have the form of saw-
teeth, sloping inward ; and of the pectoral edge the central elevation is more marked.

I have strong doubts whether B. urccolaris and B. rubens are specifically distinct.
Very different individuals may, indeed, readily be presented ; but a series do certainly
run into each other. Considering them for the present as distinct, I refer to the figs,
on Plate A, and its explanation, in which it has been selected for illustration as typically
representing the organization of the whole class. In examples which we may call more
characteristically rubens, we may see the gastric glands in a very peculiar condition ;
each consisting of two sacs, quite distinct, each separated by a long duct, and the inner
one leading by a duct to the oesophagus, while the outer is manifestly united with the
lateral canal. Then the canals themselves form several distended sacs with necks,
just before they enter the contractile vesicle, which is here unusually small, for the
genus.— P.H.G.]

Length and Habitat. As the preceding.

B. Mulleri, Ehrenberg.

(PI. XXVII. fig. 7 ; and PI. XXX. fig. 8.)

Brachionus Millleri . . . Ehrenberg, Die Infus. 1838, p. 513, Taf. lxiii. fig. 5.
„ hepatotomus . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203.

[SP. CH. The occipital spines reduced to low saw-teeth, much wider than high,
with their outer edges sinuate; the pectoral line nearly straight, notched into round
lobes. Marine.

This is a very fine, elegant, and attractive species ; and its marine habitat at once
distinguishes it. I obtained it on the Essex coast six-and-thirty years ago ; and
recently Mr. Hood has sent it to me in abundance from tide-pools in the Firth of Tay,
and Mr. Brightwell from Norfolk. It is a good traveller and lives long in small phials.
I have had it in abundance in my own marine aquarium.

Each gastric gland is a great sac divided nearly to its base, so as to appear two ; and
these vary greatly in shape and in relative size. They are very distinctly connected
with the lateral canals. Both male and female eggs are carried, and males are pro-
duced in abundance. The middle of the body in this sex is occupied by the spermatic
sac, a great pyriform vessel connected by a bottle-like neck with the head-mass. On
pressure this sac is seen to be full of bodies having a vermicular motion ; and, on the
pressure being continued, it bursts, freeing about thirty spermatozoa of unusual size, each
being ^^ inch long, a slender body merging into a long whip-like tail which maintains
a quivering undulatory motion for several minutes after exclusion. — P.H.G.]

Some fine specimens sent to me by Mr. J. Hood enabled me to make a drawing of
the ventral aspect of this Brachionus (PI. XXX. fig. 8), and to add a few notes to the
above. The transparent vesicles which embrace the buccal funnel, and, resting on the
mastax, reach up to the head, are here unusually large and conspicuous. The lateral
antennae can be readily seen protruding the tips of their heads from a dent in the lorica
on either side just below the gastric glands : they are here, as is often the case, attached
also to the floccose investment of the lateral canals, and their nerve-threads are obvious.

120 THE ROTIFERA.

On the dorsal surface it is easy to bring into view the four bases of the muscles which
work the foot ; and which show as four spots nearly in a line crossing the lorica where
it first begins to lessen in width.

Length. Lorica, VJ(7 inch ; width, T^ inch. Habitat. Sea-water. Essex and Norfolk
coasts ; Firth of Tay (P.H.G. ; C.T.H.) : common.

B. Bakebi, Ehrenberg.

(PI. XXVII. fig. 8.)

Brachionus Bakeri . . . Ehrenberg, Die Infus. 1838, p. 514, pi. Ixiv. fig. 1.
,, „ ... Gosse, Phil. Trans. 1857, pi. xv. figs. 11, 12.

[SP. CH. Occipital spines six, the intermediate 'pair almost obliterate ; the pectoral
line nearly level, undulate ; behind two large lateral spines, and two smaller bounding
the orifice for the foot. Lacustrine.

This species has been dedicated to an early English microscopist ; and it is both
named and figured in Adams's great work on the Microscope, published just a century
ago. It is a common species, and from its elegant form and ample breadth very attrac-
tive. Individuals differ much in the length, stoutness, and direction of the spines ; the
hind lateral pair being sometimes bent inward. The ventral surface is marked with
minute granules, which are arranged in a pattern of some regularity. The gastric glands
are again large, retort-shaped, with long necks, and are in contact, if not in union, with
the lateral canals, which open into a small contractile vesicle at its cloacal end. —
P.H.G.]

Length. Of lorica, 0\ inch : width, vl5. Habitat. Fresh waters around London, and
widely spread (P.H.G.) : rather common.

B. ANGULAEIS, GoSSC.

(PI. XXVII. fig. 4 ; and PI. XXX. fig. 9.)

Brachionus angiilaris . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203.
,, „ ,, Phil. Trans. 1857, pi. xv. figs. 13, 14.

[SP. CH. Occipital spines reduced to slight undulations, with a slight {usually)
rounded sinus in the middle ; pectoral edge nearly straight ; hind extremity with two
short, blunt processes ; outline more or less angular.

The figure, jutting out into blunt angles, though characteristic, is not absolutely
invariable ; for I have seen a specimen whose dorsal outline was as regular as that of
urceolaris. I first found it in the pond at Walthamstow in 1849 ; then in the orna-
mental water at Kensington Palace ; and on many occasions since ; often associated
with B. pala. The parent carries both male and female eggs to the hatching. The
male I have described and figured elsewhere. I have seen the sexual coitus. The
internal structure presents nothing notable. It is of lively, restless manners. — P.H.G.]

The highly-arched dorsal surface of the lorica is not only facetted (as I have shown
in PI. XXX. fig. 9) but is carved out into curious hollows that are well seen in
PI. XXVII. figs. 4, 4a, which drawings I made from an empty lorica of unusual beauty.
The ventral plate is quite overlapped by the dorsal, which hangs down all round it ; so
that the ventral surface, taken as a whole, is concave, although its middle portion is
convex. Nothing is easier than to clip the creature gently by its sides, so as to be able
to look into the ventral hollow ; and then, with dark-field illumination, and the binocular,
the true shape of this curious lorica can be seen at a glance. A side view shows also
the very stout, wide-based dorsal antenna ; which, as usual, plays in the hollow between
the occipital spines. The lateral antenna: are well worth notice. The tip of each
rocket-shaped head lies at an aperture in the lorica (PI. XXX. fig. 9) which has, raised
round it, a small chitinous ring ; through which the brush of seta) can be seen to protrude

BRACHIONID^. 121

(PI. XXX. fig. 9a). This is a little advance on the structure in Noteus quadricornis, in
which Rotiferon two distinct circular perforations, with smooth edges slightly raised
above the general level of the lorica, give passage to the antennal brushes.

Length. Of lorica, ^hu inch. Habitat. Near London ; Birmingham ; Dundee
(P.H.G.) ; Clifton (C.T.H.) ; pools of fresh water : not uncommon.

Genus NOTEUS.

GEN. CIL Lorica facetted, and covered with raised points ; gibbous dor sally, flat
vcntrally ; foot obscurely jointed ; toes moderately long ; eyes wanting.

N. QUADRICORNIS.

(PL XXVIII. fig. 5.)

Noteus quadricornis . . . Ehrenberg, Die Infus. 1838, p. 503, Taf. Ixii. fig. 1.

,, ,, ... Leydig, Ueb. d. Bau d. Rddcrth. 1854, p. 53, fig. 41.

„ ,, ... Eckstein, Sieb. u. Kbll. Zeits. Bd. xxxix. 1883, p. 394.

,, ,, ... Plate, Jenaisch. Zeits. f. Natur. Bd. xix. 1885, p. 65.

The lorica of this handsome creature, the sole species of the genus, consists of two
saucer-like plates ; the dorsal one convex, facetted, and stippled ; the ventral concave
all round the edge but bulging in the middle, stippled and not tesselated. The front
of the ventral plate is a concave circular segment with a minutely serrated edge, and
the front of the dorsal plate has a similar, but unserrated, edge, with its outline broken
by two projecting strips of the lorica which curve gradually over the head. At the hind
end, the lorica is armed with two long, and nearly straight spines, widely separated
by a straight edge set with a row of minute dots. The passage for the foot is a deep
funnel-shaped cavity at the bottom of the ventral surface, covered by a loose flexible skin
attached to its lower, inner edge, and also to the foot. The head is something like a
broad and very thick basin. Seen from above, it shows the sides as circular lobes, con-
nected on the dorsal side by an arched ridge. Its central hollow is small, and is laid
open on the ventral surface by a V-shaped gap. The edges of the gap bear stout cilia,
and there is a fan of similar cilia on the centre of the arched ridge connecting the
circular lobes. On each side of the corona, apparently on the edges of the circular
lobes, is a pimple bearing one or two styles. The rest of the corona is edged with
ordinary cilia. The foot has three feeble false joints, and two rather long and
sharp toes, which have the usual power of adhering to glass ; though the two dusky
objects running down its whole length are, I think, muscles for moving the toes, and not
secreting glands. The mastax has a high position, and the trophi are weak examples
of the sub-malleate type. The gastric glands are of unusual size and shape. They
spread out like fans up into the extreme front corners of the lorica, and appear to be thin
and delicately corrugated. They are joined to the apex of the stomach by long ducts.
Just below the mastax there are small pear-shaped, and probably glandular, bodies
attached by their stalks to the oesophagus. The contractile vesicle is large, and the
lateral canals and vibratile tags are very conspicuous ; the canals edging the lorica
all round down to the base of each hind spine. In the individual shown in fig. 4,
a narrow ovary had one ovum beginning to form near its smaller end ; and below this
ovum lay, in wrinkles, the empty pointed end of the ovisac. The side muscles for mov-
ing the head, a pair on each side, are unusually stout and obvious ; the others are much
as in Brachionus. A small heart-shaped nervous ganglion, with its broad end down-
wards, lies on the occiput between the frontal horns ; and, seated on it, sloping down-
wards, is the conical sheath of the short dorsal antenna, whose tip just emerges at the
base of the gap in the lorica between the horns. Dr. Plate {loc. cit.) has seen two

122 THE ROTIFERA.

lateral antennas protruding from small orifices on the dorsal surface of the lorica : one
on each side, between the edge and the five-sided facets on the centre of the back.1

This is a bottom-haunting creature; and, in my experience, not a very common one.
"When captured it betrays its presence by its slow gliding motion, trailing foot, and
white lorica : a whiteness due to the minute dots of chitine with which it is frosted.
Happily the lorica is very thin, so that it is easy to see the viscera, in spite of the ridges,
facets, and frosting.

Length. Of lorica, ?lT inch. Habitat. Ponds and ditches, near London, (P.H.G.);
Clifton (Mr. Brayley ; C.T.H.) ; Birmingham (Mr. Bolton junior) : not very common.

Family XIX. ANURyEADiE.

[Lorica box-like, broadly open in front, behind open only by a narrow slit; usually
armed with spines, or elastic setce ; foot tuholly wanting.

The genus Anurcea of Ehrenberg, already extensive, and now augmented by many
new species, ought to constitute a distinct family, very different in form, structure and
habit from the Brachionidce; and including several genera. The body is inclosed in a
compact box-like lorica, open in front and rear. They have no foot, and therefore are
incessant swimmers, never resting. The trophi differ from those of the Brachionidce
in that the manubria, though usually clubbed, never take the expanded semi-circular
shape. The cilia, too, are not set around a two-flapped corona, but on three large
eminences, each of which terminates in a globose lobe, crowned with stout setae. One
eye is conspicuous, cervical. They are both marine and lacustrine. — P.H.G.]

Genus ANURIA, Gosse, nee Ehrenberg.

[GEN. CH. Lorica an oblong box, open widely in front, narrowly in rear; dorsal
surface usually tesselated; the occipital edge always, the anal sometimes, furnished with
spines; the egg after extrusion is carried attached to the lorica. Lacustrine. — P.H.G.]

A. curvicoknis, Ehrenberg.
(PI. XXIX. fig. 9.)
Anuraa curvicornis . . . Ehrenberg, Die Infus. 1838, p. 505, Taf. lxii. fig. 5.

[SP. CH. Lorica oblong, rounded behind, tesselated, armed with six occipital spines,
of which the middle pair arc procurved ; no spines behind.

Of the tesselations, the medial row alone is perfect, of five facets ; the posterior
three are hexagons, the next square, the foremost an incomplete hexagon. From the
lateral angles other ridges proceed laterally, forming other polygons, which are usually
evanescent. Of the spines, the central pair (antlers) are strong, and curved forward,
sometimes mutually approaching, sometimes receding. The lateral pairs are short,
straight and pointed. From the outmost pair descends a prominent ridge on each side,
making a sharp lateral edge to the lorica (fig. da). The eye is very large and brightly
conspicuous; the mastax is a wide oblate spheroid, with mallei and incus well developed.
A wide sacculate stomach follows, crowned with normal gastric glands, and descending
with no distinct constriction to the hind end of the lorica, where there is a small orifice,
through which I have seen the rectum protruded for a short distance, and then retracted.
There is an ample contractile vesicle. The three main lobes of the rotatory organ are
large and prominent when in action, each bearing a great round fleshy papilla, besides
a smaller one on each side ; each carries a divergent fan or brush of stout setae. The

1 I missed these in the living animal, but, afterwards, found the apertures (fig. 5a, a') easily in an
empty lorica, in the spots mentioned by Dr. Plate.

ANUEiEAD^. 123

cilia produce vortices, but not wheels. A curved tubular antenna, with terminal bristles,
issues from the sinus between the antlers.

This pretty species occurred by myriads in one of my garden pans near London in
the autumn of 1849 ; and I met with it again in the watering pond on Hampstead
Heath ; but I have no record of it since. A great Bursaria, as well as Asplanchna,
feeds voraciously upon it. It swims giddily, to and fro, with some swiftness. — P.H.G.]

Length, ^^ inch. Habitat. Near London ; Birmingham (P.H.G.) : not rare.

A. HYPELASMA, GoSSe.

(PI. XXIX. fig. 6.)
Anurcca fissa Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202.

[SP. CH. Lorica without spines, consisting of two plates, the dorsal arched, the
ventral flat, commensurate ; and widely cleft through its medial line.

When I obtained this species, in 1850, I could not satisfactorily determine the
character of its ventral plate ; but subsequently, on many occasions, and with great
precision, I saw that it is a thin flat plate, of the full width, apparently connected with
the dorsal only by membrane. It is, moreover, divided down tbe middle by a fissure of
varying width ; I have even seen the pectoral edges of the fissure overlapping. These
peculiarities, combined with the straight transverse occipital edge, might almost entitle
this species to generic separation. The egg is (proportionally) of vast size, nearly half
as large as the whole animal ; and not symmetrical, for, from the side at one end,
projects a nipple, by which it remains attached to the parent. One I saw hatched. The
young escaped at the part where the pedicle was, head foremost, rotating freely. It was
exactly like the parent, and fully three-fourths of its size. There is evidently an anal
orifice, whence frequently protrudes a very delicate membrane (doubtless the rectum),
with its end expanded and recurved (fig. G). When the rotating front is retracted, there
are seen two shelly lobes rising from within the lorica, which approach to contact, and
thus protect the head (fig. 6a). The internal structure is normal. Some specimens
were thickly infested with a minute Infusorium (Colacimn'?). — P.H.G.]

Length, g.jo inch. Habitat. Near London ; Leamington ; Stapleton Park, York-
shire ; Dundee ; Torquay (P.H.G.) : rather common.

A. tecta, Gosse.
(PI. XXIX. fig. 10.)
Anurcca iccta Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202.

[SP. CH. Nearly as curvicornis, but more pointed ; and the tesselations are larger,
and arranged on each side of a mesial dorsal ridge, which gives to the back the form of
a vaulted roof.

Of this pretty little species I have slight record. The arrangement of its facets suffi-
ciently distinguishes it. It is high and nearly circular in transverse section. One that
I saw carried a large egg-shell. — P.H.G.]

Length, ^hs inch. Habitat. Near London ; Birmingham (P.H.G.) : rare.

A. aculeata, Ehrenberg.

(PI. XXIX. fig. 4.)

Anurcca aculeata .... Ehrenberg, Die Infus. p. 508, Taf. Ixii. fig. 14.
„ brevispina. . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202.

[SP. CH. Lorica oblong-square in outline, slightly arched dor sally, flat, or concave,
ventrally ; the normal occipital spines six, of which the antlers are procurved ; each of

124 THE ROTLFERA.

the two posterior angles produced into a slender straight spine of varying length ; sur-
face minutely punctated, and hexagonally tesselatcd.

The form of this very abundant species exactly resembles, whether viewed from the
back or side, that of a wicker hand-barrow familiar in some parts of the country.
When the empty lorica is seen, it is a beautiful microscopic object. The rotating head,
and whole internal organization agree with those common to the genus. It swims
rather swiftly, in a peculiar style, continually revolving, both on the long and the trans-
verse axis, throwing perpetual somersaults. Its irregular plunging and rolling strongly
remind me of the motion of a ship in a heavy sea.

My A. brcvispina (loc. cit.) (PI. XXIX. fig. 5) is, 1 feel assured, only a var. of this
species, with the spines degenerate, and the puncturing nearly evanescent. Ehrenberg's
A. testudo and A. valga will, I think, fall into the same category. — P.H.G.]

Length (including spines), YT5 inch ; width, -^k^ inch. Habitat. Pools and lakes
(P.H.G.) : very common.

A. cochleaeis, Gosse.
(PL XXIX. fig. 7.)

Anuraa cochlcaris .... Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 202.

[SP. CH. Lorica spoon-shaped, ending behind in a straight slender spine ; the back
ridged and tessclate, as in A. tecta.

This bears the same relation to A. stipitata, Ehr., as A. tecta bears to A. curvi-
cornis ; differing from stipitata by the roof-like back, and the mesial division of the
facets, which latter (as shown in Ehrenberg's figures) are decidedly of the hexagon
pattern. The outline, too, of stipitata is that of a broad, or even triangular shovel ;
whereas that of cochlcaris is decidedly spoon-shaped, broadly ovate. It is delicately
punctate or stippled. The protrusile front is very ample ; a great chin of two fleshy
lobes is seen sidewise, besides the lateral and frontal lobes. The eye is manifestly on a
lens, which sparkles in focusing, like a gem, but pale in hue. An egg of enormous pro-
portions is carried before the caudal spine, reaching nearly to the chin. The spine
varies much in length, from a mere tubercle to equal length with the lorica-body.

The species is not uncommon in clear waters, often associated with Asplanchna, of
which it forms a common article of food. I have taken an Asp. priodonta with an
An. cochlcaris in its stomach, which, after an hour or two, was ejected, and instantly
swam about, as lively, and apparently as uninjured as ever! — P.H.G.]

Length (including spines), T -!¥ to T^ inch. Habitat. Clear ponds and lakes (P.H.G.) :
common.

A. seeeulata, Ehrcnbcrg.

(PI. XXIX. fig. 8.)

Anurcca serrulata .... Ehrenberg, Die Infus. 1838, p. 508, Taf. Ixii. fig. 13.

[SP. CH. Lorica oblong -square, much as the shorter -spined forms of A. aculeata ;
dorsally tesselate with hexagons, except that the hind row of facets are two great poly-
gons mcsially divided ; ridges serrate ; both surfaces punctate.

The most prominent character of this species is its extreme roughness, the edges of
all the facet-divisions, and the back of every spine being jagged with minute round
excavations, which stud every part of the surface. I have counted about seventy
punctures in one facet. This roughness varies in degree. The antlers are often greatly
developed in stoutness, length, and curvature : the hind spines are sometimes nearly
obliterate. The pectoral edge makes two arches (each with an intra-marginal line) with
a notch between them. The viscera sometimes protrude in a globose form beyond the
end of the lorica: I think this is when the contractile vesicle is filling. The frontal
lobes take the form of three short cylinders, each with its fan, of vibratile seta? ; each of

ANUPwEAD/E. 125

the lateral pair projects from the midst of a much thicker cylinder. There are two
square antennae. The eye is large, sparkling in sunlight, and refractile. — P.H.G.]

Length, T\ 2 inch. Habitat. Near London; Birmingham; Dundee (P. H.G.): common.

Genus NOTHOLCA, Gosse, gen. nov.

[GEN. CH. Lorica ovate, truncate and six-spined in front, sometimes produced
behind ; of two spoon-like plates united laterally ; no hind spines ; dorsal surface
marked longitudinally with alternate ridges and furrows ; expelled egg not usually
carried. Lacustrine and marine.

The genus thus indicated may include the species biremis, striata, inermis (young ?),
acuminata, and foliacea (?) of Ehrenberg, together with others, which appear to be
hitherto undescribed. — P.H.G.]

N. acuminata, Ehrenberg.
(PI. XXIX. fig. 3.)
Anurcea acuminata . . . Ehrenberg, Die Infus. 1838, p. 506, Taf. lxii. fig. 9.

[SP. CH. Lorica produced behind into a long truncate point, spoon-shaped ; ven-
tral plate concave, one-third shorter than the dorsal.

The form is very elegant. Of the frontal spines the antlers are nearly straight, the
laterals moderately long, the intermediaries very short. From their six points, and from
their five interspaces, run strongly marked lines throughout the lorica, of which the
former are elevated, the latter depressed angularly. The junction of the ventral plate
is about one-third from the point where the cloaca opens. Here two muscle-threads are
affixed, connected with the rectum, which they draw down. An ample contractile vesicle
receives on each side a conspicuous branchial duct, which in some parts is slender, in
others much expanded and corrugated, including many vacuoles, and carrying two
vibratile tags each. A remarkable structure is seen in apparent connection with these
organs, which recalls the pyriform sacs seen in Pterodina. The oesophagus is long, and
attached to it on each side is a small vessel which seems the ordinary gastric gland.
But somewhat behind these are seen a pair of sacs, connected with the stomach on each
side, and each giving off two threads, by one of which it is fastened to the lining mem-
brane of the lorica, while the other runs down for some distance parallel with, and close
beside, the tortuous vessel (branchia?), and is then attached to the interior, where two
remarkable shelly bosses are seen. The stomach itself is tied to the lorica by threads,
which are probably muscular. — P.H.G.].

Length, -g1^ inch. Habitat. Ornamental waters near London (P.H.G.) : very rare.

N. longispina, Kellicott.

(PI. XXVIII. fig. G.)

Anurcca longispina . . . . Kellicott, Amcr. J. Micr. iv. 1879, p. 20, with fig.

„ „ . . . . (Abstracted) /. Roy. Micr. Soc. ii. 1879, p. 157, with fig.

,, „ Levick, Midland Naturalist, ii. 1879, p. 241, 1 pi.

„ spi7iosa .... Imhoff, Zool. Anzeig. Sept. 1883, No. 147, with fig.

SP. CH. Lorica greatly produced behind so as to resemble a frontal spine ; dorsal
and ventral plates commensurate ; of the six occipital spines the central pair consists of
one very long curved spine, and of one aborted straight spine ; the lateral pair, of two
long, and curved ; and the remaining pair, of two short, and straight ; the ventral plate
has a movable flap with a straight pectoral edge.

NotJiolca longispina does not readily lend itself to any theory on the cause of an

12G THE EOTIFERA.

animal's form ; as it is hard to see how its extravagantly long spines can be of much
service to it. They evidently forbid its approach to the conferva? and floating rubbish
tbat are the favourite haunts of its class, under penalty of being probably anchored for
life to the same spot ; and they can scarcely serve as floats, for the animal is a heavy
swimmer, as if overburdened with these great projections, and is usually found four or
five feet below the surface. Neither can they be very serviceable as weapons of defence,
for even the fry of a gudgeon would soon learn to snap it sidewise. At any rate it is a
most interesting form, and though rare and impatient of captivity it is easily managed in
the compressorium, as it can be firmly yet lightly held by its long curved spines without
injury. The lorica is triangular in outline, the dorsal surface convex both lengthwise
and across, the ventral slightly concave and rather more sharply curved as it approaches
the hind end. Six spines spring from the anterior edge of the lorica. Two are lateral,
and are continuations of thickened ridges running part way down the edges where the
dorsal and ventral surfaces meet. They are equal in size, taper to a point, and curve
first outward and then upwards and inwards. Then, on either side of the median dorsal
line is a strikingly unmatched pair. One, the largest of all the six, is stout at the base,
tapering to a point, and curved first downwards and then upwards, with a graceful
sweep. The other is an abortive looking spine, of uniform thickness, about one-fifth
of the length of its partner. In the gap between these two lies the dorsal antenna ; and,
as this antenna is exactly on the median line, it follows that the longest spine is not in the
middle of the lorica (as it has been hitherto drawn 1), but slightly on one side of it. There
is yet another pair of spines, of equal length, considerably shorter than the lateral spines,
and lying one on each side between the dorsal and lateral pairs. The hind end of the
lorica flows off into yet another tapering spine curving downward and then upward, like
the longest ; and, with it and the body, presenting on a side view an elegant sigmoid
curve. At the top of the ventral surface the lorica has a square flap, which can move,
as on a hinge, to permit the head to come out, and which closes over it, when it is with-
drawn. There is also a slit, like a trap-door at the hind end of the ventral surface,
through which the cloaca is emptied. All the front spines are rough, but the hind spine
is smooth. The corona has a thick dorsal wall crowned with ciliated eminences, and
surrounding a deep cavity leading to the buccal orifice. This cavity is thrown open on
the ventral surface by a scalloped V-shaped slit ; and is guarded at each side on the top
by two teat-shaped protuberances armed with stout vibrating styles. All the edge of
the corona is ciliated, and so are the edges of the ventral slit, at the bottom of which lies
the buccal orifice. The mastax with its sub-malleate tropin is close to the buccal orifice.
There is a distinct oesophagus bearing two stalked glands below the mastax, and a cluster
of rather larger glands just above the stomach. The gastric glands, stomach and intes-
tine require no notice. A contractile vesicle lies just below the latter, close to the
cloaca ; the lateral canals and vibratile tags are conspicuous. The muscular system is
like that of B. rubcns (i. p. 8) ; and it is curious to see how, owing to the flexibility of
the lorica, the longitudinal muscles can draw together all the frontal spines. As these
are really continuations of stout chitinous ridges in the lorica itself, the approaching
spines, with the flexible lorica folding up between them, look exactly like a closing
umbrella. My specimens died before I had seen the nervous ganglion ; but there is a
dorsal antenna, protruding between the longest and the abortive spine when the head is
expanded, and pulled in when the head is withdrawn. The adult had a single red eye,
at the lowest part of the occiput, near the dorsal surface. Mr. Levick says that many
of the first specimens that he found had two eyes ; and that he thinks these animals
were young ones. It would be very curious should it prove to be the case that two eyes
in the young approach with age, and coalesce in the adult ; especially as Bracliioni

1 Dr. Kellicott, Mr. Levick, and Dr. Imhoff, all place the largest frontal spine exactly on the median
line of the lorica, and half-way between two small spines ; I am satisfied that this is a mistake. Dr.
Imhoff's figure shows four small frontal spines besides the three long ones: this also is wrong; there
are only three, the abortive spine and a pair.

w/Mi

/ II

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ANUR/EAM. 127

have an eye which has every appearance of heing a coalesced pair. The extruded egg
is carried on the ventral surface just above the hind spine.

Dr. Kellicott discovered this fine Anurcea in Niagara water at Buffalo, and soon after
Mr. Levick found it in Olton reservoir. I am indebted both to Mr. Levick and Mr.
Dunlop for many living specimens, and to Mr. Levick also for several mounted.

Length. Total, tl inch; of longest spine, -j-^ inch. Habitat. Buffalo, U.S.
(Dr. D. S. Kellicott) ; Birmingham (Mr. J. Levick) ; Greenock (Mr. M. F. Dunlop).

N. thalassia, Gosse, sp. nov.
(PI. XXIX. fig. 2.)

[SP. CH. The two lorica-plates commensurate ; dorsal arched, long-ovate in out-
line ; ventral, with pectoral edge straight. Marine.

The antlers and lateral spines are moderate, nearly straight and sub-equal : the
intermediate pair mere tubercles. The pectoral edge has no conspicuous unevenness.
The lorica is scarcely changeable in outline, as if it were stiff and unyielding. Yet the
shelly substance merges so insensibly into thin and evanescent membrane at the hind
end (where a very delicate membrane, like a truncate tail [rectum?] is protruded), that
we cannot determine the point of transition. The form and lobes of the front, and the
array of fan-like setae ; the brain and great eye ; the mastax and jaws ; and the
abdominal organization, do not notably vary from what we see in Anurcea. The broad
protrusile and retractile membrane at the cloaca excretes mucus for temporary anchorage.
One which I saw forcing its way through thick clusters of diatoms, emerged with several
of them glued to its rear, which were then detached with some difficulty. In free
swimming it is headlong and rapid, and very restless. In one example the intestinal
canal was full of the frustules of diatoms. It is exclusively marine. — P.H.G.]

Length, 1 }F inch. Habitat. Tide-pools in the Firth of Tay (P.H.G.) : common.

N. scapha, Gosse, sp. nov.
(PI. XXIX. fig. 1.)

[SP. CH. Lorica nearly as broad as long ; dorsal plate greatly exceeding the ventral
in width ; pectoral edge sinuate. Marine.

The transverse outline is highly rounded, resembling the half of an egg-shell, far
within the margins of which a flat (ventral) plate is fixed across the cavity, leaving wide
overhanging edges. The lorica is very flexible, so that, when the fore-parts are forcibly
retracted, the dorsal outline suddenly appears perfectly circular, except at its spinous
front edge, and then bears much resemblance to that of a Brachionus. The cloacal
orifice is a very short and thin fissure at the extremity, and does not extend sensibly up
each side.

In swiftly swimming, the wide but thin wing-like expansions of the dorsal plate are
very conspicuous by their glassy clearness, and by their peculiar form, especially when
seen end-wise ; and this gives a very distinct aspect to the species, which is more than
usually attractive. When alarmed it suddenly retracts with a snap ; and if it happens
to be presented sidewise at the moment, the frontal spines close with the sinuous pectoral
edge, so as to cross and interlace. I saw one eagerly feasting on an Actinophrys, and
watched it for half-an-hour. At first the frontal cilia worked energetically at it, gradu-
ally drawing it into the open front of the lorica, and holding it there. But the jaws
were not applied to it ; and it seemed as if the ciliary action alone were drawing off
invisible gelatinous juices into the buccal funnel. Yet, when at length the Notholca
relinquished its hold, the prey seemed uninjured. The species has been sent me by Mr.
Hood, associated with the preceding, in sea-water from the estuary of the Tay. — P.H.G. ]

Length, T^ inch. Habitat. Firth of Tay (J.H.).

128 THE ROTIFERA.

Genus ERETMIA, Gosse.

[GEN. CH. Lorica neither tesselated nor ridged; destitute of spines proper, but
furnished icith long attenuate rigid bristles.

This seems to be a natural group, containing numerous species. They appear to be
destitute of the spines common to Anuraa, pointed extensions of the lorica itself ; for
the slender appendages are quite different in form, and probably in function. — P.H.G.]

E. tentathrix, Gosse, sp. nov.
(PI. XXIX. fig. 12.)

[SP. CH. Five long bristles projected from the lorica ; one dorsal and two from each
side : no frontal or posterior spines.

This species I know only from a single dead and empty lorica which I found in the
sediment of water, dipped in June, from a pool at Sandhurst, Berks, by Dr. Collins.
The lorica is ovate, truncate in front, with no spines of the ordinary pattern, but bearing
attached to the medial line of the dorsum a long stiff seta, or attenuate spine, the base
of which is deep but very thin, the depth gradually diminishing. From the sides, about
two-thirds down, spring a pair of similar bristles of less basal depth ; and, at a short
distance from the round extremity of the lorica, another pair. All radiate from the
surface of the lorica, and are consimilar in length and tenuity. No trace of the internal
organs was left.

This has evident affinities with the A. biremis of Ehrenberg, which he describes
from a single specimen obtained in the Baltic Sea. That species, however, has four
frontal spines. — P.H.G.]

Length, unrecorded. Habitat. Pool near Sandhurst Mil. Coll. (P.H.G.) : very rare.

E. cubeutes, Gosse, sp. nov.
(PI. XXIX. fig. 11.)

[SP. CH. Lorica bag-like, round behind, truncate before; with a diverging seta
from the dorsum and one from the venter; four straight spinous processes from the
rounded end ; the whole surface cut into cubical tesserce.

This minute and very curious form I place in the genus Eretmia, though the body
processes seem rather spines than setae. I have found it, but only as a dead lorica, on
two separate occasions, and in water from widely distant localities ; but Mr. Hood has
since found it living, and sent me a good drawing of it, which well agrees with my own.
All were in autumn and winter of 1885-86.

Tbe lorica edge is not spined, but notched. Yet the notches are but the intervals
between the tesserce of the front row, of which three are seen beside the lateral two.
For tbe entire surface of the lorica is marked with two series of depressions, those of
each series parallel to each other, but the two series crossing each other at right angles
(or nearly) ; so as to leave a multitude of square tesserae, or cubical knobs, — like dice
set corner-wise : — a form of surface quite unique, so far as I know. I was, indeed, dis-
posed to think it an Arcelline Infusory of the genus Difflugium, till I received Mr. Hood's
report, which showed it a true Anuraad. He describes the rotatory front as bearing
the normal three great ciliate lobes. The large red eye I bad myself seen.— P.H.G.]

Length (including spines), ^\-(i inch (P.H.G.) ; ^\)JS inch (Hood). Habitat. Birming-
ham (P.H.G.) ; Black Loch, Dundee (Hood) : rare.

CHAPTER XI.

SCIRTOPODA.

VOL. II.

Csetera de genere hoc mirande multa videmus,
Quae violare fideni quasi sensibus omnia querent :
Nequidquam ; quoniam pars honim maxima fallit
Propter opinatus animi quos addimus ipsei
Pro visis ut sint, qua? non sunt sensibus visa.
Nam nihil ssgrius est quam res secernere apertas
Ab dubiis, animus quas ab se protinus addit.

Lucretius, De Iicrum Natura, Lib. iv. 1. 464.

The life of the brute has commonly one immense compensation in its
favour ; the perfection of the individual existence is so rarely sacrificed
to the prosperity of the race. It is not necessary, in order that one
hippopotamus should cut his food conveniently, that another hippopotamus
should lead an unhealthy existence like a Sheffield grinder ; nor does the
comfort of any bird's nest require that another bird should slowly poison
itself in preparing acetates of copper, sulphurets of mercury, or oxides of
lead. The pride and beauty of a brute are never based iipon the enduring
misery of another brute. The wild drake's plumage, splendid as it is,
suggests no painful thought of consumptive weavers, of ill-paid lace-
makers, of harassed over- worked milliners : and the most sensitive of us
may enjoy the sight of it without painful thoughts ; for it is God's free
gift, causing no heart-burning of envy, no care nor anxiety of any kind.
— P. G. Hamehton, Chapters on Animals.

We are then in a world of spirits, as well as in a world of sense ; and
we hold communion with it, and take part in it, though we are not con-
scious of doing so. If this seems strange to anyone, let him reflect that
we are undeniably taking part in a third world, which we do indeed see,
but about which we do not know more than about the Angelic hosts; — the
world of brute animals. Can anything be more marvellous or startling,
unless we were used to it, than that we should have a race of beings about
us, whom we do but see, and as little know their state, or can describe
their interests, or their destiny, as we can tell of the inhabitants of the
sun and moon ? It is indeed a very overpowering thought, when we get
to fix our minds on it, that we familiarly use, I may say hold intercourse
with, creatures who are as much strangers to us, as mysterious, as if they
were the fabuloiis, unearthly beings, more powerful than man, yet his
slaves, which Eastern superstitions have invented. — Newman, Parochial
Sermons, 'The Invisible 'World.'

CHAPTER XL

Order IV. SCIRTOPODA.

Swimming ivith their ciliary wreath, and shipping ivith Arthropodous limbs ; foot
absent.

The fourth order, Scirtopoda, although it contains but two Rotifera, each in a genus
by itself, is one of no little importance, as it is that in which the Rotifera and Crus-
tacea most nearly touch. The true position of the Rotifera in the animal kingdom
has long been a matter of keen dispute, and the chief authorities have taken opposite
sides : Professor Owen, Dr. Leydig, and others, rank them among Crustacea ' ; while
M. Milne-Edwards, Dr. Colm, Professor Huxley, with the majority, would consider them
as VERMES. Nor is this surprising ; for the Rotifera possess many characters that are
common, in various degrees, to ARTHROPODA and VERMES alike ; and, so far as their nutri-
tive, reproductive, or nervous systems are concerned, might with little difficulty be placed
in either sub-kingdom. But there were three respects, before the discovery of Pedalion and
Hexarthra, in which the Rotifera appeared to differ from ARTHROPODA, and to resemble
VERMES. These are, first, that they do not possess pairs of jointed appendages, articu-
lated to the body, with muscles prolonged into their interior ; and on this point great
stress was laid. Secondly, that they swim by means of ciliary wreaths ; and thirdly,
that they possess a vascular system, with ciliated tags, whose chief function is probably
a respiratory one.

But the discoveries of Pedalion and Hexarthra have shewn that Rotifera exist whose
internal structure is perfectly normal, and which yet possess three pairs of unquestion-
ably Arthropodous limbs ; and these discoveries have in consequence disposed of the chief
objection to the ranking of the Rotifera among ARTHROPODA. It may, on the other hand,
be fairly urged that the balance of argument even now inclines towards those who are
in favour of the opinion that the Rotifera, as a class, are nearer to VERMES : yet no
one, I think, who has studied both Pedalion and the Nauplius larva of one of our
fresh-water Entomostraca, would feel satisfied with their being placed in two distinct
sub-kingdoms.

In conclusion, I see no reason why the Rotifera should be assigned solely to VERMES
or ARTHROPODA ; and I would propose to consider them as a class that links these two
sub-kingdoms together.2

Family XX. PEDALIONID^.

Arthropodous limbs six ; head truncate; corona of tivo concave lobes ; ciliary wreath
as in Philodinadce ; trophi malleo-ramate.

The family contains two genera, Pedalion and Hexarthra, each containing only
a single species. The two are much alike 3 in the possession of six Arthropodous limbs

1 [I consider the Rotifera a class of the sub-kingdom ARTHROPODA, co-equal in rank with
Insecta and Crustacea. — P.H.G.]

- Of course I am here treating the matter simply as one of formal classification ; and from this
point of view it is enough to say that if we knew none but the humbler forms of the Rotifera, we should
call them VERMES ; whereas if Pedalion and Hexarthra were our only examples, we should call them
the lowest forms of ARTHROPODA.

3 Mr. Julien Deby, in the J. Roy. Micr. Soc. 1879, p. 384, has suggested that the two Rotifera are

Pedalion minim

>>

ii

»>

ii

>i

i»

182 THE ROTIFERA.

ending in fans of imbricated setae, in the conical shape of the body, and in the broad
truncate corona ; but they differ strikingly in the way in which the limbs are set on the
body : for in Pedal ion they are arranged around it parallel to its longitudinal axis, while
in He.cartlira, as in tbe Nauplius larva, they radiate from the centre of the ventral surface.
Nor is this the only difference. Hexarthra's limbs are in three graduated pairs, while
Pedal ion's ventral limb is far longer than any of the others : moreover, Hexarthra lacks
two long stylate appendages, ciliated at the ends, which are to be found on the posterior
end of Pedalion's dorsal surface.

Genus PEDALION, Hudson.

GEN. CH. Limbs arranged round the body in pairs, and parallel to its longitudinal
axis ; two stylate, ciliated appendages on the posterior dorsal surface.

P. mikum, Hudson.
(PL XXX. fig. 1.)

Hudson, Man. Micr. J. vol. vi. 1871, p. 121, pi. xciv. ; and p. 215.

,, Quart. J. Micr. Sci. vol. xii. 1872, p. 333, pi. xix.

,, Mon. Micr. J. vol. viii. 1872, p. 209, pi. xxxiii.
Lankester, Quart. J. Micr. Sci. vol. xii. 1872, p. 338.

SP. CH. Ventral limb much the largest; dorsal limb on the median line; lateral
limbs in tiro unequal dissimilar pairs ; the bases of all the limbs, lying in a transverse
section dehind the dorsal antenna; their free ends terminating in fans of imbricated
setce.

It was in July 1871 that I had the good fortune to discover this remarkable Eotiferon
in a small road-side pond near the head of Nightingale Valley at Clifton. On placing a
specimen of it under the microscope I for a moment fancied that I had brought home by
mistake some Entomostracous larva, for its outline, its six limbs ending in fans of
imbricated setae, and its habit of jerking itself through the water, made it resemble the
ordinary Nauplius of a Cyclops. However, a brief examination showed it to be a true
Eotiferon, with a splendid corona and with internal organs much like those of Triarthra
lougiseta. The external form is extraordinary ; not only has it six well-developed limbs,
but all these limbs are hollow, communicating with the body cavity, and containing pairs of
opposing muscles prolonged into their interior. The arrangement of the limbs too is more
effective for locomotion than that in a Nauplius ; for in Pedalion they are attached in pairs
to its anterior end, and lie parallel to the longitudinal axis of the body, so that their united
stroke acts at a great mechanical advantage ; but in the Nauplius larva the limbs radiate
from a spot on the ventral surface; and, in consequence of this inferior method of attach-
ment, produce a very feeble skip compared with the furious rush of Pedalion. The
corona is unusually large, and consists of two oval saucer-like lobes, so set as to give
together a heart-shaped appearance to the head. The ciliary wreath is double, and
precisely on the pattern of the Philodinadce (PI. C, fig. 3). Between the upper and
lower wreath is the usual groove along which the food is conducted to the mouth. On
either side the lower wreath dips down to the buccal orifice, which is prolonged ventrally
into a great curved lip, fringed with very large cilia. The rather small mastax has two

identical, and that the differences between my description and Dr. Schmarda's "reside principally in
the incompleteness of the details given by the latter, and are consequently differences of omission
rather than anything else." It is difficult to understand how it can he an " omission " to describe and
draw all the six legs as radiating from a spot on the ventral surface, while (on the supposition of the
identity of the two creatures) there is only one on that surface, and all lie round the body and parallel
to its length. Neither can it well be an " omission " or an " incomplete detail " to say that there are
two legs <>f equal size longer than all the others, when there is only one such leg. Indeed, were Dr.
Sel mania r< ally capable of the gross blunders attributed to him by Mr. Deby, the whole of his observa-
tions wouli be worthless.

<PEDALI0NID£1. 133

chitinous lips, which may be seen constantly advancing and receding in the buccal
funnel, and apparently selecting the morsels which are allowed to reach the tropin. The
oesophagus is short, and the nearly cylindrical stomach has very thick elastic walls ; in
a dying specimen I have seen the food expelled, and the walls close in quite upon them-
selves. The gastric glands are somewhat oval ; and I think that I have seen two small
stalked glandular-looking bodies attached to the oesophagus. The intestine is a broad
short chamber with thicker walls and coarser cilia than those of the stomach. The two
ciliated straight processes, on the hind end of the dorsal surface, have also a glandular
structure and secrete a viscous fluid, by threads of which Pedalion may be found moored
to alga3, or to the floating masses of floccose sediment.

These processes vary greatly in length in different individuals ; they are always very
short in the newly hatched female, and are wanting in the male. It is unusually difficult
to demonstrate the vascular system, as its parts are so frequently obscured by the
alimentary canal and the limbs. There are two lateral canals, each commencing in a
plexus close to an eye and bearing a vibratile tag. Hence the canal runs down to a
second plexus, halfway down the body, with two vibratile tags ; and, skirting the side,
finally unites with the cloaca. There is no contractile vesicle. The ovary requires no
notice. Pedalion carries its extruded egg attached to its posterior extremity till it is
hatched. Of the large oval female eggs only one at a time is so carried ; the small,
round male eggs are carried in clusters : the eggs of different sexes are never present
together. The newly hatched female resembles its mother, and passes through no
change but that of growth. The muscular system is very greatly developed. There
are at least forty striated muscles arranged in pairs of elevators and depressors, not mere
repetitions of each other like the muscles of a caterpillar, but very various in shape and
arrangement, and obviously intended for different duties. Figs. Id, le, If show these
pairs very carefully drawn and, with the printed explanation facing PL XXX., render any
detailed account superfluous. The nervous ganglion lies closely applied to the dorsal
side of the buccal funnel, and has above it two eyes, widely apart and close to the surface
of the corona ; one in each of its lobes. They are clear refractive spheres set on plates
of red pigment. Nerve-threads pass from the ganglion to lateral rocket-headed antennae,
one on each shoulder ; and another nervous thread supplies a similar antenna which
moves up and down in a protuberance on the dorsal median line (figs, la, lb) just
behind the dorsal gap in the ciliary wreath.

The male (figs, lh, Ik) is the merest caricature of the adult female. The large,
shapely corona, with its flowing curves has become a ciliated knob ; the six limbs, with
their fan-shaped plumes, have been altered into three little stumps, with a bristle or two
at the end of each ; even the huge ventral limb has vanished, and the whole creature
has shrunk up to barely one-fifth of the length of the adult female. It swims very dif-
ferently from its mother ; for it spins constantly round its own length, like a joint on a
spit, while at the same time moving forward. Now and then it jerks its side limbs, and
it uses them to free itself from its shell. There are two longitudinal muscles for retract-
ing the head and a pair of red eyes, but I could discover no other internal organs except
the testis and penis. This latter I have seen protruded to a length quite equal to that
of half the animal.

Length. Female, corona and body, y^ inch ; from corona to end of ventral limb,
excluding seta3, ^ inch : male, z\^ inch. Habitat. Clifton (C.T.H.) ; Birmingham
(T.B.) ; warm water-lily tank in the Duke of Westminster's gardens at Eaton, and
ponds in the neighbourhood of Chester (Mr. Thos. Shepheard) : very rare.

The only other Eotiferon in this Order is Hcxarthra polyptcra (PL XXX. fig. 2),1 which

was discovered by Dr. Schmarda in some brackish water near El Kab in Egypt, in March

1853. He describes the body as a blunt cone with a right and left group of cilia on its

broad end. The trophi resemble those of Triartlira. The stomach is short and broad ; the

1 Copied from Dr. Sclimarda's rig. 1, Zur Naturgcsch. Agyptcns, Taf. iii.

131 THE ROTIFERA.

intestine is frequently constricted and narrow towards its end. The gastric- glands are two
lobed. He further notices the lateral canals, and a bladder-like organ which he conjec-
tures to be the testicle, but which was probably tbe contractile vesicle. Two red globular
eyes are seated in the corona, not far asunder. The mature eggs, which are green, are
carried at the posterior end of the body. There are three pairs of limbs attached to the
ventral surface. The foremost pair is the longest, the middle pair is less, and the lowest
pair is the least. Two streaked muscles run down the first pair of limbs, and one muscle
down each of the other four. All the limbs are terminated by fans of seta?. II. poly-
ptera does not appear to have any ciliated processes on the dorsal hind surface.

ADDENDA.

[Asplanchna MYRMELEO, Elircnbcrg (vol. i. p. 123 : footnote). This interesting
species is no longer an alien. Mr. Hood has lately sent me, from Dundee, living and
healthy examples. They seemed to possess no contractile vesicle. — P.H.G.]

[Eretmia teithrix, Gosse, sp. nov. (PL XXVIII. fig. 2). Lorica a three-sided box,
of which the posterior end is a triangle, and carries a long elastic seta at each angle :
egg, when laid, carried between the alvine setas. Length, T}. s inch. Lacustrine. — P.H.G.]

[Eretmia tetrathrix, Hood, sp. nov. (PI. XXVIII. fig. 1). Lorica shaped like a
deep obconic wine-glass, of which the foot is represented by a very long straight seta :
three similar setae stand up from the occipital margin. Length, of lorica, T^y inch ; total
^Jtf inch. Lacustrine. — P.H.G.]

Notommata Werneckii, Ehrenbcrg. I am indebted to Mr. Fred. Bates for some
threads of Vaucheria sessilis bearing many of the galls caused by this parasitical Rotiferon.
Mr. Bates says that he has found the animal in abundance inhabiting these galls, which
may occur anywhere along the thread of the Vaucheria : but that he has not found the
parasites in the reproductive cells (see vol. i. p. 39).

Length (according to Balbiani), T^ inch. Habitat. Neighbourhood of Leicester
(Mr. F. Bates).

(Ecistes ptygura, Ehrenbcrg (PL XXX. fig. 3). This is no doubt Ehrenberg's
Ptygura mclicerta. It has a two-lobed corona; a wide dorsal gap ; no visible ventral
antennae ; a pair of large dorsal hooks, adnate for half their length ; a stout wrinkled
foot ; and an irregular floccose tube. It was found last May, at Twickenham, by Mr.
G. Western, who kindly sent me the living specimen, from which fig. 3 has been drawn.
Its position, in one of the axils of the plant to which it was attached, prevented me from
measuring it ; but it seemed to be about the size of an ordinary GUcistes crystallinus.

The following remarkable Rotifera arc as yet unknown in Britain.

I'.ai.atko calvus (PL XXX. fig. G), Ed. Claparedc (15). This is an il-loricated
Rotiferon, parasitic on different species of Oligochczta. Its peculiar hind extremity is
shown in the figure. Mastax very small, containing two minute curved rami ; stomach,
simple and straight; ovary large ; ciliary wreath and antenna wanting ; nervous, and
vascular systems apparently absent.

I'mlophaga Bucephalus (PL XXX. fig. 5), F. Vejdovshj (150). An il-loricated
Proales-hke Rotiferon, parasitic on Luvibriculus variegatzis ; it adheres by its tropin to
the worm's hinder segments, and sucks its juices ; nutritive, secreting, and vascular
systems normal.

Seison Grurei (PL XXX. fig. 4), C. Clans (17, 18). A doubtful Rotiferon ; il-lori-
cated, of extraordinary form, parasitic on Ncba/ia ; ciliary wreath a few cilia at tho
mouth ; secreting system highly developed ; nutritive system present in the male as
well as in the female; vascular system very rudimentary; jaws rotiferous.

APPENDIX

THE VASCULAR SYSTEM.

*„* The numbers in brackets, as (138), refer to the memoirs in the Bibliography, pp. 140-142.

1. This system of vessels, in its usual form, has already been described in vol. i. p. 8.
There are three ' principal varieties of it, including that already given above.

(i.) The lateral canals open into a contractile vesicle, which discharges itself into
the cloaca. This is the ordinary plan.

(ii.) Each of the lateral canals ends in an expanded portion which dilates, and con-
tracts, and discharges into the cloaca. This doubling of the contractile vessel is to be
found, among others, in Conchilus volvox 2 and Salpina macracantha.3

(iii.) The lateral canals pass unexpanded directly into the cloaca, and the contractile
vesicle is absent.4

2. It is probable that the contractile vesicle is filled by a fluid flowing into it
through the lateral canals, and it is certain that it usually 6 empties itself outwards
through the cloaca. This has been directly observed 6 in Asplanchna priodonta and in
Hydatma senta by myself, and can be easily verified. It has been suggested that a
return current of fresh water is drawn up by the expanding contractile vesicle through
the cloaca ; but no one has seen any appearance of this in the cloaca itself ; and though
Dr. Colin 7 thinks that he saw a return current draw particles of carmine towards the
opening of the cloaca of Brachionus militaris, after the outward current had driven
them away from it, no one else seems to have succeeded in repeating the observation.8
Occasionally the contents of the cloaca are driven into the intestine. Dr. Moxon has
seen this in Euchlanis dilatata? and Dr. Semper has seen it in Trocliosplmra aqua-
torealis.10 In each case it was effected by closing the aperture of the cloaca and open-
ing that of the intestine simultaneously ; but this is not the usual action, and (as Dr.
Moxon suggests) seems only to be a method of obtaining a natural enema for a clogged
intestine.

3. In all the three plans, given in § 1, the lateral canals sometimes appear surrounded
by a filmy, floccose substance, through which they meander (generally two on each side)

1 Dr. Semper (138) says that in Trochosphara cequatorealis there is a contractile vesicle which has
no connection with the lateral canals : if this is really the case, it would be unique. Mr. Gosse has
described, p. 138, another variety of the vascular system in Pterodina, and in other Eotifera ; but, as
we differ widely here about the facts, as well as about the inferences drawn from them, I have (for the
sake of brevity and clearness) omitted this variety from my account.

2 Vol. i. p. 90. 3 Vol. ii. p. 85.

4 Professor Huxley (91) states that this is the case in Lacinularia socialis ; but Dr. Leydig (108)
says he has seen a small contractile vesicle in this Rotifcron. Neither Pedalion mirum, Pterodina
patina, nor P. valvata appears to have any contractile vesicle.

5 See below ; same paragraph. u Vol. i. p. 123. 7 (21).

8 I have never seen B. militaris, which from the great size of its contractile vesicle is admirably
adapted for such observations.
'•' (118). '» Vol. i. p. 88.

130 THE ROTIFERA.

in many loops and curves, and occasionally forming a plexus of complicated inter-
twining*. Attached to the canals by long stalks are the little flickering bodies called
vibratile tags. The canals are generally visible just under the head, near a plexus, and
run down each side of the body, from one plexus to another, till they reach the surface
of the contractile vesicle. There are usually five vibratile tags on a side, and a plexus
is a favourite point of attachment.

4. The tags are of various shapes. In some they seem to be simple cylinders, or
cones with their bases at the free end. In others they are somewhat wedge-shaped ; so
that they have a broad triangular surface from one point of view, and a narrow spindle-
shaped surface from another. If a tag happens to point straight up the microscope, a
full view may be obtained of its free end ; and the outlines, so obtained, of these free
ends, vary considerably : in the case of Euchlanis dilatata it is a narrow oval with pro-
longed pointed ends ; l and in that of Brachionus pala,2 only a line straight edge. When-
ever I have obtained a distinct edgewise view of a tag, it has had the appearance,
of being closed at its free end with a knob. Down the length of the tag (when so seen)
run an endless succession of swift undulations ; which, on several occasions, in the
dying animal, I have seen slowly slacken, till they have gradually resolved themselves
into what seemed to be one stout, tapering, undulating cilium, of the length of the tag
itself, attached by its broad base to the knob mentioned above, and pointing its taper
extremity to the lateral canal.

But when the tag presents its broad triangular surface to the observer, there is a
totally different appearance ; and it seems to be crossed by quivering, parallel, straight
lines that stretch from one side to the other (PI. XIII. fig. 3b). It is obvious that no
single cilium could present such an appearance. Possibly an undulating membrane
might, the cross-lines being the summits of the waves which happened to be in focus ;
but the lines seem to be too sharp for this. Dr. Moxon suggests that the cross-lines are
produced by rows of extremely minute cilia on each inner broad surface of the tag. It
is not easy to imagine what such an apparatus might look like when seen in motion
sidewise ; but possibly the apparent waves produced by the cilia on either side might
together cause the illusory appearance of an undulating cilium as long as the vibratile
tag. That many of the inner surfaces of the Rotifera are lined with minute cilia has
long been known. The whole alimentary tract is so ; and, what is more to the point,
this very appearance of a long undulating cilium is certainly produced in the tube of
Floscularia campanulata by very minute cilia running in straight lines down its length.3

5. The next point is whether these tags are open or closed at their free ends. On
this point it is enough to say that direct observation has entirely failed to decide the
question. The chief authorities have come to opposite conclusions, and there seems to
be no hope of settling the point by the microscope. The close analogy between the
vibratile tags of the Rotifera and the appendages on the water-vessels of the Naida
would, however, lead us to infer that in the former case, as well as in the latter, the
tags in spite of appearances may be open funnels, furred inside with minute cilia. A
similar difficulty awaits us when we inquire how the lateral canals originate in the
head. In some cases the canals on either side are said to have their fore ends on the
surface 4 in communication with the free water, in others to cross from side to side and
anastomose5; so that the whole apparatus forms a loop with its two ends attached either
to the cloaca or to the contractile vesicle ; while in the great majority of cases it is im-
possible to say what is the real arrangement.

0. In attempting to determine the use of this apparatus we are met by this obvious
difficulty ; that we are not sure of the facts. Are the vibratile tags open at their free

1 Dr. Plate (120) Taf. ii. fig. 10, c. 2 C.T.H. vol. ii. p. 117.

3 PL D, fit,'. 1 ; also Dr. Moxon (118).

4 As observed by Mr. Gosse in Pterodima patina and P. valvata, vol. ii. p. 138.

• As observed by Professor Huxley in Lacinularia socialis (91) ; by Dr. Leydig in the same (108) ;
and by myself in Stci>hanoccros Eichhoinii, PI, iv. iigs. 2,4.

i

APPENDIX. 137

ends, or are they closed ? Do they contain an undulating membrane, or are their inner
surfaces furred with minute cilia ? Does a current pass through them (supposing them
to be open funnels) toivards the lateral canals, as it seems to do, or in the opposite
direction ? Are the lateral canals open at their upper ends, or are they blind passages
having no outlet save at the contractile vesicle ? Is the substance surrounding the
lateral canals a glandular secreting substance, or a mere mechanical support for the
canals ? Does the contractile vesicle fill itself by drawing up fresh water through the
cloaca, or is it filled by fluid passing into it from the lateral canals ?

I do not know how these questions are to be answered with any approach to certainty,
and I have no expectation of their receiving any answers that will meet with general
acceptance, for on all these points the best observers disagree : I shall, therefore, do no
more than state, in the following paragraph, the view of those who consider the vascular
system to be an excreting one ; and leave to my colleague the advocacy of the opinion
which he has long held, viz. that the system is mainly branchial, with, possibly, a sub-
ordinate excreting function.

7. The perivisceral fluid is in part l derived from the products of digestion which pass
by endosmose through the cellular walls of the stomach ; and it is out of this fluid that
the various organs are repaired, and at its expense that the animal moves and grows.
This growth, repair, and action change the constitution of parts of the perivisceral fluid,
and render an excreting organ a necessity. The vascular system is this excreting organ ;
and, indeed, no other has ever been suggested as having an excreting function. The
lateral canals with their floccose investments, or the vibratile tags,2 or both, are the
excreting vessels ; while the part played by the contractile vesicle is one probably of
storage and discharge : for the contractile vesicle varies extremely in size and frequency
of action in different Rotifera, and in some is altogether absent.

The oxygenation of the perivisceral fluid, both in males and females, probably takes
place at the fore part of the head, where the skin is never loricated, but appears to be
thin ; and, where, too, it is possible that there may be definite spots, covered with deli-
cate membrane, so as to take advantage of the constant rush of water, drawn to the
head by the ceaseless action of the cilia.

8. Now it is obvious (from § G) that the above explanation (given in § 7) of the
vascular system, rests on a number of assumptions which it is impossible to verify. But
then as much, I think, may be said of the explanation that would make the function of
this system a branchial one, or a combination in various degrees of both.

1 Leydig is of opinion (110) that water passes by endosmosis into the body cavity. This, indeed,
seems probable ; for indigo-coloured water when swallowed (e.g. by R. vulgaris) almost instantly
imparts a blue tint to the thick cellular walls of the stomach up to their outmost boundary. It can
hardly be supposed that it goes no further, if the products of digestion do. It seems unlikely that the
inner walls of these stomach-cells should be pervious to the products of digestion, and to water, alike ;
and that the outer walls should be pervious to the former, and impervious to the latter. It has, how-
ever, been objected, that we never see the indigo-coloured water in the perivisceral fluid. But it is
hardly to be expected that we should. When we look at the blue stomach-walls, we are looking at a
colour produced by a depth of solution equal to that of one or two thick cells ; whereas the coloured
fluid, oozing out through the stomach-walls, would be presented to our eyes in films of almost
infinitesimal thinness ; which would never be suffered to accumulate and so become visible, but would
be at once broken up and lost, by the constant motion of the perivisceral fluid. Besides the blue tint
after a time disappears from the cells. It seems more likely that this is due to the indigo-solution
continuing its course through the cells into the body cavity along with the products of digestion, than
to its parting company with these latter at the outer wall, and then alone reversing its course, and
returning into the stomach.

■ If the vibratile tags be supposed to be open ciliated funnels, through which the perivisceral fluid
passes into the lateral canals, to be discharged through the cloaca, then we are met with the difficulty
that this supposition would imply the frequent discharge of a fluid analogous to blood. But, on the
other hand, if it were admitted that, in the perivisceral fluid, the products of digestion are largely
diluted with water (see previous note), the force of this objection would be much weakened ; for the
supposed difficulty would be mainly due to our having applied, to so simple a fluid, the name of such
a highly organised product as blood.

138 THE ROTIFERA.

The conclusion seems a lame one, and yet I fear that it is hardly possible to hope for
a better, when dealing with an apparatus of whose structure we know so little ; one which
we are unable to examine except with our eyes, and yet one in which we have strong
reasons for suspecting that, on crucial matters of detail, our sight deceives us.

P. H. Ct. on the Vascular System.

[My opinion is, — as it was in 1850 (" On the Anat. of Not. aurita ; " Tr. Micr. Soc.
Lond., iii. 98), — that the vascular system is a proper respiratory system, and that the
lateral canals are proper branchiae. The water enters at the head, circulates, and is
poured out at the cloaca. I believe these three facts may be predicated of the entire
class. Accessories to the process are : (1) the afferent tubules ; (2) the "gastric glands ; "
(3) the vibratile tags ; (4) the contractile vesicle.

1. In so many species that I consider the arrangement universal, I trace up the
canals to the funnel through which the head-mass constantly moves up and down. The
canals never partake of this motion, and it is evident that they are attached to the wall
of the funnel, which I presume to be perforated with minute orifices through which the
external water constantly percolates into the afferent tubules. In many species these
appear to be numerous, and they are seen to branch and to anastomose very irregularly
into each other, forming single, double, or multiple canals, which run, sometimes nearly
straight, but more commonly bent sinuately in various degrees, throughout the length of
the animal. In Pterodina, (especially in patina and chjpeata) the tubules ramify and
spread into broad fan-shaped plexuses of flat laminae (which I consider tubular, and ciliate
within), filling the wide triangular areas on each side of the mastax. Then they begin
to unite again, and presently (in P. valvata especially), bending abruptly from the ven-
tral to the dorsal side, form one broad and long pyriform sac which narrows to a long
slender duct, and joins the oesophagus one on each side, pouring the effete water into the
alimentary canal, and ultimately through the cloaca, without the intervention of a con-
tractile vesicle.

2. The " gastric glands." — The organs thus named have usually been considered as
ancillary to the digestive system. But their evident connection with the aquiferous
svstem in Pterodina makes this doubtful ; and a number of other curious facts are
observable, which confirm, more or less manifestly, this connection.

Sometimes these organs take the form of large reservoirs of delicate texture and
wrinkled surface, joined to the oesophagus by long ducts, and affixed by threads (perhaps
tubular) to the lateral canals, or to the lorica. In Metopidia solidus, each appears as
an aggregation of saccules into a large three-sided and three-angled body, one anglo
passing up to the origin of the canal, and another by a long duct to the oesophagus,
while the canal seems in some inexplicable way united with both. This, excessively
slender at its origin, expands as it proceeds, becoming corrugate, till it attains a width
almost rivalling the plexus of Pterodina patina, just before it enters the cloaca, without
the intervention of a contractile vesicle. Yet, in some individuals, the contractile
vesicle itself and its action are quite distinct.

In Notholca acuminata the "gastric gland" much resembles the pyriform of Pter.
valvata, with a slender duct to the long oesophagus, and another duct from an outer
angle leading down for some distance closely parallel with the lateral canal, and con-
nected with it by a short transverse duct at each end.

Cathypna lima has a structure somewhat like this ; and, in a less degree, Metopidia
rliomboidcs.

Several species of Brachionus display anomalies in these organs. Thus in B. Bakeri
and B. nrccolaris each is a great wrinkled sac of very delicate tissue, and of retort-shape,
at the end of a long neck. In B. rubens there are two sacs on each side, united by a
king sinuous duct. In B. MulUri there is but one on each side, but it is cleft almost to
the base into two varying portions. In all these the organs seem to have more or

APPENDIX. 139

less obvious connection with the expansions of the lateral canals. But, in one example,
which I cannot distinguish from urceolaris, the sac is, at its outer extremity, indefinitely
expanded, fore and aft, and seems to merge into the length of the canal itself, which
yet begins clearly in the wall of the head-funnel, and terminates normally in a con-
tractile vesicle.

On the other hand, in Asplanchna, the glands, which are small oval organs, are
connate, on each side of the very long oesophagus, remote from, and apparently quite
unconnected with, the canals.

3. Of the " vibratile tags " I have little to say of direct observation. In Pterodina
they seem to me wholly wanting. I judge it nearly certain that they are tubular, and that
something is driven through them, whose course is from the lateral canal to the body-
cavity.1 Assuming that the function of the system is the separation of oxygen from the
water, may it not be that the tags are reservoirs in which pure oxygen collects, and
from which it is pumped into the perivisceral blood, while the hydrogen left pursues its
course, perhaps to fulfil some office still, mechanical or vital ?

4. Of the contractile vesicle, the normal position, form, structure, and function are
well known.2 But in the two largest species of Salpina, macracantJia and eustala, there
are two of these organs, of ample dimensions, one on each side, into which the com-
paratively straight and thick lateral canals empty by trumpet-mouths. Strange to say,
in the former species the " gastric glands " seem wholly wanting.

In the great Asplanchn®, the organ, though manifest enough, is very small ; in
Metopidia, as already mentioned, it is only now and then present ; while in Pterodina,
it is (according to my experience) invariably wanting.

On the whole, then, I judge that Rotifera possess a well-marked branchial system,
which has several striking parallels with that of the Annellida — the Lumbricidce in
particular. — P.H.G.]

THE SETIGEEOUS SENSE-ORGANS.

The nervous system of the Rotifera is simple. It consists of one nervous ganglion
situated on the dorsal side of the buccal funnel, usually near the mastax ; and sending
out nervous threads to the eyes,3 and to certain organs of sense, which have been termed
antenna or tentacles as they are possibly tactile organs ; but whose function is by no
means certain. They consist of knobs or cylinders, which usually carry a bunch of fine
setae at their outer extremity. Sometimes they are enclosed in tubular sheaths rising
from the surface of the body ; and at others their extremities lie close to apertures in
that surface, through which the setae may be seen to protrude. The antenna? are in two
pairs. Of these the upper pair is invariably dorsal ; and its constituents, though some-
times widely separate,4 are most frequently pressed close together,5 or fused into one.6
The lower pair is to be found sometimes on the dorsal surface,7 sometimes on the
ventral,8 and sometimes on the line between the two.9 In one case this lower pair is
also fused together,10 and the creature has but two antennae ; both dorsal, and both on
the median line. It is only necessary to add that, in many species, one or other pair
appears to be absent ; notably the lower pair in all the Philodinadce : but in some of
these cases their absence may be only apparent ; as the antennae are often reduced to
minute setigerous pimples, and so can be easily missed.

1 The perivisceral fluid, or blood, is surely neither effused from the body, nor augmented in quantity,
sensibly.

2 Since a special reservoir would seem needless for the mere discharge of the effete water, an urinary
office may belong to this bladder.

3 When there is only one eye it is generally seated on the nervous ganglion itself.

4 As in Asplanchna priodonta, PI. xii. fig. 2c : Copcus spicatus, PI. xxx. fig. 7 : and Brachionus
plicatilis (117).

5 As in Synchceta pectinata ; PI. xiii. fig. 3c. 6 The common case.

7 As in Notops Brachionus ; PI. xv. fig. 1. 8 As in Melicerta ringens ; PI. v. fig. 4.

9 As in Stcphanoceros Eichhomii ; PI. iv. fig. 2. 10 As in Cvpcus caudutus ; PI. xvi. fig. 5a.

no

THE EOTIFERA.

BIBLIOGRAPHY OF THE EOTIFERA.

N.H. The references marked f have been copied from Herr Eckstein's list in " Sieb. a. Koll. Zeits.,"
Bd. xxxix. 1883, p. 433 ; and those marked * from Mr. Darcy W. Thompson's " Bibliography of
Protozoa, Sponges, Ccelenterata, and Worms," 1885. I possess, or have had access to nearly the
whole of these memoirs, but have been unable to consult those which are marked §.

1. Archer, W. . .

2. Atwood, EL P. .

3. Badcock, J. . .

4. Balbiani, S. . .

G. Barrois, J. . .
7. Bartsch, S. . .

9. Bcdwell, F. A. .

10. „ „ .

11. „ „ .

12. Billet, A. . .
18. Brightwell, Thos.
14. Burmeister, II.
1"). Claparede, Ed. .
10. „ „ .

17. Claus, C. . . .

18. „ „ . . .

19. Culm, F. . . .

20. „ „ . . .
21.

22. Collins" F. . .

23. Corda, A. J. C. .

24. Cox, C. F. . .

25. Crisp, F . . .

26. Cubitt, C. . .

27

M. i, ,, . .

ZJ. ,, ,, . .

30. „ „ . .

31. n ,, . .

32. Daday, E. von.

33. Dalrymple, J. .

84. Davis, II. . .

dO. ,, || . .

3(>. ,, ,, . .

37. Deby, J. . .

38. Dobie, W. M. .

39. Doyere, M. P. .

40. Dujardin, P. .

41. Eckstein, K.

42. Ehrenberg, C. G

■1 1. Eichwald, E. von
46.

4G,
47

Eyferth, B. .

68, S. A.

48. Fonlke,8. G.

49. FromenteL E.

50. Fullagar, J. .
61. < tavaret, J. .
52. Giglioli, If. .

.. r. ii.

de

PolycJuctus spinulosus, Quart. Journ. Micr. Sci., viii., 1808, p. 72.
§ Brachionus conium, Amer. Mon. Micr. Journ., ii., 1881, p. 102.
Eyes of Rotifers, Journ. Boy. Micr. Soc, ii., 1882, p. 512.
Notommata Wcrncckii, Ann. Sci. Nat. Zool., vii., 1878, (1 pi.)

„ „ Journ. Roy. Micr. Soc, ii., 1879, p. 530, (1 pi.)

Embryology of Pedalion (Synchseta), Rev. Sci., 1877, p. 303.
Die Raderth. b. Tubingen, Stuttgart, 1870.
Rotatoria Hungarian, Budapest, 1877, (4 pis.)
MeUcerta ringena (building apparatus), Mon. Micr. Journ., xviii., 1877,

p. 214, (2 pis.)
M. ringena & Conochilus volvox (mastax), Journ. Roy. Micr. Soc, i.,

1878, p. 17G, (2 pis.)

MeUcerta ringens, Midland Naturalist, i., 1878, p. 245.

* § Philodma roseola, Bull. Sci. Dep. du Nord, ii., 1883, pp. 1 & G9.

A dioecious Rotifer (Asplanclma Brightwellii), Ann. Nat. Hist.,1848,p. 153.
Die systemat. Stellung. </. Raderth, Sieb. u. Koll. Zeits., 1857, p. 152.
Misccllanees Zoologiques, Ann. Sci. Nat. Zool., viii., 18G7, p. 5, (2 pis.
„ „ Quart. Journ. Micr. Sci., viii., 18C8, p. 171.

Scison Grubei, Festschrift d. k. k. Zool. hot. Ges. inWien, 187G, (2 pis.)

* t § Z. Kennt. d. Organis. von Seison, Zool. Anzeig., iii., 1880, p. 548.
Die Fortpflanzung d. Raderth., Sieb. u. Koll. Zeits., 1856, p. 431, (2 pis.)
Bermerkungen lib. Raderth., Sieb. u. Koll. Zeits. ix., 1858, p. 284, (1 pi.)
BermerJcungen iib. Raderth., Sieb. u. Koll. Zeits., xii., 18G3, p. 197, (3 pis.)
New species of Rotatoria, Science Gossip, 1872, p. 9.
Cystophthahnus, Weitenwebkb, Beitr. z. Natur. u. Heilwissenschaft,

i., p. 178.
Rotifer vulgaris (reproduction of), Mon. Micr. Journ., xvii., 1877, p. 301.

* § New Siviss Rotatoria, Zool. Anzeig., vi., 1883, p. 564.
Floscularia coronetta, Mon. Micr. Journ., ii., 18G9, p. 133, (1 pi.)
Btephanoceros Eichornii, Mon. Micr. Journ., iii., 1870, p. 240, (2 pis.)
Winter habits of Rotatoria, Mon. Micr. Journ., v., 1871, p. 168, (1 pi.)
Floscularia cyclops, Mon. Micr. Journ., vi., 1871, p. 83, (1 pi.)
Limnias awnulatus, Mon. Micr. Journ. vi., 1871, p. 165, (1 pi.)

On the homological position of the tube-makers, Mon. Micr. Journ.

viii., 1872, p. 5, (2 pis.)
New contributions to knowledge of Rotatoria, Ann. Nat. Hist., April

1884, p. 309.
Notommata (Asplanclma) BrightweUii,Vh\\. Trans., 1849, p. 331, (2 pis.)
OZcistes longicornis, d (E. intermedins, Trans., R. Micr. Soc, xv., 1867,

p. 13, (1 pi.)
A new Callidina ; & the desiccation of Rotifers, Mon. Micr. Journ.,

ix., 1873, p. 201, (1 pi.)
Conochilus volvox, Mon. Micr. Journ., xvi., 1876, p. 1, (1 pi.)
TJte identity of Pedalion and llexarthra, Journ. Roy. Micr. Soc, ii.,

1879, p. 384.

Floscularia campanulatattF.cornuta, Ann. Nat. Hist., 1849, p. 233,(1 pi.)

§ Resurrection ties Rotifercs, Moigno, Cosmos, xiv., 1859, p. 42G.

§ La revivification et les animalcules ressuscitants, Coniptes liendus,

xlviii., 1859, p. 992.
§ S?/r les a/nimaux ressuscitants, Coniptes Rendus, xlix., 1859, p. 751.
Eistoire Nat. des Zoophytes, Infusoires, Paris, 1841.
Die Rot. d. Umgegend v. Geissen, Sieb. u. Koll. Zeits., 1883, (6 pis.)
Die Infusionsthierchen, Leipzig, 1838.

t§X>. /"". Formen d. mikr. Lebens. Verhandl.dcr. Berl.Akad., 1853, p. 183,
§ Udderthiere des Ostseewassers, Bull. Soc. Mosc, xxii., 1849, p. 5:20.
Edderthiere der finnischen Kiistc, Bull. Soc. Mosc, xw., 1852, p. 540.
Die einfachsten Lebensformen, Braunschweig, 1885.
Cupelopagus bucmedax, Amer. Mon. Micr. Journ., 1882, pp. 102, 151,

(w illi figs.)

Apsilus bipera, Proc. Acad. Nat. Sci. Pa., 1884, pp. 87, 50, (1 pi.)
Stir la revivification des Rotiferes, tic., Paris, 1878.
Tubicolaria naias, Journ. Quekett. Micr. Club.. Lv., 1876, p. 182, (8 pis.)
Quelques experiences sv/r les Rotiferes, Ann. Sci. Nat. Zool., 1859, p. B15.
On genus Callidina <t: ('. parasitica, Quart. .Journ. Micr. Sci., 1863,

p. 287, if pf.i

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141

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57.

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58.

»

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59.

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11

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GO.

n

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61.

n

1^

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62.

n

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63.

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05.

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,H

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(I ruber,

A

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A.

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1)

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11

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72.

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11

73.

11

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74.

»

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t>

11

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11

78.

11

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11

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80.

11

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93. Joliet, L. . .

J4. ,, ,, . .
Jo. ,, ,,

90. Joseph, G. .

97. Kellicott, D. S.

98. Kolliker, A. .

99. Kramer, . . .

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p. 1, (2. pis.)
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Soc, ii., 1879, p. 380.
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p. 1, (2 pis.)
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(with figs.)
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Soc, 1885, p. 008, (1 pi.)
Lacinularia socialis, Trans. Micr. Soc, London, i., 1853, p. 1, (3 pis.)
Pelagic Fauna of Swiss Lakes, Zool. Anzeig., Septr., 1883.
Observations sur les rotateurs du genre Melicerte, Coinptes Rendus,

xciii., 1881, p. 748.
Dcveloppcment de Vceufdes Meliccrtes, Comptes Rendus,xciii.,1881,p.85G.
§ Monographic des Melicertcs, Arch, de Zool. Exper. et gener., i., 1883,

p. 131.
Z. Kennt. d. in d. Kraincr Tropfstcingrotten einheimisch. Bdderth.,

Zool. Anzeig., Feb., 1879, p. 01.
Anuraza longispina, Amer. Journ. Micr., iv., 1879, p. 20.
§ Furchung u. Samenfaden b. ein. Badcrtli., Froriep, Notizen, xxviii.,

Oct. 1843.
Ub. ein. Bdderth. a. d. Fam. d. Asplanchnecn, Arch. f. Naturgesch.,

1870, p. 179, (1 pi.)
A neiv parasitic Botifer, Quart. Journ. Micr. Sci., viii., 1808, p. 54,

(with figs.)
Bemarhs on Pedalion, Quart. Jonrn. Micr. Sci., xii., 1872, p. 338.
Dictyophora vorax, Proc Acad. Nat. Sci. Pa., 1857, p. 204.
Linuiias socialis, (loc cit.), 1874, p. 140.
Bevivification of Botifer vulgaris, (loc. cit.), 1874, p. 88.
Botifera without rotary organs (Acyclus Inquietus), (loc cit.), 1882,

p. 243, (1 pi.)
Anuria longispina, Midland Naturalist, ii., 1879, p. 241, (1 pi.)
§ Egg segmentation ; Notommata, Euchlanis, Megalotrocha, Isis, 1848,

p. 170.
Lacinulaiia socialis, Sieb. u. Koll Zeits., 1851, p. 452, (1 pi.)

t § Ub. d. Geschleclit d. Bdderth., Verhandl. d. phys. Gcsellsch. Wiirz-

burg, 1854, p. 104.
Ub. d. Ban. u. d. system. Stellung. d. Bdderth., Leipzig, 1854 (4 pis.)

145

THE ROTIFKRA.

111. Levdig. F. . . .

11-2. Lord, J. E. . .

113. Maggi, L. . . .

114. Marion, A. F. . .

115. MetBchnikoff, E. .

116. Milne, W. . . .

117. Mobius, K. . .

118. Moxon, W. . .

119. Nageli, H. . . .
1-20. Peirce, C. N. . .

121. Peltier, A. . . .

122. Pereyaslavtseff.C.
12:5.

124. Perty, M. . . .

125. Elate, L. . . .
11.0. ,,„....

127. Elessis, G. Du .

128. PoggenpohL . .

129. Pritchard, A. . .

180. Eciter, II. II. . .

131. Bosseter, T. E. .

182. Rolleston, G. . .

133. Salensky, W. . .

134. Schmarda, L. K. .

135.

13G. Schmidt, 0.

137. Scoch, G. .

188. Semper, C.
13J. |, H

140. Slack, H. J.
HI. „

142. Smith, F. H.

143. Stein, F. .

111. Tatem, J. G.
1 1."/. „ „

] L6. T6th, A. .

1 17. Udekem, J. d'

148.

149. Up de Graff. T

150. Vejdovsky, F

151. Vogt, C. . .

152. Weisse, J. F.
158. m ..

154. Werneck, W

1.".:.. Williamson, "VV

156. Will.. A. \V.

157. „ „
1.08. Zacharias, O.

159. „ „

160. „ „

K'<1

C.

Hydatina senta, Miiller's Archiv. 1857, p. 404. (1 pi.)

Notes on free-swimming Rotifers, Micr. News, 1884, pp. 72, 14f>, 177,

233 ; (with tigs.)
§ Primo elenco d. ltotif. d. Valcuvia, Atti d. Soc. Ital. d. Sci. Natur.

xxi., 1878, p. 320.
§ Rotate urn parasites dea Ncbalies, Comptes Eendus, lxxiv., 1872, p. 1115.
Apsilus lentiformis, Sieb. n. Koll Zeits., I860, p. 34G, (1 pi.)
1'leurotroeha mustcla, Proc. Phil. Soc. Glasgow, xvi., 1885, p. 188, (1 pi.)
Brachionus plicatilis, Sieb. u. Koll. Zeits, xxv., 1874, p. 103.
Some pioints in anatomy of Rotatoria, Trans. Linn. Soc, xxiv., p. 455,

(1. pi.)
§ Zur EntwicMungsgeschichte d. Raderthiere, Zurich, 1852.
Stephanoceros Eichlioruii, Proc. Acad. Nat. Sci. Pa., 1875, p. 121.
Sur line nouvclle espece de Floseularia, Ann. Sci. Nat. Zool, 1838, p. 41.
§ Development of Rotifer Inflatus, Mem. Novorossian Soc, ix., 1884,(1 pi.)
Development of Rotifer Inflatus, Nature, xxxii., 1885, p. 579.
Zur Kenntniss Klcinst. Lebensf, Bern, 1852.
Zur Kenntniss d. Rotatorien, Zool. Anzeig., Oct., 1884, p. 573.
Zur Naturgcsch. d. Rotatoricti, Jenaische Zeits. f. Natur., xix., 1885,

p. 1, (3 pis.)
Note sur L'Hydatina senta, Bull. Soc. Vand., 1875, p. 1G7.
Strophosphara ismailovicnsis, Trans. Nat. Hist. Soc, Moscow, x. p. 9.
A history of Infusoria, including Dcsmidiacece and Diatomacca,

London, 1861.
t § Conochilus Volvox, Naturhistoriker, iii. Jahrg., No. 12, p. 92.
Stephanoceros Eichhornii, Journ. Jioy. Micr. Soc, 1884, p. 169 (1 pi.)
Forms of animal life (Rotifera), Oxford, 1870, p. exxxviii.
Entwicldungsg. d. Brachionus urceolaris, Sieb. u. Koll. Zeits., xxii.,

1872, p. 455, (3 pis.)

Zur Naturgesch. Agyptcns, Akad. d. Wissensch. math, natur. Kl., Wicn,

1854, (7 pis.)
Neue wirbellose Thiere {Rotatoria), Leipzig, 1859, p. 47, (pis. xii.-xv.)
D. Organisation d. Raderthiere, Archiv fur Naturgesch., 1846, p. 67,

(with figs.)
* § Die mihrosTi. Thiere d. Siisswasscraquariums, ii., Die Kaderth.,

Leipzig, 1869, (8 pis.)
Trochosphara aquatorealis, Sieb. u. Koll. Zeits., 1872, p. 311, (1 pi.)
Trochospharamguatorcalis, (Translated), Mon. Micr. Journ,, xiv., 1875,

p. 237, (3 pis.)
Ccphalosiphon limnias, Intellectual Observer, i., 1862, p. 53, (with figs.)
On a species of Triarthra, Quart. Journ. Micr. Sci., i., 1861, p. 132,

(with fig.)
§ On animal life in water containing free acids, Mem. Phil. Soc. Man-
chester, 18*76, p. 185.

§ Ub. d. Mdnnchen : v. Diglena dc, Tageblatt d. Leipzig. Naturforsch.,

1872, p. 140.
On a new Melicertian dc, Journ. Quek. Micr. Club, 1868, p. 124, (2 pis.)
Stephanops longispinatus dtc, Quart. Journ. Micr. Sci., vii., 1867,

p. 252, (with figs.)
Die Rotatorien dx. : v. Pcst-Ofcn, Verhandl. d. Zool. hot. Gesellsch.

Wicn, xi., 1861, p. 183.
Le si/steme circul. d. Lacinularia socialis, Ann. Sci. Nat. Zool., xiv.,

1850, p. 146.
§ Floseularia cornuta, LTnstitut, 1851, xix. p. 223.
.1 wu/rcea Glcasonii, Proc. Amer. Soc. Microscopists, Chicago, 1883, p. 118.
Drilophaga Bucephalus, Verlag d. konigl. bohm. Gesellschaft, 1'rag,

1883, p. 391.

Ub. d. si/stem. Stcllung d. Rddcrth., Sieb. u. Koll. Zeits., vii., 1856,

p. 111.'!.
Zur Oologie d. Raderth., Mem. Acad. Imp. St. Petersb., 1862, p. 1, (1 pi.)
Zur Oologie d. Rddcrth. Zweiter Beitrag, Bull. Acad. St. Petersb., 1865,

p. 203, (1 pi.)
§ Sur Vorganisation des Rotifcrcs, LTnstitut, x. 1842, p. 174.
M 1 1 icerta ringens, Quart. Journ. Micr. Soc, i., lH.Vi, pp. 1 & 05, (1 pi.)
CEcistea fiVula, Midland Naturalist, i., 187H, p. 302.
G^cistcs longipcs and (E.pilula, Midland Naturalist, i., 1878, p. 317, (1 pi.)
Rotifer vulgaris, (Eeproduction and Development &c), Sieb. u. Koll.

Zeits., xli., p. 226.
Rotifer vulgaris, (translated), Ann. Nat. Hist., 1885, p. 125, (with figs.)
§ Relationship of Rotifera mid Nematodes, Biol. Centralbl.,v.,18€ 5, p.228.
Relztionship of Rotifera <n<d Nematodes, abstracted in Journ. Boy.

Micr. Sue' 1H85,p. 1006.

GENERAL INDEX.

Vol.

Page

Vol.

f age

1 Vol.

Fage

Classitication ....

30

(Esophagus ....

i

7

Types of foot

i

26

Egg

10

Reproductive system

l

10

Types of ciliary wreath .

i

27

Glxnds .

7

Rotifer n, defined .

l

4

Types of trophi

l

'28

Male

10

— typical one described

i

5

Vascular system, brief de-

Mas tax

0

Rotifera, discovered before

scription of ...

l

8

Muscles

8

1838

i

17

— its functi ra (C.T.II.) .

ii

135

Nervous system

9

Setigerous sense-organs .

ii

139

(1UI.G.) . . .

ii

138

Organs of sense

9

Stomach and intestine .

l

7

INDEX OF THE ORDERS, FAMILIES, GENERA, AND SPECIES

DESCRIBED IN THIS WORK.

Actinurus

Actinurus neptunius
Acyclus .
Acvclus inquietus
Adinetadaj
Adineta . .
Adineta vaga .
Albertia .
Albertia intrusor

— naidis
Anura;ada3
Anuruea .

Ann rasa aculeata

— acuminata .

— brevispina .

— cochleaiis .

— curvicornis .

— fissa

— hypelasma .

— lon^ispiua .

— serrulata

— apinosa

— tecta .
Apsilus .
Apsilus lentiformis

— bipera
Ascomorpha anglica

— uennanica .

— helvetica
— - saltans
AsplanchnadiE
Asplanchna
Asplanchna Bowesii

— Brightwellii

— Ebbesbornii

— myrmeleo .

— priodonta .
Balatro calvus.
Bdelloida
Brachionidae .
ISrachiouus
Brachionus ampl

ceros .

— angularis .

— Bakeri

— dorcas

— Mulleri

— ocin

— pala .

— polyacanthus

— rubens

— ureeolaris .
Callidina
Callidina bidens

— bihamata .

— elegans

— parasitica .
Cathypnadas .
Cathvpna
Cathypna luna

— rusticula

— sulcata

he

to

10*

108

57

57

11-2

112

112

15

15

10

122

122

123

125

123

124

r>2

123

123

125

124

125

123

58

5.S

59

122

124

124

124

11!)

120

122

122

120

131

123

134

95

116

116

117

120

120

120

118

119

119

118

117

117

119

119

118

109

109

111

109

110

94

94

94

95

9

X

6

D

3

X

10

XVII
XVII

13
14

XXIX

3

XXIX
XXIX

7
9

XXIX

6

XXIX

8

XXIX

10

D

u

4
5

XTI
XI

1
3

XTI
XXX

2
6

XXVII

XXX

XXVII

XXVIII

XXVII

XXX

4
9
8
4

7
8

XXVII

3

XXVII

A
XXVII

5
1

6

X
X

8

7

X

9

XXTV
XXIV

XXIV

4
6

5 |

Cephalosiphon
Cephalosiphon can
didus .

— limnias
Cochleare
Cochleare staphy

linus

— turbo . .
Ccelopus .
Coelopus bracbyurus

— cavia .

— minutus

— porcellus

— tenuior .
Coluridae .
Colurus .
Colurus amblytelus

— bicuspidatus

— caudatus

— coelopinus .

— dactylotus .

— deflexus

— obtusus

— pedatus

— uncinatus .
Conochilus
Conochilus dossua

rius

— volvox
Copeus

Cope us caudatus

— cerberus

— bibiatus

— pichvurus .

— spicatus
Cupelopagus bucine

dax
Diaschiza
Diaschiza exigua

— Hoodii

— pasta .

— semi-aperta

— tenuior

— valga .
Dictyophora vorax
Digleua .
Diglena aurita

— biraphis

— catellina

— caudata

— circinator .

— clastopis

— forcipata

— gibber

— giraffa

— grand is

— permollis .
Dinocharidae .
Dinocharis
Dinocharis Collinsi

— pauper

— pocillum .

— ietractis
Diplax .
Diplax compressa

o

>

60

C3

s

i

77

i

79

l

77

VI

n

111

ii

111

XXVI

n

111

XXVI

n

67

u

69

XX

n

69

XX

n

70

XX

n

67

XX

u

68

XX

n

101

n

101

n

104

XXVI

ii

102

XXVI

n

104

XXVI

ii

105

XXVI

n

105

XXV

u

102

XXVI

ii

103

XXVI

u

105

XXV

u

103

l

89

i

91

VIII

l

«9

VIII

u

28

n

33

XVI

n

34

XVI

u

28

XVI

n

31

XVI

n

29

XVI

i

58

ii

"

ii

78

XXII

n

79

XXII

n

79

XXII

n

80

XXII

ii

81

XXII

n

1 1

XXII

l

58

n

48

n

47

n

53

XIX

n

53

XIX

n

51

XIX

n

50

XIX

a

52

XIX

n

50

XIX

n

49

XIX

n

51

XIX

n

48

XIX

u

52

XIX

n

70

n

71

n

72

XXI

n

72

n

71

XXI

n
ii

72

81

XXI

»

82

XXII

9

in

21
22
2d
18

in

5
2
6
4

12

1

3
13

13
15
11
10

14

12

3
10
8
4
5
2
7
9
6
11

1

"3

o
so

C3

V

*->

60

ii

PL,

5

s

Diplax trigona

82

XXII

9

Diplols .

ii

86

Diploia Uaviesia? .

ii

87

XXIV

3

— propatula .

ii

87

XXIV

2

Distemma

ii

54

Distemina Collinsii.

ii

55

XVIII

13

— forticula

ii

41

— labiatum .

ii

56

XVIII

12

— raptor

ii

54

XIX

1

Distyla .

ii

96

Distvla flexilis

ii

97

XXIV

7

— Gissensis .

ii

96

XXIV

8

Diurella rattu'.us

ii

67

— tigris .

ii

05

Drilophaga buce-

phalus

ii

134

XXX

5

Enteroplcea hyda-

tina

ii

10

Eosphora

ii

47

Eosphora aurita

ii

47

XVII

10

Eretmia .

ii

128

Eretmia cubeutes .

ii

128

XXIX

11

— pentathrix .

ii

128

XXIX

12

— tetrathrix .

ii

134

XXVII]

1

— trithrix

ii

134

XXVIII

2

Euchlanida?

ii

88

Euchlanis

ii

K8

Eucblania deflexa .

ii

92

XXIV

1

— dilatata

ii

90

XXIII

5

— luna .

ii

94

— lyra .

ii

89

XXIII

1

— mncriira .

ii

91

XXIII

6

— piriformis .

ii

93

XX III

2

— triquetra

ii

91

XXIII

4

— uniseta

ii

92

XXIII

3

Flosculariadae .

i

43

Floscularia

i

43

Floscularia algicola

i

54

I

3

— ambigua

i 53

I

2

— appendiculata

i

51

— calva .

i

56

III

3

— campanulata

i

52

I

1

— cornuta

i

51

I

7

— coronetta .

i

49

I

5

— cyclops

i

51

I

6

— edentata

i

57

III

4

— Hoodii

i

55

II

5

— longicaudata

i

53

I

4

— longilobata .

i

49

j — mira .

i

50

III

1

— mutabilis .

i

56

III

2

— ornata

i

50

I

9

— proboscidea

i

52

— regal is

i

49

I

8

i — trifolium

i

54

— trilobata

i

54

II

6

Furcularia

ii

40

j Furcularia aequalis .

ii

46

XVIII

15

1 — Boltoni

ii

45

XX

2

— cosca . .

ii

42

XX

4

— ensifera

ii

43

XX

3

— forticula

ii

41

XX

1

— gibba

ii

43

XIX

13

■— gracilis .

ii

42

XIX

14

— longiseta .

ii

46

XVIII

16

141

THE ROTIFERA.

5

51

- a.

3

ti

c a

<Zi

> P*

5

15

> s

5

£

ii 112

£

E

Furcularia marina .

ii 11

X'X

Notommata ansata .

ii 21

XVII

3

l'tcrodina

- micropua .

XIX

12

— aurita

ii 21

XVII

0

Pterodina clypeata.

ii 114

XXVI

14

— Reinbtrdti .

i i 15

— brachionus .

ii 11

— elliptica

ii 111

XXVI

17

Hertwiyia volvoci-

— bracbyota .

ii 24

XVII

1

— mueronata .

ii 111

XXVI

15

col«

ii 39

— centrura . »

ii 28

— patina

ii 112

XXVI

11

Hixarthra polyptera

n l:;:;

XXX

2

— clavulata .

ii 12

— truncata

ii 115

XXVI

16

I I v. lit inaihu .

ii 9

j — collaria

ii 27

XVI

6

— valvata

i 113

XXVI

13

liydaiina

ii 9

— copeus

ii 28

Pteroessa

i 4

11 \ datina senta

ii 9

XIV

1

— cyrtopna

ii 22

XVII

7

Pteroessa surda

l 4

XIII

9

U-loricata

i 117

— decipiens .

ii 30

Ptygura melicerta .

i 134

Lacinularia

i 8,">

— felis .

ii 30

Rattulidse

i 59

Laciuulaiia albo-

— forcipata .

ii 23

XVIII

1

Rattulos .

i 64

Havicana

i 87

— gibba .

ii 37

Rattulus calyptus .

i 66

XX

16

— aocialia

i 85

VIII

1

— granulans .

ii 12

— cimolius

i 66

XX

14

Lepadella

ii 106

— hyptopua .

ii 13

— helmiuthodes . i

i 65

XX

17

Lepadella oralis

i 106

— lacinulata .

ii 26

XVII

9

— lunaris

i 67

l.inuiias .

i 7.".

— longiseta .

ii 46

— sejunctipes.

i 66

XX

15

Limniaa annulatos .

i 77

VI

2

— myrmeleo .

i 123

— tigris . . . i

i 65

XX

13

— ceratophylli

i 75

VI

1

— naias . . .

ii 25

XVIII

2

Rbinops . . . i

i 10

— social is

i 76

— parasita

ii 39

Khinops vitrea . i

i 10

XIV

2

Loricatn .

i 59

— petromyzon

ii 38

Rbizota .

i 43

M istigocerca .

i 59

— pilariuB

ii 23

XVII

5

Rotifer .

i 103

Ma.-tigoccrca bicor-

— sacci^era .

ii 24

XVII

2

Rotifer citrinus

i 105

11 is

i 63

XX

5

— Sieboldii .

i 123

— hapticus

106

X

3

— carinata . . i

i 60

XX

7

— spicata

ii 29

— macroceros .

105

X

5

— clou xata . . i

i 02

XX

8

— syrinx

i 123

— macrurus .

i 107

X

4

— lophoeasa .

: 00

XX

10

— tigris .

ii 65

— motacilla .

i 105

— macera . . i

i 61

XX

12

— tripus

ii 22

XVII

4

— tardus

i 105

X

1

— rattus . . i

i 62

XX

9

— tuba .

ii 26

XVII

8

— vulgaris

i 104

X

2

— sci|iio . . . i

i 61

XX

11

— vermicttlaria

ii 36

Sacculus .

i 124

— Btylata . . i

i M

XX

6

— Werneckii .

ii 134

Sacculus viridis

i 124

XI

2

sfegalotrocha .

i 86

XTotops .

ii 11

Salpinadse . . i

i 77

Biegalotrocha albo-

Xotops brachionus .

ii 11

XV

1

Salpina . . . i

i 82

flavicans

i 87

VIII

2

— clavulatus .

ii 12

XV

3

Salpina brevispina . i

i 84

XXII

4

— socialis

i 85

— hyptopua .

ii 13

XV

2

— eustala . . i

i 85

XXII

5

— velata

83

(Ecistes .

i 79

— maciacantha . i

i 84

XXII

6

— volvox

i 89

CEcistes bracbiatus

i 83

IX

2

— mucronata . . i

i 83

XXII

1

Melicertada .

67

— crystallinus

i 80

VII

3

— mutica . . i

i 86

XXII

3

uelicerta

07

— intenncdius

i 80

VII

5

— redunca . . i

i 86

Uelicerta oephalo-

— Janus.

i 74

— spinigera . . i

i 84

XXII

9

BipfaoD .

77

— longieornis

i 82

VII

6

— sulcata . . i

i 86

XXII

7

— ceratophylii

7.5

— loagipes

i 84

— ventralis . . i

i 85

— conilera

72

V

2

— pilula .

i 82

VII

2

Scaridium . . i

i 73

— crystalline

Ml

— ptygura .

ii 134

XXX

3

Scaridium eudacty-

— janus .

74

VII

1

— serpentinus

i 80

IX

1

lotum . . . i

i 74

XXI

4

— pilula . . . i

82

— Stygis

i 85

IX

3

— longicauduin . i

i 73

XXI

5

— ptygura

83

— umbella

i 84

VII

4

Scirtopoda . . i

i 131

— ringens

70

V

1

— velatus

i 83

D

8

Scison Grubei . i

i 134

XXX

4

— socialis

82

Pedalionida .

ii 131

Squamella . . i

Kill

— (ubicolaria . i

72

V

3

Pedalion .

ii 132

Squaniella bractea . i

i 109

— tyro .

73

l'edalion miruni

ii 132

XXX

1

Stephanoceros. . i

60

afetopidia . . i

i 106

Pedetes .

ii 8

Stephanoceros Eich-

M'lopiiliaacuminata i

i i(i7

XXV

9

Pcdctcs saltator

i 8

XIII

10

liornii . . . i

60

IV

1

iir.i. ;.< i . . i

i III!)

l'hilodinada) .

i 97

— glacialis . . i

60

— lepadella . . i

i 106

XXV

0

Philmlina

i 97

— Iloratii . . i

49

— oxysternum . i

i 107

x x v

8

Philodina aculcata.

i 101

IX

5

Stcphanops . . i

i 75

— rhombuidea . i

08

XXV

10

— citrina

i 100

IX

6

Stephanopa armatus i

i 77

— solidus . . 1 i

106

X X V

11

— erythrophthalma

i 99

— bifurcus . . i

i 77

— triptera . . 1 i

108

XXV

7

— megalotrucha

i 101

IX

7

— cbhena . . i

i 76

XXI

9

Micrucodi lae . . j

118

— roseola

i 99

IX

4

— lamellaris . . i

i 75

XXI

7

Microcudon . . i

118

— tulxrcula'a

i 102

— longispinatus . i

i 77

Microcodon clavoa . i

1 18

XI

1

I'leurotrocha .

i 19

— niuticus . . i

i 75

XXI

6

Monocerca . . i

59

Pleurotrocba con-

— unisctatus . . i

l 76

XXI

8

Monocerca bicornia i

63

stricta

i 19

XVIII

3

Strophosphsera is-

— porcellua . . i

Ii7

— gibba .

i 20

XVIII

5

mailoviensis . i

89

— rati us . . i

02

— lepi lira

i 20

XVIII

4

Synchetads . . i

124

— Btylata . . i

111

I'loi'ina .

i 117

Synchajta . . i

125

Monoatyla . . i

97

I'olyartbra

i 3

Synchajla baltica . i

126

XIII

1

Monoatyla bulla . i

99

XXV

1

Polyarthra platy-

— niord ix . . i

125

— cornnta . . i

98

X X V

1

ptera . . . i

i 3

XIII

5

— oblonga . . i

127

XIII

4

— Lordii . i

99

X X V

5

• - trigla . . i

i 3

— pectinata . . i

125

XIII

3

— lonaria . . i

XXV

2

Polychstua spinu-
losis . . . 1

— treraula . . i

128

XIII

2

— qnadridentata . i

LOO

XXV

8

i 72

Taphrocampa . . ii

16

Monura . . . ii

109

— BubquadratuB . i

i 72

Taphrocampa annu-

Munura colurus . i

109

XXVI

7

I'onipholyx . . i

i 115

losa . . . ii

16

XVII

12

Mytilia . . . i

110

Pompholyx com-

— Saundersia; . ii

18

XVII

11

Mytilia Tavina . u

no

XXVI

8

planata . . i

i 1 1.,

XXVII

1

TriarthradsB . . ii

3

X'ltcll-i . . , j]

121

— sulcata . . i

i 116

XXVII

2

Tiiarthra . • ii

5

Notena quadric imis i

Xotll ■lc;l . . j,

121

XXVIII

5

Proalea . . . i

i 36

Triarthra brcviseta ii

7

XIII

7

1 2fi

Proales decipiens . i

i 36

XVIII

6

— longiseta . . ii

6

XIII

6

Notholca acuminata ii

125

XXIX

1

— felia . . . i

i 36

XVIII

17

— mystacina . . ii

7

XIII

8

— longiapina . . ii

1*5

XX VIII

6

— gibba . . i

i :;7

XVIII

B

Triophthalmua dor-

ipha . . ji

123

XXIX

1

— para.sita . . i

89

XVII]

H 1

Bualia . . . ii

56

X V i II

14

— ib.il.is.-ia . . ii

. ri

Notommata . . u
Xotommata equal

127

1 1

WIN

2

- petromyzon . i
Bordida . . i

38

:t7

XVIII
Will

9

7

Trocbospha i i i
Troi hosphtera sequa-

88

20

— tigridia . . 1 i

38

XVIII

10

torealia . . i

88

D

11

16

Pterudinada . . i

111

Tubicolaria naias . i

72

PLATE XXVI.

1. Colurus deflexus

. dorsal view

. G

la. „ „

. side view, head retracted

. G

2. Colurus bicuspidatus

. dorsal view

. G

2<z. ,, ,,

. side view

. G

3. Colurus obtusus

. side view, head retracted

. G

3a. ii h

. side view, head protruded

. G

36. „ „

. ventral view

. . G

OC. n ,|

. obliquely ventral view

. G

4. Colurus ccelopinus

. side view

. G

4a. „ „

. extremity of foot, and toe

. G

46. „ „

. junction of foot and toe .

. G

5. Colurus amblytelus

. ventral view .

. G

5a. H ii

. side view

. G

G. Colurus caudatus

. ventral view ....

. G

6a. „ „

. side view

. G

66. „ „

. rear view

. G

7. Monura colurus

. side view, head protruded

. G

7a. „ „

. side view, head retracted

. G

8. Mytilia Tavina

. ventral view .

. G

8a. ,, ,,

. side view, head and foot protruded

. G

86. „ „

. side view, head and foot retracted

. G

8c. „ „

. trophi .....

. G

9. Cochleare staphylinu

s . dorsal view ....

. G

9a. „

. side view ....

. G

10. Cochleare turbo

. dorsal view ....

. G

10a. „ „

. side view ....

. G

11. Pterodina patina

. dorsal view ....

. H

Ha. „ „

. ventral view, head retracted .

. H

116.

. side view .

. H

lie. „ „

. front view

. H

12. Pterodina patina (aval

riety) dorsal view .

. H

12a. „ „

. ventral view, head and foot retracte

1 .

. H

13. Pterodina valvata

. ventral view .

. H

13a. „ „

. dorsal view, lorica folded .

. H

14. Pterodina clypeata .

. dorsal view .

. G

14a. „ „

. dorsal view, head retracted

. G

15. Pterodina mucronata

. dorsal view . . . . .

. G

15a. „ „

. ventral view, lorica . . . .

. G

16. Pterodina truncata .

. ventral view . . . . .

. G

17. Pterodina elliptica .

. lorica, ventral view .

. H

I

I .

u

[

RPATINA.(fc/0

■

PLATE XXVII.

1. Pompholyx cornplanata . dorsal view, extended

.

. G

la- ii »

. dorsal view, retracted .

. G

16. n ii

. front view .

. G

■!•£• ii >>

. outline of corona

. G

Id, le. „ „

. occipital and pectoral edges

j of 1

srica

. G

2. Pompholyx sulcata

. dorsal view .

. G

2a. „ ,,

. side view

. H

26.

. front view .

. H

2c, 2d. „ ,,

. trophi ....

. G

3. Brachionus pala

. dorsal view

. H

3a. „ „

. ventral view

. H

36. „ „

. side view

. H

3c, 3d, 3e. „

. loricte of three varieties

. H

°J. »i )>

. male ....

. G

4. Brachionus angularis

. lorica, dorsal view

. H

4a. „ „

. lorica, ventral view

. H

5. Brachionus rubens

. dorsal view, extended

. G

5a. ,, „

. dorsal view, retracted

. G

56. „ „

. hind end of lorica

. G

5c. ,, ,,

. end of foot .

. G

5d. „ „

. brain and eye

. H

6. Brachionus urceolaris

. dorsal view

. G

6a. „ „

. male .

. G

7. Brachionus Miilleri

. dorsal view .

. G

7a. „ „

. extremities of lorica

. G

76.

. male .

. G

7c. ,, ,,

. penis and foot

. G

Id.

. spermatozoa

. G

8. Brachionus Bakeri

. dorsal view .

. G

8a. „ „

. male ....

. G

[ V DOMPLANATA 2 P SULI 5 B PALA. 4 B ANGULARIS. 5 B RUBENS 6 B JRCEOLARIS

7 B MiJLLERI 8 B BAKERI

PLATE XXVIII.

1.

Eretmia tetrathrix .

dorsal view

2.

Eretniia trithrix

side view

3.

Brachionus pala

variety ; dorsal view

3a.

)> »

variety ; ventral view

36.

» i)

male, side view

3c.

>! )1

male, dorsal view

3o\

11 ))

female egg

4.

Brachionus Dorcas .

dorsal view

4a.

» )>

side view

46.

» i)

male, dorsal view

4c.

)> )>

male, side view

Ad.

!) )t

vibratile tag .

5.

Noteus quadricornis .

dorsal view ; to show viscera

r>a.

11 1! •

lorica, dorsal view .

6.

Notholea longispina .

lorica, obliquely dorsal view

6a.

>i )>

lorica, side view

66.

»> )i

trunk, dorsal view .

6c.

)» )>

trunk, ventral view

6o\

>> >»

top of lorica, ventral view ; to

show movable flap

G
G
H
G
G

r\
or

G
G
G
G
G
G
H
H
H
H
H
H
H

"■K0— - 5 MACMTONILrS; NOTKUS; JERJETMJIA? N©TM©lL.CAo Ki"'' '

E.TETRATHB.IX2.E TRITHRlX 3 B FA1jA.(?) 4.B . DORCAS. S.NOT. PUADRIC SI H NANA

PLATE XXIX.

1. Notholca scapha .

. dorsal view, extended

. G

1(7. „ „

. dorsal view, retracted

. G

16. „ „

. transverse section

. G

2. Notholca thalassia

. dorsal view .

. G

2a. „ „ .

. lorica, dorsal view

. G

26. ,, ,,

. lorica, side view .

. G

2c. ,, ,,

. lorica, pectoral edge

. G

2d. „ .. .

. tropin .

. G

3. Notholca acuminata

. dorsal view .

. G

3a. ., „ .

. side view

. G

4. Anuraea aculeata .

. dorsal view .

. G

4a. „ „

. side view

. G

46. „

. mastax and tropin

. G

5. Anuraea brevispina

. dorsal view .

. G

5a. „ „

. side view

. G

G. Anuraea hypclasma

. dorsal view .

. G

Oa. „ „

. ventral view, with eggs

attached

. G

66. „

. transverse section .

. G

7. Anuraea cochlearis

. dorsal view .

. G

7a. „ „

. side view

. G

76. „ „ .

. rear view

. G

8. Anurica serrulata

. dorsal view .

. G

oa. ,, ,, .

. lorica, dorsal view

. G

86. „ .

. lorica, side view .

. G

9. Anuraea curvicurnis

lorica, dorsal view

. G

J(l. „ ,,

lorica, side view .

. G

10. Anuraea tecta

dorsal view .

. G

10a. „ „

lorica, side view .

. G

106. „

rear view

. G

11. Eretmia cubeutes

lorica, dorsal view

. G

11a. „

lorica, side view .

. G

L2. Eretmia pentathrix

lorica, dorsal view

. G

1 M SC PB ■ ■ A..3NACUM1W ' I LI 5.ABREVISPINA 6.A.HYPE ' M

7.A.C0CHLEARIS 3 A.SERRULATA 9 J RN I 11 5 12. E PENT

H p>]

PLATE XXX.

1. PedalioD mirum

1 i.

lb.

Id.

le.

1/

111.

2,
8.

4.

la,
46.

Hexarthra polyptcra
CEcistea ptygura
Seison Grubci .

5. Drilophaga bucephalua

B.

7.
B.
9.

Balatro calvua .
Copeus Bpicatua
Braohionus Mullen .
Braohionue angnlaria

side view H

dorsal view H

front view H

side view (side limbs removed) showing viscera H

dorsal view, showing muscles . . . H

a, dorsal limb

1, depressors

2, elevators

ft inner lateral limb I *• dfPressors

(4, elevators

6, elevators

^ , , ,- i (7, depressors

o, ventral lrmb J ' r

(8, elevators

The ventral depressors (5, 5), of the outer
lateral limbs, meet a similar dorsal pair on
the mid-dorsal and mid-ventral surfaces ;
and the four together encircle the body.
There is a similar encircling set of four
(1, 1) belonging to the dorsal lirnb.

ventral view, showing muscles . . .11

9, ventral longitudinal muscles for retract-
ing head

side view, showing muscles . . . .11

10, dorsal longitudinal muscles for retract-
ing head

11, right depressor of dorsal antenna

12, circular muscles of the neck

13, right depressor of chin

male, dorsal view ...... H

male, side view H

dorsal view . . . (after Dr. Schmarda)
head, dorsal view, showing hooks . . . H
female, retracted ; side view . \
male, extended; side view . I (after Dr. Clans)
tropin )

side view ; attached to Lumbriculus \ i_ . , \°, '

I Vejdovsky)

ventral view . . (after M. Ed. Claparcde)

side view ........ H

ventral view . . . . . . .11

dorsal view ....... II

aperture for lateral antenna . . . .11

I

Id

1a,

■v

ih

.,

It

If

lb

,^7^V

■ ■

!
I.P.M1RUM II.PQ

■

U3KL ' -

■

The accompanying Title* have been prepared
to enable tho.se who wish it to bind the Text and
Plates in separate volumes.

■B

l\*4

m ' ■ ■

m

THE KOTIFEBA;

OR

WHEEL-ANIMALCULES.

BY

C. T. HUDSON, LL.D. Cantab.

ASSISTED BY

P. H. GOSSE, F.E.S.

WITH ILLUSTRATIONS.

IN TWO VOLUMES.
TEXT.

LONDON :

LONGMANS, GREEN, AND CO

1886.

All rights reserved.

Csecam mihi in cunctis fidem haberi haud postulo ; id tantum optans, ut
continua indagationc ac studio rnea aliquando connrrnentur, aut ine a vero aberrasse
dcmonstretur. Perscrutatoris vel exactissimi, et quainvis suuimarn adhibeat,
attentionem fugere aliquando quiedam possunt ; et casus noiinunquam fortuito
nobis offert, <JU8B intensissima sa?pe cura frustra qusesivimus. — J. Baster.

C'est dans les livres de la Nature, qu'on doit lire, quand on veut travailler sur
l'Histoire Naturelle ; mais on ne peut pas y lire, quand on veut. II faut des lieux,
des saisons et des circonstances favorables pour faire des observations necessaires.
Quelques fois a la verite on peut aider a faire naitre des circonstances heureuses,
mais plus souvent il faut que le hazard nous serve. — Reamur.

THE EOTIFBEA;

OR

WHEEL-ANIMALCULES

BY

C. T. HUDSON, LL.D. Cantab.

ASSISTED BY

P. H. GOSSE, F.E.S.

WITH ILLUSTRATIONS.

IN TWO VOLUMES.
PLATES.

LONDON :

LONGMANS, GREEN, AND CO.

1886.

All rights reserved.

Those viewless beings,
Whose mansion is the smallest particle
Of the impassive atmosphere,

Enjoy and live like man :
And the minutest throb,
That through their frame diffuses
The slightest, faintest motion,
Is fixed, and indispensable,
As the majestic laws
That rule yon rolling orbs.

Shelley.

Qui curiosus postulat totum sus?
Patere menti, ferre qui non sufficit
Mediocritatis conscientiam suae,
Judex iniquus, sestimator est malus
Suique naturseque; nam rerum parens,
Libanda tantum quae venit mortalibus,
Nos scire pa\iea, multa mirari jubet.

Grotius.

m

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DATE DUE

JUN 1 5 200C

11 1M / 1 /ulll)

DEC 2 1 zliOO

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SEP 0 7 2011

Brigham Young University

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■ ■ ■ 9

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BRIGHAM YOUNG UNIVERSITY

3 1197 20639 9427

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