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I

CTED FROM THE ANNUAL KEPORT OF THE COMMISSIONER
OF FISH AND FISHERIES FOR 1887J

NOTES

ON

TOZOA OF MARINE FISHES

OF

NEW ENGLAND,

WITH

DESCRIPTIONS OF SEVERAL NEW SPECIES.

II.

By EDWIN LINTON.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.
1890.

EXTRACTED FROM THE ANNUAL REPORT OF THE COMMISSIONER
OF FISH AND FISHERIES FOR 1887. 1

NOTES

ON

AT?

U. S. Commissioner of Fish and Fisheries.

By EDWIN LINTON

WASHINGTON:

GOVERNMENT PRINTING OFFICE.
1890.

EXTRACTED FROM THE ANNUAL REPORT OF THE COMMISSIONER
OF FISH AND FISHERIES FOR 1887. ]

NOTES

ON

ENTOZOA OF MARINE FISHES

OF

NEW ENGLAND,

WITH

DESCRIPTIONS OF SEVERAL NEW SPECIES.

3P.AJRT II.

By EDWIN LINTON

WASHINGTON:

GOVERNMENT PRINTING OFFICE.
1890.

9.-NOTES ON ENTOZOA OF MARINE FISHES OF NEW ENGLAND,
WITH DESCRIPTIONS OF SEVERAL NEW SPECIES.

II.

BY EDWIN LINTON.

The following paper contains notes on forty-two species of Cestod
worms, eight of which were described in my former paper.*

After having had access to new material for study, with some added
experience in the study of these difficult and often perplexing forms, I
have been brought to somewhat different conclusions from those arrived
at in my first paper. The changes in the nomenclature of the first
paper are in brief as follows:

(1) Phyllobothrium thysanocepludum is referred to a new genus, and is
recorded in this paper by the name Thysanocephalum crispum Lt.

(2) The species recorded as Rhynchobothrium tenuieolle Rudolph! I now
regard as a different species. It is referred to a new species in this
paper, and bears the name Rhynchobothrium bulbifer.

(3) Rhynchobothrium bisulcatumof my first paper was referred to the
wrong genus. It is recorded in this paper as Tetrarhynchus bisulcatum.
The reasons for the above changes will be found among the observations
on the species.

Genera with regard to which there is some doubt are Spongioboth-
rium, Anthocephalum, Orgymatobothrium, and Crossobothrium.

There are peculiar difficulties in the way of classifying the unarmed
Tetrabothriidce and more investigation is needed in order to arrive at
the truth. Further investigation upon fresh material may render it
possible, as it is certainly desirable, to unite several genera of the
Tetrabothriidce.

It is with much reluctance that I have found myself obliged to add
several new generic names, some of which, after further study of new
material, may have to be relegated to the already spacious limbo of
synonyms in this order. I find, however, that the descriptions which

* Notes on Entozoa of Marine Fishes of New England, with descriptions of several
new species. Keport of U. S. Fish Commissioner for 1880. Pp. 453-510. Plates I- VI.
[1] 71U

720, REPORT OF COMMISSIONED -\i AND FISHERIES. [2]

r

iiave been •< -»st useful to me in the work of identification, are rbose
which give ;u;r»y details of structure and are accompanied with ill .,<;;i-
tions. Whether the name given y the describer holds or not is a
ter of secondary importance.

I have restored Van Beneden's genus AcantJiobothrium, which hrd
been combined with the genus Cattiobothrium by Diesing. This neces-
sitates au emendation of the definition of the latter genus. 1 have
ited from the genus Echeneibothrmm those species with echenci-

. which are destitute of a myzorhyuchus, and placed t.b
in the new gen as Rliiiiebo. Throe genera, in \vhich thebji*

are united into a globe or disc were discovered, whose systematic !•
tions are open to some debate. These have been named Lecanicephalum,
Tyl' '•>rin, and Discocephalum^ respectively. The fa:nily name 6V

bothriidiv is suggested for-these forms, although I have thought bes1
put them provisionally with the Tetrabothriidcc. The species which I
have described under the name Paratcenia medusia has caused mo much
perplexity, to determine its relationship.

The specimens which are described in this paper were collected
the most part, during the months of July and August 1S86-'S7, at
"Wood's Holl, Massachusetts. During tin summer of 1S87 I made most
careful and painstaking search for small forms, and was eminently s
cessful in my examination of the sting ray (Trygon centrura) and
dusky thark (Carcharias obscurus). During these researches a variety
of encysted forms were obtained. These were most abundant in the
Telcostei. Several species of Trematods, Nematods, and Acanthocephaia
have been found. Descriptions of these will appear in due time. L have
learned by experience that brief descriptions of these soft-bodied and
variable forms are of but little use in identification, and have therefore
endeavored to give such descriptions 'as will enable fntnre investigators
to identify the species accurately. It has been found that measi'
ments, even of parts that are liable to great alteration on accouir:
contraction, are invaluable as a means of identification. Measure
of hard parts, such as hooks, spines, and, to a certain extent, o
of course of the highest importance. Too much weight, "u-. • .vever,
not be attached to absolute values where the differences are
Different methods of obtaining measurements, inaccuracies in com* .ifa-
tion, and individual errors must be allowed for. On the other hand,
much weight must usually be given to relative dimensions, since in that
, several of the above-named sources of error are eliminated.

A-; ! tr as it was^ possible to do so the specimens were studied v,
they wore alive. Sketches of living forms were made by my wife
I was engaged in collecting, assorting, measuring, and recording

LI ns on the specimens. I was thus c-uibied to collect much in-
i in the short time at my disposal than would have been possil
without this assistance.

It may not he ann'ss to give hore. for flic ben >6t '-ctors, the •

[3] NOTES ON ENTOZOA OF MARINE FISHES. 721

which I adopted to keep track of my material and the notes and sketches
made at the time of collecting. Since it was not desirable usually to
attempt to identify the specimens in the short time during which they
could be studied alive, especially, as was often the case, when my table
was covered with a dozen or more dishes each containing a lot of speci-
mens to be assorted, I found it convenient to keep what I mr^y call a
numerical check-list. In this check-list each capture is denoted by a
number, while the different species or groups into which the lot was
assorted are indicated by the letters of the alphabet. The check-list
contains the date of capture, number of fish examined, and usually the
number of specimens obtained1. A few numbers quoted from the check*
list itself will illustrate the method sufficiently.

190, August G (1887), Trematods, same as No. 17'J&, gills ami stomach of Echeneis re-

mora ; stomach empty.
191a, August fi, Long red Nematods (viviparous), same as 184o, ou viscera and under

peritoneum of Lobotes surinamensis.

I'Jlb, Cysts and embryo Rlujncliobothria from viscera, under peritoneum of same.
191c, Trematods, intestine of same, fifteen specimens, small.
191rf, Two small Nematods, intestine of same.

19'2rt, August 8, Rhynchobothria from stomach of Try yon centrum ; one ray examined.
19XJ&, Phyllobothrium, one specimen, from lower part of spiral intestine of same, same

as No. 178&.
W2c, Acanthobothriiirn, numerous, spiral intestine of same.

Labels with numbers and corresponding data from check-list were
placed in the bottles or vials in which the specimens were preserved.
When greatly pressed for time temporary labels with numbers only were
placed with the specimens. These were replaced as soon as possible by
labels containing all necessary data. In cases where the living speci-
mens were studied notes were kept on small pieces of paper of uniform
size. A small tablet of unruled paper 5f by 3| inches was found con-
venient for this purpose. Where several pages of notes were filled
from the study of a single number, the pages were not only numbered,
but each page was marked with the check-list number. The pages were
then pinned together and placed in a large envelope, where they were
kept in numerical order so that they could be referred to without delay.
Sketches of living forms were made, sometimes with the notes, but
usually on separate pieces of paper. A tablet of unruled writing paper,
9 by 5| inches, was found to be a convenient size for sketches. Every
sketch was marked with the check-list number. The sketches were kept
in a separate envelope, and arranged in numerical order.

With the specimens, notes, and sketches numbered and arranged ac-
cording to a uniform system, it was scarcely possible for any mistake
to occur in the way of referring a specimen to other than its proper
host. It was also easy to collect duplicates into a group for study. In
the winter months, whenever a half-day, or even less, was at my dis-
posal it was possible to utilize the time in a way that could scarcely
have been done if no special method of work had been pursued. As far
as time and material would permit, specimens were prepared by stain-
H. Mis. lo,'j 10

722 REPORT OF COMMISSIONER OP FISH AND FISHERIES. [4]

ing and sectioning for anatotuo-histological study. In final writing all
notes were revised and their data incorporated in the description for
publication.

I have not attempted to give complete synonymies, but have in each
case given what seem to me to be the more important references. The
older synonymy can be found in Diesiug's classical work.

Under the formal heading " habitat," I have given only the host in
which I have found the species. For new species this is complete, but
it is, of course, incomplete for old species. In the latter cases I have
alluded to the usual host or hosts in connection with remarks on the
species.

So far as my investigations go, it would appear that very few of the
cestod entozoa of fish pass their adult stage in different specific hosts.
With regard to the encysted forms, however, the range of hosts appears
to be greater.

The nomenclature of fishes used in this paper is that adopted by
Prof. G. Brown Goode, in " The Fisheries and Fishery Industries of
the United States, Section I, Washington, 1884." I desire to express
here my sincere obligations to Mr. Vinal N. Edwards for his valuable
assistance in providing material for study. It is but a poor acknowl-
edgment of the valuable services rendered by my wife, Margaret B.
Linton, in the preparation of this paper, to say that the illustrations
which accompany it are the work of her hand.

ORDER CESTOIDEA.

Family I— PSEUDOPHYLLID^E Van Betieden.

Dibothriida! Diesing.

DIBOTHRIUM Kudolphi.

Usage is about equally divided between the names Dibothrium and
Botlirioceplialus for this genus. Kudolphi used the name Bothriocepha-
lus as a generic title, and divided the genus into two subgeuera to
which he gave the names Tetrabothrium and Dibothrium. The latter,
as used by Kudolphi, had about the same limitations as it now has.

1. Dibothrium restiforme, sp. uov.

\_Rcst\8, a cord. J
[Plate i, Figs. 1-10.]

I have found it necessary to make a new specific name to accommo-
date four Dibothria from the intestine of the rare silver gar (Tylosurus
caribbwus).

The head of the living worm is broad-oval, flat, two-lobed, the lobes
and somewhat radiately striated, rather squarish or

[5] NOTES ON ENTOZOA OF MARINE FISHES. 723

shouldered behind, aud tapering to a blunt point in front. Two very
deep fossa? which are marginal with respect to the head, lateral with
reference to the body, divide the head into two leaf-like lobes, with
thin flexible borders. When the edges of the lobes are closely ap-
pressed the fossa? appear as marginal slits. The fossa? extend to the
apex of the head but do not unite. Each fossa is continuous behind
the head with a narrow median furiow.

The body near the head is quite narrow', almost cylindrical, or a little
flattened on the margin to correspond with the greater marginal diam-
eter of the head. It is very much narrower than the head. The seg-
ments begin immediately behind the head, where they are short and
thick and very much crowded. They increase in length slowly until
about the posterior third where they are nearly square. The segments
of the posterior third are nearly square and quite thin. The body is of
nearly uniform breadth throughout its entire length.

Genital apertures lateral near middle of segment, male aud female
approximate. Aperture of oviduct on opposite lateral face of strobile
near anterior edge.

Maximum length 765"""; breadth of body l.Smm; breadth of head 2.5mm.

Habitat. — Tylosurus caribbtvus, intestine. Buzzard's Bay, Massachu-
setts, July 27, 1886. Four specimens.

Three of the specimens were very slender, almost filiform, the other
was more contracted aud consequently thicker, but it, too, was of nearly
uniform size throughout.

The shortest specimen measured about 64"un in length when lying
undisturbed in water. When taken by the posterior end and lifted
slowly from the water, allowing it to stretch out to its fullest extent by
its own weight, it increased in length to 240""u. The largest specimen,
measured in the latter way, was 665mm in length. After lying in sea-
water for twenty-four hours it was again measured and found to be
765ram in length. After being preserved twelve mouths in alcohol it
still measures 720""" in length. The other specimens while living meas-
ured 215 and 262""" respectively.

The genital apertures are lateral ; on the larger specimen the follow-
ing points were made out with no other aid than a simple lens : On one
of the lateral faces openings occur en the middle of the segments along
the median line. These apertures were traced to within 160mm of the
head, where they merged into a median lateral groove ; the latter is con-
tinuous with one of the marginal fossw of the head ; on the opposite
lateral face there is a small opening or pore near the anterior edge of
each segment ; these pores are not usually exactly on the median line
of the strobile, but stand a little to one side or the other and thus make
an irregularly sinuous line ; they were traced to within 240""" of the
head, where they become indistinguishable in the median groove; the
latter, like its fellow on the opposite face, extends to the head, where
it is continuous with the other marginal fossa of the head.

724 REPORT OF COMMISSIONER OF FISH AND FISHERIES. | G]

" There is danger of some confusion in the use of the terms marginal
and lateral in the description of this worm, arising from the fact that
what one naturally calls the margin of the bead is continuous with the
lateral face of the body; in a brief description of the worm, therefore,
one should say bothria lateral, if by bothria the deep fossie are meant.

The posterior segments are slightly irregular; in one case two seg-
ments were fused into one and the last segment was somewhat distorted.

The following measurements were taken from the longest specimen
after it had lain for some time in alcohol. Length of strobile 720mm;
length of head 4mm ; breadth of head at base 2lum, middle 2.51I11U, apex Lmm ;
thickness of head 1.5mm ; diameter of iieck lmm. The diameter of the
neck, or, more properly speaking, of the body immediately behind the
head, is a trifle greater when measured in a line corresponding to the
breadth of the head than it is on a line corresponding to the thickness
of the head.

In the alcoholic specimens the shape of the body differs very little
from that of the living worm. It still has the same uniformity of breadth
throughout. There are, however, some differences in the head which are
worthy of mention. The head of the alcoholic specimen is shorter,
thicker, and more bluntly pointed than that of the living specimen.
The apex of the head is almost truncate. The lips of the fossa3 are
more or less crimped and folded and the fossie are somewhat gaping,
while the brond lobes are deeply furrowed. These furrows are, in
the main, longitudinal.

The median lateral furrows of the body are, in the alcoholic speci-
mens, very strongly marked. Near the head each median furrow ap-
pears to turn to one side in order to meet the fossa of the head, in which
it terminates. The true nature of this apparent twist in the anterior
part of the body is made evident by transverse sections of the head and
anterior segments as described further on. While in the living worm
the anterior segments are very indistinct, in the alcoholic specimens
they are tolerably distinct and can be traced almost to the head.
Near the head they are about .17""" in length and llnm in breadth. At
a distance of 15mm from the head the length is .22lum ; breadth 1.2min;
thickness .S4mm. Two hundred millimeters back of the head the seg-
ments are.3Gmm loujr, 1.8mm broad and .8lum thick. At a distance of 330mm
from the head the segments are .8mm long, 1.8"'"' broad and G111"1 thick.
Near the posterior end of the longest specimen, the length of the seg-
ment is 1.9mm, breadth 1.4""", thickness .5""".

After staining with carmine, transverse sections of the head were
made in order to ascertain, if possible, the nature of the fossae as com-
pared with the cupping disks of such a species as D. microcephalum.
The sections at the apex of the head prove the fossa? to be true bothria,
Fig. 9. In these sections there is a nearly square central part meas-
uring .22 and .3""" in its two diameters, with the crescent-shaped sec-
tions of the apices of the bothria lying at the two longer sides. In the

[7] NOTES ON ENTOZOA OF MARINE FISHES. 725

first half-doxcn sections the bothria are distinct from the central part,
of which they appear to be small auriculate appendages. The position
of the bothria at this point is very plainly lateral. The bothria soon
become fused with the central part and then lose their distinctive char-
acter, appearing simply as deep indentures on the sides of the head.
Fig. 10. The diameter of the central core of the head, at the point
where the bothria cease to be distinct, measured between the bottoms
of the pits, is .26™"'. The diameter through the head at right angles to
this is .49mm. The breadth of the sections, including the edges of the
bothria is .Gmm. The latter edges are iuduplicate, if straightened the
breadth would be increased .2nu". Proceeding towards the base of the
head the sections are found to differ gradually the one from, the other.
The distance between the bottoms of the fossre becomes shorter and
shorter, until, at the point where the lobes of the head are widest, the
pits are separated from each other by a mere thread .00 to .OS1""1 diam-
eter, Fig. 13. The diameter of the head at right angles to the above,
that is, in the direction which answers to the thickness of the head, is
.74""". The diameter in the latter direction has increased from the apex
to this point from .49mm to .74"1"1, while the opposite diameter, that is,
the distance through the head from the bottom of one pit to the bottom
of the other, has decreased, in the same distance, from .2GIum to .06mm.
The edges of the fossae have, in the mean time, increased in length. In
fact they no longer appear as lips of bothria, but rather as prolonga-
tions of borders of a bi-lobed head. The inner faces of these prolonga-
tions are smooth, as shown by the entire outline of the cross-section,
while the outline of the outer faces is deeply creuulate on account of the
longitudinal furrows there cut through. The thickness of these pro-
longations at base is about .32'"'"; at the apex, that is, at the margin of
a lip of the bothria, about .08"uu. The entire breadth of the head at
this point, about the widest part, is, when the lobes are straight, in the
neighborhood of 2.6mm. Transverse sections, for the greater part of the
length of the head, bear a close resemblance to the figure eight.

Towards the base of the head the central part widens quite rapidly.
At first this widening is, for the most part, at the expense of the fossae.
For example, in a section where the greatest breadth of the head is 2mm,
the distance between the bottoms of the fossoe is .G8mm. A little further
back the fossa? are represented by deep grooves, while the sections are
nearly trapezoidal with creuulate outlines.

In the mean time the aquiferous vessels have made their appearance.
A line joining the two main vessels, as seen in section, would be very
nearly at right augle5 to a line joining the deep grooves, which repre-
sent the continuation of the fossre. The sections were carried back of
the head a short distance. In the last ones made, the deep emargina-
tious at the ends of the section show the position of what further back
on the body are the lateral grooves. The aquiferous vessels still occupy
the same relative position with reference to these emargiuatious.

726 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [8]

Since the aquiferous vessels occupy the same relative position with
reference to the fossa? of the head as the grooves ou the anterior part of
the body, and, as is shown by sections of mature segments, with refer-
ence also to the lateral rows of pores and genital apertures, the fossa)
are proved to be lateral. The apparent shifting of the grooves from
the margins of the head to the lateral sides of the body already alluded
to is, therefore, due to a simple twisting of the body behind the head.
This twisting is a natural result of the flattening of the head in a plane
which is at right angles to the plane of flattening of the body.

A longitudinal section through the head shows that the central part
resembles the entire head of such species as D. mamibriforme and D.
punctatum, which have rather long and slender heads. The thin edges
of the lobes of the head of this species, as indeed is plainly shown by
sections near the apex of the head, are simply the prolonged lips of
normal bothria.

With regard to the musculature, the longitudinal fibers are pretty uni-
formly distributed through the head — a little more abundant near the
borders and at the center. No definite arrangement into fascicles was
observed in the head. The transverse fibers are very fine and abun-
dant, and cross each other in the most intricate fashion. Towards the
base of the head the longitudinal muscle fibers predominate in the cen-
ter. Behind the head they are arranged in fascicles. In longitudinal
sections made a short distance back of the head these fascicles were
beautifully shown. They appeared as rather large isolated bundles of
slightly wavy longitudinal fibers.

The vessels of the water vascular system appear to branch irregu-
larly through the lobes of the head, and are not collected into the prin-
cipal channels until toward the base of the head. Immediately behind
the head the cut ends of the two principal vessels are seen in section
as narrow oblique apertures, .016 and .OOSnim in the two diameters.

In respect to the disposition of the reproductive organs the results of
my investigations thus far are not wholly satisfactory. The reproductive
openings proper are situated along the median line of one of the lateral
faces of the body and are about the middle of the length of the seg-
ment. The single large aperture, which, with its slightly raised border,
can be seen easily with an ordinary lens, is the common opening for
both the sexual organs of the segment. After two or three thin longi-
tudinal sections have been made on the side of the segment which bears
the reproductive opening, the vagina is brought into view lying im-
mediately behind the opening of the cirrus and close to it. The male
aperture quickly widens into the cirrus pouch. .08 to .lmm in diameter,
as the sections are carried towards the interior of the segment. The
vagina remains of uniform size, about .016 to .021mm in diameter. The
cirrus pouch in transverse sections is oval. It extends to the middle
of the interior of the segment, that is, the pouch is equal in length to
about half the thickness of the segment. The cirrus was invaginated

[9] NOTES ON ENTOZOA OF MARINE FISHES. 727

in all cases, but was plainly seen as an irregularly convoluted tube
lying- within the pouch. The vagina follows the posterior edge of the
latter as far as its base. I have not yet been able to determine its
course beyond that point with any degree of certainty.

The interior of the unripe segments, when seen either in cross or Ion-
gitudinal sections, appears for the greater part to be an open net-work
of connective fibers, in the spaces of which are granular bodies, of which
three different sets were made out. What I take to be the ovary is a
lobed body, lying near the posterior edge of the segments, and symmet-
rically 011 each side of the median line. It lies nearest that lateral face
which does not bear the sexual apertures. It is broader in its trans-
verse than in its longitudinal diameter. In its widest part it equals
about one fourth the breadth of the segment, and in its thickest part it
about equals one-fourth the thickness of the segment. Immediately
above it a small oval body was observed in some of the transverse sec-
tions, which I take to be the shell-gland. In front of the ovary and
occupying the middle of the interior of the segment there is a mass of
granular globular bodies which are differentiated into two kinds by car-
mine. The more central ones remain yellowish in color while the others
are deeply stained. The latter I take to be the testes, the former is prob-
ably the vas deferens.

The walls of the cirrus-bulb and of the vaginal tube are clearly defined
and composed for the most part of circular fibers.

Near the anterior edge of each segment, and on the side opposite that
which bears the reproductive apertures, is situated a circular aperture
about .04inm in diameter. It enlarges into an inner cavity which appar-
ently communicates with some large irregular spaces that probably rep-
resent sections of the uterus. The wall of this aperture, as well as those
of the inner cavity, with which it communicates, are rather thick and
granular. On the mature segments these apertures persist and become
larger, while those of the reproductive organs become rather indistinct.
In the mature segments they were also seen to communicate with en-
larged open spaces which, in the younger segments, contain granular
masses. The mature segments are, to a great extent, filled with the
ample folds of the uterus, which are crowded with ova. The uterus, and
the ovary together in these segments, have the appearance of the let-
ter S.

In the posterior part of the segment those folds of the uterus which
are adjacent to the ovary are crowded together so as to form an irregu-
larly lobed mass. In the middle of the segment the lobes are parallel
with each other in a direction transverse to the axis of the segment,
and, for the most part, one side of the median line. In front of this the
uterus broadens and loses its lobed appearance, while the contained
ova are not so densely crowded. This part of the uterus corresponds
to the open cellular spaces observed in the sections. It is to be noticed
that this part of the uterus, which lies in the anterior part of the seg-

728 REPORT OP COMiMISSIONER OF FISH AND FISHERIES. [10]

ment, contains the mature ova, and is, furthermore, in the vicinity of
the excretory pore, from which the ova evidently make their escape.

Upon examining a section through one of these mature segments, the
ova are discovered to be yellowish, opaque, quite irregular in outline,
without hard shells, or rather appearing as if the shells were soft and
yielding and had collapsed. While there is much variety in the shape
and size of these ova, the prevailing shape is oval and the dimensions
about .033 and .018mm in the two diameters.

None of the specimens in this lot were, strictly speaking, mature.
At least the ova did not appear to be mature, and the folds of the
uterus contained, in addition to veritable ova, slightly larger spherical
or suboval masses. The latter, in specimens stained with carmine, con-
sisted of a clear, pellucid, structureless membrane containing a granu-
lar mass, which was frequently deeply stained. There was no tendency
whatever for the segments to become detached from each other.'

2. Dibothrium manubriforme Lt.

[Report of Commissioner of Fish and Fisheries for 1886, Plate i, Figs. 1-4.]

In August, 1886, 1 had the opportunity of examining a sail-fish (His-
tiopliorus gladius) taken off Newport, Ehode Island. I found but a sin-
gle intestinal parasite, a Dibothrium, which I recognized at once, in
spite of its mutilated condition, to be very near, if not identical with, my
I), manubriforme, which was obtained the previous summer from a spear-
fish (Tetrapterus albidus).

The head of the worm could not be found and the entire specimen
was in bad condition, owing to the fact that decomposition had set in
in the viscera of its host. The specimen was trauferred to alcohol, and
the measurements which are given are therefore all from the alcoholic
specimen. It is very considerably longer than the specimens obtained
from T. albidus, but a careful comparison with those specimens con-
vinces me that it is identical with D. manubriforme.

In order to obtain a more certain identification of this specimen, I
made transverse and longitudinal sections of some of the median seg-
ments and compared them with corresponding sections made from one
of the specimens from T. albidus. This investigation confirmed me in
my view that the specimen in question should be referred to D. mami-
briforme, and also enabled me to add some additional data to the anat-
omy of that species.

The specimen from H. gladius affords the following measurements :
Length, 220mra; breadth in front about lmm; greatest breadth 5mm, at
a point 70mm from the posterior end ; breadth at posterior end 2mm,
where it terminates in a bluntly rounded point. The body is about
1.5mm thick at the thickest point. The worm is therefore rather slender,
but this habit might be very much changed by contraction. The dif-
ference in length between this specimen and those from T. albidus, the

[11] NOTES ON ENTOZOA OF MARINE FISHES. 720

longest of which measured 140mm, becomes less significant when it is
remembered that the former when found was practically dead and con-
sequently there was little or no contraction of its tissues when ii was
transferred to water and to alcohol. The tissues of the other specimens
were living and were therefore liable to contract when placed in water
after removal from their host, or when first disturbed in their resting
place.

The posterior third of the body of the specimen from H. yladius, as
in those from T. albirtus, is marked by a dark brown median stripe made
by the ripe ova in the crowded ovaries. A median furrow on one of the
lateral faces of the body begins towards the anterior and becomes punc-
tate towards the posterior region, where the minute lateral genital
apertures become visible in a zig-zag row. The margins of the strobile
are apparently entire. The segments are very short, with their poste-
rior edges slightly wavy on the median segments, thus suggesting those
of D. plicatum. The posterior edges of the median segments are
crowded together like the edges of the leaves of a book about .2mm
apart. Near the posterior end they are not so closely crowded, being
about .4mm apart. The anterior part had undergone decomposition to
such an extent that it was reduced to a mere filamentary shred which
gave no sign of the presence of either bothria or segments.

The ova in this specimen are identical with those in the other lot.
They present also the same features noted in the case of the others ;
that is there seem to be two sorts, one yellowish in mounted specimens,
with a strong shell, in some cases white and opaque; another sort
transparent, with a very thin shell. The latter, in specimens stained
with carmine, have a granular contents which is colored by the stain-
ing fluid. They are entire in outline, oval, length as much as .05inm,
shorter diameter .03mm. These measurements were obtained from both
lots. Transparent yellowish ova were found which were usually col-
lapsed on one side, thus being bowl-shaped. They measured .054mm and
.0271"111 in their two diameters. The diameters of ova given in my origi-
nal description of this species are .045imu and .03mm. These dimensions
may be taken as average.

Anatomy. — Transverse sections, made through that part of the body
which is immediately in front of the segments that contain ripe ova,
show that the body is made up of a series of concentric layers of
muscular tissue surrounding a flat core. Next to the thin cuticle is a
thick granular layer in which lie radiating, longitudinal, and circular
fibers. Of these the circular fibers are the finest. They appear,
indeed, as delicate hair-like lines under an enlargement of 600 diam-
eters.

The granules in the outer layer in longitudinal sections, stained with
carmine, in many places appear as clusters or nests of nuclei. Towards
the posterior end of each segment the circular fibers become more numer-
ous about the middle of the outer concentric layer, and presently the

730 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [12]

layer is differentiated into two distinct layers. The outer of these layers
is finely granular, and contains very few longitudinal fibers. In it the
radiating and circular fibers predominate. The inner layer, on the other
hand, is coarsely granular, and contains a cousiderable number of longi-
tudinal fibers. The outer of these two layers soon separates from the
other along the line of fine circular fibers to form the projecting pos-
terior edge of the segment. Next within the graniilo-muscular layer is
a thin layer of circular fibers, and within this again a thick layer of
longitudinal fibers. The latter are very large, although not at this point
in distinct fasciculi. Farther back towards the posterior end they be-
come fascicled. The connective tissuein this layer appears finely granu-
lar in transverse sections, while in longitudinal sections it appears as a
network of delicate fibers which fills up all the interstices between the
longitudinal fibers. The longitudinal fibers of the inner part of the
granular layer do not differ essentially from those of the longitudinal
muscle layer proper, except that they are more scattered, while their
interstices are filled with connective tissue in which are numbers of
both coarse and fine granules, highly colored in carmine-stained sec-
tions. The longitudinal muscular fibers in general do not lie parallel
with each other. They form, indeed, a maze of interlacing and appar-
ently anastomosing fibers whose general direction is longitudinal. The
diameter of the largest single longitudinal fibers in the granular layer
is about .004Ium, and, in the longitudinal muscle layer proper, twice as
much. The longitudinal muscle- layer is separated from the inner core
of the segment by a thin layer of circular fibers. It is, moreover, inter-
rupted at the margins where it is penetrated by the margins of the
inner core. The latter is fusiform in transverse section, and contains
the reproductive organs. It is crossed by numerous fine transverse con-
nective fibers, and extends nearly to the margins of the segment, where
it appears to be continuous with the inner granular layer. It is quite
narrow except in ripe segments, where the center becomes very much
enlarged on account of the presence of the numerous ova. The central
mass of ova enlarges at the expense of the longitudinal muscle layer.
The walls of the segment are also bulged outward by the mass of ova.
The reproductive apertures are near the median line on one of the
lateral sides. They are very close together and rather small. Each
aperture represents a pair of sexual organs, cirrus and vagina. Upon
making a few longitudinal sections on the lateral face which bears the
reproductive apertures, the small vaginal opening comes into view.
It opens into the common aperture from behind and near the surface.
The larger aperture continues into the cirrus-bulb, which has thick mus-
cular walls composed of circular fibers. The cirrus was retracted in all
cases. It is about .OOSwm in diameter. The bulb is rather long and
descends into the segment vertically nearly to the middle. The rela-
tive position of the various organs was not ascertained with entire sat-
isfaction. The vagina, however, lies close to the posterior side of the

[13] NOTES ON ENTOZOA OF MARINE FISHES. 731

cirrus-bulb and communicates with the ovary. The latter organ is
centrally placed and lies next the inner side of the lateral muscular
. wall on the side opposite the genital aperture.

I The testes are represented by granular masses in the marginal parts
. of the inner core.

The following measurements will assist to an understanding of the
proportions and arrangements of the various muscular layers of the
body: thickness of inner core at center .10"""; near margin .08mm ;
thickness of longitudinal muscle layer .2lnln ; thickness of inner granu-
lar layer .12mm; thickness of outer granular layer .16mm. The layers
of circular fibers are very thin, averaging about .Olimu in thickness.

Breadth of inner core, margin to margin, 3.Gnnn ; breadth of segment

4.111111

Longitudinal sections were carried through several contiguous seg-
ments. In these there were no septa to indicate a division of the body
into true segments. The only indication of a segmented condition
is the superficial character of projecting posterior edges. The longi-
tudinal muscles are continuous and the ovaries are crowded together
so as to form an almost unbroken zig-zag line. So far as any internal
characters go, the body is practically continuous.

The above observations were made on sections lightly stained with
ammonia carmine. The sections used in the description are from one
of the specimens from Tetrapterus albidns.

Habitat. — Tetrapterus albidus, intestine, young and adult, July, 1885 ;
Histiophorus yladius, intestine, adult; August, 188G. Off Newport,
Rhode Island.

3. Dibothrium punctatum Eudolphi.
[Plate n, Figs. 1-4.]

Boilirioceplialus pnnctatns Rndolphi, Entozoa Hist., m, 50, and Synopsis, 138
and 475. Lenckart, Zool. Bruchst., 40 and 04, PI. I, 40. Dmmmond,
Charleswortk's Mag. of Nat. Hist., n, 574. Eschricht, Isis 1839, 344, and
in Nov. Act. Nat. Cur. i, xx, Snppl. u, 77 and 59, PI. in, 17-18. Dujar-
din, Hist. Nat. des Helm., 617. Bellingbam, Ann. Nat. Hist., xiv, 254.
Van Beuedeu, Bull. Acad. Belgique, xvi, n, 278, and in Meui. Acad.
Belgique, XXV, 1C1, PI. xxi. Spencer Cobbold, Trans. Linn. Soc., xxn,
157. Olsson, Lnuds Univ. Arsskrift, IV, 11. Von Linstow, Compeud.
Helm., 237.

Dibothrium punctatum Rndolphi, Diesing, Syst. Helm., i, 593; Sitzuugsb.,
xin, 579; Revis. der Ceph. Ab. Par., 240. Leidy, Proceed. Acad. Phila.,
vn, 444, and vni, 46. Molin, Denkscb. d. kais. Akad, xix, 235.

For additional bibliography, etc., see Diesing's Syst. Helm, and Revisions.

Diesing's description of tbis species is as follows : Head oblong, rather broad,
with oblong lateral bothria. Neck none. First segments elongated, sub-
sequent segments snbquadrate. Genital apertures opposite on tbe lat-
eral face of each segment. Length, 300 to 450min.

This species has been very fully described by Mueller, Rudolphi,
and others. It is said to be an abundant species in various fishes of

732 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [14] |[l;il

Europe, Cottux, /SVw^m.v, Gadu*, Pleuroncctes, Trigla, Ithombns, etc.
Eleven species of European fish are enumerated by Diesing as harbor-
ing this parasite. It has been recorded in this country by Dr. Leidy in
Platessa plana (P^eudopleuronectes americanus).

I refer to this species two lots of Dibothria obtained from the intes-
tines of the spotted sand flounder (Lophopsetta maculata) and the
sand dab (f Amanda ferruginea). The first lot containing one complete
specimen and a few fragments of others, with a few cestoid cysts from
the peritoneum, was the sole result of an examination of seven floun-
ders. In the second lot about a dozen fish were examined, nearly all of
which were infested with an echinorhynchus (E. acns). These fish
were taken with the trawl by the U. S. Fish Commission steamer Fish
Haivk, south of Martha's Vineyard, Massachusetts, in about 12 fathoms
of water. Their stomachs contained several species of Annelids, frag-
ments of Squilla, and several specimens of a species of Margarita.

The sketches of the living worm (Figs. 1 and 2) were made from the
specimen obtained from L. maculata. Its dimensions while living were
as follows :

Millimeters.

Length 200.00

Length of head 2.40

Breadth of head at apex 0. 24

Breadth of head, middle 0.42

Breadth of head, base 0. 22

Breadth of first segment at an terior margin 0. 20

Breadth of first segment at posterior margin 0. 24

Length of first segment 0. 36

Breadth of one of posterior segments 2. GO

Length of same 1.20

Associated with this specimen, and doubtless belonging to it, was a
chain of mature segments, each of which was about 2.11111U in length and
I1""1 in breadth.

The head of the living worm showed little tendency to change its
shape. It maintained constantly the proportions shown in Figs. 1, 2.

It is rather flat, broadest in the middle, and tapers uniformly with
convex margins toward each end. It is terminated in front by a slightly
tumid apex. The base of the head continues in a short neck-like part,
which has a projecting border on the posterior edge like that of the
segments. The marginal pits are quite deep. In front they extend to
the tumid apicular part. They terminate behind at about the posterior
fourth or fifth of the entire length of the head, leaving a short, con-
stricted neck-like part.

The only motion observed was a slow change in the edges of the
bothria, which at times were nearly parallel and at others were pro-
foundly crenulated, In active specimens they are evidently capable
of assuming very various shapes.

After having been preserved in alcohol the head is of nearly uniform
breadth throughout. It is slender and arcuate, measuring 1.8mm in

[15] NOTES ON KNTOZOA OK MARINE FISHES. 733

length, an«t 0.16""" in breadth at the apex, increasing to 0.2'""1 in the
widest part. The length of the first segment is 0.28""", its breadth in.
front 0.1 lmm, behind 0.15""". The anterior segments for about 1(>""" back
of the head are quite slender. The body, indeed, for this distance is
decidedly filiform, and for that reason it is very difficult to determine
whether the bothria are to be regarded as marginal or lateral with ref-
erence to the body. Secondary segments appear at about the twelfth seg-
ment from the head. These are formed by a division of each segment
into two by means of a median transverse line. This is repeated farther
back in, much the same manner as described under D. microcephalum.
This evidently explains the phenomenon which the posterior segments
present of being welded together in groups of three or four, an appear-
ance which is quite characteristic of the posterior segments and which
has been alluded to in various descriptions of this species. The pos-
terior segments are squarish, with the posterior edge of each slightly
overlapping the following segments, and thus giving to the strobile a
serrate margin.

About 40inm from the head the reproductive organs become visible.
In a specimen rendered partially transparent with glycerine they appear
as a median row of white opaque masses 0.2mm long and O.OG""" broad,
lying transverse to the longitudinal axis of the worm, parallel to each
other and very close together. The apertures of the reproductive or-
gans are lateral, all on one side, and may be seen following the median
line as a row of small elevated papilhe. In the middle of the strobile
there sometimes appear to be as.many as four or more papilhe to a sin-
gle segment. These compound or fused segments probably divide into
simple segments as they mature. Toward the posterior end of the
strobile, along with and on the reproductive papilla), are clusters of ova
which have been extruded from the ripe segments. The ova are yel-
lowish-brown in color. On this account the median segments have a
median baud, which is equal in breadth to about one-third the breadth
of the segment, and which is rusty yellow, or yellowish-brown, or in
alcohol almost black. On either side of this median band the segments
are punctate with brownish spots. Upon the opposite lateral face of the
strobile also small bunches of ova were seen, which had been extruded
from minute pores in the vicinity of the median line.

The ova are rather large, elliptical or long oval in outline; length,
0.058""" ; shorter diameter, 0.0271""1.

The vessels of the water vascular system are quite distinct in a speci-
men which has been placed in glycerine.

734 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [16]
The two specimens from Limanda ferruginea Lave, iu alcohol, the fol-

lowing dimensions:

No. 1.

No. 2.

Length

Mm.
98 00

Mm

75 00

1 60

3 °0

Breadth of head at apex

40

40

50

48

Breadth of head, base

50

60

18

16

Breadth of first segment

48

50

1 00

80

Breadth of posterior segment

2.00

2 50

Greatest breadth of body

3 50

2 75

The appearance of these specimens, especially with respect to the
head and anterior segments, is quite different from that of the speci-
men from Lopliopsetta maculata. Moreover, the heads of these two
specimens differ with respect to each other. I do not, however, recog-
nize any difference, either in proportions or in special characteristics,
that can not be explained as due to different states of contraction. The
Leads of these latter specimens are arcuate, a condition which is plainly
the result of unequal lateral contraction of the longitudinal muscles ;
they are blunt at the apex with slightly tumid edges, as in the first
specimen. The fossa? are plainly lateral. This feature was uncertain
in the first specimen, but in these it is quite evident on account of the
highly contracted and consequently flattened condition of the anterior
segments.

Although the head of one of these specimens is twice the leugtL of
the other, there can be no doubt that the specimens are specifically the
same. The shorter head is of nearly uniform size throughout, averag-
ing about .5mm in diameter. It is crossed by exceedingly fine transverse
wrinkles, most abundant at the base. These are evidently the result
of contraction. The longer head is more slender for the greater part of
its length than the other, but thicker at the base. It is, as a whole,
somewhat cuneiform in shape.

When these specimens were placed in glycerine, with a little acetic
acid added, the central axis of the head was brought into view. This
is seen to be abruptly constricted behind the capitate apex, swollen im-
mediately behind the constriction and again at the base of, the Lead,
while in tLe middle of the head it is slender.

The fossa3, whicL are marginal with respect to the Lead but lateral
with respect to the body, are profound, and extend in one nearly, in
the other quite to the base of the head.

The segments begin immediately behind the head and are at first

more than twice as broad as

long.

In this feature they are quite dif-

[17] NOTES ON ENTOZOA OF MARINE FISHES. 735

ferent from the first specimen. They differ also from most descriptions
of this species. The segments in question ha*ve, however, every appear-
ance of being much contracted. Fine transverse lines appear on the
faces, while the margins are wrinkled ; the segments themselves are
quite thick and stout. A short distance back of the head the segments
are alternately shorter and longer, as noted in the first specimen,
while toward the posterior end of the body the adult segments are ar-
ranged in groups of from four to six simple segments, as if the latter
were partially fused together, which is another characteristic of this
species.

The ova have the same dimensions as in the first specimen, and are
collected in oval or oblong masses. Here and there a mass occurs
whose size far surpasses those of adjoining segments, and which causes
the walls of the containing segment to bulge out into a prominent lateral
lump. This feature was also observed in the first specimen.

The external openings of the oviducts are on one side in the shape
of a row of lateral pores along the median line. The reproductive
apertures are on the opposite side. Of these, but one, the male, could
be certainly made out in the specimen when examined entire in glycer-
ine. In nearly every case the cirrus was protruded. It is short, coni-
cal, and stands about the middle of the segment on the median line. It
was difficult to get exact measurements of the length. The following
dimensions, which were obtained by turning the strobile on edge and
measuring the cirrus in outline, are nearly correct : Length, .1""" ;
breadth at base, .04mm ; breadth at apex, .026"u". When retracted it
becomes a very short papilhe. Upon examining a few segments in
glycerine, with an enlargement of some three hundred diameters, I
noticed that there were two ducts leading to the common opening. One
of these was continuous with the protruded cirrus. The other led to a
point behind the cirrus and at its base. I am inclined to believe from
this that both reproductive organs have a common cloacal opening
about the middle of the segment and on the median line. If this is
the correct view, the vagina is quite small and opens immediately be-
hind the cirrus. This differs materially from Van Benedeii's figures of
this species.

I have had some hesitation with regard to referring these speci-
mens to D. punctatum, principally on account of its small size.

Drummond, however, in his "Notices of Irish Entozoa" (Charls-
wor th's Mag. Vol. n, p. 574) speaks of this worm as follows :

1 have found it largest in the brett, exceediug oven 3 feet iu length and as many
lines iu breadth ; in the coitus I have found it 2 lines broad, and from 12 to 18 inches
long, but in the turbot, so far as niy observation hasyetgouOj it is seldom more than
a line broad, and varies in length from 8 to 18 inches.

Since the hosts in which my specimens were found are closely related
to the turbot of the other side of the Atlantic, it is of interest to note
that the size of these Dibothria corresponds, in the main, with that of
those which Drummoud has found in the turbot.

736 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [18]

Habitat — Lophopsetta maculaia, August 10, 1887, Limanda ferruginea,
September 6, 1887, Wood's'Holl, Massachusetts.

4. Dibothrium mlcroceplialum, Budolphi.
[Place n, Figs. 5-18.]

Tcenia tetraodontis rnolw, Viborg, lud. Mus. Vet. Hafii., 241 ; Rudolpbi, Entoz.

Hist, in, 213.
Bothriocephalus microcephalus, Rudolpbi, Synops., 138 and 473 ; Drumnioud,

Cbarlawortb's Mag. Nat. Hist., iv, 241; Dnjardin, Hist. Nat. des Helm.,

619; Bellingham, Ann. Nat. Hist., xiv, 253; Von Linatow, Couipend.,

der Heliu., 274; Olsson, Lund's Uuiv. Arsek., in, 55, and iv, 11; Vau

Beneden, Mem. Acad., Belgiqtie, xxxvui, 87.
Bothriocephalus sayittatus, Leuckart, Zool. Brucbsfc., 39, PI. i, 15.
Dibothrium microceplialum, Rudolpbi, Dieaing SyaL-Heliu., i, 592 ; Sitzungsb.,

d. kais. Akad., xm, 578; Revis. d. Cepb, par., 241 ; Wagoner, Nov. Act.

Nat.'Cur., xxiv, Suppl. 16, 69, PI, VII, 77; Van Beuedeu. Bull. Acad.,

Belgique xxn, II, 521.

Head, sagittate ID marginal, oblong in lateral, view, with a rounded
button-like apex. Botliria lateral obJong, neck none, anterior part of
body slender subcylindrical, median and postero-median part broader
and thicker, narrower towards posterior. Body cylindrical or sub-
quadrate in front and rather thick throughout. First segments some-
what funnel-form, subsequently becoming very short and broad, pos-
terior segments short and narrow, squarish or sometimes indistinct.

Genital apertures marginal. Length in alcoholic specimens as much
as 6GO""", greatest breadth 7.5"IU1.

A lot of Dibothria containing thirteen individuals from the intestine
of a sunfish (Mola rotunda) was collected by the U. S. Fish Commission
off Martha's Vineyard, Massachusetts, September 10, 1886, and sent to
me after my return from the laboratory at Wood's Holl, Massachusetts.
I have therefore not had the opportunity of studying these parasites
while they were living. All the data for this description were derived
from the study of alcoholic specimens.

I have experienced much difficulty in reconciling differences between
my specimens and previous descriptions. While I have little doubt
but that the specimens in question are specifically identical with those
figured by Wageuer and Leuckart, there remains yet much to be de-
sired in the way of a detailed description of the animal.

Among the thirteen specimens, all of which were adult and approxi-
mately of the same size, there was one which differed from the others in
having an extremely small head and smaller and narrower anterior
segments. The head had but little more than half the linear dimen-
sions of the others, while the anterior segments were longer by nearly
a third, and less than half as wide. The bothria, moreover, extended
but a little way back over the first segment, while in the others they
over-lapped the first two segments. The general outline of the head
remains in other respects much the same for the two varieties.

[19] NOTES ON ENTOZOA OF MARINE FISHES. 737

These differences can not be accounted for by supposing different
states of contraction, although it is true that contraction can and does
give rise to differences in shape as well as in size. In this case, how-
ever, the differences are so profound, and, what is of still greater im-
portance, so abrupt, there being no gradation by intermediate forms.
I have felt myself obliged to recognize it by establishing two varieties.
The specimen with the smaller head and narrower anterior segments I
shall denote as variety a, the other as variety ft. One might indeed be
justified in sep^i/dting them yet further and calling them distinct spe-
cies if the same" sharp distinction is observed in other collections. In
that case variety a should retain the name D. microcephalum^ and va-
riety ft should be referred to Leuckart's I), sayittatum.

Both Leuckart and liudolphi mention the occurrence of individuals,
some of which had relatively large, others relatively small heads. In
the specimens which these observers examined, however, this difference
could be accounted for apparently by a difference in the age of the spec-
imens. The younger and immature individuals had relatively larger
heads and longer anterior segments than the more mature specimens
possessed.

I have recorded a similar difference in a lot of Dibothria from the file-
fish (Alutera sclicepfii} (U. S. Fish Commission Report, 1886, pp. 458,
459, PI. i, Figs. 5-8). In that case both varieties were equally imma-
ture. In the present instance both varieties are equally mature.

While there is, therefore, almost sufficient grounds for establishing a
new species, or rather for separating the present species into two and
restoring Leuckart's species, which has been united with D. microceplia-
lum, I shall for the present be content with referring both kinds to D.
microcephalum, but shall distinguish the kinds as var. a and var. ft, re-
spectively. Wageuer's figure, which is sketched from a young speci-
men and gives a lateral view of the head and first segments, bears a
very close resemblance to var. «. Leuckart's figure also represents a
lateral view of the head and anterior segments. It bears little resem-
blance to either variety, but resembles var. ft more than it does var.
a. In it the head is represented as being bluntly rounded in front,
while in all the specimens in the lot upon which this account is based
there is a constriction near the anterior end which produces a blunt
button-like apex. The head in lateral view is therefore oblong and
not sagittate, as in Leuckart's figure.

The terms marginal and lateral as applied to the head in this de-
scription designate those sides which correspond to the marginal and
lateral sides of the body, respectively, although this use of the terms
gives rise to the anomaly that the marginal diameter of the head is
greater than the lateral.

A comparison of Fig. 6 with Fig. 9 might lead one to infer that there
is a great difference between the two varieties with respect to the ap-
pearance of segments at the posterior end. While this is true in many
H. Mis. 133 47

738 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [20]

cases it does not represent a necessary condition of things. Some of tho
individuals of var. ft showed the same indistinctness with regard to the
occurrence of segments at the posterior end as is shown in Fig. 6 of var.
a. Indeed, as will be shown further on, the segmentation in this worm
is more apparent than real.

In the following detailed description I Save not attempted to keep
the varieties separate. The varieties themselves have been sufficiently
defined in the foregoing and in the figures.

The head is small, sagittate in a marginal view, oblong in a lateral
view. Near the anterior end is a constriction. The part in front of
this constriction is short, projecting in a thick lip with rounded edges
and bluntly rounded in front, nearly circular or somewhat quadrangular
when viewed in front, but usually with a slight lateral emargi nation
corresponding to the faces of the bothria. The latter organs are two in
number, lateral, oblong, rather deeply hollowed out in the center with
moderately thin edges, free and slightly flaring at the posterior ends.
In most of the specimens of this lot the edges of the bothria are irreg-
ularly crimped or crenulate. A. cross-section of the head shows that
the edges of the bothria are thin, so that a section made transversely
through the middle of the head resembles two crescents with their con-
vexities truncated and then applied to each other. The bothria in
most of the individuals (var. ft] extend to or beyond the posterior edge
of the first segment. In one it reached quite to the posterior edge of the
second segment. There is no neck. The central core of the head be-
comes gradually thicker and broader until it merges into the first seg-
ment. A series of transverse sections carried on into the second seg-
ment shows the outer tissues sloughing off until a concentric ring is
formed which indicates the posterior part of the first segment where it
overlaps the anterior part of the second.

The anterior part of the body is rather slender, and slightly flattened,
usually linear for a distance of 30 to 40mm, then increasing in breadth
uniformly until the greatest breadth is attained, which is about the
middle of the total length. This breadth is maintained until near
the posterior end where the body becomes distinctly narrower. In some
the posterior end tapers to a blunt point. This is notably the case in
var. a. One specimen, No. 4 of table, p. 350, measuring 010mm, was linear
for the first 50mln. In the next 75mm it increased in breadth gradually to
3.5mm ; 60mm farther on it had increased in breadth to Cmm. Tbis breadth
it maintained within varying limits to near the posterior end. In var. a
the breadth of the first part of the body increases slowly but uniformly.
At a distance of 25 or 30mm it is lmm broad ; 45mm from the head it is
2.5mm broad j 100mm from the head 5.5mm broad.

The segments which immediately follow the head are decidedly funnel-
form, the large posterior edge of each inclosing the nawow anterior end
of its successor. These in some cases are followed, in the anterior part
of the body, by segments with parallel lateral margins, and with the

[21] NOTES ON ENTOZOA OF MARINE FISHES. 739

posterior edge thin and flaring outwards at nearly a right angle. Sooner
or later, however, these segments are crossed by transverse rugsc,
which give rise in turn apparently to secondary and tertiary segments
until, in the widest part of the body, the segments or pseudo-segments
become so crowded together as to resemble transverse wrinkles.

The following details with regard to the feature just alluded to, al-
though taken from var. «, do not differ materially from what is shown
by var. /?.

About the fifty-second segment, which, in this individual is 20mm
from the head, a median transverse line makes its appearance, which
becomes more strongly marked on the next, and on the next yet more
pronounced. The fourth primary segment following the fifty-second
was plainly divided into two secondary segments, the posterior seg-
ment of this pair being the larger. Beyond this point the segments are
alternately larger and smaller, until about the seventy-eighth segment
where the same phenomenon is repeated, the secondary being divided
into incipient tertiary segments, the transverse lines become more dis-
tinct, and about the eighty-second segment give rise to distinct tertiary
segments. At a distance of 56mm from the head the primary segments
can still be distinguished by their more prominent projecting posterior
edges. The latter are at this point about 1.25mm apart. Between them
are six segments which are alternately larger and smaller. The pri-
mary segments can be traced for at least 200mm from the head. Beyond
that point no difference could be discerned, all the segments having
become very much crowded and rugajform.

In another individual the secondary segments begin about the forty-
fifth from the head, and the tertiary about the sixty-fifth. The distinc-
tive features of the primary segments are quickly lost.

In No. 4 of the table the forty-sixth and forty-seventh segments are
divided into secondary segments, but no further indication of second-
ary segments is visible until the sixty-third. Tertiary segments begin
about the eighty-fiftk segment, or 65mm from the head.

Another specimen, No. 5 of table, is somewhat narrower in habit than
the others, and presents more irregularity in the formation of secondary
and other segments. The third and fourth segments are welded to-
gether. Between the fifth and sixth, sixth and seventh, seventh and
eighth segments is a single secondary segment. Each of the next three
primaries bears two secondaries. On each of the next two primaries
there are three secondaries. On each of the four following primaries
there are five secondaries. These may be better described as primary
segments of two sizes. There is no indication that the smaller are de-
rived from the larger, and these irregularities may be due possibly to
differences of contraction. Secondary segments like those observed in
the other specimens occur about the ninetieth segment, a distance of
some 40mm from the head. In this individual the greatest breadth is
4.5mm ; breadth at posterior end 1.4mm ; length of posterior segments
about .65mm.

740 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [22]

In many of these specimens the segments become rather indistinct
near the posterior end on account of transverse wrinkles on the seg-
ments which resemble the dividing line between two segments. In No.
4 the segments 12mm from the posterior end are 3.5mm wide and .5mm
long. The last but one measures lmm in length and l.S'"m in breadth
at the front end, narrowing to 1.2mm at the posterior end. The last seg-
ment is 1.4mm broad and 1.25mm long, tapering to a bluntly rounded
point.

The following measurements are introduced for the purpose of fur-
nishing a basis of comparison between the two varieties. It will be
observed that No. 1 differs uniformly in its head dimensions from the
others, between which there are but few differences. No. 1 is var. a,
the others are var. ft.

Dimensions.

No.l.

No. 2.

No. 3.

No. 4.

No. 5.

mm.

655. 00

mm.
470 00

mm.
534 oo

mm.
610 00

mm.
660 00

Length of bothria

0 86

1 54

1 60

1 54

1 80

Breadth of head, anterior, marginal ...

0 44

0 74

0 80

0 70

0 7S

Breadth of head, anterior, lateral

0 48

0 80

0 80

0 74

0 78

Breadth of head, posterior, marginal

0.70

1.36

1.34

T 40

1 46

Breadth of head, posterior, lateral

0.54

0 84

0 80

0 70

0 80

Breadth o f first segment, anterior, marginal

0 18

0 40

0 08

0 50

0 66

Breadth of first segment, anterior, lateral

0.50

0 90

0 90

0 80

0 90

Breadth of first segment, posterior, marginal

0.50

0.80

1.06

0 76

1 OS

Breadth of first segment., posterior, lateral

0.56

1 24

1 96

1 22

1 42

Length of first segment

0 26

0 30

0 34

0 36

0 39

Some of the measurements in numbers 2 to 5 marked first segment
were really taken from the second segment, on account of the anterior
part of the first segment being obscured by the overlapping bothria.
The drfference between the first and second segments is, however, in
all cases very slight.

In variety a one of the lateral faces is marked by two distinct linear
grooves, parallel with the margins, each about 1.5mm from the nearest
margin. These are not distinct until about 125mm back of the head; are
most distinct in the middle of the body, but continue to the posterior
end. Similar lines occur on the opposite face, but they are very faint.
They probably outline the water vascular canals. They were not seen
in the other specimens.

The presence of ova is indicated in the alcoholic specimens by a dark
median line which, in var. a, begins 135mm back of the head, and con-
tinues to within Gmm of the posterior end. In the other specimens the
ova begin at about the same point. In some (Fig. 9) the ova continue
to the last segment, and the posterior segments are rather distinct. In
one individual of var. ft there is the same kind of termination to the
body as in var. a. Several of the specimens had been mutilated in collect-

[23] NOTES ON ENTOZOA OF MARINE FISHES. 741

iug, so that it was not possible to determine the normal condition of the
posterior segments.

The ova are amber colored, oval, .07 and .04mm in the two diameters.
They are usually collapsed on one side into a bowl-shape. They are
observed in some cases lying in small clusters and making a zigzag line
on one of the lateral faces of the strobile. The masses of ova \vithin
the strobile do not seem to coincide with the segment, but, as they de-
velop, push into the adjoining segments, so that the median line of ova
is an almost continuous one.

The cirrus is long, slender, marginal, irregularly alternate, and pro-
trudes from the middle part of the margin of a segment.

The cirrus bulb is pyriform, and lies with its larger end towards the
middle of the body. It is directed a little posteriorly, and extends a
little beyond the marginal vessel of the water vascular system. The
longest cirrus observed measured lmm in length, and was .04mm in
diameter at base, and .02nuu in diameter at the apex. The segments
are deeply wrinkled at the marginal genital aperture, the wrinkle
extending about one-third way to the median lateral line.

The marginal vessels of the water vascular system can be easily traced
when the specimens are placed in glycerine. Their position is shown
in the figures. It will be observed, from Fig. 6, that the vessels unite at
the posterior end, at which point there is a terminal pore-like pit.

The foregoing remarks are based on what could be made out without
the aid of thin sections. On account of limited time from other duties,
and the large amount of material upon which I have to report, 1 can do
little at present in working out the detailed anatomy of the Eutozoa
referred to me for identification. I have made, however, in this case
a lew sections which enable me to demonstrate some points in the
anatomy of this worm that may be properly recorded in this place.

Anatomy of the head and first segments. — Both transverse and longi-
tudinal sections of the head and first segments and of mature pro-
glottides were made from specimens stained in toto in carmine and
ha3iuatoxyloii, respectively.

The sections were about .02ram thick.

The first two transverse sections of the head are densely and coarsely
granular at center, finer toward the edges, with fine interlacing muscu-
lar fibers. The coarse granules are evidently the cut ends of longi-
tudinal muscular fibers. In shape they are irregularly triangular. In
the third section the interlacing fibers are more plainly seen and there
are besides four clear spaces so situated that if they were joined by
straight lines they would mark the four angles of a parallelogram. The
coarse granules still constitute the mass of the tissue. In the next three
or four sections the clear spaces are better defined and the longitudinal
muscles are not so dense at the center. Each clear space is joined to
its fellow along the longer side of the parallelogram by a curved line
which is convex towards the center. Transverse muscular stria3, .002mm

742 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [24]

in diameter and .014mm apart cross each other at right angles in the cen-
ter, more or less obliquely in the vicinity of the clear spaces. These
transverse muscular fibers appear as curved lines with their convexities
towards the center of the head. The cross-sections of the longitudinal
fibers, while irregular in outline, have a tendency towards triangularity.
The greatest diameter of any single fiber measured was .00">min. Other
larger patches were observed, but they seem to represent the coales-
cence of two or more single fibers. The sections of the head are at this
point elliptical. The cuticle is not clearly defined. The clear spaces
gradually lose their distinctness on account of the increase of transverse
fibers. At about the sixth section the transverse fibers begin to be ar-
ranged in fasciculi. Two of these fascicles are quite evident and join
opposite pairs of clear spaces in the direction of the greater diameter of
the section and along the longer sides of the central rectangular space.
The longitudinal fibers become less dense along lines which radiate from
the angles of the central rectangular space, while bet ween these radiating
lines they appear to have become massed together more densely. The
clear spaces do not have definite outlines and are certainly not closed
vessels. They are crossed by the radiating transverse fibers and ap-
pear to have loose cellular or granular contents. This feature is quite
evident in the first sections, where nucleated cells were observed in the
continuation of these irregularly outlined vessels in longitudinal sections
of a specimen stained with ha3inatoxylon. Next the two dense masses
of longitudinal fibers, which lie opposite and outside of the longer sides
of the central rectangular space, appear as two rings of dense granules
with a clear center, which is made up of two parts, an inner of transverse
or radial fibers, and an outer reticulated part. These two parts soon
separate. The inner one, with a deep notch in the middle, is the extreme
anterior end of a bothrium, the outer reticulated part is the cuticle of the
posterior side of the apical disk of the head. This feature continues for
several sections, and shows that the anterior ends of the bothria are
above the constriction and near the apex of the head. Transverse fibers
predominate in the vicinity of the constriction, while longitudinal fibers
predominate in the anterior disk. This fact was confirmed by both
transverse and longitudinal sections. The cuticle immediately in front
of the constriction is clearly defined and appears in transverse section
as a dense layer of fine stria3. It is about .Oil"1111 thick.

Clearly defined sections of aquiferous vessels were not found in sec-
tions made at the constriction or anterior to it.

The outline of a section at this point is quadrangular, with bluntly
rounded angles and concave sides; the two sides on which the bothria
lie are very deeply notched. Fascicles or bauds of transverse fibers
run in a very complicated way from one side to the opposite side and
also diagonally from one side to the adjacent side. The longitudinal
fibers do not have at this point any definite arrangement. A little far-
ther back the corners of the quadrangular sections project and curve

[25] NOTES ON ENTOZOA OF MARINE FISHES. 743

toward each other where the thin lips of the bothria are cut through.
The bottom of the bothria consists of a layer about .03mm thick of dense
transverse interlacing stride. Along the sides the tissue is looser, with
open cellular spaces about .005mra in diameter. There is here a more
definite arrangement of longitudinal fibers, which now lie in four masses,
one in each of the projecting corners of the quadrangular sections.
Each of these is at first somewhat circular with a clear central space,
a character which is presently lost. A narrow layer also lies along
the face of each bothrium immediately under the layer of transverse
tissue. Another mass lies opposite the middle of each of the shorter
sides of the section. The transverse fibers still predominate, however,
and even the masses of longitudinal fibers are quite abundant.

Two large, irregular, clear spaces, crossed by a few transverse fibers
and filled with a granular substance, which is but slightly stained by the
carmine, indicate the continuation of what was seen iu front of the
constriction. Besides these there are a number, at least four on a side,
of small spaces with definite outlines, which on account of their irreg-
ularity in contiguous sections are readily interpreted to be sections of
aquiferous vessels which pursue a spiral course. This was further
proved from longitudinal sections. Near the middle of the head a
transverse section has the appearance of two crescents pressed together
by their convex sides. The distance through the head from the bottom
of one bothrium to the bottom of the other is only .2mm, while the oppo-
site diameter is .5Gmm. Several vessels, as many as six on a side, were
counted beside the two large irregular, nervous (?) vessels. Each of the
latter is .054 by .032mm in its two diameters, the longer diameter corre-
sponding to the longer diameter of the sections. At this point the longi-
tudinal fibers are pretty evenly distributed. Back of the middle the cen-
tral part of the head grows thicker and wider ; the margins, which at
first were gently concave and then strongly einargiuate, assume a more
and more even outline, then bulge out into the rounded convex outlines
of the margins of the segments. The head is thus seen to pass imper-
ceptibly into the first segment.

In some of the sections there were remains of what appeared to be a
dense layer of columnar epithelium lining the bothria. This layer was
still adherent to the inner edge of the thin lips of the bothria and ex-
tended nearly to the bottom of the pit. Becoming separated from the
underlying cuticular layer the detached portions break up into groups
of curved cells. The thickness of this layer, coinciding with the length
of the component cells, is .008mm.

The sections which passed through the posterior parts of the bothria
also cut the posterior parts of the first segment. As the sections pro-
gress through this part, an outer concentric layer, about .09mm thick
and containing radiating, transverse, and circular fibers, separates,
leaving a central oblong core, which contains the aquiferous and nerv-

744 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [26]

ons (?) vessels. The body, indeed, can not be said to be distinctly seg-
mented.

The water vascular system at this point consists of four principal
vessels, situated in pairs, each pair lying on the inner side of what I
take to be a lateral nervous vessel. The diameter of the aquiferous
vessels is from .013 to .027mm. The two nervous vessels are larger,
being from .027 to .054nim in their longer, and slightly less in their
shorter diameter. Each of the latter is flanked on the sides next
the lateral faces by two other small vessels which appear to be of the
same nature. No nucleated cells were observed at this point in these
vessels, but they contain a net-work of connective tissue, some of the
meshes of which are filled with finely granular substance, while others
are empty.

An oblong, central part of these sections has the two nervous ves-
sels at its extremities; in it also lie the aquiferous vessels, with an
occasional transverse vessel. This central space has a few transverse-
fibers crossing it, but is made up for the most part of fine connective
tissue in which are numerous small cells which are deeply stained with
carmine, averaging about .003mm in diameter, and each containing several
dark granular specks. These cells are quite different in appearance
from the cut ends of longitudinal fibers, and present the same appear-
ance in both transverse and longitudinal section. Moreover, the cen-
tral core does not show longitudinal fibers in longitudinal sections.
Granular cells, similar to the above, are scattered pretty generally
through the tissues.

The longitudinal muscles of the body are arranged in four principal
bands, two lateral and two marginal. These muscles are very strongly
developed. Outside the four bands of longitudinal muscles is a layer
of circular muscles with radiating and longitudinal fibers interspersed.

A longitudinal section shows the lateral nervous* canals to be some-
what irregular in diameter and without definite walls. They pursue, in
the main, an tindeviating course, while the aquiferous vessels, which,
with reference to the nervous canals, lie towards the center of the body,
have a pretty uniform diameter, and pursue an irregularly spiral
course. A few nucleated cells were observed in the nervous canals.

Further investigation is needed to demonstrate the exact nature of
vessels which I have called nerves.

Anatomy of the proglottides. — Sections made near the posterior end
of one of the longest strobiles show an outer, dense granular layer in
which are numerous very fine circular fibers with a few radiating fibers.
Within this layer$ which is about .lram thick, is another layer of very
powerful longitudinal fibers. These occur in fascicles averaging .027mm
in diameter. This layer is limited on both sides by a thin layer of cir-
cular fibers; it is complete except at the two margins, where there is a
short interval where longitudinal fibers are wanting.

The reproductive openings are marginal, about the iniddleof theseg-

[27] NOTES ON ENTOZOA OF MARINE FISHES. 745

meut, now on one side, now on the other, with a tendency for several to
succeed each other on the same side. The cirrus arises from a pear-
shaped pouch, whose walls are composed of fine interlacing contractile
fibers. In most cases the cirrus is retracted and lies coiled up within the
pouch. The larger end of the pouch is directed towards the median
line, at its base lies the vas deferens in a voluminous mass. The testes
occupy considerable space. The large granular masses, of which they
are composed, are most abundant towards the margins, where they fill
the central parts of the proglottis. Towards the middle of the prog-
lottis they are displaced by the female genital organs.

The ovaries are situated near the posterior edge of the proglottis
near one of the lateral faces, which, for convenience, I will call the
ventral face. The ovary itself viewed laterally is an oblong, many lobed
organ, made up of globular, nucleated cells, some of which measured
from .008 to .013mm in diameter. The ovary in its widest place equals
about one-third the breadth of the proglottis, and is about one-half as
long as broad. Its average depth in the specimens measured is less
than .2mm. From its anterior part the vagina arises and passes outwards
towards the margin, then ascends dorsally on a level with the cirrus
pouch, the dorsal edge of which it follows closely. It opens near the
small end of the cirrus bulb, so that the two organs, cirrus and vagina,
have a common cloacal opening on the margin of the proglottis. The
position of the vaginal opening was demonstrated only after long and
careful search. The oviduct originates at the anterior part of the ovary
and is continued into a long and much convoluted tube, which in all the
segments, except those that constitute the anterior slender part of the
strobile, contains numerous amber-colored eggs.

Before sections were made, ova were seen in little clusters on one of
the lateral faces of the body. When section s were made it was discovered
that these pores not only actually exist, but that they are of invaria-
ble occurrence on the mature segments. They are not in any sense
caused by a rupture of the wall of the proglottis, but are definite aper-
tures. They lie on the ventral side, that is, the same side of the prog-
lottis as that on which the ovary lies, and near the anterior edge, a lit-
tle to one side or. the other of the median line. They thus form an
irregular zigzag line along the middle of the ventro-lateral face. The
oviduct communicates directly with this excretory pore. Mature ova
were found in what appeared to be rather immature segments. A shell-
gland was demonstrated, somewhat doubtfully, however, in front of the
ovary. The egg-inflated oviduct so crowded the middle space of the
segment as to render it very difficult to make out the relations of the
various parts.

It is to be noted that there is no really clear dividing line between
the segments when seen in longitudinal section. The relationship of
Dibothrium to Liyula is thus clearly demonstrated.

746 REPORT OP COMMISSIONER OF FISH AND FISHERIES. [28]

5. Dibothrium plicatum, Kudolphi.

[PI. in, Figs. 1-6.]

Eclilnorlujnchiis xipJiiw, Gmeliu, Syst. Nat., 3047. Zeder, Naturg., 162. Ru-
dolpbi, Eutoz. Hist., II, W8.

Botliriocephalus pUcatus, Rudolpbi, Syuops. 136 and 470, PI. in. 2. Bremser,
Icon., PI. xm, 1 ami 2. Creplin, Nov. Obs. 87,JP1. 11, 12-14; Erscb. and
Grub. Eucycl., xxxn, 297. Dujardin, Hist. Nat. des Helm., 614. Van
Beueden, Meni. Acad. Belgique, xxxvin, 36. Olssou, Lund's Uuivers,
Arsskrift iv, 11, PJ. in. Fig. 66. Von Linstow Comp., Helm., 218.

Bothriocephalus iruncatus, Leuckart, Zool. Brucbst., I, 37, PI. I, 13.

Dibothrium plicatum, Rudolpbi, Diesing, Syst. Helm., i, 591; Revis., Cepb.
Par. 243. Wagener, Nov. Act. Nat. Cur., xxiv, Suppl. 71, PI. vm, 94, 95,

This Dibothrium is peculiar tothecommon sword-fish (Xipliiasgladius},
having never yet been found in any other host. Following is the
description given of it by Diesing:

Head sagittate, compressed truncate at tbe apex, witb oblong, lateral botbria.
Neck long, soinewbat terete, swollen at tbe base, segments very sbort, at lengtb
longer, witb tbe posterior margin crisp-undulate.

I have referred to this species five specimens of Dibothria from the
rectum of Xipliias gladius. The head and neck of each of these para-
sites were completely buried in the walls of the rectum. The part thus
buried measured about 13lniu. The cavity in which the head and neck
were inclosed was, in each case, an enlarged cyst-like space filled with
transparent, watery lymph. These,spaces were noticed on the outside
of the rectum, lying immediately under the serous membrane, and were
at first taken to be encysted larval cestods, but upon cutting into one
of them the inclosed head and neck, except in one case, to be noticed
further on, were observed to be attached firmly to the inner muscular
layer of the rectum. After cutting away the remaining tissue from the
enclosed necks they were found to be continuous with the bodies of
some large Dibothria which lay in the lumen of the rectum and were
attached to its walls. The color of the head and neck was bluish-
white, that of the body grayish-yellow. After removal from their host
the worms were placed in sea- water, where they at once contracted to
about one-half their former length, while, at the same time, they be-
came much broader and thicker, with the segments so crowded together
that only their posterior edges were visible. They then had assumed
the characteristic shape and appearance which is shown in the sketch
(Fig. 1). Before they had thus contracted they bore a close resem-
blance to D. manubriforme (U. S. Fish Commission Keport for 1886,
pp. 456-458, PI. i, Figs. 1-4). The length of one after thus contracting,
exclusive of the head and neck, was 54mm, while its greatest breadth
was l^mm. Another measured 66mm in leugth, with a breadth of 7mm
throughout nearly its whole length, narrowing abruptly, however, at
the last three or four posterior segments, which measured 2mm in
breadth.

[29] NOTES ON ENTOZOA OF MARINE FISHES. 747

The head is short, in preserved specimens oblong, or even orbicular
in lateral view, sagittate, compressed in marginal view, blunt at apex.
Bothria lateral, each with shallow concavity and thickened edges, pos-
terior border slightly projecting. Length of bothria in two specimens
1.75mm and 2.4">mm, breadth 1.58:um and 2""" respectively.

That part of the body may be conveniently called the neck, which,
along with the head, is inclosed in the cyst-like cavity within the recti-
nal walls. It is broader than the head and quite irregular in outline.
It is characterized by having the cuticle raised into several irregular,
transparent folds. At places the neck is thus rendered much broader
than the head. At the point, however, where the rectinal walls are
pierced by the neck the latter is compressed on all sides and so reduced
to a slender cylinder. At its base the neck enlarges abruptly, becomes
transversely striated, and thus merges imperceptibly into the body
proper.

Two alcoholic specimens yield the following dimensions for the head
and neck :

Dimensions.
«

Xo. 1.

No. 2.

Mm.
1.75

Mm.

2 00

Diameter of head, marginal

.70

.?8

Diameter of neck, lateral .'

2.85

2.45

Diameter of neck, marginal

1. 75

1.40

The measurement for the marginal diameter of the head, given
above, was made about the middle of the bothria. Of course the mar-
ginal diameter taken through the bases of the bothria would approximate
that of the neck. The measurements of the neck were made a short
distance back of the head and at about the broadest and thickest part
of the neck. At the more slender, cylindrical portions of the neck,
near the base, the diameter varies from .5 to lmm.

The body, at first elongated, when placed in sea-water and in alco-
hol becomes rather stout. It broadens abruptly back of the neck and
soon attains its maximum breadth. In some specimens this is main-
tained until near the posterior end, in others the body tapers slowly to-
wards the posterior end. The posterior mature segments are very nar-
row at their anterior end, with broadly flaring posterior borders. Where
a few of these are retained on the strobile, they appear like a nest of
cups of graduated sizes, with widely flaring lips, piled one within the
other. In cases where the narrow posterior segments have been lost
the posterior end of the strobile is often deeply emarginate. The seg-
ments begin immediately behind the neck, are extremely regular and
very short. Their posterior edges are free and project at right angles
to the axis of the strobile. They often become undulate with short,
crisp folds, which fact imparts the peculiar characteristic appearance to
the worm which doubtless suggested the specific name.

748 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [30]

111 a mature segment which had been placet! in glycerine, it was seen
that the reproductive aperture, in the shape of a prominent papilla wns
situated at the margin, or rather on the anterior face of the marginal
projection. The diameter of the apex of this papilla, which doubtless
represents the base of the cirrus, was .16mm.

A single small individual (Figs. 2 and 3), found entirely inclosed and
free in a cysfrlike cavity, which was filled with transparent, watery
lymph, as in the case of the others, appears to be a young specimen of
this species. In it the bothria are much more elongated than in the
others and the head is truncate with a tumid border projecting on all
sides and a minute papilla at the apex. Segments in the shape of fine
transverse lines begin immediately behind the head. The posterior
segments resemble those of the adult. The specimen is, in fact, a small
copy of the larger ones whose bodies were dependent from the inner
walls of the rectum. The dimensions obtained from measurements of
this small specimen while it was still alive are as follows :

Millimeters.

Length 13.0

Breadth of head at apex 1.2

Length of hothrinm .*. 3. 0

Breadth of bothriuui 1.2

Diameter of neck 2.0

Length of posterior segments 1.0

Breadth of posterior segments 1.5

The following data with regard to the anatomy of the segments were
obtained from a study of a series of longitudinal and transverse sec-
tions of portions taken from the middle and the posterior end of an
adult specimen. The appearance of these sectionr:, particularly of the
longitudinal ones, is very peculiar and indeed unique among the Di-
bothria. In a series of about ninety longitudinal sections carried
through a piece taken from the posterior end of a strobile, only about
one-third of the number proved to belong to the segments proper. The
remaining two-thirds belonged to the prominent posterior edges which
lie about .00mm apart. These edges protrude marginally as wellas'lat-
erally to a distance equal to nearly one-third the total breadth of the
strobile. In longitudinal sections, through the middle of the segments,
these free edges form a pectinate border on each margin. Such sections
resemble a comb with teeth on the two opposite edges. The teeth are
of different shapes, some are acute, others club-shaped. These free
edges of the segments consist of two muscular walls with a central
space, which is filled with irregular granular bodies. The latter are
probably a part of the reproductive system. The reproductive organs
proper are borne, not exactly on the margins of the segments, but on
one of the lateral faces of the marginal projection. The cirrus pouch is
very muscular, and in median section is long, oval, or slipper-shaped.
The outer part contains the invagiuated cirrus, which seems to be a
very thick-walied and muscular organ, at least at the base. The inner

[31] NOTES ON ENTOZOA OF MARINE FISHES. 749

part contains a narrow convoluted tube which appears to be a part of the
vas defereus. The coils in the outer part when cut across appeared in
section as concentric rings, thus proving that they were the coils of the
iuvaginatcd cirrus. The coils in the inner part, in the same section,
gave no evidence of concentric rings, but were tilled with small gran-
ules. The latter had sharp outlines and were of nearly uniform size,
.003mm in diameter. There was in these sections no evidence whatever
of a segmented condition of the body except in the projecting edges.
The central part of the body appeared to be absolutely continuous.

The musculature, as revealed by a low magnifying power, consists of
an outer circular layer, covered by the cuticle, and an inner longitudinal
layer. The latter is very strongly developed. The fibers of which it is
composed are many times larger than the circular fibers. They show
by their irregular course, looking as if anastomosing with each other
iii an irregular network, that they were in a state of profound contrac-
tion at death.

In some transverse sections from the middle of the body, a convo-
luted tube was observed which lay beside the cirrus bulb and appeared
to open at the outer end of that organ. It follows that face of the bulb
which is toward the middle of the marginal projection. Its outer end
is wide and appears to be a kind of receptaculum seminis. It can be
traced to a glandular mass of uncertain outlines, presumably the ovary,
in the middle of the segment. If this is the vagina, then both repro-
ductive organs open marginally. It can not be a part of the vas deferens,
because the latter was seen as a distinct tube, entering the base of the
cirrus bulb and connecting with the coiled tube in the inner part of the
bulb.

On a few segments from the middle of the body, small lateral openings
were observed, which were situated about half way between the median
line and the margin. These were on but one of the lateral faces and
were not found on many segments. They are probably pores which
communicate with the oviduct and are designed for the escape of ova.

The segments from the posterior end of the strobile have a space in
the center filled with ova. These are large with thick shells and gran-
ular contents. The normal shape is long oval but owing to the appar-
ently plastic nature of the shells they occur in very various shapes.
Measurements of the largest perfect ones gave the length as much as
.lmm, with the shorter diameter from .04Gmm to .063miu. The shell as
seen by transmitted light has a thickness of .0025mm. A few ova were
observed with one end truncated. From this fact I am led to suspect
that the ova of this species may be provided with a terminal operculuui
for the escape of the embryos, but this can not be demonstrated from
my mounted sections.

There are several discrepancies to be found in existing descriptions
of this worm. Diesiug and others recognize a neck. Dujardin states
that there is no neck. I believe that there is no true neck, but that

750 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [32]

that part of the body which becomes enveloped by the tissues of its host
degenerates into a fleshy cylinder from which all traces of segments
are lost. It is easy to see how this result can follow upon such condi-
tions when it is remembered that about the only indication of a seg-
mented condition is the thin projecting posterior edges of the segments,
so that when these disappear the central core of the body would appear
without segments. For convenience of description, however, it will be
well to call that part of the body the neck which in the adult becomes
so distinctly modified at the point of attachment.

Olsson states, with a query, that the genital apertures are lateral.
Since the apertures in question occur about the middle of the free
marginal edges of the segments, and the cirrus pouch lies wholly
within that free margin, I think there should be no hesitation in say-
ing that the genital apertures are marginal.

Habitat. — Xiphias gladius. Off Martha's Vineyard, Massachusetts,
July 25, 1887. In rectum, five adult specimens, one young.

6. Dibothrium rugosum Eudolphi.

[Plate in, Figs. 7-10.]

Boihrioceplialus rugosus, Riulolplii. Eutoz. Hist., in, 42 ; Sytiops., 137. Leuck-

art, Zool. Bruchst.. 57. Dtijardin, Hist. Nat. cles Helm., 617. Cobbokl,

Traus. Liiin. Soc., xxir, 158, 159. Olssou, Lund's Uuiv. Arsskrift, iv, 10,

PI. in, Fig. 65. Von Linstow, Compend. Helm. 236.

Dibothrium rugosum, Rudolph!, Diesiug, Syst. Helm., I, 591; Revis. Ceph.

Par., 240-241. G. R. Wagener, Natuurk. Verb. Haarlem, xiu, 93.
For older synonymy see Diesiug's Syst. Helm.

Head sub-sagittate, witb oblong lateral botbria. Body with a median furrow and
unequally articulate. Lengtb, 300 to 900mm.— Dicsing.
Lengtb, 300mm to lm ; breadtb, 1.2 to 4mm.—Dujardin.
Genital apertures marginal, irregularly alternate. — Olsson.

I have referred to this species a small lot of Dibothria from the intes-
tine of the cod (Gadus morrhna). The specimens were collected by
Mr. Thomas Lee, of the U. S. Fish Commission steamer Albatross, on
the Grand Banks. Mr. Lee stated that he examined one hundred and
fifty cod and found parasites in but a few of them.

Each of the specimens in this lot has the head and anterior part of
the body buried in the pyloric creca, where they have undergone degen-
eration to such an extent that no appearance of bothria remains.
Around the parts thus enveloped by the creca is a yellowish waxy de-
posit, the degenerated tissue of the caeca. This adventitious tissue in-
vests the worm, so closely that it would be absolutely impossible for the
parasite to free itself from its host. This feature is mentioned also by
Cobbold, who makes the following statement with regard to Dibothria
from the cod :

In a cod examined on the 15th of March, 1855, two specimens of Hothriocephalus
rugosus had severally attained a length of 15 inches, and their anterior segments, for
an inch or more downwards, were so liruily impacted within the pancreatic caica

[33] NOTES ON ENTOZOA OF MARINE FISHES. 751

that it was found impossible to dislodge them without injuring the filamentary head
and neck. As if to make the anchorage doubly secure, the cartilaginoid thickening
of the invaded pancreatic cajcum had degenerated into a calcareous and contract' <l
cylinder, twisted upon itself in various ways.

The specimens were in alcohol when they were submitted to me; I
am therefore unable to give measurements ot living specimens.

The largest of the specimens measures C55mm in length. The ante-
rior part for a distance of 20111IU was buried in one of the pyloric caeca
and was removed with difficulty, by cutting away the enveloping coiouin.
The latter had degenerated into a brown, waxy secretion, which was en-
veloped by the serous coat, and formed a much twisted, rigid tube sur-
rounding the anterior part of the worm. When this encasing tube was
removed, it was found that all appearance of bothria or anterior seg-
ments had disappeared. That part of the worm which had been in-
closed in the tube was reduced to a slender white filament about .5mm
in diameter. In another specimen the inclosed anterior part was irreg-
ular in outline and graduated into a yellowish, corneous substance at
the tapering apex. In this case the anterior end of the parasite had
undergone a degeneration of its tissues similar to that of the creca of
its host.

The body is not distinctly segmented at first, but is crossed by in-
numerable fine wrinkles. The breadth near the anterior end is 2.5nim.
It narrows abruptly at the point of entrance to the ca3cum. Near the
middle of the body the breadth is 3.5mm, the length of the segments
.85mm, increasing to lmm. The posterior part of the body, for a distance
of about 40mm, is much wider, with crowded segments. Breadth, Guim;
length of segments, .45mm. This is evidently due to unequal contraction.
Thickness of the body about lmm in front, and approximating 2"im in
median and posterior segments. Another specimen had the following
dimensions: Length, 560mm; anterior part, inclosed in crecal tube, Gmiu
in length, .4mm in diameter; breadth near anterior end, 2.5mm ; middle,
5mm. length of median segments, .7mm; breadth at beginning of posterior
fourth, 4mm; length of segments, lmm ; breadth at posterior, 6mm ; length
of posterior segments, .45mm ; body rather plump, posterior half about
2mm thick.

One of the lateral sides of the strobile has a row of apertures making
an irregular zigzag series along the median line. These apertures are
oblong, the long axis coinciding with the long axis of the body. These
lateral apertures were at first naturally taken to be the genital aper-
tures. A careful examination with an ordinary lens revealed what ap-
peared to be marginal apertures. These were indistinct, but I was led
to make transverse and longitudinal sections of a series of segments in
order to demonstrate the position of the genital apertures.

The first sections were made from, segments taken from the posterior
end of the body. The marginal position of genital apertures was at
once proved. In all cases where they were observed the external open-
ings were obscured by the close approximation of the sides, so as to form

752 REPORT OF COMMISSIONER OF FISEI AND FISHERIES. [34]

a wrinkle when viewed from the exterior. This fact explained the dif-
ficulty experienced in finding the marginal apertures with a superficial
examination. The lateral apertures seem to be designed for the escape
of ova.

The mature segments, as shown by these sections, are simply sacs
with muscular walls for the protection of tlie eggs. A transverse section
is long oval, 2.6 by l'"m. The lateral muscular walls are from .1 to .IG"1111
thick, the marginal walls from .16 to .24mm thick. The segments are
separated from each other by a narrow partition from .02 to .06mm
thick. A few irregular shreds of muscular tissue and delicate strands
of connective tissue extend into the hollow, central part of the segment.
Otherwise, the segments are filled with granular bodies about .03mm in
diameter. In sections stained with hneinatoxylon these are colored
violet; and each is closely invested in a transparent, unstained mem-
brane which has an irregular or tattered outline. Some of these gran-
ular bodies which lay near the muscular wall of the segment were in-
closed in a net- work of muscular and connective tissue. In these the
investing membrane was not so prominent as in those masses which lie
farther from the walls of the segment. It would seem, therefore, that
the membranous investment of the granular masses is a result of the
degeneration or transformation of the muscular and connective tissue
of the interior of the segment. In the vicinity of the lateral apertures
several collapsed shells of ova were observed. These were unstained,
and were .027 and .016mni, respectively, in the two diameters.

One undoubted ovum was seen with granular, stained contents, and a
very thin, transparent shell, .02 and .01Gmm in the two diameters. In
order, if possible, to prove the real nature of these granular masses I made
transverse and longitudinal sections of postero-mediau segments. In
these segments the ovary is voluminous and composed of distinct _nu-
cleated cells, nearly circular in outline and from, .008 to .014mm in diam-
eter. The nuclei were about .0025mra in diameter. The ovary lies at the
middle of the posterior part of the segment with its greatest length
transverse to the axis. It equals a little less than one-fourth the
breadth of the segment and about one-fourth the length. These pro-
portions must be subject to considerable variation, inasmuch as the
ovary disappears completely in the posterior segments. At its thick-
est point, the ovary extends from the inner limit of one lateral muscu-
lar wall to the other. The ova are already abundant in these segments.
They are enveloped in a proper shell, which is thin and has an irregular
outline, owing to a wrinkling of the surface. This wrinkling or corru-
gation of the surface is apparently due to a contraction of the proto-
plasmic contents. They are approximately circular in outline, their
average diameter being about .025mlu. From a comparison of sections
made from postero-inedian segments with those from posterior segments
I am led to believe that the granular bodies contained in the latter are
ova with incomplete membranous shells.

[35] NOTES ON ENTOZOA OF MARINE FISHES. 753

*

The testis, in the postero-mediau segments, is represented by several
large granular masses situated towards the marginal portions of the
internal cavity. A convoluted tube, lying at the base of the cirrus
bulb and communicating with it, is evidently the vas-defereus. This
tube appears finely fibrous as if filled with fine filamentary particles. I
have noticed a similar appearance in some living cestods in which case
the presence of spermatozoa was demonstrated.

I was not able to fix the position of the vagina to my entire satisfac-
tion. In a few sections the cut end of a tube was observed near the
cirrus bulb and on its posterior side. This, if it represent the vagina,
would indicate that that organ opens behind the cirrus. Olsson, how-
ever, figures the vagina of D. rugosum, as opening anterior to the cir-
rus. I may be able to clear up this matter by further examination of
the material at my disposal.

Musculature of posterior and postero- median segments. — In passing
from the exterior of the muscular wall of a posterior segment to the in-
terior, one finds first a thin cuticle, next a thick, dense granular layer,
in which there are very numerous radial fibers which in turn pene-
trate the third or inner layer. This third layer consists for the most
part of very large longitudinal fibers arranged in fascicles. The fasci-
cles, in transverse sections, are somewhat triangular, with the apex of
the triangle directed toward the exterior. The triangular transverse
section of one of these fascicles measured .05 umi in length, .03 mm at base,
and .013 "im at the apex. These fascicles are largest along the lateral
sides, and smaller but more numerous at the margins. In longitudinal
sections they appear as broad parallel bands of muscular fibers, the in-
dividual fibers of which are about .002 mm in diameter.

The reproductive organs are irregularly alternate and open on the
margin of the segment near its anterior edge. In the mature segments
only the male organ could be made out. The cirrus was retracted and
lay in a slender pouch. This pouch lay wholly in the muscular wall
with its base near the interior limit of the wall and its apex at about the
limit between the outer granular layer and the inner layer of muscular
fasciculi.

The musculature of the postero-median segments was plainly shown
in the sections, and some additional data were obtained. The parts are
an outer, dense granular layer with fine radiating fibers. On the inner
side of this layer is the layer of longitudinal fasciculi. The latter are
really immersed in the granular Jayer. Transverse sections of these
bundles are oblong, usually narrowing a little toward the exterior end,
occupying a radial position. The largest lateral ones are fully .08mm
long and .027mm broad. They are separated from each other by spaces
about as wide as their own breadth, and filled with granular and fibrous
tissue, in which radiating fibers predominate. On the inner side of the
layer of longitudinal fibers is a thin layer of fine circular fibers which
H. Mis. 133 48

754 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [36]

•
separates, by a sharp division, the muscular wall from the inner cavity

of the segment, in which lie the genital organs. This layer of circular
fibers spreads out into a thin sheet of fine fibers, at intervals, to form the
septum between two adjacent segments. The fibers of this partition are
transverse, and run in the direction of the longer diameter of the seg-
ment; that is, from margin to margin. This partition is confined to the
inner portion of the segment, and does not extend into the muscular walls.
Elsewhere in the segment the inner space is crossed by fascicles of fine
fibers which pass from one of the lateral muscular walls to the other
without interruption, except where displaced by the developing ova.

Following are the measurements of a transverse section of a postero-
mediau segment : From margin to margin, 2.7mm ; from side to side, .9""" ;
thickness of muscular walls, ,3mra ; marginal diameter of inner cavity,
.2mm ; lateral diameter of same, .36min-

Habitat. — Gadus morrhua, pyloric creca, August 8. 1886, Grand Banks.

Family II.— TETKABOTHRIIDJ3 Diesing.

Tetrapliyllidfe (in part) Van Beueden.

^0

Subfamily L— PHYLLOBOTHRIN^ Van Beneden.
ANTHOBOTHRIDM Van Beuedeu.

The generic characters are thus summarized by Diesing: Body elon-
gated, articulate, depressed. Supplemental disks (auxiliary acetabula),
none. Head separated from the body by a neck. Bothria four, oppo-
site, entire or unilocular, cup-shaped or subglobose, affixed by a con-
tractile pedicel, highly versatile, unarmed. Genital apertures marginal.

7. Anthobothrium laciniatum, spec. nov.
[Plate in, Figs. 10-13, and Plate iv, Figs. 1-3.]

Head with four bothria, pediceled, trumpet-shaped, but capable of
much diversity of form. Faces of bothria concave, with entire circular
margins, but often folded and otherwise distorted by contraction. The
head proper, exclusive of the bothria, is very small, often in the living
worm, appearing to be separated by a slight constriction from the first
segment. Neck, in one variety, none, or very short ; in another, vari-
riable in length, but evident, cylindrical, or quadrate, and terminated
behind by four lacinire. First segments usually much broader than
long, rather quadrate, i. e., rectangular in cross-section, laciuiate. In
some the slender lacinise of one segment overlap the succeeding seg-
ment, and are longer than the body of the segment. In other cases the
anterior part of the body is extremely attenuated, in which case the
anterior segments may be considerably longer than broad ; the laciniie
are then onl}T about one-third the length of the segment proper. In yet

[37] NOTES ON ENTOZOA OF MARINE FISHES. 755

other cases, and usually iu those with evident neck, the laciuiae, instead
of being long and slender, are short, stout, and truncate at the distal
end. Median segments short and crowded, somewhat flattened, and
with bluntly rounded laciuiie, or with a broad crenulatiou on posterior
edge. The following segments increase in length, becoming at first as
long as broad, subsequently longer than broad. The posterior seg-
ments, which may be three times as long as broad, frequently have the
anterior end constricted into a short button-like process. The Iacinia3
persist, but are shorter, broader, and more rounded than at first. Some-
times the posterior edges of the segments are reflexed.

Genital apertures marginal, approximate, about the anterior third or
fourth. Length, 25mm.

Habitat. — Carcharias obscurus, spiral valve, Wood's Holl, Massachu-
setts, August, 1884; July 25, 1887, and August 12, 1887.

This species is near Anthobothrium cornucopia Van Beuedeu, from
Galeus canis, but differs from it iu its smaller size and relatively short
neck. The length of A. cornucopia is given as 250mm, while the maxi-
mum length of A. laciniatum, so far as I have observed, is 25mm. Al-
though no specimens were found whose pioglottides contained ova,
many were found in which the posterior segments were iu other respects
mature, and separated naturally from the strobile.

Amidst the great variety of forms represented by this species there
are two which differ so much from each other that it may become nec-
essary to classify them as constant varieties, in which event they may
be named from their principal differential characteristics, var. brevicolle
and var. filicolle.

The former is characterized by having a short or even no proper
neck, and usually slender, sharp-pointed lacinire on the first segments.
The latter has an evident neck, and often short, broad, truncate lacinine
on the first segments. For the present, however, I prefer to regard
these apparent varieties as simply different conditions of contraction,
on account of which the short neck of some becomes more or less elon-
gated in others.

In ray explanations of figures I have, for convenience, made use of
the terms var. brevicolle and var. filicolle. These and other character-
istic forms are further described in the following detailed account of
the species.

I have obtained this parasite on three different occasions, each time
from the same host, namely, the dusky shark (Carcharias obscurus).

756 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. [38]

Following are measurements of specimens mounted in Canada bal-
sam. The specimens were collected in August, 188 J.

Dimensions.

Ko. 1.

No. 2.

No. 3.

Length

in in.
21 50

mm.
10 00

mm.
6 00

Breadth of head

83

7C

fin

Length of bothrium

50

40

34

Diameter of bothrium, average

30

14

^n

Diameter of pedicel at base . .

12

10

in

Length of neck

1 80

1 10

i fin

Diameter of neck near head

09

12

06

Diameter of neck, baae

14

1°

20

Length of first segment

16

32

(U

Breadth of first segment, front

12

10

16

Breadth of first segment, rear

16

1°

ifi

Length of last segment *.. .

1 36

1 08

68

Breadth of last segment ...

56

56

18

Number of segments

62

65

60

In No. 1 the anterior segments are squarish, quadrate in cross- section,
tbeir posterior corners extended into laciuite, which, like those at base
of neck, are short, stout, and truncate at distal end. In No. 2 the laciniae.
at base of neck are like those in No. 1, but on the first segments they
are rather slender and not truncate. In No. 3 the first segments are
very short and much crowded and the posterior segments have their
laciuiate borders reflexed like a collar. The last two segments are also
soinewhatdistortedaud show a tendency to bend rather sharply towards
one margin. This specimen is evidently jTounger than the others and
the variations which it exhibits may be due to differences in age and
conditions of contraction.

The laciniae on the posterior segments of Nos. 1 and 2 are short and
broad. The bothria in all are terminally verticillate with conical pedi-
cels that enlarge rapidly towards the face, which is limited by a thick
muscular margin.

The following measurements were obtained from living specimens
which were collected July 25, 3887 :

Dimensions.

No.l.

No. 2.

Length . .. .. .

mm.
19. 00

mm.
20 00

Breadth of head .-

.80

Diameter of nock average .. ..

16

06

Length of neck

.32

1.60

Length of first segment

.18

.44

Breadth of first segment

.18

.16

Length of last segment

1.80

1.00

Breadth of last segment

1.06

.16

Number of segments ... ...

120

[39]

NOTES ON ENTOZOA OF MARINE FISHES.

757

Iii No. 1, all the segments were remarkably clear cat and definite.
The posterior end of the neck and first segment laciniate. At about
the twenty-fifth segment back of the head the lappets become rounded
and the segments closely crowded together, with a broad emargination
on the posterior edge. This emargination gradually deepens as the
segments become broader. At about the eightieth segment it becomes
a deep round notch which persists in the mature segments. The genital
apertures were marginal at about the anterior fourth. The bothria were
very flexible and the pedicels extensible. The individuals in this lot
exhibit the same varieties noticed in the two other lots. Some of these
varieties are described in connection with the lot collected August 12,
1887. It is to be noted, however, that the differences that appear to be
so profound in the alcoholic specimens were not so obvious in the living
specimens.

The following measurements are of specimens belonging to a lot col-
lected August 12, 1887 j No. 1 a living, Nos. 2 and 3 alcoholic speci-
mens:

Dimensions.

No.l.

No. 2.

No. 3.

Length ... . -

m m.
13.50

mm.
22.00

mm.
14.00

1.04

1.20

.56

.52

.66

.30

.42

Diameter of pedicel ftt base

.04

.12

.20

.10

.06

.13

.04

.18

.07

.16

2.00

1.80

1.80

.76

.GO

.52

Number of segments . --- .........

74

70

80

In this lot there were five specimens. They were associated with one
specimen of the new species, Platybothrium cervinum, eight specimens of
Orygmatobothrium anyustum, nine of Phoreiobothrium lasium. All were
in the spiral valve. There was also one young purple-red Rhyncho-
botlirlum adhering to the mucous membrane of the pyloric part of the
stomach. The place of attachment of the latter parasite was locally in-
flamed. There was also another ulcerated spot near by.

In all the Anthobothria of this lot the first segments begin almost im-
mediately behind the head, without an evident neck, and this, too, in
specimens which are much attenuated in front as well as in those which
are much contracted, so that the first segments are short and crowded
•together.

Two of the alcoholic specimens have the anterior segments very much
attenuated. The bothria also are very much altered in shape from what
was observed in the living specimens. In them the pedicels are elon-

758 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [40]

gated and slender, the botbria surmounting them as flattened or col-
lapsed disks. No perceptible difference could be noticed in these speci-
mens while tbey were in sea-water. When placed under the compres-
sor, one of them became somewhat attenuated as shown in the sketch
(Plate IV, Fig. 1).

No. 2 of the above table was probably the specimen which was kept
for some time under the compressor in order to obtain a sketcb, and when
transferred to tbe killing fluid, its tissues still retained tbe position tbey
were forced to assume under the compressor. The bothria in this alcoholic
specimen are irregular patellate, mounted on long slender pedicels, and tbe
first segments are very slender, nearly twice as long as broad. Tbe
lacinire are slender pointed and have a tendency to stand out at right
angles to the axis of the strobile. In tbe otber alcoholic specimen, No.
3, of the above table, the bothria, although somewhat distorted, have
not changed their shape materially from that sbown in Fig. 12, of Plate
in, sketched from a specimen lying free in sea water. Tbe bothria are
trumpet shaped, pedicels narrow at base but not elongated. Tbe ante-
rior segments are crowded, three or four times as broad as long, with
slender sharp pointed lacinse. The posterior segments in all the speci-
mens are, in tbe main, alike.

The bothria in two of the specimens in this lot show a peculiar kind
of modification, resulting from contraction, which, if but a single
specimen were found and so modified, might prove misleading to tbe
identifier. In these, when viewed in certain positions, each bothrium
appears to be divided almost completely into two loculi, by a transverse
constriction. A careful study of this peculiar distortion reveals the
fact that the margin of the bothrium is still entire and the appearance
of a constriction is caused by a protrusion of a part of the thin tissue
which makes the bottom of tbe hollow face of a bothrium. The latter
is transparent, and the thick, muscular, marginal rim of tbe bothrium
showing through it accounts for the deceptive appearance of two lo-
culi on the face of the bothrium. This same phenomenon was noticed
in specimens belonging to the second lot. (See Plate iv, Fig. 2.)

Anatomy of posterior segment. — In one of the posterior segments
from a specimen belonging to lot 3, the marginal genital aper-
ture was .6mm from the front end. This segment was 1.8mm in length
and was .4mm in breadth at the front end, .62mm at the middle, and .5mui
at the posterior end. The ovaries are roundish, somewhat reniform
bodies at the posterior end of tbe segment, lying one on each side of
the median line. They are about .36mm in length and .24mm in breadth.

The cirrus, which appears to be smooth, was retracted in all cases.
Its bulb is pyriform, at right angles to the axis of the segment, the
larger end within. It is .26mm long and .16mm broad at widest part.
The vagina was traced in a gently sinuous course along the median
line from the posterior end of tbe segment, at a point between tbe
ovaries, to the cirrus bulb. It bends around tbe base and anterior side

[41] NOTES ON ENTOZOA OF MARINE FISHES. 759

of the bulb and opens in front of and beside the opening of the cirrus
in a common marginal cloaca. The remainder of the interior of the
segment was filled with roundish or oval bodies about .025mm in diam-
eter. These are probably the spermatic capsules of the testis.

In looking over an unassorted lot of eutozoa from the shark which
was examined July 25, I found sixteen additional specimens of this
Anthobothrium. These present the greatest variety of shapes and fur-
nish examples of most of the forms already noticed, with many interme-
diate forms. The neck, however, in most of them, was moderately elon-
gated. Two specimens were noted with excessively attenuated necks,
the bothria directed forward with their faces appressed.

These additional specimens confirm me in the opinion that the diverse
forms comprised in these three lots are^ specifically identical, the differ-
ences being due, mainly, to different degrees and conditions of contrac-
tion ; while some of the differences are of such regular and constant oc-
currence as to deserve to rank as varieties, or at least peculiarities of
form, which are liable to occur in the preserved specimens.

8. Anthobothrium pulvinatum sp. nov.

(Ptilvinus, a cushion.)
[Plate iv, Figs. 4-9. Plate v, Figs. 1, 2.]

I was at first misled by the appearance of the bothria of this species,
which, in the specimens that I had examined when the following de-
scription was written, were uniformly convex and corrugated, and that,
too, in both the living and the alcoholic specimens.

The specimens were therefore referred to a new genus, Rhodobothrium,
so named because of the rosette-like appearance of the bothria. It
would be unnecessary to mention this change in nomenclature were it
not for the fact that I used the name Rhodobothrium in a communication
to the American Journal of Science and Arts, March, 1889.

I take advantage of an opportunity offered during the progress of
publication to note that the bothria of this species may assume a quite
different appearance from that which is represented in the figures in
this paper. In some cases the muscular ring which surrounds each
bothrium contracts to such a degree that the bothrium, together with its
pedicel, becomes vase-shaped or even globular. The convex, corrugated
surface of the bothrium is, in such cases, retracted, and the bothrium is
terminated by a simple orifice or elongated into a papillary termination
with the small orifice at its apex. When the bothria are thus contracted
the resemblance to Van Benedeu's figures of A. giganteum (Mem. Vers.
I n test., Plate vn, 5-10) is very striking.

The disposition of the genital organs in the mature proglottides is
different from that in E. giganteum, and the cirrus is echiuate instead
of smooth.

7 GO REPORT OF COMMISSIONER OF FISH AND FISHERIES. [42]

The specific naw&-pulvinatum is retained as descriptive of a common,
even if in a measure accidental, condition of the bothria.

Head cruciform, bothria four, directed forwards. The pedicels of the
bothria are short, stout, and conical, bearing on their distal extremity
the cushion-like bothria which are nearly circular in living specimens,
or shaped like the quadrant of a circle in alcoholic specimens. The
margins of the bothria are entire at the base, while their upper edges
are frilled or ruffled and their faces thrown into corrugated folds. Tke
bothria do not bear any supplemental disks, and there is no terminal
papilla or myzorhyuchus to the head. Properly speaking, there is no
head, the four pedicels simply originate from the anterior end of the
body like so many forks. That is. the neck is abruptly quadrivaricate
at its anterior end.

The neck is long, flattened, somewhat enlarged, both in breadth and
thickness near the head. It is crossed by fine transverse lines which
gradually become more distinct and later divide the body into seg-
ments.

The body is long and of approximately the same breadth throughout
or, in alcoholic specimens, somewhat thickened medianally. The first
segments are very short and crowded, increasing uniformly in length ;
median segments widest, broader than long; first mature segments
squarish, then a little longer than broad. Mature segments narrow in
anterior diameter, broad behind, at length easily detached. Free prog-
lottides somewhat elongated. All distinct segments with posterior di-
ameter greater than anterior. Genital apertures marginal ; male and
female approximate near middle of margin. Cirrus very long and
echinate.

Length of specimen 550mm, accompanied with great numbers of free
proglottides.

Habitat. — Trygon centrum, spiral valve ; one specimen, with numer-
ous free segments. Wood's Holl, Massachusetts, August 1, 1887.

The specimen which furnished the data for the foregoing description
was very much larger than any of the associated species of Eutozoa, of
which there were several. The length while living was 550""", and there
were besides, immense numbers of free proglottides, which must have
come from this strobile, as it was the only one of the kind found, and most
careful and painstaking search was made for small forms. Only a small
proportion of the whole number of these free proglottides with which
the chyle was swarming was saved. Upon counting the number, how-
ever, I find that there are about two hundred of them.

My notes made at the time of collecting contain this description of
the head : Seen from the under side, each of the four bothria rises from
a short, smooth, conical pedicel, which enlarges rapidly toward the dis-
tal end. The outer half of the length is made by the frilled and puffed
margin of the cushion-like bothrium, which at first projects abruptly
about midway from the base of the pedicel to the outer surface of the

[43] NOTES ON ENTOZOA OF MARINE FISHES. 7G1

bothrium and beyond the middle point is thrown into numerous small
folds (Plate iv, Fig. 5). In front view, the bothria look like a cluster of
white rosettes with contiguous edges in contact, and thus leaving a four-
sided central space. There is no indication of a terminal papilla to the
head or supplemental disc on the bothria. In the alcoholic specimen
the outline of the bothria has changed from nearly circular to that of a
sector of a circle. This is caused by the flattening of the sides of the
bothria, which touch each other.

Although the specimen was rather active when first placed iu sea-
water, it showed little tendency to change either the shape or the rela-
tive position of the bothria. After it had lain in sea- water for twenty-
four hours it still exhibited moderate activity. The bothria were then
found to be 3mm in length, measured from the base of the pedicel to the
outer margin of the convoluted face, when the head was inclined for-
ward so as to lie nearly on the faces of the bothria.

The resemblance of the head of this worm to a head of cauliflower is
very striking. This simile has been employed by Van Benden also in
his description of Phyllobothrium lactuca.

The living specimen had the following dimensions : Length, 550mmj
diameter of head across the top, 4.5mm; diameter of neck near the head,
1.6mm; thickness of neck, l.lmm; length of last segment, 2min; breadth
of last segment at anterior end, 1"""; at posterior end, 2m!". The spiral
intestine contained enormous numbers of free proglottides which were
about 4.5mm long and 3mm broad.

In the alcoholic specimen the breadth of head across the top is about
4imn; diameter of a single bothrium 2.4mm; diameter of pedicel at base,
l.I"im, near bothrium 1.4mni; length of pedicel and bothrium l.Cmm.

Immediately behind the head the neck is a little wider and much
thicker than it is one or two millimeters farther back. Fine trans-
verse lines are visible almost immediately back of the head, but distinct
segments do not appear until about 25llim back of the head. The transi-
tion from fine transverse lines to the sharp division into segments is so
gradual, that the first distinct segments can be located only for a limit
of four or five millimeters. At the distance of G0ram from the head the
segments average 2mm iu breadth and about .03mm in length. At this
point the segments are broader on the posterior edge than the anterior.
The posterior corners are therefore slightly salient and sharply and
clearly cut. For the last 200mm the segments appear to be mature.
They did not, however, separate easily. They have a rounded or para-
bolic outline in front and are quite distinct from each other. The trans-
verse line, which marks the division between two segments, is uiucli
shorter than the base of the segments. The mature segments are
uniform in size, and symmetrical. The cirrus was extended in many of
the posterior segments as much as .9mm, with a diameter at base of from
.1 to .16Ilim and at apex of .08mm. In the alcoholic specimen some of
the cirri are extended farther than they were observed to be in life.

762 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [44]

Many were from 1 to 2mui in length, and one very slender one 3mm. The
cirri are provided with short, sharp -pointed, broad-based, recurved
spines. Their length is about .005""". They are inserted on an epider-
mal investment of the cirrus, which is easily detached.

Some of the vessels of the water vascular system can be seen when
the specimen is made transparent in glycerine or oil of cloves. Two
large spiral vessels were seen in the neck near the head. A short dis-
tance back of the head they appear to lose their spiral character. In
the head they divide and send branches through the pedicels to the
bothria.

Anatomy of mature segments. — Fascicles of longitudinal muscle fibers
were observed in sections of mature segments. These, which were stained
deeply with carmine, differ from the longitudinal muscles which I have
thus far observed in the Cestods in being distinctly and abundantly nu-
cleated. The fascicles, indeed, appear to be made up principally of small
fusiform muscle cells, which are about .0014mra broad and .0055mm long.
The fascicles themselves vary in breadth from .005 to .014mi", with vary-
ing intervals between approximating the breadth of the fascicles. The
intervals between the fascicles are filled with granular tissue. Outside
the fascicular layer and outside of this again is a layer which contains
fine transverse, circular, and longitudinal fibers. The circular fibers lie
outside the longitudinal fibers.

Iii the free segments the ovaries are seen as large lobed organs lying
symmetrically on each side of the median line. The middle of the seg-
ments is crowded with ova. Near the margins, on each side, are the
granular masses of the testes, while near the anterior end is a large
convoluted tubular mass, made up, for the most part, of the voluminous
vas defereus. The cirrus is of extraordinary length and quite slender.
When retracted, the sheath extends into the interior of the segment, its
base lying close to the posterior folds of the vas deferens. The latter
in section is seen to be packed with exceedingly fine fibrous material,
which appearance I take to be due to the presence of spermatozoa.

The course of the vagina was not satisfactorily traced throughout its
entire extent. Its external opening is immediately in front of the cirrus,
there being, in fact, but a single external opening for the genital or-
gans. It lies close beside the front edge of the cirrus sheath. At the
base of the latter it changes its course from one at right angles to the
axis of the segment and is inclined gently towards the front end of the
segment. I have not yet succeeded in tracing it in a continuous line to
the ovary, but in several sections the vaginal tube was seen both near
its outlet and in the midst of the lobes of the ovary. It seemed to dis-
appear in the vicinity of the vas defereus. As only mature segments
were cut into sections, it seems probable that the tissues of the vagina
had already been absorbed to a considerable extent in its middle
course, in order to give room for the ova, which are not confined to a
definite uterus, but appear to fill the whote inner cavity of the segment.

[45] NOTES ON ENTOZOA OF MARINE FISHES. 7G3

The vagina near its beginning- is tubular, but near the base of the
cirrus sheath it is thrown into short, crisp folds, so that the walls in
section appear frilled or milled.

The ovaries in section when highly magnified are seen to be made up
of what appear to have been originally spherical bodies, but which on
account of mutual pressure have become somewhat polyhedral. They
measure from .008 to .Oi"1111 in diameter. The free segments contain a
few ova. These are oval in shape and had a smooth thin transparent
shell, measuring .028 and .036mm respectively in the two diameters.
The shell incloses a granular mass which measures .014 and .019"1"1
in its two diameters.

Associated with the ova were some spherical granular masses .028mm
in diameter.

Upon examining a lot of small specimens from, the same host that
yielded the large specimen I find an exceedingly small individual which
I shall, for the present, refer to this species. Its dimensions, from the
alcoholic specimen, are the following: Length, 4mm; diameter of head
across top, .52inm; diameter of single bothriutn, .32mm ; length of both-
rium with pedicel, .18mm j diameter of pedicel, .12mm ; diameter of ueckf
.10mm, swelling immediately to .16mm ; distance from head to first seg-
ments, .4mm; length of first segments, .04mm; breadth, .14mm j length of
last segment, .32mm ; breadth, .18mm.

There are about twenty-three segments in all. It agrees with the
larger specimen in the general appearance of the head, the disposition
and outlines of the bothria and pedicels, although the faces of the
bothria are not so distinctly convoluted. It differs in having a slight
constriction back of head, and in the character of the segments, which
instead of being short and crowded at first, soon become square, and
before the middle of the strobile is reached, are a little longer than
broad.

Since writing the foregoing description I have received from Dr. E.
A. Andrews, of Johns Hopkins University, a single specimen, which I
refer to this species. It was found in the spiral valve of a sting ray
at Beaufort, North Carolina, August 8, 1885. The specimen has no
mature segments. One bothrium is missing; the stump of its pedicel
remains, however, to show the position of the bothrium. It differs from
my specimen principally in its smaller size, in the relatively finer convo-
lutions on the faces of the bothria, and the cylindrical, instead of coni-
cal, pedicels.

The length is 35mm ; diameter of head across the top, 2.48mm ; diame-
ter of single bothrium, 1.25nim; length of bothrium with pedicel, .9ram ;
diameter of pedicel, .48mm ; diameter of neck, .68mm. The segments
are all very short and crowded, their length at posterior end of strobile
being about .12"'m, and their breadth l""u.

The head of this specimen was stained with carmine and cut into
transverse sections. The first sections show that the fine convolutions

764 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [46]

which cover the bothria are composed of dense granular tissue. The
convolutions in this specimen are rather narrow, measuring ,014min in
diameter. The sections very soon reveal the presence of what appear
to be strong longitudinal fibers, their cut ends measuring as much as
.OOGIU1" in diameter, A little deeper and sections of large aquiferous
vessels appear in each lobe, and the large muscular fibers become in-
distinctly fascicled. The irregularly sinuous aquiferous vessels trav-
erse the bothria and unite in each pedicel into large vessels which lie
so close together as to resemble a double tube. These evidently repre-
sent the afferent and the efferent vessel of each bothrium. A branch
of this system near the face of a bothrium, in close vicinity to the con-
volutions, measured .027 and .022mm in its two diameters ; in the pedi-
cel they were .032mra in diameter.

Near the base of each pedicel and lying near the aquiferous vessels
there is what appears to be a nervous mass from which branches
ramify to the convolutions of the bothria. These branches, as well as
the mass from which they originate, are sharply differentiated from the
surrounding tissue, are neither tubular nor striated, but uniformly
and finely granular. (Plate V, Fig. 1.)

The first sections to pass through the head are cruciform in outline.
It is here seen that many of the large muscles seen in the first sections
and supposed to be longitudinal are really transverse. Two fascicles
of these muscles from each pedicel cross the head, are continuous with
those of the opposite pedicel and at right angles to those belonging to
the adjacent pedicels, thus forming a square in the center of the section.
The inside of this square is filled with fine granular tissues. Following
these sections are others which show fascicles of muscles passing from
the base of one pedicel into the adjacent pedicels through whose tissues
they ramify. Th^se fascicles make a decussation in each axilla. Out-
side of each decussation there is a bundle of coarse longitudinal fibers
in each axilla.

Two of the sections through the center of the head have a large cen-
tral space filled with fine granular tissues from which branches proceed
into each pedicel. I take this to represent the cephalic nervous system.
A section which passes through the base of the head has a large rect-
angular central space .32min long and .24mm broad, surrounded and limited
by a layer of fine circular fibers and containing the large aquiferous
vessels which here lie in loose coils. The remainder of the body wall
outside the layer of circular fibers is composed of a layer of longitudinal
fascicles of muscles which extends to the cuticular layer. This section
passes'a short distance into the pedicels which are here composed of
large muscular fibers from the outer layer of longitudinal muscles. A
few sections farther back the central space which contains the coils of
aquiferous vessels is more nearly square, Plate IV, Fig. 8. The sur-
rounding layer of circular tissue sends out numerous branches which
ramify through the surrounding layer of longitudinal fibers forming a

[47] NOTES ON ENTOZOA OF MARINE FISHES. 765

loose spongy layer of trauverse tissues in the interstices of which the
longitudinal fibers lie. The anastomosing branches of this spongy or
irregularly reticulated layer unite again at the surface in a rather thick
cuticular layer of circular fibers. A few sections further on the follow-
ing dimensions occur: central space .3mm long and .1C"1"1 wide; thickness
of circular layer .009mm; thickness of reticulated layer .06"""; thick-
ness of cuticular layer .014mm. The aquiferous vessels are here not so
much folded. The central space contained the cross section of one
pair and the longitudinal section of a coil of the other pair. The
remainder of the central space contained some loose areolar tissue.
The inner space grows narrower very rapidly as sections proceed from
the head, and is speedily reduced to a narrow oblong space or core,
enlarging slightly towards the margin, and containing a pair of aquif-
erous vessels near each extremity. Each pair of vessels consists of a
larger and a smaller vessel, lying side by side, the larger one towards
the center of the segment. Between the outer aquiferous vessel and
the margin there is a smaller vessel without distinct outliue. These
two marginal granular vessels or cords can be traced from the cephalic
granular mass. At the base of the head they lie on opposite sides of
the rectangular central space and outside the layer of circular fibers.
The diameter of one of the larger vessels was .045mm ; diameter of
smaller vessel .032mm ; diameter of nervous vessel .022mm ; length of
inner core .45mm ; breadth of section of inner core at middle .022mm ;
thickness of section .4mm; breadth of section .6mui. The narrow core
within its limiting layer of circular fibers is composed of granular tis-
sue, and is at this point reduced to a very slender line. As the sections
proceed the layer of circular fibers which surrounds the central core
becomes thinner and in the last sections made, about I1"1" back of the
head, had become almost entirely dissipated, so that the layer of retic-
ulated or anastomosing tissue extended from the cuticular layer to the
granular core.*

ECHENEIBOTHRIUM Van Beneden.

V

The characters of this genus, according to Diesing, are :

Body elongated, articulate. Head continuous with the body or separated by a
neck with a terminal retractile myzorhynchus. Bothria four, opposite, transversely
costato-plicate, sometimes provided with longitudinal partitions, attached, by the
posterior margin to the head by means of a contractile pedicel, versatile, unarmed.
Os in apex of myzorhynchus. Genital apertures marginal.

I have separated those species which have the characteristic echeuei-
forrn bothria, but are destitute of a myzorhynchus, from the genus
Echeneibothi'ium and have placed them in a new genus Rhinebothrium.

* Dr. J. Niemiec, " Untcrsuchungeu iiber das Nervensystem cler Cestoden," in Ar-
beiten aus dem Zoolog. Institute zu Wien, T. vn, pp. 1-GO, Taf. 1 u. 2, 1838, describes
the nervous system of Antholothrium musteli. It bears a close resemblance to that
which I have made out in A. pulvinatum.

766 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [48]

9. Echeneibothrium variabile Van Beneden.

[See Report of U. S. Commissioner of Fish «ind Fisheries for 1886, pp. 460-462, Plate
I, Figs. 9-13, for description and synonymy.]

I have already noted the occurrence of this parasite in the common
skate (Raia erinacea). Since the description which is referred to above
was published, I have found this Echeneibothrium on two different oc-
casions. On August 29, 1887, I examined twenty-four skates. Their
stomachs were filled with small Crustacea, for the most part Crangon
vulgar is. Some of them contained, beside these, a few Annelids, such
as Nereis and Rhynchobolus. Many of the skates had no parasites.
About a half a dozen specimens of E. variabile and one specimen of
Rhynchobothrium erinacens were obtained from the spiral valve and a
few Nematods from the stomach and spiral valve of a few. On Sep-
tember 6, 1887, 1 examined ten skates and obtained from the lot four
specimens of E. variabile.

I add the following data, based for the most part on notes made
while observing the living worms.

The following measurements are from one of the living specimens of
the first lot : Length 5omm ; length of bothrium, including pedicel, vary-
ing with contraction from .5 to l"uu ; diameters of face of bothrium .24mm
and .6mm ; diameter of myzorhynchus at base about .26mm, length .OStnm;
diameter of neck .14mra ; distance to first segment i.4mm ; length of first
segment .025mm, breadth .16"""; length of median segments .3mm, breadth
,22mm ; length of last segment 1.2Gmi", breadth .42""".

The segments were transversely rugose. The head was opaque,
ivory white ; central core of neck also dense, opaque, white for .4mil! back
of head. When placed in Perenyi's fluid this specimen shrunk to 30mm.
Another specimen in the second lot was first placed in fresh water, then
transferred to alcohol; it measures as an alcoholic specimen 14mm. It
was not measured while living, but it did not shrink so muck as the
specimen which was killed in Perenyi's fluid.

It is very difficult to ascertain the exact number of the loculi on the
face of a single bothrium. The plan of arrangement, however, seems
to be as follows : Three transverse costre and a middle partition divide
the face of each bothrium into about eight loculi. Of these, three pairs
are median and two single loculi are terminal. The bothria, although
undoubtedly capable of expanding broadly, have a tendency to contract
and close up by the appression of the sides and ends, and this too when
first placed in sea-water. Some of the specimens are so much contracted
as almost entirely to conceal the bothrial cortre. None of the specimens
in these lots showed the posterior elongation of the head noted and fig-
ured in my former paper. One specimen, measuring 27nn" in length, was
not so active as the others; moreover no loculi could be discerned,
although the general appearance of the head was the same as that of
the others. The last segments, which were about .6mm long and .4m

[[49] NOTES ON ENTOZOA OF MARINE FISHES. 707

[broad, were convex on the margins and bluntly rounded at the ends.
Another specimen, 10mrain length, had a very irregular outline, the neck
greatly enlarged and the segments much shortened by contraction. A
fragment, 13""" in length, although without a head, exhibited a de-
cidedly progressive motion. The segments were in a state of activity;
their proportions of length and breadth changing rapidly. Some of the
segments of this fragment, when stretched out, had the shape of an
longated parallelogram. One, while in this position, measured .4imn in
eugth and .16mm in breadth ; when contracted it was nearly square
with convex margins, and measured .3tnm in length and .26"im in
>readth.

A small specimen, Gmm in length, presents some anomalies. The
bothria are small as compared with the uiyzorhynchus. The latter is
elongated, conical, smaller at apex than base.

When one of the normal scolices was compressed the bothria cou-
racted, and, so to speak, were absorbed in the head. The head was
rather swollen and globular, while the faces of the bothria, on the side
of the globular head, resembled the sucking disks of Tcenia.

When pressure was relieved the bothria were protracted again on
elongated pedicels, and became very variable in shape and size. When
he bothria were thus extended the head proper was much reduced in
size, and the pedicel of the bothria gave it a cruciform shape.

The myzorhynchus was not observed to change its shape much, but it
s evidently capable of changing its form. There is a terminal os
vhich leads to an inclosed globular proboscis. It is probable that this
)rgan is susceptible of great variation in form, but I have never ob-
served it exhibit any other change than that which was incident to
greater or less protrusion.

One peculiarity, which appears to be characteristic of this worm,
s the cylindrical form of the anterior part of the body. The neck, or
ointless part of the body, is cylindrical, as are also the anterior and me*-
iian segments. The mature segments are also quite plump, but often
rregular in outline. In all the specimens which furnished material for
;bese data, the segments, with the exception of a few mature ones, are
xceedingly regular. The margins are parallel, and the posterior edges
project little, if any, so that the strobile for its anterior and median
portions has an almost entire outline. The cirrus, although not pro-
ruded in any case that was brought under observation, was plainly
seen as it lay coiled up in its bulb. It is slender and echinate through-
out its entire length.

Olsson figures E. variabile, with a rosette-like myzorhyuchus, a feature
that I have never observed in any of my specimens. These speci-
mens which I have referred to E. var labile are also much like E. nffine
Olsson. I have not yet had an opportunity to examine type speci-
mens of European species. Upon comparison with type species this
xmn may prove to be specifically different from any of the closely re-
lated European species.

768 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [50]

RHINEBOTHRIUM gen. uov.

['Pa1//, a rasp.J

Body articulate. Head continuous with the body or separated by a
neck. Neck merging into segmented body or separated by a constric-
tion. Bothria four opposite or in lateral or marginal pairs, faces divided
into loculi by several or many transverse and one or few longitudinal
muscular partitions, mounted on slender pedicels, very versatile, un-
armed, myzorhyuchus none.

Genital apertures marginal.

The genus Rhinebothrium is established to accommodate species
with echeneiforin bothria, but which have no terminal proboscis of any
kind. The presence or absence of such a complicated organ as the
myzorhyuchus of Eclieneibothrium appears to one to indicate a generic
difference. If this view is correct, then species like Van Beneden's Ech-
eneibothrium minimum should be referred to the genus Rhinebothrium.

10. Rhinebothruini flexile sp. nov.
[Plate v. Figs. 3-5.]

Bothria four, opposite, long, slender, versatile, attached at middle
point to head by moderately short pedicels. Face of each bothrium
with numerous loculi in two longitudinal rows, forty, more or less, in each
row. The slender, free ends of the bothria very versatile, bending
readily in any direction, but especially in the plane of the supporting
pedicel and axis of the body. An apparent hinge in middle of face of
each bothrium opposite the pedicel. No head, strictly speaking, except
what is formed by the b itliria and their pedicels. Myzorhynchus none.
Neck short, cylindrical, merging imperceptible into the body. Seg-
ments begin near the head. First distinct segment broader than long,
very soon becoming squarish, then longer than broad ; mature segments
six or eight times as long as broad, subcyliudical or fusiform, narrowed
at the extremities.

Genital apertures marginal, about middle of segment; cirrus echi-

nate.
Maximum length 16mm; length of posterior segments from 1 to 1.6mm,

breadth .2 to .32mm.

Habitat.— Trycjon centrum, spiral valve, twenty-five specimens, Wood's
Holl, Massachusetts, August 10, 1887.

This species possesses some characteristic features which ally it with
Van Beueden's E. minimum from Trygon pastinaca. This is especially
true in respect to the shape of the mature segments and the entire stro-
bile, in fact, excepting the bothria. The differences shown by the latter,
however, are too profound to allow them to be referred to the same
genus. This difference can be readily appreciated when it is remem-
bered that E. minimum is characterized by having the bothria crossed
by eight to ten transverse septan, while R. flexile has in the neighbor-
hood of forty.

[51] NOTES ON ENTOZOA OF MARINE FISHES. 7G9

I found some difficulty in ascertaining the exact number of costoe
and resulting loculi, on account of a tendency on the part of the bothria
to curl up at the free ends. The arrangement of the costa; is as follows :
A thick double muscular band traverses the middle of the face of each
bothri um from tip to tip, like the keel plank in the frame-work of a
skiff. From this middle partition numerous ribs rise, curving outward
and upward to unite in a thick crenulated rim, which forms the border
of the bothrium. To carry out the figure of the skeleton of a skiff, the
curving costte answer to the ribs, and the thick crenulated rim to the
gunwale. The costre are arranged with perfect symmetry on the two
sides. I am not yet certain as to the exact number of these costa?, nor
am I certain that the number is precisely the same in every individual.
I have counted as many as were in view and estimated the number in
concealed and obscure parts with varying results, viz, from thirty-two
to forty and upwards on a side, thus making, in round numbers, from
sixty to eighty loculi on the face of each bothrium. The bothria have
a tendency to bend abruptly at the middle on a transverse hinge-like
iue. The margins of the bothria are usually slightly notched at the ex-
.reuiities of the hinge. The head of the living worm is almost transpa-
ent and the bothria are exceedingly active. On account of their trans-
parency and gracefully curving outlines they are very beautiful objects,
lie pedicels were not observed to contract or lengthen appreciably, and
in the preserved specimens they have changed their proportions but
slightly from what they were in life. In the alcoholic specimens the
pedicels have about the same diameter as the neck, or a little greater,
nd their length does not quite equal their diameter. They appear to
be arranged cruciformly. The bothria in the1 alcoholic specimens are
variously bent. In some their free ends are turned towards the axis of
the body and so curled up as to give the head an almost globular out-
line. In others the bothria are turned in the opposite direction. The
pedicels, as to their origin, are like so many forks branching abruptly
from the apex of the neck, and the bothria are like a terminal whorl of
four petiolulate leaflets at the summit of the petiole of a compound
leaf. There is, therefore, scarcely anything that can be called a head,
if the bothria and their pedicels are disregarded. The short, cylindri-
cal neck is, in some cases, slightly enlarged a short distance back of
the head. •

In five specimens of the lot of about twenty-five there was a small
red spot in the center of the neck near the base of the pedicels. There
do not seem to be any correlated features to distinguish these speci-
mens with the red spot in the neck from the others in which no red
spot is visible.

The two sorts were placed in different vials at the time of collecting,
but the red coloring matter is dissolved out by the alcohol, so that when
I came to study this species after they had been preserved for some
months, there is nothing but the label on the vials to tell that there was
ever any difference between the two lots.
H. Mis. 133 49

770 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [5!

The iieck is crossed with fine transverse lines which, in less than
millimeter back of the head, outline the first segments. These for
short distance are very short but increase in length rapidly. In j
alcoholic specimen, at the distance of 1.4""" from the head, the segmen
are as long as broad ; at a distance of 3""n they are a little over twit
as long as broad; about the middle of the strobile their length is fi>
times their breadth ; the last segment is seven times as long as its grea
est breadth; the entire specimen measured 14mm and the last segmei
1.4mm iu length.

The breadth of the body remains nearly uniform throughout. Tl
posterior segments are usually rather narrow at the two extremities an
swollen iu the middle in the vicinity of the reproductive aperture. Tl
dimensions of one mature segment, somewhat flattened, are : diameti
near anterior end .16""" ; diameter in front, at junction with precedii
segment, .lram ; diameter at middle .22nim ; diameter near posterior en
.12U1U1; diameter at junction with succeeding segment .O8'"m.

When mature segments are placed in glycerine and studied with
low magnifying power, the ovaries may be seen as two long, somewhi
opaque bodies, lying at the posterior end of the segment, one on eac
side of a transparent median space and extending nearly to the midd
of the segment.

The reproductive aperture is marginal, about the middle of the sej
meiit. The cirrus was retracted in all the specimens, but it could I
seen, together with the vas deferens, lying in a coil in the middle of th
segment. Several large ova were observed lying loosely along tL
median line, from the anterior end of the segment back to the front en
of the ovaries. These ova vary greatly in size and shape. They appea
to be quite large in proportion to the size of the segment, and- ar<
moreover, comparatively few. Measurements of average ova yielde
the following results : .017 by .Oil11"" ; .019 by .Olmm ; .022 by .Olllu
,,017 by ,013mm. An elongated ovum measured .05 by .Ollmm ; auothe
,047 by .014ram ; a pear-shaped one was .03mm long, .014mm in its greater
breadth, and .008ium in its least breadth.

The following measurements were obtained from living specimens :

Dimensions.

No.l.

No. 2.

No. 3.

No. 4.

mm.

1 50

mm.
13 50

inm.
16 00

mm.
15 I

.80

CO

80

CO

80

|

Breadth of bothriuui

.10

.20

• 09

. 10

24

1

Distance to first segment

.40

.50

.60

.0

.05

03

.04

o

Breadth of first distinct segment .....

.10

.16

.26

.1

Xjeugth of last segment

.20

1.04

1.40

1.6

Breadth of last segment

.20

.24

.34

r

Number of distinct segments

21

34

40

3

53] NOTES ON ENTOZOA OF MARINE FISHES. 771

Nos. 1 and 2 had the red pigment spot in the neck ; Nos. 3 and 4
'twere without any red coloring matter in the neck; Nos. 1 and 3 were
omewhat flattened under the compressor; Nos. 2 and 4 were notcom-
ressed ; in No. 2 the neck immediately behind the bothria was slightly
\\ollenaiid measured .2nnn in diameter, while beyond the swollen point
ts diameter was as given above ; in the same specimen the fifth segment
eafcroni the end was .SSmm in length ; in No. 4 there were twelve mature
ei jegmeuts. All the mature segments were thickest in the middle and
apered towards both ends.

The vessels of the water- vascular system are very distinct in the liv-
ng specimens ; they could be traced from the anterior part of the body,
^here they lie near the margins, through each pedicel to the bothria.
Jach pedicel contains two vessels, one of which communicates with one
f the marginal vessels of the neck and the other is continuous with
ue of the vessels in the diagonally opposite pedicel; these vessels are
11 sinuous. Strong bauds of longitudinal muscles run from the neck
uto the pedicels and to the bothria. As each of the numerous loculi
cts as an independent cupping-disk, their combined action must enable
be parasite to adhere with considerable power to the mucous niem-
>raue of its host. The cirrus, although retracted in every case, was seen
i sections of a segment to be covered with spines ; the cirrus appears
obe slender and the spines are minute.

In size of strobile, shape of segments, size of ova and echiuate cirrus,
1. flexile agrees with Van Benedeu's E. minimum. There was not a sin-
••le individual in the lot of twenty-five specimens, however, whose bo th-
ia agree with E. minimum.

11. Rhinebothrium cancellatum sp. uov.

[Canccllatus, latticed.]
[Plate v, Figs. G-8.]

H

Head with four lateral bothria, which are elliptical and mounted on
hort pedicels ; faces of bothria with about twenty-one loculi arranged
rOinewhat triliueally ; anterior margins of bothria free, slightly project-
ug, posterior margins appressed,neck broad and flat at base of bothria,
iOmewhat constricted behind head, and almost immediately crossed by
tine, closely-crowded, transverse lines ; distinct segments make their ap-
)earance 1""" or less back of head ; the segments are much broader
ihau long throughout the length of the strobile until near the posterior
md, where they are as long or even longer than broad ; they are convex

n the margins, so that the marginal outline of the strobile is creuulate ;
;he chain of posterior segments is rather moniliform ; the anterior and
nediau parts of the body are crossed at more or less regular intervals
)y distinct transverse lines, which give rise to the deceptive appearance
)f elongated transversely wrinkled bothria j body rather flat and thin;

772 KEPORT OF COMMISSIONER OF FISH AND FISHERIES. [54

length, 25""" ; breadth, 1 to 1.5ml" ; genital apertures marginal; cirru
echinate.

Habitat. — fihinoptera quadriloba; spiral valve; three specimens
Wood's Holl, Massachusetts, July 20, 1887.

The three specimens which furnish the data for the. present descrij
tiou were found in the posterior fold of the spiral valve of the
nosed ray (Rhinoptera quadriloba).

When first placed in sea-water they were rather active. The
tended bothria gave the head somewhat the appearance of a pel tat
leaf. The face of each bothrium is divided into twenty-one pits or locul
The arrangement of these loculi in every case in the living specimen
appeared to be definite and the number constant. There is first
longitudinal row of five comparatively large loculi, occupying the mir
die line of the bothrium; then a small pit at each end, and seven pit
on each side, making twenty-one in all. The loculi are larger toward
the posterior end of the bothria than they are in front. In alcoholi
specimens the edges of the bothria are curled inwards so that it is no
always easy to count the exact number of loculi. The characteristi
appearance of a circle of about sixteen loculi around the circuuifereuc'
of the bothrium and a longitudinal row of five at the bottom of the fac<
of the bothrium can be made out in most cases. In one of the speci
ineus, when cleared up in oil of cloves, there appeared to be eighteei
loculi around the border, which, together with the five central ones
would make twenty-three instead of twenty-one. From this circum
st'ance I am therefore as yet in some doubt as to whether the numbe
of loculi is always constant. The ribs which outline the loculi are thicl
and muscular and give to the margins of the bothria a creuulate out
line. The pedicels are very short and thick. The bothria are lateral
their posterior ends rather thick and slightly flaring. In consequent
of this the head of alcoholic specimens is sagittate in marginal, squarisl
in lateral view. In the living worm, when at rest, the bothria an
elliptical.

The first segments begin as fine transverse wrinkles. In one speci
men the first distinct segments began about lium back of the head anc
were .03nnn long and .4""" broad. What appears to be a characteristic
of the species is the occurrence at short intervals of very distinct trans
verse lines which divide the body into pseudo segments. These upoL
superficial examination might be mistaken for true segments. When
examined carefully, however, they are seen to be made up in each case
of a number of true segments. In one specimen the first of these trans
verse lines appeared 3.2mm back of the head, the next 3.8mm, and follow
ing this two others 5 and 71U1", respectively, from the head. These pseudo
segments are formed in some cases by the natural division between twc
segments becoming very distinct, in others by an entire segment be
coming thin and transparent.

Following are the measurements, in millimeters, of a living speci men

55] NOTES ON ENTOZOA OF MARINE FISHES. 773

jength, 25.55; length of bothrium at rest, .7; breadth, .53; breadth
f head, 1.23; breadth of first segments, about 1 back of head,l ; length,
3; breadth of median segments, .72; length, .15; average length of
losterior segments, .13 ; breadth, .8.

In the above specimen there was a constriction behind the head .28'"'"
n diameter, while immediately behind the constriction the neck was
161""1 in diameter. Near the posterior end of the strobile there was an
nlargenieut due to contraction, which was l.lmiu in diameter. In au-
ither specimen, 20"im in length, the first segment began less than lmm
roin the head, where they were .8mm broad and .05""" long. The median
egments were lAmm broad and .lmm long. The posterior segments
eere narrower, breadth, .44mm, length, .4GU1U1, with rounded angles,
he strobile here being somewhat moniliform.

The vessels of the water- vascular system were quite evident in the
iving specimens, both in the body and the bothria. One set of longi-
udiual vessels, consisting of a single vessel near each margin, was pe-
uliar in that each vessel was quite irregular, swelling out into suboval
nlargements and giving off short lateral branches at intervals. These
nay be nervous vessels.

When the specimens were placed in alcohol the longest of the three
ontracted until it was shorter than the others.

Anatomy of the segments and bothria. — A few of the posterior segments
f one specimen were stained with carmine and cut into longitudinal sec-
ions. The segments all proved to be immature, and consequently only.
b comparatively few points in their anatomy could be made out.

The outer coat of the muscular wall is composed of two layers of
inely fibrous tissue, an outer layer of circular, and an irmer of longitu-
al fibers. In sections these two sorts cross each other at right aii-
?les, forming a net-work with rectangular meshes. Beneath the outer
ibrous layers is a thick layer of densely granular tissue. The granules
tain deeply with carmine, and are from .003 to .OOGnnn in diameter.
Beneath the granular layer is a layer of longitudinal muscle fibers,
ihese are larger than the fibers in the outer longitudinal layer, and
ire arranged in straight, parallel fascicles, which are from .0025 to
0051"1" broad and .0025'"'" apart,

The most prominent organ in these segments is the cirrus and its
jheath. In all cases the former was retracted. The external opening
3f the cirrus is at the margin near the anterior edge of the segment.
' Che sheath, with the inverted cirrus, extends a little past the middle
ine of the segment. The cirrus when extruded must be therefore rela-
tively quite long. The sheath enlarges towards the center of the seg-
nent, where its diameter nearly equals the length of the segment.
The length of one was .28mm ; its diameter at base .027""". The cirrus
toroughout all its length is thickly beset with spines. The spines at
;hebase are much longer and stouter than those along the middle and
at the apex. Some of the basal spines were .008mm in length, and .003U1IU

774 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [56

broad at base. They arc straight, with sharply recurved and hooke
extremities.

I have not yet succeeded in making out the other genital organ
with entire certainty. The sections show near one of the lateral face
a number of irregular masses, which, from their striated appearanc
and absence of stained nuclei, I suspect to represent the convolute
vas defereus. Toward the interior of the segments these give plac
to irregular granular bodies from .02 to .Oi"*11 in diameter, which fi
the interior of the segment around the muscular cirrus sheath. Thes
bodies evidently represent the spermatic capsules of the testes. I fin
no traces of even the beginning of female genitalia in these segment!

Transverse sections of the head show that the loculi are formed by
dense layer of parallel radiating fibers, which is very sharply define
from the deeper tissue of the bothria. This layer is about .051""1 thic
at the bottoms of the loculi, but is somewhat thinner at the edge:
It appears to consist of columnar epithelium. Where two locnli joii
this layer of radiating fibers in each rises to form the separating cost;
The transverse section of^a costa therefore shows it to be composed c
two layers which are confluent at the outer edge. This radiate fibrou
tissue contains a few scattered granules, which, although very smal
in several instances proved to be distinctly nucleated. The radiatiu
. fibers of the bothria themselves originate from a thin layer of fin
fibers, which in many places seems to have separated from the tissu
beneath, but which, in normal position, rests on a layer of coarse long
tudinal fibers in the center of the bothria. Towards the edges of tb
bothria the coarse longitudinal fibers disappear and the layer of radia
ting fibers is succeeded by the outer granular tissue of the head, ii
which there are a good many longitudinal fibers.

Four principal vessels are cut by these cross-sections. Of these, tw<
lie near the center of the head and are .015mm and .O2'"m in diametei
near the middle of the length of the head. The others are larger, ob
long, and are situated near the margins. Near the middle of the hea<
the inside diameters of one of the marginal tubes were .025 and .016"
the outside diameters .032 and .038'""'. These dimensions are some
what exaggerated since the sections were carried a little obliquel;
through the head.

Transverse sections of the neck reveal the same alternation of mus
cular layers as noticed in the segment. The fascicles of the thick laye:
of longitudinal muscles are oblong in section and are disposed radially
around the central space. This layer is interrupted for a short distanc<
at the margins, where the granular central space is continuous with tin
granular layer, outside the fascicular layer.

In some sections there are three, in others there appear to be four
vessels near the margins. Two of these are larger than the others
The outer one of these two, that is, the one nearer the margin, has
definite limiting wall, while the other is more irregular in outline ant

ifl

[57] NOTES ON ENTOZOA OF MARINE FISHES. 773

in places contains a fine granular substance. The latter vessel I take
to represent the irregular longitudinal marginal vessel noticed in the
living specimens, and which may be a nervous vessel.

In sections of the head the bottoms of the faces of a marginal pair of
bothria lie very close together. The inner core of the head is thus very
narrow, and composed mainly of coarse longitudinal fibers, with an inner
granular core in which lie the aquiferous vessels. This species appears
to be near Echeneibothrium tumidulum Eudolphi.*

The published descriptions of E. tumidulum, however, agree, in the
main, in saying that the first segments are extremely long and narrow,
and that the bothria are divided into loculi by transverse costoe and a
median partition.

The former of these differences might be reconciled by supposing that
the pseudo-segments of R. cancellatum have been taken for true seg-
ments by former describers.

The difference between the bothria of -R. cancellatum and E. tumidulum
is too profound to admit of reconciliation. No median row of loculi is
shown in any of the published figures of E. tumidulum that I have seen,
while in R. cancellatum it is very evident and could not possibly be mis-
taken for a median partition.

12. Rhinebothrium longicolle sp. nov.
[Plate VI, Figs. 1-4.]

Bothria four, marginal, linear-oblong, attached at middle point by
short pedicels, ends free, margins crenulate, faces boat-shaped, deeply
concave from side to side or with edges appressed, divided into loculi
by about twenty-four transverse costte and a median partition, very
versatile. Neck long, slender, smooth, cylindrical, rounded posteriorly
and separated from the body by a constriction. Body behind constric-
tion a little smaller than base of neck, at first cylindrical and crossed by
minute transverse lines which soon give rise to distinct segments. Seg-
ments at first very short, increasing in length uniformly, near poste-
rior end as long as broad with posterior edge very slightly overlapping
succeeding segment. Posterior segmeut elongated or, if contracted,
with very convex margins.

Genital apertures marginal, male and female approximate. Length,
28mm ; breadth, .6mm.

Habitat. — Myliobatisfreminvillei, spiral valve; two specimens. Wood's
Holl, Massachusetts, August 5, 1887.

This description is based on two specimens from the spiral valve of
the sharp-nosed ray (Myliobatis freminvillei}: The stomach of the host
was empty and there were no other parasites found.

* Botliriocephaliis tumiduliis Rnd., B. Echeneis Lenckart, Petalocephalus tuiniduliis

9

Van Lith de Jeude, Tetraboihrium tumidithtm Rud. Dies, and Echeneibothrium tinnidu-
lum Beueden, Dies.

776 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [58]

Following are the measurements of a living specimen :

Millimeters.

Length 28.00

Length of botbria 2. 00

Breadth of botbria, middle 20

Diameter of neck near head 16

' Diameter of neck at base .- 32

Diameter of constriction between neck and body 18

Length of neck 7. 00

Length of first distinct segments 03

Breadth of first distinct segments 40

Length of median segments 20

Breadth of median segments GO

Length of posterior segments 1.00

Breadth of posterior segments 40

Measurements of median and posterior segments were made with dif-
ficulty on account of the incessant and active movements of con-
traction and expansion of those parts. The bothria, likewise, were in
constant motion and exact measurements of them could not be
obtained. The measurements given above are, however, approxi-
mately correct. In the living worm in sea-water the bothria and
pedicels are yellowish white, the neck and head between the bothria,
bluish white, anterior segments yellowish white, remaining segments
yellowish white at center with bluish white border along each margin.
The bothria were exceedingly active and they changed their position
constantly. The ends of the bothria being free and the whole organ
turning easily on its pedicels as on a pivot, it is therefore possible for
an infinite number of positions to be assumed. While the resting
position of a bothriuin is that in which its long axis is parallel with the
axis of the body, it is occasionally thrown forward and turned so as to
lie across the top of the head at right angles to the longitudinal axis
of the head. The ends of the bothria sometimes turn towards eachother,
sometimes they are reflexed. These movements and the resulting posi-
tions are all exceedingly graceful. The diameter of a pedicel, although
variable in life, is about, .36mm and the thickness of abothrium near the
pedicel about the same, .36mm. When one of the specimens was put in
fresh water the bothria became arcuate, their ends being reflexed, while
the margins of the boat-shaped faces were closely appressed. The epi-
dermis of the body also became loosened and in places was detached.

In fresh water and in alcohol the head and neck contract but little
while the body contracts very much. In the alcoholic specimens the
ends of the bothria are flexed so that the head is nearly globular.

The long, cylindrical neck of the living worm, when viewed with
transmitted light, was seen to be traversed by a dark central line and
by many wavy or crinkled longitudinal fibers. When moderately mag-
nified, the dark central line appeared to lie between two inclosing dark
lines, as if in a tube. The neck, while very flexible and often changing
its position, was not observed to contract or expand.

One of the specimens has a crenulated marginal outline to the pos-

[59] NOTES ON ENTOZOA OF MARINE FISHES. 777

terior part of tbe body on account of the convex margins of the seg-
ments. In the other specimen the margins of the segments are not
convex. The latter specimen is not so long as the other and the pos-
terior segments do not correspond in their degree of development.

The water vascular system was plainly visible in the living specimens
as rather large sinuous vessels lying a little way from each margin.

The segments are rather thick and crossed by very fine transverse
lines, so that the margins of the segments when sufficiently magnified
are finely crenulate. The posterior end of the last segment in one of
the specimens was concave and appeared to have a fluted border.
These last two features are doubtless due to the superficial layer of cir-
cular and the deeper layer of longitudinal muscles. The body, from
the constriction which separates it from the neck, to the posterior seg-
ments, was, in life, very contractile, and was constantly shortening and
elongating itself.

The genital apertures are marginal and situated about the middle
of the segment. The vagina opens immediately in front of the cirrus.
The two organs have a common external cloaca. Ova were observed
escaping from the middle of a margin of one segment and from the an-
terior edge of another, in a specimen which was somewhat flattened
under a compressor. Each ovum consisted of a hyaline envelope in-
closing a granular mass. The dimensions of these living ova are:
diameter of outer hyaline envelope .0279mm ; diameter of inner granular
part .0203"1111.

In the alcoholic specimens these ova have undergone considerable
modification. The hyaline envelope has, in most cases, collapsed and
adheres to the granular interior as a closely investing membrane. This
investing membrane has in most cases a very irregular outline. It has
the appearance of sending out radial prolongations which are often as
long as the diameter of the granular mass. In a very few cases the
hyaline envelope is but little contracted. The diameters of the ova,
with collapsed investing membrane, vary from .008 to .014IU1U. The
greatest diameter of an ovum with an unbroken envelope waa .022imn,
the diameter of its granular contents being .01Gmm. The latter is deeply
stained with carmine. These ova are not free but are in a loose cluster
which is held together and attached to the segment by flue interlacing
hair-like fibers.

The cirrus is long and slender, and, so far as observed, without spines.

Anatomy of posterior segments. — Thin sections were made of two seg-
ments from near the posterior end of one of the specimens. The cuti-
icle at the margins had disappeared in some places, in others it still
adhered and presented a brokenly serrate outline. Beneath the cu-
ticular layer is a thin coat of fine muscular fibers, consisting of an
outer layer of circular and an inner of longitudinal fibers. This is un-
derlaid by a coarse granular layerj and this again by a layer of coarse
longitudinal fibers. The latter present a very peculiar appearance.
They are surrounded by granular tissue, while many of them are char-

778 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [60]

acterized by successive enlargements, so as to Lave a decidedly monili- I
form outline. The segments from which these sections were made were I
constricted at the extremities and bulging in the middle. The longitu-
dinal fibers conformed to this subspherical shape, being straight in the
vicinity of the median line and curving towards the margins.

The cirrus in these sections is seen to be long and slender and to lie |
in many convolutions within a cylindrical sheath which extends at least
to the middle of the segment. The center of the segment is filled with
large, coarse granular masses, the spermatic capsules of the testis.

The ovary is a folded or crumpled glandular organ and lies near the
posterior edge. In the middle of the ovary, in two of the sections, there
was a circular body, like a rosette, which is probably the shell gland.

A convoluted sinuous tube extends from the ovary along the median
line. It was traced nearly to the base of the cirrus sheath where it was
lost. It is probably the vagina, which in living specimens was seen
to open immediately in front of the cirrus, but which was not evident
in these sections. These sections did not contain any ova. The speci-
men from which the sectioned segments were taken was evidently im-
mature.

The mature segments are converted into mere cases for containing
ova. Apparently all the tissue of the inner part of the segment, except
that which contributes to the formation of ova, is converted into fine
fibrous tissue which escapes from the ruptured segments along with
the ova and serves to bind them together into loose clusters. Large
convoluted masses of very fine fibrous tissue were abundant in the
mature segments.

SPONGIOBOTHRIUM Lintou.

Characters emended. — Body articulate, treniajform. Head separated
from body by neck. Bothria four, in lateral pairs, pediceled, with crisp-
folded or auriculate edges, which are crenulate and the auriculate flaps
finely costate on account of a marginal row of loculi with muscular bor-
ders ; unarmed and without transverse eosta3 on face. No inyzorhyn-
chus, no supplemental disks. Genital apertures marginal.

The crisp-folded edges of the bothria produce an effect which suggests
Leuckart's Bothriocephalus flos (Anthobothrium auriculatumvar. ccntifo-
lium Dies.) The costate flaps suggest relationship to Bliinebotlirium.

The bothria are not opposite in the sense of being cruciformly ar-
ranged, as might be inferred from the original description, but are in
lateral pairs, each being, in fact, the termination of an apparently im-
mobile pedicel.

13. Spongiobothrium variabile Lin ton.

Report of U. S. Fish Commission for 1886, pp. 462-464, Plate II, figs. 13-19.

Specific characters emended. — Head broad, appressed. Bothria four
pediceled, fan-shaped, in lateral pairs, their faces and margins with
numerous frill-like lobes which are sometimes gathered into a more or

[61] NOTES ON ENTOZOA OF MARINE FISHES. 779

less compact mass of crisp folds, sometimes expanded into long, curved
auriculate or leaf- like flaps. Borders of bothria with a row of small
loculi which give a creuulate outline to margins and a costate appear-
ance to the auriculate flaps. Behind the bothria the head is quadrato-
pyramidal tapering posteriorly, prolonged anteriorly into the pedicels
of the bothria. Neck short. First segments short and crowded, me-
dium and posterior segment squarish or elongated, according to state
of contraction. Free proglottides four to eight times as long as broad,
with irregular outlines.

Genital apertures, male and female approximate, in a marginal de-
pression about the posterior third. Maximum length 90mm.

Habitat. — Try g on centrura, spiral valve, August, 1884, July 29, 1880;
four specimens on each occasion. Wood's Holl, Massachusetts.

I append the following additional data obtained from a lot of speci-
mens collected July 29, 1886.

The specimens in this lot measured, while living, 66, 74, 82, and90mm
respectively. The bothria of all were finely frilled on the edges. The head
of one of the specimen measured 2lllm in breadth and 1.15mm in thick-
ness. The free proglottides, which accompanied these specimens, were
quite active and exceedingly changeable in form. Their usual shape
was elongated with the anterior end contracted into a kind of knob.
The greater number of these proglottides while they were yet in the
water and active burst open on one of the lateral faces. From the lat-
aral apertures thus formed, ova and a part of the geuitalia were forced
out. The latter remained protruding from the lateral aperture as an
ivory-white, cotton-like mass. The cirrus, which was protruded in
many cases, is very long and slender.

The living ova were comparatively large. Each one consisted of a
transparent globular pellicle, within which were from three to five gran-
ular masses, which seemed to be nuclei undergoing normal develop-
ment. The diameter of a single ovum was .18""". The diameter of a
single granular mass .02mm.

A re-examination of the mature segments with the aid of thin sec-
tions enables me to add the following data regarding the anatomy. The
convoluted mass of tubes in the center of the posterior segments ap-
pears densely striated in a section stained with carmine. It is evi-
dently the vas deferens crowded with spermatozoa. In the anterior
part of the section there are numerous circular patches of granu-
lar and striated tissue. The large, globular granular masses which
fill the anterior two-thirds of the median segments are evidently the
spermatic capsules of the testes. The cirrus is long and densely cov-
ered with spines, which appear to be easily removed from the protruded
organ. The spines at the base of the cirrus are relatively long, rather
slender, nearly straight, slightly recurved at the slender point and have
a short basal articulation. Length of spine at base of cirrus, in one case

780 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [62]

.01Gmm, with diameter at base .003nnn; in another case, length of spines
.022""", length of basal part .002mm, diameter .0027 to .0030"'"'.

The vagiiia is a narrow, much convoluted tube which originates be-
tween the two lobes of the ovary, in the posterior part of the segment.
It follows the median line to a point on a level with the cirrus bulb,
where it turns abruptly towards the margin to open immediately in
front of the cirrus. Immediately in front of the inner end of the cirrus
bulb it enlarges suddenly into a vaginal sinus. This vaginal enlarge-
ment, in one section, was .2mm in length and .04uim wide at widest
part. The beginning of the narrow part appears to be lined with minute
bristles. A few loose spines of the cirrus were observed in the vaginal
sinus. These may have been carried over from the base of the cirrus,
which lies near by, by the knife, or they may have become detached
from a cirrus during copulation before the specimen was killed.

In the free proglottides with ripe ova, there is. a large oval aperture
on one of the lateral faces for the escape of ova. One of these oval
apertures measured .4 and .3mm in its two diameters. In these ripe
proglottides the ova fill up almost the entire interior. The proglottides
are in fact converted into mere sacs containing ova. In the alcoholic
specimens the ova are small, granular, with a thin, irregular, and col-
lapsed investing membrane. The diameter of the granular part is .02mm.
The ovaries are elongated oval organs occupying the posterior third of
the segment, extending from the posterior end of the segment almost to
the cirrus bulb.

The costate appearance of some of the prolongations of the edges of
the bothria, which was alluded to and figured in the original account
of this species, was not properly understood when the original descrip-
tion was written. It is to be accounted for, I think, in this way : When
the border of a botliriurn is prolonged, the prolongation will, of course,
be bordered by the marginal row of loculi. As a prolongation becomes
narrower, it is at the expense of that part which lies within the marginal
loculi. In very narrow prolongations the row of loculi on opposite sides
of the prolongation become approximated on either side of a line which
is made up of the inner edges of the two rows of loculi. Such a flap
when flattened out looks something like a linear pinnate leaf with a
prominent midrib.

In this lot of specimens,, as in the lot which furnished the basis of my
former description, there are two varieties. In one the anterior and
median segments are uniformly broader than long, becoming squarish
toward the posterior end, the margins of the strobile creuulate. In the
other the segments soon become longer than broad, slender with par-
allel margins, the strobile filiform with entire margins. These two
forms are figured in my former paper. They probably arise from dif-
ferent states of contraction, but it is somewhat singular that each small
lot should furnish examples of these two distinct forms.

T63] NOTES ON ENTOZOA OF MARINE FISHES. 781

DlSCOCEPHALUM * gen. UOV.
f, a quoit. "I

Body articulate treiiireforui. Head com posed of two parts. The
anterior part a muscular disk, which is entire or notched at the edge.
The posterior part (neck), short, globose, with an inflated or corrugated
surface. Neck (unseginented part of body) much narrower than head
continuous with the body. No supplemental disks. Genital apertures
marginal.

This genus is established to accommodate some peculiar cestoids from
the spiral valve of the dusky shark (Carcharias obscurus.)

No indication of true bothria nor of supplemental disks was found
either in the living specimens or in preserved specimens made trans-
parent with glycerine or oil of cloves ; nor could any such indication
be found in a series of sections of the head.

On account of the small amount of material and the unsatisfactory
results of my study of it, I have determined to put this genus in the
family Tclrabotliriidfc for the present. If my interpretation of the
homologies of this form is correct, it should be put in a new family, for
which the term Gamobothriidw, also suggested for the problematic
genera Lecanicephalum and Tylocephalum, would be fitting.

14. Discoceplialnm pileatum gen. et sp. nov.
[Plate x, figs. 1-7.]

Head, a transversely-flattened apical disk, entire, or with a single lat-
eral notch, followed by a much smaller, globular, inflated, cervical mass,
with botryoidal or corrugated surface, yellowish in color, and sepa-
rated from the apical disk by a narrow, orange-colored band, unseg-
mented part of body narrower than head merging into segmented body.
Anterior segments very short, much crowded; subsequent segments
longer than broad ; mature segments irregularly squarish, very change-
able in living specimen. Strobile flat, increasing in breadth uniformly
to the beginning of mature segments, beyond which point it is some-
what narrower.

Genital apertures marginal a little in front of middle, male and
female approximate. Cirrus long and slender, vagina opening in front
of cirrus.

Length, maximum 530mm ; diameter of anterior disk 3 to 5mm; great-
est breadth of body 3 to 51"111.

Habitat. — Carcharias obscurus, spiral valve. Wood's Holl, Massachu-
setts, July 19, 1886. One adult, three young.

In the single lot of specimens which furnishes the data for this
description there are two distinct varieties.

* This genus is put provisionally in the family TetrabothrHdw,

782 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [64]

They may be described briefly as follows :

Var. a. — Apical disk nearly or quite entire. Of this variety there
were two specimens ; one adult with ripe segments, and which, while
living, measures 530inm in length, diameters of anterior disk 3 and 3.5mm
respectively; another, a young specimen, measuring i\\ alcohol 40mm in
length, diameters of anterior disk 2.1 and 2.2mm respectively.

Var. ft. — Apical disk large, with profound lateral notch. Of this va-
riety there were two specimens which did not differ much in size. One
of them while living measured 75mm in length, diameters of anterior
disc 4.5 and 5nim respectively.

The following measurements of the adult specimen were obtained
while it was yet living :

Miliuieters.

Length of speci men 530. 00

Marginal diameter of disk 3.50

Lateral diameter of disk 3.00

Thickness of disk l.->5

Diameter of cervical mass 2.00

Breadth of uu segmented part of hody , 1. 12

Greatest breadth of body, 115mi" from head 5.00

Length of segments, 115mm from head 1.00

Length of posterior segments 2.45

Breadth of posterior segments 3.25

Longer diameter of ova 0.11

Shorter diameter of ova 0.08

The dimensions of the posterior segments are approximate, the seg-
ments themselves being quite variable.

These parasites were found in July, 1886, attached to the mucous
membrane of the spiral valve of a dusky shark (Careliarias obscurus).
When found they were firmly attached, the flat anterior disk being en-
tirely embedded in the mucous membrane of the host. The only part
of the head that was visible was the yellow, globular, inflated mass,
behind the disk. When the worms were removed, which was effected,
in each case, with some difficulty, a flat pit with a narrow opening was
left in the mucous membrane.

That part which I have interpreted as the head is a muscular, com-
pact, transversely flattened, terminal disk, which, in the adult and one
of the smaller specimens (var. «), is slightly convex in front and con-
cave behind, with bluntly rounded entire edges. In the larger speci-
men there was a very faint indication of a lateral notch on the edge of
the disk. In these specimens there was no tendency to appress the
sides of the disk. The head, in fact, resembled in shape a cloth-covered
coat button, in which the disk represented the flat, exposed part of the
button and the inflated cervical mass that part of the button by which
it is fastened to the coat. In the alcoholic specimens the disk of var. a
is convex and yellowish- white above, flat and ashy gray below. On
the under side there are three or four radial slits, which are probably
cracks in the cuticle, due to the effect of the preservative.

[65] NOTES ON ENTOZOA OF MARINE FISHES. 783

lu the two remaining specimens (var. ft) there is a decided notch on
the edge of the apical disk. This notch is opposite a lateral face of the
strobile. In one of the specimens the sides of the disk which are oppo-
site the margins of the strobile are appressed. The apical ridge thus
formed was concave in front, so that the disk was shaped like a saddle.
In this case the notch was at one end of the apical ridge. In the other
specimen the sides of the disk which are opposite the lateral faces of
the strobile are appressed. The notch in this latter case is on one of
the appressed sides of the disk. The disk in var. ft is both relatively
and absolutely larger than those of var. a.

With the exception of a tendency to appress the edges of the disk,
which movement was accomplished slowly, no motions, either locomo-
tile or those of dilatation or contraction, were observed in the disks of
the living specimens.

Immediately behind the broad disk there is a constriction which in
the living worm is marked by a narrow orange-colored baud. Behind
this the neck expands into a globular mass, yellowish in color and with
a corrugated or fluffy surface. It is much smaller than the anterior
disk, and appears to be made up of a number of inflated folds. This part
was not observed to change its shape during life; its surface remained
pretty uniformly corrugated. The alcoholic specimens show some ir-
regularity, in that some of the inflated folds are much larger than
others.

There was no indication of either bothria or auxiliary acetabula on
either the disk or the cervical mass, although the latter, as a whole,
much resembled the head of a Phyllobothrium in a highly contracted
condition.

The body in the adult specimen (var. «), immediately after emerging
from the cervical mass, increases slightly in breadth, although still
quite narrow. Transverse strife begin a short distance back of the
head. The anterior segments are closely crowded together and several
times as broad as long. The median segments are rectangular and three
times as long as broad. The posterior segments are irregularly squar-
ish. In the living worm the posterior segments change their shape so
incessantly that it is difficult to make measurements. The strobile is
flat and increases in breadth regularly from immediately behind the
head to the first mature segments, from which point the breadth some-
what decreases. The mature segments are squarish, usually broader
than long, but quite variable. Near the posterior end there is a tendency
towards elongation, so that some segments occur which are longer than
broad; others are elongated posteriorly, the posterior end becoming
appressed and narrower than the anterior.

The posterior end of the mature segments are, in alcohol, dark colored
on account of the ova. There is also a longitudinal dehiscent opening
along the median line.

The aperture of the male genital organ is easily seen to be marginal,

784 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [66]

usually ii little iu frout of the middle point. The cirrus is very long
and. so far as could be made out, is smooth. In order to determine the
exact position of the vagina it was necessary to make an examination
of thin sections.

One of the two specimens of var. /?, after having lain for twenty-four
hours in sea-water, measured 75""" in length. For the first 35I111U the
segments were much crowded and several times as broad as long. The
posterior half consisted of segments about as long as broad. The ex-
treme posterior segments were a little longer than broad. The pos-
terior half of the body was much narrower than the autero-mediau part.

Following are measurements of the living specimens var. ft. Length
75mm; lateral breadth of disk, 5mm; marginal breadth of disk, 4.5"""; thick-
ness of disk, l.lmm; diameter of cervical mass, 2. Lmm; length, l.5"1IU ;
breadth of body immediately behind -head, I.15mm; thickness at same
point, .35mm ; greatest breadth of body, 2.45-mm ; length of posterior seg-
ments, 1.4mm; breadth of posterior segments, 1.3mm.

The strobile, particularly in the vicinity of the median segments, was
very active and constantly changing its shape by alternate contraction
and expansion.

The smaller specimen of var. a was not measured while living, but as
an alcoholic specimen, measured 40ram in length ; the two diameters of
the disk 2.1ulm and 2.2mm, respectively; thickness of disk, .9G1""1 ; diameter
of cervical mass, .8Gmm ; length of cervical mass, .44mm.

This specimen exhibited a phenomenon in the anterior part of the
body, which, if not the result of mutilation, is a curious abnormal freak.
For a distance of about 16mm back of the head, beginning at the base of
the cervical mass, the body is double. It appears to be double at the
point where it leaves the head and where inclosed bjT the ruffle-like
folds of the base of the organ.

A few small, slender, fusiform free segments were found associated with
these worms, of which they were at first taken to be the mature pro-
glottides. They were about 3mm long and lnnn broad. After a careful
examination of these segments 1 find that they do not belong to the
mature strobile^ and I am disposed to regard them as belonging to some
other cestod.

It is worthy of note that no parasites were obtained from this shark
except the four individuals mentioned in this description, and these free
segments, eight or ten in number. The only parts of the shark that
were brought into the laboratory were the head and viscera. They were
then identified as belonging to a specimen of Carcharias obscurus. I am
almost tempted now to doubt the validity of the identification, since the
parasites are so very different from what I have been accustomed to
find in C. obscurus.

The cervical mass in the adult specimen was not so distinctly yellow
as in the others, moreover the anterior part of the body, immediately
behind it, exhibited a faint pinkish tinge, a feature which was not ob-
served in the others,

[67] NOTES ON ENTOZOA OF MARINE FISHES. 7X5

Structure of head and neck. — A section was made through, the anterior
disk and carried back through the cervical mass into the anterior part
of the body. The latter enters the cervical mass from behind and at
first seems to be independent of it, being surrounded by the posterior
frill-like lobes of that organ within the cervical mass. The anterior part
of the body is seen to enlarge into a kind of central core, which in part,
at least, is continuous with the anterior disk, and into which it expands.

The cervical mass while in great measure free from the anterior disk
and the inner core, is in reality intimately connected with both. The
disk is com posed of very densely compacted muscular fibers near the
exterior, with a somewhat looser texture in the central portions. The
dense tissue of the exterior can be traced back into the core or central
part of the cervex. A line of deuiarkatiou can be distinguished be-
tween the disk and the anterior part of the core, on the one hand, and
the crisp folds of the cervex on the other, while at the posterior part of
the core no such line of deinarkation exists between it and the cervex.
Longitudinal muscular fibers from the anterior part of the body con-
tinue into the central core, thence some radiate into the frill-like folds
of the cervex, while others continue into the anterior disk, where they
diverge in all directions to form the latter organ. Branches of the
water-vascular system were observed in the anterior disk, the central
core, and the inflated folds of the cervex. A section of the latter organ
resembles a cluster of racemose glands radiating from a central core.
Bundles of muscular fibers radiate from the central core to the deeply
and crisply folded exterior. The tissues of this part are very loose and
open, and the external folds of the surface are thin and transparent.
Although no movement was observed in this organ in the living worm,
it is evident from the presence, in considerable quantity, of muscular
fibers and the voluminously folded surface as revealed in sections, that
it is capable of great change of form. Its loose and delicate structure
shows it to be, at least histologically, homologous with the crimped and
folded bothria of many of the Phyllobothrincv. The organ doubtless
serves an analogous purpose to the bothria of such forms. Its structure
shows that it is pre-eminently adapted for absorption. On the other
hand the structure of the anterior disk as clearly shows it to be an
organ whose chief use is to enable the parasite to adhere to its host.

Musculature of body. — The anterior part of the body, immediately be-
hind the head, as shown in transverse sections, consists of a thick outer
layer which appears to be composed, for the most part, of radiating
fibers. This layer is succeded within by a narrow layer of circular
fibers. The latter surrounds an elliptical central space in which there
are longitudinal fibers, most abundant on its outer circumference ad-
jacent to the circular layer. In this central space the cut ends of four
aquiferous vessels are seen. These lie in pairs toward the margins.
Each pair comprises a larger and a smaller vessel, lying near together,
the smaller being the one which is nearer the margin.
H. Mis. 133 50

786 REPOKT OF COMMISSIONER OF FISH AND FISHERIES. [68]

The walls of the mature proglottides are very thin. They consist of
an outer cuticular layer and an inner granulo-mnscular layer. The
muscular fibers in this layer are very inconspicuous.

The small amount of material at my disposal has prevented me from
making as thorough examination as the importance of the subject de-
mands.

Anatomy ofproylottides.—Th& cirrus is exceedingly long and slender
and emerges from a point a little in front of the middle of the margin.
The original opening is a little in front of the cirrus. Both sexual
organs have a common marginal cloaca which has a thickened muscular
border.

The cirrus bulb, when the cirrus is retracted, is oblong, about .28mm
in diameter and .6ram in length, and lies at nearly right angles to the
margin. The vas defereus is a very voluminous tube which lies near
the center of the segment at the base of the cirrus bulb. Some convolu-
tions of this organ in one section were found to be .14mm in diameter,
or equal to one-half the diameter of the cirrus bulb. The vas defereus
in this case was filled with spermatozoa.

In those segments which immediately precede the ripe proglottides,
the anterior part, and indeed the greater part of the interior of the seg-
ment, is filled with granular, globular masses from .070 to .08Gmm in di-
ameter. These were found in longitudinal sections of segments, to be
arranged in racemose clusters on branches which are transverse to the
axis of the segment. These granular masses evidently represent the
testes, and the branches on which they rest, ducts which communicate
ultimately with the vas deferens.

Beginning at its exterior end in front of the cirrus at the margin of
the segment, the vagina, a tube about .06nim in diameter, passes in front
of the cirrus bulb, and in front of and a little to one side of the vas
deferens, to the median line of the segment. It there turns abruptly
and follows the median line back to the posterior edge of the segment,
where it communicates with the ovary. The latter organ is near the
posterior edge of the segment. It consists of two lobes which lie sym-
metrically on either side of the median line. It is made up of a mass
of rounded cells, some of which were found to be nucleated and were
apparently unfertilized ova. The diameter of the irregular non-nuclear
masses was about .013miu. That of the nucleated masses, which had
apparently left the ovary and were in the vicinity of the shell gland,
was about .01Glum. An organ which I take to be the shell gland lies
midway between the two lobes of the ovary, is spherical in shape and
about .09mm in diameter. It appears to be a somewhat convoluted tube
which connects in front with the vagina and also apparently with a]
median groove or cleft on the face of the proglottis. Posteriorly it-
connects with an irregular mass which I take to be the vitelline gland.
This, when magnified thirty or forty linear diameters, in a section
etained with carmine, appeared as an irregular, slightly striated gland- ,

[69] NOTES ON ENTOZOA OF MARINE FISHES. 787

ular organ, which was sharply differentiated from the surrounding parts
and measured .2"1"1 in length and .24""" in breadth. The outlines of the
uterus could not be made out from the sections but amber-colored eggs
were found in clusters elongated transversely, in marginal prolonga-
tions of a median cleft of the proglottis.

In one of the mature segments ova were found that had begun to
undergo segmentation. In one case four distinct cells were observed in
a single ovum.

PHYLLOBOTHEIUM Van Beueden.

Body articulate transform, head separated from the body by a neck,
with four opposite sessile bothria, each bothrium lacinio-crispate on the
margin and provided with a single ampulla-like supplemental disk.
Genital apertures marginal.

The species which I refer to this genus resembles Van Beueden's P.
auricula,, but differs from it in having the bothria pediceled in marginal
pairs, a feature, which, it would seem, requires the generic characters
to be emended so as to admit this peculiarity.

I have referred Phyttobothrium thysanocephalum, of my former paper
to the new genus Thysanoceplialum, of the sub family Phyllacanthincv.

15. Phyllobothrium foliatum sp. nov.

[Plate vi, Figs. 5-10.]

Head broad and ilat. Bothria four thin, leaf-like, sessile in marginal
pairs, each pair mounted on a short, stout pedicel. Faces of bothria
finely reticulated, directed forward; borders of bothria with a distinct
row of loculi, and with creimlate margins. Edges of bothria more or
less ruffled and folded. Each bothrium provided with a single supple-
mental disc on its anterior edge. Neck long, broad, and flat, immedi-
ately behind the head, quickly narrowing and becoming cylindrical,
merging into the body. Segments begin as fine, trarflverse lines on the
neck, first distinct segments very short, appearing as transverse,
crowded wrinkles. Subsequent segments increase in length, becoming
as long, as broad, and ultimately longer than broad. Mature segments
with convex margins, appressed at the two extremities, but most at the
anterior end, many of them, therefore, flask-shaped.

In alcoholic specimens, median part of body thickened and fusiform,
posterior segments often elliptical, and posterior part of strobile, there-
fore niouiliform, neck sometimes extremely attenuated.

Genital apertures marginal, near middle of margin. Cirrus echinate.
Length, maximum, 185mm.

Habitat. — Trygon centrura, spiral valve, August 1, 1887, very numer-
ous. August 8, one specimen. August 10, four specimens. Wood's
Holl, Massachusetts.

The following measurements are of a living specimen of the first lot :
Length, 85mm j breadth of head, 3mm j thickness of head, lmm 5 greatest

788 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [70]

diameter of face of bothriuin, about 1.2mm; diameter of neck, lateral,
immediately behind head, lmm, a little farther back, .4""u ; distance to
first distinct segment, about 23mm; length of last segment, 1.5mm,
breadth, l.lmw. The longest specimens in this lot measured, while liv-
ing, from 105 to 185mm.

The head of the living worm in lateral view appears to be distinctly
bi-lobed, and very broad. In marginal view it is quite narrow and ob-
long. Upon a closer examination it will be seen that what appears to
be one of two marginal lobes is really a marginal pair of bothria. The
latter in the living worm are capable of considerable change of form.
The edges are constantly changing their outline, but are usually more
or less crinkled or ruffled. This sometimes assumes an apparently
ragged appearance, but in no case, so far as I have observed, are the
edges of the bothria tattered.

The specimen obtained Augusts, 1887, was studied while living rather
more carefully than any of the others, and some features noted that were
not observed in other cases. I append the following data from notes
made while observing the living specimen.

The length of the specimen was 50mm ; length of pedicels about .4mm ;
diameter of pedicel, lateral view, .28mm; breadth of head at bases of
pedicels, lateral view, .72mm. Bothria thin, leaf- like sessile on the pedi-
cel which bears each marginal pair. From the manner of their attach-
ment it is difficult to make out their shape. At rest the pedicels point
forward with #11 interval between equal to a little less than the diameter
of a single pedicel. The bothria appeared as if bent around the end of-
the pedicel so that one edge curved into the space between the pedicels,
while the opposite edge bent around until it touched the margin of the
neck. Bach bothriuin bears an auxiliary acetabulum on the middle of
that margin which lies next to its mate. That is, the auxiliary acetabu-
lum of a bothriuin is directly opposite to that of the other botlirium of
the same marginalspair. The edges of the bothria, while at rest, project
and are slighly incurved, so that the face is concave from the acetabu-
lum to the edge opposite, while it is convex in a line at right angles to
this, or, in other words, in the line which joins the two reflexed edges of
the bothrium. In a state of activity the bothria effect a progressive
movement by prolonging that part of the border which bears the aux-
iliary acetabula. When in this position the bothria are somewhat tri-
angular, the acetabulum marking the apex of an isosceles triangle, while
the base is thrown into about three folds. The edges of the bothria are
not broken or laciniate, although often folded in such a manner as to
present a laciuiate appearance. The edges are finely crenulate, the
creuulatious being about .3mm in diameter. The faces of the bothria
are covered with hexagonal reticulations, like the surface of a honey-
comb. The fibrous tissue which forms the frame- work of this reticulated I
surface, near the edges of the bothria, rises into parallel ribs, so that
the outer rim of the thin, free edge of the bothrium, instead of being

[71] NOTES ON ENTOZOA OF MARINE FISHES. . 780

reticulated like the remainder of the face, is divided into comparatively
regular elongated loculi, about .0""" long and .3""" wide. The rounded
ends of these locular cells give a creuulate outline to the edge of the
bothria.

An oblong reddish patch .2mm in length and .06lum in breadth, lying
transversely to the axis of the body, is situated in the head, about .12""u
back of the apex or angle formed by the two pedicels.

On the lateral face of the head four shallow pits or pores were observed,
about .05mm apart, along the median line. The first two were narrow, the
greatest diameter, about .12mm, transverse to the axis of the body.
The third is rounder, deeper, and more evident than the others; its
diameter about .08mm.

At the apex of the head, that is, in the angle formed by the pedicels,
there was a low papilla not well defined. The pedicels were marked
with longitudinal ruga?.

The neck, at a distance of .34mm from the apex of the head, was .64mm
broad ; at the distance of l"im it was about .4mm in diameter. Like the
head it was flat, thin, and smooth, and decreased in lateral diameter
for some 4mm or more back of the head. The aquiferous vessels could be
seen passing up to the head and lying, two on each side, about .lmm from
the margin. Tbe margins of the neck outside the longitudinal aquif-
erous vessels seemed to be made up largely of transverse muscular tis-
sue, and the central part of a mass of longitudinal spiral vessels. The
latter are shown further on to be bundles of longitudinal muscle fibers.
Transverse stride appeared about 7mm from the head. The first dis-
tinct segments were about .04""" long and .4mm broad. Towards the
posterior end the segments became squarish, then longer than broad.
Near the posterior end the segments grew somewhat narrower. At
10mm from the posterior end the segments were .5mm long and .72inm
broad; the last segment was lmm in length and .34""" in breadth. The
posterior segments of this specimen in alcohol are elongated, with nearly
parallel margins ; the strobile is therefore not moniliform, as is usual
in the specimens of the other lots.

The foregoing description is based on a specimen that had tain for
twenty-four hours in sea- water. It was still capable of motion, and was
at first rather transparent. After some two hours more the head and
bothria became opaque, and the latter contracted. The measurements
were made while the specimen was lying free in the water.

In the specimens of the lot collected August 1, from which the
sketches of living forms were made, the red pigment spot in the head
was not observed, neither were the lateral pits nor the terminal papilla,
which was faintly indicated in this specimen. In the specimens col-
lected August 10, I recorded in my notes the following observations :
Head and body yellowish white, neck bluish white ; last segments with
large ivory-white opaque spot in the center.

790 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [72]

. The following data arc from tbe larger lot ami heiicc represent more
general characters.

The meshes of the reticulations on the face of the bothria are about
.04""" in diameter. The effect of this reticulation, of the crenulated bor-
der, of the marginal row of loculi, and of the ramifications of the water
vascular system on the transparent bothria of the living worm is very
striking. It is a very beautiful object indeed. The loculi on the bor-
ders of the bothria in alcoholic specimens measure .05 by .07min, outside
diameters, and .03 by .04min inside. The auxiliary acetabulum, while
usually visible on the anterior edge of the bothria of living specimens,
is often found only with great difficulty in the alcoholic specimens. *

There is really no head, properly speaking. The neck simply be-
comes a little broader towards the anterior end and bifurcates, thus
forming the two fleshy columns or pedicels which support the marginal
pairs of bothria. In the alcoholic specimens the bothria are somewhat
contracted and the pedicels shortened, so that the head loses something
of its distinctively bilobed appearance and in lateral view appears to be
transverse, making with the neck a figure like the letter T. The cren-
ulated borders are much folded and crumpled.

The character of the neck is much the same in all as in the specimen
already described, except that the four large aquiferous vessels which
lie in pairs about midway between the median line and the margins
are usually sinuous. In general the neck is flattened and rather broad
near the head. It soon grows narrower and for some distance is nearly
cylindrical. In the living specimens the surface appears to be perfectly
smooth for the first 7 to 12mm, at which point fine transverse lines are
discernible, which a little farther on give rise to the first segments.
In the alcoholic specimens, however, fine transverse lines occur imme-
diately behind the head.

At the point where the segments begin there is, in the living worms,
a slight enlargement of the neck, at which point, in some, the inner tis-
sues of the neck appear to end abruptly in a rounded stopper-like ter-
mination, which, like the neck proper, is more transparent than the
body which follows. This abrupt transition from neck to body is not
so apparent in the alcoholic specimens, but in all there is a rather
sudden enlargement about the point where the first segments begin.

When these worms were placed in Pereuyi's fluid they contracted to
nearly one-half their length in sea-water, and with few exceptions as-
sumed a highly characteristic shape. The head is contracted, loses
its forked or bilobed appearance, and viewed laterally is oblong and
placed transverse to the neck. The latter is rather narrow, cylindrical
for about 8 Inm, when it enlarges rapidly and merges into the body. The
maximum breadth is soon attained, and for some 12 lllin, more or less,
varying with the size of the specimen, remains of nearly uniform size.
The breadth is apt to decrease slightly with the maturing segments.
The latter are squarish. The specimens which have many mature seg-

[73]

NOTES ON ENTOZOA OF MARINE FISHES.

791

meuts become decidedly moniliform posteriorly, each proglottis becomes
compressed anteriorly until it is reduced to a mere neck. It is also
compressed, but not so much, posteriorly. The margins are therefore
strongly convex. There is a tendency also on the part of some of the
posterior segments to assume an arcuate form, in which one of the lat-
eral faces is convex and the opposite one concave. Most of the alco-
holic specimens are somewhat fusiform, and the last segment is elon-
gated and compressed posteriorly as though the strobile had not yet
lost any segments.

While examining the living specimens of the large lot I was for a
time disposed to think that there were two species, or at least two vari-
eties. A few appeared to be destitute of auxiliary acetabula. The
heads were smaller and the bothria had thinner margins than was the
case in the majority of examples. When the specimens were placed in
alcohol, six out of the forty-eight individuals at once assumed a marked
difference in form. The heads became flatter and thinner, somewhat
flaccid, truncate in front, and wedge-shaped; the necks were much at-
tenuated, even filiform, while the posterior end of the strobile was more
decidedly moniliform than in the normal type. This difference, while
quite striking, is, I think, due simply to difference in age and condi-
tions of contraction. It is to be noted that most of the individuals with
the slender necks are considerably longer than the others and have a
much larger proportion of mature segments. In the one or two whose
length does not exceed the average of the normal type, there is an ap-
pearance of general flaccidity as though the individuals were imper-
fectly developed. The difference between the two sorts with respect to
the bothria is probably due to a deterioration on the part of the smaller
lot, a conclusion which is further strengthened by the general appear-
ance of maturity of the strobiles.

In the following table of measurements, Kos. 1 and 2 belong to the
smaller lot, that is, those with the attenuated necks, Nos. 3 to 6 to the
larger lot, or normal type. All the measurements are of alcoholic spec-
imens :

Dimensions.

No. 1.

No. 2.

No. 3.

No. 4.

No. 5.

No. 6.

•
Length.... . . .

in»i.
76.00

mm.
45.00

Mini.
30.00

mm.
46. 00

nun.
46.00

mm.
2$. 00

Breadth of head :

.90

l.GO

1.48

l.CO

1.40

1.50

Thickness of head

30

.50

.60

.60

.70

.50

Diameter of neck near head, lateral

.28

.31

.56

.68

.50

.56

Diameter of neck at narrowest point

.08

.15

.40

.CO

.40

.40

Distance to first segment . . ...

14.00

12. 00

12.00

10.00

10.00

10.00

Length of first segment (approximate)

.02

.02

02

02

.02

.02

Breadth of first segment

1.00

.90

1.00

.80

.60

.80

Greatest breadth of hody

1.00

94

1 50

1.06

.80

1.60

Length of last segment

1 40

1 30

1 60

1 30

1.30

.80

Breadth of last segment

.90

'.76

.80

.80

.70

.70

792 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [74]

The posterior segments of corresponding degree of development in
the two sorts dp not differ materially in their auatomj7.

Anatomy of posterior segments. — The posterior segments of the al-
coholic specimens are opaque near the margins and transparent along
the median region. The opacity of the marginal regions is due to great
numbers of granular bodies about .03mm in diameter. These marginal
granular masses evidently represent the vitelliue glands. The ovaries are
two pale, oval organs lying one on-each side of the lateral line at the pos-
terior end of the Segment. Each is about .28mm long and .15mm broad. In
section, when highly magnified, the ovaries are seen to be made up of
small polygonal cells about ,005mm in diameter. The vagina opens im-
mediately in front of the cirrus. The two organs have a common ex-
ternal opening, situated near or a little in front of the middle of the
margin. The vagina at first follows the front side of the cirrus bulb,
and then continues as a much convoluted tube, in an irregularly sinu-
ous course to its termination in a bulbous enlargement between the
lobes of the ovary. An elongated and rather broad organ, appearing
in section to have ruffled or lobed margins, occupies the middle of the
segment, extending from the ovary nearly to the anterior edge of the
segment. In longitudinal sections this organ shows a number of empty
spaces and others filled with fine granules: I take it to represent the
uterus, as yet destitute of ova. The vas defereus is a voluminous, con-
voluted tube lying near the anterior end of the segment and adjoin-
ing the base of the cirrus bulb. In sections this organ was densely and
finely striated, due as I infer to the spermatozoa which fill it. No ova
were found in any of the segments.

The cirrus is of moderate length. As it was retracted in every case
its exact length uould not be ascertained. One was estimated to be
.'25inm in length ; the diameter of the base was in one case .036mm, in 1
another .03mni. Another was .38mm long, diameter of base .05mm, middle
.O27.mm The cirrus bulb is pyriforin, its length equal to about one-third
the breadth of the segment, the large end inward. The cirrus is covered
with minute, recurved spines which are about .002mm in length. When
highly magnified the margins of the segment are finely serrate.

Anatomy of head and neck. — Transverse sections of the head and part
of the neck of a specimen stained with eariuiue furnished the following
data :

The superficial tissue of the bothria is mainly granular. The thick-
ened, crenulated border is composed of short radiating fibers with a few
longitudinal interspersed and a layer of circular fibers as its base. Very
coarse muscular fibers .005mm in diameter, which originate by the split-
ting up of the large fascicles of longitudinal muscles of the neck, radiate
from the center of the head, and constitute the predominant tissue of
the two pedicels. The vessels of the water vascular system apparently
originate at that part of the bothria where the edges of a marginal pair
approach each other.

[75] NOTES ON ENTOZOA OF MARINE FISHES. 793

A transverse section of the neck near the head presents a highly
characteristic appearance. The outer part consists of two thin but
sharply-defined layers. The outer or cuticular layer is made up, in
part, of circular and possibly of longitudinal fibers. The inner layer is
also a layer of circular fibers. Within this is a somewhat indefinite,
narrow region of granular material. Within this again is a very thick
coat of longitudinal muscles surrounding a central space which contains
the aquiferous and nervous vessels. These longitudinal muscles are
collected into broad fascicles, placed side by side and 'standing radially
around the central space. This coat is from .05 to .OG"1"1 thick. These
dimensions represent the breadth of the muscle fascicles. The thick-
ness of the latter is from .008 to .016mm. These masses of muscular
tissue, although parallel, do not yield sections with symmetrical sides.
They have, in fact, a crinkled or folded outline. The appearance of
central vessels, noted in the neck of the living worm, is thus clearly ex.
plained. That appearance is caused by these bundles of longitudinal
muscles. In the center of the neck they would, of course, be seen in
the direction of their greatest diameter, and would therefore appear
more opaque than the surrounding tissues. They would not be defined
towards the margins, because there they would be seen in the direction
of their least diameters, and moreover several lying in the same enfilad-
ing line of vision, they would therefore appear homogeneous.

The central space, in transverse sections, appears as two oval spaces
lying toward the margins and connected at the center by a very narrow
line, where the opposite lateral sides of the longitudinal muscle layer
almost meet. In each marginal compartment of this central space lie
the two aquiferous vessels and another, which I take to be a nervous
vessel. Of the two aquiferous vessels, the one in each pair which is the
nearer to the center of the neck is the larger. Each is provided with
a wall .O03'um thick, which is very sharply defined from the surround-
ing granular tissue. The cross-sections of these tubes are oval, and yield
the following measurements : Larger vessels, longer diameter, .027111"1;
shorter, .019mm ; smaller vessels, longer diameter, .015mm ; shorter, .012""".
The longer diameters of these sections nearly coincide with the breadth
of the longer diameter of the neck. The measurements given above
include the walls of the tubes.

Lying close to the marginal side of each pair of aquiferous tubes is
another vessel, which I take to represent the nervous system. In
transverse sections of the neck, stained with carmine, these appear at
first as circular and later as oval patches, which are plainly differen-
tiated from the surrounding tissue, but are destitute of the thick limit-
ing walls which characterize the aquiferous tubes. These nervous chan-
nels are filled with a fine granular tissue, which is but little affected by
the staining fluid, although the surrounding tissues are, without excep-
tion stained deeply. Where first observed, at the base of the head, the
cross-sections of these nervous vessels was circular and .02inm in diam-

794 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [76]

eter. A little farther back they are oval, and measure .02mm and .Olmm
along the two diameters.*

This species is evidently near Van Beneden's Phyllobothrium auricula
(Mem. Vers. In test., 124, Plate xvi, 6-12), from Try gon past inaca.

ANT HOCEPII ALUM, gen. nov.

Body articulate tsenireform ; head separated from body by neck ;
bothria four, unarmed, cruciformly disposed, mounted on very versatile
pedicels, which contract in alcoholic specimens so as to appear sessile.
Borders of bothria very flexible, crenulate, with a single supplemental
disc on anterior edge; face smooth, no myzorhynchus; genital apertures
marginal.

The alcoholic specimens suggest the genus Phyllobothrium. The dis-
tinctly pediceled bothria, however, which were quite evident in the
living specimens, exclude them from that genus. The crenulate border
of the bothria, which is caused by a row of small loculi, the long neck
and the slender, versatile pedicels exclude them from the genus Crosso-
bothrium. The immature segments of the strobile bear a strong resem-
blance to those of Spongiobothrium variabile.

1C. Anthocephalum gracile, sp. nov.
[Plate vn, Figs. 1 and 2.]

Head in the living worm with four leaf-like, opposite bothria, mounted
on very flexible pedicels. Each bothrium with a single supplemental
disk on the inner anterior border, and a marginal row of small loculi.
Face of bothria smooth ; edges very flexible, creuulate. In the alcoholic
specimens the pedicels are usually contracted, so much so, in some
cases, that the bothria appear sessile. The head is then broad, sub-
globose; the margins of the bothria are entire, but with a tendency to
lie in crinkly folds. The short-ribs which form the marginal row of
loculi and the creuulate border are prominent, especially in specimens
made transparent in some refractile medium. The bothria are some-
what triangular in shape, with the apices directed forward ; each one,
in fact, bears some resemblance to a cocked-hat.

The neck is short, subcylindrical, and merges imperceptibly into the
body. The segments are at first indicated by fine transverse lines. The
first distinct segments are much broader than long ; next squarish, then
oblong. The entire neck and body are slender, linear, and much nar-
rower than the head. Mature proglottides not seen. Genital apertures
marginal, about posterior fourth.

*I take advantage of the opportunity afforded by the passage of tlie proof sheets of
this paper through my hands to note that the above general observations on the mus-
culature of this species agree in many particulars with the more detailed researches
of Dr. Frit/, Zschokke on P. thridnx, in his admirable monograph on the Anatomical
and Histological Structure of the Cestods. (Rwherches sur la Structure Anatomiquc et
Histologiqite des Ccstodes. Me"m. Inst. uat. Gene"v. Vol. xvn, 1888.)

[77] NOTES ON ENTOZOA OF MARINE FISHES. 795

Habitat. — Tri/yon centrum, spiral valve, two specimens; August 1,
1887, Wood's Uoll, Massachusetts.

The specimens were immature. The larger afforded the following
measurements while living :

Millimeters.

Length 17.00

Length of bothr ia CO

Breadth of bothria 50

Diameter of pedicel 14

Diameter of head at base of pedicels 4G

Diameter of neck immediately back of head 16

Diameter 4""" back of head 12

Distance to first distinct segment 60

Length of first distinct segment 04

Breadth of first distinct segment 12

Length of last segment l.GO

Breadth of last segment 28

As the measurement .4mm back of the head shows, there is a slight
narrowing of the body at that point. There is, in fact, a slight con-
striction, for the diameter immediately increases again from .12 to
.14nim. In the alcoholic specimen the breadth of the head, including
the bothria, is .Smm, the length .Gmm, diameter of the anterior part of
the body .14"1"1, length of posterior segment 1.16mi", breadth .3mm.

The posterior segments are not mature. They agree very nearly,
however, with the median segments of 8. variabile. The segments in
question are slender, rectangular with slightly rounded angles. The
ovaries lie at the posterior end of the segment on either side of the
median line. The two oblong oval lobes are confluent at their posterior
ends and extend forward along the margins to the vicinity of the cirrus
pouch. The latter is not yet clearly defined, but enough to show that
the genital apertures are marginal and situated about the posterior
fourth. In front of the genital aperture the interior of the segment is
filled with the globular spermatic capsules of the testis. They are
about .04mm in diameter. Along each margin inside of the muscular
wall there is a narrow space filled with small granular bodies. This
space is limited on the inner side by the slightly sinuous aquiferous
vessels.

The resemblance of the strobile of this species to Spongiobothrium
variabile is so close as to lead me to suspect that it might be the young
of that species. Thelacinio-crispate bothria of 8. variabile might easily
be conceived to develop from the simpler leaf-like bothria of Antlio-
cephalum gracile. The fact, however, that the bothria in 8. variabile
are in distinct lateral pairs, while in A. gracile they are almost cruci-
formly disposed, reveals a difference so profound that it is not only ex-
tremely unlikely that the one form should follow the other in the same
individual, but is sufficient to create a just doubt as to whether that
would be a true classification which would refer them to the same
genus. Moreover, no supplemental disks have been discovered in 8.

79G REPORT OF COMMISSIONER OF FISH AND FISHERIES. [78"

var labile while in A. gracilc they are quite distinct in living specimens,
although it must be confessed they were found with extreme difficulty
in the alcoholic specimens.

ORYGM^TOBOTHRIUM, Diesing.

Body elongated, articulate depressed. Head separated from body by a nock, with
four opposite cap-shaped bothria, attached by a contractile pedicel, highly versatile,
and each provided with two scrobiculiform supplementary disks (auxiliary acetalmla).
Genital apertures marginal. (Diesing.)

Van Beneden originally described the species 0. versatile Dies, under
the name Anthobothrium musteli. The species was taken out of the
genus Anthobothrium by Diesing on account of the two supplemental
disks on each of the bothria.

The name Anthobothrium was retained by Diesing, and is used in this
paper, to designate those Tctrabothriidw whose bothria are unprovided
with auxiliary acetabula.

With regard to the supplemental disks at the center of the bothria
Van Beneden says :

Upou studying these appendages (bothria) with the aid of a compressor, other
characters appear which seem to be peculiar to this species* In the middle there is
a circular baud surrounded with fascicles of muscular fibers making a circle at the
center which produces the effect of a cupping disk.

The essential generic characters of these specimens, from Carcharias,
are about as follows :

Body elongated, articulate, depressed. Head separated from body by
a neck, with four opposite cup-shaped bothria attached by short con-
tractile pedicels, highly versatile, each provided with a single supple-
mental disk on anterior end of border. Border of bothria entire, with-
out loculi. Genital apertures marginal.

In 0. crispum (Tetrabothrium (Anthobothrium,) crispnm Moliu), the
second of the two species which Diesiug includes in this genus, it ap-
pears to ine, judging from Molin's figure, that the "central nmbo" of
that author, while probably of the same nature as Van Beneden's "cir-
cular baud," is not to be regarded as a supplemental disk.

Whatever may be the final disposition of the genus Orygmatobothri-um
there can be little doubt of the relationship of 0. angustum to Van
Beueden's Anthobothrium musteli.*

17. Orygmatobothrium angmtu'in Lt.

(.Plato vn, Fig. 3.]
Report of IT. S. Fish Commissioner for 1S8G, pp. 4G8-9, Plato in, Figs. 1-3.

In the summer of 1S87 I obtained this parasite of the dusky shark!
(Carcharias obscurus) on two different occasions. I give the following ^

*Zschokke's admirable monograph, Rectierclies stir Structure Anat. ct Ifist. des Ces-l
todes (Menu. lust. nat. Geudv., Vol. xvn, 1883), which readied mo before these iiotesl
were published, leaves no doubt whatever about the presence of two auxiliary aceta-
bula on each boturium of Anthobothrium (Orygmatobotlvrium) musteli Van Ben., and of
Oryfjmatobothrium longicolle Zschokke

79] NOTES ON ENTOZOA OF MARINE FISHES. 797

•

memled description of the species, together with some additional data
resulting from a study of living specimeus :

Head, when bothritl are at rest, pyramidal, bothria four, triangular
or ovate, terminating in front in a narrow rounded point, broadly
rounded at posterior end, with a thickened, entire border, sessile, or at
least pedicels not evident. Each bothrium terminated at anterior end
by a supplemental disk. Neck long. First segment squarish, subse-
quently longer than broad ; posterior segments four or five times as long
as broad and usually rounded at the extremities. Neck and segments
with tine parallel, transverse furrows which give a serrate outline to
margins. Genital apertures marginal, opening near anterior fourth.
Length as great as 35nmi.

Habitat. — Carcharias obscurus, spiral valve, very abundant; July and
August, Wood's IIoll, Massachusetts.

The following measurements of strobile and last segment are from the
living specimens :

Dimensions.

No. 1.

No. 2.

No. 3.

mm.
35 50

mm.
32 00

mm.
17 50

Length of last segment

3.00

2,50

1 60

Breadth of last segment ..

0 50

0 55

0 30

The following additional measurements are from No. 3, specimen
slightly flattened under the compressor: Breadth of head, anterior,
.32mm: breadth of head, posterior, .6mmj length of neck, 2.Snmi ; breadth,
.18mm; length of first distinct segment .2mm, breadth, .3Cmm.

One lot of specimens obtained August 12 contained only sixteen in-
dividuals of this species. On July 25, however, a very careful search
was made for Eutozoa in a dusky shark and with astonishing results.
Besides several specimens of Anthobothrium laciniatum and Phoreio-
bothrium lasium, there were in the neighborhood of four hundred speci-
mens of Tetrarhynchns bisulcattts and enormous numbers of the species
under consideration. The chyle of the intestine was absolutely swarm-
ing with them. They were saved and partially assorted at the Wood's
Holl laboratory. During the following winter I attempted to com-
plete the assorting of this lot in order to find out the exact number
of these parasites, but found the work insufferably tedious. The worms
are in many cases felted together in a tangled mass which can not be
untangled except by mutilating the strobiles. This peculiar felting
together along with a kind of tough or indurated secretion was observed
when the worms were first removed from their host. I have examined
this unassorted lot carefully for other species, but succeeded in finding
onty the species mentioned above, which were separated from the lot
at the time of collecting.

Desiring to form some idea of the number of individuals in this lot,
I attempted to separate them from the tangle of strobiles and chyle, so

798 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [80]

•

that they could be counted. I continued this work as long as my
patience and the time at my disposal lasted. Upon counting the speci-
mens that I had thus separated I found that there were one thousand
nine hundred and sixty-three. In numbering the specimens I counted
only the scolices. As the number was so near two thousand I re-
turned to the work of assorting, and in a few minutes added fifty more
scolices to the above number. One may therefore be very safe in say- •
ing that there were over two thousand individuals of this species in
the spiral valve of this dusky shark. There yet remain several hundred
specimens in the unassorted lot. The specimens of this lot vary in size
from 5 to30wm. The short specimens are doubtless in most cases frag-,
ments of longer strobiles. The alcoholic specimens show a great variety
of size and proportions, due to different stages of contraction. Some
are slender and filiform, others so thick as to be almost wedge-shape.
Between these two extremes there are a great variety of gradations.

Two distinct kinds were recognized among the living specimens.
One very slender, transparent, bluish white ; the other stouter, shorter,
opaque, and ivory white. These differences are plainly due to different
states of contraction. One of the former had the following dimensions
while living: Length, 27mm; breadth of neck near head, .lmm; seg-
ments begin about 6mm back of the head; length of posterior segment,
3.2mm; breadth, .32mm.

The bothria, while quite active during life, do not exhibit a very
great diversity of outline. Their anterior ends frequently elongate and
curve outward and back in horn-like prolongations. An opposite move-
ment is that in which the anterior ends of the bothria are closely ap-
pressed and the broadly rounded posterior ends are curved outward
and forward. These movements give to the head quite diverse out-
lines, but with all the flexibility of the bothria they were not observed
to exhibit any tendency to crumple or become folded on the margins.
In the alcoholic specimens, however, there is a tendency in the edges
of the bothria to become more of less irregular in outline. Some of
the specimens have the edges of the bothria slightly folded. There
are no loculi along the border.

This cestod can be very easily recognized by the fine transverse fur-
rows and ridges which give the margins of neck and segments a serrate
outline. These can be seen with low magnifying powers. In some of
the alcoholic specimens this feature is somewhat indistinct, as if the
epidermal tissue had become loosened by the preserving fluid.

None of the posterior segments contained ova. The ovaries are rather
small, paired organs at the posterior end of the segment. The vagina,
originating between the ovaries as a convoluted tube, can be traced
along the median line to the cirrus bulb, around which it bends like the
handle of a shepherd's crook, to open beside and in front of the cirrus
in a genital cloaca common to both vagina and cirrus. The latter is
long and slender. It was retracted in every case, and its exact length

[81] NOTES ON ENTOZOA OF MARINE FISHES. 799

could not be determined. It is about .03mm iii diameter at base. The
interior of the segments was filled with long, oval masses, which lie close
together and at right angles to the long axis of the segment and along
the central part of the segment on each side of the median line. In the
anterior part of the segment the masses are globular, and along the
margins smaller and granular.

The cirrus bulb lies in the crook of the vagina, and contains, besides
the retracted cirrus, a part at least of the vas deferens. When thin
sections of a stained segment were made, the cirrus was found to be
covered with exceedingly minute spines. The long-oval masses in the
interior of the segment now appear densely granular, or like nests of
nuclei in some of the segments ; in others which are more mature
they are not so much elongated, and contain both nuclei and fibrous
tissue.

This species is apparently near Van Beueden's Anthobotkrium mustcli
(Orygmatobothriuni versatile Dies., Re vis. Ceph. Par. p. 27G). I have,
however, experienced the same difficulty in finding a second supple-
mental disk in the center of the bothria, as in the case of the specimens
which furnished the material for my former description. I notice the
same curved band of muscular fibres crossing the faces of the bothria
about the anterior third. This does not rise into a transverse rib.

I am not at all satisfied that there is a second supplemental disk
(auxiliary acetabulum) in this species. It is certainly .very faintly out-
lined by the curved baud of muscular fibres.*

CROSSOBOTHEIUM Linton.
18. Crossobothrium laciniatum Lt.t

[Plate vii, Fig. 4.]
U. S. Fish Commission Report for 1886, pp. 469-474 ; Plate in, Fig. 4-18.

I have already given a tolerably full account of this parasite of the
sand shark (Odontaspis littoralis).

* In attempting to follow Diesing's system of classification of the unarmed Tetra-
tothriidcv I have experienced much perplexity, and nowhere more than among the
forms kindred to those which Van Beneden has grouped under the generic name
A nthobothrium .

The specimens which I have referred to the genus Orygmatobothrium possess many
of the characters ascribed to the genus Monorygma Dies. There ie, however, no
niyzorhynchus, unless an indistinct papilliforin apical termination of the head be
regarded as such.

Diesing'fl genera Orygmatobothriuni and Monorygma are included by Van Beneden
in his genus Anthobothrium.

tThis species bears a close resemblance to Oerley's Orygmatototltrium Dolirni: Die
Entozoen der Haien und Eochen, p. 219, pi. x, figs. 16-19, Phyllobothrinm Dolirni Oerley,—
Zschokke, Mem. Inst. nat. Gentv., vol, xvii, 328-338, pi. vm, fig. 138 and pi. ix, figs,
•J39-144.

800 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [82]

Iii the summer of 1886 and 1887 I had several opportunities of exam-
ining this shark. In each instance I found this entozooii in abundance,
and usually no others. I take the following data from my memoranda
made at the time of collecting :

August 2, 1880. — Eighty-one specimens of C. laciniatum, adult and
young, obtained from the spiral valve of a single sand sliark (0. litto-
ralis). The chyle was swarming with mature proglottides. One indi-
vidual of this lot differed from all other specimens of this parasite that
I have yet seen in having a moderately elongated neck. In the normal
form the neck is short and corresponds to one of the anterior segments.
A description of this unusual form is given below. No other entozooii
found, except a few cysts (Xenosites Van Beuedeu) in the muscular
coats of the stomach and intestine.

July 13, 1887. — Seventy-five specimens of same parasite, young and
adult; same host; no other eutozoon found.

July 22, 1887.— Fifty-three specimens of same, maximum length
160mm ; same host; no other entozooii.

August 12, 1887. — Ninety-two specimens of same, mainly immature,
maximum length 40mm; same host; also five small Ehynchobothria and
one Nematod.

August 13, 1887. — Forty-four specimens, mainly adult, maximum
length, 125mm ; same host ; also five Nematods, four large and oce small,
with their heads embedded in the mucous membrane of the stomach,
near the pyloric constriction. In this lot there was an abnormal form
which measured only 18mmin length, but which had mature segments.
This form is more fully described below.

Variety longicolle. — The abnormal form found in the lot of August 2,
188G, deserves something more than a passing notice. It is the only
one of all that I have yet found that has a distinctly elongated neck.
In other cases, with this single exception, the length of the neck, that
is, the distance from the bases of the pedicels of the bothriato the first
segment, is about equal to the length of the first segment. In other
words, the segments begin immediately behind the head.

When first measured, which was after it had lain in sea-water about
eighteen hours, the length of this specimen was 14.7mra, the length of
the neck 2mm. The first segment at this time was enlarged and inflated.
This latter feature disappeared in a few hours and the neck became
relatively longer and thinner. After having been in sea-water for
twenty-four hours, the length of the specimen was 21mm, its neck 5mm.
There were eighteen segments in the strobile, all of which seemed
to be adult and equally developed, while the last two were mature and
contained ova. In this respect it was in sharp contrast with the other
individuals of this and other lots, which had mature segments. These,
as a rule, measured from 100 to 200mm and over, in length, the anterior
and median segments being immature. On the other hand, the dimen-
sions and general appearance ot the head and bothria are in no essential

[83] NOTES ON ENTOZOA OF MARINE FISHES. 801

particular different from the normal type. The neck, which presents
the greatest apparent difference, can hardly be taken, from this isolated
example, as a type for a new species. If that part of the head which
lies behind the bothria in a normal individual were stretched out, which
it may have the power of doing, there would then result a form of neck
exactly like that which characterizes this abnormal specimen.

The absence of segments corresponding to the anterior and median
t immature segments of the normal individuals constitutes a difference
which is much more difficult to reconcile with the typical specific char-
acters. If other forms should be discovered answering to this, which I
conceive to be an abnormal form, the discoverer would be justified in
erecting a new species. It may be regarded at present as a variety.

The arrangement of the genital organs in the posterior segment is
normal. The segments likewise have a lateral opening for the escape
of ova. The size of the ova is the same, viz, .02 to .03mm in diameter.
When placed in alcohol the segments contracted very much in length,
while the neck remained relatively unaffected.

Of the specimens, detailed measurements of which are given below,
No. 1 is the abnormal form, No. 2 normal, here repeated for compari-
son. The dimensions of the abnormal specimen are those recorded
when it was first measured :

Dimensions.

No. 1.

No. 2.

mm.
14.70
1.00
2.00
2.00

mm.
195. 00
1.45
1.80

.18

.70
1.05
1.40
1.23

.50
.70
1.60
1.90

In No. 2 no dimensions are given for the neck. The dimensions given
for the first segment, however, do not differ materially from those of
that part of the head which lies behind the bothria.

In the lot obtained August 13, 1887, among quite normal forms,
were some which bore mature segments although much shorter than
the normal strobiles. In one of these anomalous forms, measuring 18mm
in length, the head and first twenty segments were normal in shape and
size and character of the flaps. From the twentieth to the twenty-
fifth segment the breadth of the strobile increased rapidly from less
than lmm to about 3mm. There were thirty-six segments in all. The
last ten or twelve were about the same breadth, that is, 3mm, and each
was about lmm in length. There were a few other specimens which
were much like this one, but longer. They were, in fact, transition,
forms between it and the normal type.
H. Mis. 133—51

802 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [84]

The individuals of this species are usually an opaque, ivory-white
color. A few in one of the hosts were observed to be tinged with a
greenish color. This may have been due, however, to the action of
some food which had been taken into the alimentary canal of the host
a short time before the specimens were collected.

i

LEG ANICEPH ALUM*, gen. UOV.

[Aexavj'c, a platter.]

Body taBniteform, articulate, head transversely flattened, circular or
subquadrangular, and consisting of two disciform plates. Posterior
plate with four supplemental disks (auxiliary acetabula). Neck short
or none. Genital apertures marginal.

Van Beuedeu mentions (Poiss. des cotes Belgique, I, Parasit. et com. p.
19, Plate v, h'g. 13), among the parasites of Trygon pastinaca, a genus
which he names Diacobothrium. The name which he gives to the species
is D.fallax. He publishes no description of the worm, but figures the
head and anterior segments. The figure is a good one, but there is no
explanation of the number of times it is magnified. When, however,
one is obliged to choose between a short description and a good figure
in the identification of the Cestoda, the latter is to be preferred. Van
Beneden's figure of D.fallax shows it to be a Cestod, with a thick, mus-
cular anterior disk surmounting a quadrangular base, the angles of
which are prolonged into prominent, tubular bothria, the sucking-disks
of which are circular.

Although I do not feel justified, from such meager data, in referring
a parasite, which I have obtained on three different occasions from the
spiral valve of Trygon centrum, to the genus Discobothrium, I yet find
sufficient resemblance between Van Beuedeu's figure and my specimens
to incline me strongly to the belief that they are closely related, if not
geuerically identical. The near relationship, if not actual identity, of
their hosts, makes the close affinity of these parasites the more
probable.

19. Lecanicephalum peltatum, sp. uov.

[Plate ix, Figs. 2-4.]

Head nearly circular, disciform, and joined to the neck or anterior
part of the body at the middle of the posterior side, after the manner of
a peltate leaf. In the living worm the head looks like two thin plates,
placed the one on top of the other. The anterior plate is almost circu-
lar with their edges, which are more or less ruffled or irregularly creii-
ulate. In preserved specimens they are sometimes so much folded at
the edges as to obscure the characteristic disciform shape. The second,

* The genera Lecanicepltalum and Tylocephaliim are put among the Tetrabothriidos
although neither genus possesses the characteristic bothria of the family. It may
become necessary, upon further examination of theso interesting forms, to put them
in a distinct group under the name Gamobothriida; or some equivalent term.

[85]

NOTES ON ENTOZOA OF MARINE FISHES.

S03

or posterior, plate is of about the same thickness as the anterior one,
and, in the living specimen, is nearly circular, and bears four supple-
mental disks (auxiliary acetabula), which are nearly equidistant on the
margin. In the alcoholic specimens, however, the posterior plate is
found to be somewhat smaller than the other. Its margins are entire,
smooth and quadrangular. The largest sides of the quadrangle cor-
respond to the lateral side* of the strobile, and the supplemental disks
are at the angles. In some cases the angles which bear the supple-
mental disks are slightly prolonged.

The supplemental disks are directed sometimes forward, sometimes
backward. Their usual direction is probably outward, or at right
angles to the axis of the body. The diameter of a single disk, measured
in an alcoholic specimen, is .lmm.

The neck, or anterior part of the body, is attached to the posterior
side of the disk-shaped' head, like the petiole of a peltate leaf to its
blade.

Segments begin about limn, or less, back of the head. The first dis-
tinct segments are broader than long. The segments are, at first, rather
flat, squarish or rectangular, with parallel sides and sharp angles, but
as the reproductive organs begin to mature, the segments become
rounded and somewhat thickened, giving a mouiliform outline to the
strobile. The posterior segments are considerably elongated, sometimes
bacilliform, rounded at the angles and slightly constricted at the ends,
at other times elongated and rectangular.

Eeproductive apertures marginal, a little in front of the middle of the
segment. Cirrus bulb large, oval, with anterior prolongation. Cirrus
echinate.

Habitat. — Trygon centrum, spiral valve, July 29, 1886, July 10, 1887,
and August 1, 1887. Wood's Holl, Massachusetts.

I have obtained this eutozoon on three different occasions, each time
from the spiral valve of the sting ray (Trygon centrura), and each time
but few specimens. The first lot contained but one specimen; the
others four or five each.

The following measurements were made on living specimens, one from
each lot :

Dimensions.

No. 1.

No. 2.

No. 3.

Length

mm.

8.20

min.
12. 50

mm.
14.00

Diameter of head

.90

68

80

Thickness of head

.40

Diameter of neck

.16

.12

. 14

Distance to first distinct segment

20

1.00

Length of first segment

.04

.02

.10

Breadth of first segment

. 16

.12

.18

Length of last segment

.85

1.50

.80

Breadth of last segment

.30

.32

.26

Number of segments ....

60

804 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [86]

In No. 1, which was lightly distorted under the compressor, the head
measured across the top 1.4ram and was quite thin, as shown in the
sketch (Fig. 2). The dimensions of alcoholic specimens differ but little
from those of the living specimens.

Although in this species the bothria, being represented by the undi-
vided posterior disk of the head, are strictly one, the occurrence of four
definite auxiliary acetabula on the margins of the bothrial disk shows
its relationship to the family Tctraphyllidce. The anterior plate or disk
is probably to be regarded as homologous to the myzorhyuchus of
Echeneibothrium.

Although the head of Lecanicephalum ptltatum, as a whole, is some-
what suggestive of Van Benedeu's figure of Discobothrium fallax, the
differences are also very profound. Indeed, the figure of D.fallax sug-
gests some of the forms of Echeneibothrium variabile, especially one fig-
ured by Olsson (Lunds. Univ. Arssk., Vol. m, Plate I, Fig. 15).

Anatomy of posterior segments. — Two posterior segments were stained
with luematoxylon and cut into longitudinal sections. They furnished
the following data: The segments were about .7mm in length and .24mm
in breadth. The body wall is composed of two layers. The outer of
these is a musculo cuticular layer, which is characterized by having a
transversely crackled appearance ; the broken lines which produce this
effect are about .Olmm apart. The inner layer of the body wall is coarsely
granular, the granules being very irregular in shape.

The genital aperture is marginal, and in a section measuring ,7mm in
length was exactly .3ram from the anterior end. Under a low magnify-
ing power the genital aperture appears to lead directly into a some-
what pyriform clear space, which is .16min long and .08™" broad, and is
directed towards the anterior end at a sharp angle. Its anterior ex-
tremity was, in one case, only .16rni" from the anterior end of the segment.
When the sections are examined under a magnifying power of from
250 to 300 diameters, the appearance of this apparent cirrus bulb is very
remarkable. It is then seen to be lined with a dense coat of very fine
bristle like spines, which point towards the external aperture. The true
nature of this bulb is thus revealed. It is in fact the base of the cirrus
itself, and lies in a larger cavity, which also contains additional coils
of the cirrus. The walls of the true cirrus bulb appear to be thin and
weak in proportion to the size of the organ to be evaginated. The
diameter of a section of one of the folds of the cirrus lying beside the
enlarged base was .02ram. The shape and appearance of the cirrus when
extruded must be very remarkable. It is evidently quite long. The
spines with which it is beset «ore quite slender and bristle-like, and
measure .006mm in length. The true cirrus bulb is .19ram in length and
,11mm in breadth. It lies nearest that margin on which is the genital
aperture, and in one of the sections extends to within .14mm of the an-
terior end of the segment. The same measurement was obtained from
one of the segments in which the iuvagiuated cirrus appeared in the
shape of a loop,

[87] NOTES ON ENTOZOA OF MARINE FISHES. 805

The ovaries are two oval or elliptical organs, .17mm long and .05mm
broad, lying one on each side of the median line at the posterior end of
the segment. They appear to be continent at the extreme posterior end
of the segment. The granular elements of which they are composed
measure .005mm in diameter.

A thick-walled tube originates between the lobes of the ovary, and fol-
lows the region of the median line in a sinuous course to the posterior
edge of the cirrus bulb. It then turns abruptly toward the margin,
where it opens into the genital cloaca behind the cirrrus. This tube is
evidently the vagina.

In some of the sections there are to be seen, near the vagina, what
appear to be parts of a larger and convoluted tube. This I take to be
the vas deferens. It differs radically in appearance from the vagina.
The latter in longitudinal sections is linear; its thick walls inclose an
empty space. The former is massive and filled with very fine striated
material. This latter appearance, in sections of cestod segments, is
! occasioned by the presence of spermatozoa.

Along the margins of the segments, and in the interior among the
other organs, there are numerous granular bodies. These are not always
of definite shape, but are often elliptical, oval, or circular in section.
They are probably sections of spheroidal masses. They are from .02 to
.05uim in diameter, and the granular nuclei with which they are filled are
.003mm in diameter. Some of these bodies, near the margins of the
segment, had an incipient striated appearance. They are probably
spermatic capsules of the testes, in the nuclear contents of which sperma-
tozoa are beginning to be differentiated. There was no indication of
ova in these segments.

TYLOCEPHALUM, * gen. nov.

a knob.]

it'!

elv

rus

Body articulate ; head globose ; bothria united into a globular disk
and bearing four supplemental disks, which are arranged in lateral
pairs; myzorhynchus also globose, as large as remainder of head.
Neck, i. e., nnjointed anterior part of body, moderately long.

Genital apertures marginal (?).

I have found it necessary to establish this genus to accommodate
a single small cestod from the spiral valve of the cow-nosed ray
(Rhinopterus quadrilola). As the specimen was associated with a few
specimens of Rhinebothrium cancellatum, I at first supposed that it
might prove to be the young of that species. The total absence of any-
thing like costse, and, moreover, the presence of supplemental disks, at
once shows that it can not be referred to either Echeneibothrium orRhine-
bothrium.

* See foot-note on page 84.

806 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ' [88]

The character of the head suggests a possible close relationship with
Discocephalum. The large, globular inyzorhyuchus of Tylocephalum
may be homologous with the broad, muscular head of Discocephalum,
in which case the globular acetabular disk of the former would be ho-
mologous with the corrugated, inflated, cervical mass of the latter. If
the acetabular disk of Tylocephalum were, in the adult, to divide into
independent bothria, it would then exhibit a close resemblance to Van
Benedeu's Discobothrium.

/•

Until more material is obtained the exact position of this Cestod must
remain in some doubt.

20. Tylocephalum pingue, sp. nov.

[Pinguis, plump.]
[Plate ix, Figs. 5-9.]

Head divided into two spherical parts by a median transverse constric-
tion, the anterior part a tnyzorhyuchus, the posterior a bothrial disk,
bearing four supplemental disks not evident in the living worm, but
when the specimen is made transparent they are seen to be arranged in
pairs, which are marginal with respect to the head, lateral with respect
to the body.

Anterior segments begin some distance back of head, very short,
much broader than long, subsequently squarish, ultimately longer thau
broad. Habit of body rather plump in subcyliudrical. Genital aper-
tures marginal (?). Length of immature specimen 20mln.

Habitat. — Rhinoptera quadriloba, spiral valve, one specimen, Wood's
Holl, Massachusetts, July 20, 1887.

The description of this genus and species is based on the examina-
tion of a single specimen. While no sexually mature segments exist
the adult or strobile condition is well assured. I shall first give the
description made of it while it was yet living, and then add the few
observations I have been able to make after a study of the alcoholic
specimens.

When the specimen was first found it was firmly attached to the
mucous membrane about the middle of the spiral valve of its host.
The anterior part of the head, or myzorhynchus, was imbedded in the
mucous membrane. It was carefully removed without damage and the
specimen placed in sea water. It then measured 20rano. Its form was
subcylindrical, and it had an arcuate outline on account of a flexure
towards one of its margins. No movements were observed in it at first,
and until it was examined with a lens it was taken to be a specimen of
some Echinorliynclms.

The shape of the head was very peculiar, and totally unlike that of)
any cestod I had ever seen. In my notes made at the time I described
it as shaped like a dumb-bell with a very short handle, the axis of the
handle coinciding with the axis of the body. The anterior globular

[89] NOTES ON ENTOZOA OF MARINE PISHES. 807

part of the head, that part which was imbedded in the mucous mem-
brane, when removed appeared to be more delicate than the posterior
part. It was delicate and translucent, and of a faint pink or carnation
color.

Behind the anterior tumid part of the head there was a constriction,
making the handle of the dumb-bell. The band which formed this con-
striction was also pinkish in color. Behind this constriction was the
second tumid part of the head, which was dense and opaque and of an
ivory-white color. The color of the body was yellowish-white.

The head preserved its singular shape unchanged when placed in sea
water, although the worm showed signs of life by very slow movements,
especially of the posterior segments. The worm as a whole, however,
was practically immobile, and in this respect was in sharp contrast
with the very active movements of some specimens of RMnebothrium,
which were associated with it.

Following the head was a nearly cylindrical neck, which makes a
slight but abrupt enlargement a little less than lmm back of the head.
Transverse lines, which rim from the margins towards the middle of the
lateral faces, very soon make their appearance, but do not meet so as to
divide the body into distinct segments until about Smm back of the head.
The segments are at first quite short. Farther back they become
squarish. Near the posterior end they are longer than broad. Four or
five of the posterior segments, excepting the last one, had beautiful
curving marginal outlines, being convex in front and concave behind.
The last segment was considerably elongated.

The following measurements are from the living specimens :

Millimeters.

Length 20.00

Length of head 1.16

Length of my zorhynchus 58

Diameter of myzorhynchus 76

Length of median constriction 14

Diameter of median constriction 56

Length of acetabular disk 44

Diameter of acetabnlar disk 74

Diameter of neck immediately behind head 30

Diameter lmm b^ack of head 36

Length of median segments 13

Breadth of median segments 50

Length of segments near posterior end 40

Breadth of segments near posterior end 40

Length of last segment 66

Breadth of last segment 28

The habit of the body throughout is rather plump, inclining to cyl-
indrical.

The specimen was further examined after it had lain some four months
in alcohol. When placed in glycerine the anterior bulb of the head
became transparent. Longitudinal muscular fibers could be seen enter-

808 REPORT OF COMMISSIONER OF. FISH AND FISHERIES. [90]

ing it from behind and diverging in all directions to the periphery.
The posterior bulb remained too opaque to show its structure. Imme-
diately back of the head the neck was somewhat flattened for a short
distance, beyond which it was rather plump and cylindrical. The short,
flattened part of the neck was transparent, and within it could be seen
a band of about ten longitudinal muscles or vessels, or both. There
were no indications of reproductive organs.

The specimen was next examined io oil of cloves. The character of
the head was now found to be quite different from what it had been
supposed to be when studied in the living specimen. The anterior part
proves to be a large globular and muscular myzorhynchus, which may
possibly be retractile. The central constricted part of the head is dis-
tinct, and surrounds the compressed base of the myzorhynchus like a
collar. The posterior part of the head is not strictly globular, but is
longer in that diameter which corresponds to the marginal diameter of
the body than it is in the opposite direction. It is entire in outline,
undivided, and at its base surrounds the constricted neck like a collar.
On its anterior surface it bears four supplemental disks. These are
oval or oblong, in shape, and are directed forwards. They appear to be
arranged in pairs, which are marginal with respect to the head, lateral
with respect to the body. They are about .Olmm in diameter, cup shaped,
with depressed centers, in which there is a reticulated muscular tissue,
and with raised edges which are composed mainly of radiating fibers.

The middle of the neck and anterior part of the body is traversed by
a number of strong muscular bands of longitudinal fibers. These
bands, or fascicles are distinct from certain broad sheets of longitudinal
muscular fibers which can also be seen in this part of the body. The
central band of fibers, or vessels, continues to be visible to the posterior
end of the body.

The posterior bulb of the head is very muscular. The outer part of
it is granular with radiating and circular fibers. Of these the radiat-
ing fibers predominate. Beneath this outer layer towards the center
and the anterior part of the bulb there are numerous strong diagonal
fibers crossing each other so as to make a net- work with rhombic meshes.
The middle constricted part of the head is made up of granular tissue
with very numerous radiating fibers, which enter from behind and di-
verge to the free collar-like border. Its center is composed of longi-
tudinal fibers, which, entering the base of the anterior enlargement or
myzorhynchus from behind, make the divergent longitudinal fibers
which form the predominating fibrous tissue of that organ.

The head is thus seen to be made up of three parts : First, the myzo-
rhynchus, which is globose in front, but contracts to a comparatively
narrow base. The latter is surrounded by the anterior rim of the sec-
ond part. This second or middle part of the head is short, separated
from the posterior part by a deep furrow, and surrounds the base of the
myzorhynchus with its anterior raised border. It may possibly be a

"91] NOTES ON ENTOZOA OF MARINE FISHES. 809

sincl of terminal os into which the muscular proboscis can be retracted.
The third part is a muscular disc, which bears four auxiliary acetabula
on its anterior edge. It is truncate in front, globular in lateral, oblong
n marginal view. At its base it forms a collar, with thick, rounded
edges, which surrounds the abruptly-narrowed neck.

Anatomy of posterior segments. — The last three segments were stained
with hrematoxylon and cut into longitudinal sections. The segments
ire as yet too immature to allow one to say certainly that the genital
apertures are marginal. There is, however, a dense, pyriform nuclear
jluster towards the front end of each segment and nearer to one mar-
sjin than the other, which I believe outlines the beginning of the cirrus
mlb. There is also a nuclear aggregation at the base of each segment,
which probably marks the beginning of the ovary. Although no ex-
ernal genital apertures as yet exist, I feel quite confident, from the
vppearance of these segments, that, when adult specimens of this species
ire found, the genital apertures will be found to be marginal.

The sections show first a soft, granular epidermis, wliicb has a tend-
ency to slough off. ISText a fine granular layer containing delicate cir-
iiilar fibers. Beneath this is a layer with coarse granular and longi-
udinal fibers. The center of the segment is granular with no fibers
)f any kind. There are, however, many clusters of nuclei with a clear
?pace in the center of the cluster. These are apparently sections of tub-
ilar bodies which are beginning to take shape in the parenchyma of the
nterior of the segment. Some of these nuclear clusters are elongated.
Fwo rather prominent aquiferous vessels were observed. Each of these
ies a distance from the nearest margin equal to nearly one-third the
breadth of the segment. These pursued a somewhat sinuous course
and passed without interruption from one segment to another.

The segments are sharply defined, the one from the other. At the
dividing line between two segments an abundance of circular or trans-
verse fibers is developed. The posterior edge of each segment pro-
jects a very little to overlap the front end of the succeeding segment.

Sub-family II. — PHYLLACANTHIN^E Van Beneden.
CALLIOBOTHRIUM Van Beneden.

Tbe restoration of Van Beneden's genus Acanthobothrium necessitates
an emendation of the definition of the genus CaUiobothrium, The char-
acters of this genus, thus emended, following Diesiug's definition, are :

Body articulate tseniseform ; head continuous with the body or separated by a neck,
quadrangular, with four angular bothria, which are attached to the head in front by
the dorsal face, trilocular on account of two transverse costae, each armed in front
with four simple hooks, and provided in front of hooks with a versatile supplemental
cup-shaped, trilocular or contracted into a globe. Genital aperture marginal.

810 REPORT OF COMMISSIONER OF FISTI AND FISHERIES. [92]

21. Calliobothrium verticellatum Bndolphi.

See Report of U. S. Fish Commission, 1886, pp. 476-479, Plate IV, Figs. 1-8, for de-
scription and synonymy.

I have already published a description of this Cestod, which 1 ob-
tained in August, 1884, from the spiral valve of Mustclus canis.

Since then I have made several captures of this parasite in the same
host.

Date of
capture.

No. of dog-
fish exam-
ined.

Number of parasites found and remarks.

1880.

July 22

1

A single specimen.

23

3

Several in one, one in another, none in third.

24

4

, Several in each.

31

1

Twenty specimens more or less, maximum length 154mnl.

1887.

July 19

6

Several from two of the hosts, maximum length 9'imm.

21

10

Moderately abundant in all.

Aug. 4

3

Several obtained from each.

6

1

Three specimens, maximum length 115IB1>1.

10

3

About a dozen from one, ten from another, none from third, 110raln maximum.

12

1

A few specimens much attenuated and flaccid.

13

2

About forty specimens in one, nine in the other.

I add the following data to my former account of this worm. The
length of the adult strobile evidently far exceeds 10()mm, the maximum
of my former paper. The longest living specimen that I have measured
was 154mm in length. I also find several alcoholic specimens measuring
as much as 90mm in length. The free proglottides are ranch larger than
the posterior segments of the specimens upon which I based my former
description.

Following are measurements of posterior and free segments of alco-
holic specimens :

Milli-
meters

Milli-
meters.

Milli-
meters.

Milli-
metera.

5. C

4.6

3.6

5.4

1.3

1.4

2.2

1.3

In a living strobile, 115mm in length, the last segment, when at rest,
measured 3.5mm in length and 1.75mm in breadth. Free proglottides iu
the same lot were very active, in some cases stretching themselves out
to a length of 10mm.

The following points were made out without the aid of thin sections:
The genital apertures are marginal, near, or in front of, the anterior
third. There is sometimes a low papilla in the vicinity of the aperture.
The cirrus is comparatively short, small and covered, at least at base,
with exceedingly minute spines. It was not seen fully everted. Diameter

[93] NOTES ON ENTOZOA OP MARINE FISHES. 811

at base in one case about .03mm. The cirrus bulb in this instance small,
nearly circular in outline, and .6mm in diameter. In one instance the cir-
rus was protruded about .044'"™ and measured .023mm in diameter. No
spines were visible on the everted cirrus. In the posterior segments
the ovaries occupy about the posterior fourth, and under moderate en-
largement appear as finely granular organs, somewhat two lobed, but
confluent at the middle line. In segments which precede the extreme
posterior ones the ovaries occupy as much as the posterior third, their
anterior edge making a line transverse to the axis of the segment. The
inner termination of the vagina is in a bulbous enlargement — seminal
receptacle — between the lobes of the ovary. A wide duct or sinus, the
uterus, occupies the median line of the segment from the ovary almost
to the anterior end of the segment. The vagina leaves the uterus
opposite the genital aperture and proceeds directly to the margin of
the segment, thus making a right angle with the axis of the segment.
The vas defereus is represented by a cluster of tubes at the ant rior
end of the segment. The remainder of the interior of these segments is
filled with large, spherical, granular bodies, which I take to be the testes.
In the mature free proglottides the anatomy is quite different from what
has been given for the posterior segments. In the former an inner ob-
long space, the uterus, which is of considerable extent, becomes converted
into an ovisac which is filled with small ova. Such a proglottis when
rendered transparent in glycerine resembles a double sac. The tissue
of the outer sac appears homogeneous, with the exception of a few small
granular masses, which apparently represent the remnants of the testos
and vas deferens. The inner sac is sharply defined from the outer by
a thin limiting membrane and is filled with ova.

The foregoing points in the anatomy of the segments were confirmed
by thin sections, and a few additional facts obtained. In longitudinal
sections the cirrus was seen to be armed with minute spines throughout
its entire length. Both the cirrus and its bulb are remarkably small in
proportion to the size of the mature proglottis. The vagina was seen to
open immediately in front of the cirrus. The vas defereus was found to bo
quite voluminous, and appeared in sections as convoluted vessels filled
with a dense, filamentous substance, which I take to be spermatozoa.
Some of the large, granular bodies already mentioned, were seen, in sec-
tions, to contain, besides the granular nuclei, abundant fibrous tissue. I
have interpreted this as indicating the transformation of the nuclear con-
tents of the testicles into spermatozoa. In some sections in which the
uterus appeared as a broad median sinus with irregular outlines the
vagina was seen to lie, not in the median sinus, but along one of its
sides, within the dense, granular tissue which form the boundary walls
of the sinus. This was about the middle of the segment. In some sec-
tions, however, which showed the posterior part of the segment, the va-
gina was seen as a convoluted tube between the lobes of the ovary, and
appeared for a short time after leaving the ovary to lie in the median
sinus.

812 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [94]

The ova when highly magnified are seen to be oval and measure
about .OGGram and .055Inm in the two diameters. Each ovum contained
about a half a dozen globular masses, which are densely granular, stain
deeply, and measure about .019mm in diameter.

22. Calliobothrium esckrichtii Van Beneden.

[Plate vii, Figs. 5-12.]

Acanthobothrium eschriclilii Van Beueden, Bull. Acad., Belgique, xvi, n

280.
Onchoboilmum (Calliobothrium') elegans, Diesiug, Sitz., der kais. Akad.,

xin, 585.
Calliobothrium eschrichtii Van Beneden, Me"m. Acad. Belgique, XXV, 142

and 193, Plate xiv ; Diesing Re vis. Ceph., Ab. Par. 280.

I have found a Calliobothrium repeatedly in Mustelus canis, which in
most particulars agrees with Van Beuedeu's G. eschrichtii from Muste-
lus vulgaris. Van Beneden's description of this species is thus epitom-
ized by Diesing :

Head subangnlar, bothria four, angular, subelliptical, each divided into three un-
equal loculi by two transverse costse, armed in front by four simple subequal hook-
lets, and provided in front of booklets with a supplemental disk (auxiliary acctabn-
lum), which is sometimes simple, trilocnlar. Neck short. Anterior segments of the
body subquadrate, subsequently longer than broad. Genital apertures marginal.
Length 4 to 6mm.

I find in my notes records of eight different captures of this species,
each time in the spiral valve of the smooth dog-fish (Mustelus canis).
All the captures were made at Wood's Holl, Massachusetts.

Following is a summary of the records :

Date of
capture.

No. of dog-
fish exam-
ined.

Number of specimens obtained and remarks.

1886.

July 22

1

Eighteen.

23

3

Five in one host, near anterior end of spiral valve.

24

4

One in one of the four hosts.

Aug. 6

1

One.

1887.

July 19

6

Two from one of the six hosts.

21

10

Six found Jn a few of the ten hosts.

Aug. 10

3

Eleven from one of the three hosts.

13

2

Two from one, and one from the other host.

These specimens were almost invariably associated with C. verticilla-
turn, Rhynchbothrium bulbifer, and R. tumidulum. The same host was
examined on twelve other occasions in the latter part of July and fore
part of August without finding this parasite.

The length of the specimens which I have obtained varies from 5 to
14mm. The average of nine specimens from the capture of July 22, 1886,
is 9.56mm, maximum, 14mm ; minimum, 6mm.

[95] NOTES ON ENTOZOA OF MARINE FISHES.

i II The folio wing detailed measurements were made on living specimens:

Dimensions.

No. 1.

No. 2.

mm.
9.00

mm.
6.00

.90

.60

.04

.34

.20

.24

.20

.24

1.00

1.00

.CO

.32

In No. 1 there were six large proglottides preceded by five smaller
ones and a few indistinct ones near the head. In No. 2 there were fif-
teen distinct segments. The first six or eight of these were only mod-
erately distinct, merging into fine transverse wrinkles near the head.
In another specimen the five posterior segments were larger than the
others and were preceded by nine smaller segments, gradually dimin-
ishing towards the head, where they merged into indistinct segments,
indicated by transverse lines. Tbe posterior segments are, in general,
elongated, loosely attached to each other, and separating easily from the
strobile. Usually there are from three to five mature segments. Six
is the greatest number observed on a single strobile.

The greatest difference observable between these specimens and Van
Beneden's C. eschrichtii is in respect to the dimensions of the posterior
segments. The dimensions given by Van Beneden for C. eschrichtii
are: Length, 4 to 5mm; length of bothria, .6'"m ; length of hooks, .I"11";
breadth of neck, .2mni ; length of free proglottis, 8 to 9mm. A compari-
son of these measurements with those given above will show that the
principal difference is that which exists between the posterior segments
of my specimens and the free proglottis of Van Beueden's description.

On one occasion I found a large proglottis associated with some indi-
viduals of these species which I at first thought might prove to belong
to C. eschrichtii. Upon comparing it carefully with posterior segments
of C. eschrichtii and of Rhynchobothrium bulbifer I found that it be-
longed to the latter. I am therefore tempted to believe that Van
Beuedeu has mistaken the free proglottis of some other Cestod for that
of G. eschrichtii. I have frequently found mature segments on the
longer strobiles of G. eschrichtii, as well as free proglottides, from which
the large ova were issuing, but have never found them to exceed about
1.5mm in length, while on the other hand, associated with them, I have
often found specimens of R. bulbifer with posterior segments and free
proglottides measuring 5mm and Gmm in length.

The description given above is peril aps enough to render identifica-
tions of this species certain, but as Van Beueden's description would
indicate that there may be some constant differences between his speci-

814 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [96]

mens aud these which were obtained ou this side of the Atlantic, I add
the following data:

The head at rest is somewhat rectangular in outline. The bothria,
four in number, are opposite, that is, not arranged in marginal pairs,
oblong, rather bluntly rounded posteriorly, hollowed out on the face,
boat-shaped. They are divided into three loculi by two transverse
costoe. The two posterior loculi are of nearly equal length and shorter
than the anterior one. At the anterior end each bothriuui bears four
simple hooks. These are in pairs, a pair near each margin. The bases
of the hooks in each pair are closely articulated, but do not spring from
a common base. The hooks are relatively long aud slender, pointing
backward. They curve outward slightly at first, but near the points
return until they are nearly parallel with the axis of the head. The
outer hook of each pair (outer with reference to bothrium) is a little
longer and more slender than its mate. The inner hooks have very
broad subcutaneous basal supports ; a prolongation of each approaches
that of the other and almost meets it. There seems, indeed, to be a small
solid piece which fills up the interval between the bases. Muscular
fibers can be traced to the basal supports of all the hooks. The hooks
themselves when magnified are seen to be hollow and filled with finely
granular material. The combined effect of these hooks is to form a
crown of sixteen hooks.

In front of the hooks each bothrium is surmounted by a triangular
pad which bears a single supplemental disk. This part of the bothrium
is capable of considerable variation in shape. I have seen it approach
the trefoil shape figured by Van Beueden, but have never seen it assume
that shape definitely.

The posterior ends of the bothria are free aud are susceptible of much'
variety of motion. In progressive movements the bothria are thrust
forward either by diagonally opposite pairs, by adjacent pairs, or singly.
When a specimen was placed under a compressor and slight pressure
applied a bothrium was pushed forward in front of the head aud at-
tached to the cover-glass by the supplemental disk aud the posterior
loculus. By this means the head was dragged forward. The last part
to detach itself from the cover-glass was the posterior loculus, which
was acting as an independent sucking-disk. In ordinary progression
the entire face of the bothrium is attached to the supporting surface.
The head of the living worm is almost transparent. The bothria are
strengthened by bands of muscle fibers, which lie near the margins at
the bottom of the trough-like face aud send up short branches to the
upper edge or rim. Each bothrium is further strengthened by two trans-
verse muscular bands, which form the characteristic costse. A single
bothrium in the living worm suggests a wire flower basket. When the
posterior ends of the bothria are reflexed they are seen to be joined to
the head by a broad membrane, in which lie bands of muscular fibers.
When the bothria are reflexed sufficiently, that is, when their posterior

t

|[97] NOTES ON ENTOZOA OF MAKINE FISHES. 815

lends are turned outward and forward over the books, as is often the
Jcase in active worms, a short neck is revealed, which is cylindrical and
jlightly tumid just back of the point of attachment of the bothria. The
.neck or anterior part of the body is very elastic and in life contracts
jaud expands constantly. Transverse striae appear very soon and seg-
ments make their appearance soon after the striie begin. A few of the
first segments are broader thaii long. These are followed by a few
which are as long as broad. The subsequent segments are longer than
broad. The posterior segments are usually several times as long as
broad; occasionally they are contracted until they are nearly as broad
as long, often with narrow extremities.

Genital apertures marginal, about posterior third. Cirrus long and,
so far as observed, smooth ; vas deferens long and much convoluted.
Vagina a slender tube opening in front of cirrus. Ovaries two oblong
;obes lying on either side of the median line, confluent at posterior end
of segment and occupying nearly the posterior third of the length of
bhe segment. The ova are relatively large. They were frequently seen
issuing from the ruptured walls of mature segments which had lain for
\ few hours in sea water. They are globular in shape and consist of a
granular center surrounded by a thick but perfectly transparent
envelope, with a very thin limiting membrane. In some the granular
nterior appeared to be undergoing segmentation. This segmented
nterior in some of the ova had assumed a stellate shape on account of
prolongations of its substance, which penetrated the surrounding
envelope. These prolongations were generally knobbed at the ends.
Measurements of several ova which had escaped from a mature segment
and had been lying for some time in water gave the following results:

Longer
diameter.

Shorter
diameter.

1

Mm.
0.32

Mm.
0.26

2

0.24

0.20

3

0.26

0.22

4

0.26

0.26

5

0.18

0.16

The ova evidently increase in size after being discharged from the
segment, by the imbibition of water through the investing pellicle.

VanBenedeu describes and figures the ova of C. eschrichtii as having
very long filamentous appendages. While I have never seen any
appearance of that kind in the ova of my specimens there does not
seem to be anything inconsistent with it. The thick transparent en-
velope which surrounds the granular or nuclear interior might assume
under certain conditions of contraction very diverse shapes.

It will be seen by the foregoing description that there are some irn-

816 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [98]

portant differences between these specimens and C. eschrichtii. The
points of resemblance are so many, however, that I do not feel justified,
at present, in making a new specific name.

ACANTHOBOTHRIUM Van Beneden.

Boihriocephali (Onchobothrii) spec., Rudolphi.
Calliobothrii spec., Diesiug.

Body articulate tseniseform. Head separated from the body by a
neck, quadrangular. Bothria four, opposite, attached to head by autero-
dorsal side, each with two transverse costse on face, and armed in front
with two bifurcate hooks, and surmounted in front of hooks by a tri-
angular pad, bearing a supplemental disk which is capable of assuming
diverse forms. Genital apertures marginal.

The genus Acanthobothrium was established by Van Beneden to ac-
commodate forms whose scolices resemble those of Calliobothrium, but
which bear forked instead of simple hooks. To the genus Acantho-
bothrium he referred the species A. coronatum (Bothriocephalus coronatus
End.), and a species which he named in honor of Dujardin, A. dujardinii.
The former species has since been referred to the genus Calliobothrium by
Diesing, whose classification is accepted by Von Liustow. Van Bene-
den's species, A. dujardinii, is placed in a new genus by Diesiug, and
is now known as Prosthecobothrium dujardinii.

The genus Acanthobothrium is thus briefly characterized by Van
Beueden :

The four botliria armed each with two hooks united at their base and forked at
the apex.

I have been led to restore the name Acanthobothrium on account of a
small species, the scolex of which agrees very closely with A. coronatum,
and the strobile with A. dujardinii Van Ben. (Prosthecobotlirium dujar-
dinii Dies.). According to this view the species C. coronatum should
be henceforth known as Acanthobothrium coronatum Eud.

Acanthobothrium paulum, sp. nov.
[Plate vin. Figs. 1-7.]

Head subquadrate. Bothria four, opposite, oblong, faces hollowed
out and boat shaped, borders usually somewhat iuflexed, with two
transverse costte, the anterior costa a little back of the middle of the
bothrium, the other near the posterior end. The posterior ends of the
bothria from about the anterior costa free and versatile, narrowed and
bluntly rounded, each bothrium with two forked hooks at anterior end.
The bases of these hooks meet on the median line of the bothrium.
The inner prongs are the longer, the distance between them is about
equal to the distance between two prongs of the same hook. The outer
prongs bend outwards and backwards sharply. The bases of the hooks
arc slender, about same diameter as the prongs, and are not quite as long

[99] NOTES ON ENTOZOA OF MARINE FISHES. 817

as the shorter prong. Tliey join by a simple articulation. In front of
each pair of hooks is a triangular pad which bears a1 single, circular,
supplemental disk. The neck is rather long and merges imperceptibly
into the segmented body. The first segments are broader than long,
but increase in length uniformly. The median segments are squarish,
posterior segments longer than broad, slightly irregular in outline. In
all specimens thus far observed the posterior segments are from four
to eight times as long as broad. In most of the specimens, especially
the shorter ones, the last segment is attenuated at the posterior end.

Genital openings marginal, near the middle of the segment. Cirrus
very long when fully extended, bulbous at base when partly everted,
densely echinatc. Length, maximum 20""".

Habitat — Tnjgon cenlrura, spiral valve, July, 1886 ; August, 1887.
Wood's Holl, Massachusetts.

I have obtained this parasite on four different occasions from the
spiral valve of the sting ray (Trygon centrum^. Following is a brief
summary of the different captures :

July 29, 1886 ; about thirty specimens from spiral valve of one ray. longest speci-
men about 20mm.

August 1, 1887; four specimens obtained from a lot of three rays; longest speci-
men about 9mm.

August 8, 1887 ; about two hundred and fourteen specimens ; all quite small ; max-
imum about 5""", from a single ray.

August 10, 1887; live specimens; maximum 13.5mm, from two rays. Three of these
specimens, maximum 13.5mm, had black hooks. The remaining two, maximum 6mm,
had the ordinary amber-colored hooks. The black color, however, disappeared from
the former when the specimens were placed in alcohol.

The following measurements, with the exception of the hooks of one
or two specimens, were made from living specimens :

Dimensions.

No.l.

No. 2.

No. 3.

No. 4.

No. 6.

mm.
19.00

mm.
9.00

mm.
4.50

mm.
13.50

mm.
6.00

0.60

0.26

0.26

0.30

0.42

0.80

0.50

0.80

0.64

0.24

0.12

0.20

0.18

0.20

0.18

0.14

0.16

0.16

0. 14

0.13

0.10

0.10

0.12

0.24

0.10

0.10

0.08

0.18

1.40

1.00

0.80

1.00

0.70

0.06

0.06

0.04

0.03

0.05

Breadth of first distinct segments - - .........

0. 16

0.14

0.12

0.14

0.24

1.40

1.60

0.68

1.50

1.06

0.20

0.26

0.18

0.20

0.24

There is some difference between the larger specimens, 15 to 20mm in
length, and the smaller specimens, 4 to 6mm in length, besides a differ-
ence in size. This difference, however, is confined to the region of the
posterior segments, where considerable variety is to be expected in
H. Mis. 133—52

818 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [100]

specimens of different ages. The books in the smaller specimens are
relatively longer in proportion to the length of the bothria than is the
case in the larger specimens. In the smaller specimens the posterior
segments are slender, somewhat fusiform, tapering slightly towards
anterior end, more decidedly towards posterior end. In the larger speci-
mens the posterior segments are in general linear oblong. If these
differences should be found to persist in specimens with ripe proglot-
tides they should be separated into different species.

The most conspicuous organ of the posterior segments is the cirrus.
It is near the middle of the segment, and, when retracted, lies as a
prominent pyriform or fusiform body near the median line. It may be
seen to be densely covered with spines in specimens placed in glycerine.
In specimens which measured not more than 4mm in length and contained
only from sixteen to twenty distinct segments the cirrus could be dis-
tinguished in the last eight or ten segments. In one of the larger
specimens, about 16mra in length, one of the posterior segments .9mm
long and .3Cmm broad, somewhat flattened, the cirrus is unrolled until
it is nearly as long as the segment. The spines in this instance are
nearly all lost, a few patches of epidermal tissue bearing slender spines
adhere to its surface. lu some cases the pyriform basal part of the
cirrus is protruded, and can be seen to contain the remainder of the
cirrus coiled up in the interior. The spines on the basal part of the
cirrus are short triangular, with broad bases and acuminate points.
They are about .005miu in length and .004mm in breadth at base. The
remaining spines are very slender, about .007lum in length and .0005mm in
breadth.

In one segment I observed what appears to be the extremity of a
very slender vagina protruding as a vulva from the margin immediately
in front of the cirrus. The length of this segment was .8mm, its breadth
.36mm ; length of cirrus .8mm ; diameter at base .OSmm ; at apex .018mm.
The vulva protruded .035mra from the margin of the segment, and was
at first .OOSmm in diameter, enlarging to a funnel-shaped extremity
.035mm in diameter.

No ova were found in any of the segments. The interior of the pos-
terior segments is filled with the spherical spermatic capsules of the
testes, about .03mm in diameter.

When sufficiently magnified, several bundles of longitudinal muscles
can be seen in the neck near the head. A specimen that had been
killed by flattening between two slips of glass and immersing in alco-
hol was stained with carmine, and then mounted in Canada balsam.
By this means the bundles of longitudinal muscles are well differen-
tiated. Of these there are eight; four larger median, and four smaller^
the latter arranged two on each margin.

These bundles are distributed to the bothria and the anterior tri-
angular cushions which bear the supplemental disks. Longitudinal,
transverse, and diagonal muscular fibers can be distinguished in the
bothria. Their arrangement can not be made out, however, on account

"101] NOTES ON ENTOZOA OF MARINE FISHES. 819

rf the distortion resulting from compression. Behind the hooks the
}othria contain a great many circular fibers, which are arranged con-
centrically, with the hooks as a center. Some of these concentric fibers
ire attached to the base of the hooks. Other fibers, also attached to
Dhe base of the hooks, cross the circular fibers radially and extend back
through the bothria parallel with their long axis. Both of these sorts
}f fibers are exceedingly delicate. The circular muscles evidently effect

e motion of circurnd notion or rotation in the hooks, while the radial
iiuscles effect the motions of abduction and adduction respectively.
Short, blunt processes on the under side of the hooks afford means of
ittachmeut for the muscles. These processes are on the under side of
:he inner prongs of the hooks. In this compressed, stained specimen

e pads or cushions, \vhich bear the supplemental disks, are emargin-
ite posteriorly and have therefore a cordate shape. The supplemental
lisk measures .0711"11 and .06mm in its two diameters, inside measurement.
Che largest bands of muscular fibers in the neck are .04SIU1U broad, a
single fiber measuring as much as .004mm in breadth. The bundles of
ibers in the neck can be seen plainly in specimens which have not been
3ompressed. They are usually sinuous or waving in outline.

The smaller specimens have many characters in common with Van
Beuedeu's Acanthobothrium ditjardinii (Prosthccobothrium dujardinii
Dies.), but as Van Beneden describes and figures that species as having
the bothria destitute of transverse costre, and, moreover, each provided
with a posterior versatile flap, there can not be even a generic identity
stablished between the two species. If Van Beneden's species had
jeeu based on alcoholic specimens one might suppose that he had mis-
taken the posterior fossette for a posterior appendage ; I have "seen
such a deceptive appearance as this in a few alcoholic specimens. This
consideration is hardly admissible, however, as Van Beneden mentions
;he extraordinary versatility of this posterior flap in active worms.

A. paiilum differs from A. coronatum principally in its very much
smaller size and in the different proportions of its segments.

PHOREIOBOTHRITJM Liuton.

24. Phoreiobothrium lasium Lt.

Report of IT. S. Fish CommissioLer, pp. 474-476, Plate iv, Figs. 24-29.

I encountered this parasite twice in the summer of 1887 at Wood's
Holl, Massachusetts, each time in the dusky shark (Carcharias obscurus).
The first lot, collected July 25, contained nine specimens, two of them
small ; the second lot, collected August 12, contained fourteen speci-
mens. Since the description which I have given for this species was
based on alcoholic specimens, I add the following data obtained from
living specimens :

One specimen had the following dimensions while living: Length,
32mm . i^gt^ of bothria, .48mm ; breadth, .26min ; length of hooks, longest

820 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [102 1

prong, .14mm; diameter of head in front, .48mm ; at posterior end, .62mm
diameter of nock, .13"1"1 ; distance to first segment, .8mi" ; length of seg
inent, 10nim from head, .10mm ; breadth, .10IIim ; length of last segment
1.28unn ; breadth, .42IU1U ; number of distinct segments, sixty. The spec
irneii was slightly flattened under the compressor.

Another specimen of the same lot was 35mm in length ; its last seg-
ment 1.12mm in length and .5miu in breadth.

The proportions of the living worm do not differ materially from thost
of alcoholic specimens. It was observed, however, that after they had
lain for twenty- four hours in sea water the specimens were not sc
straight nor symmetrical as at first. The apparent varieties in pre-
served specimens are evidently due to different degrees of contraction.
The minute epidermal spines were found in isolated patches on several
of the specimens.

PLATYBOTHRIUM, gen. nov.

[nAarrjs, broad.]

Body articulate, toeniajform. Head decidedly flattened, squarish, or
trapezohedral. Bothria four, subtriangular, sessile arranged in mar-
ginal pairs, armed with compound hooks, and each terminating poste-
riorly in a cup like depression or loculus. A single indistinct circular
depression (supplemental disk "?) on each bothrium in front of hooks.
Genital apertures marginal.

A single specimen furnishing, as I suppose, the type of anew genus,
with some characters which ally it to Prosthecobotkrium Dies., from the
spiral valve of the dusky shark (Garckarias obsvurus), presents such
decided differences from any genus included in Diesing's Revisions that
I am obliged, for the present, to describe it under a new generic name.
In the flattened head and marginal pairs of bothria it is unique among
the armed Phyllacanthinw. An objection to referring the specimen to
the genus Prosthecobothrium is that the apparent homologue of the pos-
terior bothrial appendage which is characteristic of that genus is, in
this specimen, to be regarded rather as a loculus formed by a transverse
costa near the posterior end of the bothrium, or as a kind of posterior
cupping disk. Further, there is a faint indication of a single supple-
mental disk on each bothrium in front of the compound hooks.

Again, the doubtful character of the supplemental disk, the single or
no transverse costa, and the character of the hooks exclude the genera
Calliobothrium, Acanthobothrium, and Onchobothrium. The flattened
bothria and their arrangement in marginal pairs exclude the problemat-
ical genus Cylindrophorus as well as Phoreiobothrium.

25. Plcityboihrium cermnum, sp. nov.
[Plate vin, Figs. 8-10, and Plate ix, Fig. 1.]

Head quite flat, squarish, rhomboidal or irregularly hexagonal in j
outline, in lateral view; thickness less than half the breadth. Bothria

[103] NOTES ON ENTOZOA OF MAIilNE FISHES. 821

four, subtriangular iu closely appresscd marginal pairs. When seen
from the lateral side the two bothria, which are then in view, resemble
right triangles with their acute angles truncated, and so placed with
reference to each other that the hypothenuses are parallel and separated
by a narrow space along the median line of the head. The shorter legs
of the triangles then form the antero-lateral boundary of the head and
the longer legs, the postero-lateral boundary. The truncated acute an-
gles form the apex and base of the head, respectively. There appears to
be a faint supplemental disk near the anterior end of each bothrium in
front of the hooks, although its identification in the alcoholic specimen
is not altogether satisfactory. At the posterior end of each bothrium
there is a highly characteristic modification, the exact nature of which
I am not sure that I understand. In the sketches made of the living
worm it appears to be a transverse costa, which is convex toward the
front, lying near the posterior end of the bothrium and making a locu-
lus in the face of the bothrium. In the alcoholic specimen, however,
the appearance is somewhat different. Each bothrium appears to be-
come somewhat tubular at its posterior extremity, and what, in the liv-
ing specimen, appeared to be a posterior loculus, now seems to be the
thickened tubular end of the bothrium. The inner boundary of this
tubular end extends farther back than the outer boundary, so that the
appearance iu a specimen which had been slightly compressed would,
of course, be the same as if the bothrium were crossed by a transverse
costa near the posterior end. The faces of the bothrium are but little
hollowed out.

Each bothrium bears near its anterior border a very characteristic
set of compound hooks. The hooks showed with perfect distinctness
through the transparent tissues of the head. The system of hooks on
each bothrium is in three distinct parts, all of which are joined together.
The arrangement of the hooks is shown in the sketches of the head.
It is, in brief, as follows: Two booklets, or rather the two prongs of
a single hook, terminate the system on the inner side of the bothrium.
These inner prongs are long and slender, directed backward, and lie
close beside the corresponding pair in the other lateral bothrium. These
prongs are terminal forks of a slender, arcuate bar, which is convex
iu front and articulates by means of an overlapping joint with a short,
slender process, which, in turn, articulates by a plain hinge-joint with
the basal prolongations of the outer set of booklets at the marginal
angle of the bothrium. This latter cluster appears at first sight to
consist of three booklets. There are iu reality but two. These, like
the inner booklets, are forks of a basal part. They are long and slender,
recurved, and a little larger than the inner pair. The basal part of the
outer booklets sends back a subcutaneous prolongation, which, on ac-
count of the transparency of the soft tissues of the head, looks as if
it were a third prong of the compound hook. It can be easily proved
to lie beneath the external coat of soft tissue. The booklets are hoi-

822 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [104]

low, as are also the basal supports ami, in fact, the whole system, with
the exception of the short bar which connects the long basal support
of the inner set with the shorter prolongations of the outer set.

The neck is very long and slender. No distinct segments occur un
til 25mm or 30lum back of the head. The first segments are squarish ;
the succeeding segments increase in length slowly ; median segments
square, becoming subcircular in outline, and towards posterior end elon-
gated ; last segments three or four times as long as broad and in life
somewhat cylindrical.

Genital apertures marginal, near middle of segment, male and female
approximate. Length G7mm.

Habitat. — Carcharius obscurus, spiral valve, a single specimen. Wood's
Holl, Massachusetts, August 12, 1887.

The following measurements were made on the living specimen held
in place by slight compression :

Length, 67mm; length of head, .52mm ; greatest diameter of head,
.54111111 . diameter in front of hooks, .20mm ; diameter, posterior, .24mm ;
thickness of head, .24"""; greatest breadth of single bothrium, ,26min ;
length of hooks, .16mm; lateral diameter of neck, .08mm; marginal di-
ameter, .OGmra j length of neck, about 16mni ; length of first distinct seg-
ments, .10mm ; breadth, .26mm; length of postero-mediau segments, .60mm;
breadth, .36mmj length of last segments, 1.40; breadth, .40lum.

With regard to the occurrence of supplemental disks in this species I
am in some doubt. When the living worm was first examined the sketch
which my wife made of it showed that the anterior ends of the bothria
were somewhat elongated and rounded, with a circular depression
showing plainly in each. When I examined the specimen an hour or
two later, in order to obtain measurements, the anterior ends of the
bothria were abruptly truncated and there was no sign of circular de-
pressions. Afterwards, when the worm, as an alcoholic specimen,
was transferred to glycerine, something like supplemental disks were
faintly visible. These are circular and about .033mm in diameter. It
would appear that the anterior ends of the bothria contract or fold in-
ward, thus obscuring the faint depression, which is probably to be re-
garded as a supplemental disk.

When the posterior segments were flattened out in glycerine they
appeared quite regular in outline, rectangular, and somewhat confluent,
so as to give to the margins of the strobile in places a gently undulat-
ing outline. None of the segments are mature. The posterior seg-
ments are filled with granular bodies about .03mm in diameter. These
bodies are globular in shape in the anterior part of the segment. In
the posterior part of the segment they are more irregular and collected
into large elongated masses. These granular masses extend to the
extreme posterior edge of the segment, while at the anterior end there
is a space of clear, finely granular tissue, which extends backward
along each margin between the central granular masses and the ex-
ternal cuticular layer.

[105] NOTES ON ENTOZOA OF MARINE FISHES. 823

Two of the posterior segments were stained with red and green ani-
line and a few additional points in the anatomy were made out. The
vagina was traced from the posterior end of the segment along the
median line in a "straight course to about the anterior third, where it
turned toward one of the margins, then back a little, and opened be-
side and in front of the cirrus, which, retracted in its bulb, lay in the
bend of the vagina.

The cirrus bulb is oblong and apparently constantly angled or bent
about the middle. That is, the cirrus bulb, from the marginal aperture,
is inclined inward and backward. At about half its length it turns so
that the inner end is inclined inward and forward. The length of the
cirrus bulb, in one of the posterior segments, is about .22Ium; its diame-
ter .055mm.

When the segments were cleared up in oil of cloves the ovaries be-
came visible at the posterior end, lying one on each side of the median
line and separated from each other by the vagina, which at this point
wae somewhat enlarged.

THYSANOCEPHALUM, gen. nov.

PhyUobothrium, spec. Linton.

Body articulate, tseniaefonn. Head separated from body by neck,
very small, quadrangular, with four sessile bothria, each armed with
two simple hooks and provided with a single loculus in front of hooks.
Neck at first slender, then expanding into a voluminous mass of lobed
and crisped folds. Genital apertures marginal.

I was led into error in my original description of the Cestod upon
which this genus is founded by its singularly close resemblance to Van
Beneden's PhyUobothrium lactuca (Vers. Cesto'ides, Plate iv, Figs. 1-7).
What was taken to be a rostellum, and so described by me, was present
only in the smaller specimens of the lot. This so-called rostellum
proves, upon subsequent examination, to be the true iScolex. The
sketches of this organ (see Notes on Entozoa, U. S. Fish Commission
Report for 1886, Plate n, Figs. 7, 7a, and 76) are misleading, particu-
larly with regard to the hooks. The scolex is very small in comparison
with the cervical ruff which follows it and which increases in size with
the age of the strobile, while the scolex of the adult is no larger than
that of young specimens.

26. Thysanocephalum crispum Lt.

PhyUobothrium thysanocephalum Lt., Report of U. S. Commissioner of Fish and
Fisheries, 1886, pp. 464-468, Plate n, Figs. 1-12.

Scolex very small, minute when compared with the cervical ruff or
pseudoscolex of an adult specimen, quadrangular in outline and pro-
vided with four oblong bothria. Each bothrium is divided about the
anterior third into two loculi by a thick, transverse, chitinous (?) parti-

824 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [106]

tion, which bears at each of its extremities a short, straightish hook.
The posterior loculus is long-elliptical with irregular borders. The an-
terior loculus is nearly circular, with thick and nearly entire borders.
The tissue of the sides and bottoms of these loculi is dense and firm.
The neck immediately behind the scolex is slender, short, and cylin-
drical, It expands abruptly into a large, lobed, crisped, and folded
mass, which, in alcoholic specimens, is more or less globose, but in liv-
ing specimens may spread out into a flat, suctorial organ with fimbri-
ated edges. This organ is so conspicuous and takes the place of bothria
so effectually, particularly as the scolex appears to be missing in the
larger specimens, that it may be called, with some degree of propriety,
the pseudoscolex. The ratio of the diameter of the pseudoscolex to the
true scolex may be from five to one, in young specimens, to thirty or
more to one in adult specimens.

Behind the pseudoscolex the body is slightly flattened and longitud-
inally rugose. The uusegmeuted portion of the body is long, the seg-
ments appearing at first as transverse wrinkles, subsequently tlie seg-
ments decrease slightly in breadth and increase slowly in length.
Near the posterior end they become squarish and at the extreme pos-
terior end two or three times as long as broad. The ripe proglottides
are easily detached and continue active for a long time after removal
from the host.

Genital apertures marginal, approximate, cirrus long.

Length of strobile as much as one meter; breadth of pseudoscolex
up to 15mm ; free proglottides as much as 8""" long and 4.5"1"1 broad.

Habitat. — Tiger shark (Galeoccrdo tiyrinm}, adult, half-grown, and
young specimens together in spiral valve, July 23, 1885, AVood's Holl,
Massachusetts.

Family IV. TETRAEHYNCHID.E.

Subfcrihe Tri/panorhyncha Dicsing.
Subfamily Phyllorlnjncliina', V;m Bencden.

Subfamily I. DIBOTIIRIORHYNCHIN^E.

Family Dibothriorhynchidw Dies.

KHYNCHOBOTHRIUM Etidolphi.

Tetrarhynchns of authors.

Body trenireform. Neck tubular. Head continuous with neck, with
two opposite bothria, parallel or converging at the apices, lateral or
marginal, entire or undivided, or, either bilocular with a longitudinal
partition, or bilobed or divided. Proboscides four, terminal, filiform,
armed, retractile in the neck, for the most part longer than the head.
Genital apertures, male marginal, female lateral, or male and female
marginal approximate.

[107] NOTES ON ENTOZOA. OF MARINE FISHES. 825

27. Rhyncfiobothrium bulbifer Lt.
[Plate x, Figs. 8 and 9, and Plate xi, Figs. 1 and 2.]

Rhyncholotltrium ienmcolle Rud., Lt., Report of U. S. Fish Commissioner

for 1886, pp. 486-488, Plate v, Figs. 17 aud 18.

Since publishing my first notice of this parasite, I have encountered
it on several different occasions in the same host in which I first found
it, viz, the smooth dog-fish (Mustelus canis). A careful revision of the
subject in the light afforded by this additional material has convinced
me that I was mistaken in referring this species to B. tenuicolle. I have,
indeed, found it necessary to make a new specific name to accommo-
date it.

The species R. bulbifer may be briefly described as follows : Bothria
two, suborbicular, but somewhat variable, with a raised and rather
thick border, emargiuate on posterior edge, more or less approximate
in front, divergent posteriorly. The head in marginal view is there-
fore sagittate. Neck long, slender, subcylindrical, tapering gently
for a short distance back of the head, then increasing in diameter
slightly to the contractile bulbs. Immediately behind the bulbs there
is a constriction, distinct in some, slight in others, behind which the
neck enlarges to form a rounded or even globular base which is sep-
arated from the body by a profound constriction. The body behind this
constriction is slender, subcyliudrical, and for some distance is without
segments or transverse markings of any kind. The first segments are
rather faintly outlined ; they are squarish, or even a little longer than
broad ; the segments increase in length towards the posterior end ; the
posterior segments are very large, three to four times as long as broad,
rounded at the two extremities, held together feebly by narrow commis-
sures, separating easily from the strobile. Free proglottides very active
and apparently continue to grow after their release from the strobile.
Proboscides very long, slender, aud graceful, armed with hooks of dif-
ferent shapes. Proboscis sheaths slender, spiral ; bulbs linear, oblong.
Genital apertures marginal, usually indicated by a broad, square notch
about the posterior third of the segment. Entire strobile lanceolate,
with finely serrate margins aud few, rarely as many as twelve, segments.

Length, 20 to 40""" ; length of free proglottides as much as 12lu'".

Habitat.— Miistelm canis, spiral valve, of frequent occurrence, July and
August, Wood's Holl, Massachusetts.

826 EEPORT OP COMMISSIONER OF FISH AND FISHERIES. [108]
Following is a list of the captures of this worm ;

Date of
capture.

No. of Dog-
fish
examined.

Number of specimens obtained and remarks.

1880.

July 22 ...

1

Three, and free proglottides.

23 ..

3

Twenty, and free proglottides with dark colored ova.

24...

4

Several.

31...

1

Twelve.

1887.

July 10 . .

6

Several in each.

21...

10

Abundant in each.

23...

1

Eight.

Aug. 4...

3

One.

6...

1

Two.

10 ..

3

Twelve, eleven from one host.

11...

2

Few.

12...

1

Two proglottides in bad condition.

13...

q

it

Five, two from one host, three from the other.

These specimens were associated in most cases with R. tumidulum,
Calliobothrium verticillatum, and C. eschrichtii.

In the alcoholic specimen, of which I gave detailed measurements in a
former paper, the entire length was 31mm, and the length of the last seg-
ment 3mm. I have since measured living specimens which differed little
from the alcoholic specimens, except in the dimensions of the last seg-
ment. In one specimen, which measured 23IU1U in length, the last seg-
ment was 3.5mm in length, and a free proglottis 6imn long and 2mm broad.
In another lot two strobiles yielded the following measurements :
Length of one; 27mra ; length of last segment, 7ram. Length of the other,
38mm ; length of last segment, 8.0IUU1. Free proglottides were associated
with these, which were as much as 10mm and 12mm in length. These are
extremely active and evidently continue to grow after they have sepa-
rated from the strobile.

The following detailed measurements were made of an alcoholic speci-
men: Length, 20min ; length of head, .44mm ; diameter of head, .50min;
diameter of neck, near head, .24mm, middle .20mm, base .30ram; length
of head and neck, 1.60mm ; distance to first distinct segments, 711"11 ;
length of first segment .60mm, breadth .60mm; length of last segment
3.7mm, breadth .90mm; length of proboscis 1.80mm, diameter .04mm.

The diameter given for the head is from the base in marginal view of
strobile; the corresponding diameter in lateral view of strobile was .40""";
the diameter of head near the apex is .34mm in both views. In my
former account of this parasite there is a typographical error on page
488, where the diameter of the proboscis should read .033mm instead of
.33m™.

Arrangement of hooks on proboscides. — The figures published in this
and the former paper give different views of the proboscides in this

[109] NOTES ON ENTOZOA OP MARINE FISHES. 827

species. There seems to be a considerable degree of diversity in the
hooks on different sides and in different parts of the same proboscis.
In general there appear to be three different styles of hooks. One kind
is very minute, while of the larger and more conspicuous hooks one
sort is broad and abruptly recurved, the other long and slender. The
broad hooks are about .008lum long and .006mm wide at the base, maxi-
mum. They resemble pruning-hooks with short, stout blade. The long,
slender hooks are of two kinds, one with an abruptly recurved apex, the
other uniformly arcuate, tapering gradually to an acute point. The
length of the long, slender hooks is about .016mm, breadth at base
.0027mm. The arrangement of the small hooks at one point is shown in
Fig. 1, Plate xi.

The distribution of the hooks appears* to me to be somewhat in this
wise : There is first a longitudinal series of short, broad hooks, appar-
ently in two double rows, flanked on either side by a series of long,
slender hooks with recurved points and arranged side by side in groups
of three ; the two latter series are separated from each other on the side
of the proboscis opposite the short, broad hooks by a series of slender,
arcuate hooks with other minute booklets interspersed. Of the latter
there are two longitudinal rows on either side of arow of the largearcuate
hooks. Each hook in the latter row has a small hooklet situated near
its base on the posterior side.

Anatomy of mature segments. — The following data were obtained from
stained sections and from segments stained with carmine, hnematoxylon,
green, and red aniline respectively, and studied entire. The best results
were obtained from an almost mature proglottis which had been flattened
between two cover glasses, killed while in that position, stained with
Beale's carmine, made transparent in oil of cloves, and studied entire.
This segment was long, oval, somewhat slipper-shaped, length 6mm,
breadth 2mm. The reproductive opening was marginal a little in front
of the posterior third. The greater part of the interior was filled with
roundish, granular bodies from .08 .to .12mm in diameter. These, when
highly magnified, are seen to consist of a thick coat of dense fibrous
tissue, inclosing a nest of nuclei or small granules. Behind the ovaries
these granular bodies are more elongated and more closely crowded.
These granular bodies, at least those which occupy the central parts of
the proglottis, I take to be the spermatic capsules of the testes.

The ovary is situated near the posterior end of the proglottis and
consists of two finely granular lobes, which are separated along the
median line for the greater part of their length, but are confluent be-
hind. Threy are surrounded on all sides in the same plane by the gran-
ular bodies mentioned above.

There are three distinct tubular organs in the interior of this pro-
glottis, to which I give the following interpretation : First, the vagina,
a comparatively large duct which appears to have its exterior opening
at the margin, coincident with or immediately behind the opening of

REPORT OF COMMISSIONER OF FISH AND FISHERIES. [110]

the cirrus. From this point it can be traced towards the median line
after having made a slight bend forward at the base of the cirrus bulb.
It then leads to the ovaries, at the anterior end of which it enlarges ab
ruptly and is joined to a much smaller tube, which continues in a very
sinuous course to the base of the cleft between the two lobes of the
ovary. A second small and very much folded tube, evidently the vas
deferens, enters the inner end of the cirrus bulb at its anterior angle.
From that point it can be traced forward a short distance, then back
along the median line, where it lies in dense folds or plaits, nearly to
the anterior edge of the ovary, where its course becomes somewhat
doubtful. A third large, straight tube with thick granular walls lies
along the median line from about the anterior third to a point a little in
front of the ovaries ; there it becomes abruptly enlarged, rounded, or
pyriform and is joined by a small duct. This duct is much folded or
plaited, lies between the lobes of the ovary, but extends a little way in
front of the ovaries to enter the pyriform termination of the straight
median duct. In some segments a round, lateral aperture was observed
at a point which corresponds to the anterior termination of the median
duct. In segments with ripe ova the region along the median line be-
comes distended with ova, which may be seen, in some at least, issuing
from the lateral aperture. The ova, in some of the sections stained
with carmine, are of a light amber color, oval, much collapsed, about
.05mm in length and .O.I1"111 in breadth. In other sections there were a
few ova which were apparently not yet provided with shells. They
were shorter oval than the mature ova, about .035mm and .OJ4mm in their
two diameters, and their granular contents deeply stained. The central
mass of ova in mature segments appears as a dark colored spot in alco-
holic specimens, sometimes likewise in living specimens.

In stained sections the ovary was seen to be composed of polygonal,
nucleated cells, about .OOSnim in diameter. The nuclei were about
OO-miu jn diameter. Flat nucleated cells, somewhat smaller than the
cells of the ovary were found in the walls of the convoluted tube which
lies between the two lobes of the ovary. In sections of some of the
segments the nests of nuclei, which constitute the tcstes, were seen to
be breaking up into fine fibrilhie, presumably spermatozoa. This phe-
nomenon was best seen in segments which had but few or no ova. In
sections of segments which contained many ova there were large spaces
from which the nuclear aggregations of the testes had disappeared, leav-
ing a net-work of connective tissue. In the strands of this net-work
there are occasional minute fusiform nucleated cells.

The walls of the mature segments, even those which are crowded with
ova, are plentifully supplied with both longitudinal and transverse
muscular fibers. These are pretty evenly distributed. The fact that
the muscular tissues do not soon degenerate is also shown by the long
continued vitality of the free proglottides. They continue active after
lying in sea water for several hours. It is probable that they continue
to grow for some time after becoming free from the strobile.

[Ill] NOTES ON ENTOZOA OF MARINE FISHES. 829

The sketch made from a living1 proglottis, Fig. 8, Plate X, shows the
diameter of the eirru s bulb, the vagina, and some of the eon volutions of
the vas defereus. The vagina expands to -form a large receptaculum
seminis. This feature was indicated in sections of preserved specimens
by the relaxed and folded walls of the vagina. In the figure the ovaries
are obscured by the large, globular, spermatic capsules of the testes. The
cirrus bulb is oblong, its inner end directed forward. It frequently
protrudes in a broad, expanded collar a short distance beyond the mar-
gin of the segment. The cirrus is smooth. It is shown in Fig. 9 with
spermatozoa issuing from its extremity. The spermatozoa are ejected
in large quantities and appear to be felted together in elongated masses
without any fluid medium.

28. JRhynchobothrium tumidulum, sp. nov.
[Plate xi, Figs. 3-11.]

Head with two round-oval or elliptical bothria, which are marginal or,
by torsion, lateral, approximate anteriorly, widely separated poste-
riorly, emargiuate on posterior border in life, almost entire in alcoholic
specimens, very mobile. Neck variable in length according to state of
contraction, but comparatively long — that is, three to five times the
length of the head ; in life su bey lindrical, very elastic, capable of being
much elongated or greatly shortened, and with a crimson spot in front
of contractile bulbs. Proboscides long, slender, longer than the bothria,
slightly enlarged at base; armed with minute booklets of two kinds,
one short, sharply and abruptly recurved with a broad base, the other
slender, a little longer than the first kind, arcuate. Booklets on tumid
base short, and crowded in close spirals. Proboscis sheaths spiral, con-
tractile bulbs long, slender, arcuate, sometimes decussate. Body con-
tinuous with neck, the first segments faintly outlined by transverse
stria3. The first distinct segments appear at a short distance behind
the contractile bulbs and are much broader than long; succeeding seg-
ments squarish, sometimes with rounded corners, soon becoming longer
than broad ; posterior segments several, five or more times as long as
broad, often fusiform, sometimes with deep emargination at posterior
end, separating easily from strobile. Whole number of segments twelve,
more or less. Male genital aperture, marginal, near posterior third.
Length, 5 to 12mm.

Habitat. — Mustelus canis, spiral valve, frequent, Wood's Holl, Massa-
chusetts, July and August.

L have obtained this species from the spiral valve of the smooth dog-
fish (Mustelus canis) on several different occasions, but never in great
numbers. It is usually associated with R. bulbifer, Calliobothrlum verti-
cillatum, and C. eschrichtii.

830 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [112]
Following is a list of the captures of this worm :

Date of capture.

No. of dog-fish examined.

No. of specimens of R. tumi-
duluni obtained.

1886.
July 23

Three

Twelve

24

four • ....

Five

31

One

Two.

1887.
19

Six

Eighteen.

21

Ten

Eight

23

One

Two.

Anrr. 4

Three

One.

10

Three

One.

11

Two

Fifteen.

Accurate measurements of the living worm are very difficult to ob-
tain on account of the extreme variability of form due to the excessive
contractility. The longest specimens measure from 10 to 12mm and con-
sist of from twelve to fourteen distinct segments. In one specimen,
which measured 10mm in length and had twelve segments, the last seg-
ment varied in length from 1.5 to 4mm, with different degrees of con-
traction. The head and neck in this specimen were much contracted,
and measured lmm in length. Of the twelve segments, the first four
or five were very short and crowded together, the next squarish, the
following ones longer than broad, the last three capable of considerable
elongation. The posterior end of the last segment was deeply and
abruptly emarginate. The bothria appeared to be marginal.

The following measurements are of living specimens:

Dimensions.

No. 1.

No. 2.

No. 3.

Length

mm
5.20

mm
5.40

mm
11.60

Length of bothrium .. .. ...... ... ...

0 26

0 30

Breadth of bothrium

0.30

Breadth of head ..

0.54

Jjength of head and neck ... .

0. 80

1 00

Diameter of neck

0.44

1.46

1 30

3.20

Breadth of last segment

0.44

0.46

0.80

For No. 3 of the above table the following additional measurements
are given: Length of last segment but one, 2.80mm; breadth, 0.72ram ;
distance from base of contractile bulbs to first distinct segment, 0.20mm;
length of first distinct segment, O.OS™in; breadth, 0.36"""; number of seg-
ments, 14; length of crimson spot in the contractile neck, 0.44mm;
length of contractile bulbs, 0.40mm. The crimson spot in front of the
contractile bulbs is due to the coloration of granules in the parenchyma
of the neck. It is quickly dissolved by alcohol.

[113] NOTES ON ENTOZOA OF MARINE FISHES. 831

The bothria are very mobile in life, being sometimes turned forward
so as to present two capping dishes directly in front; at other times
both are turned over so as to be applied to the same surface, when they
act as suctorial discs to aid the worm in locomotion. The edges of the
bothria are somewhat thickened, the face hollowed out and the poste-
rior margins emargiuate. This latter feature is retained in but few of
the alcoholic specimens, and in them usually with not much distinct-
ness.

On two different occasions I have observed what I am disposed to
interpret as embryos which have escaped from the ova before leaving
the mature segments. They presented exactly the same character on
each occasion. They are long ovate, or rather conical, broadly rounded
at one end, tapering to a point at the other, with a few clusters of curved
bristle like spines at the smaller end, and near the larger end. They
were first noticed in the summer of 1886, when they were seen, along
with undoubted ova, issuing from living segments in sea-water. They
measured .055""u in length and .023mm in diameter near larger end, while
the length ot the bristles was about .012mm. The ova were about the
same length as these bristle-bearingembryosandtwiceas broad. In July,
1887, while examining some specimens of this rhyuchobothrium which
had been placed in sea water under a compressor, I observed multitudes
of these highly characteristic objects. They were .04Smm in length and
.01G'nm in breadth at larger end. It was observed that segments of this
worm, after lying for a few minutes in sea water, burst at irregular
places, allowing the escape of these embryos. Along with these conical
bodies were great numbers of small globular masses ,0076mra in diam-
eter. The latter were highly refractile and contained two or three,
sometimes more, nuclear granules. They probably come from a layer
of roundish granular bodies which lie beneath the muscular walls of the
segment. In a few instances the wall of a segment was observed to
swell out into one or more bud like prominences from which the em-
bryos and the small refractile bodies presently burst forth. The em-
bryos, after having been discharged for about an hour in sea water,
changed from a transparent or translucent white to a very dark brown
or black. My attention was first called to this fact by noticing patches
of some black substance in the bottom of a dish of sea water in which a
number of these worms had been placed. Upon examination these
patches proved to be made up of these characteristic embryos, but
most of them quite black. A few were unchanged, or but little changed.
In the dark-colored ones the bristle-like spines are much more dis-
tinct than in the colorless ones. This is doubtless due to the change
of color which affects the bristles as well as the rest of the object,
making them opaque. These spines are now seen to be strongly
curved, to occur at the smaller end and also in a ring of irregular
bunches near the larger end. No movements were observed in any of

REPORT OF COMMISSIONER OF FISH AND FISHERIES. [114]

these objects. An examination of the alcoholic specimens has resulted
in finding several of these embryos clinging by their spines to the pro-
boscides and other parts.

Thin longitudinal sections were made of a mature segment, the ante-
rior half and more of whose interior was dark colored from the pres-
ence of ova. The sections show that the anterior part of the segment
is a veritable egg-sac. Instead of ova with definite outlines, however,
it seems to contain nothing but a mass of collapsed egg-shells or cases
of a yellowish-brown color. In two or three cases 1 was able to make
out irregular conical outlines which agree in shape and size to the free
embryos. I saw nothing which I could certainly identity as embryos.
Anatomy of mature segments.— My investigations on the anatomy of
the posterior segments have as yet been rather unsatisfactory. The
cirrus, which was not seen everted, appears to be short and smooth, and
in one instance was about .03mm in diameter. The cirrus bulb is oval
and lies nearly at right angles to the axis of the segment. In segments
which do not contain ova the ovaries can be seen at the posterior end
as comparatively small paired organs, while the remainder of the inte-
rior of the segment, except so much as is occupied by the cirrus bulb,
is filled with oblong tescicular bodies, which lie close together, at right
angles to the axis of the segment and in two longitudinal rows, one on
each side of the median line. These are separated from the marginal
walls by a row of smaller, roundish granular masses. In the stained
sections which I have thus far prepared there are but few traces of tubu-
lar organs or ducts. A rather large convoluted mass lies in front of
the ovaries which may represent the vas defereus. A tubular vessel,
somewhat folded or sinuous, could be seen leading from the vicinity of
the ovary forwards along the median line. I infer from the disposition
of such parts as I can make out that the vagina opens marginally be-
side the cirrus. In front of the cirrus a space along the median line
becomes modified into a capacious uterus with, at first, sacculated walls,
but which ultimately comes to occupy all the anterior two-thirds of the
segment.

The following dimensions of proboscides and hooks may be of assist,
ance in future identifications :

Base.

Middle.

Diameter of proboscis, exclusive of hooks

mm.
0 0°2

mm.

0 ||];|

Length of hooks

0 006

0 008

Distance between spirals

0 008

0 014

Number of hooks visible in one spiral

12

12

This species seems to be near R. rubromaculatum Dies. (Tetrarhyn-
chus Trygonis pastinacew Wageuer.)

[115] NOTES ON ENTOZOA OF MARINE FISHES.

29. Rhynchobothrium hispidum, sp. nov.
[Plate xi, Figs. 12-17.]

Bothriatwo, lateral, entire, subelliptical, edges elevated, face hollowed
out to form a cupping-disk, widely separated posteriorly, somewhat
approximate anteriorly. Keck relatively long, wider than first seg-
ments, sub-cylindrical, very contractile, with two small crimson spots
immediately in front of the contractile bulbs; when highly magnified
seen to be densely covered with minute short bristles. Proboscides
very long, slender, armed with hooks of two principal sorts, one sort
short, sharply recurved and very broad at the base, the other sort slen-
der and arcuate, but stouter than those of R. tenuispinc, and not so close
together. First two segments short, squarish, indistinct, broader than
long, third segment about as long as the first two, fourth segment about
as long as the second and third, remaining segment increasing in
length, last segment very much longer than broad. Whole number of
segments about six. Posterior segments separating easily, usually very
long and slender and somewhat fusiform. Genital apertures, male
marginal, about .posterior third. Length from 4 to 8Ium.

Habitat — Trygon centrura, spiral valve, July and August. Wood's
Holl, Massachusetts.

At different times during the past two summers I have found some
exceedingly small Rhynchobothria in the spiral valve of the sting-ray
(Trygon centrura), the most of which were characterized by having two
small red spots in the substance of the neck in front of the contractile
bulbs. It has so happened that I have obtained several other more
conspicuous forms at the same time, so that these smaller forms have
never been studied carefully while living. Upon examining the alco-
holic specimens I find it necessary to separate these small Rhynchoboth-
ria into three distinct species on account of the profound difference in
the style of hooks. These species bear a close resemblance to Van
Beneden's TetrarJiynchus minutus from Squatina angelus, but differ from it
in having the crimson spots in the neck. Van Beneden, furthermore,
represents his species as having the bothria profoundly bilobed and the
hooks, according to his figure, of uniform size. The species R. tenuispine
resembles R. heteromerum Dies, in some particulars. The resemblances
and differences are mentioned under the description of R. tenuispine.

R. longispine may prove to be a variety of R. hispidum.

I have found R. hispidum on three different occasions as follows:

Date of capture.

No. of rays examined.

No. of worms found.

Jul y 29, 1 886

One

Twelve

Aug. 1,1887

Three ... .

Many

Aug. 10, 1867

Two ..

v

H. Mis. 133 53

834 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [H6]

It was found almost impossible to make satisfactory measurements
of living worms on account of their great activity and consequent ex-
treme variability. In the following measurements of living specimens
the dimensions of the head, neck, and length of strobile are approximate :

Dimensions.

No. 1.

No. 2.

mm-.
4.50

mm.
7.80

0.20

0.16

0.45

0.34

1.00

0.80

0. 1C

0.20

0.60

0.46

0.04

0.08

0.06

0.16

1.10

3.60

0.16

0.46

5

6

The following additional measurements of No. 2 are given to show
the proportions of the segments : Length of first segment, .06"nu; sec-
ond, .10mm; third, .26™'"; fourth, .70""" ; -fifth, 2.10""11; sixth, 3.60mm.

The following measurements are of alcoholic specimens :

Dimensions.

No. 1.

No. 2.

No. 3.

No. 4.

mm.
4.00

mm.
4.20

mm.
4.40

mm.
4.00

0.30

0.24

0.28

0.26

1.20

1.10

1.30

1.20

0.20

0.20

0.20

0 24

0.56

0.56

0.64

0.50

0.06

0.04

0.06

0.05

0.17

0.15

0.12

0.16

0.16

0.12

0.14

0.14

0. 14

0.14

0.11

0.14

0.36

0.30

0.34

0.32

1.40

2.10

1.00

1.40

0.20

0.16

0.14

0.22

6

6

G

6

The first segment is here reckoned from the base of the contractile
bulbs to the first transverse line. The second segment has about the
same dimensions as the first. In specimens that are in glycerine the
segments are somewhat opaque, while the neck and head are quite
transparent.

Only one of the alcoholic specimens had more than six segments. It
had about eight distinct segments, which were more rounded, bead-like,
and shorter in proportion to the length than in the others. The last
segment is not so long in proportion to the others. The proboscides
were retracted and the hooks could not be seen plainly, but the speci-
men is apparently the same species as the others.

l[117] NOTES ON ENTOZOA OF MARINE FISHES. 835

One free segment, alcoholic, measured 2.Gmm in length, 0.22mm in
breadth at anterior end, 0.1Gmm at posterior end, and0.32mm at posterior
third at the genital aperture.

Many of the alcoholic specimens have the proboscides everted as much
as .7lum, or more than three times the length of the bothria. Their diam-
eter is about ,02mm, exclusive of hooks ; greatest diameter observed
from tip to tip of hooks, .04""".

The character and arrangement of the hooks is shown in the sketches.
There is a single longitudinal row of short hooks with very broad bases.
1 On each side of this row there is a series of about four rows of long
slender hooks, and on the opposite side of the proboscis a series of about
five small slender hooks. There is considerable variety in shape and
size of the slender hooks. The broad hooks are recurved at the point
and widen rapidly towards the base, at which there is a prominent
posterior prolongation, which makes the length of the base exceed the
length from base to apex. One of the broad hooks measured ,011mm
in length, while the breadth of the base was .01Gmm; another .OOSmm in
length was .Ollmm broad at base. The hooks are larger at the base of
the proboscis than they are at the apex. The slender hooks present
rather more variety in size, if not also in shape, than the broad hooks.
In general they are somewhat longer than the broad hooks, slender,
tapering uniformly to the point and slightly recurved or arcuate. They
also become smaller towards the apex of the proboscis. One of the
largest measured .013mm in length and .004mm in breadth at base.

The ova, which were seen issuing from the posterior segment of a liv-
ing specimen under the compressor, measured .025nuu in diameter.
They consist of a thin, fragile hyaline shell surrounding a clear space
in which is a granular nucleus.

The last segment in the largest specimen contained mature ova. The
last but one is characterized by having the greater part of the interior
filled with rather large, oblong, or squarish masses, which lie in two
longitudinal rows on either side of the median line. The median and
anterior parts of the segment are filled with ova.

The male genital aperture is marginal and near the posterior third.
The segment usually has its greatest diameter in the vicinity of the
genital aperture. In one segment a smooth, slender cirrus was extruded
from the center of a wide marginal sinus. I have not yet succeeded in
demonstrating the position of the vaginal aperture. The posterior seg-
ments in alcoholic specimens are often arcuate.

30. Rhynchobothrium longispine, sp. nov.
[Plate xi, Figs. 18-20.]

Head short and broad. Bothria two, marginal (? ), suborbicular,
widely separated ; neck rather long, broader than first segments ; pro-
boscides long, slender, and armed with relatively large, prominent hooks;

83G KEPORT OF COMMISSIONER OF FISH AND FISHERIES. [H8J

sheaths spiral ; contractile bulbs long, slender, and parallel. First seg-
ments rectangular, broader than long; subsequent segments increasing
in length rapidly; posterior end of last segment emarginate.

Genital aperture of male marginal, about posterior third. Species
near R. hispidum, but with relative longer and larger hooks on pro-
boscides.

Habitat. — Trygon centrura, spiral valve, July, 1886 ; August, 1887 ;
Wood's Holl, Massachusetts.

In two lots of small Rhynchobothria which were distinguished at the
time of collecting by their small size and the occurrence, at least in a
majority of them, of two red spots in the neck, in front of the con-
tractile bulbs, and which were found to be made up for the most part
of the two species R. Mspidum and R. tenuispine, there were two very
small individuals which I am obliged to refer to a distinct species.
These specimens have lost the posterior segments. The description
given rests mainly on the characters of the bothria, proboscides, neck,
and first segments. It is probable that there are red pigment spots in
the neck as in the two associated species, but this can not be affirmed
certainly, since the specimens were not separated from R. Mspidum
until after they had been for some time in alcohol.

The short and broad character of the head may not be true for the
living specimens, since the bothria are doubtless mobile. It is to be ob-
served, however, that the shape of the heads of these two specimens is
unique when compared with the alcoholic specimens of R. Mspidum,
although individuals of that species were observed to assume positions
while living that were much like that which characterizes R. longispine.

In the larger specimen of the two the first two segments are rectan-
gular, broader than long, the third is nearly square, the fourth is con-
siderably longer than broad, while the fifth and last is as long as all the
preceding segments taken together; its posterior end is emarginate.
The smaller specimen differs from the larger only in having three in-
stead of five segments.

The principal difference between this species and R. Mspidum is in
the hooks. These, at least near the base, appear to have the following
arrangement: There is first a longitudinal row of broad, stout, abruptly
recurved hooks ; second, the row of broad hooks is flanked on either
side by a series of long, slender, arcuate hooks arranged side by side in
groups of four. Between the two latter series, on the side of the pro-
boscis there is a longitudinal space from which hooks are apparently
absent. All the hooks are prominent and stand out at nearly right
angles to the axis of the proboscis. The following measurements show
some of the differences between this species and R. Mspidum : Diameter
of proboscis exclusive of hooks 0.02mm, including hooks 0.05mnj; length
of broad hooks at base of proboscis 0.01 9™m, breadth 0.019mm ; length
of broad hooks middle of proboscis 0.008mm, breadth 0.009mra; length of
slender hooks 0.02inm, breadth 0.006; distance between transverse
spirals 0.02mm.

[119] NOTES ON ENTOZOA OF MARINE FISHES. >37

Following arc the dimensions of the two alcoholic specimens :

Dimensions.

No. 1.

No. 2.

Ill III.
2.30

in in .
1.26

Length of head

ii. ]<;

0.20

Breadth of head

0. 30

0.42

0. 80

1.00

ii. 1(1

0.23

0.40

0.48

0.04

O.OG

0.14

0.14

1.04

0. !20

5

3

The first two segments are rather indistinct and indicated by two
transverse lines. The last segment in No. 1 is linear, rectangular, and
about the same breadth as the first segment. There is an ovary at the
posterior end and a series of comparatively large, snbelliptical bodies,
presumably the testes filling up the interior. There is also a faint in-
dication of the beginning of a cirrus bulb just back of the posterior third
and near the margin.

I would prefer to regard this species as a variety of R. hispid-urn if it
were not for the difference in the character of the hooks.

31. Rkynchobothriwm tenuispine, sp. nov.

[Plate Xll, Figs. 1,2.]

Head and neck much as in R. hispidum, but red spots in neck indis-
tinct or absent altogether. Proboscides long and slender, densely be'set
with exceedingly minute spinose hooks, slightly swollen near the base.
A few of the hooks behind the tumid part are strongly recurved and a
little stouter than the others. On the tumid part and as far forward
as could be seen the hooks are slender, spinose, and slightly recurved.
On one side of the tumid base there are a few slender honks with ab-
ruptly recurved points. First two segments usually mouiliform ; re-
mainder of strobile much as in R. hispidum.

Habitat. — Try yon centrum, spiral valve, August 1 and 3, 1887, Wood's
Holl, Massachusetts.

In the following measurements from alcoholic specimens the diameter
of the head is the maximum, obtained by measuring the head in lateral
view, in which the bothria appear as widely flaring at the posterior
edges. Only the measurements of head, iieck, and first segments are
given. In all the alcoholic specimens the posterior segments have
dropped off.

REPORT OF COMMISSIONER OF FISH AND FISHERIES. [120]

Dimensions.

No. 1.

No. 2.

No. 3.

No. 4.

Length of head and neck

mm.
1 10

mm.
1 00

mm.
1 00

mm.
1 30

Breadth of head

0 20

0.22

0 32

Breadth of neck

0.14

0 10

0 10

0 14

Breadth of neck at contractile bulbs

0.20

0 16

0. 16

0.26

Length of contractile bulbs

0 50

0 40

0 40

0 60

Length of first segment

0.10

0.12

0 12

0 12

Breadth of first segment

0 10

0 08

0 12

0 20

/

In all the above, except No. 4, the first two segments were rounded
at the extremities so as to appear distinctly beaded.

A few mature segments associated with this lot measured as much
as 1.6mm in length and 0.3ram in breadth. They are elongated, oppressed
at the ends, tapering gently towards the posterior end, with somewhat
irregular sinuous outline.

The proboscides are evidently very long, since, although none were
seen fully everted, they could in some instances be traced back, not
only through the entire length of the sheaths, but into the contractile
bulbs themselves.

The following measurements of proboscides and hooks are from alco-
holic specimens :

Dimensions. '

No. 1.

No. 2.

No. 3.

No. 4.

Diameter of tumid base of proboscis

mm.
0 027

mm.
0 O1^

mm.
0 025

mm.
0 019

Length of hooks in front of tumid base

0.003

0 003

0 005

Maximum length of hooks near base

0 006

0 006

0 007

Breadth of largest hooks

0 001

- o 001

Diameter of proboscis in front of tumid base

0 0°0

0 016

0 017

0 014

In all cases, with one exception, these specimens with the fine hooks
on the proboscides had mouiliform anterior segments, usually two in
number. Conversely the coarser hooked proboscides of R. hispidum
were associated with indistinct, squarish, anterior segments.

This species is evidently near R. lieteromerum Diesing, with which it
agrees closely, with the exception of that very important character, the
length of the proboscides. According to Diesiug's description, the pro-
boscides are scarcely longer than the bothria. Diesiug's species is made
to accommodate Wagener's Tetrarliynclms trygonis brucconis. Wage-
Tier's figure of this species represents a worm with short proboscides, or,
•what is more likely, with long proboscides partly everted. In the ab-
sence of a better description of the hooks on the proboscides than is
given for R. heteromerum, it is not possible to refer any of these small
Rhynchobothria from Trygon centrum to that species.

[121] NOTES ON ENTOZOA OF MARINE FISHES. 839

32. Khynchobothrium heterospine, ep. nov.
[Plate xn, Figs. 3-6.]

On August 4, 1886, I obtained a single immature Rhynchobothrium
.from the spiral valve of the smooth dog-fish (Mustelus canis), which,
upon re-examining at leisure, I find is specifically different from the
other Rhynchobothria in my collection. I either neglected to make notes
of this specimen while it was living or, if notes were made, they have
not since turned up. The specimen has been subjected to some press-
ure while in a fresh state, and its flattened condition makes it difficult
to determine whether the bothria are marginal or lateral, and, of coarse,
exaggerates the measurements of breadth.

Bothria two, opposite, lateral, short-elliptical or suborbicular. Neck
loug, cylindrical, compressed, slightly enlarged at base, in vicinity of
contractile bulbs. Proboscides very long and slender, sheaths spiral,
contractile bulbs linear-oblong. Hooks mostly slender, but of very
diverse shapes.

Segments begin some distance back of contractile bulbs. Last seg-
ments elongate. Genital apertures marginal.

Habitat. — Mustelus canis, spiral valve, single immature specimen, Au-
gust 4, 1886, Wood's Holl, Massachusetts.

The dimensions of the alcoholic specimen, much flattened, are as fol-
lows : Length, 13.50ram ; length of head, 0.601U1" ; breadth, 0.70mm ; di-
ameter of neck, 0.26mm; length of head and neck, 3.00mm; length of
proboscides, approximate, l.COmm ; length of contractile bulbs, 0.52mm;
breadth, 0.12ram.

In this specimen, which is evidently immature, the segments are in-
distinct. The last segment measures l.SO1""1 in length and 0.50mm in
breadth and tapers to a blunt point at the posterior end. Three or four
elongated segments are marked off at the posterior end of the strobile by
faint transverse lines. These are filled by the characteristic nuclear
masses which precede the geuitalia in the Cestoda, and from which the
organs of the segment are differentiated. The genital organs are not
yet distinct but are sufficiently developed to show that the male genital
aperture is marginal.

The diameter of the proboscides, exclusive of hooks, is about 0.03mm;
with hooks included it is about 0.05lnln. The maximum length of hooks
is 0.027mm, their breadth 0.005lum. In general the hooks are of at least
four kinds, which, graduating as they do into each other, produce some
very diverse forms. First, there are nearly straight hooks tapering to
a sharp point; second, slender, arcuate, sharp-pointed hooks; third,
slender, straightish hooks with abruptly recurved point, some transition
forms with gentle sigrnoid curve like the leter S partly straightened out;
fourth, like the third form, into which it graduates, except that the shaft
of the hook is quite broad in a plane coinciding with the longitudinal
axis of the proboscis, the recurved end separated from the shaft by a

840 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [122]

narrow notch. Since these varieties graduate into each other, it can be
readily understood that there must be much diversity in the shape of
the hooks of this species. Some of the straight, slender hooks, when
seen as they lie on the side of the proboscis which is directly in view, are
quite broad toward the base, being flattened in a plane which isatright
angles to the longitudinal axis of the proboscis. These hooks when
seen in this position with their broad basal supports look like broad,
thin tacks. Eight or nine hooks can be seen at once in a single trans-
verse spiral. The longest hooks that were measured were near the base
of the proboscis. The hooks vary in length from 0.013 to 0.027mm. The
average length is perhaps not far from 0.01Gmm.

33. Rhynckobothrium imparispine, sp. nov.
[Plate xn, Figs. 7-9.]

Bothria two, lateral, oblong-elliptical, distinctly emargiuate poster-
iorly, deeply hollowed out on the face, margins slightly inverted, very
versatile, head quite broad, bluntly sagittate, the bothria flaring out-
ward at their posterior edges,, approaching each other but not touching
anteriorly. Neck three or four times as long as the head, cylindrical in
front, flattened posteriorly. Proboscides long, moderately slender,
armed with hooks which present great differences both in shape and
size; sheaths spiral ; contractile bulbs long, slender, tapering slightly
posteriorly. First segments begin a short distance behind the neck,
exceedingly short, subsequently increasing in length uniformly, becom-
ing at length elliptical-oblong and longitudinally striated. Ultimate
and free segments much longer than broad, with about fourteen longi-
tudinal muscular stria} on a lateral side.

Genital apertures ; male, marginal near posterior end, from deep
rectangular marginal notch. Length 50Iuni.

Habitat. — Raia erinacea, spiral valve, one specimen, Wood's Holl,
Massachusetts, August 29, 1887.

On August 29, 1887, I examined twenty-four specimens of the Sum-
mer-skate (Raia erinacea). Their stomachs were filled with small crus-
tacea, mostly shrimps (Crangon vulgaris), and annelids of the genera
.Nereis and Rhynchobolus. The eutozoa from this lot of skates were
several specimens of Eclieneibothrium variabile from the spiral valve of
some, a number of Nematods from the stomach and spiral valve of some,
and a single Rhynchobothrium, the subject of this sketch.

The living specimen was very active when placed in sea-water and
changed its form so incessantly that it was impossible to obtain satis-
factory measurements. The bothria were plainly two, although appear-
ing bilobed, on account of the deep posterior emargiuation. They were
very versatile and were frequently directed forward, assuming then a
cupular shape. The last segments were plump, the whole worm being
in fact rather thick. The length was 50mm; breadth of head, lmmj

[123] . NOTES ON ENTOZOA OF MARINE FISHES. 841

breadth of neck, 0.6ml" ; length of neck, 4.5""" ; length of last segment,
2.5mmj breadth, 1.05""". A free segment, which 1 think belonged to
this specimen, measured 5111IU in length. When placed in sea-water it
discharged a mass of eggs which spread out on the bottom of the dish
making a spot 5mm iu diameter which was at first an opaque white
color changing after a few hours to dark brown.

The following data were obtained from the alcoholic specimen : The
bothria are llum iu leugth and 0.7G'UI" in breadth. In lateral view, mar-
ginal as to the body, the head is 1.26mm broad in posterior diameter,
0.6'mn in anterior diameter. The neck in front of the contractile bulbs
is cylindrical and about 0.6Ium in diameter immediately behind the both-
ria, increasing to 0.8min immediately iu front of bulbs. In the vicinity
of the bulbs the neck flattens to coincide with the flattened body. At
the base of the contractile bulbs the marginal diameter is 0.47'""', lateral
O.G6ram. Length of contractile bulbs 1.66"11", breadth 0.28mm. Approxi-
mate length of proboscides 2"""; diameter, exclusive of hooks, O.lllim,
diameter including hooks from 0.14 to 0.1Cmm. In general there are
two sorts of hooks classified according to size. The largest hooks have
linear dimensions which are ten or even twenty times those of the
smallest hooks. There are, however, a few that are intermediate be-
tween the larger and smaller hooks. Of the larger hooks there are three
principal types. In the first type the hooks have broad bases abruptly
and strongly recurved, the recurved part parallel with the axis of the
proboscis or even turned a little toward the proboscis and equal in length
to half the entire length. These hooks are the largest and strongest of
all. At the base of the proboscis they measure 0.06nu" from tip to oppo-
site extremity of basal support, length of base 0.04'"'", breadth of hook
near middle 0.02mm. Toward the end of the proboscis these hooks grow
smaller, the corresponding dimensions of a similar hook there being
0.03""", 0.02Ium, 0.01mm. There appears to be a single longitudinal row of
these stout hooks, with two additional rows of hooks of nearly similar
shape but smaller iu size. The second type of large hooks is long, more
sleuder than the foregoing, and strongly but not so abruptly recurved,
with rather blunt points. One row stands near the row of stou^ hooks.
At the base of the proboscis they measure, with the curve, as much as
0.06"'m in length and are about 0.0 lmm broad at base. Towards the
apex of the proboscis they become shorter and more sleuder. The tip
of the recurved part was in some cases observed to bend toward the
proboscis to form a veritable hook. The third style of large hook is
slender, arcuate, rather sharp pointed, 0.04""11 in length and 0.013"""
broad at base, tapering uniformly to the tip. There are also some simi-
larly shaped hooks about one-half as long and about one-third as broad.
Closely allied to this style are some sleuder hooks which are curved iu
two planes, like the horns of an ox. Next below these come the largest
of the small hooks, not more than 0.014""" iu length. The smallest hooks
are only about 0.002mm in length. On one side of the proboscis these

REPORT OF COMMISSIONER OF FISH AND FISHERIES. [124"

small hooks are arranged in double transverse rows between the trans
verse rows of large hooks. In this case the hooks in the anterior row
are much longer than those in the posterior row, while in both the hooks
are slender. On the side of the proboscis opposite the row of broad,
stout hooks there is, at least at the base of the proboscis, a longitud]
nal space in which there are no large hooks. This space is densely
covered with small hooks, which are very short, with broad bases.
There appear to be about nine longitudinal rows of large hooks, the
hooks iu each row differing more or less from those in every other.
The figures (Figs. 8 and 9, Plate xn),— while not showing all the varie-
ties of hooks, nor their arrangement in toto, give a very correct idea of
the kind of hooks and their arrangement.

Transverse striae, indicating the beginning of segments, begin about
0.4""" back of the contractile bulbs. The first distinct segments are
0.6""" wide and O.OG""" long. One of the posterior segments had the
following dimensions: Length, 2.4"""; breadth, anterior 1.2""", at mar-
giual aperture 1.48'"% posterior 1'"'" ; thickness, 0.9""" ; marginal geni-
tal aperture about 0.7""" from the posterior end. When the cirrus is
retracted it leaves a rectangular notch or emargination, with rounded,
projecting lips. The cirrus was partly everted in one segment; it
scarcely extended beyond the marginal notch, which it filled completely.
It measured 0.12""" in length and 0.1""» in diameter, was smooth, tumid
at outer end and at base, with constriction in the middle.

When placed in glycerine the posterior segments are seen to be
marked with a number— fourteen, more or less— of longitudinal strire,
which converge at the two extremities near the median line, whence
they radiate like meridian lines from the poles of a globe.

Anatomy of posterior segments.— An examination of a few thin sections
of posterior segments yields the following rather meager data : The
ovaries lie near the base of the segment and consist of two paired, round-
ish organs, lying on either side of the median line, each about 0.2""" in
diameter, and made up of small, polygonal, nucleated cells 0.005""" in
diameter. A convoluted mass of one or more tubes lies immediately in
front of the ovaries, occupying the median line from the anterior edge of
the ovaries to a point a little in front of the cirrus bulb, thence it bends
back and communicates with the cirrus bulb. It is evidently, in part at
least, the vas deferens. In front of this convoluted mass there is a.
thick-walled tube of very different appearance, which extends along the
median line and appears to approach the exterior at the anterior edge
of the segment. This is probably the uterus, and its extremity at the
anterior edge of the segment an external orifice whence ova are ex-
pelled from ripe proglottides. I can find no trace of a vagina, unless
the thick-walled tube which I suppose to be the uterus should prove to
represent that organ. A very characteristic feature of these segments
is the strong bands of longitudinal striae which lie in the lateral walls.,
Ova were observed in some of the sections. They lay in the postero-

Dl

[125] NOTES ON ENTOZOA O'F MARINE FISHES. 843

median part of the segment and were much collapsed. They measured
about 0.05miu and 0.025111"1 in their two diameters.

On September 6, 1887, I obtained a large, free proglottis from this
same species of skate (Raia erinacea) which belongs undoubtedly to
this Rhynchobothrium, although no Rhynchobothrium scolex was found.
The proglottis was lmm broad and 3.5Ium long. Ova were observed
making their escape from the compressed segment in glycerine at the
genital aperture near one of the margins. They are collapsed and
measure 0.055 and 0.027mm in their two diameters. Longitudinal strite
appear which converge at the two ends to a small circular hilum, which
marks the former point of attachment to adjoining segments.

This species is evidently near Van Beneden's Tetrarhynchus erinaceus
from Raia rubus, which it closely resembles in the character of its hooks.
It also possesses niauy characters common to Rhynchobothrium com-
mutatum Dies., and It. ambiguum Dies.

34. Rhynchobothriiim tcageneri, sp. nov.
[Plate xii, Figs. 10-12.]

Bothria two, lateral, orbicular, or, in alcoholic specimens, broadly
elliptical, emarginate on posterior edge, somewhat bilocular, converg-
ing in front, widely divergent behind, with smooth, thickened, and ele-
vated edges. Proboscides four, in two pairs, a pair issuing from an-
terior part of each bothrium. Inner side of base of each proboscis with
a prominent shoulder, and with a single large, recurved hook on outer
side opposite the shoulder; base of proboscis covered with small, slender
hooks, remainder of proboscis armed with larger hooks. Proboscides
three or four times as long as bothria, tapering gradually to apex. Neck
long, cylindrical, broader than the body, very contractile in front of
bulbs ; proboscis sheaths in loose spirals ; contractile bulbs very long,
parallel. Body crossed by a narrow, transverse, crimson baud immedi-
ately behind the contractile bulbs. The segments begin almost imme-
diately behind the contractile bulbs. The first three or four distinct
segments are broader than long. The next are squarish. At about
the tenth they begin to elongate and mature. They increase rapidly
in length towards the posterior end, the median ones becoming bacilli-
form while the last one is, in some cases, eight or ten times as long as
broad. The last two or three are usually very long, fusiform, of an
ivory-white color, and discharge ova when placed in water. The body
throughout is almost cylindrical. Genital apertures marginal near
middleof segment. Ova spheroidal, 0.029U1IU in diameter. Length, 18mm.

Habitat. — Trygon centrura, spiral valve, about ninety specimens from
two rays, Wood's Holl, Massachusetts, August 10, 1887.

844 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [126"

Of the following measurements, those of No. 1 are of a living sped
men, Nos. 2 and 3 are of alcoholic specimens. •"""

Dimensions.

No. 1.

No. 2.

No. 3.

Length

mm.
18.00

mm.
13.00

mm .
14.01

lireadth of bead

0.80

0.54

0.5!

0.46

0.28

0.2'

Length of Lead and neck

3.00

2.20

2. 4(

Diameter of neck

0.64

0.32

0. 3(

Length of contractile bulbs .....

2.00

1.20

1.21

0.20

0.10

0.11

Length of first segment approximate

0.03

0.03

o.o:

0.30

0.24

0.2:

Length of last segment

4.00

2.40

2.81

0.4G

0.50

0.4<

Length of proboscis

1.60

1.40

1.21

0.08

0.08

0.0)

0.04

0. OS

o.o;

Number of segments . ...

20

16

It

In the alcoholic specimens the length of bothriuin was 0.28mm.
breadth 0.30mm. The anterior segments were indistinct.

The base of each proboscis for a distance of about 0.12""" is O.OS1"111 ir
diameter. At this point there is a sudden offset where the diametei
suddenly diminishes to 0.06mra, thus giving rise to a prominent shouldei
which is always on the inner side of the proboscis. The basal part ol
the proboscis is thickly covered with slender, slightly recurved hooks,
which are from 0.005 to0.010imu in length and less than 0.002mm in thick-
ness. These hooks are arranged in spirals, the coils of which make
rows of hooks almost transverse to the axis of the proboscis. The hooks
are longer and straighter near the head than they arc at the offset. On
the outer side of the proboscis, opposite to and a little way back of the
basal shoulder, there is a single large hook. This hook is broad, recurved
and has a strong basal support. Its length is 0.04""", breadth at sur-
face of proboscis 0.017mm, breadth of basal support 0.021"11". Beyond
the basal shoulder the proboscis tapers very gradually to the apex,
which in well everted proboscides is about 0.04"1"1 in diameter, or one-
half the diameter at base. The proboscis in front of the basal shoulder
is covered with slender hooks, which are for the most part but slightly
recurved. The maximum length of these hooks is about 0.015mm, breadth
at base 0.002mm. They are arranged in spirals 0.016mm apart, eight or
nine hooks being visible in a single spiral. The coils of the spiral are
more rapidly ascending than they are at the base. Towards the apex
the hooks grow somewhat smaller. There is a slight difference between
the hooks of opposite sides of the proboscis immediately above the basal
part. On the outer side — that is. the side which bears the large basal
hook — they are small, short, rather stout, sharply recurved, and about

127] NOTES ON ENTOZOA OF MARINE FISHES. 845

,005mm in length, or one-eighth the length of the large hook. On the
pposite side they are slender, slightly recurved, and about 0.015""" in

ngth.
I The narrow crimson band at the base of the contractile bulbs is 0.02"""

ide, and occupies the entire breadth of the body. The elongated rod-
Ike segments which immediately precede the mature segments contain

double row of large, elliptical bodies, lying one on each side of the
nedian line. The cirrus is smooth, slender, of* moderate length, and
>pens about the middle of the margin of the segment. The interior of
,he mature segments is filled with the very numerous ova.

This Rhynchobothrium is evidently the adult form of a species either
dentical with the larval Rhynchobothrium from Cepola rubescens figured
ay Wageuer (Nov. Act., Nat. Cur., xxiv, Suppl. 48 and 82, Plate xix,
130-234), or at least closely related to it.

The figure of the proboscis given by Wagener shows the same re-

arkable peculiarities which characterize this species. The shape of
he bothria, the proportions of the head, neck, proboscides, contractile
ulbs, as shown in Wagener's figures, agree with these specimens from

'rygon centrura. Wagener does not give a specific name to the larval
brm. He simply designates it as "A Tetrarhynchus from Cepola rubes-
cens.'"

So far as I am aware, the adult has not been found. I therefore pro-
pose, as a proper specific designation for this species, the name R. icag-
leneri, in honor of the original describer of what is probably the larval
jform of the species.

35. Rhynchobothrium lomentaceum Dies.

[Plate xin, Fig. 1-3.]

Diesing, Syst. Helm., i, 571 ; R6vis. dea Cepth. Par., 290. Von Linstow,
Comp. Helm., 280.

I refer a single Rhynchobothrium from Mustelus canis to Diesing's R.
lomentaceum from If. vulgaris. This is done with some hesitation, for,
although it does not disagree with Diesing's description, the latter is
confined to such general characters that specific differences might still
exist between my specimen and R. lomentaceum. It should also be re-
marked that the armature of the proboscides resembles very closely that
of R. caryophyllum Dies, from Scoliodon lalandii. (Denks. der kais.
Akad., xn, 30, Plate iv, figs. 16-20.)

Diesing gives the following description of R. lomentaceum:
Head with oval, lateral bothria converging at the apex. Neck slightly depressed.
Body lanceolate, first segments very short, transversely oblong, each with rounded
margin and swollen in the middle. Genital apertures. . . . Length of head and
neck, 4mni ; length of body, 36mm ; breadth of posterior, 4mm.

My specimen consists of the head, neck, and a few of the first seg-
ments, the whole measuring, when living, 9nim. There is also a frag-
ment containing a number of median segments and measuring, when

846 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [128]

living, 10.5mm. The last segment of this fragment was l.lmm long and
1.7mni broad. The length of the head and neck in the living specimen
was 3.5mm ; length of contractile bulbs lnim.

Following are dimensions of the alcoholic specimen : Length of head
1.44mm, breadth 1.66mm; length of bothria 1.60inni, breadth 0.92"im ;
length of head and neck, 3.14mm ; diameter of neck, marginal, I.l0mm,
lateral lllim; length of contractile bulbs 1.08mm, breadth 0.26; dis-
tance from base of bulbs to first distinct segment, •S111'11 ; length of first
distinct segment 0.1Gmm, breadth 1.20"""; greatest breadth of seg-
ments 1.80nim, length 0.80mm ; lateral diameter behind bulbs, 0.90mm j
marginal diameter, 0.56mm ; diameter of proboscides, 0.12mm.

The following description is based on the single alcoholic specimen:
Head broadly sagittate. Bothria two, oval, narrow in front, broad be-
hind, with thick, entire edges, a very faint emargi nation on posterior
edge, converging at apex of head, flaring posteriorly, so as to give
to the head the shape of an equilateral triangle. Neck a little
longer than head, swollen in front of contractile bulbs, fusiform on
account of contraction in length, slightly constricted at base of con-
tractile bulbs. Proboscis sheaths spiral, contractile bulbs four times
as long as broad. Proboscides longer than bothria; hooks of two prin-
cipal sizes, the larger ones stout, broad, and strongly recurved, the
smaller ones also broad and strongly recurved, but some of them pro-
portionally more slender than the larger ones, a few slender and arcu-
ate. Larger hooks on outer side of proboscides, smaller ones on inner
side. First segments very short and broad; succeeding segments also
short and broad, with rounded margins ; margins of segmented part
of strobile creuulate.

Male genital aperture marginal, about middle of segment.

Habitat. — Mustelus canis, spiral valve, one specimen. Wood's Holl,
Massachusetts, August 11, 1887.

The only details that the small amount of material at hand permits
relate to the disposition of the hooks on the proboscides. The largest
hooks are 0.04mm in their greatest length, and 0.02mm broad at base.
The smaller hooks are from 0.01 to 0.02mm in length, and from 0.004mm
to 0.01mm in breadth. The spiral series of hooks are 0.035mm apart,
and the hooks in each series are situated from 0.01mm for the larger
to 0.02mm for the smaller from each other. The arrangement seems to
be as follows : On the outer side of the proboscis there are four longitu-
dinal rows of large, strongly recurved hooks. On the opposite or outer
side there are four longitudinal rows of hooks, much like the large
hooks in shape and proportion, but having only about half their lineal
dimensions. The series of large hooks is flanked on each side by two
rows of hooks which are somewhat smaller and proportionally a little
more slender than the large hooks. Between each of these two series
of intermediate hooks and the inner series of small hooks there is a
single row of hooks consisting of alternately large and small hooks.

[129] NOTES ON ENTOZOA OF MARINE FISHES. 847

The larger of these two styles of hooks are, however, small-sized, and
correspond, both in shape and size, to the hooks in the inner series. The
smaller alternates of this row are but slightly recurved. The larger al-
ternates are about 0.0 17mm long and O.OOS""U broad at base; the smaller
ones are O.OU"11U long and 0.005™m broad at base. To recapitulate,
there are four rows of large hooks on outer side of proboscis, four rows
of small hooks on inner side, two rows of intermediate hooks on each
side of the series of large hooks, one row of alternately larger and
smaller hooks on each side of the series of small hooks, thus making
fourteen rows in all. All the nooks are smaller and more slender near
the base of the proboscis.

The fragment of strobile which was found associated with the scolex,
and which evidently belongs to it, does not contain any mature segments.
The posterior segments are somewhat elongated and are narrower than
the preceding segments. None of the genital organs could be made out
except the cirrus, which could be seen through the walls of the seg-
ment when the latter were rendered transparent with glycerine. The
male genital aperture is marginal about the middle. The walls of the
segments are traversed by many strong, longitudinal, muscular fibers.

36. Rhynchobothrium longicorne, sp. nov.
[Plate xin, Figs. 4-8].

Head appressed, truncate, and emarginate in front. Bothria two,
lateral, oblong-elliptical, parallel in front, slightly divergent behind,
slightly emarginate on posterior edge, somewhat bilobed by a low, short,
longitudinal, median ridge near the posterior end of the shallow face.
Neck long, but capable of great contraction, subcyliudrical. Pro-
boscides very long, three or four times as long as the bothria, tapering
to apex, with tumid basal portion covered with tine, slender, straighti?h
appressed booklets ; remainder of proboscis armed with longer, slender,
curved booklets of nearly uniform size. Proboscis-sheaths very long,
in contracted specimens lying in broad, crowded, sinuous folds. Con-
tractile bulbs elliptical or elliptical-oblong. Segments begin very soon
behind contractile bulbs; at first very short, subsequently increasing
in length, then becoming as long as broad ; last segments rectangular,
longer than broad. Body relatively short, compressed, at first a little
wider than neck and increasing in breadth but little throughout its
length.

Genital apertures male marginal, near anterior edge, its position in
some specimens marked by an evident notch ; female lateral at middle
point of median line ('?). Eggs oval about 0.04mm in longer diameter.

Habitat. — Odontaspis littoralis, spiral valve. Wood's Holl, Massa-
chusetts, July, 1885 ; August, 1886.

I have found this species on two different occasions, each time in the
sand shark (Odontaspis littoralis). The first specimens, three in num-
ber, were collected July 15, 1885; the second, four in number, August
12, 1887.

848 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [1 30]

In the following, No. 1 was a living specimen somewhat flattened
under the compressor ; Nos. 2 and 3 alcoholic. Nos. 1 and 3 are doubt-
less the same individual.

Dimensions.

No. 1.

No. 2.

No. 3.

Length

min.
14 00

turn.
8 50

mm.
10 00

2 00

0 99

1 23

l!rf ailtli of botbria

0 C6

0 80

Length of bead and neck

5 20

2 80

3 10

Diameter of oeck.

0 46

0 52

Length of contractile bulbs

1 06

0 80

1 04

Diameter of contractile bulbs

0.34

0.16

0.18

Length of proboscis

6 40

Distance from base of bulbs to first segment

0.80

0 60

0.60

Length of first distinct segment

0.10

0. 10

0 10

1 00

0 68

0 60

Length of last segment

2.20

1.20

J.56

Breadth of last segment

1.40

0.86

1.04

Number of segments

24

16

24

In No. 1 the last 17 segments show the reproductive organs.

From a specimen collected July, 1885, the following measurements
were obtained: length of head, 3mm, breadth, 2mm ; length of neck,
6mm; breadth, 1.3ram; length of contractile bulbs, lrai", breadth, 0-5mm;
length of posterior segment, 4mra, breadth, 2.5mm.

Some dimensions of proboscides and hooks are: diameter at base, ex-
cluding hooks, 0.097mm; including hooks, O.linm ; median diameter, ex-
cluding hooks, O.OC6mm ; including hooks, 0.102mm ; length of hooks on
base of proboscis, 0.02 to 0.03mm; breadth, 0.004mmj length of median
hooks, 0.04mm, breadth, 0.007mm.

The tumid base of each proboscis is prominently shouldered on the
outer side. In this respect it resembles R. tvageneri. There is, how-
ever, no single large hook as in that species, and besides there is a very
great difference between R. icageneri and R. longicorne in respect to the
conformation and arrangement of the hooks.

Behind the basal enlargement the hooks are nearly straight, ap-
pressed closely to the surface of the proboscis, slender, sharp-pointed,
and, many of them, with a single short lateral basal prolongation. The
spirals are about 0.01nmi apart, while the longest hooks are over 0.031111" in
length. The points of the hooks in one spiral therefore cover the bases of
the preceding series. The hooks on the outer side of this part of the pro-
boscis are larger than those on the inner side. On the anterior part of the
basal enlargement of the proboscis they are smaller and crowded together
closely. The spirals are here about 0.005mm apart, and twenty-five hook-
lets and over may be counted in a single trans versejspiral. There is some
variety in the shape oi the hooks on the basal enlargement. On its outer
part they are, in the main, straight and slender. Toward the inner side
on the anterior slope there are about five spiral series in which the
hooklets are placed close together side by side. These booklets stand

[131] NOTES ON ENTOZOA OF MARINE FISHES. 849

nearly erect, are moderately broad and abruptly recurved at the point.
In front of the basal enlargement the hooks are, in the main, slender,
sharp-pointed, and arcuate, from 0.02'2mm to 0.033mm in length, the spirals
about 0.02mm apart, about eight booklets visible in each spiral. The
hooks, for the most part, are nearly erect. There are, however, on one
side of the proboscis, two longitudinal rows of hooks, which are stouter
than the hooks in the other longitudinal rows, and are strongly appressed,
the hooks in each row pointing toward the other row. This arrange-
ment seems to be very similar to that figured by Van Beneden for his
Tetrarliynclius minutus from Squatina angelus. These two rows of ap-
pressed hooks are flanked on the "one side by a row of rather short
broad-based hooks, strongly recurved, and on the other by a row of
rather short arcuate hooks. The remaining booklets do not differ from
each other either in size or shape. They are long, slender-pointed,
arcuate, nearly erect, and impart a characteristic bristly appearance to
the proboscis. The proboscides taper gently toward the apex, where
there is much less diversity both in size and shape of hooks than there
is farther back.

The lateral vessels of the water vascular system remain plainly visi-
ble in an alcoholic specimen lightly stained with ha3matoxylou. The
body is short, broad, and much flattened. In the mature segments the
ova are collected in a mass at the bottom of an elongated clear space}
which begins at the marginal genital aperture near the anterior end,
runs directly to the median line, follows the latter to near the posterior
end, where it expands into the cavity in which the ova are lodged.
The cirrus was not observed. I have not been able to demonstrate the
position of the female genital aperture in the alcoholic specimens, but
am disposed to think that it is lateral, from the fact that, in a living
specimen, there were distinct median lateral apertures on the squarish
segments in front of the mature segments.

OTOBOTHRIUM, gen. nov.

[ovf, (Jr6f, the ear.]

Body articulate, tsenireform, head separated from body by a neck.
Bothria two, opposite, lateral, each with two supplemental ciliated pits
at the posterior free angles. Proboscides four, terminal, filiform, armed,
retractile in neck. Reproductive apertures marginal.

According to Diesing's classification this genus belongs to the sub-
bribe Trypanorhyncha and the family DibothriorliyncMdcv. The number
of the bothria allies it with the genus Rhynchobothrium. On the other
hand the neck of Otobothrium bears a close resemblance to that of Tet-
rarhynchus. The reason for separating it from Rliynchobothrium and
erecting it into a new genus is found in the presence of the four otosacs
or ciliated pits. These, if not homologous with the supplemental disks
of Calliobothrium, etc., certainly furnish a character of as much weight
in classification as they.
B. Mis. 133 54

850 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [132]

37. Otobothrium crenacolle, sp. nov.
[Plate xin, Figs. 9-15, and Plate xiv, Figs. 1-4. ]

Head broad, transverse, hammer- shaped, or, in alcoholic specimens,
bluntly rounded in front and cordate, compressed. Bothria two, oppo-
site, lateral, sub-rectangular or oblong-elliptical, bilocular, slightly
emargiuate on posterior edge, converging in front, widely divergent
behind ; each bothrium with two eversible, ciliated pits at the posterior
edge. Faces of bothria hollowed out, edges somewhat thickened.
Neck short, cylindrical, slightly compressed, broader, and much thicker
than anterior part of the body, from which it is quite distinct, posteri-
orly projecting into a kind of collar with four deep notches opposite the
sides and margins of the body. Proboscides slender, about twice the
length of a bothrium, armed, for the most part, with strongly recurved
hooklets, which are sharp-pointed with broad bases of uniform size and
symmetrically disposed ; about five visible at once in each of the diag-
onal rows. There are beside these some minute slender hooklets near
the base of the proboscides. The proboscis-sheaths are spiral. The
contractile bulbs are short, oval, and lodged at the base of the neck in
the projecting lobes made by the posterior notches of the neck. The
body is slender, compressed, and much narrower at first than the neck.
First four segments very short, three or four times as broad as long.
The remaining segments increase in length, rapidly becoming very long
and slender, the posterior segment often from twelve to fifteen times as
long as broad. Free proglottides slender, somewhat irregular in out--
line, very active. Ova subglobular, .abundant. Genital apertures, at
least male, marginal a little behind middle point.

Habitat. — Kphyrna zygwna, spiral valve, July 28, 1886, one hundred
and fifty specimens; July 18, 1887, one hundred specimens; chyle
swarming with free proglottides on both occasions. Wood's Holl,
Massachusetts.

Numbers 1 and 2 of the following are from living specimens ; 3 and 4,
alcoholic.

Dimensions.

No. 1.

No. 2.

No. 3.

No. 4. '

mm,
14.00

0.22

mill.
11.20
0.22
0.32
0.36
0.12
0. 10
0.10

mm.

10.80
0.22
0.32
0.40
0.12
0. 1G

m Hi-
ll. 50

0.20
0.30
0.36
0.14
0.18
0.08
0.05
0.10
3.00
0.36
17

0.36
0.14
0.18
0.06
0.04
0. 12
3.30
0.30
20

•

0.05

0.08
1.90
0.28
16

0.10
2.40
0.20
18

[133] NOTES ON ENTOZOA OF MARINE FISHES. 851

The following details are taken from a living specimen slightly dis-
torted under the compressor : Length, 9.30 IUI" ; length of bead and ueck»,
0.36 mm; breadth of head, 0.32 mm; length of bothria, 0.17 mm ; diameter
of neck, 0.10 min; diameter at contractile bulbs, 0.13 mm; length of each
of first four segments, 0.02 mm ; breadth, 0.07 ; length of h'fth segment,
0.04 mra ; sixth, 0.08 mm ; seventh, 0.12 lum ; eighth, 0.16 mui ; ninth, 0.30 mui;
tenth, 0.44 "*" j eleventh, 0.60 mm; twelfth, l.mm; thirteenth, 1.25 Dim ;
fourteenth, 1.8 mui ; fifteenth, 3 mm. The last of these segments were
0.10, 0.14, and 0.2 mm broad, respectively.

The length of the proboscides, estimated from specimens that had
been made transparent, so as to show the retracted proboscides, seems
to be from 0.5 to0.6mm. TJie longest everted proboscis measured 0.4 mm ;
diameter, excluding hooks, 0.011 to 0.016 mm; including hooks, 0.019 to
0.025 "'»' ; length of hooks, 0.007 to 0.008 mm ; breadth 0.003 ram ; length of
minute hooks at base of proboscides, 0.003 ; breadth, 0.001 mm ; length
of free proglottis, living, 4.4 mm ; breadth, 0.8 ram.

In alcoholic specimens the bothria are invariably opposite and diver-
gent at the bases, so as to give to the head, when viewed laterally, margi-
nally as to body, a cordate or even reuiform outline. The outline of the
head and neck together is like that of a hammer, in which the neck
represents the short thick handle. The head is only about half as thick
as it is wide, c. g. in an alcoholic specimen the breadth of head was
0.28 mm ; thickness, 0.14 uim ; in this specimen the length of a single both-
riuui was 0.2 mm; its breadth, 0.14 mm. In another specimen the head
was 0.32 mm broad and 0.14 mm thick.

In the living worm the faces of the bothria are frequently directed
forward, and when viewed in this position their anterior edges are seen
to be separated by a moderately wide space. A pair of proboscides
emerges from the anterior edge of each bothriuin. There is a slight
emargiuation on the anterior edge of each bothriuin, and another shal-
low emargiuation on the posterior edge. A median line extending from
the shallow posterior notch to the front edge divides the bothrium
into two loculi. This latter feature is often lost, or at least much
obscured, in alcoholic specimens, in which the faces of the bothria are
deeply concave, the lips sometimes much iuflexed.

Supplemental pits or otosacs. — These organs appear under low magni-
fying power as four round spots, lying one at each of the posterior angles
of the two bothria. When highly magnified, 250 to 300 diameters,
these spots are seen to be oval or conical pits, lined with minute ciliary
bristles, and about 0.025mm in diameter. While examining one of these
pits with a magnifying power of about 300 diameters, the specimen was
subjected to a slightly increased pressure, when one of the pits was
observed to evert itself, changing from an oval pit lined with ciliary
bristles to a blunt conical papillary elevation, which was covered with
erect bristles. In the alcoholic specimens some of these pits are everted
into low papillae. These remarkable pits are strongly suggestive of low

852 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [134]

or rudimentary sense organs. A careful histological examination of
the scolex may throw some light on their true nature.

Anatomy of mature segments. — The male genital aperture is marginal
a little back of the middle. A lateral aperture was observed in a few
free segments. It was situated near the anterior end of the segment,
and is probably an opening for the discharge of ova, since careful search
failed to reveal any corresponding opening on immature segments. The
cirrus was not seen fully everted. The length in an alcoholic specimen
was estimated to be about 0.6mm, and the diameter at base 0.12ram. It
emerges from the center of a comparatively wide but shallow marginal
notch. The vagina appears to open immediately behind the cirrus in
the same marginal notch. The cirrus bulb is rather small, oval, and
directed slightly forward. The vas deferens lies in a coil in front and
at the base of the cirrus bulb, and enters the base of the bulb. The
ovaries are small obloug, or oval, and lie one on each side of the median
line and at about one-third the distance from the genital aperture to
the posterior end of the segment. Back of the ovaries are a number of
oval clear spaces.

The ova are nearly globular. A living ovum measured 0.024 and
0.022mm in its two diameters. Ova in the preserved specimens, mounted
in glycerine and slightly compressed, appear almost globular, and are
0.027mm in diameter. They have smooth and rather thin shells, which
must be quite rigid, as no eggs were observed with the shell collapsed
or indented. In a few cases the ova are aggregated into a globular
mass about the middle of the segment and a little in front of the genital
aperture. This mass causes an abrupt swelling in the walls of the seg-
ment, which, upon slight pressure, bursts, releasing the eggs in vast
numbers. Ova were also seen lying along the median line and in
small clusters near the anterior end, whence they apparently find their
natural outlet.

The anterior part of the mature segments which do not yet contain
ova is filled with oval or elliptical bodies, which, according to analogy
with other forms, doubtless represent the testes. In some these have
disappeared along the median line, leaving a median sinus which evi-.
deutly becomes a receptacle for ripe ova. There are usually only from
12 to 15 segments present in a single specimen. As the segments
mature they separate easily.

On both occasions of finding this worm the chyle of the intestine was
swarming with them and with the free proglottides. A few were found
in the pyloric division of the stomach. The free proglottides, when
placed in sea- water, continued very active for several hours. They were
capable of active progressive motion by alternate contraction, and ex-,
pansiou of the body, during which each end often assumed the shape
and performed the function of a sucker. The masses of ova in the liv-^
ing proglottides were, in some cases, ivory-white and opaque. In others
they passed from white through yellowish to brown. Others were yel-
lowish green.

[135] NOTES ON ENTOZOA OP MAKINE FISHES. 853

I have had the opportunity of examining but two specimens of the
hammer-head shark (Sphyrna sygwna). These were obtained in different
years, and both yielded this parasite in abundance. The only other
parasites found in this host were a single Nematod in the spiral valve
of one, and a few cysts (Xeuosites) in the muscular coats of the stomach
of each.

Subfamily II. — Tetrabothriorhynchina3.

Family Tetrabothriorhynchidce Dies.

TETRARHYNCHUS Rudolphi.

Bothriocepliali spec. Bartels.

Ehynchobothrii spec. Vail Beueden aud R. Leuckart.

Tetrarhynchi spec. Van Beueden.

AspidorhyncJius Moliu.

Tetrarhynchobothrium Dies.

Body articulate, tseui reform. Neck tubular. Head with four bothria
in two lateral pairs, parallel with the head. Proboscides four, termi-
nal, filiform, armed, retractile in the neck, free, i. e., not running through
the bothria. Genital apertures marginal or lateral.

38. Tetrarhynchus tenue, sp. nov.

[Plate xiv. Figs. 5,6.]

Head variable, but often sagittate. Bothria four, in two lateral pairs,
long-oval, long-elliptical, or oblong. Proboscides four, somewhat quad-
rangular, a little shorter than the bothria, densely beset with very slen-
der straightish or slightly arcuate spine-like hooklets, which are of nearly
uniform size and shape. The proboscides emerge from a point a short
distance back of the apex of the head. Neck tubular, contractile. In
life it may be twice as long as the bothria, but in alcoholic specimens
it is usually shorter than the bothria. Posteriorly it is continued in a
collar which incloses the anterior part of the body. It is ordinarily
broader than the anterior part of the body. The proboscis sheaths are
nearly straight, with the exception of a single spiral kink in front of
the contractile bulbs. The latter organs are short-oval — in alcoholic
specimens less than one-third the length of the bothria. The segments
begin immediately behind the neck as fine transverse wrinkles. The
first distinct segments are very short, subsequently increasing in length,
becoming squarish, then longer than broad. The posterior mature seg-
ments are considerably longer than broad, with a tendency, in alcoholic
specimens, to become convex on the margins, thus giving a decidedly
repand outline to the margins of the mature portions of the strobile.

Genital apertures : male, marginal, a little in front of the middle point.
Cirrus rather short and smooth ; female aperture lateral (?). Ova small,
spheroidal, escaping from lateral aperture. General habit of body more
slender, especially head and anterior part of body, than T. robustum.

854 REPORT OP COMMISSIONER OF FISH AND FISHERIES. [136]

Habitat. — Tryyon centrura, stomach arid pylorus. August, 1884 and
1887. Wood's Holl, Massaclui setts.

Upon four different occasions I have obtained a few Tetrarliyncld from
the stomach of the sting ray (Trygon centrura), which, with the some-
what hurried examination that was made of them while they were alive,
were supposed to belong to the same species. After an examination of
the alcoholic specimens, however, I find that there are two entirely dis-
tinct species in each of the four lots. These differ from each other most
in the character of the hooklets on the proboscides, T. tenue, having
minute spinose hooklets, while the hooklets of T. robustum are short,
stout, and strongly recurved.

These parasites were found as follows :

Date of capture.

No. of rays
examined.

No. of para-
sites found.

Aiifust, 1884

One

One.

August 1 1887

Three

Two.

August 8, 1887

One

Three.

August 10 1887

T wo

One.

These specimens were all found either in the stomach proper or in
the pylorus.

Of the following measurements No. 1 was a living specimen, the
others alcoholic :

Dimensions.

No. 1.

No. 2.

No. 3.

Length .. . .

mm.
19 00

mm.
20.00-

mm.
13.50

Length of bothria .....

0.46

0.36

0.40

Breadth of head

0.30

0.24

0.26

Length of head and neck ..

0.56

0.48

Diameter of neck 1<k ...

0.24

0.18

0.20

Length of contractile bulbs

0.14

0.11

0.12

Breadth of contractile bulbs .

0.05

0.05

0.04

Length of proboscides

0.28

0.20

Diameter of proboscides

0.02

0.026

Length of hooklets . .... .

0. 0055

Breadth of hooklets

0. 0014

Length of anterior segment approximate

0.04

0.02

0.02

Breadth of anterior segments

0.18

0.12

0.16

Length of posterior segments

1.16

0.88

0.80

Breadth of posterior segments

0.70

0.58

0.24

In No. 1 the diameter of neck at collar wns 0.1S1'"11; length of neck
proper, 0.40mni ; length of collar, 0.14mm ; length of bothria, varying from
0.30 to 0.56mm ; posterior segments, from 0.94 to 1.16mm.

In an alcoholic specimen, 13mm in length, the length of the head and
neck was 0.78mm ; in another, 17ram in length, the length of the head and
neck was 0.48mm.

[137] NOTES ON ENTOZOA OF MARINE FISHES. . 855

I take the following descriptive paragraph from notes made at the
time of collecting : Bothria elongated in two lateral pairs, the bothria
constituting a single pair united at the apex, each with an irregularly
hollowed face and posterior bluntly rounded edges reflexed from the
neck. Anterior part of head projecting about O.I1'"" in front of the
bases of the proboscides, the latter shorter than the bothria. Neck
short, tumid, constricted behind the short contractile bulbs and con-
tinued posteriorly into a collar which surrounds the anterior part of the
body. The body is joined to the neck at the base of the bulbs. Fine
transverse lines begin at once behind the collar. The first segments
are broader than long. They increase in length rapidly and at a dis-
tance of 8mm from the head are more then twice as long as broad. The
posterior mature segments are somewhat irregular in outline and tumid
in the middle. When placed in water the ripe segments are apt to
burst at the middle of a lateral face, by means of a rapid papillary
swelling from which the eggs escape. Under the compressor the di-
viding line between the ripe segments is indistinct.

The spheroidal ova measure about 0.019 and 0.014mm in the two diam-
eters. Some are nearly spherical and 0.019mm in diameter.

The epidermis of one specimen exhibited a tendency to slough off
after lying for a short time in sea-water. In some specimens, after
having been placed in sea-water, it was observed that the mature seg-
ments had curved towards one of the lateral faces, burst about the
middle, and discharged ova in such quantity as to leave a milky white
patch at the bottom of the dish.

When alcoholic specimens were highly magnified the apex of the
head and the edges of the bothria are seen to be densely covered with
minute hair-like bristles, which are a little longer than the hooklets of
the proboscis. These bristles belong to the epidermis, are easily rubbed
off, can be seen only with a high magnifying power and hence may be
easily overlooked.

In the mature segments the nearly spherical ova lie in scattered
masses. These small aggregations are probably what remain of the
ova, the greater part having escaped through the lateral aperture.
The cirrus emerges near or a little in front of the middle point of the
margin, thus differing from T.robustum, in which the cirrus opens near
the anterior margin.

This species has many characters in common with T. infulatum (As-
pidorhynchus infulatus Molin).

39. Tetrarhynchus robustum, sp. nov.

[Plate xiv, Figs. 7-9. J

Head bluntly rounded in front. Bothria four, oblong, hollowed out
on the face, with flexible borders, distinctly arranged in lateral pairs,
the bothria in each pair approximating at their fore posterior edges.
Neck variable, usually cylindrical, broader than anterior part of body,

856 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [138]

continued posteriorly into a collar which incloses the anterior part of
the body, iu alcoholic specimens often transversely wrinkled. Probos-
cides nearly equaling the bothria in length, armed with short, strongly
recurved booklets, sheaths nearly straight with a single spiral turn im-
mediately in front of the contractile bulbs. The latter are long-oval,
and a little more than one-half as long as the bothria. The body begins
immediately behind the contractile bulbs, and is at once crossed by
transverse lines which soon outline distinct segments. The first seg-
ments are very much broader than long. Subsequently they increase
in length slowly, the posterior mature segments becoming at first squar-
ish, then a little longer than broad. Male genital apertures marginal,
irregularly alternate, near anterior edge. Cirrus small, smooth ; cirrus
bulb slender. Female genital aperture lateral(f).

! Ova small, very abundant, nearly spherical, about 0.016ram in diam-
eter, and with a thin shell.

Habitat. — Trygon centrura, stomach and pylorus, August, 1884 and
1887, Wood's Holl, Massachusetts.

The general habit of T. rolustum is stouter than T. tpnue. The head,
neck, and segments are relatively broader ; the head is more blunt at
the apex ; the proboscides emerge from the apex of the head instead of
a little way back of the apex ; the booklets on the proboscides are much
stouter and more sharply recurved ; the contractile bulbs are longer;
the cirrus opens near the anterior end of the segment instead of near
the middle.

I have found this species associated with T. tenue, as follows : August,
1884, two specimens; August 1, 1887, two specimens; August 8, frag-
ments ; August 10, one specimen.

The following measurements were obtained from alcoholic speci-
mens:

Dimensions.

If 0.1.

No. 2.

Length

mm.
20. 00

mm.

2*. 00

Length of bothria

0.68

0.60

Breadth of head . . . ..

0.70

0.64

Length of head and neck

1.20

1.18

Diameter of neck. ... .

0.50

0.42

Length of proboscides .

0. GO

0.60

0.03

0.03

Length of booklets

0.011

0.014

Breadth of h ooklets

0.005

0.005

Length of contractile bulbs

0.33

0.32

Breadth of contractile bulbs

0.10

0.08

Length of anterior segments approximate

0.02

0.02

Breadth of anterior segments . ..

0.38

0.40

Length of posterior segments

0.52

0.86

Breadth of posterior segments

0.96

0.80

The booklets are nearly uniform in shape, which is much like that of
the claw of a cat. The breadth of base equals about half the length. At

[139] NOTES ON ENTOZOA OF MARINE FISHES. 857

the base of the proboscides the booklets have only about half the linear
dimensions of those at the middle and near the apex. They are simi-
lar in shape except perhaps a little more recurved at the point. The
hooklets are arranged in uniform spirals, which are about 0.01711'"1 apart-
Seven hooklets can be seen in each spiral on one side of the proboscis.

The proboscides bear some resemblance to those of T. bisulcatum
(Rhynchobothrium lisulcatum of my former paper), but are much smaller,
being about half the diameter, and the hooks are about half as long.
The hooks are also relatively more slender. The head and neck of T.
rob ust um also resemble that of T. bisulcatum, but are not so plump. The
edges of the bothria were covered with fine capillary bristles as in T.
tenue. They were, however, not so abundant, iior were they observed
at the apex of the head.

The segments in all but one of the specimens that I have yet seen
were much broader than long. In one, the posterior segments to the
number often or twelve, are squarish, and the last two or three a little
longer than broad. The cirrus bulb in the mature segments extends
from the marginal aperture, near the anterior edge, half the distance or
more to the median line, and inclined forward toward the anterior edge.
The vas deferens shows plainly, lying in voluminous coils at the base of
the bulb and along the median line. The ovary is a broad two-lobed
organ centrally placed. The ova lie along the median line. There yet
remains much to settle with respect to the disposition of the genitalia
of these segments which I have not yet studied from thin sections.

40. Tetrarhynchus bisulcatum Lt.
[Plate xiv, Figs. 10-12, and Plate xv, Fig. 1.]

Rhynchobothrium bisulcatum Lt. Report of U. S. Commission of Fish and
Fisheries for 1886, pp. 479-486, Plate IV, Figs. 9-23.

In my original description of this species I regarded the bothria as
two in number, but distinctly bilobed. Since writing the first descrip-
tion I have had an opportunity to study living specimens and have de-
cided to refer the species to the genus Tetrarhynchus. I was perhaps
misled by the close resemblance to Van Beueden's figures of Tetra-
rhynchus lingualis Cuv. (Rhynchobothrium paleaceum End. and Vail
Ben., Diesiug, Bevis. Ceph. Par., 294).

The only emendation necessary in the original description is to change
from " bothria two, divided into two distinct lobes," to bothria four, ar-
ranged in two lateral pairs. Also the female genital aperture is mar.
ginal, beside cirrus.

On the 25th of July, 1887, 1 obtained from the pyloric division of the
stomach of a dusky shark (Carcharias obscurus) a large lot of this spe.
cies. There were about four hundred of these parasites crowded into a
space of 8 or 10 inches in the narrow pyloric constriction of the stom-
ach. A portion of this part of the alimentary canal cut open so as to

858 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [140]

show the worms attached, is shown in Fig. 1, Plate xv. The bodies of
the living worms were very much crumpled and folded and the heads
and anterior segments were buried in the walls of the pylorus. On this
account they were very difficult to remove. Usually the scolices were
buried together in groups of from three to six or more in a common
cavity. These cavities or pits extended through the mucous and sub-
mucous coats into the muscular layers. The heads of many of the
specimens were yellowish green, and nearly all were characterized by
having a greenish baud at the base of the neck or a greenish tubular
neck.

In iny former description I recognized three distinct varieties. In
this lot the same varieties can be distinguished with, perhaps, a greater
tendency to intermediate forms. A living specimen, with mature seg-
ments and measuring only 32mm length, agrees in all essentials with
var. a. Two others, which were quite long and slender, measuring
280 and 330mm, respectively, answer, in the main, to the conditions
established for var. p.

In general the specimens were not much changed by immersion in
alcohol, hence the measurements already published for this species need
not be added to in these notes.

An interesting abnormal form was found in this lot. It consisted of
two slender but distinct strobiles with a single scolex. The strobiles
measured 25 and 65mm, respectively. This does not seem to be a mu-
tilated specimen, since the two strobiles are distinct as they emerge from
the cervical collar. The segments do not begin at once, and when they
do they make their appearance at different distances from the head. The
segments on the latter half of the longer chain agree in outline with
those of var. ft. The cirrus is quite distinct and emerges near the middle
of a margin, or a little in front of the middle and runs thence diagonally
to the anterior edge at the median line. There is no sign of lateral
apertures. The posterior segment is 0.76miu long and 0.66mm broad.

In this species, in general, the cirrus emerges near the margin not
far from the anterior edge of the segment. The only exception that I
have noticed is in the case of some individuals of variety /?, where the
cirrus emerges not far from the middle of a margin. In all cases, J
however, the cirrus and its bulb extend from the marginal opening
inward and forward until its base reaches almost to the anterior edge of

o

the segment at the median line. The cirrus is slender, smooth, and
tapering.

Anatomy of scolex. — I have not yet made a careful histological study
of this species, but in endeavoring to settle some points in the anatomy
of the mature segments I found it necessary to make thin sections of a
few segments, and at the same time stained a scolex with carmine and
cut it into transverse sections.

The muscular walls of the contractile bulbs are of surprising thick-
ness. The bulbs lie close together, the limiting membrane of one fusing s

[141] NOTES ON ENTOZOA OF MARINE FISHES. 859

with that of the other at the point of contact. The inner cavity, as
shown in these sections, is very small, being, in fact, but little more than
twice the diameter of the retractor muscle which it contains. The cav-
ity instead of being central is really at one side. In each case it is at a
side which adjoins one of the other bulbs, but so disposed that each of
the four cavities lies at one of the partitions which separate the bulbs
from each other. The thick wall of a bulb is composed of several, in
some places as many as six or seven, alternating layers of muscular
fibers, whose cut ends show that they run in alternating spiral di-
rections from one end of the bulb to the other. The layers are rather
thick, in some cases at least being equal to the diameters of a dozen
fibers. The retractor muscle, which is itself made up of a number of
parallel fibers, is usually oblong or elliptical in section, but sometimes
nearly circular.

The following maximum dimensions show the proportions of these
parts :

mm.

Diameter of the bulb 0.158

Diameter of inner cavity of bulb 0.039

Diameter of retractor muscle 0. 019

Thickness of muscular wall of bulb 0. Ill

Sections made near the anterior end of the head reveal a very dense
tissue throughout. They are divided into quadrants by two bands of
transverse fibers which bisect each other at the center. Toward the
outer edge these transverse fibers become indistinct amidst the denser
tissue of the outer part of the head. In each of the quadrants thus
formed one of the proboscis sheaths lies. The walls of the sheaths are
made up for the most part of fine circular fibers. In some of the sec-
tions the sheath, the proboscis, and the retractor muscle of the latter
could be plainly seen. The walls of the proboscides are thicker than
those of the sheaths, and like them are composed of circular fibers.
The sheaths are accompanied on all sides, except that which is turned
toward the central axis of the scolex, with strong longitudinal muscular
fibers.

Near each sheath on the inner side, or rather between each sheath
and the point at which the transverse bands of fibers cross, there is an
irregular circular cluster of granules. They indicate the presence of
longitudinal vessels, of whose exact nature I am not certain. They are
stained deeply by the carmine, and are quite different in appearance
from the cut ends of longitudinal muscle fibers. Towards the base of
the sheaths these vessels have a distinct limiting membrane. Their
cross-sections, in the mean time, become somewhat circular. They now
lie close to the proboscis-sheaths. They follow the proboscis-sheaths to
the anterior ends of the bulbs, where they disappear. I am inclined to
regard them as nervous vessels.

In the sections behind the bulbs the tissues appear rather spongy,
with longitudinal fibers interspersed. Towards the circumference there

860 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [142]

is a predominance of circular fibers, which form an indistinct layer and
in which a division presently takes place, the outer part and the gran-
ular tissue which is outside of it sloughing off to form the collar. Part of
the circular layer then goes to form the outer cuticular la;/ er of the body
and another part goes to form the inner cuticular layer of the collar.
In sections made through the anterior part of the body, still within the
collar, the latter now appears as a concentric circle of dense granular
tissue with a few circular fibers. The tissues of the body proper are,
first, a thin cuticular layer; then a thick layer of spongy tissue with
irregular open spaces and a few longitudinal fibers interspersed; next
a layer of longitudinal fibers, into which most of the longitudinal fibers
of the neck are now collected. This layer is about 0.027mm thick, and
surrounds a central core which is about 0.324mm long, from margin to
margin, and 0.035mm broad.

Sections of longitudinal vessels lie at the marginal extremities of the
central core. Of these there are three principal ones near each margin.
Two of these, at each margin, have definite outlines; the other, at least
at first, is somewhat indefinite. In some sections they are oblong, the
largest about 0.01lum in diameter; in others they are nearly circular and
as much as 0.016mm in diameter. These longitudinal vessels appear first
in sections immediately behind the contractile bulbs, before the inner
core is differentiated.

Anatomy of posterior segments. — In my former account of this species
I stated that the female genital aperture is lateral. In this I was mis-
taken, being misled by the median lateral aperture for the escape of
ova. A few segments were stained and cut into thin sections. In them
the vagina was traced from the ovary forward along the median line,
where it lay as a small tube, with short sinuous curves, to the base of the
cirrus bulb. It there turns abruptly towards the margin, and in some
can be traced for a short distance behind the cirrus bulb. It very soon
passes to the side of the bulb, and consequently in longitudinal sec-
tions disappears from view. The cirrus emerges not exactly on the
margin but a little way from the margin. The vagina appears to open
immediately beside the cirrus, between it and the margin, or, what is
more probable, the vagina and cirrus have a common marginal cloaca.
In some sections, which passed diagonally through the segment, the
tube of the vagina was seen lying close beside the cirrus bulb and near
its outer extremity. The cirrus, in these sections, is seen as a slender,
convoluted tube lying in the elongated bulb. The vas deferens is a
much convoluted tube, which lies in an irregular or pyriform mass in
front of the ovary. It enters the base of the cirrus bulb near the an-
terior edge of the segment. The ovary is centrally situated, about
.36mm broad and .16mm long. In some of the sections it seemed to be
made up of elliptical lobules, each containing a number of polygonal,
often nucleated cells, each of the latter about .008mm in diameter.

In segments which did not contain ova the walls are quite muscular.

[143] NOTES ON ENTOZOA OF MARINE FISHES. 861

They consist of an outer layer of fine muscular fibers crossing the lon-
gitudinal fibers of an inner layer at right angles. Beneath this there is
a fine granular layer, with a few longitudinal fibers. Some of the gran-
ules of this layer are distinctly nucleated. In sections of some of the seg-
ments there is a layer of longitudinal muscles in which the fibers are
arranged in rather thick parallel fascicles. The interior of the imma-
ture segments is, in great part, filled with the oval or elliptical sper-
matic capsules, .03 to .06nim in diameter, and containing granular cells,
some of which are nucleated, from .025 to .005"'m in diameter.

Sections of ripe segments show the entire segment to be filled with
ova, with the excep'.ion of a small space in the center, which is occu-
pied by the remnant of the ovary, and one of the anterior corners into
which the cirrus bulb is crowded. The ova are yellowish in color, with
unstained granular contents, measuring about ,014mm in diameter, and
for the most part with an extremely irregularly collapsed membranous
shell. Some ova were found near the margin in which the shells were
entire, and were then seen to be very thin and delicate and separated
by a clear space from the granular interior. These measured from
•028mm to .038mm in diameter, and the granular contents .022mm in diam-
eter.

The ova occur in these segments in enormous numbers. They fill
the segment to its extreme outer margins. The division between the
mass of ova of two adjacent segments was found to be reduced to a thin
partition .008mm thick. The marginal walls of the segments were re-
duced to about the same thickness.

SYNDESMOBOTHRIUM Diesing.

«

This genus is characterized by Diesiug as follows : Body articulate
tseniajform ; neck tubular, rounded at the base ; head tetragonal, with
four terminal prominent bothria attached to head by posterior margin,
cruciformly disposed, oval, slightly convex, joined with each other at
the base by a membrane ; proboscides four, filiform, armed, each one
running through a bothrium (pedicel) exctirrent at apex, long, re-
tractile in the neck. Genital apertures marginal ('?). In intestines of
marine fishes of tropical America.

Syndesmobothrium filicolle, sp nov.
[Plate xv. Figs. 2-4. J

A single specimen belonging to the genus Syndesmobothrium, without
mature segment, the neck attached to a linear oblong body (blastocyst)
and with the proboscides retracted was found in the spiral valve of a
sting ray (Trygon centrura) in August, 1884, at Wood's Holl, Massachu-
setts.

This description is necessarily so meager that I have hesitated to
bestow a specific name on the specimen which furnishes the data for it.

862 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [144]

The head is tetragonal transverse, cruciform. Bothria four, subcircu-
lar, convex, cup-shaped, each the termination of a short cylindrical
pedicel. They are arranged in a cruciform manner, but also somewhat
in pairs and capable of being directed either forward or backward in
pairs. Proboscides very long and slender, each one running through
a pedicel and emerging at the apex, apparently beside the bothrium
proper. Neck very long and slender, cylindrical, enlarging slightly at
the contractile bulbs and rounded at the base, tapering to a point, where
it is connected with the body (blastocyst) ; proboscis-sheaths spiral, con-
tractile bulbs linear oblong ; booklets long and slender, falcate ; blasto-
cyst linear oblong, a little longer than the head and neck.

Dimensions of alcoholic specimen, somewhat flattened: Length of
head and neck, 4.60mm ; length of blastocyst, 5.25mm j diameter, 0.76mm ;
breadth of head, about 0.50mm ; diameter of bothrium, 0.12mm ; diameter
of pedicel, 0.14mm; diameter of neck, 0.14to0.30mm at contractile bulbs;
length of proboscides about 3mm ; length of contractile bulbs, 0.84mm ;
breadth, 0.08mm.

The proboscides were retracted but the hooks could be seen through
the transparent neck. At the base of the proboscides they were about
0.032mmin length ; near the middle of the proboscides they were 0.06mm
long, with basal supports as much as 0.03mm wide. The hooks appear to
be of pretty uniform shape ; being long, slender, recurved, falcate, with
rather broad basal supports.

I have met with encysted forms similar to this in various species of
the Teleostei such as Pomatomus saltatrix, Cybium regale, etc. One
from the Spanish mackerel (Cybium regale) was described by me in the
American Naturalist for February, 1887, ujider the name of a larval
Tetrarhynchobothrium.

Family V.

Tetracotyleidce Diesing.

PARATJENIA, gen. nov.

Body tpeniseform, articulate. Head subglobose, with four small op-
posite, sessile bothria. Terminal os and sixteen protractile tentacular
proboscides. Genital apertures marginal.

This form appears to be related to the genus Tcenia. The tentacular

proboscides are probably hoinologues of the proboscis of avian Tccnlmdce.

•»

43 Paratcenia medusia,* sp. nov.
[Plate xv, Figs. 5-9.]

Head somewhat globose but variable according to state of contrac-
tion, wider than strobile. Bothria four, small, sometimes papilli-

* The reference of this species to the T(cnwd<x is provisional. Certain structural
peculiarities suggest the propriety of referring it to the Tetrabotliriidai near Eclienei-
bothrium.

[145] NOTES ON ENTOZOA OF MARINE FISHES. 863

form. Circular os at apex of head from which sixteen soft teutacle-
like proboscides may be protruded. Neck none. First segment short ;
succeeding segments often mouiliform, then lengthened ; last segments
four or five times as long as broad, loosely attached to each other.
Genital apertures marginal ; cirrus echiuate, ova numerous with thin
membranous shell. Strobile small, so far as observed not exceeding

Cmm

Habitat. — Trygon centrum, spiral valve, August 1, 3, and 10, 1887.
Wood's Holl, Massachusetts.

During the mouth of July and August, 1887, I made careful and
painstaking search for entozoa in the sting ray (Trygon centrum). On
three different occasions, in the course of these examinations, I found
a few small cestods in the spiral valve which I at first took to be frag-
ments or immature forms of some of the various species of the Tetra-
bothriidfc which I found at the same time in most of these hosts. On
one occasion, however, I examined a sting ray which yielded no eutozoa
except these small forms, a very minute Rhynchobothrium and a few
cysts from the stomach wall. When these small cestods were exam-
ined, while they were yet alive, they showed no signs of activity in the
sea- water in which they had been placed, and as the short chains of
segments all exhibited a tendency to fall to pieces readily, the idea
was naturally suggested that they were Tetrabothriidw which had been
introduced into the ray in a mature condition along with their proper
host and had succeeded in resisting the action of the digestive fluids
of the ray for a while, but were now succumbing to the influence of
their uncongenial surroundings.

On account of the number of larger and more • attractive new species
that were collected at the same time, these very small and apparently
unpromising forms were given but a superficial examination at first. I
found, however, that they possessed four bothria or acetabula and a ter-
minal opening at the apex of the head. It was only after the specimens
had lain for some time in alcohol and I had leisure to study them carefully
that their true nature was revealed. One is tempted, when doing syste-
matic work on any group, to pronounce each new form that meets his
eyes the most remarkable of all. I have become accustomed to having
my first notions, with regard to these soft-bodied forms, rudely shaken
by more careful subsequent study, but I think I have never encountered
any forms of entozoa that have proved to be so different from first con-
ceptions as these have done.

In the first place the worms are quite small. The longest living
specimen that was measured was less than 5mm. They must grow
somewhat longer than this, however, as an alcoholic specimen has been
found which measured Gmm. The chains of joints that remain attached
to the heads of alcoholic specimens are few of them as much as 2mm in
length. The head is of various shapes. When the tentacular probos-

864 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [146]

cities are retracted it is usually globular, often truncated at the apex.
Again it may be elongated glandiform or pyriform on account of a con-
striction behind the bothria.

The bothria, four in number, are opposite and of varied appearance.
In some cases they are sessile and difficult to see, in others they are
elevated on low papilla?. The latter usually stand at right angles to
the axis of the body, although in cases where the proboscides are re-
tracted, they are sometimes directed forward. In one case they were
so arranged as to give to the head a decidedly cuboidal shape. In this
case the diameter of the head was .36nim, the outside diameter of a tubu-
lar bothriuin was .OSram, the inside diameter .04mm. Seen from the front
the bothria made the four corners of a square. The bothria are some-
times on the anterior part of the head, this of course only when the
proboscides are retracted, sometimes about the middle.

The most remarkable changes take place in the head when the ten-
tacular proboscides are protruded in whole or in part ; these proboscides
are sixteen in number ; among the lot of thirty specimens, more or less,'
there were fortunately four or five which had the proboscides protruded,
and of this number two at least in which they were fully protruded so
as to form a terminal rosette-like cluster, made by the sixteen radiating
tentacular-like proboscides. It is probable that these organs can be ex-
tended farther than was indicated in the alcoholic specimens. In one
specimen the head was .5mm in length, including the terminal rosette j
diameter of head behind bothria, .16mm; diameter of rosette, ,34ram; length
of bothrial papilla about .06mm ; diameter of first segment .06mm.

Only a few of the more frequent shapes which these scolices assume
have been mentioned, but enough have been alluded to which, together
with the sketches, should make future identifications reasonably cer-
tain. It is to be hoped that the polymorphous character of the head of
this species may not be made the occasion of multiplying species un-
necessarily.

An illustration is here afforded of the importance of preserving every
specimen, and of not neglecting what may appear to be unimportant
fragments. It is certainly possible to have obtained one-half of the
specimens of this species that are in my collection without finding any
that show the real structure of the head .

The proboscides are soft, tentacle-like, slender when fully extended •
they are probably extended by evagiuation, although of this fact I am
not yet certain ; when all are fully extended they are found to be exactly
sixteen in number, and form a terminal crown or rosette; in this con-
dition they resemble the expanded tentacles of a sea-anemone. Some-
times only a few of these tentacles are protruded, and in one instance
a single tentacle arose from the apex of the head and was surrounded
closely by the four bothria ; if found by itself it would have been a puz-
zle indeed and might have furnished the type of a new species. The
longest tentacle that was observed measured .2mm in length, and was

'[147] NOTES ON ENTOZOA OF MARINE FISHES. 865

,02mm in diameter at base. When the tentacles are retracted, the head
is terminated by a circular opening; the sheath or cavity in which the
jtracted tentacles lie sometimes extends to, and sometimes beyond, the
>othria ; at other times it is wholly in front of the bothria, in which
ises the anterior part of the head is prolonged; in one case the length
>f the head was .34mm and the depth of the sheath .18mm.

The largest alcoholic specimen yielded the following measurements :
jength. 6mm; length of head, .28"""; diameter of head, .23mm ; diameter
>f first segment, .12mm; length of last segment, 1.8mm; breadth, .22rara.
?he length of the head in a living specimen was .48mm, length of stro-
)ile 4.8mm. In most of the specimens the first distinct segments begin,
immediately behind the head. In some, however, there is a slight ob-
turation of the first segments on account of differences of contraction.
In the latter cases the first segments have the appearance of a short
neck and are broader than in those cases where the first segments are
distinct.

In the measurement often alcoholic specimens the maximum length
of head was .5mm, minimum .22mm, average .314mm; maximum breadth
.3Gmm, minimum .24mm, average .276mm. The average length of first seg-
ment in these specimens was .038mm, maximum .04mm, minimum .02mm,
while in three of the specimens they were obscure. The average breadth
if the first segment was .09mra, maximum .16mm, minimum .06mm.

Usually the first two or three segments are quite short and crowded
ogether, while these are succeeded by a few rounded segments which
impart to that part of the strobile a moniliform appearance. The suc-
eeding segments increase in length rapidly, are distinctly separated
rom each other, and become detached easily. Very often there is a
istiuct constriction near the anterior end, with a corresponding swell-
ing in the middle. The posterior mature segments are much elongated.
In one specimen the last two proglottides, which are filled with ova, are
together almost as long as the remainder of the strobile. The shape of
.he mature segments is quite characteristic. They are elongated, arcu-
,te, of nearly uniform breadth throughout, except at a point near the
anterior end, where they are narrowed by a neck-like constriction.
They are rounded, blunt, and slightly swollen at each extremity. Ova
fill the interior completely, with the exception of the cirrus and its
ulb, the only part of the genitalia that persists in the mature segments,
o within .28mm of the anterior end, where the uterine cavity stops
Jbruptly, being limited by a transverse partition. The interior of the
j segment is, indeed, converted into a sac for containing ova. The an- '
I terior end of the mature segment in front of the transverse partition
.'! appears to be composed of the muscular walls alone. It probably re-
; tains some contractile power, and serves as a kind of locomotive organ
for the free proglottis.

The ova consist of globular masses of granules or nuclei, surrounded
|y a thin transparent envelope, which is sometimes collapsed and irregu-
II. Mis. 1.'33 55

866 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [148]

lar in outline. The diameter of the granular or nuclear masses range
from .02 to .027ram, that of the entire ovum from .03 to .05mm. In
case, in a stained segment, there were observed amoug these grauula
masses with the transparent envelope a small cluster of amber-colorec
collapsed shells of ova about .036 and .022mm in the two diameters.

The cirrus was invagiuated in every case, but could be plainly seei
through the walls of the segment when the latter were rendered trans
parent in glycerine. The retracted cirrus is pyriform in shape, th<
inner end is the larger, directed anteriorly and a little toward one of the
lateral sides. It is very thickly beset with fine bristles. It measurec
.094mm in length, and .05mm in diameter, narrowing to ,02mm near
external aperture. The external opening of the cirrus is near
margin, about the middle of the segment. In the posterior mature
ments, which were apparently slightly distorted, the genital apertun)
was situated from the margin. a distance equal to one-fourth the breadtl
of the segments.

The ovaries are elongated, glandular, paired organs lying near thJ
posterior end of the segment, one on each side of the median line. ThJ
vagina appears to open beside the cirrus on its posterior side. ThiJ
fact, however, requires further verification. In segments which prc
cede the mature ova bearing segments the retracted cirrus was
to lie nearly transverse to the axis, inclined a little forward at the inue|
end, and equal in length to about three-fifths of the segments.

The testes are represented by a few globular or oval bodies
along the middle line from the front end of the ovaries to the anteriol
end of the segment. These range iu diameter from .055mm in sotn
specimens to over .08mra iu others. One of the largest of these oval U
tides measured .086 and .047mm in its two diameters. In those segment
in which the testes are best developed the ovaries are scarcely at all de
veloped. Furthermore, the transition from segments with large testi
cles and incipient ovaries, to those in which the interior is completely
filled with ova, is quite abrupt.

The exceeding sraallness of this anomalous worm has doubtless cause*
it to be overlooked heretofore, while the extreme variability of the heac
might easily lead collectors to regard it as simply fragmental remain
of other and larger cestods with which the sting ray abounds.

•[149] NOTES ON ENTOZOA OF MARINE FISHES.

List of the Entozoa described in Hits paper, and their hosts.

867

. No

Entozoa.

Host.

Page.

Plate.

Fig-
ures.

1

o

*j

3

4
5
6

7

8

9
10
11

12
13
14
15
10
17
18
!!>
20
21
22
23
21

25

26

27
28
2U
30
31
32
33
31
35
3fi

37

38

3'J

40

41
42

Dibothrium restiforme sp. nov

Tylosurus c&ribbcFits

I

1-16

Dibothrium manubriforme Lt

TetrapluruK albidus. Histio-
phorus gladius.

Limandafcrruginea. Lophopsetta

maculata.

Mold rotunda

Dibothrium punctatum Rud ...

II

II
III
III
III
IV
IV
V

1-4

:> 18

Dibothrium microcephalum Rud

Dibothrium plicatum Rud

Siphias gladius

1-6
7 10

Dibothrium rugosum Rud

Gadus tnorrhua

^ItitAo&othritcm 2aci?iia(um sp. nov

Carchari&s obscurus <

10-13
1-3
4-9
1-2

A.nthobothrium pulvinatum sp nov

Tt'ygon ccntruro, <

Echeneibothrium variabile sp. nov

Raia erinacect

Rhinebothrium flexile gen. et sp.nov ...

Rhinebothrium cancellation gen. et sp.
nov.

Rhincbothrium longicolle gen. et sp. nov
Spongiobothrium variabile Lt

Trygon centrura

V

V

VI

3-5
G-8

V-i

Rhinoptera quadriloba

jtfyliobatis freminvillei

Tryjon centrura

Discocephalum pileatum gen. et sp. nov .
PhyUobothriumfoltatum sp. nov
Anthoccphalum gracile gen. et sp. nov . .
Orygmatobothrium anqustum Lt -

Carcharias obscurus

X

VI
VII
VII
VII
IX
IX

1 7

Trygon centrura

5-10
1-2
3

4
2r4
5-9

Trygon centrura

Carcharias obscurus .

Crossobothrium laciniatum Lt

Odontaapiti littoralis

Lecaniccphalum pcltatum gen. et sp. nov
Tyloccphalumpingue gen. et sp. nov
Calliobothrmm verticillatum Rnd

Trygon centrura

Rhinoptera quadriloba

Mustelus canis

Calliobothri-u m cschrichtii Van Ben

Mustelus ctznis

VII
VIII

5-12
1 7

Acanthobolhrium paulum, sp. nov
Phoreiobothriu in lasium Lt

Trygon centrura

Carcharias obscurus

Platybothrium cervinum gen. ot sp. nov
Thysanocephalum crispum Lt

Carcharias obscurus <

VIII
IX
X
XI
XI
XI
XI
XII
XII
XII
XII
XIII
XIII
XIII
XIV
XIV
XIV
XIV
XV
XV
XV

8-10
1
8-9
1-2
3-11
1J-17
18-20
1-2
3-6
7-9
10 12

Galcocerdo tigrinus

Rhy nchobothrium bulbifcr Lt

Hustelus canis

Rhynchobothrium tumidulum sp. nov . . .
Rhynchobothrium hispidwn sp. nov

Mustelus canis

Trygon centrura

Rhynchobothrium longispine sp. nov

Tryc;on centrura

Rhwchobothriurn tcnuispine sp. nov
Rhynchobothrium hcterospine sp. nov
Rhynchobothrium imparispine sp. nov .. .
Rhynchobothrium wagneri sp. nov

Try non i-enlrura

Muttehis canis

Raia erinacea

Trygon centrura

Rhy nchobothrium loin entaceum Dies

Mustelus canis

1-3

4 8

Rhynchobothrium longicorne sp. nov
Otobothrium crenacolle gen. et sp. nov...

Tctrarhynchus tenue sp. nov

Odontaspis littoralis

Sphyrna zygcena }

9-15
1-4
5-6
7-9
10-12
1
2-4
5-9

Trygon centrura

Tetrarhynchus robustum sp. nov

Trygon centrura,

T&trarhynchus bisidc&tum Lt

Carcharias obscurus J

Trygon centrura. .

Syndcsmobothrium filicolle sp. nov

Paratcenia mcdmia geu. et sp. nov

Tryqon centrura, .

WASHINGTON AND JEFFERSON COLLEGE,
Washington, Pa,., October 6, J888,

8G8

REPORT OF COMMISSIONER OF FISH AND FISHERIES. [150

PLATE I.

Dibothrium restiforme, sp. uov.

FIG. 1. Adult strobile, from life, X H.

FIG. 2. Lateral view of bead, from life, X 4^.

FIG. 3. Anotber view of bead, from life, X 3.

FIG. 4. Marginal view of bead, sbowing continuation of fossa into beginning o
lateral groove, from life, X 3.

FIG. 5. Head and anterior part of body, from alcobolic specimen, X 9.

FlG. 6. Outline of mature segments, sbowing position of uterine aperture, X 12.

FIG. 7. Outline of same, sbowiug opposite side of strobile with genital aperture
X 12.

FIG. 8. Posterior segments witb ova, from alcobolic specimen, X 30.

FIG. 9-16. Outline of transverse sections of bead, eacb magnified about 24 diame
tcrs. Fig. 9, section near apex ; Figs. 10-12, sections between apex am
middle; Fig. 13, about middle of bead; Figs. Hand 15, between uiiddl
and base; Fig. 16, at base of bead bebiiid fossa;. Tbe lateral groove
appear at tbe margins of tbe sections.
All figures made by Margaret B, Liukm.

Report U. S. F. C. 1887.— (To face page 150.) Linton. Entozoa.

PLATE I.

iW.333P."''.-,"-C;-'j5

ES& &.*&''•'"', ' VV -SSfS

«H*:-,§:

^^^^^fe/^^v^^^^^2^

870 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [152]

PLATE II.
Diboihrium piinctatum Rud.

FIG. 1. Lateral view of bead and first segments, from life, x 27.

FIG. 2. Marginal view of same, from life, X 27.

FIG. 3. Lateral view of head, alcoholic specimen made transparent in oil of cloves

X 22.
FIG. 4. Posterior part of strobile, showing characteristic grouping of segments, X 6.

Dibothrium microcephalum Rud.

FIG. 5. Far. a, marginal view of head and first segments, from alcoholic specimen,
X 24.

FIG. 6. Posterior end of strobile of same. X 15.

FIG. 7. Far. /3. Marginal view of head and first segments, from alcoholic specimen,
X 24.

FIG. 8. Outline of posterior segments of same, X 4.

FIG. 9. The same enlarged, showing ova, X 15.

FIG. 10. Transverse sections near middle of body ; a, ovary ; 6, vas deferens ; c, testes;
d, cirrus bulb and cirrus ; e, layer of longitudinal muscle fascicles ; /,
ova, X 33.

FIG. 11. Collapsed ova, x about 200.

FIG. 12-18. Transverse sections of head, X 24 ; Fig. 12, near apex, showing cut ends
of longitudinal muscles with a few transverse muscles ; the beginnings
of fosste are indicated by crescent-shaped clear spaces with their con-
vexities turned toward each other; Fig. 13, transverse muscles more
numerous, crossing each other at right angles, anterior ends of lateral
fossae clearly outlined ; Fig. 14, sections near anterior end of head, behind
apical cushion; Fig. 15, section near middle of head; Fig. 16, section
towards base of bothria ; Fig. 17, section near base of head, bothria no
longer united with head ; Fig. 18, section through first segment ; an outer
concentric ring is beginning to separate from the inner core to form the
posterior salient border of the segment.
All figures made by Margaret B. Linton.

Report U. S. F. C. 1837. — (To face page 152.) Linton. Entozoa.

PLATE

mgz

1300

872 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [154]

PLATE III.
Diboihrium plicatum Rud.

FIG. 1. Mature strobile after lying for a short time in sea water, from life, X H.

FIG. 2. Young specimen found wholly inclosed in a cyst-like cavity of the rectitial
wall, from life, X 4.

FIG. 3. Lateral view of head of same, X 4.

FIG. 4. Posterior segments of adult strobile, from alcoholic specimen, X 10. The
sketch was made from a segment made transparent in oil of cloves, a, cir-
rus and cirrus bulb. The relatively large ova are plainly seen through
the transparent walls of the segment.

FIG. 5. Ovum, alcoholic, X about 200.

FIG. C. Longitudinal section through the postero-median part of the strobile; a, a.
cirrus bulbs in marginal prolongations; 6, longitudinal muscles; c, ova:
d, granular masses, presumably testes, x 15.

Dibothrium rugosum Rud.

FIG. 7. Longitudinal section through ripe segments; a, fascicles of longitudinal
muscles; b, b, partitions separating adjacent segments; c, ova filling
the interior of the segments ; d, shred of connective tissue; other sitnilai
shreds are shown lying among the ova, X 21.

FIG. 8. Transverse section of a ripe segment ; a, lateral aperture ; 6, b, layer of fas-
cicled longitudinal muscles ; c, shred of connective tissue extending iuU
the interior of the segment which is filled with ova.

FIG. P. Transverse section of antero-mediau segment, near the point where the ova
first appears ; a, position of cirrus and its bulb ; b, vas deferens ; c, c
layer of fascicled longitudinal muscles.

FIG. 10. Ova, alcoholic, X 200.

Anihobothrium laciniatum, sp. nov.

FIG. 11. Var. filicolle, head and neck from life, X 34.
FIG. 12. Var. brevicolle, head and neck from life, X 38.
FIG. 13. Var.filicolle, front view of head, compressed, from life, X 42.
All the figures made by Margaret B. Linton.

Report U, S. F. C. 1887.— (To face page 154.) Linton Entozoa.

PLATE III.

'¥

874 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [156]

PLATE IV.

Anthobothrium laciniatum, sp. nov.

FIG. 1. Var. brevicolle. Outline of strobile, from life, X 15.

FIG. 2. Head of au alcoholic specimen with the thin faces of the bothria protrudingi

X 30.
FIG. 3. Outline of strobile, from life, an occasional form, X 6.

Anthobothrium pulvinatum sp. nov.

FIG. 4. Hoad and part of neck, lateral view, from life, X 8.

FIG. 4a. Part of face of bothrium of alcoholic specimen.

FIG. 5. View of head from behind, showiug pedicels and cushion-like bothria, from
life, X 4.

FIG. 6. Outline of posterior segments, from life, X 3.

FIG. 7. Spines of cirrus, from life, X about 750.

FIG. 8. Transverse section at base of head ; a, thick layer, composed for the most
part of longitudinal muscles, not shown in sketch; b, layer of circular
fibers; c, c, the two pairs of aquiferous vessels, X 54.

FIG. 9. Transverse sectiou a short distance back of head ; a, a, aquiferous vessels ;
b, b, lateral nerves ; c, c, part of connective tissue fibers seen in the sec-
tion.
Figure 2 by the author, all others by Margaret B. Linton.

Report U. S. F, C. 1887. — (To face page 156.) Linton. Entozoa.

PLATE IV.

876 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [158]

PLATE V.
Anthobothrium pulvlnatum, gen. et sp. nov.

FIG. 1. Diagrammatic sketch of transverse section of head and pedicels of bothria ;
a, central nervous mass ; b b, nerve masses of pedicels ; c, c, commissures
connecting central mass with masses of pedicels ; d. d, nerves from nerve
masses of pedicel to bothria ; e, transverse muscles. Only a small part
of the musculature is shown ; //, aquiferous vessels, X 40.

FIG. 2. Anatomy of mature segment as revealed in longitudinal section ; a, vas def-
erens ; b b, ovaries; c, shell gland; d, vagina; e, longitudinal muscles;
/, cirrus, X 14.

Rhinebothrium flexile, gen. et sp. nov.

FIG. 3. Strobile, outline from life, details of last two segments filled in from alco-
holic specimen, X 22.

FIG. 4. Head and neck of same, from life, X 45.

FIG. 5. Disposition of aquiferous vessels in neck and bases of pedicels, from life,
compressed and greatly enlarged.

Rhinebothrium cancellatum, sp. nov.

FIG. G. Head and neck, from life, X 36.

FIG. 7. Diagram of bothrium showing arrangement of loculi, X 45.
FIG. 8. Side view of single bothrium and its pedicel, outline from life, X 36.
Fig. 1, by the author, all others by Margaret B. Liuton.

Report U. S. F. C. 1887.— (To face page 158.) Linton. Entozoa.

PLATE V.

-? 3 30

878 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [160]

PLATE VI.

Rhinebothrium longicoUe, sp. uov.

FIG.
FIG.

1. Strobile, from life, X 18.

2. Head and neck of same, X 36.

FIG. 3. Diagram of bothrium showing plau of loculi, X 56.
FIG. 4. Side view of bothrium with its pedicel, from life, x 30.

Phyllobothrium foliatum, sp. nov.

FIG. 5. Head and neck, lateral view, from life, X 22. In this sketch the aquiferous
vessels in the neck and bothria, the spiral fascicles of muscles iu the
neck and pedicels aud the reticulated faces of the bothria are shown.

FIG. 6. Strobile, outline from life, x 3.

FIG. 7. Marginal view of head and neck, outline from life, X 12.

FIG. 8. Posterior segments, from life, X 12.

FiG. 9. Strobile, from alcoholic specimen, usual form.

FIG. 10. Strobile with attenuated neck, from alcoholic specimen.
All the figures made by Margaret B. Liaton,

Report U. S. F. C. 1887. — (To face page 160.) Linton. Entozoa

PLATE VI.

23

880 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [162]

PLATE VII.
Anthobothrium gracile, geii. et sp. nov.

FIG. 1. Head and neck of living specimen, X about 50.

FIG. 2. Head and neck of same individual in alcohol, X about 50.

Orygmatobotlirium angustum Lt.
FIG. 3. Outline of head and neck, from life, X 21.

Crossobothrium laciniatum Lt., var. lo^gicoUe.
FIG. 4. Outline of strobile, from life, X 8.

Calliobothrium eschrichtii Van Ben.

FIG. 5. Head of living specimen, X 20.

FIG. 6. Bothriura with edges appressed, from life, X 20.

FIG. 7. Posterior segment, from life, X 30.

FIG. .w. Ovum undergoing segmentation, from life, X about 115.

FIG. 9. Another ovum, with granular stellate interior, also undergoing segmentation,

from life.

FIG. 10. Outline of mature segment with ova issuing from the margin, from life.
FIG. 11. Outline of strobile, from alcoholic specimen, X 12.
FIG. 12. Hooks of a single bothriuui, with part of the musculature, X 200.
All the figures made by Margaret B. Liutou.

Report U. S. F. C. 1887.— (To face page 162.) Linton. Er.tozoa.

PLATE VII.

882 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [164]

PLATE VIII.

Acanthobothrium pantiim, sp. nov.

FIG. 1. Outline of strobile, from life, X 15.

FIG. 2. Head of same at rest, X 24.

FIG. 3. Same with one pair of bothria thrust forward, X 27.

FIG. 4. Head of alcoholic specimen, X 40.

FIG. 5. Hooks of a single bothrium with a part of the musculature, X about '200.

FIG. 6. Posterior segment with everted cirrus, from alcoholic specimen, X 27.

FIG. 7. Cirrus, X about 200.

Platylothrium cervintim, gen. et ep. nov.

FIG. 8. Head and neck of living specimen nfter it had lain iu sea-water an hour ox-
more. The head was very flat and thin, and semi-transparent, X £>H.
FIG. 9. Posterior segments, in glycerine, X 40.

FIG. 10. Set of hooks belonging to a single bothriuin, X about 200.
All the figures made by Margaret B. Linton. .

Repor: U. S. F. C. 1887.— (To face page 164.) Linton. Entozoa.

PLATE VIII.

884 KEPORT OF COMMISSIONER OF F1S1I AND FISHERIES. [166]

PLATE IX.

Platybolhrium cervinum, geu. et up. nov.
FIG. 1. Outline of living strobile, x 12.

Lecanicephalum peltatum, gen. et sp. nov.

FiG. 2. Outline of living strobile, X 27.

FIG. 3. Top view of head of same, X 27.

FIG. 4. Posterior segments of same, compressed, X 27.

Tyloceplialum pingue, geu. et sp. nov.

FIG. 5. Outline of living specimen, x 3.

FIG. 6. Head and neck of living specimen, x 18.

FIG. 7. Outline of posterior segments, x 24.

FIG. 8. Head and neck of same individual, when made transparent in oil of

cloves, X 24.
FIG. 9. Outline of same, showing posterior part of head at its junction with the

neck, X 24.
All the figures made by Margaret B. Linton.

Report U. S. F. C. 1887.— (To face page 166.) Lmton. Entozoa.

PLATE IX.

t

StTr

886 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [168]

PLATE X.
Discocephalum pileatum, gen. et sp. nov.

FIG. 1. Var. a. Head and neck, from life, X 9.

FIG. 2. Var. (3. Head aiidjieck of living specimen, X 9.

FIG. 3. Another view of the same, X 9.

FIG. 4. Outline of median segments, from life, X 6.

FIG. 5. Outline of posterior segments, from life, var. a, X 6.

FIG. 6. Outline of section through head, X 38.

FIG. 7. Section of mature segment, X about 8; a, a, ovaries; ft, b, uterine cavities with
clusters of ora ; b', !>', uterine cavities without ova; c, vagina; d, base
of iuvagiuated cirrus; c, e, convolutions of the vas dtfereus; /,/, testes.

Rhynchobothrium lulllfer Lt.

FIG. 8. Free proglottis, from life, X 15; a, bulb of cirrus partly protruding from
margin of segment ; I, vagina, near its exterior opening ; c, enlargement
of vagina into a receptaculum seminis ; d, d, vessels of the water- vascular
system ; e, e, spermatic capsules of testes ; /, cirrus bulb with vas deferens
entering the anterior part of the inner extremity; g, g, ova: /*, posterior
coils of vas defereus.

FIG. 9. Cirrus of same everted with escaping spermatozoa, from life.
All figures made by Margaret B. Liuton.

Report U. S. F. C 1887.— (To face page 168 ) Linton. Entozoa.

PLATE X

888 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [170]

PLATE XI.
Rhynchobothrium bulbifer Lt.

FIG. 1. One view of proboscis, from youug specimen, X about 400.
FIG. 2. Principal forms of larger booklets, X about 400.

NOTE.— For additional figures of this species see TJ. S. Fish Commission Report for
1886, p. 508, Plate v. Figs. 17 and 18, under R. tenuicolle.

Rhynchobothrium lumidulum, sp. nov.

FIG. 3. Strobile, from life, X 15.

FIG. 4. Lateral view of bead of same, botbria directed forward, from life.

FIG. 5. Top of bead of same, from life ; tbe botbria are not usually so strongly ernar-

giuate in alcobolic specimens.
FIG. 6. Lateral view of bead at rest ; from life.
FIG. 7. Proboscis, at base, X about 400.
FIG. 8. One view of proboscis aborit the middle, x about 400.
FIG. 9. Anotber view of proboscis near tbe middle, X about 400.
FIG. 10. Embryo(?). from life, X about 200.
FIG. 11. Enibryo(f), from alcobolic specimen, X about 200.

lihynchobothriiim hispidum, sp. nov.

FIG. 12. Strobile, outline from life, some of tbe details supplied from alcobolic spec-
imen, X 45.

FiG. 13. Strobile, from life, X 30.

FIG. 14. Outline of bead, botbria directed forward ; from life.
FK;. 15. One view of proboscis, middle, X about 400.
FIG. 16. Anotber view, near middle, X about 400.
FiG. 17. Mature segment, from alcobolic specimen, X 27.

s Rhyncliobolhrium longispine, sp. nov.

FiG. 18. Head and neck, from alcobolic specimen, X 27.
FIG. 19. One view of proboscis, X about 400.
FIG. 20. Anotber view of proboscis, X about 400.
All tbe figures made by Margaret B. Linton.

Report U. S . F. C. 1387.— (To face page 170.) Linton, Entozoa.

PLATE XI.

S3

jjfr

t*

•\

t*

\

X-,..

t*

\
\

t '1

7

^-^ « £ «

<^r «t ^ a- ff

^////-

890 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [172]

PLATE XII.
Ehynchobothrium tennispine,sp. nov.

FIG. 1. Proboscis, near apex, X about 900.
FIG. 2. Tumid base of proboscis, X about 900.

Rhynchobothrium heterospine, sp. nov.

FIG. 3. Head and neck, from alcoholic specimen, X 27.

FIG. 4. Principal forms of booklets, highly magnified.

FIG. 5. Portion of proboscis, X about 400.

FIG. (J. Posterior segment, from alcoholic specimen, X 4$ ; a, hilum left by separa-
tion of this from the preceding segment ; b, the characteristic notch form-
ing the marginal genital aperture.

lihynchobothrium imparispiiie, sp. uov.

FIG. 7. Head and neck, from alcoholic specimen, X 15.
FIG. 8. Proboscis near middle, X about 200.
FIG. 9. Proboscis near apex, X about 200.

Rhynchobothritim wagtneri, sp. nov.

FIG. 10. Strobile, outline from life, details of last segment filled in from alcoholic

specimen, X IB.
FIG. 11. Base of proboscis, showing the arrangement and relative sizes of the basal

hooks and the single large hook. The latter lies on the outer side of the

proboscis as shown in Fig. 10, X about 400.
FIG. 12. Proboscis near apex, X about 400.
All the figures made by Margaret B. Linton.

Report U. S. F. C 1887.— i To face page 172.) Linton. Entozoa.

PLATE XII.

<?V#.2

892 RKPORT OF COMMISSIONER OF FISH AND FISHERIES. [174]

PLATE XIII.
lihynchobothrium lomentaceum Diesing.

FJG. 1. Head and neck, from life, x 4-J.
FIG. 2. Fragment of strobile, from life, X 4-J.
FIG. 3. Part of proboscis-, x about 200.

Bhynchobothrium longicorne, sp. nov.

FIG. 4. Head and neck, from alcoholic specimens, x 12.

FIG. 5. Posterior segments, from alcoholic specimens, X 4£.

FIG. 6. Tumid base of proboscis, x about 200.

FIG. 7. Middle of proboscis, X about 200.

FIG. 8. Proboscis near apex, X about 200.

Otobothrium crenacolle, gen. et sp. nov.

FIG. 9. Strobile, outline from life, details of last segment supplied from alcoholic

specimen, x 30.

FIG. 10. Lateral view of head, from life, bothria appressed in front, X 54.
FIG. 11. Another view, from life, bothria separated in front, X 54.
FIG. 12. Otosac, retracted and forming a ciliated pit, from alcoholic specimen, X

200.

FIG. 13. Otosac, everted and forming a ciliated papilla.
FIG. 14. Proboscis near base, X about 900. The small booklets are not always easily

seen.

FIG. 15. Proboscis, usual appearance, X about 900.
All the figures made by Margaret B. Liiiton.

Report U S. F. C. 1887.— (To face page 174.1 Linton. Entozoa.

PLATE XIII.

894 REPORT OP1 COMMISSIONER OF FISH AND FISHERIES. [176]

PLATE XIV.

Otobothrium crenacolle, gen. et sp. uov.

FIG. 1. Outline of strobile, from life, X 8.

FIG. 2. Outline of a more slender strobile, from life, X 10.

FIG. 3. Proglottis, from alcoholic specimen, X 18 ; a, a, ovaries.

FIG. 4. Proglottis, the central portion tumid on account of an aggregation of ova ;

the size of the latter is somewhat exaggerated in the sketch; from an

alcoholic specimen, x 12.

Tetrarhynchus tenue, sp, nov.

FIG. 5. Outline of strobile, from life, X 21.

FIG. 6. Proboscis, X about 400.

>

Tetrarliynchus robustum, sp. nov.

FIG. 7. Head and neck, from life, X 36.

FIG. 8. Proboscis, X about 400.

FIG. 9. Posterior segments with ova, from life, X 24.

Tetrarhynchus blsulcatum Lt.

FIG. 10. Outline of section through base of bothria, X 24; a, a, sulci separating the
bothria of the lateral pairs' from each other; b, b, marginal spaces separ-
ating the pairs of bothria ; c, the four contractile bulbs of the probos-
cides ; for an enlarged sketch of one of these sections see Fig. 12.

FIG.. 11. Outline of section through the tubular neck and contractile bulbs, X 24.

FIG? 12. Transverse section through a contractile bulb, X about 200: a, interior
cavity which in life is filled with a fluid containing a few refractile
granules, the function of the fluid, when compressed, being to evert the
proboscis ; 6, section of retractor muscle ; c, section of muscular wall of
the bulb, showing the alternating layers of diagonal muscles.
All the figures made by Margaret B. Liutou,

Report U. S. F C. 1887.— (To face page 176. j Linton. tntozoa.

2

PLATE XIV.

^

896 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [178]

PLATE XV.
Tetrarhynchus Msulcatum Lt.

FIG. 1. Portion of pyloric division of the stomach of Carcharias obscurus with the para-
sites attached to the mucous membrane. In some cases two or more
scolices are buried in a common pit, X 1-J.

Syndesmobothrium filicolle, sp. nov.

FIG. 2. Sketch of alcoholic specimen, X 15. The specimen is immature and the pos-
terior part a is evidently a blastocyst from which the anterior part or
scolex has been everted.

FIG. 3. Hooks, the smaller ones from the base, the larger from the middle of a pro-
boscis, X 200.

FIG. 4. View of top of head, from alcoholic specimen, x 50.

Paratasnia medusia, gen. et sp. nov.

FIG. 5. Strobile; outline from living specimen ; details of anatomy supplied from alco-
holic specimen, x lo. The last two segments are filled Avith ova. The
tentacular proboscides were everted after the specimen had been placed
in alcohol.

FIG. '). Outline of strobile, from alcoholic specimen, the tentacular proboscides re-
tracted, X 18 ; a, terminal os into which the proboscides are retracted.

FIG. 7. Outline of strobile with three of the tentacular proboscides protruding, from
alcoholic specimen, x IB.

FIG. 8. Top of head, all the tentacular proboscides extended, making a terminal
rosette, or sixteen-rayed crown, from alcoholic specimen, x 200.

FIG. 9. Side view of head showing tentacular proboscides and two of the bothria,

from alcoholic specimen, X 200.
Figures 6, 7, 8, and 9, by the author, the others by Margaret B. Linton.

Report U. S. F. C. 1G87. — (To face page 178.) Linton. Entozoa.

PLATE XV.

All

A:

A:

A-
it

[179]

NOTES ON ENTOZOA OF MARINE FISHES.

897

INDEX

[NoTB. — The references are to page-figures in brackets.]

Page.

Acanthobothriam 2,3,91,98,102

coronatum 98

dujardinii ... 98,101

eschrichtii

panlum, anatomy of

description of.
dimensions of.
habitat of

Acanthocephala. .
Alutera schcepfii .

94
100
98
99
99
2
19

Anthobothrium 36, 81

auriculatum 60

cornucopia 37

giganteum 41

laciniatum 79

anatomy of 40

description of. 36

dimensions of. 38, 39

habitf^of 37

musteli 47,78,81

pulvinatum 47

anatomy of. . 44

description of 40

Anthocephlanm 1

description of 76

gracile 77

description of 76,77

habitat of 77

Aspidorhynchus 135

infnlatus 137

Auxiliary acetabula 36

Bothriocephali 98, 1 35

Bothriocephalus 4

coronatus 98

flos 60

microcephalus • 18

plicatua 28

punctatus 13

rngosus 32

sagittatns 18

t run cat us 28

tumidulus 57

Brevicolle 37

Calliobothrii 98

Calliobothrium 2,91,98,102,131

elegans 94

eschrichtii 94, 95, 108,111

anatomy of 95

dimensions of . . 95

verticellatum 92,94, 108, 111

anatomy of.. 92

H. Mis. 133 57

Page.

Carcharias 78

obscurus 2, 37, 63, 64, 66,

79, 101, 102, 104, 139

Centifolium 60

Cepola rubescena 127

Cestoidea 4

Cottus 14

Craugon vulgaris 48, 122

Crossobothrium 1, 76,81

laciniatum 81, 82

dimensions of . . 83

longicolle 82

Cylindrophorus 102

Dibothria 4

Dibot hriorhy nchidaj 106, 131

Dibothrinm 4

relationship of 27

manubriforme 8, 10, 28

anatomy of 11

habitat of 13

microcephalum 6,15,18, 19

anatomy of. . . 23, 26
dimensions of. 22

•plica t inn 11, 28

dimensions of 29,30

habitat of 32

punctatum , 8, 13, 17

habitat of 18

restiforme, description of 4

habitat of 5

rugosum 32, 35

dimensions of 33

habitat of 36

musculature of 35

sagittatnm 19

Discobothrium 84

fallax 84,86

Discocephalum 2, 88

description of 63

pileatum 63

anatomy of 68

description of . . 63

dimensions of . . 64

habitat of 63

musculature of . C7

structure of 67

Echeneibothrium 2, 47, 48, 86, 87, 144

affine 49

minimum 50, 53

tumidulum 57

variabile 48, 49, 86, 122

898 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [180]

Echeneis remora

Echinorhynchus

acus

giganteum
xiphise

Edwards, Vinal N

Filicolle

"Fish Hawk" ,

Gadus

niorrhua

Galeocerdo tigrinu,s.

Page.

3

88

14

41

28

4

37

14

14

32

106

Gamobothriidse 2,63,84

Goode, G. Brown 4

Histiophorus gladius 10, 11,13

Lecanicephalum 2, 63

description of 84

peltatum 86

anatomy of 86

description of. . 84

dimensions of. 85

habitat of 85

Limanda ferraginea 14, 18

dimensions of 16

Linton, Margaret B 4

Lobotes surinamensis 3

Lophopsetta maoulata 14, 16, 18

Mola rotunda 18

Monorygma 81

Mustelns canis 92, 94, 107, 111, 121, 127, 128

•vnlgaris 94, 127

Hyiiobatis freminvillei 57

Nematods 2

Nereis 48,122

Niemiec, Dr. J 47

Odontaspis littoralis 81, 129

Onchobothrium 102

elegans 94

Orygmatobothrium 1, 78, 81

angustum 39, 78, 79

dimensions of 79

habitat of ... 79

crispnm 78

dorni 81

littoralis 82

versatile 78, 81

Otobothrinm 131

description of 131

crenacolle, anatomy of 133, 134

description of 132

dimensions of 132,133

habitat of 132

Paratsenia, description of 144

medusia 2

description of 144

dimensions of 146, 147

habitat of 145

Phoreiobothrium 101,102

lasium 39,79

Phyllacanthinse 69,91,102

Phyllobothrinas 36,67

Phyllobothrium 3, 65, 69, 76, 105

anricnla 76

dohrni 81

foliat ura, anatomy of 74

description of. . . 69

Page.
Phyllobothriam foliatum, dimensions of. . 73

habitat of 69

lactuca 43,105

thridax 76

thysanocephalum 1,69,105

Phyllorhynchinse 106

Platessa plana 14

Platybothrium, description of 102

cervinum 39

anatomy of — 103
description of. 102
dimensions of . 104

habitat of 104

Pleuronectes 14

Prosthecobothrinm 102

dujardinii 98,101

Pseudophyllidoe 4

Psetulopleuronectes americanus 14

Raiaerinacea 48,122, 125

rubus. 125

Rhinebothrium .2, 47, 50, 60, 87, 89

description of . — 50

cancellatum 57, 87

anatomy of 55

description of 53

habitat of 54

flexile 50,53

description of 50

dimensions of 52

habitat of 50

longicolle, anatomy of. . . 59

description of 57, 56
habitat of .... 57

minimum 50*

Ehinoptera qnadriloba 54, 87, 88

Rbodobothrium 41

pnlvinatnm, habitat of .. 42

Rhombus 14

Rhynchobolus 48,122

Rhynchobothria 3, 82, 115, 118

Rhynchobothrii 135

Rbynchobothrium 39, 106, ] 25, 131 , 145

ambiguum 125

bisnlcatum 1,139

bulbifer 1, 94, 95, 107, 111

anatomy of 109

dimensions of 108

habitatof 107

proboscides of 108

caryophyllum 127

commutatum 1!

heteromerum 115,1

heterospine, habitat of 121

description of 121

hispidum 115, 118, 119, 120

description of 115

dimensions of

habitatof 115

imparispine, anatomy

of

description of

dimensions of i23

habitatof

lomentaceum

description of

[181]

NOTES ON ENTOZOA OF MARINE FISHES.

899

Page.

Rhyncobothrium

dimen-

128
128
130
129
130
129

lomentaceum,

sions of

habitat of

longicorne

description of ...
dimensions of ...

habitat of

.longispine 115,118

description of 117

dimensions of 118,119

habitat of 118

paleaceum 139

rubromaculatum 114

tenuicolle 1,107

tenuispine 115, 118

description of 119

dimensions of 120

habitat of 119

tutoidulum 94, 107, 112

anatomy of 114

description of 111

dimensions of 112, 114

habitat of

wageneri

description of...
dimensions of ...
habitat of . .

Scoliodon lalandii .
Sphyrna zygaena . .
Spongiobothrium

characters of .

Ill
130
125
126
125
127
132
1,60
60

variabile 60, 76, 77

characters of 60

habitat of. . . 61

Squatina angelus 115, 131

Syndesmobothrium 143

filicolle, description of 143
dimensions of 144

Taenia tetraodontis mote 18

Tseniaedaa 144

Teleostei 2

Tetrabothriidse 1, 2, 36, 63, 81, 84, 144, 145

Tetrabothriorhynchidas 135

Tetrabothrium 4

t umidulum 57

Page.

Tetracotyieidae 144

Tetraphyllidse 36,86

Tetraptnrus albidus 10, 11, 13

Tetrarhynchi 135, 136

Tetrarhynchidfo 106

Teti arhynchobothrium 135

Tetrarhynchus 106, 131, 135

bisulcatum 1,79,139

anatomy of. . 140, 142
dimensions of 141

erinaceus 125

infulatum 137

lingualis 139

minutus 115,131

robustum 135,136,139

* description of . 137

dimensions of . 138

habitat of 138

tenue 136, 138, 139

description of 135

dimensions of 136

habitat of 136

trygonis brucconis 120

pastinaceae 114

Thy sanocephalum 69

description of 105

crispum 1,105

habitat of. . 106

Trematods 2

Trigla 14

Trygon cencrura 2, 3, 42, 50, 61, 69, 77, 84, 85, 99

115, 118, 119, 120,125,127,136, 138, 143, 145

pastinaca 50, 76, 84

Trypanorhyncha 106,131

Tschokke, Dr. Fritz 76

Tylocephalum 2,63,84,88

description of

pingue, anatomy of.

description of

dimensions of

habitat of

Tyloanrus oaribbseus

"Wood's Holl, Massachusetts

Xenosites

87

91

88

89

88

4,5

2

82

Xiphias gladius 28,32

LIST OF INDEXES IN VOLUME.

Page.
Index to Report of Commissioner LIX-LXIII

Fisheries of the Great Lakes in 1885 330-333

Keport upon the Division of Fisheries 335, 336

Work of ihe Albatross 433-435

Construction and Equipment of the Grampus 489, 490

Operations of the Grampus 599", 600*, 601*

Review of the Labroid Fishes of America and Europe 693-699

Some Lake Superior Entomostraca 717

Notes on Entozoa of Marine Fishes of New England, with Descrip-
tions of Several New Species 897-899

*

900