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268 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
The head-bulb (text-figs. 16-18) is, relatively to the size of
the worm, very small. It consists of two hemispheres separated
laterally but continuous dorsally and ventrally, and is thus
comparable with that of very young examples of Z. tiara. The
striations are very well-marked.
The esophagus occupies from one-twelfth to one-eighth of the
total length. The cervical sacs (text-figs. 16 & 17) are relatively
short, extending through, roughly, the first quarter of the length
of the cesophagus.
There is nothing in the number, shape, or arrangement of the
caudal papille of the male (text-fig. 19; Pl. IV. fig. 14) to dis-
tinguish this form from 7’. tiara. The preanal ‘ sucker-like
organ,” referred to by v. Linstow (1904 a), appears to us to have
been simply the terminal portion of the intestine, seen in optical
transverse or oblique section by transparency through the body-
wall. Wecan find no superficial sucker-like organ on the ventral
surface.
The vulva is situated at about one-third of the body-length
from the posterior end. The vagina is short, and opens at right
angles into the uterus. Thelatter has two branches, which usually
proceed at once from the termination of the vagina to run
anteriorly and posteriorly respectively. In a young specimen
from Z'ropidonotus asperrimus (text-fig. 20), the muscular vagina
appeared to be very short, and continued as a common uterine
tube for a short distance before the divergence of the two
branches.
Specific Diagnosis.
TANQUA ANOMALA (v. Linst.).
Head-bulb divided in the adult into two swellings, situated
dorsally and ventrally, each containing two ballonets. Head not
retractile within the cuticular ollie Vulva at about the
junction of the middle and last thirds of the body. Uterus
with two opposed branches.
Habitat: stomach of semi-aquatic snakes ( Zropidonotus, etc.).
For list of hosts, see p. 271.
3. TANQUA DIADEMA * Baylis, 1916. (Text-figs. 21-23; Pl. ILI.
fig. 15; Plo Votes i)
Tunqua diadema Baylis (1916, p. 227; text-figs. 3, 4).
This species, which is now redescribed with some slight correc-
tions, is readily distinguished from the preceding form from
snakes by the prepuce-like fold of cuticle within which the
head-bulb and lips can be completely retracted. The cuticle,
especially anteriorly, is often very thick and wrinkled, reminding
one of the condition frequent in G'nathostoma.
* For specific diagnosis, see p. 271.
YHE NEMATODE FAMILY GNATHOSTOMID&. 269
The head-bulb (text-fig. 21) 1s divided into two hemispheres,
as in 7. anomala. The lips (text-fig. 21) are rather large
relatively to the head-bulb. The cesophagus occupies about
one-tenth of the total length. The cervical sacs are short.
In the ‘male the tail (Pl. Lil. fig. 15; Pl. IV. fig. 16) has
rather wide ale. The caudal papille are similar in number and
arrangement to those of the other species. The second pair from
the tip of the tail, however, are relatively small in some specimens,
and do not always show the basal swelling to a very marked
extent. The spicules are suddenly narrowed at the extremity to
form a little, conical, smooth tip (text-fig. 22).
Text-figure 21. Text-figure 22,
O/ mm.
Text-fig. 21.—Tanqua diadema. The head, with the cuticular sheath removed ;
dorsal (or ventral) view.
Text-fig. 22—Tanqua diadema. ‘Terminal portion of spicule.
Text-figure 23.
OS mm.
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Tanqua diadema. Female genital organs. (Mature specimen.)
In the female the tail is tapering and sharply pointed. The
vulva opens in the middle third of the body. The vagina (text-
fig. 23) is short and thick. It opens at right angles into the
uterus, the two branches of which at once pass off in opposite
directions, without further subdivision.
MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
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THE NEMATODE FAMILY GNATHOSTOMIDA.,
Specific Diagnosis.
TANQUA DIADEMA Baylis.
Head-bulb divided in the adult into two swellings, situated
dorsally and ventrally, each containing two ballenets. Head
retractile within the cuticular collar, which forms a prepuce-like
sheath. Vulva in middle third of the body. Uterus with two
opposed branches.
Habitat: “‘intestines” (? stomach) of a snake, Helicops angu-
latus, in Brazil.
Taste IV.—Hosts and Distribution of the Species of Tanqua.
Species. Host. Locality. Recorder.
;
EV EUORON | 56 ii. 2 Varanus “ ornatus” | Natal. v. Linstow (1879).
(probably V. albigularis). | |
Varanus salvator. | Sumatra. Parona (1898).
Ps 3 | Cevion. v. Linstow (1904 a). |
ir | India. | Baylis & Lane |
| (present paper).
bra aeara| ... - 53 | Fed. Malay | Leiper (1908).
[Hydrosaurus bivittatus.] States.
Varanus gouldii. | Australia or | Parona (1898).
New Guinea.
Varanus bengalensis. | Ceylon. v. Linstow (1904 a).
| Varanus niloticus. White Nile. Leiper (1908).
| 3 7, Gold Coast. Baylis (1916).
- a [V. sp.]| Zanzibar. ieee se
| Varanus exanthematicus. | Northern Baylis (1916) |
| ’ Nigeria. (specimens deter- |
mined by Leiper).'
T.anomala ......| Tropidonotus piscator. Ceylon. _v. Linstow (1904).
ri 3 India. Baylis & Lane
(present paper).
| Tropidonotus asperrimus | Ceylon. Baylis (1916) [ve-
[=T7. quineunciatus | cordedas 7. tiara |.
(local form of 7. piscator). |
| Homatopsis buccata. Siam. | Baylis & Lane
| | (present paper).
© Water-snake.” | India. “ i
| “Snake.” I, 38 i
|
DT, diadema +o... | Helicops [| Uranops| angu- | Baylis (1916).
| Brazil.
| latus. |
Doubtful Species of Tanqua.
a
ASCARIS SPH ZROCEPHALA Rud., 1809.
Rudolphi (1809, p. 188).
On account of. certain resemblances between the characters of
this species, as described by Rudolphi, and those of the worms
of the Gnathostomid group, we mention it here for the sake of
D2, MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
completeness. It is quite uncertain to what genus it belongs,
but if Redolphi’s account of the head-bulb is correct it seems to
approach more nearly to Zangua than to any other. On the
other hand, its host (a fish) and its habitat (the spiral valve of
the intestine) suggest very strongly that it may have been an
Hehinocephalus (q.v., p. 273). Rudolphi distinetly states, how-
ever, that the head-bulb is transversely striated and composed of
two hemispheres, and he makes no mention of any armature
of hooks oy spines.
The species is briefly diagnosed as follows :—
‘* Ascaris: membrana capitis utrinque semiorbiculart, striata ;
cauda obtusiuscula.”
The following is a rough paraphrase of the further account
(originally in Latin) of the worm, which was found in the lower
part of the intestine of the Sturgeon, Acipenser sturio, in the
spiral valve. |
Worms an inch long, slender, white. Head spherical to naked
eye, separated from the body by a constriction, and inflexed.
Under the microscope a hemispherical membrane is seen on
either side, transversely striated, giving the head a spherical
shape. Mouth smali, surrounded by three large, bluntly conical
lips, joined at the apex, but not at the base, by lateral membranes,
“so that they become obscured.” Body smooth, attenuated at
both ends, more so anteriorly. ‘ail rather blunt. Lips of vulva
prominent, in third quarter of body. Alimentary canal like that
of Asearids. Eggs very peculiar, greatly elongated, blunt-ended
(oblong-elliptical), clear at one end.
tudolphi says (as we understand him) that on account of the
general shape of the body and of the lips the worm belongs to
the “‘ Ascarides,” but that the arrangement and “ obscuring” of
the lips [sc. by the ‘‘membrane” referred to] and the peculiar
eggs mark it off as something different. His description suggests
that the ‘“‘ three lips ” he saw were the three tooth-bearing lobes
of one lip, seen from the side by transparency, and the ‘*mem-
brane” joining them at the apex the cuticle of the outer or more
lateral portion of the lip.
PHYSALOPTERA CONSTRICTA Leidy, 1856.
Leidy (1856, p. 53).
“ Body white, with the brown intestine shining through,
cylindrical to within a short distance of the extremities, incurved ;
anterior extremity with one or two constrictions, and abruptly
inflexed. Lips large, lateral, constricted from the body, each
trilobate. Tail of female incurved, abruptly conical and acute ;
of the male alated, with the ale narrow, long, and turgid.
Length of female 1? inches, breadth two-fifths of a line; male
half the size.
“Found frequently in the stomach of Zropidonotus sipedon,
with the anterior extremity of the body hooked through the
THE NEMATODE FAMILY GNATHOSTOMIDA. 273
mucous membrane, and very tightly adhering by means of the
one or two constrictions.”
The form thus described by Leidy so strongly suggests a
Tanqua, both on account of several points in the brief “descrip-
tion and on account of its host and habitat, that we feel obliged
to include it in our account of the genus. It is impossible, how-
ever, without further investigation, to assign it to a definite
position.
ECHINOCEPHALUS * Molin, 1858.
Echinocephalus Molin (1858, p. 154).
ee haeo le pao LL),
Cheiracanth ws (in part) v. Linstow, in Shipley and Hornell
(1904, p. 100).
ny (in part) v. Linstow, in Shipley and Hornell
(1905, p. 54).
Molin’s original generic diagnosis was as follows :—
‘“ Canut discretum, echinatum ; os orbiculare, terminale, magnum
- ? . fl f ’ ? Yy ?
inerme, vel armatum; corpus cylindricum, inerme, vel echinatum ;
Laguna penas dipetala ; [anus lateralis t ].—Avium et pisciwm endo-
parasita.”
Under this generic name two species were originally enume-
vated by Molin, £. uncinatus and H. cygni. The latter was
regarded as a species inquirenda, leaving #. uncinatus the un-
disputed type-species. 4. cygni belongs : to the genus Hystrichis,
and is, in fact, a synonym or ia. pachycephalus Molin. Into the-
affinities of Hystrichis 1t is beyond our present scope to enter,
but in spite of the rather strong superficial resemblance borne by
some of its species to some of the Gnathostomide, we regard it as
being of quite a different type from this group. Molin’s generic
characters for Lchinocephalus seem, however, to have been based
in part on the characters of £. cygni, and for this reason it
becomes necessary to emend the diagnosis, besides adding to it
from our own observations (see p. 275). Thus the ‘os orbiculare”
and the statement that the genus is parasitic in birds as well as
in fishes belong rather to Hystrichis than to Hchinocephalus.
Molin (186!) rightly suggests the relationship of this genus
to Cheiracanthus (i. e., Gnathostoma). It shows equally great
resemblances to Zangua, and may, in fact, be looked upon as a
Tanqua-like form complicated by the development of rows of
spines or hooks along the cuticular ridges or “striations” of the
head-bulb.
The lips are, in most cases, very similar in plan to those of
Tanqua, and show a similar interlocking arrangement of the
internal, tooth-like, cuticular ridges. In one form, however, the
arrangement is complicated by the multiplication of the teeth on
* For generic diagnosis, see p. 275.
+ Added in 1861.
274 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
the dorsal and ventral lobes of the lips, so that each lip bears
some 20 teeth altogether.
The head-bulb forms a continuous ring surrounding the base
of the lips; it is never, in the species hitherto met with, divided
externally into two or four swellings, as in Zanqua, though it
still contains the same four ballonets connected with the cervical
sacs. ‘The latter sometimes end in a httle button-like appendage
(text-figs. 30, 33, a).
The size of the hooks on the head-bulb, the number of rows,
and the number of hooks in each row, show considerable variety,
and afford useful specific characters.
‘The body is smooth, as in Zanqua, the cuticle being, as a rule,
finely striated transversely. The neck-papille are rather pro-
minent. Molin’s statement (1861) that the anus is lateral is
entirely erroneous. The excretory pore 1s very inconspicuous,
and is always to be found at about the same level as the cervical
papille.
The tail of the male is coiled ventrally, and is provided with
slight cuticular ale, into which a series of paired caudal papillee
project. Of these there are always eight pairs, as in 7anqua, but
the arrangement of the pairs differs somewhat in the different
species. One constant feature is the long space separating the
eighth or most anterior pair from the rest. Some of the papille
are rather large, with a swelling at the base recalling that seen
in Tanqua, but never so well-developed. The spicules are very
characteristic. They are tubular and usually rather long and
slender, the left spicule being apparently always a fraction of a
millimetre longer than the right. Instead of the broken, external,
rasp-like markings seen on the spicules of Z'anqua, we find in
Echinocephalus an irregular transverse striation, which only
breaks up into a rasp-like pattern near the tip. The markings.
appear to be internal, the outer surface being smooth and trans-
parent. The tip of the spicules consists of a thickening of the
smooth outer layer only,and may be sharply pointed or somewhat
blunt in different species.
The tail of the female is short and bluntly rounded at the tip.
The vulva is invariably situated near the posterior end of the
body, within a very short distance of the anus. The long vagina
runs forward, and it seems to be characteristic of the genus that .
it forms a single coil in its course before opening into the uterus.
The latter consists of a wide oblong egg-sac, which becomes very
voluminous in the gravid female, and two horns which run for-
ward from its anterior end. The ova have a finely granulated
surface, and are of a similar oval shape to those of Zanqua.
They do not contain fully-formed embryos when laid.
The adults are found in the intestine (usually in the spiral
valve region) of sting-rays (Trygonide and Myliobatide). There
is evidence that the development is indirect, requiring an inter-
mediate host in the form of one of the bivalve molluscs upon
which the final hosts feed. The larve of one species, at least,.
THE MEMATODE FAMILY GNATHOSTOMID. 275
are found occupying cysts in the tissues of such bivalves as the
pearl-oyster (see p. 277), where they appear to select chiefly the
adductor muscle of the shell as their habitat.
Generic Diagnosis.
ECHINOCEPHALUS* Molin.
Gnathostomine: head-bulb armed with transverse rows of
hooks; not externally divided into swellings, but containing
four ballonets internally. Body unarmed. No cuticular collar
behind the head-bulb. ‘Tail of male with shght ale and eight
pairs of papille, the most anterior pair always separated by a
long interval from the rest. Spicules slightly unequal (left
longer than right), tubular, long and slender, marked with
transverse striations. Vulva near posterior end of body. Vagina
long, opening into a wide uterine sac, which gives off two branches
anteriorly. Eggs oval, with thin shells ornamented with fine
granulations. Embryos not fully-formed at the time of laying.
Habitat (adult): imtestine (usually in spiral valve region) of
sting-rays and other EKlasmobranch fishes.
Genotype: H. uncinatus Molin, emend. Baylis and Lane.
Key to Species of Mchinocephalus
(excluding /. striatus Mont.).
A. Head-bulb with not more than six rows of hooks...... EB. uncinatus.
B. Head-bulb with more than six rows of hooks.
a. Dorsal and ventral lobes of lips each with two
teeth.
a’. Head-bulb with 15 to 18 rows of about 150 to
200 hooks each ........ .. HH. southwelli (p. 288).
b’. Head-bulb with 30 to 40 rows-of v ery 1 numerous ‘
hooks ...... E. spinosissimus (p. 277).
b. Dorsal and ventral ‘lobes of. lips each with a
number (eight or more) of teeth..................... HE. multidentatus (p.285).
1, EcuinocePHALus uncinatus T Molin, 1858. (Text-fig. 24.)
Echinocephalus wneinatus (in part) Molin (1858, p. 154).
(in part) Molin (1861, p.311; pl. xiii.
fies. 7, 8).
Cheiracanthus uncinatus v. Linstow, in Shipley and Hornell
(1904, p. 1003; pl. ii. figs. 41, 44, 45-48).
Echinocephalus gracilis Stossich, in Shipley and Hornell (1906,
p- 89).
The original description of this, the type-species of the genus,
appears to us to have been based on two distinct species, both of
which we have been able to recognize among our material. The
head-bulb is described by Molin as having about 30 rows of small
hooks in the male, and only six rows of larger hooks in the
29 he)
* For measurements, see Table V., p. 288.
+ For specific diagnosis, see p. 277.
Proc. Zoou. Soc.—1920, Nu. XIX. 19
«
2°76 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
female. These two forms are also clearly figured in his later.
paper (1861). The size, number, and arrangement of the hooks,
in our material, appear to give good and constant specific
characters, and we feel little hesitation in concluding that Molin’s
male ‘ wnetmatus ” corresponds to what will be described below as
E. spinosissinus v. Linstow, while his female is a distinct form.
We are, therefore, faced with the necessity of deciding which of
Molin’s two forms is to be designated as the type of £. wncinatus.
A good and appropriate specific name already existing for the
form with 30 or more rows of hooks, we have thought it advisable
to retain it; and we feel justified in selecting Molin’s female
form, with 6 rows of hooks, as the true #. uncinatus *.
Our own material is scanty, consisting of one larval individual
found encysted in a Pinna and three very young specimens from
a sting-ray, JJyliobatis nieuhofi. As none of these individuals
Text-figure 24.
C
a wer
ea af \ C
15 #9 0.9988 phtynna
hr 79999 0909 0A
me
Pro.ou
O-3mm.
Echinocephalus uncinatus. Anterior end of larval specimen ; lateral view.
contain fully-developed sexual organs, our description must
remain incomplete.
The lips are not yet fully developed in any of the specimens,
and we are unable to describe their structure. The head-bulb
(text-fig, 24) is armed with 6 rows of hooks, each row containing
between 40 and 50. The spines increase in size from before
* The question of nomenclature is somewhat further complicated by the fact that
Shipley and Hornell appear to have submitted larval forms of a species of Hehino-
cephalus to both von Linstow and Stossich, and these two authorities held different
opinions as to their identity. von Linstow ascribed them to Molin’s species
uncinatus, while Stossich created for them a new species, gracilis. We cannot,
however, find anything in Stossich’s (in Shipley and Hornell, 1906) remarks upon the
larvee to justify this step, and as the specimens are definitely stated by both
authorities to have 6 rows of hooks, we regard the name gracilis as a synonym of
wncinatus.
: THE NEMATODE FAMILY GNATHOSTOMIDA. Ori ks
backwards. The neck-papille were not seen. Caudal papille
could not be detected, nor was the position of the vulva yet
visible. The cuticular striation is extremely fine and indistinct.
As regards the occurrence and life-history of this species, it
seems fairly clear that it requires an intermediate host, in the
shape of a bivalve mollusc, for its transference into the alimentary
canal of its final host. Molin’s original adult material was found
in Trygon brucco in the Adriatic. von Linstow (in Shipley and
Hornell, 1904) states that 1 also occurs in 7’. pastinaca. The
larval stages are found encysted in the tissues of bivalves, usually
in the adductor muscle of the shell. Thus they have been found
fairly frequently in the pearl-oyster (see Shipley and Hornell,
1904, pp. 101-102), and we have now recorded their occurrence
in Pinna sp. In the pearl-oyster the larve are occasionally
found ‘entombed in the nacreous lining of the sheli” (Shipley
and Hornell, 1904), where their shape is said to be wonderfully
preserved.
In addition to the bivalves, the trigger-fishes, Balistes mitis
and B. stellatus, are recorded by Shipley and Hornell (1904) as
hosts for the later larval stages. It is not quite clear whether
these fishes are regarded as a necessary second host of the parasite
or not. The species of Tygon are said to devour both the Balistes
and the oysters, but the presence of the worms in Lalistes may
have been abnormal. In these fishes they were found not only in
the alimentary canal, but also in the peritoneum and connective
tissue, in which they were thought to burrow by the help of the
head-bulb, which was seen in both inflated and deflated conditions.
Specific Diagnosis.
EcHINOCEPHALUS UNCINATUS Molin, emend. Bavlis and Lane.
Head-bulb with six rows of heoks, each row containing from
40 to 50 hooks.
For list of hosts, see p. 289.
ECHINOCEPHALUS SPINOSISSIMUS * (v. Linst., 1905). (Text-
ives. 20-29.;, Pl; LV. figs. 1/, 18.)
Echinocephalus uncinatus (in part) Molin (1858, p. 154).
(i861, p..d11; plexi.
fgs..D, 6).
Cheiracanthus spinosissimus v. Linstow, in Shipley and Hornell,
(1905; p. 94; pl.) figs. 12, 13).
This specific name was proposed by von Linstow for a form
having 30 to 33 rows of hooks on the head-bulb, each row
containing some hundreds of hooks. The host of the type-
specimens was Iyliobatis aquila, from the Gulf of Manaar.
99 19 99 99
* Kor specific diagnosis, see p. 283.
oh
278 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
We believe, as has been stated above, that the male form
described by Molin under the name of Echinocephalus uncinatus
is referable to this species. The host, in this case, was Trygon
brucco. Among our own material there are specimens from the
sting-rays, Trygon walga and Urogymnus asperrimus, which
appear to belong to the same species.
From their size (13°7 mm. in length) von Linstow’s examples
seem to have been immature, and few details are given of their
internal stucture. We will therefore give a fuller description
based upon our own material, chiefly upon the specimens from
Urogynnus.
The worms are rather long and slender in general appearance.
The largest female in our possession is not quite mature.
The lips (text-figs. 25 & 26) are large, very prominent and
massive, each consisting of an outer portion bearing the three
papille, and internally a rounded middle, and a dorsal and a
ventral triangular, tooth-bearing lobe. These lobes meet those
of the other lip and guard the mouth. The middle lobe is
without teeth, while the other lobes are each provided with an
internal thickening of the cuticle which is produced into tooth-
like ridges (text-fig. 28). The teeth interlock, as in Vanqua,
with those of the opposite lip. The pcesterior surface of the
dorsal and ventral lobes bears a row of small tooth-like serrations
(text-figs. 25, 26, ser.).
The head-bulb (text-figs. 25, 26) is distinctly marked off from
the neck, and is visible to the naked eye as a little knob. The
hooks (text- -fig. 27) are very minute and very numerous. They
are arranged in from 30 to 40 transverse rows, each row containing
a very large number (several hundreds) of hooks. _ The rows are
not always complete circles, but sometimes break off suddenly,
while dichotomous branching of the rows is not infrequent.
The cuticular striation on the body is oy fine. von Linstow’s
statement that the csophagus is only ; of the body-length
appears unintelligible, unless it is a misprint for 4-3, and even
in this case it does not agree very well with our own measure-
ments.
Of the eight pairs of caudal papille in the male (Pl. IV. fig.
17), those of the first pair are small and lateral, the second pair
more ventral. Pairs 3 to 6 form a group on either side of the
anus, the 6th pair being apparently adanal. The 5th pair is
situated somewhat more laterally than the rest. These four pairs
are placed close together, but a longer space separates pairs 2
and 3 and pairs 6 and 7. The 8th pair is separated by a very
long interval from the 7th, and stands quite far forward, these
last two pairs being both preanal. All the papille, except the
small first pair, have a somewhat swollen base, not unlike
the strueture seen in Janqua, though less strongly developed.
The stout spicules (Pl. IV. fig. 17) are very slightly unequal in
length, the left being the longer. Hach spicule terminates in a
smooth, conical point (Pl. IV. fig. 18).
THE NEMATODE FAMILY GNATHOSTOMID,
Text-figure 25.
\ mh \
PAIN ANIA
PP ATERATAEA LEADER A
TT APAMATARLAL LLAMAS
(OATES LATA
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it
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Echinocephalus spinosissimus. ‘The head; dorsal (or ventral) view.
Text-figure 26.
L40,/%8,
OPAL ATTIRE TL
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Echinocephalus spinosissimus. ‘The head; lateral view.
280 MR. H. A, BAYLIS AND LT.-COL. CLAYTON LANE ON
Text-figure 27.
e
g
Ni 2
y |
Echinocephalus spinosissimus. Hooks: a, in profile; 6, in surface view.
.
O-OS1m™m
Text-figure 28,
Ol mm.
Echinocephalus spinosissimus. ‘Transverse section through the lips. (The section
is somewhat oblique, passing through the middle lobe and only one outer
lobe of each lip.)
THE NEMATODE FAMILY GNATHOSYTOMIDA. 281
The vagina (text-fig. 29) including the unpaired portion of the
uterus, runs forward for nearly 5 min. before giving off the two
Text-figure 29.
“U/W ()-/
a ° ° ° °
Echinocephalus spinosissimus.
Posterior end of female ; lateral view, showing genital organs.
uterine branches. Weare unfortunately unable to describe the
ova, none having been seen in a fully-developed condition in our
specimens.
Text-figure 30.
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Head and csophageal ve
Lichinacephalus southwelli.
THE NEMATODE FAMILY GNATHOSTOMID. 283
Specific Diagnosis.
ECHINOCEPHALUS SPINOSISSIMUS (v. Linst.),
Head-bulb with 30 to 40 rows of hooks, each row containing
several hundreds. Dorsal and ventral lobes of lips bear two
teeth each.
For list of hosts, see p. 289.
3. ECHINOCEPHALUS SOUTHWELLI*, sp. n. (Text-figs. 30-32 ;
Pl. LV. fig. 19;_Pl. V. figs. 20-23.)
This species, which we name in honour of Mr. Southwell, to
whose kindness we are indebted for this and much of our other
material, was also found in Urogynunus asperrimus. It is a form
intermediate in several features between LZ. spinosissimus and
a third species (1. multidentatus) to be described below, and all
these three species were found together in the same individual
host.
The present species is rather shorter and considerably more
slender than #. spznosissumus.
The lips (Pl. IV. fig. 19; Pl. V. fig. 20) are rather squat,
and their dorsal and.ventral lobes bear only two teeth each, as in
E. spinosissimus. The head-bulb (text-fig. 30), however, is much
Text-figure 31.
cd.p
O+mm.
Echinocephalus southwelli, Caudal extremity of female; ventral view.
more like that of the next species, H. multidentatus, though
smaller and less flattened antero-posteriorly. ‘There are from 15
to 18 rows of hooks, which have a maximum length of 0°035 mm.,
and are thus intermediate in size between those of ZH. spinosissi-
mus and L. multidentatus. The number of hooks in each row is
also intermediate, there being, as nearly as can be estimated, from
150 to 200.
Lhe cuticular striation on the body is rather coarse. The cervical
sacs are nearly as long as the cesophagus. In the male, the first
pair of caudal papille (Pl. V. figs. 21, 22), near the tip of the tail,
* For specific diagnosis, see p. 285.
Posterior end of female ;_lateral view,
showing genital organs.
oon fupeataineanaaters
setesiiaaiieeii
LUT.
O
Text-figure 32
és.
Va
V.
“Ws E-O
Ue:
Echinocephalus southwelli.
THE NEMATODE FAMILY GNATHOSTOMID. 285:
are quite lateral; the 2nd, 5th, 6th, 7th, and 8th form a longi-
tudinal series, while the 31d and 4th are a little nearer to the
mid-ventral line. Pairs 2—5 forma group rather close together,
of which 2 and 4 are small papille and 3 and 65 relatively large.
The intervals between 5 and 6 and between 6 and 7 are about
equal, and greater than those between the posterior pairs, while a
much longer interval separates 7 and 8.
The spicules (Pl. V. figs. 22, 23) are rather slender. A little
before the tip each spicule is narrowed and then expanded some-
what, before terminating in a conical point.
In the female the tail (text-fig. 31) is very short. The vagina
(text-fig. 32) leads into a very wide uterine sac.
Specific Diagnosis.
ECHINOCEPHALUS SOUTHWELLI Baylis and Lane.
Head-bulb with 15 to 18 rows of hooks, each row containing
about 150 to 200. Dorsal and ventral lobes of lips bear two
teeth each..
For list of hosts, see p. 289.
4, KCHINOCEPHALUS MULTIDENTATUS*, sp.n. (Text-figs. 33-36 ;
Pl. VI. figs. 24-27; Pl. VII. fig. 28.)
This is the third species obtained from the sting-ray, Uvro-
gymnus asperrimus. In general naked-eye appearance it closely
resembles #. southwelli, but is rather shorter and proportionately
stouter. The head-bulb (text-fig. 33) is very conspicuous, and
gives the worm much the appearance of a small nail.
The lips (Pl. VI. figs. 24, 25) are well-developed, but not
prominent. In structure they are more complex than in any of
the other forms studied by us. The outer portion bears the usual
three papille, and the inner portion is, as usual, trilobed. The
cuticle of the opposed inner surfaces of the dorsal and ventral
lobes is raised into a number (from 8 to 11 on one lobe) of tooth-
like ridges. These teeth are not constant in number or arrange-
ment, and are not always symmetrical on the two lobes of the
same lip, as may be seen in P]. VI. fig. 25. Whether the teeth
of the two lips can be interlocked is uncertain, though their
appearance suggests that this is probably the case.
The head-bulb (text-fig. 33) is very wide compared with the
neck which follows it, and is somewhat flattened antero-posteriorly .
There are from 1] to 13 rows of large hooks (text-fig. 34). Hach
row may be estimated to contain some 100.
The cervical sacs are, as in /. southwelli, of approximately the
same length as the cesophagus, both terminating at a point a
little more or less than 2 mm. from the anterior extremity.
* For specific diagnosis, see p. 289.
286 MR. H. A. BAYLIS AND LY.-COL. CLAYTON LANE ON
The cesophagus is thus very short as compared with that of
HL. uncinatus and EH. spinosissimus. The neck- papille are
prominent.
Text-figure 33.
Labs ANA As
oN faa sagangy
Noa r A
ida oS da eae
Soin [Manan arent 042g
SSA PPP PPI LS PRES
et Wig! HIT A DIDI
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Echinocephalus multidentatus. Head and cesophageal region; lateral view. (The
triangular opening in the head-bulb is due to an artificial splitting of the
cuticle.)
Of the eight pairs of caudal papille in the male (PI. VI.
26, 27), the first, as usual, is lateral, while the rest are more
figs. 2
ventral in position. Pairs 1 to 5 appear to be postanal, 6 to 8
THE NEMATODE FAMILY GNATHOSTOMIDA. 287
Text-figure 34.
5 é
Vt
Echinocephalus multidentatus. Hooks: a & b, various profile and surface views ;
ce, a strip of cuticle with hooks, from a macerated specimen.
Text-figuire 35.
Echinocephalus multidentatus. Posterior end of female; lateral view.
preanal. Pairs 3, 7 and 8 are conspicuously larger than the
remainder. There is a long space between 7and 8. Nos. 4and 5
are small papille, one pair, which we call 4, being in a line with
Nos. 2 and 3, while No. 5 is displaced laterally and posteriorly so
as tole at the same transverse level as No. 4. The papille
project into a very feebly developed ala on either side. The
MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
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THE NEMATODE FAMILY GNATHOSTOMID&. 289
spicules are rather slender. Their tips (P]. VII. fig. 28) are
smooth and rather blunt.
The vagina (text-figs. 35, 36) passes into a voluminous uterine
sac.
Specific Diagnosis.
EcHINOCEPHALUS MULTIDENTATUS Baylis and Lane.
Head-bulb with 11 to 13 rows of large hooks, each row contain-
ing about 100. Dorsal and ventral lobes of lps bear 8 or more
teeth each.
Taste VI.—Hosts and Distribution of the Species of Hcehinocephalus.
Species. Host. | Locality. Recorder.
ais ae ena ae Mae a ae
EB. uncinatus (adult) | Trygon brucco. | Adriatic. Molin (1858).
| Fe Trygon pastinaca. Ea vy. Linstow, in Shipley
| & Hornell (1904).
(immature) | Wyliobatis nieuhoft. Ceylon. Baylis & Lane
(present paper).
a Balistes mitis. es Shipley & Hornell
(1904).
i‘ Balistes stellatus. | ae ae
(larva) | Margaritifera marga- | | #. re
ritifera. | M. vulgaris. |
| : | Pinna sp. | Baylis & Lane
| (present paper).
E. spinosissimus......, Myliobatis aquila. | Ceylon. y. Linstow, in Shipley
| | & Hornell (1905).
| Trygon brucco. ; Adriatic. Molin (1858)
(recorded as
| | E. uncinatus |.
Trygon walga. | Ceylon. Baylis & Lane
(present paper).
| Urogymnus asperrimus. 93 55 "
et ieee ma ee sae eee
HH. southwelli lhe th Urogymnus asperrimus. Ceylon.
ee al lens SE Ae eee been ar a ie are oe Se a
HY. multidentatus ee, Urogymnus asperrimus. Ceylon. a 55
Hi. striatus ............ Scyllium sp. Peru. Monticélli (1889).
5 (?) .........| Aélobati narinari. Loyalty Is. Shipley (1900).
5. EKCHINOCEPHALUS stRIATUS Monticelli, 1889.
Monticelli (1889, p. 71).
¢Shipley (1900, p. 560; text-fig. E).
The name /. striatus was given by Monticelli to some specimens
from the stomach of Scylliwm sp., from Payta, Peru. Sub-
sequently Shipley doubtfully referred to the same species some
Text-figure 36.
6.5
O-5 mm,
Posterior end of female; ventral view,
Echinocephalus multidentatus.
showing genital organs.
THE NEMATODE FAMILY GNATHOSTOMIDA, 29]
worms from the intestine of a four-spined sting-ray, dAétobatis
narinari, from Loyalty Islands. ‘The name #. striatus, however,
seems to be a nomen nudum, and we have no means of identify-
ing the species, though we mention it here for the sake of com-
pleteness. Shipley ( (i. c.) gives a figure of the head of the form
referred to by hin, ae in this figure some 14 rows of hooks are
indicated, so that his species would seem to approach closely to
our &. southwelli, and is possibly identical with it.
GNATHOSTOMA* Owen, 1836.
Gnathostoma Owen (1886, p. 125).
Cheiracanihus Diesing (1838, Be 189).
a Diesing (1839, p. 221) [not Chetracanthus Diesing
of v. Linstow, in Shipley and Hornell (1904, p. 100) nor
(1305, ‘p. 54) J.
Filaria (in part) Schneider (1866, p. 98).
Cheiranthus v. Linstow (1893, p. 202) [misprint].
Gnathostomum Mitter (1912, p. 150). °
The members of this genus ave stout worms with the characters
of the subfamily. The head-bulb is, according to the state of
contraction of the contained muscles, globular or somewhat
flattened antero-posteriorly, and beais in the known species from
eight to twelve transverse rows of simple hooks, lke those of
Lichinocephalus, set on a cuticle which shows no external trace of
the four underlying ballonets. Some of the anterior and posterior
vows may be obscured, the first by the inrolling of the anterior
part of the head- bulb, as the result of contraction of the internal
taaieeles, the second by the partial retraction of the head-bulb
into the neck and the resulting interposition of the densely set
seale-like spines which cover this part of the body. hese are set
more or Jess alternately in transverse rows and have their free
edges indented to varying degrees, so that they come to possess
sharp points of varying shay pe ‘and number. ‘Towards the middle
of the body the spines become simple and either continue as such
to the posterior end or progressively diminish in size and finally
disappear, leaving the posterior part of the body naked. The
excretory pore has not been detected, a failure easily understood
when one considers the dense covering of spines and the minute-
ness of the pore in other genera of the subfamily.
The male has lateral caudal ale each sustained by four large
papillee and by the tip of the tail, which has the general appearance
of, and has sometimes been counted as, an unpaired terminal
papilla (Schneider, 1866, p. 86 and text-fig.; v. Linstow, 1893,
p. 206, fig. 11). Between the ale are two pairs of small, sessile,
ventral papillee. The male has two ee equal spicules and no
ACceSSOry ae although vy. aay (189 oe p. 206, fig. 13) has
desevibed, | lying venir ally to the spicules, a body which he seems
to regard as such, calling it a “ Stiitzapparat.”
* For generic diagnosis, see p. 292.
Proc. Zoou. Soc.—1920, No. XX. 20
292 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
The female has a blunt tail; the vulva probably always lies
behind the middle of the body; the vagina is long; there are two
uteri; the eggs have a thin colourless shell, marked by a very
fine external stippling, and have at one pole an appearance
as of a watch-glass-shaped cap due to a thinning of the shell
combined with a recession of the shell-membrane, and providing
a means of exit for the embryo. It has, however, sometimes
been described as a polar thickening of the shell (Schneider,
1866, p. 98; v. Linstow, 1893, p. 207).
The genus (vide Table VIII, p. 304) has a wide distribution
in a number of carnivorous hosts. Its normal habitat is clearly
the wall of the stomach. The genotype acquires an added
interest in that it has been found in man (in the subcutaneous
tissue). The presence of certain species in the lumen of the gut
we attribute to their having been parasitic in some host which
was devoured by the animals from which they were actually
recorded. Regarding one record of a Gnathostoma from the
colon judgment must be suspended (vide p. 305).
Generic Diagnosis.
GNATHOSTOMA * Owen.
Gnathostomine: head-bulb armed with simple hooks, the
ballonets giving no external evidence of their presence; body
armed with cuticular spines, anteriorly scale-like with the free
edges incised into points varying in number and shape, more
posteriorly becoming less subdivided and finally appearing as
simple spines, which either continue as such to the posterior end
or disappear, leaving the hinder part of the body unarmed; the
male with unequal spicules and four pairs of large lateral and
two pairs of small ventral caudal papille ; vulva behind the middle
of the body; vagina long; uteri two in number; ovum with thin
colourless shell, a marked thinning at one pole causing a weak
spot through which the embryo escapes.
Habitat: Normally the gastric wall, usually of carnivorous
mammals,
Genotype: G. spinigerum Owen, 1856.
Nore.—The name Giathostoma has been placed on the official
list of generic names by the International Commission on
Zoological Nomenclature 7.
Key to Species of Gnathostoma.
A. Body completely clothed with spines ........................ Gi hispidum (p. 298).
B. Spines clothe only the anterior half or two-thirds of
the body.
a. The spines immediately behind the head-bulb comb-
like, having four points of about equal length...... G. spinigerum (p. 293).
* For measurements, see Table VII., p. 302.
+ Opinion 66 (Smithsonian Institution, Washington).
THE NEMATODE FAMILY GNATHOSTOMIDA. 293
6. The spines immediately behind the head-bulb leaf-
like, having five points, one at the tip and two
BlOmeyeINMEr Side Ne is: ch. uiehetes oe eo tee ne. .t Gre gracile (p: 300).
G. horridum and Gt. turgidum are too insufficiently described
to be capable of inclusion in a key.
1. GNATHOSTOMA SPINIGERUM * Owen, 1836. (Text-figs. 37-40 ;
Pl. Vil. figs. 29-32; Pl. VIII. figs. 33-38).
Gnathostoma spinigerum Owen (1836, p. 125).
Cheiracanthus robustus Diesing (1838, p. 189) [nomen nudum].
Cheiracanthus robustus Diesing (1839, p. 222; pl. xiv.
figs. 1-7, pl. xvi. figs. 1-24).
Cheiracanthus socialis Leidy (1859, p. ne
Filaria radula Schneider (1866, bp: US epl vies. }9 a9):
Cheiracanthus siamensis Levinsen (1889, Pono23 se plevil.
figs. 9-14).
Gnathostoma paronai Porta (1908, p. 8).
Gnathostomum spinigerum Mitter (1912, p. 150; pl. v.).
The contradictory and incomplete character of existing
descriptions of this nematode, and the consequent unnecessary
multiplication of species, fully justify its redescription.
Text-figure 37.
eS Bes Ab
TS or CCG v ee ae
b CAE, yy RENN 2
a : ee tre by Voy Wb ae WN LR SS SN
BEEN il VVVVVV vy VV. ye \
Gn ae SUIT Ben Se 5 N
bar () 4d (> tw? ZO fies 2 ap fk \
O-3 mm.
Gnathostoma spinigerum. Anterior end; dorsal (or ventral) view (surface).
The specimens now described are from Felis pardus and were
received in part from the Veterinary College, Belgachia, Calcutta,
where they were collected by the late Mr. 8S. N. Mitter, and in
part from the Parel Laboratory, Bombay. In each case the
worms had produced fatal perforation of the gastric wall.
In this species the cuticle lining the inner aspect of each lobe
of either lip is. longitudinally thickened into a ridge which meets
its fellow of the opposite side. In our specimens the head-bulb
* For specific diagnosis, see p. 298.
20*
294 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
(text-figs. 37, 38; Pl. VII. fig. 29) carries from 8 to 11 rows of
hooks (text-fig. 39), The comb-like spines immediately behind
the head (text-fig. 40, @) carry on their straight distal edges four
short points. These rapidly give place to three-pointed spines
(text-fig. 40, 6), the middle point of which is typically the longest.
Spines of this type extend posteriorly to beyond the termination
Text-figure 38.
Ser ae Ree TS
Vg F Toy vos Vv N misminswaor t=
A. b. Fer UN oy) ww SSG
Bad aha y
ai ehh OO Vay) Yan
WEE oe yy WW
i, ( y VV V MY
Mili a a v Wy aw V Vy VVy y =
WyyvyyY * Se
=> Vryy 4 yi / w
= ? N
\
\
Gnathostoma spinigerum. Anterior end; lateral view (surface).
Text-figure 39.
Gnathostoma spinigerum. Hooks from the head-bulb: a, surface; b, profile view.
of the esophagus. There follow progressively two-pointed and
single-poitited spines (text-fig. 40, c, d), which in turn diminish
in size so that at 8 mm. from the head-end they form mere
points protruding beyond the transverse striations of the cuticle.
These soon disappear, leaving the posterior part of the body
naked, except for the spines to be described below on the tail of
the male.
THE NEMATODE FAMILY GNATHOSTOMID. 295
The diameter of the cesophagus immediately behind the head
is 0°125 mm.; its widest diameter is 0°6 mm. and lies at about
0°6 mm. from its termination.
The cervical papille (Pl. VIE. figs. 30, 31) are coarse, rounded
knobs with their terminations directed posteriorly, each lying in
a small bald area among the spines.
In the male the four large caudal papille on each side (Pl. VII.
fig. 32; Pl. VIII. fig. 33) lie close together in the caudal ale.
No. 1 is the smallest, the others being all of about the same size
but varying in relative proportions according to the aspect from
Text-figure 40.
See age ea
0-05 7m
SS
i.
gy
Gnathostoma spinigerum. Body-spines: a, from the neck, immediately behind
the head-bulb; 6, from the wsophageal region; c. from behind the
cesophagus (about 4 mm. from the anterior end); d@, from about the middle
of the body.
which they are viewed. ‘Their nerves are particularly large and
obvious. Near the bases of Nos. 1 and 2 of these papille lie the
two pairs of small ventral papille. The cloacal opening les in
front of these.
On the greater part of the posterior 0°8 mm. of the ventral
surface of the caudal extremity the cuticular striae are closely set
with small spines (Pl. VII. fig. 32; Pl. VIII. fig. 33), the general
296 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
direction of whose points is away from the cloacal opening.
There exists, however, a bald Y-shaped area whose narrow stem
reaches from the tip of the tail to the anus and whose broad
arms stretch thence laterally and anteriorly as far as the most
anterior of the lateral papille.
The short right spicule (Pl. VIII. fig 34) is wide at the base
and narrows somewhat abruptly about its middle, continuing
narrow thence to its rounded point. The long left spicule has
the same general shape as the right except that the shaft narrows
at about the junction of the anterior and middle thirds, and that
the middle third has at least the appearance of being the narrowest
part. When the large spicule is extruded it is seen that it is
hollow-looking, faintly striated, with a fine colourless outer layer
which thickens to form the extreme point of a slight terminal
expansion (Pl. VIII. fig. 35).
In the female, the vuiva, shaped as a slight tranverse slit, opens
into a vagina with a general anterior direction. In the specimen
examined its first 2 nm. was strongly muscular and narrow, the
beginning being markedly tortuous; the next 0°5 mm. was dilated
and full of eggs; then followed a narrow muscular loop running
posteriorly and dorsally nearly to the level of the vulva and
returning on itself to enter another short dilatation close to the
first one; thence it ran forward as a narrow muscular tube taking
a nearly straight course to the posterior end of the esophagus.
Immediately after turning posteriorly at this point it was found
broken and the continuation could not be discovered. ‘The course
traced measured 11-5 mm. Owen’s (1836, p. 126) account of his
dissection gives 1t a course of over 25 mm. before dividing into
the two uteri. The tail of the female is, in a lateral view
(Pl. VIII. fig. 37), rounded dorsally and flattened ventrally,
while in a ventral view (Pl. VIII. fig. 36) its end is bluntly
rounded and carries close to the tip a pair of unusually massive
caudal papille. It is clear that a collapse of the cuticle about
these papille might readily produce the “three-lobed” appearance
which Levinsen (1889) figures (vide infra, p. 297).
The ovum has a thin colourless shell with a very fine granu-
lation on its outer surface and the usual polar cap. In the
female examined the ova contained fully-formed embryos, some
of which were found in the act of escaping through the thinned
pole (Pl. VIII. fig. 38).
The justification for the correctness of the list of synonyms
given above is to be sought in the following lnes and in
Table VIT., page 302.
The original description of Gnathostoma spinigerum (Owen,
1836) based on specimens removed from tumours in the stomach-
wall of a young tiger which died in the London Zoological
Gardens, corresponds, so far as details are given, with that just
written above, except that he described the armature of the head-
bulb as similar to that of the body and noted only one spicule and
four pairs of papille, apparently three of the large lateral ones
THE NEMATODE FAMILY GNATHOSTOMID®. ASW E
and the sessile pair behind the cloacal opening. He found also
small worms, possibly young individuals of the same species,
5 lines long *. :
Diesing (1839, p. 222) in describing Cheiracanthus robustus
noted its closeness to Gnathostoma spuugerum, but, accepting as
correct Owen’s description of the head and spicule, he, with
diffidence, separated the two forms. Itis probably not doubted
at the present time that Owen and Diesing were working on the
same species. Ln his subsequent description of Diesing’s material,
v. Drasche (1883, p. 126) described four pairs of large and three
pairs of sessile papille.
Under the name of Cheiracanthus siamensis Levinsen (1889)
described a single poorly preserved immature female nematode
which had been removed from an abscess in the breast of a young
native woman in Siam. He was able to deal with external
characters only. The distribution and shape of the spines on the
head and body weve identical with those of Gnathostoma spini-
gerum. In his Latin synopsis (é, c. p. 525) he uses the expression
“ Corpus tir partem caudalem trilobatum desinet.” His figure of
the ventral aspect of the tail shows, however, that what actually
existed was merely a slight compression of the lateral outline of
the tail posteriorly to the anus, a condition which does not
correspond to the idea conveyed by the term “ three-lobed.”
Leiper (1909, p. 70) has described a male of Gnathostoma
siamense which, as the context indicates, came from a _ sub-
cutaneous swelling in a native of Siam. ‘The lips were large and
fleshy, measuring “1:5 by 0°5 mm.” [20°15 by 0°05 mm.] and
each bearing two papille witha median protrusion between them.
The cephalic hooks measured 0:015 by 0:005 mm. Spines covered
the anterior four-fifths of the body, the most anterior having
three digitations, the most posterior one only. The ejaculatory
duct was l-Smm.long. Later Leiper (1911, p. 18; 1913, p. 281),
after re-examining Diesing’s original examples of Cheiracanthus
robustus (which, however, he speaks of as having come from the
leopard), reaches the conclusion that the male form obtained from
man corresponds exactly with the male of Cheiracanthus robustus,
which, he remarks, “1s acceptedly the same as Gnathostoma spini-
gerum.” In no respect, indeed, do the forms from the sub-
cutaneous tissue of man differ, except in the matter of maturity,
from those from the stomach of Felide, but must be considered
merely as individuals which have strayed into an unnatural
habitat in an unnatural host (cf. Leiper, 1909, p. 80).
Cheiracanthus socialis Leidy (1859, p. 53) was found in cavities
in the thickened stomach-wall of the mink (Mustela vison). There
is in its size, in the character of its lips, head and hooks, in the
shape and distribution of the spines on the body, in the internal
organs, so far as described, and in the genital papille, nothing to
* Owen did not describe the males as 5 mm. long and the females as twice that
length, nor the tail of the female as trilobed (wide Stephens, in Fantham, Stephens
and Theobald (1916, p. 385)).
298 MR. H. A. BAYLIS AND LY.-COL. CLAYTON LANE ON
distinguish it from Gnathostoma spinigerum. It does not seem
reasonable to consider the name otherwise than as a synonym,
pending re-examination of the original material.
Gnathostoma paronai Porta (1908, p. 8) is a name based on a
single badly preserved female so opaque that no internal structure
was made out. Its meagre description is in every way applicable
to Gnathostoma spinigerum. It was found free in the intestine of
Rattus [Mus] rajah. Its unusual habitat and poor condition
suggest that it.was in reality a moribund parasite of some animal
eaten by the rat.
Schneider (1866, p 98) described from the gastric wall of
Paradoxurus philippinensis a parasite, Milaria radula, with the
general external appearance of Grathostoma spinigerum. He also
notes particularly that the egg-shell was finely stippled and
thickened at one pole, but detected only three pairs of caudal
papille in the male. He refused to identify his specimens
with Gnathostoma spinigerum, partly on account of their different
geographical distribution and partly because the tail-papille,
as he believed them to be situated, had an arrangement which
he associated with the genus ilaria. These reasons for separating
it from G. spinigeruwm cannot be accepted as cogent, nor are there
any cogent ones to be found in the description.
Specific Diagnosis.
GNATHOSTOMA SPINIGERUM Owen, 1836.
Gnathostoma: eight to eleven rows of hooks on the head-bulb ;
posteriorly-directed spines cover the anterior half or two-thirds
of the body, the anterior being comb-like, with four subequal
points, while the three-pointed spines have typically the middle
point the longest; in the male, small spines with the points directed
away from the cloacal opening cover most of the ventral aspect of
the posterior 0°38 mm. of the body; right spicule three or four
times as long as the left; tail of the. female, in ventral view,
uniformly rounded, with very massive papille.
For list of hosts, see p. 304.
GNATHOSTOMA HISPIDUM * Fedchenko, 1872.
Gnathostoma hispidum Fedcheuko (1872, p. 106; pl. xv.).
Cheiracanthus hispidus v. Linstow (1893, p. 201; pl. vii.
figs. 1-16). |
Cheiranthus hispidus v. Linstow (1893, p. 202) [misprint].
The description which follows is based partly on a translation
which we have privately (ee ined of the essential parts of
Fedchenko’s Russian paper tT, in which he describes material from
* For specific diagnosis, see p. 300.
+ The principal contents of the paper are rendered more accessible through its
Latin summary, and through an abstract of it in German by Leuckart (1873).
THE NEMATODE FAMILY GNATHOSTOMIDA. 299
the wild pig of Turkestan and the domestic pig of Hun gary, and
partly on descriptions of material from Hungarian pigs by
Csokor (1882), v. Ratz (1900), and v. Linstow (1893), and ve
Roumanian pigs by Ciurea (1911). A paper by Strdse (1892
and one by Collin (1893) in which he claimed to ‘have found ig
species in the ox in Berlin, we have been unable to consult. The
last is of minor importance in that Collin later authorised
Wolffhiigel (1912) to withdraw this statement, since, in the cir-
cumstances under which the material was received, he could not
exclude the pig as the possible host. In these descriptions
variations from the subfamily and generic characters detailed
above (vide pp. 254, 291) have, as we believe incorrectly, been
described by v. Linstow and Ciurea.
The anterior Lat spines (vide Table VII., p. 302) have sub-
equal points, which accordingly, as in Gnathostoma spinigerunr,
terminate at about the same level. More posteriorly the median
point tends to become the longest (Fedchenko), the others
gradually disappearing, so that at about the posterior end of the
esophagus the spines are simple but long. They extend as such
over the rest of the body except, judging by v. Linstow’s figures,
the large caudal papille of the male. Of these there are four pals,
No. 1 being the smallest and separated by an anterval from the
other three, which lie close together and are of about the same
size (Ciurea). Of te papille Fedchenko figures a pair between
the bases of Nos. 1 and 2 of the larger ones; v. Linstow omits
these but descr ee /suinilar pair close to one cee and anterior
to the cloacal opening, while Ciurea, in addition to the two pairs
which we have described as generic characters, finds three more
pars, two in front of and one behind the Eloneal opening, By all
these authors the termination of the tail is counted aman described
as an unpaired median papilla,
Tlie vulva les in the middle of the body (Fedchenko) or some-
what behind (v. Linstow) or in front of (Csokor, Ciurea) this
point. Csokor’s description of the cesophagus suggests that the
anterior part of his specimens was much contracted, which may
explain the anterior position of the vulva in them. We have
disregarded these statements in the description of the family.
Ciurea and v. Linstow agree in describing the egg as having a
hyaline appendage or wart-shaped structure at one pole ; the
former describes the outer surface of the shell as showing small
dimples, the latter finds it smooth. It is stated by v. Linstow
that im his specimens embryonic development had begun, and
that at the vulva there were a number of many- nucleated cells,
ee have, however, in his figure an appearance very suggestive
of ov
Baceopt for Collin’s statement, later withdrawn, the described
habitat (Table VIIT., p. 304) has always been the stomach-wall
of the pig, penetration into which may be partial or complete,
the worms in the latter case (Fedchenko) lying between the
gastric tunics.
300 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
Specific Diagnosis.
GNATHOSTOMA HISPIDUM Fedchenko, 1872.
Gnathostoma: nine to eleven rows of hooks on the head-bulb;
posteriorly directed spines cover the whole of the body, the
anterior being comb-like, with seven points, and shorter than
the more poster ior. The left spicule is twice as long as the right.
For list of hosts, see p. 304.
3. GNATHOSTOMA HORRIDUM (Leidy, 1856).
Cheiracanthus horridus Leidy (1856, p. 53).
Under the name of Cheiracanthus horridus Leidy described
from the stomach, presumably from the stomach lumen, of
Alligator mississippiensis four females, 2? inches long and a line
and a half thick, with the body “ cylindrical, incurved, posteriorly
subclavate, obtuse; anteriorly covered with palmate plates
furnished with as many as eight spines and degenerating
posteriorly to simple spines.” It is uncertain whether this last
expression implies that the spines reached the posterior end of
the worm.
The want of mention of any burrowing and the fact that the
host was a reptile and predatory are in favour of the belief that
these worms were really parasites of some host devoured by the
alligator; while, with the possible exception of size, there is no
characteristic by which this worm can be distinguished from
Gnathostoma hispidum. Regarding this last point it is probably
not disputable that a dead or dying worm commonly increases
in size as its muscles relax and decomposition begins.
Gnathostoma hispidum and G. horridum are not, however, here
described as synonyms, partly because no certain conclusion is
possible from the evidence, and partly because to do so would
necessitate the substitution of a name based only on females very
imperfectly described for one based on specimens which have
been investigated with considerable thoroughness. No specific
diagnosis of G. horridum is attempted.
4, GNATHOSTOMA GRACILE (Diesing, 1838).
Cheiracanthus gracilis Diesing (1838, p. 189), nomen nudum.
* 2 Diesing (1839, p. 225; pl. xiv. figs. 8-11;
pl. xvu, figs. 1- 20).
ss v. Drasche (1882 2, p. 126: pliix. figs. [2
[Not Echinocephalus 9 gracilis Stossich (in Shipley and Hed nell,
OG) oe EE |
Apart from its length (vide Table VII. p. 302) this nematode
has the following specific characters. The spines on the anterior
part of the body are leaf-like, with a maximum of five points,
one at the tip and the others along the lateral edges, two on
i
THE NEMATODE FAMILY GNATHOSTOMID. 301
each border. Each cervical sac displays a constriction near its
posterior end, a condition, however, which v. Drasche (1882,
p. 126) looks upon as a temporary local contraction; the spicules
are stouter than in “Cheiracanthus robustus”; the four large
lateral caudal papille of the male are so arranged that there is
a considerable interval between Nos. 1 and 2; the egg is figured
as being without a polar cap, and the habitat was the intestinal
canal of a fish which reaches a length of 15 feet and is presumably
carnivorous.
The great length and unusual habitat suggest, as in the case. of
Gnathostoma horridum, that the real host was some mammal! which
was devoured by the “ Pirarucu.”
Specific Diagnosis.
GNATHOSTOMA GRACILE (Dies., 1838).
Gnathostoma: anterior body-spines leaf-like, with five points,
one at the tip and two along each edge.
5, GNATHOSTOMA TURGIDUM Stossich, 1902.
Gnathostoma turgida Stossich (1902, p. 13).
This species is based on a short description of the external
characters of two poorly preserved females. Stossich is convinced
that it is distinct from Gnrathostoma spinigerwm, basing his con-
viction on the statement that the discoidal head-bulb has from
10 to 12 rows of spines, the body is cylindrical and tapers in
both directions, and its spines are of varying shape. There is no
further information beyond the details to be found in Table VIT.,
p. 302, and Table VIII., p. 304. The name is likely to be a source
of future confusion. Since there is nothing specifically distinctive
in the description no specific diagnosis is possible.
Species which have been attributed to the Genus Gnathostoma.
GNATHOSTOMA SHIPLEYI Stossich, 1900.
Gnathostoma shipleyi Stossich, in Shipley (1900, p. 560, fig. G).
fiictularia paradoxa v. Linstow (1903, p. 272; pl. xviii. fig. 5).
Acuaria pelagica Seurat (1916, p. 785, figs. 1-5).
Seuratia shipleyi Skrjabin (1916, p. 971).
Seurat’s careful description of the female of this species dis-
closes neither cervical sacs nor ballonets. ‘The absence of these
and of trilobed lips excludes the worm from the Gnathostomide.
GNATHOSTOMA PELECANI (Chatin, 1874).
Sclerostoma pelecant Chatin (1874, p. 6; pl. viil. fig. 125; pl. ix.
igs. 1, 2).
Gnathostoma pelecani Skrjabin (1916, p. 972).
Leneth-of tail oie. he eee
| Ova (maximum measurements) .
| Length of ballonets
| Breadth of lips
_ Distance between rows of hooks|
| Distance between rows of Dody-|
_ Portion of body “covered by
202 MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON
Thickness (maximum)
Described by ......
f
Under the name of)
|
eet Wes veneers y c o) 4 > . |
| behind middle. magia veh ede: of middle. |
0°06 X 0'03d 0°072 X 0'039 | | C0741 X 00418 |
a
7
7
7
7
-
vy
=
-
;
_
oT
-
-
:
fo
:
:
2
-
out}
i.
oem
6
oT
7
_
iT
a)
>
ia -
&
2
7
S
5 7
mo =
.
: I
“tn
_
-
- _—
es
- :
7
3
a
= —
7
'
_
20 -
7 -
a 7 7
Z
ood 1
-
\
¥
} 7
a Lo]
a
7 a
“
: —
wa
o—
: a
le
Ce
.
*
7
am 6%
a
_
7
‘ =
,
302 MR. H, A. BAYLIS AND Lf.-COL. CLAYTON LANE ON
Taste VIT.—
Measurement of
Al '
(All Measurements
| G. Spinigerum,
| . .
| Diesing, si te
bed by ...... Owen. Dajardin, chneider, Leidy, iH |
a | v. Drasche. | Tevinsen,
(| Gnathostoma Cheiracanthus | Filaria Gnathostoma Chej»
Under the name of | uy spinigerum. robustus. radula. sociale. Prec
| ae 2 3. 2. moe
GED EEN rey settee totes ote 2 10tol2 | 10to12 Py ees || 4
Thickness (maximum) ......... 3 2 26 2 || leis 1
Length of head ..........---.....+
Length of head-bulb ...............]
|
Transverse diameter of head-bulb, |
|
Length of ballonets :
Distance from head-end to ter- 2
mination of cervieal sacs 5 |
| Length of neck of cervical saes . |
Breadth of lips
Number of rows of hooks on!
head-bulb.. aos 6 or 7 6 or 7 8
Length of hooks on head-bul Ee }
Breadth of hooks on head-bulb.. |
Distance between rows of hooks
on head-bulb .........0.......
| Distance between rows of body-
spines re its |
Portion of body ‘covered hy 2. anterior
spines ...... y two-thirds.
Maximum number of points on
body-spines . 3 4 3 3
Distance from he:
cal papilla ..........
Distance from head-end to ner ve!
ring TENE ore et |
Distance from head: eal to ter- 2 i
mination of wsophagns ..,.. S|
ENE trout) eee |
ie
| Length of spicules...
Distance from oP of tail to
DMR LLG SS) < Sere Rie ats eal 8 |
|
Ova Gece measurements) , | , te)
| ae oe
THE NEMATODE FAMILY GNATHOSTOMID®,
303
Fs gpecies of Gnathostoma.
iD pillimetres.)
Ze oe ae | 2 F = =
% G, hispidum. G. G. | G.
gracile. \ horridum. turgidum.
_—_— a ail ie = a we | —— |—
a |
Leiper Baylis & Lane. v. Linstow. | — Csokor, Ciurea. \, isin Leidy. | Stossich.
eiper ) . Drasche.
Cheir Gnathostoma |
siamensiS- spinigerum. | \
el 7 = SSS aon are
~~ co eae ee eee
6 | seu | 18'to Ito | 22to | 5, | 3, |19to | 32 to| a y st
1055 }|to1675| 183 || 18 | 25 sal 25 45 36 35 2:
Fl, eee | tec a : 4
06 | 19 12 | 1:38 1:85 2 | or 5 2
| Od 0°32 ™ 037 | 0°37 |
| 0:23 Gea i
| 0525 . |
| 05 to 075
| 06
a 0°25
ae (| 1:9 to |} 0: 07
1 18 rl 2:0 88
|): deers 03
| ( 019
ay Wey asia) 0:2 | |
(025
ef Sak a 9 toll 12 | iene
0015 | 0:025 0:029 07018 |
0005 O01 0-007
0'023 |
: |
; 022 |
anterior | RS ue | erale u ‘ EO
half. two-thirds. |) : | alt.
4 7 7 9 5 8
| 07 to 075
| 08 | | |
(| 315 | 34 | 1/56 - |
) to to of 343 | 65
U| 35 4 | total length.
| 082 | O16 |} ol2
I = ———__—__—_—
E =} - | —
ae te R. Ibis 9 4)| eels | L. Longer. Short’r.) | |
WU Tape) 2h) | MG. a ca te aa on i |
2°63 08 | O-4 | 0°88 1:29 fe | | |
4 | Somewhat | bane i eon | |
behind middle. wisdaletiidss| 2° mice I |
0:06 X 0035 || 0-072 x 0039 G-0741 X00418 |
. |
MittTeEr, S. N.
Morin, R.
MontIcE Ltt, F. S.
Owen, R.
Parona, C.
Porta, A.
BAYLIS AND LT.-COL. CLAYTON LANE ON
(1911)—Notes on recent and some new records of Hel-
minthes of Man of which there are few records.
Journ. London Sch. Trop. Med., Part I. pp. 16-19.
(1913)—Observations on certain Helminths of Man.
Trans. Soc. Trop. Med. & Hyg., vi., 8., pp. 265-
297. 4
(1873)—Bericht tiber die wiss. Naturg. der niederen 'Thieren,
- 1872-1875. Arch. f. Naturg., Berlin) xox:
pp. 560-561.
(1889)—Om en ny Rundorm hos Mennesket, Cheiracanthus
siamensis, nov. sp. Vidensk. Meddel. Naturh.
For., Kjébenhavn (1890), pp. 323-326, pl. vii.
figs. 9-14.
Abstract in German by H. Krabbe in Centralbl. f.
Bakt. u. Parasit., Jena, viii. p. 182 (1890).
(1879)—Helminthologische Untersuchungen. Wirttemb.
Naturw. Jahresh. xxxv. pp. 313-342, pl. v.
(1893)—-Oxyuris paronai un. sp. und Cheiracanthus hispidus
Fedt. Arch. f. Naturg., Berlin, lix., 1., pp. 201-
208, pl. vii. figs. 1-16.
(1903)—Entozoa des Zool. Mus. der k. Akad. Wiss. zu
St. Petersburg. If. Ann. Mus. Zool. Ac. Imp.
Sci., St. Petersburg, vii. 38-4., pp. 265-294,
pls. xvii.—xix.
(1904a)—Nematoda in the Collection of the Colombo
Museum. Spolia Zeylanica, i. pp. 91-104,
pls. 1-11.
(1904 6)—Beobachtungen an Nematoden und _ Cestoden.
Arch. f. Naturg., Berlin, Ixx., 1., pp. 297-309,
pl. xiii.
(1906)—Helminthes from the Collection of the Colombo
Museum. Spolia Zeylanica, iii, 11., pp. 163-188,
pls. 1.111.
(1909)—Parasitische Nematoden: in Brauer, Die Siiss-
wasserfauna Deutschlands, Jena, Heft 15,
pp. 47-92.
(1910)—Gnathostoma spinigerum in a domestic Cat.
Journ. Trop. Vet. Sci., Calcutta, pp. 284-285,
Dl: xxiv.
(1912)—Noteon Gnathostomum spinigerum. Parasitology,
Cambridge, v., 2., p. 150, pl. v.
(1858)—Prospectus helminthum, que in prodromo faunge
helminthol. Venetiz continentur. Sitz. k. Akad.
Wiss., Wien, xxx. pp. 127-158.
(1860)—Trenta specie di Nematoidi. Sitz. k. Akad. Wiss.,
Wien, xl. pp. 831-358.
(1861)—Prodromus Faunz Helminthologicee Veneta. Denk.
k. Akad. Wiss., Wien, xix. pp. 189-888, pls. ixy¢.
(1889)—Elenco degli Elminti raccolti dal Capitano G,
Chierchia durante il viaggio... della R. corvetta
“Vettor Pisani.” Boll. Soc. Nat., Napoli, (1)
iu. pp. 67-71.
(1836)—Proc. Zool. Soc., London, Part IV. pp. 123-126.
(1898)—Elminti raccolti dal Dott. Elio Modigliani alle
isole Mentawei, Engano e Sumatra. Ann. Mus.
Genova, (2) xix. pp. 102-124, pl. i.
(1908)—Descrizione di una nuova specie di Gnathostomide
(Nematodes). Zool. Anz., Leipzig, xxxiil. pp. 8-9,
of molar
SOUTH AFRICAN THEROCEPHALIAN REPTILES. 349
teeth. In many skulls when no molars are found we suspect
that they may have been lost, but here this can hardly be the
ease. Both maxille are well preserved and the dentary as well,
yet in none of the three bones is there any trace of molars.
Further, the alveolar margin is narrow and sharp, and would be
much too slender for the accommodation of molars large enough
to be serviceable to an animal of the size.
The lacrimal is fairly large, and forms a considerable part of
the facial surface, which is very smooth.
The prefrontal forms the anterior and upper quarter of the
orbital margin. It meets the frontal, nasal, maxilla, and
lacrimal bones.
The frentals are relatively small, and the two form most of the
Text-figure 5,
\
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. “4 A
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a
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Upper surface of skull of Alopecopsis atavus Broom.
slightly concave interorbital surface. In front each has a short
articulation with the nasaland a much longer oblique articulation
with the prefrontal, and as the prefrontal nearly extends back-
ards to the postorbital, the frontal only forms a very small part
of the orbital margin. Posteriorly the frontal has a long articu-
lation with the postorbital, and a short interdigitating suture
with the parietal mainly hidden by the postorbital.
There is no postfrontal.
The postorbital is a peculiarly twisted bone. Its inner end
lies against the narrow parietal crest, and from this, passing
350 DR. R. BROOM ON SOME NEW
outwards, it forms the back wall of the frontal region and the
anterior border of the temporal fossa. From the point where it
meets the frontal at the orbital margin it passes almost directly
backwards, forming most of the posterior half of the upper
orbital margin. It then passes downwards behind the jugal to
nearly the level of the lower side of the orbit.
The jugal is a large bone. It forms almost the whole of the
suborbital arch and about half of the postorbital. Posteriorly it
passes back below the squamosal to near the quadrate region.
The parietals are narrow, and form a median crest which in
front is overlapped by the postorbitals. The pineal foramen 1s
rudimentary.
The back of the skull is not well preserved, the bones being
very rotten, but so far as can be seen the structure does not differ
from that of typical Therocephalians.
Text-figure 6.
xf Vo = Pas.
Section through skull of Alopecopsis atavus Broom, immediately behind
postorbital arch.
A section through the skull immediately behind the post-
orbital arch shows the relations of the parietals and postorbitals
above and the pterygoid below, with between them a thin
anterior process of the basisphenoid, and above them the feebly
developed element which I believe to be the true vomer, but
which moss others call the parasphenoid.
The right mandible is fairiy complete and the dentary almost
perfect. In front there are three incisors which together measure
9mm., and theseare closely followed by a long procumbent canine
which has antero-posterior diameter of 8°5 mm. and a height of
something over 20mm. ‘lhere appear to be no serrations on either
the incisors or the canine. Though the alveolar margin of the
dentary 1s perfectly preserved, there is no trace to be seen of any
SOUTH AFRICAN THEROCEPHALIAN REPTILES, oo
molars. The dental formula of Alopecopsis atavus is thus the
very remarkable one :—i. $, c. +, m.?=+. As will be seen from
the figure I give, the dentary is very peculiarly shaped. Behind
the canine the upper border of the bone is deeply concave, so
that, even if there had been teeth, they could not have met molars
in the upper jaw unless they were exceptionally long. The back
part of the dentary is powerful, and there is a long but thick
coronoid process. ‘The coronoid bone is well developed, not so
deep as and much thicker than the coronoid in Gorgonopsians
or Cynodonts. The back part of the jaw is not sufficiently well
preserved to admit of description, but itis relatively much shorter
than in Gorgonopsians and apparently more like that of Bauria.
MoscHoRHINUS KITCHINGI, gen. et sp. nov.
This new genus and species is founded on a well-preserved
specimen discovered by Mr. James Kitching near New Bethesda
Road. It consists of the anterior two-thirds of the skull of
Text-figure 7,
Upper surface of front of skull of Moschorhinus kitchingt Broom.
a moderately large Therocephalian. The specimen is slightly
crushed, but the matrix is only slightly harder than the bone.
and it has been found possible to display almost every detail
of the structure of the palate.
The skull is manifestly that of a broad-headed short-snouted
form, the front of the snout being usually blunt and wide.
The premaxillaries are broad and powerful, and each carried
six well-developed incisors. As preserved, each bone has only
five teeth, but quite manifestly the 3rd is lost from the right
side and the 6th from the left. The whole series measures 41 mm.
The first four incisors are much flattened and with the long axis
352 DR. R. BROOM ON SOME NEW
directed mainly antero-posteriorly. The posterior two incisors
are more rounded.
The septomaxillary is large, and forms the lower border of the
nostril, but does not extend far backwards between the nasal and
the maxilla. ‘The foramen, usually present between the septo-
maxilla and maxilla, 1s small.
The nasal bone is exceptionally large and broad. In front it is
erushed down on the nostrils and the details of structure cannot
be made out, but doubtless the arrangement 1s similar to that in
typical Therocephalians. Poster iorly ‘the nasal meets the frontal
a little in front of the plane through the centre of the orbit.
The shape of the bone will be best understood from the figure.
The maxilla is a short but powerful bone. It overlaps the pre-
maxilla to between the roots of the 3rd and 4th incisors. It has
one large canine which measures 24 nm.x 12mm. Behind the
canine only a very small part of the maxilla shows on the palatal
aspect, and in the specimen there are no teeth, but on each side
there are indications of two old sockets with a possible third very
small one; and J think we may assume that there were three
molars, of which the 3rd was small. ‘The three would measure
about 19mm. The upper dental formula would thus be 1.°, ¢.', m.3
The prefrontal is relatively small, and wedged in between the
nasal and frontal above and the maxilla and lacrimal below.
The lacrimal is slightly larger than the prefrontal, and it forms
most of the front of the orbit. Near the middle of the bone and
on the orbital margin is a well-developed bony boss, and on the
inner side of this and near its upper end is a large lacrimal
foramen.
Very little of the jugal is preserved, but the part underneath
the orbit forms with the maxilla a very deep and powerful sub-
orbital arch.
The frontals are large and wide, as seen in the figure.
There is no postfrontal. The postorbital les on the frontal
and parietal.
The parietal crest 1s narrow as in typical Therocephalians, but
the pineal foramen is rudimentary.
The palate is beautifully preserved and remarkably interesting.
The palatal portion of the premaxillaries has not been displayed
as the matrix 1s required to support the fragmentary incisors,
The prevomers form a large part of the bony roof of the mouth.
In front they are anchylosed and form a wide plate between the
internal nares. At the back part of the nares they are much
constricted, but beyond this widen out again into a fan-shaped
structure which lies between the palatines and meets the ptery-
goids. In this back part a median suture between the two
prevomers is very distinctly seen.
The palatine is a large and powerful bone. Externally it has
a long articulation with the maxilla, and here the palatine is so
thickened that it forms more of the wide alveolar surface than
does the maxilla. In front and nearly on the plane of the back of
SOUTH AFRICAN THEROCEPHAIIAN REPTILES. Bae,
the canine, where the maxilla passes up to form the vault of the
palate, the palatine hes closely against the maxilla except where
there is a large foramen, presumably for a nerve. Haughton
figures two foramina in a corresponding structure in
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CHALICOTHEROIDEA from BALUCHISTAN. :
. oli
ON CHALICOTHEROIDEA FROM BALUCHISTAN, B57
19. Chalicotheroidea trom Baluchistan. By C. Forstrer-
Cooper, M.A., F.Z.S., Superintendent of the Uni-
versity Museum of Zoology, Cambridge.
‘Received April 16, 1920: Read May 11, 1920.]
(Plate I.* and Text-figures 1-7.)
Dr. Pilgrim, in his report f on the fossil vertebrate fauna of
the Bugti Hills, has described two forms of Chalicotheres, of which
the salen is represented by material too fragmentary to be
named, while to the larger he has given generic rank with the
name of Phyllotillon naricus.
My own collections have produced a small amount of further
material for study, fragmentary and in some cases much worn,
but sufficient to add in some poimts to our knowledge of these
two forms.
Holland and Peterson { in thei very complete memoir on
Moropus elatus and the osteology of the Chalicotheroidea have
taken exception to the creation by Dr. Pilgrim of a separate
genus for his species, Phyllotdlon naricus. This objection is
reasonable, seeing that the chief character on which the genus
is founded is one which occurs in other genera of Chalicotheres.
Dr. Pilgrim states$ that “the difference is particularly -well
shown in the structure of the upper premolars. ... .An unworn
specimen of pm.3....shows that the large inner cusp was
united to the ectoloph by a double instead of a single crest.”
This statement, as Holland and Peterson point out, 1s open to
alternative interpretations—viz., either that there is a crest
vunning from each side of the inner cusp to the ectoloph, or that
each crest is double.
The former interpretation represents the actual condition of
the tooth, and is the meaning Dr. Pilgrim wished to convey||. As
this condition is found in Moropus it loses its value as a generic
character, On the other hand, to judge from Dépéret’s figure of
Macrotheriwm grande ¥, the fourth premolar does appear to differ
in the arrangement of the crests from that of the Bugti specimens
in that the anterior crest seems less developed in MW. grande, in
which form the anterior external cusp is a separate rounded
hillock. Gaudry’s figure of Schizothertwm modicum shows both
* For explanation of the Plate, see p. 366.
+ Rec. Geol. Surv. Ind. x]. p. 67, and Mem. Geol. Surv. Ind. n.s. vol. iv. Mem. 2,
p. 33.
£ Mem. Carnegie Mus. vol. iii. no. 2, 1913.
§ Mem. loc. cit. p. 33.
|| I had the opportunity of consulting Dr. Pilgrim on this point during a short
visit made by him to Cambridge, and have his author ity for a eae this statement.
© Arch. du Mus. d’Hist. Nat. de Lyon, xol. v. 1892, pl. iii. fig.
oie
358 MR. C. FORSTER-COOPER ON
ridges, but the anterior seems to be weaker than the posterior,
while the preceding premolars seem to have no anterior ridges.
Chalicotherium sivalense is like Schizotherium in this respect,
according to Falconer’s figures in the ‘ Fauna Antiqua Sivalensis,’
plate Ixxx.
There are other differences from Macrotheriwm in the shape of
the various teeth, so that there are some grounds for Dr. Pilgrim’s
separating them.
Whether or not the Bugti specimens can be placed in any
other described genus is even more difficult to decide. Our com-
bined material is scanty and none too well preserved, so that
many characters remain unknown or at best uncertain, and for
the present it seems useful to retain the generic name of
Phyllotillon.
The material forming the basis of the present description
consists of :—
1, A series of upper teeth, pm. 3-4, m. 1-2, much worn but
giving the outline and general shapes of the teeth.
. A moderately worn third and fourth upper premolar.
. Three separate upper molars.
. A fourth upper premolar only a little worn.
. fragmentary lower molars and lower jaws, sufficient when
combined to give an outline of the middle portion of
the mandible.
6. Some separate toe bones.
Ou HR Co bo
The first and second specimens (text-fig. 1) supplement Dr. Pil-
grim’s figure * in giving a better preserved shape of pm. J and
Text-figure 1.
Phyllotillon naricus. 38rd and 4th premolars, 1st and 2nd molars. X
NH
in adding the shape of the second molar. The third premolar as
well as the fourth (this outline filled in from the second specimen)
have, roughly speaking, a square outline; the anterior outside
border is produced into a somewhat prominent style, more pro-
nounced than in Macrotheriwm and to much the same degree as
in Moropus. In proportions the teeth differ from other deseribed
* Mem. loc. cit. pl. xii. fig. 2.
CHALICOTHEROIDEA FROM BALUCHISTAN. 359
forms in the greater approximation of the length and breadth,
being square r ather than transversely elongated.
The upper figure in Plate I. represents the fourth upper
premolar in a slightly worn condition, and illustrates the two
ridges described by Pilgrim; in the centro-internal cusp and
broad internal cingulum it shows features characteristic of all
Chalicotheroids.
The molars are all elongated, and in this respect differ from
those of Ifacrotheriwm, where they are all square, and from Nestori-
therium and Circotherium, where the molars change from square
in the front one to elongate in the third. They agree best with
those of Moropus, but carry the elongation to a still greater
degree, and represent the greatest modification in this respect.
The lower figure in Plate I. shows two right upper molars just
erupted, only the posterior half of the second being preserved.
The condition of this fragment is excellent. In shape and in
pattern they resemble Dépéret’s figures * of the milk teeth of
Macrotherium and also those figured by Pilgrim for this species ¥.
They are, however, in all probability the permanent second and
third molars, being considerably larger than the measurements of
the milk teeth given by Pilgrim—7. e., the third molar is 48 mm.
long and 36 mm. wide in the front half as against 40 mm, and
31 mm. The only points in which these teeth differ from
Pilgvim’s description of his specimen are that here the whole
external surface of the metacone—z.e., from mesostyle to
metastyle—is considerably smaller in the third molar than in the
second, and that faint ribs are present on the external surface of
the metacone of the second tooth and quite absent on that of ee
third. A corresponding rib, rather more clearly marked, 1
present on the paracone external surface of the third sae
and presumably would be found in the other molars. ‘These ribs
are not shown in Dépéret’s figures t, and in Holland and Peterson’s
figures of JMoropus they are shown only on the protocones of
all three molars, where, however, they appear to be strongly
marked.
Text-fig. 2 shows the outline of one of the fragments of mandible
which has the socket for three incisors, or the second and third
incisor and a canine—all apparently small-rooted teeth—and the
whole premolar-molar series except the last half of the third
molar. ‘This is continued by another fragment (the dotted outline
in the figure) with the third and the second half of the second
molar. As these fragments coincide in size they may be con-
sidered as belonging to the same species.
The mandible thus reconstructed shows certain peculiarities.
Compared with the best-known Chalicothere (J/oropus elatus), as
figured by Holland and Peterson §, it has a much flatter lower
* Loc. cit. pl. ii. figs. 4 & 5.
+ Mem. pl. xu. fig. 3
{ Loe. cit.
§ Loe. cit. pl._lii,
340 MR. C. FORSTER-COOPER ON
border and is without the swelling under the anterior pre-
molar. There is evidence, however, of a similar swelling further
forward, which in this jaw is just under the mental foramen.
This point marks the beginning of the symphysis, and the lower
border in the region just behind the symphysis is sharp and
vidge-like. There is apparently only one mental foramen instead
of several, but it is much larger in proportion than those of
VM. elatus. he diastema between the incisor and anterior
premolar is small (cirea 25 mm.), and the latter tooth seems to
have been very much reduced in size. ‘The jaw is about half the
length of J, elatus, while the teeth are nearly as big, so that
Text-figure 2.
Phyllotillon naricus. Fragment of mandible with dotted outline of another
fragment in continuation. X 3.
the proportions are entirely different. The hinder part of the
jaw is not known, but in the fragments at hand there is no sign
of a downwardly-turned angle, though Pilgrim’s figure * suggests
a slight one.
The flat lower border is a point of difference from Macro-
therium rhodanicum and other forms in which this feature is
known, while the shortening of the anterior part 1s a point in
eommon with WW. rhodanicum and Chalicotherium sivalense.
The subjoined measurements show that the animal occurred in
two sizes, which possibly represents a sexual difference :—
* Loe. cit. pl. xi. fig. 4a,
CHALICOLHEROIDEA FROM BALUCHISTAN. 361
Opper Teeth.
Premolars. Molars.
| fhird. | Fourth. First. Second. Third.
i | aaa | | Peper ij ieee hb ak 7
| Length Breadth Length Breadth) Length} Breadth: | Length! Breadth : Length Breadth:
| | | pote hind front hind front hind:
23 Oe ear 3G | pee |
23 Me i 2orr i 2h, Ne 82) |) PR B02) 47 3735
| | | ' | |
=a | 2 po ge hag” I ge ' 84. |
|
c
Three separate molars |
| 2 9nd or Brd
\
| |
| lL, 41 | 82 28
| Lower Teeth.
Toes | 23 ieee tess) iG lor 42 21 99 P| on F
pee on is || 98? |16 18°] 40 | 21 21] 46 | 23 93
| | | | | |
wee.) 18 24 15 il |
| | | | | 4 | 22 21}
| | | |
| | | | |
| : |
\
Measurements in millimetres.
A few toe bones found in these deposits are noticed at the end
of this paper. They show certain characters of interest, but as
they may be the smaller toes of this species or the larger ones of
the following, they are of no specific value.
The main characters of this form may be summarised as
tollows :—
3 1 0 3
Seni o) PMs sy Ti, 5.
Lower pm.2 small (pm.1 absent above and below). pm.3 & 4
elongate. All molars elongate, especially the second. Lower
border of lower jaw unusually flat: one mental foramen. Jaw in
section rather flat outside and slightly convex inside. Moderate
diastema in front of anterior lower premolar. There is thus a
mixture of various generic chaiacters, the balance, perlans,
favouring a general resemblance to Moropus. The form is at
present insufficiently known, but there is enough to warrant the
vetention of Dr. Pilgrim’s generic name until further material is
discovered,
Dentition Upper premolars square.
362 MR. C. FORSTER-COOPER ON
SCHIZOTHERIUM PILGRIMI, sp. n.
Pilgrim also mentions the presence of a smaller form in these
deposits, indicated by some fragments too much worn for accurate
description. In the present collection are two unworn and per-
fectly preserved upper molars (Plate I., central figure) of an
animal much smaller than those of ae species just described,
and which may belong to Pilgrim’s undescribed species although
even a shade smaller than the latter.
The smaller size of these teeth suggests at first that they are
milk teeth, but there are certain arguments against this view,
which is not adopted here. The specimen fortunately has just
enough of the anterior part on the zygomatic arch to show the
moles position of the teeth in the maxilla (text-fig. 3). A
reference to Holland and Peterson’s figure * shows that in the
Text-figure 3.
Schizotherium? pilgrimi. 1st and 2nd upper molars in side view, showing their
position relative to the zygomatic arch. The position of the antorbital foramen
is marked with an * Nat. size. Type-specimen.
milk and permanent molars of Moropus the last milk tooth lies
well in front of the anterior root of the maxillary process of the
zygoma, the first molar under the root of this process, and
the second under its posterior border. If the present specimen
is grown in a similar way, it supports the view that the teeth are
the first two true molars, The anterior tooth is slightly worn, the
second only just erupted. Beneath them there are cavities without
trace of successional teeth and too small to allow of them. The
teeth being fully formed and practically in wear, the germs of the
succeeding teeth would have been comparatively well developed.
Moreover, of two fragments of lower jaws one has the last milk
molar fairly well worm and the front part of the first lower molar
just erupted. One side of this specimen has been ground away,
and the section (text-fig. 4) shows the last milk molar with the
* Loe, cit. pl. li. figs. 1-2.
CHALICOTHEROIDEA FROM BALUCHISTAN. 363
section of the edge of the permanent succeeding tooth below it;
there is no germ below the next tooth, whose roots are much
larger and straighter. This tooth fits the front tooth of the two
upper molars mentioned above.
A second specimen shows two lower molars well worn, of which
the first is about the same size as the first true molars of the
previous specimen. The fragment is broken away underneath,
and the roots show that they belong undoubtedly to permanent
teeth.
Text-figure 4.
Schizotherium ? pilgrimi, Fragment of lower jaw with last deciduous tooth and
Ist true molar. One side of the specimen is ground away, showing the edge of
the germ of the 4th premolar, marked with an *. The anterior root of the
deciduous toothis im section, the level of the posterior root not being quite
reached by the grinding. The stout front root of the 1st molar is in section, the
posterior is partly in section and partly a cavity: 7. e. the lower half, where the
root has fallen out. Nat. size.
The upper dentition being the best preserved is here made the
type-specimen of the species.
Measurements (in millimetres) :—
Upper molars. Type-specimen.
1st molar, 2nd molar.
Mere tlie 2558 ees ent Yee 2] 20
Breadth, front half ... 20 24
fe second half.. 20 23
Lower molais. dst. 2nd. | Ist. 2nd,
TBS Tet Neer oes ery otis: 18 — 18 22
Breadth, front half...’ 10 — 10 12
iy second half... 2 —- let 12
Figured specimen (text-fig. 4). Second specimen.
The upper molars are square, and resemble those of Schizo-
therium modicum in size as well as in shape. The attribution of
the present species to the genus is tentative.
364 MR. C. FORSTER -COOPER ON
There is yet another specimen of a lower jaw with a much-
worn first molar and roots of the last premolar and second and
third molars. The first molar is 22 mm. long and about 12 mm.
broad, and is therefore larger than the other specimens. The
lower border of the jaw is extremely straight, as in Phyllotillon
naricus. In size it seems to correspond with Pilgrim’s unnamed
fragment. Whether it represents a sexual difference from
Schizotherium pilgrimi ov yet a third species remains unsolved.
Text-figure 5,
° Metacarpal or metatarsal! of a Chalicotheroid. Nat. size.
Until the anatomy of these animals, and indeed of all Chalico-
theres with the exception of Moropus, is better known, it is
impossible to feel sure of their generic position. A good deal
of interest lies in the condition of the feet and the gradual loss of
the first and fifth toes. According to Holland and Peterson *,
both should be present in the fore foot of the Schizotherune. In
the present collection are several phalanges and one bone which
may be a lateral podial (text-fig. 5); 1t is just possible that it
may represent a fifth metacarpal or tarsal. Of the phalanges
three out of six show the co-ossification of the proximal and
median (text-fig. 6), which was evidently a common feature, as
Holland and Peterson describe it in Moropus. The free proximal
phalanges all show strongly-marked tubercles on the posterior
faces (text-fig. 7) for the flexor attachments. Some of the
fused bones show this feature, but to a less degree. They are
not to be found in corresponding bones of dMacrotheriwm or
* Loe. cit. p. 201,
CHALICOTHEROIDEA FROM BALUCHISTAN. 365
Chalicotherium in the British Museum collection, nov have they
been noted or figured elsewhere. It 18 not possible at present to
assign these bones to one or other of the Baluchi species.
Text-figure 6.
Co-ossified proximal and median phalanges of a Chalicotheroid,
lateral surface. XX 4.
Text-figure 7.
Median phalanx of a Chalicotheroid, posterior surface showing
the two tubercles. XX 3.
It is interesting to note that while remains of Anthracotheres
and Rhinoceroses of all kinds are very abundant in the Dera
Bugti deposits, Chalicothere remains are here, as elsewhere,
extremely rare. They seem to have Leen of solitary as well as
of strange habits, though recent discoveries seem to point to
Moropus having been to some extent gregarious.
Note.—The specimens mentioned in this paper together with
all the other Chalicothere material from Baluchistan have been
added to the British Museum collections. —
366 ON CHALICOTHEROIDEA FROM BALUCHISTAN.
EXPLANATION OF PLATE I.
Upper FIGURE. ‘
Phyllotillon naricus. 4thupper premolar. Nat. size.
LOWER FIGuRE.
Phyllotillon naricus. 3rd upper molar and part of 2nd, Nat. size.
CENTRAL FIGURE.
Schizotherium ¥ pilgrimi. 1st and 2nd upper molars. Nat. size; type-specimen.
DAKIN, PI.
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16. Median part of vas deferens, with mass of spermatozoa. X 200.
17. Terminal thick-walled part of vas deferens. > 200.
18. Longitudinal section. Ductus ejaculatorius. XX 200.
19, Diagrammatic transverse section in plane of last pair of legs. X 24.
20. Diagrammatic transverse section in plane where vas deferens crosses below
nerve-cords posteriorly. X 24.
21. T.S. Part of wall of anal gland of male. X 240.
22. Diagram showing connections of receptacula seminis with oviducts, and
ovaries. X 200.
23. T.S. Infundibular region of oviduct. xX 200.
24, L.S. Wall of ovary and oviduct. X 240.
25. T.S. Duct of receptaculum seminis. X 280.
ONYCHOPHORA OF WEST AUSTRALIA. 389
EXPLANATION OF LETTERING.
A. Anus. Or.Pap. Oral papilla.
An.Gl. Anal gland. Ov. Ovary.
Cil.R. Ciliated portion of nephri- | Ovid. Oviduct.
dium. Pie Pharynx.
Cee. Ceelomic cavity. : Rec.Sem. Receptaculum seminis.
Coll.Ves. Collecting vesicle. Rect. Rectum.
‘Cr.G1. Crural gland. Sal.Gl. Salivary gland.
er Gl.’ Crural gland of 1st leg. Sal.G.d. Salivary gland duct.
Cr.Gl.”” = Crural gland of last leg. S.V. Seminal vesicle.
Crur.pap. Crural papilla. | Sli.G@l. Slime gland.
Cut. Cuticle. | Sp. Spermatozoa.
pid. Epidermis. | Tes. Testis.
elie Heart. | Ut. Uterus.
N. Position of leg. | Vag. Vagina.
NC. Nerve cord. | Vas.def. Vas deferens.
Neph. Nephridium. Vas.def.r. Vas deferens of right side.
Neph.’ Ditto of 4th and 5th legs. | Vas.def.l. Ditto of left side.
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ON MARINE WOOD-BORING ANIMALS. 391
21. Notes on Marine Wood-boring Animals.—I. The Ship-
worms (Teredinide). By W.T. Catman, D.Sc.
(Submitted for Publication by permission of the Trustees of the British Museum.)
[Received April 27, 1920: Read June 1, 1920.]
(Text-figures 1-11.)
The specimens discussed in this paper were collected, for the
most part, on behalf of a Committee appointed by the Institution
of Civil Engineers to inquire into the deterioration of structures
exposed to sea-action. This Committee, at my suggestion, re-
quested its correspondents at various seaports to send in speci-
mens of animals damaging the timber of harbour works. The
result has been to get together a collection of very considerable
importance, both from the point of view of the practical engineer
and from that of the scientific zoologist. A set of the specimens
will be placed in the Museum of the Institution of Civil
Engineers, and the remainder have been presented by the
Committee to the British Museum (Natural History). I desire
to express my sense of obligation to the members of the Com-
mittee, more especially to the Chairman, Sir William Matthews,
K.C.M.G., and the Secretary, Mr. P. M. Crosthwaite, as well as
to the various harbour engineers named below, by whom the
specimens were collected and preserved.
In dealing with the Teredinide I trespass with reluctance on
the domain of the malacologists. It is only the impossibility of
finding a student of Mollusca ready to undertake the description
of the collection that leads me to publish these notes, to which,
however, the very accurate figures drawn by Miss G. M. Wood-
ward may give some per manent value. I am indebted to my
colleagues, Mr. B. B. Woodward and Mr. G. C. Robson, for much
guidance aa help in exploring the lhterature and in examining
the Museum collections of Mollusca.
Many writers have commented on the difficulties that stand in
the way of a systematic study of the Teredinide. The lack of
agreement as to the characters to be regarded as generic is
strikingly shown in the recent synonymy of several species, while
the inconstancy of specific characters drawn from the valves of
the shell was commented on long ago by Forbes and Hanley
(Hist. Brit. Mollusca, i. p. 87 (1848)). ‘These difficulties I cannot
pretend to have solved, but some general considerations suggested
by study of my material may be worth recording.
The changes in form of the shell-valves during growth seem to
have received little attention, although several writers mention
the obvious fact that the number of the striz on the anterior
and antero-median divisions of the valves increases with age.
Together with this, however, there goes on a resorption of the
392 DR. W. T. CALMAN ON
posterior margin, beginning on the dorsal side, just behind the
hinge-knob, and extending downwards. The rapidity and extent
of this erosion appears to differ in different species. Incon-
spicuous, as a rule, in 7’. navalis*, it becomes very marked in
certain tropical species. For example, in many specimens of
Teredo mannii, mentioned below, the auricle and nearly the whole
of the postero-median area have been removed, while the antero-
median (vertically striated) area occupies the greater part of the
surface of the valve. It may be suggested as a possibility that
the absence of extensive erosion In most specimens of 7. navralis
is due to the fact that this is a short-lived and indeed almost an
annual species, the individuals rarely surviving the winter, while
the much larger 7. mannit may be longer lived, the individuals
perhaps surviving for several years in the warmer waters which
it inhabits. From the practical point of view it would be very
important to ascertain the duration of life and the rate of growth
in the different species.
Genus TEREDO Linn.
Hedley (Proc,.. Linn, Soc. N.S. Wales, xxi. 1898) 5.0 s2;
regarded the presence of a ‘‘cup-shaped mantle which ......
surrounds the bases of siphons and palettes” as the chief
distinctive character of a genus to which he applied at first the
name Calobates of Gould, and later (Mem. Austral. Mus. Sydney,
ili. 1899, p. 508) Vawsitoria (i. e. Nausitora) of Wright. Hedley
states that the type of the genus Teredo, ‘“‘according to the
figures of Forbes and Hanley and other writers,” entirely lacks
this structure. 'The accompanying figure (text-fig. 1, A) 1s taken
from a well-preserved specimen from the estuary of the Thames,
for which I am indebted to Dr. W. M. Willoughby, Medical
Officer of Health for the Port of London. This specimen appears
to be referable, without doubt, to the typical 7. navalis Linn.
It will be seen that the base of pallets and siphons is surrounded
by a fleshy collar or fold of the mantle, entirely similar to that
found in Veredo mannii and various other species which Hedley
refers to Vausitora or Calobates.
TEREDO NAVALIS Linn. (Text-fig. 1.)
Teredo navalis Linnseus, Syst. Nat. ed. x. 1758, p.651; Forbes
and. Hanley, Hist, -Brit., Moll. 1...1848,; p: 74, pl 1. tess sistas
pl. xvi. figs. 3,4; Gatliff and Gabriel, Proc. R. Soc. Victoria,
xvi, (mi. .s.) 19d. 1p. ali
¢Teredo pedicellata Quatrefages, Gwyn Jeftreys, Brit. Conch.
iii. 1865, p. 174, and v. 1869, pl. liv. fig. 3.
* Gwyn Jeffreys’ description of the “var. divaricata” of T. norvagica, the
“var. occlusa”’ of T. navalis, and the analogous varieties of other species, as well as
the specimens named by him in the Norman collection, suggest that these varieties
are based on unusually old specimens, in which the antero-median area occupies a
much larger portion than usual of the surface of the valves while the auricle has
been almost completely removed.
MARINE WOOD-BORING ANIMALS. 393
Locality.—Simon’s Town, South Africa. Specimens forwarded
by Lieut. L. H. A. Shadwell, R.N.V.R., Officer in charge of
Works, H.M. Dockyard. From Blue Gum timber, Ordnance
Jetty, EH yard; from Pitch Pine, Old Ordnance Jetty, E yard ;
and from creosoted Danzig, A, No. 3 slip
Remarks.—Teredo navalis and T. pedicellata have both been
recorded by Gatliff and Gabriel from Victoria, but, so far as I
know, neither has been recorded from South Africa.
Some of our South African specimens agree very closely, as
regards the structure of the pallets, with specimens from
Alderney in the Norman collection determined, apparently by
Gwyn Jeffreys, as 7’. pedicellata. Jeffreys himself remarks that
Text-figure 1.
Teredo navalis Linn.
A. Siphons and associated structures in a specimen from the estuary of the
Thames at Gravesend. ‘The fleshy collar at the base of the siphons has
peen divided and reflected, showing the insertion of the right pallet from
the inner side. B. Pallet of a specimen trom Simon’s Town. Actual
length about 5 mm.
‘this is not a satisfactory species,” and the identification of his
specimens with the form described by Quatrefages appears to
be largely conjectural. Quatrefages’s description (Ann. Sci. Nat.
Zool. ser. 3, x1. 1849, p. 26) contains little to suggest it except
the statement that the pallets are coloured dark brown. In the
Alderney specimens and in some of those from South Africa
(text-fig. 1, B). the stalk of the pallets may be as long and less
than one-fourth as wide as the blade. The blade is flattened on
the inner and convex on the outer surface, with the basal half
calcified, white, and nearly opaque. The distal half is mostly
394 DR. W. T. CALMAN ON
composed of a more or less translucent horny material varying in
colour from yellowish to dark brown, within which the distal ond
of the calcified part is seen to pr oject as a rounded cone. On the
outer surface, the central area of this horny part is occupied by
a calcified plate, rectangular or irregularly rounded in outline,
which reaches the distal but not the lateral margins. The distal
end of the pallet is concave or notched, with a more or less deep
central conical pit.
The structure described above is most easily seen in the
smaller specimens from South Africa, measuring about 40 mm.
in length of body and having the pallets about 5 mm. long. The
Alderney specimens are a good deal smaller. In some South
African specimens of about the same size, however, the distal
calcified plate cannot be seen, and in some larger specimens the
basal calcification, instead of penetrating into the interior of the
horny part, extends up along its lateral margins. In the largest
specimen of all, in which the body is a foot “long, t the pallets are
wholly calcified, with the distal portion slightly yellowish but
not horny. This large specimen does not appear to differ in any
but the most trivial details from European specimens referred
to 7’. navalis. The valves of the shell afford no distinctive
characters.
In the absence of any more satisfactory definition of the
supposed species 7’. pedicellata, all our South African specimens
may be referred to 7’. navalis.
TEREDO NORVAGICA Spengler.
Teredo norvagicus Spengler, Skriv. Nat. Selsk. Kigbenhavn, ii.
H. 1, 1792, p. 102, pl. ii. tigs. 4-6, B; fone and Hanley, Hist.
Brit. Moll. i. 1848, p 66, pl. i . figs. 1-5; (norvegica) Calman,
Marine Bor*ng Animals, ae Wins: Nee, Hist. Economic Series,
No. 10,1919. on 9 aig 22.0 nla, ices,
Teredo bruguierit Delle Chiaje, Memorie &e. iv. 1829 (1830),
. 32, pl. 54. figs: 6. 12,13; Suter, Manual N. Z. Molkiions:
p. 1019, pl. lv. figs. 7 a-d; Gatliff and Gabriel, Proc. R. Soc.
Victoria, xxviu. (n,s.) 1916, p. 118, pl: xi. figs. 9 & 12.
Remarks.—Suter recorded this species from Auckland, where,
however, he considered that it was in process of being displaced
by Xylotrya saulit (i. e. X. australis). It is therefore of interest
to note that the latter species alone occurs in the collection which
we have received from Auckland.
Suter has adopted Delle Chiaje’s name for this species on the
ground that Spengler’s was “not binomial,’ and he is followed
by Gatliff and Gabriel. It is true that, in the part of Spengler’s
memoir which deals with the genus Zeredo (but not in that
dealing with Pholas), the specific name is followed by a comma,
not by a full stop. Those who consider this an adequate reason
for displacing a name long in use and widely known will, no
doubt, continue to refer to this species as 7’. brugwierit.
MARINE WOOD-BORING ANIMALS. 395
Trerepo MANNII Wright. (Text-figs. 2 & 3.)
Kuphus manni Wright, Trans. Linn. Soc. xxv. pt. 3, 1866,
p. 565, pl. lxv. figs. 1-8; Hedley, Rec. Austr. Mus. i. 1899,
p. 134.
Nausitaria mannt Hedley, Rep. Austr. Ass. Adv. Sci. vill.
1901, p. 248.
Locality.— Brisbane, Queensland. Specimens forwarded by
Mr. E. A. Cullen, Engineer for Harbours and Rivers. From
Jetties Ge. in river 5 or 6 miles from Moreton Bay, in Ironbark
(Hucalyptus paniculata) and Pine (Araucaria cunningham).
Remarks.—Of this species, already recorded by Hedley from
Cooktown, in the north of Queensland, the holotype, from
Singapore, is in the Museum collection. Unfortunately, it has
been allowed to dry, but it has been possible, by soaking it in
water, to extract the valves and pallets and to restore the siphons
Text-figure 2.
Teredo mannii (Wright), from Brisbane.
A. Outer, B. Inner surface of pallet. C. Siphons and associated structures.
The fleshy collar has been divided and the right pallet removed.
to something like their original form. In all the characters thus
ascertained the specimens now recorded from Brisbane show a
close resemblance to the holotype.
The most characteristic feature of the species is the form of
the pallets (text-fig. 2, A & B). ‘The blade or expanded portion
is roughly crescentic in shape. The concave distal edge has a
convexity in the centre, giving it somewhat the outline of a
cupid’s bow, and the convexity is usually, but not always, incised
by a narrow median notch. The inner surface of the blade is
flat, the outer excavated distally; along the margin of the
excavated area is a border of dark brown horny substance which
is continued along the distal margin of the inner surface. The
396 DR. W. T. CALMAN ON
remainder of the surface of the blade is chalky white, and the
material composing it envelops the distal end of the more trans-
lucent stalk and ends in a sharp irregular line*.,
The valves of the shell in all the specimens I have examined
show, to an unusual degree, the effects of secondary absorption
already referred to. This is marked, not only in the dorsal
region, posterior to the articular knobs, as in the valves of more
normal Teredinide, but along the whole of the posterior margin
as far as the ventral articular knob. In most specimens the
whole region of the auricle has disappeared and the greater pait
of the postero-median region. In some specimens, as in the
Text-figure 3.
Teredo mannii (Wright), from Brisbane.
Valves of shell. A. Right, B. Left valve of a spec!men in which the eroded area
(seen in B) only occupies the upper margin, while the lower part of the
auricle still persists. C. Right valve of a specimen of about the same
size in which the erosion extends down the posterior margin as far as
the lower point of the shell and the auricle has been entirely removed.
holotype, this latter region is represented by a narrow border
along the greater part of the hind margin; in one of the
specimens figured (text-fig. 3, C) it has been entirely removed
* The extremely close resemblance, pointed out by Wright, between the pallets.
of this species and those of Kuphus arenarius as figured by J. HE. Gray is very
surprising, if the statements as to the widely different habitat of the last named.
species are correct.
MARINE WOOD-BORING ANIMALS. 897
except for a small piece near the ventral angle. In another
specimen (text-fig. 3, A, B), in which the lower part of the
auricle still remains, it extends only a very little below the level
of the anterior division of the valve; on the inner surface it
is not defined anteriorly, passing with quite unbroken surface
into the postero-median division.
The siphons (text-fig. 2, C), of which the ventral, or inhalent,
slightly exceeds in diameter the dorsal, or exhalent, are separate
quite to the base. The fleshy collar which surrounds them is of
considerable size, and, in the contracted state of the preserved
specimens, conceals the siphons for about half of their length.
Genus XyLorrya J. E. Gray.
Xylotrya (Leach M8.) J. E. Gray, Proc. Zool. Soc. 1847,
py 133.
Whatever Leach’s Xylotrya may have been (the reference by
Menke, Syn. Méth. Moll. 2nd ed. 1830, p. 121, and the description
by J. H. Gray, Syn. Brit. Mus. 44th ed. 1842, p. 76, suggest that
it was the genus now known as Xylophaga), the name appears to
have acquired validity only when Gray in 1847 referred to it the
Teredo bipalmulata of Lamarck.
The species of the genus are for the most part sharply
differentiated from those of TZeredo by the segmented blade of
the pallets. This blade is composed of a series of hollow cones
successively ensheathing one another and arranged on a central
axis forming a continuation of the stalk. The only approach to
a transition between the two genera that I have seen is found in
Nausitora dunloper Wright, in which the ensheathing cones are
very numerous and closely set, and appear, in the solitary type-
specimen which I have examined, to be partly consolidated on
the inner surface. They thus come to resemble the laminze of
which the blade is built up in some, at least, of the species
of Teredo, differing from them, however, in their more regular
arrangement *.
Many of the species referred to this genus have been only im-
perfectly described, and still more imperfectly figured. Possibly
the two species to which new names are applied below may be
identical with forms already named, but they are certainly
distinct from any in the Museum collection.
XYLOTRYA AUSTRALIS, sp.n. (Text-figs. 6, 7, & 8.)
Calobates saulit Hedley, Proc. Linn. Soc. N.S. Wales, xxii.
1898, p. 94, figs. 7-9.
Nausitoria sauliti Hedley, Rep. Austr. Ass. Adv. Sci. vin. 1901,
ps 248, pl: x fig. dD.
* Cf. Fischer, Journ. Conchyl. v. 1856, p. 131.
398 DR. W. T. CALMAN ON
Teredo (Xylotrya) saulii Suter, Man. N. Z. Moll. 1913, p. 1021,
pl. lv. fig. 8, a, 6; Gatliff and Gabriel, Pree. Roy. Soe. Filet
(ns. ) xxvii 1916)p. 121) ple xr eiies lay
Nec Nausitora saulii Wright, Trans. Linn. Soc. xxv. 1866,
p. 067, pl. Ixv. figs. 9-15.
Localities.— Brisbane, Queensland. Specimens forwarded by
Mr, E. A. Cullen, Engineer for Harbours and Rivers. From
Jetties &c. in river 5 or 6 miles from Moreton Bay, in Ironbark
(Hucalyptus paniculata) and Hardwood (£. maculata).
Auckland, New Zealand. Specimens forwarded by Mr. Hamer,
Engineer to the Auckland Harbour Board. From Kauri and
Black Butt timber.
Remarks.—Wright states that the type-specimens of his
Vausitora saulii, which were presented to the British Museum by
Miss Saul, came from Port Phillip, Australia, and it is perhaps
this statement rather than any verv exact correspondence with
his description or figures that has led Australasian naturalists to
apply the name to the species common in Australian and New
Zealand waters. It appears, however, that Wright’s statement
was in error. ‘The specimens in the Museum collection labelled
as “Types” and presented by Miss Saul are stated, on the label
and in the Register of Mollusca, to be from Callao, Peru tT. It is
true that none of the valves or pallets can be definitely recognised
as the original of any one of Wright’s figures, but there are
two characters in which these specimens agree closely with his
account; the auricle shows, on the inner surface, a series of
conspicuous curved ridges indicated in Wright’s pl. Ixv. fig. 10,
and several of the pallets have the outer surface worn away so
as to expose the ‘central core-like body” mentioned in the
description (p. 568) and shown in pl. Ixv. fig. 15.
These type-specimens, however, appear to me to be specifically
distinct from those I have examined from Brisbane and Auckland,
which undoubtedly belong to the species called NW. saulic by
Hedley and other Australasian naturalists. The chief differences
may be briefly stated as follows :—
A. saulii (Wright) (text-figs. 4 & 5). Dorsal outline of valve
sloping steeply without break into the upper margin of the
auricle, which exceeds half the total depth of the valve and
descends on the hind margin for more than half the distance
from the anterior notch to the ventral edge. ‘The auricle is
marked with rather widely spaced lines of growth which, espe-
cially on the inner surface, appear as strong curved ridges. The
anterior border of the auricle on the inside overlaps as a narrow
band and is closely appressed to the inner surface. The pallets
(text-fig. 5) have the segments strongly calcified and closely set,
the average interval being estimated at not more than one-fifth
* Suter (Man. N.Z. Moll. 1913, p. 1022) mentions Callao among the localities
for. the species, but states that the type is from Port Phillip. [ do not know the
source of his information.
MARINE WOCD-BORING ANIMALS. 399
of the width. The distal edges of the segments are acutely
V-shaped (this may be partly but not altogether due to their
being worn away), and no trace of serration can be seen in any of
Text-figure 4.
Xylotrya saulii (Wright). Syntype from Callao.
A. Right, B. Left valve of shell.
Text-figure 5.
Xylotrya saulii (Wright). Syntype from Callao. Pallet.
Text-figure 6,
Soon SS
wh" \\\ -
4 | (a J an i AN
eh Ds #19)))))
Y/N) i Dy
Ki, Lic N
AX, mr NANIAS
Sf .\ \\ ‘})
Xylotrya australis, sp. n. Syntype from Auckland.
A. Right, B. Left valve of shell.
the specimens. The stalk is smooth. The soft parts are un-
known. The valves measure up to 7'°3 mm. in length and a little
less in depth.
400 DR. W. T. CALMAN ON
X, australis, sp. n. (text-figs. 6, 7, & 8). Dorsal outline form-
ing a distinct angle or concavity at the base of the auricle, which
is not more than half the total depth of the valves and descends
on the hind margin for not more than half the distance from the
anterior notch to the ventral edge. The lines of growth on the
auricle are much more closely set and less prominent, and are not
at all conspicuous on the inner surface. The anterior border of
the auricle on the inside overlaps as a broader band which is
Text-figure 7.
Xylotrya australis, sp.n. Syntype from Auckland.
A, External surface of pallet. B. Single segment of
the pallet, further enlarged.
generally slightly raised from the inner surface. the pallets
(text-fig. 7) have the segments thin and fragile and more widely
spaced, the average interval being estimated at about one-third
of the width. ‘The distal margins of the segments are concave
or obtusely V-shaped, with a delicate membranous border, at the
base of which the calcified portion shows a series of coarse and
somewhat irregular serrations which become very conspicuous in
dried specimens. The stalk is smooth and shorter than three
MARINE WOOD-BORING ANIMALS. 401
times the width of the distal part. The siphons (text-fig. 8) are
adherent for two-thirds of their length in preserved specimens.
Text-figure 8.
Xylotrya australis, sp.n. Syntype from Auckland.
Siphons and associated structures from the right side. The fleshy collar
has been divided and reflected, the pallets remaining attached.
Text-figure 9.
Xylotrya capensis, sp.n. Syntype from Simon’s Town.
A. Right, B. Left valve of shell.
The largest complete specimen (from Auckland) is about 35 em.
long in the preserved state. The valves measure up to 13°5 mm.
in length and about the same in depth.
402 DR. W. T. CALMAN ON
XYLOTRYA CAPENSIS, sp.n. (Text-figs. 9, 10, & 11.)
Locality. Simon’s Town, South Africa. Specimens forwarded
by Lieut. L. H. A. Shadwell, R.N.V.R., Officer in charge of
Works, H.M. Dockyard. From Blue Gum timber, Ordnance
Jetty, E yard, and from Pitch Pine, Old Ordnance Jetty, E yard.
Description.—Valves of shell (text-fig. 9) with dorsal outline
not steeply sloping posteriorly, where it is defined from the
auricle by a shallow concavity. ‘The auricle is very deep, exceed-
ing half the total depth of the valve and extending downwards
Text-figure 10.
Xylotrya capensis, sp.n. Syntype from Simon’s Town.
A. Distal portion of pallet. B. Stalk of pallet. C. Single segment
of pallet, further enlarged.
for about half the distance from the anterior notch to the ventral
edge. The lines of growth on the auricle are rather closely set
and not conspicuous on the inner surface. The anterior border
of the auricle on the inside overlaps as a broad band, which is
distinctly raised from the inner surface. The pallets (text-fig. 10)
have the segments thin and fragile and closely set, the average
interval being estimated at one-sixth of the width. The distal
margins of the segments are regularly crescentic (on the outer
surface) with a broad striated membranous border but without
MARINE WOOD-BORING ANIMALS. 403
any trace of serration. On each side the border is produced as
a long filament which extends beyond three or four segments in
front. The stalk 1s minutely roughened and, in the specimen
measured, nearly five times as long as the width of the distal
part. The siphons (text-tig. 11) are adherent for at least five-
sixths of their length in preserved specimens,
The largest complete specimen is about 30 em. long in the
ogee state uae the pallets). The valves measure
12°5 min. in length by 11°5 mm. in depth. The pallets are about.
46 mm. long.
Text-figure 11.
Xylotrya capensis, sp.n. Syntype from Simon’s Town.
Siphons and associated structures from left side. The fleshy collar
has been divided and reflected, the pallets remaining attached.
Remarks.—In the structure of the pallets, especially in the
elongated peduncle, the broad, closely-set segments, and the long
lateral filaments into which they are produced, this species differs
from all those of which I have seen specimens. Blainville’s
description of the pallets of X. pennatifera, with the segments
‘““pourvues de chaque cdté d'un long cil” suggests a comparison
with our species. Specimens in the Museum collection referred
to XV. pennatifera, however, differ widely, having the segments
but little wider than the stalk and beari ing a fringe of filaments
in place of the striated membranous border,
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ON ENTOZOA FROM ANIMALS WHICH DIED IN THE GARDENS. 405
22. Report on Entozoa collected from Animals which died
in the Zoological Gardens of London during Might
Months of 1919-1920. By G. M. Vevemrs, M.R.C.S.,
L.R.C.P., F.Z.S., Beit Memorial Research Fellow,
Demonstrator in Heiminthology at the London School
of ‘Tropical Medicine, and Honorary Parasitologist to
the Zoological Society of London.
[Received June 1, 1920: Read June 1, 1920. |
During the past eight months I have made an attempt to
examine systematically for Entozoa all animals dying in the
Gardens, and have attended post-mortem examinations of four
hundred animals for this purpose.
Before the body was actually opened, a microscopical exami-
nation of the feces was made, whenever practicable, for ova and
embryos of Entozoa which would give some indication of the
parasites harboured, and would direct attention to the particular
regions for special search.
Whether this preliminary investigation gave a positive or
negative result, a subsequent search of all organs was carried out.
I have also applied this method of diagnosis to living animals
in the Gardens, and these examinations have in some cases given
positive results. On the death of the animal the diagnosis has
been confirmed by the discovery of the adult parasites; for
example, the Cylichnostomes recorded from the Grevy's Zebra in
the accompanying chart were detected in this manner.
Of the four hundred animals examined 76 or 19 per cent. were
found to harbour parasites.
The Entozoa found fall into the following Phyla and
Classes :—
Number
of Species Percentage.
found.
@estoma we tp ee 15 21°40
PLATYHELMIA,
VOM AVOGA Ses vasceaccs if 16:00
Nematoda 2. 6.20.52: AD 64:40
NEMATHELMIA. {
Acanthocephala ...... 3 4:20
otal. ve. 2 70 100:00
In all cases of Nematoda and Acanthocephala there was a pre-
ponderance of female forms. In four cases females only were
found. ‘There were 13 animals which harbouved more than one
species of parasite. In a Leopard Cat (Felis bengalensis) as many
as five different species were found.
The material afforded a valuable opportunity of determining
27"
AN6 MR. G. M. VEVERS ON ENTOZOA FROM ANIMALS
the length of life of parasites of various groups in their hosts.
Very little reliable information has been gathered on this im-
portant point. The evidence given by the incidence of parasites
which have intermediary hosts is, of course, more trustworthy
than that of forms which have a simple life-cycle. In the latter,
infection 1s accumulative, and may either be acquired in the
paddock or be brought into the Gardens on food: thus nine
examples of G'astrodiscus egyptiacus were found in a Grevy’s
Zebra which had been in the Gardens for six years. This parasite
normally occurs in Africa, and requires as an intermediary host
a freshwater molluse (Cleopatra bulimoides) which has not been
recorded from Europe. There can be no doubt, then, that the
specimens found had actually lived in the Zebra since it came
from Africa, and were, therefore, over six years old.
In the same Aebra were a number of species of Bursate
Nematodes, some of which have been recorded both from Africa
and Kurope. The life-cycle here is a simple one. That it is not
possible to draw trustworthy conclusions in such a case is well
illustrated by the findings in an Onager (Hquus onager) which
died quite recently. A number of the same species of parasites
which occurred in the Zebra were found in this Onager, which
had been born in the Gardens.
Two of the species of Cylichnostomes in the Grevy’s Zebra had
not been previously recorded, and it is possible that these were
originally imported, but the infection may have been renewed
in the paddocks. In this connection it is noteworthy that a
Chapman’s Zebra which died last year, after nine years in the
Gardens, had oniy species of Bursate Nematodes which occur in
European Horses.
We have, as another example of the contaminative group which
might accumulate in the Gardens, an apparently unrecorded
species of Atractis in the Elephant. Many specimens of this
Nematode were found in the Indian Elephant which died in
December last and which had been in the Gardens for twelve
years. Recent examination of the feces of the Elephant living
in the next paddock showed that this one also is heavily infected.
The minute but fully mature females of Aéractis are passed
from time to time in the feces, and these contain embryos so far
advanced as to have the adult form. If these embryos are
discharged by the mother worm in the intestine of the host,
it is conceivable that they might attain sexual maturity almost
immediately, and would then provide an exception to the general
rule that parasitic worms do not produce a second generation of
adult forms within the body of their definitive host.
The following points of especial interest were noted in
individual species of Parasites :— |
Two specimens of G'nathostoma spinigerum were obtained from
the stomach of a Leopard Cat (Helis bengalensis). A dissection
of the head-parts of a still Lving worm showed that the neck-
glands are hollow and contractile, and contain a fluid which plays
WHICH DIED IN THE ZOOLOGICAL GARDENS. 407
a part in altering the size of the head, thus supporting the view,
as to the function of the “ ballonets,” recently put forward in a
paper read before this Society by Baylis and Lane*.
A microscopical examination of the feces of the same Leopard
Cat showed many minute Nematode embryos.
Inst of Localities.
The localities fall into three divisions :—
1. Brivis Kast AFRICA.
Nairobi.
Parklands, Nairobi.
Besil, about 50 miles south of Nairobi.
Donya Sabuk, 30 miles from Nairobi.
Thika, about 50 miles from Nairobi.
Kagiatlo, about 100 miles due west of Makindu, which is on
the Port Florence-Mombasa Railway.
Kedong Valley, about 100 miles from Nairobi, and south of
Escarpment Station on the railway.
Kenia Forest.
Tumu Tumu, on the road from Thika to Mt. Kenia.
2, Ex-German Hasr Arnica (now Tanganyika Territory).
Gonya, about 50 miles south of Kilima-Njaro.
Longido West, about 50 miles west of Kilima-Njaro.
Amani, 40 miles from Port Zanga.
Dodoma, about 110 miles west of Morogoro, on the Dar-es-
Salaam—Tanganyika Railway.
Kongwa, about 20 miles north of Mpapua.
Morogoro, about 100 miles west of Dar-es-Salaam on the
railway.
Tulo, ]
Duthumi, {
* Pipide should also have been represented, but the large series of Xenopus
collected were lost in transit.
50 and 60 miles south of Morogoro.
412 MISS JOAN B. PROCTER ON TAILLESS
Mhonga, about 20 miles east of Morogoro.
Dar-es-Salaam.
3. PortuGuEsE East AFRICA
Lumbo.
RANID2A.
Rana, s. str.
1. Rava nutri Blgr.*
Nairobi. Morogoro. Longido West.
35 specimens. Average length of adult males 55 mm., of
adult females 70 min.; largest female 83 mm.
: : : ae
Snout variable both in length and in degree of acumination.
Subgenus TOMOPYERNA.
2. RANA DELALANDII Bibr.
Kagiado. Ex-G.E.A.
4 specimens. Length of adult females 41 and 45 mm.
A fine white vertebral line in one specimen ; a linear vertebral
groove in three specimens.
Subgenus PrycHADENA.
3. RANA OXYRHYNCHUS Sund.
Thika. Nairobi. Morogoro. Duthumi. Gonya.
72 specimens. Average length of adult males 40 mm., of
adult females 55 min.
An extremely variable species. Snout equal to or twice as
long as diameter of eye, rounded or acutely pointed, sometimes
very projecting. Length of tibia 14 to 1% times in length of
body, more often 14 times in females. Posterior corner slit-
like opening of male’s vocal sac in line with lower border of arm.
No hght vertebral band.
4, RANA MASCARENIENSIs D. & B.
Nairobi. Gonya. Ex-G.E.A.
15 specimens. Average length of adult males 47 mm.; females
half-grown.
Hind limb very variable in length, tibio-tarsal articulation
reaching anywhere between eye and “tip of snout ; length of tibia
1% to 13 times in length from snout to vent in males, 12 to 2
fie: in females. Vocal sac of male in line with upper header
of arm; 11 half-grown females have rudimentary vocal sacs.
Markings very regular, the first two series of spots coinciding
with the first two glandular folds, and often bisected by them ;
almost all specimens have a broad light vertebral band, and
often a still lighter fine vertebral line in addition.
* “ A specimen of Nutt’s frog was taken at Kabete, which had retained its tail
though nearly full-grown.”’—A. LovrripeGs, Field Notes.
BATRACHIANS FROM EAST AFRICA. 413
Subgenus HiILDEBRANDTIA.
5. RANA ORNATA Ptrs.
Ex-G.E.A.
1 specimen, 2. Length 56 mm.
Exquisitely marked with series of dark, large, elongated spots,
broad temporal bands, barred hinbs ; tga and bre ast mottled
with dark brown, with the characteristic paired Y-markings.
CHIROMANTIS.
6. CHIROMANTIS XERAMPELINA Ptrs.
Ex-G.E.A.
1 specimen, probably a female. Length 66 mim.
7. CHIROMANTIS PETERSII Blgr.
Dodoma. Ex-G.H.A.
3 specimens. Length 50, 55, and 59 mm.
Inner fingers with a mere rudiment of web, outer differing
from those of the type in being j instead of 3 webbed.
PHRYNOBATRACHUS.
8. PHRYNOBATRACHUS NATALENSIS Smith.
Kagiado. Nairobi. Longido West. Morogoro.
29 specimens. Average length of adults 30 mm.
An extremely variable species. ‘Toes sometimes 3 instead of, 4
webbed. Skin perfectly smooth or extremely warty; all male
specimens from Nairobi are of the latter description, but three
females from the same locality are smooth. A wide white
vertebral streak in three specimens.
9. PHRYNOBATRACHUS RANOIDES Bler.
Morogoro. Ex-G.H.A.
2 specimens. Length of larger 33 mm.
10. PHRYNOBATRACHUS BOULENGERI de Witte.
Morogoro. Duthumi. Gonya. Tulo. Ex-G.Hi.A.
61 specimens. Average length of adults 26 mm.
Skin perfectly smooth or warty. Markings variable, three
forms with and one without vertebral bands; five specimens
have a very broad vertebral band, two havea broad one, and two
have a fine white vetebral line. These four forms are shown
in figures of P. natalensis *, P. Z.S. 1907, pl. xxi.
* Boulenger, “Second Report on the Batrachians and Reptiles collected in South
Africa by Mr. C. H. B. Grant.
414 MISS JOAN B. PROCTER ON TAILLESS
11. ARTHROLEPTIS WAHLBERGII Gthr.
Morogoro. Amani.
2 specimens. Length 25 mm.
Dark without distinct markings; dermal ridge along the
vertebral line. Back of ene specimen covered with minute
tubercles.
12. ARTHROLEPTIS WHYTII Bler.
1 specimen. Length 35 mm.
Pale brown above, with a dark subtriangular marking between
the eyes; a fine dermal ridge along the vertebral line.
13. ARTHROLEPTIS MINUTUS Bler.
Kenia Forest. Nairobi.
33 specimens. Average length 17 mm.; large specimens 22 mm.
The majority of the specimens are dark olive, without distinct
markings; four have a fine, and two a broad white vertebral
line.
14. ARTHROLEPTIS STENODACTYLUS Pfeff.
Morogoro, Duthumi. Ex-G.K.A.
16 specimens. Average length of adults 32 mm.
This species, described by Pfeffer * from a single female from
Kihengo, is new to the collection of the British Museum.
Text-figure 1.
Hand of male and female Arthroleptis stenodactylus.
Underside, X 2.
Head broader than long; canthus rostralis obtuse; loreal
region oblique, concave; interorbital width greater than that of
upper eyelid ; tongue with a conical papilla; tympanum distinct,
usually 4 diameter of eye. First and second fingers equal in
length, third 13 times length of second in females, 12 to 2 times
in males; tips of fingers and toes somewhat swollen but not
* Jahrb. Hamb. Wiss. Anst. x. (1893) Taf. i. fig. 11.
BATRACHIANS FROM EASY AFRICA. 415
dilated ; toes with a rudiment of web; inner metatarsal tubercle
as long as or slightly shorter than inner toe; no outer tubercle.
Tibio-tarsal articulation reaches the eye or slightly beyond;
length of tibia 3 times its breadth, twice in length of body.
Skin smooth. Reddish brown or olive-grey above, with the
dark vertebral markings characteristic of the genus; a fine white
vertebral line in five, a broad one in three specimens ;_ barred
limbs; whitish beneath, sometimes with a dark throat; a few
spots on lower lip. A fine linear vertebral ridge in two
specimens. Males with an internal vocal sac.
RAPPIA *,
15. RapprA GRANULATA Bler.
Ex-G.E.A.
6 young.
16. RAPPIA PUNCTICULATA Pfeff.
Morogoro. Ex-G.H.A.
7 specimens. Length 22 to 32 mm,
Text-figure 2.
Rappia puncticulata. Nat. size.
Interorbital space varies from 14 to 2 times width of upper
eyelid. lingers with a rudimentary web, toes ?# webbed.
Length of tibia 24+ to 23 times its breadth, 3} to 4 times in,
length of body.
The specimen figured by Pfeffer is of a uniform colouring,
* “ Rappia, sp. A Tree Frog was found impaled on the spike of an Aloe, in
company with sundry grasshoppers which formed the larder ot a Shrike.”—
A. LovERIDGE, Field Notes.
€
416 MISS JOAN B. PROCTER ON TAILLESS
with a light dark-edged lateral band passing round snout and
ending on the sacral region; it has also a fine dark vertebral line.
Several young in the British Museum collection have similar
markings, but the seven noted above differ considerably. In
these the light lateral band is heavily bordered with black, the
enclosed dorsal area and upper surfaces of tibia, tarsus, and
forearm irregularly spotted with black or dark grey; they have
also a large white dark-edged spot on the heel. The markings
of the smallest specimen are so light and indistinct that it more
resembles the type specimen.
17. RAPPIA PLATYRHINUS, Sp. n.
Nairobi.
] specimen, ¢.
Head small, broad as long, moderately depressed ; snout flat,
markedly truncate, as long as diameter of eye; canthus rostralis
feebly marked ; loreal region oblique, concave; nostril at end of
Text-figure 3.
Rappia platyrhinus. Nat. size.
snout; interorbital space nearly twice width of upper eyelid ;
tympanum hidden. Fingers long, z webbed, second longer than
first; toes slender, fully webbed; subarticular tubercles soft,
flat, small; inner metatarsal tubercle also soft and small; no
outer one. Tibio-tarsal articulation reaches middle of eye;
length of tibia 5 times its breadth, 13 times in length from snout
to vent. Skin smooth above, granular below. Uniformly
brownish-grey above, finely speckled with black pigment cells
which are slightly concentrated along canthus rostralis. Male
with internal vocal sac and adhesive subgular dise,
BATRACHIANS FROM EAST AFRICA. 7b Lg
Measurements ir millimetres.
SMO UI UORVEITOM 75.
i., intestine; po., postanal papilla; pr., preanal papilla; sp., long spicule ;
spi., short spicule.
Female 30-43 mm. in length; the body attains a thickness
of 0-9 mm.
Anus about 0:1 mm. from the rounded extremity. The vulva
projects slightly from the ventral surface, 0°35 mm. from the
cephalic end. Vagina short, 0-9-1 mm. in length.
Oviparous. Eggs thick-shelled, measuring 0:045-0:05 x
0:03 mm. .
DIPLOTRIZNA FLABELLATA (v. Linstow, 1888).
My material includes a single specimen of a female Diplotriena
from the body-cavity of the Red Bird of Paradise, Paradisea
rubra. I take it to be the same species as LD. flabellata described
from Paradisea apoda by v. Linstow in the ‘ Challenger’ Reports
(1888).
Specific diaqnosis.—Iiplotriena : Body short, more attenuated
anteriorly than posteriorly.
WORMS FROM MAMMALS AND BIRDS. 503
Cuticle transversely ringed. QCisophagus not divided into two
regions, harrow anteriorly, increasing in width gradually behind
the nerve-ring, the latter 0°3 mm. from the oral end.
Trident 0°25 mm, long, its antevior stem truncated.
Text-figure 11.
‘
1
'
t
Diplotriena flabellata (v. Linst.).
Lateral view of anterior extremity of female. x 120,
Lettering as in the preceding text-figures.
Female 44 mm. in length, with a maximum thickness of about
1 mm. Caudal extremity rounded, broader than the head,
Position of anus not ascertained.
Vulva prominent, 0°6 mm. from the anterior extremity ; the
thick muscular vagina has a length of 2 mm.
Oviparous. Eggs thick-shelled, 0°04—-0:045 mm. x 0°25 mm,
INCERTA SEDIS.
FILARIA ARAMIDIS, sp. 0.
A single specimen of this species was obtained from the leg-
muscles of the Cayenne Rail, Aramides cayennensis. In the
absence of the male it is impossible to place the form in its
HOA PROF. C. L. BOULENGER ON FILARIID
proper systematic position ; I have, therefore, retained it in the
genus Milaria s.1. In some respects it appears allied to certain
species known from the muscular system of Mammals, e. g.
Filaria scapiceps Leidy (Hall, 1916).
Specific diagnosis.—Kilaria s.1.: Body comparatively short
and thick, tapering nearly equally at both extremities.
Cuticle finely striated transversely.
Text-figure 12.
Filaria aramidis, sp.n.
A. Anterior extremity ; B. Posterior extremity. Lateral view. > 75.
Lettering as in the preceding text-figures. ov., loop of ovary.
Head rounded, bearing four very small submedian papillee ;
lateral papille not seen.
(Esophagus narrow and simple, 2.¢., not divided into anterior
and posterior regions. Nerve-ring close to the anterior extremity.
Female 25 mm. in length, with a maximum breadth of about
lmm. Width of nead 0°2 mm. The csophagus has a length of
1-lmm. Posterior extremity rounded ; position of anus uncertain,
about 0°15 mm, from the end of the body.
WORMS FROM MAMMALS AND BIRDS. 5O5
Vulva 0°82 mm. from the anterior extremity; the slender
vagina is directed posteriorly and has a length of 2°4 mm.
Kegs thin-shelled, measuring 0:03-0:035 x 0°02 mm.
BIBLIOGRAPHY.
Dissine, K. M. (1861).—‘“ Revision der Nematoden.” Sitz-
ungsber. d. Kais. Akad. Wiss. Wien, xi. 1860, pp. 595-736.
Haut, M. C. (1916).—“ Nematode Parasites of Mammals of the
Orders Rodentia, Lagomorpha, and Hyracoidea.” Proc. U.S.
Nat. Mus. Washington, |. pp. 1-258.
Henry et Ozovux (1909).—“ La Filaire du Foudi.” Bull. Soc.
Path. Exot. Paris, 1. pp. 544-547,
Liystrow, O. von (1888).-—‘‘ Report on the Entozoa collected by
H.M.S. ‘Challenger’ during the years 1873-6.” ‘Challenger’
Reports, xx1u. pp. 1-18.
—— (1891).—‘“* Ueber Filaria tricuspis und die Blutfilarien der
Krihen.” Arch. f. Naturg. Berlin, Ivii. p. 292.
~—— (1899).—*‘ Nematoden aus der Berliner Zoologischen Samm-
lung.” Mitt. a.d. Zool. Samml. d. Mus. f. Naturk. Berlin,
i, (2), pp. 1-28.
Primer, H. G. (1915).-—“ Report on the deaths which occurred
in the Zoological Gardens during 1914, together with a list
of the blood-parasites found during the year.” Proc. Zool.
Soc. London (1), pp. 1238-130.
Ratuiiet, A., Henry, A., et Lancrron, M. (1912).—‘‘ Le genre
Acanthocheilonema Cobbold, et les Filaires péritonéales des
Carnivores.” Bull. Soc. Path. Exot. Paris, v. pp. 392-395.
Srossico, M. (1897).—‘“ Filarie e Spiroptere. Lavoro Mono-
grafico.” Bull. Soc. adriat. di sci. nat. Trieste, xviii.
pp 11-162
Proc. Zoou. Soc,—1920 No. XXXIV, 34
A Au AIM Lhe WORLD a eRe)
Me ee
GST kane i | td Ui 4 ey
ON THE FAUNA OF THE AFRICAN LAKES, 5O7
32. The Fauna of the African Lakes: a Study in Compara-
tive Limnology with special reference to Tanganyika.
By Wiuuiam A. Cunninaton, M.A., Ph.D., F.Z.S.
‘Received May 31, 1920: Read November 16, 1920. ]
(Text-figures 1-2.)
InDEx.
Page
EESCOMCATOOUIVEY inctesccnct sachs teaine teeter ore ke a OUT
General Introduction .......... Miia ee Cee Le
Systematic Account and iste of Spies PORES Tris yt 5Y ie,
General Discussion and Conclusions ...,.............. 592
SRA sass gd seuss abs sci. Maeedeapeeeeans 14009
JE OABYOVSAG O10 ew ae ae Bf Het eet ORO REE cs PRET gH
1. HISTORICAL SURVEY.
Ever since the days of the great African explorers and their
quest of the sources of the Nile, there has existed a certain
fascination about the big lakes of Central Africa. While the
scientific world was at first concerned principally with the
geography of the heart of the continent, opportunity soon offered
of learning something of the organisms which live in the vast
inland seas, and it then became evident that matters of no little
biological interest were involved.
It is the object of this paper to deal in comparative fashion
with the animals of the principal lakes, and since Tanganyika*
holds a unique position as regards its fauna, a somewhat detailed
account of its zoological exploration seems fitting, as it will afford
both an introduction to a study of the lakes and an enumeration
of certain outstanding facts.
Little more than sixty years have passed away since Burton
and Speke, the first Europeans to penetrate to Lake Tanganyika,
reached the shores of this big inland sea. ‘Their expedition, after
encountering numberless hardships, arrived at the lake between
the Malagarasi River and Ujiji on the thirteenth of February,
1858. Although little was done in the way of exploring Tan-
ganyika, Burton described, with a surprising degree of accuracy,
various facts concerning it which he learned from the Arabs and
natives, while Speke, on his return, brought certain shells from
the lake shore, which came into the possession of the British
Museum.
* Some years ago I called attention to the orthography of the name ‘Tanganyika,’
advocating the adoption of the spelling ‘'Tanganika’ by English writers (69).
The arguments advanced in favour of the change have not lost their force, and still
seem worthy of consideration. As there is no indication that writers in this country
are prepared to accept the moditication, I adhere reluctantly to the old form.
34%
D08 DR. W. A. GCUNNINGTON ON THE
It was in the examination of these shells that the unusual
interest which still attaches to certain forms of life found in
Tanganyika had its origin. 8. P. Woodward, who reported on
the collection, was struck by the fact that some of the shells were
curiously marine in appearance, Of one of them, which he
named Lithoglyphus zonatus (now known as Spekia zonata), he
said (205, p. 348) that it so much resembled a Nerita or Calyptrea
that it might have been taken for a sea-snell. Of another, he
remarks that “Its colour, solidity, and tuberculated ribs give
it much the appearance of a small marine whelk (Vassa).” At
the time, these opinions attracted little attention, although the
matter was destined to come into prominence at a later date.
Some twenty years later-—_in 1878—there was established the
first settlement of Kuropeans on the shores of Tanganyika, when
August of that year. With praiseworthy public spirit, the
Directors of the Society had given instructions that the gathering
of scientific information should be considered among the duties
of this pioneer expedition, and thus it is that E. C. Hore (101),
a member of the party, was the first to attempt a systematic
collection of the forms of life occurring in the lake. While the
collections since made by trained naturalists have, of course,
added very largely to the knowledge of the fauna and flora, the
forms obtained by Hore embraced many different groups, and
afforded the first comprehensive glimpse of the organisms which
the lake contains.
This English Mission was very shortly followed by the estab-
lishment of a French Catholic Mission, and it should be noted
that these White Fathers of Algeria have also been instrumental
in gathering information, and in particular have made large
collections of shells which have been described in later years by
French conchologists.
At the end of 1879, Tanganyika was visited by Joseph
Thomson. Collections of shells made by Hore and Thomson were
reported on by Edgar Smith in 1880 and 1881 (159, 160, 161),
and he also had occasion to remark on the marine appearance
of some of them. ‘This matter being brought to the front once
more, Thomson put forward the view (190, vol. ii. p. 85) that the
water of the lake had probably been saline until recent geological
times, when it became freshened through circulation and outflow
to the Congo (compare also 191, where he goes further, and
suggests the origin of the lake from a former sea occupying the
Congo basin).
The discovery of meduse by Bohm (114), a German explorer
who crossed Tanganyika in 1883, only emphasised matters and
laid stress on the supposed marine character of the lake fauna,
since, with few exceptions, such organisms are confined to the
ocean. Von Wissman (204, p. 253) confirmed this discovery
when sailing on the lake in 1887, and a few years later, F. L. M.
Moir, the manager of a British trading company, undertook to
FAUNA OF THE AFRICAN LAKES. 509
obtain specimens of these meduse properly prepared for scientific
investigation. This valuable material, on its arrival in England
at the Pond of 1892, was placed for examination in the hands of
R. T. Gunther of Oxford. |
It was Giinther who first put forward a detailed theory to
account for the presence in a central African lake of animals
with apparently marine affinities. In his report on the Tan-
ganyika medusa he suggested (95, p. 289) that if at some early
period the interior of Africa stood at a much lower level, with
the Atlantic Ocean extending over the Congo basin and the lake
existing as an arm of the sea, it would then be possible readily
to explain the presence in it both of the medusa and the remark-
able molluscan forms. As the lake became separated from the
sea, so the salinity of the water would tend to decrease if 1t were
supplied with inflowing rivers and found an outlet through which
to carry away the salt.
Since the problem presented by Tanganyika had now become
so interesting and definite, it seemed very desirable that the lake
fauna should be investigated upon the spot by some trained
zoologist. The matter was taken up by Ray Lankester, who,
with the help of others interested in the question, obtained the
necessary grants from the Royal Society and organised the First
Tanganyika Expedition. This was put in charge of J. E. S.
Moore of the Royal College of Science, who from that time
onwards contributed largely to the knowledge of the lakes of
Jentral Africa.
The expedition left England in the autumn of 1895, and Lake
Shirwa was visited as well as Nyasa, while Moore spent several
months on the shores of Tanganyika. As a result of this journey,
the original problem seemed far from being solved, for the expedi-
tion brought matters to light which only made the lake appeax
more remarkable. Many strange and unique animal forms were
collected, certain of which were thought to show marine aflinities,
while the majority were new to science. The collection included
a number of types not unexpected in a tropical lake; only a
proportion of the fauna exhibiting the unusual features to which
reference has been made. Moreover, although the expedition had
visited Nyasa and Shirwa, in neither of these lakes had marine-
like forms been found resembling those of Tanganyika.
Through a study of the newly acquired material, especially the
anatomy of certain of the molluscs, Moore arrived at the conclu-
sion that the forms exhibiting a marine appearance could not be
compared directly with any marine types of the present day, but
vather possessed archaic and generalised characters which sug-
gested that they were the relics of a marine fauna of a previous
age. Further, he considered that some of the Tanganyika shells
offered a strong resemblance to certain marine Jurassic fossils, in
particular those of the Inferior Oolite of the Anglo-Norman
basin. Taking this as evidence of the period from which these
remarkable living forms had been derived, Moore propounded
510 DR. W. A. CUNNINGTON ON THE
once more a theory of the former connection of Lake Tanganyika
with the sea, asserting that this connection existed in Jurassic
times (131).
The discoveries of the First Tanganyika Expedition, while
stimulating interest in the faunas of the African lakes, only
emphasised the need for further information. It was still to
be determined whether any of the other big lakes contained
organisms with a marine appearance, and it was very desirable
that more should be learned of the geology of the Tanganyika
basin, as having a direct bearing on the question of a former con-
nection with the sea. Ray Lankester, therefore, took the initiative
once more, formed a comiittee of scientific men interested in the
subject, and organised a second expedition. In view of the
geological and geographical work to. be undertaken, a liberal
grant was made by the Royal Geographical Society, and Moore
was accompanied by Malcolm Fergusson as surveyor and geologist.
The Second Tanganyika Expedition (136) left England in 1899,
and after proceeding up lakes Nyasa and Tanganyika, visited
Kivu, Edward Nyanza*, and Albert Nyanza before returning to
the coast by way of the Victoria Nyanza.
An examination of the collections obtained in the latter lakes
only laid additional stress on the unique nature of Tanganyika,
for in none were found animals suggestive of the sea. Indeed,
the already long list of forms found only in Tanganyika was aug-
mented by the expedition, more particularly as regards the fish.
Certain of the little-known regions between Tanganyika and the
Albert Nyanza were mapped, and considerable attention was paid
to the study of the geology of this district as well as that of the
Tanganyika basin. Not long after the return of the expedition,
Moore published a volume entitled ‘The Tanganyika Problem”
(137), in which he dealt at some length with the question which
had so occupied his attention. A large amount of new informa-
tion was given in this work. It treated in a comprehensive
manner the physiography and geology of the part of Africa con-
cerned, and besides giving a complete review of the fauna of
Tanganyika as then known, discussed the origin of fresh-water
faunas in relation to the matter.
While a great deal of information bearing on the geology and
geography of the lake regions had been obtained, and extensive
collections had afforded a knowledge of the fauna of Tanganyika,
the flora of the lake had not been dealt with as it deserved. To
those who had been impressed with the marine characteristics of
certain animals living in the lake, it appeared quite conceivable
that when the flora came to be investigated, plants equally
remarkable and equally suggestive of marine affinities would be
discovered. If, for example, specimens of the red Algz so charac-
* The lake, formerly known as the Albert Edward Nyanza, is always referred to in
this paper 4s Edward Nyanza or Lake Kdward. ‘The change of name was approved
by the late King Edward, and should be universally adopted in order to avoid
confusion with the Albert Nyanza or Lake Albert (ef. 55, p. 129).
FAUNA OF THE AFRICAN LAKES. 5I1
teristic of the ocean were to be found, this would afford very
valuable evidence concerning the ancient history of the lake.
Jt was with this end in view that a Third Tanganyika Expe-
dition (68) was organised by the Committee, with the conduct of
which I had the honour of being entrusted. One of the principal
objects of this expedition was therefore to make a careful collec-
tion of the water plants of Tanganyika, at the same time
collecting in Nyasa, with the idea of affording a comparison with
a more normal African fresh-water lake. My instructions also
provided “ That other groups of organisms likely to throw hght
on the Tanganyika Problem, and especially fishes, shall not be
neglected.”’ Including observations en various points of interest,
the work before the expedition was thus sufficiently extensive,
although matters of geology and geography were outside the field
of enquiry.
I left England in the spring of 1904, proceeding via the
Zambezi and Shiré rivers to Lake Nyasa, w here e a few weeks were
spent in collecting. My stay on and around Tanganyika lasted
about eight months, which were fully occupied in making collec-
tions and observations as far as facilities offered. Returning to
the coast by way of the Victoria Nyanza, an opportunity was
afforded of obtaining representatives of the flora of that lake for
purposes of comparison with the plants collected in Nyasa and
Tanganyika.
It may at once be stated that the flora of Tanganyika fails to
exhibit quite the remarkable features which some had expected
it to show. As regards the higher aquatic plants, a comparison
of the species from Tanganyika with those from Nyasa and
Victoria Nyanza does not throw any light on the hypothesis of a
marine origin for Tanganyika. The “Frosh: water Algze of the
lake, however, have proved to be a strange and interesting
assembly, a considerable number being peculiar to ‘Tanganyika
while several show undoubted marine affinities. The lower forms
of vegetable life which occur thus tend to confirm the unique
biological nature of the lake.
On the zoological side, my collections have added not a little
to the number of forms known from the lakes, the results
appearing as a series of memoirs principally in the Proceedings
of the Zoological Society. For the first time systematic tow-
nettings were made in ‘Tanganyika on an extensive scale, and as
a result, detailed infor mation is to hand about whole eroups of
organisms, only the bare existence of which in the lake was
known before. ‘Thus reports have now been published on the
smaller Crustacea (Copepoda and Ostracoda) as well as on the
Rotifera, while in addition the groups Branchiura and Hydrach-
nida are new records from the lake.
In completing this brief review of the zoological exploration of
Tanganyika, it is only necessary to refer to the Belgian expe-
dition to that lake and to Lake Mwero undertaken by the late
Louis Stappers, This expedition visited Tanganyika in 1912-
by DR. W. A. CUNNINGTON ON THE
1913, and brought back valuable information concerning the
‘depth of the lake and the salinity of its water, as well as repre-
sentatives of its fauna. kivuensis Bue a K
Ree TAGCUMG oo... 0 scenes E
a ec)
» fergussonit ....... Senet oe
‘fold Cc 0 E§ oo
a) COWATOINNUS .......,.... ae E
i CUNVSHOMIUS —............ E
» Yhoadesu see iis E
se platy MMAMWS ..2......... i
eC ee E
3 JOMTIBTONM .. ..... 2... E
woe trimacwiabus ......... i P vist
las bu Cie: P
i; © Paludinosms ............ P
» thikensis ee A ie
PS caghto be AS
» wminchini E
» tetraspilus K
» sexradiatus on 10)
by MONT MNOS foc ce vee eee es aes K
» apleurogramma ...... 9
» innocens te Se P ,
Be MECOMOMLEUTA. <2 066... E
sy UTOSTICNMA’......... E
» arcislongee we} K
PPUMMETIMNCC Ss 556.5. hls. fe P|
ee mispilopleura ......... Pr ||
» doggetti ae E
» lafukiensis E
» magdalenz bane E
Barilius microcephalus......... ee EK ne
+ MIMOOTN oeecce css eka cesses iP; P
be tanganice wie K
sh microlepis ............ E
Engraulicypris sardella...... pe 10)
- argenteus... a E
rs minutus ...... E
Family S1LuRID&.
Clarias anguillaris................ se
PPPOE Perc ones en E
» Mmossambicus ......... Ma eee
RU PHUAIZBE Ne reteset ove site P Ve
» carsoniil Beate: ue, dec
» submarginatus fe ued
» locephalus wae P és
ee UCTS ee ee 1D
PLY CUMLOM NS cx a6 sect. esos ans ae i
Dinotopterus cunningtoni Gen. E
Eutropius niloticus ............ we le
RE SR ats P
Schilbe mystus
Other parts of
the world.
Nile.
Upper Shiré R.
Victoria Nile .
Abyssinia to fambeai.
KE. Africa.
Rusisi R.
Victoria Nile.
Zambezi, Angola.
i. Africa.
K. Africa, Natal,
K. Africa. (Angola.
Uellé R.
Malawa R.
E. Africa.
Nile.
Abyssinia.
Upper Shiré.
Upper Shiré.
Nile, Chad.
Abyssinia, E. A‘rica.
Syria, Nile, W. Africa.
Uganda.
Cameroon, Ituri kh,
Ubanghi R.
Uganda.
Nile, Senegal.
Nile, Tropical Africa.
§ Not actually recorded from the lake itself.
|| This record: needs confirmation.
—~
026 DR. W. A. CUNNINGTON ON THE
; Tangan- Victoria Albert Edward jy... Other parts of
Name of See yika. Nyanza. ~*7** Nyanza. Nyanza. the world.
Bagrus bayad 1 ar ae 1B Nile, W. Africa.
fs ORIEN bal Ts wee hvala ces.” ¥ ae iP; E. Africa.
Bnd | ACLOCIIAG, hositseanietopecen axe Je iv Nile.
» degeni i ey E
wpa MCTIGIONALlIS ........4.... me E§ Upper Shiré R.
Chrysichthys sianenna. E
os CAE LIQe neces E
x cranchii ......... 12 Congo.
5 stappersil ...... E
ms myriodon ...... y
* @randis 061. 4. 1D)
br achynema EK
Phy lonemus typus Gen. E
Amphilius platychir. .......... 2 iP = K. Africa.
Auchenoglanis occidentalis ... P P Nile, W. Africa.
Synodontis granulosus ......... E
A dhonti me aD)
*, zambesensis ...... fs P Zambezi, E. Africa.
* melanostictus... iP Zambezi, Bangweolo,
ri multipunctatus ... E [ Mwero.
5 VICE OMM Ce memesere kee i Malawa R.
rs afro-fischeri ...... D
TUTICA pelea eons ets Boe sh 12 Nile, W. Africa.
Malapterurus ‘electricus ee P Pp Nile, Tropical Africa.
Family CyPRINODONTID.
Fundulus teniopygus ......... ae KE. Africa.
Haplochilus dhonti ............ E§ Lukuga R.
%; PUMAUSe eee ea 1g
johnstonii ...... aft P§ Nyasaland, Zululand.
Lamprichthys tanganicanus.. Gen. EK
Family SERRANIDZ.
Lates niloticus cee As Nile, W. Africa.
a) UMMICTOLE PIS Aten aes E
Sy aM OUStUTOMSe a. eee E
Luciolates stappersil ......... Gen. E
i NOVA OTe. ne.cecee mate EK
Family CicHLipz +.
Hnlapiatshinarial. a ey eee P Zambezi.
- mossambiea ............ At P§ = .. #. Africa, Natal.
pag) A LILOUICAl oa cnt io eee re ae P iP P Syria, Nile, W. Africa.
> eduardiana nee P§ P§ E. Africa.
Ss varia bil isn ao eee ee es Victoria Nile.
4 auromarzinata’..(....,” E
> squamipmnis 2... oa E ... Upper Shiré.
3 Melanopleura “.--. eg 1g P W. Africa, Zambezi,
sy, HIDUTLONT = een ee ig P { Zululand.
»» adolphi- frederici ...... i E
28 pCallliipterawe ee Ve Zambezi.
55 williamsiitseel ee of E
Sh wpe liOUli aa cee men sat. csr nee E
§ Not actually recorded from the lake itself.
+ Quite recently, and since this section on the Pisces was completed, an important paper
dealing with the classification of the Cichlids has been published by Regan (145).
Entering
on a revision of the fishes of this group, he deals in this introductory article with the
Tanganyika genera.
Since he has not yet completed his investigations, I have not attempted
to revise my list in accordance with his views, and merely call attention to the paper in this
place.
It is clear that in this tabulation I am compelled to conform to the standard
originally adopted, which cannot be brought into line with the suggestions put forth in
the above-mentioned preliminary essay.
FAUNA OF THE AFRICAN LAKES.
Name of Species.
WilapiaPerGel? .......0.... 60.60.
5 ~ bimmilior
3 pallida
3 pappenheini .........
2 Sli st
» nhubila
PMU RMCTODS hs...
‘| QS ON ON
» bayoni
» Migricans
Oe Uo
ai 74S ea
on CVOSCRIED, oooh Se eee
oy) | PLCUTORAAT.............
» johnstonii
3 «6 «tebraSHISMA .....:.....
ie a0" er
» lateristriga
» lethrinus
+ rostrata aster
PO OMOEWIAIT a 50. 5.5 scent
» Mmacrophthalma ......
we Orevis
» mornata Syaeee
“3 trematocephala ......
» | beops
» grandoculis
Petrochromis tanganice ......
3 andersonil ......
i polyodon ......
. PYVSSOO cs
fasciolatus......
29
Cunningtonia longiventralis..
Simochromis diagramma......
Tropheus WNOOril ...............
55 WMNNECHENS /o. cess...
Asprotilapia leptura............
Lobochilotes Jabiatus .........
Docimodus johnstonii .........
Haplochromis hivingstonii
MEMUSUUS «ici cs cuss
29
mn Sehubotz! ”.........:
- nuchisquamulatus
» jeanneli
3 angustifrous ......
ie mshimaeli: .....s 1.5.
ms PODER so. sees cuca
s SUP ge
= percoides............
Hs graueri
ie strigigena .........
- desfontainesii
sg cA URE RUC ee
Paratilapia gest¥r- ae wee Ee Atiicas
5) ONC! (en a a ee ey her P ae o ... KE. Africa.
& PULPULENS.. 2.00... £% se iG ter a vai be Adrica.
- schweinfurthi ...... nee EK
-s sinistrorsus ......... P - ae eo oe ... . Africa.
*Leroya bourguignati .....,... Gen. E
Family HypRosiip™.
*Spekia zonata 4 oar tana, ts) Ne) O)
*Tanganyicia rufofilosa ......... Gen. E
*Rumella neritinoides .......... Gen. E
*Stanleya giraudi ................ Gen. E
_ rotundata .........+.. K
= smartiiana ' 2.05.3...) {)
*Limnotrochus thomsoni ....... Gen. E
MOhytra kirkit..................:... Gen. EB
ithynia-alberti. ~............<. ze ae n P i
o umerdsar .....05.04. ee Ae. Ie Pe P
55 multisulcata ......... E
rs SUM VT ok, oats tins = Bs E
a WALTEEN) cocc sec... e ec be E
*Syrnolopsis carinifera ..,....., Gen, E
BS WaGustris™ .,.0.2... E
+ Additional particulars and bibliographies will be found in von Martens’ account
of Kast African forms (116) and Smith’s review of the Mollusca of Tanganyika
(170). There have been but few additions since the dates of these ;apers,
* Genera described.as thalassoid,
544
DR. W. A. CUNNINGTON ON THE
: Tangan- Victoria : Albert Edward
Meme onienecc:) yika. Nyanza. hese, Nyanza. Nyanza. —
eee TIARIDA.
Tiara || admirabilis E
oy ATGUACUIA wees crcl = ses E
- iTICINCTA) So. .nmiselee 343 E
a MOGICINCHA | sx = eee -o- Pp
> nyassana (
* PereTAciis| o..-.ce-- es ER
a polymorpha ........-++. 3 E
br pupiformis q
nf simonsi . ee oe iE
Re tanganyicensis A K
, tuberculata iP Ik ip P p P
turritispira ia i
¥Giraudia foai . hee Gen. E
- erandidieriana steed K
a horei EK
5 lavigeriana ......... E
i. AO INOL, Ane eae reece E
‘, preclara E
ss quintana E
tanganyicensis ...... EK
*Lechaptoisia ponsonbyl ...... Gen. E
*Burtonilla terebriformis ...... Gen. E
*Baizea giraudi sak setonis ee T Ey
a leucoraphe 3. .-cenece EK
*Anceya admirabilis Gen. E
0 APPA coe hy ace ae K
, Tufocincta E
*Bythoceras iridescens ......... Gen. E
minor. E
*Paramelania bridouxi ......... Gen. E
‘3 crassigranulata .. EK
s damoni ¢:..-:... i
*Joubertia baizeana Gen. E
— Spimlosa jcedace eee KE
st Stamleyana icscea.. 266 0)
*Lavigeria callista ............... Gen. E
i combsag tench EK
uf Coronata aee.n ee E
a diademata ......... E
grandis nee 1D
a joubertis.::)05 eee E
Ke pereximia ............ E
as ruellaniana -......... EK
*Randabelia catoxia ............ Gen. E
x hamyana ee. EK
*EKdgaria bourguignati ......... Gen. E
3 Crassilabrisi.. ssa E
» lechaptoisi E
nassa ; EK
55 paucicostata ......... E
is reymondi E
a singularis E
. tiarella E
variabilis .. E
*Hirthia globosa.. Gen. EK
¥ littorina EK
Family TrPHoBitpm,
*Tiphobia horei Gen. E
* Bathanalia howesi Gen. E
Other parts of
the world.
Angoni Land.
India, Malay Pen.
* Genera described as thalassoid,
| Olim Melania,
FAUNA OF THE AFRICAN LAKES. HAD
Tangan- Victoria
Name of Species. yika. Nyanza. Nyasa. Nyanza. Nyanza. the world.
Family LiIMNHIDZ.
Limnea natalensis iP P Pp Natal.
35 ny ansee si ae K
3) MGdussuMme ......... aS P Me .. EE, Africa.
Tsidora coulboisi cae e EK
. Jor ee P of Kgypt, Natal,
5 nyassana a ee E [Angola.
Pe TAMOMOOM — i... es 5c. EK
CCE ne ee E ae K. Africa,
1 SUECINEOIGES ........... he EK
py uetraMSVErSAlIS «..,.<....05 K
PPR M5) sp cede ses ts ves K
Physopsis africana wf P K, Africa, Natal,
oe ovoidea Tae: ee P K. Africa.
a8 fangamyicez ......... E
Family PLANORBID&.
Planorbis adowensis ............ de ee x Abyssinia.
a, alexandrina ......... Ve a RP uae Egypt.
OR Ba K
fe bridouxiana ......... iE
» choanomphalus P Ec Is?
is crawfordi .. i aus a ... Cape Colony.
a gibbonsi a P P eee acY (Be Afries,
- 1S EK
‘5 lavigerianus ......... {
* monceti ..... .. q
eo ee oo y
e sudanmicus ......... Be 1 i P .. RK. Nile.
zs WICHOTIGD is. vce. .vos ves q
Family ANCYLID&.
Ancylus stuhlmanni_......... os E
» tanganyicensis ...... EK
Seamus tenet. aatex tc) LE TP: dP: 6 P. ay 6 P. DN ey
BBEMCTE, Scie dcacdcsisianes 2M LLP, IP: vP, 6 P. 6 P. QE
(35)
TORE PECIES .0...45.2; ees he, E
Burtonia bourguignati ...... Gen. E
. tanganyicensis ... i
Brazzea anceyl:.:............ Gen. E
Family MureLip2.
Miutela alata onrse.. na oh eee ais » E
» bourguignati .. ... oe P sp ce a EK. Africa.
ae WOXOLICA 27,4 anes iP it Pe re a N. Africa.
ee milogiea<: os. nso ae a LA i P Egypt.
se) A SOLENTIOVIMIS) 222-6 i
3 subdiaphana 2 .2.-a. ne E
Pleiodomspekel: ..os.+..0-0e: y
Spatha anceyd cet eee a fe E
o3 DIOV ORI Koos. eacenacn Memeo. Pp a: en a K. Africa.
a kirks eer bat Be E
5 » Myassaensis ....-.... ae E
Fie URAD OZ laser scenes es E
Moncetia anceyi_ ............ Gen. E
Family ATHERIIDA.
Aitheria elliptica ............ iP P hee ee Ae Tropical Africa.
Satamiliesipn. ate ee 4, 5 3 4 4
di wenera “noc. 6e sence oH, 6.P: Male 4P. Aisles 4P,
(8)
53 species ............... I4H,3P. 12E,6P. 7E,6P- 2EH,6P.. 2 oP:
(17) (18) (13) (8) (5)
The table of distribution in this case displays no outstanding
features such as are to be seen in other groups. The not incon-
siderable total of 53 species is reached, but the details of
distribution have, in most cases, little significance. Firstly, it
may be noted that the vast majority of the forms (there are only
4 exceptions) are on record merely from a single lake ; secondly,
it is interesting to find that no species in the whole list occurs
outside the African continent. .
Victovia Nyanza, as already stated, exhibits the largest number
of types, viz. 18, but is closely followed by Tanganyika with 17
and by Nyassa with 13. Lakes Albert and Edward follow in the
usual order with 8 and 5 species respectively. A fact which
emerges from an examination of these figures, is that the two
lakes with the highest totals only contain about one-third of the
number of species enumerated (Lake Victoria 33°9 per cent.,
Tanganyika 32 per cent.). Contrasted with this, the Gasteropoda
of Tanganyika constitute over 63 per cent. of the total number
of Gasteropods enumerated, while in other groups the corres-
ponding figures for Tanganyika reach 80 per cent. and even
90 per cent. (Branchiura).
FAUNA OF THE AFRICAN LAKES, 553
Tanganyika with 14 endemics out of 17 leads the way as far
as endemic Lamellibranclis are concerned (82 per cent.), Lake
Victoria coming near with 12 out of 18 (66 per cent.), while
Nyasa has 7 out of 13 (54 per cent.). Even the smaller lakes
have each two endemic species. It will be observed that the
proportion of peculiar forms is very high in this group also ;
indeed, in some instances it is higher than in the case of the
Gasteropods. Hndemic genera are known only from Tanganyika,
three being retained in the lst out of a larger number distin-
guished by Bourguignat. The genus Moncetia of Bourguignat,
inserted in the table as endemic, though not definitely rejected,
is nevertheless considered by Smith as ‘only doubtfully separable
from Spatha (170, p. 101).
A brief survey of the list of species will suffice. Corbicula
radiata, a representative of the Cyrenide, is the only form which
is on record from all the lakes concerned. It is a widely distii-
buted African type, being known from other parts of Hast Africa
and from the valley of the Nile-—The family Spheriide is
represented by the genera Spherium and Hupera. It is some-
what strange that the four species enumerated are all found in
Lake Victoria, but not in Tanganyika or Nyasa. Spheervune
NYANZE 1S ipa n from Victoria, Albert and Edward Nyanzas, as
well as from other parts of the continent, but it is associated in
Victoria with two additional species which are peculiar to that
lake. Hupera parasitica, which is a Nilotic and N. African form,
is at present only recorded from Victoria Nyanza.—In the family
Unionide there are associated with the extensive genus Unio
itself only the two closely related genera Burtonia and Lrazzca,
which are confined to Tanganyika. No fewer than 29 different
species of Unio are enumerated, not one of which is on record
from more than a single lake. ‘Tanganyika exhibits 8 and Lake
Victoria 7 endemic species. Of 7 types in Nyasa 3 are endemic ;
of 5in Lake Albert 2 are endemic. Lake Edward, lastly,
contains 2 forms, both of which are endemic.—In addition to
three genera of wider distribution, the Mutelide contains the
doubtful genus MZoncetia, to which reference has already been
made—a genus described as peculiar to Tanganyika. J/utela
nilotica 1s the only species in the family recorded from more than
one lake, it being found in both Albert and Edward Nyanza as
well as in EKegypt. Each of the bigger lakes exhibits a single
endemic form of Jutela. The genus Pleiodon is only represented
by P. spekei, confined to Tanganyika—it is one of the species
named by Woodward from Speke’s original collection. Spatha is
unrepresented in Tanganyika and the ‘smaller lakes, but a series
of three endemic forms is known in Nyasa. —lastly, Mtheria
elluptica, sole representative of the A‘theriide, occurs in ‘Tangan-
yika and Victoria Nyanza, but has not been recorded from the
other lakes, although it 1s widely distributed in Tropical Africa.
While a considerably smaller number of forms is involved here
than was the case with the Gasteropods, there is yet an indication
Proc. Zoot. Soc.—1920, No. XXX VII. Beer
504 DR. W. A. CUNNINGTON ON THE
that fewer species occur in the smaller than in the larger lakes.
With the exception of Tanganyika, the lakes are arranged in
order of size, and the figures for the species are as follows :—
Tanganyika 17, Victoria 18, Nyasa 13, Albert 8, and Edward 5.
Regarding ‘Tang ganyika as a lake apart, the remaining figures fit
ip satisfactorily with this suggestion.
The features which are characteristic of the different lakes may
be summed up in a few words. ‘Tanganyika alone contains
endemic Lamellibranch genera. Spheriwm, Hupera, and Spatha
are unrepresented, but a number of endemic species of Unio are
known.— Victoria Nyanza, with the largest total of species,
displays, notwithstanding, little of interest. Most of the genera
are represented, except those peculiar to Tanganyika, and a series
of forms belonging to Spherium and Unio are to be observed.—
Of Nyasa there is likewise little to record. The lake only
contains species from the four well-known genera Corbicula,
Unio, Mutela, and Spatha, 3 endemic types of the last-mentioned
being an outstanding feature.—Both Albert and Edward Nyanza
are similar in type to Nyasa, but contain a representative of
Spherium and not Spatha.
From this survey of the Lamellibranchs, the following points
emerge :—No thalassoid types occur in Tanganyika, but that lake
contains a number of endemic species, as well as three endemic
genera. All the lakes show a high percentage of endemic forms,
but in most cases these are merely species belonging to widely
distributed genera. While Tanganyika does not exhibit in this
instance so remarkable a series of unique genera and species as
in the case of the Gasteropods and other groups, it retains never-
theless a distinctness from the remaining lakes quite in keeping
with its general character.
MACRURA.
The only Macrurous Crustacea which appear to occur in the
big African lakes are the prawns, these being quite common
types in the fresh-waters of the tropies. An examination of the
forms now known to exist in the lakes of Africa reveals, how-
ever, many points of interest. In the first place, no fewer than
twelve species have been discovered in Tanganyika, of which ten
were obtained for the first time by the Third Tanganyika
Expedition. ‘This is in itself a large number of different species
to be found within the limits of a single lake, but the interest is
greatly increased when it is realised that all these forms occur
in Tanganyika alone. ‘This 1s the only well represented group in
which such is the case. Again, with the exception of a single
species of the well-known fresh-water genus Palemon, all the
genera are equally to be regarded as endemic.
FAUNA OF THE AFRICAN LAKES. 555
Table of Distribution of Macrura ‘.
Tangan- Victoria Albert Edward Other parts ot
Beit: da aw
eee peries.: yika. Nyanza. vases Nyanza. Nyanza. the world.
Family PALHMONIDS.
Paleemion moorel ...............
E
Family ATyIp.
Caridina nilotica
WANCORMCMIPES ....5.....0.- 20% - | es P pes pA Asia, Australia.
Limnocaridina retiarius ...... Gen. E
- paryula .....-. i
_ tanganyikee ... K
ie similis) te e.e y
Mt latipes (2044.. EK
i BOCIIIG tcc ese ves E
ve spinipes ...... EK
Limnocaridella alberti ......... A rs fe Gen. EK
Caridella cunningtoni ......... Gen. E
sf POMTAUUGR, . iiaiee Sinwiate aces E
Atyella brevirostris ............. Gen. E :
7 LOWMETEOSINIS” .... 6.2... E
6 genera BH, Ee ie slg 1 Da ee eP
PAVSCCIES 0 atc... ss... L2H, IE; PP. VE Ve. IP;
The adjoining table shows at a glance the iost striking
feature of distribution, namely that while Caridina nilotica var.
gracilipes ~ occurs in nearly all the big lakes of Africa, it is not
found in Tanganyika, but is replaced there by 12 endemic species
belonging for the most part to endemic genera. Lake Albert
also contains an interesting endemic form (obtained by the
German Central Africa Expedition and deseribed by Lenz
(109, p. 132) and Bouvier (52, p. 575)) in addition to the above-
mentioned widely distributed Caridina, while Kivu is the only
lake of those at present under review in which prawns have not
hitherto been observed.
The first species of prawn ever taken in the African lakes was
+ A detailed account of the Macrura of the Third Tanganyika Expedition is given
by Calman (61), and forms the principal source of information on this group.
* The species of prawn collected by Schubotz at Kassenje on Lake Albert was
described by Lenz (1O9, p. 130) as Caridina longirostris Milne-Edwards. It is,
however, commonly agreed that longirostris is identical with the earlier nilotica,
so that, apart from the varietal name, this is the same form that occurs so widely
distributed in Africa. Since the type described as Caridina nilotica var. gracilipes
is certainly rather variable, it seems probable that the Lake Albert specimens are not
sufficiently distinct to be recorded under a different name, and this is the view which
I have taken in compiling the table of distribution above. For a discussion of these
questions of synonymy consult the paper of Calman (61, p. 189 et seg.) and the
subsequent paper of de Man (110), which arrives at somewhat different conclusions.
~ I adopt the varietal identifications of Hilgendorf (100), Calman (61). and Lenz
(109), bat it is only right to point out that de Man (110) takes a different view.
He appears to consider that the form occurring in Lake Victoria is to be referred to
the typical Caridina nilotica itself, and the form from Nyasa to his newly estab-
lished variety natalensis, The type Caridina nilotica var. gracilipes he records
only trom the islands of Celebes and Salayer in the Malay Archipelago.
556 DR. W. A. CUNNINGTON ON THE
obtained in Victoria Nyanza by Stuhlmann in 1890 (100, p. 36).
It was re-taken in the lake by Neumann, and more recently by
Alluaud, by myself, and by Degen. From Nyasa a species of
prawn was brought for the first time by my expedition. These
species prove to be one and the same form—the Caridina nilotica
var. gracilipes, to which reference has just been made. During
the German Central Africa Expedition of 1907-08 this prawn
was collected by Schubotz in both Lakes Albert * and Edward
(109, p. 180). It is thus the only common species in the African
lakes, while it has in fact a yet wider distribution, ranging in
Africa from Natal to the Nile and extending into Asia and
Australia. The eastward range of this type has indeed an
additional interest on account of the well-marked resemblance
noticeable in other groups between the East African and Indian
faunas.
Only the first of the twelve species enumerated from Tangan-
yika can be compared at all closely with forms which are known
from other parts of the world, and it has no very pronounced
affinities. The remaining eleven species belong to the group of
the Atyide, and are not so nearly connected with types hitherto
known. Moreover, in common with Limnocaridella alberti, they
differ from all the other species of the family in having a smaller
number of branchie +, which is a feature undoubtedly due to
specialisation.
To sum up then, there occurs in most of the great lakes of
Africa only a single species of prawn having a very wide
distribution. In Lake Albert this is associated with an endemic
form, and in Tanganyika it 1s replaced by twelve other endemic
forms, the majority of which are among the most highly special-
ised members of the family to which they belong. Under the
circumstances, it is impossible to resist the suggestion that there
is exhibited here something very similar to what was seen in the
case of the fishes, and particularly the Cichlide. If the extra-
ordinary variety of form, and high degree of specialisation, which
is characteristic of the Cichlids of Tanganyika, may have been
due to prolonged isolation and comparative freedom from com-
petition, it at least seems not improbable that the remarkable
Macruran fauna of the lake owes its origin to the same cause f.
BRACHYURA.
There are five different species of crabs now known: from
Tanganyika, of which one has been left unnamed for the present.
In a manner closely corresponding with the case of the prawns,
* See footnote above.
+ A yveduced branchial formula is also characteristic of the remarkable West
Indian form for which Bouvier has established the genus Micratya (51, p. 181),
formerly Calmania (50, p. 334). Bouvier regards this as allied to the Tanganyikan
genera, but this view is not accepted by Calman (62, p. 796).
¢ An important paper dealing with the origin of the peculiar prawn fauna of
Tanganyika was communicated by Bouvier to the International Zoological Congress
at Monaco (52). Consult also Bouvier’s paper on the classification of the Atyidee
(51).
FAUNA OF THE AFRICAN LAKES. 557
while two species belong to a widely distributed and common |
fresh-water genus (Potamonautes), the remaining three, though
members of the typical fresh-water group (Potamonide), con-
stitute a remarkable genus, which occurs only in Tanganyika.
All the forms from the other lakes under review belong to well-
known genera of the same family. No Brachyurans have as yet
been reported from Albert Nyanza.
Table of Distribution of Brachyura*.
Tangan- Victoria Nitsa: Edward ene Other parts of
ame of Species. . é vu.
Name of Sp yika. Nvyaunza. Nyanza. the world.
Family PoTaMONID#.
Potamon (Potamonautes)
inflatus ..
orbitospinus ”
platynotus.. i
Natal.
cola)
Potamon ecomielplnica)
berardi ... Bk vee me nie P Egypt, Abyssinia.
emini ...... ap P a i PE. Africa, Abyssinia.
Potamon (Acanthothelphusa)
GS MUNDAS! F-51205 nw ee de A P ae > ... Egypt, Abyssinia.
Platythelphusa ar mata......... Gen. E
maculata... E
conculeata ... )
4 genera and subgenera... 1K, 1P. Deke. ies TP. PP,
39°
GWepecies +... .2..<0-23--.... 4K, 1 P. 2P. Oe ae ia ey 2 Pi
as
The table of distribution makes it clear that while each of the
lakes in the list exhibits one or more representatives of the very
well-known genus Polamon with its sub-genera, these types are
associated in Tanganyika with three species of an interesting
endemic genus. Both Nyasa and Tanganyika possess species of
Potamonautes which are peculiar to A Nemec ives but it is in
‘Tanganyika alone among the big lakes that an endemic genus is
found, All the species enumerated appear to be confined to the
continent of Africa.
Apart from the case of ‘Tanganyika, it will be noted that (with
the exception of Potamon (Potamonautes) orbitospinus from
Nyasa), the forms from the different lakes are by no means con-
fined to them, and indeed are often of wide distribution. This
whole series of types—types such as are known from all the
tropical fresh-waters of the Old World—may be considered as
the normal African group, and calls for little further remark.
In the paper already cited (70, p. 263) the present writer
expressed a conviction that the number of African species has
been unduly multiplied, and the unnamed forms included in the
+ For further details concerning most of these forms, consult the Report on the
Brachyurous Crustacea of the Third Tanganyika Expedition (70).
558 DR. W. A. CUNNINGTON ON THE
table are to be regarded as specimens which, in the existing state
of our knowledge, it is impossible to identify. It is nevertheless
clear that the precise distribution in the lakes of these repre-
sentatives of the subgenera of Pofamon is of little, if any,
significance.
In this connection it should perhaps be explained that the
evounds of identification of the river-crabs are unsatisfactory on
the whole, external characters of a comparatively trivial and
fluctuating nature forming the basis of distinction. Systematists
are thus on less sure ground than in the case, for instance, of the
prawns, where a matter like the branchial formula affords more
satisfactory evidence of affinity.
Tanganyika, with no less than three species of the endemic
genus Platythelphusa, is evidently a case sui generis. There are
certain features in the anatomy of this unique genus which
suggest that it is of a somewhat primitive and unmodified
character, but at the same time nothing to indicate that it is
more definitely marine than the other members of the family to
which it belongs. Further, it is only to be regarded as unspecial-
ised in comparison with allied forms which have adopted a semi-
terrestrial mode of life, so that it affords in reality no support
for Moore’s view that Tanganyika is the altered remains of an
ancient sea. The genus with its three distinct species is rather
to be looked upon as one more example of variation and
divergence, brought about, in all probability, by prolonged
isolation. Finally, it may be noted that this lake, with five
species, contains a larger number of different crabs than any of
the others under consideration.
Those groups of smaller Crustacea which are often associated
under the heading Entomostraca, are (with the exception of the
marine Cirripedia) well represented in the African lakes. In-
formation concerning them is, however, for the most part, of
fairly recent date, since such organisms would be overlooked
by any but trained biologists, and the use of the tow-net in
Central Africa has even yet yielded results which are but
fragmentary and incomplete. All the earher records are due
to the zeal and energy of Stuhlmann, and concern in particular
Lakes Victoria and Edward. In 1898-1900, extensive collections
were made in Nyasa and its neighbourhood by Filleborn, and
this material, together with a supply from Victoria Nyanza
collected by Borgert, forms the basis of a comprehensive treatise
by Daday (76), in which the whole of the microfauna is dealt
with. The collections made by the writer during the Third
Tanganyika Expedition have afforded information for the first
time concerning the Entomostraca of Tanganyika, as well as
providing additional records for Nyasa and Lake Victoria.
Finally, the work of Schubotz during the German Central Africa
Expedition has furnished further particulars relating to Lakes
Kivu, Edward, and Albert.
It may here be pointed out that these lower Crustacea, with
FAUNA OF THE AFRICAN LAKES. 559
the exceptional opportunities they are known to possess for
obtaiming world-wide distribution, cannot afford evidence of the
same value as the higher forms. When—as is particularly
the case among the Cladocera—even specific forms of cosmo-
politan range reappear in the great lakes, it becomes clear that
the precise geographical distribution of such species 1s a matter
of no great significance. At the same time, the possibility is not
excluded that the lakes may differ in their suitability to harbour
certain types, while it is highly probable that new types can and
will develope in some cases, constituting species or even genera
of an endemic nature. ‘Thus a study of the distribution of these
forms in the lakes of Central Africa is nevertheless not devoid of
interest, and may indeed furnish testimony of some importance.
EUCOPEPODA.
The Eucopepeda so far observed in the lakes with which this
paper is concerned reach the not inconsiderable total of 54
species. Of these, more than half (31) have been found in
Tanganyika, to which lake a large proportion exclusively belong.
There is every reason to believe that further investigation will
bring to light additional forms, particularly from Victoria
Nyanza and the smaller lakes, which, in this respect, have
received less attention than Tanganyika and Nyasa.
Table us Distribution ae ECP ENON ES Te
Other parts of
Name lof Species, Tangan- Victoria Nyasa Albert Edward reat
yika. Nyanza. Nyanza. Nyanza. the world.
Family CENTROPAGID®.
Diaptomus galeboidest ... ee P is: Ie
me MMXGUS 0s... Ar < )
i africanus ..,.... ie ba PR Bt vy ... E, Africa.
fr stuhlmann1 ... a E
=; Stmuplexs vy... KE
- cunningtoni ... eee oe E
- kreepelini ...... a ~ jeg - sae ww +H, Africa,
Family HARPACTICID®.
Canthocamptus schréder1 ae E
Attheyella decorata ......... = ie Bs ae ahs ... Asia, S. America.
33 erandidieri ...... Aer ae Neate Bae: ise ... S. America, New Guinea.
Dactylopus jugurtha ...... ae ~ P a — ... Asia, New Guinea.
Schizopera inopinata...... EK
* WaliGiOr> o..cs. 635 i
a consimilis ...... le E
a unenlata......... EK
minuticornis ... E
+ Detailed information concerning a large proportion of these species is given by
Sars (151). The other sources of most importance are Daday (76, p. 106) and
Meek (189). For the Lernaid consult Cunnington (73).
t I follow Sars (151, p. 34) in assuming that this form, which is one of the
commonest and most characteristic species of Lake Victoria, is not identical with
the Egyptian D. galebi Barrois, as supposed by Mraézek and Daday.
§ Not actually recorded from the lake itself, but from within its drainage area,
560 DR. W. A. CUNNINGTON ON THE
Albert Edward
Tangan- Victoria Other parts of
SITE (OU JETS yika. Nyanza. SS ERE Nyanza. Nyanza. a the world.
Schizopera spinulosa ...... E
Ms fimbriata ..... ey ee E
a SCAVATIS secu sae E
Ilyophilus perplexus......... q
Family CrcLopip2.
Cyclops aspericornis ......... Ore av Ps a ie ... Kast Indies.
3) lenckanti 200 22. P P P Pp. P P Cosmopolitan.
Dive PVE MLD GA eee Ree ae Rie iE? Eg iP i ee a.) SH. Abkeres,
a 6 6omeslectus* |... P ie P Pp ie P Senegal, Sumatra.
mr EteNellUS' | eae eee E
oe) albidus eat eet ay 8 P re Be ... Cosmopolitan.
eo eat teMmuatus 1.0.53. E
Pe WA VALICHING: @ 720.0. e ee: Pp ~ Ve iP oa .... Europe, New Zealand.
Pee PDICOLORNNT ec ee e) my, P§ ie: lis ... E. Africa, Europe.
“ exiguus Riese, E
, cunningtont, ...... E
6 spachycomusis. 4. E
so. Seraulatusiy tee aa P§ PS 4 P .... Cosmopolitan.
» Ssemiserratus «.... E
Sy lee VINA ZO" 2a. eee E
Sy maerars eae ee uy. Pes Be ss 44 .... Cosmopolitan.
5) warnomshuis) 10,62: 7eyece P ue P P
» ‘stublmanni,.1.2... ag E
3) eo Tais pins © eee ee E
by) 2 AS MOIMES eee sree oe IP iP iP
» euacanthus ... E§
» ciliatus Scie E
ery ONTOS DIS) eae mens ne es)! sei ne KE
jg - - PLASINUS 452405 0008s: sk P iP ae - ... EH. Africa, Europe.
we | Dhaleratisiese. 3. as P§ P§ a xs .... Cosmopolitan.
COMmMpactus (2) peace P§ i an: Lisp i) ... Central Africa.
Ms oligarthrus ......... E
Family ERGASILIDz.
Ereasilus kandtr 2-40.05 se: nt Wa: EK
a3 SDseacceten a Oe = le or
Ergasiloides megacheir ... E
macrodactylus E
- brevimaunus .., J2 P
Family LERN#ID&.
Lerneeocera diceracephala .. E
os haplocephala ... P A Ae ne act ... Nile, Congo.
LO genetar tere Gk. BP; GP, 3 P. iI ine
5A Species ...-1,.-uss08. a. 22H9P. BE IOP, (4ROR: WKcGR: 3P:; 2uP;
(31) (13) (23) (7)
§ Not actually recorded from the lake itself, but from within its drainage area.
* As explained by Sars (151, p. 51 & 74, p. 82), this species has been wrongly
identified with C. oithonoides G. O. Sars or with C. hyalinus Rehberg by other writers
en African Copepoda. I adopt the new name introduced by Sars.
+ A number of the forms which succeed this in the list belong to the group for
which C. serrulatus Fischer is the type. While the species C. serrulatus is recorded
by Mrdzek (139, p. 3) for Victoria Nyanza, by Daday (76, p. 108) for Nyasa, and
by van Douwe (80. p. 492) for Edward Nyanza, it is not unlikely that the specimens
in question might rather belong to one of the species in the “‘ serrulatus” group as
described from the lakes by Sars, than to C. serrulatus, s. str. At present it is
impossible to settle this point, so I take the course least open to objection and insert
the records of Mrazek, Daday, and yan Douwe as they stand,
FAUNA OF THE AFRICAN LAKES. 561
An examination of this long list of forms reveals in the first
place the large proportion of the recorded species which has been
observed in Tanganyika. The latter lake contains 31 out of a
total of 54 different forms, Nyasa contains 23, Victoria Nyanza
13, and the remaining lakes still smaller numbers. The contrast
between the lakes is greater than is disclosed by these figures, for
out of 31 species known from Tanganyika, 22 are peculiar to that
lake, and in comparison only 4 out of 23 for Nyasa and 3 out
of 13, for Lake Victoria. In the three smaller lakes there is only
a single recorded species which is endemic, and that occurs in
Albert Nyanza. Expressed in percentage form, th's means that
nearly 71 per cent. of the Copepods of Tanganyika are found in
that lake alone, while of the species found in Nyasa only some
17 per cent. are peculiar to the lake, in Victoria 23 per cent., and
in Albert 14 per cent. Excluding Tanganyika, it will be observed
that only 8 of the forms recorded are endemic, so that with 22
endemic species, Tanganyika has nearly three times as many
endemic EKucopepoda as the other lakes can muster between them.
Turning now to the distribution of families and genera in the
lakes, the genus Diaptomus, sole representative of the Centro-
pagidze, calls for little comment. A single species of this genus
occurs in Tanganyika, to which it is peculiar: it appears to be
a most characteristic plankton form in that lake. Lakes Victoria
and Nyasa each contain endemic species as well as types of wider
distribution, so that the three big lakes may each be said to have
their own particular forms. None of the species of Diaptomus
in this list have been observed outside the continent of Africa.
The representatives of the Harpacticide are of far greater
interest. An endemic species of Canthocamptus has been re-
corded from Victoria Nyanza, and widely distributed species of
Attheyella and Dactylopus from Nyasa. It is on the genera
Schizopera and Llyophilus, at one time regarded by Sars as strictly
marine, that interest really centres. The genus Schizopera is
represented in the collections made by the writer by no less than
8 species, of which 6 are peculiar to Tanganyika and one to
Nyasa, while one occurs in both Lakes Tanganyika and Victoria.
The genus was established hy Sars for the reception of a species
found in a brackish-water ]Jagoon on the Chatham Islands, while
subsequently species have been obtained from the Caspian and
from Egypt. It is obvious that such a genus can hardly be
regarded as strictly marine. Three questions suggest themselves
in “this connection. How does the genus come to be represented
in the heart of Africa; how is it that brackish-water types are
living there in perfectly fresh-water ; and how is it that so many
different species are recognisable in Tanganyika ¢ Sars points out
(151, p. 69) that the most obvious explanation would be to regard
these as genuine ‘‘ relict” forms, in which case the Tangany ikan
species would be important members of Moore’s so-called ‘ halo-
limnic” series. He rejects on general grounds the view advanced
by Moore, and indicates transport by the aid of migratory
aquatic birds as suflicient explanation for this remarkable
562 DR. W. A. CUNNINGTON ON THE
discontinuous distribution. He asserts the probability that
forms transported from brackish water would not be unable to
survive in fresh water, and finally maintains that the several
species occurring in Tanganyika have been produced by diver-
gence during a period of isolation—a view entirely in accord with
that already expressed in the case of other animal groups.—The
genus [lyophilus is represented in Tanganyika by a single species
which is endemic. ‘The type species of this genus was described
from the Baltic and has also been obtained near Christiania, so
that the remarks concerning transport and establishment in
fresh water are as applicable here as in the case of Schizopera.
No fewer than 27 species, all belonging to the genus Cyclops, are
enumerated under the family Cyclopide. It will be noted that
Tanganyika again leads the way with 17 species, while Nyasa
contains 13 and Lake Victoria 8: moreover, 11 of the Tangan-
yikan species are peculiar to that lake, while the other two lakes
each contain only a single endemic form. ‘The three smaller
lakes possess fewer representatives, viz. :—Lake Albert 5, Lake
Edward 3, and Lake Kivu only 2. All the latter are of fairly
wide—some of cosmopolitan—distribution.
The family Ergasilide, which may be regarded as intermediate
between the free-living and the highly degenerate parasitic
Copepods, is represented by 5 species belonging to two genera.
An endemic form of the genus Hrgasilus has been recorded from
Albert Nyanza, and the genus has also been recognised both in
Nyasa and Victoria. In Tanganyika it would seem to be
replaced by the genus Argasiloides, described from material
obtained by my expedition. Two endemic species are on record
from Tanganyika, while a third is found in that lake and also
in Nyasa.
The Lerneide with two forms of Lernaocera concludes the
list. The two species were obtained by the Third Tanganyika
Expedition from fishes in that lake, and while one proves to be
endemic, the second was found to be identical with specimens in
the British Museum collection taken on Nile fish.
Reference may again be made here to the statement that the
number of different animal forms existing in the lakes varies in
proportion to the size of the latter (cf. pp. 5385, 548). It is only
when many forms are enumerated that such a comparison is
justified, but in this case it may fairly be undertaken. Apart
from Tanganyika, the lakes are arranged in the table in descend-
ing order as regards size, and the total figures are as follows :—
Tanganyika 31 (species), Victoria 13, Nyasa 23, Albert 7,
Edward 3, and Kivu 2. It is very clear that Tanganyika is
quite unique, but apart from that lake, beginning with Victoria
Nyanza, the Copepods exhibit a regularly decreasing total with
the exception of Nyasa, where the higher figure is probably due
to the more thorough exploration of its waters.
The distribution of Copepoda in the individual lakes may be
summarised as follows:—Tanganyika, with 31 species, 22 of which
are endemic, is clearly in a category by itself. Containing a
FAUNA OF THE AFRICAN LAKES. N63
single species of Diaptomus which 1s peculiar to it, the lake
is chiefly characterised by a number of remarkable forins belong-
ing to the genera Schizopera and Llyophilus, nearly the whole of
which are not known elsewhere. Even of the cosmopolitan genus
Cyclops, Tanganyika exhibits 11 endemic types, as well as others
of wider distribution, while of the three species of Argasiloides,
two are found here alone. Two forms of the parasitic Lerncocera
occur in the lake, one of which is likewise endemic.
The Copepoda cr Lake Victoria are referred not only to fewer
types, but form a much less interesting assembly. ‘They comprise
a single endemic species in each of the genera Diaptomus, Can-
thocamptus, and Cyclops, but otherwise are forms of wider, often
of world-wide distribution.
A larger number of species 1s known from Nyasa, but out of
23, only 4 are endemic. Of the latter, two are species of
Diaptomus, while there is a single endemic form of the striking
genus Schazopera and one of Cyclops. Most of the remaining
species are widely distributed, a considerable proportion being
well-known forms of Cyclops. Nyasa contains a species of
Krgasilus as well as Lrgasiloides brevimanus which is otherwise
confined to Tanganyika. ‘There is no reason to suppose that
Nyasa will be found to contain so many more Copepoda than
Victcria Nyanza when the latter lake has been equally well
investigated.
Seven species have been observed in Lake Albert, of which
merely a single form (Hrgasilus kandti) is endemic. Apart from
this and from a species of Diaptomus found also in Lake Victoria,
the lake contains only representatives of the genus Cyclops, which
are of fairly extended, and in some cases of the widest possible
range.
Lake Edward with 3 species, and Kivu with 2, come last in
the series, and it. should be noted that not only do they contain
very few types of Copepoda, but that these types have little
significance, being in each case widely distributed species of
Cyclops.
It is thus apparent that with increase in size the Jakes exhibit
an increase in the number of forms which they contain; that
only in the larger lakes do endemic species appear; and, finally,
that Tanganyika possesses a large number of unique types which
may well have been produced during a period of prolonged
isolation.
BRANCHIURA.
This small group of animals, which are parasitic for the most
part on fish, was for long but poorly represented in the collections
from the grent lakes ae Africa. The collections made by Stubl-
mann im Ryarseria Nyanza (184, p. 154) and Edward Nyanza
(187, p. 47 & 188, p. 37) and by Filleborn in Nyasa (18%, p. 47
& 188, pp. 37 & 44), resulted in a total of three species belonging
to as many genera. ‘To these may now be added no fewer chai
seven new species of Argulws which were obtained for the first
time by the Third Tanganyika Expendition (72), while there are
[97 |
564 DR. W. A. CUNNINGTON ON THE
further records of distribution now available which make our
knowledge more complete. It is safe to predict that future
investigation will add to the localities in Africa from which these
parasitic forms are known, even though it may not materially
increase the number of recognised species.
Table of Distribution of Branchiura tT.
Tangan- Victoria Albert Edward Other parts of
Name of Species. yika. Nyanza. Nyasa. Nyanza. Nyanza. the world.
Dolops ranarum ............ iP Jef P beh A Nile.
ATCULUS INGISUS, <..;5 02.006 EK
» Yubropunctatus ... qj
5} spersonatus <..7..0) q
yy ORIOUUS: Bcc. nese {
» angusticeps......... q)
pa MEESLTIOUU San ere eee E
9». XUDESCENS: , s.2...02 y
5) weatriegnius oC. ae P iP iP iP P Nile.
Chonopeltis inermis ......... M; *, Gen. E
LO USPeCleSs freee. et ee 23 PH21. 1: 1 Ps
The outstanding feature revealed in the above list is that while
two species occur widely distributed in Africa, these are asso-
ciated in Nyasa with a single endemic form, but in Tanganyika
with no less than seven. Thus out of ten known African species,
nine are found in Tanganyika, which is therefore seen to possess
not only a larger number of characteristic species, but a much
richer Branchiuran fauna than the other great lakes with which
it may reasonably be compared. All the species enumerated are
confined to the African continent so far as is at present known.
Dolops ranarum is the only African representative of a genus
which is otherwise exclusively American. The genus Chonopeltis
was established from a single female specimen from Lake Nyasa,
while Argulus alone has a distribution which is world-wide.
OsTRACODA.
It seems probable that the Ostracod-fauna of the great lakes is
less well represented in the collections hitherto obtained than is
the case with any of the other groups of Entomostraca. This
is due to the fact that nearly all fresh-water Ostracods are
bottom-living rather than planktonic forms, and require other
methods than surface tow-netting for their capture, while the
bulk of the material at present examined was collected by the
tow-net. This implies, of course, that many additional types
will probably be found when the lakes are more adequately
explored. Nevertheless, 22 species are on record for Tanganyika
(of which 20 ave peculiar to that lake), and 17 and 7 respectively
for Nyasa and Victoria Nyanza. No Ostracoda have so far been
recorded from Lakes Edward and Kivu.
+ For further particulars, bibliography, etc., consult Cunnington (72).
FAUNA OF THE AFRICAN LAKES. 565
Table of Distribution of Ostracoda *.
Nemec of Species. Tangan- Victoria Nyasa Albert Other parts of
yika. Nyanza. * Nyanza. the world.
Family Cypripm.
Mima CAStanea... 6. ise. es 7 a P na Natal.
eer denticularis — sc;..:- he a P§ ae Madagascar.
Paracypria declivis ......... Y
5 complanata ... Y
mA conoidea ........ E
re OQUGUGE. ces ices cos P. ne 4, P
- defiexas is)... E
5 subangulata ... E
is reniformis ...... E
a bunnies ox .s:e. E
K Opacar cee. e. iE
- claviformis _... q
7” MEXMOSAr 46. oss oes E
re curta cs 1
Iliocypris propinqua......... a E
Fs 1) eRe Oe ire ara 1D)
Heterocypris dubia ......... ve KE
Kucypris flabella ............ we E
ed ee bit AS P§ Natal.
s laticauda ....... =: ae =A E§
Stenocypris sinuata ......... i: im P§ Ae Madagascar.
5 malcolmsoni ... at ie a a Asia, Australia.
5 marginata... ... a bee i §
_ perarmata... ... Pp ea i Ss Natal.
53 fiilleborni ...... a a 1 §
a fasciculata... we ee E§
an stagnalis”. ....... fe ee: q
Cypridella fossulata ......... és P§ sine Kilimandjaro.
Cypridopsis obliquata ...... K
sintiatde.:....... y
5 cunningtoni ... ee be K
x pusillay 4)... .:. y
- monodonta ... y
* serrata: .. 2.2... y
is bidentata ...... K
we tumidula ...... y
“5 congenera ...... K
ee PAIN s es. ana: a E
Potamocypris fiilleborni ... ae 2 E
ap) viduella ...... a ye P§ I Cape Colony.
Zonocypris costata ......... P P8§ bg E. Africa, Madagascar.
ts desis che... K
Family CYTHERID2.
Limnicythere obtusata...... a 10)
. michaelseni.. ds ‘ P§ HF Lake Rukwa.
MUI PCIEU Aas se. « cso satis nites Ae. OL: OrP. IP.
AMepeeiese 26.2). fa... 2OH)2P.) 5H, 2Ps. SE; 9 P. 1P.
(22) (7) (17)
+ This account is based in the main on the report published by Sars on the
Ostracoda collected by the Third Tanganyika Expedition (152).
§ Not actually recorded from the lake itself, but from within its drainage area.
566 DR. W. A. CUNNINGTON ON THE
The existence of a large number of Ostracods which are
peculiar to Tanganyika is the principal feature displayed by the
list of species. Of the total number of forms on record, it will be
noted that Nyasa with 17 species does not fall far short of Tan-
ganyika with 22, while Victoria Nyanza is a long way behind
with only 7. This is probably due—at all events in part-—-to the
fact that Nyasa and its drainage area have been more thoroughly
investigated in this direction than Lake Victoria. It may further
be remarked that less than half the records from Nyasa are from
the actual waters of the lake itself, the remainder coming from
ponds and swamps etc. in the vicinity. Corresponding collec-
tions from the surrounding ponds, swamps, and rivers are wanting
in the case of both Victoria and Tanganyika; indeed, the whole
of the material collected in the three biggest lakes by the author’s
expedition came only from the lakes themselves. Additional
records are therefore to be expected, particularly from Lakes
Victoria and Tanganyika whenever a more complete investigation
of the Entomostraca becomes possible.
While Nyasa is shown to contain nearly as many different
forms as Tanganyika, it will be seen that in the nature of these
forms the lakes differ profoundly. More than half the species
from Nyasa have also been obtained elsewhere, but of the 22
species from Tanganyika only two have so far been observed out-
side the confines of that lake, or to put it in another manner,
47 per cent. of the Nyasa forms are endemic in the lake, while
nearly 91 per cent, are endemic in the case of ‘Tanganyika.
Another feature of distribution which this table brings into
prominence is the association of certain groups of forms with
certain lakes. Only in three cases have species been recorded
from more than one lake—/Stenocypris perarmata trom Tanganyika
and Nyasa, Zonocypris costata from Victoria and Nyasa, and
Paracypria obtusa from Tanganyika and Albert. In every other
instance the species from the lakes differ from one another, and
appear to be either peculiar to or at least characteristic of the
lakes in which they are found. Without referring to the species
seriatim, it may be pointed out that the genera Stenocypris,
Potamocypris, aud Cypria seem to be associated in particular with
| Nyasa, and Cypripodsis with Tanganyika, while Paracypria, with
the exception of a single species, occurs only in Tanganyika
among the lakes.
Apart from the forms peculiar to Tanganyika (which number
20 out of a total of 44in the list of Ostracoda), it is to be observed
ee 8 species are peculiar to Nyasa and 5 to Victoria Nyanaza,
- 13 in all. It will thus be seen that when Tanganyika is
leaed more endemic forms are known from the remaining
lakes than is the case among the Copepoda, It is also singular
to note how restricted is the distribution of even the non-
endemic forms recorded, for only in a single case (that of Steno-
cypris malcolmsoni which is known from Asia and Australia) has
a species been obtained outside the continent of Afriea with
Madagascar.
To the g genera Paracypria and Cypridopsis, which are so largely
FAUNA OF THE AFRICAN LAKES. 567
represented in Tanganyika, it is necessary to call special attention
on account of their remarkable nature. Of the former genus, no
fewer than twelve different species have been described frem that
lake, eleven of which are peculiar to it, and they all, as Sars points
out (152, p. 756), exhibit striking features of specialisation.
It is also a remarkable coincidence—if it is only that—that the
type species of Paracypria was obtained from the same brackish
lagoon on the Chatham Islands as was the type of the Copepod
genus Schizopera, which is likewise very characteristic of Tan-
ganyika among the lakes. The case of Cypridopsis is perhaps
more significant still, since of the ten species obtained by the
Third Tanganyika Expedition two only display all the features
characteristic of the genus, and these are the two forms taken
respectively in Lakes Nyasa and Victoria. ‘The other eight types,
which are confined to Tanganyika, exhibit certain divergences
which suggest that they might more suitably be removed to a new
genus which would then be endemic in the lake (152, p. 757).
It is quite clear that in the case of this group also, Tanganyika
contains an unusually large number of forms, an exceptional
proportion of which are peculiar to the lake, and that of these
peculiar forms many show undoubted signs of specialisation.
CLADOCERA.
The outstanding fact concerning the Cladocera is the absence
of any representatives from the plankton of Tanganyika, and
also apparently of Kivu, which is in direct communication with
it. Thus the survey of this group of organisms resolves itself
into a comparison of the records from the remaining lakes, and
this, it is not surprising to find, lacks the interest which the
inclusion of species from Tanganyika usually affords.
Table of Distribution of Cladocera *.
Waine of Species Victoria Nogan Albert Edward Other parts of
c a . a Code
Nyanza. Nyanza. Nyanza. the world.
Family Srpipz.
Parasida szalayl ii... 600 1. a ie a4 - Asia.
Diaphanosoma excisum ... rE Jed + Me K. Africa, Australia.
Family DAPHNID2.
Daphnia kirimensis ......... Ae - ae E
és Jongispina ......... P oh se Cosmopolitan.
Pi hyalina ss ee le Ae a ee Cosmopolitan.
33 ee eet ek P iP ss eds Palestine, Australia,
ss monacha ......... lite sis y
Hyalodaphnia barbata ...... P ay K. Africa.
Ceriodaphnia bicuspidata... E vas ‘ E,
e. cout Rage, : P§ 7. a ae Australia, S. America.
55 LOU ODE Chg asanae ne ao a Sumatra.
si Weaudd, 7... P P§ ‘a ae Almost cosmopolitan,
oe 2
+ For further particulars consult especially Daday (76, p. 120). Additional
records for Lake Victoria are given by Delachaux (77) and for the smaller lakes by
Brehm (54).
§ Not actually recorded from the lake itself, but from within its drainage area.
568
DR. W. A. CUNNINGTON ON THE
Name of Species.
Simocephalus vetulus ......
Moinodaphnia macleayi
Momandiualbiat es, eeeee cee
Ag 0 SRDS EW aa ene Nee
» SD).
Family BosMIniIpH.
Bosmina longirostris
Bosminopsis deitersi
Bosminella anisitsi
Family MacroTHRIcID2s.
Macrothrix laticornis
- hirsuticornis ...
53 chevreux1
Ilyocryptus longiremis
Family CHyDORID®.
Camptocercus australis
Alonopsis singaiensis
Euryalona orientalis .........
Pseudalona longirostris ...
(Alona ats i200 ccss sgeceeees
» costata
De UU CAUAN Is es eincerneg +
epulchellag.s.cte-eness:
quadrangularis
3, mhecban@ulay 222.8 tan te:
Rhynchotalona rostrata ...
‘Alonella, excisa a. ssa ..cee-
as elobulosa He
4 ATU (Ate cee ee
= pumctatal 2c. sar.
is diaphana, 22.09.05
Pleuroxus similis ............
Fe SiRlatuSt see ace
s assimilis) ... 2...
Chy dorus)baivoist ce eee
- spheericus
As ventricosus ......
as leomardi tse...
a DIGere ete ees
> zlobosus
Dadaya macrops
Monospilus dispar
DA SONETA gts changes eer
a
HI SPeCies hee ae oe
§ Not actually recorded from the lake itself, but from within its drainage area.
Albert Edward
Nyanza. Nyanza.
Other parts of
the world.
Victoria ies
Nyanza. i.
iP iP
ne PS
E P
id
Pe P
Pp
P
iP ee
EU bade
P Pes
12 a
Pp
P
” P§
Pp “i
deg
les ae
ee p
B)
Pp rs
PS§ ae
B)
oe 3g
P
iP ei
P
alia
P§ hae
ie
le i
P§ Ps
ie pe
oe P
P
IGP. 20 P.
31 P.
50
P
iP. ole,
J
LE. 5 P.
Cosmopolitan.
Almost cosmopolitan.
K. Africa, Egypt.
Zanzibar.
Cosmopolitan.
Central Africa, S. America.
S. America.
Cosmopolitan.
Algiers, Europe.
Africa, 8. America.
Cosmopolitan.
Australia.
Ceylon, S. America.
Cevlon, S. America.
S. America, New Guinea.
Cosmopolitan.
Europe.
E. Africa, Europe.
Australia, 8. America.
Europe.
Cosmopolitan.
Europe.
Kurope.
Ceylon, S. America.
Australia, S. America.
E. Africa, S. America.
Australia, S. America.
S. America.
Europe, N. America.
Natal.
Asia, S. America.
Cosmopolitan.
Ceylon, S. America.
Australia.
Kurope.
Kurope.
Asia, S. America.
Europe, N. America. '
ee
The list of Cladocera from the big lakes of Africa differs from
all the corresponding lists in the absence of a column for Tan-
ganvika.
While the group is entirely unrepresented in Lake
Tanganyika itself, various Cladocera occur in the surface tow-
nettings which | made in the broad mouth of the Lofu River,
which enters the south-western corner of the lake. I had intended
myself to report on the Cladocera collected by the Third Tan-
ganyika Expedition, but I have not yet been able to do so, and
the specimens from the Lofu remain unexamined. During his
FAUNA OF 'THE AFRICAN LAKES. 569
investigations on the Copepoda and Ostracoda of the expedition,
G. O. Sars, however, kindly isolated and identified certain
Cladocera from Victoria Nyanza and Nyasa, and these forms are
included in my list of species without further comment, although
they constitute In some cases new records of distribution.
The reason for the absence of Cladocera from Tanganyika
remains a matter for speculation, but the most likely explanation
would seem to be that the water of the lake either contains
certain salts which are fatal to such organisms, or is perhaps of
too saline a nature to permit them to survive. Colour is lent to
this view by the already-mentioned occurrence of Cladocera
in the river Lofu and also by the marked difference in nature of
the Rotatorian fauna of the lake proper and the river mouth.
Rousselet (150, p. 794) reports that in a small quantity of
material from the river he distinguished 23 different species
of Rotifera, while in a large series of tow-nettings from different
parts of Tanganyika he was only able to find 10 species, of which
but one was common to Jake and river. It thus seems highly
probable that though the salinity of the lake water has not made
it impossible for certain Rotifers to live in Tanganyika, it is at
least the factor which has determined the striking difference
between lake and river in this respect. Further, it may be
pointed out that a somewhat similar state of affairs has been
observed in the case of the phytoplankton. G.S. West in his
report on the fresh-water Alge of my expedition states (200,
p- 96):—‘‘ Of the thirty species observed in this river-plankton,
only one occurred in the plankton of the lake itself.” This
evidence 1s very suggestive, and appears to confirm the view put
forward, as it is well ‘known that the distribution of these delicate
plant organisms is profoundly influenced by the nature of the
water.
This is not perhaps the place to discuss at all fully what is
known of the nature of the lake water, but the principal features
may be indicated as follows. The total amount of dissolved
saline matter is rather higher than in the case of Thames water,
but is not excessive. The amount of calcium salts is, however,
low, while salts of magnesium are present in much larger
quantities than is characteristic of fresh waters. It is an obvious
suggestion that the presence of this excess of magnesium salts—
which are characteristically bitter to the taste-—-while not ren-
dering the water unfit to drink, might be sufficient to affect these
organisms and prevent them from obtaining a footing in the lake.
Tt becomes necessary in this connection to refer to the nature
of the water of Lake Kivu, which is in direct communication with
Tanganyika. Here the quantity of saline matter is excessive,
and indeed most remarkable for a relatively large lake, From an
analysis by Hundeshagen (103) it appears that while the water
is almost entirely free of mite salts, it contains a very unusual
amount of salts of sodium and magnesium—particularly salts of
magnesium, of which there are more than twice the amount
present in Tanganyika. ; 7
The plankton of Kivu, among other lakes, was collected by the
Proc. Zoo. Soc.-—1920, No. XXX VIII. a8
570 DR. W. A. CUNNINGTON ON THE
German Central Africa Expedition of 1907-08, and Brehm,
reporting on the Cladocera obtained by the expedition (54, p. 168),
refers to the complete absence of these forms from Kivu, and
expresses the opinion that the nature of the water may explain
the fact. It seems, nevertheless, that a very occasional specimen
may be found—pr esumably i in the littoral zone,—for in the collec-
tion examined by Brehm was a tube labelled ‘‘ Surface, Lake
Kivu—one specimen Alona.” ‘This specimen he failed to find,
but there is little doubt that such individuals must be carried
into the lake by streams entering it. Indeed, the conditions are
probably paralleled in ‘Tanganyika, for not only does the existence
of Cladocera in the Lofu River suggest this, but Sars (151, p. 67)
actually observed an isolated specimen of J/oima during his
examination of plankton from the lake. Both these records J
have purposely omitted from my list.
It only remains to suggest that since the river Rusisi, which
is the outlet of Kivu, brings a considerable volume of water into
Tanganyika, it 1s likely that Kivu is the principal source of the
magnesium salts which appear to have an influence on the fauna
of both the lakes in question.
It would be interesting, and should not prove difficult, to
determine by experiment whether Cladocera are susceptible to
the presence of small quantities of magnesium salts in the water,
and, if so, whether they are affected by amounts too small to have
any adverse influence on other Entomostraca*. Indeed, a whole
field of experimental research is indicated, which might go some
way towards determining whether the very special nature . of
the fauna of Tanganyika may not in some degree be related to
the unusual nature and quantity of the salts dissolved in the
water.
Turning from these matters to a survey of the list of Cladocera,
it will be noted that 51 species in all have been enumerated.
Of these, 31 species are recorded from Lake Victoria, 30 from
Nyasa, 6 from Edward Nyanza, and only one from Albert Nyanza.
It is interesting, though perhaps not surprising, to observe that
an overwhelming majority of the forms were already known from
other parts of the world, only 2 species out of 51 being described
as endemic, to wit Daphnia monacha from Lake Albert and
D. kirimensis from Lake Edward. A number of the forms are
truly cosmopolitan and many more are known from two or three
continents, while only four are restricted to other parts of Africa
in addition to the lakes. On comparison with the particulars
given for the Copepoda and Ostracoda, it becomes clear that while
the former group holds an intermediate position, the Ostracoda
are the most limited in range and the Cladocera the most
extended. Of 44 species of Ostracoda enumerated, 33 are described
as endemic in one or other of the lakes: cut of 54 species of
Copepoda, 30 are endemic: while out of 51 species of Cladocera
only 2 are endemic. It can hardly be doubted that this is due to
* A brief reference is made by Gurney to his observations of the injurious effect
of magnesium salts on the growth of fresh-water Daphnia (97, p. 469).
FAUNA OF THE AFRICAN LAKES. ay a
the exceptional facilities for distribution afforded by the thick-
shelled ‘‘ resting” eggs of the Cladocera.
A detailed survey of the distribution of the genera in the lakes
does not seem called for, but certain features may be pointed out.
All the well represented and more important genera appear to
occur in two or more of the lakes, while it is the less outstanding
forms which are only known at present from one of the lakes in
question. Chydorus ana Alona are the best represented genera,
each with 6 species, Daphnia and Alonella following closely with
) species each. From Albert Nyanza, as alr eady mentioned,
there is only the record by Brelm (54, p. 169) of a single species
of Daphnia. I have, however, in my possession a small quantity
of Sa au from the lake collected i in July 1907 by my friend
R. 'T. Leiper (cf. 74), and though I have not yet found an oppor-
tunity of properly studying the Cladocera which it contains, I can
at least indicate the occurrence of the genera Diaphanosoma,
Moina, Camptocercus, Alona, and Chydorus. Having made no
specific determinations, these new records are not included in my
list of forms, but attention is merely called to them in this place.
The addition of these genera to its ‘fauna brings Lake Albert far
more into Jine with Lake Edward and the lar ger lakes.
To sum up—Lakes Tanganyika and Kivu quite unexpectedly
contain no Cladocera. This is very probably due to the salinity
of the water, and perhaps in particular to the excess of magne-
sium salts in those lakes. Apart from this, the distribution of
species in the Jakes affords little of interest, many of the forms
being cosmopolitan and only an insignificant number endemic.
BRANCHIOPODA.
Although representatives of this group have been found in
various parts of the African continent, there is, as far as I am
aware, only a single record which concerns the lakes under
review. A species belonging to the family Estheride, viz.
Cyclestheria hislopi, was collected by Fulleborn in the neighbour-
hood of Nyasa, though not actualiy in the lake itself (76, p. 159).
This form, originally described as Kstheria, but subsequently
separated from that genus, is of wide distribution in the tropics,
and its occurrence in the fauna of Lake Nyasa has no particular
significance.
PENTASTOMIDA.
These parasitic Arachnids have not, I believe, been hitherto
recorded from any African fishes. 1 obtained a number of speci-
mens of Porocephalus from Tanganyika fish, encysted forms from
the body-cavity and others from the intestine. ‘Che materiai nas
been submitted for expert examination, but no detailed report is
yet available. Since the specimens came from very distinct
hosts—a Siluroid in the one case and a large Lates (Serranid) in
the other,—it may be they will prove to belong to different
species. It is open to question whether such Ponte should be
included in a description of lake faunas.
38*
572 DR. W. A. CUNNINGTON ON THE
HYDRACHNIDA.
It is probable that the Hydvachnida of the great African lakes
are but imperfectly known to science, although 31 species in all
have been enumerated. Comparatively small and inconspicuous
forms as these mites are, there seems little doubt that a good
many more species will come to light in the future. Following
on the earliest collections made by Stuhlmann, come those of
Fulleborn in and around Nyasa and of Borgert in Victoria
Nyanza. Specimens from both those lakes and also from Tan-
ganyika were obtained by the expedition which I conducted
in 1904-05. It seems likely that Lake Nyasa, from which
the largest number of types (14) is on record, has been better
explored in this direction than the remaining lakes. No
Hydrachnids have hitherto been collected in either Albert
Nyanza or Kivu.
Table of Distribution of Hydrachnida *.
AO hs ternal ee Tangan- Victoria s Edward Other parts of
Naine of Species. yika. Nyanza. Nyasa. Nyanza. the world.
Family HypDROPHANTID®.
Georgella incerta ....,........-4: a ee P§ ok Quilimane, Nossi-Bé.
Diplodontus despiciens ...... iP te A igs Cosmopolitan.
Family Hy@rospatipm.
Limnesiaarmata 2... 40.6.0. As K
os campanulatay y e-tes oe 1)
Anisitsiella africana ............ Ay ha) E§
Hygrobates edentipalpis ...... KE
Oxus stuhlimannt %.0.......2 +. ce E
Unionicula borgerti ............ _ E
‘5 ClaSsIpes eee We iP i ne Europe.
5 digitatus ......... an nee P Ra, Nossi-Bé.
ES falenier’ See ae ia E
¥ fgUTalis feta. stk P P n as Europe.
a Ny NGCUS Maan ann a8 a es E
aa cunningtoni ...... ae Aa E
Encentridophorus borgerti ... fs E
99 koenikei ... oa et 1 §
_ spinifer ... Ai P als td Zanzibar.
Neumania paucipora......... i a os 1 Kast Africa.
% simulans (255 Sen bs ie Bs if Soudan, Quilimane.
5 SpIMIpes) | Soysinss.0: ae P a =A Kurope.
i papillosa oo... ss: aD)
Koenikea tessellata ............ ae ae E§
Pionacalizitera yes oe ke ise ie Piss hie Madagascar.
soc) SOU UICLUIS! ay eek ee a P Ls, ee Europe.
Forelia liliacea US arya P Europe.
Mideopsis minuta ............... aD)
Arrhenurus plenipalpis....... bei oe P. fe Madagascar, Quilimane.
SArGiMatuUs «chs. ab. i P§ ae Madagascar.
” feeMVA pS” eo adae ba a E§
RS Vigorans: Oss sh! eh; ne P§ hee Nossi-Bé.
3 voeltzkowi...... p a bis P§ A Madagascar, EK. Africa.
14 penera’ 5:1. teen Oe 6 P. our iP.
SL Species Aeaicis io. deenteenes Lube 6E,6P. 5H, 9P. 1E.
(6) (12) (14)
+ For additional information refer to Daday (76, p. 237) and Soar (172).
§ Not actually recorded from the lake itself, but from within its drainage area.
FAUNA OF THE AFRICAN LAKES, 573
The distribution in the lakes of the forms at present recorded
is made clear by the adjoining list of species, and it will at once
be observed that the exceptional position held by Tanganyika in
the case of other animal groups is not in evidence here. While
the possibility is not excluded that further investigation may
bring to light an unusual number of remarkable species in the
lake, it is not in this group of animals that such a discovery is
very probable. Nyasa with 14 different forms is closely followed
by Lake Victoria with 12. Only 6 species are recorded from
Tanganyika and one from Lake Edward. 'The number of species
which are endemic affords no striking contrasts, 5 out of 14
being peculiar to Nyasa, and half the total number in each
ease being peculiar to Victoria and Tanganyika. The only species
known from Edward Nyanza is endemic. ‘There are no endemic
genera on record.
A point of more interest is the fact that of 31 species men-
tioned in the table, only two have been observed in more than
one lake, viz. Unionicula figuralis in Tanganyika and Victoria
and Hneentridophorus spinifer in Victoria and Nyasa. In every
other case the species from the lakes differ from one another,
and have been recorded only from a single lake, where, in some
instances, they are endemic. Although this is so, there is not
much evidence of that association of certain groups of forms with
certain lakes, which is elsewhere a noticeable feature. It may,
however, be pointed out that both species of Limnesia are re-
corded only from Lake Victoria, while all the species of Arrhenurus
come only from Nyasa. Other genera well represented are
Unionicula and Newmania, but they both have an extended
range and have representatives in each of the three bigger lakes.
While 15 species in all are described as endemic, 10 of the
remainder are known from other parts of Africa (including
Madagascar) and 6 possess an even wider distribution. Under
these circumstances there seems every probability that future
exploration will prove many of the types to occur more generally
in the lakes, though on the whole it may be predicted that in
any case their precise distribution is little likely to afford evidence
of a striking character.
TARDIGRADA.
It is not surprising that inconspicuous organisms belonging to
this group have been seldom observed in the fresh-waters of
Africa, Apart from a record of the existence of these forms in
the Azores, there is, I believe, only the account given by Daday
(76, p. 236) of specimens which Fiilleborn collected in and around
Lake Nyasa. The specimens in this collection all belong to the
species Macrobiotus tetronyx, which Daday established to receive
them. While this form must be regarded as endemic in Nyasa,
the genus Macrobiotus is known to have a cosmopolitan distri-
bution, so that the existence of this particular species in the lake
is doubtless a matter of little import.
OLIGOCH ATA.
ft is necessary, in compiling an account of the Oligochete
worms from the lakes, to distinguish as far as possible between
DT 4 DR. W. A. CUNNINGTON ON THE
the purely aquatic and the purely terrestrial forms. Yet this is
nota simple task, for not only are there a number of types which
lie on the border-line, but even the true earthworms in the
tropics are semiaquatic in habit, living in very wet places not far
from water. For the purposes of this paper, the border-lne
species as well as the true aquatics have been retained, those
forms being excluded which are generally recognised as earth-
worms. It follows from what has been said, that even worms
with specific names such as tanganyike have been omitted fiom
the list when the name has been applied to a terrestrial species.
Aquatic Gligocheta ave recorded from five out of the six
lakes under review, but there is reason to suppose that a good
many more records will be for theoming. The list which follows
‘gives the impression of being incomplete, yet it incorporates, I
ations. all the available information. Since a number of these
forms are small and inconspicuous, it is not unlikely that they
have hitherto escaped notice. No species have been reported from
Edward Nyanza. In a few eases, records have been inserted
without specific determination. While these are unsatisfactory.
they still bave a certain value, as proving the occurrence of a
particular genus.
Table of Distribution of Oligocheta *.
a Tangan- Victoria : Albert 7a Other parts of
Name of Species, yika. Nyanza. yeaa Nyanza. a the world.
Family NarpOMORPHA.
Naidium sp. r
Nais sp. 2
Dero sp. ire ite P
Anlophorn us stuhlmanni ...... K
Pristina tengiseta ..;...........- EF Kurope, America.
Family ALLUROIDID®.
Alluroides tanganyike ...... le Rhodesia.
Family MEGASCOLECID&. P
Sub-family Ocnerodriline.
Ocnerodrilus ee
cunningtonl pees taco EK
Pygmeodr lus affinis ......... E
% bipunctatus ... i P Pr K. Africa.
5 bukobensis i K
KS prawerti ...... E
. kiwuensis ...... E -
Family GLOSSOSCOLECIDZ.
Subfamily Oriodriline.
Alma emini. Rech camaatcree i
. stuhlmanni .......c. ig big | Re Atpadar
9 genera ...... Bee 4P. ook. Py 12s eS
14 species .. 2H, 1P. 4B, 2 BP, 2P. LE £P.
(2)
(3) (6)
+ The records of these forms from the African lakes are somewhat scattered in the
literature of the subject.
(120: 121), who gives a bibliography.
Refer especially to Beddard (12:
13) and to Michaelsen
FAUNA OF THE AFRICAN LAKES. 57D
An examination of the table of distribution suggests in the
first instance that there are certain gaps in the list etch future
investigation will surely fill. It is strange, for example, that no
representatiy es of the Naidomorpha have been found in Tangan-
yika or in the smaller lakes, for it does not seem likely that
they are entirely wanting. Secondly, it is clear that very few of
the forms enumerated have been observed in more than one
lake, half of them being classed as endemic. Out of a total of
14 species, the highest ‘number recorded from a single lake is
6 (Victoria Nyanza).
There is no indication in this case of a marked pre-eminence
for Tanganyika either in the number or peculiarity of its forms.
Lake Victoria leads the way with 6 species, 4 of which are
endemic, Tanganyika coming second, with exactly half that
number (3 in all, 2 endemic). Lake Kivu also contains an
endemic form. The species are distributed among a large
number of genera (nine), only two of which—Pygmecodrilus and
Alma—are represented by more than a single type. Lake
Victoria again heads the list with representatives of four genera,
Tanganyika and Nyasa coming next, each with three. No
endemic genera occur.
It would serve no good purpose to review in detail the distri-
bution of the different genera and species, but reference may be
briefly made to the nature of the Oligochete fauna of each
lake. Tanganyika alone contains a member of the Alluroidide.
This worm—Alluroides tanganyike—was first described from
Tanganyika, but has since been obtained from Rhodesia in the
neighbourhood of the Victoria Falls. Two endemic species
of Ocnerodrilinee complete the list: there are no Naids or
Criodrilines known.-——-In Victoria Nyanza the types are more
uniformly distributed among the families concerned. Of four
endemic species, two belong to the genus Pygmeodrilus and
one each to 4Aulophorus and Alma.—From Nyasa only three
Naid genera of wide range are on record. Pristina longiseta,
which I collected in that lake, is the only worm in the list which
occurs outside the continent of Africa, being known both from
Europe and America. It is strange that ether aquatic Oligo-
cheetes have not been forthcoming from this lake as a result “of
its careful exploration by Fiilleborn.—Lakes Albert and Kivu
each contain but two species. Two forms of Pygmcodrilus
(one endemic) come from Kivu, with one Pygmaodrilus and
an Alma from Albert. Ne Naids have so far been observed.
These lakes, together with Lake Edward, have recently been
visited by the German Central Africa Expedition, and it is,
therefore, the more surprising that no Oligochete worms have
been found in Lake Edward.
HIRUDINEA.
There is but little known of the leeches which inhabit the
great lakes of Central Africa: indeed, there appears to be only
a single published record concerning them, which is that of
576 DR. W. A. CUNNINGTON ON THE
Blanchard (15) deseribing forms collected by Stuhlmann. It is
in a measure surprising that these creatures should have escaped
attention, since they are neither minute nor inconspicuous.
During my expedition to the great lakes I was able to collect a
considerable number of specimens, the majority of which were
obtained in Tanganyika. Some examples, however, were found
in Victoria Nyanza (from which a representative had already
been recorded by Blanchard), and also in Nyasa, where they
constitute a new record. With this opportunity for gaining a
fuller knowledge of these forms, it 1s the more to be regretted
that no report has yet been received from the expert to whom the
collection was submitted for examination.
The leech which is already known from Lake Victoria was
termed [Hirudo hildebrandti by Blanchard (15, p. 5). It is not
confined to the lake, specimens having been collected also in
Mombasa. In the same paper a new genus and species belonging
to the family Herpobdellide is described under the name of Salifa
persprcax. This form was collected by Stuhlmann in Kiriwia,
which is described as north-west of Edward Nyanza. I have not
been able to identify this locality, but it appears doubtful whether
this species should be included in the fauna of this or any of the
lakes.
It is hardly safe to foreshadow the results of a proper exa-
mination of the specimens collected by the Third Tanganyika
Expedition. It may nevertheless be stated that they will in all
probability prove to belong to some five or six different species,
of which the greater number come from Tanganyika. This is only
in accordance with what has already been observed in so many
animal groups. ‘The leeches were found for the most part in
shallow water, under stones or on shells, but some were dredged
in about 10 fathoms.
NEMATODA.
There is hardly any information available concerning the
Nematodes of the great lakes. In the extensive plankton
material collected by Filleborn in and around Nyasa, Daday
detected certain free-living forms, which he identified and de-
scribed. Reporting on Stuhlmann’s collections, Collin records a
single specimen of a free-living Nematode (which he leaves
undetermined) from Victoria Nyanza, and also examples of a
well-known parasitic type—Ascaris spiculigera—obtained from a
pelican on Lake Edward (64, p. 10).
During -my expedition to the three big lakes, I was able to
procure a considerable number of parasitic Nematodes from the
fish which passed through my hands. Whether such forms can
be legitimately regarded as part of the lake fauna may be ques-
tioned, but as they are associated in this case with genuine
inhabitants of the lakes, I am disposed to include them. Un-
fortunately these specimens have not been reported upon, so that
little can be added to this bare record of their existence. The
majority of them are from the body-cavity or gut of Tanganyik
FAUNA OF THE AFRICAN LAKES, 577
fishes, but some were obtained from a large Siluroid taken in
Victoria Nyanza. In all, these parasites were collected from
8 different species of fish, belonging to 8 genera and 5 families.
Since these fishes are, with a single exception, endemic forms,
it is likely that their parasitic Nematodes will prove interesting
and perhaps new to science.
1t does not seem logical to regard the Ascaris from the Edward
Nyanza pelican as belonging to the fauna of that lake, and as the
specimens I collected have not been identified or described, the
only records available for the purposes of this paper are those of
the free-living types from Nyasa. The species *, which all belong
to the family Anguillulide, may be enumerated as follows :—
1. Monhystera filleborni.
Described as new from a single specimen in the surface
plankton.
2. Monhystera vulgaris.
A species known previously only from Europe. Obtained near
the mouth of a river which enters the lake.
3. Monhystera similis.
Likewise recorded from Europe and found in the neighbour-
hood of Nyasa.
4, Trilobus graciloides.
This species has been described as new by Daday. It comes
from the vicinity of Nyasa, but has also been taken on the
swampy shores of Lake Rukwa.
5. Mononchus tenwis.
Under this name Daday described a single male specimen
which he found in a sample of mud brought from the bottom of
Nyasa at a depth of 200 metres.
6. Monochus macrostoma.
Collected in a pool near the lake. Also known from Europe.
7. Dorylaimus macrolaimus.
A European species which appears to be common in the waters
around Nyasa, but has not been observed in the lake itself.
Out of a total of 7 species, 2 may be regarded as peculiar to
the lake fauna, while one of the remaining forms is confined to
Kast Africa. The others are known also in Europe.
Thus there is no indication that the free-living Nematoda of
Nyasa are in any way remarkable or specialised, and information
is not available concerning either free-living or parasitic types
from any of the other lakes.
* Particulars of these will be found in Daday’s monograph (76, p. 44).
578 DR. W. A. CUNNINGTON ON THE
RoOriIrERA.
The Rotifera of the African lakes are still very imperfectly
known, and the table of distribution which follows probably
gives quite an inadequate idea of the fauna. No information is
available for Lakes Edward and Kivu, and very little for Lake
Albert. Tanganyika, Victoria Nyanza, and Nyasa have been
better, though very unequally investigated. The latter has been
fairly well explored in this direction by the efforts of Fiilleborn,
who obtained numerous examples of the lake plankton and, in
addition, suitable material from neighbouring ponds, swamps,
and rivers. ‘Tow-nettings from all three lakes were procured by
my expedition, the largest series coming from Tanganyika, but
with the single exception of samples taken in the broad mouth
of the Lofu River, which enters Tanganyika, I did not collect
outside the confines of the lakes themselves. Thus, while the
truly lacustrine types from Nyasa and ‘Tanganyika may be fitly
compared, the Nyasa total is enormously swollen by species from
the adjoiming neighbourhood, whereas the region around Tan-
ganyika remains almost entirely unexplored. In addition to my
small collections from Victoria Nyanza, there have been those of
Stuhlmann, Borgert, and Alluaud, but the Rotifera of the rivers
etc., within its drainage area are likewise practically unknown.
Table of Distribution of Rotiferat.
: Tangan- Victoria F Albert Other parts of
Name of Species. yika. Nyanza. Nyasa. Nyanza. the Sou
Order PLoIMA. ;
Notommata copeus ............ Pet P§ ; .... Europe, Asia, N. America.
ts pachwurd’./-...... P§ Europe, N. America.
f tripus Hos ieee ae P§ Cosmopolitan.
Pleurotrocha daphnicola ...... PS oe Europe, N. America.
Cephalodella forficula ......... P§ Cosmopolitan.
Diaschiza forficata P§ Europe, America.
. gibba ae P8§ Cosmopolitan.
i EosiGhi sleeper eee PS Europe.
Monommata orbis eee P§ Kurope, N. America.
Dicranophorus auritus—...... P§ Europe, Asia, N. America.
Pe forcipatus P§ Europe, Asia, N. America.
Encentrum caudatum ......... P§ Europe, N. America.
Epiphanes oblonga ee ‘3 i K§
if clavulatus ......... Bt P ae Europe.
is lotos P§ Asia.
x brachionus
SpiNOSUS .0.4....5 bi a. P§ ... Europe, S. America.
Pmacrourus ....... ee P iP :.. .. Asia Minor:
+ The principal sources from which this table has been compiled are Rousselet
(150), Collin (64), and Daday (76, p. 59), where further particulars will be found.
It is well to explain that the names under which the species are enumerated are
mostly those adopted by Harring in his “Synopsis of the Rotatoria”, Washington,
1913.
§ Not actually recorded from the lake itself, but from within its drainage area.
FAUNA OF THE AFRICAN LAKES, 579
Name of Species. Tangan- Racers Nyasa. pee te ben es
yika. Nyanza. Nyanza. tlie world.
Brachionus angularis ......... oe Ie P§ ... Cosmopolitan.
39 39
caudatus ... .... ae 1a PS ... Rhodesia, N. America.
e calyciflorus ...... P Be P .... Cosmopolitan.
bP) be)
GONCAS'..s een, - ae P ... Europe, N. America.
sy sapsuliflorus ...... ee es Ps .. Cosmopolitan,
bys) 99
bidentatus ...... i a ae P Asia, Europe.
55 AUC AL US! 2.5, soe tectve P Te ... Cosmopolitan.
k forticmlan: i e..s... P Ag ... Kurope.
i mirabilis [........ an a sess ... New Guinea, S. America.
¥) CEA UU ae RR PS§ E Ez .... Cosmopolitan.
., quadridentatus ... P P tis ;
~-urceus see ie. ip PS fe f
Platy ias Quadricornis ......... PS BE Ps rE "
99
brevispinus Ieee P§ nee - ... Asia, S. America.
Schizocerca diversicornis
MOMOCETOS, 6.04. ho ks eee eee oe g ba ... Europe.
Keratella cochlearis ............ 2 leg P§ ... Cosmopolitan.
uae @uadrata ...az..... PB P Pp eae Ps
valga ...... PS ike 1 P
Notholea striata GIDIS) ys siege aes 7 Le leg - is
AMuTeOpsis fissa” |... ..s i oS: PS *
Mytilina compressa ............ oe ca P&S Kurope, N. America.
a mucronata . nee Re - PS Cosmopolitan.
. s spinigera ae Sal P§ Europe, Asia.
is MEMGEALISS 25a: -vaewc. 3 ES Rs Ps ... Cosmopolitan.
Si brevispina. P ee P Es 4
Euchlanis dilatata ............ i ba iS A, s
re ro 10) 0): hr P§ te ei ...° Kurope, N. America, Aastralia.
ao triqwetra sl... i002... re ae PS Cosmopolitan.
- hy alina .. P§ Be ee ... Europe.
Dipleuchlanis pro opatula ...... P§ P§ me .... Europe, N. America, Asia.
Lecane gissensis. ............... a ie le ... Europe, N. America.
59 Tipara De ee eye e ae Ps. Europe.
3 Chena Pe P§ Cosmopolitan.
5 leontina aed es BS Asia, America.
ipo LALO CL ee ee ee a Es
ungulata es oe as .... Kurope, N. America, Asia.
Monosty la bulla P iE Nee P = Cosmopolitan.
- lunaris P§ RP P§ ‘5
3... hamata PS Europe, America.
Lepadella ovalis + eee be Cosmopolitan.
es ACUMIRAUA’ © seco acka: P§ :,
ae Clisbabasnitet Es Europe, N. America.
e patella 4 PS§ Sosmopolitan,
Colurella colui'a: ....6c..<.02 00: P§ Europe, N. America, Australia.
- adriatica eo PS Europe, Asia.
9 Hicuspidata ...2.... Bs Cosmopolitan.
deflexa P§ ... Europe, America.
5 uncinata det P§ +s.) Hurope:
Trichotria pocillum ............ P§ Cosmopolitan.
Scaridium longicaudum ...... Sa ses ES ”
Pedaliatmaia hsnks fw wck\ 2. a Me P wre »
Milinvagoneiseta. ..ovs ot dso. ae P. P§ : 5
Tetramastix opoliensis ......... a Je P .... Europe, Rhodesia.
Trichocerca bicristata ......... P§ Ae a ... Europe, Asia, N. America.
5 etastatay asi oc. At a BS .... Cosmopolitan.
§ Not actually recorded from the lake itself, but from within its drainage area,
580 DR. W. A. CUNNINGTON ON THE
Neead Mele ee tes Tangan- Victoria oy yes Albert Other parts of
aa yika. Nyanza. yas.“ Nyauza. the world.
Trichocerca elongata ......... a at PSs .... Cosmopolitan.
fe MOVMIS) co esteee cic P§ mS ie ... Europe, N. America.
a longiseta ......... Ps re ane .... Cosmopolitan.
s MMAGETA (open bis P§ i ee ... Europe, N. America.
Ms rattus iB Cosmopolitan.
ss SCIPIO’ Lacceeseeeee ash P§ is
i SLY lata eset P P Europe, S. America.
Diurella stylata P Europe, N. America.
55 benuior P§ Cosmopolitan.
i Heris Re SNe ae PS§ e
Syncheta oblonga............... P§ P§ Europe, N. America, Australia.
F pecuimatads cc. aan P Cosmopolitan.
Oo Ne EYGMUME Meet nce tee eee ee P§ e
Rolyarthra trigla ees nee P # i kok RA
Sphiyrias loiuana; -.. 20.4 see P§ a. a .. o N, Amentigas
Asplanchna brightwellii ...... see P iP ... Europe, N. America, Australia.
i intermedia ...... P a4 cs .. Europe, N. America.
Asplanchnopus multiceps P§ Cosmopolitan.
Testudinella patina ............ J. ef PS ae sf
ee trilobata: su: -.. P§ Australia.
Order RHIzZOTA.
Floscularia ringens ............ P Cosmopolitan.
Limnias melicerta............ ae P z
Ptyoura mucicola <5... P§ ye ae .. IN. America,
Sinantherina spinosa ......... e aH Ps .... Cosmopolitan.
Conochilus hippocrepis....... P§ is
Collotheca ornatay...<..0..02.-2 iP Europe, N. America, Australia.
Order BDELLOIDA.
Philodioascitrinas 7s oscee A P§ Cosmopolitan.
r GMAT Uy gare ees t ase E§
i TOSCONA Yevctcatsntees P§ Cosmopolitan.
Rotifer macroceros ............ Pe ee P§ re SI
Sih) MMACTOTUSS secu aaaen em La PS es 53
oh. WLI PATS. ihn cee a P§ P§ a ‘5
Sactinurus oes P§ *
ee
——- ——_—— —_——
AD ONCTA alton ot eos. «el Ogee ile es 37 P. 4P,
ee Se
—__— —_—_
105 species and subspecies... 1E,28P. 1KH.24P. 1E,84P. 4P.
(29) (25) (85)
§ Not actually recorded from the lake itself, but from within its drainage area.
Attention has already been called to the fact that the Rotifera
of Nyasa are in all probability better known than those of the
other lakes. Of 105 forms enumerated, 85 are reported from
that lake, while only 29 are given for Tanganyika, 25 for Victoria
Nyanza, and 4 for Albert Nyanza. Examination of the Nyasa
records shows that a much smaller total has been observed in the
lake proper, and indeed it is the latter figure, compared with cor-
responding figures.from the other lakes, which affords a truer basis
of comparison than those given above, since the forms collected
from the surrounding neighbourhood are almost unknown except
for Nyasa. Disregarding Albert Nyanza—from which informa-
tion is very meagre,-—the totals of those Rotifers taken within
the limits of the lakes themselves are found to be:—Nyasa 22,
FAUNA OF THE AFRICAN LAKES. 58]
Victoria Nyanza 21, and Tanganyika only 8. Clearly there is
little disproportion between Lakes Victoria and Nyasa, but Tan-
ganyika shows a marked reduction in number. It is probable
that the low figure for Tanganyika proper has some relation to
the nature of the lake water, which appears to be somewhat. un-
suited to these organisms. Lousselet points out in his report on
my collections (150, p. 794) that there is a striking difference
between the scanty Rotiferan fauna of the lake and the far
richer fauna which he observed in a small quantity of material
from the Lofu River. ‘Tanganyika water contains an unusual
amount of magnesium salts, and though very little is really
known concerning the influence of such salts on fresh-water
organisms, this seems likely to be the cause of the dissimilarity
between lake and river in this respect. The matter has already
been discussed in some detail in connection with the complete
absence of Cladocera from the lake (cf. p. 569).
On examining the list of Rotifera more closely, it will be
observed that with three exceptions, the forms are all known
from other parts of the world, many of them, in fact, being
cosmopolitan in their distribution. A single endemic species is
enumerated from each of the three bigger lakes, but apart from
Lecane lofwana described from the Lofu River, these are of only
doubtful value. The facilities for dispersal which the Rotifers
possess are well known, and quite account for this wide distri-
bution. In the case of these organisms, therefore, no deductions
of any value can be made from the presence or absence of a
species in a particular lake, and the interest attaching to a com-
parative table of distribution is, in consequence, small.
Nor does a study of the actual genera and species occurring
disclose features of much significance, although one or two com-
ments may be offered. In all, 42 genera are enumerated, of
which again the largest number is found in Nyasa. ‘Those best
represented are Brachionus with 12 species, or well-marked
varieties, Z'richocerca with 9 and Lecane with 6, while nearly all
the more important genera are known from at least two of the
lakes. Certain cosmopolitan species have been identified from
all the four lakes under consideration. There is little to note in
the way of unexpected forms or of types unaccountably absent.
A subspecies of Lrachionus—B. capsuliflorus bidentatus,-—-which
was isolated from the Albert Nyanza material, is apparently very
rare, having been observed only in Calcutta and more recently in
Bulgaria. Furthermore, Rousselet has pointed out that the
genus tsplanchna is recorded from the lakes, but has not been
obtained in South Africa.—In conclusion, it will be observed that
asin the case of the Cladocera — which are also of extended distri-
bution,—there is no indication of an exceptional fauna peculiar
to Tanganyika, or indeed to any of the lakes.
GASTROTRICHA.
Representatives of this group may eventually prove to be
widely distributed in the African lakes, but at present there is
58Y DR. W. A. CUNNINGTON ON THE
little information at hand concerning them. An account of
certain forms collected by Stuhlmann at Bukoba, Lake Victoria,
is given by Collin (64), while other species which Fiilleborn
otis in the neighbourhood of Nyasa have been identified by
Daday (76, p. 56). No Gastrotricha were observed by me during
my expedition to the great lakes. The species * may be enume-
rated as follows :—-
1. Lepidoderma squamatum.
A species well known in Kurope and occurring also in North
America. A single specimen was collected in a pool near the
shores of Nyasa.
2. Lepidoderma hystria.
Under this name Daday described a form obtained from the
sauine locality as the above. It has not been observed elsewhere.
3. Lehthydium macrurum.
This type was described as new by Collin, but the species rests
upon a diagrammatic figure and a very incomplete description.
It was found at Buleoba, a station on the shores of Victoria
Nyanza, and has not been re-discovered, so that it may be looked
upon as a species of rather doubtful value.
Chetonotus formosus.
This form, like the two species of Lepidoderma, has been
identified from the vicinity of Lake Nyasa. Previous to this
discovery it was only known from North America.
5. Chetonotus pusillus.
A single specimen of this type, hitherto only recorded from
Paraguay, was isolated by Daday from material collected in the
Mbasi River close to its entrance into Nyasa.
Two species of Chetonotus are, according to Collin, among the
Gastrotricha which Stuhlmann recorded from Lake Were 1a, but
in neither case has it been possible to identify them further.
Brief notes made on the spot, accompanied in one case by a sketch,
form all the information available. It is doubtful whether either
of these types was observed in water from the lake itself.
6. Gossea pauciseta.
Another species previously known only from Paraguay.
Several specimens of this were obtained from a pond in the
Nyasa district.
On a survey of this list the following facts appear. Five
species are on record from Nyasa, one of which 4 is peculiar to that
* For further particulars of these forms, consult Collin (64, p. 9) and Daday
(76, p. 56).
FAUNA OF THE AFRICAN LAKES. 583
lake. From Victoria Nyanza three different forms have been
reported, of which one was described as new and has not been
found elsewhere. ‘The two remaining types were not specifically
identified, and indeed all three species from this lake rest on
a somewhat insecure basis. None of the recorded species occur
in both Victoria and Nyasa, and it appears probable that none
were actually observed in the waters of the lakes themselves.
No Gastrotricha are known at present from any of the other
African lakes.
TURBELLARIA.
There can be little doubt that Turbellavians are relatively
uncommon in the lakes as well as in other parts of Central
Africa. Stuhlmann, a careful observer, who had opportunities
for collecting in many parts of the country, remarks on the
scarcity of these organisms, and in particular on the scarcity of
the fresh-water Dendroceels, which are usually common in ponds
and streams (181, pp. 1262 & 1268: 182, p. 652: 185, p. 349).
During my expedition to the great lakes, 1 only obser ved Aurbel-
larians in Tanganyika. They were found on the under side of
stones in shallow water, and all proved to belong to a single
species of the well-known genus Planaria. Prior to the
description of this Tanganyikan form by Laidlaw (107), the only
work dealing with species from the lakes was that of Bohmig (17),
who reported on the collections made by Stuhlmann. Unfortu-
nately, the accounts in this paper are based almost entirely on
sketches and notes made on the spot, which often lack details of
importance for systematic determination. Although the records
must thus be regarded as of doubtful value, I insert them here
without further comment. The following species * come within
the scope of this survey :—
1. Planariatanganyike.
This is the type from ‘Tanganyika to which reference has been
made. It is the only species known from that lake and has not
been obtained elsewhere.
2. Stenostoma leucops.
A form known in Europe and also in North America. On the
evidence of drawings, recorded from the neighbourhood of
Bukoba, on Victoria Nyanza.
3. Stenostoma stuhlmanni.
Described as new by Bohmig from Stuhlmann’s notes and
sketches. Observed at Bukoba, Lake Victoria aud unknown
elsewhere.
4. Stenostoma gilvun.
Another species based only on a drawing and a few notes and
* For details, consult the above-mentioned papers: Bohmig (17) and Laidlaw
(107).
584 DR. W. A. CUNNINGTON ON THE
recorded from the same locality as 8S. stuhlmanni. Nothing
further is known of this form
Kxamples of two species of Stenostoma from Bukoba were
among the material examined by Bohmig, but their unfavourable
state of preservation did not permit of nearer identification.
5. Gyrator hermaphroditus.
A pelagic Turbellarian collected in Victoria Nyanza is identified
with this species by Bohmig. It is well known in Europe.
6. Vortex quadridens.
This type is established merely on the evidence of sketches and
notes by Stuhlmann. It is admitted that certain important
features of the genital apparatus are unknown. Obtained from
stagnant water at Bukoba.
From the above it will be observed that 'Turbellaria are only
recorded at present from Lakes Victoria and Tanganyika. From
Victoria Nyanza and its neighbourhood five forms have been
specifically identified, three of them being peculiar to the lake.
There are, in addition, two types which are unnamed. ‘These
records of Bohmig, however, need confirmation, as they are based
on very meagre evidence. From Tanganyika a single endemic
species is known, which belongs to the widely distributed genus
Planaria *, No doubt further representatives of this group will
eventually be found in the great lakes, but they appear to be less
common than might have been expected. There is no suggestion
of a striking Tur bellarian fauna in Tanganyika and little indica-
tion that such will be discovered in the future.
TREMATODA.
Practically nothing is known of the distribution of these
exclusively parasitic animals in the lakes of Africa. Following
the argument advanced in the section dealing with the Nematoda,
it seems only logical to include such forms in a lake fauna. In
the case of these organisms they may be obtained in the free-
swimming larval stage, or infesting an intermediate Molluscan
host or in their final vertebrate host. As far as I am aware, the
description given by Daday (76, p. 39) of two Cercaria larvee from
the neighbourhood of Nyasa is the only account which concerns
any of the lakes. Both were found in material from ponds near
Nyasa and were described as new larvee, though it seems doubtful
whether such determinations have much systematic value. They
have received the names of “ Cercaria” schizocerca and “ Cercaria”
hoplophora %6, p. 288).
* It seems clear that Stuhlmann’s statement that Planarians cannot survive
temperatures of over 25° C. (185, p. 349) is not universally true. The specimens I
collected in Tanganyika were taken in quite shallow water, where the temperature
tends to be highest, yet my thermometer readings for the surface of the lake showed
a higher average than 28°.
FAUNA OF THE AFRICAN LAKES, 585
In the course of my expedition I collected in Tanganyika a few
Trematodes which are parasitic on fish. They constitute a new
record for this lake, but have not yet been examined and
described. The specimens were taken from large Siluroids,
one case from the gill-arches, in another from the gut.
CESTODA.
As far as I have been able to ascertain, no records have been
published of tape-worms from the lakes included in this survey,
although Daday described two new larvee which he observed in
Kast’ African Copepods. Different forms of tape-worm proved
common in the gut of fishes examined for parasites by my
expedition, and I succeeded in getting a considerable number of
specimens. These all came from Tanganyika, where I had better
opportunity than elsewhere to seek such organisms, but it is
clear that systematic examination would not only bring to hght
enteric parasites from the fishes of other lakes, but would result
in a far richer series from Tanganyika. My material has only
received a preliminary examination, so that little information
can yet be given as to the nature of the Tanganyika forms. » aureus Ps Kurope.
» globator Ps Europe, Asia, America.
Order DINOFLAGELLATA.
Ceratium brachyceros ......... ee K
* hirundinella ......... Be: Pp es Cosmopolitan.
= macroceros eh Aye Pp. Kurope, Asia.
Peridinium africanum ......... IP. Ie
a berolinense......... P Me Kurope.
‘> imconspicuum ... re P Cosmopolitan.
ie palatinum ......... Ps Europe.
- quadridens......... 2 Europe, Asia, S. America.
5 tabulatum ..0.. 4 x iP Cosmopolitan.
Peridiniopsis cunningtonil ... A)
Glenodinium pulvisculus ... P le P Europe, Australia.
Class CILIATA.
Order CILIATA VERA.
Enchelyodon farctus P Europe, N. America.
Coleps hirtus®.) ..:..0..:5..02 P§ Cosmopolitan.
Loxophyllum meleagris ...... P Europe, N. America.
Trachelius ovum Pp Cosmopolitan.
Dileptus anser Rett Ahad gamer ole ad P Europe, America, Australia.
Nassua Spy. sheik OP ee at Ne
Colpidiam:sp, 74423 45N ae OP
Paramecium aurelia ......... be ae Bis Cosmopolitan.
Spirostomum ambiguum ...... sr iP ie Cosmopolitan.
Condylostoma isp. i% 20905," PR
Stentor roeselii 94.0.0 .-2.02.6002; vet iP Se Europe, America.
Tintinnopsis ovalis ............ iP. Kurope.
Uronychia paupera Hd eee KH §
Trichodimasp.'G0....22°2 eS —P
Morticellanliunarneee st). o tar oe P§ Kurope, N.America, Australia.
be microstoma ......... ag Pp P Cosmopolitan.
“f nebulifera ......... ae P Bes Kurope, America, Australia. —
Zoothamnium arbuscula ...... Ps Europe, America.
o patasitas 2% ec ie Ps Europe.
Epistylis anastatica ............ 00... Pr P§ Cosmopolitan.
eae y Ps Buren tee
> umbellaria, ...)01 R 2 P§ Europe. |
Operculariasnutans <: 02. ee P. hd Europe, America, Australia.
Cothurnia crystallina ......... “ ike P§ Cosmopolitan.
Be UT CISEL:. | n hteceaMeeeeee ay aaa K
* lobatas .8tulpalae GN as i
Order SucTORIA.
Podophytais. a.cee scree ene 8
Tokophyra cyclopum Ps Europe, N. America,
Acineta symbiotica le K. Africa.
» tuberosa Ps Europe, Asia.
AS SENNA ci sucicsclhacqemseneten, WOME 25 Ps it ae 4 P. Me
O7 SPECIES .2.u.24.07. 1 eee Olea noe tee 21K,58P. 4 P, Bhs ee
(7) (37) (60)
§ Not actually recorded from the lake itself, but from within its drainage area.
FAUNA OF THE AFRICAN LAKES. 59]
The most obvious comment on the table of distribution is the
great inequality in the totals recorded from the biggest lakes—an
Inequality which is obviously due in this instance to unequal
investigation. Of the 87 species enumerated, 60 occur in Nyasa,
37 in Victoria Nyanza, and only 7 in Tanganyika. While it is
impossible to predict what figures will be forthcoming when the
Protozoa of the lakes are better known, the figures at present
available are mevely an index of this disproportionate investiga-
tion. The records from Nyasa are the result of the extensive col-
lections made by Fiilleborn, which were reported on by Daday (76).
It will be noticed that more than half the species identified were
not obtained in the lake itself, but came from river mouths,
pools, and swamps in the vicinity. Victoria Nyanza has been less
adequately explored in this direction, smaller collections being
made by Stuhlmann and more recently by Borgert and others.
In his book on the Tanganyika Problem, Moore devotes a few
paragraphs to the Protozoa of the lake (137, p. 323). The two
forms which he mentions by name—a Condylostoma and a large
Infusorian which he refers with some hesitation to the genus
Colpidium— have been inserted in the table of distribution. He
describes the latter organism as the cause of the yellow clouds
which occur on the surface at times and make the water appear
“as if tinged with a fine golden dust.” This effect was also
observed by Livingstone, who thought the yellow scum to be of
vegetable origin. [I have repeatedly observed the phenomenon
myself, not only on Tanganyika, but on Nyasa, and without
denying other possibilities, I can confidently assert that it is
usually due to hmnetic Algee. In conclusion, Moore remarks that
he found some twenty types of Protozoa belonging to groups
common in tropical fresh-waters.
A consideration of the lst of species shows that in the
great majority of cases the forms are widely distributed if not
cosmopolitan in range. There are very few endemic species
enumerated—four in Lake Victoria, two in Nyasa, and one in
Tanganyika—and most of these are ‘of little interest. Peridind-
opsis cunningtonii from Tanganyika, and Uronychia paupera from
Nyasa, are perhaps of more interest, since in each case they are
only the second described species of the genus. Forty-eight
genera are mentioned in the table of distribution, of which the
greatest number occur in Nyasa. This is a large proportion e
genera to species, but is accounted for by the aannver of gener
represented by only a single species. None of the genera are
endemic,
No good purpose would be served by commenting in detail on
the genera and species in the list, but one or two further remarks
on their distribution may be offered. As far as the Rhbizopoda
are concerned, the lists from Victoria Nyanza aad Nyasa may be
reasonably compared, and they exhibit a close degree of similarity.
The well-known genera Arcella and Dijfflugia are each represented
by a number of species. It is in the remaining groups that there
592 DR. W. A. CUNNINGTON ON THE
has been inequality of investigation, so that the Euflagellata, for
example, are only represented in Lake Victoria by a couple of
forms as contrasted with a large number from Nyasa. Volvow
africanus is an interesting species which was established to
receive specimens brought by Leiper from Albert Nyanza. It
can no longer be regarded as endemic, since it has been observed
in another part of Hast Africa. The Dinoflagellates are recorded
from four lakes, and a comparison may thus be instituted. Lake
Victoria contains representatives of the genera Ceratium and
Glenodimum*. The former genus is wanting in Tanganyika,
where, however, Peridiniwm and Peridiniopsis replace it. In
Nyasa, Ceratium and Peridiniwm occur; in Lake Albert, Peri-
dinium and Glenodinium. It is particularly among the ciliated
forms that a number of genera occur represented only by a single
species. The Z’richodina mentioned, which has not been specific-
ally identified, is parasitic upon the Tanganyika jelly-fish. Since
the latter, or a variety of it, 1s known from Victoria Nyanza, it
may well be that a U'richodina accompanies the medusa there
also, but I have no information on the subject.
In conclusion, it only remains to point out that the Protozoa,
as at present known, give no indication of an exceptional fauna
peculiar to any lake. At the same time it is precisely in
Tanganyika, if anywhere, that such might be expected, and that
lake remains virtually unexplored in this direction.
4, GENERAL DISCUSSION AND CONCLUSIONS.
Having completed the systematic review of the animals at
present known to oecur in the lakes, the points of interest
’ concerning their distribution may now be fittingly discussed.
Far the most noticeable feature is that which has so repeatedly
shown itself, namely the unique nature of the fauna of ‘Tan-
ganyika. With a recorded total of over 400 different animal
types, the lake is clearly exceptional ; moreover, no details of
certain groups which are known to occur are yet available for
incorporation. As this treatise is concerned so largely with
Tanganyika, it may not be out of place to illustrate here in a
graphic manner, the growth of knowledge concerning its fauna.
The curve which follows may be regarded as approximately
correct. It is clear that the labour of ‘ascertaining the date of
discovery or description of every type—even if possible—would be
out of proportion to the value of such a record. The largest
addition to the total (159 species in all) was made by the writer’s
expedition, which obtained, moreover, practically all the infor-
mation on the flora of the lake.
* Virieux states that in the plankton which he examined he observed a specimen
of Peridinium, but was unable to identify the species (197, p. 6).
FAUNA OF THE AFRICAN LAKES. 593
Text-figure 1.
Curve showing growth of knowledge of Tanganyika fauna.
400
300
STAPOERS 192-13 %
se! 1904-0
200
| OORE 1839450,
100
BIOORE 1898
1850 1860 i870 1880 1890 1900 1910 1920
The relative peculiarity of each lake fauna, as far as totals only
are concerned, can be best illustrated by giving the figures in
parallel columns with the marks E or P against them.
Tangan- Victoria
yika. Nyanza.
Albert | Edward
Nyasa.
y Nyanza. Nyanza.
Kavu.
Geneta:) 6/011 P) 2, 1387 P.| 6H. 172 PP.) 1. 47 P- | 1K, 34P. sj] a
| (68) (139) (vs) | (48): |. 1@s)
| |
———_.
Species 2931, 109 P.| 110K, 179P.| 86K, 275P. 9H, 58P. 11E, 43P. 48, 19 P. |
t (402) (289) (B61) = | © (67) (54) (23)
An examination of these totals at once reveals the chief points
in which the fauna of Tanganyika is distinct. In the first place,
the lake contains a more extensive series of forms (402) than any
other. In the second place, those types greatly predominate
which are unknown elsewhere (293 out of 402). Both these
points, viz. total number of species and corresponding number
of endemics, are shown graphically for each lake in the following
table :—
594 DR. W. A. GUNNINGTON ON THE
Text-figure 2.
Table to illustrate richness of fauna and proportion of
endemic species to the whole.
450 —— fi en
400
350
300
250
100
VICTORIA. ALBERT EDWARD KIVU
Te RCNA aa NYANZA NYANZA NYANZA
The height of each column represents the total number of species,
and the shaded portion the number of endemic forms.
FAUNA OF THE AFRICAN LAKES. 59D
It will be observed that the total figure for Nyasa, though
some way behind that of Tanganyika, is still very large. Since
in many cases—e. g. fishes, molluscs | prawns—Tanganyika has a
much richer fauna, such a result is perhaps a little surprising.
It is worth while to recount the facts which explain this. Firstly,
the group of the Cladocera is entirely absent from Tanganyika,
but well represented in Nyasa and elsewhere. This is probably
due to the nature of the salts dissolved in the water, which
appears also to have a restrictive influence on the Rotifera of the
lake. Secondly, there are one or two groups of animals-—notably
the Protozoa and free-living Nematoda—almost uninvestigated as
far as Tanganyika is concerned, although tolerably well known
for Nyasa. Lastly, the collections made by Fulleborn extended
to the waters surrounding Nyasa, while the rivers, ponds, and
swamps in the neighbourhood of Tanganyika remain unexplored.
This has greatly increased the records for Nyasa, particularly
in the groups Rotifera, Protozoa, and Enutomostraca.
In the matter of endemic types, however, Tanganyika leaves
Nyasa (and the other lakes) far behind, exhibiting an astonishing
series of forms for which it is difficult to find a parallel.
Expressing in percentages the figures already furnished, nearly
73 per cent. of the species in Tanganyika are peculiar to the lake,
whilst Victoria Nyanza comes a poor second with 38 per cent.,
and Nyasa still further behind with some 24 per cent. The
smaller lakes have not only smaller totals, but have a reduced
proportion of endemic forms, namely 20 per cent. for Lake
Edward, 17 per cent. for Kivu, and only 13 per cent. for Lake
Albert. Nor is this all, for the number of endemic genera which
Tanganyika contains places it in a category by itself. No fewer
than 57 out of 168 are regarded as peculiar to the lake, or rather
more than one-third of the total. As against this, Nyasa has
6 endemic genera out of 178, and Victoria Nyanza 2 out of 139,
while Lakes Albert and Edw ard each possess but a single endemic
genus. Tanganyika alone among these lakes has a family which
can be regarded as endemic—that of the Tiphobiidee (Gasteropoda).
It is thus clear that Tanganyika exhibits by far the most
striking series of endemic animals of any of the Jakes under con-
sideration—indeed, it must be recognised as one of the most
remarkable lakes in the world. ‘There are only two lakes, as far
as I know, which merit comparison with Tanganyika in this
direction, viz. the Caspian Sea and Lake Baikal. Unfortunately
I have been quite unable to obtain trustworthy figures of recent
date with which to compare the particulars now available for the
African lake. It seems probable, however, that Baikal even
surpasses Tanganyika in the number of animal forms peculiar
; It appears that while relatively few groups are
to its waters*.
* Consult the series of monographs dealing with the results of the most recent
scientific expedition—Wissenschaftliche Ergebnisse einer Zoologischen Expedition
nach dem Baikal-See unter Leitung des Professors Alexis Korotneff in den Jahren
1900-1902. Lieferungen 1-5. Kiew und Berlin 1905-1912. It is to be regretted
that this work remains uncompleted, doubtless on account of the European war.
596 DR. W. A. CUNNING'TON ON THE
represented, there is often a great richness of species within the
groups. ‘The fishes are far fewer than those of Tanganyika and
only half of them are endemic, while the Mollusca agree pretty
closely in the number of endemic types. On the other hand, there
are most extensive series of Oligochetes and Turbellarians, and an
extraordinary wealth of Gammarids, the species being in each case
nearly all endemic. In the case of the Caspian, T am able to
quote figures, according to which some 64 per cent. of the animal
forms are found nowhere else in the world (155, p. 34). If this
statement can be relied upon, the Caspian Sea, while sufficiently
remarkable, is less so than Tanganyika, which has nearly 73 per
cent. of endemic types.
Returning to a consideration of the fauna of Tanganyika,
other features revealed in the Systematic Account may be
summarised in a few sentences. Those groups which are most
conspicuous in possessing endemic genera and species are the
Pisces, Mollusca (especially Gasteropoda), and Macrura, with the
Brachyura following closely. The Copepoda and Ostracoda are
well represented by endemic species (but not genera), with the
Porifera and Polyzoa showing smaller numbers. While other
groups with few endemic species, appear, by contrast, devoid of
significance, there are only five of ali those represented in the
alee Mammen Crocodilia, Chelonia, Batrachia, and Ccelen-
terata—which do not contain endemic types. It may be added
that certain endemic forms are held to exhibit a marine aspect
and have been termed thalassoid (halolimnic according to Moore).
Such are many of the Gasteropod molluscs and perhaps a Polyzoon.
In the same category comes the medusa, which, of course, 1s not
confined to Tanganyika.
The exceptional character of the Tanganyika fauna having
been sufficiently emphasised, an explanation of this marked
peculiarity must be sought. In other words, a general con-
sideration of what Moore called the Tanganyika ‘ problem” must
be undertaken. In order to appreciate the actual value of the
purely biological evidence, it is necessary clearly tc understand
the relations which exist between marine and _ fresh-water
organisms. ‘lhe essential points may therefore be stated as
briefly as possible *
In the first place, while certain organisms are characteristic of
the sea and others of fresh water, the distinctions which exist
between marine and fresh-water forms are neither very great nor
very definite. Secondly, it may be emphasised that the barriers
which tend to prevent a change of medium are not wholly insur-
mountable. At the same time fresh-water types are usually
recognised in consequence of certain structural peculiarities
directly due to their mode of life. Such features should be
excluded as far as possible when deciding the systematic position
of an organism, for it is only thus that a true idea of its inter-
* These matters are discussed at greater length in several recent papers. Consult
Solas (1'73), Cunnington (71), Gurney (97).
FAUNA OF THE AFRICAN LAKES. 597
relationships—which are quite independent of habitat—can be
obtained.
The undoubted affinities existing between marine and fresh-
water organisms are the direct result of a community of descent,
for there is no escape from the conclusion that life had its origin
in the ocean. ‘Thus the forms now found in fresh-waters must
have attained their present distribution in one of three ways :—
(1) by a direct, active or passive migration from the sea; (2) by
becoming terrestrial or swamp-loving in nature, and a tered
adapting themselves to life in fresh water; (3) as a result of the
isolation and subsequent freshening of some portion of the sea,
due to movements of the earth's crust. Without speculating as
to which of these methods has played the most important part, it
may be pointed out that the salinity of the ocean has not been
constant throughout the ages, but is doubtless greater now than
in past geological times. Since certain types are known to have
recently migrated from the sea, it is not hard to believe that many
forms may have achieved the change during former epochs when
the obstacles to be surmounted were somewhat less. It is hardly
necessary to repeat that the view advocated by Moore assumes
that the remarkable organisms found in Tanganyika have attained
their present distribution by the third means, and have been
modified from marine types in a basin cut off from the sea.
Since the flora of a lake perforce exists under the same con-
ditions as the fauna, it will be well, before proceeding, to make
further reference to the plants of Tanganyika. The higher plants
show no outstanding peculiarities. There are certainly 8 species
of true aquatics which have been collected in Tanganyika alone
among the lakes, but all these are well-known African—-or even
cosmopolitan— -forms (¢f Rendle, 147). On the other hand, the
Alge of Tanganyika differ markedly from those found in the
aie big alae. a number being endemic, while a few are usually
marine or brackish in habit. In all, some 21 species and 5
varieties are described as peculiar to Tanganyika. It is, however,
the phytoplankton of the Jakes which affords the most interesting
comparisons. The plankton of Tanganyika is much richer in
species than that of either Nyasa or Victoria Nyanza. Out of a
total of 85 species, more than 70 per cent. do not occur in the
other two lakes, so that 1n this instance once more the features
characteristic of ‘Tanganyika are exhibited. The presence in the
lake of brackish-water and quasi-marine Algee may perhaps be
accounted for by a period of growing salinity prior to the estab-
lishment of an outlet. (For further particulars consult the
detailed Report on the Fresh-water Alge of the Third Tanganyika
Expedition, 2C0).
It is natural that a good deal of attention has been attracted
‘to Tanganyika by the singular nature of its fauna, and it is
not surprising that various suggestions have been offered in
explanation of the facts. While it will be necessary to recount
the several views which have been advanced, it is appropriate to
598 DR. W. A. CUNNINGTON ON THE
deal in the first instance with Moore’s hypothesis that Tang: anyika
represents an old Jurassic sea. ‘This view, first put fomene dina
paper published in 1898 (131), was subsequently developed and
the evidence detaiied at considerable length in “ The Tanganyika
Problem,’ 1903, (137). Being thus a widely known theory, it is
only necessary to inquire how it accords with the facts which have
since come to hight. From the botanical and geological, as well
as from the zoological side, more information is available than
when this hypothesis was propounded, and it may at once be
said that recent discoveries do not favour the theory. As the
zoological evidence has been examined and discussed in the body
of this paper, it is only needful to summarise the conclusions.
Moore’s view rests in the main on his comparison of certain
marine fossil shells of the Jurassic period, with those of Gastero-
pods living in the lake at the present day—coupled with his
deductions as to the anatomy and relationships of the latter forms.
It has already been explained (p. 549) that, in the opinion of
leading experts, neither of these claims can be substantiated. If
the comparison with Jurassic fossils is held to be inadmissible,
the period of the supposed connection with the ocean remains in
doubt, but while Moore subsequently declared that he attached
no great weight to this comparison (138, p. 602). he still adhered
to his view that the so-called halolimnic animals were truly
marine or relict forms. As faras the molluscs are concerned, the
opinion of Pelseneer is in direct conflict with this view, for he
regards the halolimnic Gasteropods as emphatically fresh-water
types.
In this connection it may well be asked—-why are there no
thalassoid Lamellibranchs in Tanganyika? There seems no
obvious explanation of the fact, yet surely some members of this
group would also exhibit a thalassoid appearance had they been
relict forms from the ocean. ‘This itself is evidence which tells
against the view of a reliet origin for the fauna.
Nor do the other members of Moore’s group of halolimnic
animals definitely support his contention. The medusa, once so
important, and admittedly a marine type, has lost most of its
significance. Not only are fresh-water meduse known to occur
more widely than was formerly supposed, but the Tanganyika
species has been found in the Niger and in Victoria Nyanza
The Decapod Crustacea—prawns and crabs—regarded in ‘ The
Tanganyika Problem” as constituents of the halolimnic group,
have been shown to belong to typically fresh-water families.
Much stress was formerly la id upon the incrusting gymnolematous
Polyzoon Arachnoidea, but recent discoveries lave modified its
importance. Since the genus is now actually living in Asiatic
seas, it can hardly be regarded as an ancient marine type
persisting only in Tanganyika, but must rather be looked upon as
a recent importation (cf. the analogous case of Victorella, p. 540).
Finally the sponges belong to the family Spongillide, a charac-
teristically fresh-water assemblage. Thus, of the succession of
FAUNA OF THE AFRICAN LAKES. 599
animals from different groups which constituted Moore’s halo-
limnic series, none are accepted as pecularly marine save the
Polyzoon Arachnoidea and the medusa.
But more than this. The endemic animal forms have been
described almost without exception as specialised and not primi-
tive types. It is true that Moore regarded the remarkable
Gasteropods as essentially primitive in nature, but this view is
not shared by other writers (p. 550). If the halolimnic animals
ave inaeed relict forms, they must have been cut off at some
remote era—though it need not have been the Jurassic period —
and ought in consequence to exhibit primitive rather than
specialised characteristics.
This review of the zoological evidence makes it clear that on
such grounds it is impossible to justify the contention that
Tanganyika was connected with the sea in Jurassic times, or
indeed that a connection with the sea ever existed. It is there-
fore necessary to inquire what light may be thrown on the subject
by the evidence of geology.
In his book, Moore maintained that resting on the Archean
granites, gneisses, and schists which appear to constitute the
basement rocks of the continent, three types of sedimentary rock
are to be recognised. The lowest of these consists of beds of
sandstone and shale, which are not only well developed in the
neighbourhood of the great lakes, but appear to extend over vast
aveas of the African interior, including a large part of the Congo
basin. Then follow the beds discovered by Drummond _north-
west of Nyasa, and covering these in turn, white shelly deposits
(Pleistocene) laid down by the lakes themselves. Drummond’s
beds being regarded as Triassic in age and probably estuarine,
Moore considered the great beds of sandstone and conglomerate
as evidence of an extensive ocean which at some still earlier
period covered a great part of the lake regions of Central Africa
(137, p. 65 et seq.).
It is particularly to this last point that exception is taken by
other writers on the geology of these regions. Some regard Drum-
mond’s beds and the great sandstone series as of like age, and
on the evidence of the fossils occurring in the former, regard the
whole as beds of the lower Karoo (Trias)—or at least as a forma-
tion of corresponding age, deposited under similar conditions. A
very recent writer on the stratigraphy of this part of the continent
(Behrend) speaks of the unfossiliferous conglomerates, quartzites,
and sandstones which are particularly well displayed in the
neighbourhood of the great lakes, as the Tanganyika System ”
(14, p. 52). These beds he distinguishes as of different age from
similar rocks occurring near Nyasa and in parts of the Congo
basin, assigning them to an earlier period—Devonian or even
prior to that (14, p. 73 and Taf. iii.). While it may be that the
relative age of these different strata is by no means conclusively
fixed, these recent investigations show that Moore’s lowest
series—the ‘Old African sandstones” as he calls them—really
600 DR. W. A. CUNNINGTON ON THE
comprises two or more formations. In any case all the evidence
goes to prove that these sandstones and conglomerates, whatever
their age, were laid down under continental, z.e. fresh-water and
terrestrial conditions, and thus afford no support for the view
that the ocean formerly extended over these large tracts in the
heart of Africa.
There is yet another geological objection to the view that
Tanganyika contains relict forms from an ancient sea, and that
is, that the depression itself would not appear to date back to
the remote times required by Moores hypothesis. There is every
reason to believe that the extensive faulting which produced the
Great Rift Valley took place in Middle- Tertiary times, and if
this be accepted, the basin of Tanganyika was actually not
in existence at the time when the Tiurassic theory supposes it to
have received its marine fauna *,
Clearly the geological evidence does not favour a marine
“relict” origin for the peculiar fauna of Tanganyika, and it has
been shown that the testimony of zoology is against it. In order
to be convineing, a theory must not run counter to the findings
of either branch of science.
Since it does not seem possible to accept the Reine: put
forward by Moore, alternative suggestions have now to be con-
sidered. In the first place, it is important to point out that
shells of the thalassoid 'T angapyika genus Paramelania had been
compared by White (202: 203) and Tausch (186) with those of
the fresh-water Cretaceous genus Pyrgulifera some time before
Moore drew his comparisons with marine Jurassic shells. It has
been held by conchologists that the resemblance in this case is
every whit as close as between any of the forms compared by
Moore. This may constitute slender evidence on which to
theorise, but it is significant that the beds from which the fossil
type comes are not only more recent, but are fresh-water in
character and not marine. Thus, if any value attaches to the
evidence, it would suggest that the unusual molluscan genera
should be regarded as the little modified representatives ota a late
secondary fresh-water assemblage rather than those of a much
earlier marine one. This view, which implies that the thalassoid
Gasteropods are relics of an ancient lake fauna preserved in this
basin, obviously did not find acceptance by Moore. He urged
against it the pertinent fact that im such a case, similar types,
living or fossil, ought to be found in other areas, and yet they are
conspicuously absent (137, p. 335), While agreeing that this
constitutes a serious objection, the same objection, to my mind,
may be raised with equal force against the marine Jurassic
hypothesis.
Reference has already been made to the fact that certain fossil
Gasteropods from the ‘Balkan Peninsula exhibit a considerable
resemblance to some of the thalassoid types from Tanganyika
* Certain geological exper ts, indeed, regard the Tanganyika basin as more recently
produced than other parts of the Rift Valley system.
FAUNA OF THE AFRICAN LAKES, 601
(p. 550). The forms in question, described and figured by
Brusina (58:59), come from fresh-water Pliocene beds in Dal-
matia, Croatia, and Slavonia. From this it might be argued that
the lakes of the Mediterranean region which existed in Tertiary
times were the source from which the Tanganyika Gasteropods
have been derived. It is not unreasonable to suggest that com-
munication was possible between these lakes and the region of
Tanganyika by way of the valley of the Nile and the Great Rift
Valley. While less objection can be taken to this view than to
Moore’s, or even to the suggestion of a Cretaceous origin for the
molluses, there are difficulties in accepting it as a complete
solution of the problem. To confirm this theory, either fossil
forms of like nature should be forthcoming in some intermediate
region, or (as a communication to the north of Tanganyika is
assumed) living types should be found in Lakes Kivu, Edward, or
Albert. Since neither are known to occur, the case for this
source of origin is unsupported.
Since the shells of the thalassoid molluses have been held to
resemble (1) marine Jurassic types of the Anglo-Norman basin,
(2) in one instance a widely distributed fresh- or brackish-water
genus from the Upper Cretaceous of Hungary and North
America, (3) a series of fresh-water fossils from beds of Newer
Tertiary age in Jugo-Slavia, the evidence afforded is so contra-
dictory as to offer little guidance in determining the origin of the
fauna of Tanganyika.
It is a very natural suggestion that the thalassoid appearance
of the Tanganyika Gasteropods is directly due to the size, depth,
and quasi-oceanic conditions prevailing in such a lake *. ‘That is
to say, that a marine aspect has been produced in certain
members of the ordinary African fresh-water series as the result
of convergence. To those who have visited these lakes and
realised their vastness this seems plausible, but the difficulty has
then to be faced, that similar forms are not forthcoming in Nyasa
and Victoria Nyanza.
An hypothesis in which this view is introduced, but which has
other novel features, was brought before the International
Congress of Zoology in 1913 by Germain (87). He holds that
previous writers have been wrong in considering Tanganyika by
itself, and urges that a clearer understanding of the facts becomes
possible on taking into account the organisms which inhabit
neighbouring lakes and rivers. Dealing with the Prosobranch
Gasteropods, which exhibit par excellence a thalassoid facies,
Germain asserts that while Tanganyika contains a much larger
series of such forms than any other lake, it is not the sole locality
in which they may be found. He considers that Lakes Mwero
and Nyasa, as well as the Upper and Middle Congo, contain a
number of Prosobranchs (chiefly Melaniide) the marine aspect
of which it is impossible to deny. Proceeding to discuss the
* A corresponding suggestion has been made to explain the marine appearance of
certain Crustacea and other organisms in Lake Baikal.
Proc, Zoou. Soc.—1920, No. XL. 40
602 DR. W. A. CUNNINGTON ON THE
geological aspect of the problem, he states that very extensive
lacustrine deposits are actually known in Central Africa, reaching
from the Congo basin to ‘Tanganyika and from that lake nf
Victoria Nyanza on the one hand and Nyasa on the other. From
such considerations he supposes that there formerly existed in
east-central Africa a vast lake basin which united the Middle
and Upper Congo with Nyasa and Tanganyika and_ probably
Victoria Nyanza. Living in this region was a uniform fresh-
water fauna specially rich in Prosobranchs. After the formation
of the Great Rift Valley the lakes were isolated in their present
basins, where modifications of the original fauna resulted from
the new environment. Lake Tanganyika, possessing most nearly
the characteristics of the ocean, became inhabited. by molluscs
which have assumed (by a phenomenom of convergence) a marine
aspect in the highest degree*.
With this conception I do not find myself wholly in accord.
Without expressing an opinion on the nature of the Gasteropods
of Nyasa and the Upper Congo region, there are two serious
objections to its acceptance. In the first place, there is in-
sufficient geological evidence for a lake basin so large in extent—
the deposits in this area being probably terrestrial and fluviatile.
In the second place, there is no reason why the conditions in
Nyasa and Victoria Nyanza, which closely resemble those of
Tanganyika, should not have produced an equally striking series
of thalassoid Gasteropods in those lakes, and yet this is not the
case. At the same time I am quite prepared to agree that
the marine aspect of the molluscs is probably due to convergence.
Another obvious suggestion is that the salinity of the water
has been a determining factor in producing marine-like forms.
Here it is much less easy to come to a decision, for the question
of increased salinity is of course directly associated with that of
a period of isolation. But prolonged isolation itself, with the
opportunity it affords of development free from competition with
the outside world, is obviously a cause predisposing to the pro-
duction of new characters. Where isolation and a gradual
increase in salinity have coexisted, it is difficult to recognise
which factor is responsible for a particular result. Experimental
evidence is not wanting to: show that certain salts, even im
minute quantities, exert a profound influence on aquatic organ-
isms, but it does not follow that a marine aspect would be
produced as a result. West, indeed, goes so far as to assert
that the Algz of Tanganyika which exhibit marine affinities may
well have been produced by a gradual increase in the salinity of
the lake during an extended period of time (200, p. 191). Here,
it is true, the Eco factors are inextricably associated, but if the
suggestion is not unreasonable for the Alge, the surmise may be
* Since this account has been in the press, a still more recent. paper by Germain
has reached my hands—* Histoire Océanographique des Lacs de |’ Afrique Orientale.”
Bull. Inst. Océanogr. Monaco, No. 369, 1920. In it, he adds little which is new,
merely re-affirming the opinions expressed in his earlier article,
FAUNA OF THE AFRICAN LAKES. 603
hazarded that the thalassoid Gasteropod shells owe their nature
to the same cause. Be this as it may, there are additiona] com-
plications affecting the salinity of Tanganyika.
It has been shown that Tanganyika had probably no outlet
until a portion of the Nile basin became cut off and Kivu drained
south into the lake (p. 515). It has also been pointed out that
since Kivu water contains an excessive amount of magnesium
salts, that lake is probably the source from which the high per-
centage in Tanganyika has been derived (p. 570). If these
probabilities be accepted, certain conclusions as to salinity follow.
During the first period the salinity may well have been consider-
able, though there is no evidence as to its nature. The lake
subsequently freshened, but eventually its waters became rich in
salts of magnesium. ‘Thus any effect which the saline nature of
the water may have exerted on the organisms of the lake may
have been due to either of these conditions, or to a combination
of both. As already suggested, there may even exist an irregu-
larity in the outflow of the lake, due to the forming and breaking
of dams in the bed of the Lukuga River (p. 515). If this be the
case, the salinity of Tanganyika has not only changed consider-
ably in the past, but may still be changing materially from time
to time.
The view that Tanganyika owes its remarkable organisms—not
merely the thalassoid forms—to a long-protracted period of
isolation, has been advocated by several writers, and remains,
on the whole, the most likely suggestion put forward. The
possible effect of an increased salinity, which isolation would
involve, must of necessity be coupled with this, but it is not
regarded as the prime factor. This view has the _ positive
advantage that it does not run counter to geological conceptions,
but fits in with what is believed to be the past history of the lake.
‘Testimony in favour of it is afforded by the very remarkable
nature of the Cichlid fishes which Tanganyika contains. This
group has long been known to show a ‘peculiar facility for
colonising isolated and often saline waters, though the agency by
which this is effected is not understood. What then more likely
than that the Cichlids were among the earliest inhabitants of the
lake, where, without having to compete with other types of fish,
they multiplied unchecked and became differentiated into new
genera and species (cf. 26, p. 423).
It is hardly necessary to point out that this isolation
hypothesis does not assume that Tanganyika was stocked from
any exceptional source. That is to say, the lake did not receive
its fauna from an ancient sea, but in the same manner as the
neighbouring fresh-waters, the original similarity of its fauna to —
those of the other lakes being secondarily lost by marked
divergences of form consequent upon prolonged isolation. The
marine aspect of certain Gasteropods would thus be regarded
merely due to convergence. Viewed in this light, the case
of Tanganyika is closely analogous to that of oceanic islands,
40*
604 DR. W. A. CUNNINGTON ON THE
which, as isolated areas of land, are well known to possess faunas
and floras largely peculiar to themselves.
The last-mentioned hypothesis, even if satisfactory in the main,
makes no attempt to account for the presence of the medusa in
Tanganyika, and accordingly a few sentences are needed on this
aspect of the question.
In dealing with the distribution of African fresh-water fishes,
Boulenger has discussed the problem of Tanganyika, and states
that he cannot admit Moore’s contentions (26, p. 422). He refers
to the inconclusive evidence afforded by the so-called halolimnic
Gasteropods, and clearly regards the medusa (now known from
other parts of the continent) as the only organism in the lake for
which it is necessary to aecount in any special manner. He
points out that paleontological evidence exists of a Middle
Kocene (Lutetian) sea which extended over a large area in
Northern Africa (vide also Hudleston 102, p. 352), and suggests
that this would afford a rational explanation of the present
distribution of the medusa in Africa.
With this view Gravier is not in agreement (90, p. 221). He
gives it as his opinion that the medusa may well have migrated
from the sea at a recent epoch, especially should it possess a
hydroid stage, as is held likely by Browne (cf. 56, p. 306). Its
present distribution in Africa he explains by reference to the
possibilities of intercommunication between the river systems.
Having dealt at considerable length—as becomes its 1mport-
ance --with the fauna of Tanganyika and the views put forward
to account for its very unusual character, 14 is now possible to
proceed to a brief study of the remaining lake faunas. While
there are smaller totals and fewer peculiar types, the bigger lakes
at least are not devoid of interest.
Victoria Nyanza, with 38 per cent. of endemic species, clearly
has characteristics of its own, these being more prominent in
some groups than in others. By far the most conspicuous group
is the Pisces, containing, as in the case of Tanganyika, the largest
series of forms. It comprises also over half the total number of
endemic species and the only two endemic genera. ‘The Mollusca
again are noteworthy, but in this case the Lamellibranchs are
more striking than the Gasteropods, exhibiting a larger pro-
portion of endemic types. Of the few Ostracods recorded from
the lake, 5 out of 7 are described as peculiar, and the Oligochete
worms are represented by 6 species, 4 of which are endemic.
Victoria is the only lake besides Tanganyika which contains the
medusa, though this should perhaps be regarded as subspecifically
distinct. It is only in this lake that the common Hydra is
known to occur. Many groups are wholly without endemic
representatives.
Generally speaking, Lake Nyasa exhibits very similar features,
but with rather fewer peculiar forms. Fishes constitute half the
total number of endemics, and 5 endemic genera out of 6,
A considerable number of molluscs are known, nearly half being
FAUNA OF THE AFRICAN LAKES. 605
peculiar to the lake. Nyasa contains an endemic genus belong-
ing to the Argulide, and the Ostracoda are well represented,
8 species being endemic out of 17. It is strange that no aquatic
snakes and no Polyzoa have yet been recorded ; on the other hand,
Nyasa alone of the lakes under review contains aquatic tortoises
referred to the Trionychide.
The three smaller lakes contain representatives of fewer animal
groups, but it is possible that this is merely due to less syste-
matic investigation.— Albert Nyanza displays only i3 per cent.
of endemic forms, which are mostly Mollusca, while it has no
endemic fish. The genus Limnocaridella (prawn) is the only
genus peculiar to the lake.—Edward Nyanza contains a more
interesting series of fish, with one genus and six species endemic.
Only 3 molluscs are peculiar out of a total of 15, and there is
little else which calls for comment.—In Kivu, representatives
of only 6 groups of animals are at present known to occur.
While future exploration may bring other forms to light, the
poverty of its fauna is probably connected with the exceptional
salinity of the water. Out of a total of 23 species, there are
13 fishes, 3 being endemic, while the only other endemic type
is an Oligochete worm. The apparent absence of the hippo-
potamus and the crocodile is a point of some interest. Similarly
no Lamellibranchs appear to occur, although two forms of
Gasteropod are known.
It is obvious that none of these lakes exhibit such striking
forms as Tanganyika, and that while endemie types are not
wanting, these are fewer in number and for the most part only
specific in character. Apart from the presence of the medusa in
Lake Victoria, there is nothing to suggest a special connection
with the sea. In broad terms it may be said that the lakes
contain the ordinary fresh-water fauna of Africa modified in
varying degree in each case. Where such modification is con-
siderable, as in Victoria Nyanza and less markedly Nyasa, it may
well have been caused by a period of isolation proportional to the
relative peculiarity of the fauna. It is more especially the fish -
fauna of these lakes which is rich in endemic species and shows
certain endemic genera, and from this evidence 1t would seem
that Lake Victoria remained isolated for a longer period than
Nyasa (cf. p. 536). If isolation be accepted as accounting for the
remarkable fauna of Tanganyika, it is clear that a still longer
period must have been necessary in that case to produce such
notable results. 3
There are certain other matters concerning the distribution of
animals in the African lakes which are brought out by this com-
parative survey. While representatives occur of most of those
groups which may be expected in tropical fresh-waters, there are
some interesting exceptions. It comes as a surprise to a Euro-
pean naturalist to find no fresh-water Isopods such as Asellus, or
Amphipods such as Gammarus, yet these familiar forms appear
to be conspicuously absent from the tropical parts of Africa,
606 DR. W. A. CUNNINGLON ON THE
though the genus Gammarus is recorded from. the north and
south of the continent. Why such types are wanting it would
be idle to speculate, but the fact is also emphasised by Stuhlmann
in more than one place (181, p. 1268: 182, p. 652). It is strange
too, that among the intestinal parasites of the fresh-water fish
there appear to be no species of Hcehinorhynchus, although they
are common in the fish of European rivers. Daday, it is true,
has described a larval form from a species of Ostracod taken in a
small East African lake (76, p. 55). Thus, while Asellws and
Gammarus are commonly the intermediate hosts, it is evident
that the absence of these genera does not form a complete
barrier to the distribution of Mchinorhynchus, and Daday con-
siders that it will yet prove common. in Africa. At present,
however, the adult form is entirely unknown.
Concerning the numerical distribution of species in the lakes,
there is one point which calls for further notice. From a study
of the lists of forms found in each lake, Moore believed that a
definite relation existed between numbers and size. After
reviewing the facts then at his disposal, he writes :—‘“ It is thus
obvious that from some cause or other the number of specific
forms in an African lake is roughly proportional to the size of the
lake itself” (137, p. 146). This does not mean that the smaller
lakes are less well stocked with animals, but simply that the
number of species they contain is less. The matter has already
been referred to in the systematic section, and it has moreover
been shown that the principle appears capable of extension to the
number of genera and even families (pp. 535, 548). With the
total figures for the six lakes now available, it is possible to test
the correctness of this conception on a more extended basis.
The totals for species and genera are therefore given in tabular
form, with the lakes (apart from Tanganyika) arranged in order
of size.
Tangan- Victoria Albert Edward
yika. Nyanza. lyels Nyanza. Nyanza. —
Number of Species ......... 402 289 361 67 54 23
OO & Goneean eee 168 139 178 48 35 13
‘Tanganyika, which heads the list, is in every sense to be
regarded as a case apart, but the figures for the remaining lakes
should accord with this law-—if such it be. A descending series
is seen to exist: Nyasa it is true constitutes an exception, but,
as already explained, its totals have been artificially swollen in
certain directions “p. 595). Nyasa conforms to the rule in the
case of the Pisces and Mollusca—it is the addition of many types
of Rotifera and Protozoa which chiefly accounts for the large
total figure for the lake. pl
FAUNA OF THE AFRICAN LAKES. 607
A very similar result is arrived at on comparing the number of
groups represented in the different lakes. From Victoria Nyanza
downwards the decrease in size is accompanied by a decrease in
the number of groups present. The figures (including Tangan-
yika for comparison) are found to be as follows :—Tanganyika
26 (groups), Victoria 25, Nyasa 24, Albert 15, Edward 14, and
Kivu 6. It is possible, however, that the low totals for the
smaller lakes are, in part, a result of less complete investigation.
Enough has been said to show that Moore’s contention is
substantially correct as far as these African lakes are concerned.
It would be interesting to discover whether a similar relation
between size and number of specific forms can be made out for
other groups of lakes or even if it is a principle of general appli-
cation. Moore makes a comparison, which would seem to be
justified, between this phenomenon and that exhibited by the
flora of oceanic islands, where the smaller the island,—although
it may be as thickly covered with vegetation as any other area,
the fewer the species of plants which inhabit it.
The last matter to be considered is the undoubted affinity
which exists between certain African and Indian fresh-water
types—an affinity which has been noticed already, when re-
viewing the groups In which it is most pronounced, This inter-
relationship i is exhibited in many groups of animals, and extends
not merely to forms from the Indian Peninsula itself, but from
the whole of that part of Asia, including the Malay Archipelago.
An interesting account of these affinities is given by Annandale
in a paper entitled “The African Klement in the Freshwater
Fauna of British India” (10). So far as the present treatise is
concerned, consideration is limited to those animals which are
known to occur in one or other of the big African lakes. Briefly
enumerating the cases, the Cyprinide and Mastacembelidee among
the fishes indicate this affinity in a marked degree. The Polyzoa
afford striking evidence, since the genus Arachnoidea is known
from Tanganyika and East indian’ seas, while in the case of
Plumatella (Afrindella) tanganyike the actual species has been
found in an Indian lake as well as in Tanganyika. Caridina
nilotica with its varietal forms occurs in several of the African
lakes, while it 1s widely distributed in Indian and Malay regions
and extends still further east into Australia. Among the
Coelenterata a medusa has now been found in India which is
generically identical with that from Tanganyika and Victoria
Nyanza, while finally among the sponges Spongilla carteri from
Lake Victoria is known in India and Java.
This is not the place to discuss the geological evidence for a
former land-connection between these areas, but the views
commonly held can be stated in a few words. During the
Carboniferous period, and persisting subsequently through the
Permian and Triassic, there appears to have existed a vast
tropical continent which extended from Brazil to Australia,
embracing of course Africa and India. This continent is known
608 DR. W. A. CUNNINGTON ON THE
as Gondwanaland. In the ensuing period—the Jurassic—Gond-
wanaland began to break up, but there is some evidence that in
late Cretaceous or even early Tertiary times a land-bridge still
existed between Hast Africa and the Indo-Malayan region, by
way of the Seychelles and Maldives. The geological record
is thus quite in keeping with the facts of distribution to which
reference has been made.
In bringing this study to a conclusion, it must be admitted
that in many directions information is very limited. There is no
doubt that the discovery of additional species is to be expected
whenever a re-examination of any of the lakes occurs, but there
are other points of considerable interest on which knowledge is
much to be desired.
Despite the investigations of Moore in Nyasa and Tanganyika,
very little is really known concerning the deeper regions of any
of the lakes, and the existence of a distinct abyssal fauna is
uncertain. In a paper dealing with the distribution of the
molluses, Moore speaks of obtaining certain thalassoid forms in
Tanganyika at a depth of 800-1200 feet (244-366 metres)
(129, p. 171). He vegarded these particular Gasteropods as a
deep-water assemblage, but a more thorough examination may
well reveal other animals which permanently inhabit the bottom
muds. There is little doubt from an analogy with other deep
lakes that the deeper waters of these African Jakes are almost, if
not quite, devoid of life. At the same time, further investigation
may indicate a definite association of abyssal forms not only in
Tanganyika, but in the other lakes under review.— Associated
likewise with the distribution of organisms within the limits of
the lakes are questions such as the vertical distribution of
plankton forms, as ascertained by tow-nettings. During the
Third Tanganyika Expedition my operations were practically
confined to surface tow-nettinys, but special tow-nets worked
from suitable craft would afford the necessary information.—-
Again, the seasonal variations of plankton organisms are almost
unknown, although [ was able to detect a marked decrease in the
quantity of material during the rainy season. Detailed know-
ledge of this kind can only be gained by the aid of large collections
extending over many months.—The distribution of local forms or
varieties within the limits of a single lake was discussed by
Moore in his book. He considered that certain well-marked
varieties or even species were confined to particular areas in the
greater African lakes (137, p. 149). My own observations lead
to a different conclusion, and the matter undoubtedly merits
further investigation.
Lastly, there are some outstanding physical matters which are
of importance on account of their relation to biological pheno-
mena. Very little is known concerning the chemical impurities
of the water in these lakes, and even the depth and general
nature of the basin is imperfectly known save for Tanganyika,
Victoria and Nyasa. Further knowledge is likewise desirable as
FAUNA OF THE AFRICAN LAKES. 609
to water temperatures, seiches, and the possible occurrence ot
temperature seiches.
It is clear, nevertheless, that from the facts already established,
a reasonably tsue conception may be formed both as to the nature
of the lakes themselves and that of the organisms which they
contain. It has been the aim of this work to supply a connected
account of these facts, based on the most recent particulars.
Considering the difficulties which beset the investigator in a
tropical climate far from civilisation, the amount of information
available is not disereditable to those concerned.
5. SUMMARY.
The special interest attaching to this comparative study of
African lakes is due to the remarkable nature of the fauna of
Tanganyika. That lake was discovered in 1858 by Burton and
Speke, the latter bringing back with him shells considered to have
a distinctly marine appearance. Subsequent collections emphasised
this point, and interest was further increased by the discovery of
a medusa by Bohm. A scientific expedition to investigate the
fauna was despatched in 1895 in charge of J. E.S. Moore. ‘The
rich and unusual nature of the fauna then collected led him to
formulate the hypothesis that Tanganyika represents an old
Jurassic sea. In order to test the validity of this: hypothesis,
a second expedition, on which Moore was accompanied by Fer-
gusson, left England in 1899. The result was held by Moore to
justify the theory, and he embodied his conelusions in a work
entitled ‘* The Tanganyika Problem,” published in 1903. As the
aquatic flora had not been taken into account, a third expedition
was despatched to rectify that omission and make a further
collection of animals. This left in 1904 in charge of the writer,
returning in 1905. More recently still, in 1912-13, the Belgian
expedition of Louis Stappers visited the lake and obtained
additional information.
The scope of this paper includes, besides Tanganyika, the five
adjacent lakes of most interest, viz.:— Victoria Nyanza, Nyasa,
Albert Nyanza, Edward Nyanza, and Kivu. All these, with the
exception of Lake Victoria, occupy portions of the Great Rift
Valley, which has probably been formed by trough-faulting on a
stupendous scale. They he in long narrow depressions bounded
by escarpments rising to a height of two or three thousand feet
above the level of the water. Nyasa and Tanganyika are very
deep, the former reaching to over 780 metres and the latter to no
less than 1435 metres. Victoria Nyanza has the largest area, but
occupies only a shallow basin bounded by low hills.
In all the lakes, but especially the largest, conditions are almost
oceanic. Climatic differences are negligible, but water tempera-
tures are uniformly high, showing an average of about 26° C.
Analyses of the water have been made in very few instances.
The water of Tanganyika, while fresh, is unusually rich in salts
610 DR. W. A. CUNNINGTON ON THE
of magnesium, and that of Kivu contains excessive quantities of
the latter as well as sedium salts. It is likely that the salinity
of Tanganyika was greater formerly, and may still be subject to
variation. Hvidence exists of a considerable rise and fall in the
level of the lake, yet it seems probable that rainfall and evapora-
tion are very nearly balanced. ‘There is reason to believe that
Tanganyika had no outlet until it received an additional water
supply from the Kivu basin, which was cut off from the Nile, and
added to the drainage area of the big lake by the formation of a
volcanic dam in recent geological times. ‘Tanganyika would thus
have been completely isolated and its waters more saline until an
outflow was established. The present efHuent appears to have been
formed as an afiuent, its bed being finally captured by a tributary
of the Congo.
MOVEMENTS OF NECTURUS AND CRYPTOBRANGHUS. 65]
by him in Vecturus does not include the gross flapping of the ex-
ternal gills. ‘There is, therefore, an apparent textual discrepancy
between his account and mine, which will doubtless be cleared by
further independent observations. Bruner fortifies his statements
concerning the ‘“ bucco-pharyngeal mechanism” by a careful
description of the choanal valve of WVectwrws; and he seems to
assign a preponderating role to the gill-clefts in the branchial
respiration of this genus. It is not altogether inconceivable that
in different parts of its climatic range, as well as under diverse
laboratory conditions, the several components of the respiratory
tract may vary in the relative frequency of their turns. The
behaviour of Cryptobranchus informs us that not every yawn is
an act of breathing. No contrast could be more realistic than
that between the restless, air-craving Cryptobranchus and the
listless, gill-waving Vecturus when viewed at the right biological
moment in the splendidly appointed tanks of the New York
Aquarium.
McGill University, Montreal,
October 10, 1920.
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