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TREASURY DEPARTMENT
Public Health and Marine-Hospital Service of the United States

HYGIENIC LABORATORY.— BULLETIN No. 60

April, 1910

A STUDY OF THE ANATOMY OF WATSONIUS
(n. g.) WATSONI OF MAN

AND OF

NINETEEN ALLIED SPECIES OF MAMMALIAN TREMATODE
WORMS OF THE SUPERFAM1LY PARAMPHISTOMOIDEA

CH. WARDELL STILES

and

JOSEPH GOLDBERGER

WASHINGTON

GOVERNMENT PRINTING OFFICE

1910

TREASURY DEPARTMENT
Public Health and Marine-Hospital Service of the United States

HYGIENIC LABORATORY. — BULLETIN No. 60

April, 1910

A STUDY OF THE ANATOMY OF WATSONIUS
(n. g.) WATSONI OF MAN

AND OF

NINETEEN ALLIED SPECIES OF MAMMALIAN TREMATODE
WORMS OF THE SUPERFAMILY PARAMPHISTOMOIDEA

CH, WARDELL STILES

and

JOSEPH GOLDBERGER

WASHINGTON

GOVERNMENT PRINTING
1910

OFFICE

Of PHYSICIANS

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ORGANIZATION OF HYGIENIC LABORATORY.

Walter Wyman, Surgeon-General,
United States Public Health and Marine-Hospital Ser vice.

ADVISORY BOARD.

Lieut. Col. Walter D. McCaw, Surgeon, U. S. Army; Surgeon Charles St. J. Butler,
U. S. Navy; Dr. A. D. Melvin, Chief of U. S. Bureau of Animal Industry, and John

F. Anderson, U. S. Public Health and Marine-Hospital Service, ex officio.

Prof. William H. Welch, Johns Hopkins University, Baltimore., Md.; Prof. Simon
Flexner, Rockefeller Institute for Medical Research, New York; Prof. Victor C.
Vaughan, University of Michigan, Ann Arbor, Mich.; Prof. William T. Sedgwick,
Massachusetts Institute of Technology, Boston, Mass., and Prof. Frank F. Wesbrook,
University of Minnesota, Minneapolis, Minn.

LABORATORY CORPS.

Director. — Passed Assistant Surgeon John F. Anderson.

Assistant director. — Passed Assistant Surgeon Edward Francis.

On leave. — Surgeon M. J. Rosenau.

Senior pharmacist. — Louis C. Spangler, Ph. G.

Junior pharmacist. — C. 0. Sterns, Ph. G.

Artist. — Leonard H. Wilder.

Acting librarian. — E. B. K. Foltz.

DIVISION OF PATHOLOGY AND BACTERIOLOGY.

Chief of division. — Passed Assistant Surgeon John F. Anderson.

Assistants. — Passed Assistant Surgeons Edward Francis, Claude H. Lavinder, L. L.
Lumsden, T. B. McClintic, A. M. Stimson, Carroll Fox, B. J. Lloyd, W. H. Frost,
and Walter D. Cannon, M. D.

DIVISION OF ZOOLOGY.

Professor of zoology.— Ch. Wardell Stiles, Ph. D.

Assistants.— Passed Assistant Surgeon Joseph Goldberger, Charles G. Crane, B. S., and

G. F. Leonard, A. B.

DIVISION OF PHARMACOLOGY.

Professorof pharmacology.— Reid Hunt, Ph. D., M. D.

Assistants.— Atherton Seidell, Ph. D., W. H. Schultz, Ph. D., Worth Hale, A. B.,
M. D., Murray GaltMotter, A. M., M. D., and Martin I. Wilbert, Ph. M.

DIVISION OF CHEMISTRY.

Professor of chemistry. —
Assistants.— Passed Assistant Surgeon Norman Roberta and Elias Elvove, M. S,

CONTENTS.

Page.

List of illustrations ?

Summary ' 9

Introduction H

Tautonymy in genotypes 11

Bibliographic references 11

Terminology H

Supergeneric systematic units 13

Technique 13 .

Paramphistomoidea { 15

Gastrothylacidx 15

Gastrothylacinse • 16

Gastrothylax Poirier, 1883, type crumenifer 16

Fischoederius new genus, type fischazderi 17

F. fischcederi new species 17

F. siamensis new species 28

F. ceylonensis new species 39

Carmyerius new genus, type gregarius Looss ■. . . 50

Synethes new subgenus, type synethes Fischceder 50

Carmyerius new subgenus, type gregarius Looss 50

Gastrothylacias new subgenus, type spatiosus Brandes 51

Gastrothylacides new subgenus, type mancupatus Fischceder. . . 51

Thylogaster new subgenus, type minutus Fischceder 51

Wellmanius new genus, type wellmani new species 51

Wellmanius wellmani new species 51

Paramphistomidse 60

Paramphistominse 62

Cotylophoron new genus, type cotylophorum 63

Cotylophoron colylophorum 63

Cotylophoron indicum new species 63

Paramphistomum Fischceder, 1901, with key to species 73

Paramphistomum subgenus (Fischceder, 1901) 77

Orlhocrr.lium new subgenus, type or ihoccelium 77

Bolhriophoron new subgenus, type bothriophoron 77

Paramphistomum papilligerum new species 78

Cauliorchis new subgenus, type cauliorchis 86

Paramphistomum cauliorchis new species 86

I'liramphistomum crassum new species 101

I "aramphistomum papillosum new species 112

(?) Cauliorchis subgenus 121

Paramphistomum indicum new species 121

Subgenus uncertain 131

Paramphistomum fraternum new species 131

Paramphistomum parvipapillatum new species 143

Paramphistomum shipleyi new species 150

Paramphistomum siamense new species 161

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Paramphistomoidea — Continued. Page
Paramphistomidx — Continued.

Stephanopharynginse jgg

Stephanopharynx Fischceder, 1901 168

Cladorchiinx Igg

Cladorchis Fischceder, 1901 169

Cladorchis subgenus, Fischceder, 1901 169

Slichorchis subgenus, Fischceder, 190J 170

Taxorchis (Fischceder, 1901) 170

Pseudodiscus Sonsino, 1895 170

Pseudodiscus subgenus, Sonsino, 1895 173

Ps. stanleyii 173

Ps. collinsii 187

Hawkesius new subgenus, type hawkesii 200

Ps. hawkesii 200

Watsonius new genus, type watsoni 212

Watsonius watsoni 212

Pseudocladorchis Daday, 1907 232

Pfenderius new genus, type papillatus 232

Pfenderius papillatus 232

Microrchis Daday, 1907 246

Chiorchis Fischceder, 1901 246

Balanorchis Fischceder, 1901 247

(?) Diplodiscinse Cohn 247

Diplodiscus Diesing, 1836 248

Opisthodiscus Cohn, 1904 248

Catadiscus Cohn, 1904 248

Gastrodiscidx new family 249

Homalogaster Poirier, 1883 249

Homalogaster philippinensis 249

Gaslrodiscus Leuckart, 1877 252

List of abbreviations 253

Index to zoological names 254

List of Hygienic Laboratory Bulletins 261

LIST OF ILLUSTRATIONS.

Fig. 1- 10. — Fischcederius fischcederi from Bos kerabau, Ceylon.
Fig. 11- 22. — Fischcederius siamensis from "Cow," Siam.
Fig. 23- 32. — Fischcederius ceylonensis from Bos kerabau, Ceylon.
Fig. 33- 42. — Welhnanius wellmani from Cervicapra bohor, Africa.
Fig. 43- 52. — Cotylophoron indicum from Ovis aries, India.

Fig. 53- 56. — Paramphistomum papilligerum from Cervus eldi, locality not known.

Fig. 57- 70. — Paramphistomum cauliorchis from Bos indicus, India.

Fig. 71- 80. — Paramphistomum crassum from Bos indicus, India.

Fig. 81- 91. — Paramphistomum papillosum from Bos indicus, India.

Fig. 92-102. — Paramphistomum indicum from Bos indicus, India.

Fig. 103-113. — Paramphistomum fraternum from Buffelus indicus.

Fig. 114-122. — Paramphistomum parvipapillatum ix 'om Bos indicus, Siam.

Fig. 123-130. — Paramphistomum shipleyi from Cervus eldi, locality unknown.

Fig. 131-136. — Paramphistomum siamense from Bos indicus var., Siam

Fig. 137-151. — Pseudodiscus stanleyii from Equus caballus, India.

Fig. 152-162. — Pseudodiscus collinsii from Equus caballus, India.

Fig. 163-174. — Pseudodiscus hawkesii from Elephas indicus, India.

Fig. 175-189. — Watsonius watsoni from Homo, Africa.

Fig. 190-202. — Pfenderius papillatus from Elephas indicus, India.

Fig. 203-205. — Homalogaster philippinensis from Bos, Philippines and Siam.

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A STUDY OF THE ANATOMY OF WATSONIUS
(n. g.) WATSONI OF MAN,

AND OF NINETEEN ALLIED SPECIES OF MAMMALIAN TREMATODE
WORMS OF THE SUPERFAMILY PARAMPHISTOMOIDEA.0

By Ch. Wardell Stiles,

Professor of Zoology,
and Joseph Goldberger,
Passed Assistant Surgeon, United States Public Health and Marine-Hospital Service.

SUMMARY.

The present paper contains the results of an anatomical study of one parasite of man
( Watsonius watsoni) and comparison with 19 other closely related trematodes, part of
which were sent to us for determination.

Watsonius watsoni, originally classified as Amphistoma, later as Cladorchis, represents
the type of a new genus. Its testes are one caudad of the other, instead of side by side,
as heretofore interpreted.

The families Paramphistomidx and Fasciolidse should be raised to superfamilies as
Paramphistomoidea and Fascioloidea. Paramphistomoidea contains three families,
Gastrothylacidx, Paramphistomidse, and Gastrodiscidx.

These families may be divided into various subfamilies, genera, and subgenera, as
shown in the table of contents (pp. 5-6) and in the various keys (pp. 15, 16, 50, 61,
62, 63, 74, 131, 173, 247, 249.

Anatomically, the group in question is very interesting, but a careful study of any
given species is exceedingly tedious because of the thickness of the specimens. The
projection method was found to be the most satisfactory in preparing drawings to
illustrate the topography.

Of rather special interest is the perisuctorial cavity, which may be very large in
some species. Dorsal and ventral mesenterium-like bands traverse this cavity, bind-
ing the oral sucker to the body parenchyma. The structure in question is strongly
suggestive of a rudimentary body cavity, the absence of which is characteristic for
the group of Flat Worms, to which these parasites belong.

We have been fortunate in having for study some of Cobbold's original material of
Amphistoma stanleyii and A. collinsii, with the result that we accept Pseudodiscus as a
valid genus. Anatomically, the fact is important that these species show a very com-
plicated structure of the oral sucker and its pouches, the latter being separated from the
former by intermediate bulbs.

Summaries of the separate groups may be found in the respective diagnoses and keys.

" Submitted for publication September 23, 1909.
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INTRODUCTION.

Among the parasites recently sent to this laboratory for determina-
tion have been several species of amphistomes, which prove to be
new to science. In studying them it has been found necessary to
compare certain known forms especially the so-called Cladorchis
watsoni of man. Fortunately for this work, we have had at our
disposal some of Cobbold's original material of species of the little-
known genus Pseudodiscus and one series of sections of the original
material of Cladorchis watsoni.

The study has resulted in certain changes in classification and the
proposition of several new genera and subgenera.

TAUTONYMY IN GENOTYPES.

One of us (Stiles) has upon several former occasions expressed the
view that in the case of genotypes absolute or virtual tautonymy is
exceedingly desirable. In accordance with this view we have,
whenever the occasion presented itself, purposely formed the names
so that either virtual or absolute tautonymy results. A consistent
application of this principle would do much to reduce confusion in
classification.

BIBLIOGRAPHIC REFERENCES.

Bibliographic references and systematic names of parasites refer to
the citations given in Stiles & Hassall's Index Catalogue of Medical
and Veterinary Zoology (Authors, Bull. 39, United States Bureau of
Animal Industry; Trematoda, Bull. 37, Hygienic Laboratory, United
States Public Health and Marine-Hospital Service).

TERMINOLOGY.

As some of the technical terms used in this paper are not in common
use in helminthology, it may be well to give a few words of explana-
tion in regard to them.

Oral sucker and pharynx. — The initial suctorial organ of the diges-
tive tract of trematodes is usually named the "oral sucker," while
the term "pharynx" is reserved for an organ of less constant nature
which develops in the esophagus. In recent amphistome litera-
ture the term "pharynx" has been substituted by authors for the

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"oral sucker" of the amphistomes. We agree with Looss that this
substitution does not appear to be well founded and we therefore
revert to the term "oral sucker."

Acetabulum.— The term "acetabulum" is reserved exclusively
for the "caudal sucker," homologous with the "ventral sucker (aceta-
bulum)" of the distomes.

Evaginations of oral sucker— This is a general term used to desig-
nate any kind of an evagination from the lumen of the oral sucker;
the evagination may be paired or circular.

Bulbs and pouches. — As these terms are used in this bulletin, a
"pouch" is a cecal evagination, regardless of its histological structure
or position relative to the sucker. In some species (as in Pseu-
dodiscus) the pouch is separated from the sucker by a " bulb" namety,
not a cecal structure.

The pouches vary somewhat in histological structure in different
species. The walls usually present a loose mesh or parenchyma-like
texture with few if any muscular elements; in some cases the mesh-
work appears more or less condensed, approaching the structure of
the oral sucker as the latter occurs in Homalogaster philippinensis and
Watsonius watsoni.

The bulbs agree with the oral sucker histologically, whether the
latter be dense or loose in structure.

Testes and testicles. — We favor the use of the term "testis" and
"testes" for the two male glands of the trematodes; if these glands
are divided, as in Pleorchis or as in the cestodes, the subdivisions may
well be called " testicles."

Genital pore. — The genital pore is the opening which leads from the
external (ventro-median) surface of the worm into the genital atrium.

Genital atrium. — This is the cavity or depression into which the
genital papilla projects. Its dimensions vary greatly in the different
forms in which it occurs. In some it is partly divided into a ventral
and a dorsal chamber by a more or less sharply developed projecting
ring.

Porus hermaphroditicus. — The external opening of the ductus her-
maphroditicus is the hermaphroditic pore and usually discharges into
a genital atrium.

Topographic terms. — In a paper now in course of preparation, one
of us (Stiles) is proposing a departure in the topographic terminology
of the trematodes, and some of the terms are used in this bulletin.
In brief, longitudinal and transverse straight lines are drawn at the
periphery of the various organs; the longitudinal lines bound fields,
the transverse lines bound zones. Portions of the body bounded by
other than straight lines (as that portion bounded by the intestinal
ceca) are termed "areas." Organs are then located with reference
to these fields, zones, and areas. Thus, the testicular zones may

coincide, overlap, abut, or be separate; the testicular fields may
coincide, overlap, abut, or be separate. An ovary may be described
as in the pretesticular, testicular, or posttesticular zone, or in the
extratesticular, testicular, or intertesticular field; a given organ
may be in the prebif ureal zone, preacetabular zone, postacetabular,
postovarial, postuterine zone, etc. The body is also divided into five
transverse zones, each representing 20 per cent of the body length;
these zones, beginning at the oral pole, are called the first, second,
third, fourth, and fifth. It is believed that by aid of this system,
descriptions may be made more exact than they frequently are at
present, and that, especially in the case of tabular keys, the system
will be found useful. A key to the figured species of distomes is now
being formed on this principle; a preliminary study, based upon about
150 illustrations, has thus far been found to be very satisfactory.

SUPERGENERIC SYSTEMATIC UNITS.

During recent years, especially since 1898, the tendency in helmin-
thology has been to raise species to generic rank, and genera to sub-
family or even to famhV rank. In this tendency, helminthology has
simply followed in the wake of other specialties in zoology. If in
continuing this tendency we fail to recognize certain other systematic
units, such as the superfamily (ending in oidea), and tribes and sub-
tibes (ending in idi and ini), the danger is present that natural
groups will be separated, units coordinate in rank will not be coordi-
nate in actual value, and the classification will become confused.

It is true that the superfamily and the tribes and subtribes have not
yet been recognized in the International Code, but they have been
used by so many authors that they can be looked upon as recognized
units. We here recognize the superfamily as standing between the
suborder and the family, and we adopt for it the ending (oidea) pro-
posed by Gill. The tribe (ending idi) and the sub tribe (ending ini)
we recognize as standing between the subfamily and the genus.

It would seem to us wise to raise the former trematode families
Fasciolidse. and ParampJiistomidse to superfamily rank Fascioloidea
and Paramphistomoidea, in order to leave room for expansion of
systematic units made advisable because of recent changes in taxo-
nomic conceptions in these groups. The present paper deals entirely
with the Paramphistomoidea.

TECHNIQUE.

The material which forms the basis of this paper consisted, in the
main, either of specimens sent to us for determination or of preserved
specimens forming a part of the helminthological collection of the
United States National Museum. Some of this latter material was

quite old, dating back as far as 1875 (Ps. stanleyii), but was remarkabl y
well preserved. In the beginning of this work, after studying the
external characters of the individuals of a species, we made "toto"
mounts of stained and cleared specimens and a series of transverse
and, if sufficient material was available, of sagittal and frontal sec-
tions. The general topography of the internal characters could more
or less clearly be made out from the "toto" mounts and this would
be corrected or amplified by a study of the serial sections. This
method of procedure is obviously only applicable where several indi-
viduals, at least two, of one form are available for the study of the
internal anatomy. Inasmuch as some of our most valuable material
consisted of forms comprising not more than two individuals and only
one of these was available for such study, the following method of
procedure was devised by one of us (Goldberger) and applied with
exceedingly satisfactory results. The external characters of the
specimen selected were first carefully noted and then such drawings
made as seemed desirable. These always included one of the ventral
and another of the profile aspect, the outlines being made with the
aid of the camera lucida. The specimen was next stained. We
have used both carmine (para-carmine, carmalum, acetic acid alum-
carmine) with and without counterstain (picric acid) and Mayer's
hsemalum, but on the whole the carmine stains without counter
stain gave us the most satisfactory pictures. After staining we
dehydrated with alcohol and cleared in xylol. The cleared specimen
was now examined under the microscope and drawings and notes
made of such points in the internal topography as could be made out.
After this the specimen was infiltrated and embedded in paraffin of a
melting point of 54° C, careful note being taken of the orientation;
this was always such as to give transverse sections at right angles to
the median sagittal plane of the worm. Depending on the size of the
worm the sections were cut at either 10// or 20/z. In this connection
it may perhaps be mentioned that, as has been repeatedly observed
by one of us (Goldberger), the most favorable temperature for obtain-
ing good ribbons of sections of this thickness is between 27° and 29° C.

The next step is the reconstruction of the worm from measurements
of the sections with the ocular micrometer. The reconstruction is
by projection on paper of a series of significant points at selected
levels in either a ventral or a sagittal view. The base line in the
former case may be one of the lateral margins, or, more simply and
equally satisfactorily, the median sagittal plane (represented as the
median longitudinal axis); in the case of the sagittal projection the
profile line of the dorsum is used as the base line. The projected
points belonging to the various organs are connected by lines which
give, in effect, the outline, on a suitable scale, of the projected shadow
of the body of the worm and of the organs or systems of organs. A

convenient scale is 50 for sections of 20 fi and 100 for those of 10 p.
in thickness. On this scale each section is represented in projection
as 1 mm. thick, and consequently the frontal apparent length of the
worm would be represented as equal to the total number of the sec-
tions in millimeters. Given a satisfactory series of sections, this
method enables one to work out the topography of the organs or
systems of organs with a high degree of precision. It must be said,
however, that it is also very tedious and time consuming. Our
figures 1, 2, 23, 24, 45, 46, 61, 62, 72, 73, 83, 84, 94, 95, 105, 106, 139,
140, 192, and 193 were constructed in this way.

PARAMPHISTOMOIDEA, new superfamily.

Superfamily diagnosis. — Tremaioda, Malacocotylca, Digenca: Acetabulum caudo-
terrainal, subterminal, or ventral close to caudal end. Oral sucker and esophagus
present, ceca 2. Hermaphroditic. Genital pore ventro-median, preequatorial, pre-
testicular, preovarial.

Male organs: Testes 1 or 2, usually preovarial.

Female organs: Vitellaria paired.

Type fam i ly . — Paramphistomidse.

This superfamily is practically Paramphistomidse Fischceder. It
should, we believe, be divided into three families, as follows:

Key to families of Paramphistomoidea.

A1. Body discoidal; divided into an anterior (cephalic) and a posterior (caudal) por-
tion; venter with many, large papillae; acetabulum ventral, at caudal end; ven-
tral pouch absent Gastrodiscidx, p. 249.

A2. Body not discoidal, not divided, venter not provided with many large papillae:

B1. Ventral pouch present Gastrothylaeidse, p. 15.

B2. Ventral pouch absent Paramphistomidx, p. 60.

GASTROTHYLACIDiE, new family.

Family diagnosis. — Paramphistomoidea (p. 15): Ventral pouch present.
Type genus. — Gastrothylax Poirier, 1883.

This group has heretofore been considered a genus in the family
Paramphistomidse, subfamily Paramphistominse, but the presence of
a ventral pouch separates it so radically from the other forms that
distinct family rank seems justified. The typical, and thus far the
only, subfamily Gastrothylacinse, contains 13 species, which may be
divided at present into 4 more or less natural groups. At least one
of these groups (type gregarius) will doubtless soon require further
subdivision. The question as to whether these groups should at
present be given generic or subgeneric rank is one upon which there
may be a very legitimate difference of opinion, but we believe that
the entire tendency of the present day, wise or unwise as it may
eventually prove to be, is to consider the differences in question as
generic, and in the present paper we shall so regard them.

GASTROTHYLACINjE, new subfamily.

Subfamily DIAGNOSIS. — Gastrolhylacidx (p. 15): Body elongate, venter Htraight
to concave, dorsum convex, cephalic end attenuate, rather pointed, straight, may
curve slightly dorsad, caudal end slightly attenuate to rounded, usually slightly con-
stricted immediately preacetabular, in transverse section more or less circular but form
influenced by pouch. Ventral pouch opens slightly postoral, extending nearly or
quite to acetabulum. Acetabulum relatively small, terminal to ventro-subterminal,
slightly sunken, margin not raised. Genital pore without sucker. Excretory pore
postvesicular or nearly so, in acetabular zone, caudad of pore of Laurer's canal. Oral
sucker without evagination; esophagus without muscular thickening; ceca narrow,
wavy or not wavy, long or short, end postequatorial.

Male organs: Testes 2, considerably smaller than acetabulum, coarsely lobate, rarely
postovarial, chiefly preovarial, postequatorial, not widely separated from acetabulum;
musculosa never enormous; cirrus-pouch absent.

Female organs: Ovary and shell-gland in testicular or posttesticular zone, never pre-
testicular; vitellaria extend from oral sucker to acetabulum, nearer ventral pouch than
body wall, more ventral than dorsal, follicles in small groups; Laurer's canal anatom-
ically prevesicular, but because of curve may lie partly in vesicular zone; uterus of
2 types (see genera).

Eggs: Operculated (at least in some forms).

Type GEXtus.^Gastrothylax Poirier, 1883.

The four genera here recognized for the subfamily Gastrothylaciwe
may be distinguished by the following key :

Key to genera of Gastrothylacid;e, Gastrothylacin^e.

A1. Vas deferens and cephalic half of uterus in separate, right and left, largely extra-
suctorial fields; uterus crosses to other side near equator of body ; testicular fields

separate, zones coincide; type crumeni/er Gastrothylax, p. 16.

A2. Vas deferens and cephalic half of uterus chiefly or entirely in suctorial field:
jB1. Testicular fields separate (lateral), zones coincide:

Cl. Vesicula seminalis with a straight and a coiled portion; testes in inter, extra,

and cecal areas; type wellmani Wellmanius,a p. 51.

G2. Vesicula seminalis without straight portion; testes inter or postcecal; type

gregarius Carmyerius, p. 50.

B2. Testicular fields coincide or overlap (median), zones coincide or overlap; type
elongatus Fischocderius, p. 17.

GASTROTHYLAX Poirier, 1883.

Generic diagnosis.— Gastrothylacinas (p. 16): Vas deferens and cephalic half of
uterus in separate right and left, largely extrasuctorial fields, uterus crosses to other side
near equator of body. Testicular fields separate, zones coincide and, chiefly, post
cecal; ovary in intertesticular field. Cross section of ventral pouch triangular, with
apex dorsad, base ventrad. Ceca end preovarian, preacetabular, in fourth zone, not
wavy.

Type. — G. crumenifer (Creplin, 1847).

This genus is apparently Asiatic, and at present contains two spe-
cies, which can be easily distinguished by the following key :

Ceca end pretesticular; body 9 to 11 mm. long; type host Bos indicus. [Probably
from Asia] compressus Brandes, 1898.

a In general we prefer masculine endings in zoological generic names,

Ceca end in testicular zone; body 9 to 18 mm. long; type host Bos indicus, Asia; also
in Bos kerabau, Ceylon G. crumenifer (Creplin, 1847).

F1SCHCEDERIUS, new genus.

Generic diagnosis.— Gastrothylacinx (p. 16); Vas deferens and cephalic half of
uterus chiefly or entirely in suctorial field. Testicular fields median, coincide or over-
lap, zones coincide or overlap, one testis more dorsal than the other, inter or postcecal;
vesicula without straight portion. Ventral pouch divides body into 3 longitudinal
body segments, a dorsal segment containing uterus, and 2 ventro-lateral segments.

Type species. — F. fischcederi. Asiatic.

This genus, which we dedicate to Fischoeder (the well-known author
who has done so much to advance our knowledge of the mammalian
amphistomes), contains four very closely allied species, which may be
distinguished by the following key :

a1 Ceca end posttesticular, postovarian, in acetabular and fourth zone; testicular fields
overlap, zones nearly coincide; body 8 to 10 mm. long; type host Palonia frontalis,

Java F. cobboldii (Poirier, 1883).

a 2 Ceca end pre testicular, preovarian, preacetabular:

b1 Genital pore on vertex of prominent hemispherical bulging; testicular fields and
zones overlap:

c1 Ceca end in third zone; ovary and shell gland not intertesticular; body 10 to 20
mm. long; type host " Palonia" frontalis, Java; also in Bos kerabau in China,

and Anoa depressicornis F. elongatus (Poirier, 1883).

c2 Ceca end in fourth zone; ovary and shell gland intertesticular; body 6.4 mm.

long; type host Bos kerabau, Ceylon F . fischaideri, p. 17.

6 2 Genital pore not on vertex of prominent hemispherical bulging; ceca end in
third zone:

c3 Testicular zones overlap; ventral pouch not continued posttesticular; body 6.6
to 15. 5 mm. long; type host Bos sp., Siam F. siamensis, p. 28.

c4 Testicular zones coincide; ventral pouch continued posttesticular; body 6 to 7
mm. long; type host Bos kerabau, probably from Asiatic region.

F. ceylonensis, p. 39.

FISCHffiDERIUS FISCHCEDERI, new species.
[Figs. 1 to 10.]

Specific diagnosis. — Fischozderius (p. 17): Body 6.4 mm. long, 2 mm. broad, 2
mm. thick; buff color (alcohol specimen); rather conical, greatest transverse diameter
near equator, greatest dorso-ventral diameter in caudal third; attenuated cephalad, and
very slightly caudad ; longitudinal axis somewhat curved, concavity ventrad; cephalic
extremity bluntly pointed; caudal extremity blunt; dorsum convex longitudinally;
venter slightly concave longitudinally; transverse sections nearly circular, but tending
toward a bluntly rounded triangle, with apex ventrad, especially in equatorial region.
Surface smooth except for a few blunt papillae in cephalic region and on lip of aperture
of ventral pouch. Opening of ventral pouch 0.5 millimeter from cephalic margin;
pouch begins with a narrow neck, which at the genital pore widens into a large
cavity, extending dorsally to near genital glands, ventrally slightly farther; transverse
section of aperture and neck crescentic, of the cavity rather triangular with apex
ventrad. Genital pore seemingly very slightly postbifurcal on a prominent bulging.
Acetabulum 1.04 mm. in diameter, terminal, slightly sunken below surface of body,
with 0.5 mm. aperture directed caudad but very slightly ventrad. Mouth terminal;
oral sucker 0.6 mm. long, slightly larger than esophagus; perisuctorial cavity roomy;
13893— Bull. 60—10 2

Fig. 2.

Fig. 3.

intestinal bifurcation about one-sixth of body length from oral margin; intestinal
ceca extend to caudal end of equatorial third of body. Excretory pore 0.16 mm.

caudad of pore of Lau-
rer'B canal ; excretory
canal runs ventro-ceph-
alad to dilated vesicle
cephalad of acetabulum.

Male organs: Testes
somewhat lobate, one
ventral of the other, sep-
arated by ovary, one
extending to right the
other to left of median
line, thus zones and
fields overlap; the testes
lie between acetabulum
and fundus of ventral
pouch; vasa efferentia
arise on dorsal aspect,
unite slightly cephalad
of equator of body; vas
deferens much coiled;
pars prostatica less
coiled; ductus ejacula-
torius probably dis-
charges independently
of metraterm.

Female organs: Ovary and shell gland between testes; vitellogene glands consist
of sparsely scattered follicles in
ventrolateral body segments ex-
tending from slightly caudad of
apparent genital pore to acetab-
ulum; uterus extends from shell
gland caudad, dorsally, turns
cephalad, and runs between
vasa efferentia, dips ventrally,
extending cephalad, ventrally
of vas deferens, to genital pore ;
Laurer's canal runs from ovi-
duct dorso-caudad, opens on
plane of cephalic margin of
acetabulum, about 0.16 mm.
cephalad of excretory pore.

Eggs: Few in number, 135
by 75/i in sections.
Type— U.S.B.A.1. 15328.
Habitat. — In (? organ of)
Bos kerabau, from Ceylon.

Source of material. —
The single specimen stud-
ied was taken from bottle numbered 3377, containing a label with
the following legend :

Fig. 4.

Name, Gastrothylax elongatus Poir. Host, Bos kerabau. Locality, Konigsberg,
Tiergarten (from Ceylon). Determined by Fischoeder. Collected by Fischceder.
Presented by Luehe, Juno, L902.

The specimen was sectioned with a view to serving for purposes
of comparison, but was found to differ from G. elongatus in several
respects. Its new number is 15328.

EXTERNAL CHARACTERS.

Size. — The measurements taken from the sectioned specimen
give a length of 6.4 mm. and greatest transverse and dorso-ventral
diameters of about 2 mm. each.

Color. — The specimen was of a buff color.

Form. — In form it closely resembled F. elongatus, being some-
what spindle or cone shaped. While the greatest transverse diameter
was in the equatorial re-
gion, the greatest dorso-
ventral diameter was in
the caudal third of the
body. This appears to
have been brought about
by slight compression or
shrinking from side to side
of the caudal portion. The
longitudinal axis is curved
with the concavity ven-
trad. The cephalic ex-
tremity is bluntly pointed ;
the caudal is broad though
somewhat attenuated as
compared with the equa-
torial region. In the ce-
phalic portion the trans-
verse section is nearly circular but with some flattening ventrally in
the region above the aperture of the ventral pouch (fig. 3); in the
equatorial region the form in transverse section tends to assume a
rounded- triangular outline (figs. 6 and 7) with the apex of the tri-
angle ventrad.

Surface. — The surface cuticle is unarmed; but a few blunt papilla?
were observed on the cephalic portion and on the lip of the aperture
of the ventral pouch (fig. 4).

Ventral pouch. — About 0.5 mm. caudad of the cephalic margin
there is a transverse slit which marks the ventral aspect of the animal
and serves as the aperture of the ventral pouch (see fig. 4). The
lip of the aperture curves latero-cephalad from the median line form-
ing two lateral ridges (see fig. 3), which rapidly fade out. Included
between these ridges is a portion of the ventral aspect of the cephalic

Fig. 5.

extremity which is Battened and continuous with the dorsal wall of
the neck of the pouch. The aperture gives entrance to a ventro-
dorsally narrow passage which extends caudad to the level of the
genital pore, beyond which this neck dilates rather rapidly to form
the body of the pouch (fig. 2). The pouch extends caudad to a point
slightly cephalad of the genital organs. The fundus of the pouch
bulges somewhat cephalo-ventrad into the lumen in such a manner
that the dorsal wall of the pouch is the shortest, the ventral the
longest, and the lateral walls intermediate between the two. A
dorso- ven tr ally very narrow, crescentic, slit-like prolongation of the
pouch extends caudad in front of the ventral testis to the plane of
the caudal aspect of the latter (figs. 2, 8, 9). In transverse section
the aperture of the ventral pouch is a crescentic slit, measuring 0.45
mm. from horn to horn and about 0.1 mm. ventro-dorsally; the canal
above (cephalad of) the genital pore retains the crescentic outline
of the aperture, but below this level it tends to a triangular form,

which becomes well denned
in the body of the pouch.
The apex of this triangle, like
that of transverse sections
of the body of the animal,
is directed ventrad. Corre-
sponding to the position of
the angles of this triangle
the inclosing body is con-
stricted, marking off three
segments, a dorsal and a
right and left ventro-lateral,
of which the dorsal is some-
what the largest (see figs. 6
and 7). In the equatorial
region the longitudinal axis of the pouch and that of the body are
substantially identical.

Genital pore— On the dorsal wall of the neck of the ventral pouch
at the vertex of a large muscular somewhat hemispherical bulging
is the genital pore (figs. 2, 5). The pore leads into an atrium, the
dorsal wall of which is in the form of a papilla, at the vertex of
which is the opening of the ductus ejaculatorius and beneath and
adjacent to this that of the metraterm. In the only specimen avail-
able for study the genital pore seemed to be in a plane slightly post>-
bifurcal. This appears to be due, however, to an artificial crowding
or bending caudad of the hemispherical bulging which bears it. It
is easily conceivable that a crowding or bending in the opposite
direction would bring the pore to, or close to, the aperture of the
ventral pouch.

V.t/ <i£

Fig. 6

Acetabulum,. — This muscular organ, measuring about 1.04 mm. in
diameter, occupies the caudal terminal portion of the body. It is,
Hike that of F. elongatus, dome shaped, having an aperture measur-
iing 0.05 mm., which is directed caudad and, because of the bending
of the body axis, very slightly
ventrad.

INTERNAL ANATOMY.

Digestive tract. — The
bluntly pointed cephalic ex-
tremity is pierced by the
mouth, which leads directly
into a muscular oral sucker
about 0.6 mm. long. This
sucker lies in a large cavity
(p. s. sp. figs. 3, 4), strongly
suggestive of a rudimentary
body cavity, which is trav-
ersed dorsally and ventrally
by mesenterium-like bands Fig. 7.

(m. 6. figs. 3, 4). The lumen of the sucker, in transverse section, is
roughly circular near the mouth, but spindle shaped at its equator
(fig. 3), with the long axis of the spindle in the transverse diameter

^ of the animal; farther cau-

dad this spindle becomes
flattened dorso-ventrally so
that the lumen becomes a
transverse slit, which even-
tually becomes reduced to a
small circular aperture as it
gives entrance to the esopha-
gus. It is provided with a
number of not very promi-
nent papillae. The esopha-
gus, as it leaves the base
of the sucker, describes a
fairly abrupt curve having
its convexity ventrad and
then passes caudo-dorsad to
divide into two intestinal
ceca; the esophagus measures about two-thirds the length of the
oral sucker; dorsally of its cephalic portion is found a well-devel-
oped nerve complex.

tvtf.

The simple intestinal ceca pass for a short distance latero-caudad
then in irregular sinuous course caudad in the dorsal body segment'
They terminate at the junction of the middle with the caudal third
of the body.

The lumen of the oral sucker and that of the esophagus are lined
by a cuticular layer in anatomical continuation with that of the body
surface. It is thin in the sucker, thicker in the esophagus, and ceases
abruptly at the fork. The intestinal lumen is lined by a layer of
epithelial cells.

Genital system.— The two testes, the ovary, and the shell gland
are in the caudal portion of the body between the fundus of the ven-
tral pouch and the dome of the acetabulum, one testis lying dorsally.
the other ventrally of the female glands.

Male organs. — The testes lie in about the same dorso-ventral plane,
the left in front (ventral) of the right and separated from the latter

by the interposition of the
ovary, shell gland, and
the dome of the distended
excretory vesicle. The
ventral testis extends
more to the left of the
median line, while the
greater portion of the dor-
sal testis lies immediately
to the right of this line,
their fields consequently
overlap; the latter testis
lies also in a plane that is
slightly lower (more cau-
dad) than that of the for-
mer, their zones overlap-
ping (figs. 1, 2, 8, 10).
Both glands appear much
shrunken, and each is made up of several lobes; the right is slight lv
larger than the left and the caudo-dorsal aspect of the latter appears
excavated and molded to the contour of the ventro-cephalic aspect of
the distended excretory vesicle (fig. 9). From the dorsal aspect of each
testis there arises a vas efferens. These ducts pass dorso-cephalad, that
from the left or ventral testis describing a somewhat sinuous course
as it curves around to the left of the shell gland and ovary. Near the
dorsum of the animal and in a plane just above (cephalad of) the
testes, these ducts, one on each side of and slightly removed from the
median line, turn directly cephalad and pursue a slightly sinuous
course to the equator of the animal; at this level they begin to arch

Fig. 9.

inward toward the median line and soon unite to form the vas deferens
(fig. 6). In the greater part of their course cephalad they lie more
or less close to the ventro-median aspect of the corresponding cecum
with the uterus between them (fig. 7).

The vas deferens, almost immediately after it begins, develops a
complex coil and its lumen becomes more or less dilated and filled
with spermatozoa; this portion represents the vesicula seminalis.
Soon its walls, which appear as delicate as those of the vasa efferentia,
become abruptly thickened by an enormous increase in the muscular
layers and its lumen becomes much reduced in caliber. This portion
of the vas deferens (pars musculosa) continues the coil begun by the
vesicula, but after

pursuing a course y^ffSS^£l'

cephalad becomes
less and less wind- FlG' 10'

ing and the thickness of its muscular wall slowly diminishes; this
portion represents the pars prostatica. The coils of the vesicula,
musculosa, and the windings of the first portion of the prostatica
lie in the space between the corresponding portions of the intes-
tinal ceca. As the prostatica nears the esophageal fork it tends ven-
trad and eventually reaches the ventral aspect of the fork at which
level it describes a curve in the sagittal plane of the body with the
convexity of the curve cephalad (fig. 2). At the vertex of this
curve the prostatic cells abruptly cease and the duct, which at this
point has become somewhat reduced in size though still with walls
of considerable thickness, turns ventro-caudad, approaches and
then penetrates the base of the genital papilla, at the vertex of which,

cephalad for about
twice as long a dis-
tance as that of the
vesicula, the mus-
cular wall of the
duct becomes en-
closed in a moder-
ately thick layer of
cells. From this
point, which is
about at the junc-
tion of the first
with the middle
third of the body,
the complexity of
its loops becomes
very greatly re-
duced, its course

having become rapidly reduced in size, it opens by a minute pore
just above the aperture of the metraterm (or possibly by a pore that
is common to both ducts). The single specimen available for study
does not show this with sufficient clearness for definite interpretation.
To the portion of the male spermatic canal beyond the prostatica the
name ductus ejaculatorius may be applied.

Female organs. — Lying in the axial region of the body between
the upper (cephalic) portions of the two testes are the ovary and the
shell gland, the latter being close to the left ventro-lateral aspect of
the former (figs. 8, 9). The superior aspect of the ovary lies in a
transverse plane that is slightly below (caudad of) the superior mar-
gin of the ventral and slightly above (cephalad of) that of the dorsal
testis. The oviduct springs from the ventro-caudal aspect of the
left pole of the ovary at the level of the caudal aspect of the shell
gland to which the duct runs and which it penetrates, bending
cephalad as it does so. In the shell gland it is joined by the vitello-
duct. The shell gland is an egg-shaped body, considerably smaller
than the ovary, close to the left ventro-lateral aspect of which it
lies, with its long axis in the transverse diameter of the body of the
parasite and with the broader, more bluntly rounded pole to the left.
It is penetrated by the oviduct and the vitello-duct ; the former at
the caudal and the latter at the left ventro-lateral aspect. The
two unite and the joint duct thus formed passes transversely to the
right and slightly cephalad, forming the ootype in the center of the
gland. Beyond this dilatation the duct is continued as the uterus,
which emerges from the right pole of the gland (fig. 8). From this
point the uterus curves over to the left of the shell gland. As it
skirts close to the left of the shell gland, ovary, and dorsal testis in
its course to the middle line of the dorsal segment some coils dip
caudad to the left of the excretory vesicle. Having reached the
median line it winds its way cephalad first between the vasa efferent ia
then under their arch and close to the ventral aspect of the vas
deferens, retaining this relation to the male genital duct in the
remainder of its course and forming a curve similar to that of the
pars prostatica at the level of the esophageal fork before it, as the
metraterm, penetrates the genital papilla at the vertex of which it
opens either just below and separate from the aperture of the male
genital duct or in common with it.

' The uterine canal contains relatively few eggs; these were most
numerous in the portion nearest the ovary. Measurement of one of
these in section gave a length of 135/z and a width of 75/i. Laurer'a
canal leaves the oviduct from a point close to the shell gland and t hen
passes dorso-caudad to open by a minute pore in the dorso-median
line a little below the superior margin of the acetabulum and about
0.16 mm. above the excretory pore.

The vitellaria consist of sparsely scattered follicles confined to the
ventro-lateral body segments. In a vertical direction they extend
from a little below the level of the genital pore to the level of the
superior margin of the acetabulum. The transverse vitello-ducts
pass transversely inward with a tilt cephalad to unite in the median
line dorsally and slightly caudally of the superior margin of the
ventral testis and just cephalad of the plane of the superior margin
of the shell gland. Their point of union is not dilated into a reser-
voir, but a slender duct is given off which passes at first caudad for a
ver}^ short distance, then to the left, skirting the ventral aspect of the
shell gland which it penetrates near the left extremity and, describing
a sharp curve as it does so, becomes directed to the right and unites
with the oviduct.

Excretory system. — The excretory vesicle is large and distended
and fills the space between the male and female sexual glands above
(cephalad) and the acetabulum below (caudad) (figs, 2, 9, 10). From
its dorsal aspect there springs a short excretory duct which passes
caudo-dorsad to open in the dorso-median line about 0.16 mm.
caudad of the pore of Laurer's canal. The duct is lined by a fairly
thick cuticular layer in anatomical continuation with that of the
general body surface. Two large longitudinal excretory canals are
found at about the level of the esophageal fork, where they lie near
the dorso-lateral aspect of the corresponding ceca. As the intestines
shift latero-dorsad, the canals come to lie first close to the median side
and later close to the ventro-median and ventral aspect of the ceca
(figs. 6, 7). The canals pass caudad to a point in the transverse plane
of the superior margin of the ventral testis, when they bend somewhat
ventrad to empty into the excretory vesicle.

RELATION TO OTHER SPECIES.

This worm seems most closely related to F. elongatus, from which
it differs chiefly in the greater proportionate length of its intestine;
in the position of the ovar}^ and shell gland, which lie between the
upper portion of the testes in this form, whereas in F. elongatus they
are caudad of the dorsal testis.

ILLUSTRATIONS.

Fig. 1. — Frontal projection showing oral sucker (o. s.), esophagus
(es.), intestinal ceca (i.), portion of the uterus (ut), the testes (t.),
vasa eff erentia (v. e.) , and acetabulum (ac.) . a-a, b-b, c-c, d-d, e-e,f-f,
g-g, h-h, planes of section. Enlarged. Original.

Fie. 2. — Profile projection showing oral sucker (o. s.), esophagus
(es.), left intestine (i.), the ventral pouch (v. p.), the genital bulging
with the genital pore leading into the genital atrium (g. a.), the uterus

(ut), shell gland (s. r/.), ovary (ov.), the testes (t), left vas efferens
(v. e.), vesicula seminalis (v. s.), pars musculosa (p. m.), pars prostatica
(p. p.), ductus ejaculatorius (d. e.), Laurer's canal (L. c), excretoiy
vesicle (ex. v.), excretory pore (ex. p.), and acetabulum (ac). a-a,
b-b, c-c, d-d, e-e,f-f, g-g, h-h planes of section. Enlarged. Original.

Fig. 3. — Transverse section at a-a figs. 1 and 2. Shows oral sucker
(o. s.), perisuctorial space {p. s. sp.), and a dorsal dorso-venti al
mesenterium-like strand (m. b.). Enlarged. Original.

Fig. 4. — Transverse section at ~b-b figs. 1 and 2. Shows aperture of
ventral pouch (a. v. p.), papillae on lip of aperture (s. pap.), oral sucker
(o. s.), dorsal and ventral mesenterium-like strands (m. b.), perisuc-
torial space (p. s. sp.). Enlarged. Original.

Fig. 5. — Transverse section at c-c figs. 1 and 2. Shows form of
body, ventral pouch (v. p.), ductus ejaculatorius (d. e.), metraterm
(va.), uterus (ut.), pars prostatica (p. p.), and intestines (i.). En-
larged. Original.

Fig. 6. — Transverse section at d-d figs. 1 and 2. Shows form of
body, form of ventral pouch (v. p.), intestines (i.), excretory canals
(ex. c), the vasa efferentia about to unite (v. e.), uterus (ut.), and
vitellogene glands (v. g.). Enlarged. Original.

Fig. 7. — Transverse section at e-e figs. 1 and 2. Shows form of
body, form of ventral pouch (v. p.) , position and relations of intestines
(i.), excretoiy canal (ex. c), vasa efferentia (v. e.), uterus (ut), and
vitellogene glands (v. g.). Enlarged. Original.

Fig. 8. — Transverse section at /-/ figs. 1 and 2. Shows form of
body, form of ventral pouch (v. p.), position and relation of the testes
(t), ovary (ov.), shell gland (s. g.), transverse vitello-ducts (t. vd.),
the vasa efferentia (v. e.), uterus (ut.) , vitellogene glands (v. g.), ;u id
excretoiy canals (ex. c). Enlarged. Original.

Fig. 9. — Transverse section at g-g figs. 1 and 2. Shows form of
ventral pouch (v. p.), position and relations of the testes (t), dome
of excretory vesicle (ex. v.), ovary (ov.), caudal extremity "of shell
gland (s. g.), oviduct penetrating shell gland (ov. d.), right transverse
vitello-duct (t. vd.), uterus (ut.), and vitellogene glands (v. g.). En-
larged. Original.

Fig. 10. — Transverse section at h-h figs. 1 and 2. Shows position
and relations of the superior margin of the acetabulum (ac), excretory
vesicle (ex. v.), dorsal or right testis (*.), Laurer's canal (L. c), and
uterine loops (ut.). Enlarged. Original.

FISCIUEDERIUS SIAMENSIS, new species.

[Fifts. 11 to 22.]

Specific diagnosis. — Fischcederius (p. 17): Body 6.6 to 15.5 mm. long; buff color
(alcohol specimens); rather spindle shaped, with truncated caudal end, but most
specimens distorted; greatest diameter somewhat preequatorial ; oral end very

bluntly pointed; longitudinal axis straight or slightly curved with concavity ventrad;
transverse sections near both poles circular, but at equator nearly circular or oval to
triangular with apex ventrad. Surface with coarse transverse sulci or striations, best
defined near poles; otherwise smooth, except for papillae at oral pole. Crescentic
opening of pouch varies in position from oral plane to equatorial plane of oral sucker;
neck of pouch with triangular to semicircular outline in transverse section, extends
caudad of genital pore, body of pouch is triangular to circular in outline and extends
nearly to ventral testis, but a ventral prolongation may enter testicular zone; in
equatorial region, longitudinal axis of pouch coincides with axis of body. Genital
pore about 0.7 mm. from aperture of pouch, either bifurcal, or slightly pre or post
bifurcal; a larger external (ventral) and a smaller internal (dorsal)

: atrium present, the latter nearly filled by the genital papilla. Ace-
tabulum 1.5 mm. in diameter, aperture circular, 0.6 to 1.0 mm.,
directed slightly ventrad. Mouth in a crateriform depression; oral

• sucker pyriform, 0.2 mm. long, 0.2 mm. in dorso-v en tral diameter;
perisuctorial space distinct; esophagus about as long as oral sucker;
bifurcation about on plane of genital porejceca short, extend to

■ equator or slightly beyond, tortuous, in longitudinal dorsal body

: segment. Excretory pore dorso-median or right or left, about on
plane of cephalic margin of acetabulum, caudad of pore ofLaurer's

i canal.

Male organs: Testes median, one dorsal of the other, markedly
indented, fields and zones overlap, immediately preacetabular;
vasa efferentia unite in preequatorial body zone about at junction
of cephalic and equatorial thirds; vesicula and musculosa coiled,
prostatica sinuous; ductus ejaculatorius opens separately from metraterm.

Female organs: Ovary in testicular zone and field, dorso-caudad or caudad of dorsal
testis, median, right, or left of median line; vitellaria chiefly in ventrolateral longi-
tudinal body segments, but to some extent in dorsal segment lateral of ceca, extending
about from plane of genital pore to or near the first testis; uterus
extends from shell gland dorso-lateral, may dip caudad, turns ceph-
alad, runs dorsally of testes, under union of vasa efferentia, in
suctorial field to genital papilla, discharging separately from ductus
ejaculatorius; Laurer's canal extends from oviduct in sinuous
course cephalo-dorsad to dorsum, and discharges median or right
or left, in plane slightly cephalad or caudad of cephalic margin of
ovary.
Eggs: Not measured.

Habitat. — In (? organ of) "Cow" (Bos sp.), Phrapatoom Siam.
Type.— U.S.P.H.& M.H.S. 9956.

Source of material. — These worms form part of
a sending by Dr. P. G. Woolley from Phrapatoom,
Siam. The host was given as Bos ("cow").

EXTERNAL CHARACTERS.

Size. — Measurements of 28 specimens show considerable variation
in size. The length varies from 6.66 mm. to 15.5 mm. ; in only 7 of 28
specimens does the length exceed 10 mm.

Color. — The worms (fixed, and preserved in glycerine alcohol) are
of a buff color.

Fig. 12.

Fig. 13.

Form. — Most of the specimens appear more or less distorted;
only a few appear to have preserved what is presumed to be their
natural shape. These show considerable variation (figs. 11-14) in
form; in general, however, this is not unlike a spindle with a trun-
cated caudal extremity. The greatest diameter of this spindle form
is not in the equatorial region of the worm but somewhat preequa-
torial. The cephalic extremity is very bluntly pointed.
The longitudinal axis is straight or very slightly curved
with concavity of the curve ventrad. The caudal ex-
tremity is truncate; it presents the aperture of the ace-
tabulum, the plane of which, being directed with a cer-
tain obliquity from the venter to the dorsum and
downward, appears to be tilted more or less ventrad.

The outline of the worm in transverse section is ap-
proximately circular both at the caudal and the ce-
phalic extremities. In the equatorial region, however,
some specimens show a triangular, some a triquadrant,
and others a more or less circular or oval form. When
triangular, the apex of the triangle is directed ventrad.
This ventrally directed angle is replaced by a vertical
groove in those specimens presenting a triquadrant form.

Surface. — The general cuticular surface is marked by coarse trans-
verse striations or sulci, that are best defined about the cephalic and
the caudal extremities; it is smooth otherwise except at the cephalic
pole where it is beset by short, more or less conical
papillae which are most numerous and most prominent
immediately around the oral aperture. The papillae
measure up to 0.03 mm. in length and up to 0.045 mm.
in width at the base.

Ventral pouch. — The position of the aperture of the
pouch varies ; in some it is in the same transverse plane
as the mouth (fig. 16); in others it is somewhat caudad
of this plane, namely, about in the equatorial plane of
the oral sucker (fig. 15).

The aperture is followed by a passage the dimen-
sions of which increase but slowly up to the level of the
genital pore; beyond this its dimensions increase rapidly
and soon this passage, which may be regarded as the neck, expands
into the body of the pouch. The pouch extends caudad to a point in
a transverse plane slightly cephalad of the ventral testis, though in
some a more or less crescentic slit-like prolongation is tucked in, as
it were, ventrally of this gland.

The fundus of the pouch is in a plane direct ed more or less obliquely
from the dorsum ventrad and caudad so that the dorsal wall of the
pouch is shorter than the ventral.

Fig. 14.

The dorsal wall of the neck of the pouch is arched ventrad, rela-
tively slightly in the vertical, but considerably in the transverse direc-
tion. It differs markedly, however, from the semipedunculated glob-
ular bulging in F. fischcederi (fig. 2) .

The form of the pouch in transverse sections depends somewhat
on the level. The aperture is a simple transverse crescentic slit (fig.
1 5) . At the level of the genital pore the form of the neck of the pouch
is or tends to a triangular outline with the apex ventrad (fig. 17). In
one of the specimens, however, the outline approached more nearly
that of a semicircle, with the arch ventrad.

In the equatorial region of the animal the outline of the pouch va-
ries in different individuals. In some it is triangular; in others it is
almost circular, though in some of the latter specimens the pouch
may present a triangular
outline in a plane farther
cephalad.

At the level of the
cephalic aspect of the
dorsal testis the outline
of the pouch in trans-
verse section also varies
considerably in different
specimens; in some it is
a crescentic slit ; in others,
a caret-like slit, and in
still others more or less
irregularly circular.

In the equatorial re-
gion of the animal the
longitudinal axis of the
pouch coincides substan-
tially with the longitudi-
nal axis of the body. Whatever the form of the pouch in transverse
section, the encircling body is divided into three approximately equal
longitudinal segments by constrictions; one of the latter occupies the
median ventral line and the others the right and left dorso-lateral
regions, respectively (fig. 21). These constrictions correspond in
position to the angles of the triangle when the pouch has this form.

Genital pore. — On the dorsal wall of the pouch, about 0.70 mm.
from the aperture, is the genital pore. It is at about the level of the
esophageal fork in 3 of 7 specimens; in 2 it is above and in 2 slightly
below this level. The pore gives entrance to an atrium which appears
to be divided into 2 chambers by a ring-like projection of the atrium
wall. Of the 2 chambers thus formed, the outer, or ventral, is

much the larger. The inner, or dorsal, is almost completely filled by
the genital papilla, leaving only a narrow slit-like space around the
latter. The genital papilla projects into the chamber from what
would be its dorsal wall. At the vertex of the papilla is the crater-
like orifice of the metraterm and immediately above the latter is the
minute aperture of the ductus ejaculatorius (figs. 17, 18, 19).

The projecting ring on the atrium wall varies considerably in prom-
inence. In some specimens it is very well marked; in others it is but
ill defined and apparently due only to a slight fold or narrow groove
in the atrium wall.

Acetabulum. — This excavated somewhat hemispherical muscular
organ occupies the caudal portion of the body. The terminal aper-
ture is circular, tilted slightly ventrad, and in two sectioned speci-
mens measured 0.6 mm. and 1.00 mm. in diameter, respectively.

Fig. 16.

The muscular dome measured 0.45 mm. and 0.34 mm., respectively,
in thickness in these two sectioned specimens.

The greatest diameter of the acetabulum measured in sectioned
specimens was 1.5 mm. in one and 1.17 mm. in another.

INTERNAL ANATOMY.

Digestive tract.— The vertex of the bluntly pointed cephalic
extremity is more or less depressed in the form of a more or less shal-
low irregularly circular crater, at the bottom of which is the mouth of
the animal . This leads directly into a muscular pyrif orm oral sucker.
The latter lies in a distinct cavity (figs. 15, 16), which is crossed dor-
sally and ventrally by dorso-ventral strands. Besides these strands,

the sucker is attached at both its poles to the body parenchyma.
The lumen of the sucker varies somewhat in form in different individ-
uals. In a general way it is a transversely broad, but dorso-ventrally
i a rather narrow space. In transverse sections the outline of the
I lumen varies at different levels. In the region of the mouth it is
imore or less circular or elliptical; farther caudad, about in the plane
i of the equator of the sucker, the outlines become spindle shaped with
;the major axis of the spindle in a transverse direction. This spindle-
shaped outline is rapidly reduced to a transverse slit, and the slit in
iits turn, as the result of a contraction of its transverse diameter,
I becomes reduced to a small circular aperture which leads into the

Fig. 17.

esophagus. The lumen is lined by a thin cuticle which, over about
the cephalic half, is beset by very minute conical papillae. The esoph-
agus springs from the base of the oral sucker, and for a very short dis-
tance passes caudad in the axis of the latter; then rather abruptly it
turns dorsad with but a slight inclination caudad. Its length is about
equal to but does not exceed that of the sucker and it divides, later-
ally, into two intestinal cecal tubes. The angle formed by the fork
appears to be somewhat in excess of 90°. The lumen is lined by a
thick, cuticular layer.

The intestinal ceca, from their point of origin, pass, at first, latero-
caudad, then directly caudad to terminate about midway between
the cephalic and the caudal extremities. The ceca may extend
13893— Bull. 60—10 3

slightly beyond this point, or they may fall distinctly short of it.
They pursue a somewhat tortuous course in the dorsal body segment
from one-fourth to one-third of the width of the segment mediad of
the constriction marking off this segment from the others. The
lumen of the esophagus is lined with a cuticle-like layer, which ceases
abruptly at the fork. Here it is replaced by a nucleated cell layer
which extends throughout the intestine.

Genital system.— Male organs: The testes lie in the caudal por-
tion of the axial region of the body immediately preacetabular (fig.
22). One is more or less directly dorsad of the other, but in slightly
different though overlapping zones. The dorsal of the two testes is,
as a rule, the one found in the higher (cephalad) of the testicular zones.

Fig. 18.

As a rule the testis from which the right vas efferens springs (the [ ?]
right testis) is also the dorsal (and cephalic) one. In two of eight
specimens studied this arrangement was reversed, the left testis
(namely, the testis from which the left vas efferens springs) being
dorsad and slightly cephalad of the right.

The margins of the testes are markedly indented, the indentations
marking off lobes of different dimensions. From the dorsal or dorso-
cephalic aspect of each testis there springs a vas efferens which passes
dorsad and slightly cephalad. The vas from the ventrally placed
of the two testes, usually the left, describes a curve outward in its
course as it skirts the margin of the dorsally placed gland. At about
the level of the superior aspect of the superior testis the vasa effer-

entia change their course and proceed directly cephalad in the dorsal
longitudinal body segment more or less close to and one on each side
of the uterus. At about the level of the equatorial plane of the body
of the animal the vasa efferentia come into relation with the intestinal
ceca close to the ventro-median aspect of each of which they then
continue on their way cephalad. They maintain this relation for
some distance, then they bend rather abruptly inward toward the me-
dian line to unite and form the vas deferens. This union takes place
at about the junction of the anterior with the middle third of the body.

The vas deferens, immediately after it begins, develops coils as it
winds its way cephalad. These coils show a lumen which is more or
less dilated in different specimens with walls no thicker than those of

Fig. 19.

the vasa efferentia. This is the vesicula and, after proceeding a short
distance, its walls become abruptly thickened by a marked increase
in the muscular layer. This portion is the pars musculosa which also
forms coils as it proceeds cephalad. These coils have a lumen that in
some specimens is little if any smaller than that of the vesicula. This
pars musculosa proceeds cephalad to within a short distance of the
esophageal arch, where its direction is changed to cephalo-ventrad.
At about this point, too, it ceases to form coils and is continued as the
pars prostatica of the vas deferens. The pars prostatica pursues a
more or less sinuous course and is inclosed in a thick layer of cells with
well-defined nuclei. On reaching the base of the genital papilla this
cell layer abruptly ceases. Before this point is reached there is ob-

servable also a gradual reduction in the thickness of the muscular
coat. After penetrating the genital papilla, the wall of this duct,
which now corresponds to the ductus ejaculatorius of other forms'
becomes progressively thinner and its caliber becomes rapidly reduced
in diameter so that at the vertex its opening is but a minute slit above
the largo female aperture.

F( male organs.— The ovary lies in the testicular zone, dorso-caudadj
or directly caudad of the dorsally placed testis whether the latter be
the left or the right. In other respects, however, its position is sub-
ject to considerable variation. In four of seven specimens the ovary
was to the right, though close to the median dorso-ventral line; in
two it was found in the median line, while in one it was to the left
of this line.

The shell gland lies close to the ovary, but in other respects its
relation to the latter varies considerably. In five of eight specimens
the shell gland was found close to the left ventro-caudal aspect of the
ovary, in two it was close to the right ventro-caudal aspect, and in

one instance it was
directly ventrad of
the ovary.

The oviduct
springs from the
ovary and passes to
the shell gland,
which it penetrates.
Variations were ob-
served both as re-
gards the aspect of
the ovary from
which the duct sprang and the path which it pursued in its course to
the shell gland. In six of eight specimens the oviduct sprang from
the left lateral aspect of the ovary, in one from the right, and in one
from the caudal aspect.

The path which the oviduct describes is more or less curved and is
either in a transverse (horizontal) or in a more or less vertical plane.

The uterus emerges from the ventral, right or left lateral, or cephalic
aspect of the shell gland. In none of the specimens studied did it
emerge from either the dorsal or the caudal aspect. From this the
uterus passed to the left dorso-lateral area of the body in seven of the
eight specimens studied by us; in one instance the uterus passed to
the right dorso-lateral region. In these areas the uterus at first may
dip somewhat caudad, then it, turns dorso-cephalad and toward the
median line, passing dorsally of the dorsal testis and of the right or
the left vas efferens, according as the uterus occupied the right or the
left dorso-lateral areas. Having reached the median dorsal line it
pursues a zigzag winding course cephalad with a vas efferens on each

e*.c.

side and passes beneath the arch formed by their union to gain the
ventral aspect of the coiled vas deferens. It maintains this relation
in the remainder of its course cephalad and ventro-cephalad to the
genital papilla, which it penetrates. In this latter portion of its course
the zigzag windings have become markedly reduced. Its terminal
portion, the metraterm, pierces the genital papilla and opens by a
large crateriform pore at the vertex of the latter.

The uterus contains a few eggs and the first portion also some sper-
matozoa; in one case it contained large cells resembling germ cells.
Laurer's canal leaves the oviduct a little before the latter penetrates
the shell gland.
It then passes
to the dorsum
of the animal,
describing a
more or less
sinuous course
cephalo-dorsad
to the right or

left over or be-
neath the ovary
to its pore on
the dorsal sur-
face; the pore
lies in the medi-
an line or more
or less to the
right or left of
it and in a
transverse

plane, which may be slightly above or below the superior margin
of the ovary. In seven of eight specimens this point was more or
less above the superior margin of the acetabulum, while in the
eighth the pore of Laurer's canal was in a plane slightly below the
superior margin of the acetabulum. ,

The vitellaria consist of sparsely scattered somewhat globular folli-
cles, for the most part confined to the ventro-lateral body segments,
but encroaching to some extent on those portions of the dorsal body
segment external to the line of the intestinal ceca. They extend from
about the level of the genital pore to a little short of or occasionally
partly overlapping the zone of the superior testis. The transverse
vitello-ducts pass mediad and slightly caudad from the lateral regions
of the body about at the level of the ovary and ventrad of the latter
to unite at the right or the left of and close to the shell gland, at
which point a somewhat triangular dilatation is formed. From the

Fig. 21.

dorsal aspect of this dilatation (? vitelline reservoir) a relatively slen-
der vitello-duct passes toward the shell gland and skirts one of the
oaudo-lateral aspects of the latter; on reaching the dorso-lateral as-
pect of this gland it curves cephalo-ventrad to penetrate the gland
and then unites with the oviduct in the formation of the ootypc

Excretory system. — In the specimens studied the excretory vesicle
was collapsed or only slightly distended and was placed dorso-cepha-
lad of and at about the level of the dome of the acetabulum. The
excretory duct leaves the dorsal aspect of the vesicle and passes to
the dorsum in a more or less sinuous course, in most cases with a slight
tendency caudad, but in some horizontally, and in others with a slight
tilt cephalad. The excretory pore is caudad of the opening of Laurer's

canal and is about at the
level of the superior margin
of the acetabulum, though
in none of the specimens
was it exactly so; in three
of eight specimens it was
slightly above and in five
slightly below this point.
Usually, also, it is in about
the median dorsal line, but
we found it somewhat to
the right in one instance
and considerably to the
left in another. In each
of two specimens it meas-
ured about 30/x in diameter.

There are two main lon-
gitudinal canals which pass
caudad in the dorsal longi-
tudinal body segment lying
near and ventral of the in-
testinal ceca in the cephalic half of the body, and they maintain this
relative position beyond the termination of the ceca to the excretory
vesicle.

ILLUSTRATIONS.

Fig. 22.

Fig. 11.— Ventral view. Enlarged. Original.
Yig, 12. — Profile view of specimen shown in Fig.
Original.

Figs. 13 and 14.— Profile views to show variation in form

larged. Original.

Fig 15.— Transverse section at level of aperture of ventral pouch.
Shows form of body, surface papillae (s. pap.), form of aperture of

Enlarged.

En-

wentral pouch (a. v. p.), form of oral sucker and its lumen (o. s.),
i perisuctorial space (p. s. sp.), and dorsal and ventral mesenterium-like
strands (m. &.)• Enlarged. Original.

Fig. 16. — Sagittal section through oral extremity. Shows mouth
(m.), oral sucker (o. s.), perisuctorial space (p. s. sp.), aperture and
neck of ventral pouch (v. p.), genital pore (g. p.), genital atrium (g. a.),
genital papilla (g. pap.), intestine (i.), and uterus (ut.). Enlarged.
I Original.

Figs. 17, 18, and 19. — Series of three transverse sections. Show
fform of body, form of neck of ventral pouch (v. p.), knuckle of esoph-
;agus (es.), intestinal ceca (i.), pars prostatica (p. p.) containing
imass of spermatozoa (sz.), separate openings of ductus ejaculatorius
{(d. e.) and metraterm (va.), genital papilla (g. pap.) and genital atrium
ig. a.). Enlarged. Original.

Fig. 20. — Frontal section through oral extremity to show sucker
(o. s.) and perisuctorial space (p. s. sp.). Enlarged. Original.

Fig. 21. — Transverse section to show form of body and of ventral
pouch (v. p.) in equatorial region. Shows also excretory canal (ex. c),
intestines (i.), vasa efferentia (v. e.) and vitellaria (vg.). Enlarged.
(Original.

Fig. 22. — Sagittal section of caudal extremity showing relations of
acetabulum (ac), excretory vesicle (ex. v.), testes (t), shell gland
,(s. g.), and fundus of ventral pouch (v. p.). Enlarged. Original.

FISHffiDEBIUS CEYLONENSIS, new species.
[Figs. 23 to 32.]

Specific diagnosis. — Fischoederius (p. 17): Body 6 to 7 mm. long by 2.56 mm.
broad by 2.52 mm. thick; buff color (alcohol specimen); rather conical, but greatest
diameter about at junction of equatorial and caudal thirds; rather prominently
attenuated cephalad, slightly attenuated caudad; longitudinal axis slightly curved,
concavity ventrad; cephalic end bluntly pointed; caudal extremity rather truncate;
dorsum somewhat convex, venter slightly concave; lateral margins convex longi-
tudinally; transverse sections near both poles nearly circular, but in equatorial region
triangular with rounded angles, apex ventrad. Surface smooth, with exception of a
few papillge around mouth and aperture of ventral pouch. Opening of ventral pouch
0.02 mm. from oral margin; pouch begins with a narrow neck which extends to caudal

i margin of genital atrium (ventral chamber), then dilates into cavity which extends
along dorsal wall to cephalic margin of testes and along ventral wall to equator of

I acetabulum; transverse sections of aperture and neck crescentic, and of cavity rather
triangular with apex ventrad. Genital pore 1.18 mm. from cephalic margin, some-

' what prebifurcal, in esophageal zone; a large external (ventral) and a small internal
(dorsal) atrium present. Acetabulum 1.6 mm. in transverse and about 1 mm. in
dorso-ventral diameter, terminal, slightly sunken in body, its 0.46 mm. aperture
directed caudad and because of curvature of body axis very slightly ventrad. Mouth
terminal, leads directly into oral sucker which is rather elongate pyriform, 0.62 mm.
long, 0.33 mm. broad, 0.3 mm. thick, and lies in a well-developed cavity which is
traversed dorsally and ventrally by mesenterium-liko bands; esophagus relatively
long, 0.72 mm., hence longer than oral sucker; bifurcation at junction of first and second

Fig. 23.

Fig. 24.

fourths of body, ceca short, extend about to junction between third and fourth fifths of
body. Excretory pore dorso-median about at equator of acetabulum and slightly
(0.3G mm.) caudad of pore of Laurer's canal; duct short, vesicle not much distended
in type specimen.

Male organs. — Testes large, indented, one dorsal of the other, immediately pre-
acetabular, median, zones coincide, fields overlap, one testis extending more to the
right, the other more to the left, of median line; vasa efferentia unite at equator of
body; vesicula and pars musculosa well defined and coiled; pars prostatica long,
nearly straight; ductus ejaculatorius relatively short, but distinct, discharges separ-
ately from metraterm.

Female organs. — Ovary and shell gland ventro-caudal of and very much smaller
than dorsal testis; vitellaria in ventro-lateral and dorsal body segments, lateral of
ceca, extending from level of caudal end of pars prostatica into but not beyond equa-
torial third; uterus extends from shell gland dextrad, dips slightly caudad, turns
cephalad, forming loops dorsally of ventral and to right of dorsal testis, expands, passes
under arch of vasa efferentia, then in slightly irregular line, but without loops, it
extends cephalad in suctorial field ventrally of vas deferens, the metraterm discharges
just below ductus ejaculatorius into atrium; Laurer's canal extends from oviduct
dorso-caudad to dorso-median line 0.36 mm. cephalad of excretory pore and about on
plane of cephalic margin of acetabulum.

Eggs: Not observed.

Host. — Bos kerabau, apparently from Ceylon, died in zoological garden in Germany.
Type.— U.S.B.A.I. 15358.

Source of material. — The single specimen studied was taken
from a bottle numbered 3376, containing a label with the following
legend :

Name, Gastrothylax syneihes Fischceder. Cotype. Host. Bos kerabau. Locality,
Kcenigsberg, Tiergarten [Leipzig]. Collected by Fischceder. Determined by
Fischceder. Presented by Luehe; date, June, 1902.

The specimen, after staining with carmine, dehydration, and clear-
ing, was found to differ from Gastrothylax synethes in several respects.
It was then numbered 15358, sectioned, and studied in detail.

EXTERNAL CHARACTERS.

Size. — The alcohol specimen measured 7 mm. in length and 3 mm.
in greatest width. Measurements from sections give 5.98 mm.
length, 2.56 mm. greatest width, and 2.52 mm. greatest dorso-
ventral diameter.

Color. — The worm was of a buff color.

Form.— In a general way this specimen resembles both G. synethes
and G. elongatus. Its greatest transverse and dorso-lateral diameters
are at about the junction of the equatorial with the caudal third of
the body. From this region toward the poles these diameters
become progressively reduced, markedly toward the oral, slightly
toward the aboral pole.

The longitudinal axis is slightly curved with the concavity ventrad.

In transverse section the outline of the body near the oral and
aboral extremities is substantially circular (figs. 25-27, 30-31),

i though just above the aperture of the ventral pouch the venter is
I flattened. In the equatorial region (figs. 28, 29) it is triangular in
t'forin with rounded angles, one of which occupies the median ventral
; longitudinal line.

Surface. — The surface cuticle is unarmed, but there are a few
i minute papillae at the oral pole immediately around the mouth and on
i the lip of the aperture of the ventral pouch (fig. 26).

Ventral pouch. — On the ventral aspect of the animal, 0.62 mm.
(measured from sections) caudad of the oral margin, there is a trans-
averse depression which is the aperture of the ventral pouch (figs.

.24, 26). This aperture leads into a ventro-dorsally narrow, slit-like

[passage which may be regarded as the neck of the pouch. This

textends caudad to the lower (caudal) margin of the ventral chamber

tof the genital atrium, caudally of which it rapidly dilates into the body

>of the pouch. The body

i of the pouch extends cau-
dad to just above the plane
of the superior margin of

;the ventral testis. The

I fundus of the pouch (as in
F. jisclmderi) bulges some-
what cephalo-ventrad into

I the lumen in such a man-

mer as to make the dorsal

'wall of the pouch much

: shorter than the ventral,

; and the lateral walls inter-

i mediate gradations be-
tween the two. As a result

• of this there is (in transverse sections) a crescentic slit-like prolonga-
tion of the pouch caudad between the ventral testis and acetabulum,

i on the one hand, and the ventral wall of the worm on the other
(figs. 24, 30, 31). It extends caudad to a little below the superior
margin of the acetabulum.

The outline of the pouch in transverse sections varies at different
levels; the aperture is a narrow crescent measuring 0.135 mm. (in
sections) in dorso-ventral diameter, with rounded horns, the distance
between which is 0.525 mm. (in sections) ; the neck of the pouch
retains the crescentic outline of the aperture; in the equatorial region
of the worm the body of the pouch is somewhat triangular in outline
with the apex directed ventrad. Corresponding to the position of
the angles of this triangle the inclosing body shows constrictions
which divide it into three segments, one dorsal and two ventro-lateral,
of which the former is somewhat the largest (figs. 28, 29).

Fig. 25.

In the equatorial zone the pouch occupies substantially the axial
region of the animal.

Genital pore. — On the dorsal wall of the neck of the ventral pouch
there is a longitudinally elliptical opening, the genital pore, measuring
0.40 mm. in length by 0.30 mm. in width, leading into a large some-
what circular depression measuring 0.20 mm. in greatest depth (figs.
23, 24, 27). At the bottom of this depression (ventral chamber of
genital atrium) is a small pore about 0.05 mm. in diameter leading into
the slit-like dorsal chamber. The dorsal wall of this is formed by
the genital papilla. At the vertex of the latter may be seen the
minute aperture of the ductus ejaculatorius, and immediately
beneath this, the considerably larger opening of the metraterm.

This papilla is just
above (cephalad of)
the level of the eso-
phageal fork.

Acetabulum. — This
organ of adhesion,
measuring about 1.16
mm. in transverse and
about 1 mm. in dorso-
ventral diameter, oc-
cupies the caudal ter-
minal portion of the
body, and its aperture,
directed downward
(caudad) and, because
of the curvature of the
body axis, slightly ven-
trad, measures about
0.46 mm. in diameter.

INTERNAL ANATOMY.

Digestive tract. — The bluntly pointed cephalic extremity is
pierced by the transversely elongated spindle-shaped aperture of the
oral sucker (the mouth). The sucker consists of a dorsal and a ven-
tral muscular mass continuous laterally (figs. 23-25). The sucker
measures 0.62 mm. in length, 0.30 mm. in greatest dorso-ventral, and
0.33 mm. in greatest transverse diameter. Its lumen is a narrow
transverse slit, which becomes reduced to a minute aperture at the
opening into the esophagus. The sucker rests in a roomy space
(p. s. sp., figs. 25, 26), in which it is held in position by its anchorage
to the parenchyma and cuticle at its oral extremity, by the esophagus
at its caudal extremity, and between these points by dorsal and ven-
tral mesenterium-like strands.

The esophagus begins at the base of the sucker and passes caudad
with but a slight tilt dorsad. It measures 0.72 mm. in length, and
at the junction of the first with the second fourths of the body length
it forks into the two intestinal ceca. The latter pass at first (for
about one-fourth of their length) latero-caudad then in a direct
though slightly sinuous course directly caudad in the dorsal body
segment to terminate by cecal extremities at about the junction of
the third with the fourth fifth of the body length. The cecal ex-
tremities lie, however, in slightly different transverse planes, the
left being slightly above the right. As in F. elongatus, the lumen of
the sucker and that of the esophagus are lined by a cuticle in ana-
tomical continuation with that of the body surface; it is thin in the

-sucker, thicker in the esophagus, and ceases at the bifurcation.

" The intestinal ceca

. are lined throughout
by a layer of epithe-

, lial cells.

Genital sts-

item. — The testes,

t the ovary, and the

s shell gland are in the

( caudal portion of the

I body immed i a t e 1 y

( cephalad of the ace-

I tabulum.

Male organs . — The

t two large testes lie

i in the same dorso-

i ventral line, the left

i dorsad of the right.

' The bulk, however,
of the left testis lies to the left of the median line while that
of the right or ventral testis lies to the right of the median line,

- so that their fields overlap. Both testes show marked indenta-
tions. A vas efferens springs from the dorsal aspect of each
testis (fig. 30). From its point of origin the left vas efferens
passes almost directly cephalad in the dorsal body segment a little
to the left of the median line. The right vas efferens, on account
of the difference in the position of the testes, is longer and at first
runs almost horizontally dorsad but very soon turns and runs
directly cephalad a little to the right of the median line. The
two vasa efferentia unite in the median line in the equatorial
plane of the body. Just before they unite each vas describes a
curved course mediad so that by their union they form a trans-
verse arch (figs. 29, 23). In their course the vasa are separated
one from the other by coils of the uterus and their distal portions

v.ff-

Fig. 27.

run more or less close to the ventromesial aspect of the terminal i
portions of the corresponding intestinal ceca.

The vas deferens, formed by the union of the vasa efferentia
shows a well-marked, thin-walled vesicula seminalis, a well-defined
pars musculosa, 127 fi in diameter with walls 37 ,i in thickness (both
portions very much coiled) and a long pars prostatica. The latter
pursues an almost direct course cephalo-ventrad beneath, and then
ventrally of the esophageal fork and caudal portion of the esophagus
to the base of the genital papilla. At this point the prostatic cells
enclosing the pars prostatica cease and the continuation of the duct
pierces the genital papilla and opens by a minute aperture at the
vertex of the latter. This terminal portion of the male canal becomes

Fig. 28.

very rapidly thin walled and greatly reduced in caliber and corre-
sponds to the ductus ejaculatorius.

Female organs. — The ovary and shell gland lie obliquely side by
side, close to the ventro -caudal aspect of the dorsal (left) testis
(figs. 31, 24). The ovary lies obliquely to the left of the shell gland
and gives origin to the oviduct from its right lateral aspect . The I
oviduct at first passes slightly caudad from its point of origin, then
turns abruptly to the right and cephalad to penetrate the dorso-
caudal aspect of the shell gland, within the bod}7- of which it is joine
by the vitelloduct and forms the ootype. The shell gland lies close
to the right cephalo-mesial aspect of the ovary. It is penetrated,!
as already described, by the oviduct and a little to the right of thel

latter by the vitelloduct; these unite to form the ootype which is
continued as the uterus, emerging as such from the cephalic aspect
of the shell

gland. From its h »d

point of emer-
gence the uterus
passes to the
right, dips slight-
ly caudad, and
then ascends
cephalad form-
ing coils dorsally
of the ventral
and to the right
of the dorsal tes-
tis. Gradually
the distended
coils tend toward
the median line

of the body and soon come to occupy the space between the vasa
efferentia. When the uterus reaches the arch formed by the union
of the vasa efferentia it passes beneath and ventrally of the latter
and ceases to form coils. It now takes an almost direct though

slightly sinuous
course cephalad
close to the ven-
tral aspect of the
coils formed by the
vesicula and pars
prostatica and

Fig. 29.

we.

finally close to the
ventral aspect of
the pars prostatica
and ductus ejacu-
latorius, to open
by a pore of rela-
tively consider-
able size at the
vertex of the geni-
tal papilla below
but very close to,
though apparently
quite distinct
from, the male genital pore. Laurer's canal leaves the oviduct at
about the point where the latter turns abruptly cephalad in order to
penetrate the shell gland, passes dorso-caudad, and opens by a minute

(IV

pore on the dorsum about 0.60 mm. cephalad of the caudal pole of
the body and about 0.36 mm. cephalad of the excretory pore.

The follicles composing the vitellogene glands (figs. 28, 30) are
scattered through the ventro-lateral body segments in a manner
similar to that obtaining in F. elongatus, and in the dorsal bo
segment external to the intestinal ceca. Longitudinally the glani
follicles extend from a plane corresponding to the caudal end of th<
pars prostatica caudad to the plane of the cephalic aspect of th.
testes. From about the caudal extremity of each vitelline gland a
duct passes medio-caudad; the two transverse ducts unite close to
the ventral aspect of the shell gland at about the level of the ootype.
A well-defined vitelline reservoir is not present, unless the transverse
ducts which are of considerable caliber and filled with vitelline cells

may be so regarded.
From the point of union
of the transverse ducts
a duct passes off in a
direction caudad close
to the ventral aspect
of the shell gland, and
follows its contour
around to its dorso-cau-
dal aspect. Here this
duct penetrates the
gland to unite in its
substance with the
oviduct.

Excretory sys-
tem.— The excretory
vesicle lies caudo-ven-
trally of the ovary and
shell gland and dor-
sally of the dome of the acetabulum. In the single specimen studied
the vesicle appears for the most part as a transverse slit, distended
slightly only in its caudal portion. From its caudal aspect a short
duct is given off which passes dorso-caudad to open by a pore
caudad of Laurer's canal. This duct is lined by a cuticle in ana-
tomical continuation with that of the surface.

RELATION TO OTHER SPECIES.

The topography of the genital system and the termination of the
intestinal ceca in the equatorial region bring this worm close to
F. elongatus and F. fischozderi. The long esophagus and the roomy
ventral chamber of the genital atrium, quite distinct from that in
either F. elongatus or F. fischozderi appear to indicate that this is a
distinct species ;md clearly differentiates it from both of them.

Fig. 31.

ILLUSTRATIONS.

Fig. 23. — Frontal projection. Shows oral sucker (o. s.), esophagus
(es.), position of genital pore (g.p.), intestinal ceca (i.), testes (t.),
vasa efferentia (v. e.), vesicula seminalis (v. s.), pars musculosa
(p.m.), pars prostatica (p.p.), uterus (ut.), and acetabulum (ac).
a-a, b-b, c-c, d-d, e-e, f-f g-g, h-h planes of section. Slightly
diagrammatic. Enlarged. Original.

Fig. 24. — Profile projection. Shows oral sucker (o. s.), esophagus
(es.), right intestine (i.), testes (t.), right vas efferens (v.e.), vas

deferens (v.s.; p.m.; p.p.), shell gland (s.g.), ovary (ov.), uterus
(ut.), Laurer's canal (L. c), excretory vesicle (ex. v.), excretory pore
{ex. p.), and acetabulum (ac). a-a, b-b, c-c, d-d, e-e, f-f , g-g, h-h

■^planes of section.

-Slightly diagrammatic.

[•Enlarged. Original.
Fig. 25. — Transverse

^section at a-a figs. 23
and 24. Shows outline
of body, form of oral

;eucker and of its lumen

(i(o. s.), perisuctorial

-space (p. s. sp.), and
mesenterium-like

« strands (m. b.). En-
larged. Original.

Fig. 26. — Transverse

■^section at b-b figs. 23
and 24. Shows outline
of body at level of aper-
ture of ventral pouch
'(a.v.p.) and relation of

I Jatter to beginning of the
esophagus (es.), the perisuctorial space (p. s. sp.) and surface papillae
(s.pap.) on margin of aperture of ventralpouch. Enlarged. Original.
Fig. 27. — Transverse section at c-c figs. 23 and 24. Shows out-

liline of body, form of ventral pouch (v. p.), dorsal chamber (g.a.),

\ ventral chamber of genital atrium (g. a. c), ductus ejaculatorius
(d.e.), metraterm (va.), esophagus (es.), and longitudinal excretory
canals (ex. c). Enlarged. Original.

Fig. 28. — Transverse section at d-d figs. 23 and 24. Shows tri-
angular form of body, ventral pouch (v. p.), intestines (i.), excretory
canals (ex. c), pars musculosa (p.m.) of the vas deferens, uterus
(ut.), and vitellaria (v. g.). Enlarged. Original.
13893— Bull. 60—10—4

Fig. 32.

Fig. 29.— Transverse (equatorial) section at e-e figs. 23 and 24
Shows form of body and of ventral pouch (v. p.), arch of union of
vasa efterentia (v. e.), vesicula (v. s.), uterus (ut.), intestines (i)
excretory canals (ex. c), and vitellaria (v. g.). Enlarged. Original'

Fig. 30.— Transverse section at /-/ figs. 23 and 24. Shows form of
body, caret-like form of ventral pouch (v. p.), testes (t.), uterus
(ut.), origin of vasa efferentia (v. e.), and vitellaria (v. g.). Enlarged
Original.

Fig. 31.— Transverse section at g-g figs. 23 and 24. Shows form
of body, slit-like prolongation of ventral pouch (v. p.), superior
margin of acetabulum (ac), caudal aspect of dorsal testis (t), cephalic
margin of ovary (ov.), shell gland (s.g.), transverse vitello-duct
(t.vd.), common vitello-duct (c. vd.), and uterus (ut.). Enlarged.
Original.

Fig. 32— Transverse section at h-h figs. 23 and 24. Shows form
of body, slit-like extremity of ventral pouch (v. p.), acetabulum
(ac), ovary (ov.) and origin of oviduct (ov. d.), caudal aspect of
shell gland (s. g.), common vitello-duct (c. vd.), uterus (ut.), slit-like
beginning of excretory vesicle (ex. v.). Enlarged. Original.

CARMYERIUS.i new genus.

Generic diagnosis.— Gastrothylacinae (p. 16): Vas deferens and cephalic half of
uterus chiefly or entirely in suctorial field. Testicular fields separate, zones nearly
coincide, postcecal or intercecal; vesicula without straight portion. African and
Asiatic.

Type species.— C. gregarius (Looss, 1896) [Gastrothylax gregarius Looss, 1896b, 5-13,
170-177, pi. 1, figs. 1-3].

This group, as at present constituted, contains 5 species which
agree in certain characters, and yet are so different that they will
certainly submit to further grouping as soon as additional forms
become known. At present at least 4, probably 5, subgroups can
be more or less clearly foreseen. For the sake of conservatism we
will here recognize 5 monotypic subgenera, as follows:

A1. Genital atrium with very large ventral chamber; testes postcecal:
B1. Ceca corkscrew like, rather narrow, long, end in fourth zone; testes deeply
indented; transverse section of pouch triangular, apex ventrad; vitellaria
fine; type Gastrothylax synethes Fischceder, in Bos kerabau, from Ceylon.

New subg. Synethes.

B2. Ceca straight, broad, short, end in third zone; testes lobate, very lateral; trans-
verse section of pouch triangular, apex dorsad; vitellaria coarse; type Gastro-
thylax gregarius Looss, in Bos bubalus, Egypt, also in Bos taurus, East Africa.

New subg. Carmycrius.

1 This genus is dedicated to Miss Caroline Myer, technical clerk in the United
States Bureau of Animal Industry, in recognition of the obligation which we feel that
helminthologists owe to Miss Myer for her years of faithful work on the Index Cata-
logue of Medical and Veterinary Zoology.

A2. Genital atrium without ventral chamber; testes post or intercecal:
B3. Ceca straight, narrow, rather long, end in fourth zone; testes lobate, postcecal;
transverse section of pouch circular; type Gastrothylax spatiosus Brandes, in

Bos taurus, Arabia New subg. Gastrothylacias.

Bi. Ceca rather sinuous, narrow, long, end in fourth and fifth zones; testes intercecal;
transverse section of pouch triangular, apex ventrad ; type Gastrothylax man-

cupatus Fischceder, in Bos taurus, East Africa New subg. Gastrothylacid.es.

Bs. Ceca swollen in caudal half, rather long, end in fourth zone; testes inter and
postcecal; transverse section of pouch rather triangular, apex ventrad; type
Gastrothylax minutus Fischceder, in Tragelaphus scryptus, Kamerun, also in
Antilope sp New subg. Thylogaster.

WELLMANIUS, new genus.

Generic diagnosis. — Gastrothylacinse (p. 16): Vas deferens and cephalic half of
i uterus chiefly or entirely in suctorial field. Testicular fields separate, zones coincide,
• testes in inter, extra, and cecal areas, dorsal of ceca; vesicula seminalis consists of a
i caudal straight and a cephalic coiled portion.

Type species. — Wellmanius wellmani new species. Africa.

This new species, new genus, separates out very easily from the
i other forms of Gastrothylacidse. Both the genus and the species are
dedicated to the American student of African tropical medicine who
sent us the material. The "virtual tautonomy" used here and else-
where is intentional.

WELLMANIUS WELLMANI, new species.

[Figs. 33 to 42.]

Specific diagnosis. — Wellmanius (p. 51): 6.5 to 8.25 mm. long, by 3 to 4 mm.
broad, more or less conical in form, straight or curved, circular in transverse section,
greatest diameter near acetabulum. Surface unarmed, but bluntly pointed cephalic
end bears small papillae. Opening of ventral pouch 0.67 mm. from anterior end;
pouch extends to acetabulum; its transverse section triangular (then pentagonal),
with apex ventrad; shorter dorsally than ventrally, ventral end extending in acute
angle, caudal wall thus not representing a transverse plane. Genital pore at about
the equator of the esophagus; genital papilla may be prominent, nearly filling atrium.
Acetabulum terminal, 1.7 to 2.5 mm. in diameter, its aperture tilted slightly ventrad.
Oral sucker rather pyriform; esophagus, shorter than sucker, bifurcates one-fifth to
one-fourth the body length into 2 tortuous wavy ceca which extend to the acetabu-
lum. Excretory system well developed with large vesicle and with thick-walled
efferent canal opening dorso-median, caudad of the opening of Laurer's canal.

Male organs: Testes lobate, lateral, in same transverse zone, but their fields are sep-
arated by dome of acetabulum and excretory vesicle; vas deferens median; vesicula
seminalis, pars musculosa, pars prostatica, and ductus ejaculatorius well developed.

Female organs: Ovary usually left, shell gland right of median line, between cephalic
end of testes; uterus coiled; metraterm straight; Laurer's canal opens median, cephalad
of excretory pore; vitellaria extend from slightly caudad of intestinal fork to near
termination of ventral pouch; at first (cephalad) the follicles are small, sparse, and
scattered, then larger and more numerous, extending ventrad of intestinal ceca and
ventral pouch.

Eggs: 112.5 by 60//, oval, operculated.

Habitat. — Lesser Reed Bok (Cervicapra bohor), Benguella (type locality), Africa.
Type.— U.S. P.H.&M.H.S. 9831, alcoholic material and sections.

Fig 33.

Source of material. — This material was sent to us by the Ameri-
can Society of Tropical Medicine. It was collected by Dr. F. C.
Wellman in Benguella, West Africa, from the stomach of the Lesser
Reed Bok (Cer-vicapra bohor). The sending contains a piece of

stomach showing how these trematodes attach
themselves to the mucosa.

EXTERNAL CHARACTERS.

Size. — The specimens vary in size from 6.5 to
8.25 mm. in length by 3 to 4 mm. in breadth.
Color. — Alcohol specimens are of a buff color.
Form. — The specimens differ somewhat one from
another, but all are more or less conical in form,
with the longitudinal axis either straight or more
or less curved with the convexity dorsad. The
cephalic extremity is rather bluntly pointed and bears the terminal
mouth which may be directed slightly dorsad or slightly ventrad.
The body is more or less circular in cross section and its greatest
diameter is more or less near the caudal extremity which bears a
large terminal acetabulum, the terminal circular orifice of which, in
some of the specimens, is also tilted slightly ventrad. In some of
the specimens the body is somewhat constricted transversely at or
slightly caudad of the equator (figs. 33, 34).

Surface. — The surface cuticle is devoid of spines or hooks, but is
marked by fine transverse sulci and at the oral
extremity it is sparsely beset by bluntly rounded
papillae. It is marked at one point, a little (0.675
mm. in one series of sections) below the oral
margin, by a small transverse slit, which is the
aperture of the ventral pouch and indicates the
position of the venter of the animal. Immedi-
ately above this slit the surface over a circum-
scribed area is slightly depressed (see figs. 33, 34).

Ventral pouch. — The ventral pouch extends from
its aperture, which is situated a little (0.675 mm. in
a sagittal section) below the level of the oral mar-
gin to a little above the level of the upper margin
of the acetabulum. In transverse sections the form and dimensions
of its lumen vary greatly at different levels and to a considerable
extent in different specimens. The aperture lies in a slight depression
of the venter. It is crescentic and more or less slit like in form (fig.
37), measuring 0.39 mm. from horn to horn in one of the sectioned
specimens. A little below the level of the genital pore, which is on

Fig. 34.

the dorsal wall of the pouch, the outline in transverse sections is
found to have become changed from the crescentic slit to nearly a tri-
angular form with the apex ventrad (fig. 38).
In its further course caudad the triangular lumen of the pouch

j gradually shifts toward the axial region of the body which it then

: comes to occupy. Coincident with this shifting of position there is
a further change of outline, the triangular form becoming more or
less pentagonal but with the apex still directed ventrad (fig. 39).

! At first the caliber of the lumen of the pouch increases, but as the
fundus of the pouch is approached, its ventro-dorsal diameter becomes
rapidly contracted because the fundus instead of occupying a hori-

zzontal (transverse) plane occupies ^
a, plane which is directed obliquely

icaudo-ventrad, the dorsal wall of

tthe pouch being shorter than the

i ventral; in consequence of this,

:the outline of the pouch in sagittal

? section is somewhat that of a tri-
angle with its apex at the entrance

«of the pouch (fig. 35). The lining
of the pouch is a cuticle in anatom-
ical continuation with that of the

: surf ace and appears to be in irregu-
lar longitudinal and transverse
folds, producing an appearance
somewhat suggestive of papillae in
sections. In the specimens sec-
tioned, the pouch contained some
granular matter and a few eggs.

Genital pore. — On the dorsal wall
of the pouch a little (0.375 mm.
in one sagittal section) below its
aperture and in about the equator
of the esophagus is the genital pore
somewhat flattened hemispherical bulging. In a sagittal section
of one specimen this bulging measured 0.40 mm. in its longitudinal
diameter. The genital pore leads into a chamber which is almost
completely filled by a papilla (genital). In one sectioned specimen a
part of this papilla protruded into the ventral pouch through the pore,
its margin closely embracing and somewhat constricting it (fig. 35).

Acetabulum. — This muscular organ of adhesion occupies the caudal
extremity and its aperture, which is more or less circular, is in the
axial line with a slight tilt ventrad in some of the specimens. The
diameter of the acetabulum varied from 1.7 to 2.5 mm. in the speci-
mens in which it was measured. The ventro-dorsal diameter of the
aperture in one specimen measured 0.40 mm.

.JZa

Fig. 35.

This pore is at the vertex of a

INTERNAL ANATOMY.

Digestive tract.— The bluntly pointed cephalic extremity is
pierced by the more or less circular mouth which leads directly into a
very muscular, somewhat pyriform, oral sucker. In cross (transverse)
section the outline of the sucker varies in different specimens from an
ellipse to a circle. The oral pole of the sucker extends to the sur-
face where it forms a ring around the oral aperture, being marked off
from the general body surface by a narrow more or less deep encircling
groove (fig. 40). Inclosing the sucker is a space which is traversed,
dorsally and ventrally, by dorso-ventral strands. At the esophageal

end the sucker is attached to
the body parenchyma so that
the organ is anchored at both
its poles.

The lumen of the sucker,
when studied in transverse
sections, is circular in outline
at its oral end, becoming
somewhat spindle shaped in
the equatorial region ; beyond
this region the lumen at first
becomes dorso-ventrally con-
tracted, forming a transverse
slit; this eventually becomes
reduced to a small circular
orifice at the entrance into
the esophagus. It is lined
by a thin cuticle-like laj^er,
anatomically continuous
with that of the surface, and
it is beset by small more or
less conical papilla1; these papillae are sparsely scattered in the region
of the mouth but numerous and closely aggregated in the remaining
portion (figs. 37, 40). From its origin at the base of the sucker the
esophagus passes caudo-dorsad ; at a point a little less than one-fiftli
to one-fourth the body, length from the oral margin it forks into two
intestinal ceca. The esophagus is somewhat shorter than the sucker.

From their point of origin the intestinal ceca, without giving off
any branches, pass at first latero-caudad, then having reached the
dorso-lateral region of the body they take a dorso-ventrally wavy
course caudad to terminate ventrad of the corresponding testis at or
a little above the level of the upper margin of the acetabulum (fig.
36, 41).

The lumen of the esophagus is lined by a thick layer of cuticle.
At the point of origin of the intestinal ceca the cuticular lining is

Fig. 36.

replaced by a nucleated cell layer which extends throughout the

irreniaining length of the intestine.

The intestinal ceca do not appear to be exactly of equal length,
nor is the level at which they terminate absolutely fixed. They
may terminate at the level indicated or somewhat above (cephalad

.of) that point.

Genital system. — Male organs: The two testes are situated in the
same transverse zone near the caudal extremity of the worm at or
just cephalad of the level of the anterior (cephalic) portion of the
acetabulum, and separated in the former case by the dome of the
acetabulum, ventrally, and the excretory vesicle, dorsally, and in the

Hatter case by the excretory vesicle alone (figs. 36, 41, 42). The
testes are somewhat compressed laterally and their margins are deeply
indented, the indentations marking off lobes of different dimensions.

(Cephalo-ventrad

teach is in relation

^with the correspond-

iing cecum. From

I the dorsal aspect of

teach gland arises a

1 vas eff erens ; these

(two ducts take a

< course at first dorsad

land slightly cepha-

] lad, then toward the

i median line, and

i unite at a point a
little above the level

• of the upper margin

• of the testes, to form
the vas deferens (fig. 36). The vas deferens is clearly divisible into a
vesicula, musculosa, prostatica, and ejaculatorius. The vesicula may
be described as consisting of two portions ; the first pursues quite a
st raight course cephalad, close under the dorsum, about in the median
line, close to the dorsal aspect of the uterus, and with rather a thick
Wall proportionate to its empty contracted lumen. The second por-
tion of the vesicula forms numerous compact coils, its walls are thin-
ner, and the caliber of its lumen is increased. Farther cephalad the
wall changes in structure, becoming quite muscular (pars musculosa),
while the duct still forms compact coils; the cephalic end of the pars
musculosa turns abruptly ventrad, the duct becomes surrounded by
numerous cells and loses its muscular layer, turns sharply cephalad,
and proceeds as the pars prostatica toward the genital pore. It
passes ventro-cephalad of the intestinal arch, runs dorsally of the
metraterm, ventrally of the esophagus, decreases gradually in diam-

FiG. 37.

eter, and loses its prostatic cells; it now continues as the ductus ejacu-
latorius. The latter enters the genital papilla, and unites with the
metraterm to form the short ductus hermaphroditicus, which opens
at the vertex of the papilla as the poms hermaphroditicus (fig. 35).

Female organs.— The ovary and the shell gland are in the caudal
portion of the body, but further than this considerable variation wd
observed in their position and their relation to each other and to the
excretory vesicle. This was thought to be dependent in part on the
degree of distention of the excretory vesicle. The ovary lies imme-
diately to the right or to the left of the median sagittal plane, cephalo-
dorsad or dorsad of the excretory vesicle and somewhat above the
level of the superior margin of the acetabulum. In 3 of 4 sectioned

specimens it was to
the left of the me-
dian plane; in the
fourth it was to the
right. In 3 of the 4
specimens t he ovary-
was close to the
dorsal portion of the
cephalic aspect of
the excretory vesi-
cle (fig. 35), rather
than dorsally of the
body of the vesicle.
With respect to its
relation to the ace-
tabulum, it was
found that while in
3 of the 4 specimens
the ovary was ceph-
alad of the dome of the acetabulum, with the excretoiy vesicle
interposed (fig. 36), in the fourth series of sections the ovaiy
was distinctly below (caudad of) the transverse plane of the superior
margin of the acetabulum. In all cases it was distinctly nearer
the dorsum than the venter. The shell gland lies close to the
right or to the left and more or less cephalad of the ovary, in
one instance, cephalo-ventrad of the ovaiy. Both organs vary in
form in the different specimens; for the most part they are somewhat
flattened, oblong bodies, but may appear pyriform or subglobular.
The ovary is somewhat the larger of the two. From the aspect of
the ovary nearest the shell gland the oviduct arises and passes to
the shell gland, which it penetrates. Just before entering the latter
it gives off Laurer's canal. In the shell gland it is at once joined by
the vitello-duct; the common duct so formed then dilates some-

FlG. 38.

what to form the ootype and beyond this point the canal is continued
as the uterus, which emerges from the shell gland at the ventro-cephalic
aspect. The uterus then winds its Way dorsad over the shell gland;
a coil of it forms a loop which is tucked in between the dorsum, on
the one hand, and the shell

: gland and the ovary on the

■ other, before beginning its

• course cephalad. In the first
part of its course cephalad
it is included between the
two vasa efferentia, but
passes ventrad beneath the
arch formed by their union
to gain the ventral aspect
of the vas deferens. It
maintains this ventral re-
lation to the vas deferens
and its terminal portion,
pars prostatica, etc., in the
remainder of its course to
the genital papilla. As al-
ready mentioned, it opens near the vertex of the latter into a short
duct (ductus hermaphroditicus) common to it and the ductus ejac-
ulatorius.

Numerous eggs were observed filling the loops here and there and,
near the shell gland, some of the loops contained masses of sperma-
tozoa.

Laurer's canal passes from its point of origin dorso-caudad to open

in the median line slightly
below the upper margin of the
acetabulum and a little above
the excretory pore. The ca-
nal is long and slender; it is
lined by a thick cuticle in an-
atomical continuation with
the cuticle of the surface, and
its lumen may contain cells
resembling those in the vitello-
ducts. Receptaculum semi-
nis is wanting.

The vitellaria begin in a
transverse plane somewhat caudad of the esophageal bifurcation.
At first there are a few small scattered follicles ventrad of the intes-
tinal ceca, but gradually follicles appear which are larger and some-
what more numerous and scattered (dose around and vent rally of the

FlQ. 40.

t.vd,.

Fig. 41.

intestinal ceca and ventral pouch. They extend caudad to a plane
slightly above (cephalad of) the termination of the ventral pouch;
at about this point and ventro-centrad of the intestinal ceca, the
vitello-ducts arise, and each passes medio-dorso-caudad or caudad

«* (between the testes) ; the

two ducts unite about in
the median line immedi-
ately cephalad of the ori-
gin of the excretor}'' vesi-
cle. The common duct
thus formed passes dor-
sad toward the shell gland
and pierces the caudal or
the right (? or in some
specimens left) lateral as-
pect of this gland to join
the oviduct just before
the latter dilates into the
ootype.

Eggs. — The eggs are oval in outline and provided with a small
operculum at one end. We found some difficulty in obtaining them in
a condition satisfac-
tory for measurement.
One egg measured
112.5 by 60^.

Excretory sys-
tem.— The excretory
vesicle, when distend-
ed, is of considerable
size. It lies immedi-
ately above the ace-
tabulum and between
the two testes. Its
ventro-dorsal diame-
ter is about equal to
the corresponding di-
ameter of the ace-
tabulum. It receives
on either side, at about
its ventro-lateral aspect, a large excretory canal, which may be
observed to wind its way from the cephalic portion of the body
caudad on the ventro-lateral aspect of the corresponds ii: tot is,
then beneath the latter to its destination. From th<> <lorso-
idal aspect of the vesicle a thick-walled canal arises, which after a

Fig. 42.

cauc

short course caudo-dorsad opens on the dorsal surface at the excre-
tory pore a little below the opening of Laurer's canal (fig. 35).

ILLUSTRATIONS.

Fig. 33. — External appearance, ventral view. Enlarged.
Original.

Fig. 34. — External appearance, ventral view. Enlarged.
Original.

Fig. 35. — Diagrammatic sagittal section, showing internal anat-
omy: ac, acetabulum; d. e., ductus ejaculatorius; d. h., ductus
hermaphroditicus ; es., esophagus; es. /., esophageal fork; ex. p.,
excretory pore; ex. v., excretory vesicle; %., intestinal ceca; L. c,
Laurer's canal; o. s., oral sucker; p. m., pars musculosa; p. p., pars
prostatica; s. g., shell gland; s. pap., surface papilla?; v. e., vasa effer-
entia; v. p., ventral pouch; v. s., vesicula seminalis; ut., uterus.
Enlarged. Original.

Fig. 36. — Diagrammatic frontal section shows internal anatomy:
g. p., position of genital pore; ex. c, excretory canals; ov., ovary;
t., testes. For other abbreviations see fig. 35. Enlarged. Original.

Fig. 37. — Transverse section at level of aperture of ventral pouch.
Shows form of body, aperture of ventral pouch (a. v. p.), oral sucker
(o. s.), papillae of suctorial lumen (pap. o. s.), and the perisuctorial
space (p. s. sp.). Enlarged. Original.

Fig. 38. — Transverse section slightly caudad of level of genital
pore. Shows form of body, triangular outline of ventral pouch (v. p.)
at this level the intestinal ceca (i.) and their relation to the ventral
pouch, to pars prostatica (p. p.) and uterus (ut.), excretory canals
(ex. c.) and vitellaria (v. g.). Enlarged. Original.

Fig. 39. — Transverse section at about the junction of the second
with the equatorial fifth of the body length. Shows form of body,
irregularly pentagonal form of ventral pouch (v. p.), intestinal ceca
(i), vesicula seminalis (v. s.), uterus (ut.), and vitellaria (v. g.)
Enlarged. Original.

Fig. 40. — Sagittal section showing oral sucker (o. s.), perisuctorial
space (p. s. sp.), mesenterium-like strands (m. b.), esophagus (es.), and
aperture of ventral pouch (ap. v. p.). Enlarged. Original.

Fig. 41. — Transverse section immediately cephalad of superior
margin of acetabulum shows the laterally placed testes (t.) separated
by the excretory vesicle (ex. v.) and the position and relation of the
(caudal portion of the) ovary (ov.), uterus (ut.), vasa efTerentia
(v. e.), intestinal ceca (i.), transverse vitello-ducts (t. vd.) and caudal
terminal portion of ventral pouch (v. p.). Enlarged. Original.

Fig. 42. — Transverse section immediately below superior margin
of acetabulum. Shows the laterally placed testes (t.) separated by

the acetabulum (ac.) and excretory vesicle {ex. v.). Shows also the
shell gland (s. g.), uterus (ut.), and common vitello-duct ' (c. vd.).
Enlarged. Original.

Family PARAMPHISTOMID^ Fischoeder, 1901, restricted.

Family diagnosis. — Paramphislomoulca (p. 15): Ventral pouch absent.
Type genus. — Paramphistomum Fischoeder, 1901.

The family Parampliistomidse, Fischa>der, 1901, is here restricted to
the forms without a ventral pouch. Our work is based primarily
upon the amphistomes of mammals, but it seems not entirely excluded
that further study of the amphistomes of other vertebrates may result
in a further restriction of the family to forms in which the oral sucker
is without an evagination.

Fischoeder (1901a), in writing upon species found in mammals,
recognized 2 subfamilies for Parampliistomidse., namely, Parampliis-
tominse and Cladorchinse. Cohn (1904), in dealing with species found
in amphibians and reptiles, recognized the subfamily Diplodiscinse
for three genera, but he did not compare his forms with the forms
discussed by Fischoeder. Daday (1907) later described forms from
fish, classifying some of them near some of the forms described by
Fischoeder, others in Diplodiscus, but he did not enter into a discus-
sion of the classification of the subfamilies. Disregarding the new
genera proposed in the present paper, the classification stands at
present as follows :

Paraviphistomidx Fischoeder, 1901.

Paramphistominx Fischoeder, 1901.

Paramphistomum Fischoeder, 1901.

Stephanopharynx Fischoeder, 1901.

Gastrothylax Poirier, 1883.
Cladorchiinx Fischoeder, 1901.

Cladorchis Fischoeder, 1901.

Subg. Cladorchis Fischoeder, 1901.
Subg. Taxorchis Fischoeder, 1901.
Subg. Stichorchis Fischoeder, 1901.

Microrchis Daday, 1907.

Pseudocladorchis Daday, 1907.

Pseudodiscus Sonsino, 1895.

Gastrodiscus Leuckart, 1877.

Homalogaster Poirier, 1883.
Diplodiscinx Cohn, 1904.

Diplodiscus Diesing, 1836.

Catadiscus Cohn, 1904.

Opisthodiscus Cohn, 1904.
Subfamily not given.

Balanorchis Fischoeder, 1901.

When we consider the status of this group prior to 1901, the great
advance in our knowledge which we owe to Fischoeder must be
immediately recognized, and this advance has been further supported,

especially by Cohn and Daday. That the classification as it now
stands is not final lies in the nature of things ; and on account of the
fact that definite data are lacking in the case of many species it must
be expected that in the future rather radical changes may perhaps
be necessary. In the immediate future, changes are more or less
experimental, though they may appear justified.

Gastrothylax should, we believe, be placed in a separate family
(see p. 16).

Stephano'pharyrix presents such a striking character in its circular
evagination of the oral sucker that it seems wise to separate it entirely
from Parampliistominse; but if left in this subfamily, it should at least
be placed in a tribe distinct from Paramphistomum.

Gastrodiscus and Homalogaster are so different from the other
members of CladorcMinse that they should either be placed in a distinct
subfamily or in a distinct family.

Diplodiscinse will probably be justified as a distinct subfamily, or
at least as a distinct tribe, but further data are desirable in regard to
its genera.

BalanorcTiis is placed with difficulty. It probably represents a
distinct subfamily; if classified in CladorcMinse, it should represent a
distinct tribe.

It is exceedingly difficult at present to draft a key representing the
natural relations of members of this family, but the following key,
admittedly more or less artificial, will be found of use in tracing the
genera. This key is based primarily upon the type species :

Key to the Known and New Genera op Paramphistomidae s. str.

A1. Oral sucker without evagination [this probably represents a distinct subfamily
Paramphistominse, p. 62]; cirrus pouch absent; body not divided; ovary not
pretesticular [eventually these may be tribal or sub tribal characters]:

B1. Genital sucker absent; type cervi Paramphistomum, p. 73.

[For subgenera, see p. 74.]

B1. Genital sucker present; type cotylophorum Cotylophoron, p. 63.

A2. Oral sucker with evagination:
B3. Evagination circular [this will probably prove to be of supergeneric value, indi-
cating a sub tribe or tribe, probably a subfamily, Stephanopharynginx]; genital
sucker and cirrus pouch absent, body not divided [these characters will
probably prove to be supergeneric]; type compactus.

Stephanopharynx, p. 168.

B*. Evagination paired [if of subfamily value, this unites Cladorchiinx and Diplo-
discinse. in one subfamily; later investigations may show that these groups
can be separated on the excretory system, cf. Diplodiscus]:
C'1. Genital sucker present; testes clearly branched:
D1. Vitellaria entirely posttesticular; testicular zones coincide, preequatorial,
widely separated from acetabulum, fields separate; uterus of unusual
course, first runs near dorsum cephalad to testes, then diagonally caudad
. near venter, then cephalad near venter to pore; type schistocotyle.

Taxorchis, p. 170

D2. Vitellaria not entirely posttesticular; lesics in equatorial third; uterus
not as in Taxorchis; type pyrijormis Cladorchis, p. 169.

C2. Genital sucker absent; testes lobate or lobulate:
D3. Cirrus pouch absent:

El. Each oral evagination single (only pouch present), type watsoni.

Watsonius, p. 212.

E2. Each oral evagination double (pouch and bulb present), type stanleyii.

Pseudodiscus, p. 170.

Z>4. Cirrus pouch present [perhaps in part a special subfamily, see Diplodiscinse,
p. 247]:

E3. Acetabulum divided into two parts by constriction; one testis present;
esophagus with muscular swelling at bifurcation; type dolichocotyle.

Catadiscus, p. 248.

E*. Acetabulum with central projecting sucker; two testes present; esoph-
agus without muscular swelling; type diplodiscoides.

Opisthodiscus, p. 248.

E&. Acetabulum cavity with prominent papillae; excretory system does not
enter acetabulum; testes preovarial, at least not postovarial; evagina-
tionsof sucker well developed, at least not confined to wall; esophagus
without pronounced muscular thickening; testicular zones coincide;

excretory pore vesicular, type papillatus Pfenderius, p. 232.

E6. Acetabulum otherwise:
Fl. Excretory system branches radially in acetabulum [perhaps special
subfamily Diplodiscinx, with Diplodiscus, Catadiscus, Opisthodiscus];
testes coalesce in adult; esophagus with muscular swelling at bifur-
cation; type subclaratus Diplodiscus, p. 248.

F2. Excretory system does not appear to enter acetabulum:
G1.. Testes postovarial, portuterine, postequatorial; type anastrophus.

Balanorchis, p. 247.

G2. Testes preovarial, at least not postovarial:
H1 . Evaginations of sucker not well developed, confined to wall of
sucker; sucker with two phincters; type cylindricus.

Pseudocladorchis, p. 232.
H2. Evaginations of sucker well developed, at least not confined to
wall; sucker with one sphincter; esophagus with muscular
thickening; testicular zones separate; excretory pore pre-
vesicular:

P. Testes not lobate; excretory pore equatorial; type megacotyle.

Microrchis, p. 246.

P. Testes 4-lobate; excretory pore postequatorial, posttesticular,
with powerful sphincter; type fabaceus Chiorchis, p. 246.

Subfamily PARAMPHISTOMIN-ffi, restricted.

Subfamily diagnosis.— Paramphistomidx (p. 60): Oral sucker without evagination.
Type genus. — Paramphistomum.

There seems every indication that the group here defined will

represent a subfamily.

Additional characters for the two known genera are: Cirrus pouch absent, ovary not
pretesticular, excretory system does not enter acetabulum.

As additional genera become known, these characters may result
in dividing the subfamily into tribes and subtribes.

The two known genera may easily be distinguished as follows:

Genital sucker absent; type cervi Paramphistomum, p. 73.

Genital sucker present; type cotylophorum Cotylophoron, p. 63.

COTYLOPHORON, new genus.

Generic diagnosis. — Paramphistominse (p. 62): Esophagus with or without mus-
cular thickening; ceca long, wavy, end in acetabular zone. Acetabulum of moder-
ate size, terminal, tilts ventrad. Excretory vesicle and canal directed cephalad;
excretory pore prevesicular. Genital sucker present, genital papilla present, ventral
chamber of genital atrium absent.

Male organs: Testes smaller than acetabulum, lobate, immediately preacetabular,
zones overlap slightly, fields nearly coincide, crossing median line.

Female organs: Ovary ventral of excretory vesicle; Laurer's canal crosses excretory
vesicle; its pore opens caudad and laterad of excretory pore, in acetabular and vesicular
zones.

Type species. — Cotylophoron cotylophorum (Fischoeder, 1901).

Thus far, two easily separated species may be classified in this
genus. They are distinguished as follows:

Esophageal muscular thickening present; genital pore bifurcal; body 5 to 8 mm. long;
type hosts: Bos taurus, Togo; Bos taurus indicus, German East Africa.

C. cotylophorum, p. 63.

Esophageal muscular thickening absent; genital pore postbifurcal; body, 4.3 to 5.5
mm. long; type host: Ovis aries, India C. indicum, p. 63.

Species COTYLOPHORON COTYLOPHORUM (Fischoeder, 1901) Stiles & Goldberger, 1910.

1901: Paramphistomum cotylophorum Fischoeder, 1901a, 370 (stomach of Bos
taurus, Togo; Bos zebu, German East Africa).

1909: Cotylophoron cotylophorum (Fischoeder, 1901) Stiles & Goldberger,
1910a, 63. For full bibliography, see Stiles & Hassall, 1908, Index Cata-
logue, etc., Trematoda.

COTYLOPHORON INDICUM, new species.
[Figs. 43 to 52.]

Specific diagnosis. — Cotylophoron (p. 63): Body 4.3 to 5. 5 mm. long by 1.5 to
2 mm. broad; color (in glycerine alcohol) faint brown tint; slender, conical in form,
greatest breadth near caudal extremity; tapers to bluntly pointed oral extremity;
longitudinal axis curved, concavity ventrad; dorsum convex longitudinally and
transversely, venter concave longitudinally, convex transversely; lateral margins
slightly excurvate longitudinally, convex dorso-ventrally ; transverse section elliptical.
Surface without spines or papillae except possibly at oral aperture which may (?) bear
minute papillae. Genital pore distinctly postbifurcal, on vertex of slight but not
sharply defined bulging about one-third of body length from oral pole, and surrounded
by genital sucker. Acetabulum caudal, sunken so that apparent aperture is formed
by body, margin not projecting, 1.14 mm. in dorso-ventral diameter, aperture tilted
somewhat ventrad, 0.6 mm. in diameter, muscular dome 0.24 mm. thick. Mouth at
blunt cephalic extremity; oral sucker pyriform in sagittal section, its lumen papillate,
narrow dorso-ventrally, rather broad transversely; maximum measurements of sucker
0.52 mm. long, 0.42 mm. in dorso-ventral and 0.6 mm. in transverse diameter; peri-
suctorial space roomy; esophagus about two-thirds as long as sucker and curved slightly
ventrad; ceca arise from dorso-lateral aspects of end of esophagus, slightly loss than
one-fourth the body length from oral extremity, at first forming with each other a very
acute angle they approach the lateral margins of body, then extend caudad in well-
marked dorso-ventrally wavy course to terminate about £ of body length from mouth,
postovarial, in acetabular zone, the left cecum ending slightly caudad of the right;
ceca of relatively considerable caliber. Excretory pore dorso-median about at junc-
tion of equatorial with caudal third of body, about 0.16 mm. cephalad of acetabulum,

cephalad of caudal margin of caudal testis and about 0.56 mm. cephalad of pore of
Laurer'a canal; excretory canal short, thick walled, runs caudo-ventrad to well-devel-
oped elongate, slightly bag-shaped vesicle, the fundus of which is close to dome of
acetabulum, intercecal, at end of ceca.

Male organs: Testes large, but somewhat smaller than acetabulum, irregularly
globular, lobate, in median line, cephalad of acetabulum, intercecal, fields nearly
coincide, zones overlap; union of vasa efferentia slightly cephalad of cephalic testis;
vas deferens coiled; its vesicula seminalis much coiled, dilated; pars musculosa not
coiled, narrow; pars prostatica about as long as musculosa, directed ventrad; ductus
ejaculatorius short, unites with metraterm to form ductus hermaphroditicus, which
is 195/t long and opens at porus hermaphroditicus on vertex of cylindrical genital
papilla, which is 105/t long, 75/z in diameter; the latter almost fills a chamber 105/z
deep, 105/i in diameter; this in turn is surrounded by a hemispherical, sharply defined,
muscular genital sucker.

Female organs: Ovary and shell gland in testicular to posttesticular zones, inter-
cecal, sinistral, close to acetabulum in cephalic portion of acetabular zone, shell gland
in ovarian and postovarian zones; vitellaria with sparse and scattered, but well-devel-
oped follicles, chiefly extra-cecal, extending throughout cecal zone and slightly post-
cecal; a few follicles enter also the cecal and intercecal areas; uterus extends from
ventral pole of shell gland, runs cephalo-ventrad, forming coils, turns dorsad, skirting
the left lateral aspect of the caudal testis, turns cephalad dorsally of this testis, passes
dorsally of both testes, ventrad over cephalic margin of cephalic testis, under arch of
vasa efferentia, cephalad again ventrally of vas deferens to penetrate genital sucker
caudad of penetration of male duct, and unites with latter in wall of genital sucker to
form the ductus hermaphroditicus; Laurer's canal passes from oviduct in a curve
(convexity cephalad) dorsally, crossing on left aspect of excretory vesicle to left of
dorso-median line and opens dorsally of excretory vesicle, about 0.56 mm. caudad of
excretory pore.

Eggs: Not observed.

Type.— U.S.N. M. 5781.

Habitat. — In (? organ of) sheep, Ovis aries, India.

Source of material. — Six specimens, in bottle of the Hassall
Collection bearing the Smithsonian number 5781, were labeled:
" Amphistoma conicum;" host, Ovies aries; locality, India; presented
May 19, 1886.

EXTERNAL CHARACTERS.

Size. — The specimens (in glycerine alcohol) varied in length from
4.3 to 5.5 mm. and in width from 1.5 to 2 mm.

Color. — The specimens in glycerine alcohol are of a faint brown
tint.

Form. — The worms are of a slender conical form, broadest near the
caudal extremity and tapering to a bluntly pointed attenuated oral
extremity. The longitudinal axis is more or less curved, with the
concavity directed ventrad. The dorsum is convex longitudinally
and transversely; the venter is concave in the longitudinal direction,
but convex transversely, its convexity being less marked, however,
than the corresponding convexity of the dorsum. The lateral mar-
gins are slightly excurvate in the longitudinal direction and convex
dorso-ventrally. In transverse section the body of the worm is

elliptical in outline, with a somewhat greater transverse than dorso-
ventral diameter.

Surface. — The general cuticular surface is smooth; that is, unpro-
vided with spines or papillae. Around the oral aperture some minute
papillae may be present, but this could not be deter-
mined with certainty.

Genital pore. — In the median sagittal line of the
venter, about one-third of the worm's length from
the oral extremity, there is the genital pore. It is
situated at the vertex of a slight but not sharply
denned ventral bulging.

Acetabulum. — This is in the caudal extremity, with
a terminal though a more or less ventrally tilted aper-
ture. The rim is sunken or more or less retracted be-
neath the inclosing body surface (fig. 45), so that the
(apparent) aperture is formed by the inclosing paren-
chyma. Measured from a projection of one sectioned specimen
(which measured 3.9 mm. in length), the maximum dorso-ventral
diameter of the acetabulum was 1.14 mm. and of its aperture 0.60
mm., with a thickness of dome of about 0.24 mm.

Fig. 43.

INTERNAL ANATOMY.

The following description of the internal anatomy is based on a
series of transverse sections of one specimen (5781a) which measured
3.90 mm. in length, 1.66 mm. in greatest transverse and 1.42 mm. in
greatest dorso-ventral diameter as measured from
projections made from the sections.

Digestive tract. — The mouth, which pierces the
blunted cephalic extremity, leads directly into the
oral sucker. The latter is muscular and of a pyri-
form outline as viewed in median sagittal section.
Its maximum dimensions as measured in projection
of a series of transverse sections are: Length, 0.52
mm.; dorso-ventral diameter, 0.42 mm.; transverse
diameter, 0.60 mm. Its attenuated pole presents
the aperture of the mouth and is marked off from
the oral surface by a narrow encircling groove (fig.
45). Its broad blunt base gives origin to the esophagus. A roomy
space incloses the body of the sucker (fig. 47). The lumen of the
sucker is a dorso-ventrally narrow but transversely a rather broad
space; it is lined with a cuticle which is beset with short conical
papillae.

13893— Bull. 60—10 5

Fig. 44.

<;<;

Fig. 45.

The esophagus, from its point of origin at the base of the sucker,
passes caudad for a distance equal to about two-thirds the length of
the sucker, where it gives off the intestinal ceca from both dorso-
lateral aspects. The esophagus describes a slight curve ventrad.
Its walls are thick and its lumen is lined with a thick cuticular layer!
Dorsally of the first part of the esophagus there is a transverse nervous
cord (fig. 45).

The intestinal ceca take their departure from the esophagus at a point
slightly less than one-fourth the body length from the oral extremity.
At their origin they form a very acute angle one with the other. The
ceca at first approach the lateral margins of the body, then pass
caudad in a well-marked dorso-ventrally wavy course, to terminate
cecally at about the junction of the fifth with the caudal sixth of the
body length; the right intestinal cecum terminates at a slightly

higher (more ce-
phalic) level than
the left. The ceca
are of relatively
considerable caliber
and are lined by a
layer of epithelium.

Genital sys-
tem.— Male or-
gans.— The two
testes are in the
axial region of the
body, one caudad
of the other, but
the caudally placed
testis presents a
cephalic lobe which overlaps the caudal portion of the right ventro-
lateral aspect of the cephalic testis. The two testes occupy a zone
immediately cephalad of that of the acetabulum and equal to one-
fourth of the body length of the worm. The testes are irregularly
globular in form and are indented by fissures marking off numerous
lobes on their surface. Each testis gives origin to a vas efferensj
that from the cephalic testis springs from its left dorsal aspect
(fig. 49), while that of the caudal testis springs from its dorso-
cephalic aspect (fig. 51). The vas from the cephalic testis at first
passes cephalad close to the left lateral aspect of the testis from which
it springs, later it passes cephalo-dorsad and toward the median line,
arching over the testis and the uterus to unite with its fellow of the
right side (from the caudal testis) to form the vas deferens. The
right vas efferens, after its origin from the caudal testis, passes at first
to the right and cephalad (dorsally of the cephalic lobe of the caudal

Fig. 47.

testis) to gain the right lateral aspect of the cephalic testis at some
slight distance from which it ascends cephalad, eventually arching
over the cephalic testis and the uterus to unite, as already described, in
forming the vas deferens. The first part of the vas deferens is a much
coiled, thin-walled, dilated duct (vesicula seminalis), distended with
spermatozoa. Tins is abruptly succeeded by a narrow, thicker, and
more muscular walled uncoiled part (pars musculosa), which ascends
cephalad for a short distance, when it in turn is succeeded by a portion
which is inclosed in a thick layer of cells. This portion (par prosta-
tica) passes directly ventrad, and after a course about equal in length
to the musculosa it penetrates the genital sucker. Here the prostatic
cells cease and the continuation of the duct may be regarded as the
ductus ejaculatorius. This joins near the base of the genital papilla

Fig. 48.

with the terminal portion of the uterus to form the ductus herma-
phroditicus which is 195/* long and pierces the axial region of the
genital papilla. The copulatory apparatus presents the genital pore
in the median line of the venter at about the junction of the cephalic
with the equatorial third of the body and considerably caudad of the
esophageal fork (figs. 45, 48). This pore leads into a cylindrical
chamber 105// in depth and about 105// in diameter, that is almost
entirely filled by a cylindrical genital papilla, which, arising from the
dorsal wall of the chamber, projects forward (ventrad) into it. The
papilla, measured in transverse section, was 75// in diameter and 105//
in length. Inclosing this genital atrium is a muscular mesh presenting
somewhat the form of a hemisphere and in outline suggestive of a
sucker. The genital atrium may be regarded as the cavity of the
sucker and the genital pore as its aperture. It presents a sharply

defined limiting layer delimiting it from the body parenchyma
(fig. 48).

Female organs. — The ovary is in the caudal portion of the body to
the left of the median sagittal plane, close to the dome of the acetabu-
lum and immediately
caudad of the ce-
phalic margin of the
acetabulum. The
oviduct takes origin
from the dorsal as-
pect of the ovary and
at first passes directly
caudad. It then
bends and passes to
the right toward the
shell gland, which it
penetrates, but giv-
ing off Laurer's canal
just before it does so.
Immediately after entering the shell gland it unites with the common
vitello-duct to form a fusiform ootype, which is directed obliquely
from the left and dorsally to the right and ventrally to be continued
as the uterus. Laurer's canal passes dorsad close to the left aspect
of the excretory vesicle to reach the dorsum at a point to the left of
the median line and
about 0.56 mm. cau-
dad of the excretory
pore.

The shell gland
lies in close apposi-
tion to the right side
of the ovary; their
zones are, however,
not identical but
overlap, that of the
ovary being a little
the more cephalad
of the two. On ac-
count of this rela-
tion to the ovary, the shell gland lies just to the left of the median
sagittal plane and of the excretory vesicle, which at this level is
crowded over to the right. As already stated the shell gland is
penetrated by the oviduct, the point of penetration corresponding 1 1 1
the dorsal pole of the gland. It is also penetrated by the common
vitello-duct, the point of penetration being close to but a little caudad

Fig. 49

of the point of penetration of the oviduct. The uterus emerges from
its ventral pole, being, as already described, a continuation of the
fusiform ootype. Immediately after emerging, the uterus ascends
cephalad, forming some coils close to the right ventro-lateral aspect of
the ovary, and ascending further ventro-cephalad it forms some coils
directly cephalad of the acetabulum and ventrad of the ventro-caudal
aspect of the caudal testicle. It now turns dorsad, skirting the left
lateral aspect of the caudal portion of the caudal testis to gain a posi-
tion dorsally of this testis, where it turns cephalad. The uterus now
ascends dorsally of the testes until it reaches the level of the cephalic
aspect of the cephalic testis, when it passes ventro-cephalad over this
testis and beneath the coiled vesicula and arch- of union of the vasa
efferentia to gain the ventral aspect of the former. Here it bends
cephalad again, eventually penetrating the genital sucker at a point
slightly caudad of
that of the pars
prostatica and, as
already described,
uniting with the
ductus ejaculato-
rius to form the duc-
tus hermaphrodit-
icus.

The vitellaria,
consisting of
sparsely scattered
but well-developed
follicles, are placed
in the extracecal
fields; longitudi-
nally they are coextensive with the cecal zone, though a few follicles
are found slightly caudad of this zone, and not only in the extracecal
fields but also in the cecal and intercecal areas.

The transverse vitelloducts pass transversely toward the median
line, ventrally of the corresponding testis, and unite close to the
ventro-caudal aspect of the shell gland. From their point of union
the common vitello-duct takes its departure, skirts closely the caudal
aspect of the shell gland and, as already described, penetrates this
gland close to its dorsal pole.

Eggs. — Eggs were not observed in the uterus.

Excretory system. — The excretory system is well developed. A
well-developed excretory vesicle lies in the caudal portion of the body.
It is in the form of an inverted elongate pouch, the fundus of the
vesicle being close to the dome of the acetabulum in the intercecal
field at the level of the cecal ends of the intestines. The body of the

vesicle extends cephalad and toward the dorsum, its diameters in
transverse section becoming progressively smaller. Eventually it
gives place to a short, thick walled duct, which opens in the median
line of the dorsum at about the junction of the equatorial with the
caudal third of the body length and about 0.16 mm. cephalad of the
transverse plane of the cephalic margin of the acetabulum and
slightly cephalad of the level of the caudal margin of the caudal test is.

RELATION TO OTHER SPECIES.

Cotylophoron indicum comes close to G cotylophorum, from which
it differs chiefly in the structure of the esophagus, which is provided
with a bulbus thickening in the latter species but is without it in the

VA it

Fig. 52.

former. The two differ also in the details of structure of the copula-
tory apparatus and in the position of the genital pore. In G indicum
the genital sucker is less sharply delimited, projects less, has a much
smaller genital atrium, and the genital pore is decidedly postbifurcal;
on the other hand, in G cotylophorum the genital sucker is sharply
marked, with rim prominently bulging the venter, with a relatively
roomy genital atrium and with the genital pore in the bifurcal zone.

ILLUSTRATIONS.

Fig. 43. — Profile view. Enlarged. Original.

Fig. 44. — Ventral view. Enlarged. Original.

Fig. 45. — Profile projection of same, showing oral sucker (o. s.),
esophagus (es.), esophageal ganglion (e.g.), right intestine (i.), genital
sucker (g. s.), testes (£.), right vas efferens (v. e. d.), vesicula seminalis
(v. s.), pars musculosa (p. m.), pars prostatica (p. p.), ductus hernia-

phroditicus (d. h.), porus hermaphroditicus (por. h.), genital pore
(g. p.), metraterm (va.), uterus (ut), shell gland (s. g.), ovary (ov.),
Laurer's canal (L. c), excretory vesicle (ex. v), excretory pore (ex. p.),
and acetabulum (ac). a-a, b-b, c-c, d-d, e-e, f-f, planes of section.
'Slightly diagrammatic. Enlarged. Original.

Fig. 46. — Ventral projection of same. Lettering as in fig. 45.
"Slightly diagrammatic. Enlarged. Original.

Fig. 47. — Transverse sections at a-a, figs. 45 and 46. Shows oral
sucker (o. s.) with the papillae lining the lumen, perisuctorial space
\(p. s. sp.), and mesenterial band (m. b.). Enlarged. Original.

Fig. 48. — Transverse section at b-b, figs. 45 and 46. Shows genital
atrium (g. a.), genital papilla (g. pap.), genital sucker (g. s.), ductus
1 hermaphroditicus (d. h.), pars prostatica (p. p.), intestinal ceca (i),
witellaria (v. g.). Enlarged. Original.

Fig. 49. — Transverse section at c-c, figs. 45 and 46. Shows form
tof body at equator, cephalic testis (t. s.), origin of left vas efferens
((v. e. s.), position of the right vas efferens (v. e d.), uterus (ut.), intes-
fctinal ceca (%.), and vitellaria (v. g.). Enlarged. Original.

Fig. 50. — Transverse section at d-d, figs. 45 and 46. Shows caudal
iportion of cephalic testis (t. s.), and cephalic lobe of oaudal testis
((t. d.), right vas efferens (v. e. d.), uterus (ut.), intestinal ceca (%.),
i and vitellaria (v. g.). Enlarged. Original.

Fig. 51. — Transverse section at e-e, figs. 45 and 46. Shows caudal
testis (t. d.), origin of right vas efferens (v. e. d.), uterus (ut.), intestinal
ceca (i.), vitellaria (v. g.), and excretory canals (ex. c). Enlarged.
< Original.

Fig. 52. — Transverse section at e-e, figs. 3 and 4. Shows ovary
(ov.), shell gland (s. g.), first part of uterus (ut.), Laurer's canal
(L. c), excretory vesicle (ex. v.), intestinal ceca (i.), vitellaria (v. g.),
tand acetabulum (ac). Enlarged. Original.

Genus PARAMPHISTOMUM, Fischoeder, 1901.

Generic diagnosis. — Paramphistominse (p. 62): Body tends to a conical form,
with convex dorsum and cancave venter, rather attenuate cephalad, rather blunt

'Caudad; ventral pouch absent. Acetabulum terminal, tilts ventrad, small to very
large, sunken, margin not raised, aperture small to large. Genital sucker absent, pore
\ < ntro-median, pretesticular. Excretory vesicle at least partly in acetabular zone.
Oral sucker without evagination; esophagus with or without muscular thickening;
ceca long, nearly straight to wavy, end postequatorial, posttesticular, usually in

j acetabular zone.

Male organs: Testes 2, usually intercecal, small to large, finely lobulate to coarsely
llobate, exceptionally nearly smooth, fields coincide to separate, zones coincide to
."Beparate; cirrus pouch absent.

Female organs: Ovary and shell gland usually posttesticular, never pretesticular;
1 Laurer's canal may cross vesicle; uterus runs dorsally of testes, under arch of vasa
• efferentia, then ventrally of vas deferens.

Eggs: With (or without ? ?) operculum.

Type species. — P. cervi (Schrank, 1790).

The species of this genus may be arranged in several groups, the
individual members of which appear more closely related to each
other than to individual members of other groups. Still it is some-
what difficult at present to separate the forms with entire satisfaction.
That several of these groups will eventually be recognized as of generic
rank seems certain, but in the interest of conservatism, we propose
to recognize them temporarily only as subgenera, as follows:

Subgenus Paramphistomum, with cervi (type), epiclitum, liorchis, and bathycotyle .

Subgenus Orthoccelium., with orthoccelium (type), and dicranoccelium.

Subgenus Bothriophoron, with bothriophoron (type), and papilligerum.

Subgenus Cauliorckis, with cauliorchis (type), crassum, probably papillosum, and

doubtfully indicum and calicophorum.
Subgenus uncertain: All the other known species.

The following key will aid in separating the species in question :

Key to species of Paramphistomum

A2. Laurer's canal crosses excretory canal or vesicle p. 75.

A1. Laurer's canal does not cross excretory canal or vesicle, its pore is always cephalad
of excretory pore; ovary prevesicular; testes touch median line:
Bl. Ceca nearly or quite straight, end in pre- or acetabular zone; esophagus with
slight muscular thickening; acetabulum small; excretory vesicle club-shaped;
ventral chamber of genital atrium absent; testes lobate, distinctly and con-
siderably preacetabular, fields coincide; vitelline follicles coarse, grouped;

type orthoccelium Subgenus Orthoccelium, p. 77.

C". Excretory vesicle and canal directed dorso-cephalad, excretory pore slightly
prevesicular; genital pore bifurcal; vitelline follicles usually in single row
each side; testes about as large as acetabulum; oral sucker with sphincter;
esophagus twice as long as oral sucker; ceca deep, end pre- to acetabular;
body 5 to 11 mm. long; type host Bos kerabau, from Ceylon.

P. orthoccelium, p. 77.

C2. Excretory vesicle and canal directed dorso-caudad, excretory pore post-
vesicular; genital pore postbifurcal; vitelline follicles usually in two rows
each side; testes larger than acetabulum; oral sucker without sphincter;
esophagus about one and one-half times as long as oral sucker; ceca rather
narrow and in section nearly circular, end preacetabular; body 5 to 8 mm.

long; type host Bos indicus P. dicranocaelium, p. 77.

B2. Ceca sinuous to wavy, end in acetabular zone; [subgeneric position as yet
uncertain, but not typical subgenus Paramphistomum] :

C3. Esophageal muscular thickening absent; esophagus about as long as sucker;
ceca wavy; excretory pore in vesicular zone; acetabulum terminal small to
moderate; genital pore postbifurcal; ventral chamber of genital atrium
small; testes (? about equal to and) removed from acetabulum, fields
coincide, zones slightly separate; musculosa long, coiled; ovary slightly
ventro-cephalic ; vitellaria in esophageal, cecal, and cephalic part of post-
cecal zone; body 5 to 11 mm. long; type host Bos kerabau, Ceylon.

P. streptoccelium.

C*. Esophageal muscular thickening present; testes lobate; acetabulum moderate:
D1. Excretory pore prevesicular; ventral chamber of genital atrium present,
genital atrium (dorsal chamber) papillated; ceca wavy; testicular zone
overlaps acetabulum; body 3 to 3.9 mm. long, 1.8 to 2.3 mm. broad;
type host Bos indicus, Siam P. parvipapillatum, p. 143.

D-. Excretory pore in vesicular zone; ventral chamber of genital atrium small,
complicated; musculosa quite large, coiled; ceca wavy; testicular zone
slightly preacetabular, testes slightly larger than acetabulum, testic-
ular fields nearly coincide; ovary acetabular; vesicle not club-shaped;
body between 4.5 and 7 mm. long, 2.46 mm. broad, 2.26 mm. thick;

type host Cervus eldi P. shipleyi, p. 150.

D3. Excretory pore postvesicular; ventral chamber of genital atrium absent;
ceca sinuous; testicular zones abut to separate, slightly preacetabular;
testicular fields coincide; vitelline follicles coarse, grouped, extend eso-
phageal, cecal, postcecal; vesicle not club-shaped; body 2 to 6 mm. long,
0.7 to 2.5 mm. broad; type host Bos bubalus, Cochin China, and B. taurus,

Annam P. scoliocoslium Fischoeder, 1904.

2. Laurer's canal crosses excretory canal or vesicle; Laurer's pore (except in caulior-
chis and possibly papilligerum) caudad of excretory pore; ovary never entirely
cephalic of vesicle, but always ventral; testes not distinctly larger, but usually
smaller than or about equal to acetabulum; esophagus without muscular
thickening; ceca sinuous to wavy, not straight:
B3. Ventral chamber of genital atrium very large; testes lobate, about equal in size
to acetabulum, testicular fields median, nearly coincide, zones slightly sepa-
rate, nearly abut, preacetabular; acetabulum moderate; ceca long, end in
acetabular zone, moderately broad; type bothriophoron.

Subgenus Bothriophoron, p. 77.
C6. Ventral chamber not papillate; pore of Laurer's canal latero-caudad of excre-
tory pore, which is prevesicular; testes a little removed from acetabulum;
genital sphincter present; body 6 to 9 mm. long; type host Bos indicus,

Madagascar P. bothriophoron, p. 77.

C8. Ventral chamber papillate; pore of Laurer's canal slightly caudad of excre-
tory pore; testes slightly preacetabular; body 8.5 mm. long, 4.3 mm. broad;

type host Cervus eldi P. papilligerum, p. 78.

B*. Ventral chamber of genital atrium absent or small:
C7. Acetabulum large to very large:
D4. Excretory pore prevesicular:
E1. Testicular fields separate, not median, zones overlap, testes lobate,
much smaller than acetabulum, acetabular to somewhat preacetabu-
lar but not far removed; musculosa long and thick; Laurer's pore
postero-lateral of excretory pore; ventral chamber (?); genital pore
postbifurcal, excretory vesicle not narrow, but swollen; acetabulum
large; body 5 to 8 mm. long; type hosts Bos taurus, Togo, Bos zebu,

German East Africa P. calicophorum, Fischceder, 1901.

E2. Testicular fields median, coincide or overlap, zones lobate, testes much
smaller than and near the acetabulum; ventral chamber absent;
excretory vesicle long and narrow; acetabulum very large:
Fl. Genital pore in suctorial zone; musculosa straight, narrow, prostatica
shorter than musculosa; acetabulum less than half as long as body;
testes large; ceca wavy, broad; excretory vesicle long; body 9.75
mm. long, 4.5 mm. broad; type host Buffelus indicus.

P.fraternum, p. 131.

F2. Genital pore in esophageal zone; musculosa coiled; testes large; ace-
tabulum more than half as long as body; ceca wavy, moderately
broad, end in acetabular zone; body 6 to 9 mm. long, 4 mm. broad;
type host Bos indicus, Siam P. siamense, p. 161.

F3. Genital pore in postbifurcal zone; musculosa (?); prostatica longer
than musculosa; acetabulum less than half as long as body; ceca
sinuous, moderately broad, end in acetabular zone; body 8 to 13
mm. long; type host Bos indicus at Berlin, Germany.

P. explanatum Creplin, 1847.

Ds. Excretory pore in vesicular zone; testes small, much smaller than acetabu-
lum, cauliflower shaped, near acetabulum; vesicle bag-like; ceca wavy:
E3. Testicular fields separate, not median, testes pre- and acetabular; muscu-
losa enormous; vasa efferentia convex cephalad; ovary ventro-
cephalic of vesicle; pore of Laurer's canal slightly latero-cephalic of
excretory pore; genital pore postbifurcal; ceca moderately broad; body
6 to 7.5 mm. long, 3.6 to 4.25 mm. broad; type host Bos indicus,

India P. cauliorchis, p. 86.

E4. Testicular fields overlap, median; testes diagonal, pre- and acetabular,
musculosa large; ovary ventral of vesicle; pore of Laurer's canal cau-
dad of excretory pore; genital pore in suctorial zone; ceca broad; body
6 to 6.5 mm. long, 4 to 4.76 mm. broad; type host Bos indicus,

India P. crassurn, p. 101.

Es. Testicular fields coincide, median, testes preace tabular; musculosa
large; ovary ventro-cephalic of vesicle; pore of Laurer's canal caudad
of excretory pore; ventral chamber small, papillate; genital pore in
esophageal zone, ceca moderately broad; body 5 to 6 mm. long, 2.6

mm. broad; type host Bos indicus, India P. ■papillosum, p. 112.

C8. Acetabulum small to moderate; ventral chamber absent; testicular fields
median, coincide or overlap; ovary ventral of vesicle:
Z)6. Testes distinctly removed from acetabulum; genital pore postbifurcal;
vesicula club-shaped; excretory pore pre vesicular:
E6. Acetabulum small, about one-eighth as long as body; genital sphincter
absent; pars prostatica large, oval; musculosa short, not coiled; body
11 to 15 mm. long; type host Bos kerabau, also in Portax tragoca-

melus P. gracile Fischoeder, 1901.

E7. Acetabulum moderate; genital sphincter present; pars prostatica thin;
musculosa long, coiled; body 8 to 11 mm. long; type host Antilope
dorcas P. microbothrium Fischoeder, 1901.

D7. Testes near acetabulum :
jE8. Testes much smaller than acetabulum, cauliflower-like; excretory vesicle
bag shaped, distended; excretory pore in pre- and vesicular zones;
body 5.25 to 9.5 mm. long, 2 to 3 mm. broad; type host Bos indicus,

India P. indicum, p. 121.

E9. Testes about equal to (or slightly smaller or larger than) acetabulum;
excretory pore distinctly prevesicular; type cervi.

Subgenus Paramphistomum, p. 77.
F*. Testes nearly smooth; genital pore prebifurcal; pars musculosa very
short; body 3 to 8 mm. long; type hosts Cervus simplicicornis, C.
campestris, C. mexicanus, C. rufus, C. dichotomus, C. namby,

Brazil P. liorchis Fischoeder, 1901.

Fs. Testes lobate:

G]. Testes distinctly smaller than acetabulum; acetabulum one-third as
long as body; body 11 to 15 mm. long; type host Bos kerabau,
Ceylon P. bathycotyle Fischoeder, 1901.

G2. Testes not distinctly smaller than acetabulum:
IP. Genital pore bif ureal or only slightly postbifurcal; body 5 to 12 mm.
long; type host Cervus elaphas, Europe. .P. cervi (Schrank, 1790).
G3. Genital pore markedly postbifurcal; body 5 to 9 mm. long, 2 to 3
mm. broad; type hosts Bos bubalus, Cochin-China, and Bos indicus,
at Berlin, Germany P. epiclitum Fischoeder, 1904.

Subgenus PARAMPHISTOMUM.

Subgeneric diagnosis. — Paramphistomum (p. 73): Ceca sinuous to wavy, not
straight; long, end in or close to acetabular zone; esophagus without muscular thick-
ening. Acetabulum moderate, terminal. Excretory vesicle elongate, more or less
club shaped, its pore prevesicular. Ventral chamber of genital atrium absent.

Male organs: Testes lobate to smooth, near and about equal to acetabulum, at least
neither very much larger nor very much smaller (except possibly bathycotyle), testicular
zones slightly separate or abut or slightly overlap, fields median, nearly or quite
coincide.

Female organs: Ovary ventral of vesicle; Laurer's canal crosses excretory canal or
vesicle, its pore caudad of excretory pore; vitellaria in esophageal, cecal, and post-
cecal zones.

Type species. — P. cervi (Schrank, 1790).

This subgenus contains at least 4 species (cervi, epiclitum, liorchis,
and bathycotyle), all of which have been studied by Fischoeder.

ORTHOCCELIUM, new subgenus.

Subgeneric diagnosis. — Paramphistomum (p. 73): Ceca nearly or quite straight,
end preacetabular or in proximal portion of acetabular zone; esophagus with slight
muscular thickening. Acetabulum small, terminal, tilts ventrad. Excretory vesicle
club shaped. Ventral chamber of genital atrium absent.

Male organs: Testes about equal to or larger than acetabulum, lobate, zones abut
and are considerably preacetabular, fields coincide, in median line.

Female organs: Ovary prevesicular; Laurer's canal does not cross excretory vesicle
or duct, its pore cephalad of excretory pore; vitelline follicles coarse, grouped, extend
from esophageal into postcecal and even into acetabular zone.

Type species. — Paramphistomum orthoccelium Fischoeder, 1901.

This subgenus, which at present contains two species (orthoccelium
and dicranoccelium, see key p. 74), will probably eventually be
recognized as a distinct genus. Both of these species have been
studied by Fischoeder.

BOTHRIOPHORON, new subgenus.

Subgeneric diagnosis. — Paramphistomum (p. 73): Ceca sinuous to wavy, not
straight; long, end in acetabular zone, and moderately broad; esophagus without
muscular thickening. Acetabulum moderate, terminal. Excretory vesicle distended,
not club shaped. Ventral chamber of genital atrium very large.

Male organs: Testes lobate, about equal in size to and not far away from acetabulum,
testicular zones slightly separate, nearly abut, fields median, nearly coincide.

Female organs: Ovary ventral of vesicle; Laurer's canal crosses excretory canal or
vesicle, its pore (in the type species at least) caudad of the excretory pore; vitellaria
well developed, extend from bifurcation to slightly caudad of ceca.

Type species. — Paramphistomum bothriophoron (Braun, 1891).

Two species (namely, bothriophoron and papilligerum) may be
classified here. They are easily separated by the papillate or non-
papillate condition of the ventral chamber of the genital atrium.
P. bothriophoron has been recently studied by Fischoeder.

PAKAMPH Intom l M PAPILLIGEBUH, new Bpeeiea.

[Figs. 53 to 50.]

Specific diagnosis. — Paramphistomum (p. 73): Body 8.5 mm. long by 4.3 mm.
broad; color (?); greatest breadth near caudal end; tapers gradually to bluntly pointed
oral pole, very rapidly to very bluntly rounded caudal pole. Surface without papillaj.
Genital pore at junction of cephalic with equatorial thirds of body, with elliptical
bulging 1.08 mm. in transverse, 0.8 mm. in longitudinal diameter, with 2 transverse
labia; genital pore about 0.61 mm. by 0.37 mm.; surface of bulging sparsely papil-
late; at this point a crateriform, papillate atrium. Acetabulum terminal, sunken in
parenchyma, its margin not projecting, 1.88 mm. in transverse diameter, opening
caudad (terminal) 0.46 mm. in transverse diameter. Mouth in depression at cephalic
pole; oral sucker rather oval in frontal section, its lumen papillate; lies in a well
developed perisuctorial cavity; esophagus bent, convexity ventrad, its wall rather
uniform in thickness; ceca long, wavy dorso-ventrally, extend caudad about to equator
of acetabulum. Excretory pore about dorso-median, slightly cephalad of pore of
Laurer's canal; excretory canal runs to dorsal (or dorso-caudal?) aspect of well-devel-
oped vesicle lying dorsally and dorso-cephalad (?) of acetabulum.

Male organs: Testes large, lobate, in median line, intercecal, fields overlap, zones
slightly overlap; union of vasa efferentia slightly cephalad of cephalic testis; vas
deferens dilated, coiled; pars intermedia connects this with coiled musculosa; pars
prostatica relatively short, passes directly ventrad; ductus ejaculatorius opens just
above metraterm into transverse (in frontal plane) slit-like chamber, whence a duct
passes ventrad apparently piercing a papilla ; the latter projects into a chamber which is
connected by a very short duct with the papillated genital atrium.

Female organs: Ovary and shell gland between caudal testis and acetabulum, ovary
slightly to left of median line, shell gland about median ; vitellaria with well-developed,
sparsely scattered follicles, chiefly in extracecal area, extending from esophageal to
slightly caudad of cecal zone; uterus extends from shell gland slightly caudo-sinistrad,
then ventrally of ovary and shell gland dextrad, bends cephalad dorsally of testes,
ventrad under arch of vasa efferentia, cephalad ventrally of vas deferens to open caudad
of male opening into the slit-like chamber.

Eggs: Oval, 135/z by 67ju, operculated (?).

Type.— U.S. P.H. & M.H.S. 10706 (returned to Doctor Shipley).
Habitat. — In (stomach (?) of) Cervus cldi, locality not known.

Source of material. — The material, consisting of a series of
frontal sections, was kindly loaned us by Dr. A. E. Shipley.

EXTERNAL CHARACTERS.

Size. — Measurements taken from the sections give about 8.5 mm.
for the maximum vertical diameter and about 4.3 mm. for the maxi-
mum transverse diameter.

Form. — The greatest width of the worm is near the caudal extrem-
ity, from which region it tapers in both directions. The caudal
extremity is broad, rounded from side to side, and presents the aper-
ture of the acetabulum; the cephalic extremity is bluntly pointed and
presents at its vertex a well-marked depression, at the bottom of which
is the oral aperture.

Surface. — The general surface of the worm appears unprovided
with such structures as spines or hooks, and except for the genital
bulging is without papillae.

Genital pore. — In about the median sagittal line of the venter and
about at the junction of the cephalic with the middle third of the body

[length there is a bulging, elliptical in outline and measuring at the

Ibase about 1.08 mm. in transverse and about 0.80 mm. in vertical
diameter. At the vertex of this bulging there are two transverse
lip-like structures, continuous laterally, which bound, as it were, a
transversely elliptical aperture. This aperture may be regarded as

• the genital pore, and measures 0.61 mm. in transverse and about 0.37

imm. in median sagittal diameter. The surface of the bulging is

! beset by minute sparsely scattered papillae.

The genital pore gives entrance to a crateriform depression or

: atrium, the surface of which is closely beset by nipple-like papillae
(fig. 53), which are considerably larger than those of the surface of

i the genital bulging.

Acetabulum. — The acetabulum is in the caudal extremity of the
worm and measures 1.88 mm. in greatest transverse diameter. Its

; aperture is terminal and measures 0.46 mm. in maximum transverse
diameter. The rim of the acetabulum does not project beyond the
caudal body surface, but appears rather retracted and its aperture

: slightly encroached upon by folds of the encircling portions of the
body.

INTERNAL ANATOMY.

Digestive tract. — The mouth is at the bottom of the depression
: at the cephalic pole of the worm, and leads directly into the lumen of
; a large muscular oral sucker.

In frontal section the sucker has an oval form with a broad rounded
basej which gives origin to the esophagus. The oral pole of the sucker
projects in a ring-like manner beyond the adjacent surface. A roomy
perisuctorial space is present. The lumen of the sucker is closely
beset by well-marked conical papillae. The esophagus at first passes
directly caudad in about the median sagittal plane, then bends
ventrad and describes a short curve, or possibly forms only a moderate
bend (the interpretation is difficult) with its convexity ventrad. It
then passes caudo-dorsad and forks into the lateral intestinal ceca at
or somewhat cephalad of the level of the genital pore. This relation
could not be made out with precision from the sections. The thick-
ness of the esophageal wall is substantially uniform throughout. Its
lumen is lined with a cuticle-like layer. In about the equator of the
esophagus and dorsally of it there is a transverse ganglionic cord.
The intestinal ceca pass at first laterad and slightly cephalad at or
slightly less than a right angle with the esophagus, then turn caudad
pursuing a dorso-ventrally wavy course approximately parallel to
the lateral body wall, terminating by blind extremities about 5 mm.
caudad of the esophageal arch close to the corresponding dorso-
lateral aspect of the acetabulum.

Genital system. — The sexual organs, with the exception of the
vitellogene glands, are disposed in the intercecal area.

Male organs. — There are two lobate testes, one caudad of the other,
their opposing aspects being in close apposition. The cephalically
placed of the two is a little nearer the left and the caudally placed a
little nearer the right lateral body margin. In some of the sections
the testes appear somewhat wedge-shaped, the left edge of the cephalic
testis and the right of the caudal testis being (vertically) the longer
of the vertical edges of the 2 testes. As the testes are in fairly close
apposition, the line of separation between them runs somewhat
obliquely from the right to the left and caudad, and consequently
their zones overlap to a slight extent (fig. 54). A vas efferens springs
from each testis; that from the caudal gland passes cephalad with a

slight tilt dorsad be-
tween the cephalic
testis and the right
gut, and is of consid-
erable transverse di-
ameter; that from the
cephalic testis passes
at first dorsad, then
to the left and ceph-
alad. The latter is of
a smaller caliber and
soon reaches the up-
per part of the space
between the dorso-
lateral aspect of the
gland from which it
springs and the left
gut, and then dilating
rather abruptly it curves cephalo-mediad to unite with its fellow of the
right side, which likewise curves cephalo-mediad to meet it, and the two
thus form the vas deferens. The vasa efferentia in uniting form a
transverse arch at a level apparently slightly cephalad of that of the
superior margin of the cephalic testis; beneath this arch the uterus is
seen to pass as it arches cephalo-ventrad over the cephalic testis.
The vas deferens presents at first a much dilated, thin-walled, coiled
vesicula measuring about 0.27 mm. in diameter; this is succeeded by a
long, thick-walled, coiled pars musculosa of about 180/t in diameter and
with a thickness of wall of about 60//. Between the vesicula and the
musculosa there is intercalated a relatively thick- Availed segment meas-
uring about 75/rin diameter. The musculosa is succeeded by a relatively
short prostatica; this part of the vas deferens is inclosed in a thick
layer (75/j.) of prostatic cells and passes directly ventrad. The prostatic

Fig. 53.

portion is succeeded by a ductus ejaculatorius which, with the metra-
term, is inclosed in a thin layer of an ill-defined muscular mesh and
opens with, but just above, the metraterm into a frontally transverse
slit-like chamber. From this chamber a duct passes ventrad, appar-
ently piercing a papilla, the form of which can not satisfactorily be

Fig. 54.

made out. This papilla projects ventrad into a chamber (from the dor-
sal wall of the latter sis it were) so that the duct piercing it opens into
this chamber. This chamber in its turn communicates with the cra-
terif orm, papillated ventral genital chamber (previously described) by
13893— Bull. 60—10 6

a very short and quite narrow duct. This series of atria and connecting
ducts of the hermaphroditic copulatory apparatus seems to resemble
that of Paramphist. shipleyi. The marked and striking difference
between the two, so far as one can judge from the sections avail-

Fig. 55.

able for study, consists in the difference (1) in the size and form
of the genital pore (that of P. papilligerum is large, elliptical, and
measures 610/i in transverse diameter, while that of P. shipleyi is
small, approximately circular, and measures about 75/t in transverse

diameter) ; and (2) in the size and form of the ventral chamber of
the genital atrium), which in P. papilligerum is large crateriform,

Fig. 56.

with its surface beset by well developed nipple-like papilla?, while in
P. shipleyi the ventral chamber is small, slit-like, and without papillae
on its surface.

Female organs. — The ovary and shell gland arc in the caudal por-
tion of the worm, between the caudal testis and the acetabulum, and
nearer the venter than the dorsum. The ovary is the larger of the
two female glands and is also the nearer to the venter and is placed
a little to the left of the median sagittal plane. The oviduct springs
from the dorsal pole of the ovary; it passes to the right, curving
gently caudad as it proceeds toward the shell gland, close to the
cephalic aspect of which it forks. One limb of the fork, which may
be regarded as the continuation of the oviduct, turns sharply caudad
to penetrate the shell gland; the other limb bends dorso-caudad and,
as Laurer's canal, at first skirts the right side of the dome of the
excretory vesicle, but as it tends more and more caudad it crosses
the right side of the vesicle and eventually reaches the dorsum a
little to the right of the median sagittal plane and about, or perhaps
a little less than 0.52 mm. caudad of the excretory pore. The shell
gland is close to the right caudo-lateral aspect of the ovary, close to
the ventro-cephalic aspect of the excretory vesicle, and in about the
median sagittal plane of the worm.

As already described, it is penetrated on its cephalic aspect by the
oviduct which unites in the substance of the gland with the common
vitello-duct. The latter duct penetrates the gland at its caudal
aspect. The union of these ducts results in the formation of the
ootype, which is directed ventrad in the substance of the gland. The
ootype is continued as the uterus, which emerges from the ventral
pole of the gland. After emerging, the uterus dips caudad and to
the left, then doubling back it forms coils ventrally of the ovary and
shell gland, then winds its way dorsad to the right of the shell gland
beneath the caudal testis, close to and on the right of Laurer's canal.
On reaching the space between the caudal testis and the dorsum it
begins to wind its way cephalad. Eventually it reaches the level
of the superior margin of the cephalic testis, where it bends ventrad,
passing, as already mentioned, beneath the arch of union of the vasa
efferentia to gain the ventro-lateral aspect of the coiled vas deferens.
Here it bends cephalad, ascending in close relation to the vas deferens,
ultimately arching ventrad close to the caudal aspect of the pars
prostatica and ductus ejaculatorius to open, as has been described,
just beneath the latter into a small slit-like chamber. The uterus
is distended more or less in various portions of its course by eggs
and by masses of spermatozoa. The eggs are oval in form; some of
them measured 135/t in length by 67/* in width.

The vitellaria consist of sparsely scattered well developed follicles
in the extracecal areas. Vertically they extend from about the
level of the base of the oral sucker to or perhaps slightly caudad of
the level of the cecal ends of the gut. Their zone, therefore, is about
coextensive with the combined zones of the esophagus and intestinal

ceca. A transverse vitello-duct from each gland passes mediad
ventrally of the corresponding intestine. These ducts unite close
to the ventro-caudal aspect of the shell gland. The common vitello-
duct thus formed passes dorsad close to the shell gland, the caudal
aspect of which it eventually penetrates.

Excretory system. — This seems well developed. A large vesicle
lying dorsad of the acetabulum is present. An excretory duct leaves
the dorsal, probably caudo-dorsal, aspect of the vesicle and passes
to about the median vertical line of the dorsum to open at a point
in a transverse plane slightly cephalad of that of the pore of Laurer's
canal.

RELATION TO OTHER SPECIES.

This species appears most nearly related to Param. hotliriophoron,
from which it differs mainly in the structure of the copulatory appa-
ratus. In P. papilligerum the genital chamber is papillated and the
genital pore is without a sphincter; in P. oothriophoron the chamber
is not papillated and the genital pore is encircled by a sphincter.
Besides this, large papillae line the suctorial lumen of P'. papilligerum;
they are absent in P. bothriopJwron.

ILLUSTRATIONS.

Fig. 53. — Optical section through genital bulging near its vertex.
Shows papillae in genital atrium. Enlarged. Original.

Fig. 54. — Optical section. Shows depression at oral pole leading
to the mouth; oral sucker (o. s.) with papillae, perisuctorial space
(p. s. sp.), pars prostatica {p. p.), pars musculosa {p. m.), vesicula
seminalis (v. s.), uterus (ut.), lobate testes (t.), ovary (ov.),- shell
gland (s. g.), intestine (i) of left side, vitellaria (v. g.), and acetabulum
(cc). Enlarged. Original.

Fig. 55. — Optical section. Shows oral sucker and papillae (o. s.),
perisuctorial space (p. s. sp.), esophagus (es.), point of change from
musculosa to prostatica (p. p.), pars musculosa (p. m.), pars inter-
media (p. %.), vesicula seminalis (v. s.), uterus (ut), testes (t.), ovary
(ov.), oviduct (ov. d.), shell gland (s. g.), Laurer's canal (L. c), trans-
verse vitello-ducts (t. vol.), intestinal ceca (i.), vitellaria (v. g.), and
acetabulum (ac). Enlarged. Original.

Fig. 56. — Optical section. Shows portion of oral sucker (o. s.),
perisuctorial space (p. s. sp.) with granular coagulum, intestinal ceca
(i.), vesicula seminalis (v. s.), arch of union of vasa efferentia (v. e. a.),
right vas efferens (v. e. d.), left vas eff'erens (v. e. s.) passing dorsad
from its point of origin on one of the testicular indentations, testes
(t), excretory vesicle (ex. v.), Laurer's canal (L. c), uterus (ut.),
acetabulum (ac), and vitellaria (v. g.). Enlarged. Original.

CAULIORCHIS.o new subgenus.

Stjbgeneric diagnosis. — Para in phis tomum (p. 73): Ceca distinctly wavy, end
in acetabular zone; esophagus without muscular thickening. Acetabulum very large,
terminal, tilts ventrad, aperture likely to be rather small. Excretory vesicle not
elongate-club shaped, but distended and bag-shaped, its canal rather short, directed
dorsad and may extend slightly cephalad or caudad, its pore in vesicular zone.
Ventral chamber (?) of genital atrium.

. Male organs: Testes very much smaller than acetabulum, cauliflower-like, in pre-
or acetabular zones, testicular zones separate, or overlap or coincide, fields separate
or overlap or coincide; musculosa well developed, may be enormous, coiled.

Female organs: Ovary ventral to ventro-cephalic of vesicle; Laurer's canal crosses
excretory vesicle or canal, its pore is in vesicular zone, caudad to caudo-laterad of
excretory pore, the two pores may be quite close to each other.

Type species. — P. cauliorchis n. sp.

At least 2 species {cauliorchis and crassum), probably a third
species (papillosum), and possibly, but doubtfully, two other species
(indicum and calicophorum) may be placed in this subgenus.

PARAMPHISTOMUM CAULIORCHIS new species.

[Figs. 57 to 70.]

Specific diagnosis. — Paramphistomum (p. 73): Body 6 to 7.5 mm. long by 3.66
to 4.25 mm. in maximum breadth; grayish buff in color (alcohol specimens); viewed
ventrally, pear shaped; viewed laterally, reminds one of an infant's shoe (the caudal
end representing the top, the dorsal angle representing the heel, and the oral pole
representing the toe); greatest diameter about at junction of equatorial and caudal
thirds; tapers rapidly, then gradually to bluntly pointed, rather truncated conical
oral pole; caudal end bluntly rounded when viewed ventrally, truncated when
viewed laterally; sagittal line of dorsum markedly convex, almost circular at broadest
diameter; transverse section nearly circular. Surface with transA^erse grooves, espe-
cially ventrally; oral pole with small conical papillae; surface folds around aperture
of acetabulum. Genital pore ventro-median, about one-fourth of body length from
oral pole and at or somewhat caudad of oral sucker and intestinal bifurcation;
the pore is situated on large, 0.7 mm., hemispherical, erectile, retractile, bulging
structure, the latter encircled by a ridge; it leads into an atrium into which
from its dorsal wall, extends an elongate genital papilla, bearing at its vertex
the porus hermaphroditicus; the genital papilla is closely encircled by a broad
band-like muscular wall of the atrium; atrium divided into a larger dorsal and a
smaller ventral portion by a deep circular groove; when the erectile bulging structure
is retracted the encircling ridge forms a pair of transverse labia, between which is a
transverse slit. Acetabulum anatomically terminal, but because of bending of body
of worm it comes to lie ventro-subterminal; sunken into body of worm; very large,
2.5 mm. in dorso-ventral, 3 mm. in transverse diameter, aperture about 0.95 mm.,
directed ventro-caudad ; cavity very deep. Mouth terminal, buccal cavity crateri-
form, papillated; oral sucker large, 1 to 1.1 mm. long or one-fifth to one-sixth of body
length, 0.74 mm. thick, 0.98 mm. broad, pyriform, its papillated lumen broad and
flat; sucker lies in a perisuctorial cavity and is bound to parenchyma dorsally and
ventrally by mesenterium-like bands; esophagus tortuous, about as long as (at least
not shorter than) oral sucker; bifurcation usually cephalad of genital pore; ceca long,

« From caulis (from kouXSc), a cabbage stalk, a cabbage [Brassica oleracea is the
cauliflower], and 'Spxic, testicle.

extending in wavy course to near caudal margin of acetabulum. Excretory pore
dorso-median at or near plane of caudal margin of aperture of acetabulum, 60 to 320/t
caudad of Laurer's canal; excretory canal thick walled, arises about on border be-
tween third and fourth quarter of length of vesicle; excretory vesicle dorsal of ace-
tabulum, of moderate dimensions.

Male organs: Testes immediately caudad of equator, in same transverse plane,
though one may extend very slightly farther cephalad, and farther dorsad also, than
the other; irregular in outline, cauliflower-like in section; vas efferens arises from
lateral aspect, passes in an archmedio-cephalo-dorsad, then caudad, then medio-dorso-
caudad about to plane of origin, then mediad to unite with its fellow to form vas def-
erens; vas deferens very highly developed, occupying most of intercecal area cephalad
of testes; vesicula seminalis intricately coiled; pars musculosa enormously developed,
attains 0.4 mm. in thickness; pars prostatica nearly straight, attains 1.2 mm. in length,
runs cephalo-ventrad or almost directly ventrad; ductus ejaculatorius rather short,
straight, opens into dorsal dilatation of ductus hermaphroditic us cephalad of metra-
term. Ductus hermaphroditicus with dorsal dilatation and runs through genital
papilla.

Female organs: Ovary considerably smaller than testes, right or left of median line
but caudo-mediad of one testis; shell gland smaller than ovary, median and caudad
or cephalad of ovary; vitellaria with sparsely scattered small follicles, lateral, extends
from about equator of oral sucker about to end of ceca; uterus runs in loops ventrally
from shell gland, then turns dorsad, extends cephalad in dorsal portion of median
field, bends ventrad under arch of vas deferens, cephalad ventrally of pars muscu-
losa to open into dilated portion of ductus hermaphroditicus; Laurer's canal runs
from oviduct, crosses on right or left of excretory vesicle, and opens slightly to right
or left of median line, 60 to 320/z cephalad of excretory pore.

Eggs: Not observed.

Type: U.S.N.M. 7155. Cotype U.S.B.A.I. 15026.

Habitat. — In (organ? of) Bos indicus, Sanawaar, Punjab, India.

Source of material. — Four specimens were found in a bottle bear-
ing the U.S.N.M. number 5775 and three in a bottle bearing B.A.I,
number 1723. These were renumbered U.S.N.M. 7155 and 15026,
respectively. Aside from the difference in the numbers the labels in
the two bottles bear the following legend :

"Name Amphistoma crumeniferum. Locality, Sanawaar, Punjab, India. Host, Bos
indicus. Collected by Dr. Giles. Date, III, 1893. Determined by Dr. Giles.
Date, 1893. Presented by Dr. Giles. Date, 1893."

EXTERNAL CHARACTERS.

Size. — The 7 specimens forming the collection vary from 6 to 7.5
mm. in length. The greatest width varies from 3.66 to 4.25 mm. in
3 of the 7 specimens in which this diameter was measured.

Color. — The worms were of a grayish buff tint.

Form. — The form is typically shown in figs. 57-60. In transverse
section the body of the worm is approximately circular and its greatest
transverse and dorso-ventral diameters are at about the junction of
the equatorial with the caudal third of the body. From this region
of the body these diameters become gradually reduced in the direction
of both poles; toward the oral pole the reduction is rapid for a short

Fig. 57.

distance, then it becomes very slow, the total reduction being con-
siderable; while toward the aboral pole it progresses uniformly, but
the total is slight. In consequence of this the worm is bluntly pointed
and the cephalic portion of the body appears somewhat cylindric and

distinctly attenuated as contrasted with the
massive ventrally bent caudal portion.

Surface. — The surface cuticle is unarmed;
that is, it is devoid of scales or spines, but at
the oral pole close to the aperture of the mouth
the surface is provided with small rounded and
conical papillae. It is also marked by trans-
verse grooves, which are best defined on the
venter. At the caudal extremity around the
aperture of the acetabulum the worm is deeply
wrinkled, forming rounded folds and tabs which
encroach upon and apparently reduce the size
of the acetabular aperture (figs. 57, 60).

Genital pore. — In the median line of the ven-
tral surface at about the junction of the first
with the second fourth of the body is the genital pore (figs. 57-59,
61-63, 67). This pore, which measured 0.08 mm. in diameter in one
specimen, is at the vertex of a hemispherical bulging which measured
about 0.7 mm. in diameter. Encircling the base of this bulging struc-
ture is a ridge in the form of a transverse ellipse. The genital pore
leads into a cylindrical dorso-ventrally running atrium, from the dorsal
wall of which arises a somewhat elongate trum-
pet-shaped genital papilla. This papilla pro-
jects ventrad into the atrium for about two-
thirds the length of the latter and is closely
embraced by the encircling muscular ring-like
atrium wall (figs. 62, 67). The atrium wall is
divided into two unequal rings by a deep nar-
row circular groove ; the larger or dorsal of the
rings forms about two-thirds of the atrium wall
and is the portion which has just been described
as closely embracing the genital papilla. In sec-
tion it is seen that these rings differ markedly in
structure, the larger or dorsal ring being of a dense
muscular structure, whereas the structure of the
smaller ring is loose and but slightly muscular.

The hemispherical bulging which bears the genital pore at its ver-
tex, is of an erectile nature, and the worm has the power of causing its
retraction. In the retracted state the ridge which has been described
as forming an encircling ellipse about the base of the hemispherical
bulging, forms two transverse lips continuous laterally (figs. 59, 63).

Fig. 58

Fig. 59.

Between these lips is a transverse more or less slit-like aperture which
gives entrance to an irregular dorso-caudally directed passage which

Heads directly to the hermaphroditic pore.

Acetabulum. — The acetabulum is in the caudal terminal portion of

tthe worm,, but on account of the more or

Hess decided bending ventrad of tins por-
tion of the body the acetabular aperture is

i tilted in the same direction. In one of the

■sectioned specimens this muscular organ,

'with an aperture measuring about 0.95 mm.
in diameter, measured 2.5 mm. in dorso-

' ventral, 3 mm. in transverse diameter.

INTERNAL ANATOMY.

Digestive tract. — The bluntly pointed
i cephalic extremity presents a circular cra-
teriform depression which is beset by con-
ical papillae; it leads into the oral sucker
through a small circular opening which
may be designated its oral aperture. The
sucker is large and muscular, varying in length between 1.08 and 1.18
mm., or from one-fifth to one-sixth the body length as measured in

sections of 5 specimens. In one of
these (figs. 61, 62) the extreme dorso-
ventral and transverse diameters were
0.74 mm. and 0.98 mm., respectively;
its form in median sagittal plane is
shown in figure 62. It will be noticed
that it resembles the retracted pear-
shaped sucker of P. calicopJiorum, as
described and pictured by Fischoeder
(1893h, p. 542, fig. 30). The sucker as
a whole may, for purpose of descrip-
tion, be regarded as consisting of a dor-
sal and a ventral muscle, continuous
one with the other laterally. These
two muscles are each thickest in the
median sagittal plane; they grow less
thick as they extend laterad, being
thinnest laterally where they are con-
tinuous one with the other. The opposing faces of these muscles are
closely approximated, so that the lumen of the sucker is reduced to
a dorso-ventrally very narrow slit-like space; the latter is lined with
a cuticle-like layer in anatomical continuity with that of the surface

Fig. GO.

and is beset by very small closely aggregated papillas. These papilla
are largest and most prominent in about the equatorial region of the
sucker, becoming gradually smaller and less distinct as the oral and
esophageal apertures are approached, close to both of which these
papillie do not appear to be present. Except at the oral and the
esophageal ends the sucker is separated from the body parenchyma
by a distinct circumsuctorial space, strongly suggestive of a body
cavity, which is traversed here and there by mesenterium-like strands
attaching the sucker, particularly the dorsal and ventral walls, to the
inclosing parenchyma. The space contains, but does not appear to
be at all filled with, a granular material and a few nuclei (?), the cell
bodies of which are not clearly definable.

Dorsally of the circumsuctorial cavity and on a plane near the
caudal end of the sucker is found the brain.

The esophagus takes origin at the base of the sucker. At a point
about midway between its point of origin and the dorsal wall of the
worm and at about the same or slightly lower (more caudad) level,
namely, at from two-sevenths to one-fourth the body length from the
oral margin, the esophagus divides into two intestinal ceca. The
path pursued by the esophagus between its point of origin and its
bifurcation was found to vary according to two general types; in one
(figs. 61, 62, 64), to which 3 of the 5 sectioned specimens conformed,
the esophagus almost immediately after leaving its point of origin
tends ventrad and to either the left (2 specimens) or the right (1
specimen), curving around and skirting more or less closely the base
of the sucker until it gains either the left or right dorso-lateral aspect
of the latter, beyond which it proceeds in a more direct course to its
point of bifurcation. In the second type (fig. 63), to which 2 of the
5 specimens conformed, the esophagus passes from its point of origin
in a direction caudad and at the same time more or less ventrad for a
variable distance. It then abruptly doubles back on itself, describing
a U-shaped course in about the median sagittal plane of the body.
The dorsal limb of the U quickly assumes a more or less direct course
dorsad to the point of its bifurcation.

From their point of origin the intestinal ceca pass at first almost
horizontally laterad, then curve gently latero-caudad and slightly
ventrad to reach a point about 0.33 mm. from the body wall. Occa-
sionally one or both ceca may arch slightly cephalad of their point of
origin as they pass laterad. The ceca terminate at slightly different
levels, but close to the dorso-lateral aspect of the acetabidiun and a
little above the plane of the caudal margin of the latter. In their
path caudad the ceca describe a Wavy course approximately parallel
to the dorso-lateral aspect of the body Wall (figs. 61, 62).

The lumen of the esophagus is lined with a continuation of
the cuticle-like layer of the sucker. The intestines are lined with a

Fig. 61.

Fig. 62.

Fig. 63.

; layer of epithelium, which begins abruptly at the bifurcation of the
i esophagus.

Genital organs. — Excepting the vitellaria, both the male and the
f female genital organs are situated in the intercecal area.

Male organs. — The testes are in the zone immediately caudad of
[the equatorial plane, one
on either side of the median
■ sagittal plane. Further
Ithan this, however, the re-
lation which they bear one
ito the other and to the
I acetabulum is subject to
marked variation. Their
: superior (cephalic) mar-
igins may be in the same
(3 specimens) or in differ-
«ent (2 specimens) trans-
verse planes ; in 2 specimens
in which the latter condition obtained the superior margin of the left
testis was 0.2 mm. cephalad of that of the right in one case, while in
i the other it Was the superior margin of the right testis that was
i cephalad of that of the left, and in this instance the difference was

0.26 mm. Further-
more, in each of these
2 specimens the
higher (cephalad) tes-
tis was also the far-
ther dorsad. In 2 of
the 3 specimens in
which the superior
margins of the testes
were found in the
same transverse plane
the right testis was a
little farther dorsad
than the left; in the
third of these speci-
mens both testes were
in about the same
frontal plane. It may
be observed in this
connection that a certain relation appears to exist between the posi-
tion of the testes and that of the ovary and shell gland, namely, in 4
of the 5 specimens in which one of the testes was placed farther dor-
sad than the other the ovary and shell gland were found on that side
of the median sagittal plane to which the dorsally placed testis belonged.

0.*.

In 2 of the specimens the testes were immediately cephalad of theJ
superior margin of the acetabulum; in 2 others they were imme-
diately caudad of this level, and in a fifth they were at this level <
They are greatly branched, cauliflower-like in sections, and differ
slightly in size in the same and in different specimens. Measure-
ments, from projections, of the left testis in one of these worms gave^
1.2 mm. for the greatest dorso-ventral, 0.6 mm. for the greatest!
transverse, and 0.64 mm. for the greatest longitudinal diameter. X\
vas efferens arises from the external lateral aspect of each testis;
these unite to form the vas deferens. The point of union of the vasa
efferentia is generally at about the same level as the point of origin

Fig. 65.

of one or both the vasa efferentia and more or less dorsad of the mid
point in the ventro-dorsal diameter. The path pursued between their
point of origin and their union is peculiar and differs from that in
any of the other forms studied. Each vas at first passes medio-
cephalo-dorsad for a variable distance, in some of the specimens con-
siderably above the superior margin of the testis (figs. 61, 62) from
which one or both originates. Each then turns caudad, describing a
more or less well-marked curve, with its convexity cephalad, and thes
proceeds medio-dorso-caudad to about the level at which one or both
originated, where they pass more or less directly inward to unite, as

is already been said, in the formation of the vas deferens. The
isa are fairly thick-Walled ducts, measuring 60 to 75 p. in diameter
one of the specimens.

The vas deferens is very highly developed and occupies most of
ae space in the axial region of the body between the intestinal ceca
pphalad of the testes. As in the other forms of this group, it is
early differentiated into four portions. The first portion, or vesi-
lla, is an intricately coiled, thin-walled,- and but slightly dilated duct,
inch is succeeded by a strikingly large, thick, muscular-walled second
ort ion, or pars musculosa, which measured 0.4 mm. in diameter, with

thickness of Wall of 0.15 mm. in one specimen. The change from
esicula to musculosa is abrupt and is marked not only by the
normous increase in the diameter of the duct and in the thickness

Fig. 66.

if its wall, but by the interposition of a short section, which from its
arrangement probably serves the purpose of a valve. This valvular
segment — or pars intermedia (p. i., fig. 68), as it may be designated — is
k& direct continuation of the vesicula, but the caliber of its lumen is
:greatly reduced, its Walls are thick and muscular, but its total diam-
'eter is little, if at all, greater than that of the vesicula. Its distal end
pierces the enormously thick muscular wall of the pars musculosa,
onto the lumen of winch it projects in a manner resembling the pro-
jection of the cervical portion of the uterus into the human vagina.
pThe musculosa is compactly coiled; the windings run in a vertical
direction and, unlike those of the vesicula, can be traced without
nmuch difficulty. The musculosa is succeeded by the pars prostatica;
! the change from one to the other is marked by a structure suggesting

a valvular function (fig. 67). Except that there is not interposed an
intermediate section between the musculosa and the prostatica, the
valve-like arrangement appears to be exactly like that at the junc-
tion of vesicula and musculosa, with the further difference that the
former is considerably smaller in diameter. As this point is ap-
proached, the musculosa becomes gradually reduced in diameter and
its wall in thickness. The prostatica is not coiled; it pursues an
almost straight or slightly sinuous course ventrad or cephalo-ventrad.
In the latter case it describes a slight cuive in a sagittal plane, with

g. fiaf^
Fig. 67.

the convexity of the curve cephalad. Throughout its length it is
inclosed in a mass of cells; in projection of one specimen the prosta-
tica measured 1.2 mm. in length.

The diameter of this portion of the vas deferens becomes gradually
reduced in its course ventrad. The reduction is for the most part at
the expense of the lumen, for the walls remain highly muscular and
but slightly reduced in thickness. The pars prostatica is succeeded
by the fourth or terminal portion of the vas deferens. This portion,
or ductus ejaculatorius, is a direct continuation of the prostatica, the

change from one to the other being defined only by the cessation of
the cell mass characteristic of the prostatica. It passes directly
ventrad and opens by a minute pore into the dorsal dilated vesicle-
like portion of the ductus hermaphroditicus immediately above and
quite separate from the aperture of the metraterm (fig. 62). It
measures about 0.24 mm. in length in one specimen. The ductus
hermaphroditicus is a delicate duct which pierces the axial region of
the genital papilla to open externally as the poms hermaphroditicus.
It leads from an atrium or vesicle "which may perhaps be regarded as
the dilated internal extremity of the duct. Into this vesicle or
atrium there open the ductus ejaculatorius and the metraterm.

Fig. 68.

Female organs. — The ovary varies somewhat in size, form, and
position, and in its relation to the shell gland. It is considerably
smaller than either testis, close to one of which it is placed. In 3 of
5 specimens studied the ovary was on the right side of the median
line close to the ventro-mesio-caudal aspect of the right testis; in the
other 2 specimens it Was on, the left side, in one slightly caudad of
the testis and in the other close to the ventro-mesio-caudal aspect of
the left testis. The shell gland is smaller than the ovary but like the
latter varies somewhat in size, form, and position; in 4 of 5 speci-
mens it was close to the mesio-dorso-caudal aspect of the ovaiy; in
the fifth specimen it lay close to the mesio-cephalic aspect of the
ovary. The oviduct springs from the dorsal pole of the ovary and
13893— Bull. 60—10 7

passes to the shell gland which it penetrates at some point on its
dorsal aspect, describing in its more or less horizontal course a well-
marked curve with its convexity dorsad.

Laurer's canal leaves the oviduct from some point more or less
close to the shell gland and opens on the dorsum by a minute pore
slightly to the right (twice) or to the left (fig. 70) (three times) of
the median line and from about 60/z to 320// cephalad of the excretory
pore. It will be remembered that in the 5 specimens studied the
ovary was found on the right side in 3 ; in 1 only of these 3 specimens
did Laurer's canal open to the right of the median line, in the other 2
it opened to the left of this line. In the 2 of the 5 specimens in which
the ovary was found on the left side, Laurer's canal opened on the
left side in one and to the right in the other. It may therefore be

easily understood
that the path de-
scribed by Lau-
rer's canal in its
course to the dor-
sal opening varies
widely. In gen-
eral it may be said
that this canal,
after leaving the
oviduct, passes di-
agonally to the
other side of the
median line over
the excretory
vesicle to gain the
dorsal aspect of
the latter, then
proceeds dorso-
caudad to the opening on the dorsal surface. In the minority of cases
(2 in 5) the canal remains on the side (either right or left) in which
it takes origin, skirts the lateral margin of the excretory vesicle as it
proceeds dorso-caudad, gains the dorsal aspect of the vesicle and
opens on the dorsal surface on the same side of the median line with
its point of origin.

The vitellaria, consisting of sparsely scattered insignificant follicles,
occupy the lateral fields of the body external to the intestinal ceca.
They extend longitudinally from about the level of the equator of the
sucker to about the level of the cecal extremities of the intestines. A
duct leaves each gland at a point a little caudad of the level of the
superior margin of the acetabulum and passes transverseh7 inward
with a more or less marked tilt cephalad, ventrally of the correspond-

Fig. 69.

ing testis, to unite with its fellow close to the caudo-ventral aspect of
the shell gland. From their point of union a duct passes dorsad
skirting the caudal or one of the caudo-lateral margins of the shell
gland to penetrate the latter at some point at its caudo-dorsal aspect.

Within the shell gland this vitello-duct joins with the oviduct to
form a common canal which almost immediately forms a fusiform
ootype. The direction of the ootype is ventrad or ventro-cephalad,
sometimes with a slight tilt to either the right or left. The ootype is
continued as the uterus which emerges at some point on the ventral
or ventro-lateral aspect of the shell gland. After emerging the uterus
forms some coils ventrad or ventro-mediad of the shell gland ; it then
winds its way dorsad over the excretory vesicle or skirts one side of
the superior portion of the latter. Dorsad of the excretory vesicle
several loops dip
caudad ; it then
winds its way ceph-
alad in the dorsal
part of the median
field, then bends
ventrad winding its
way beneath the
arch of the vasa ef-
ferentia close to the
caudal aspect of the
coiled pars muscu-
losa to reach the
ventral aspect of the
latter ; having
reached this point
the uterus bends ab-
ruptly cephalad and
with but few wind-
ings maintains this relation to the vas deferens throughout the re-
mainder of its course, opening, as has already been mentioned, into
the dilated vesicle-like portion of the ductus hermaphroditicus imme-
diately beneath the opening of the ductus ejaculatorius.

Eggs. — Eggs were not observed in any of the specimens.

Excretory system. — The excretory system is well developed. A
vesicle of moderate dimensions lies dorsally of the acetabulum. From
the dorsal aspect of this vesicle from a point which varies considerably
in position, but which may be described as at about the junction of
the third with the fourth quarter of the length of the vesicle, there
arises a moderately thick excretory duct. This duct of somewhat
variable length passes at a variable angle caudo-dorsad to open in the

Fig. 70.

100

median line of the dorsal surface at or somewhat caudad of the level
of the caudal margin of the aperture of the acetabulum, and, as has
been described, from 60/z to 320// caudad of the aperture of Laurer's
canal.

ILLUSTRATIONS.

Fig. 57. — Ventral aspect of P. cauliorchis, copulatory apparatus
evaginated. Enlarged. Original.
Fig. 58. — Profile of same.

Fig. 59. — Ventral aspect, copulatory apparatus invaginated. En-
larged. Original.

Fig. 60. — Profile of same.

Fig. 61. — Ventral projection of P. cauliorchis shown in figs. 57 and
58. g. p., position of genital pore; es., esophagus; i., intestinal ceca;
o. s., oral sucker; ov., ovary; s. g., shell gland; t., testes; v. e., vasa
efferentia. Uterus and vas deferens not shown; a-a, b-b, c-c, d-d,
e-e,f-f planes of section. Slightly diagrammatic. Enlarged. Original.

Fig. 62. — Profile projection of P. cauliorchis shown in figs. 57 and
58. ac, acetabulum; g. p., genital pore; d. e., ductus ejaculatorius;
es., esophagus; ex. p., excretory pore; ex. v., excretory vesicle;
g. pap., genital papilla; i., intestinal ceca; L. c, Laurer's canal; o. s.,
oral sucker; ov., ovary; p. m.,pars musculosa; p. p., pars prostatica;
s. g., shell gland; t., left testis; ut., uterus; v. e., left vas efferens;
v. s., vesicula seminalis; a-a, b-b, c-c, d-d, e-e,f-f planes of section.
Slightly diagrammatic. Enlarged. Original.

Fig. 63. — Profile projection showing genital papilla retracted and
lips of genital aperture slightly ajar. Lettering as in fig. 62. Slightly
diagrammatic. Enlarged. Original.

Fig. 64. — Transverse section at a-a, figs. 61 and 62. Shows oral
sucker (o. s.), perisuctorial space (p. s. sp.), mesenterium-like strands
(m. b.). Enlarged. Original.

Fig. 65, — Transverse section at b-b, figs. 61 and 62. Shows base of
oral sucker (o. s.), the esophagus (es.), origin of intestinal ceca (i.),
and some vitelline follicles (v. g.). Enlarged. Original.

Fig. 66. — Portion of a transverse section to show valve at junction
of pars musculosa {p. m.) and pars prostatic (p. p.).; i., intestinal
ceca; va., metraterm. Enlarged. Original.

Fig. 67. — Portion of a transverse section at c-c, figs. 61 and 62, to
show evaginated copulatory apparatus, g. pap., genital papilla; va.,
metraterm; uterus (ut.). Enlarged. Original.

Fig. 68. — Transverse section at d-d, figs. 61 and 62. Shows pars
musculosa (p. m.), vesicula seminalis (v. s.),pars intermedia (p. i.),
valve at junction of vesicula and musculosa (v. m.), uterus (ut.), right
vas efferens (v. e.), intestines (i.), and vitellaria (v. g.). Enlarged.
Original.

101

Fig. 69. — Transverse section at e-e,figs. 61 and 62. Shows position
and relations of the cauliflower-like testes (t.), uterus (ut). Caudal
margin of pars musculosa (p. m.), arch of union of the vasa efferentia
(v. e.), the intestinal ceca (i.), and the vitellaria (v. g.). Enlarged.
Original.

Fig. 70. — Transverse section at/-/, figs. 5 and 6. Shows acetabu-
lum (ac), excretory vesicle (ex. v.), excretory duct (ex. d.), Laurer's
canal (L. c), vitellaria (v. g.), and intestines (i.). Enlarged. Original.

PARAMPHISTOMUM CBASSUM, new species.
[Figs. 71 to 80.]

Specific diagnosis. — Paramphistomum (p. 73): Body 6.12 to 6.5 mm. long by 4.2
to 4.76 mm. broad; color drab (alcohol material); in ventral view broad pyriform,
greatest transverse diameter at junction of equatorial and caudal thirds; tapers gradu-
ally cephalad to plane of genital pore, then abruptly, then gradually to blunt oral
pole; caudad it tapers rapidly, so that caudal margin is very bluntly rounded; longi-
tudinal axis curved, convexity dorsad; in transverse section transversely elliptical.
Surface with transverse grooves, more marked on venter; cephalic cone with acne-
like papillae, which become more acuminate and slender around oral aperture. Gen-
ital pore ventro-median in suctorial zone at junction of oral with second fifth of body;
at this point there is a slight ventral elevation. Acetabulum large, ventral, 3.1 mm.
in transverse, by 2.74 mm. in dorso-ventral diameter, sunken into body, cavity deep,
aperture very small, 0.5 mm. in transverse diameter, directed slightly ventrad.
Mouth subterminal; oral sucker very large, 1.34 mm. long, 1.26 mm. broad, 0.98 mm.
thick, its lumen broad and shallow, papillated; perisuctorial space narrow; esophagus
shorter than sucker, bent U-shaped, convexity ventrad; ceca run at first latero-
cephalad, then in wavy to zigzag course to zone of acetabular aperture, then turn
slightly cephalad and end about at equator of acetabulum. Excretory pore opens
at postovarial plane; canal short, thick; vesicle large, dorsal of acetabulum, extends
from preovarian plane into zone of acetabular aperture, and is crossed by Laurer's
canal.

Male organs. — Testes large, cauliflower like, in intercecal area, diagonal, zones over-
lap, fields overlap; vasa efferentia arise from lateral aspect, run cephalad, then dorso-
mediad, uniting slightly postequatorial, in zone of anterior testis; vesicula seminalis
loosely coiled; musculosa complexly and compactly coiled, connected with vesicu-
laris by a pars intermedia; prostatica nearly straight; ductus ejaculatorius pierces a
well-developed muscle mass and opens with metraterm into a slit-like space at base of
minute genital papilla, and continued as ductus ejaculatorius, which opens at apex
of genital papilla.

Female organs. — Ovary dextral of median line, in acetabular zone, partly in testicu-
lar zone, in field of anterior testis, smaller than testis; shell gland dorso-caudad of
ovary and nearer median line; vitellaria consist of sparsely scattered follicles, extend-
ing from plane of genital pore to slightly postcecal; uterus extends in coils from shell
gland cephalad, turns caudad ventrally of left testis, cephalad dorsally of same, under
arch of vasa efferentia, ventrally of vesicle to the same slit-like space into which the
ejaculatorius discharges; Laurer's canal extends from oviduct dorso-caudad, crosses
excretory vesicle and opens submedian, about 0.7 mm. caudad of excretory pore.

Eggs. — Not observed.

Type.— U.S.N.M. 7156 (Coll. Hawaii).

Habitat. — In (organ ? of) Bos indicus, India.

102

Source of material. — The material consisted of 3 specimens
found with other forms in bottle 5775, collected by Doctor Giles in
1893 in India (Sanawaar, Punjab), from Bos indicus. These speci-
mens were given the number U.S.N.M. 7156.

EXTERNAL CHARACTERS.

Size.' — Two of the specimens, measured in glycerin alcohol, were
6.5 mm. long; the third specimen measured in sections was 6.12
mm. long. The greatest transverse diameter of one of the speci-
mens, measured in glycerin alcohol, was 4.20 mm., while that of
another specimen measured in sections was 4.76 mm.

Color. — The worms are of a drab color.

Form. — The form of these worms is shown in fig. 71. They some-
what resemble ParampMst. cauliorcliis. The greatest transverse
diameter is at about the junction of the equatorial with the caudal

third of the body length. From this region,
in the direction of both poles, the breadth of
the animal becomes progressively reduced,
rapidly toward the caudal pole, making this
extremity broad and rounded, more gradually
toward the oral pole until the level of the
genital pore is reached. Here there is a rather
hf abrupt reduction in the transverse diameter,
clearly shown in fig. 71. Beyond this point
the progressive reduction in breadth is very
gradual, so that the lateral margins of this
oral portion of the worm are very nearly
straight lines, whereas the other portions of
the lateral margins of the worm are decidedly curved. The dorso-
ventral diameter is relatively shorter in this form than in ParampMst.
cauliorcMs, so that when viewed ventrally it gives the impression of
being more decidedly flattened. Viewed in profile it is seen that the
longitudinal axis of the worm is curved with the concavity of the
curve ventrad. The outline of the worm in transverse section is
transversely elliptical.

Surface. — The surface cuticle is without spines or hooks, but is
marked by transverse grooves, which are best denned and deepest on
the ventral surface. The cephalic cone-like portion is beset by acne-
like papilla?. In the region immediately around the oral aperture
the papillae become somewhat acuminate and appear slender and
somewhat more raised above the general cuticular surface.

Genital pore. — In the median line of the ventral surface, at about
the junction of the oral with the second fifth of the body, there is a
transverse buttonhole-like slit, measuring in one alcohol specimen

103

aC/.
Fig. 72.

Fig. 73.

105

about 0.45 mm. in length. This slit, or slit-like depression, is at the
vertex of a moderate, transversely elongate elevation, and repre-
sents the genital pore.

Acetabulum. — The acetabulum is large, and, as in the other forms
of this group, it is in the caudal portion of the body. Its relatively
small aperture is directed slightly ventrad on account of the curve
of the body. Measurements taken from the projection of one sec-
tioned specimen give 2.74 mm. as the greatest dorso-ventral and
3.10 mm. as the greatest transverse diameter of the acetabulum,
with 0.34 mm. as the greatest verticle and about 0.50 mm. as the
greatest transverse diameter of the acetabular aperture. The true
aperture of the acetabulum is somewhat reduced in size by being

<J"W. (rf

Fig. 74.

encroached upon by folds of the adjacent body surface, much as in
the case of Paramjihist. cauliorchis .

INTERNAL ANATOMY.

Digestive tract. — The cephalic pole is marked by an irregularly
circular aperture, measuring in section 90/* by 120/z in diameter.
This aperture leads into a shallow irregular cavity which gives en-
trance to the oral sucker. The latter is a large muscular organ,
which in projection of one specimen measured 1.34 mm. in longitu-
dinal axis, 0.98 mm. in greatest dorso-ventral diameter, and 1.26
mm. in greatest transverse diameter. The dorsal and ventral walls
are thick, measuring 0.46 mm. and 0.50 mm. in thickness, respectively,

106

when measured in the greatest dorso- ventral diameter of the sagittal
plane. Laterally these muscular plates are thinner and continuous
one with the other. The organ is inclosed in a narrow space in the
body parenchyma (figs. 74, 75), in which it is retained in position
by attachments at its two poles and by dorsal and ventral mesen-
terium-like strands. The lumen of the sucker is a dorso-ventrally,
very narrow, but transversely quite broad, cavity. In transverse
sections it appears as a transverse slit lined by a thin cuticle-like
layer, which is beset by short conical papillae; the latter are largest
in the oral half of the lumen, become gradually smaller and more
slender in the direction of the esophageal end, near which they disap-
pear altogether. The esophagus springs from the caudal or basal
aspect of the sucker, then describes a more or less well-marked U-

Fio. 75.

shaped course with the base of the U ventrad. The caudal limb of
the U is much the longer and is directed almost horizontally dorsad,
having only a slight tilt caudad; it divides into the 2 intestinal ceca.
These at first pass laterad with a tilt cephalad to a plane slightly
above their plane of origin, describing at the same time a slight curve
having its convexity dorsad. After approaching the ventro-lateral
aspect of the body wall, each of the intestinal tubes bends caudad and
describes a decidedly wavy, almost zigzag, course caudad, approxi-
mately parallel to the lateral body wall of the worm. The cecal
extremities are directed ventrad close to the sides of the acetabulum
and at about the level of the upper margin of the acetabular aperture.

The lumen of the esophagus is lined by a cuticle-like layer continu-
ous with that of the oral sucker, but terminating abruptly at the

107

I point of origin of the ceca. The latter are lined by an epithelial

I I cell layer.

Genital system. — With the exception of the vitellaria, the genital
■ organs are disposed in the intercecal space.

Male organs. — The testes are in the equatorial zone of the worm,
one laterad of the other, and separated by a moderate interspace.
They are in separate but more or less overlapping testicular zones
and fields (fig. 72). In both of two sectioned specimens the right
testis was the more cephalad. In transverse sections the testes ap-
pear to be composed of numerous lobules suggesting a cauliflower-like

; appearance (fig. 78). From the external aspect of each testis there

temerges a vas efferens, which tends at first cephalad, then dorso-
mediad, finally uniting with its fellow to form the vas deferens (fig.

'72). The vas deferens is distinctly divisible into a vesicula, muscu-
losa, prostatica, and ductus ejaculatorius. The vesicula is loosely
but complexly coiled, thin walled, and but slightly dilated. It is

succeeded by a complexly and somewhat more compactly coiled
musculosa. The muscular walls of this portion of the vas deferens

: are well developed, but not nearly

: so much as mParampMst. caulior-

ichis; measured at a favorable
point the diameter of the duct was

1 0.24 mm., with a thickness of wall

i of 0.067 mm. There is in this, as
in Paramphist. cauliorchis, a short
intermediate segment or pars in-

itermedia between the vesicula

;and musculosa. This segment is muscular but of less diameter and
both much thinner walled and of smaller caliber than the musculosa.
The change from musculosa to prostatica is clearly marked by a

i change in the structure of the wall and by the appearance of a thin
layer of cells which inclose this third portion of the vas deferens.
The prostatica is not coiled, but pursues a direct course cephalo-
ventrad. As it nears a prominent somewhat globular muscular
mass, which incloses the terminal genital (copulatory) apparatus,

i the prostatic cells are lost, and the prostatica now continues as the

(ductus ejaculatorius. It penetrates this muscular mass in close

' relation to the dorsal aspect of the terminal portion of the uterus.
This portion of the male duct is still of considerable caliber and
thin walled, giving the impression of a vesicle, but after a very

i short course becomes abruptly reduced to a relatively very narrow
and short canal, which is interpreted as opening with the termi-
nal portion of the uterus into a minute slit-like space at the base of
a minute genital papilla (fig. 75). The latter is pierced in its long

: axis by a very delicate canal, interpreted as the ductus hermaphro-

10S

diticus. The genii al papilla is interpreted as retracted into the body
of the worm. Leading from it is a canal, which terminates at the
surface in the genital pore. The walls of this canal are indented as
seen in figure 73. When evaginated a structure is probably pro-
duced, which may in a general way resemble the corresponding
structure in Paramyhist. cauliorchis. The termination of the ductus
hermaphroditicus at the vertex of the minute genital papilla is the
poms hermaphroditicus, and in the evaginated condition of this ter-
minal (copulatory) apparatus this pore would probably appear on
the surface. None of the 3 specimens, the subject of this studv,
presented this structure in an evaginated state.

Fig. 77.

Female organs. — In both of the sectioned specimens the ovary was
to the right of the median line (fig. 72), considerably caudad of the
right testis. Its zone overlaps the zone of caudal portion of that of
the left testis to a variable extent. The oviduct arises from the caudal
aspect of the ovary, passes in a more or less sinuous course to the
left toward the shell gland, the right aspect of which, it penetrates.
The shell gland lies a little to the left of the ovary in both of the
sectioned specimens. In one of these this places the shell gland in the
median line, in the other slightly to the right of this line. In both
of the sectioned specimens the zone of this gland slightly overlaps the
caudal portion of the ovarian zone, and in one also the caudal portion
of the left testicular zone. The common vitello-duct penetrates the
caudal aspect of the shell gland and is joined at an angle in the sub-

109

-stance of the latter by the oviduct to form the ootype which is con-
I tinued as the uterus. The latter (fig. 72) emerges from the cephalic
aspect of the gland, cephalad of which it describes some coils. It
then winds its way cephalad at first close to the left of the ovary,
then toward the right ventrad of the ovary. It then again turns
cephalad, forming coils between the ovary and the right testis, then
passes sinistro-caudad in front of the left testis, gains the left latero-
ventro-caudal aspect of this testis where, after forming some coils, it
passes dorsad and obliquely to the right to gain a position directly
ventrad of the dome of the excretory vesicle. Here it turns, winding
its way cephalad, at first between the dorsum on the one hand and
the left testis and ovary on the other, later for a short distance
between the dorsum and the right testis. It then bends ventrad,

passes to the left of the right testis beneath the transverse arch
formed by the union of the vasa efferentia and over the left testis to
reach the ventral aspect of the pars musculosa. The uterus now
again bends and proceeds cephalad, maintaining throughout the
remainder of its course the ventral relation to the pars musculosa
and prostatica. Its terminal portion greatly reduced in caliber pene-
trates, as already described, the muscular mass inclosing the copula-
tory apparatus and opens immediately beneath the ductus ejacula-
torius into the minute, slit-like space already described.

Laurer's canal (fig. 73) leaves the oviduct just as the latter is
about to penetrate the shell gland. It then proceeds dorso-caudad,
skirting either the right or the left aspect of the excretory vesicle in
about the equatorial zone of the latter, and opens on the dorsal sur-

110

face a little to the right or to the left of the median line; in one sec-
tioned specimen, about 0.72 mm. caudad of the excretory pore.

The vitellogene glands consist of sparsely scattered follicles in the
area between the intestinal ceca and the ventro-lateral, lateral, and
dorso-lateral margins of the body. They extend in a vertical direc-
tion from about the level of the genital pore to a plane slightly
caudad of the cecal terminations of the intestines. From each
gland a duct passes more or less directly transversely inward, ventrad
of the corresponding intestine, to unite with its fellow near the
ventro-caudal aspect of the shell gland, between the latter and the
acetabulum. From their point of union a duct, the common vitello-

Fig. 79.

duct, passes to the shell gland, penetrating it on its caudal aspect as
has already been described.

Excretory system. — The excretory system is well developed. A
fairly large excretory vesicle is situated between the dorso-cephalic
aspect of the acetabulum and the dorsum of the worm. A little
caudad of the dome of this vesicle a thick duct leaves it and passes
obliquely dorso-cephalad to open on the dorsal surface a little caudad
of the superior margin of the acetabulum.

ILLUSTRATIONS.

Fig. 71. — Ventral aspect. Enlarged. Original.
Fig. 72. — Ventral projection of specimen shown in fig. 71 : ac.f
acetabulum; g. p., position of genital pore; es., esophagus; %., intes-

Ill

i&inal ceca; ov., ovary; o. s., oral sucker; s. g., shell gland; t., testes;
if., uterus; v. e., vasa eff'erentia; a-a, b-b, c-c, d-d, e-e, f-f, planes- of
section. Slightly diagrammatic. Enlarged. Original.

Fig. 73. — Profile projection of same: ac, acetabulum; d. e., duc-
tus ejaculatorius; es., esophagus; ex. v., excretory vesicle; ex. p., excre-
tory pore; i., intestines; L. c, Laurer's canal; ov., ovary; o. s., oral
sucker; p. m., pars musculosa; p. p., pars prostatica; s. g., shell gland;

right testis; ut., uterus; v. e., right vas efTerens; a-a, b-b, c-c,
1-d, e-e, f-f, planes of section. Slightly diagrammatic. Enlarged.
Original.

Fig. 74. — Transverse section at a-a figs. 72 and 73. Shows oral
sucker (o. s.), perisuctorial space (p. s. sp.) and mesenterium-like
strands (m. b.). Enlarged. Original.

Fig. 75. — Transverse section at b-b, figs. 72 and 73. Shows caudal
portion of oral sucker (o. s.), perisuctorial space {p. s. sp.), ductus
Bjaculatorius (cZ. e.), and vitellaria (v.g.). Enlarged. Original.

Fig. 80.

Fig. 76. — Portion of fig. 75. To show on a larger scale the copu-
Story apparatus: d. e., ductus ejaculatorius; d. 7b., ductus hermaph-
roditicus; g. a., genital atrium; g. pap., genital papilla. Enlarged.
Original.

Fig. 77— Transverse sections at c-c, figs. 72 and 73. Shows esoph-
agus (es.) forking into the intestinal ceca (i.), the uterus (ut.), pars
musculosa (p. m.), pars prostatica (p. p.), and vitellaria (v. g.). En-
larged. Original.

Fig. 78.— Transverse section at d-d, figs. 72 and 73. Shows the
testes (t), uterus (ut.), intestinal ceca (i.), and vitellaria (v. g.). En-
larged. Original.

112

Fig. 79. — Transverse section at e-e, figs. 72 and 73. Shows
excretory pore (ex. p.), excretory vesicle (ex. v.), shell gland (s. g.)}
oviduct (ov. d.), uterus (ut.), vitellaria (v. g.), intestinal ceca (i.), and
acetabulum (ac). Enlarged. Original.

Fig. 80.— Transverse section at figs. 72 and 73. Shows pore
of Laurer's canal (L. c), excretory vesicle (ex. v.), vitellaria (v.g.),

intestinal ceca (%.), and acetabulum (ac). Enlarged.

Original.

Fig. 81.

PAKAMPHISTOMUM PAPILLOSUM, new species.
[Figs. 81 to 91.]

Specific diagnosis.— Paramphistomum (p. 73): Body between 5.12 and 6 mm.
long by 2.6 mm. in maximum breadth; gray-brown ocher tint (alcohol specimen);
somewhat conical, greatest diameter? (transverse and sagittal) about at border of

equatorial and caudal thirds; tapers gradually to quite a
blunt oral extremity; caudal extremity broadly rounded
when viewed ventrally or dorsally, but beveled on its ven-
tral aspect; lateral margins nearly straight; transverse
section circular; surface coarsely grooved transversely, espe-
cially on venter; oral pole with numerous very minute
conical papilla?. Genital pore ventro-median, about one-
fourth the length from oral margin, and at transverse plane
of caudal margin of pharynx. Acetabulum ventro-subter-
minal, sunken beneath surface, relatively large, 1.8 to 1.9
mm. in diameter, with small 0.36 mm. circular aperture,
mouth terminal crateriform, closely beset with small digi-
tate papillae; oral sucker large, 0.8 mm. long, 0.9 mm. broad,
0.64 mm. in sagittal diameter, the oral two-thirds of its
lumen with small papillae; esophagus short, strongly flexed
ventrad, extends beyond genital pore about to border be-
tween oral and equatorial thirds of body; intestinal ceca very long, at first trans-
verse, then turned caudad and extend in very wavy course, each about midway
between median line and corresponding lateral margin, more
dorsal than ventral, nearly or quite to aperture of acetabulum;
slings distinctly dorso-ventral and somewhat parallel to body
wall. Excretory pore dorso-median, slightly caudad of cephalic
margin of acetabulum and cephalad of Laurer's canal; excretory
vesicle well developed, broad; excretory canal arises about from
equator of vesicle, short, runs directly dorsad to its pore.

Male organs. — Testes deeply branched, cauliflower like, in
axis of equatorial region of body, close together one caudo-dorsad
of the other; each vas efferens arises from lateral aspect , passes
cephalo-dorsad, then mediad, uniting with its fellow somewhat
cephalo-dorsad of anterior testis to form the much-coiled vesi-
cula seminalis; pars musculosa thick walled, coiled, ventral of
vesicula; pars prostatica relatively straight, passes ventro-
cephalad, ventral of esophagus, is continued in a short ductus
ejaculatorius which opens into dilated ductus hermaphroditicus;
the latter pierces the axial region of genital papilla, which is separated from a papil-
lated cylindrical antechamber by a nonpapillated ridge or ring; the papillated
chamber opens externally through the apparent genital pore. Cirrus pouch absent.

Fig. 82.

113

Fig. 83.

115

Female organs— Ovary slightly sinistral, slightly ventral, immediately cephalad of
acetabulum; shell gland smaller than and dorso-dextro-caudal of ovary; also slightly
dextral of median line; vitellaria with sparsely scattered small follicles, lateral of ceca,
extending from base of oral sucker to caudal end
of ceca; uterus passes from shell gland ventrad
caudally of ovary, then coils ventrally of ovary,
then passes dorsad between shell gland and testis
on right of ovary, dorsally around testes, ventrad
beneath vasa efferentia, cephalad ventrally of
vas deferens, opening ventrally of ductus ejacula-
torius into ductus hermaphroditicus. Laurer's
canal runs dorso-caudad at right of excretory
vesicle to a point 0.4 mm. caudad of excretory
pore, and slightly dextral of median line.

Eggs. — Not observed.

Type.— U.S.B.A.I. 15025, sectioned.

Host. — The Zebu (Bos indicus) at Sanawaar,
Punjab, India.

Source of material. — This single specimen was found in a bottle
with other forms bearing the B. A. I. No. 1723; it was renumbered
15025. The label in this bottle reads as follows:

Name Amphistomum crumeniferum. Host Bos indicus. Locality Sanawaar,
Punjab, India. Collected by Doctor Giles. Date III. 1893. Determined by Dr.
Giles. Date III. 1893, Presented by Dr. Giles. Date III. 1893.

EXTERNAL CHARACTERS.

Size. — Measured from sections the worm was 5.12 mm. long and
2.6 mm. in greatest width; in alcohol it was 6 mm. long.

Color. — The worm was of a
gray-brown ocher tint.

Form. — The form of this
worm is weU shown in figs. 81
and 82. The worm has a some-
what conical shape, having its
greatest transverse and dorso-
ventral diameters in the region
of junction of the middle with
the caudal third whence it tapers
gradually to quite a blunt oral
extremity. The aboral pole is
broad and rounded from side to
side, but beveled on its ventral
aspect where it presents the aperture of the acetabulum. In trans-
verse section the outline is circular.

Surface. — The surface cuticle is coarsely grooved transversely,
particularly on the venter. At the oral pole there appear to be
numerous very minute conical papillae.
13893— Bull. 60—10 8

Fig. 86.

116

Genital pore. — In the median longitudinal line of the venter
about one-fourth the length from the oral extremity is a small
aperture, the genital pore, measuring about 0.20 mm. in diameter.

Acetabulum. — The acetabulum is in the caudal portion of the body,
distinctly sunken beneath the body surface in the specimen examined.
It is relatively large, measuring about 1.8 to 1.9 mm. in diameter
but is provided with a rather small circular aperture which measures
0.36 mm. in diameter; the portion of the rim of the aperture formed
by the body of the worm (as distinguished from the portion formed
by the acetabulum) is slightly puckered (fig. 82).

INTERNAL ANATOMY.

Digestive tract. — The oral pole of the worm presents an irregu-
larly crateriform depression, closely beset by numerous, small digi-
tate papillae. This depres-
sion leads by a minute irreg-
ularly circular aperture into
a large muscular oral sucker.
The latter is about 0.86 mm.
long, about 0.90 mm. in
greatest width and 0.64 mm.
in greatest ventro - dorsal
diameter; it lies in a cavity
(fig. 85), suggestive of a rudi-
mentary body cavity, and is
bound to the body paren-
chyma at its oral and aboral
poles and by distinct me-
senterium - like bands on
both its dorsal and its ven-
tral median aspects. In median sagittal section it is somewhat
pyriform in outline; in frontal section it is almost circular, while in
transverse section (fig. 85) it is elliptical in outline. The muscular
wall is thickest in the ventro-dorsal and thinnest in the transverse
axis. The lumen is a transversely broad, dorso-ventrally narrow
slit-like space and is lined by a thin cuticle-like layer seemingly (no
sagittal sections available for confirmation) in anatomical continuity
with the surface cuticle. In about the upper (cephalic) two-thirds
of the lumen the lining is beset by very small slender conical papilla?;
these give to the cuticle a serrate appearance (transverse sections),
with the papillae of the dorsal wall fitting into the interspaces between
the papillae of the ventral wall.

At the two extremities of the oral sucker the lumen becomes con-
tracted so as to form at each end a small circular aperture; at the

jL,

Fig. 87.

117

caudal extremity this aperture gives entrance into the esophagus;
very slightly caudally of this point may be distinguished a well de-
veloped ganglion-complex (fig. 86), lying dorsally of the esophagus
and sending off strong nerve strands in various directions. The
esophagus passes from the base of the sucker and describing a
U-shaped course with the base of the U ventrad, divides into two intes-
tines at about the level of junction of the cephalic with the middle
third of the body. The intestinal tubes pass one to the right and
the other to the left in a transverse plane latero-dorsad to a point
about midway between the longitudinal axis and the body wall;
they then pursue a wavy course caudad (figs. 83, 84), to terminate
by cecal extremities latero-dorsad of the acetabulum about in the
transverse plane of the
upper (cephalic) mar-
gin of the aperture of
the acetabulum. In
their wavy course cau-
dad the ceca continue
in a general way about
midway between the
longitudinal body axis
and the body wall but
approaching closer to
the dorsal than to the
ventral median longi-
tudinal line; further-
more, the slings or
coils have a distinctly
dorso-ventral direc-
tion (figs. 84, 87, 89, 90) and run somewhat parallel to the body wall.
The lumen of the esophagus is lined by a thick cuticular layer, which
ceases abruptly at the point of origin of the intestines. The latter
are lined by an epithelial cell layer.

Genital system. — Male organs. — The testes, one caudad of the
other, are in the axial portion of the equatorial region of the body,
though in general slightly nearer the venter than the dorsum (figs.
84, 88, 89); of the two, the superior (cephalic) testis is' nearer the
venter, and, being somewhat smaller, is also farther from the dorsum
than is the inferior (or caudal) testis. The opposing aspects of the
testes are closely approximated. Both testes are much branched,
suggesting a cauliflower in appearance (figs. 88, 89). (The projec-
tions do not show this well.) From the right lateral aspect of the
caudal, and from the left lateral aspect of the cephalic testis there

Fig. 88.

118

spring the corresponding vasa efferent ia; these pass cephalo-dorsad,
then mediad, describing an arch as they unite a little above the
superior testis to form the vas deferens (fig. 84). Beneath this arch,
and between it and the superior testis, the uterus passes ventrad.
The vas deferens presents at first a much coiled thin walled portion
(vesicula) the lumen of which in the single specimen studied was not
noticeably dilated. This is succeeded by a coiled quite thick walled
(45//) portion, pars musculosa, measuring about 150> in diameter
which is situated ventro-cephalad of the coiled thin-walled portion.
The caliber of this muscular portion appears somewhat greater than
that of the vesicula. The muscular portion is succeeded by a rela-
tively straight pars prostatica of moderate length, the walls of which,
though thick and muscular at first, rapidly become thinned and are
inclosed in a mass of cells. This portion passes ventro-cephalad,

being in relation to

the ventral aspect of
the esophagus, and in
still closer relation to
the dorsal aspect of
the terminal portion
of the uterus; it is
finally succeeded by a
short duct (by homol-
ogy, the ductus ejacu-
latorius) not inclosed
in prostatic cells and
opens by a minute pore
immediately above
the metraterm into a
small slit-like atrium
at the base of the gen-
ital papilla. This atrium may be regarded as the dilated dorsal portion
of the ductus hermaphroditicus which pierces the axial region of the
genital papilla. The genital papilla is embraced by a ring, one aspect
of which is applied to it and separated from it only by a narrow slit;
the other aspect forms the dorsal wall of a relatively large cylindrical
atrium (figs. 84, 86) ; this latter is beset by small papillae (hence the spe-
cific name papillosum), which do not occur, however, on either surface
of the ring embracing the genital papilla. The genital pore gives
entrance and exit to this chamber, and, as will be seen from figure 84,
it is at or slightly caudad of the level of the base of the oral sucker.

Female organs. — The ovary is in the axial region of the body,
though a little to the left of the median sagittal plane, and a little
nearer to the venter than to the dorsum and just above (cephalad of)
the acetabulum. From its dorso-median aspect there arises the

Fig. 89.

119

oviduct which passes to the right and dorso-caudad toward the shell
gland. The shell gland, somewhat smaller than the ovary, lies a
little to the right, and a little dorso-caudad of the ovary (figs. 83, 84,
90) and also slightly to the right of the median sagittal plane of the
body of the worm. It is penetrated on its dorso-median aspect by
the oviduct and on its dorso-caudal aspect by the vitello-duct.
These unite in the substance of the shell gland to form the ootype,
which is continued as the uterus, the latter emerging from the ventral
aspect of the gland (fig. 90). Laurer's canal leaves the oviduct just
before the latter penetrates the shell gland; it then passes to the right
and dorso-caudad, skirting the upper portion of the right lateral
aspect of the excretory vesicle (figs. 84, 91), and opens on the dorsum
about 0.40 mm.

caudad of the excre-
tory pore, slightly
to the right of the
median line.

The vitellogene
glands, composed
of sparsely scat-
tered insignificant
follicles, lie in the
lateral regions of the
body between the
intestinal ceca and
the body walls.
They extend longi-
tudinally from
about the level of

the base of the oral fig. 90.

sucker to the level of the termination of the intestinal ceca. From
each gland there arises a duct, which passes transversely inward ven-
trally of the intestines; the two unite at the level of the superior
margin of the acetabulum and close to the ventro-median aspect of
the shell gland. From their point of union a duct is given off which
skirts the caudal aspect of the shell gland, penetrating the latter at
the caudo-dorsal aspect.

The uterus, as already described, emerges from the ventral aspect
of the shell gland (fig. 90), passes ventrad, then for a short distance
cephalad forming some coils ventrally of both ovary and shell gland;
it then passes dorsad to the right of the ovary and between the shell
gland and caudal testis. Having reached the space between the
caudal testis and dorsum it passes cephalad behind (dorsally of)
both testes, then ventrad above (cephalad of) the superior testis
and beneath the arch of union of the vasa efferentia, to gain the ven-

120

fcral aspect of the coil formed by the pars musculosa. It next passes
in a general way cephalad and reaches the ventral aspect of the pars
prostatica; this relation it maintains in the remainder of its course
ventro-cephalad to terminate by a minute pore immediately beneath
the pore of the ductus ejaculatorius in the manner already described.
In its course the uterus is moderately coiled. Neither eggs nor
spermatozoa were observed in its lumen.

Excretory system. — The excretory vesicle (figs. 84, 90, 91)
lies dorsally of the acetabulum between the terminal portions of the
intestinal ceca. Its transverse diameter is greater than its ventro-
dorsal diameter; it discharges by a thick walled duct which arises
from about the middle of its dorsal aspect; this duct passes almost
directly dorsad to open, in the median line, somewhat (about 0.28

Fig. 91.

mm.) below the level of the upper margin of the acetabulum, and
about 0.4 mm. cephalad of the pore of Laurer's canal.

Fig. 81. — Ventral aspect. Enlarged. Original.

Fig. 82. — Profile of same. Enlarged. Original.

Fig. 83. — Ventral projection of specimen shown in figs. 81 and 82:
ac, acetabulum; g. p., genital pore; es., esophagus; %., intestinal
ceca; ov., ovary; o. s., oral sucker; p. m., pars musculosa; p. p., pars
prostatica; s. g., shell gland; t, testes; ut, uterus; v. e., vasa efferentia.
a-a, b-b, c-c, d-d, e-e, f-f, g-g, planes of section. Slightly diagram-
matic. Enlarged. Original.

121

Fig. 84. — Profile projection of specimen shown in figs. 81 and 82:
ac, acetabulum; d. h., ductus hermaphroditicus; es., esophagus;
fox. p., excretory pore; ex. v., excretory vesicle; i., intestine; L. c,
Laurer's canal; ov., ovary; o. s., oral sucker; p. m., pars musculosa;
p. p., pars prostatica; s. g., shell gland; t., testes; ut., uterus; v. c,
vas efferens; v. s., vesicula seminalis; a-a, b-b, c-c, d-d, e-e,f-f, g-g,
planes of section. Slightly diagrammatic. Enlarged. Original.

Fig. 85. — Transverse section at a-a, figs. 83 and 84. Shows oral
sucker (o. s.), and perisuctorial space (p. s.sp.). Enlarged. Original.

Fig. 86. — Transverse section through b-b figs. 83 and 84. Shows
papillated genital ventral chamber (g. a. c), genital dorsal chamber
(g. a.), genital papilla {g. pap.), esophagus (es.), esophageal ganglion
(e. g.), and vitellaria (v. g.). Enlarged. Original.

Fig. 87. — Transverse section at c-c figs. 83 and 84. Shows uterus
{ut.), pars musculosa (p. m.), intestinal ceca (i), and vitellaria (v. g.).
Enlarged. Original.

Fig. 88. — Transverse section at d-d figs. 83 and 84. Shows
superior testis (t.), intestines (i.), uterus {ut.), right vas efTerens
(v. e. d.), and vitellaria (v. g.). Enlarged. Original.

Fig. 89. — Transverse section at e-e figs. 83 and 84. Shows caudal
testis (t), origin of right vas efferens (v. e. d.), uterus {ut.), intestines
(i.), and vitellaria (v. g.). Enlarged. Original.

Fig. 90. — Transverse section at/-/ figs. 83 and 84. Shows uterus
{ut.), right transverse vitello-duct (t. v. d.), caudal portion of ovary
{ov.), shell gland (s. g.), Laurer's canal (L. c), excretory vesicle
(ex. v.), intestines (%.), and vitellaria (v. g.). Enlarged. Original.

Fig. 91. — Transverse section at g-g figs. 83 and 84. Shows
acetabulum (ac), intestines (i.), excretory vesicle (ex. v.), Laurer's
canal (L. c), excretory pore (ex. p.), and vitellaria (v. g.). Enlarged.
Original.

PARAMPHISTOMUM INDICUM, new species.

[Figs. 92 to 102.]

Specific diagnosis. — Paramphistomum (p. 73): Body 5.25 to 9.5 mm. long by 2
to 3 mm. in maximum breadth; gray-brown ochre (alcohol specimens); somewhat
conical, greatest transverse diameter about at border of equatorial and caudal thirds;
tapers moderately to blunt, almost truncated oral extremity ; caudal extremity rounded
on ventral view, but with tendency to beveled ventro-lateral aspect on lateral view;
lateral margins nearly straight to slightly curved; body bent, with venter rather
strongly concave (longitudinally) and dorsum convex; transverse section circular
anteriorly, but with greater transverse than dorso-ventral diameter from near genital
pore for some distance caudad, then the dorso-ventral diameter becomes the greater.
Surface coarsely wrinkled transversely; cephalic half provided with irregular, trans-
verse rows of papillae which are more numerous, acutely conical in circumoral region,
but more scattered, shorter, broader, and blunt elsewhere. Genital pore ventro-
median about at border between cephalic and equatorial thirds of body, caudad of
esophagus, but nearer to this than to anterior testis. Acetabulum terminal, but aper-
ture appears ventro-sub terminal because of curvature of body, sunken beneath surface,

122

Fig. 92.

rather large, 1 .(] mm. in longitudinal diameter, very slightly less in transverse diameter,
with rather circular to somewhat irregular, 0.53 mm. to0.65 mm. aperture which appears
ventrad and slightly caudad. Mouth terminal, hour-glass form, provided with papil-
la*; oral sucker large, oval, 0.96 mm. long, 0.84 mm. broad, 0.58 mm. in greatest dorso-
ventral diameter, the oral two-thirds of its lumen with small
blunt papilla;; esophagus about half as long as sucker, at first
directed caudad, then suddenly dorsad, does not extend to
genital pore; intestinal ceca long, pursue dorso-ventrally wavy
course about to anterior margin of aperture of acetabulum.
Excretory pore dorso-median, cephalad of acetabulum, about
on caudal plane of caudal testis, and about 1 mm. cephalad of
pore of Laurer's canal; excretory duct short, runs from pore to
dorso-cephalic aspect of very large excretory vesicle which lies
dorsally of cephalic portion of acetabulum.

Male organs: Testes deeply notched (lobulated), in transverse
section cauliflower like, in axis of body, one caudad of the other,
slightly caudad of equatorial plane, very slightly nearer to venter
than to dorsum, one very slightly nearer each lateral margin than
is the other; each vas efferens arises from dorsal aspect of testis,
passes cephalo-mediad, unites with its fellow about 0.5 mm.
cephalad of superior testis to form vas deferens; vesicula semi-
nalis and pars musculosa both much coiled and extend in ven-
trocephalic direction; pars prostatica short, nearly straight,
directed ventrad; pars ejaculatorius very short, unites with
metraterm dorsally of pore to form ductus hermaphroditicus, which pierces a
small papilla to discharge into a narrow nonpapillated atrium, which in turn
discharges at the genital pore; cirrus pouch absent.

Female organs: Ovary right or left of median line,
just cephalad of acetabulum; shell gland smaller,
dorso-median and slightly caudad of ovary; vitellaria
with sparsely scattered, very small follicles, lateral
to dorso-lateral of ceca, from base of oral sucker to
cephalic margin of acetabulum (not quite to end of
ceca); uterus passes in wavy course ventrally of shell
gland, dorsad caudally of posterior testis, cephalad of
both testes, ventrad under arch of vasa efferentia,
cephalad ventrally of vas deferens, to ductus herma-
phroditicus; Laurer's canal arises from oviduct about
midway between ovary and shell gland, runs dorso-
caudad at right of excretory vesicle to pore situated on
dorsum, 0.8 to 1.0 mm. caudad of excretory pore, and
either median or very slightly to the right of median
line.

Eggs: Not observed .

Type.— U.S.B.A.I. 1723; cotype U.S.N.M. 5775.
Host.— The Zebu (Bos indicus) in Punjab, India.

Source of material. — These worms were
found with some other forms in 2 bottles,
bearing the numbers "B.A.I. 1723" and "U.S.N.M. 5775," respec-
tively. The other material in question has been separated out and
renumbered.

Fig. 94.

124

Fig. 95.

125

EXTERNAL CHARACTERS.

Fig. 96.

Size —The alcohol preserved specimens— 14 in all — measured from
5.25 to 9.5 mm. in length. On account of the damaged condition of
6 of them the width could be measured in 8 only, and in these the
maximum breadth varied from 2 to
3 mm.

Color. — The worms are of a gray-
brown ocher.

Form. — The specimens are some-
what conical in form (figs. 92, 93)
and the ends are bent more or less
ventrally, so that the longitudinal
axis is a curve with a concave venter
and a strongly convex dorsum.
The greatest transverse diameter is
near the junction of the equatorial
with the caudal third of the body; the worm tapers moderately to a
blunt, and in some specimens, slightly bulbous oral extremity. On
transverse section the cephalic portion is circular, but beginning
slightly cephalad of the genital pore the outline undergoes a slight
change, the transverse diameter becoming greater than the dorso-

ventral diameter; near
the caudal end the
outline again changes,
the dorso-ventral di-
ameter being the
greater.

Surface. — The sur-
face of the worms, ex-
cept for some trans-
verse wrinkling, is
smooth in the caudal
half of the animal;
in the cephalic half,
however, the cuticle
is provided with nu-
merous papillae, which
are acutely conical in
the circumoral region,
but relatively shorter, broader, and more blunt over the remaining
portion of the surface covered by them; at least some of these appear
to be of sensory nature. The papillae around the oral aperture are

Fig. 97.

126

fairly numerous and closely aggregated; the others are relatively less
numerous, more scattered, and arranged in irregular transverse rows.

Genital -pore. — In the median longitudinal line of the ventral sur-
face, at about the junction of the cephalic with the middle third of
the body, is the genital pore (figs. 94, 95, 98). This gives entrance
into a canal which leads into a small nonpapillated atrium, the dorsal
wall of which is formed by a short papilla in the center of which is
the porus hermaphroditicus. Sections show the genital allium to
be inclosed in considerable muscular mass (figs. 95, 98).

Acetabulum. — This is terminal anatomically, but appears ventro-
subterminal because of the curvature of the body. In one of the
sectioned specimens it measured about 1.6 mm. in greatest (longi-
tudinal) diameter. Its more or less circular aperture is directed
ventrad and slightly caudad, appearing ventro-subterminal, and in 7

specimens varies from 0.53 to
0.65 mm. in diameter.

INTERNAL ANATOMY.

Digestive tract. — The
mouth, which pierces the cephalic
blunt extremity, leads into a
large muscular oral sucker of
oval form and rather similar to
that of P. papillosum. The
cephalic two-thirds of the lumen
of this sucker is beset with small
but distinct bluntly pointed
conical papillae (fig. 96); in the
esophageal third there is a
slight indication of much more minute papillae. The sucker lies in a
cavity suggestive of a rudimentary body cavity, held in place by its
attachments at its poles and by mesenterium-like bands extending
from the dorsal and ventral aspects through the cavity to the body
parenchyma. The sucker leads into the esophagus, and dorsalry of
the point of union there is a distinct nervous band giving off branches
in various directions (fig. 97). At first the esophagus passes almost
directly caudad, then bending at almost right angles it is directed for
the remainder of its short course dorsad to fork into two intestinal
ceca. The length of the esophagus is equal to about one-half of that
of the sucker. The intestinal ceca pursue a dorso-ventral wavy
course (approximately parallel to the body wall) caudad to terminate
dorsally of the acetabulum and in a transverse plane just above
(cephalad) of the acetabular aperture (figs. 94, 95).

127

Genital system. — Male organs. — The testes are in the axial region
of the cephalic portion of the caudal half of the body, between the
equatorial plane and the plane of the cephalic margin of the acetabu-
lum (figs. 94, 95), somewhat nearer to the venter than to the dorsum.
The testes are deeply indented or lobulated, so that in transverse sec-
tion they appear as if branched in cauliflower-like fashion (figs. 99,
100). They are situated almost directly caudad one of the other,
their opposing surfaces being either in the same or in slightly separated
transverse planes. From the dorsal aspect of each testis arises a vas
efferens; in one (figs. 94, 95) of the two sectioned specimens the right
vas belonged to the inferior, and in the other to the superior testis.
The vasa efferentia pass cephalad, and about 0.5 mm. above the
superior testis unite in the axial region of the body to form the much
coiled vas deferens,
(vesicula), and its
general course is
ventro-cephalad.
The second portion,
also much coiled,
is provided with
thick muscular
walls. The third
portion of the vas
deferens is short,
fairly straight, di-
rected almost hori-
zontally ventrad,
and its walls are
inclosed in a mass
of cells; this, the
pars prostatica, becomes suddenly greatly reduced both in the caliber
of its lumen and the thickness of its walls, and now devoid of prostatic
cells this terminal (fourth) portion represents a very short ductus
ejaculatorius, which unites with the metraterm to form a short ductus
hermaphroditicus (fig. 95).

Female organs. — The ovary lies in the superior (cephalic) part of the
caudal third of the axial region of the body (fig. 101), a little either
to the right or to the left of the median sagittal plane. Its cephalic
aspect is in the same transverse plane as, or in the plane immediately
caudad of, the plane of the caudal aspect of the caudal testis. The
shell gland lies on the dorso-median aspect of the ovary, slightly
caudad of and either close to or somewhat removed from the latter.
The oviduct springs from the ovary from the aspect nearest the shell
gland in one specimen, but very slightly more dorsally in another; it
passes toward the shell gland which it penetrates. In the substance

The first portion of the latter is thin walled

Fig. 99.

128

of the shell gland the oviduct unites with the vitelline duct to for
the ootype. Laurer's canal leaves the oviduct at a point about mid
way between the ovary and the shell gland, or slightly nearer th
ovary, and passes dorso-caudad, skirts the right side of the excretor
vesicle (both in the specimen with dextral and in the one with sinis
tral ovary), and reaches the dorsal body surface at a point about on
level with the middle of the acetabular aperture and between 0.80
mm. and 1 mm. caudad of the excretory pore. In the specime
with the dextral ovary the pore of Laurer's canal is median, whil
in the specimen with sinistral ovary it is very slightly to the right c
the median line. The vitellogene glands, consisting of sparsely
scattered insignificant follicles, lie in the lateral and dorso-lateral
regions of the body, between the intestinal ceca and the body surface,

and extend longi-
tudinally be-
tween the plane
of the base of the
sucker and that
of the upper mar-
gin of the ace-
tabulum. The
transverse vitel-
lo-ducts unite
dorsad of the
acetabulum and
i m m edi ately
caudad of the
shell gland.
From their
point of union,

which is not dilated into a reservoir, a duct springs which penetrates
the caudal aspect of the shell gland.

The uterus, as a continuation of the ootype, emerges from that
ventro-lateral aspect of the shell gland which is away from the ovary,
and then forms coils ventrad of the shell gland and ovary as it winds
its way for a short distance cephalad before it turns dorsad beneath
the caudal testis. In its course dorsad it passes to the right of the
upper portion of the excretory vesicle. On reaching the region dorso-
caudally of the caudal testis it resumes its course cephalad between
the dorsum and the testes; just above the plane of the cephalic aspect
of the superior testis it bends ventro-cephalad, passing beneath t lie-
arch formed by the union of the vasa efferentia, and gains the ventral
aspect of the vas deferens; this relat ion it maintains in the remainder
of its course, its terminal portion or metraterm uniting with the

-o.

Fig. 100.

129

ductus ejaculatorius to form the ductus hermaphroditicus. Eggs
were not observed in the uterus of either of the specimens studied.

Excretory system. — The excretory vesicle is large and lies dor-
sally of the acetabulum, its fundus extending caudad to a plane some-
what above the caudal margin of the acetabulum. The vesicle opens
by a short duct which leaves it from the dorso-cephalic aspect and
opens on the dorsum a little above the plane of the upper margin of
the acetabulum and as already stated almost 1.00 mm. cephalad of
the pore of Laurer's canal.

RELATION TO KNOWN SPECIES.

This species resembles most closely Paramphist. gracile Fischceder.
It differs from the latter in possessing an esophagus that is only about
one-half as long as
the sucker; in the
position of the testes
which in this species
are placed relatively
farther caudad than
in P. gracile; in the
position of the ovary
which in this form is
separated little, if at
all, in a longitudinal
direction from the
caudal testis; and in
the position of the
pore of Laurer's canal
which in this form is
very much farther
caudad, opening
about opposite the
middle of the acetab-
ular aperture whereas in P. gracile it opens in the plane of the supe-
rior aspect of the ovary some distance above the upper margin of the
acetabulum.

ILLUSTRATIONS.

Fig. 92. — Ventral aspect. Enlarged. Original.

Fig. 93. — Profile view of same. Enlarged. Original.

Fig. 94. — Ventral projection of specimen shown in figs. 92 and 93:
ac., acetabulum; g. p., genital pore; es., esophagus; i., intestines; ov.,
ovary; ov. d., oviduct; o. s., oral sucker; s. g., shell gland; t, testes;
v. d., vas deferens; v. e., vasa efferentia; ut., uterus, a-a, b-b, c-c,

130

d-d, e-e,f-f, g-g, planes of section. Slightly diagrammatic. Enlarged
Original.

Fig. 95. — Profile projection of specimen shown in figs. 92 and 93:
ac, acetabulum; g. p., genital pore; c. vd., common vitello-duct; es.,
esophagus; d. li., ductus hermaphroditicus; ex. p., excretory pore;
ex. v., excretory vesicle; %., right intestinal cecum; L. c, Laurer's
canal; o. s., oral sucker; p. m., pars musculosa; p. p., pars prostatica;
s. g., shell gland; t, testes; v. e. d., right vas efFerens; v. e. s., left vas
efferens; v. s., vesicula seminalis; ut., uterus, a-a, b-b, c-c, d-d,
e~e> f~f> 9~a> phmes of section. Slightly diagrammatic. Enlarged.
Original.

Fig. 96. — Transverse section at a-a figs. 94 and 95. Shows surface
papillae (s. pap.), oral sucker (o. s.), and perisuctorial space (p. s. sp.).
Enlarged. Original.

Fig. 97. — Transverse section at b-b figs. 94 and 95. Shows base of
oral sucker (o. s), perisuctorial space {p. s. sp.), esophageal ganglion

(e. g.), and vitellogene glands
(v. g.). Enlarged. Original.

Fig. 98. — Transverse sec-
tion at c-c figs. 94 and 95.
Shows genital papilla (g. pap.),
ductus hermaphroditicus
(d. h.), metraterm (va.), pars
prostatica (p. p.), intestinal
ceca (i.), and surface papillae
{s.pap.). Enlarged. Original.

Fig. 99. — Transverse sec-
tion at d-d figs. 94 and 95.
Shows superior testis (t.),
right vas efferens (v. e. d.),
the uterus (ut), intestines
(i.), vitellaria (v. g.). En-
larged. Original.

Fig. 100. — Transverse sec-
tion at e-e figs. 94 and 95. Shows caudal testis (t), origin of right
vas efferens (v. e. d.), uterus (ut), intestines (i), and vitellaria (v. g.).
Enlarged. Original.

Fig. 101.— Transverse section at/-/ figs. 94 and 95. Shows ovary
(ov.), excretory pore (ex. p.), excretory vesicle (ex. v.), uterus (ut.),
and intestines (i.). Enlarged. Original.

Fig. 102.— Transverse section at g-g figs. 94 and 95. Shows ace-
tabulum (ac), excretory vesicle (ex. v.), and pore of Laurer's canal
(L. c). Enlarged. Original.

Fig. 102,

131

SUBGENERIC POSITION UNCERTAIN.

The subgeneric position of the following species is left open for the
present :

Paramphistomum fraternum, close to the subgenus Paramphistomum, very close to
P. cxplanatum.

P. siamense, close to subgenus Paramphistomum, very close to P. explanation.
P. shipleyi, close to P. parvipapillatum and P. scoliocoelium.
P. parvipapillatum, close to P. shipleyi and P. scoliocazlium.

PARAMPHISTOMUM FRATERNUM, new species.
[Figs. 103 to 113.]

Specific diagnosis. — Paramphistomum (p. 73): Body 9.75 mm. long, at least 4.5
mm. in maximum breadth; grayish olive green in color (alcohol specimens); viewed
ventrally, conical; viewed laterally, gourd shape; greatest diameter at junction
between equatorial and caudal thirds; tapers gradually but considerable to truncated
conical oral pole; caudal end bluntly rounded when viewed ventrally, beveled ven-
trally when viewed laterally; long axis curved moderately, concavity ven trad ; dor-
sum arches both longitudinally and tranversely; venter concave longitudinally, con-
vex transversely; transverse sections in general elliptical to semicircular with rounded
angles. Surface with fine transverse striations, no papillae. Genital pore apparently
slightly sinistrad (due to torsion?) in suctorial zone about one-eighth of body length from
oral pole; shallow genital atrium; genital papilla only slightly elevated. Acetabulum
large, ven tro-sub terminal, 3.75 mm. long, 3.25 mm. broad, aperture 1.85 by 1.52 mm.,
margins projecting slightly, cavity very deep. Mouth terminal, crateriform, not
papillated; oral sucker 0.96 mm. long, 0.98 mm. broad, 0.52 mm. thick, rather oval in
outline; perisuctorial space narrow; esophagus about three- fourths as long as sucker;
ceca pass at first laterad, then caudad to end at equator of acetabulum, about at junc-
tion of third with caudal fourth of body, the ends bending medio-caudad. Excretory
pore opens on preacetabular plane (about five-ninths of body length from oral pole) and
one-fifth of body length cephalad of pore of Laurer's canal; excretory vesicle crosses
Laurer's canal, long, extends postovarian, beyond equator of acetabulum.

Male organs. — Testes equatorial, pre- and acetabular, zones and fields overlap, in
extra-, inter-, and cecal areas, very large, lobate; vasa efferentia unite about at junction
of oral and equatorial thirds of body; vas deferens highly developed; vesicula semi-
nalis much coiled, extending about from pretesticular plane nearly to bifurcal plane;
musculosa short, nearly straight, extends nearly to postsuctorial plane; prostatica much
shorter than musculosa; ejaculatorius and ductus hermaphroditicus very short.

Female organs. — Ovary about at equator of acetabulum, at end of ceca, slightly dex-
trad; shell gland in ovarian zone, slightly sinistrad; vitellaria large, follicles large, in
extra-, inter-, and cecal areas, dorsal and ventral of ceca, from slightly above postsuc-
torial plane to caudal margin of shell gland, hence slightly postcecal; uterus extends
from shell gland a short distance cephalad, coils, then ascends a short distance, then
coils and becomes very much distended by eggs, passing dorsally of testes and beneath
arch of vasa efferentia, then runs in nearly straight course ventrally of vas deferens to
Bischarge into ductus hermaphroditicus; Laurer's canal runs at first cephalo-dorsad ,
then dorsad to open slightly sinistrad of median line, slightly caudad of preovarial
plane, about 1.72 mm. caudad of excretory pore.

Eggs. — Numerous, operculated, 120 by 67.5/x.

Type. — B.A.I. 3066.

Habitat. — In (organ? of) Buffclus indicus.
13893— Bull. 60—10 9

132

Fig. 103.

Source of material.— The 2 specimens forming the collection
were in a bottle bearing the B.A.I. No. 3066, the label in which bore
the following information:

Name Amphislomum explanalum. Host Buffelus indicus. Determined by Prof.
A. Railliet. Date 1899. Presented by Prof. A. Railliet. Date 1899.

The specimens are in poor condition; one is greatly distorted
having its cephalic third bent acutely ventrad; the other also appears
somewhat distorted by irregular shrinkage, but is
sufficiently preserved for study, and the following
description is based chiefly upon it.

EXTERNAL CHARACTERS.

Size. — Measured in alcohol this specimen was
9.75 mm. in greatest length and 4.5 mm. in greatest
transverse diameter. After embedding and section-
ing, the length (calculated from the sections) was
found to be 8.94 mm., the greatest transverse
diameter 4.10 mm., and the greatest dorso-ventral
diameter 4.4 mm. The measurement of the great-
est transverse diameter was unsatisfactory on account of the distor-
tion by flattening in that region of the worm; this measurement is
therefore regarded as considerably under what it would be in the
perfect specimen.

Color. — The specimens were of a grayish olive-green color.
Form (figs. 103, 104). — The greatest dorso-ventral and tranverse
diameters are in about the region of junction of
the middle with the caudal third of the body.
From this region it tapers gradually but consider-
ably toward the oral pole, which appears rela-
tively sharply pointed; a short length of the
terminal portion is contracted into a small trun-
cated cone. The aboral pole remains broad and
thick and rounded, and may be considered as bev-
eled at the expense of its ventral aspect, where it
presents the terminal irregularly circular acetabu-
lar aperture. The longitudinal axis of the worm
is moderately curved with its concavity ventrad.

The dorsum is arched both longitudinally and transversely,
whereas the venter is concave longitudinally and convex from side
to side; this convexity, however, is much less marked than that of
the dorsum and in certain regions almost disappears. Transverse
sections are in a general way elliptical in outline, but in the region
where the transverse convexity of the venter almost disappears, the
outline approaches that of a semicircle with rounded angles.

Fig. 104.

Fig. 105.

Fig. 106.

135

Surface. — The surface cuticle presents fine transverse striations,
jbest marked near the oral extremity. There are also irregularities
of t he surface, which are probably due to irregularities in contraction
in the process of fixing and in the preservation.

Genital pore. — On the ventral surface apparently slightly to the
left of the median longitudinal line and at about one-eighth of the
body length from the oral extremity is a small bulging, on the vertex
of w hich' may be noted a small (160/i) transversely elongate button-
hole-like pore, the genital pore (figs. 104, 108). This pore leads into
a relatively shallow chamber, which is almost entirely filled by a
plump, slightfy elevated, genital papilla which arises from what
corresponds to the dorsal wall of the chamber. At the vertex of

Fig. 107.

this papilla is an orifice, the porus hermaphroditicus, the external
termination of the ductus hermaphroditicus.

Acetabulum. — This muscular organ is in the caudal portion of the
body. On account of the curvature of the longitudinal axis of the
worm its aperture is tilted slightly ventrad and gives the appearance
of a ventral bevel to the caudal extremity of the worm. The dome
of the acetabulum (measured in projection of one sectioned specimen)
was about 3.75 mm. in vertical by about 3.25 mm. in transverse
diameter with an aperture about 1.85 mm. in vertical by about
1.52 mm. in transverse diameter. The margin of the acetabular
aperture is formed by the slightly projecting muscular rim of the
acetabulum itself, a thin, closely applied layer of the body parenchyma
extending to its margin but not overlapping it, so that the aperture

136

appears to have a narrow enclosing lip, which is readily discernible
on the surface, where it is marked off from the general body surface
by a shallow groove (figs. 104, 106, 112, 113).

INTERNAL ANATOMY.

Digestive tract. — The cephalic extremity of the worm present
a transversely elliptical crateriform depression, the base of whic
presents the oral aperture. The latter leads directly into a muscula
oral sucker. No papillae were observed. The sucker is relativel
small, measuring in projection about 0.96 mm. in length, with
maximum transverse diameter of 0.98 mm. and with a maximum
dorso-ventral diameter (measured in median sagittal plane) o
0.52 mm. In both sagittal and frontal planes it is of an oval outline;

Fig. 108.

in transverse section it has the form of an ellipse with its major axis
corresponding to the transverse diameter of the worm (fig. 107).
The lumen of the sucker is a dorso-ventralhy narrow, transversely
broad space; in transverse section in the region of its equator the
form of the lumen is somewhat that of a spindle. The body of the
sucker is inclosed in a narrow perisuctorial space, in which it is retained
in position by attachments at both its poles and by dorsal and ventral
dorso-ventral strands. The lumen is lined by a thin, smooth, cuticle-
like layer. The esophagus springs from the base of the sucker,
passes directly caudadfor about half its length, then bending slightly,
passes dorso-caudad to divide into two lateral ceca at a point slightly
nearer the dorsum than the venter and about one-fifth of the body
length from the oral extremity. The length of the esophagus is

137

about three-fourths that of the sucker. Its anterior extremity is
slightly caudacl of the level of the genital pore. In the first half of
its course the lumen of the esophagus maintains substantially a
uniform diameter; in the second half, however, it dilates moderately
but distinctly and with some abruptness. The esophagus is lined
by a cuticle-like layer and is inclosed in a scant layer of sparsely
scattered cells.

The intestines pass at first laterad from their point of origin from
the esophagus, then, describing a curve, they pass directly caudad in
fairly close proximity to the dorso-lateral aspect of the body. Their
form in transverse section is very irregular and their caliber varies
greatly at different levels. They terminate by cecal extremities
dorsad of the acetabulum and slightly caudad of the center of the

Fig. 109.

aperture, or at a level somewhat caudad of the junction of the third
with the caudal fourth of the body. They are lined by an epithelial
cell layer.

Genital system. — With the exception of the vitellogene glands,
the genital organs he in the intercecal area.

Male organs. — The two testes are large irregular masses. One is a
little to the right of the other and a little nearer the oral extremity,
so that their zones and their fields overlap to a considerable extent
(figs. 105, 106, 111). The testis from which the right vas- efferens
springs lies in the equatorial fifth of the worm and is a little to the
right and at a slightly higher level than the testis from which the left
vas efferens springs. The latter testis is therefore somewhat farther
from the oral extremity and overlaps the left side of the caudal

138

portion of the, ventral aspect of the right testis. Both testes are
indented by deep fissures which mark off huge lobes. A vas efferent
(•merges from the dorsal aspect of each testis. On account of the
relative positions of the testes, the right vas is much the shorter.
They at first pass more or less directly cephalad; then a little above
t he cephalic aspect of the right testis they pass transversely inward,
forming an arch beneath which the uterus passes as they unite in the
formation of the vas deferens. The firs! portion of the vas deferens
is a relatively thin walled, long, intricately and compactly coiled
vesicula, the lumen of which is dilated and filled with spermatozoa
(figs. 105, 106, 110). It is succeeded by a relatively short, uncoiled,
and almost straight pars musculosa (figs. 105, 106, 109). The change
from one to the other is quite abrupt. The musculosa has a relatively
small lumen and its walls, though more muscular and thicker than

that of the vesicula, are
not very greatly devel-
oped. Its direction is
cephalo-ventrad.

At a point in a trans-
verse plane slightly cau-
dal of that of the base
of the sucker this duct
becomes inclosed in a
mass of cells and its ex-
ternal layer of longitu-
dinal muscle fibers be-
comes much thinned;
this is the beginning of
the pars prostatica.
The pars prostatica (fig. 105) is both absolutely and relatively quite
short and is succeeded by the ductus ejaculatorius. The ductus ejac-
ulatorius is quite short, its walls more delicate than those of the
prostatica, and the change from one to the other is marked by the
disappearance of the prostatic cells. At the base of the genital
papillae the ductus ejaculatorius and the uterus unite to form the
ductus hermaphroditicus which pierces the genital papilla and ter-
minates at the vertex of the latter at the porus hermaphroditicus.
The genital papilla and the wall of the genital atrium are inclosed
in a sharply defined mass of muscular fibers (fig. 108).

Female organs. — The ovary lies in the caudal portion of the body,
slightly caudad of the plane of junction of the third with the caudal
fourth of the body, dorsad of the dome of the acetabulum, and a little
to the right of the median sagittal plane. The oviduct springs from
the caudo-mesial aspect of the ovaiy and passes transversely to the
left toward the shell gland, near which it appears to fork into two
ducts (fig. 113). The forking takes place in a transverse plane; one

139

of the forks is Laurer's canal, the other should be regarded as the
continuation of the oviduct. The latter curves slightly cephalo-
lentrad to penetrate the shell gland. Laurer's canal curves around
$he right latero-dorsal aspect of the shell gland to gain a position
dorsad of the latter, then it passes cephalo-dorsad close to the left
of the excretory vesicle and opens on the dorsum a little to the left
of the median line at a point in a transverse plane slightly caudad
of that of the cephalic aspect of the ovary and about 1.72 mm.
kar about one-fifth of the total body length) caudad of the excretory
pore. The shell gland is considerably smaller than the ovary and
lies a little to the left of it and of the median sagittal plane.

On its mesio-caudal aspect the shell gland is penetrated by the
oviduct and on its caudal aspect near its mesial margin by the

Fig. ill.

vitello-duct. These ducts unite almost at once to form the ootype.
This fusiform canal pierces the shell gland obliquely cephalad and to
the left, emerging from the left latero-cephalic aspect of the gland
as the uterus. The uterus after emerging from the shell gland tends
cephalad, curving around the dorsal aspect of the shell gland to gain
the axial region of the worm. Here the uterus in its ascent cephalad
describes intricate coils. It forms some loops in the space between
the caudal portion of the left testis and the acetabulum, then doubles
back passing underneath this testis somewhat obliquely to the left
and turns cephalad in the space dorsad of this testis. It ascends in

140

this position in an almost straight course for a considerable distance
before it again begins to form coils. These coils are in the intereecal
space dorsad of the testes and a I first ventrad of the excretory vesicle
and duct, and later between the testes and dorsum. The coils .nc
distended with very numerous oval, operculated eggs. As the level
of the cephalic aspect of the right testis is approached, the coils tend
cephalo-ventrad between the vasa efferentia and gradually gain the
ventral aspect of the coiled vesicula, ascending cephalad in this
relation for a short distance, after which the windings cease and the
eggs disappear from its lumen. It now ascends in only a slightly
wavy course close to the ventral aspect of the vas deferens to unite

Fig. 112.

with the ductus ejaculatorius at the base of the genital papilla in
the manner already described.

The vitellogene glands resemble those of P. cervi, but are not quite
so highly developed. The follicles are large and prominent and
occupy the extracecal areas, but extend along underneath the lateral
margins toward both the ventral and dorsal median sagittal line,
approaching closer, however, to the latter than to the former, and
coming into relation with both ventral and dorsal aspects of the ceca.
Vertically the glands extend from slightly above the level of the base
of the sucker to about the level of the plane of the caudal margin
of the shell gland. It will be observed, therefore, that in length they
exceed that of the intestinal ceca; that is, they extend beyond the
limits of the cecal zone.

141

A transverse vitello-duct leaves the caudal portion of each gland,
passes obliquely caudo-mediad ventrally of the corresponding intes-
tine to unite close to the dome of the acetabulum at a point in a
transverse plane just above that of the cephalic aspect of the shell
gland. Their union results in the formation of a common duct
which passes caudo-dorsad, skirting the ventral and ventro-caudal
aspect of the shell gland, finally to penetrate the latter at its caudal
aspect as already described.

Eggs. — The eggs are operculated and very numerous. One of the
eggs measured in section of the uterus was 120// long by 67. 5 n broad.

Excretory system. — The excretory vesicle is relatively small,
being a rather long, and dorso-ventrally very narrow, almost slit-like

Fig. 113.

space. Its dome is in the caudal portion of the body about midway
between the acetabulum and dorsum and about 1 .48 mm. (or about
one-sixth of the body length) from the caudal margin of the worm.
From the dome the body of the vesicle extends cephalad, gradually
coming nearer the dorsum as it ascends in the intercecal area. As it
ascends also it gradually narrows in both transverse and dorso-
ventral diameters until it becomes reduced to a cylindrical duct
about 52 [i in diameter and 240/x long, with thickened walls, which
opens on the dorsum at about the level of the superior margin of
the acetabulum, namely, about five-ninths of the total body length
caudad of the oral margin, and, as already stated, about one-fifth
the body length cephalad of the opening of Laurer's canal.

142

KKLATION TO P. ex planatUW AS DESCRIBED BY FISCINEDER.

Comparing our specimens with P. explanatum, as described by
Fischoculer, 1904, 454-458, figs. A, 1-3, the following differences are
noticed: In explanatum the genital pore is immediately postbifurcal
instead of suctorial; the ceca end at the cephalic margin of the
acetabular aperture, instead of at the acetabular equator; excretory
pore is equatorial, some distance cephalad of acetabulum, instead of
on preacetabular plane; the excretory vesicle ends cephalad of acetab-
ular equator instead of at its equator; the testes are distinctly
farther cephalad, the anterior testis not reaching the acetabulum;
the pars prostatica is longer instead of shorter than the pars muscu-
losa; the ovary is at the anterior margin, instead of at the equator
of acetabulum, and is distinctly and entirely in the intercecal an a
instead of at and caudad of end of ceca; Laurer's canal is distincl ly
preacetabular instead of at the equator of the acetabulum.

These differences would appear to indicate that we are dealing
either with a distinct species, or a distinct subspecies, or with a
rather marked case of individual variation; they are certainly more
marked than the characters now being used to distinguish between
some species of distomes. As it is easier to suppress a synonym
than it is to disentangle anatomical and biological data of separate
forms confused in one alleged species, we incline to the view (con-
trary to most authors) that in case of doubt the more conservative
action consists in proposing a new species, hence we publish this form
as such.

ILLUSTRATIONS.

Fig. 103. — Profile view. Enlarged. Original.

Fig. 104. — Ventral view of same. Enlarged. Original.

Fig. 105. — Profile projection of specimen shown in figs. 103 and
104. Shows oral sucker (o. s.), esophagus (es.), right intestinal
cecum (i.), genital pore (g. p.), ductus hermaphroditicus (d. h.),
pars prostatica (p. p.), pars musculosa (p. m.), vesicula seminalis
(v. 8.), right vas efferens (v. e.), right (t. d.) and left (t. s.) testis,
ovary (ov.), shell gland (s. g.), uterus (ut.), Laurer's canal (L. c),
excretory vesicle (ex. v.), excretory pore (ex. p.), and acetabulum
(ac); a-a, b-b, c-c, d-d, e-e, f-f, g-g, planes of section. Slightly
diagrammatic. Enlarged. Original.

Fig. 106. — Frontal projection of specimen shown in figs. 103 and
104. Shows oral sucker (o. s.), esophagus (es.), intestinal ceca (i.),
ovary (ov.), shell gland (s. g.), uterus (ut.), the right (t. d.) and left
(t. s.) testis; the vasa efferentia (v. e.), vesicula seminalis (v. s.), and
pars musculosa (p. m.), position of genital pore (g. p.), and the
acetabulum (ac); a-a, b-b, c-c, d-d, e-e, f-f, g-g, planes of section.
Slightly diagrammatic. Enlarged. Original.

143

Fig. 107. — Transverse section at' a-a, figs. 105 and 106. Shows
form of body, form of oral sucker (o. s.), perisuctorial space (p. s. sp.),
and dorsal and ventral mesenterium-like strands (m. b.). Enlarged.
Original.

Fig. 108. — Transverse section at b-b, figs. 105 and 106. Shows
'genital atrium (g. a.), genital papilla (g. pap.), oral sucker (o. s.),
perisuctorial space (p. s. sp.), and some vitelline follicles (v. g.).
Enlarged. Original.

Fig. 109. — Transverse section at c-c, figs. 105 and 106. Shows
pars musculosa (p. m.), uterus (ut.), esophagus (es.), and vitellaria
(v. g.). Enlarged. Original.

Fig. 110. — Transverse section at d-d, figs. 105 and 106. Shows
position and relations of uterus (ut.), vesicula seminalis (v. s.), intes-
tines (i.), and vitellaria (v. g.). Enlarged. Original.

Fig. 111. — Transverse section at e-e, figs. 105 and 106. Shows
position and relations of the testes (t.), left vas efferens (v. e.), uterus
(ut.), intestines (i.), superior margin of acetabulum (ac), the excre-
tor}^ pore (ex. p.), and the vitellaria (v. g.). Enlarged. Original.

Fig. 112. — Transverse section at f-f, figs. 105 and 106. Shows
positions and relations of ovary (ov.), uterus (ut.), excretory vesicle
(ex. v.), Laurer's canal (L. c), intestines (i.), vitellaria (v. g.), right
transverse vitello-duct (t. vd.), and acetabulum (ac). Enlarged.
Original.

Fig. 113. — Transverse section at g-g, figs. 105 and 106. Shows
origin of Laurer's canal (L. c.) from oviduct (ov. d.), the ovary (ov.),
shell gland (s. g.), excretory vesicle (ex. v.), vitellaria (v. g.), and
acetabulum (ac). Enlarged. Original.

PARAJKPHISTOMUM PARVIPAFILLATUM, new species.
[Figs. 114 to 122.]

Specific diagnosis. — Paramphistomum (p. 73); Body 3.1 to 3.9 mm. long by
1.8 to 2.3 mm. broad; buff color (alcohol specimens); rather oval, longitudinal outlines
of lateral margins nearly straight; tapers very gradually; cephalic extremity slightly
lees bluntly rounded than caudal extremity; surface smooth. Genital pore post-
bifurcal, about one-fourth of body length from oral margin. Acetabulum subterminal,
aperture about 0.5 to 0.6 mm. in diameter. Mouth terminal to ventro-sublerminal
(distortion?); oral sucker rather pyriform to oval; esophagus bulbous, short (?), about
as long (?) as sucker, bifurcation about midway between oral margin and genital
pore; ceca wavy, long, extending to or slightly caudal of equator of acetabulum. Ex-
cretory pore dorso-median, a little caudad of pore of Laurer's canal, dorsal of equator
[of acetabulum and not crossed by Laurer's canal; excretory vesicle dorsal of
acetabulum.

Male organs: Testes occupy greater part of median field from equator to acetabulum;
tone caudad of the other; of irregular outline (in part artifact?); vasa efferentia unite
in vas deferens; vesicula seminalis convoluted; pars musculosa short; pars prostatica
short, but well developed, ductus ejaculatorius exceedingly short, unites with metra-
term to form ductus hermaphroditicus, which opens on vertex of genital papilla; the
latter is surrounded by an atrium into which projects a circular ridge bearing numerous

144

exceedingly minute papillae which also extend over on to the genital papilla; cirrus
pouch absent.

Female organs: Ovary median but extending more to the left than to the right, near
dorsum, immediately caudad of caudal testis and on a plane of upper margin of acetab-
ulum; shell gland on ventro-caudal aspect of ovary; vitellaria highly developed,
close to lateral margins, lateral, dorsal, and ventral of ceca, extend about from base of
sucker to or slightly beyond equator of acetabulum; uterus passes from ventrally of
shell gland and ovary, dorsad between ovary and caudal testis, cephalad dorsally of
testes, ventrad under arch of vasa efferentia, cephalad to ductus hermaphroditicus;
it is coiled, and filled with a fairly large number of eggs; Laurer's canal passes from
oviduct dorso-medio-cephalad and opens in median line.

Eggs: Numerous, oval, abou t 135 by C7//.

Type.— U.S.P.H.& M.-H.S. 9962.

Habitat. — Reticulum of "calf" (Bos indicus var.) at Phrapatoom, Siam.

Source of material. — This material was sent to us by Dr. Paul
G. Woolley, who collected it in Phrapatoom, Siam, on September 22,
1906, from the reticulum of a calf (Bos indicus var.).

EXTERNAL CHARACTERS.

Size. — The specimens vary from 3.1 mm. to 3.9 mm. in length and
from 1.8 to 2.3 mm. in maximum breadth.

Color. — Alcohol specimens are of a buff color.

Form. — In the process of fixing and in the course of preservation
the specimens appear to have undergone considerable distortion, so
that from the material at hand it is difficult to more than suggest
very roughly their original form (fig. 114). They are oval in outline,
with lateral margins approximately parallel in the equatorial region
and with extremities that are bluntly rounded. The dorsal (and
perhaps also the ventral) surface is probably arched in the fresh state,
but in our specimens they are marked by ridges and depressions due
probably to the shrinking influence of the fixing and hardening
solutions.

Surface. — The general surface is smooth, except for an indication
of transverse wrinkles or striations. No surface papillae are evident.
The cephalic extremity is marked by the presence of a more or less
circular oral aperture, and the caudal by the presence on its ventral
aspect of a large subterminal acetabulum, distorted in form in most
of the specimens in such a manner as to make its aperture longitu-
dinally elliptical in outline, though one or two retained what is prob-
ably their normal circular form.

Genital pore.— The genital pore is ventro-median (figs. 114, 115,
119, 120) on a somewhat flattened rounded elevation or bulging
about one-fourth the body length from the cephalic end and caudad
of the bifurcation of the esophagus.

Acetabulum— The acetabulum is distinctly subterminal in all
specimens. It varies considerably in respect to form, position, and
aperture, these variations being largely due, in all probability, to the

145

Fig. 114.

distorted condition of the body. Two specimens presented circular
apertures 0.5 to 0.6 mm. in diameter; four specimens presented more
or less elliptical apertures, varying from 0.6 to 0.7 mm. in longitudinal
and 0.17 to 0.4 mm. in transverse diameter. The rim of the acetabu-
lum appears to project beyond the body parenchyma
i in a manner very like that in Pseudodiscus collinsii,
and there is a strong suggestion of a ring around the
aperture similar to that which occurs in Ps. stanleyii
and Ps. collinsii. As a matter of fact, however, the
apparently projecting ring is covered by a thin layer of
parenchyma. The deep narrow groove which marks off
i this ring in Ps. stanleyii and Ps. collinsii, while strongly
: suggested, is not so clearly recognizable in this species (figs. 116,
122). The dome of the acetabulum measures about 126/z to 135^ in
thickness.

INTERNAL ANATOMY.

Digestive tract. — The more or less circular oral aperture gives
i entrance directly into a somewhat pyriform muscular oral sucker

(fig. 116). In transverse section
(fig. 117) the latter is ellipti-
cal in form, with its major axis
in the transverse diameter of the
body. Its lumen is a dorso-
ventrally more or less narrow,
transversely fairly broad space.
It is lined by a thin cuticle-like
layer which appears to have dis-
appeared from some portions of
the lumen, and bears some con-
ical papillae of moderate size on
its surface. The sucker lies in a
perisuctorial space (figs. 116, 117)
suggestive of a rudimentary body
cavity. Dorsally of its esophageal
extremity there is a transverse
ganglionic cord (fig. 115). The
sucker is succeeded by the esoph-
agus. From our preparations it
is impossible to determine satisfac-
torily its length; it is estimated,
however, that it is not shorter than
the sucker. It passes at first for a short distance caudad, then bends ab-
ruptly and passes almost directly dorsad, but with an inclination caudad
(fig. 118), terminates, and gives origin laterally to the intestinal ceca.

Fig. 115.

146

The esophagus has somewhat the form of an Indian club; its caudal
half becoming, rather abruptly, very much swollen by a very great
increase in thickness in its muscular layer (figs. 115, 118). The intes-
tines, from their point of origin, pass at first in a nearly horizon-
tally transverse plane laterad, del

Fig. 11G.

scribing in this part of their course
a gentle curve nearly parallel to
the dorsum. They then, rather
abruptly, bend caudad and pursue
a wavy path approximately par-
allel to the dorso-lateral aspect
of the worm, terminating by
blind extremities in slightly dif-
ferent planes at about the level
of the equator of the acetabulum.

The lining of the lumen of the
mouth, sucker, and esophagus
appears to be a thin cuticle in
anatomical continuation with
that of the body surface. With
the termination of the esophagus
at its point of division into the
intestinal ceca the cuticular lin-
ing ceases and is replaced in the
intestinal ceca by a layer of epi-
thelial cells.

Genital system. — Male organs. — The testes occupy almost all of the
interspace between the intestinal ceca from the equator (or a little
anterior of this) to the acetabulum. They are placed one directly cau-
dad of the other, with
but a slight interval be-
tween. Their form is
very irregular (figs. 115,
116, 121), a result, per-
haps, of the shrinking <
and distortion of the
worm as a whole, but
their surface is but little
indented. AvasefFerens
rises from each testis;
that from the posterior
springs apparently from
the superior aspect of its right extremity and passes cephalad between
the anterior testis and the right intestine; that from the anterior
testis springs from its dorsal aspect, passes cephalo-centrad to unite
with the left vas to form a vas deferens. The vas deferens consists of:

Fig. 117.

147

a well-developed thin-walled vesicula, which is very much coiled; a
short but well-developed pars musculosa ; a short but very well-defined
prostatica ; and a terminal excessively short ductus ejaculatorius. The
latter unites with the metraterm to form a ductus hermaphroditicus.
The ductus hermaphroditicus pierces the axial region of a well-devel-
oped truncated conical genital papilla. The genital papilla (figs. 115,
119, 120) projects into an atrium, which it almost fills. Embracing
the genital papilla is a ring-like collar, the surface of which is beset by
excessively minute papillae (hence i^arvipajnllatum) , which also extend
to some extent over the base of the genital papilla. External to the
ring-like collar and marked off from it by a groove is another ring.
This latter ring almost disappears in some positions of extrusion of
the copulatory apparatus, forming a shallow crater, in the center of
which is the genital pore.

Female organs. — The ovary lies in the median line (fig. 121), close
under the dorsum just caudad of the posterior testis, and at the level
of the upper margin of
the acetabulum. It ap-
pears somewhat elon-
gated in the transverse
diameter and com-
pressed dorso-ven-
trally, hence somewhat
pyriform, and extends
somewhat more to the
left than to the right of
the median line. The
point of origin of the ovi-
duct was from the right
extremity in one prep-
aration and from the left in another; from its point of origin the oviduct
passes to the opposing aspect of the shell gland. The latter lies close
to the ventral aspect and lower margin of the ovary. The relation of
the shell gland to the ovary varies somewhat in the different specimens
studied. It is penetrated by the oviduct, which is then joined by the
vitello-duct, after which the duct thus formed dilates somewhat to form
the ootype; the latter is continued and emerges from the shell gland
as the uterus. After emerging, the uterus passes at first caudad
for a short distance, then turns, forms a loop, and passes cephalad
in front of the shell gland and ovary, dorsad between the posterior
testis and ovary, then cephalad between the testes and dorsum of
the worm. In its progress it forms coils which are distended with
eggs. At the level of the cephalic aspect of the anterior testis it
takes a course ventrad beneath the arch of union of the vasa effe-
rentia and penetrates the base of the genital papilla in company
13893— Bull. 60—10 10

148

with the terminal portion of the vas deferens, with which it opens
into the ductus hermaohroditicus.

The yolk glands are highly developed. They consist of numerous
closely aggregated follicles m the lateral portion of the body close
to the lateral margins. They inclose dorsally, ventrally, and later-
ally the corresponding intestinal cecum. The gland of the left side
extends somewhat farther toward the median line than that of the
right side, so that it comes into relation with the dorsal and the ven-
tral aspects of the left ends of both testes. The glands extend, longi-

FlG. 119.

tudinally, from the termination of the sucker to about the equator
of the acetabulum (or slightly caudad of the level of termination of
the intestinal ceca). A little above the level of the caudal termina-
tion of the yolk glands the duct of either side is given off and passes
toward the middle line, ventrally of the corresponding intestinal tube,
to unite with the duct of the opposite side; by the union of these a
duct is formed which passes dorsad toward the shell gland, which it
penetrates on its caudal aspect to join the oviduct.

Laurer's canal leaves the oviduct about where the latter is on the
point of penetrating the shell gland and passes dorso-mediad and very

Fig. 120.

slightly cephalad to open on the dorsal surface about in the median
line (fig. 122).

Eggs. — The eggs are numerous, oval in form, and as seen in the
uterus they measure about 135^ by about 67/z.

Excretory system. — The excretory vesicle lies in the caudal por-
tion of the body behind (dorsad of) the acetabulum. In the specimens
studied it appears collapsed. From its caii do-dorsal aspect a short
thick-walled duct passes dorsad to discharge through the excretory
pore in the median line in a plane a little caudad of the opening of
Laurer's canal and near the caudal extremity of the body. It is
not crossed by Laurer's canal.

149

ILLUSTRATIONS.

Fig. 114. — Ventral aspect: ac, acetabulum; g. p., genital pore;
m, mouth. Enlarged. Original.

Fig. 115. — Sagittal section. Shows portion of oral sucker (o. .<?.),
perisuctorial space (p. s. sp.) containing granular coagulum, caudal

Fig. 121.

portion of esophagus (es.), left intestinal cecum (£.), esophageal
ganglion (e. g.), genital papilla (g. pap.), ductus hermaphroditicus
(o\ h.), pars prostatica (.p. p.), vesicula seminalis (v. s.) distended

with spermatozoa, metraterm (va.), uterus (ut.) distended with eggs,
testes (/.), and acetabulum (ac). Enlarged. Original.

Fig. 116. — Sagittal section. Shows oral sucker (o. s.), perisuc-
torial space (p. s. sp.) with granular coagulum, left intestinal cecum
(i.), the two testes (t.), left vas efferens (v. e. s.), uterus (ut.), excre-
tory vesicle (ex. v.), excretory pore ([ex. p.), and acetabulum (ac).
Enlarged. Original.

150

Fig. 117. — Transverse section. Shows oral sucker (o. ,9.) and
perisuctorial space (p. s. sp.) filled with a granular coagulum. En-
larged. Original.

Fig. 118. — Transverse section. Shows bulbous portion of esopha-
gus (es.), right intestine (i.), vitellogene gland (v. g.). Enlarged.
Original.

Fig. 119. — Transverse section of copulatory apparatus. Shows
genital papilla (g. pap.), ductus hermaphroditicus (d. h.), genital
atrium (g. a.), and minute papillte on ring-like collar and base of
genital papilla. Enlarged. Original.

Fig. 120. — Transverse section through copulatory apparatus to
contrast with figure 119. Shows form of genital papilla (g. pap.)
encircling papillated ring, slit-like dorsal chamber (g. a.), (d. Ti.) and
shallow crater-like depression (ventral chamber) at vertex of genital
bulging due to retraction of outer ring. Enlarged. Original.

Fig. 121. — Transverse section. Shows superior testis (L), right
vas efferens (v. e. d.), intestines (i.), and vitellaria (v. g.) and uterus
(ut.) filled with eggs. Enlarged. Original.

Fig. 122. — Transverse section at level of pore of Laurer's canal.
Shows pore of Laurer's canal (p. L. c), caudal margin of ovary (ov.),
caudal margin of shell gland (,?. g.), uterus {ut), excretory vesicle
{ex. v.), left intestinal cecum (i.), vitellaria {v. g.) and acetabulum
(ac.) with an apparent though not actual projecting rim. Enlarged.
Original.

PARAMPHISTOMUM SHIPLEYI, new species.

[Figs. 123 to 130.]

Specific diagnosis. — Paramphistomum (p. 73): Body apparently somewhere
between 4.5 and 7 mm. long by 2.46 mm. broad by 2.26 mm. thick; color (?); greatest
breadth about at junction of equatorial and caudal thirds; tapers toward bluntly
pointed oral pole, diameters at genital pore 2 mm. (transverse) and 1.98 mm (dorso-
ventral). Surface with minute papillae on oral pole. Genital pore ventro-median,
about 75/i in diameter, about at junction of cephalic and equatorial thirds, very
slightly postesophageal and postbifurcal, in cecal zone; at this point there is an ill-
defined slightly bulging area. Acetabulum ventrosubterminal ; very slightly sunken
below surface, 1.15 mm. in transverse, 1.95 mm. (?) in dorso-ventral diameter, aperture
about 0.39 mm. Mouth nearly terminal, with ventrosubterminal tendency, in
papillated depression; oral sucker rather large, pyriform, but somewhat flattened
dorso-ventrally, its oral pole projecting slightly, its lumen papillate; lies in a well
defined pseudobody-cavity; esophagus acutely bent, convexity ventrad, caudal half
with greatly thickened muscular wall; ceca of very irregular diameter, wavy, extend
about to equator of acetabulum. Excretory pore dorso-median, caudad of Laurer's
canal, somewhat caudad of equator of acetabulum ; thick walled excretory canal runs
from pore slightly caudo- ventrad to dorso-caudal aspect of well-developed excretory
vesicle, which lies dorsad of acetabulum, extending from near anterior plane of
acetabulum to caudal acetabular plane.

Male organs. — Testes large, lobate, one ventro-caudad of the other, fields nearly
coincide, zones overlap, nearer venter than dorsum; vasa efferentia run cephalau at
side of testes, their point of union is undetermined; vas deferens composed of: (1)
coiled vesicula seminalis, which lies dorsally of (2) a pars intermedia and (3) the

151

highly developed coiled pars musculosa, (4) pars prostatica straight, relatively short,
but well developed, and separated from musculosa by a sphincter-like constriction;
(5) thick walled ductus ejaculatorius; the latter opens into a slitdike space into which
metratcrm also discharges; from here a short duct passes ventrad to another slitdike
atrium; from the latter a duct passes ventrad to open into a small atrium which opens
to the exterior through the genital pore; this series of atria and canals is inclosed
in a mesh of muscular fibers.

Female organs. — Ovary and shell gland dorso-caudal of and very much smaller than
caudal testis, dorsal of cephalic portion of acetabulum, slightly dextral of median
line; shell gland ventrodateral of ovary; vitellaria with well developed, not numerous
follicles, in extracecal areas, extend from slightly preesophageal zone to caudal end
of cecal zone; uterus extends slightly caudad then cephalad, dorsally of testes, ven-
trally of the greater mass of pars musculosa, to open into same slit as does ductus
ejaculatorius.

Eggs. — Oval, 135 by 71/i, operculated at smaller pole.

Type. — U.S. P. II. & M.H.S. No. 10717 (returned to Shipley).

Habitat. — In (? stomach of) Cervus eldi, locality (?).

Source of material. — The material, consisting of a series of
transverse sections of one specimen, was loaned to us by Dr. A. E.
Shipley. Host. — Cervus eldi (J), stomach.

EXTERNAL CHARACTERS.

Size. — The specimen came to us already sectioned. We do not
know the thickness of the individual sections, so can not do more than
roughly estimate the length of the worm. It is probably not less
than 4.5 mm. nor more than 7 mm. long, with a maximum dorso-
ventral diameter of about 2.26 mm. and a maximum transverse
diameter about 2.46 mm. as measured in sections.

Form. — The worm is broadest and thickest in the regions of junc-
tion of the middle with the caudal thirds of the body length. From
this region the bod}7- tapers toward the oral pole, which is bluntly
pointed and at about the level of the genital pore, measures about 2
mm. in width and about 1.98 mm. in dorso-ventral diameter.

Surface. — The surface cuticle is unprovided with hooks or spines,
but minute papillae could be made out at the oral pole.

Genital pore. — In the ventro-median line, about at the junction of
the first with the middle third of the bod}r length, is a small orifice
about 75/i in transverse diameter, the genital pore. This is in the
center of a circular, ill-denned, slightly bulging area.

Acetabulum. — The acetabulum is in the caudal portion of the body
with, probably, a terminal (or subterminal) aperture, though this is
shown as ventro-subterminal in the diagram (fig. 123). At the level
of the excretory pore the acetabulum measures about 1.15 mm. in
transverse diameter with an aperture of about 0.39 mm. in the same
diameter. The rim of the acetabulum, although it does not project
beyond the embrace of the body parenchyma, is covered only by a
relatively thin layer of it for a distance of about 255/i (fig. 130) from

152

153

the margin of the aperture. Judging from the appearance of this in
section, the unsectiohed specimen probably presents corresponding
to it a collar-like area immediately around the acetabular aperture
delimited from the general surface by a shallow, more or less well-
defined groove, somewhat like but not so well defined as that in
P. siamense.

INTERNAL ANATOMY.

Digestive tract. — The mouth is at the bottom of a circumscribed
depressed area at the vertex of the cephalic extremity. It is an
irregular orifice which leads directly into the lumen of a well-developed
sucker. The crater-like depression of the surface is beset with digitate
papillae. In form the
sucker is pyriform
though somewhat
flattened dorso-ven-
trally. Its caudal
pole is broad and
rounded and gives ori-
gin to the esophagus;
its oral pole projects
in an irregular ring-
like manner beyond
the parenchyma and
its aperture is the
mouth. The sucker is
placed in a well-
marked perisuctorial
space (fig. 124), which
is traversed dorsally
and ventrally by
mesenterium-like
strands. The suctorial wall may be regarded as consisting of a ven-
tral and of a dorsal muscular plate, the two, however, being contin-
uous laterally. The muscular fibers form a dense inner and a looser
meshed and relatively thicker outer zone, as seen in transverse sec-
tion. The lumen is a dorso-ventrally narrow, transversely broad
space which caudally becomes reduced to a small circular aperture
leading into the esophagus. It is lined by a thin cuticle which is beset
by small hemispherical to conical papillae. These are more numerous
and larger near the oral pole. Close to the dorso-caudal aspect of
the sucker, slightly above the level of the origin of the esophagus
and just without the perisuctorial space, there is a well-defined trans-
verse nerve trunk (fig. 123) which gives off branches cephalad and
caudad; these, however, can not be traced satisfactorily.

Fig. 124.

154

The esophagus passes at first ventro-caudad for approximately half
its length, then, bending acutely, it turns dorsad, with a slight tilt
cephalad, to fork into the lateral ceca at a point in a transverse plane
slightly eaudad of that of the base of the sucker and a little cephalad
of that of the genital pore, and about or slightly more than one-third
of the dorso-ventral diameter of the worm at that level from the
dorsum. The muscular wall of this second portion of the esophagus
is very greatly increased in thickness; the increase begins at about
the point where the esophagus bends, and it augments progressively
almost but apparently not quite to its caudal end. The esophageal
lumen is lined by a fairly thick cuticle-like layer.

Fig. 125.

The intestinal ceca pass at first for a short distance laterad, then
curve ventro-laterad, at the same time tilting caudad until they reach
a point in a frontal plane somewhat dorsad of that of the bend or knee
of the esophagus. Here each intestine rather abruptly curves dorsad
and proceeds in this spirally, wavy course caudad until it reaches
about the level of the cephalic margin of the acetabular aperture,
where each intestine terminates by a cecal extremity.

The diameter of the gut varies at different points in its course,
there being marked dilatations (fig. 126) succeeded by equally marked
constrictions (fig. 127). The lumen of the ceca is lined by an epithe-
lial cell layer.

Genital system. — The sexual organs, with the exception of the
vitellogene glands, are disposed in the intercecal area.

155

Male organs.— There are two la rue Lobate testes, one of which is
caudad of the other; the cephalic portion of the caudally placed testis
overlaps the right ventro-lateral aspect of the caudal portion of the
cephalically placed testis. They are nearer the venter than the dor-
sum in a zone which exceeds somewhat in vertical diameter one-fourth
the body length, in other words, comprising the third and to some
extent the fourth quarter of the body. Each testis gives origin to a
vas efferens, that of the caudal testis passes to the left and that of the
cephalic to the right, and then each proceeds cephalad. The left vas
efferens (from the caudal testis) ascends at first close to the left lateral
aspect of the cephalic testis (between it and the intestine) and later,

-/[, w.

Fig. 120.

■as it tends dorso-cephalad, it skirts the left lateral aspect of the coiled
pars musculosa, eventually entering the coil complex of the vesicula,
which is presumably formed by its union with the right vas ; but this
point can not be satisfactorily traced in the complexity of the coils.
The course of the right vas (from the superior testis) is similar to that
of the left, but is of course much shorter, and almost at once after its
origin it begins to skirt the left lateral aspect of the coiled pars mus-
culosa, eventually entering and becoming indistinguishable among
the coils of the vesicula. The vesicula forms an easily distinguishable
thin-walled coil complex placed close to the dorsal aspect of the coil
formed by the pars musculosa. The latter is the second portion of
the vas deferens, but there is intercalated, between the vesicula and

156

the musculosa, a short, relatively tluck-walled narrow duct, which has
been noted in some of the other forms and named the pars intermedia.
The pars musculosa (fig. 127) is highly developed, thick, muscular
walled, and very much coiled; measurements at favorable points
give a diameter of about 225^ to 300/;, with a thickness of wall of
about 45fi to 60/z. The caliber of the lumen of this part of the \ as
deferens considerably exceeds that of the vesicula. The musculosa
is succeeded by a relatively short (42O/0 but well-developed prostatica,
a sphincter-like constriction marking the transition from one to the
other. The prostatic cells arc well developed and form a thick, encir-
cling layer about the duct, the diameter of which is decidedly reduced

Fig. 127.

as compared with that of the musculosa, and its wall is much thinner
than that of the latter. The pars prostatica is straight and p asses
almost directly ventrad. In its turn the prostatica is succeeded by a
thick-walled duct about 75/z in diameter and about 120/x long; this
may perhaps be regarded as the ductus ejaculatorius. The ductus
ejaculatorius is directed ventrad and opens with, but separate from,
and just above the uterus, into a small narrow slit-like space. From
this space a short duct passes ventrad and may be regarded as piercing
the axial region of a mushroom-like structure (figs. 123, 120) to open
into another slit-like atrium somewhat larger, however, than the one
into which the male and female ducts open. A duct about 30ft in
diameter leads from this atrium and a pparently pierces a stout conical

157

papilla, which may be regarded as the genital papilla, to open into a
small genital atrium which connects with the exterior by the genital
pore. The series of atria and ducts connecting them, between the
termination of the ductus ej aculatorius and the genital pore, which
may be regarded as forming the hermaphroditic copulatory appara-
tus, is inclosed in a cylindrical mesh of muscular fibers, which do not,
however, form such a well-defined structure as is described, for
example, in Watsonius watsoni or ParampMst. crassum.

Female organs. — The ovary and the shell gland, the latter close to
the right ventro-lateral aspect of the former, are in the caudal portion
of the intercecal space, caudo-dorsad of the caudal testis, dorsad of the
cephalic portion of the acetabulum, and immediately to the right of

Fig. 128.

the median sagittal plane and the dome of the excretory vesicle. The
' ovary is the larger of the two glands. The oviduct takes origin from
the left lateral aspect of the ovary, and at first, for a short distance,
passes to the left, then again, for a short distance, it curves cephalad
and to the right, after which it proceeds obliquely ventrad and to the
right with a very slight tilt cephalad toward the shell gland, at the
i same time giving origin to Lani er's canal. This occurs in about the
: same transverse plane as the one in which the uterus is seen to emerge
from the shell gland. The oviduct penetrates the left pole of the
shell gland, in the substance of which it is joined by the common
vitello-duct, the two uniting to form the ootype. The latter is directed
obliquely to the right and ventro-caudad and is continued as the
T uterus. Laurer's canal, after parting from the oviduct, passes at

158

first directly caudad then with a tilt to the left and dorsad to a point
slightly caudad of the level of origin of the oviduct, where it bends I
and passes cephalo-dorsad to open on the dorsum in about the median
sagittal line at a point in a transverse plane slightly caudad of those
of the cephalic margins of the ovary and the acetabulum and in about
the plane of the caudal margin of the caudal testis (fig. 129).

The shell gland lies close to the right ventro-lateral aspect of the
ovary; its major axis is directed obliquely from the left to the right
and ventro-caudad. As already stated, it is penetrated at the left I
pole by the oviduct; at its left latero-cephalic aspect, it is penetrated I
by the common vitello-duct, the two uniting in the ootype. The uterus,
which is the continuation of the ootype, emerges from the right pole

Fig. 129.

of the gland and turns to the left and cephalad. It forms some coils
ventrally and to the left of the shell gland and ovaiy, then skirts the
right and dorsal aspects of the dome of the excretory vesicle to reach
the left dorso-lateral aspect of the dome of this vesicle. Here, in the
area between the vesicle and the left intestine, it dips caudad for a
short distance, then doubles sharply cephalad to begin its ascent. It
forms winding ascending coils in the intercecal space between the
dorsum and the testicles. At the level of the cephalic margin of the
superior (cephalic) testicle, the uterus passes ventrad, skirting the
caudal aspect of the coiled vas deferens, after having first, however,
ascended a short distance between this coil and the dorsum. On
reaching the ventral aspect of the coil, it ascends in close relation to it
and with only slight and few windings which eventually cease alto-
gether. It finally comes in close relation to the caudal aspect of the

159

i ejaculatory duct, opening, as has already been stated, immediately
oaudad of the latter into a small slit-like chamber. The first portion
of the uterus contains a considerable number of yolk cells; the coils
w hich are between the testicles and the dorsum are distended to a
variable degree with eggs, among which in the more proximal coils
;may also be seen some clumps of spermatozoa. The eggs are oval
i in form with a small operculum at the more pointed end and measure
; about 135/t by 71//.

The vitellogene glands, consisting of well-developed but not numer-
i ous follicles, are disposed in the extra-cecal areas (between the intes-
i tine and lateral body wall) , extending vertically from a little cephalad
• of the level of the esophageal fork — slightly cephalad of the base of
the oral sucker to or very slightly caudad of the level of the cecal ends
i of the gut. At about
the level of the ce-
phalic margin of the
acetabulum a duct
leaves each gland and
passes obliquely i n -
ward and caudad, ven-
trally of the corre-
sponding intestine,
then bends dorsad.
The two transverse
ducts unite in about
the median sagittal
plane at a point close
to the acetabulum and
close to the right ven-
tro-lateral aspect of the
dome of the excretory vesicle in about the same transverse plane as
that in which Laurer's canal takes its departure from the oviduct.
From their point of union the common vitello-duct takes its depar-
ture; it passes obliquely dorsad and to the right with a slight tilt
cephalad in the direction of the shell gland which it penetrates at its
left ventro-cephalic aspect and in the substance of which it unites
with the oviduct. Both the transverse and common vitello-ducts
contain yolk cells, but the ducts are not notably distended and no
vitelline reservoir is distinguishable.

Excretory system. — A well-developed excretory vesicle is placed
dorsally of the acetabulum between the latter and the dorsum. The
dome of the vesicle reaches cephalad to a plane only a little caudad
of that of the superior margin of the acetabulum. Caudad the
vesicle extends to about the level of the caudal margin of the aceta-
bular aperture. From the dorso-caudal aspect of the vesicle a duct

160

takes origin; this duct passes dorso-cephalad to open in about the
median sagittal line of the dorsum (fig. 130) at a point in a transverse
plane passing through about the middle of the acetabular aperture and
about one-ninth the body length caudad of the opening of Laurer's
canal. There is no crossing of Laurer's canal and vesicle, the former
lying altogether dorsally of the dome of the latter. The excretory
duct is thick walled and lined with a cuticular layer in anatomical
continuity with that of the surface.

RELATION TO OTHER SPECIES.

P. shipleyi appears most closely related to P. parvipapillatum and
P. scolioccdium, from both of which it differs in the somewhat
greater complexity of its copulatory apparatus, which is characterized
by the presence of a relatively thick ring-like partition separating the
ventral chamber of the genital atrium from the dorsal chamber, the
two chambers being connected by a short, narrow duct. In P. par-
vipapillatum there is no partition between ventral and dorsal cham-
bers, the line of demarcation being a fold or groove which may be
(with a certain degree of evagination of the genital papilla) almost
obliterated. Besides this, however, the genital atrium and base of
the genital papilla of P. parvipapillatum are beset by minute papillae.
In P. scolioccdium the genital atrium forms one undivided chamber.

ILLUSTRATIONS.

Fig. 123. — Diagrammatic sagittal projection.0 ac, acetabulum;
es., esophagus; e. g., esophageal ganglion; ex. p., excretory pore; ex. v.,
excretory vesicle; g. a., dorsal chamber; g. a. c, ventral chamber of
genital atrium; %., intestines; L. c, Laurer's canal; o. s., oral sucker;
ov., ovary; p. m., pars musculosa; p. p., pars prostatica; s. g., shell
gland; t., testes; ut., uterus; v. s., vesicula seminalis; a-a, b-b, c-c,
ol-d, e-e, f-f, g-g, planes of section. Enlarged. Original.

Fig. 124. — Transverse section at a-a, fig. 123. Shows oral sucker
(o. s.), perisuctorial space (p. s. sp.), and mesenterium-like strands
(m. b.). Enlarged. Original.

Fig. 125.— Transverse section at b-b, fig. 123. Shows esophagus
(es.), esophageal bulb (es. b.), intestinal ceca (i.), vitellogene follicles
(v. g.). Enlarged. Original.

Fig. 126.— Transverse section at c-c, Fig. 123. Shows terminal
portion of pars musculosa (p. m.), the pars prostatica (p. p.), terminal
copulatory apparatus, intestinal ceca (i.), and vitellaria (v. g.). En-
larged. Original.

a The vertical measurements are not in accurate proportion to the dorso-ventral
diameters and the dorsal line is hypothetical. It is based on a series of transverse
sections, the thickness of which was not known and could not be determined accurately.

161

Fig. 127. — Transverse section at d-d, fig. 123. Shows uterus (ut),

• coils of pars musculosa (p. m.), the vesicula seminalis (v. s.), intes-
tinal ceca (i.), and vitellaria (v. g.). Enlarged. Original.

Fig. 128. — Transverse section at e-e, fig. 123, through overlapping
portions of the testes; t. d., cephalic testis; t s., caudal testis; v. e. s.,
left vas efferens from caudal testis; %., intestines; ut, uterus; v. g.,
vitellaria. Enlarged. Original.

Fig. 129. — Transverse section at f-f, fig. 123. To show pore of
iLaurer's canal (L. c), ovary (ov.), shell gland (s. g.), uterus (ut),

• excretory vesicle (ex. v.), caudal testis (t s.), right and left transverse
vitello-ducts (t. vd.), intestinal ceca (i.), common vittello-duct (c. vd.),

: acetabulum (ac), and vitellaria (v. g.). Enlarged. Original.

Fig. 130. — Transverse section at g-g, fig. 123 (level of excretory
pore). Ex. p., excretory pore; ex. v., excretory vesicle; v. g., vitel-
logene gland (right); ac, acetabulum. Enlarged. Original.

PARAMPHISTOMUM SIAMENSE, new species.

[Figs. 131 to 136.]

Specific diagnosis. — Paramphistomum (p. 73): Body 6 to 9 mm. long by 4 mm.
'broad; rather cornucopia-like in form, greatest transverse diameter just caudad of
■ equator; greatest dorso-ventral diameter about at cephalic margin of aperture of
; acetabulum; tapers at first moderately then more rapidly to a bluntly pointed oral
i extremity; caudal 'extremity bluntly rounded; longitudinal outline of lateral mar-
! gins decidedly convex; anterior half of body, especially, somewhat compressed dorso-

• ventrally, venter somewhat concave (to some extent, at least, artifact), dorsum
: arched (convex) in both axes. Surface smooth, except for slight transverse ridge-
like striations and a few scattered, small ventral papillae. Genital pore ventro-
medial about one-sixth of length of body from oral end and at zone of intestinal
bifurcation. Acetabulum very large, 3.5 to 5 mm., in press preparation 2.6 mm. in
vertical diameter, in sagittal section anatomically terminal, but because of curving of
body appears to open ventro-caudad subterminally ; aperture 1.2 to 1.3 mm. in longi-
tudinal and 1.3 to 1.4 mm. in transverse diameter, directed ventro-caudad, sunken

i slightly below surface of worm. Mouth terminal, leads directly into globular oral
; sucker the lumen of which is without papillae ; esophagus somewhat shorter than
i sucker; intestinal ceca long, extending about to equator of acetabulum. Excretory
pore dorso-median, cephalad of pore of Laurer's canal, 2.35 mm. cephalad of caudal
i extremity in a sagittal section, and about on plane of cephalic margin of acetabulum;

• excretory vesicle dorsal of acetabulum, long, extending from near cephalic margin of
: acetabulum to near caudal end of body.

Male organs: Testes situated in axial region of equatorial third of body, one dorso-
i caudad of the other; vasa efferentia arise on cephalic aspect of testes, vas deferens

• with much coiled vesicula, continued as musculosa to near base of genital papilla,
' where it changes to pars prostatica; short ductus ejaculatorius in papilla, joins with
i metraterm to form ductus hermaphroditicus, which opens at vertex of papilla, the
! latter projecting into a shallow atrium.

Female organs: Ovary somewhat pyriform, slightly lateral of median line, dorsal of
i equator of acetabulum; shell gland somewhat globular, about on same transverse
] plane but a little median of ovary; vitellaria with closely aggregated follicles, in lat-
< eral region, extending caudad from base of sucker to slightly beyond intestinal ceca;
i uterus extends cephalad from shell gland, coils ventrally of shell gland and ovary,

162

passes cephalad dorsally of testes, beneath arch of vasa efferentia, then cephalo
ventrad to genital papilla; it is very well developed and nearly nils space between
ceca ; Laurer's canal skirts right side of excretory vesicle and opens slightly dextral
of dorso-median line, candad of excretory pore.

Eggs: Rather numerous, 120> in length as measured in sections of uterus

Type.-U.S.P.H. & M.-H.S. 9970.

Habitat.— Bile ducts of a calf (Bos indicus var.) in Phrapatoom, Siam.

Source of material.— This parasite was sent from Phrapatoom,
Siam, by Dr. P. G. Wooley, who obtained it from the common bile
ducts of a "calf" (variety of Bos indicus).

EXTERNAL CHARACTERS.

Size.— One specimen measured in glycerin alcohol was about 6

mm. long by about 4 mm. in greatest
width; another measured on the slide as
a press preparation was 9 mm. long.

Form.— In form (fig. 131) the worm re-
sembles a Sicilian fisherman's cap or a
cornucopia. The caudal extremity is
large, formed by the acetabulum, the aper-
ture of which is directed ventro-caudad.
The body tapers toward the cephalic ex-
tremity which is bluntly pointed and
pierced by the mouth; the latter may be'
directed slightly forward (ventrad). The
body of the animal appears somewhat
compressed dorso-ventrally. The venter
appears slightly excavated, due perhaps
to the contraction incident to fixing. The
dorsal surface is arched from side to
side, and the longitudinal axis of the body forms a curve with con-
vexity dorsad.

Surface. — The surface cuticle is smooth, except for a few slight
transverse striations and a few small scattered ventral papillse near
the region of the genital pore.

Genital pore. — In the ventro-median line, about one-sixth the
length of the body from the oral extremity, is a slight circumscribed
bulging, in the center of which is the genital pore.

Acetabulum. — The acetabulum is large and occupies the caudal por-
tion of the body. In three press preparations it measured 3.5, 4, and
5 mm. in diameter respectively; in a sagittal section it measured 2.6
mm. in vertical diameter, with an aperture 1.23 mm. in the same diam-
eter. In three alcohol specimens the aperture, which is directed
downward and forward (ventro-caudad), measured from 1.2 to 2 mm.
in longitudinal diameter and 1.3 to 1.4 mm. in transverse diameter.

Fig. 131.

163

INTERNAL ANATOMY.

Digestive tract. — The mouth, which pierces the bluntly pointed
cephalic extremity, leads directly into the sucker. The latter is
muscular and globular in form (figs. 132, 133, 135) and is inclosed in
a well-defined space, being held in place by its attachments at its
oral and basal poles and
by mesenterium-like
strands. Its lumen,
somewhat spindle-
shaped and without pa-
pillae, leads into a short
esophagus. Close to the
dorso-caudal aspect of
the sucker there is a
transverse ganglionic
cord. The esophagus,
passing from its origin,
appears to describe a U-
shaped curve, with the
base of the U ventrad,
and then divides into two
intestinal ceca. The in-
testinal ceca pass latero-
ventrad from their point
of origin and after ap-
proaching the lateral
margin, from which they
are separated by the vi-
telline glands, they
change their course cau-
dad. They terminate by
blind extremities at
about the level of the
equator of the acetabu-
lum. The cecal end of
the right intestine extends a little farther caudad than that of the
left. In transverse section they are of irregular, variable outline,
and of considerable and variable caliber in the same specimen. The
lumen of the sucker and esophagus is lined by a thin layer of cuti-
cle which ceases abruptly at the esophageal fork. The intestinal
ceca are lined by a layer of epithelium.

Genital system. — Male organs. — The testes (fig. 132) are placed
one dorso-caudad or latero-caudad of the other in the axial region of
13893— Bull. 60—10 11

Fig. 132.

164

the equatorial third of the body. They appear crowded together, so
that the contiguous portions may overlap. In one of the specimens
the degree of this overlapping was very great, whereas in another
there was none at all, the testicular zones being separate, though
contiguous.

The form of the testes is irregular and varies in the different speci-
mens; this variation is probably due partly to a difference in the
degree to which the uterus is filled with eggs and partly to the degree
of general contraction in the fixing and hardening processes. As seen
in sections, their surface is more or less indented. There appears
also to be considerable variation in their position in relation to the
acetabulum. In some specimens the posterior testis is above (cepha-

lad of) the upper margin of the
acetabulum; in others (figs. 132,
136) it extends to the equator
of the acetabulum, the caudal
aspect of the anterior testis ap-
pearing to rest on the upper mar-
gin of the acetabulum.

In neither of two series of
transverse sections could the
two vasa efferentia be followed
for quite their entire extent, al-
though in one of them only a
very small portionof their course
was not observed. Completing
this portion from the other se-
ries, the following results were
obtained:

A vas efferens rises from each
testis; that from the right (or
caudal) testis springs from the superior (cephalic) margin of the right
lateral aspect and passes cephalad close to the right lateral aspect of
the superior (or left) testis.

The vas efferens of the left (or superior) testis springs from the
cephalic aspect of the latter and passes mediad and slightly caudad
to unite with the right vas efferens to form the vas deferens. The
latter is directed dorsad and almost at once dilates to form the much-
coiled thin-walled vesicula. The latter passes ventrad, its waU
becomes thick and its lumen becomes contracted (pars musculosa);
as this latter approaches the base of the genital papilla it becomes
surrounded by a large mass of cells (pars prostatica) which disappear
as the duct enters the papilla. The exceedingly short terminal por-
tion or ductus ejaculatorius joins with the metraterm in a common
canal, the ductus hermaphroditicus, which opens at the vertex of
the genital papilla (fig. 132).

Fig. 133.

165

Female organs. — The ovary (fig. 136) lies a little to the left of the
median line in the caudal portion of the body, dorsally of and in a
; .lane passing through about the equator of the acetabulum. It is
Somewhat pear-shaped, with its larger pole to the right. From this
sxtremity the oviduct arises and passes to the shell gland. The

hell gland is close to and a little to the right of the ovary and in
i .bout the same transverse plane. It is somewhat globular, with a
ttiliameter about equal to the ventro-dorsal diameter of the broader
ind of the ovary. It is pierced on its left aspect by the oviduct and

in its caudal aspect by the vitello-duct winch joins the former; the

Fig. 134.

iiuct formed by their union is directed obliquely cephalad and to the
right dilating to form the ootype, beyond which it is continued as the
uterus. The uterus emerges from the cephalic or ventro-cephalic
taspect of the shell gland and proceeds cephalad, first forming some
coils ventrally of the shell gland and ovary. In its course cephalad
it passes dorsally of the testes, and its coils, with lumen distended
with eggs, fill the space between the intestinal ceca. Above the level
of the anterior testis it forms coils beneath the vas deferens and
passes ventrad toward the genital papilla, and opening, as already
mentioned, into a short duct common with it and the male canal.
The genital pore opens on the ventral surface at the level or slightly

166

cephalad of the esophageal fork. It leads into a shallow atrium, the
dorsal wall of which is formed by a low conical papilla at the vertex
of which is the opening (porus hermaphroditicus) of the short duct
(ductus hermaphroditicus) into which, as has been noted, the male
and female canals open.

The vitellogene glands consist of well-developed follicles (of the
type of P. cervi), more or less closely aggregated close underneath the
lateral body walls. They are found not only laterally, but also dor-
sally and ventrally of the ceca. They begin about at the level of the
base of the sucker and extend into the caudal portion of the body
to a point a little beyond the termination of the intestinal ceca. A
duct leaves each gland a little below the level of the upper margin of
the acetabulum and passes ventrad of the corresponding intestine
toward the shell gland, near the ventro-caudal aspect of which they
unite to form a dilated reservoir (fig. 136). From this reservoir a

slender duct arises and
pierces the caudal as-
pect of the shell gland
to join the oviduct.

Laurer's canal
springs from the ovi-
duct just as the latter
is about co enter the
shell gland. It de-
scribes a slight curve
to the right around
the corresponding
margin of the excre-
tory vesicle, to open on the dorsal surface a little below the excretory
pore, slightly to the right of the median line.

Excretory system. — Only the excretory vesicle, terminal canal,
and excretory pore could be satisfactorily traced. The vesicle lies
in the caudal portion of the body dorsally of the acetabulum. Its
fundus extends to near the caudal extremity of the worm, and its
body extends cephalad close under the dorsum to the level of the
upper margin of the acetabulum, at which it terminates by a short
duct which opens in the dorso-median line (fig. 134) at the excre-
tory pore, and about 2.35 mm. from caudal extremity, measured in
sagittal section.

RELATIONS TO OTHER SPECIES.

This species resembles Paramphist. cervi and P. fraternum. It dif-
fers from P. cervi in the form of the body, that of P. cervi being mom
slender and more elongate; in the size of acetabulum, that of f
cervi being definitely smaller; in the position of the genital pore, tha

Fig. 135.

167

of P. cervi being relatively farther caudad, about one-third of the
body length from the oral margin and at or caudad of the esophageal
fork, whereas in this species the genital pore is only about one-sixth
the body length from the oral margin at or cephalad of the esopha-
geal fork — that is, relatively much nearer the level of the base of
the sucker than is the genital pore of P. cervi.

From P. fraternum also it differs in the form of the body, that of
P.fraternum being markedly less flattened and its cephalic third
decidedly more slender and more nearly conical; in the size of the
acetabulum, that of P.fraternum being relatively smaller; in the posi-

Fig. 136.

tion of the genital pore, that of P. fraternum being proportionately
] nearer the oral extremity, namely, about one-eighth the body length
I from this extremity and at or slightly cephalad of the level of the
lbase of the sucker.

ILLUSTRATIONS.

Fig. 131. — Ventral aspect. Enlarged. Original.

Fig. 132. — Sagittal section. Shows oral sucker (o. s.), section of
tright intestinal cecum (i.), the two testes (t.), the vesicula seminalis
{v. s.), the pars musculosa (p. m.), the genital pore (g. p.), the uterus
{ut.), and the acetabulum (ac). Enlarged. Original.

168

Fig. 133. — Sagittal section of oral extremity. Shows oral sucker
(o. s.), perisuctorial space (p. s. sp.), esophagus (es.), section of right
intestinal cecum (%.), the vesicula seminalis (v. s.), pars musculosa
(p. m.), ductus ejaculatorius (d. e.), ductus hermaphroditicus (d. h.)t
genital papilla (g. pap.), the metraterm (va.), uterus distended with
eggs (ut), and cephalic portion of superior testis (/.). Enlarged.
Original.

Fig. 134. — Sagittal section of caudal extremity. Shows acetab-
ulum (ore), the testes (t.), excretory vesicle (ex. v.), excretory pore
(ex. p.), Laurer's canal (L. c), shell gland (s. g.), and uterus (ut.).
Enlarged. Original.

Fig. 135. — Transverse section, shows oral sucker (o. s.), peri-
suctorial space (p. s. sp.), and follicles of right vitellogene gland (v. g.).
Enlarged. Original.

Fig. 136. — Transverse section through caudal extremity of right
(caudal) testis (t.). Shows position and relations of ovary (ov.)}
shell gland (s. g.), vitelline reservoir (v. r.), uterus (ut.), vitellaria
(v. g.), intestinal ceca (i.), and acetabulum (ac). Enlarged. Original.

STEPHANOPHARYNGINjE, new subfamily.

Subfamily diagnosis. — (Paramphistomidx, p. 60): Oral sucker with circular
evagination.

Type genus. — Stephanopharynx Fischceder, 1901.

The circular evagination of the oral sucker appears to be an impor-
tant character. At first thought it seems more important than the
sexual characters, still, when one recalls that the intestinal characters
of the distomes are not of such great value as one is tempted to accord
to them, it is not absolutely excluded that subfamily value is higher
than this character justifies. Accordingly, this subfamily is proposed
with some reserve.

The one genus (Stephanopharynx) known for this group, presents!
also the following important characters: Genital sucker and cirrus
pouch absent, body not divided.

Fischceder classified Stephanopharynx in Paramphistominse. With
this view it is difficult to concur, and if Stephanopharynx were classified
with the Cladorchiinse, there should be a distinct tribe erected for it.

Genus STEPHANOPHARYNX Fischceder, 1901.

Generic diagnosis.0 — Stephanophayrnginx (p. 168): Body compressed, slightly
concave ventrad, convex dorsad, but slightly flattened dorso-ventrally, cephalic and
caudal ends rounded, sides excurvate longitudinally. Ventral pouch absent . Acetab-
ulum ventro-subterminal, large, not sunken, margin not raised, aperture large.
Genital pore with considerable musculature which is not sharply defined in form of a
sucker, atrium divided into large ventral and small dorsal chamber, ductus hermaph-

a Based on Fischceder, 1903h.

169

roditicus present. Excretory pore prevesicular in acetabular zone, caudad of Laurer's
canal. Oral sucker with circular evagination, larger dorsally than ventrally; esoph-
agus without muscular thickening; ceca very wavy, end postequatorial, posttesticular.

Male organs: Testes 2, smaller than acetabulum, with small lobes, fields nearly
coincide, zones abut or separate, preovarial, not widely separated from acetabulum,
in equatorial and caudal thirds; musculosa well developed, but not enormous; cirrus
pouch absent.

Female organs: Ovary and shell gland posttesticular; vitellaria pre- and cecal,
profuse; uterus intercecal; eggs many; Laurer's canal entirely preexcretory.
Type species. — S. compactus Fischceder, 1901.

Subfamily CLADORCHIIN^ Fischceder, 1901.

Subfamily diagnosis. — Paramphislomidx (p. 60): Oral sucker with a pair of
evaginations.
Type genus. — Cladorchis Fischceder, 1901.

Fischoeder included in this subfamily the genera Cladorchis (subg.
Cladorchis, Taxorchis, and Stichorchis) , Chiorchis, Gastrodiscus, Eoma-
logaster, and (as doubtful) Diplodiscus.

We have separated out (seep. 249) Gastrodiscus and Homalogaster,
thereby restricting the group in one sense, and by eliminating certain
characters from the subfamily diagnosis we have widened the scope
of the group in another sense. It is very possible that the group
may undergo further changes on basis of the different kinds of
evaginations.

Genus CLADORCHIS Fischoeder, 1901.

Generic diagnosis. « — Cladorchiinse (p. 169): Genital pore with sucker. Evagina-
tions of oral sucker recognizable outside the wall of the sucker; esophagus without
muscular thickening.

Male organs: Testes branched.

Type species. — C. pyriformis (Diesing, 1838) Fischceder, 1901.

Fischceder divides this genus into 3 subgenera, but it seems to us
possible that his genus Chiorchis is perhaps of tribal value and his
subgenera of generic value.

Subgenus CLADORCHIS Fischoeder, 1901.

Subgeneric diagnosis. a — Cladorchis (p. 169): Body rather pyriform, venter
flattened to convex, dorsum convex, cephalic end attenuate, caudal end rounded.
Ventral pouch absent. Acetabulum caudal, ventral, rather large to large, apparently
sunken or not sunken, margin apparently raised or not raised, aperture circular,
apparently medium to large. Ge*rtal pore with sucker, ductus hermaphroditicus
present. Excretory pore postvesicular, post- or acetabular, caudad of pore of Laurer's
canal. Oral sucker with paired strongly developed evaginations, and with not
sharply bounded sphincter; esophagus without muscular thickening; ceca very wavy,
long, end postequatorial, posttesticular, post- or acetabular.

Male organs: Testes 2, smaller than acetabulum, branched, fields abut, zones nearly
coincide, preovarial, near acetabulum, in equatorial third, near venter; cirrus pouch
present.

"Based on Fischceder, L903h.

170

Female organs: Ovary and shell gland posttesticular; vitellaria in cecal zone, tes-
ticular and post-, may be pretesticular, stretching ventrally and dorsally; uterus inter-
cecal; Laurer's canal entirely prevesicular.

Type. — C. pyri/ormis (Diesing, 1838).

Habitat. — Cecum of South American Tapirns.

Generic diagnosis a — Cladorchis (p. 169): Body straight, venter rather flat,
dorsum convex, cephalic third notably attenuate, caudal end attenuate but rounded.
Ventral pouch absent. Acetabulum caudal, ventral, slightly sunken, margin (?),
aperture circular, large. Genital pore with sucker, latter with distinct sphincter.
Excretory pore apparently postvesicular, in acetabular zone, caudad of pore of
Laurer's canal. Oral sucker with sphincter and paired evaginations; esophagus
without muscular thickening; ceca slightly wavy, long, end postequatorial, post-
testicular, in acetabular zone.

Male organs: Testes 2, about as large as acetabulum, branched, fields and zones
overlap, preovarial, somewhat separated from acetabulum, near venter, in equatorial
third; cirrus pouch small.

Female glands: Ovary and shell gland almost entirely posttesticular; vitellaria
from bifurcal to postcecal zones; uterus intercecal; eggs (?); Laurer's canal entirely
prevesicular.

Type species. — S. giganteus (Diesing, 1835).

Generic diagnosis.0 — Cladorchiinx (p. 169): Body elongate^ flattened, venter flat,
dorsum somewhat convex. Ventral pouch absent. Acetabulum terminal, rather
large, aperture elongate. Genital pore with sucker, ductus hermaphroditicus present.
Excretory pore (?). Oral sucker with sphincter and well-developed paired evagina-
tions; esophagus without muscular thickening; ceca broad, slightly wavy, near dorsum,
long, end postequatorial, posttesticular, in acetabular zone.

Male organs: Testes 2, nearly as large as acetabulum, branched, fields separate,
zones coincide, preovarial, preequatorial, widely separated from acetabulum and
ovary; cirrus pouch present.

Female organs: Ovary and shell gland posttesticular, near acetabulum; vitellaria
in cecal zone, entirely posttesticular; uterus intercecal, chiefly posttesticular, unusu-
ally well developed, first runs near dorsum cephalad to testes, then diagonally caudad
near venter, then near venter cephalad to pore; ova numerous. Laurer's canal (?).

Type. — T. schistocotyle Fischceder, 1901.

Habitat. — Cecum of Brazilian Dicotyles.

Fischoeder gives Taxorchis as a subgenus of Cladorchis, but the
form and position of the testes and the position of the uterus seem to
us to entitle it to generic rank.

1895: Pseudodiscus and Amphist. (Pseudodiscus) Sonsino, 1895, 5, 8 (for hawlrsi,
collinsi, ornatum); 1895, 184, 185, 186; 1896, 310.— Fischceder, 1903h, 489,
631-632.— Piana & Stazzi, 1900a, 523.
Generic diagnosis.— Cladorchiinx (p. 169): Body oval, venter convex to concave,
dorsum convex, cephalic end less blunt than bluntly rounded caudal end, transverse
section elliptical. Ventral pouch absent. Acetabulum ventral relatively small,
margins prominently projecting. Genital pore postbifurcal without sucker, ductus

Subgenus STICHORCHIS Fischoeder, 1901.

Genus TAXORCHIS (Fischceder, 1901).

Genus PSEUDODISCUS Sonsino, 1895.

a Based on Fischceder, 1903h.

171

hermaphroditicus present. Excretory pore postvesicular, in postacetabular zone,
caudad of pore of Laurer's canal. Oral sucker prominently constricted at equator,
with a pair of evaginated horns, each with a globular pouch; esophagus without mus-
cular thickening; ceca wavy, long, end postequatorial, posttesticular, in acetabular
zone.

Male organs: Testes 2, smaller than acetabulum, cauliflower-like, testicular fields
separate, zones coincide, preovarial, considerably or slightly removed from acetabu-
lum, chiefly or entirely in equatorial third, near venter; musculosa not enormously
developed; cirrus pouch absent.

Female organs: Ovary and shell gland chiefly posttesticular; vitellaria extend
extracecal about from buccal pouches to acetabulum; uterus intercecal, chiefly post-
testicular; ? eggs; Laurer's canal cephalad and dorsal of excretory vesicle.

Eggs: Not observed.

Type species.— Amphist. stanleyii Oobbold, 1875, from Equus caballus in India,
type by present designation.
Hosts. — Horses and elephants.

This genus is left provisionally in the subfamily CladorcJiiinx,
although indications are not entirely absent that it may eventually be
eliminated from this group.

Sonsino (1895, anno 6, 5, 8) proposed this genus as a member of the
Amphistomidse and gave to it the following generic diagnosis :

Corpo allungato, convesso pianeggiante, sensa manico anteriore distinto. Ventosa
posteriore subterminale piccola.

He included in the genus the species: Ampliist. hawlcesi [stanleyii]
collinsi, and ornatum.

Piana & Stazzi (1900, 523) accept Sonsino's genus, adding to
its diagnosis the phrase: "La faringe coi due diverticoli e il bulbo
esofageo musculosa."

Fischceder (1902a, 48-49) gives the species Amphist. hawkesi,
collinsi, stanleyi, and ornatum as species inquirendse.

Fischceder (1903h, 489, 631-632) mentions the genus Pseudodiscus,
but in view of the slight anatomical details then known for its species
he lists them all as species inquirendse of Amphistomum.

In reference to 'the species which come into consideration as mem-
bers of this genus, Cobbold (1879b, 357-359, 398) states:

More importance attaches itself to the study of the amphistomatoid flukes [in
equines]. These parasites, though in a scientific sense only recently discovered in
equine bearers, have been long known to the natives of India. They appear to be
capable of producing serious intestinal irritation. I have described two forms (Am-
phistoma collinsii and A. coll. var. stanleyi, which infests the colon. The specimens
sent to Professor Simonds from India by Mr. Stanley, V. S., were much larger than
those sent to me from Simla by Mr. Collins, V. S., some ten years later (1875). As
in all other amphistomes obtained from the intestines of elephants and cattle the
worms, when fresh, were of a bright brick-red color. By the natives of India these
parasites are called Masuri; but no description of the worms had been published prior
to the account which I gave of the contributions forwarded by Major-General Hawkes,
Mr. Collins, and Mr. Stanley.

I shall have occasion to speak of the elephant's Masuri further on; but in the mean-
time I must remark that the generally received notion as to the parasitic cause of the

172

earth-eating propensities of various animals seems to have some foundation in fact.
Not alone from Major-General Hawkes in Madras, from Mr. Folkard in Ceylon, and
from various other trustworthy sources, have I been informed of this habit on the part of
I ndian horses; but Doctor Rowe told me that Australian horses, and even sheep, infested
with stomach worms, are in the constant habit of consuming large quantities of sand.
From all the facts that have come before me, I am inclined to think that gastric or
intestinal irritation, however brought about, may induce the habit in question, para-
sites being only one of the many sources of irritation giving rise to symptoms of colic
in solipeds and pachyderms alike. At all events the African elephants at the London
Zoological Society's menagerie, as repeatedly witnessed by myself, are in the habit
of swallowing large quantities of soft mud during the summer months, but no traceB
of masuri have as yet been detected in their faeces.

When by letter I informed Major-General Hawkes of an interesting find by Mr.
Collins of about a thousand Amphistomes in the colon of a horse that had died at Simla,
the announcement called forth a reply which is sufficiently instructive to be quoted.
Writing from Secunderabad, in July, 1875, he says respecting this "find:" "Your
statement has incidentally thrown light upon a subject which has puzzled many of
us in this country. It occasionally happens that a horse, on being opened after
death, is found to have accumulated in his intestines large quantities of sand and
gravel. In a recent case this.accumulation amounted to 14J pounds. Until recently
it was always held that this gravel or sand could only be introduced with the animal's
food. All grain in this country is trodden out by bullocks on an earthen floor, and
the grain undoubtedly contains a proportion of sand and gravel derived from this
source. Although this ought to be carefully washed out before it is given to the
horse, still, owing to the carelessness of the native horse keepers, this cleaning is, I
expect, often omitted. In the daily 'feed' of 8 or 10 pounds of grain given to each
horse the utmost quantity of sand or gravel that could be found admixed therewith
would not probably exceed 2 or 3 ounces. Consequently it would take from seventy-
seven to one hundred and sixteen days to accumulate so large a quantity as 14£
pounds. Now, the advocates of the theory of the gradual accumulation of sand in
this way have never been able to explain why the grain, grass, hay, and other ingesta
should pass in the ordinary way through the intestines whilst this sand or gravel
remains behind. One can understand the possibility of such substances as wool,
hair, or similar matters concreting in the alimentary canal, though I believe they are
usually found in the stomach and not in the intestines; but how a most incohesive
substance, like sand, can possibly accumulate in the gradual way required by their
theory I have never heard even plausibly explained. On the other hand, the fact
that horses are often excessively addicted to eating earth is well known; and if my
memory serves me correctly, it was found necessary, about twenty years ago, to remove
the mud walls of the pickets surrounding some of the horses of a mounted corps in
this presidency in consequence of this habit. Now, given the fact that the amphis-
toma has been found in the horse (as your specimens prove), may we not fairly sup-
pose it possible that the animal resorts to the same mode of ridding himself of this
parasite as does the elephant; and, also, would it not in a much more natural man-
ner account for the large quantity of gravel or sand found in the intestines than
does the theory of gradual accumulation? Reasoning from analogy, as in the case
of the elephant, this eating of earth in the horse would be an instinctive effort
on the part of the 'host' to rid himself of the parasite. This self-taken remedy is
doubtless in many cases quite effectual, though unnoticed. The fatal cases are
probably those in which the horse has either overdone the remedy or where the sys-
tem was too debilitated to carry off a quantity of sand or gravel that would otherwise
have safely passed through the intestines of a horse in more robust health. The
actual fact must, of course, be verified by careful investigation."

173

When describing the parasites of the horse (p. 358), I spoke of Collins's amphis-
tome from that animal; but in the letter addressed to me from Simla, March 22, 1875,
Mr. Collins made no allusion to the earth-eating habit. He wrote: "I forward you
by this mail parasites found in the colon of a horse that died, a subject of fever pecu-
liar to this country. There were about a thousand of the parasites, and nearly the
whole of them were situated close to the csecum and were loose in the gut. Not hav-
ing seen parasites at all similar to these, I have forwarded them for identification.
They were of a brick-red color when first obtained." These explicit statements by
Mr. Collins are interesting from many points of view. One has only to place his
specimens side by side with those from the elephant in order to satisfy one's self
that the two forms are distinct. For the reasons already stated, I provisionally called
the worm Amphistoma collinsii. It is probable that other veterinary surgeons have
encountered this entozoon in India; but unless they can point to some published
account of the fact Mr. Collins is entitled to be considered as its discoverer. Doubt-
less many other European residents in India, Ceylon, and Burmah must, like Doctor
Gilchrist, be well acquainted with the masuri as such, though unaware of their
zoological position.

The known species0 of Pseudodiscus may be distinguished by the
following key:

a1. Testicular zones nearly or quite coincide, fields separate; esophagus without

muscular thickening subg. Pseudodiscus, p. 173.

bl. Testes more than half as large as acetabulum; intertesticular field less than
half as broad as testicular field; body 8.6 to 9 mm. long; type host Equus

caballus, India Ps. stanleyii, p. 173.

b2. Testes less than half as large as acetabulum; intertesticular field much broader
than testicular field; body 5 to 5.7 mm. long; type host Equus caballus,

India Ps. collinsii, p. 187.

a2. Testicular zones separate, nearly abut, fields nearly or quite coincide; esophageal

muscular thickening present; tpye hawkesii subg. Hawkesius, p. 200.

b3. Body 3.5 to 5 mm. long; type host Elephas indicus, India. . .Ps. hawkesii, p. 200.

Subgenus PSEUDODISCUS.

Subgeneric diagnosis. — Pseudodiscus (p. 170): Esophageal muscular thickening
absent. Testicular zones nearly or quite coincide, fields separate.
Type species. — Ps. stanleyii.

PSEUDODISCUS STANLEYII (Cobbold, 1875) Stiles & Goldberger, 1910.

[Figs. 137 to 151.]

1875: Amphist. stanleyii Cobbold, 1875n, 818, 819 as possible syn. of Amphist.

collinsii [in Equus caballus, India].
1879: Amphist. collinsii var. stanleyi Cobbold, 1879b, 357 for stanleyii 1875 (in

Equus). — Piana & Stazzi, 1900a, 519, as syn. of hawkesi. — Sons., 1895, 182.
1895: Amphist. collinsi var. stanleyi Cobbold. — Sons., 1895, 4 syn. of Amphist.

hawkesi.— Fischceder, 1902a, 48; 1903h, 631, 632.
1895: Amphist. stanleyi Cobbold. — Ward, 1895, 338 as syn. of A. collinsi (in Equus

caballus).— Fischceder, 1902, 48.

Specific diagnosis. — Pseudodiscus (p. 170): Body 8.6 to 9 mm. long by 5.5 to 5.6
mm. broad, by 3.5 to 4 mm. thick; flesh color (alcohol specimen); oval, somewhat
flattened dorso-ventrally, cephalic extremity bluntly pointed, caudal extremity very

"Except ornutus, for which definite data are kicking.

174

bluntly rounded; lateral margins convex, greatest diameter (both transverse and
sagittal) about at caudal end of equatorial third of body; cephalic extremity bears
bluntly pointed slender papillae. Genital pore ventro-median in cephalic portion of
equatorial third, about midway between oral extremity and anterior margin of ace-
tabulum, postbifurcal. Acetabulum ventro-subterminal, 1.7 mm. in diameter, aper-
ture circular, 1 to 1.25 mm. in diameter, surrounded by a distinctly raised margin;
cavity rather shallow. Mouth terminal; oral sucker constricted at equator into
globular oral and bibulbous esophageal portions; each lateral bulb connects with a
globular pouch; the bibulbous portion of sucker and the pouches lie on each side
in a cavity, but are bound dorsally and ventrally to the parenchyma by mesenterium-
like bands; esophagus arises from base between bulbs and extends (at first in the ven-
tral mesenterium-like band) nearly to border between cephalic and equatorial thirds
of body; ceca long, extend caudad slightly beyond equator of acetabulum, each form-
ing in its course 2 strongly convex lines latero-dorsad, which come together near caudal
margin of testis. Excretory pore dorso-median, caudad of acetabulum; excretory
vesicle well developed, dorsal of acetabulum.

Male organs: Testes large, somewhat lobulated or cauliflower-like, ventral, equa-
torial, postbifurcal, preacetabular, their center slightly nearer caudal than cephalic
margin; vasa efferentia spring from dorsal aspect, run cephalo-mediad, then mediad,
unite about in median line slightly caudad of equator of body to form vas deferens;
vesicula seminalis intricately coiled, moderately dilated; pars musculosa dilated,
moderately coiled, extends slightly cephalad of genital pore; pars prostatica relatively
short, vesicular, dorsal of pore, with short narrow muscular canal (ductus ejaculatorius)
to the short ductus hermaphroditicus which leads to the pore; cirrus pouch absent.

Female organs: Ovary and shell gland submedian, posttesticular, preacetabular,
nearer acetabulum than testes, ovary cephalad of shell gland; vitellaria, with well-
developed follicles, lateral of ceca, extend about from base of esophageal pouches to or
slightly caudad of intestinal ceca; vitello-ducts arise about at plane of shell gland;
uterus forms coils dorso-mediad of ovary, then passes cephalo-ventrad in suctorial
field between testes, crossing ventrally of vasa efferentia, and runs in but slight coils
ventrad of vas deferens to enter ductus hermaphroditicus dorsal of pore; Laurer's
canal runs from its origin (between dorsal margin of ovary and shell gland) caudo-
dorsad to dorso-median line slightly caudad of cephalic margin of acetabulum.

Eggs: Not observed.

Type.— U.S.N.M. (Coll. Stiles) 5274; cotype U.S.N.M. (Coll. Hassall) 5779, sec-
tioned and used as basis for present anatomical discussion.
Habitat. — Colon of the horse (Equus caballus), India.

Source of material. — The material used as basis of this dis-
cussion represents some of Cobbold's original specimens which he
gave to Hassall; the latter brought them to this country. Cobbold
was not in the habit of designating any particular specimen as type,
but Hassall has designated 5274 as such on the label.

Historical review. — In the first mention of the name Amphis-
toma stanleyii Cobbold (1875n, 818, 819) states that the parasites
were collected by Edward Stanley, jr., from the colon of the horse
in India; in size they appear nearer to A. Jmwkesii than they do to
A. collinsii, still "this is apparently nothing more than a large
variety of the above [collinsii] (?)."

Ward (1895, 338) merely mentions this form as a synonym of
Amphist. collinsi, in a list of parasites of the horse.

175

Fig. 137.

Sonsino (1895, 4), quoting Cobbold, mentions the worm as a syno-
nym of Amplvist. liawkesi.

Fischoeder (1902a, 48; 1903h, 631, 632) quotes the measurements
as 10 mm. long by 6 mm. broad, states that this form occurs in the
colon of Equus caballus in India, and marks
the parasite as a species inquirenda.

EXTERNAL CHARACTERS.

Size. — The specimens, preserved in alcohol,
measure 9 mm. and 8.6 mm., respectively, in
length; 5.5 and 5.6 mm. in greatest width,
and 3.5 and 4 mm., respectively, in greatest
dorso-ventral diameter.

Color. — The worms are of a flesh tint.

Form. — The worms are ventro-dorsally
somewhat flattened oval objects, with a
bluntly pointed oral and a broad rounded
caudal extremity (figs. 137, 138). The
greatest transverse and ventro-dorsal diam-

eters are about in the region of junction of the middle with the
caudal third of the bod}r. In transverse sections the form of the
body is somewhat that of an ellipse.

Surface. — The surface of the oral pole is beset by small, more or
less bluntly pointed, quite slender papillae. They presented much

the appearance of spines, but any doubt as to
interpretation was dissipated on studying the
sectioned specimen.

Genital pore. — On the ventral surface in the
median longitudinal line, about midway between
the oral extremity and the anterior margin of
the acetabular aperture, is the genital pore.
This pore is situated in about the center of a
broad shallow depression of the ventral surface.
In sections it is seen that what appears to be
the genital pore is a fairly large circular aperture
that leads into a circular slit-like atrium, on the
dorsal wall of which appears a minute pore
which leads into another, somewhat better de-
fined, chamber. On the dorsal wall of the lat-
ter is the opening of the ductus hermaphro-
diticus. These atria and the ductus hermaphroditicus are surrounded
by a globular mesh of muscular fibers (fig. 146).

Acetabulum. — The acetabulum is in the caudal portion of the body,
with its aperture ventro-subterminal. In one specimen it measured
(in sections) about 1.7 mm. in diameter; the aperture of the acetab-

Fig. 138.

Fig. 139.

177

Fig. 140.

178

Fig. 141.

ulum in the 2 worms measured 1 mm. and 1.25 mm., respectively, in
diameter. This aperture is surrounded by a narrow ring which is
marked off from the general surface by a deep and more or less nar-
row circular groove. This ring is seen in sections to be part of the

acetabulum (fig. 151).
The cavity of the ace-
tabulum is relatively
shallow.

internal anatomy.

Digestive tract. —
The oral aperture,
which pierces the ce-
phalic extremity of
the worm and is un-
provided with a
sphincter, leads di-
rectly into a muscular
sucker. The latter

shows a well-marked constriction or isthmus at about its equator,
which divides it transversely into two portions almost equal in length —
the anterior, which may be designated as the oral, and the posterior,
as the esophageal (or bulbous) portion. The oral portion of the sucker
is somewhat globular in form, measuring (in sections) about 0.64 mm.
in longitudinal axis, 0.64 mm. in transverse, and 0.58 mm. in ventro-
dorsal diameter. The esophageal or bulbous portion differs in form
quite markedly
from the oral por-
tion (figs. 139, 140,
141, 142, 143). It
measures (in sec-
tions) about 0.50
mm. in longitudinal
axis and 0.48 mm. in
greatest ventrodor-
sal diameter. In
transverse diameter
this part of the
sucker is narrowest
at the constriction
marking its anterior limit, where it measures 0.40 mm., but it increases
rapidly to a maximum width of 1.10 mm. at its base, namely, at the
level at which the esophagus takes its departure. In sections it is seen
that this increase in width is due to the formation of lateral bulbs which
extend caudad on either side of and in line with the esophagus for a dis-
tance (measured in the long axis of the bulb) of about 0.40 mm. beyond

Fig. 142.

179

i the level or plane of origin of the esophagus (figs. 139, 140). Attached
to the dorso-caudal aspect of these bulbs there is on each side a
. globular pouch.

Fig. 143.

In consequence of this relation between the pouches and the cor-
responding bulbs, the former are found close to, on either side, and
-slightly dorsad of the esophagus. The suctorial bulbs, which are an
integral part of the sucker, are, like the latter, muscular in structure-
'The portion of these bulbs which on surface inspection is seen to

Fig. 144.

extend beyond the base of the sucker, that is, caudad of the level of
(origin of the esophagus, measures about 0.40 mm. in its longitudinal
axis, about 0.56 mm. in its greatest dorso-ventral diameter, and about

ISO

0.40 mm. in its greatest transverse diameter. The suctorial
"pouches" (wl ich are here distinguished from the "bulbs") are in a
general way globular in form. Their long axes have about the same
direction as the long axis of the worm itself and exceed their trans-
verse diameter by about 0.20 mm., the latter measuring about 0.80
mm. In structure the pouches are entirely different from the bulbs,
The walls of each pouch, which measure about 0.30 mm., are made
up of parenchyma-like cells and some muscular fibers. These
parenchyma-like cells, though large, are much smaller than those of
the body parenchyma, from which they are sharply separated by a
thin membranous layer which at the same time forms the outer
covering of the wall of the pouch. Beneath the lining cuticle is a
layer of structures which are very irregular in size and which at first
sight are not very easy to interpret; they have something of the

sponding to these structures. Immediately external to this layer is
found a thin layer of circular muscles.

The portion of the sucker caudad of the isthmus, together with the
two pouches, lies in a cavity which reminds the observer strongly of a
rudimentary body cavity. From the dorsal and the ventral surfaces
of the sucker a line of tissue, reminding the observer of a mesen-
terium, extends dorsad and ventrad to the body parenchyma, thus
holding . these structures in place; similar mesenterium-like bands
connect the pouches with the somatic parenchyma (figs. 142-145);
at their insertion, these bands spread around the sucker and pouches'
like a peritoneum; the esophagus runs in the ventral mesentery!
band, which also contains the esophageal ganglion.

Whether the cavities in question actually represent a rudimentary
body cavity is a question which may be left open, but such an inter-
pretation is rather tempting. Similar cavities are found or at least
strongly indicated in Homologaster philijipinensis (see Stiles and (lold-
berger, 1908a, figs. 34-36) Watsonius watsoni, and in other Paramphis-

Fig. 145.

appearance of poorly
preserved nuclei; some
seem to be solid, others
appear to be hollow, with
a peripheral row of dots;
in some fields they re-
mind the observer very
strongly of cross-sections
of longitudinal muscles,
and it seems probable
that they are such, for
the terminal sections of
the pouch show distinct
fibers apparently corre-

181

tomid®. The lumen of the sucker differs in form in the different por-
tions of the suctorial tract; that of the oral portion is somewhat spin-
dle-shaped, while that of the esophageal portion is a transverse slit,
slightly crescentic in both transverse and sagittal sections v'th the
convexity directed dorsad. In about the equatorial plane of this
portion of the sucker a shallow, transverse, slit-like diverticulum of
the suctorial lumen is formed in the dorsal muscular wall, so that
the lumen of the sucker in sagittal plane at this point presents a
triradiate form (fig. 140); in transverse section at this point the
impression obtained is that of a transverse tongue-like ridge or par-
tition projecting upward into the lumen of the sucker (fig. 142).
Caudad of this level the horns of the crescentic lumen seen in trans-
verse section rapidly shift and assume a more or less direct dorso-

Fig. 146.

ventral direction and form the dorso-ventral slit-like lumen of the
bulbs so that in a section, say, at the level of origin of the esophagus,
the lumen of the sucker and bulbs combined has a broad H -shape
(fig. 143). The caudo-dorsal extremity of the slit-like lumen of the
bulbs leads into the irregular lumen of the pouches (fig. 144). The
sucker, bulbs, and pouches are lined throughout with a cuticle in
anatomical continuation with that of the body surface. That of the
second portion of the sucker and of its bulbs is provided with minute
irregularly scattered conical papillae. The esophagus (figs. 139, 140,
143, 145) springs from the base of the sucker in the space between
the downward projections of the bulbs.

From this point it passes caudad, describing a slight curve ventrad,
to a point but very little less than one-third of the body length from
the oral extremity, slightly nearer the venter than the dorsum and
about equidistant from the lateral margins, where it terminates,
giving origin to the intestinal ceca. This terminal portion is some-
13893— Bull. 60-10 12

182

what expanded, and its musculature distinctly though not very
greatly increased in thickness. The musculature of the esophagus
consists of 2 layers, an internal of circular and an external of longi-
tudinal fibers. The increase in thickness of the muscle wall of the
caudal portion of the esophagus takes place gradually, and is due
mainly to an increase in thickness of the internal circular layer.
The intestinal tubes leave the latero-dorso-caudal aspect of the
slightly-expanded caudal extremity of the esophagus and curve
downward (caudad) and outward (laterad) and slight lv dorsad
forming a transverse arch in the first part of their course. They
terminate by blind extremities in the caudal portion of the body, the
left at a very slightly higher level than the right, and both slightly
caudad of a transverse plane through the equator of the acetabulum
and about midway between the latero-dorsal aspect of the latter and
the corresponding aspect of the body surface of the worm (figs. 139'

140, 151). In their
course caudad the in-
testinal ceca describe
an undulating path.
The undulations are
of moderate ampli-
tude, directed from
front (venter) to back
(dorsum) and main-
tain about an equal
distance from the lat-
ero-dorsal, curved
surface of the worm.
The ceca approach nearest the dorso-median longitudinal line in the
testicular zone, and reach a position dorsad of the caudal portions
of the corresponding testis. The diameter of the intestines varies
somewhat in different portions, and although they are, in a general
way, cylindrical tubes, yet they are compressed here and there in
one diameter or another, so that in transverse sections they present
quite a variable outline. The lumen of the esophagus is lined with
a cuticular layer in anatomical continuation with that of the sucker,
but apparently somewhat thicker than that of the latter. This
lining ceases abruptly at the beginning of the intestinal ceca, which
are lined throughout with an epitheial cell layer.

Genital system. — The male and the female genital organs, with
the exception of the vitellogene glands, are disposed in the median
field bounded laterally by the intestinal ceca.

Male organs. — This worm is provided with 2 fairly large lobulated
(cauliflower-like) testes (fig. 148). They are placed one on each side
of and close to the median sagittal plane in the same zone, slight ly

Fig. 147.

183

nearer the caudal than the oral extremity and decidedly nearer the
renter than the dorsum. There is but slight if any difference in the
size of the two organs. Such difference as may exist is in favor of
the left.

From the dorsal aspect of each testis there emerges a vas efferens
(fig. 148), which is directed at first slightly cephalo-mediad, then
more directly mediad to unite with its fellow at a point in about the
median sagittal plane, slightly nearer the caudal than the oral
extremity, and considerably nearer the dorsum than the venter, to
form the vas deferens. The first portion of the vas is an intricately
coiled thin walled moderately-dilated duct or vesicula seminalis. At
a point which may be clearly distinguished (fig. 147) the thin walled
vesicula gives place to a relatively thick (15/*) muscular walled canal
(pars musculosa) of considerable caliber (150/*), which is much less

Fig. 148.

intricately coiled, so that its longitudinal windings may be followed
in transverse sections. A valve-like constriction of the lumen marks
the change from vesicula to pars musculosa. The windings of these
two portions of the vas deferens form a fairly compact mass, which
lies in the axial region of the body between and cephalo-dorsad of
the testes, and longitudinally between the equatorial plane and a
i transverse plane slightly cephalad of the genital pore. The terminal
portion of the vas deferens is relatively quite short, and, like that of
the pars musculosa, its beginning is clearly and sharply marked by
a change in the character of the wall, which becomes thin and sur-
i rounded by glandular cells, which are relatively few in number, and
I by a valve-like constriction of the lumen. This portion of the vas
i deferens, which by analogy may be called the pars prostatica, is in
i the form of a small vesicle dorsal of the genital pore. From its ven-
itral aspect there passes ventrad a short muscular duct (ductus ejacu-
llatorius), which unites with the metraterm to form a ductus her-

184

maphroditicus. The latter, a short delicate canal, opens into a
small chamber, which in its turn opens into a slit-like genital atrium
(fig. 140).

Female organs. — In the axial region of the body, a little to the left
of the median line, between two transverse planes, one of which is

Fig. 149.

just caudad of the caudal plane of the testes and the other just
cephalad of the upper margin of the acetabulum, are the ovary and
shell gland, the former just above (cephalad) and slightly to the left
of the latter. From the dorso-caudal aspect of the ovary there

Fig. 150.

springs the oviduct, which turns caudad as it passes to the dorsal
aspect of the shell gland at the superior margin of which it divides
into two branches, one of which curves slightly to the right to penetra < e
the dorsal aspect of the shell gland, in the substance of which it is
joined by the vitello-duct to form the ootype. The shell gland is con-

185

■ siderably smaller than the ovary, immediately caudad of which it
I lies. It is penetrated by the vitello-duct and, as just described, by
: the oviduct on its caudo-dorsal aspect. These two ducts unite to form
;a fusiform ootype (fig. 149), which is directed dorso-ventrally and is
i continued as the uterus, the latter emerging from the ventral aspect

of the gland. The uterus, after emerging from the shell gland, curves
i to the right, then dorsad, and describes some coils in the axial region
i of the body to the right and dorsad of the shell gland and ovary, as
i it winds its way cephalad. At about the level of the superior aspect

of the ovary it passes obliquely cephalo-ventrad to reach the ventral
i aspect of the coiled vas deferens. From this point onward its course
lis but slightly wavy, maintaining throughout its relation to the vas
i deferens as it passes at first directly cephalad, then gradually tilts
'ventrad, uniting with the ductus ejaculatorius at about the level and
,• a short distance dor-
:sad of the genital
ipore. The second
• of the two ducts
iinto which the ovi-
iduct has been de-
ascribed as branch-
iing at the level of
tthe superior margin
i of the shell gland is
Laurer's canal (fig.

140). This canal
| passes caudo-dorsad
i to open in the mid-
i die line of the dor-
:sal surface, a little caudad of the level of the upper margin of the
: acetabulum. The vitellogene glands, consisting of well-developed
I follicles, occupy the lateral regions of the body, external to the intes-
itinal ceca, and extend from about the level of the plane of the
!base of the esophageal pouches to or slightly caudad of the plane of
i the cecal extremities of the intestines. At about the level of the
shell gland a duct leaves each of the vitellogene glands and passes
i transversely inward ventrally of the ceca, the two uniting at the level of
j and close to the ventro-caudal margin of the shell gland (fig. 150).
From their point of junction a duct passes dorsad, skirting the caudo-
i mesial margin of the shell gland and penetrating the latter at its
i caudo-dorsal aspect.

Excretory system.— This is highly developed. Two large and
•several small excretory canals enter the cephalic aspect of the excre-
itory vesicle, which lies in the caudal portion of the axial region of
ithe body dorsad of the acetabulum (figs. 140, 151). The vesicle is

Fig. 151.

186

an elongate sack, the lumen of which as it extends caudad gradually
becomes reduced in caliber, linally becoming a narrow canal, the
terminal portion of which is lined with a cuticle in anatomical con-
tinuation with that of the surface. This terminal portion or excre-
tory duct opens in the middle line of the dorsal surface only a little
above the caudal margin of the worm and at a considerable distance
caudad of the opening of Laurer's canal.

ILLUSTRATIONS .

Fig. 137. — Ventral view of Ps. stanleyii. Enlarged. Original.

Fig. 138. — Profile view of same. Enlarged. Original.

Fig. 139. — Frontal projection. Shows oral sucker (o. s.), suctorial
bulbs (s. b.), suctorial pouches (s. p.), esophagus (es.), intestines (i.),
testes (t.), vasa efferentia (v. e.), ovary (ov.), shell gland (s. </.), uterus
(tit.), position of genital pore (g. p.), and acetabulum (ac). a-a, b-b,
c-c, d-d, e-e, f-f, g-g, li-h, j-j, k-k, planes of section. Slightly
diagrammatic. Enlarged. Original.

Fig. 140. — Profile projection. Shows oral sucker (o. s.), suctorial
bulb (s. b.), suctorial pouches (s. p.), esophagus (es.), intestines (i.),
right testis (t), right vas efferens (v. e.), vas deferens (v. d.), ovary
(ov.), shell gland (s. g.), uterus (ut.), oviduct (ov. d.), Laurer's canal
(L. c), excretory vesicle (ex. v.), excretory pore (ex. p.), and genital "
atrium (g. a.), a-a, b-b, c-c, d-d, e-e, f-f, g-g, h-h, j-j, k-k, planes
of section. Slightly diagrammatic. Enlarged. Original.

Fig. 141. — Transverse section at a-a figs. 139 and 140. Shows '
form of body, surface papillae (s. pap.) and oral sucker (o. s.). En-
larged. Original.

Fig. 142. — Transverse section at b-b figs. 139 and 140. Shows
form of body, form of esophageal portion of sucker (o. s.), perisuctorial
space (p. s. sp.), and dorsal and ventral mesenterium-like bands
(m. b.). Enlarged. Original.

Fig. 143. — Transverse section at beginning of esophagus through
plane at c-c figs. 139 and 140. Shows form of body, form of oral
sucker (o. s.), H-shaped form of suctorial lumen, perisuctorial space
(p. s. sp.), and dorsal and ventral bands (m. b.). Enlarged. Original.

Fig. 144. — Transverse section through plane d-d figs. 139 and 140.
Shows form of body, esophagus (es.), extension of lumen of suctorial
bulb (s. b.) into suctorial pouch (s. p.), and caudal extension of
perisuctorial space (p. s. sp.), which is filled with a granular coagulum.
Enlarged. Original.

Fig. 145. — Transverse section through plane e-e figs. 139 and 140. |
Shows position and relations of suctorial pouches (s. p.) to esoph-
agus (es.), the esophageal ganglion (e. g.), and the caudal extensions j
of the perisuctorial space (p. s. sp.), which contains some granular j
coagulum. Enlarged. Original.

1 87

Fig. 146. — Transverse section through plane at/-/ figs. 139 and
it 140. Shows genital pore (g. p.), pars musculosa (p. m.), the intes-
)• tinal ceca (%.), and the vitcllaria (v. g.). Enlarged. Original.

Fig. 147. — Transverse section through plane g-g figs. 139 and 140.
It Shows position and relations of intestines (i), pars musculosa (p. m.),
t the valve-like junction of the vesicula seminalis (v. s.) with the pars
musculosa, the uterus (ut), and vitellaria (v. g.). Enlarged.
Original.

Fig. 148. — Transverse section through plane h-Ji figs. 139 and 140.
Shows position and relations of the testes (t), the point of origin of
the right (v. e. d.) and the left (v. e. s.) vas efferens, uterus (ut),
| intestinal ceca (i.), vitellaria (v. g.), and excretory canals (ex. c).
Enlarged. Original.

Fig. 149. — Transverse section through plane i-i figs. 139 and 140.
Shows position and relations of shell gland (s. g.), Laurer's canal
(L. c), uterus (ut), intestines (i.), vitellaria (v. g.), and excretory-
canals (ex. c). Enlarged. Original.

Fig. 150. — Transverse section through plane Tc-Tc figs. 139 and.
140. Shows position and relations of transverse vitello-ducts (t. vd.),
the common vitello-duct (c. vd.), base of shell gland (s. g.), Laurer's
canal (L. c), the uterus (ut.), vitellaria (v. g.), intestinal ceca (i.),
and excretory canals (ex. c). Enlarged. Original.

Fig. 151. — Transverse section at plane l-l figs. 139 and 140.
Shows position and relations of Laurer's canal (L. c), excretory
vesicle (ex. v.), vitellaria (v. g.), intestines (i.), and acetabulum
(ac), with its projecting rim. Enlarged. Original.

PSEUDODISCUS COLLINSII (Cobbold, 1875) Stiles & Goldberger, 1910.

[Figs. 152 to 162.]

1875: Amphist. collinsii Cobbold, 18751, 741 (in Kqv,us caballus; Simla, India);
1875n, 818, 819; 1879b, 357, 359; 1883x, 515.— Fischccder., 1903h, 489 to
Pseudodiscus by Sonsino— Huber, 1896a, 580 (India).— Sonsino, 1895, 182,
fig. 2; J895, 4-5, fig. 2.— Tbeobold, 1900, 51.
1895: Amphist. (Pseudodiscus) collinsi (Cobbold, 1875) Sonsino, 1895, 182, 187;

fig. 2; 1895, 9, fig. 2.
1895: Amphist. collinsi Ward, 1895, 338 (in Equus caballus) .— Fischceder, 1902a, 48
(E. c; India); 1903h, 631, 632.
Specific diagnosis.— Pseudodiscus (p. 170): Body 5 to 5.76 mm. long by 3.5 to 4 mm.
broad; brick red (fresh) or flesh tint (alcohol specimens); oval, cephalic extremity
somewhat blunted, caudal extremity very broadly rounded, nearly semicircular,
lateral margins convex, greatest diameter slightly caudad of equator, about in
testicular zone; cephalic extremity bears minute, slender, conical papilla*. Geni-
tal pore ventro-median about nine twenty-thirds of length from anterior end, in
cephalic portion of equatorial third, postbifurcal, halfway between oral margin
and cephalic margin of acetabulum. Acetabulum ventro-subterminal, 1.58 mm.
broad, 1.1 mm. long, aperture 0.5 to 0.7 mm. in diameter, surrounded by very promi-
nently raised margin; cavity relatively deep. Mouth terminal; oral sucker con-
stricted at equator into a globular oral and a bibulbous esophageal portion; each

188

lateral bulb connects with a large globular pouch; these pouches and a portion of the
sucker lie in cavities strongly suggestive of a rudimentary body cavity, but they are
connected with the body wall by dorso-ventral mesenterium-like bands; esophagus
arises from base between bulbs and extends about to border between cephalic and
equatorial thirds of body; ceca long, extend about to equator of acetabulum, each
forming in its course two strongly convex lines latero-dorsad, which come together
near caudal margin of testis. Excretory pore medio-terminal, caudal of acetabulum;
excretory vesicle well developed, dorsal of acetabulum.

Male organs: Testes rather small, somewhat globular and cauliflower like, ventral,
equatorial, slightly nearer median line than corresponding lateral margins; zones
nearly coincide, fields separate; vasa efferentia spring from dorso-median aspect,
run dorso-mediad, unite about in equator in median line to form vas deferens; vesicula
seminalis and pars musculosa compactly coiled in median field, extending very
slightly cephalad of genital pore; pars prostatica short; ductus ejaculatorius very
short, opens above metraterm into an atrium; the latter appears to communicate with
a slit-like atrium from which a slender ductus hermaphroditicus extends ventrad to
open on vertex of the small genital papilla; cirrus pouch absent.

Female organs: Ovary and shell gland submedian, posttesticular, preacetabular,
nearer acetabulum than testes, ovary cephalad of shell gland; vitellaria, with sparsely
scattered follicles, lateral of ceca, extending from equatorial plane of esophagus to
plane of caudal end of ceca; vitello-ducts pass ventrally of ceca; uterus forms coils
dorso-medio-lateral of ovary, and from a point about on the cephalic plane of the
ovary it passes ventro-cephalad in a somewhat wavy course, crossing ventrally of the
vasa efferentia, and eventually the metraterm opens into a slit-like atrium into which
the ductus ejaculatorius also discharges; Laurer's canal from its origin (dorsally of
shell gland) runs dorsally of excretory vesicle caudo-dorsad to dorso-median line,
over equator of acetabulum, its pore being some distance cephalad of excretory pore.

Eggs: Not observed.

Type.— U.S.N. M. (Coll. Hassall) 5778 (C in sections) ; cotypesU.S.N.M. (Coll. Stiles)
5266, and U.S. B.A.I. 1720; all from Cobbold's original material.
Host. — The horse (Equus caballus; India).

Source of material. — The material, consisting of six specimens
in all, was obtained from bottles as follows: U.S.N.M. (Coll. Stiles)
No. 5266, containing 1 specimen; U.S.N.M. (Coll. Hassall) No. 5778,
containing 4 specimens; U.S.B.A.I. No. 1720, containing 1 specimen.

These specimens represent part of Cobbold's original material,
presented by him to Hassall in 1882. The worms were collected from
Equus caballus in India.

Historical review. — Cobbold (18751, 741) quotes from a letter
from Collins, dated Simla, as follows :

I forward you by this mail parasites found in the colon of a horse that died a subject
of fever peculiar to this country. There were about a thousand of the parasites, and
nearly the whole of them were situated close to the coecum, and were loose in the gut.
Not having seen parasites at all similar to these, I have taken the liberty to forward
them for identification.

Cobbold states that the worms are considerably smaller than are
Ampliist. liawkesii from the elephant, and he names the worm A.
collinsii. In a later paper (1875n, 818, 819) he refers to them again
very briefly and gives the colon as the habitat.

189

Fig. 152.

Ward (1895, 338) merely mentions the worm, with Amphist.
stanleyi as synonym, in a list of the parasites of the horse.

Sonsino (1895, 4-5, fig. 2) gives the size as 7 mm. long by 5 mim
broad, figures the worm, and, referring to its similarity to AmjMst.
hawlcesii, places it in his new genus Pseudodiscus.

Huber (1896a, 580) simply states that this species " which occurs in
horses, is also said to give rise to fatal disease
in India."

Fischceder (1901a, 48) merely cites this form
as a species inquirenda, gives the measure-
ments as 7 mm. long by 3 mm. broad, and
states that it occurs in the colon of Equus
caballus in India.

EXTERNAL CHARACTERS.

Size. — The 6 specimens preserved in alco-
hol-glycerine varied from 5 to 5.76 mm. in
extreme length and from 3.5 to 4 mm. in greatest width.

Color. — The worms are of a flesh tint.

Form. — The specimens are not in very good state of preservation
and are contracted in various ways, so that all specimens are not
uniform; on this account it is somewhat difficult to give an accurate
description of -the outline. In general, however, it may be said to
be oval, with a somewhat blunted oral and a broadly rounded caudal

extremity; it bears quite a resemblance to
Ps. stanleyii, but the sides appear more uni-
formly convex, the cephalic end seems to
have less tendency to be pointed, and the
caudal extremity seems to be relatively more
blunt (figs. 152, 153).

Surface. — At the oral pole the surface is
beset by minute, slender, conical papillae.
They resemble those on Ps. stanleyii but are
more minute. Around the oral aperture and
concentric with it are a number of circular
shallow grooves; the one nearest the oral
margin appears rather prominent and marks
off a narrow circular zone about the mouth.
In some of the specimens there were noted fine transverse lines on
the ventral surface. The dorsal surface is irregularly grooved,
probably the result in part of irregular contraction of the body,
and in part, perhaps, the result of the action of the fixative and
preservative.

Fig. 153.

I!H)

Fig. 154.

191

Genital pore —On the ventral surface in the median longitudinal
line and about midway between the oral margin and the anterior
margin of the acetabular aperture is the genital pore. In one speci-
men this was at the vertex of a small circular bulging of fche venter
and, with the genital papilla? (apparently) filling it , suggested the
form of an umbillicated smallpox vesicle.

Acetabulum. — The acetabulum, measuring 1.58 mm. in transverse
and 1.1 mm. in longitudinal diameter, is in the caudal portion <>f the
body, its aperture being ventro-subterminal and measuring 0.5 to
0.73 mm. in diameter. Encircling the aperture there is a prominent
ring marked off from the general surface by a deep circular groove
(figs. 152, 153, 161, 162). This projecting ring is seen in sections to
be a portion of the acetabulum. The acetabulum is relatively much
larger in this than in Ps. stanleyii, and its cavity is deeper.

Fig. 150.

INTERNAL ANATOMY.

Digestive tract. — The cephalic extremity is pierced b}r a more or
less circular aperture which measured 0.41 mm. and 0.36 mm., re-
spectively, in 2 specimens. This oral aperture leads directly into a
muscular sucker. As in the case of Ps. stanleyii the sucker ma}^ be
divided for purposes of description into 2 portions, which are marked
off by a constriction (or isthmus) at about its equator. The first or
oral portion is of a somewhat globular form and measures 0.64 mm.
in transverse and 0.52 mm. in dorso-ventral diameter; its lumen is
of relatively considerable diameter, both transversely and ventro-
dorsally (fig. 156). Corresponding to the region of constriction
referred to as the dividing line between the two portions of the sucker
the lumen becomes a transverse slit and leads into the second,
esophageal (or bulbous), portion of the sucker. This port ion broadens

193

out and, on each side of the origin of the esophagus, it extends
caudad for a short distance of about 0.24 mm. in the form of a
muscular bulb (figs. 154, 155). This portion of the sucker measures
about 0.52 mm. in greatest dorso-ventral diameter, which is at about
the equator of this portion of the sucker, and about 1 mm. in transverse
diameter measured at the level of origin of the esophagus. Compared
with the corresponding portion of the sucker of Ps. stanleyii this is
relatively much larger in Ps. collinsii. From the ventral and from
the dorsal wall of this portion of the sucker a transverse muscular
ridge projects into the lumen of the sucker (figs. 155, 157) in a manner
which strongly suggests the relation between the pharynx and oral
sucker in FascioU JiepaMca. The lateral projecting edges of these ridges
serve as inner (median) boundaries of the dorso-ventrally-running
slit-like lumen of the suctorial bulbs (fig. 158). In transverse section
just above the level of- origin of the esophagus the relation of the

Fig. 157.

lumen of the sucker to that of its bulbs is such that combined they
form a broad letter H (fig. 158).

From the dorso-caudal aspect of the lateral suctorial prolongations
or bulbs there springs on each side a pouch. These pouches are
roughly globular in form, of relatively considerable dimensions.
The right is a little larger than the left. They are in relation to the
latero-dorsal aspects of the esophagus (fig. 159) and extend caudad
to about the level at which the latter gives origin to the intestinal
ceca. The pouches are sharply delimited by a cavity from the sur-
rounding body parenchyma. Their walls consist of cells which,
though large and resembling those of the body parenchyma, are
much smaller than those of the latter. A considerable portion of
the sucker, together with the bulbs, lies in a cavity strongly sug-
gestive of a rudimentary body cavity and similar to the condition
described for Ps. stanleyii; mesenterium-like bands are found dor-

194

sally and ventrally extending from the body wall to the digestive
apparatus in question. The upper limit of this cavity is as in Ps.
stanleyii at the level of the suctorial isthmus. Ai or slightly above
the level of origin of the esophagus this cavity becomes definitely
divided into two (fig. 158), which inclose the bulbs and extend caudad
to a point slightly below (caudad of) the corresponding caudal
margin of the pouch. The cavity contains a granular mass (fig. ] 58)
resembling if not identical with the granular material encountered
here and there in the excretory canals. The lumen of the second
portion of the sucker is transversely elongate, more or less contracted
ventro-dorsally, and extends laterally into the lateral suctorial pro-
longations; in these the lumen, though still slit-like, is directed
ventro-dorsally. In its turn this dorso-ventral slit-like lumen is
continued from its dorsal extremity into the lateral pouches. The

fi.tr-

Fig. 158. ~

lumina of the latter are irregular in form and variable in the degree
of distention, both in different specimens and at different levels in the
same specimen. The esophagus leaving the sucker, as already
described, passes caudad, describing in its course a slight curve, with
convexity ventrad, and at about the junction of the first with the
middle third of the body length it terminates, giving origin laterally
to the intestinal ceca. The intestines, as simple tubes, pass at first
dorso-laterad and at the same time slightly caudad to a point about
one-fourth the width from the lateral margins, where they bend
almost directly caudad, describing a wavy course both transversely
and ventro-dorsally, similar to that in Ps. stanleyii, and terminate by
cecal extremities laterally of the acetabulum at about the level of
the lower margin of the aperture of the latter. In their course
caudad they markedly approach the median line at one point,
namely, dorsad of the corresponding testis.

195

The lumen of the digestive tract from the oral margin to the intes-
tinal ceca is lined by a cuticle-like layer in anatomical continuation
with that of the body surface. It is thickest in the esophagus. In
the region of the mouth in the esophageal portion of the sucker and
in that part lining the lumen of the lateral suctorial prolongations or
bulbs it is beset by numerous small conical papillae. These papillae
were not observed in any other portion of the sucker or in the suc-
torial pouches. The intestinal lumen is lined by an epithelial cell
layer.

Genital system. — As in Ps. stanleyii, the male and the female
genital organs, except the vitellogene glands, are disposed in the
median field, namely, between the intestinal ceca.

Male organs. — This worm is provided with two roughly globular,
cauliflower-like (fig. 160) testes. They are disposed in one of the

Fig. 159.

transverse diameters, (very) slightly (if at all) caudad of the equator
of the worm. Each testis is a little nearer the median-sagittal plane
than the corresponding lateral margin and much nearer the venter
than the dorsum (figs. 154, 155, 160). From the dorso-median
aspect of each testis there springs a duct, vas efferens, which passes
more or less horizontally dorso-mediad, uniting with its fellow to
form the vas deferens. The vas deferens is clearly differentiated
into three portions, the first and second, vesicula and pars musculosa,
being compactly coiled in the axial region of the body of the worm.

The vesicula is thin walled, but is not notably dilated ; the muscu-
losa, measuring about 112 /z in diameter, is provided with a relatively
thick (37 n) muscular wall; its terminal portion passes ventro-
cephalad, and its wall becomes somewhat reduced in thickness as it
passes into the third division (pars prostatica) of the vas deferens.

19G

The latter is distinguished, as in other forms of this group, by being
inclosed in a mass of nucleated cells; the prostatica is short and
maintains the direction assumed by the distal portion of the pars
musculosa, coming into close relation to the dorsal aspect of the
terminal portion of the uterus; the prostatic cells cease a little before
the male duct ends; this terminal portion appears to be very short
and corresponds to the ductus ejaculatorius of the other forms. The
ductus ejaculatorius appears to open just above t he metraterm on the
vertex of what may be regarded as a papilla forming the dorsal wall
of a curved slit-like atrium. This atrium appears to communicate
(?) with a smaller slit-like space immediately ventrad of it, from which
there passes a slender duct, interpreted as the ductus hermaphroditic
cus, that opens on the vertex of a small genital papilla. The ductus
hermaphroditicus, the two slit-like atria, the ductus ejactulatorius,

Fig. 160.

and metraterm are inclosed in a somewhat globular mass of muscular
fibers.

This description of the termination of the male and female canals
and of the ductus hermaphroditicus is tentative, as it is based only on
transverse sections of poorly preserved material, which are of difficult
and doubtful interpretation.

Female organs.— h\ the posttesticular axial region of the body, but
a little to the right of the median line and just above the upper mar-
gin of the acetabulum, is the ovary. Close to the caudo-mesial aspect
of the latter is the slightly smaller shell gland (figs. 154, 155). The
oviduct springs from the caudal aspect of the ovaiy and passes at first
directly caudad for a very short distance, then it passes dorso-mediad
and skirts the dorso-caudal aspect of the shell gland which it pene-

197

trates. Laurer's canal leaves the oviduct at a point just before the
latter begins to skirt the shell gland ; it passes caudo-dorsad, cephalad
of the excretory vesicle, the dorsal aspect of which it gains, and ulti-
mately it reaches the middle line of the dorsal surface at a point in a
plane slightly cephalad of the equator of the acetabulum, and rela-
tively some distance above the excretory pore. The vitellogene
glands consist of sparsely scattered follicles in the lateral regions of the
body (external to the intestinal ceca) , appearing also ventrally and
dorsally of the ceca. They extend longitudinally from the level of
the middle of the esophagus to the level at which the intestinal tubes
terminate. From each gland a duct passes transversely mediad in
front of the corresponding intestine to unite with its fellow close to the
ventro-caudal aspect of the shell gland. From their point of union

Fig. 161.

(fig. 161) a smaller duct originates and passes dorsad and a little to
the right, skirting the corresponding aspect of the shell gland which it
penetrates at its caudo-dorsal aspect a little to the left of the point of
penetration of the oviduct. Within the gland the vitello-duct unites
with the oviduct, the duct resulting from their union forming the

• ootype and continuing beyond as the uterus.

The uterus emerges from the ventral aspect of the shell gland, winds

iits way to the left, and then forms a number of coils in the axial body

i region to the left and dorsad of the ovary as it winds its way cephalad.
Its windings cease at about the level of the cephalic aspect of the
ovary; beyond this point the uterus pursues a direct, though slightly

'Wavy, course ventro-cephalad to gain the ventral aspect of the coiled

198

vas deferens, passing beneath and ventrad of the arch of union of the
vasa efferentia. In the remainder of its course the uterus retains this
relation to the ventral aspect of the male duct and, as has been de-
scribed, appears to open immediately below the latter into the slit-
like atrium (fig. 155.)

Excretory system. — The excretory system appears well devel-
oped. The excretory vesicle is in the caudal portion of the body
dorsally of the acetabulum (figs. 155, 162). It extends caudad to
about the level of the caudal margin of the acetabulum. At this point
its lumen becomes reduced to a duct, with a narrow lumen but strong
wall, which passes directly caudad and opens in the median line of the
dorsum almost if not quite at the caudal extremity of the worm.

Fig. 162.

Relation to Pseudodiscus stanleyii.

Except for the difference in size, the two species are much alike in
external appearance. A study of their internal anatomy brings out
several points of difference. The esophageal portion of the sucker in
Ps. collinsii is relatively much broader than that of Pis. stanleyii, and
presents both a dorsal and a ventral transverse projecting ridge in its
lumen; Ps. stanleyii presents a dorsal ridge only. The testes are
actually and relatively much smaller in Ps. collinsii than in Ps. stan-
leyii, and furthermore they are more widely separated in Ps. collinsii
than in Ps. stanleyii. The anatomy of the terminal portions of the
genital canals appears to differ markedly in the two forms, though
too much emphasis should not be placed on tins because of the diffi-
culty of interpretation of sections and of the limited and unsatisfac-
tory nature of the material. The opening of Laurer's canal is much

199

farther caudad in Ps. collinsii than in Ps. stanleyii; in the former it is
a little above the caudal margin of the acetabulum, whereas in the
latter it is only a little below the upper margin of the acetabulum.
The acetabulum of Ps. collinsii is relatively much larger than of Ps.
stanleyii, and its cavity is deeper. The ovary and the shell gland are
at about the level of the upper margin of the acetabulum in Ps. col-
linsii, but distinctly above this level and nearer the level of the caudal
aspects of the testes in Ps. stanleyii.

ILLUSTRATIONS .

Fig. 152-153. — Ventral aspect showing some of the variations in
outline.

Fig. 154. — Frontal projection from transverse sections of specimen
shown in fig. 152. Shows oral sucker (o. s.), suctorial bulbs (s. b.),
suctorial pouches (s. p.), esophagus (es.), intestines (i.), genital pore
(g. p.), testes (£.), vasa efferentia (v. e.), uterus (ut.), ovary (ov.), shell
gland (s. g.) and acetabulum (ac). a-a, b-b, c-c, d-d, e-e, f-f, g-g,
planes of section. Slightly diagrammatic. Enlarged. Original.

Fig. 155. — Profile projection of specimen shown in fig. 152. Shows
oral sucker (o. s.), left suctorial bulb (s. b.), suctorial pouch (s. p.),
esophagus (es.), vas deferens (v. d.), uterus (ut.), ovary (ov.), shell
gland (s. g.), Laurer's canal (L. c), excretory vesicle (ex. v.), excretory
pore(e:r. p.), and genital pore (g. p.). a-a, b-b, c-c, d-d, e-e, f-f, g-g,
planes of section. Slightly diagrammatic. Enlarged. Original.

Fig. 156. — Transverse section through plane a-a figs. 154 and
155. Shows form of body and form of oral sucker (o. s.). Enlarged.
Original.

Fig. 157. — Transverse section through plane b-b figs. 154 and 155.
Shows oral sucker (o. s.) with ventral and dorsal ridges projecting into
its lumen, and perisuctorial space (p. s. sp.) containing some granular
coagulum. Enlarged. Original.

Fig. 158. — Transverse section through plane c-c figs. 154 and 155.
Shows H-shaped lumen of oral sucker (o. s.) and suctorial bulbs (s. b.),
the superior margin of the left suctorial pouch (s. p.) and the peri-
suctorial space (p. s. sp.) containing some granular coagulum. En-
larged. Original.

Fig. 159. — Transverse section through plane d-d figs. 154 and 155.
Shows esophagus (es.), esophageal ganglion (e. g.), caudal portion
of right suctorial bulb (s. b.), suctorial pouches (s. p.), and caudal pro-
longations of perisuctorial space (p. s. sp.). Enlarged. Original.

Fig. 160. — Transverse section at plane e-e figs. 154 and 155. Shows
position and relation of the testes (t.), intestinal ceca (i.), arch of
union of vasa efferentia (v. e.), origin of left vas efferens (v. e. s.), (he
uterus (ut.), and vitellaria (v. g.). Enlarged. Original.
13893— Bull. 60—10 13

200

Fig. 161. — Transverse section at plane /-/"figs. 154 and 155. Shows
position and relation of caudal margin of shell gland (s. g.), union of
transverse vitello-duct (t. vd.), the common vitello-duct (c. vd.)/.
Laurer's canal (L. c), uterus (ut.), vitcllaria (v. g.), intestines {%.), and
acetabulum (ac). Enlarged. Original.

Fig. 162. — Transverse section at plane g-g figs. 1 54 and 1 55. Shows
position and relation of intestines (i.), excretory vesicle (ex. v.), Lau-
rer's canal (L. c), vitellaria (v. g.), and acetabulum (ac.) with its pro-
jecting rim. Enlarged. Original.

HAWKESIUS, new subgenus.

Subgeneric diagnosis. — Pseudodiscus (p. J 70) : Esophageal wall with pronounced
muscular thickening in caudal half. Testicular zones separate, nearly or quite abut,
fields coincide.

Type species. — Pseudodiscus (Hawkesius) hawkesii.

PSEUDODISCUS HAWKESII (Cobbold, 1875) Si lies k Goldberger, 1910.

[Figs. 163 to 174.]

1875: Amphist. hawkesii Cobbold, 1875n, 818, 819 (in Elephas indicus; India);
1877e, 234; 1879b, 393, 396, 399; 1882, 238-240, fig. 8; 1883x, 515.— Braun,
1893a, 874, 905; 1893d, 466 (hawkesi).— Fischder., 1902a, 48 (hawkesi) (in
E. indicus; India); 1903h, 489 (to Pseudodiscus by Sons., 1895). — Galli-
Valerio, 1901c, 364 (in elephant).— Huber, 1896a, 579-580 (in elephant).—
Looss, 1902m, 439 (hawkesi).— Megnin, 1882v, 455— Piana & Stazzi, 1900a,
511, 519-525, 529, figs. 12-14 (hawkesi); 1901, 416.

1893: Amphisl. hawkesi Braun, 1893d, 466 for haivkesii.

1895: Amphist. hawkesi Sonsino, 1895, 182 for haiokesii; 1895, 187, fig. to Pseudo-
discus; 1896, 310.

1895: Amphist. (Pseudodiscus) hawkesi (Cobbold, 1875) Sonsino, 1895, 187 (9),
fig. I-

1895: Amphist. (Pseudodiscus) haivkcsi Sonsino, 1895, 9, fig. 1.

1896: Pseudodiscus hawkesi (Cobbold, 1875) Sonsino, 1896, 310. — Piana & Stazzi,
1900, 519 to Amphist.
Specific diagnosis. — Pseudodiscus (p. 170): Body 3.5 to 5 mm. long by 2 to 3 mm.
broad; light buff in color (alcohol material); oval, oral pole bluntly rounded, tilted
slightly ventrad, caudal pole very bluntly rounded, almost semicircular; lateral mar-
gins convex in transverse section, straight to convex longitudinally, dorsum convex,
venter fiat to slightly concave longitudinally and transversely; oral pole with slender
digitate papillae. Genital pore ventro-median, postbifurcal, two-fifths of body length
from oral margin with subhemispherical bulging. Acetabulum ventral at caudal
end, oval to circular, 1.2 mm. in sagittal diameter, aperture 0.58 mm., dome 0.30 mm.
thick; its margin projects and is separated from the body by circular groove; cavity
rather shallow. Mouth subterminal; oral sucker constricted at equator into globular
oral and a shorter broader esophageal portion; well-defined bulbs absent, but there
are 2 large pouches which extend caudad about to equator of esophagus; esophageal
portion of suckerrend the pouches lie in a perisuctorial cavity; esophagus arises from
base of sucker, extends to caudal margin of oral third of body; the anterior half of
esophagus about 90/t thick, with wall 22/i thick, its caudal half increased enormously
(up to 330/() m diameter by increase of muscular tissue; ceca long, extend in wavy
course to or slightly beyond equator of acetabulum; their course is wavy and at equa- I
tor of animal they approach toward median line. Excretory pore at caudal extremity;

201

excretory vesicle dorsal of acetabulum, extends from near shell gland to postacetabu-
lar zone.

Male organs: Testes preacetabular in same longitudinal median field, with sepa-
rate or slightly overlapping zones, deeply lobate but not of cauliflower type, noticed
in Ps. stanleyii; vasa efferentia arise from dorsal aspect, extend cephalo-dorso-laterad,
then cephalad, uniting about 120/x cephalad of cephalic testis to form vas deferens;
vesicula much coiled, musculosa coiled and well developed, prostatica and ejacula-
torius short, the latter uniting with metraterm to form wide ductus hermaphroditicus,
which discharges at genital pore; cirrus pouch absent.

Female organs: Ovary posttesticular, in testicular fields, in pre- and acetabular
zone; shell gland postovarial; vitellaria, with small follicles, chiefly in extracecal
area, apparently confined to cecal zone; uterus emerges ventrally from shell gland,
passes in coils dorsad, caudad, then cephalad dorsally of ovary and testes, ventro-
cephalad under arch of vasa efferentia, to ductus hermaphroditicus; Laurer's canal
long, extends from oviduct caudo-dorsad, dorsally of excretory vesicle to dorso-median
line, opening slightly cephalad of caudal margin of acetabulum, cephalad of excre-
tory pore.

Eggs: Not observed.

Type. — Unknown.

Habitat. — Colon of elephant (Elephas indicus), India.

Source of material. — The material at our disposal, consisting of
11 specimens, was kindly sent to us by Prof. Pietro Stazzi, of Milan,
Italy. The specimens are presumed to be some of those collected by
Piana and Stazzi (1900) from the colon of an elephant.

Historical review.— Cobbold (18751, 736) originally named this
species without giving any anatomical details, but discussing its pos-
sible effects upon the host. The worms were collected from the ele-
phant and sent to him from Secunderabad, India. They were
named in honor of the sender. In his second paper (1875n, 818, 819)
no details were added. Later Cobbold (1877e, 234) refers to having
noticed some papillae in the acetabulum of this species (but the ques-
tion arises as to whether he did not perhaps have before him speci-
mens of Amphist. pap>illatum from the same host). Still later (1879a,
393, 396, 399) Cobbold refers to the worms in connection with the
habit of dirt-eating among elephants, and states that he had also
found hawkesii in an elephant which died in England.

Megnin (1882v, 455) states that Cobbold had admitted in a letter
that Amphist. hawkesii and A. ornatum represent two varieties of the
same species.

Cobbold (1882a, 224, 238-240, 241, fig. 8) gives Amphist. collinsii
var. stanleyi as synonym of hawkesii, but states that he thinks that
stanleyi will eventually prove to be a good species. He publishes
the following specific diagnosis of hawkesii, which really represents
the first attempt at a detailed zoological description:

Body of a pink color, smooth, plano-convex, finely wrinkled transversely, bluntly
pointed and contracted in front, broadly rounded behind. Head surrounded by a
few regular but not well-pronounced folds, armed with numerous email and extremely
minute warty papilla. Mouth terminal, circular. Ventral surface often slightly

202

depressed near the center, forming alight prominences on either side. Caudal sucker
placed well forward, rather large, circular, with a broad lip and smooth concavity.
Reproductive papilla small, situated nearly midway between the mouth and upper
margin of the caudal sucker. Length, on the average, three-eighths of an inch; the
longest specimen seven-sixteenths of an inch. Breadth one-fourth of an inch, llab.,
large intestines of Elephas indicus.

Cobbold's figure 8 does not add any essential details-
Cobbold (1883x, 515) again refers to this species incidentally, but
gives no further details. Neither are any additional data given bjj
Braun (1893a, 874, 905; 1893d, 466), Huber (1896a, 579-580), Fis-
choeder (1902a, 48; 1903h, 631), or Looss (1902m, 439), none of whom
examined this species.

Sonsino (1895, 4) considers liawkesii as identical with collinsii,
transfers the species to Pseudodiscus, and gives the following specific
characters :

Color rosso carnicino come generalmente tutti gli Amfistomidi di mammiferi. 10
mm. by 6 mm. Corpo allungato, convesso pianeggiante, sensa peduncolo distinto,
con leggiere striscie trasverse e coll' estremo anteriore ristretto, ma ottuso e 1' estremo
posteriore arrontondato. Bocca terminate e circolare. Superficie ventrale spesso
alquanto depresse verso il centro, dando cosl apparenza di superficiale escavazione,
con due leggiere prominenze laterali corrispondenti probabilmente alle due masse
testicolari. Ventosa posteriore subterminale, larga, circolare con margine grosso e con
cavita liscia. Papilla genitale piccola a mezza distanza tra la bocca e il margine
superiore della ventosa posteriore.

Later, Sonsino (1896, 310) merely mentions the worm.

Piana and Stazzi (1900, 520-525) described specimens of worms
determined as Amphistomum hawkesi found in the colon of an elephant
autopsied in Milan. Their diagnosis reads :

Corpo di color rosso carnicino, oblungo, convesso nel superficie dorsale ed escavato a
doccia in quella ventrale. Estremila arrotondate, quella posteriore piu larga della
anteriore. Lunghezza del corpo, in tutti gli individui esaminati, no superiore a
fa' mm.; larghezza corrispondentemente al terzo anteriore del corpo 2.70 mm., corris-
pondentemente al terzo posteriore 3.70 mm. La superficie cuticolare, guardata con
lente, appare irregolarmente striata nel senso trasversale. Sul margine della parte
anteriore del corpo, alquanto verso la superficie ventrale, si trova la bocca oblunga in
senso verticale circondata da una piccola ventosa del diametro di 0.18 mm., la quale
e limita da un orlo della larghezza di 0.10 mm. Sulla superficie ventrale a livello del
limite tra il terzo anteriore e il terzo mediano delle larghezza del corpo, si trova il poro
genitale, in forma di un orifizio oblungo in senso trasversale, lungo 0.25 mm. c largo
0.15 mm. Sempre sulla superficie ventrale, alia distanza di 4.80 mm. della ventosa
boccale, e quindi nella parte posteriore del corpo, si trova la ventosa posteriore, la
quale b circondata da un orlo largo circa 0.17 mm. ed ha un orifizio del diametro di
0.40 mm.

Of the internal anatomy they recognized the "pharynx" (oral
sucker), with a diverticulum each side, an esophagus 0.7 mm. long
with posterior muscular thickening, and 2 long wavy ceca which end in
the suctorial /one; the ovary and "vitellogene gland" [=shell gland]
are located near the acetabulum; the uterus is llexuous and extends
cephalad to the genital pore; dextral of the "female pore" there are
seen structures indicative of the cirrus, vas deferens, and the 2 testes,

203

but they figure (fig. 14) 2 pairs of testes, 1 pair cephalad of the other,
zones separate, Ileitis coincide.

Piana and Stazzi point out that their specimens are smaller than
Cobbold's, but explain this fact by assuming that they are dealing
with young "worms.

We accept the specific determination of their worms as AmpTiist.
Tiawkesii on the principle that when an author claims to have iden-
tified a species his identification is to be assumed
to be correct until proved to be incorrect. At the
same time we may be permitted to recall the fact
that recent work on trematodes has caused a great
many surprises and it is not by any means ex-
cluded that if Cobbold's original specimens can be
found, the material here accepted as Tiawkesii may
eventually prove to be a distinct species.

In order to avoid a troublesome nomenclatural
difficulty which frequently arises, and in regard to
which authors are at present divided in opinion, we
would state that should the original material of
Tiawkesii prove to be distinct from the material
here described, the subgenus Ilawkesius is based upon the material
now on hand, without any reference to characters which may or may
not be present in the type of Tiawkesii. In other words, the species
represented by U.S.P.H. & M. H.S. no. 10545 is the type of Hawkesius.

EXTERNAL CHARACTERS.

Size. — The alcohol-preserved specimens varied in length between
3.5 and 5 mm., and in greatest width between 2 and 3 mm.

Color. — The worms are of a light buff tint.
Form. — The bottle in which the specimens were
sent to us was found on arrival to be broken and
the specimens dried out. They were put into 70 per
cent, alcohol in which they regained to a consider a-
/ \ ble extent their original form, but they are still

shrunken and deformed to a considerable degree
(figs. 163, 164). They suggest Ps. collinsii in form,
but appear more elongate and with the oral pole
relatively more acutely pointed.

The dorsum is convex both longitudinally and from
fig km s^e ^° S^G> ^he venter is flat or slightly excavate in

both the longitudinal and transverse directions, the
concavity being best defined in the caudal half of the venter. The
oral pole is bluntly rounded, presents a slightly bulbous appearance
and is tilted to a variable degree ventrad. The caudal pole is broad
and rounded from side to side. The lateral margins are convex in
transverse section and straight or but slightly curved longitudinally.

204

Surface.— The cuticle is marked on its ventral surface by fine
transverse sulci. These sulci are most clearly defined in the region
between the genital pore and acetabulum. Around the oral pole there
are slender digitate papilla (fig. 172), some of which measure 90>
in length when measured in sagittal sections.

Genital pore— -In about the median line of the ventral surface, about
two-fifths of the body length from the oral margin, is a distinct subhemi-
spherical ventral bulging (figs. 163, 169) of variable extent, measuring in

sections of one specimen 0.375 mm. in
longitudinal diameter. At the ver-
tex of this bulging is the genital pore.
This pore measured 150ti in longitu-
dinal diameter in one sectioned speci-
men. It leads into an irregularly
cjdindrical chamber into the lumen of
which there arises from its dorsal wall
the genital papilla (fig. 165).

There was observed in several of the
specimens still another ventral bulg-
ing. This is elongate, in the median
longitudinal line (fig. 163) and extends
from a little below the bulbous oral ex-
tremity to almost the genital bulging.
This elongate bulging is found in sec-
tions to correspond to the esophageal
bulb (fig. 168). In the median line of
the caudal portion of the venter the
aperture of the acetabulum presents
itself. It is irregularly oval or circu-
lar in form encircled, as in Ps. collinsii
and Ps. stanleyii, by a rim which is
marked off from the general surface
by a deep narrow groove. On each
side of this aperture the venter of the
worm bulges out so that it appears to be in a more or less well-marked
fairly broad vertical groove (fig. 163).

Acetabulum. — The acetabulum is in the caudal portion of the body,
and, as already stated, its aperture is on the ventral aspect of the
caudal extremity. Measured in sagittal sections of one specimen the
vertical diameter was 1.20 mm., with an aperture of 0.5S mm. in the
same diameter, with a thickness of dome of 0.30 mm. As in Ps.
collinsii and in Ps. stanleyii the acetabular aperture is encircled by a
projecting ring (figs. 163, 165) marked off from the general body sur-
face by a deep narrow groove. This ring is formed by part of the
acetabulum itself.

.avet.

205

INTERNAL ANATOMY.

Digestive tract. — The cephalic extremity is pierced by the mouth
which is somewhat elliptical in form and directed dorso-ventrally.
The aperture of the mouth leads directly into the oral sucker; this
appears to be divided into two portions by a circular constriction at
about its equator. The first or oral portion appears somewhat globu-
lar in form. The form of the second or esophageal portion can not be
made out accurately from the material at our disposal. In a general
way, however, it is shorter but broader than the oral portion. The
increase in the transverse diameter is preparatory to the formation of
lateral suctorial pouches which project caudad and laterad of the
point of origin of the esophagus. They are irregularly globular in
form and extend caudad on each side and dorsally of the esophagus
(figs. 165, 167, 168) to about the equator of the latter. A well-
defined suctorial bulb, such as was described for Ps. collinsii and Ps.
stanleyii, is not present. The suctorial walls are muscular (figs. 166,
172), but the arrange-
ment of the muscular
bundles is less compact
than in Ps. collinsii.
The structure of the
pouch wall (figs. 167,
168) is distinctly less
muscular than that of
that portion of the
sucker from which the
pouches project and
the transition in struc-
ture from one to the
other can readily be made out. The cell structure of the pouch
walls is loose but the cells are decidedly smaller than those of Ps.
collinsii. The lumen of the sucker and pouches is lined by a thin
cuticle-like layer. That of the second portion of the sucker is closely
beset by small conical papillae. A space around the caudal portion
of the sucker and the pouches similar to that in Ps. collinsii is present
(figs. 166, 167, 168). The esophagus springs from the ventral aspect
of the b ase of the sucker. For about one-third its length it passes in
a slightly wavy course caudad, then turns rather abruptly and passes
directly dorso-caudad to a point in a transverse plane at about the
junction of the first with the equatorial third of the body and about
midway between venter and dorsum, where it gives off the intestinal
ceca. The walls of the first portion of the esophagus measured in
transverse sections of one specimen were about 22// in thickness, the
diameter of the esophagus at the same point being about 90/i. In the
second portion of the esophagus the walls become greatly thickened

Fig. 166.

20(>

by the development of its muscular layers. In this portion thr
layers can readily be made out, an internal and an external of longitu-
dinal, and a middle, very thick layer, of circular fibers (figs. 172, 17.3).
This portion of the esophagus measured, in a sagittal section of one
specimen, was 750/x long with a maximum dorso-ventral diameter of

Fin. L67.

330// and with a thickness of wall of between 90> and 105^. The
esophagus is lined by a fairly thick cuticle-like layer.

The intestinal ceca pass laterad, at first almost at right angles
with the esophagus, then describing a gentle curve they pass caudad

Fig. 168.

in a ventro-dorsal wavy course apparently similar to that in Ps. col-
linsii (fig. 174). At about the level of the equator of the animal the
ceca approach close to the corresponding dorso-lateral aspect of the
superior testis. This is also the point where in their course the intes-

207

tines come nearest together. A similar peculiarity has been noted
in Ps. collinsii andPs. stanleyii. The intestines extend caudad to or
slightly beyond the equator of the acetabulum. In transverse sec-

FlG. 169.

tions the ceca are irregularly circular in outline and are more or less
constricted at irregular intervals, causing considerable variation in
diameter. The lumen is lined by an epithelial eell layer.

Genital system. — With the exception of the vitellogene glands
the genital organs
are disposed in the
intercecal space.

Male organs. —
The two testes are
in the axial region
of the body, some- H
what nearer the
venter than the dor-
sum. They occupy
about two-ninths of "9
the body length in
the zone immedi-
ately cephalad of
the acetabulum.
They are placed one directly caudad of the other, their zones
either overlapping very slightly or separated by a very narrow
interspace. The two testes are of about the same size; measured

Fig. 170.

208

from a series of transverse sections of one specimen the superior
testis was 420/i long by 365/* wide by 210/t thick, while the caudal
testis was 40G> long by S90ft wide by 180> thick. Each testis
is divided into numerous lobes by deep infoldings of its inclosing
membrane. The testes are not quite of the cauliflower-type, such as
those of Ps. collinsii and Ps. stanleyii. From the dorsal aspect of
each testis there emerges a vas efferens (figs. 170, 171). After emerg-
ing from the testes the vasa elferentia tend cephalo-dorsad and away
from the median line, the vas from the superior testis going to the
left and that from the inferior (or caudal) to the right. After reach-
ing a point near the mesial aspect of the corresponding intestine the
vasa pass directly cephalad until they reach a plane slightly (about
120/0 cephalad of the superior aspect of the superior testis, when each
curves inward to unite with its fellow to form the vas deferens. In

Fig. 171.

so doing the vasa elferentia form a transverse arch, beneath which
the uterus passes as it ascends cephalo-ventrad. The vas deferens
presents in the first part of its course a much coiled vesicula, which is
succeeded in the second part by a coiled, well-developed musculosa.
The latter gives place to a short prostatica. The terminal portion
of the vas deferens is a short narrow duct, the ductus ejaculatorius,
which unites at the base of the genital papilla with the terminal por-
tion of the uterus to form the ductus hermaphroditicus (fig. 165, d. //.).
The latter is a wide duct which pierces the genital papilla to open on
the vertex of the latter at the porus hermaphroditicus.

Female organs. — The ovary lies posttesticular, a little to the left of
the median sagittal plane, close to the acetabulum, and in or imme-
diately caudad of the transverse plane of its superior margin. The
oviduct springs from the dorsal aspect of the ovary and passes caudo-

209

dorsad, skirting the dorsal aspect of the shell gland and giving off
Laurer's canal close to the dorso-caudal aspect of the latter. The
main duct then penetrates this aspect of the shell gland. The shell
gland, apparently somewhat larger than the ovary, lies immediately
caudo-dorsad of the latter. It is, as just described, penetrated on
its cauclo-dorsal aspect by the oviduct; on its caudal aspect it is
penetrated by a duct which is interpreted as the vitello-duct. The
union between these ducts is not satisfactorily made out in our prep-
arations, but no doubt it takes place to form a fairly distinct ootype,
the continuation of which emerges from the ventro-cephalic aspect

Fig. 172.

1 1 of the gland as the uterus (fig. 165). After emerging, the uterus
1 1 turns to the right and dorsad, then dips caudad dorsally of the shell
gland and in the axial region of the worm, forming some coils, then
I turns cephalad describing coils as it ascends between the dorsum and
I 'the testes. It passes ventro-cephalad over the superior testis and
beneath the arch of union of the vasa efferentia to gain the ventral
: aspect of the coiled vas deferens. It retains this relation in the
i remainder of its course to the base of the genital papilla, where it

unites with the ductus ejaculatorius in the formation of the ductus
hermaphroditicus.

Laurer's canal passes caudo-dorsad doisally of the excretory]
vesicle to open in aJx.nl the median line of the dorsum, cephalad of
the excretory pore and slightly cephalad of the level of the caudal
margin of the acetabulum.

The vitellogene glands, consisting of small insignificant follicles,
are longitudinally disposed in the extracecal area, their caudal por-
tions extending, however, into the cecal and to a slight extent into
the intercecal area. Longitudinally they do not appeal- to extend

Fig. 173.

outside of the cecal zone, but this point can not be made out from our
preparations as satisfactorily as is desirable.

Excretory system. — The excretory vesicle lies close to the dorsal
aspect (the dome) of the acetabulum (fig. 165, ex. v.). It begins close
to the ventro-caudal aspect of the shell gland and extends to slightly
above the caudal margin of the acetabulum, beyond which point it is
continued as a relatively thick duct to open in about the median line
of the caudal extremity. This duct is inclosed in a well-marked
layer of nuclei, probably of cells, the bodies of which, however, are
not satisfactorily discernible. The excretory canals can not be sat-
isfactorily followed in our preparations.

211

ILLUSTRATIONS.

Fig. 163.— Ventral aspect. Enlarged. Original.

pIG. 164— Profile view of same. Enlarged. Original.

FlG 165.— Diagrammatic sagittal section, showing oral sucker
(o. «.), suctorial pouch (s. p.), esophagus (es.), testes (t), vas deferens
(v. d.), uterus (w*.), ovary (ov.), oviduct (ov. d.), shell gland (s. .9.),
ILaurer's canal (Z. c), excretory vesicle (ex. v.), excretory pore (ex. p.),
genital papilla popOj ductus hermaphroditicus {A. h.), and ace-
itabulum (ac). Enlarged. Original.

Fig. 166. — Transverse section (about through equator of oral por-
tion of sucker, 0. s.) to show its form and the perisuctorial space
(p.s.sp.). Enlarged. Original.

Fig. 167. — Transverse section
((at level of origin of esophagus)
ito show position and relations of
suctorial pouches (s. p.) and be-
ginning of esophagus (es.) ; also
shows extension of perisuctorial
space (p. s. sp.). Enlarged.
(Original.

Fig. 168. — Transverse section
aat beginning of bulbous por-
ttion of esophagus to show posi-
tion and relation of fundi of suc-
ttorial pouches (s. p.) to this
(portion of the esophagus (es.).
>*Shows also extension of perisuc-
ttorial space (p. s. sp.) and
imolding of venter over the
cesophagus. Enlarged. Original.

Fig. 169. — Transverse sec-
ttion at level of genital pore, showing subhemispherical genital bulging,
^genital pore (g. p.), pars musculosa (p. m.), ductus ejaculatorius
[(d. e.), and intestinal ceca (i.). Enlarged. Original.

Fig. 170. — Transverse section at level of origin of left vas efferens
((v. e. s.) from superior testis (£.). Shows also position and relations
iof intestinal ceca (%.), uterus (ut.), right vas efferens (v. e. d.), and
vitellaria (v. g.). Enlarged. Original.

Fig. 171. — Transverse section at level of origin of right vas efferens
((v. e. d.) from caudal testis (t.). Shows also position and relations
iof intestinal ceca (i.), uterus (ut.), and vitellaria (v. g.). Enlarged.
(Original.

Fig. 172. — Sagittal section through oral extremity. Shows mouth
(///.), oral sucker (0. s.), and first portion of esophagus (es.); also
shows mesial wall of suctorial pouch (s. p.). Enlarged. Original.

212

Fig. 17:?. -Sagittal section through second portion of esophagus
(es.); shows also portion of suctorial pouch (s. p.). Enlarged.
Original.

Fig. 171.— Diagram to show topography of digestive tract, acl
acetabulum; g, p., position of genital pore; es., esophagus; %.. intes-
tinal ceca (showing constrictions and dilatations); m., mouth; o. 8\
oral sucker (and pouches); t., testes; Enlarged. Original.

WATSONIUS, new genus.

Generic diagnosis— Cladorchiiwe (p. 169): Body pyriform. Ventral pouch
absent. Acetabulum ventral or ? ventro-subterminal; very large, margin« projecting;
aperture small. Genital pore prebifurcal, without sucker; ductus hermaphroditicus
apparently absent, Excretory pore caudad of vesicle, in acetabular zone, caudad of
pore of Laurer'8 canal. Oral sucker with a pair of latero-caudal irregularly "lobular
suctorial pouches; esophagus with distal thickening of muscular layer (esophageal
thickening); ceca long, not wavy, end postequatorial. posttesticular, in acetabular zone]

Male organs: Testes 2, lobulate, smaller than acetabulum, fields nearly or quite
coincide, zones abut to slightly overlap, preovarial, not far removed from acetabulum,
in equatorial and caudal thirds; musculosa not enormously developed; cirrus pouch
absent.

Female organs: Ovary and shell gland immediately posttesticular; vitellaria extend
about from bifurcal zone to slightly postcecal, into acetabular zone; uterus intercecal,
in part posttesticular; Laurer's canal cephalad of excretory vesicle.

Type species. — Watsonius watsoni (Conyngham, 1904).

WATSONIUS WATSONI (Conyngham, 1904) Stiles * Goldberger, 1910.

fFigs. 175 to 189.]

1904: Amphist. watsoni Conyngham, 1904, Aug: 13, 464; Aug. 27, 355; 1905, Sept.

8; 1902, Sept. 17, 663, figs. 1-2 (in Homo, Africa); 1905, Sept. 29, 1480; 1905,

Oct. 8, 710.— Shipley, 1905, 8 to Cladorchis.
1905: Cladorchis watsoni (Conyngham, 1904) Shipley, 1905, 129-135, pi. 4, figs]

1-10 (in Homo, Africa); 1905, 1-9, pi. 4, figs. 1-10; 1905, Apr., 205; 1905, Apr.

8, 950; 1905, Nov. 2, 1298; 1905, 9 pp., 10 figs.— Braun, 1908, 4 ed., 175-

176, figs. 125-126.

Specific diagnosis.— Watsonius (p. 212): Body 8 to 10 mm. long, by 4 to 5 mm.
in maximum breadth, by 4 mm. thick; fresh specimens reddish-yellow, translucent;
gelatinous; preserved specimens dark slate to dirty brown in color; pyriform, greatest
diameter about at border of equatorial and caudal thirds; tapers cephalad to about 2.5
mm.; tapers more rapidly caudad so that the caudal extremity is very bluntly rounded :
lateral margins convex on ventral view; venter somewhat flattened and slightly
indented posteriorly at margin of acetabulum; venter surrounded by an elevated ridge
and bulges posteriorly [transverse sections are too irregularly contracted from preser-
vation to permit of safe interpretation]. Surface with transverse ridges, coarser, and
better defined ventrally. Genital pore ventro-median, "about 2 mm. from the oral
sucker," or rather prominent, about one-fourth of body length from anterior end;
about at equator of esophageal zone and in zone of suctorial pouches. Acetabulum
ventro-subterminal (or ventral?), very large, over 1 mm. in diameter; its free margin
projects considerably; aperture small. Mouth ventro-subterminal in a dorso-ventral
groove (contraction?), with digitate papilla1; oral sucker sunken in body, very large,
about one-fifth as long as body, attains 1.2 mm. in transverse and 1. 1 nun. in dorso-
ventral diamelcr; with a pair of latero-caudal irregularly globular suctorial pouches,
which extend about halfway to bifurcal zone; esophagus slightly longer than oral

216

• sucker, distinctly bent, its convexity ventrad, its muscular wall thicker in its caudal
I half; ceca extend into fifth zone, ending in anterior half of acetabular zone, their lumina
compressed laterally so that their dorso-ventral diameter is about 5 times as great as
their transverse diameter. Excretory pore dorsal, apparently slightly einistrad of
median line, in zone of aperture of acetabulum; excretory duct thick- walled ; excretory
vesicle relatively small, dorsal of acetabulum, extends about from plane of transverse
- vitello-ducts to equator of acetabulum.

Male organs: Testes huge, deeply notched (lobulated), each about one-seventh as
loug as body, one caudad of the other, in median line, fields coincide, zones overlap
very slightly; each vas efferens springs from dorso-cephalic aspect [point of union not
definitely traced]; vas deferens consists of vesiciila seminalis intricately coiled and
i dilated, pars musculosa relatively short and not coiled, a dilated portion (correspond-
i ing to pars prostatica), in which no prostatic cells were found, a relatively long, narrow
ductus ejaculatorius which opens on genital papilla, cephalad of metraterm, into
ipapillated genital atrium; terminal portion is surrounded by a muscular mesh which
: forms a genital bulging; true cirrus pouch absent.

Female organs: Ovary slightly sinistrad (but apparently touches median line),
( dorso-caudad of posterior testis, dorso-cephalad of acetabulum ; shell gland dorsad of
i ovary; vitellaria with moderate number of well-developed follicles, ventro-laterad of
< ceca, in extracecal and cecal area, extend from bifurcal zone into postcecal zone about
: to equator of acetabulum ; uterus passes from shell gland ventro-dextrad into acetabular
. zone not quite to end of ceca, bends cephalad, runs in coils dorsally of testes, then in
: rather straight to sinuous course ventrally of vas deferens to its opening caudad of male
i opening; apparently no ductus hermaphroditicus present; Laurer's canal opens appar-
ently in dorso-median line, very slightly caudad of cephalic limit of acetabular zone.
Eggs: Eggs oval, 122 to 130/x long by 75 to 80/i broad.
Type.— (?). Cotype TJ.S.P.H.&M.H.S. 10720.

Habitat. — Jejunum and duodenum of man (Homo); German West Africa.

Source of material. — We are indebted to the kind courtesy of
!Dr. A. E. Shipley, to whom we desire to express our sincerest thanks,
I for the loan of a series of transverse sections of this worm.

Historical review. — At a meeting of the Section of Tropical

Diseases of the British Medical Association, on July 27, 1904, Dr. H.
(C. Conyngham, demonstrator at the London School of Tropical Medi-
(cine, presented a paper entitled "A new trematode of man (AmpMs-
Itoma watsoni)." This paper was abstracted in the Lancet, 1904,
.August 13, page 464, and Journal of Tropical Medicine, 1904, August

15, page 252. The full paper, which appeared in the British Medical
t Journal, September 17, page 663, reads as follows:

A new -trematode of man (Amphistoma watsoni).

Last February Doctor Watson, of Northern Nigeria, sent six curious trematodes
from the small intestine of a negro, who had died of starvation and diarrhea, to the Lon-
don School of Tropical Medicine. These proved to be a species of amphistome, totally
unlike the Gastrodiscus hominis of Lewis— so far the only one of that genus found in
i man— and also unlike any hitherto described as occurring in animals. A specimen
'was sent to Professor Blanchard, of Paris, who very kindly examined it and reported
i that he considered it a new species. Doctor Watson sent some clinical notes of the
(case; they are as follows;

The patient— one of a gang of freed slaves, all of whom were in a pitiable condition
( due to starvation— was brought from Adamawa, German West Africa, to Zola, Northern

Nigeria, lie was found to be suffering from diarrhea, and was admitted to hrspital,
where he died the same night. His stools were numerous, watery, and of a bilious
color, but containing no blood or mucus. In the stools were found many reddish-
yellow, translucent, gelatinous, oval bodies (the trematodes). Necropsy revealed
the spleen small, hard, and black. In the stomach some undigested milk was found.
The duodenum and upper part of the jejunum were found full of these oval bodies,
some of which were alive and adherent. The mucus membrane showed no hemor-
rhages, but appeared to be slightly red. The other parts of the bowel, as also the other
organs, were normal. A few of the bodies were seen lying in the large intestine. The
patient was extremely fond of eating raw meat .

The animals are pear shaped, flattened ventrally and slightly indented posteriorly
at the margin of the posterior sucker, but owing to the preservative used they have
shrunk considerably and are now of a dark slate color. The anterior sucker in most of
the specimens is retracted and lies at the bottom of a sulcus, which is terminal and
ventral; the posterior sucker is very large, its cavity measuring over 1 mm. across; it
is subterminal and ventral. The genital pore lies about a quarter of the length of the
parasite from the anterior end and is rather prominent. The cuticle of the body is
marked with transverse ridges, these being coarser and better defined on the ventral
surface; the latter is flattened, surrounded by an elevated ridge and bulges posteriorly.

The worms measure 8 mm. long, 5 mm. at point of greatest breadth, this tapering
gently anteriorly to 2.5 mm.; their greatest thickness is about 4 mm.

The genital pore lies 2 mm. from the anterior sucker. The ova as seen in the uterus
are oval and measure 130/i by 75/<. It was found impossible to clear the specimens
sufficiently to make out definitely their internal anatomy, but the general arrange-
ment seems to be like that of the Amphistoma conicum (Zeder).

That these parasites may have been the cause of death is not at all unlikely, when
it is considered that the larger part of the small intestine contained a great number of
them and that at least one other species of the same genus causes serious sickness in the
higher animals, namely, the amphistome of Collins in India, causing masuri, a condi-
tion of severe intestinal irritation in horses; and another, the Gastrodiscus of Sonsino,
is supposed to cause death in horses and mules in Egypt, Senegal, and Guadeloupe.
Another trematode of a different genus, the Fasciolopsis buski, inhabitating the small
intestine of man, has been credited with causing intestinal irritation and typhoid-like
symptoms, and this is occasionally followed by death.

These worms are, therefore, a new parasite of man, probably causing serious intes-
tinal disturbance, diarrhea, marasmus, and death. Whether their distribution is
limited, which is likely, remains to be seen; but by a careful examination of feces
for ova, or adults in cases of diarrhea, it may be found again in at least that part of
Africa in which the patient resided.

It is not at all probable that the eating of raw meat, which Doctor Watson notes, has
anything to do with their introduction into the body, as parasites of that genus are,
as a rule, ingested in the larval or cercarial form, encysted on some vegetable substance.

I would suggest that the name Amphistoma watsoni be given to the interesting
parasite.

Shipley (1905, 3-9, pi. 4, figs. 1-10) gave the history of this trema-
tode, as furnished by Doctor Watson, as follows :

The patient was a Pagan who had come from Adamawa, German West Africa— one
of a gang of freed slaves brought to the resident of Zola, Northern Nigeria, nearly all
of whom were in a terrible condition, due to starvation.

He made a certain amount of progress at first, but did not improve as the others,
and had constant diarrhea. The stools were watery and of a bilious color, no blood or
mucus in the same. He was taken into the hospital, but died the same night, and on

210

inspecting the stools passed during the night numerous reddish-yellow, translucent,
gelatinous, oval bodies were found.

Post-mortem— The lungs and heart were normal. Liver normal. The spleen
email, hard, and black. The stomach contained some food, and on opening the small
intestine the duodenum and upper part of the jejunum were found full of the oval
bodies, none of them adherent, although they were alive. The mucous membrane
was reddish, but no hemorrhages or petechiae were apparent. The rest of the bowel
was normal, a few of the oval bodies found loose in the large intestine. The kidneys
were normal. The oval bodies have shrunken considerably, and are only about a
third of the normal size.

These Pagans appear to be extremely fond of raw meat, and eat fowls raw.

As Shipley made a careful anatomical study of this parasite, and
as our results differ in some respects from his, Shipley's account is
here reproduced for comparison:

II. Anatomy.

Alimentary canal— There is no true sucker at the anterior end. The mouth is a
simple aperture leading into a pharynx, the walls of which form an almost spherical
bulb. The lumen is lined with chitin, and the bulb is separated from the general
parenchyma of the body by a basement membrane. Between the basement mem-
brane and the chitinous lining lies a loose tissue crossed by numerous muscle fibers,
which mostly run in a radial direction, but a few run circularly.

At first the lumen of the pharynx is compressed from side to side, but after about
30-35 sections from the anterior end the lumen has become depressed from above
downward, and just here are found two short dorsal and ventral valves projecting like
tongues into the lumen, only directed backward. They are attached anteriorly and
free posteriorly. Behind these valves the lumen becomes diamond-shaped, the long
axis being the transverse one, and here the bulb is at its largest and occupies a good
deal of the area within the body wall. Its wall is also now divided into an outer and
inner layer by a well-marked layer of circular muscles. The inner layer consists
largely of radiating muscle fibers. The whole bulb lies somewhat freely in the very
loosely vacuolated parenchyma, which seems to form a space around it, transversed
only by a few sparse threads of protoplasm.

As we pass into the posterior half of the bulb the diamond-shaped lumen becomes
a slightly oval slit whose angles shortly afterwards are turned clown, thus forming a
crescen tic-like space in cross section. At the hinder end of the bulb these turned-
down corners are cut off from the central lumen and form two lateral diverticula, the
pharyngeal pouches. The diverticula, although they have their origin in the turned-
down corners of the lumen, soon come to lie dorso-lateral of the central channel, and
this alteration in relative position is caused by the central channel passing toward the
ventral surface of the body. The pharyngeal pouches consist of the same kind of
loose vacuolated tissue as the bulb ; they are very thick walled and with small lumina.

Behind the bulb the lumen of what may now be called the esophagus deepens, and
in the region of the anterior border of the genital pore the central portion of the ali-
mentary canal is no longer surrounded by the characteristic tissue of the bulb, though
the two dorso-lateral diverticula, which still persist, are. The lumina of these diver-
ticula then become slightly coiled so as to appear twice in one section, and then each
of them fades out and disappears altogether. At about the level where the anterior
third of the body joins the posterior two-thirds, the esophagus divides into the two
lateral diverticula, and around the a -shaped lumen at this point is a thick bulb or
sheath of muscle fibers mostly circular in their arrangement, though some are radial.
Around them is a layer of longitudinal muscles. The lateral diverticula now pass
outward and begin to include between them the reproductive organs. Each diverticu-
13893— Bull. 60—10 14

lura is flattened sideways aud has a considerable dorso-ventral axis. They give off
no secondary diverticula, though they are wavy or wrinkled, especially posteriorly
and here also they diminish in size, pass dorsally, and come to an end just about the
level of the anterior lip of the great posterior sucker.

It does not seem possible to make out any cells lining any part of the gut. No
epithelium is recognizable. The lumen is lined by a deeply-stained layer which
looks like mucus, very thin in the pharynx, but quite thick in the intestinal diverticula.
At the outer surface of this deeply-staining layer, darkly-stained structures, which
may be nuclei, are here and there to be seen. The whole rests on a very definite
basement membrane, and outside this in the region of the diverticula is a single layer
of longitudinal muscles, the whole recalling in appearance the structureless lamella
and the muscle tails of the ectoderm cells lying on it, in a hydra.

The excretory system. — The excretory pore lies in the middle line above the
posterior sucker. It opens into a tube lined with cuticle directly continuous with
that which clothes the body. This canal is pushed a little way out of the median line
and lies, in the single specimen reduced to sections, a little to the left. Its walls soon
thicken, and numerous darkly stained structures appear in its periphery; there may
be nuclei or possibly sections through minute muscle fibers. Passing forward the
canal enlarges and forms a spacious vesicle, which still lies over the sucker, spreading
over its anterior end; from this vesicle, secondary canals pass up into the surrounding
tissue. These, however, can not be traced farther in sections. The bladder or vesicle
narrows again as we pass forward, and by the time the anterior edge of the sucker is
reached it comes to lie between the hindermost ends of the diverticula of the ali-
mentary canal. In front of this the main trunk seemed to divide into two, but beyond
this they could not be traced.

The parenchyma. — This packing or ground tissue consists of large cells usually
diamond-shaped in section. They are evidently very soft, and have been pulled out
into strand-like structures where the cuticle has been elevated. The cells contain a
granular-looking protoplasm. The cells underlying the cuticle are much smaller than
those of the parenchyma within; the details could not be made out, but amongst and
between them are some obvious muscle fibers. Similar muscle fibers lie outside the
gut-diverticula, and many such fibers surround the outer parts of the reproductive
ducts.

The reproductive organs. — There is a genital papilla situated in the middle
ventral line about the level where the anterior quarter joins the posterior three-
quarters. On this open close together the canal of the cirrus and the metratrema, the
vas deferens opening slightly in front of the latter. The whole papilla is but slightly
projecting; its tissue is closer and firmer than the usual body tissue. The distal end
of the cirrus canal is muscular for a short space, and seems to have glands opening
into it, but it soon gives a bend and opens into a thin-walled vesicle on the ventral
surface, the vesicula seminalis, which in the specimen that was cut into sections
contained a mass of spermatozoa. The genital papilla is on a level with the lateral
diverticula of the esophagus, but the vesicula seminalis lies beneath the muscular
pharynx, just where the alimentary canal is beginning to split into two diverticula.
Ventral to it lies the small vagina with muscular walls which, just behind the level of
the opening of the cirrus canal into the vesicula seminalis, expands into the thin-
walled uterus.

The vesicula seminalis opens into the vas deferens dorsally, and begins to pass
backward as a slightly coiled, thick-walled duct. This is still packed with sperma-
tozoa. The thick-walled duct suddenly passes into a thin-walled duct, which is
closely coiled and still packed with spermatozoa. The junction of the two is at the
level where the uterus begins lo pass dorsally; it continues, however, to lie ventral
to the coiled thin-walled portion of the vas deferens. The testes are double, and

lie side by side, though one projects farther back then the other. They are ventral
to the uterus, which for a short space lies between the glands and their ducts. The
testes are closely adpressed to one another, and it is just possible that they unite at
one point. They open straight into the thin-walled vas deferens. Each testis is
deeply lobulated. The glands are packed with sperm morulas in various stages of
development, their darkly stained nuclei giving the tissue a very characteristic
appearance.

The metratrema or distal and modified end of the uterus opens close behind the
vas deferens: it is a thick, muscular duct which passes backward for a short distance
in a straight line. Just in front of the anterior border of the testes it enlarges into
the uterus, and this begins to twist and loop, lying between the dorsally placed vas
deferens and the ventrally placed testes. The uterus contains ova, but not in very
great quantities; the eggs are incased in a shell and contain many deeply staining
yolk granules, but little more can be made out. My measurements for an ovum,
which looked unusually large, were 122/t by 80/t, but Conyngham gives 130/z by 75/i.
Undoubtedly the eggs vary in size to a certain extent. The uterus coils a good deal
over the testes, and at the posterior end of these glands its lumen enlarges, and it
becomes filled with a glairy looking coagulum in which the ova lie embedded.

The ovary or germarium lies close behind the testes, and rather to the right of the
body; it contains minute ova with large nuclei, closely packed together in some
places and loosely in others. The whole, like the testes, is ensheathed in a connect-
ing tissue casing. The oviduct leads from the anterior end and curves back above the
ovary, it becomes almost immediately surrounded by the shell gland, and may here
be called the ootype. Close behind the shell gland the ootype receives the opening
of the vitelline duct and the inner end of Laurer's canal. The shell gland and the
ovary come to an end at about the same level as the anterior edge of the posterior
sucker. There is a well-marked canal of Laurer which passes almost directly dorsal-
ward and opens in the dorsal middle line just in front of the posterior sucker.

The yolk glands are conspicuous, follicular structures, which take no stain, but
remain a somewhat dirty -brown color, somewhat glistening. They extend forward
as far as the reproductive pores, and they lie near the edge of the body, ventral to the
right and left branches of the alimentary canal. The glands increase in number
posteriorly, and in the region of the great sucker are very numerous. Their minute
ductules fuse together and gradually unite into right and left ducts that open into
the ootype, which is surrounded by the shell gland, and in which the egg is made up.
Into the same space opens the duct of the yolk reservoir, which is a coiled receptacle,
full of yolk, lying to the left and opposite the ovary.

III. Systematic Position.

The trematode we have to do with has been described by Mr. H. F. Conyngham as
a species of the genus Amphistoma, which he calls Amphistoma watsoni. Dr. F.
Fischoeder has recently pointed out that the name Amphistoma is in reality a synonym
of the genus Strigea, but the original Strigea has since been described as Ilolostomum
macrocephalum, and if Strigea is to be revived it must be for that form. Hence,
Doctor Fischoeder proposes to us the name Paramphistomum for what we have used to
term Amphistomum, and the name Paramphistomidx for the family to which they
belong. Whether we follow the classification of Bronn's Thierreich or, as I propose
to do, the later classification of Fischoeder, it is impossible to class the new human
parasite described above as an Amphistomum, because that species is characterized,
amongst other things, by the absence of the lateral diverticula of the pharynx, which
form so characteristic a feature of our species. This fact, however, could only be
Betermined by cutting the animal into sections, and therefore escaped the notice of
Mr. Conyngham.

— I

Fischceder divides the Paramphislomidse of the Mammalia into two subfamilies: (hj
the Paramphistominx with the genera Paramphislomum, Stephanopharynx, and Gas-
trothylax, all these being devoid of pharyngeal side pouches, and (ii) the Cladorchinie
with the genera Cladorchis, Chiorchis, Gastrodiscus, Homalogaster, and Balanorchis
Of these genera Cladorchis is characterized by having the body not divided into anterior
and posterior portions, by having the lateral edges rounded, by having the ventral sur-
face slightly hollowed, and in all these respects our genus agrees with Cladorchis, and
differs from the other members of the subfamily. I therefore place it in this genus.

CLADORCHIS WATSONI (Conyngham).

Synonym. — Amphistomum watsoni (Conyngham).

Length, 8-10 mm.; greatest breadth, 4-5 mm., tapering toward the anterior end
to about 2.5 mm.; and depth about 4 mm.; color, when fresh, reddish-yellow, when
preserved, a dirty brown; when fresh, translucent and gelatinous; the ventral sur-
face transversely wrinkled, the aperture to the posterior sucker small, but the sucker
itself big; no distinct sucker anteriorly but a well-marked pharyngeal bulb; the two
pharyngeal pouches project beyond the outer limit of the bulb; circular sphincter
round the esophagus just where it forks; distinct genital papilla, testis lobed, divided
into two, side by side, anterior to ovary; Laurer's canal straight, opening anteriorly
to excretory vesicle in middle line above the posterior sucker; the latter is very large
and vaulted; the ova measure from 122-130/i by 75-80/1.

Habitat. — Homo sapiens, a West African negro, jejunum and duodenum, very
few in the large intestines.

So far as we are aware, all other reference to this species are based
upon the foregoing papers.

EXTERNAL CHARACTERS.

Size. — Conyngham (1904) states that the worms measure 8 mm. in
length and 5 mm. in greatest breadth, tapering gently cephalad to
2.5 mm. in breadth, and 4 mm. in greatest thickness.

Shipley (1905) gives the length as from 8 to 10 mm., greatest
breadth 4 to 5 mm., tapering toward the oral extremity to about
2.5 mm., and 4 mm. in dorso-ventral diameter.

Color. — In Watson's clinical notes quoted by Conyngham (1904)
the fresh specimens are described as reddish-yellow, translucent,
gelatinous bodies. Conyngham states that after fixing and in the
preserved state they become a dark slate color. Shiplej^ (1905)
gives the color as reddish-yellow, translucent, and gelatinous in the
fresh state and a dirty brown when preserved.

Form. — Conyngham describes them as pear shaped (figs. 175, 176),
flattened ventrally and slightly posteriorly at the margin of the
posterior sucker, but very much shrunken from the action of the
preservative.

Surface.— Conyngham states that the cuticle is marked by trans-
verse ridges which are more coarse and better defined on the ventral
surface. The anterior sucker is described as being retracted in
most of the specimens and as lying at the bottom of a ventro-

terminal sulcus. The venter is described as flattened, surrounded by
an elevated ridge and as bulging posteriorly.

Genital pore— The genital pore is given as being 2 mm. from the
anterior sucker, presumably in the ventro-median line, or about one-
fourth of the length of the parasite from the anterior end and is
stated to be rather prominent. Shipley (1905) states that there is
no true oral sucker, and that the venter is trans-
versely wrinkled. Shipley mentions a genitalpa-
pilla as situated in the midventral line about the
level where the anterior fourth joins the poste-
rior three-fourths.

Acetabulum. — Conyngham states that the "pos-
terior sucker is very large, its cavity measuring
over 1 mm. across; it is subterminal and ventral."
Shipley describes the posterior sucker as big, but
with a small aperture.

We find that the rim of the acetabulum pro-
jects considerably beyond the embrace of the
body parenchyma in a manner very similar to
that which obtains in Ps. stanleyii and, as in the latter, it forms a
ring around the aperture, being encircled by a deep, narrow groove
(figs. 175, 189), which marks it from the general surface.

Fig. 175.

INTERNAL ANATOMY.

Digestive tract. — The oral extremity of the worm is marked by
a dorso-ventrally directed groove-like depression which encroaches
slightly on the ventral surface. By Conyngham this
is described as a ventro-terminal sulcus and this is
pictured, though not mentioned, by Shipley (fig. 175).
The surface of this depression is beset by digitate pa-
pillae. It leads by an irregularly circular aperture
about 165^ in diameter directly into the oral sucker.
The latter (figs. 178, 179) is a large organ; in length
it equals about one-fifth of the total body length.
Its maximum transverse and dorso-ventral diameters
are at about its equator, and measured from sections
are 1.2 mm. and 1.1 mm., respectively. These
diameters decrease in the direction of both poles, but
more particularly toward the oral pole, which is bluntly
pointed. The decrease in these diameters, in the direction of the
caudal pole or base, is progressive though slight. A little above
the level of the base the decrease in the transverse diameter ceases;
soon this diameter begins to expand, this expansion being due to

Fig. 176.

■r

the extension at first laterad and then dorso-laterad in the form of
pouches of the sucker from the region of its caudo-lateral aspect.
The ventro-dorsal diameter, however, continues progressively to
decrease, the base of the sucker viewed in sagittal plane being

rounded, tilted some-
what ventrad and giv-
ing origin to the
esophagus.

The pouches are ir-
regularly globular in
form and as they ex-
tend latero - caudad
come to lie close to
the dorso - lateral as-
pects of the first por-
tion of the esophagus.
The caudal third of
the sucker and its
pouch -like prolonga-
tions are in a well-
marked perisuctorial
space (fig. 181), in
which they are re-
tained in position by
mesenterium - like
strands extending
from the parenclryma
particularly to the
dorsal and ventral as-
structure of the suctorial wall differs
At the oral pole the suctorial wall

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via...

/ "YK

/ *#'
/ •'zii

i ':
is

■,

\ it^P

\ ''^ytr*

...V* v*>Ny
\ W

l../ve.y.

"'tvd.

Fig. 177.

pects of the sucker. The
somewhat at different levels
consists of parenchyma-like cells with some radial, circular, and
longitudinal muscular fibers arranged beneath
the cuticular lining of the lumen. Farther cau-
dad, however, these muscular fibers increase in
number and except for the radial bundles are
massed into a well-defined inner zone as con-
trasted to an outer zone of the parenchyma-like
cell structure. Just above the level of origin
of the pouches the inner muscular zone forms
the greater portion of the thickness of the wall,
the cell structure of the outer zone at the same time becoming
greatly condensed. The structure of the pouch walls shows a simi-
lar inner relatively narrow muscular zone in which the circular
fibers are most prominent, and an outer parenchyma-like zone.

Fig. 178.

£t£ix

Fig. 179.

The lumen of the sucker, in a general way, is a dorso-ventrally nar-
row, but transversely a relatively broad space. Cau do-laterally it
extends into the caudo-lateral prolongations or suctorial pouches of
the sucker. Besides variations in the dorso-ventral diameter of the
lumen at different levels, naturally to be expected from irregulari-
ties in the degree of contraction at the time of fixing, there are dif-
ferences due to peculiarities in
form of the suctorial wall itself.
Beginning at the oral aperture of
the sucker the lumen for some dis-
tance caudad maintains a fairly uni-
form dorso-ventral diameter, then
rather abruptly this becomes de-
cidedly increased. This increase is
due to a retraction in the dorsal
and in the ventral suctorial wall so
as to form what Shipley describes
as "dorsal and ventral valves pro-
jecting like tongues into the lumen, only directed backward " (fig. 179).
These transverse projecting tongues or ridges are not continuous
laterally; the interval thus left increases to a corresponding degree
the dorso-ventral diameter of the lumen at its lateral angles; the
form in transverse section of the lumen at the level where these
ridges are formed suggests to a slight extent the letter H (fig. 180).

Almost at once, however,
the dorso-ventrally ex-
panded lumen resulting
from the retraction of the
dorsal and the ventral suc-
torial walls, above described,
begins to contract and con-
tinues progressively to de-
crease to the level of origin
of the pouches. In this re-
gion the lumen becomes
very abruptly greatly nar-
rowed dorso-ventrally by the
projection upward into the
lumen from its dorsal wall of
a transverse tongue-like ridge recalling a similar structure in Ps. stan-
leyii (fig. 179). In transverse sections the first portion of the suc-
torial lumen is a transverse slit, the second portion is at first fusiform
or diamond-shaped in outline, eventually becoming crescentic with
the concavity of the crescent ventrad (fig. 181). By the projection

Fig. 180.

upward of the tongue-like transverse ridge the horns of the cres-
eentic lumen become partly separated from the body, so that at this
level the lumen, as in Ps. stanleyii, somewhat suggests the letter H.
The terminal portion of the suctorial lumen also appears as a trans-
verse slit in section.

The lumen of the sucker and that of its pouches is lined with a
cuticle-like layer; in the first portion of the sucker the cuticle is beset
with conical papillae of moderate size.

From its point of origin the esophagus passes at first ventro-caudad,
then at about its equator it bends abruptly and sharply dorsad with
a tilt caudad. Viewed ventrally the esophagus is apparently much
shorter than the sucker, but in sagittal plane it is at once seen that
it slightly exceeds the length of the latter. The esophageal wall is
muscular throughout, but in the caudal half the muscular layer is par-
ticularly well devel-
oped, attaining a
maximum thickness
of about 67/i. Be-
cause of the obliqui-
ty of this portion of
the esophagus cer-
tain of the transverse
sections cut its wall
almost tangentially,
and consequently
the observer is read-
ily misled into in-
terpreting such a
section as indicating
an enormously thick
muscular wall (fig.
183). Viewed ventrally, therefore, this portion of the esophagus
would have somewhat the appearance of a muscular bulb, such as
Shipley describes and pictures.

The first half of the esophagus is dilated in the dorso-ventral diam-
eter, but compressed from side to side. The esophageal lumen is
lined throughout with a rather thick cuticular layer.

The intestines spring from the lateral aspects of the caudal por-
tion of the esophagus. At first they arch caudo-laterad, the}' then
pass directly caudad in relation to, though at some distance from, the
dorso-lateral aspect of the body. They terminate by cecal extremi-
ties slightly caudad of the junction of the fourth with the caudal
fifth of the body length, or slightly caudad of the plane of the cephalie.
margin of the acetabulum, the right tube extending slightly farther
caudad than the left. In transverse section the ceca appear com-
pressed from side to side with proportionately a greatly elongated

Fig. 181.

dorso-ventral diameter, the former bearing a relation of 1 to about
5 of the latter.

Genital system. — With the exception of the vitellaria and the
eopulatory apparatus the genital organs are situated in the inter-
cecal area.

Male organs. — The testes are in the axial region of the body,
though somewhat nearer the venter than the dorsum; the superior
testis is in the equatorial zone of the worm, occupying in this region
about one-seventh of the body length; the inferior or caudal testis
also occupies about one-seventh of the body length in a zone con-
tiguous to and immediately caudad of that of the superior testis.
Both testes are deeply indented by fissures and sulci in such a man-
ner as readily to lead to the erroneous interpretation that the testes
are side by side in close apposition, particularly as the caudal asj>ect
of the superior and the cephalic aspect of the inferior testis are in
close apposition and their contiguous lobes marked off by their fis-
sures and sulci over-
lap slightly, and con-
sequently portions of
both testes appear in
certain of the trans-
verse sections (fig.
185).

A vas efferens
springs from the
dorso-cephalic aspect
of each testis (fig. 184) ;
then it passes cephalo-
dorsad, that from the
superior testis tending
to the left and that
from the inferior to the
right of the median
sagittal plane. At
about the level of the
cephalic aspect of the
superior testis the left
yas efferens approaches close to the mesial aspect of the left
intestine; it then curves inward as it courses cephalo-dorsad
and very soon enters the complex of the coils formed by the vas
deferens amongst which it can not be followed. The right vas,
as already stated, passes cephalo-dorsad and to the right immediately
after its origin from the caudal testis. It skirts the caudal aspect
■of the superior testis, then after reaching the right caudo-dorsal
aspect of this testis it bends and proceeds almost directly cephalad
m close relation to the right dorso-lateral aspect of the superior testis

■ft. a. *ffu

Fig. 182.

until it reaches a level a little short of that at which the left vas
efferens originates, when it begins to tilt dorsad, at the same time
becoming considerably distended with spermatozoa (fig. 184).
Shortly beyond this point it begins to wind and enters the coil-
complex of the vas deferens, beyond which point it is impossible to
trace it satisfactorily. The two vasa efTerentia presumably enter
into the formation of the vas deferens and it would appear, though
this can not be made out satisfactorily in this series of sections, as
if each, before their union, became considerably distended and coiled,
their coils being indistinguishable from those of the first portion of
the vas deferens.

The vas deferens presents at first a thin-walled intricately coiled

dilated portion or
vesicula seminalis.
These coils are in
the intercecal space,
elongated from ven-
ter to dorsum and
dorsum to venter and
winding cephalad;
they are succeeded
by a muscular-walled
segment or pars mus-
culosa, the wall of
which, measured at a
favorable point, was
about 60// thick.
This portion is rela-
tively short, un-
coiled, though mak-
ing about one spiral
turn in its somewhat
sinuous course ventro-cephalad. In its turn, at about the level of the
esophageal fork, this is abruptly succeeded by a short greatly dilated
portion with muscular walls intermediate in thickness between those of
the vesicula and pars musculosa. This portion, which Shipley inter-
preted as the vesicula seminalis and which corresponds to the vesi-
cula seminalis interna of the forms with a cirrus pouch, appears
homologous with the type of pars prostatica of Homalogaster pMlip-
pinensis and that of Ps. stanleyii, more particularly the latter, in
which the prostatic cells are few, while in this (Watsonius watsoni)
species no prostatic cells at all can be distinguished. It is abruptly
succeeded by a thin walled duct of a much smaller caliber which
with the terminal portion of the uterus close to its ventral aspect at

LJ*JKJ

once plunges into a sharply delimited muscular mesh as it proceeds
eephal< >-ven1 rad. This is relatively long and eventually opens at the
vertex of a genital papilla by a small pore separate from and imme-
diately cephalad of the opening of the metraterm. This terminal
portion of the vas deferens is homologous with the ductus ejacula-
torius. It may be well to describe at this point what may be desig-
nated as the copulatory apparatus.

In the median line of the ventral surface at a point about one-
fourth the length of the worm from its oral margin is a well-marked
ring-like elevation or bulging which encircles a second more sharply

Fig. 184

defined truncated cone-like bulging measuring about 225 \x from base
to vertex, about 600 p. in transverse diameter at the base, and about
375 /i at the vertex. The vertex of this second cone-like projection is
depressed or crateriform and may perhaps be regarded as the genital
atrium, from the dorsal wall of which the genital papilla projects.
These structures are well shown in surf ace view in figure 175 and in
transverse section in figure 182. The crateriform depression into which
the genital papilla projects is beset by numerous quite small papillae.
The form of the genital papilla can not be made out satisfactorily;

one gains the impression that it is a low, broad , rounded elevation. In
sections it may be seen that the internal structure of the genital
bulging is made up of a muscular mesh which is sharply delimited
from (ho body parenchyma by a well-defined curved (with convexity
dorsad) muscular layer of transverse, radiating, and vertical bundles.
It is this curved limiting layer (somewhat suggestive of a cirrus pouch)
that, as already mentioned, is pierced by the ductus ejaculatorius and
the terminal portion of the uterus or metraterm. The structure of
this copulatory apparatus suggests the probability that it may be
collapsible or retractable. The genital papilla is just caudad of the

level of the base of the
sucker (or origin of the

about 0.25 mm. in the transverse diameter. From its dorsal-cephalic
aspect (fig. 186) the oviduct takes origin. This passes directly dorsad
for about 150/z of its length and then bends caudad, almost immedi-
ately penetrating the cephalic aspect of the shell gland, at the same
time giving off Laurer's canal. The latter proceeds dorsad (fig. 187)
with but a slight inclination caudad and reaches the dorsum in about
the median line or only slightly if at all to the right of it, and at a point
in a plane marking the caudal limit of the ovarian zone and there-
fore only slightly caudad of that of the superior limit of the acetabular
zone (or superior margin of the acetabulum) (fig. 188).

Female organs. — The
ovary is in the axial
region of the body in
the intercecal area a
little nearer the left
than the right intes-
tine, caudo-dorsad of
the caudal testis and
dorso-cephalad of the
acetabulum and in a
zone directly caudad
of and slightly over-
lapping the zone of the
caudal testis (fig. 186)
superiorly and to a
slight degree overlap-
ping the acetabular
zone inferiorlv (caud-
ally). The ovary is
dorso-ventrally elon-
gate, measuring about
0.66 mm. in this and

esophagus).

Fig. 185.

The shell gland is placed directly dorsad of the ovary; the caudal
limit of its zone is the same as that of the ovarium, though because the
vertical diameter of the shell gland is slightly less than that of the
latter the zones of the two glands are not quite coextensive, the upper
(cephalic) limit of the shell gland being slightly below (caudad) of that
of the ovary. As already mentioned the oviduct penetrates the ce-
phalic aspect of the shell gland, in the substance of which it unites with
the common vitello-duct. The duct resulting from this union at once

Fig. 186.

forms a fusiform dilatation, the ootype, which passes ventrad with a
slight obliquity to the right and caudad in the major axis of the shell
gland. The continuation of the ootype becomes the uterus which
en terges from the ventral pole of the gland (fig. 187) . After emerging,
i the uterus passes vento-dextrad into the field between the ovary and
i the right intestine, but doubles back before it has quite reached the
frontal plane of the ventral margin of this intestine, and thus cora-
ipletes a loop directed ventrad. On reaching a point to the right of
the dorsal pole of the shell gland it dips caudad, the loop thus formed

coming into close relation to the right aspect of the dome of the excre-
tory vesicle. After forming this loop the uterus continues dorsad until
it reaches the field to the right of the line of Laurer's canal and dorso-
mediad of the right intestinal cecum, where it forms some coils and
begins its ascent cephalad, forming dorso- ventral loops, at first in the
field between the right intestine on the one side and the ovary and
shell gland on the other; later these loops are in the median line in
the intercecal area between the testes and the dorsum. The uterus
winds its way cephalad in this field, dorsad of the testes, until it

Fig. 187.

reaches the level of the caudal aspect of the vas deferens. Here it
tends ventrad to gain the ventral aspect of the vas deferens, arching
across the cephalic aspect of the superior testis. At the same time it
ceases to form coils, proceeding in a sinuous but direct course cephalo-
ventrad. From the level of the esophageal fork it is continued as the
metraterm, and, as already mentioned, t his pierces the muscular mesh
of the copulatory apparatus to open immediately caudad of the
ductus ejaculatorius at the vertex of the genital papilla.

The first loop formed by the uterus after its emergence contains a
considerable number of \ it el line cells, suggest ing the idea of a yolk

reservoir. It is probably on this account that Shipley was led into
interpreting this as a separate structure, to which he applied the name
"yolk reservoir." In the remaining loops a considerable number of
eggs were noted. Here and there in the coils dorsad of the testes
there are masses of spermatozoa in which some of the eggs are
embedded.

The vitellogene glands, consisting of a moderate number of loosely
aggregated, well-developed follicles, are situated in the fields between
the ceca and the ventro-lateral aspect of the body; that is, ventrad

Fig. 188.

and ventro-laterad of the ceca and ventro-laterad of the upper (ce-
phalic) portion of the acetabulum. Longitudinally they extend from
about the level of the esophageal fork to or slightly cauclad of the
level of the upper margin of the acetabular aperture. The gland of
the left side is a little shorter than that of the right. A duct of con-
siderable caliber, distended with yolk cells, leaves the gland of each
side — that of the left at a point slightly cephalad of the superior
margin of the ovary; that of the right at about the level of the ootype.
These duds, the transverse vitello-ducts, pass dorso-mediad and more
i or less caudad ventrally of the intestinal ceca to unite close to the

L>:io

caudal aspect of the shell gland. From their point of union, which is
not dilated into a reservoir, a common vitello-duct arises and passes
very obliquely dorso-cephalad and almost at once penetrates the
shell gland. The common, like the transverse ducts, is distended
with yolk cells and at first is of about the same caliber as the latter
but as it enters the substance of the shell gland its caliber becomes
rapidly reduced in diameter. As has already been stated, it joins
with the oviduct to form the ootype.

Excretory system.— The excretory vesicle is in the caudal pod
tion of the body, dorso-cephalad of the acetabulum. It is relatively
small; its dome extends a short distance cephalad into the caudal

portion of the intercecal
space, attaining the level
at which the vitello-ducts
unite; caudad it extends
to about the level of the
upper margin of the ace-
tabular aperture. Here it
gives off a thick-walled
duct which passes dorso-
caudad to open on the
dorsum, apparently
slightly to the left of the
median line, at a point in
a plane slightly cephalad
of that of the o wer margin
of the acetabular aperture,
and therefore at some con-
siderable distance caudad
of the pore of Laurer's
canal. The excretory duct is lined with a cuticular layer. Excretory
canals are seen to enter the excretory vesicle, but they can not be
satisfactorily traced.

ILLUSTRATIONS.

Fig. 175— Ventral view, X about 4. (After Shipley, 1905, fig. 1.)

Fig. 176.— Profile view, X about 4. (After Shipley, 1905, fig. 4.)

Fig. 177. — Ventral projection (diagrammatic) to show internal
anatomy: d. e., ductus ejaculatorius; es., esophagus ;e. g., esophageal
ganglion; g. a., genital atrium, with openings of ductus ejaculatorius
(upper pore) and metraterm (lower pore) ; %., intestinal ceca; o. s.,
oral sucker; ov., ovary; p. m., pars musculosa; p. p., (?) pars pros-
tatic^; s. g., shell gland (dorsally of ovary) ; s. p., suctorial pouch;
t., testes; t. vd., transverse vitello-ducts; ut, uterus; v. e. d., right
vas efferens; v. e. s., left vas efferens; v. g., vitellaria; v. s., vesicula
seminalis. Enlarged. Original.

Fig. 189.

231

Fig. 178. — Ventral projection of oral sucker (o. s.), suctorial pouches
(s.p.), and portion of esophagus (es.). a-a, b-b, c-c, planes of section.
Enlarged. Slightly diagrammatic. Original.

Fig. 179. — Profile projection of oral sucker (o. s.), suctorial pouch
of left side (s. p.), and esophagus (es.). Shows also the position of
the genital atrium (g. a.), a-a, b-b, c-c, d-d, planes of section.
Slightly diagrammatic. Enlarged. Original.

Fig. 180. — Transverse section through plane a-a figs. 178 and 179.
Shows oral sucker (o. s.) ; H -formed lumen of oral sucker (with
papillae) at this level. Enlarged. Original.

Fig. 181. — Transverse section through plane b-b figs. 178 and 179.
Shows crescentic lumen of oral sucker (o. s.), with transverse tongue-
like ridge projecting upward into it. Shows also perisuctorial space
(p. s. sp.) with ventral mesenterial banci (m. b.). Enlarged. Original.

Fig. 182. — Transverse section through plane c-c figs. 178 and 179.
Shows genital bulging with genital atrium (g. a.) beset with papilke;
the genital papilla (g. pap.) with opening of the ductus ejaculatorius;
the limiting muscular layer of the copulatory apparatus ; the esoph-
agus (es.), suctorial pouches (s. p.), and extensions of the peri-
suctorial space (p. s. sp.) inclosing the pouches. Enlarged. Original.

Fig. 183. — Transverse section through plane d-d fig. 179. Shows
metraterm (va.), ductus ejaculatorius (d. e.) just after its departure
from the (?) pars prostatica (p. p.), which contains a mass of sperma-
tozoa (sz.), and the esophagus (es.) with its dorsal wall cut tangentially,
..giving the impression of great thickness. Enlarged. Original.

Fig. 184. — Transverse section at level of origin of left vas efferens
(v. e. s.). Shows terminal portion of right vas efferens (v. e. d.) dis-
tended with spermatozoa, the superior testis (t.), uterus (ut.), intes-
tines (%.), and vitellaria (v. g.). Enlarged. Original.

Fig. 185. — Transverse section through overlapping portions of the
superior testis (t. s.) and inferior testis (t. d.). Also shows uterus
(ut.), intestine (%.), vitellaria (v. g.), and right vas efferens (v. e. d.).
Enlarged. Original.

Fig. 186. — Transverse section through caudal extremity of inferior
testis (t d.). Shows ovary (ov.) with oviduct (ov. d.), uterus (ut),
intestines (i.), and vitellaria (v. g.). Enlarged. Original.

Fig. 187. — Transverse section immediately above level of superior
margin of acetabulum. Shows ovary (ov.), shell gland (s. g.) with
ootype and emerging uterus (ut.), Laurer's canal (L. c), intestines
(i.), and vitellaria (v. g.). Enlarged. Original.

Fig. 188. — Transverse section at level of the pore of Laurer's canal
(L. c). Shows acetabulum (ac), formation of common vitello-duct
(c. vd.) by the union of the transverse vitello-ducts (t. vd.), loop of
uterus (ut), intestines (i.), and vitellaria (v. g.). Enlarged, Original.
13893— Bull. 60—10 15

232

Fig. 189. — Transverse section at level of excretory pore (ex. p.).
Shows acetabulum (ac.) with projecting rim of aperture. Enlarged.
Original.

PSEUDOCLADORCHIS Daday, 1907.

Generic diagnosis.** — Cladorchiinx (p. J 09): Body rather cylindrical, venter
rather convex, dorsum convex, cephalic end rather attenuate, caudal end rounded,
sides rounded. Ventral pouch absent. Acetabulum ventro-subterminal, large; aper-
ture circular, medium, directed slightly ventrad. Genital pore without sucker.
Excretory pore postvesicular, in equatorial zone, caudad of pore of Laurer's canal.
Oral sucker with 2 sphincters, one anterior, the other esophageal, and with paired not
very well-developed evaginations; esophagus springs from caudal end of sucker and
is without muscular thickening; ceca straight or slightly wavy, rather long, end post-
equatorial, preacetabular.

Male organs: Testes 2, much smaller than acetabulum, elongate, lobate, fields sepa-
rate or abut, zones overlap or nearly coincide, preovarial, quite removed from acetab-
ulum, never in caudal third; cirrus pouch present.

Female organs: Ovary and shell gland posttesticular; vitellaria never pretesticular,
are close to ceca in cecal to postcecal zones, chiefly posttesticular, "branched, tree
like;" uterus chiefly in intercecal field, with tendency to transverse slings, ventral
of cecal plane; Laurer's canal chiefly prevesicular, does not cross excretory canal or
vesicle.

Type species. — P. q/lindricus (Dies., 1836).

PFENDERIUS,l> new genus.

Generic diagnosis. — Cladorchiinx (p. 169): Body rather conical, dorsum convex,
venter slightly convex, cephalic end attenuates gradually but considerably, caudal
end slightly, sides rounded. Ventral pouch absent. Acetabulum terminal, with
projecting margins, relatively large, its shallow cavity provided with prominent
papillae, aperture large. Genital pore without sucker. Excretory pore in vesicular
zone, in acetabular zone, postcecal, caudad of pore of Laurer's canal. Oral sucker
with one (anterior) sphincter, and with a pair of well-developed evaginations; esoph-
agus springs from ventral aspect of base of sucker and is without muscular swelling;
ceca wavy, long, end postequatorial in acetabular zone.

Male organs: Testes 2, very much smaller than acetabulum, lobate, fields separate,
zones coincide, considerably removed from acetabulum, preovarial, equatorial; cirrus
pouch present.

Female glands: Ovary and shell gland distinctly and considerably posttesticular:
vitellaria in cecal zone, from bifurcation to end of ceca, with sparsely scattered small
follicles; uterus intercecal, with marked tendency to dorso- ventral slings; Laurer's
canal entirely preexcretory, does not cross excretory canal or vesicle.

Eggs: Operculated, rather numerous.

Type species.— Pfenderius papillatus (Cobbold, 1882) as represented by U. S. N. M.
2554.

Habitat. — Colon of elephants, India.

PFENDERIUS PAPILLATUS (Cobbold, 1882) Stiles & Goldberger, 1910.

[Figs. 190 to 202.]

1882: Amphist. papillatum Cobbold, 1882a, 240-242, figs. 10, pi. 24, fig. 11 (in
Elephas indicus). — Braun, 1892a, 580, 663; 1893a, 874, 905; 1893d, 466.—
Fischoeder, 1902a, 49 (in Elephas indicus; India).— Sonsino, 1895, 184,
187, figs. 4-5.

Specific diagnosis. — Pfenderius (p. 232) : Body 4.5 mm. to 5.5 mm. long, 2.5 to 2.75
mm. broad, 1.7mm. thick; pearl tint or opaque olive green in color (alcohol specimen);

"Based on Daday, 1907.

6 Dedicated to Dr. Charles A. Pfender, in recognition of his work on the Index-
Catalogue of Medical and Veterinary Zoology.

233

rather conical, but bent slightly ventrad, greatest diameter between third and fourth
fourth of body, attenuating gradually and considerably cephalad, slightly caudad;
dorsum convex longitudinally and transversely, venter slightly convex from side to
side, straight to slightly convex longitudinally; lateral margins curved both longi-
tudinally and in transverse plane; transverse section of body transversely elliptical
to circular. Genital pore in esophageal zone about one-fourth of body length from
oral margin. Acetabulum terminal, with projecting margin, about 1.7 mm. in trans-
verse, 1.4 mm. in dorso-ventral diameter, aperture directed slightly ventrad, 1.28 by
1.2 mm., cavity shallow, surface with prominent papillae which attain 90/i long by
60/i broad at base. Mouth terminal at bluntly pointed cephalic extremity, with
small papillae; oral sucker with 2 caudal lateral bulbs, and with a well-defined sphincter
about 120 to 140/t from oral margin; perisuctorial space very narrow; esophagus mark-
edly curved dorsad, convexity ventro-caudad ; ceca wavy, extend to acetabular zone,
then curve slightly cephalad and terminate. Excretory pore about dorso-median,
slightly caudad of preacetabular transverse plane; excretory duct almost transverse;
excretory vesicle well developed, dorsal of cephalic half of acetabulum.

Male organs: Testes equatorial, ventral of ceca, fields separate, zones nearly coin-
cide; irregularly globular, 0.4 mm.; vasa efferentia rather short, run dorso-cephalad,
unite about on pretesticular plane; vesicula seminalis coiled; cirrus pouch pyriform,
large, 0.44 mm. long, greatest diameter 0.32 to 0.34. mm., muscular wall 0.12 mm.;
ductus hermaphroditicus present.

Female organs: Ovary posttesticular, intercecal, preacetabular, nearly or quite
median, at junction of equatorial and caudal third of body; shell gland caudo-lateral
of ovary; vitellaria with sparsely scattered small follicles, external, ventral, and to
some extent dorsal of ceca, in cecal zone from bifurcation to end of ceca; uterus forms
dilated dorso-ventral slings in suctorial field, to near cirrus pouch, then runs more
directly cephalo- ventrad to ductus hermaphroditicus; Laurer's canal runs dorsally in
curve (convexity caudad) in zone of shell gland, to pore slightly dextrad of median
line, about 0.5 mm. cephalad of excretory pore.

Eggs: Rather numerous, elliptical, about 150 by 70/x, operculated at one pole and
bearing short knob at the opposite pole.

Type.— Unknown. Cotypes U.S.N.M. 1721, 2554, 5777.

Habitat. — Colon of elephant (Elephas indicus; India).

Source of material. — The material consists of 7 specimens which
were found in 3 bottles, as follows: 5 specimens in bottle No. 5777, 1
in bottle No. 2554, and 1 in bottle No. 1721.

The labels in these bottles bear the following data: ''Name Am-
pJiistomapapillatum; Host Elejyhas indicus ;hoca,\ity India; Determined
by T. S. Cobbold; Date 1882; Presented by T. S. Cobbold; Date, 22,
XII, 1882." Our material therefore represents Cobbold's original
specimens.

Historical review.— Cobbold (1882a, 224, 240-242, fig. 8, pi.
24, fig. 11) originally described this species with the following
diagnosis :

Body of a bright pink color, smooth, conical, bluntly pointed in front, broadly
rounded off behind, with fine and regularly disposed transverse rugae forming distinct
rings in the region of the head. Caudal sucker subterminal, very large, its cup being
armed with numerous large fungiform papillae, closely set, and regularly disposed over
the entire surface of the concavity. Reproductive papillae placed well forward.
Length, one-sixth to one-fourth of an inch. Breadth, one-eighth to one-seventh of an
ch. Hab. Large intestine of Elephas indicus.

234

Fig. 190.

Cobbold's figure 11, drawn from a fresh specimen, shows certain
anatomical del ails. The outline is rather different from that of our
specimens. The position of the genital pore agrees fairly well, though

not exactly, with its position in our material.
The acetabulum and its aperture are relatively
large. No indication of suctorial evaginations is
given ; the esophagus is short ; the ceca are long,
not wavy, and end in the acetabular zone. The
testes are figured as relatively much larger than
those in our specimens, and as having zones
winch overlap slightly, fields which coincide.
This latter condition does not agree with our
material, which distinctly shows coinciding tes-
ticular zones and separate fields.

Braun (1892a, 580, 663; 1893a, 874, 905)
refers to the papillae in the acetabulum, to the
short esophagus, and mentions the worm as a
parasite in the colon of EJephas indicus. His
later reference (1893d, 466) merely cites the worm as a parasite
of the elephant.

Sonsino (1895, 184, 187 (6, 9), figs. 4-5) figures Amphist. papillatum
with an outline so very distinct from Cobbold's figure that a ques-
tion might arise as to whether he is dealing with the same species.

Fischoeder (1902a, 49; 1903h, 631) adds no new observations.

In view of the position of the testes, as figured
by Cobbold, the question naturally arises as to
whether we are dealing with the same or with a
different species. As our material represents some
of Cobbold's material, and as various authors
have been misled in interpreting the relative posi-
tion of the testes, especially in the case of rather
thick trematodes, we hesitate to draw the con-
clusion that our material represents anundescribed
species. Should more of Cobbold's original ma-
terial be found, or should the Indian elephant
prove to harbor another amphistome winch agrees
with Cobbold's illustration, it will then become
necessary to accept the name papillatum for that
form and to recognize our material as representing a new species.

Fig. 191.

EXTERNAL CHARACTERS.

Size. — The specimens, measured in alcohol, varied in length be-
tween 4.5 and 5.5 mm. and in greatest width between 2.5 and 2.75
mm. They were, however, more or less shrunken and had evidently

237

undergone some distortion, so that these measurements must be
regarded only as approximations to the original.

After sectioning, one of the specimens measured 4.14 mm. in length,
2 mm. in greatest transverse, and 1.70 mm. in greatest dorso-

ventral diameter.

Color.— Five of the specimens were of a pearl tint. These were
slightly translucent, enabling the observer to determine the position
of the testes. The remaining two specimens were of an opaque olive-
green color.

Form.— As has been stated, the specimens were obviously shrunken
and variously distorted.

One of them, however, had undergone these changes to so slight a
degree as to serve fairly well for the purpose of this description.

This worm (shown in figs. 190, 191)
appeared somewhat conical in form,
but bent slightly ventrad. Its great-
est width was at the junction of the
third with the terminal fourth of the
body length.

From this region the body tapers in
both directions; gradually and con-
siderably toward the bluntly pointed
oral extremity, slightly in the direc-
tion of the caudal extremity. The
dorsum is arched both longitudinally FlG* 194'

and transversely; the venter is slightly convex from side to side,
but straight or slightly concave in a longitudinal direction. The
lateral margins are curved slightly both longitudinally and in a
transverse plane. In transverse section the outline of the body is
transversely elliptical to circular.

Surface. — The surface cuticle is without spines or scales. It is
marked, however, by fine transverse striations. The bluntly pointed,
attenuated extremity presents the oral aperture, which is encircled by
a narrow ridge marked off from the surface by a narrow, fairly deep
groove (fig. 194). Concentric with this and about equally spaced
there are observed four shallow grooves (fig. 194).

Genital pore. — In the median longitudinal line of the venter, about
one-fourth of the body length from the oral margin, there appears a
slight, globular bulging of relatively small diameter, which presents the
aperture of the genital pore. This pore leads into an elongate irregu-
larly cylindrical chamber about 0.28 mm. long, from the fundus of
which there arises a papilla, about 105^ in height and about 120/* in

238

diameter at the base, which almost fills the corresponding portion of
the lumen of this chamber. At the vertex of this (genital) papilla is
the porus hermaphroditicus.

At the caudal extremity, encircling the aperture of the acetabulum
and at a distance of about 0.20 mm. therefrom, there is a shallow cir-
cular groove. Tins groove marks the region at which the acetabulum
emerges from the embrace of the caudal portion of the body of the
worm. The portion of the caudal extremity of the worm between this
groove and the margin of the acetabular aperture, and having some-
what the appearance of a collar, is formed by the projecting portion
of the acetabulum.

Acetabulum. — The acetabulum occupies the caudal extremity of the
body, and, as already described, a portion emerges at the surface at the

Fig. 195.

caudal extremity of the worm and forms a well-defined rim around the
crateriform cavit}', somewhat as in Ps. stanleyii, but without the deep
narrow groove of the latter to mark it off. Measured from a recon-
struction of a sectioned specimen the acetabulum was about 1.70 mm.
in greatest transverse and 1.40 mm. in greatest dorso-ventral diame-
ter, with an aperture 1.28 mm. in greatest transverse and 1.20 mm.
in greatest dorso-ventral diameter. The cavity of the acetabulum
is shallow, and this surface is beset by teat-like papillje, some of which,
in sections, measured 90/* in height and 60u in diameter at the base.

239

INTERNAL ANATOMY.

Digestive tract. — The bluntly-pointed cephalic extremity of the
worm is pierced by the oral aperture. This aperture is transversely
elliptical, and its margins are beset by small conical papillae (fig. 194).
This aperture leads directly into the oral sucker, a relatively large
muscular apparatus (figs. 192, 193, 196, 197). The caudo-lat-
eral aspects of the sucker are prolonged somewhat caudad of the
transverse plane of its base into the forms of lateral bulbs. Measured
from a reconstruction of one sectioned specimen, its greatest longi-
tudinal axis was 0.64 mm., the greatest dorso-ventral diameter about
0.52 mm., and the greatest transverse diameter 0.78 mm. Measure-
ments from sagittal sections of another specimen gave 0.66 mm. for
the greatest longitudinal axis, 0.70 mm. for the greatest dorso-ventral,
and about 0.72 mm. for the greatest transverse diameter. The
bulbs measured from the
reconstruction were about
0.40 mm. in greatest dorso-
ventral and 0.30 to 0.34
mm . in greatest transverse
diameter and extended
about 60/z caudad of the
base of the sucker.

The body of the sucker
appears to be inclosed in
a very narrow space (fig.
196) and appears to be re-
tained in its position by
attachments at its poles
and by dorso-ventral mes-
enterium-like and muscu-
lar bands. The long axis of the sucker coincides with the long
axis of the body of the worm. In median sagittal section, the
sucker has something of an oval outline with the blunt end of the
oval corresponding to the base. About 120/* to 140/* caudad of
the oral margin there is observed in the muscular wall a well-defined
sphincter-like muscular bundle measuring about 100/4 in thickness.
Caudad of this sphincter the muscle walls maintain a substantially
uniform thickness throughout up to the point of formation of the
canal leading into the esophagus. Cephalad of the sphincter, how-
ever, the thickness of the walls becomes progressively and rapids-
less, so that the muscular rim forming the oral aperture as it projects
on the surface is relatively thin and sharp (fig. 196).

Fig. 196.

240

In transverse section the outline of the sucker is that of a hlunt
ellipse with its major axis in the transverse diameter of this region
of the worm. Studied in median sagittal section, the base of the
sucker appears slightly beveled at the expense of its ventral aspect,
from which region the esophagus is seen to take its departure. On
each side of and closely embracing this portion of the esophagus
the caudo-lateral projections of the sucker or suctorial bulbs may
be seen.

In form these bulbs are irregularly globular. Their walls,
considerably thinner than those of the body of the sucker, are of
relatively loose muscular mesh-like structure. The lumen of the
sucker is a transversely wide, dorso-ventrally narrow space; it is

Fig. 197.

directly continuous with the irregular and variable lumen of the
bulbs. Both are lined by a thin cuticle-like layer.

The esophagus, as already described, takes its departure from the
ventral aspect of the base of the sucker. It passes at first caudad,
describing a slight curve in its course with its convexity ventrad,
then turns almost directly dorsad, and having reached a point about
one-fourth the body length from the oral margin and about one-
fourth the dorso-ventral diameter of the worm in this zone
from the dorsum the esophagus curves directly caudad and almost
immediately forks into two lateral intestinal tubes. This fork is
slightly caudad of the genital pore. The intestinal tubes from their
point of origin pass at first latero-caudad then in dorso-ventrally
wavy course caudad. They finally terminate by bending abruptly

241

ventro-cephalad in a hook-like form at a point in a transverse plane
slightly caudad of that of the cephalic margin of the acetabulum.

As in the other species of this group, the esophagus is inclosed in
a well-marked layer of cells. The lumen of the esophagus is lined
by a cuticle-like layer, which ceases abruptly at the fork. The
intestines are lined by an epithelial cell layer.

Genital system. — With the exception of the vitellogene glands
and the testes the genital organs are situated in the intercecal area.

Male organs. — The testes are situated in the equatorial zone on
each side of the median sagittal plane and ventrad of the corre-
sponding intestine. They are irregularly globular in form, measuring
about 0.40 mm. in diameter, but with their vertical diameter a
little longer than either the transverse or dorso-ventral. From their

a 4.

Fig. 198.

• dorsal aspects, slightly above their equator, there emerges from each
a vas efferens. These pass in a curved course dorso-cephalad and
i toward the median line to unite at about the level of the cephalic
i margins of the testes to form the vas deferens. The vas deferens
i consists first of a thin-walled, dilated, complexly coiled vesicle. This
I terminates abruptly in a short narrow duct, which pierces the very
l thick walled cirrus pouch and is continued within the latter and
i almost fills its lumen as a thin-walled duct (vesicula seminalis interna)
I to the cirrus; in a series of sagittal sections the cirrus is distinctly

242

seen in an invaginated condition, but with its terminal (distal)
portion pointed outward (not invaginated) ; the canal formed by
the invaginated portion unites distally with the metraterm to form
a genital cloaca apparently representing a ductus hermaphroditicus,
which opens on the apex of the genital papilla. The cirrus pouch
is directed obliquely ventro-cephalad ; in form it suggests that of
an Indian club. Its walls become gradually less thick, this reduction
taking place mainly at the expense of the (internal or) longitudinal
layer, and its diameter becomes progressively reduced as it passes
ventro-cephalad. Its greatest diameter, measured in sections, varied
in two specimens from 0.32 mm. to 0.34 mm., with a thickness of
wall of 0.12 mm. In length it measured about 0.44 mm. The
ductus hermaphroditicus, formed as already described, pierces the
axial region of the genital papilla, on the vertex of which it opens
as the porus hermaph-
roditicus. The pres-
ence of a distinct pars
prostatica can not be
definitely asserted, but
in two places (within at
the distal end of the
cirrus pouch, and with-
out at the proximal
end) are groups of
nuclei which may come
into consideration in
this connection if well-
preserved material can
be obtained.

The wall of the cham-
ber surrounding the genital papilla is provided with a well-developed
muscle-complex, suggestive of the genital sucker figured by Fischoeder
for several species of Cladorchis, but the muscles are not arranged
in so distinctly acetabular-like manner as Fischoeder figures for the
species he discusses ; it therefore can not be stated that Pfenderius
pa-pillatus possesses a true genital sucker.

Female organs. — The ovary lies in about the median line of the body
somewhat nearer the dorsum than the venter, posttesticular in a
plane a little above that of the cephalic margin of the acetabulum—
that is, about at the junction of the middle with the caudal third
of the body. The oviduct emerges from the dorsal aspect of the ovary,
passes at first directly dorsad, then curves caudad tow ard the dorsal
aspect of the shell gland (fig. 201). The shell gland lies close to
the right caudo-lateral aspect of the ovary and just at about the

Fig. 199.

243

level of the cephalic margin of the acetabulum. On its dorso-caudal
aspect it is penetrated by the oviduct and on its caudal aspect by
the vitello-duct. These ducts unite to form the ootype, the con-
tinuation of which pierces the surface of the gland and emerges from
its ventro-cephalic aspect as the uterus. The uterus, immediately
after its emergence from the shell gland, describes numerous compact
coils in front of and to the right of the shell gland, and then, as it
proceeds cephalad, to the front (ventrad of) and to the right of the
ovary. Beyond this point it forms some dorso-ventral coils in the
space between the ceca. These coils are dilated and filled with eggs.
The uterus then continues in the axial region of the body in a more
direct course cephalad. Part of its course is through the space
between the caudal portions of the testes, tilting later nearer the
dorsum of the body to enter the interspace between the intestines,

Fig. 200.

Jltthen it passes beneath the arch of union of the vasa efferentia to
^;iin the ventral aspect of the cirrus pouch. In the remainder of
its course it maintains this relation to the male duct forming but
few coils, and terminates by uniting with the male duct to form
the ductus hermaphroditicus.

Laurer's canal takes its departure from the oviduct at a point
j;< close to the dorsal aspect of the shell gland. It then passes dorsad
i describing a curve in its course with its convexity caudad and opens
Icon the dorsum somewhat to the right of the median line about
! (0.54 mm. cephalad of the excretory pore in a transverse plane slightly
i hove that of the cephalic margin of the acetabulum.

244

The vitellogene glands consist of sparsely scattered insignificant
follicles, irregularly grouped to the external, ventral, and to some
extent dorsal aspect of each of the intestinal ceca. Longitudinally
they extend from about the level of the esophageal fork to the level
of the cecal ends of the intestines. From each of the glands a duct
passes more or less transversely inward ventrally of the intestines
to unite near the ventro-caudal aspect of the shell gland. From
their point of union a duct passes dorsad, skirting the caudal aspect
of the shell gland which it penetrates and in the substance of which
it unites with the oviduct as already described.

Eggs. — Eggs were observed crowded together in some of the
proximal coils of the uterus. They appeared to be elliptical in form,

Fig. 201.

and 2 which appeared to have been sectioned in a favorable plane,
measured each 150/x by 75/t in diameter. One end is operculated,
and the opposite pole bears a short mammillate knob.

Excretory system. — The excretory system is well developed.
An excretory vesicle of moderate size is situated dorsad of the dome
of the acetabulum. From its dorsal aspect a little caudad of its
equator a duct originates and passing directly dorsad opens in
about the median line of the dorsum slightly caudad of the plane of
the cephalic margin of the acetabular aperture and about 0.54 mm.
caudad of the aperture of Laurer's canal. This excretory duct is
about 0.24 mm. in length.

245

ILLUSTRATIONS.

Fig. 190.— Ventral view. Enlarged. Original.

Fig. 191.— Profile view of same. Enlarged. Original.

Fig. 192. Ventral projection to show internal anatomy, a-a, b-b,

c-c, d-d, e-e, f-f, planes of section; ac, acetabulum; c p., cirrus
pouch; es., esophagus; %., intestine; ov., ovary; o. s., oral sucker; s. p.,
suctorial pouch; s. sph., suctorial sphincter ; s. g., shell gland; t, testes;
ut, uterus; v. e., vasa efferentia. Slightly diagrammatic. Enlarged.
Original.

Fig. 193. — Profile projection of same, a-a, b-b, c-c, d-d, e-e, f-f ,
planes of section, ac, acetabulum; g. p., genital pore; c. p., cirrus
pouch; es., esophagus; ex. p., excretory pore; ex. v., excretory vesicle;

Fig. 202.

■')., intestine; L. c, Laurer's canal; ov., ovary; ov. d., oviduct; o. s., oral
sucker; s. p., suctorial pouch; s. sph., suctorial sphincter; s. g., shell
•land; t., testes; ut., uterus; v. e., vasefferens; v. s., vesicula seminalis.
lightly diagrammatic. Enlarged. Original.
Fig. 194. — Oral extremity seen from above and in front to show
concentric grooves (slightly exaggerated) around oral aperture.
[Compare fig. 196. Enlarged. Original.

Fig. 195. — Sagittal section through cirrus pouch (c. p.). Shows
aalso the vesicula seminalis interna (v. s. %.), the small cirrus (c), the
ductus hermaphroditicus (d. 7i.), the genital papilla (g. pap.), the

246

metraterm (va.), the uterus (id.), a loop of the vesicula seminalis
externa (v. s.), some loops of the uterus (id.), and a section of the
intestine (?'.). Slightly diagrammatic. Enlarged. Original.

Fig. 196. — Sagittal section through oral extremity. - Shows the oral
sucker (o. s.), the suctorial sphincter (s. spli.), the mouth (m.), and the
perisuctorial space (p. s. sp.). Enlarged. Original.

Fig. 197. — Transverse section at a-a figs. 192 and 193. Shows oral
sucker (o. s.) and perisuctorial space (p.s.si).). Enlarged. Original.

Fig. 198. — Transverse section at b-b figs. 192 and 193. Shows oral
sucker (o. s.), the suctorial pouches (s. p.), entrance to the esophagus
(es.), and the perisuctorial space (p. s. sp.). Enlarged. Original.

Fig. 199. — Transverse section at c-c figs. 192 and 193. Shows the
thick, muscular cirrus pouch (c. p.), vesicula seminalis interna (v. s.i.),
the intestines (i.), uterus (ut.), and vitellaria (v. g.). Enlarged.
Original.

Fig. 200. — Transverse section at d-d figs. 192 and 193. Shows the
testes (t.) and their relation to the intestinal ceca (i.) at this level,
the uterus (ut.), and vitellaria (v. g.). Enlarged. Original.

Fig. 201. — Transverse section at e-e figs. 192 and 193. Shows
caudal portion of ovary (ov.), cephalic portion of shell gland (s. g.),
the oviduct (ov. d.), Laurer's canal (L. c), some uterine coils (ut),
intestinal ceca (i.), vitellaria (v. g.). Enlarged. Original.

Fig. 202. — Transverse section at/-/ figs. 192 and 193. Shows ex-
cretory vesicle (ex. v.) and pore (ex. p.) and acetabulum (ac), with
some of its papilla? (ac. pap.). Enlarged. Original.

Genus MICRORCHIS Daday, 1907.

Generic diagnosis.0 — Cladorchiinse (p. 169): Body elongate, venter concave, dor-
sum convex, gradually attenuate from acetabulum to mouth, caudal end rounded (on
ventral view), sides rounded. Ventral pouch absent. Acetabulum large, terminal,
aperture medium, directed ventrad. Genital pore without sucker. Excretory pore
prevesicular, equatorial, very close to and at left of pore of Laurer's canal. Oral sucker
with well-dcveioped sphincter and with pair of evaginations; esophagus springs ven-
trally from oral sucker, cephalad of evaginations, and has a distal muscular thickening,
ceca straight, long, end far postovarial, but preacetabular.

Male organs: Testes 2, very much smaller than acetabulum, unbranched, somewhat
irregular in outline, fields apparently overlap, zones separate, preovarial, preequatorial,
far removed from acetabulum, intercecal; cirrus pouch present.

Female organs: Ovary and shell gland preequatorial, at equator of vitellaria, post-
testicular; vitellaria near ceca, equatorial, nearly one-third as long as body, "branched,
tree-like;" Laurer's canal prevesicular.

Type. — M. megacotyle (Diesing, 1836).

Genus CHIORCH1S Fischoeder, 1901.

Generic diagnosis. 6 — Cladorchiinx(\>. 169): Body straight, venter flat, dorsum con-,
vex, cephalic end attenuate, caudal end rounded, sides sharp, not divided by con-<
striction. Ventral pouch absent. Acetabulum distinctly ventral, relatively small,
extends beyond surface, margin raised, aperture large. Genital pore without sucker,

"Based on Daday, 1907.

b Based on Fischoeder, 1903h.

247

ductus hermaphroditic™ present. Excretory pore prevesicular, preacetabular,
caudad of Laurer's canal. Oral sucker with paired evaginations; esophagus with pro-
nounced distal muscular thickening; ceca nearly straight, end postequatonal, post-

testicular. .

Male organs: Testes 2, slightly smaller than acetabulum, each with 4 lobes forming
cross on ventral view, fields coincide, zones separate, preovarial, in equatorial and
caudal thirds; musculosa not enormous; cirrus pouch present.

Female organs: Ovary and shell gland posttesticular; vitellaria in extracecal.
and cecal areas, extend through part of esophageal and entire cecal zones, close to
ceca; uterus intercecal; Laurer's canal, chiefly prevesicular, does not cross excretory
vesicle or canal.

Type.— C./abaceus (Diesing, 1838).

Habitat.— Small and large intestines of marine mammals.

Genus BALANORCHIS" Fischoeder, 1901.

Generic diagnosis.— Clachrchiinx (p. 169): Body small, rather conical, venter
slightly concave, dorsum convex, cephalic end attenuate, caudal end slightly attenuate
but rounded, transverse section circular. Ventral pouch absent. Acetabulum small,
terminal, not sunken, margin (?), aperture relatively large. Genital pore with mus-
cular ring; no ductus hermaphroditicus. Excretory pore postvesicular, posttesticular,
apparently near cephalic margin of acetabular zone, caudad of pore of Laurer's canal.
Oral sucker with paired evaginations; esophagus without muscular thickening;
ceca long, slightly wavy, end postequatorial, in or near acetabular zone. Genital
papilla absent.

Male organs: Testes 2, larger than acetabulum, elongate-elliptical, fields separate,
zones nearly coincide, chiefly postovarial, postequatorial, close to acetabulum, cirrus
pouch present.

Female organs: Ovary and shell gland in cephalic half of testicular zone; vitellaria
S-shaped, following ceca, extend through nearly entire cecal zone, follicles united
in globular groups; uterus slightly developed, intercecal, almost entirely pretesticular,
not posttesticular; metraterm opens on caudal margin of pore, caudad of cirrus pouch.

Type. — B. anastrophus Fischoeder, 1901.

Habitat.— First stomach of Cervidse, Brazil.

Subfamily DIPLODISCIN^ Cohn, 1904.

Subfamily diagnosis. b — Paramphistomidx (p. 60): [The characters of this sub-
family are still in some doubt. If the excretory system of Diplodiscu? is characteristic
for the entire group, that would make an excellent subfamily character.]

Key to Genera of Diplodiscin^e.

Acetabulum round, opens caudad, with central excavation; 2 testes in young, coalesce
in adult; genital pore near mouth; esophagus long, straight, with muscular thick-
ening ("pharynx") at bifurcation; excretory canals with dark concretions.

Diplodiscus, p. 248.

a Based on Fischoeder, 1903h.

b Original diagnosis. — Amphistomiden von gedrungener, konischer Form und runden
Querschnitt. Mundsaugnapf gut ausgebildet, mil 2 retrodorsalen Taschen. Ein
s grosser Endsaugnapf, ueber welchem dorsal dor Exkretionsporus liegt. Mundceffung
I terminal, Darmschenkel bis zum Endsaugnapf reichend, relativ sehr brcit. Leben im
Enddarm von Amphibien und Reptilien. — Cohn, 1904, 242,

13893— Bull, 60—10 16

248

Acetabulum elongate-oval, ventro-subterminal, divided into 2 parte by constriction;
1 testis; genital pore slightly postbifurcal; esophagus long, straight, with muscular
thickening ("pharynx") at bifurcation; excretory canals with dark concretions.

Caladiscus, p. 248.

Acetabulum round, opens caudad, with central projecting sucker; 2 testes in adult;
genital pore near mouth; esophagus short, bent, without muscular thickening
("pharynx"); excretory canals without concretions Opislhodiscus, p. 248.

Genus DIPLODISCUS Diesing, 1836.

Generic diagnosis." b — Diplodiscinx (?) or Cladorchiinx (?) (p. 247): Body conical
to cylindrical, venter concave, dorsum convex, cephalic end attenuate bluntly
pointed, caudal end obliquely truncate. Ventral pouch absent. Acetabulum
terminal, very large, aperture large, tilted ventrad. Genital pore without sucker.
Excretory pore postvesicular, in acetabular zone, caudad of Laurer's canal; radial
excretory branches profuse in acetabulum. Oral sucker with paired evaginations;
esophagus with distal muscular thickening; ceca straight, long, end postequatorial,
posttesticular.

Male organs: Testes 2 in young; may unite in adult , intercecal, much smaller than
acetabulum, globular, unbranched, preovarial, rather distant from acetabulum, about
equatorial; cirrus pouch present.

Female organs: Ovary and shell gland largely posttesticular; vitellaria extend from
esophageal into postcecal zone; uterus intercecal; eggs with operculum; Laurer's
canal entirely prevesicular.

Type. — D. subclavatus (Gceze, 1782).

Habitat. — In rectum of amphibians, Europe.

Genus OPISTHODISCUS Cohn, 1904.

Generic diagnosis. c — Diplodiscinx (?) (p. 247): Acetabulum with central projects
ing sucker. Esophagus without pharyngeal swelling.

Male organs: Testes 2, in part postovarial; cirrus pouch long and narrow.
Female organs: Ovary in testicular zone.
Type species. — 0. diplodiscoides (Cohn, 1904).

Genus CATADISCUS Cohn, 1904.

Generic diagnosis. d — Diplodiscinx (?) (p. 247): Acetabulum divided into 2 halves.
Esophagus with distal muscular thickening.

a Diplodiscus after Cohn, 1904, 242. — Diplodiscinx: Der runde Endsaugnapf ist
nach hinten gerichtet, mit zentraler Exkavation. 2 Hoden, die bei alten Exemplaren
verschmelzen. Genital porus ziemlich nahe der Mundoeffnung. Oesophagus lang und
gerade verlaufend, ein Pharynx an der Darmgabelung. Exkivtionskansele mit den
typischen dunkeln Konkrementen.

b Combined from various authors.

cOriginal diagnosis. — Diplodiscinx: Der runde Endsaugnapf ist nach hinten
gerichtet, mit centralem vorragendem Zapfen. Dauernd 2 Hoden. Genitalporus
nahe an der Mundoeffnung. Oesophagus kurz, um den Mundsaugnapf herum gebogen.
Kein Pharynx. Die msechtige entwickelten Saugnapftaschen reichen bis zu J der
Gesammtlange. Darmasymmetrisch. Exkretionskanal ohne dunkele Konkretion. —
Cohn, 1904, 243.

d Original diagnosis. — Diplodiscinx: Der langovale Endsaugnapf liegt subterminal-
ventral und ist durch Einschnuerung in 2 Theile geteilt. Ein Hoden. Genitalporus
wenig vor der Kcerper medial, dicht hinter der Darmgabelung. Oesophagus lang,
gerade verlaufend; ein Pharynx an der Darmgabelung. Exkretionskanale mit typi-
schen Konkretionen.— Cohn, 1904, 243.

249

Male organs: Cirrus pouch present. Testis single, median.
Female organs: Ovary, at least in part posttesticular.
Type species. — C. dolichocotyle (Cohn, 1903).

GASTRODISCIM), new family.

Family diagnosis.— Paramphistomoidea (p. 15): Body rather discoidal, divided
by transverse constriction into cephalic and caudal portions; ventral pouch absent,
venter with many large papillae. Acetabulum ventral at caudal end.

Type genus. — Gaslrodiscus Leuckart, 1877.

This family contains two genera {Gastrodiscus and Homalogaster),
which differ so strikingly from the genera of the Paramphistomidse
that distinct family rank seems justified. The one point which
speaks against eliminating them from Cladorchiinse, Paramphisto-
midse, is the paired evaginations of the oral sucker.

The genera may easily be separated by the following key :

Genital glands confined to large anterior portion; acetabulum moderate; type
palonix Homalogaster, p. 249.

Genital glands confined to large caudal portion; acetabulum small; type sondnoii=
segyptiacus Gastrodiscus, p. 252.

Genus HOMALOGASTER Polrler, 1883.

Generic diagnosis. — Gastrodiscidse (p. 249) : Body divided by constriction into large
cephalic, flat portion with genital glands, and small, caudal portion with acetabulum;
venter flat or excavate, provided with alternating longitudinal rows of large mamma-
like structures; of these, the papillae near the middle of the rows (both longitudinal and
transverse) are larger than those further from the middle; dorsum convex. Acetabu-
lum large, caudal, A^entral, not sunken, margin raised, aperture medium. Genital
pore without sucker, on large protrusile papilla, ductus hermaphroditicus absent.
Excretory pore postvesicular in acetabular zone, caudad of pore of Laurer's canal.
Oral sucker with paired evaginations; esophagus rather long, with muscular swelling
(at least in H. philippinensis); ceca slightly wavy, long, end postequatorial, post-
testicular.

Male organs: Testes 2, smaller than acetabulum, preequatorial, lobate, widely
separate from ovary and acetabulum; musculosa not enormously developed; cirrus
pouch absent.

Female organs: Ovary and shell gland posttesticular; vitellaria cecal, about from
bifurcation to ovary; uterus intercecal, pre-, post-, and testicular; eggs operculated;
Laurer's canal entirely prevesicular.

Type.—//, palonix Poirier, 1883.

Habitat. — Large intestine of ruminants. Asiatic.

HOMALOGASTER PHILIPPINENSIS Stiles & Goldberger, 1908.

[Figs. 203-205.]

A reexamination of the sectioned material that was used as the
basis for the description of this species by Stiles and Goldberger,
1908, has disclosed one or two additional interesting points.

Oral sucker. — The oral sucker and suctorial pouches are inclosed
in a well-marked cavity (figs. 32-36, Stiles and Goldberger, 1908).
The oral sucker is held in position by attachments around its oral

250

extremity and by mesenterium-liko strands extending from its ven-
tral and dorsal aspects to the parenchyma. Caudally of the base of
the oral sucker similar dorso-ventral strands run from the dorso-
mesial aspects of the bulbs toward the dorsum, anchoring them to
the parenchyma, and other strands run ventrad from the esophagus.
Besides these mesenterium-like strands, consisting of a loose paren-
chyma-like membrane, there are muscle bundles which attach these
structures to the subcuticular muscle layers ventrally and dorsally.
In this cavity or perisuctorial space is a considerable amount of a
granular material (coagulum) in which a few cell-nuclei are scattered.
These nuclei are surrounded by a narrow, clear, nongranular area, but
a well-defined cell wall could not be made out.

Esophagus— The caudal extremity of I he esophagus is character-
ized by a somewhat fusiform bulb-
ous enlargement (fig. 203) due to a
very marked thickening of the
muscular layers. Measured in
sagittal section this bulbous thick-
ening is about 280/z long with a
maximum thickness of wall of
about 67//. The thickness of the
esophageal wall just above (cepha-
lad of) the beginning of this
bulbous enlargement was found to
be, in the same section, about 15//.

Acetabulum. — The rim of the
acetabulum projects beyond the
body parenchyma, which embraces
its dome in a manner resembling
somewhat that in Pseudodiscus
stanleyii, though it is not marked
off as in stanleyii by an encircling
groove (figs. 204, 205).
The foregoing observations change the original specific diagnosis to
read as follows:

Specific diagnosis. — Homalogaster (p. 249): Body 7.5 to 9 mm. long by 4.5 to 5
mm. (or flattened to 7 mm.) broad, canoe shaped, cephalic extremity attenuated,
caudal extremity rounded; when flattened, sides very convex longitudinally; dorsum
may show submedian longitudinal depressions. Genital pore 1 mm. from oral margin
(about one-ninth to one-seventh of body length from mouth and about at equator of
esophagus), surrounded by depressed circular area bearing numerous small papilla;.
Venter with alternating longitudinal rows of large papilla; extending from about 2 to
2.5 mm. from oral margin to acetabulum. Margins curved ventrally and are fairly
sharp. Acetabulum about 2.5 by 2.7 to 3 mm., its margin projects beyond the body

251

parenchyma. Oral sucker with a single pair of evaginations; the sucker and evagi-
nations lie in a well-marked perisuctorial space; esophagus extends to about one-fifth
of body length from oral margin; the caudal end of the esophagus is provided with a

fusiform bulbous muscular enlargement
about 280/x long by C7/i thick; intestinal ceca
narrow, slightly tortuous, long, extending to
acetabulum. Excretory pore postvesicular,
dorso-median, about at equator of acetabu-
lum, caudad of pore of Laurer's canal.

Male organs: Testes lobate in cephalic half
of space between ceca; one caudad of the
other; vesicula seminalis quite compactly
coiled; pars musculosa distinctly but not
highly developed ; pars prostatica not promi-
nent, may enlarge to quite a large diameter,
thus resembling a "vesicula seminalis in-
terna;" ductus ejaculatorius present; cirrus
absent.

Female organs: Ovary and shell gland sub-
median, near end of one of the ceca, ovary
cephalad of shell gland; vitellaria extend
about from the bifurcation of the esophagus
to caudal plane of ovary; uterus with many
coils, well developed, passes cephalad, dor-
sally of testes, ventrally between vasa efferentia, ventrally of vas deferens, to pore;
Laurer's canal opens dorso-median at plane of termination of ceca. Genital papilla,
when extruded, resembles human penis with glans; bears on its vertex a pore, from
which runs the short ductus hermaphroditicus; when retracted the papilla resembles
a partially inclosed cirrus pouch.

Eggs: Egg oval, opercu-
lated, with small knob at
opposite pole; 125 to 139/i
by 67.5 to 86/i.

Habitat. — Cecum of Bos
sp., at Manila, P. I. (type
locality), and Phrapatoom,
Siam.

Type.— U . S . P . H . &
M.H.S. 9580 (mounted);
Cotypes 9581 and 9960.

ILLUSTRATIONS.

Fig. 203.— Sagittal
section shows bulbous
thickening of caudal
end of esophagus (e. b.) ; oral sucker (o. s.) ; perisuctorial space (p.s. sp.) ;
suctorial pouch (s. p.) ; pars prostatica (p. p.) ; uterus (ut.) . Enlarged.
Original.

Fig. 204. — Sagittal section of caudal extremity to show acetabulum
(ac). Shows also the excretory vesicle (ex. v.) and intestines (i.),
section of transverse vitello-duct (t. vd.), and ventral papillae (v. pap.).
Enlarged. Original.

252

Fig. 205. — Transverse section through caudal extremity. Shows
acetabulum iac), excretory vesicle {ex. v.), and intestines (i.). En-
larged. Original.

Genus GASTRODICUS Leuckart, 1877.

Generic diagnosis." — Gastrodiscidx (p. 249): Body divided by constriction into
small, cephalic, slender, nearly cylindrical portion without sexual glands, and large,
caudal, flat, discoidal, ventrally excavate portion containing the genital glands.
Ventral pouch absent. Acetabulum small, caudal, ventral, margin raised, aperture
relatively large. Genital pore without sucker. Excretory pore postvesicular, in
acetabular zone, caudad of pore of Laurer's canal. Oral sucker with paired evagi-
nations; esophagus with muscular thickening; ceca not wavy, long, end postequato-
rial, posttesticular.

Male organs: Testes 2, larger than acetabulum, branched, diagonal, fields and zones
overlap, preovarial, widely separated from acetabulum, about in equatorial third;
musculosa not enormous; "cirrus pouch not completely closed."

Female organs: Ovary and shell gland posttesticular; vitellaria extracecal, extend
from bifurcation into postcecal zone; uterus intercecal; Laurer's canal entirely pre-
vesicular.

Type. — Gastrodiscus segyptiacus Cobbold, 1876.

Habitat. — Small and large intestines of Equus in Egypt and India, and Homo in
India.

a Based upon the writings of various authors.

LIST OF ABBREVIATIONS.

a. ac aperture of acetabulum.

a. v. p. . . .aperture of ventral pouch.

ac acetabulum.

ac.pap acetabular papilla?.

c cirrus.

c. p cirrus pouch.

c. vd common vitello-duct.

cu cuticle.

d. ac dome of acetabulum.

d. e ductus ejaculatorius.

d. h ductus hermaphroditicus.

e. g brain (esophageal ganglion).

es esophagus.

es. b esophageal bulbous thickening.

es. f esophageal fork.

ex. c excretory canal.

ex. d excretory duct.

ex. p excretory pore.

ex. v... excretory vesicle.

g. a. c ventral chamber of genita

atrium.

g. a genital atrium or dorsal cham-
ber of genital atrium.

g. b genital bulging.

g.pap genital papillae.

g. p genital pore.

g. s genital sucker.

g.sph genital sphincter.

i intestine.

L. c Laurer's canal.

m mouth.

m.b mesenterium-like strands (of

oral Bucker).

m. p musculosa-prostatica, junc-
tion of.

o. pap oral papillae.

o. h oral sucker.

ot ootype.

ov ovary.

ov. d oviduct.

p. i pars intermedia.

p. L. c pore of Laurer's canal.

p. m pars musculosa.

po. gr peri-oral groove.

por. h porus hermaphroditicus.

p. p pars prostatica.

pap. o. s. . papilla? of oral sucker.

p. s. sp perisuctorial space.

pa. gr peri-acetabular groove.

pap. g. a. .papillae of genital atrium.

par parenchyma.

r. ac rim of aperture of acetabulum.

s. b suctorial bulb.

b. g shell gland.

s. p suctorial pouch.

s. pap surface papillae.

s. sph suctorial sphincter.

sz spermatozoa.

t testis (t. d., right or inferior

t. s., left or superior).

t. g. p true genital pore.

tr.gr transverse grooves.

t. vd transverse vitello-duct.

ut uterus.

v. e vas efferens (right = v. e. d.;

left=v. e. s.).
v.e.a arch of union of vasa efferen-

tia.

v. d vas deferens.

v. g vitellogene glands, vitellaria.

v. m vesicula-musculosa, junction

of.

v. p ventral pouch.

v. pap ventral papillae.

v. r vitellene reservoir.

v. s veaicula seminalis.

v. s. i vesicula seminalis interna.

va metraterm.

(253)

INDEX TO ZOOLOGICAL NAMES.

I'age.

segyptiacus (Gastrodiscus) 249,252

Amphistoma ; 9, 170, 171, 200, 217

collinsi 171,173,174,187

collinsi stanleyi 173

collinsii 9, 171, 173, 174, 187, 188, 201

collinsii stanleyi 171, 173, 201

conicum 64,214

crumeniferum 87,115

explanatum 132

hawkesi 171,173,175,200

hawkesii 174, 187, 188, 200, 201, 202, 203

ornatum 171, 201

papillatum 201, 232, 233, 234

stanleyi 173, 189

stanleyii 9,171,173,174

watsoni 212, 213, 214, 217, 218

Amphistomida; 171

anastrophus (Balanorchis) 62,247

Anoa depressicornis 17

Antilope 51

dorcas 76

aries (Ovis) 63,64

Balanorchis 60, 61, 62, 218, 247

anastrophus 62, 247

bathycotyle 77

(Paramphistomum) 74,76,77

bohor (Cervicapra) 51,52

Bos 29,251

bubalus 50,75,76

indicus 16, 17, 74, 75, 76, 87, 101, 102, 115, 121, 144, 162

kerabau 17,20,21,42,50,74,76

taurus 50, 51, 63, 75

taurus indicus 63

zebu 63,75

Bothriophoron 74, 75, 77

bothriophoron ' 74,75,77

papilligerum 74,77

bothriophoron (Bothriophoron) 74,75,77

(Paramphistomum) 75,77,85

Brassica oleracea 86

bubalus (Bos) 50,75,76

Buffelus indicus 75, 131, 132

buski (Fasciolopsis) 214

(254)

255

Page.

caballus (Equus) 171, 173, 174, 175, 187, 188, 189

calicophorum (Cauliorchis) 74,86

(Paramphistomum) 75,89

campestris (Cervus) 76

Carmyerius I6' 50

gregarius 16, 50

Catadiscus 60,62,248

dolichocotyle ^2, 249

Cauliorchis 74,86

calicophorum 74,86

cauliorchis. 74, 86

crassum 74,86

indicum 74,86

papillosum 74,86

cauliorchis 75

(Cauliorchis) 74,86

(Paramphistomum) 76, 86, 100, 102, 105, 107, 108

cervi (Paramphistomum) 61, 62, 73, 74, 76, 77, 140, 166, 167

Cervicapra bohor 51, 52

Cervidse 247

Cervus campestris 76

dichotomus 76

elaphas 76

eldi 75,78,151

namby ., 76

mexicanus 76

rufus 76

simplicicornis 76

ceylonensis (Fischcederius) 17, 39

Chiorchis 62,169,218

fabaceus 62,247

Cladorchiinse 60, 61, 168, 169, 170, 171, 212, 218, 246, 247, 248, 249

CladorchinEe 232

Cladorchis 9, 60, 61, 169, 170, 212, 218, 242, 246

pyriformis 61,169,170

watsoni 11,212,218

cobboldii (Fischcederius) 17

collinsi 170

(Amphistomum) 171,173,174,187

( Pseudod iscus) 187

collinsi stanleyi (Amphistomum) 173

collinsii 202

(Amphistoma) 9, 171, 173, 174, 187, 188, 201

collinsii stanleyi (Amphistomum) 171, 173, 201

collinsii (Pseudod iscus) 145, 173, 187, 193, 198, 199, 203, 204, 205, 206, 207, 208

compactus (Stephanopharynx) 61, 169

compressus (Gastrothylax) 16

conicum (Amphistoma) 64,214

Cotylophoron 61,62,63

cotylophorum 61,62,63,72

indicum 63,72

cotylophorum (Cotylophoron) 61, 62, 63, 72

(Paramphistomum) 63

256

Pago.

crassum (Cauliorchis) 74,86

(Paramphistomum) 76, 86, 101, 157

crumenifcr (Gastrothylax) 16, 17

crumeniferum (Amphistoma) 87,115

cylindricus (Pseudocladorchis) 62,232

depressicornis (Anoa) 17

dichotomus (Cervus) 76

Dicotyles 170

dicranocoelium (Orthocoelium) 74,77

(Paramphistomum) 74

Digenea 15

Diplodiscinaj 60, 61, 62, 247, 248

diplodiscoides (Opisthodiscus) 62, 248

Diplodiscus 60, 61, 62, 169, 247, 248

subclavatus 62, 248

dolichocotyle (Catadiscus) 62, 249

dorcas (Antilope) 76

elaphas (Cervus) 76

eldi (Cervus) 75, 78, 151

Elephas indicus 173, 200, 201, 202, 232, 233, 234

elongatus (Fischcederius) 16, 17, 21, 23, 27, 45, 48

(Gastrothylax) - 21, 42

epielitum (Paramphistomum) 74, 76, 77

Equus 173,252

caballus 171, 173, 174, 175, 187, 188, 189

explanatum (Amphistomum) 132

(Paramphistomum) 75,131,142

fabaceus (Chiorchis) 62, 247

Fasciola hepatica 193

Fasciolidse 9, 13

Fascioloidea 9, 13

Fasciolopsis buski 214

fischcederi (Fischcederius) 17, 31, 43, 48

Fischcederius 16,17,28,39

ceylonensis 17, 39

cobboldii 17

elongatus 7 16, 17, 21, 23, 27, 45, 48

fischcederi 17, 31, 43, 48

siamensis 17,28

fraternum (Paramphistomum) 75, 131, 166, 167

frontalis (Palonia) 1 7

Gastrodiscid* 9, 15, 51, 249, 252

Gastrodisciis .. 60, 61, 160, 214, 218, 249, 252

segyptiacus 249,252

hominis 213

Gastroth y lacias 51

Gastrothylacidse 9, 15, 16

Gastrothylacidcs 51

Gastrothylacinae 15, 16, 17, 50, 51

Gastrothylax 15, 16, 6D, 61, 218

compressus

crumenifcr 16, 15

elongatus 21,42

257

Page.

Gastrothylax gregarius 50

mancupatus 51

minutus 51

spatiosus - - 51

synethes 42, 50

giganteus (Stichorchis) 170

gracilc (Paramphistomum) 76, 129

gregarius 15

(Carmyerius) - 16, 50

(Gastrothylax) 50

liawkesi ■ 170, 173, 200

(Amphistomum) 171,173,175,200

(Pseudodiscus) 200

hawkesii - £00,201,202,203

(Amphistomum) 174, 188, 189, 200, 201, 203

(Hawkesius) '. 173,200

(Pseudodiscus) 173,200

Hawkesius 173,200,203

hawkesii 173,200

hepatica (Fasciola) 193

Holostomum macrocephalum 217

Homalogaster 60, 61, 169, 218, 249, 250

paloniae 249

philippinensis 12,180,224,249

hominis (Gastrodiscus) 213

Homo - 212,213,252

sapiens 218

indicum (Cauliorchis) 74, 86

(Cotylophoron) 63,72

(Paramphistomum) 76,121

indicus (Bos) 16, 17, 74, 75, 76, 87, 101, 102, 115, 121, 144, 162

(Bostaurus) 63

(Buffelus) 75,131,132

(Elephas) 173, 200, 201, 202, 232, 233, 234

kerabau (Bos) 17, 20, 21, 42, 50, 74, 76

liorchis (Paramphistomum) 74, 76, 77

macrocephalum (Holostomum) 217

malacocotylea ■ 15

mancupatus (Gastrothylax) 51

Masuri 171,214

mexicanus (Cervus) 76

megacotyle (Microrchis) 62, 246

microbothrium (Paramphistomum) 76

Microrchis 60,62,246

megacotyle 62,246

minutus (Gastrothylax) 51

namby (Cervus) 76

bleracea (Brassica) 86

Opisthodiscus 60,62,248

diplodiscoides 62 248

ornatum 170^173

(Amphistomum) J7j

Orthoccelium 74 77

258

Page.

Orthocoelium dicranocoolium 74,77

orthocoelium 74, 77

orthocoelium (Orthocoelium) 74,77

(Paramphistomum) 74,77

Ovisaries 63,64

Palonia frontalis 17

palonise (Homalogaster) 249

papillatum 234

(Amphistoraum ) 201, 232, 233, 234

(Pfenderius) 62. 232, 242

papilligerum ■ 75

(Bothriophoron) 74,77

(Paramphistomum) 75, 77, 78, 82, 83, 85

papillosum (Cauliorchis) 74, 86

(Paramphistomum) 76, 83, 112, 118, 126

Paramphistomidae 9, 13, 15, 60, 62, 169, 217, 218, 247. 249

Parainphistominse 15, 60, 61, 62, 63, 73, 168, 218

Paramphistomoidea 9, 13, 15, 60, 249

Paramphistomum 60,61,

62, 73, 74, 76, 77, 78, 86, 101, 112, 121, 131, 143, 150, 161, 217, 218

bathycotyle 74,76,77

bothriophoron : 75,77,85

calicophorum 75,89

cauliorchis 76, 86, 100, 102, 105, 107, 108

cervi 61 , 62, 73, 74, 76, 77, 140, 166, 167

cotylophorum 63

crassum 76,86,101,157

dicranoccelium 74

epiclitum 74,76,77

explanatum 75,131,142

fraternum 75,131,166,167

gracile 76,129

indicum 76,121

liorchis 74,76,77

microbothrium 76

orthocoelium 74, 77

papilligerum 75, 77, 78, 82, 83, 85

papillosum 76,83,112,118,126

parvipapillatum 74, 131, 143, 147, 160

scoliocoelium 75,131,160

shipleyi 75,82,83,131,150,160

siamense 75, 131, 153, 161

Btanleyii 14

streptocoelium 74

parvipapillatum (Paramphistomum) 74, 131, 143, 147, 160

Pfenderius 62,232

papillatus 62,232,242

philippinensis (Homalogaster) , 12> 180, 224, 249

Pleorchis

Portax tragocamelus *"

Pseudocladorchia 60,62,23-

cylindricus 62,232

Pseudodiscus 9, 11, 12, 60, 62, 170, 171, 173, 187, 189, 200, 202

259

Page.

• 1 87

Pseudodiscus colhnsi

collinsii 145, 173, 187, 193, 198, 199, 203, 204, 205, 206, 207, 208

hawkesi -' : 200

hawkesii 173,200

stanleyii 62, 145, 173, 186, 189, 192, 193,

194, 195, 198, 199, 201, 204, 205, 207, 208, 219, 221, 222, 224, 238, 250

pyriformis (Cladorchis) 61> 169> I70

rufus (Cervus) ?6

sapiens (Homo) 218

schistocotyle (Taxorchis) 61, 170

scolioccelium (Paramphistomum) 75, 131, 100

scryptus (Tragelaphus) 51

shipleyi (Paramphistomum) 75, 82, 83, 131, 150, 160

siamense (Paramphistomum) 75, 131, 153, 161

siamensis (Fischoederius) 17, 28

simplicicornis (Cervus) 76

spatiosus (Gastrothylax) 51

stanleyi 201

(Amphistomum) 173, 189

stanleyii 173, 250

(Amphistoma) 9, 171, 173, 174

(Paramphistoma) 14

(Pseudodiscus) 62, 145,

173, 186, 189, 192, 193, 194, 195, 198, 199, 201,
204, 205, 207, 208, 219, 221, 222, 224, 238, 250

Stephanopharynginto 61, 168

Stephanopharynx 60, 61, 168, 218

compactus 61, 169

Stichorchis 60, 169, 170

giganteus 170

streptocoelium (Paramphistomum) 74

Strigea ; 217

subclavatus (Diplodiscus) 62, 248

Synethes 50

synethes (Gastrothylax) 42, 50

Tapirus 170

taurus (Bos) 50, 51, 63, 75

taurus indicus (Bos) 63

Taxorchis 60, 61, 169, 170

schistocotyle 61, 170

Thylogaster 51

Tragelaphus scryptus 51

tragocamelus (Portax) 76

Trematoda 15

watsoni (Amphistomum) 212, 213, 214, 217, 218

(Cladorchis) '. Hj 212, 218

(Watsonius) 9, 12, 62, 157, 180, 212, 224

Watsonius ' g2 212

watsoni 9, 12, 62, 157, 180, 212^ 224

wellmani (Wellmanius) 16 51

Wellmanius 16 51

wellmani -i^ cm

y
t

Q
1

LIST OF HYGIENIC LABORATORY BULLETINS OF THE PUBLIC HEALTH
AND MARINE-HOSPITAL SERVICE.

The Hygienic Laboratory was established in New York, at the Marine Hospital on
Staten Island, August, 1887. It was transferred to Washington, with quarters in the
Butler Building, June 11, 1891, and a new laboratory building, located in Washington,
was authorized by act of Congress March 3, 1901.

The following bulletins [Bulls. Nos. 1-7, 1900 to 1902, Hyg. Lab., U. S. Mar.-Hosp.
Serv., Wash.] have been issued:

*No. 1.— Preliminary note on the viability of the Bacillus pestis. By M. J. Rosenau.

No. 2.— Formalin disinfection of baggage without apparatus. By M. J. Rosenau

*No. 3. — Sulphur dioxid as a germicidal agent. By H. D. Geddings.

*No. 4.— Viability of the Bacillus pestis. By M. J. Rosenau.

No. 5— An investigation of a pathogenic microbe (B. typhi murium Danyz) applied
to the destruction of rats. By M. J. Rosenau.

*No. 6.— Disinfection against mosquitoes with formaldehyde and sulphur dioxid.
By M. J. Rosenau.

No. 7.— Laboratory technique: Ring test for indol, by S. B. Grubbs and Edward
Francis; Collodium sacs, by S. B. Grubbs and Edward Francis; Microphotography
with simple apparatus, by H. B. Parker.

By act of Congress approved July 1, 1902, the name of the "United States Marine-
Hospital Service" was changed to the "Public Health and Marine-Hospital Service of
the United States," and three new divisions were added to the Hygienic Laboratory.

Since the change of name of the Service the bulletins of the Hygienic Laboratory
have been continued in the same numerical order, as follows:

*No. 8. — Laboratory course in pathology and bacteriology. By M. J. Rosenau.
(Revised edition, March, 1904.)

*No. 9. — Presence of tetanus in commercial gelatin. By John F. Anderson.

No. 10. — Report upon the prevalence and geographic distribution of hookworm dis-
ease (uncinariasis or anchylostomiasis) in the United States. By Ch. Warded Stiles.

*No. 11. — An experimental investigation of Trypanosoma lewisi. By Edward
Francis.

*No. 12. — The bacteriological impurities of vaccine virus; an experimental study.
By M. J. Rosenau.

*No. 13.— A statistical study of the intestinal parasites of 500 white male patients at
the United States Government Hospital for the Insane; by Philip E. Garrison, Bray-
ton H. Ransom, and Earle C. Stevenson. A parasitic roundworm {Agamomermis
culicis n. g., n. sp.) in American mosquitoes (Culex sollicitans) ; by Ch. Warded Stiles.
The type species of the cestode genus Uymenolepis; by Ch. Warded Stiles.

No. 14.— Spotted fever (tick fever) of the Rocky Mountains; a new disease. By
1 John F. Anderson.

No. 15.— Inefficiency of ferrous sulphate as an antiseptic and germicide. By Allan
iJJ. McLaughlin.

*No. 16.— The antiseptic and germicidal properties of glycerin. By M. J. Rosenau.
*No. 17.— Illustrated key to the trematode parasites of man. By Ch. Warded Stiles.

(261)

262

*No. 18. — An account of the tapeworms of the genus Hymenolcpis parasitic in man,
including reports of several new cases of the dwarf tapeworm (//. nana) in the United
States. By Bray ton II. Ransom.

*No. 19. — A method for inoculating animals with precise amounts. By M. J.
Rosenau.

*No. 20. — A zoological investigation into the cause, transmission, and source of
Rocky Mountain "spotted fever." By Ch. Wardell Stiles.

No. 21.— The immunity unit for standardizing diphtheria antitoxin (based on Ehr-
lich's normal serum). Official standard prepared under the act approved July 1, 1902.
By M.J. Rosenau.

*No. 22. — Chloride of zinc as a deodorant, antiseptic, and germicide. By T. B.
McClintic.

*No. 23. — Changes in the Pharmacopoeia of the United States of America. Eighth
Decennial Revision. By Reid Hunt and Murray Gait Motter.

No. 24. — The International Code of Zoological Nomenclature as applied to medicine.
By Ch. Wardell Stiles.

No. 25. — Illustrated key to the cestode parasites of man. By Ch. Wardell Stiles.

No. 26. — On the stability of the oxidases and their conduct toward various reagents.
The conduct of phenolphthalein in the animal organism. A test for saccharin, and
a simple method of distinguishing between cumarin and vanillin. The toxicity of
ozone and other oxidizing agents to lipase. The influence of chemical constitution on
the lipolytic hydrolysis of ethereal salts. By J. H. Kastle.

No. 27. — The limitations of formaldehyde gas as a disinfectant with special reference
to car sanitation. By Thomas B. McClintic.

*No. 28. — A statistical study of the prevalence of intestinal worms in man. By Ch.
Wardell Stiles and Philip E. Garrison.

*No. 29. — A study of the cause of sudden death following the injection of horse
serum. By M. J. Rosenau and John F. Anderson.

No. 30. — I. Maternal transmission of immunity to diphtheria toxine. II. Maternal
transmission of immunity to diphtheria toxine and hypersusceptibility to horse serum
in the same animal. By John F. Anderson.

No. 31. — Variations in the peroxidase activity of the blood in health and disease.
By Joseph II. Kastle and Harold L. Amoss.

No. 32. — A stomach lesion in guinea pigs caused by diphtheria toxine and its bear-
ing upon experimental gastric ulcer. By M. J. Rosenau and John F. Anderson.

No. 33. — Studies in experimental alcoholism. By Reid Hunt.

No. 34. — I. Agamofilaria georgiana n. sp., an apparently new roundworm parasite
from the ankle of a negress. II. The zoological characters of the roundworm genus
Filaria Mueller, 1787. III. Three new American cases of infection of man with horse-
hair worms (species Paragordius varius), with summary of all cases reported to date.
By Ch. Wardell Stiles.

*No. 35.— Report on the origin and prevalence of typhoid fever in the District of
Columbia. By M. J. Rosenau, L. L. Lumsden, and Joseph H. Kastle. (Including
articles contributed by Ch. Wardell Stiles, Joseph Goldberger, and A. M. Stimson.)

No. 36. — Further studies upon hypersusceptibility and immunity. By M. J. Rose-
nau and John F. Anderson.

No. 37. — Index-catalogue of medical and veterinary zoology. Subjects: Trema-
toda and trematode diseases. By Ch. Wardell Stiles and Albert Hassall.

No. 38.— The influence of antitoxin upon post-diphtheritic paralysis. By M. J.
Rosenau and John F. Anderson.

No. 39.— The antiseptic and germicidal properties of solutions of formaldehyde and
their action upon toxines. By John F. Anderson.

No. 40.— 1. The occurrence of a proliferating cestode larva (Sparganum prolifcrum)
in man in Florida, by Ch. Wardell Stiles. 2. A reexamination of the type specimen

263

ofFilaria rcstiformis Leidy, 1880 =Agamomermis restiformis, by Ch. Wardell Stiles. 3.
Observations on two new parasitic trematode worms: Homalogaster phihppmensis
n. sp., Agamodistomum nanus n. sp., by Ch. Wardell Stiles and Joseph Goldberger.
4. A reexamination of the original specimen of Tarnia saginata abietma (Wemland,
1858), by Ch. Wardell Stiles and Joseph Goldberger.

*No. 41.— Milk and its relation to the public health. By various authors.

No. 42— The thermal death points of pathogenic micro-organisms in milk. By
M. J. Rosenau.

No. 43 —The standardization of tetanus antitoxin (an American unit established
under authority of the act of July 1, 1902). By M. J. Rosenau and John F. Anderson.

No. 44. Report No. 2 on the origin and prevalence of typhoid fever in the District

of Columbia, 1907. By M. J. Rosenau, L. L. Lumsden, and Joseph H. Kastle.

No. 45. Further studies upon anaphylaxis. By M. J. Rosenau and John F.

Anderson.

No. 46.— Hepatozoon perniciosum (n. g., n. sp.); a hsemogregarine pathogenic for
white rats; with a description of the sexual cycle in the intermediate host, a mite
(Lelaps echidninus). By W. W. Miller.

No. 47. — Studies on Thyroid: I. The relation of iodine to the physiological activity
of thyroid preparations. By Reid Hunt and Atherton Seidell.

No. 48. — The physiological standardization of digitalis. By Charles Wallis Ed-
munds and Worth Hale.

No. 49. — Digest of comments on the United States Pharmacopoeia. Eighth decen-
nial revision for the period ending December 31, 1905. By Murray Gait Motter and
Martin I. Wilbert.

No. 50. — Further studies upon the phenomenon of anaphylaxis. By M. J. Rosenau
and John F. Anderson.
No. 51. — Chemical tests for blood. By Joseph H. Kastle.

No. 52. — Report No. 3 on the origin and prevalence of typhoid fever in the District
of Columbia. By M. J. Rosenau, L. L. Lumsden, and Joseph H. Kastle.

No. 53. — The influence of certain drugs upon the toxicity of acetanilide and anti-
pyrine. By Worth Hale.

No. 54. — The fixing power of alkaloids on volatile acids and its application to the
estimation of alkaloids with the aid of phenolphthalein or by the Volhard method.
By Elias Elvove.

No. 55. — Quantitative pharmacological studies; adrenalin and adrenalin-like bodies.
By W. H. Schultz.

No. 56. — Milk and its relation to the public health. (Revised edition.) By various
authors.

No. 57. — I. The presence of tubercle bacilli in the circulating blood in clinical and
experimental tuberculosis. By John F. Anderson. II. The viability of the tubercle
bacillus. By M. J. Rosenau.

No. 58. — Digest of comments on the Pharmacopoeia of the United States of America
(eighth decennial revision) and the National Formulary for the period ending Decem-
ber 31, 1906. By Murray Gait Motter and Martin I. Wilbert.

No. 59. — The oxidases and other oxygen catalysts concerned in biological oxida-
tions. By Joseph Hoeing Kastle.

No. 60— A study of the anatomy of Watsonius (n. g.) watsoni of man, and of 19
allied species of mammalian trematode worms of the superfamily Paramphistomoidea.
By Ch. Wardell Stiles and Joseph Goldberger.

In citing these bulletins, beginning with No. 8, bibliographers and authors are

requested to adopt the following abbreviations: Bull. No. , Hyg. Lab., U. S.

Pub. Health & Mar. Hosp. Serv., Wash., pp. .

13893— Bull. 60—10 17

MAILING LIST.

The Service will enter into exchange of publications with medical and scientific
organizations, societies, laboratories, journals, and authors. All applications for
these publications should be addressed to the " Surgeon-General, U. S.
Public Health and Marine-Hospital Service, Washington, D. C," except

those marked (*).

The editions of the publications marked (*), available for distribution by the
Surgeon-General of the Public Health and Marine-Hospital Service, have been
exhausted. Copies may, however, be obtained from the Superintendent of Docu-
ments, Government Printing Office, Washington, D. C, who sells publications at
cost, and to whom requests for publications thus marked should be made.

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