GEOLOGICAL AND NATURAL HISTORY SURVEY OF MINNESOTA
HENRY F. NACHTRIEB STATE ZOOLOGIST

The Collembola of
Minnesota

BY

JOSEPH E. GUTHRIE M. S,

ZOOLOGICAL SERIES IV

EDITED BY

HENRY F. NACHTRIEB

MARCH 1903
MINNEAPOLIS MINNESOTA

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GEOLOGICAL AND NATURAL HISTORY SURVEY OF MINNESOTA
HENRY F. NACHTRIEB STATE ZOOLOGIST

THE

COLLEMBOLA OF MINNESOTA

BY

JOSEPH E. GUTHRIE M. S.

ZOOLOGICAL SERIES IV

EDITED BY

HENRY F. NACHTRIEB

MARCH 1903
MINNEAPOLIS MINNESOTA

LETTER OF TRANSMITTAL.

To the President of the Board of Regents of

The University of Minnesota.

Sir : — I have the honor herewith to submit to the Board
of Regents the fourth number of the Zoological Series of the
reports of the Geological and Natural History Survey of Min-
nesota under the title The Collembola of Minnesota by Joseph
E. Guthrie, M. S., a graduate of the University.

Mr. Guthrie carried on the work on this interesting group
of insects under my general direction and the more immediate
supervision of my assistant Oscar W. Oestlund.

The material and notes upon which the report is based are
now stored with the special collections of the Department of
Animal Biology and are at all times accessible to students and
investigators.

Very respectfully, your obedient servant,

HENRY F. NACHTRIEB,
The University of Minnesota, Zoologist of the Geological

January 12, 1903. and Natural History Survey,

THE BOARD OF REGENTS OF
THE UNIVERSITY OF MINNESOTA.

The Honorable GREENLEAF CLARK, M. A., President, St. Paul
The Honorable STEPHEN MAHONEY, B. A., Sec'y, Minneapolis

The Honorable ELMER E. ADAMS, B. A Fergus Falls

The Honorable THOMAS WILSON St. Paul

The Honorable WILLIAM M. LIGGETT Benson

The Honorable A. E. RICE Willmar

The Honorable THEODORE L. SCHURMEIER St. Paul

The Honorable O. C. STRICKLER, M. D New Ulm

*

The Honorable JAMES T. WYMAN Minneapolis

EX-OFFICIO.

CYRUS NORTHROP, LL. D Minneapolis

The President of the University.

The Honorable SAMUEL R. VAN SANT Winona

The Governor of the State.

The Honorable JOHN W. OLSEN Albert Lea

The State Superintendent of Public Instruction.

CONTENTS

Letter of Transmittal iii

The Board of Regents iv

Part I. General.

Economic Importance of the Collembola 3

General Characters of the Collembola 5

Relationships of the Collembola 9

Collecting and Preserving Collembola. . 13

Literature 15

Part II. Systematic.

Terms Used 23

Keys for the Determination of Orders, Families, Gen-
era, etc 25

Order Collembola 25

Family Sminthuridae 25

Genus PAPIRIUS 26

" SMINTHURUS 27

Family Entomobryidae 29

Genus ORCHESELLA 30

u ISOTOMA 31

" ENTOMOBRYA 33

TOMOCERUS 35

CYPHODEIRUS 35

SEIRA 35

" LEPIDOCYRTUS 36

Family Poduridae 37

Genus ACHORUTES 38

PODURA 39

" XENYLLA 4°

" -FRIESIA 40

u
u

vi CONTENTS

Family Aphoruridae 40

Genus APHORURA 41

" ANUROPHORUS 42

" ANURIDA 42

•' NEANURA 42

" APHOROMMA 42

List of new species 105

Index 107

Plates and Explanations.

PART I
GENERAL

ECONOMIC IMPORTANCE OF THE
COLLEMBOLA

From an economic point of view, the Collembola are re-
garded as of minor importance when compared with certain
other better known insects ; yet some of them have been accused
of rather serious depredations upon garden crops. Harris, in
speaking of some of the Sminthuri, says : "Several years ago I
observed that cucumber vines were much infested by some
minute jumping insects. They injured the vines very much
by eating holes into, or puncturing the leaves, and were ex-
pelled by dusting the plants with flour of sulphur."

Mr. Curtis, in his work on farm insects, says : "In Nova
Scotia the crops of turnips and cabbages are principally de-
stroyed, whilst in the seed-leaf by some Smynthurus, the size
of a pin's head, and nearly globular. It hops with great facility
by means of its forked tail and may be found on every square
inch of all old cultivated ground, but it is not plentiful on new
land."

Dr. Asa Fitch says: "Our gardeners universally regard
these fleas as being injurious, but not so severely injurious as
the larger-sized flea-beetles (Haltica) with which they are almost
always associated. And this appears to be a correct estimate
of their character. I have sought to ascertain the exact nature
of the injury which they do, and from the best observations
which I have yet been able to make, I think these fleas never
perforate holes in the leaves or gnaw their texture where it is
green and in a healthy growing state. Their small jaws are
probably too soft and weak to enable them to break down and
masticate the substance of the leaf. But when a flea-beetle per-
forates a hole in the leaf, these garden fleas afterwards gather
around the perforation to feed upon the soft matter which is
there formed by the evaporation of the exuding juice. This

4 COLLEMBOLA OF MINNESOTA

matter makes a kind of scab upon the raw surface of the wound,
covering it and enabling- it to heal. These garden fleas feed
upon this scab, thus tearing open the healing wound and caus-
ing it to bleed afresh. Hereby the holes in the leaf become
much larger than they are first made by the flea-beetle, and
nature is interfered with and embarassed in her efforts to re-
cover from the injuries done by the flea-beetles and other insects
which wound the leaves. It is chiefly in this manner, I think,
that these little garden fleas are detrimental to the plants on
which they occur. Dusting the infested plants with ashes, sul-
phur, etc., and most of the other remedies which we resort to for
expelling the flea-beetles from them, are still more efficacious
in driving off these garden fleas also." Fitch says also of an-
other species (Sminthurus arvalis Fitch) that: "It is common
to see them in the garden, upon the leaves, particularly of the
pie rhubarb. Rheum Rhaponticum, where these leaves are per-
perforated with holes by the flea-beetles." I have never met any
gardeners in this state who were acquainted with the ravages of
these insects, and have never observed them feeding upon green
leaves, but the fact that they are known to do so in other places
and that they are common here, makes it at least advisable that
they should be known and guarded against.

Sometimes some species of the Aphoruras become very
abundant on the surface of water in cisterns and cause consider-
able inconvenience and annoyance on account of their great
abundance. Of course they are not positively harmful in this
case. They are easily killed by pouring a few drops of kerosene
on the water.

From Prof. H. E. Summers, State Entomologist of Iowa, I
learned a new fact in regard to their economic relations. This
time it was one of the species that lives in the soil that was the
culprit. Probably, from the description, it was one of the Ach-
orutes. They were very abundant in the soil in which the gar-
dener planted some seeds, and kept the soil so thoroughly
worked up that the little plants found no chance to root and many
of them died.

Some species of Achorutes might give trouble to the raiser
of mushrooms, though I am not certain that they would attack
a perfectly fresh mushroom.

GENERAL CHARACTERS OF THE
COLLEMBOLA

HEAD. — Among the Collembola we have considerable dif-
ferences in the form of the head, from the elongate forms, where
it is borne almost horizontally, to the shorter-bodied Sminthur-
idae, in which it approximates the vertical position. The mouth -
parts are typically mandibulate, each mandible bearing usually
•four or five teeth on its inner edge. That the "Entognatha"
could constitute a separate group merely by virtue of having the
mouth-parts withdrawn (?) into the head, has been proven fal-
lacious by embryology. Dr. J. W. Folsom, in his work on the
development of the mouth-parts in Anurida maritima Guer., has
shown that, developmentally, the mouth-parts are external as
in the Orthoptera and other pterygote insects ; but that, by a
downward folding of the genae, which unite ventrally with the
labium, the mouth-parts are pocketed and thus appear with-
drawn.

The eyes are of a form, which, I think, has its counterpart
in no other order of the Hexapoda. Compound eyes are un-
known, and simple ocelli in the positions where they are borne
by other insects are likewise unknown. The two dorso-lateral
eye patches of pigment material, nearly always dark, are in the
normal position for compound eyes ; yet they bear simple ocelli,
and only a few of these. The normal number throughout most
of the genera appears to be sixteen, each eye spot containing
eight, which are usually arranged approximately in the form of
a letter S, with the lower (posterior) part straighter than the
upper part. The eye patch is commonly more or less convex,
especially so in the Sminthuridae, where it is quite biscuit-form,
with most of the eyes set round the edges. It is evident that the
group is degenerating in regard to the eyes at least, and it seems
not unreasonable to suppose that one of the stages to be passed

6 COLLEMBOLA OF MINNESOTA

through in the degeneration of compound eyes might appear
not unlike the typical collembolan eye. If, as I have supposed,
the Machilis is very like their ancestor, then we must conclude
that the eye patches with their grouped ocelli represent the orig-
inal compound eyes. The degeneration in the number of ocelli
has already been noted.

The antennae vary greatly in their comparative length and
segmentation. We may regard four as the normal number of
segments ; the proximal segment being usually short, and very
often the second segment as well. The two distal segments
differ among different genera. In Papirius and Tomocerus the
end segment is short and ringed with whorls of short hairs, as
is also at least a part of the third segment. In Sminthurus only
the fourth is ringed, and that not always. The antennae are im-
portant tactile organs, as one will soon discover by watching
these creatures moving about and keeping the antennae in con-
stant motion. The antennae are always haired, but, besides the
ordinary hairs, special long, slender hairs are often borne stand-
ing out at nearly right angles to the members which bear them.
In some of the lower genera, as among the Achorutes and Ne-
anura, where the habit is less active, there appears to be a cor-
responding degeneration of the antennae ; the third and fourth
segments being sometimes reduced to one. Whether the ringed
condition of the antennae of such forms as Tomocerus points to
a primitive multiarticulate condition as in Machilis is a matter
of doubt. While it is possible, yet I incline to think rather that
the partial sub-jointing has been developed in the Tomocerus
and Sminthuridae independently in response to a demand for
more flexible tactile organs.

The post-antennal organ is characteristic of some of the
genera, yet can hardly be regarded as belonging to the group
as a whole. It will be noticed under the genera where it occurs.

THORAX. — The thorax is typically that of a hexapod.
Three free segments bear each a pair of typical walking legs.
In the Sminthuridse these segments are fused together.
Usually the prothorax is the smallest of the three, and in sev-
eral of the genera the tergttm of the following segment pro-
jects over it to a greater or less extent. The fact that the meso-
and metathorax tend to be larger than the prothorax has lent

COLLEMBOLA OF MINNESOTA 7

credence to the opinion, sometimes still advanced, that these two
segments have attained their super-growth to give more room
for the attachment of wing muscles, but inasmuch as the first
pair of legs are, as a rule the smallest, I think the other ex-
planation not only far-fetched, but unnecessary.

The legs are five-jointed ; consisting, usually, of two short
basal segments, coxa and trochanter, a long femur and a still
longer tibia, with a very small tarsus, which bears, in all but
the lowest genera, two apposable claws, an outer larger, and
an inner smaller one. Clubbed hairs, the tenent hairs of many
authors, very often project from the end of the tibia over the
outer claw. The name ''tenent" hair came from the notion that
they assisted the claw in grasping, or getting a foothold ; yet
I think there is little doubt that they are merely tactile in func-
tion. The claws often bear notches or teeth (denticles) espec-
ially along their inner edges, and the kind and distribution of
these present valuable systematic characters. In some of the
lower genera, as, for instance, in Achorutes, the inner claw is
disappearing, while in Podura and in most of the Aphoruridre
it is gone altogether.

ABDOMEN. — This part is usually more or less swollen,
and consists of six segments, of which the apical and pre-apical
are usually small. The first abdominal segment bears on its
ventral surface the so-called ventral tube. This is the typical
organ of the Ccllembola, and one which all possess. True,
there is a wide difference in appearance between the ventral tube
in Papirius on the one hand, with its long stock and two very
long, slender, flexible, tuberculated filaments, and that of Achor-
utes or Neanura on the other hand, where the tube is hardly
more than a tubercle split in the middle so that the two sides
shut together like the jaws of a steel trap, and the exsertile part
is only so far exsertile as to produce a convex surface when the
jaws are open and a concave surface when they are closed. The
function of this ventral tube is not well understood. Formerly
it was supposed to be an external reproductive organ. Latre-
ille held this opinion, but Nicolet said he could not agree with
the former author, although he had been unable to discover any
sexual organs. He seems to think it an organ which, by its

8 COLLEMBOLA OF MINNESOTA

mncosity, assists the insect when travelling over a smooth, pol-
ished surface, as glass, for instance. To be sure, the feet are
not adapted to smooth surfaces. But what smooth surfaces are
there where these insects live?

The second abdominal segment bears the tenaculum, catch
or halthaken, as it is called by various authors. Although several
of the best writers mention it as a character of prime impor-
tance in clasification, yet I think few have been able to use it
to advantage. It probably represents one of the pairs of prim-
itive jointed abdominal appendages, their basal portions fused
to each other and their second (terminal) parts turned laterad
so as to form a sort of catch to hold the spring in place when
not in use. Short notches or teeth serve the better to retain
their hold upon the furcula, which is so placed as to extend a
ramus (dentes) on either side of and close to the tenaculum,
whose two blades extend below them, holding them in position.

The fourth abdominal segment, or sometimes the fifth,
bears what is variously called the furcula, saltatory organ, spring,
springgabel, tail, caudal appendage, etc. It undoubtedly rep-
resents a pair of jointed appendages. Dr. A. S. Packard com-
pares the ovipositor of some Neuroptera (Panorpa and Bittacus)
to "the leaping ovipositor of the Podura and its allies." In
speaking of Westwood's description of the winter neuropter,
Boreus, he says: "In this description we are reminded of the
Spring-tails (Podura) which leap by means of the long ovipos-
itor, and corresponding male organs, bent beneath the body."
I feel inclined to question this statement of the furcula being even
primitively an ovipositor. Evidence gained by a comparison
with the thysanuran genus Machilis would certainly seem to
deny it. Machilis has a sort of primitive furcula, as well as a
long, well-developed ovipositor. When at rest, the furcula is
carried beneath the body, its muscles continually at tension,
and ready for a leap when the tension on the blades of the ten-
aculum is loosened so as to release the furcula. The powerful
muscles of the furcula are balanced by the less powerful muscles
of the tenaculum, on account of the shorter leverage of the latter.
The final abdominal segment, the sixth, often bears anal horns
in the Poduridse and Aphoruridas. The anus is terminal, and
the genital papilla opens on the ventral side of the preceding
segment.

RELATIONSHIPS OF THE COLLEMBOLA.

The peculiar interest centering in the Collembola .is due
largely to the fact of their association with the Order Thysanura,
which contains the Campodea, an insect supposed by many to
represent pretty nearly the ancestry from which the Pterygota
have evolved. Whether the Pterygota did actually come from a
Campodea-like form, we do not know ; one thing is evident, how-
ever : if they did, the line of descent was not by way of the Col-
lembola. As to the connection between the two orders of the
Apterygogenea, various opinions exist. Some writers see no
connection at all, others would place them in the same order. I
believe that the differences are marked enough to justify the
separation into the two orders, though the evidence seems con-
vincing that the order Thysanura is the older of the two, and is
perhaps not far out of the direct line of descent from a common
ancestor.

While I confess myself unable to point out the ancestor
of the Collembola among the members of the order Thysanura,
yet I feel pretty certain that such an ancestor must have
closely resembled members of the genus Machilis in many im-
portant respects. Machilis is not the ancestor, but there is no
other form known which possesses organs comparable with the
characteristic organs of the Collembola: the furcula, the ten-
aculum and the ventral tube. Scales are also found on tin-
Machilis as on several genera of the Collembola. It is interest-
ing to note even in this connection that the Machilis shows a very
primitive, even pre-hexapod, character in the possession of
biramous appendages. That the Collembola are scions of a very
old house seems probable, yet their minute size and their com-
paratively soft bodies make it equally probable that geological
rock-writings have but meager records to offer us concerning
them. As is so often the case, science must speculate, more

io COLLEMBOLA OF MINNESOTA

or less futilely, upon the line of descent which brought forth
the Collembola. That they are degenerates, retrograded from
an early pterygote stock, as some very good scientists have
guessed, seems to me a position more and more untenable the
better we become acquainted with these insects.

Let us glance, in passing, at some of the evidence. There
are no wings, even vestigial, to be found in any members of
the group ; and even embryological research fails to reveal
any wing traces. This fact, while important, should not be over-
strained. It is merely a negative character possessed in common
with the Pediculidae and others which we have good reason
to believe have evolved from various winged orders. The
biramous, crustacean-like legs of Machilis, together with its
possession of a full set of small, jointed abdominal appendages ;
its campodiform body and simple mouth-parts and internal
structure ; all claim for it a place among very ancient insects.
The apposable claws of Collembola are more like the chelae
of crustaceans than like the claws of any others of the hexapods.

Compound eyes were probably acquired, or possibly in-
herited, by the early hexapods ; and were possessed even by
those which failed to develop in a pterygote direction. The
collembolan eye is essentially a compound eye in process of
decadence. While most of the Thysanura are very simple and
rather sluggish insects, yet the Machilis has begun the devel-
opment of an organ which has become in the Collembola a very
important organ of locomotion — the furcula. If Collembola
were descended from pterygote insects, we would expect to find
among the latter some organ which we could conceive to have
specialized into the furcula. But such is not the case, though
Machilis does have the last pair of abdominal appendages larger
than the rest, and uses them together as a leaping organ. These
appendages are three-jointed, and the constant use of the pair
together as one organ would naturally tend to make their bases
approximate until they would grow together and form one piece,
the manubrium of the furcula in the Collembola. The two
more distal segments are free from each other. Probably none
of the appendages of the Machilis are used as a tenaculum ;
but all the appendages are there, and it is not surprising thai
one pair should have been so modified, for the tenaculum is

COLLEMBOLA OF MINNESOTA 11

evidently only a modified pair of jointed appendages which have
taken the function of holding the furcula in position when not
in. use. As a fore-runner of the ventral tube in Collembola,
we have the exsertile vesicles in Machilis in which they are
found at the bases of the legs. Perhaps the common ancestor
had them on all the appendages, or at least on those of the
first abdominal segment, and that this pair persisted and moved
toward the median line until they grew together and formed
one tube.

That the Collembola are extremely old is indicated by
the fact that, despite their wingless condition, the same species
with almost no variation will occur often throughout three con-
tinents. Dr. Folsom considers that this remarkable distribu-
tion has been effected by the inland streams and ocean currents,
which latter are known to convey inland species to great dis-
tances.

Many considerations, on the other hand, point to their
being a regressive branch ; such, for instance, are furnished by
their retiring, dark-loving habit, and minute size. The habit
mentioned is, in turn, probably responsible for the tendency
noticed in most of the genera toward a loss of the eyes. In
isolated species in several genera we find all or nearly all pig-
ment in the body lost, and the occeli entirely atrophied, owing,
probably, to the cave-habit. Worthy of note, along with the
assumption of the cave habit and consequent degradation and
atrophy of optical sense, has come an hypertrophy of senses
along other lines: at least this is the obvious way of accounting
for the abundance of multiform tactile hairs in positions where
the touch power could be best utilized. Whether we are to rec-
ognize merely a protective function in the scales which adorn
Tomocerus and Seira, etc., or whether they also act as sense
media, is a matter for further investigation.

No small part of the difficulty arising in the study of this
order is due to their diminutive size. Not only does their minute-
ness, coupled often with extreme agility, render them difficult to
observe and still more to capture ; but it is often no easy matter to
make out such small microscopic characters as the form and dis-
position of teeth on the claws and furcula. Remembering that
several species never attain more than a half millimeter in length,

12 COLLEMBOLA OF MINNESOTA

and that one of five millimeters is a veritable giant among the
Collembola, it may readily be imagined how nice are the distinc-
tions which must be looked to for species determination.

It is rather difficult to realize at the outset that a character
which will hold true and invariable, and therefore of prime im-
portance in separating the species of one genus, may be so
variable in another genus as to be absolutely worthless. Thus,
while color is in some genera of little value as a specific dis-
tinction, in others it alone would serve to identify species.

In a group which exhibits, throughout, such a tendency to
atrophy of ocelli, it is not surprising that genera should have
been founded upon the number of ocelli, or, in other words,
upon the particular stage to which the ocellar atrophy had pro-
gressed. It was almost inevitable that the intervening stages
would sometime be found and that the genera founded on
nothing more than specific characters would have to be aban-
doned. This point will receive further consideration under the
different families.

Before taking up the more technical portion of this report
it may be well to say a few words about the methods found use-
ful in collecting and preserving Collembola for study.

COLLECTING AND PRESERVING
COLLEMBOLA

It is often desirable to examine specimens alive, and this,
owing to their small size, is impracticable in the field. Small vials
containing some moist wood, earth or filter paper, serve well to
carry the creatures in, if they can once be induced to enter without
being so roughly handled as to injure their health. Moisture in
the vial is essential, as their lease of life in a dry atmosphere is
extremely brief. It is best to keep the vials containing live spec-
imens in the dark as much as possible, as the insects are liable
.to injure themselves by the effort to find dark crannies; and the
scaled species are almost certain to become denuded of their
scales by their activity under cramped conditions. For ordinary
work, I find it best to collect and preserve the material in 80%
alcohol. It seems to require as high a grade as that to sink
them. Apparently they are covered by a sort of wax which re-
quires a solvent before they will sink in liquid. Species vary
somewhat in their readiness to sink in alcohol. Mr. MacGilli-
vray recommends the use of a mixture of alcohol and glycerine
to collect in, and later transfers the specimens to 80^ alcohol.
The virtue of the mixture is that it is sticky and the insect will
stick readily to a tooth-pick wetted in it, while with clear alco-
hol one must use a camel-hair brush. Dr. Folsom collects his
collembolans in vials and brings them in alive. He kills them
by pouring upon them hot 95^ alcohol.

Specimens may be examined either alive or in alcohol, but
to get at their minute characters it is preferable to clear and
mount them. Dissection and mounting in glycerine is very good
for a quickly prepared, non-permanent mount ; while one may
preserve a good glycerine mount, if desired, by ringing it with
asphalt cement. I have found it best, however, to mount in
xylol damar, which is clear, easily manipulated, and seems to

14 COLLEMBOLA OF MINNESOTA

give good permanent results. Formerly I used xylol as a clear-
ing agent, but found it rather too rapid in evaporation ; so that
in mounting a dozen or more insects under one cover, it was
difficult to keep some of them from getting too dry before apply-
ing the damar. Cedar oil is slower in evaporating, and is there-
fore preferable. The colors in the Collembola are generally al-
most permanent when in damar mounts, though I think glycer-
ine jelly keeps them brighter, and has, besides, the merit of do-
ing away with the necessity for clearing.

When it is desired to destroy the pigment to better study
ocelli, post-antennal organs, etc., a drop of a 5^ potash (KOH)
solution may be run under the cover glass, and its action arrested
by the introduction of alcohol or water when the specimen is
clear enough ; after which dehydration and mounting may pro-
ceed as usual. For a minute examination of the claws, furcula,
etc., of some of the thicker bodied species, it will be found nec-
essary to dissect off the parts wished for examination, as the
body often makes too thick a mount to allow of focussing with
a high power lens.

LITERATURE CONSULTED.

In working upon the order Collembola, one is confronted
at the very outset by a paucity of American literature on the
subject. Excepting for Sir John Lubbock's Notes and Mono-
graph on the Thysanura, the latest of which has passed its first
twenty years and is therefore slightly out of date, there is com-
paratively little in the English language to guide the systematic
student. Dr. Folsom and Miss Claypole have taken up one or
two species embryologically ; and Say, Packard, Ryder, Mac-
Gillivray and Harvey have described not a few new American
species. In case of Say and Packard no figures accompany the
descriptions, or at best, very useless ones in a few cases. Pack-
ard's species seem not unlikely to stand good, though most of
them need re-description. Some of this has been already done
by MacGillivray.

To Tullberg, and more especially to Schott, must we look
for scientific treatises upon the order — works which present the
real microscopic characters of furcula and claws, so necessary in
determining the species. To the English-taught student the dif-
ficulty of pursuing ideas through the French, the German and
the Latin, the Italian, the Scandinavian tongues and the Bohemi-
an, often at second-hand by necessity, is not one to be considered
lightly. Yet, for all the lingual difficulties, I am very grate-
ful to Professor H. F. Nachtrieb, who has procured for me the
greater part of the standard literature upon the subject. With-
out this aid, much of my work would have been impossible

There was need of a survey of the order which should do
more than merely list species. Working keys of American spec-
ies, accompanied by figures of the important features, and by de-
scriptions in English, regardless of whether a species is newly
described or not ; in short, a practical help to American students
has been the aim in this work.

16 COLLEMBOLA OF MINNESOTA

Of the American Collembola known hitherto, a few were
reported by Fabricius (1780) in his Fauna Groenlandica, some
by Say (1841) from New York State, also from the same part
by Fitch (1846). Packard described mostly from Essex Coun-
ty, Mass., though some of his came from Maine, and others from
Tennessee and Texas. A. D. MacGillivray, in the Canadian
Entomologist, 1891-1896, gives not only several new species, but
some very helpful keys. His list of the American species of
Collembola, and his key to the American species of Isotoma are
especially valuable. His specimens were from Massachusetts,
New York, Washington, D. C., Washington State, Tennessee,
Florida and New Mexico. Harvey and Folsom have published
several descriptions, based mostly on Maine specimens, in the En-
tomological News and in Psyche. Besides these in the English lan-
guage, Schaffer has described two collembolans from Southern
Georgia, and Schott has a very good paper on California Coll-
embola. These, with a few Chilian species of Nicolet, and a
single Venezuelan species by MacGillivray, comprise nearly the
whole American list. Thus, the east, the west and the south
have been all studied in varying degrees, but from the upper
Mississippi basin, few if any species have ever been reported.
Probably Dr. Folsom's collection is the only one in the country
that contains many specimens from the states of the middle
west. Our Collembola fauna would naturally be expected to
contain species which have never been described, nor, indeed,
found elsewhere ; and such proves to be the case. While not
nearly all the known American species have been found in Min-
nesota, so far ; yet, on the other hand, many species described
from Europe and never hitherto reported from the Western Hem-
isphere, are found to occur here in Minnesota.

List of Publications Consulted.

ARRANGED ALPHABETICALLY BY AUTHORS.

Articles marked by a star are those that have been found especially
important and helpful. To some of these, especially to Schott, Schaffer
and MacGillivray, I am largely indebted for many of the keys as
well as other things.

Absolon, C. Karl.

1900. TSinige Bemerkungen xiber die mahrische Hohlenfauna. Zool.

Anz. Bd. XXIII, pp. 1-0, 57-60, 189-195.
1900. Vorlaufige Mittheilunsr liber einige neue Collembolen aus den

Hohlen des mahrischen Karstes. Zool. Anz. Bd. XXIII, pp. 265-269.

4 figures.

COLLEMBOLA OF MINNESOTA 17

1900. Vorlaufige Mittheilung- iiber die Aphoruriden aus den Hohlen
des mahrischeii Karstes. Zool. Anz. Bd. XXIII, pp. 406-414. 12
figures.

1900. Uber zwei neue Collembolen aus den Hohlen des osterreich-
ischen Occupationsgebietes. Zool. Anz. Bd. XXIII, pp. 427-431. 2
figures.

Borner, C.

1901. Vorlaufige Mittheilung iiber emigre neue Aphorurinen und zur
Systematik der Collembola. Zool. Anz. Bd. XXIV, pp. 1-15.

Brook, George

1883. *Notes on some little-known Collembola, and on the British
species of the Genus Tomocerus. Journ. Linn. Soc. Zoology. Vol
XVII, pp. 19-25, PI. I.

1SS3. *A Revision of the Genus Entomobrya Rend. Journ. Linn. Soc.
Zoology. Vol. XVII, pp. 270-288, Plates 10 and 11.

Claypole, Agnes Mary.

1898. The Embryology and Oogenesis of Anurida maritima (Guer.).
Journ. Morph. Vol. XIV, pp. 119-300, Plates XX-XXV, and 15 text-
figures.

Comstock, John Henry.

1888. An Introduction to Entomology. P. 63.
1895. A manual for the Study of Insects. Pp. 82-85.

Curtis, John,

1883. Farm Insects. Pp. 408-410.

Cuvier, Georges.

1846. Le Regne Animal. Les Insectes, I, pp. 63-69, PI. 13.

Dalla Torre, K. W.

1895. *Die Gattungen und Arten der Apterygogenea (Brauer.) Sechs-
undvierzigtes Programm d. K. K. Staats-Gymnasiums in Inns-
bruck, 1S94-1895. Pp. 1-23.

Duncan, Martin P.

Transformations (or Metamorphosis) of Insects. Being an adapta-
tion, for English readers, of M. Emile Blanchard's "Metamorphoses,
moeurs et instinctes des insectes;" and a compilation from the
works of Newport, Darwin and others.

Fitch, Asa.

1862. *Smynthurus hortensis n. sp., S. arvalis n. sp., S. novaebor-
acensis, S. elegans, S. signifer. Eighth Annual Report of the N.
Y. Agr. Society. Pp. 668-675, 2 figures.
Folsom, J. W.

1896. *Tvvo new Species of Papirius. Can. Ent. Vol. XXVIII, p. 119-
121.

1896. *New Species of Papirius. Psyche, Vol. VII, pp. 344-345.

1896. Notes on the Types of Papirius Texensis Pack, and Descrip-
tion of a New Smynthurius. Psyche, Vol. VII.pp. 384-385.

1896. Neelus murinus, Representing a New Thysanuran Family.
Psyche, Vol. VII, pp. 391, 392, PI. S.

1896. *New Smythuri, Including Myrmecophilous and Aquatic Spe-
cies. Psyche, Vol. VII, pp. 446-450, pi. 10.

1901. *The Distribution of Holarctic Collembola. Psyche, Vol. IX,
pp. 159-162.

1901. *Review of the Collembolan Genus Neelus and Description of
N. minutus n. sp. Psyche, Vol. IX, pp. 219-222, PI. 2.

i8 COLLEMBOLA OF MINNESOTA

Gervais. M. Paul.

1844. Histoire Naturelle des Insectes. Apteres par Walkenaer. Vol.

Ill, pp. ^77-456. Thysanoures.
Harvey, F. L.

1892. An American Species of Templetonia. Ent. News, Vol. Ill, pp.
57-59, 3 figures.

1892. *A New Smynthurus. Ent. News, Vol. Ill, pp. 169-170, 1 figure.

1893. *A new Papirius. Ent. News. Vol. IV, pp. 65-68, PI. IV.

1893. A New Achorutes. Ent. News, Vol. IV, pp. 182-184, 6 figures.

1894. *The American Species of the Thysanouran Genus Seira.
Psyche, Vol. VII, pp. 159-162, 2 figures.

1894. A New Species of Lepidocyrtus. Ent. News, Vol. V, pp. 324-326,
4 figures.

1895. Two New Species of Entomobrya. Psyche, Vol. VII, pp. 196-
199, 3 figures.

1896. A Thysanouran of the Genus Anoura. Psyche, Vol, VII, pp.
422, 423, 3 figures.

1898. A new Poduran of the Genus Gnathocephalus. Ent. News, Vol.

IX, pp. 216-217, 3 figures.
1900. New Maine Collembola. Ent. News, Vol. XI, pp. 549-553, PI.

XV.

Hyatt, Alpheus, and Arms, J. M.

1890. Insecta. Guides for Science Teaching. No. VIII.
Kolenati, Fr.

1858. Zwei neue oesterreichische Poduriden. Sitzber. d. mathem.-'
naturw. Classe d. kais. Akademie d. Wissenschaften. Bd. XXIX, Nr.
10, pp. 241-246, 1 pi.
Krausbauer, Th.

1898. Neue Collembolen aus der Umgebung von Weilburg a. Lahn.
Zool. Anz. Bd. XXI, pp. 495-499, 501-504.

Lie-Petterson, O. J.

1897. *Norges Collembola. Bergens Museums Aarbog for 1896. No.
VIII. Pp. 1-24, Plates I. II.

Linnaeus, Carolus.

1758. *Systema Natura. Ed. X. Pp. 608-609.

Lintner, J. A.

1885. Second Annual Report of the New York State Entomologist.
Pp. 202-210.

Lubbock, John.

1862. *Notes on the Thysanura. Par I. Smynthuridae. Trans. Linn.

Soc. Vol. XXIII, pp. 429-448, pi. 45, 46. Part II, Smynthuridse. Id.

Pp. 589-601, pi. 59.
1867. *Notes on the Thysanura. Part III. Trans. Linn. Soc. Vol.

XXVI, pp. 295-304, Plates 21, 22.

1869. *Notes on the Thysanura. Part IV. Trans. Linn. Soc. Vol.

XXVII, pp. 277-297, Plates 45, 46.

1873. *Monograph of the Collembola and Thysanura. The Ray So-
ciety for 1871. Pp. I-X, 1-276, Plates 1-78.

1874. On the Origin and Metamorphosis of Insects. Pp. 71 and 91-
95.

MacGillivray, Alex. D.

1891. *A Catalogue of the Thysanoura of North America. Can. Ent.
Vol. XXIII, pp. 267-276.

1893. *North American. Thysanura. Can. Ent. Vol. XXV, pp. 127-128,
173-174, 218-220, 313-318.

COLLEMBOLA OF MINNESOTA -.9

1894. *North American Thysanura. Can. Ent. Vol. XXVI, pp. 106-xlO.
1896. *The American Species of Isotoma. Can. Ent. Vol. XXVIII, pp.

47-58.
Marlatt, C. L.

1869. The American Springtail. American Naturalist. Vol. XXXI,
pp. 163, 164.

Meade, R. H.

1881. The Generic Term "Degeeria." Ent. Monthly Mag. Vol. XVIII,

p. 19.
Nicolet, H.

1841. *Recherches pour servir a 1'histoire des Podurelles. (Mem. de
la Soc. Helvetique. VI.) Pp. 1-88, plates 1-9.

Oudemans, J. Th.

1SS7. Bijdrag-e tot de Kennis der Thysanura en Collembola. Pp. 104,
Plates I-III.

1896. Systematische Beschrijving der in Nederland voorkomende
Thysanura. Tidschr. v. Entom. Nederl. Entom. Vereen. 38 D. 4 Afl.
Pp. 164-178, 6 figures.

Packard, A. S.

1873. *Synopsis of the Thysanura of Essex County, Mass., with De-
scriptions of a few Extralimital Forms. Fifth Annual Report Pea-
body Acad. Sci. 23-51.

1884. Thysanura. Standard Natural History. Vol. II, pp. 135-138.

1890. Entomology for Beginners. Pp. 54-58.

1898. A Text-book of Entomology. Pp. 72, 164, 486.

Poppe, C. A., & Schaffer, C.

1897. Die Collembola der Umgegend von Bremen. Abh. naturwiss.
Ver. Bremen. Bd. XIV. pp. 265-272.

Reuter, O. M.

1890. *Collembola in Caldariis viventia enumeravit novasque species
descripsit. Meddel. af Societas pro Fauna et Flora Fennica. XVII,
pp. 17-28, Tab. I.

1895. *Finlands Collembola och Thysanura. Acta Societatis pro
Fauna et Flora Fennica. XI, No. 4, pp. 1-35, Tab. I, II.

1898. Collembola pa sno. Meddel. af Societas pro Fauna et Flora
Fennica. XXIII, pp. 44-51, fig. 1.

Ridley, Henry N.

1880. A new species of Lipura. Ent. Monthly Mag. Vol. XVII, p. 1.

1880. A New Species of Machilis. Ent. Monthly Mag. Vol. XVII, pp.
2, 3.

1881. A New Species of Degeeria. Ent. Monthly Mag. Vol. XVII,
pp. 270-271.

1881. Notes on Thysanura Collected in the Canaries and Madeira.
Ent. Monthly Mag. Vol. XVIII, p. 14-.

Ryder, John A.

1879. 'Description of a New Species of Smynthurus. Proc. Acad.
Nat. Sci. Philadelphia for 1878. P. 335, 1 figure.

Say, Thomas.

1883. The Complete Writings of Thomas Say on the Entomology of
North America. Edited by John L. Le Conte, M.D. Vol. II, pp. 7-9.

Schaffer, Caesar.

1891. Die Collembola von Siid-Georgien nach Ausbeute der deutschen
Station von 1882-83. Jahrb. Hamburg. Wiss. Anstalten. IX, pp. 1-
'9, 8 figures.

1896. *Die Collembola der Umgebung von Hamburg und benach-

20 COLLEMBOLA OF MINNESOTA

barter Gebiete. Jahrb. Hamburg. Wiss. Anstalten. XIII, pp. 149-
216. Taf. I-IV. (Aus. "Mittheil. a. d. Naturalist. Museum. XIII.)
Schott, Harald.

1891. Nya Nordiska Collembola. Ent. Tidskr. Arg. 12, pp. 191-192,

2 figures.
1893. Zwei neue Collembola aus dem indischen Archipel. Ent. Tidskr.

Arg. 14, pp. 171-176, PI. 2.
1893. Beitrag-e zur Kenntniss der Insekten-Fauna von Kamerun. I.

Collembola. Bihang till K. Svenska Vet. Akad. Handlingar. Bd. 19,

Afd. IV, No. 2, pp. 1-28, Taf. I-VII.
1893. *Beitr;ige zur Kenntniss kalifornischer Collembola. Bihang till

K. Svenska Vet. -Akad. Handl. Bd. 17, Afd. IV, No. 8, pp. 1-25, Taf.

I-IV.
1893. *Zur Systematik und Verbreitung palsearctischer Collembola.

Kongl. Svenska Vet.-Akad. Handl. Bd. 25, No. II, pp. 1-100, Taf.

I-VII.
1896. Collembola pa sno och is. Ent. Tidskr. Arg. 17, pp. 113-128, PL

3.

Sharp, David.

1895. Insects. Part II. The Cambridge Natural History. Vol. V, pp.
182-197.

Sommer, A.

1885. Ueber Macrotoma plumbea. Beitrage zur Anatomie der Podur-
iden. Zeit. Wiss. Zool. Bd. XLJ, pp. 683-718, Tafeln 34, 35.

Stscherbakow, A.

1899. Vier neue Collembolen-Formen aus dem siidwestlichen Russ-
land. Zool. Anz. Bd. XXII, pp. 79-81, 8 figures.

Tullberg, Tycho.

1871. *Forteckning ofver Svenska Podurider. Ofversigt af Kongl.
Vet.-Akad. Forhandl. 1871, No. 1, pp. 143-155.

1872. *Sveriges Podurider. Kongl. Svenska Vet.-Akad. Handl. Bd. 10,
No. 10, pp. 1-70, Taf. I-XII.

1876. *Collembola Borealia. — Nordiska Collembola. Ofversigt af
Kongl. Vet.-Akad. Forhandl, 1876, No. 5, pp. 23-42, Taf. VIII-XI.

Uzel, Jindrich.

1890. *Thysanura Bohemia?. (Descriptions of new species in Latin,
the rest in Bohemian.) Sitzb. Kongl. Bohm. Gesellsch. d. Wiss.
Jafcrg. 1890, Bd. II, pp. 1-82, Tab. I, II.

Wahlgren, E.

1901. Ueber einige neue Collembola-Formen aus dem Siidwestlichen
Patagonien. Ent. Tidskr. Arg. 21, pp. 265-270, Taf. 2.

PART II
SYSTEMATIC

TERMS USED

Abd. I, Abd. II, &c. An abbreviated expression of "first abdominal
segment," "second abdominal segment/' &c.

Anal horns. (Analdornen). Small horns borne dorsally on the most
caudal abdominal segment.

Anal organs. The two modified hairs arising from a tubercle ventro-
cephalad of the anus, and usually curving caudo-dorsad.

Anal papilla or tubercle. The tubercle bearing the anal organs.

Ant. 1, Ant. II, &c. An abbreviated expression of "first segment of
the antenna," "second segment of the antenna," &c., the number-
ing of the segments beginning with the proximal (basal) segment.

Antennal organs. Sense organs borne usually, when present, on the
distal segment of the antennae.

Clavate (tenant) hairs. Hairs with swollen or clubbed ends, borne
most commonly on the tip of the tibia.

Claws. Inferior or inner claws — the smaller claw of the collembolan
foot, absent in some of the lower genera.

Superior claw or outer claw — the larger of the two claws borne by
the tarsus.

Dentes. The second or middle part of the furcula, consisting of two
separate parallel pieces which proceed from the distal end of the
manubrium, and bear at their own distal ends the two mucrones.

Furcula (saltatory appendage, spring). The organ borne by the fourth
or fifth abdominal segment and used for leaping. The furcula is
considered to be in normal position when lying along the ventral
side of the body and pointed cephalad, and its dorsal and ventral
sides are considered as taken in this position. As a matter of con-
venience, the drawings are often made with furcula extended, in
which the ventral side turns dorsad and vice versa.

Genital papilla. A papilla noticeable in the Sminthuridse upon which

opens the genital aperture.

Length is reckoned from the most cephalic part of the head when held
in natural position, to the caudal end of the abdomen, not to the
tip of the extended furcula.
Manubrium. The basal piece of the furcula, joined by its proximal end

to the abdomen and at its distal end to the two dentes.
Mucrones. The two small end pieces of the furcula proceeding 'from

the two dentes.

Post-antennal organs. Oblong or elliptical organs situated just caudad
to the bases of the antennae.

Tenaculum or catch. A small organ which holds the furcula in posi-
tion under the abdomen when at rest.

Th. I, Th. II, &c. An abbreviated expression of "first thoracic seg-
ment," "second thoracic segment," &c.

Ventral tube. A tube or tubercle proceeding from the ventral side of
the first (anterior) abdominal segment.

COLLEMBOLA OF MINNESOTA 25

KEYS FOR THE DETERMINATION OF ORDERS, FAMILIES,
GENERA AND SPECIES .

The figures immediately following the names of the orders,
families, genera and species refer to the pages on which the
descriptions are begun.

SUB-CLASS APTERYGOGENEA.

a — Antennae multi-articulate. Eyes compound or wanting.
No ventral tube or furcula. Abdomen consisting of about
ten segments and terminated by long setae or forcipate ap-
pendages. Palpi large, projecting. Order THYSANURA.

b — Antennae 4-6 jointed. Eyes of degenerate compound type,
with few (usually 16) ocelli, or sometimes with none. Ven-
tral tube invariably present, furcula typically so. Abdomen
consisting of six segments, and never terminated by caudal
setae or forcipate appendages. Palpi not evident.

Order COLLEMBOLA.
KEY TO THE ORDER COLLEMBOLA.

a — Body sub-globular, abdomen little longer than broad, the
segments fused together. Ventral tube and furcula well-
developed. Scales never present. Claws two. Antennae
4-jointed, no post-antennal organ.

Family Sminthuridae, 25.

b — Body sub-cylindrical, segments of abdomen free. Furcula
usually on penultimate segment. Scales present or absent.
Antennae 4-6- jointed. Claws two.

Family Entomobryidae, 29.

c — Body sub-cylindrical, segments of abdomen free, body
without scales (in any of our species). Furcula present,
on antepenult. Antennae 4-jointed. Claws 2 or i.

Family Poduridae, 37.

d — Body sub-cylindrical, segments of abdomen free. Furcula
wanting. Body naked or hairy, never with scales. Anten-
nae 4-jointed, often poorly developed. Claws 2 or i.

Family Aphoruridae, 40.
Family Sminthuridae.

This family seems to have pretty well defined limits, and its
species are not likely to be confused with those of other fam-

26 COLLEMBOLA OF MINNESOTA

ilies. The shape of the abdomen, and the fused condition of its
segments separate it from the family Entomobryidse to whicl. it
seems most closely related. The shortening- up of the body is
accompanied by a vertical position of the head, which gives way
in a few forms to an approximation to the primitive, horizontal
position. The ventral tube is always long and well-developed,
and has two long, exsertile filaments, glandular in appearance,
which can be thrust out or retracted at will. All are strong
jumpers and show a well-developed furcula and tenaculum. The
eyes show fewer cases of degeneration than in any other fam-
ily, the normal number of sixteen being almost always present.

The family is represented in Minnesota by two genera,
which differ in the form of the antennae. Neither of the genera
possesses the post-antennal organ.

a — Ant. IV short, with whorls of hairs. The distal part of
Ant. Ill ringed. Genus Papirius, 26.

b — Ant. IV long, usually ringed. Ant. Ill not ringed.

Genus Sminthurus, 27.

Genus Papirius Lubbock 1862.

This genus is represented by at least two species, both of
which are large and rather common. They are among the most
specialized of Collembola, inhabiting dark, shady places under
loose bark, under the caps of mushrooms, etc., where there is
a little moisture ; but I have never taken them on the surface of
water where so many other collembolans are found. In fact,
their furcula is not adapted for water leaping. There seems to
be little structural difference between our two species, but the
difference in color is so marked that one need have little dif-
ficulty in separating them.

KEY TO THE GENUS PAPIRIUS.

Color blue or purple marbled with pearly or lilac, sometimes
somewhat yellow. Ant. Ill with about five or six well de-
fined sub-segments, not including those fused into the large,
clubbed end. maculosus, 58.

Color uniform over the body, usually purplish brown. Ant.
Ill with six or seven well-defined sub-segments besides
those fused into the clubbed end. unicolor, 59.

COLLEMBOLA OF MINNESOTA 27

Genus Sminthurus Latreille 1804.

Of the eleven species of Sminthurus taken in the state,
three are new to science and others new to the continent.

In the genus are found several interesting modifications.
One species is an albino without ocelli and almost without pig-
ment, others are modified for a life on the water, and have their
furcula so specialized as to constitute the most efficient instru-
ment for leaping that nature could devise. The normal number
of ocelli is present in all our species excepting the above-men-
tioned albino ; though certain ocelli exhibit a tendency to dimin-
ish in size in some of the species. For greater convenience in
study, most authors have separated the Sminthuri into two
groups of species: I, Setosi, those covered with strong hairs
or setae; and II, Pilosi, those covered with fine, short hairs. The
latter group contains, as a rule, the smaller species, and the
former the larger ones. They are to be found in dark, slightly
moist situations, some of them even around and on the water.
Many of them occur under loose bark, among leaves and rubbish
in the woods, etc. They are remarkably spry, and challenge the.
liveliest movements on the part of their would-be captors.

KEY TO THE GENUS SMINTHURUS.

1. a — Ant. IV distinctly ringed. 2.

b. — Ant. IV not distinctly ringed. 7.

2. a. — Eyes present, body dark, or at least well pigmented. 3.
b. — Eyes wanting, body white with small reddish-brown

specks. Two outward-pointing spurs at distal end of
manubrium. Mucrones Y<\ as long as dentes.

caecus, 49.

3. a. — Furcula adapted for water leaping. Dentes with two

rows of laterally developed bristles. Mucrones spoon-
like. 4.

b. — Furcula not adapted for water leaping. Mucrones nar-
row, grooved. 5.

4. a. — Furcula fan-like, lateral bristles on dentes very long,

especially on the inner side, mucrones not. ribbed, broadest

at distal end. Back set with long bristles among the

shorter hairs. Length, 2 mm. spinatus, 57.

28 COLLEMBOLA OF MINNESOTA

b. — Furcula not fanlike, lateral rows of bristles on dentes

rather short, mucrones broadly elliptical, ribbed. Back

without long bristles. Smaller claw bearing a branched

hair at tip. Length i mm. penicillifer, 55.

5. a. — Large claw enclosed in a tunic, which gives it a plump

appearance. Ant. IV about as long as I, II and III to-
gether. Mucrones dentate. Length 2 mm.

fuscus, 53.
b. — Large claw not enclosed in a tunic. 6.

6. a. — Ant. IV little longer than III. Mucrones dentate.

Body beautifully marbled, sparsely covered dorsally with
long, much-curved bristles. Length i.5mm.

minnesotensis, 52.

b. — Ant. IV about as long as II and III together. Mucron-
al edges smooth. Body dark, without dorsal bristles but
with short, fine hairs. Length I mm.

pruinosus, 48.

7. a. — Back set with strong, truncate bristles. 8.

b. — Body short-haired, without bristles, often nearly naked.
9-

8. a. — Three or four clavate hairs present on the tibia, also

several very long ones on the dentes. Ant. II equalling
III in length, each of these segments bearing a few long,
straight bristles. Length 1.25111111.

longisetis, 51.

b. — No clavate hairs on tibia or dentes. Ant. II shorter than
III, long bristles not present. Length 1.25111111.

curvisetis, 50.

9. a. — Body black, sometimes with bluish or brownish tint,

bearing four white spots dorso-laterally, and with two
small white spots mediad to the eyespots. Length i mm.

quadrimaculatus, 45.
b. — Body without the four white spots. 10.

10. a. — Body yellow, sometimes darkening to orange or olive,

young specimens darker. Eye-spots and a frontal spot
between the bases of the antennae black. Length mini.

aureus, 43.
b. — Body dark. n.

COLLEMBOLA OF MINNESOTA 29

ii. a — Body inky black excepting lower part of anal segment.
Head black as far front as the eyespots. Fore part of
head, antennae, legs and lower part of anal segment bright
yellow, furcula pale. Length i mm.

minutus, 44.

b. — Black, with antennas nearly so. Legs and furcula brown.
A white spot mediad to each eyespot. Length i mm.

niger, 47.

Family Entomobryidae.

This large family is rich in genera as well as in species. It
differs from the preceding in the different form of the body,
the general form being elongate and the segment unfused. In
most of the genera the antennae are four-jointed, and the anten-
nal segments are seldom ringed. The ocelli show the tendency
to atrophy in most of the genera. The prothorax is short and
usually more or less hidden by the projecting dorsal part of the
mesothorax. The feet are two-clawed, and very frequently clav-
ate hairs are borne on the tips of the tibiae. The furcula is
found in various stages, but is usually strongly developed and
of very material assistance in keeping its owner out of harm's
way. The family contains both haired and scaled genera. It is
interesting to note that many instances of parallelism occur be-
tween species of genera which are only separated by this dif-
ference. Probably the family would be a more natural one if
we omitted the genus Tomocerus, but as a matter of convenience
it is regarded as belonging here.

KEY TO THE FAMILY ENTOMOBRYIDAE.

1. a. — Body naked or covered with hairs. 2.
b. — Body covered with scales. 4.

2. a. — Antennas composed of six segments. Ocelli 12.

Genus Orchesella, 30.

b. — Antennae composed of four segments. Ocelli usually
16. 3.

3. a. — Abd. Ill and IV about equal in length.

Genus Isotoma, 31.

b. — Abd. IV at least four times as long as III.

Genus Entomobrya, 33.

30 COLLEMBOLA OF MINNESOTA

4. a. — Antennae ringed on III and IV.

Genus Tomocerus, 35.
b. — No Antennal segments ringed. 5.

5. a.— Eyes absent. Genus Cyphodeirus, 35.
b. — Eyes present. 6.

6. a. — Pronotum projecting forward so as to partly hide the

head. Genus Lepidocyrtus, 36.

b. — Pronotum not produced forwards.

Genus Seira, 35.

Genus Orchesella Templeton 1835.

Orchesella is especially interesting as the only collembolan
genus with six-segmented antennae. In size all our species are
rather large for Collembola, and nearly all species of the genus
are quite strikingly colored. I have generally taken them singly
or in small numbers under stones, etc., but once found them
very abundant after a rain on the tops of stumps. They are active
in their movements. Each eyepatch has six ocelli, and I believe
there are no cases of degeneration from this number throughout
the genus. The body is without scales but well covered with
hairs, the larger of which are clubbed.

Three species have been taken in Minnesota, of which at
least two are new.

KEY TO THE GENUS ORCHESELLA.

1. a — Body yellow mottled with dark blue. 2.

b. — Body white or almost colorless, with no dark markings.
Ant. Ill with a dark ring at distal end, longer than the
width of Ant. II. Head with a black median spot front
of the eyes. albosa, 61.

2. a. — Antennae short, not so long as the distance from ceph-

alic end of head to Abd. IV. Ant. Ill colorless, short,
its length being not greater than the width of Ant. II.
Ant. II, IV and V with dark distal rings.

zebra, 61.

b. — Antennae reaching as far as middle of Abd. IV. Ant. II,
III and IV with black distal rings. Ant. Ill much longer
than II is wide. Sides of head with dark lateral stripes
which include the eyespots.. (n. sp. ?)

COLLEMBOLA OF MINNESOTA 31

There is but one specimen of the third species in the
collection and I do not feel safe in giving it a name. It
is certainly distinct from both of the others but may pos-
sibly be a variety of some known species.

Genus Isotoma Bourlet 1839.

This genus is represented in our fauna by at least n species
and it is likely that more may be found.1

The body is cylindrical, sometimes a little flattened dorso-
ventrally.

In color we may expect anything from pure white or black
or modest gray, to gorgeous greens and purples. The species
are all pretty active, especially those in which the legs and fur-
cula are long. The four-jointed antennae are rather short and
stout, often little longer than the head. In most species there are
sixteen ocelli present, but some cases of atrophy are found in
which the number on each side is reduced to seven, two, or
none. A postantennal organ, consisting of a more or less elon-
gate ring just caudad to the base of each antenna of found in
most species, and is often of importance in species determin-
ation. The feet bear two claws which are furnished with teeth
in many cases, and the tips of the tibia; are often provided with
one or several clavate hairs. The abdominal segments are sub-
equal in length. The furcula is usually fastened to the fifth,
though in a few of the lower species it seems to be shifting for-
ward so that it seems to proceed from the fourth segment as in
the Poduridse. It seems to me probable that in all of the Iso-
tomas at least, the furcula really belongs to the fifth segment.
Perhaps further embryological studies will determine this for
certain, both in this genus and also in the Poduridse. The ventral
tube is well developed, and quite prominent.

We are especially fortunate in having the American spec-
ies of this genus written up by our best authority upon the sub-
ject, Mr. Alex. D. MacGillivray. In vol. XXIII of The Can-
adian Entomologist may be found his key to the more than
thirty species then known to be found in the United States. He
says "No measurements are given, as they have been looked up-
on as worthless ; the formulae of the claws and mucro are all that
are necessary to recognize the species, young or adults."

32 COLLEMBOLA OF MINNESOTA

On neither of these points can I fully agree with him.
However he has certainly made available many of Dr. Packard's
species by redescribing them from the types, and has added not a
few new species.

KEY TO THE GENUS ISOTOMA.

1. a. — Furcula short, not reaching ventral tube. Claws un-

armed. Antennae little longer than head, post-antennal
organ long, narrowly elliptical. 2.

b. — Furcula reaching nearly or quite to the ventral tube.
Antennae considerably longer than the head. 5.

2. a. — Mucrones tridenticulate. Color light gray-blue. Ocelli

16. Length .75 mm. minima, 63.

b. — Mucrones bidenticulate. 3.

3. a. — Entirely white. Ocelli absent. Dentes about twice as

long as manubrium. Length 1.25 mm. fimetaria, 64.
b. — White or pigmented. Ocelli 4 or 16. Manubrium long-
er than dentes. 4.

4. a — White or light blue. Ocelli 4. Length i mm.

quadrioculata, 65.
b. — Gray-blue or brown. Ocelli 16. Length 1.5 mm.

bidenticula, 66.

5. a. — Dentes much longer than manubrium. Male and fe-

male alike. 6.

b. — Dentes little longer than manubrium. Clavate hairs on
tibia. Color dense black. Male with prominent horns on
Abd. IV, and with a covering of yellow sensory tuber-
cles, muskegis, 72.

6.a. — Ant. II curved. Tawny yellow or white. Claws un-
armed. Manubrium about half as long as dentes. Mu-
crones tridenticulate. Length 2,33 mm.

leonina, 67.
b. — Ant. II straight. 7.

7. a. — Body marked with blue, green or purple. No clavate
hairs on tibia. 8.

b. — Bluish or greenish gray. Tibiae with clavate hairs.
Length 2 mm. sensibilis, 67.

COLLEMBOLA OF MINNESOTA 33

8. a. — Mucrones tridenticulate, no small apical tooth present.

Neither entirely dark, nor with longitudinal markings.
Body covered with short hairs, interspersed with a few
longer ones. Post-antennal organ broadly elliptical.
Large claw witli one outer and one inner tooth. Length
2 to 5.5 mm. viridis, 68.

b. — Mucrones quadridenticulate. 9.

9. a. — Long pre-apical tooth, far over-reaching the apical,

which is very minute. Short hairs on body interspersed
with long. Large claw with one outer and two inner
teeth; small claw with one inner tooth. Length 3.8 mm.

catena, 69.

b. — Apical tooth of mucrones projecting at least as far as
pre-apical. 10.

10. a. — Dark blue, Abd. V and VI with a few long hairs.

Apical mucronal tooth outstanding, projecting far distal
to preapical tooth. Two proximal teeth set nearly opposite
to each other and at right angles to the mucrones.

caeruleatra, 70.

b. — Dorsal median dark stripe, hair entirely short. Apical

tooth projecting little beyond pre-apical, proximal teeth

set obliquely to mucrones. pointing distally. Length

2.75 mm. palustris, 70.

Genus Entomobrya Rondani 1861.

This genus, formerly known as Degeeria, stands next to
isotoma, from which it is separated by the much greater length
of Abd. IV. In Entomobrya this segment is at least as long as
the three preceding taken together. The antennae are shorter
than the body. Each eyespot contains eight ocelli in all our
species ; and indeed in all the species excepting those which be-
long to the genus Sinella. The latter genus was erected for the
reception of those Entomobryas having but two ocelli on each
side of the head. The weight of authority today seems in favor
of relegating these species back to the genus Entomobrya, as
the number of ocelli alone is not thought sufficient to constitute
a generic difference. There is no postantennal organ. The body
is well covered with fine short hairs, besides which, on the an-
terior part of the body there are longer, clubbed ones ; and on

34 COLLEMBOLA OF MINNESOTA

the posterior end of the abdomen, geniculate ones. The claws
are armed with teeth. Clavate hairs are borne on the tibiae. The
ventral tube is well-developed. The furcula is long, slender and
arcuate. The mucrones is small and bears always two strong
teeth : a hooked or much curved apical, and a straight, strong
tooth about the center of the mucrones, and at right angles to it.
Besides these there is usually, if not always, a very slender basal
tooth which points distally, its point almost reaching that of the
middle tooth. In fact this type of mucrones, with but slight
variations, is common to the scaled genera : Lepidocyrtus, Seira
and Cyphodeirus, to all of which this genus is closely allied. I
have taken five species of Entomobrya in the state, of which
two are new. Some, as E. cliteDaria, are perhaps local ; but
others as E. multifasciata are common under bark and rubbish
throughout the state. None of the species live upon or about
the water. In certain species, color variations and gradations
are frequent and puzzling ; and on this account many varieties
have been described as species. In 1883 George Brook revised
the genus, and, by careful synonymizing, reduced the number
of species then recognized to less than half. His work is not
universally accepted by more recent writers.

KEY TO THE GENUS ENTOMOBRYA.

1. a. — Abd. IV about seven times as long as III. A large

species, very long and slender. Length 3 mm.

bicolor, 73.

b. — Abd. IV not more than five tifnes as long as III. 2.

2. a. — Color yellow with the exception of a distinct, saddle-

like, dark marking covering Th. Ill and Abd. I, II and
III. Abd IV about five times as long as III. Length
2 mm. clitellaria, 75.

b. — Color other than yellow. 3.

3. a. — Color nearly uniform purplish thoughout. No seg-

mental crossbancls. purpurascens, 76.

b. — With segmental cross-markings. 4.

4. a. — Yellow, with four very strongly defined dark cross-

bands situated on Th. Ill, on the dorsal part of Abd. Ill
taking in the caudal edge of II, on Abd. IV, and on V

COLLEMBOLA OF MINNESOTA 35

and VI. Head yellow with small median black spot be-
fore the eyes. spectabilis, 77.
b. — Cross-bands less clearly marked. Some dark color on
Th. II and III. The band on Abd. IV usually broken.
Head commonly with anchor-shaped marking between
the eyes. multifasciata, 77.

Genus Tomocerus Xicolet 1841.

The genus Tomocerus seems so distinct from the other
members of the family Entomobryidas that some good author-
ities recognize a. family Tomoceridse. For convenience sake,
however, we let it remain where it is usually placed. The mere
fact that Tomocerus is scaled should not receive too much stress
in determining its relationships to other scaled genera, as its
scales are quite markedly different from those of Lepidocyrtus,
Seira, etc. The body is long and somewhat cylindrical in form,
and is heavily mailed with scales which have a leaden, semi-me-
tallic lustre. The long antennas have, like those of Papirius, a
short apical segment. The third and fourth segments are
whorled with short hairs and are very flexible. This genus re-
sembles Orchesella in having but twelve ocelli. The mucrones
is large and long and differs in form from all others excepting
a few closely allied genera, which are not represented in our
fauna. Another striking peculiarity is the presence of sharp
spines on the inner edges of the dentes.

KEY TO THE GENUS TOMOCERUS.

Spines on dentes about 7 or 8. Mucrones with the large, spur-
like tooth somewhat removed from the base.

arcticus, 79.

Spines on dentes about 12 or 16. Mucrones with the large,

spur-like tooth close to base on inner edge, and a smaller

one opposite it on outer edge. niger, 80.

Genus Cyphodeirus Xicolet 1841.

There is but one species of this genus known here, so far ;
and it is the type species upon which the genus was founded.
It is essentially merely a white, eyeless Entomobrya with scales.

albinus, 82.

Genus Seira Lubbock 1869.
This is another scaled genus of the Entomobrya group and

36 COLLEMBOLA OF MINNESOTA

probably from Seira the preceding genus became specialized by
a cave habit which caused it to lose its eyes and color.

Both of our species were originally described from England
by Sir John Lubbock, and are likely to be found in greenhouses
and dwelling houses. The Seiras seem to flourish in dryer
places than are chosen by other Collembolans. Our species are
readily distinguished by their difference in color.

KEY TO THE GENUS SEIRA.

General color dark purple. Head yellow except the eyespots
and their connecting dark band. buskii, 83.

General color dark yellow, with a few dark blue markings.
Very narrow cross-bands on the caudal edges of Abd. Ill,
IV and V, all of Abd. VI, and the cephalic and lateral edges
of Th. II, dark. Noticeable dark spots on the sides of Abd.
IV near its caudal edge. nigromaculata, 84.

Genus Lepidocyrtus Bourlet 1839.

This is also an entomobryoid genus bearing scales and hav-
ing the pronotum more or less produced forwards so as to con-
ceal the head wholly or in part. The scales have a brilliant me-
tallic lustre, being brightly iridescent in some species. We
may recognise two types of species in the genus: first, those
with a strongly produced pronotum, to which belongs our L.
albicans ; and, second, those smaller forms in which the pronotum
is more massive and projects less. To this latter division our
other five species may be referred. These latter are heavier
bodied throughout, and have less rangy limbs and shorter an-
tennae in proportion to the length of the body. The fourth ab-
dominal segment is from three to four times as long as the
third. Ocelli (in our species) 16, 10 or 6. Antennae never more
than half as long as the body.

KEY TO THE GENUS LEPIDOCYRTUS.

1. a. — Pronotum strongly produced forwards so as to con-

ceal much of the head. Color yellowish white, with some
blue on antennae. Length 1.5 mm. albicans, 85.

b. — Pronotum massive (see figures). Smaller, heavier bod-
ied species. 2.

2. a. — Color silvery white. 3.

COLLEMBOLA OF MINNESOTA 37

b. — Color blue of purple. 4.

3. a. — With two rounded eyespots, 10 ocelli, antennae blue.

decemoculatus, 85.

b. — With four eyespots, the anterior ones each containing
two ocelli ; the posterior ones, one each. Antennae white.

sexoculatus, 86.

4. a. — Color dark purple ; with legs, top of head, and bases of

antennae brownish yellow. purpureus, 87.

b. — Color blue and white. Antennas entirely blue. 5.

5. a. — Rather blackish blue with five white segmental cross

bands. Head entirely blue, antennas dark blue, concolor-
ous throughout. Tibiae blue. aenescens, 89.

b. — Rather a clear blue, without noticeable white cross-
bands. Head rather light on top. Antennas light blue at
base, gradually becoming darker distally. Tibiae clear.

pusillus, 88.

Family Poduridae.

The family Poduridae is a large one and seems to occupy a
position somewhat lower than the Entomobryidae. Its genera
show rather less specialization, or perhaps, as seems to me, they
show the specialization of reduction. Among them we fail to
find any of the long, slender antennae modified for tactile uses.
To be sure, many have curious sense bulbs at the ends of the
antennae, but such modifications as ringed antennae are altogether
unknown. In most cases the typical four-jointed antenna i^
found in its simplest form. The claws show reduction. In some
genera the inferior claw is absent, while in others it is reduced
in some species to little more than a bristle. In others, again,
the claws are both well developed. The forms are mostly low
and more or less flattened, which necessitates a short ventral
tube in most cases. The furcula is generally short, sometimes
so short as to make it difficult to determine whether a species
is a Podurid or an Aphorurid. On the other hand, the gulf be-
tween some of the lower Isotomas and the Poduridae is not so
great as some of the older collembolists supposed, basing their
conclusions upon the forms then known. "Furcula on the
antepenultimate (fourth) abdominal segment," used always to
mean a Podurid, but now a few Isotomas are known of which

38 COLLEMBOLA OF MINNESOTA

the same may be said. Most of the Podurids love the dark
and are to be found beneath bark, moss, stones, etc., where there
is moisture, and some of them live about or upon the water. The
social instinct is often very apparent, and sometimes a colony
of Podura or Achorutes may be found to fairly blacken the snow
or water by thousands. We have four genera in the family, three
of which are represented in the state by one species each.

KEY TO THE FAMILY PODURIDAE.

1. a. — Feet two-clawed. Two anal horns. Post-antennal or-

gan present. Ocelli 16. Genus Achorutes, 38.

b. — Feet with a single claw. No post-aritennal organ. 2.

2. a.- — Anal horns present. Furcula short, not reaching to

ventral tube. 3.

b. — Anal horns absent. Furcula reaching as far as ventral
tube, dentes much bowed. Body shortened. Ocelli 16.

Genus Podura, 39.

3. a. — Three anal horns. Furcula extremely short and thick.

Body robust. Ocelli 16. Genus Friesia, 40.

b. — Two anal horns. Furcula short but very slender. Body
slender, Ocelli 10. Genus Xenylla, 40.

Genus Achorutes Templeton, Schaffer 1834.

These insects are of a slightly flattened cylindrical form,
with strong legs and a heavy body. The four-jointed antenna?
are stout, and about as long as the head. Sometimes the third
and fourth antennal segments appear fused when seen from cer-
tain positions. Each eye-spot contains eight ocelli, and there is
present a post-antennal organ composed of about four or five
tubercles arranged in a ring. The prothorax can be seen dor-
sally, although quite short. In our species each tibia bears a
single clavate hair at its tip. The body is sparsely haired. Ven-
tral tube very short, the two halves of its end apposing when
closed. No extensible filaments. Abd. IV bears the short,
stout furcula, which consists of a very heavy manubrium, thick
dentes, usually tapering but little. On the ventral side of the
dentes are one or several long, straight hairs ; which are not,
however, clavate, as in some Sminthtiridae. The mucrones is
of various forms, more or less toothed at apex, and sometimes

COLLEMBOLA OF MINNESOTA 39

equals half the length of the dentes. At or near the apex of
Abd. VI are borne the two anal horns. Sometimes these arc-
long, sharp, curved and quite prominent; sometimes scarcely
visible; and in certain species (the Achorutes of MacGillivray)
entirely lacking. Our five species all have them. These chit-
inous horns proceed from the papilse more or less raised above
the dorsal surface. The Achorutes are among the snow insects,
several species having been found on the surface of snow-pools,
in early Spring. They are often found in wet places, in decaying
wood, under bark and stones, and on fungi, on which some of
them feed.

KEY TO GENUS ACHORUTES.

1. a. — Superior claw with a tooth. Tenant hair strong. Mu-

crones less than half as long as dentes (except A. schotti).
Anal horns short. 2.

b — Superior claw not toothed. Tenant hair feebly devel-
oped, not very distinctly clavate. Mucrones about half
as long as dentes. Anal horns long, curved and sharp. 4.

2. a. Dentes with several sharp pointed spikes borne ventrally

near its distal end. Dark blue, pruinose. Mucrones two-
toothed. Anal horns hardly visible. Inferior claw taper-
ing suddenly in its distal third. socialis, 92.
b. Dentes without spikes. 3.

3. a. — Inferior claw very slender, almost bristle-like. Mu-

crones more than half as long as the dentes.

schotti, 93.

b. — Inferior claw becoming bristle-like beyond the middle
Mucrones one-third to one-fourth as long as the dentes,
which tapers considerably. schneideri, 91.

4. a. — Uniform dark blue in color. longispinus, 90.

b. — Light ground color, whitish beneath, covered dorsally

with gray specks. boletivorous, 89.

Genus Podura Linne 1758.

The genus Podura seems to be merely a form adapted for
life on the surface of the water. The bow-legged appearance of
the furcula reminds one strongly of the water Sminthuri : S. spi-
natus and S. penicillifer. And here too the mucrones is flattened
in such a manner as to be most efficient in leaping by striking the

40 COLLEMBOLA OF MINNESOTA

surface of the water flatwise. The body is considerably shortened
for a Podurid. There are no anal horns present, and no post-
antennal organs. The legs are strong and longer than in
Achorutes, and bear no clavate hairs, though there is a long
hair in the position of a tenant hair. There is no inferior claw
present, but the single claw is long, strong and unarmed.

Our single species is that upon which the genus was found-
ed, and is perhaps the most cosmopolitan of all the Collembola

aquatica, 93.
Genus Xenylla Tullberg 1869.

I believe this is the first record of this genus in the United
States. The genus is not a large one. Its position would
seem to be inferior to Achorutes, from w7hich it has perhaps de-
generated. Xenylla is characterized by its slender body, the
abdomen being somewhat fusiform, as in Achorutes, but less
stout ; the absence of the inferior claw as well as of the postan-
tennal organ ; by its having the ocelli reduced to ten, five in each
eyespot ; the presence of anal horns and by the small, weak
furcula. The single species found in Minnesota appears to be
quite new and its slender form suggests the name"gracilis."

gracilis, 95.

Genus Friesia Dalla Torre 1895.

This genus is represented in Sweden and England by the
type species. F. mirabilis Tullberg, which was the only species
known hitherto. Whether ours is a true Minnesota species or
only a sojourner here, I cannot say, for it has only been found
in the greenhouse.

The characters of the genus are the absence of the inferior
claw and of a post-antennal organ, and the unique presence of
three anal horns. The body is stout and the furcula extremely
short and thick. caldaria, 95.

Family Aphoruridae.

These insects are at the very foot of the ladder of Collem-
bolans. Rather slow-moving, sluggish, dark-loving creatures
they are, living in the soil, in moist, decaying wood, etc. A few
species live on the surface of the water, both salt and fresh.
The Aphoruridae are in some ways less degenerate than some
of the lowest Poduridse.

COLLEMBOLA OF MINNESOTA 41

The most characteristic point to be noted is the absence of a
furcula. The head is held nearly horizontal. Th. I is apparent
from the dorsal side. In some of the genera the feet bear one
claw, in others, two. The cuticle is usually quite plainly gran-
ular. In most cases a post-antennal organ is present, consisting
of a ring of raised tubercles situated in a slight hollow. We have
five genera in this family.

KEY TO THE FAMILY APHORURIDAE.

1. a. — Dorsal side of the body with large, warty protuberances.

Abdomen ending in four rounded tubercles. Post-an-
tennal organs present or absent. Genus Neanura, 42.
b. — Dorsal part of body without such protuberances. 2.

2. a. — Pseudocelli present. Post-antennal organ nearly pres-

ent, generally elongate. Anal horns o or 2. Feet with two
claws. Genus Aphorura, 41.

b. — Pseudocelli absent. Feet with but one claw. 3.

3. a. — Post-antennal organ absent. Anal horns wanting.

Genus Anurophorus, 42,
b. — Post-antennal organ present. Anal horns wanting. 4.

4. a. — Ocelli absent. Mouthparts produced cone-like beneath

the head, mouth opening in a narrow transverse slit.

Genus Aphoromma, 42.
b. Ocelli present. Mouth-parts not produced conelike.

Genus Anurida, 42.

Genus Aphorura MacGillivray 1893.

The Aphoriiras are small, white, slender insects, somewhat
flattened, and are often very abundant in rotten wood, in loose
soil, or under stones. They are characterized by the absence of
eyes, and the presence of the inferior claw which the other
Aphoruridre lack. Our two species, though appearing the same
to the naked eye, are easily distinguished.

KEY TO THE GENUS APHORURA.

a. — \Yithout anal horns. Each post-antennal organ com-
posed of 14 to 1 6 tubercles. Length i mm.

inermis, 96.

42 COLLEMBOLA OF MINNESOTA

b. — With two long anal horns. Each post-antennal organ
composed of 12 to 14 tubercles. Length 2 mm.

ambulans, 97.

Genus Anurophorus Nicolet 1841.

Anurophorus has neither post-antennal organ nor anal
horns. The body is slender and appears more like one of the Isc-
tomas in that the granular appearance common to most of the
Poduridse and Aphoruridce is hardly apparent. Probably our
species is the type species upon which the genus was founded.

laricis, 98.
Genus Anurida Laboulbene 1864.

This genus differs from the preceding in the possession of
a post-antennal organ. There are no anal horns. The body is
longer and comparatively more bulky than in Anurophorus. Our
species is an inhabitant of fresh water surfaces, unlike A. mar-
itima which occurs on the surface of some of the ocean tidepools
and is said to be found only on and near salt water.

tullbergi, 99.
Genus Neanura MacGillivray • 1893.

The Neanuras are sluggish, uncouth looking insects, with a
velvety appearance due to the granular surface.

They may be readily recognised by their short, tapering an-
tennae, and broad, flat bodies. They occur in moist, rotten wood,
wandering around in old worm holes, or under bark or moss.
Some species grow to a large size, four millimetres. Our com-
monest species is one which is found almost all over the world.
KEY TO THE GENUS NEANURA.

Dark colored, heavy, with very prominent abdominal tu-
bercles. A rather large species. Ocelli 6.

muscorum, 100.

Yellowish white, with body less noticeably tubercled.
A small species. Two black, separated ocelli on each side
of the head. quadrioculata, 101.

Genus Aphoromma MacGillivray 1893.

I am in doubt as to whether this should be recognized as

a distinct genus, as the principal character which separates it

from Anurida is the absence of ocelli. This character alone

would be hardly of generic importance ; yet the peculiar conical

COLLEMBOLA OF MINNESOTA 43

extension of the mouthparts allies it rather to Neanura from
which it differs in the transverse slit-like opening of the mouth.
We have the single species of the genus. granaria, 102.

Sminthurus aureus Lubb.
PI. V, Figs. 5-9.

1862. Smynthurus aureus. Lubbock, Notes on the Thysanura. In Trans.
Linn. Soc. Part II, p. 589. PI. 59, f. 1-3.

1872. Sminthurus aureus. Tullberg, Sver. Podur. p. 32.

1873. Smynthurus aureus. Lubbock, Monogr. Coll. and Thys. p. 112. PI.

VII and LXIII, 9-

1890. Smynthurus aureus. Uzel, Thys. Bohem. p. 31.
1893. Sminthurus aureus. Schott, Paleearct. Collemb. p. 31.
1896. Sminthurus aureus. Schaffer, Collemb. v. Hamburg, p. 208.
1896. Sminthurus aureus. Lie-Pettersen, Norges Collemb. p. 10.

Lubbock's description is as follows : "Yellow with black
eyes. Antennae four-jointed; basal segment shortest, terminal
segment longer than the other three. Under side of body pale,
saltatory appendage white. Body with a few scattered hairs,
which are longer and more numerous toward the posterior ex-
tremity. The four segments of the antennae increase in length
progressively from the base to the apex, each being about twice
as long as the preceding. The long apical segment has whorls
of short hairs, but no distinct evidence of segmentation. The
eyes are situated as usual on a black ground, and near the cen-
tral line, a little in front of the antennae, is a black double spot
which looks like the seat of two ocelli. The two claws are simple.
The feet are also provided with four or five tenant hairs.

"Length, 1/30 of an inch. Common from February to June
under dead pieces of wood in Kent."

My specimens were taken in December, March and April,
under leaves and boards, in places which were slightly moist and
somewhat light. In all important respects they agree with Lub-
bock's description. In color, however, they exhibit a variation
noted neither by Lubbock nor Tullberg. Many of the young
specimens up to a half a millimetre in length, show an olive tint-
ing on the back which often extends even to the antennae, and but
few of those measuring three-fourths of a millimeter had entirely
lost the olive on the back. My largest specimens measure i mm.

44 COLLEMBOLA OF MINNESOTA

The mucrones has its lower edges very finely serrate. In Lub-
bock's figures there are but six occelli depicted on each eye spot,
and no one seems to have noted the great reduction of the second
ocellus from the front on the inner row. It has shifted in posi-
tion until it has come to lie close to the front margin of the ocel-
lus lying next behind it, and has become triangular in shape.
The central ocellus is small as is commonly the case in this
genus, and particularly so in the closely allied species: niger, 4-
maculatus and minutus. The eyespot itself is broader than in
any of the three species named. The sub-anal papilla is slender
as in 4-maculatus, but squarer on the end.

I have noticed that when this insect takes a full leap it nearly
always lights on its back.

Sminthurus minutus MacG.

Plate V, Figs. 113-15.
1862. Smynthurus minutus. MacGillivray, Canad. Ent. XXVI, p. 109.

It is always unfortunate that a species should be described
without accompanying figures, as was the case in this following
description by MacGillivray, yet with a description so carefully
written of a species so characteristic in coloration little confusion
is liable to result. "Black and yellow; head yellow, except be-
hind and the eyespots which are black, black extending around
on the side of the face below the epespots, eyespot narrowly en-
circled with yellow ; on each side below the eye spot, three clear
spots arranged in a transverse line ; a black, ocellus-like spot
on the vertex between the antennae ; antennae reaching beyond
the apex of the thorax ; basal segment black, globular, one-half
the length of the second ; second segment sub-equal to the
third, petiolate at base, naked; third segment about one-half
the length of the fourth, enlarged at middle, yellow, with
a few scattered hairs ; fourth segment yellow, blunt at tip, mod-
erately hairy, not ringed ; thorax black, except a small part of
the sternum, which is yellow; legs short, stout, yellow; claws
short, outer claw about as long as the tibia is broad, sinuate be-
neath, with a single tooth above ; three tenant hairs present ;
abdomen black except a yellow spot on the under side of the
anal tubercle, naked, except a few bristles on anal tubercle ;
furcula slender, slightly hairy beneath ; manubrium reaching the

COLLEMBOLA OF MINNESOTA 45

middle of the anal tubercle ; dentes sub-equal in length to the
manubrium ; mucrones one-third the length of dentes, simple,
pointed, with a slight hook at apex, with a high power appear-
ing very finely serrate. Length, I mm. Habitat: Ithaca, N. Y.
Under pieces of wood in a plant jar in the University Insectary."

My specimens agree pretty closely with the foregoing in
most particulars, though I have failed to find any denticle on the
larger claw, and Ant. I is invariably yellow. The mucrones is
the same as in aureus, but the claws differ slightly from that
species. The claws of the second and third pairs are alike, but
the inferior claw of the first pair becomes narrower and has no
distinct inner denticle. The antennae are like those of niger,
fig. 18, having Ant. Ill plumper than in aureus.

Taken only in the University greenhouse, where the spe-
cies is common in empty, inverted flower pots, under loosely
lying boards, etc.

Though so minute, the species is readily identified even with
the unaided eye, from the strongly contrasting bright yellow
and inky black, which are seen rather less plainly in the young,
as their black is less intense. The yellow spot on the anal
tubercle is so large as to be seen at the sides of the tubercle from
a dorsal view. The positions of the ocelli are shown in fig. 12.

The sub-anal papillae are rather stout, and bear a flattened
bristle of the same form as in 4-maculatus, figs, na and lib.

Sminthurus quadrimaculatus Ryder.

PI. V, Figs. loa, lob.
1878. Smynthurus quadrimaculata. Ryder, Proc. Acad. Nat. Sci. Phila. p.

335 and figure.
1892. Smynthurus 6-maculata. Harvey, Ent. News. III. pp. 169-170. fig.

Ryder describes the species as follows: "Dark brown, nearly
black on the sides ; median dorsal and ventral surfaces lighter ;
spring and middle of legs still more pale. Its distinguishing
character consists in the two pure white spots, low down on
each side of the abdomen, the posterior ones larger than the an-
terior by one-third to one-half, are arranged, when the back of
the animal is viewed from above, in an equilateral quadrangle.
The surrounding dark color immediately bordering the white
spots is intense, but becomes paler more remote from them in

46 COLLEMBOLA OF MINNESOTA

all directions, and especially in the middle of the back. An-
tennae four-jointed, sminthuriform, resembling those of S. Bour-
letii Gerv." Harvey, in describing the species which he names
"6-maculata," speaks of it as deep blue-black, with four conspic-
uous enamel-white spots on the body and two smaller ones be-
tween the eyes. The posterior pair of spots on the body some-
what reniform in outline, with the sinuses on the dorsal side.
Antennae and legs paler, shaded with purple. Antennas slender,
nearly two-thirds the length of the body and head, the terminal
segment composed of about nine subjoints." Harvey also re-
marks : "The species is apparently related to S. quadrimaculata
Ryder, but differs in the larger size, broader body, purplish
color and white spots between the eyes."

There is little doubt that the two species are identical. As
to color, it is rather difficult on some specimens to be certain of
the presence of the pearly spots beside the eyes, yet I am con-
vinced that they are always present. Indeed, Ryder's figure
shows that he saw white, or at least clear spots in exactly the
right position, though he makes no mention of the fact. These
particular markings are homologous with those on S. niger,
and caused Tullberg to name that species S. bimaculatus, which
has since been reduced to a synonym of S. niger. The same
spots are likewise present in the allied species : S. minutus and
S. aureus, though on these two species, that part of the head
being yellow, their pearly color is not very evident. Some of my
specimens have the general body color brownish black, which be-
comes a light yellowish brown on the legs, while on others the
purplish black prevails, in which case the legs are often light
purple also. Quite likely Ryder had immature specimens before
him, as his description shows them to be both smaller and lighter
colored on the back than Harvey's.

As to the antennae: Ryder's figure shows no indication of
subjoints on Ant. IV, yet he speaks of them "resembling those
of S. Bourletii/' having, probably, Lubbock's figure before him,
in which the antennae are shown almost exactly as in Harvey's
figure of S. 6-maculata. My largest specimens measure almost
i mm. The furcula and legs are proportionately longer than in
S. aureus or S. minutus. The mucrones also is more coarsely
serrate, being like that of S. niger, fig. 17. The claws are like

COLLEMBOLA OF MINNESOTA 47

those figured for S. minutus, having the same difference be-
tween those of the first pair and the others. The sub-anal pa-
pilla? are slender when seen from the sides, and the accompany-
ing bristles, the "appendices anales" ofTullberg, have the appear-
ance of simple, curved bristles when seen laterally, that is, look-
ing at their edge. When the end is slightly turned, however,
as is usually the case, it appears somewhat ragged or serrate,
fig. lob. When viewed on the flat it is seen to be much flattened,
rather palmate in form, with the median edge deeply cleft or slit
up, fig. loa. The papillae are grooved along their front sides, the
bristles proceeding from the groove as shown in fig. lib, which
is a cross-section of the papilla at the base of the bristle in S.
minutus. The eyes are like those of S. minutus, as seen in fig
12. S. quadrimaculatus is a summer species, usually found under
loose bark. On account of its size and color it is not an easy
species to sec ; but when once located, the four white spots render
it easy to identify, even with the naked eye.

Sminthurus niger Lubb.
PI. V, Figs. 16-18.

1867. Smynthurus niger. Lubbock, Notes on the Thys. Part III, p. 297.

Plate XXI, figs. 11-12.

1871. Sminthurus bimaculatus. Tullberg, Sver. Podur. p. 145.
18/3. Smynthurus niger. Lubbock, Monogr. Coll. and Thys. Part III.

PL VI, and LXIII, fig. 3.

1890. Smynthurus niger. Uzel, Thys. Bohem. p. 35.

1891. Sminthurus niger. Schott, Kaliforn. Collemb. p. 12. PI. II, I.
1893. Sminthurus niger. Schott, Palaearct. Collemb. p. 32. PI. II, 12.

1895. Sminthurus niger. Renter, Finlands Collemb. och. Thys. p. 13.

1896. Sminthurus niger. Lie-Pettersen, Norges Collemb. p. 12. PL II, i,

Lubbock describes this species as "Bluish black; feet, ter-
minal segment of spring, and a spot on the front inner corner
of each eye patch pale. Hairs short, white, more or less in lon-
gitudinal rows. Length, 1/23 of an inch. Under boards in my
kitchen-garden. Not common, solitary. August to December.
This ugly little species does not resemble any yet described. It
differs from S. ater DeGeer in the form of the spring etc., and
from S. fuliginosis Nicolet in the absence of white patches on
the body and in having the head and antennas black. The ter-
minal portion of the antennae is not distinctly ringed, the posi-

48 COLLEMBOLA OF MINNESOTA

tion of the subsegments being, however, indicated by the whorls
of hairs. The large claw is simple, the smaller one is narrower
in the anterior legs than in the posterior ones. The terminal
lamellae of the saltatory appendage are narrow and pointed. Both
appear to have on the same side a row of fine teeth ; in fact
there are two rows on the under surface, which, being almost
always thrown either to one side or the other, give the appear-
ance of a symmetry."

Evidently the species does not vary much, for the above de-
scription exactly fits my specimens. The sub-anal papillae bearing
the anal appendages, are hardly stouter than those of S. quadri-
Tiaculatus, fig. 10, but are rather squarer on the ends. The ap-
pendages are apparently of the same form as in that species.
The antennae, fig. 18, are slightly stouter than in S. aureus, es-
pecially the third segment. The mucrones is of the same type,
but not so minutely serrate as in either S. minutus or S. aureus.
The claws differ little from those of the former species. My
specimens reach i mm. in length.

Some were taken under bark of a dead log, others from the
under side of chips in rather a damp place, where a stagnant
pond was drying up. Besides these from the southern part of the
state, it was found to be quite common under loose bark in the
region around Lake Vcrmillion, being frequently taken in com-
nany with S. quadrimaculatus.

Sminthurus pruinosus Tullb.
PI. Ill, Figs. 14, 15.

1871. Sminthurus pruinosus. Tullberg, Fort, ofver Sv. Podur. p. 145.

1872. Sminthurus pruinosus. Tullberg, Sver. Podur. p. 34. PI. Ill, 15-16.
1890. Smynthurus f rontalis. Uzel, Thys. Bohem. p. 37. PI. I, 3 ; II, 3-5.
1893. Sminthurus pruinosus. Schott, Palnsarct. Collemb. p. 28. PI. II,

13-16.

I have a single specimen which I think belongs to this spe-
nes. Gathering from the various descriptions given, it seems
that it is a dark species; mine is very dark, greenish black above,
and lighter, somewhat violet below, as well as on the antennae,
except at their proximal ends, and on the entire furcula. The
legs are very light violet. On the back are a few lines and dots
of a light yellow color. The top of the head between the eyes

COLLEMBOLA OF MINNESOTA 49

»

is bright yellow. The antennae have the first joint short, the
others increasing in length distally ; Ant. IV is about as long as
the sum of II and III ; its proximal one-third is not apparently
annulated, the other two-thirds quite distinctly so; showing, in
my specimen, six pretty well-marked subdivisions, besides some
others not so plain. The tibiae have two or three clavate hairs
each. The claws appear to me unarmed, though Schott has fig-
ured a small inner tooth on the superior tooth of the third pair.
The furcula is rather stout; when extended, the manubrium
hardly reaches beyond the caudad end of the final abdominal
segment. The dentes is a little longer than the manubrium
and nearly three times the length of the mucrones. The dentes
bears ventrally a row of short hairs, and two longer ones sit-
uated near its two ends. The mucrones is of the narrow type,
but not acuminate. Its edges are quite smooth. The species
is rather heavy-bodied. It bears no long or strong spines on the
back, but is covered quite thickly with fine, short hairs, giving it
a pruinose appearance. The specimen was taken under a stone
in rather a damp situation in a rocky coulee which runs down the
side of the bluff to the Mississippi River below Red Wing, Minn.
I believe the species has not hitherto been reported from this con-
tinent, though known in Sweden, Germany and Bohemia.

Sminthurus caecus Tullb.
PI. IV, Fig. 13; V, Figs. 1-4.

1871. Sminthurus cascus. Tullberg, Fort, ofver Sv. Podur. p. 146.

1872. Sminthurus caecns. Tullberg. Sver. Podur. p. 33. PL III, 24-25.
1890. Sminthurus ccecus. Renter, Coll. in Gaidar, viv. p. 19.

1890. Smynthurus cascus. Uzel, Thys. Bohem. p. 36.

1893. Sminthurus csecus. Schott, Palaearct. Collemb. p. 38.

1895. Sminthurus. ccecus. Renter. Finl. Coll. och. Thys. p. 13.

1896. Smynthurus benitus. Folsom, Psyche. VII, 446.

1896. Sminthurus coecus. Schaffer, Coll. von Hamburg, p. 208.
1896. Sminthurus coecus. Schaffer, Coll. von Hamburg, p. 208.

Tullberg's brief description serves well to identify this al-
bino among the Sminthurids. His description reads : "White,
dotted all over with rufous. Ocelli none. No clavate hairs on
the tibia. Mucrones equalling three-fourths the length of the
dentes. Length 2/3 mm."

It seems to have been found chiefly under flower pots,

50 COLLEMBOLA OF MINNESOTA

though I have taken it out of doors as well; where it occurs
throughout the summer months under damp boards and drift-
wood, in low, moist woods. It is an active species when touched,
but much more easily caught than eyed species. Ant. IV is
slender and well haired, especially toward the end. It is distinctly
ringed. The legs are unusually long and slender. The claws
are long and slender, especially so on the first pair of feet, fig. 4.
A peculiarity of the furcula is to be found in the presence of
two stout spines, probably originating from hairs, which are
borne by the distal ends of the dentes at their outer sides, fig.
2 ; smaller ones are found farther up on the dentes, on the inside.
The sub-anal papillae, fig. i, are not slender, but short and bunch-
like; and the bristle is nearly straight, appearing narrower than
in most species, and less branched, if at all. The reddish-brown
spots which appear under a low magnifying power, are seen upon
greater magnification to be clusters of many exceedingly minute
pigment dots. Older specimens show more pigmental color than
do younger ones. The clearness of the body makes it an espec-
ially favorable species for the study of the muscles in situ.

Although occasional individuals have been found, yet the
species was taken in abundance on one occasion only. On March
27, 1901, I found them in abundance on a small island in the
Mississippi River below Red Wing, Minn.

Sminthurus curvisetis n. sp.
PI. Ill, Figs. 1-7.

Dull black above ; around the eyes, under side of anal seg-
ment and two low lateral spots just in front of the base of the
manubrium, yellow. Antennae, legs and furcula dark blue. The
back is sparsely set with strong, truncate, backward-curving
spines. Antennae slender, with segments increasing progres-
sively in length and decreasing in breadth custally ; of a
purplish blue throughout. Legs rather stout, claws stout,
unarmed, the tip of the inner claw bearing a strong, clavate
hair which slightlv overreaches the end of the lareer

-> o

claw. Tibiae without clavate hairs. Furcula rather stout;
manubrium about as long, measured ventrally when extended,
as the dentes and mucrones together ; dentes tapering

COLLEMBOLA OF MINNESOTA 51

somewhat. A few long hairs are borne on the ventral side
of the dentes, but none clavate, or longer than the breadth of the
dentes itself. Mucrones short and stout, with a single notch on the
outer edge, and about five on the inner edge ; at the base, on the
dorsal side, is a notch extending part way around. The sub-anal
bristles are very much curved, and from them the species derives
its name; they are pinnate in form. Length, 1.25 mm.

Not very common. Found only, so far, in low, dark woods,
on the bottom lands of the Mississippi, where it was taken under
chips and pieces of drift-wood.

Sminthurus longisetis n. sp.
PI. Ill, Figs. 8-isb.

A brownish-black species, indistinctly mottled with yellow.
Back and top of head set with strong, truncate bristles, nearly
straight, and pointing backward. Antennas very slender ex-
cepting Ant. I ; Ant. II as long as Ant. III. The antennal seg-
ments measure in the ratio 5: 14: 14: 19. Ant. IV is not dis-
tinctly ringed, but whorls of short hairs indicate where rings
would come. On Ant. II and III are a few stiff sense hairs,
about as long as three times the width of the antennae, and
standing out at right angles to those organs. The head bears
at its vertex a prominent tubercle, as in S. minnesotensis and
S. curvisetis. The eye-spots are dark yellow in color, and very
convex. Legs short and with very stout claws, the larger one
bearing a notch-like inner tooth. At the tip of the inferior claw
is borne a slender, simple hair, which projects about half its own
length beyond the tip of the larger claw. The tibia bears four
clavate hairs. Furcnla strong; manubrium as long as dentes
and mucrones taken together, and reaching back as far as the
tip of the anal segment when, extended. Dentes stout and some-
what tapering, each ramus bearing on its ventral side three long
sense hairs, set at almost right angles to the dentes. Mucrones
short and stout ; the outer edge nearly smooth, except for the
rounded scollop near the tip, the inner edge somewhat coarsely
serrate, a rounded tooth at the back running part way around
the base. The anal organs are deeply cleft and much curved.
Length, 1.8 mm.

COLLEMBOLA OF MINNESOTA

Found in deep, dark woods, under drift-wood. Quite rare.
Srninthurus minnesotensis n. sp.
PI. II, Figs. 10-16 and PI. XIV.

Purple and yellow above; antennae, legs, furcula and under
side of body dark blue ; under side of small abdominal segment
yellow; head marbled with yellow and purple. A narrow, me-
dian, dorsal band of purple on the thorax ; in front of this, two,
and behind it, four or five cross-bands of purple, alternating with
broader ones of yellow. Ant. IV showing about seven distinct,
bead-like rings, each bead most enlarged at the distal end,
fig. 10. Head broad in proportion to the body, bearing on the
vertex an elevated mound, on which may be seen a pair of
short, horn-like hairs, fig. 16. The central ocellus is small, the
rest about of a size, with a slight preference in favor of the front
one of the median row, fig. 13. The long, curved bristles on the
head point forward. The body is elliptical from a dorsal view;
rather low, and sloping from the thorax, as seen from the side.
The back is covered with long, pale, backward-curving bristles.
Abdomen not broader than the thorax, its apical segment large.
Anal appendages, genital papillae and tenaculum shaped much
like those of S. fuscus. The furcula also resembles that of S.
fuscus in general form, but differs in the dark color, and in the
mucrones, which has the outer edge entirely smooth, and is
more inclined to the acuminate form, and not quite so deeply
trenchant. The feet differ slightly, the upper claw of the third
pair being rather more slender than on the first and second pairs.
In the third pair, too, the inferior claw is of slightly different
form, fig. 14, and appears to bear the hair at its very apex, in-
stead of farther up, as in the others. The superior claw bears
a small, inner tooth. No clavate hairs are present. The claws
are not enclosed in a tunic. The dorsal side of the trochanters
is colorless. Length 1.5 mm.

Taken all through the summer, though never very abun-
dant, under bark and pieces of drift-wood, in low, dark woods
along the Minnesota and Mississippi Rivers, and in July at Lake
Vermillio'n. They often occur with Papirius muculosus Schott,
which they closely resemble in general coloration. Sometimes
I have taken them with S. niger Lubb. Their general appear-

COLLEMBOLA OF MINNESOTA 53

ance suggests that of S. multifasciattis Renter, and I was long
in doubt as to whether it might not be merely a variety; but
the mucrones is distinctly serrate, while that of Renter's species,
to quote Schott, "hat die Rander ganz glatt." S. multifasciatus
also differs in wanting the inner denticle on the claw. Again,
in color, neither the figure of Renter nor that of Schott shows
the median dorsal band.

Sminthurus fuscus (L.).

PI. II, Figs. 1-9.

1743. Podura fusca, globoso, antennis longis articulis plurimis. DeGccr,

Vet. Akad's Handl. Vol. IV, p. 296.

1746. Podura globosa fusca. Linne, Fauna Suecica.

1758. Podura fusca. Linne, Syst. Nat. Ed. X. Tome I, 608.

1762. Podura fusco-nigra ; abdomine globoso signaturis ferrugineib.

Geoffrey, Ins. Env. Paris.

1762. La Podure brune enfumee. Geoffrey, Ins. Env. Paris.

1767. Podura atra. Linne, Syst. Nat. Ed. XII. Tome I, 2. p. 1019.

1776. Podura atra. Miiller, Zool. Dan. Prod.

1778. La Podure brune ronde. DeGeer, Gescb. d. Ins.

1781. Podura atra. Schrank, Entim. Insect. Austr. p. 495.

1781. Podura atra. Fabricius, Spec. Ins. I. p. 381.

1781. Podura signata. Fabricius, Spec. Ins.

1804. Smynthurus fuscus. Latreille, Hist. Nat. VIII, p. 82.

1804. Smynthurus signatus. Latreille, Hist. Nat. VIII, p. 82.

1835. Smynthurus fuscus. Lacordaire & Boisd., Faun. Ent. Env. Paris.

1835. Smynthurus ater. Lacordaire & Boisd., Faun. -Ent. Env. Paris.

1835. Smynthurus signatus. Lacordaire & Boisd., Faun. Ent. Env. Paris.

1835. Smynthurus ater. Templeton, Trans. Ent. Soc. I.

1838. Smynthurus fuscus. Burmeister, Handb. d. Entom. II. 2, p. 451.

1839. Smynthurus fuscus. Bourlet, Mem. Soc. Roy. Lille.
1842. Smynthurus fuscus. Lnoa:, Hi jr. N:-.'. Ani'i. Art.
1842. Smynthurus ater. Lucas, Hist. Nat. Anim. Art.
1842. Smynthurus signatus. Lucas, Hist. Nat. Anim. Art.
1842. Smynthurus fuscus. Bourlet, Mem. Soc. Roy. Douai.
1842. Smynthurus signatus. Nicolet, Mem. Soc. Helv.
1844. Smynthurus ater. Gervais. in Ins. Apt. Ill, 492.
1844. Smynthurus signatus. Gervais, in Ins. Apt. III. 400.

1862. Smynthurus buskii. Lubbock, Notes on the Thys. Pt. I, p. 431.

1869. Smynthurus signatus. Porath, Of. af. k. Vet-Akad. Forhandl.

1871. Smynthurus fuscus. Tullberg, Fort, ofyer. Sv. Podur. p. 144.

1872. Smynthurus fuscus. Tullberg, Sver. Podur. p. 29. PI. I, 1-27; II,

I-I5-

54 COLLEMBOLA OF MINNESOTA

1873. Smynthurus fuscus. Lubbock, Mongr. Coll. and Thys. PI. II, pp.

101-107.

1890. Smyntburus fuscus. Uzel, Thys. Bohem. p. 34.

1893. Smintburus fuscus. Schott, Insekten-Fauna v. Kamerun, p. 6.

1893. Smintburus fuscus. Schott, Palasarct. Collemb. p. 21.

1895. Sminthurns fuscus. Renter, Finl. Coll. och Thys. p. 9.

1896. Sminthurus fuscus. Schaffer, Coll. v. Hamberg, p. 209, PI. IV, 124.

1897. Sminthnrus fuscus. Poppe & Schaffer, Coll. v. Bremen, p. 271.

Schott describes the species as "Yellowish-brown or red-
dish-violet, shining. Antennae little longer than the head. Su-
perior claw vaginate. Dentes set with very long hairs. No
clavate hairs on the tibia. Mucrones with both edges dentate.
Length, 2 mm."

This description applies to the principal form, of which I
have taken but two individuals in the state. These were taken at
Lake Vermillion. They are very dark, appearing black when
seen dorsally. The antennae are pale violet. Legs deep blue,
and furcula dark blue even on the mucrones. Besides this prin-
cipal form, we have another form which differs much in color,
but seems the same in structure and is probably merely a variety
of this species. Our variety is unique in having three lon-
gitudinal dark stripes on head and thorax. The middle one is
narrow, and extends down the front of the head to a point
midway between the bases of the antennae. The two side stripes
run forward over the top of the head, taking the eyespots in
their course, and reaching down almost to the mouth in front,
their ends approaching but not uniting. From the head they
pass backward along the sides of the thorax. These stripes are
of the same color as the back of the abdomen ; being usually
of a dark sepia brown in the older specimens, and lighter in
younger ones. The young have the three stripes continued
back to the posterior part of the abdomen. Between the stripes,
and the lower part of the body are citron yellow in older spec-
imens, and rather brighter in young. The rings on Ant. IV
are about 16 in number, and are more distinct in the very young
than in adults. Compare figures 8 and 9. The antennae are
deep violet and bear a few very long sense hairs on the second
and third segments. The superior claw is enclosed in a tunic
which seems to be pierced by the tip of the claw, and by the one
strong inner denticle. A distinct, much-curved hair, from the

COLLEMBOLA OF MINNESOTA 55

under side of the tip of the tibia, bends up into, or beside the
superior claw. There are no tenent hairs on the tibia. The
inner claw is slender, and bears, near its tip, a hair which
slightly over-reaches the superior claw.

The ocelli are about equal in size, and are situated on a
black patch. The legs and furcula are brown. Several long
hairs are borne by the dentes. their ends very slightly clavate,
fig. i. The mucrones is grooved, truncate at the end, serrate on
the inner edge, and smooth with the exception of two or three
teeth on the outer edge. I believe this is the only species in which
the anal appendages have been noted heretofore. Both Tull-
berg and Lubbock have figured them, and the latter remarks:
"At the base of the spring are two scimitar-shaped organs
which appear to be hairs specially modified and of unusual size.
The apical half of the inner margin and a small part of the outer
edge are roughened by irregular teeth ; which, however, are so
unsymmetrical as to suggest the idea of the borders being fretted
by use. The two scimitars often differed considerably in the
extent to which they were thus affected. "They arise from
slight papillae and bend outwrard and upward in a wide curve.
The tenaculum is directed backward as usual and appears rather
pointed from a side view, fig. 33, truncate when seen from the
lower surface, fig. 3b, bearing on each side three lobe-like pro-
cesses which project backward. On the tip are a few hairs.
The genital papilla is prominent, and is situated beneath the
base of the small abdominal segment, fig. 2. Its opening is
horizontally slit-like. Length, 2 mm. Not very common. Found
under boards in a low, damp meadow.

Sminthurus penicillifer Schaff.
PI. IV, Figs. 9-12.

1896. Sminthurus penicillifer. Schaffer, Coll. v. Hamburg, p. 211.

PI. I. /; and IV, 117-119.

1897. Sminthurus penicillifer. Poppe & Schaffer, Coll. v. Bremen, p. 272.

Schaffer gives the following description of this species :
"Color yellowish. Abdomen marked above with two broad,
dark-blue, longitudinal spots. Sides of the abdomen each with
a dark-blue, longitudinal band. This dark-blue color also broad-

56 COLLEMBOLA OF MINNESOTA

ens out over the entire surface of the small abdominal segment.
At the insertion of the legs, the thorax is a faded, grayish-blue,
a continuation of the side bands of the abdomen. Legs, manu-
brinm, dentes, and medial part of the mucrones gray-blue. A
dark-blue spot between the antennae. Ocelli on a black patch.
Antennas bright violet, at least Ant. II, III and IV. Antennae
much longer than the head. Ant. IV ringed, composed of
about seven rings. Upper claw slender, without a tooth, ap-
parently without a tunic. Under claw ending in a brush-like,
much-slit continuation (Untere Klaue in eine pinselformig,
zerschlitzten Fortsatz auslaufend), which reaches considerably
beyond the end of the upper claw. Tenent hair wanting on the
tibia. Dentes about three times as long as the mucrones. Mu-
crones broad, lancet-like with hyaline edges ; the dorsal edge
broad, with about n or 12 distinct ribs, the ventral narrow with
indistinct ribs. Length, .75 mm.

"In the nature of the mucrones it approaches S. aquaticus
and S. malmgrenii. In breadth of mucrones it comes between
these two species. S. penicillifer is, however, distinguishable
from them in the ringed form of Ant. IV, the shape of the under
claw and the color markings." In our collection this species is
represented by but one specimen, which would indicate that it
is probably rare. Schaffer had but three specimens, which
were taken in a small pool near Bremen. Mine was taken in
the edge of a slough on Gray Cloud Island, in the Mississippi
River, July, 1899. The antennas are distinctly reddish violet.
Ant. IV rather noticeably ringed, fig. n. The feet of the third
pair, fig. 9, are smaller and shorter than those of the first and
second pairs. Though the "pinselformig" prolongation is not so
much branched as in that figured by Schaffer, there is little
doubt of the species, and possibly if the other claws in the
specimen were more favorable for observation they might prove
the correctness of his figure. Schaffer has made no mention
of several very long, brownish bristles which proceed from the
manubrium, and reach beyond the middle of the dentes when
the furcula is held erect. My specimen is darker than that de-
scribed ; the dark bluish color entirely covering the back and
the terminal segment, but shading down on the sides to a citron
yellow ground color. The sides of the abdomen are lighter than

COLLEMBOLA OF MINNESOTA 57

the back, hardly well enough defined to be called banded. The
specimen measures I mm., which is somewhat larger than those
described. Possibly further collecting will prove this a distinct
American variety.

Sminthurus spinatus MacG.
PI. IV, Figs. 1-8.

1893. Smynthurus spinatus. MacGillivray, Canad. Ent. XXV, p. 127.

1894. Smynthurus spinatus. MacGillivray, Canad. Ent. XXVI. p. 109.

This singular ispecies is thus described by MacGillivray:
"Olive, tinted with purple, lighter on the sides, olive around
the mouth and eyes ; coarsely and sparsely punctate, punctures
light olive, each bearing a white hair. Antennae purplish, basal
joint lighter, as long as the body; apical segment with from 17
to 20 subsegments. Abdomen fuscous with lighter spots ; the
apical part with an olivaceous cloud, the remainder fuscous
with whitish or olveaceous blotches ; on the middle of the back
a number of groups of circular white spots, and on the posterior
part of each side a row of white spots, varying from four to
ten. Underneath olive. Anal papillae large, distinct, with nu-
merous bristles ; the upper part and the sides purplish or fus-
cous, the remainder olive with darker spots. Legs long and
slender, purplish or fuscous, mottled with variously formed olive
or whitish blotches ; apex of the tibiae and base of the larger claw
blackish purple. Claws long and slender, inner claw indistinct;
apex of the tibiae with a few clubbed hairs. Spring long, broad
and flat, reaching the mouth ; second joint broad, each side with
a row of long, stiff bristles ; bristles twice as long as the spring
is broad; third join long, broad, bluntly rounded. Length, 2
mm. Habitat, Ithaca, N. Y.

"A very variable species, in young specimens the back is
pea-green, and in some specimens there is a broad olive band
down the middle of the back. The color varies from pea-green
to purplish and fuscous. Collected on the surface of standing
water. Ihe species can be easily recognized by the row of stiff
hairs on each side of the spring." To the above description a
hitle might, perhaps, be added.

The species is evidently an American relative of Tullberg's
S. novemlineatus, which it very much resembles. In coloration

58 COLLEMBOLA OF MINNESOTA

there is quite a difference, but that counts for little in a species
in which the color is so variable. Tullberg's species is known
to have three distinct varieties. S. spinatus is about a third
larger than its European relative, however, and differs some-
what both in the claws and in the furcula. I find no mention
of the inner tooth on the superior claw in the original descrip-
tion, yet it is plainly apparent, though small, in my specimen?.
A reference to the figures will ishow that quite a difference ex-
ists between the claws of the first pair and those of the third
pair. It seems to me that the male and female are more differ-
entiated in this species than in others of the genus. The male
is the more slender-bodied of the two. The mucrones in S.
spinatus is not so elliptical as in S. novem-lineatus, being more
abruptly terminated at its distal end.

Like S. penicillifer, and like Podura aquatica, though in far
greater degree than either, this species possesses a highly spec-
ialized furcula, well adapting- it to its mode of life on the surfaces
of ponds. Although quick and powerful jumpers on water, yet
when undisturbed they appear to prefer to rest on leaves just
above the water. They are rather common along the bottom
lands of the Minnesota and Mississippi rivers, also among wet
grass and debris upon the shores of Lake Vermillion.

Papirius maculosus Schott.

PI. I, Figs. 1-7.
1891. Papirius maculosus. Schott, Kaliforn. Collemb. p. 14. PI. Ill, 1-3.

"White or brownish yellow, with blue spots scattered about
on the back and head. Antennae blue, shorter than body. Su-
perior claw naked, armed with two teeth, inferior claw with
one perpendicular tooth. Length, 1.5 to 2 mm."

Besides this description, Schott says of the species that
"it approaches P. ater (L). The manu'brium is short, the dentes
about three times as long as the mucrones. The dentes bears
two distinct kinds of hairs ; .some of them simple, some pinnate
or notched (ausgesperrten), which are systematically situated
with respect to one another, so that in general two simple hairs
have between them two pairs of the spurred hairs. The most
distal of the simple hairs reaches almost to the very end of the

COLLEMBOLA OF MINNESOTA 59

mucrones. The animal has a white ground color, sometimes
varying to a yellowish or grayish tone. Almost the entire upper
part of the body shows dark spots of various forms and dark-
blue color, which often varies to a sky-blue. Antennae dark
blue. Legs with distal half of tibia white. Furcula pale violet,
and the ventral side of the animal clear white."

Schott described the species from three specimens taken in
California. He distinguishes it from P. marmoratus Packard
by its having but two inner denticles to the superior claw. On
examination of a large series, however, I am led to conclude
that there may possibly be a mistake here, for while some show
the inner edge of the claw smooth, others show quite a decided
notch near the base, amounting, indeed, almost to a tooth. Hav-
ing but three specimens, Schott may have had no opportunity
to see this notch. There is, moreover, the possibility that Min-
nesota specimens would show a gradation between those found
in Massachusetts or Maine, and those from the Pacific coast.
Packard mentions no tooth on the inferior claw, however, so the
species are probably distinct.

I have often taken this species with S. minnesotensis, and
the two resemble each other very greatly in coloration. Evi-
dently the species is well distributed throughout the state, as
it has been taken along the Mississippi from St. Paul to the
Iowa border, as well as in the Vermillion Lake region in the ex-
treme northern part of the state.

Papirius unicolor Harvey.

1893. Papirius unicolor. Harvey, "A new .Papirius." Ent. News, IV, p.
65. PI. IV.

"Light brownish purple throughout ; color much like that
of a Delaware grape with the bloom removed. Back, ends
of the legs and apical half of the antennae darker. Dorsum often
with two interrupted stripes of darker shading. Head, base of
antennae, base of legs, spring and ventral surface lighter; one
specimen had the two terminal segments of the antennae con-
spicuously clear. Young, half-grown specimens, and full-grown
specimens in damp situations paler. Occasionally a very large
specimen and those taken in dry places are more brown, but all

60 COLLEMBOLA OF MINNESOTA

show the purple tint ; sides of the full-grown specimens often ob-
scurely marked with much paler, oblong spots.

"Body, including head, twice as long as broad, breadth and
depth equal ; gradually widening from the neck to the greatest
breadth, abruptly narrowing with a slight reentering angle to
the conspicuous terminal segments. Head, viewed from front,
as long as broad, depth half the length. Eye patches prominent,
elevated, black, conspicuous, bearing eight ocelli; four on the
inner row, three on the outer, and a single smaller one in the
middle ; the second ocellus from the front on the inner row is also
smaller than the others ; front of the head between the eyes,
elevated and bearing a tuft of long hairs. Antennae long, slen-
der, elbowed at the second joint, nearly as long as the body; basal
joint short but slightly longer than the terminal; second joint
shorter than third, the portion beyond the elbow usually some-
what longer than the two basal joints; third joint usually long-
est, the terminal half composed of seven or eight short sub-seg-
ments ; terminal joint short, conical, narrower than the clubbed
end of the third joint; composed of about ten subsegments,
the three basal of which are about the same width, and obscure;
fourth and fifth wider and well-defined; sixth and seventh nar-
rower and somewhat obscure ; each segment bears a whorl of
hairs ; and as there are three whorls on the portion beyond the
seventh segment, probably it represents three more ; when walk-
ing, the basal portion is projected upward and outward from the
head, the apical portion below the elbow, outward and down-
ward. Legs long, claws prominent, the larger curved, and bear-
ing two teeth on its inner face below the middle; smaller claw
slender, over half the length of the other. Suckers nearly as
long as the body, cylindrical, white, covered with papillae ; ten-
aculum cylindrical, prominent. Spring rather long and slender,
about three- fourths the length of the body; terminal segment
less than half the length of the second, lanceolate, unarmed,
concave below, and bearing on each edge of the concavity a
row of about forty teeth ; the teeth increase in size outward, and
at the end join in a common tubercle.

"Hairs are sparsely found on all parts of the body. Under a
high power those on the second joint of the spring, which I
especially examined, were barbellate. Length, 2.5 mm.

COLLEMBOLA OF MINNESOTA 61

"Under rubbish and the loose bark of stumps, also on agar-
ics and boleti. Found under boards as late as November, prob-
ably hibernating there. Common in Maine."

This is our most common species in Minnesota, often oc-
curring with P. maculosus, which it much resembles in anatom-
ical details. Harvey mentions no inner denticle on the inferior
claw. He may have overlooked it, as it certainly shows on all
my specimens.

Orchesella albosa n. sp.
Plate I, Figs. 14, 15.

Yellow or white in color, antennae more or less purplish,
shading evenly out to tip of Ant. VI, which is darkest of all.
Sometimes the antennae are almost entirely yellow, excepting
the dark distal end of Ant. III. The body is comparatively
shorter than in O. zebra, and the antennse longer, the ocelli also
differ in being relatively smaller and farther apart. Perhaps,
as the lighter coloring indicates, this is more of a dark-loving
species, and the tendency is toward a reduction in the size of the
ocelli on that account. In respect to the character of the claws,
furcula, etc., it resembles O. zebra, but I believe it is the only
species of Orchesella recorded, in which neither b®dy nor legs
show color markings. Length, 2.5 mm. Found under boards
near Minneapolis. Not common.

Orchesella zebra n. sp.
PI. I, Figs. 8-13; XVI, Fig. i.

Form elongate. Color, dark purple and yellow. Along the
median dorsal line is a dark stripe, sometimes narrowing to a
mere line or entirely broken, again broadening out into almost a
cross-band on Abd. Ill and Th. III. Two lines of longitudinal
spots situated dorso-laterally on all segments except the pro-
and meso-thorax, constitute another series of markings, while
the body markings are completed by another such line of spots,
only larger and more widely separated, situated laterally. The
head has a black band connecting the eyes, but no other color
markings. Eyes black. The ocelli are larger in proportion to
the eye spot, and therefore closer together than in the case of

62 COLLEMBOLA OF MINNESOTA

O. albosa. Antennae slender and hairy, about three times as
long as the head. Ant. Ill is yellow with the faintest possible
tinge of blue in a spot at the distal end in some of the darker
specimens. IV and V have each about the distal halves dark
blue, VI shades out distally from yellow to a dead, blackish
purple. While I am aware that color characters are often of
doubtful value, yet the species at hand varies so little in the
scores of specimens examined, that I believe an antenna alone
would serve to identify it.

The body is thickly covered with short hairs, some longer
ones appearing on Abd. V and on the furcula, also bunches of
long, clubbed hairs on dorsal parts of head and thorax. The
claws are of the ordinary Orchesella type — long and slender,
the inner claw narrow lanceolate, with a small outer tooth, the
outer claw with an outer and two inner teeth. The tibia bears
one clavate hair.

The whole furcula is very hairy, two or three feather-like
hairs project from dentes beyond mucrones, the longest pro-
jecting over by nearly the length of the mucrones. Manubrium
slightly arcuate, dentes slender, slightly longer than manubri-
rm, arcuate, serrulate beneath.

Mucrones small, tridenticulate ; the apical tooth curved,
acute, the next stouter; proximal tooth very islender and point-
ing towards the tip of the next tooth, it stands on the outer lat-
eral side of mucrones.

The antennae seem quite subject to mutilation, and one
finds many different forms in consequence. Figures I2a and I2b
show two such antenna?. Lubbock's experiments upon the an-
tennas of O. cincta, as recorded in his notes on the Thysanura,
Part IV, p. 285, show that when an antenna is mutilated by the
loss of one or more segments the terminal remaining seg-
ment elongates often far beyond its norm, coming to resemble
the normal Ant. VI in form; but that no new segments are
formed. Thus in figs. a and b, which were found on the same spec-
imen, and were of equal length, a had lost only Ant. VI, or
possibly in addition a part of Ant. V, while the long distal seg-
ment on b is Ant. Ill, which is normally very short. Perhaps
we might better say that the distal segment is not merely the
third, but essentially all the segments from the second one out.

COLLEMBOLA OF MINNESOTA 63,

Although it has lost the power of sub-segmenting- into the nor-
mal number, yet the normal amount of growth-power remains
unimpaired by the mutilation.

While the species is rather common, I have taken it but
once in great numbers. One morning after a night shower they
appeared by hundreds in all stages of growth on the moist sur-
faces of stumps in the woods, where they seemed to be enjoying
the moisture from the wood, and perhaps feeding on the soft-
ened particles of decaying wood. They moved about fitfully at
times, but often stopped and squatted down to bring the ven-
tral tube into contact with the moisture.

Isotoma minima n. sp.
PI. IX, Figs 17-19; X, Fig. i.

Light grayish-blue in color, body subcylindrical, elongate,
almost naked except on the fifth and sixth abdominal segments,
which bear some long scattered hairs. Fourth, fifth and sixth
abdominal segments apparently so fused as to form almost a con-
tinuous segment. Antenna gray, little longer than the head ; Ant.
IV longest, very much swollen, III much rounded, shorter than II
and slightly longer than I. Ocelli 16. Post-antennal organ long,
narrowly elliptical, slightly emarginate aong anterior edge.

Furcula short, not reaching to ventral tube ; insertion at
junction of fourth and fifth abdominal segments. Manubrium
stout and thick. Dentes straight, not tapering greatly toward
di?tal end, irregularly serrulate along greater part of lower edge,
upper edge with a few stout, scattered hairs. Mucrones and
dentes together about as long as the manubrium. Mucrones
long and narrow, tridenticulate. the distal tooth almost straight,
the ante-distal tooth close to, and at right angles to it ; proximal
tooth smaller and set about the middle of the mucrones, point-
ing slightly distal-wards. Each tibia bears one long simple hair
in the position of a tenent hair. The claws are unarmed.

The species may be that referred to by Schott in his Sys-
tematik und Verbreitung der palaearctischen Collembola as I.
minuta Tullb. His figure of the mucrones certainly comes
nearer to mine than to that given by Tullberg in his "Sveriges
Podurider" as I. minuta; moreover, Tullberg also expressly
states, as his figure also shows, that the two ante-apical teeth

64 COLLEMBOLA OF MINNESOTA

are set next one another and near the end. Length, three-fourths
millimetre.

This species probably occurs more abundantly than its num-
bers in my collection would show, its minute size and light gray
color lending a mimicry which shields it from all but the most
careful observation. It seldom jumps, seeming averse to that
mode of motion, but moves about uneasily when its hiding places
are exposed to the sunlight. I have taken it in the green-
house of the University, under moist boxes and flower pots,
where it usually lived among the faeces of a certain small mil-
ipede, though possibly this cooccurrence was purely accidental.
Out of doors it is sometimes met with under stones and damp
boards, usually where there is a slight layer of thin, slimy mud.
Not uncommonly it is taken with I. bidenticula, the light-colored
young of which it greatly resembles until one observes it with
a compound lens.

Isotoma fimetaria (L.), Tullb.
PL X, Figs. 5, 6.

1746. Podura terrestris alba. Linne, Fn. Sv. Ed. I. p. 343.

1758. Podura fimetaria. Linne, Syst. Nat Ed. X. Prt. I, p. 609.

1871. Isotoma alba. Tullberg, Fort, ofver Sv. Podur. p. 152.

1872. Isotoma fimetaria. Tullberg, Sver. Podur. PI. IX, 32-33.
1876. Isotoma fimetaria. Tullberg, Coll. Borealia, p. 37.
1890. Isotoma fimetaria. Uzel, Thys. Bohemiae. p. 66.

1893. Isotoma fimetaria. Schott, Palsearct. Coll. p. 75.

1895. Isotoma fimetaria. Reuter, Finl. Coll. p. 28.

1896. Isotoma fimetaria. Schaffer, Coll. von Hamburg, p. 183.

1896. Isotoma fimetaria. Lie-Pettersen, Norgcs Coll. p. 18.

1897. Isotoma fimetaria. Poppe & Schaffer, Coll. v. Bremen, p. £68.
1900. Isotoma n. sp. Harvey, Ent. News. XI, p. 552.

Tullberg thus describes it : "Third abdominal segment
shorter than the fourth into which the furcula is inserted.
Ocelli none. Dentes nearly twice as long as the manubrium,
straight; mucrones bidenticulate. Length, i mm."

Some specimens found in the state measure i.25mm., but
otherwise the correspondence is exact, except that the slender
dentes is often arcuate. Claws unarmed, no clavate hairs on the
tibia;. Post-antennal organ narrowly elliptical as in I. quadri-
ocuiata. It is a more slender species than I. quadrioculata, and

COLLEMBOLA OF MINNESOTA 65

has the antennae comparatively longer and slenderer, though the
proportions between the segments are about as in I. minima,
III being little shorter than II, which is nearly twice as long
as I ; I and III together about equal IV. The claws are straighter
and rather more slender than in I. quadrioculata.

This species is well distributed, though seldom very numer-
ous ; under bark, sticks and stones, under flower pots in the
green-house, almost anywhere where there is darkness and moist
mud, it may be sought. I have once taken it among the gills
of mushrooms. Not infrequently it lives with other white col-
lembolans such as Aphorura ambulans and Cyphodeirus albinus,
and the unaided eye can hardly distinguish the difference be-
tween the three species.

Isotoma quadrioculata Tullb.
PI. X, Figs. 7, 8.

1871. Isotoma quadrioculata. Tullberg, Fort, 6'fver Sv. Podur. p. 152.

1872. Isotoma quadrioculata. Tullberg, Sver. Podur. p. 48. PL IX, 25-31.
1876. Isotoma quadrioculata. Tullberg, Coll. Borealia, p. 36.

1890. Isotoma quadrioculata. Uzel, Thys. Bohemias, p. 66.

1893. Isotoma quadrioculata. Schott, Palasarct. Coll. p. 74. ,

1895. Isotoma quadrioculata. Renter, Finl. Coll. p. 28.

1896. Isotoma quadrioculata. Sckaffer, Coll. v. Hamburg, p. 183. PI III,

71-

1896. Isotoma quadrioculata. Lie-Pettersen, Norges Coll. p. 18.

1897. Isotoma quadrioculata. Poppe & Schaffer, Coll. v. Bremen, p. 268.

Tullberg's description is : "Third abdominal segment
shorter than the fourth, into which the furcula is inserted.
Ocelli 4, 2 on each side of the head. Dentes not longer than
the manubrium, straight ; mucrones bidenticulate. Length,

mm."

This has the shortest furcula of any species we have seen,
the dentes and mucrones together do not equal the manubrium.
There is one long hair at the base of the dentes as in I. bidentata.
No clavate hairs are borne by the tibiae. The claws are unarmed.

Tullberg gives the color as -gray-blue. One of our spec-
imens, measuring i mm. in length, answers well to the descrip-
tion in all but size. It is gray-blue, with furcula and ends of legs
lighter or colorless. The others are entirely white with the ex-
ception of the eye spots, and they measure but .75 mm. The

66 COLLEMBOLA OF MINNESOTA

body is sparsely covered with short hairs interspersed with
a few longer ones. As Schott and Lie-Pettersen both mention
having found white specimens, it is not improbable that there is
a white and a colored variety.

They are found under bark of logs and under flower pots
in the greenhouse.

Isotoma bidenticula n. sp.
PI. X, Figs. 2-4.

Dull blackish gray, varying from light to dark, and bearing
usually a brownish, though sometimes a bluish tint. Lighter be-
neath, also on furcula and at junction of body segments. An-
tennae darker, and not longer than head ; Ant. I shortest, III
slightly longer than II, and less than twice the length of I.
Ant. I and III together nearly as long as IV. Body sparsely
haired, the hairs being longest and most numerous on the final
abdominal -segment. Claws without teeth or tenent hairs, outer
one curved, inner one very slender. Furcula small, straight,
reaching only to anterior edge of third abdominal segment.
Manubrium rather longer than dentes and mucrones together.
About the middle of the dorsal edge of dentes are a few rounded
serrations. The same edge has, besides several short hairs, one
long straight hair, borne not far from the manubrium. Mu-
crones bidenticulate, the aoical tooth somewhat curved, the
other pointing a little towards the front so that they form almost
a right angle. The fourth and fifth abdominal segments are
so fused as often to appear but one. The furcula seems to be
borne by the fourth. Length, 1.5 mm.

This species very closely resembles I. minima in general
body form, and sometimes, when young, in color as well, though
the tendency is more often towards a brown than a blue. The
post-antennal organ is of the same shape in both, but is com-
paratively longer in I. minima. As to comparative length of
furcula, antennae, abdominal segments, etc., they differ but little,
but a glance at the mucrones will at once separate the two
species. Again I. bidenticula is much the larger of the two,
measuring twice the length of the other species named. Found
under stones and bark, and under flower pots in the University
greenhouse. Rather common.

COLLEMBOLA OF MINNESOTA 67

^1 Isotoma leonina Pack.

PI. IX, Figs. 1-4.

1873. Isotoma leonina. Packard, Synopsis of the Thys. of Essex Co.,

Mass. Fifth Report Peabody Acad. Sci.
1896. Isotoma leonina. MacGillivray, The Amer. sp. of Isotoma. Canad.

Ent. XXVIII.

Light tawny yellow, the young nearly white. Ground color
whitish, pretty uniformly spotted with rather coarse brown
specks. A remarkably long, slender species with body some-
what sparsely covered with short hairs, except on Abd. V, where
they are long. The head is rather longer than broad and square
in front. Antennae less than twice the length of the head ; Ant.
II much curved, slightly longer than I, which is equal to III,
IV longest of all. Claws without teeth or tenent hairs. Fur-
cula long and slender, though shorter than usual in the genus,
extending beyond body by a distance about equal to greatest
breadth of abdomen ; when pointed forwards it reaches the ven-
tral tube. Dentes about twice as long as the manubrium, becom-
ing very slender at distal end. Mucrones much curved, tri-
denticuiate ; apical tooth distant from the second, and making
a prominent curve ; second and third vertical, the latter (prox-
imal) slightly the shorter of the two. Eyes on a conspicuous
black patch, ocelli 16. Post-antennal organ broadly elliptical.
Length, 2.33 mm. Under bark of stranded pine logs along the
Mississippi River, not very abundant.

Isotoma sensibilis Tullb.
PI. IX, Fig. 20.

1876. Isotoma sensibilis. Tullberg, Coll. Borealia. p. 36. PI. IX, 23-26.

1894. Isotoma sensibilis. Schott, Palsearct. Collemb. p. 72. PI. VI, 31-32.

1895. Isotoma sensibilis. Renter, Finlands Collembola.

The original description may be rather freely translated
as follows: "Hairy, Abd. Ill and IV about equal in length. An-
tennas slightly longer than the head. Ant. Ill shorter than II.
the Mucrones bears three teeth inserted one after the other. On
the anterior pair of tibiae two clavate hairs, on the posterior
tibiae, three. Length, 2 mm."

The post-antennal organ is broadly elliptical. The species
is slender, blue-gray or greenish gray in color. Manubrium very

68 COLLEMBOLA OF MINNESOTA

thick and stout, dentes unusually slender and whip-like, the fur-
cula just about reaching the ventral tube. Tullberg's figure
shows a minute inner tooth near the distal end of the large claw.
Schott's figure shows no such tooth. I have seen this in some
specimens.

Isotoma viridis Bourl.
PI. IX, Figs. 5-7.

1778. Podura viridis. Gmelin, Linnaeus Syst. Nat. Ed. XIII, p, 2910.

1839. Isotoma viridis. Bourlet, Mem. cur. les. Podures. p. 401.

1841. Desoria cylindrica. Nicolet, 1'Hist. des Podurelles. p. 60.

1841. Desoria viatica. Nicolet, 1'Hist. des Podurelles. p. 61.

1841. Desoria pallida. Nicolet, 1'Hist. des. Podurelles, p. 61.

1841. Desoria ebriosa, Nicolet, 1'Hist. des Podurelles. p. 61.

1841. Desoria annulata. Nicolet 1'Hist. des Podurelles. p. 61.

1841. Desoria fusca. Nicolet, 1'Hist. des Podurelles. p. 62.

1843. Podura viridis. Bourlet, Mem. sur les Podurelles. p. 24.

1844. Isotoma viridis. Gervais, Hist. Nat. des Ins. Apt. III. p. 433.
1844. Heterotoma chlorata. Gervais, Hist. Nat. des Ins. Apt. III. p. 421.
1862. Isotoma lineata. Lubhock, Notes on the Thys. Pt. II, p. 597.

1871. Isotoma palustris. Tullberg, Fort. ofv. Sv. Podur. p. 151.

1872. Isotoma palustris. Tullberg, Sver. Podur. p. 46.

1873. Isotoma anglicana. Lubbock, Monogr. Coll. and Thys. p. 171.
1873. Isotoma tricolor. Packard, Thys. of Essex Co., Mass. p. 34.
1890. Isotoma viridis. Uzel, Thys. Bohemian

1893. Isotoma viridis. Schott, Palsearct. Coll. Plates V & VI.

1895. Isotoma viridis. Reuter, Finl. Coll.

1896. Isotoma viridis. Lie-Pettersen, Norges Coll.

1896. Isotoma viridis. Schaffer, Coll. der Umgebung von Hamburg.

Several color varieties of this species have been described,
but the specimens taken so far all appear to answer best
the description of the principal form, as given by Schott. The
color is rather a brownish yellow, darkening to an obscure pur-
ple along the back. There are no longitudinal markings. Legs
yellow, becoming purple in the darker specimens. Antennas
dark purple, often slightly paler at their base. Furcula pale.
A dark spot on the head. Ant. IV usually a little longer than
III and more plump than in I. palustris. Post-antennal organ
broader than in I. palustris, broadly oval. Abd. Ill slightly
longer than IV. Claws without tenent hairs. Superior claw
with one outer and two inner denticles, as in I. catena, fig. 15.
but without the minute apical tooth. Length, 2-4 mm.

COLLEMBOLA OF MINNESOTA 69

Although one of the most widely distributed among the
Isotomas, I have taken the species but a few times. When
once found, however, the social habit of this insect insures to
the collector a considerable number of specimens. They are
active, avoiding the light less than most Isotomas. Under
stones and boards in low, damp places near the edge of the
river, or in springy places (I have only taken them in May)
along the Minnesota and Mississippi rivers.

Isotoma catena n. sp.
PI. IX, Figs, i5-i6b.

This species seems to be a link in the chain which connects
together the two species I. palustris and I. viridis. In most of
its characters it approaches more nearly to the latter than to
the former species. It is a dirty, obscure purple above, shading
down laterally to a lighter tint, and showing brownish purple
beneath. The antennae are dark purple throughout, the legs
rather a weak purple. The dentes, and sometimes the legs as
well, show a tendency to a yellow-green tint. The head is dark
throughout. Like I. palustris, the mucrones is provided with
four teeth ; the apical one being quite small, the ante-apical very
large and long, (in this character resembling I. palustris, var.
fucicola Renter, of which Schott says: "Der zweite grosse mu-
cronale Zahn ist langgezogen und ueberragt die anderen be-
deutend an Grosse.") ; the other two are set nearly opposite
each other as usual. In antennae, again, it resembles I. palus-
tris; Ant. IV being noticeably more slender than III, and sel-
dom so long. Here the resemblance to I. palustris ceases, and
that to I. viridis begins. The claws are armed with one outer
and two inner teeth on the superior clawr, and one inner tooth
on the inferior claw. The body is covered with short, closely
set hairs, among which, especially on the posterior end of the
abdomen, are interspersed longer hairs as in I. viridis. There
are no tenent hairs. Length, 3.8 mm. Taken at Minneapolis
by Mr. Oestlund. Also by myself near Le Sueur, Minn., on
the high wooded bank of the Minnesota River, under the loose
bark of a log in May, 1899. A few specimens were found at
Lake Vermillion in 1901. Apparently the species is not abun-
dant.

70 COLLEMBOLA OF MINNESOTA

Isotoma caeruleatra n. sp.
PI. IX, Figs. 11-14.

Dark clear blue, nearly black. Legs yellow, excepting
coxae and basal part of trochanters, which are dark blue. An-
tennas entirely blue, slightly lighter at proximal end of Ant. I.
Manubrium blue, the same color extending onto the dentes
very slightly. Dentes yellow, growing paler toward distal end
Head broad, blue, marked dorsally with yellow. Body narrow,
short-haired except for a few longer hairs on the two last abdom-
inal segments. Abd. II, III and IV about equal in length. Ant.
II equal to III, Ant. IV about twice as long as III, I very small.
Superior claw with two small teeth set on opposite edges and so
placed that one covers the other when the claw is seen in profile.
They show well when one views the claw from below. Inferior
claw with one small inner tooth situated on the most prominent
part of the inner hump. The inferior clawr seems to bend away
from the superior one, particularly in the third pair (the figure
is from the second pair), making the hump appear the more
prominent. No tenent hairs present.

Manubrium about half as long as dentes and mucrones to-
gether. Dentes short and comparatively thick, arcuate, set dor-
sally with a row of stiff hairs, rather slender at distal end,
crenulate or dentate on lower margin, the proximal one-third
irregularly so. Mucrones four-toothed : the ante-apical tooth
long and slender, the two proximal teeth set nearly opposite
each other. Length, 2 mm. Taken but once, in Apr. 1894, by
Mr. O. W. Oestlund near Minneapolis.

The species approaches very closely to I. grandiceps Renter.
but lacks the outer denticle on the superior claw, and possesses,
besides, the normal number of ocelli. I. grandiceps has but
seven to each eyespot. From I. hiemalis, to which it is even
more closely related, it differs in its much darker color, and
in the presence of teeth on the claws.

Isotoma palustris Miiller. Forma principalis.
PI. IX. Figs. 8-10.

1740. Podura aquatica cinerea. DeGeer, Act. Soc. Roy. Ups.
1776. Podura palustris. Miiller, Zool. Dan. Prodr. p. 184.

COLLEMBOLA OF MINNESOTA 1\

1788. Podura palustris. Gmelin, Linnaeus Syst. Nat. Ed. XIII. Prt. VI.

p. 2911.
1842. Podura palustris. Bourlet, Mem. Soc. Roy. Douai.

1842. Aetheocerus aquaticus. Bourlet, Mem. Soc. Roy. Douai.

1843. Podura palustris. Bourlet, Mem. sur les Podurelles. p. 29.
1857. Podura psi. Herklots, Notices Entomologiques.

1872. Isotoma palustris. Tullberg, Sver. Podur. p. 45. PI. IX, 1-8.

1873. Isotoma palustris. Lubbock, Monogr. Coll. and Thys. p. 169.
1890. Isotoma palustris. Uzel, Thys. Bohemiae. p. 62.

1893. Isotoma palustris. Schott, Palsearct. Coll. p. 63. PI. V, 8, and VI,

3-5-

1895. Isotoma palustris. Renter, Finl. Coll. p. 26.

1896. Isotoma palustris. Lie-Pettersen, Norges Coll. p. 16.

1896. ^Isotoma palustris. Schaffer, Coll. der Umgebung von Hamburg,
p. 1 86.

Schott gives about the best diagnosis of this variety : "'Yel-
low with a median black dorsal line. On the sides of the apical
segments of the abdomen, scattered fuscous spots which some-
times from dark longitudinal bands. Length, 2.5 to 3 mm."

Ground color a dirty yellow with a dark blue median band.
The sides are usually a dirty purple, sometimes forming well-
defined lateral bands, sometimes shading off lighter to the dor-
sal yellow. Two characteristic, dark purple spots appear on
the sides of the last abdominal segment. Often the furcula, un-
der side of body and of head, mouth-parts, lower sides of femurs
and of tibias, and basal part of ventral tube are of a bright
green. Distal part of ventral tube yellow. Dorsal side of femur
purple, cheeks washed with purple, antennae purple, also purple
around their base. Post-antennal organ oval. A dorsal purple
spot on the head. Older specimens are darker than young and
usually show more green. Ant. IV is more slender than III,
and seldom quite as long. The whole antenna is covered with
short, stout hairs. Indeed, the entire body is set thickly with
short, dark brown hairs of uniform length, in this differing from
I. viridis which has some longer hairs as well. The mucrones
is four-toothed. The claws are much the same as in I. caerul-
eatra, but lack the inner tooth on the superior claw. Sometimes
the claws of the second and third pairs show a small outer tooth
on the superior claw as in I. viridis, but less noticeable than in
that species. No tenent hairs present. Some authors give the
length as 4.5 mm., but I have never taken any that measured

72 COLLEMBOLA OF MINNESOTA

more than 2.75 mm. Found on the surface of stagnant water,
and on leaves and rubbish along the edge of lakes and streams
during the whole summer; and in winter as well, when one can
find a place where the snow is sufficiently melted to allow access
to their haunts.

Isotoma muskegis n. sp.
PI. XIII.

Dense blue-black, somewhat lighter on distal portions of
legs and furcula, also with a few lighter dorsal markings on the
body. Tubercles and abdominal horns (in the male) light yel-
lowish brown, giving to the body a yellow, floured appearance
to the naked eye. Head and body sparsely haired. Head squar-
ish, mouth-parts slightly protruding and light yellow. Anten-
nae blue-black, considerably longer than head, sparsely haired;
Ant. I shortest and thickest. II the longest, IV longer than III,
I and II together about as long as the rest of the antenna. No
post-antennal organ. Ocelli 16, about equal in size, 8 in each
eyespot. Eye spots black. Body somewhat flattened, prothorax
showing from dorsal side, meta-thorax broader than meso-thor-
ax, and of about the same length. Abdominal segments sub-
equal. Legs strong, third pair longer than the others, especially
in the tibiae. Tibise bearing two clavate hairs. Superior claw
with a well-marked inner tooth. Inferior claw slender, un-
armed. Tenaculum well-developed, its two blades each four-
footed. Furcula on Abd. IV. Manubrium much flattened, breadth
about twice as great as thickness, slightly shorter than dentes.
Dentes pale, rather slender, tapering but little, bearing a few
scattered hairs, ventral surface granular or papillated as in Po-
dura, to which there is also a slight resemblance in the bowed
form of the two rami. Mucrones about one-sixth the length of
the dentes, and bearing two strong teeth. Length, 2.5 mm.

I found this species twice during the summer of 1901 in
marshes along the shore of Lake Vermillion, on Pine Island in
St. Louis Co. On both occasions they wee on the upper ends
of partially submerged roots, or other decaying pieces of wood.
They seem to live socially, hundreds being seen together. They
resemble the heavier species of Achorutes in habits, being rather
slow in their movements. When exposed to the light, they be-

COLLEMBOLA OF MINNESOTA 73

come restless, and move about uneasily seeking for dark corners.
Unless considerably disturbed they prefer not to jump, and are
not particularly strong leapers when they do.

The most noticeable and interesting thing about the spe-
cies is the dimorphism, probably due to sex. I have not been
able to satisfy myself on this point as yet, but Mr. MacGillivray
suggests that it is the males that bear the horns and tubercles.
They possess a pair of strong, curved horns on very conspicuous
tubercles situated at the outer angles of the fourth abdominal
segment. These horns project caudo-laterad and somewhat dor-
sad. Besides the horns, the males possess variously shaped
tubercles upon almost every part of the body surface, most
conspicuous and largest on the caudal edge of the segments.
Each tubercle is thickly set with short hairs. There seems no
doubt that the tubercles are merely modified hairs, for one finds
on the same individual nearly all gradations from the thick, stout
hair with a very few short hairs at its end to the much swollen
tubercles with their haired areas greatly distended. Some of
the small tubercles with which the final abdominal segments
are thickly set, have the haired surface so much swollen as to
form a cap over the rest of the tubercle, giving to the whole a
mushroom-like appearance. It appears that the tubercles are
haired on one side only, and the swelling of this side causes the
opposite (unhaired) side to bend under, as seen in the series of
tubercles, figures 8-u, The females possess neither horns nor
tubercles, the skin appearing smooth and Abd. IV not widening
out laterally. After examining nearly a hundred specimens I
have found but one which seems to come between the two. This
specimen is without the horns, and has the general build of a
female, yet bears some few tubercles, mostly small, on the
body. In the male there are tubercles on the antennas and even
on the tibiae. This anomalous specimen may possibly be an im-
mature male.

Entomobrya bicolor n. sp.
PI. XVI, Fig. 2.

Dark brown or blue-brown and yellow, appearing yellow
and black to the unaided eye in life. More hairy than any other
species I have seen. Head and body very dark, with the follow-

T4 COLLEMBOLA OF MINNESOTA

ing yellow exceptions: Abd. I, II and VI, dorsal part of III, some
elongate dorsal spots on the front part of IV, and the ventral
part and two dorso-lateral spots on V. Markings vary some-
what in degree according to age, but not in position. The dark
parts are less dark on younger than on older specimens. Legs
with trochanter, femur and tibia light yellow, basal segment
brown or yellowish. Antennae at least four-fifths the length of
the body ; Ant. I light yellow, excepting the dark ring at its
base. II and III brownish yellow with narrow, dark rings at
their proximal ends, and purplish tinting at distal ends, IV a
dirty purplish gray, considerably longer than II, which exceeds
III almost as much as the latter exceeds I. The superior claw
bears three inner teeth, the inferior claw is unarmed and lance-
olate. Mncrones tridenticulate, being provided, as usual in the
genus, with a slender basal, and a stout middle and distal tooth.
Length, 3 mm.

The species agrees with E. orcheselloides Schott, and also
with E. dorsalis Uzel in many ways, such as the great compar-
ative length of Abd. IV, which is about seven times as long as
III ; in the greater length of the antennae, etc. ; and even agrees
to some extent with the latter in coloration. It must be noted,
however, that while the legs of E. bicolor are yellow, the femurs
and tibiae of E. dorsalis are dark-ringed, although in general
Uzel's species is the lighter of the two. Again, the antennae
of E. dorsalis are entirely yellow, while those of E. bicolor
show dark markings. The mucrones, too, seems to differ, for
Uzel says of it "Mucronibus duobus dentibus aequalibus in-
structis. Nulla spina sub dente inferiore."

The species is not very common, yet seems to be pretty
well distributed. Taken principally in spring and autumn, under
boards lying loosely upon the grass. It usually remains per-
fectly quiet until disturbed, relying upon its protective color-
ation, probably, to shield it from observation. I have found
them in considerable numbers, both old and young, in April,
on a damp paper which was partly submerged in a snow pool,
in a vacant lot here in Minneapolis.

COLLEMBOLA OF MINNESOTA 75

Entomobrya clitellaria n. sp.

PI. XV.

Color brownish yellow with the exception of Th. Ill, Abel.
I, II and the dorsal part of III, the cephalic margin of Th. II,
and the dorsal aspect of Th. I, the eye spots, and a connecting
patch which also forms a ring at the bases of the antennae;
all of which parts are very dark blue in color, appearing black
in life to the unaided eye. The antennae are tingad with dusky
bluish-black at the distal ends of Ant. Ill and IV, and at the
proximal ends of III. The dorsal part of the head between
the eye spots, just caudad of the heavy dark connecting spot
between the two rings at the bases of the antennae is light pur-
plish. The color description is given rather fully because I
believe this is a species varying but little in coloration. Very
young individuals have the dark parts rather lighter than those
which are mature, yet are so plainly marked that one readily
recognizes even them with the unaided eye. The dark region,
taking in the metathorax and the first three abdominal segments
(on the dorsal side) looks very like a saddle, hence the specific
name. The antennae have the three ultra-basal segments sub-
equal in length, the basal one shorter and stouter. Legs rather
long, each tibia bearing one clavate hair. The superior claw
is armed with two well-defined teeth on its inner edge, and one
small one on the outer edge. The inferior claw is rather slender,
attaining its greatest width near its distal end. The furcula
is as usual in the genus, it reaches forward to the ventral tube.
The dentes is as usual, serrate beneath, and the mucrones has
the typical three-toothed structure. The long hairs on the dis-
tal end of dentes reach a very little beyond the tip of the mu-
crones. Abd. IV five times as long as III. This species was
taken in the pine woods in the northern part of the state. Some
individuals were taken on the camp tables, where they were
running about apparently in search of food ; but the favorite
haunts were under and among the loose scales of bark of the
standing Norway pines (Pinus resinosa) where they were fairly
abundant.

76 COLLEMBOLA OF MINNESOTA

Entomobrya purpurascens Pack.

1873. Degeeria purpurascens. Packard, Thys. from Essex Co., Mass. p.

39-

1883. Entomobrya purpurascens. Brook, Revis. of Genus Entomobrya.
p. 282.

Packard's description is, as usual more generic than spec-
cific, yet I think there is little doubt as to the species. He
says : "Eyes black with no connecting line. This is rather a
large species with unusually long, slender antennae, with the
body, legs, and antennae of a purplish lead color, the purplish
tint especially noticeable on the two basal joints of the antennas.
Not very hairy ; the hairs on the prothorax and head of quite
uniform length, club-shaped, those on the posterior part of
the body very slender, no bowed ones among them( though my
specimens are somewhat rubbed). Legs slender, claws long and
slender, larger claw with two acute prominent teeth along the
inner edge. Elater with long dense hairs along upper side of
second joint; serrulate, the teeth suddenly ending, leaving the
end narrow, slender, naked, slightly bent, with a long hair pro-
jecting beyond the tip of third joint. This joint rather short,
much curved on the outer side, ending in a rather slender hook,
with an inner one of nearly the same 'size. 'Catch' large ; basal
joint longer than broad, with a stout bristle arising from middle
of anterior edge and reaching nearly to tip of second joint, both
front and hind, edges with three of four notches, second joint
very slender on the toothed portion, four-toothed ; whole joint
over half as long as first joint. Length, .08 to .09 inch."

The species has been taken by Packard in the N'ew England
states, and in ^ennessee by Dr. J. Curtis. The difference in
darkness of color between the two first antennal segments and
the rest of the body is not very marked in our specimens ; nor
are the antennae unusually long if we compare them with those
of such forms as E. bicolor or E. dorsalis Uz.

Packard has regarded the narrow proximal part of the mu-
croncs as a part of the dentes, but in this he is evidently in
error. The prinicpal characters, then, which distinguish the
species, are the uniform purple color and the absence of seg-
mental cross-bands. The slender basal tooth is present, as

COLLEMBOLA OF MINNESOTA 77

usual in this genus, on the mucrones, but was* probably overlooked
by the describer. The tenent hair is not greatly swollen. Length,
2.36 mm. Somewhat rare in the southern part of the state, more
common in the northern part. Taken under bark and boards
in rather damp places.

Entomobrya spectabilis Reut.
PI. VIII, Figs. 12-16.

1890. Entomobrya spectabilis. Renter, Coll. in Gaidar, viv. p. 26. PL I, 7.

1893. Entomobrya spectabilis. Schott, Palsearct. Coll. p. 49. PL III, 12-14.

1895. Entomabrya spectabilis. Reuter, Finl. Coll. p. 21.

1896. Entomobrya spectabilis. Schaffer, Coll. v. Hamburg, p. 194.

The species is described by Reuter as : "Yellow, hairy, sides
of the head and hind part of mesonotum slightly ferrugineous,
eyespots, margins of meso- and metanotum, also the I, II, IV
and V abdominal segments, almost the entire metanotum, pos-
terior part of Abd. II, a regular transverse rectangle on the
front part of Abd, IV, with lateral extensions confluent at the
sides and behind by curved lines, black; Ant. Ill and IV cy-
anescent. Length, 1.5 mm."

The species is very abundant in the greenhouse of the
University, but I have never taken it elsewhere, hence there
is some doubt as to its being a native of the state. A very
constant species as to color. In size, our specimens exceed those
of the original description by almost a third, measuring 1.9 mm.

Entomobrya multifasciata Tullberg.

1821. Podura fasciata. Say, Jour. Acad. Phil. II. p. 12.

1838. Podura variegata. Guer. & Per. Gen. des Ins.

1840. Podura simplex. Koch, Fauna Ratesbonensis. Herrich-Schaffer's,
III. p. 354-

1840. Podura Striata. Koch, ibid. p. 354.

1841. Degeeria nivalis. Nicolet, Soc. Helv. p. 70.
1841. Degeeria lanuginosa. Nicolet, Soc. Helv. p. 74.
1841. Degeeria disjuncta. Nicolet, Soc. Helv. p. 71.
1841. Degeeria corticalis. Nicolet, Soc. Helv. p. 72.

1862. Degeeria nivalis. Lubbuck, Notes on the Thys. Pt. II. p. 594.

1867. Degeeria Nicoletii. Lubbock, Linn. Soc. Trans, p. 229.

1871. Degeeria muscorum. Tullberg, Fort ofv. Sv. Podur. p. 148.

1871. Degeeria multifasciata. Tullberg, Fort. ofv. sv. Podur. p. 148.

1871. Degeeria arborea. Tullberg, Fort. ofv. sv. Podur. p. 148.

78 COLLEMBOLA OF MINNESOTA

1871. Degeeria marginata. Tullberg, Fort. ofv. sv. Podur. p. 148.

1873. Degeeria decemfasciata. Packard, Thys. Essex Co., Mass. p. 40.

1881. Degeeria pulchella. Ridley, Ent. Mo. Mag. XVII, p. 270.

188,3. Entomobrya mtiltifasciata. Brook, Revis. Genus Entdmobrya.

1890. Entomobrya multifasciata. Uzel, Thys. Bohemia?, p. 57.

1893. Entomobrya multifasciata. Schott, Palsearct. Coll. p. 49.

1896. Entomobrya multifasciata. Schaffer, Coll. v. Hamburg, p. 197.

"Type. — Antennae about half the length of the body ; the
three terminal segments usually sub-equal, but the second may
be either a little longer or a little shorter than the other two.
Color yellow, shading off to violet in the lighter specimens, to
brown in the darker ones ; there is sometimes a brown ring
at the tip of the first segment. Head yellow, with a broad dark
band around the margin as seen from above crossing the eye
patches. The anchor-shaped band on the crown of the head
is usually well defined.

"Mesothorax slightly longer than metathorax, with a dark
band on its anterior margin which runs along the epimera as
far as the fourth abdominal segment; there is also a strong
central basal band not reaching the margin ; there is a similar
basal band on the metathorax. The first three abdominal seg-
ments increasing in length with similar dark basal bands on
each ; that on the first shows a little thickening at the extrem-
ities; those on the second and third have this thickening in-
creased to a triangular patch. Fourth abdominal segment not
so long as the first three and the metathorax taken together,
fusiform, with two interrupted bands, one across the center and
one across the basal portion of the segment, sometimes the two
bands unite by triangular patches on each side of the median
line ; this segment is narrower at the base than the mesotho-
rax. Fifth and sixth' abdominal segments small, with strong
basal bands.

"Spring not passing the ventral tube. Claws strong; the
upper one with a tooth about the center of the inner margin,
but there is often another smaller one, and sometimes a very
small one on the outer margin. Lower claw lanceolate. Lateral
plates lanceolate and a little curved ; sometimes the tip of one of
these plates is in such a position as to be easily mistaken for a
strong tooth on the upper claw.

"Length, 1/15 inch; width, 1/50-1/60 inch."

COLLEMBOLA OF MINNESOTA 79

The description is taken entire from Brook's "Revision
of the genus Entomobrya." The ' species is regarded as quite
variable, and according to the author quoted, exhibits several
varieties which have been described as different species. While
many of my specimens answer well to the above description,
many others do not, and indeed it is the most perplexing spe-
cies I know of. Our most common form seems to me rather
larger, proportionately narrower, and with less distinct mark-
ings than the type. Not unlikely it is more than a variety,
yet the color gradations are so perfect in a large series that it
seems safer for the present to lea.ve it as it is. A few very pale
specimens have been taken which show scarcely any color on
the body.

Tomocerus arcticus Schott.
PI. VI, Figs. 1-9; VII, Figs. i-4b.

1893. Tomocerus arcticus. Schott, Palasarct. Coll. p. 43. PL III, 89.
1896. Tomocerus arcticus. Schaffer, Coll. v. Hamburg, p. 204.

"Antennse not longer than the body. Dental spines simple,
seven or sometimes eight in number, the innermost small. The
superior claw armed with four or five teeth, the inferior claw
lanceolate. Length about four millimeters. Denuded of its
scales the animal is bright yellow in color." Taken in
Tschuktsch Lande.

This species appears to be very abundant throughout the
state, and is the only species I found out of doors, T. niger oc-
curring only in the greenhouse. Dark leaden, with a slight
purplish metallic reflection when .seen alive with undisturbed
scales. While I feel no doubt as to the identification being
correct, yet a few points may well be noticed which illustrate
the variability of the species. The type seems, by comparison
of a very large number of individuals, to have four denticles on
the superior claw of each pair of feet, but in not a few instances,
the claws of the first pair showed but three denticles. The
inferior claw is more slender in the second and third pairs
than in the first. In the first pair the inferior claw often shows
a very minute inner denticle, which may sometimes be detected
even in the other two pairs. The dental spines would be some-
what perplexing if only a few individuals were at hand, but a

8o COLLEMBOLA OF MINNESOTA

careful comparison of many shows that, aside from an occa-
sional spine which has strayed clear out of position, as sometimes
occurs, the variation has well-defined limits. One may always
expect to find the two most distal spines large; then, there
are commonly four or five much smaller ones before the large
proximal spine is reached. Occasionally the number of these
small spines varies to three, or even six. Often there is a small
spine even more proximal than the large one just mentioned,
and situated slightly more mesad. In one individual, three
small spines instead of one were present. A point of interest
may here be mentioned. The specimens from the northern
part of the state differed somewhat from those taken in the
central and southern parts in that the latter showed a tendency
toward a larger number of the small spines on the dentes.
Six small spines were not very uncommon, besides those sit-
uated proximal of the large proximal spine. These latter
small spines, one, two, or even three in number, were also more
likely to occur in the southern specimens than in the northern.
The minute denticle of the inferior claw, sometimes observed
in the northern specimens, was seldom or never present in the
others. Notwithstanding these slight differences, I believe
they are no more than locality variations, and certainly not to
be taken as indicating distinct species.

From T. niger this species may be very readily distin-
guished by the form of the mucrones, which in T. niger, bears
a large, spur-like tooth close to its base, while in T.arcticus the
tooth is noticeably separated from the base, and there is a smaller
tooth set almost opposite, on the other (outer) edge of the mu-
crones. The mandibles are respectively four and five-toothed.
Rather common throughout the summer under stones, bark, etc.

Tomocerus niger Bourlet.
PI. VI, Figs. 10-12; VII, Fig. 5.

1839. Macrotoma nigra. Bourlet, Mem. Soc. Roy. Lille, p. 390.

1839. Macrotoma ferruginosa. Bourlet, Mem. Soc. Roy. Lille, p. 390.

1842. Tomocerus celer. Nicolet, Mem. Soc. Helv.

1844. Macrotoma celer. Gervais, Ins. Apt. Walckenaer. Vol. III. p. 407.

1844. Macrotoma nigra. Gervais, Ins. Apt. Walckenaer. Vol. III. p. 408.

1844. Macratoma lepida. Gervais, Ins. Apt. Walckenaer. Vol. III. p. 409.

1847. Tomocerus celer. Nicolet, Mem. Soc. Ent. France.

COLLEMBOLA OF MINNESOTA 81

1847. Tomocerus lepida. Nicolet, Mem. Soc. Ent. France.

1871. Tomocerus niger. Lubbock, Monogr. Coll. and Thys. p. 139.

1871. Macratoma vulgaris. Tullberg, Fort, ofver Sv. Podur. p. 149

1876. Macrotoma vulgaris. Tullberg, Coll. Borealia. p. 31.

1882. Tomocerus vulgaris. Brook, Some little-known Coll. etc. p. 22 PI.

I, 15-19-

1890. Macrotoma vulgaris. Uzel, Thys. Bohemise. p. 47.

1893. Tomocerus vulgaris. Schott, Palaearct. Coll. p. 41.

1895. Tomocerus vulgaris, Reuter, Finl. Coll. och Thys. p. 15.

1895. Tomocerus niger. Reuter, Finl. Coll. och Thys. p. 15.

1896. Tomocerus vulgaris. Schaffer, Coll. v. Hamburg, p. 204.

1897. Tomocerus vulgaris. Poppe & Schaffer, Coll. v. Bremen, p. 27-1

Bourlet describes the species as follows : "Same length
as the preceding (T. plumbeus) as to body and antennae ; body
covered with black scales, showing to the unaided eye a slightly
silvery reflection. The body denuded of scales waxy yellow
(Jaune de cire), anterior border of the thorax garnished with a
fringe of short, black hairs ; antennae gray or fawn-gray ; feet of
a greenish-brown, tarsi brown, ventral side yellowish."

Tullberg, whose description of this species as M. vulgaris.
has been generally accepted in lieu of Bourlet, says : "Anten-
nas not longer than the body. 12 to 16 simple spines on the
dentes. Greater claw armed with 4-6 teeth, lesser claw blunt,
lanceolate. Length, 4 millim." I have seen no other record
of this species having been taken in America, and am not cer-
tain but that it may be an exotic species as it has only been
taken in the green-house of the University, where it is rather
common. It differs from our common out-door species, T.
arcticus, in the number and arrangement of the spines on the
dentes, which range from 12 to 16, being more numerous than
in the above-named species. Another difference is that the
distal spine of T. niger is always much larger than the two pre-
.ceding. while in T. arcticus it is the second or ante-distal which
is large. The mucrones also differs considerably in the first two
(proximal) teeth, which are placed almost opposite each other
and at some distance from the end of the dentes in T. arcticvis ;
while in T. niger they are less prominent, and close upon th<.
heel of the mucrones. The antennas differ somewhat from that
figured for T. arcticus in that Ant. I is shorter and stouter as
compared with Ant. II.

82 COLLEMBOLA OF MINNESOTA

Cyphodeirus albinus Nic.
PI. VIII, Figs, 9-1 1.

1783. Crystalpoduren O. Fabricius, Danske Vidensk. Selsk. p. 303.

1842. Cyphodeirus albinus. Nicolet, Hist, des Podurelles. p. 67 PI.

VII, 7

1844. Lepidocyrtus albinos. Gervais, Hist. Nat. Ins. Walckenaer. Vol. III.

1867. Lepidocyrtus albinos. Lubbock, Notes on the Thys. Pt. III. p. 301.

1871. Cyphoderus albinus. Tullberg, Fort. ofv. Sv. Podur. p. 150.

1872. Cyphoderus albinus. Tullberg. Sver. Podur. p. 38. PI. VI, 12-21.

1873. Beckia albinos. Lubbock, Monogr. Coll. and Thys. p. 49. PI. XXIV.
1890. Cyphoderus albinus. Uzel, Thys. Bohem. p. 49.

1893. Cyphoderus albinus. Schott, Palsearct. Coll. p. 44.

1895. Cyphoderus albinus. Reuter, Finl. Coll. p. 16.

1896. Cyphoderus albinos. Schaffer, Coll. v. Hamburg, p. 199.

1896. Tullbergia immaculata. Lie-Pettersen, Norg. Coll. p. 16. PI. II, 1-4.

Described by Nicolet as "Oblong, entirely white, Ant. I
and III short and obconiform in shape; Ant. II and IV much
larger and oblong. Body slightly hairy and very brilliant. In-
sect very agile, about i mm. long. Inhabits worm-eaten trunks
where it lives socially (on il vit en rassemblement nombreux),
and under mosses of forests where it lives solitary. Very com-
mon, especially in Autumn and in early winter."

Aside from the very short description given by Tullberg:
"Undique albus. Ocelli nulii. Unguiculus superior uno dente
magno armatus. Long, i mm.," we look in vain for a helpful
characterization of this species until 1896, when O. J. Lie-
Pettersen, in his "Norges Collembola," attempted to base his
new genus, Tullbergia, on this species. His figures agree
pretty closely with those of Nicolet and Tullberg. Thae latter
has, however, overlooked the smaller tooth on the superior
claw, quite likely on account of insufficient material, as he speaks
of it as found "sparsamt." His figure of the claw indicates that
he did not get a true profile view, as it seems unusually narrow.
When the claw is thus tipped to one side, the lesser tooth is only
with difficulty visible. Not improbably, too, different localities
may produce individuals differing slightly in their minute char-
acters. As to the presence of clavate hairs on the tibia, there
seems to be some doubt ; Tullberg's figure shows a hair with
very slightly swollen tip, while Lie-Pettersen states that they
are not present. The figure given by the latter really shows

COLLEMBOLA OF MINNESOTA 83

the same hair in the ordinary position of a tenent hair, but it
is drawn as a simple, pointed hair. The tip of this hair appears
to me perceptibly swollen. Lie-Pettersen gives the size as
1.5 mm. which corresponds with those I have taken. The species
is very common here throughout the summer, among- damp, de-
caying leaves in the woods, at least along the Mississippi val-
ley. Its agility is very astonishing when we consider the ab-
sence of eyes.

Seira buskii Lubb.
PI. VIII, Fig. 8.

1869. Seira buskii. Lubbock, Notes on the Thys. Pt. IV. p. 280.

1871. Degeeria cyanea. Tullberg, Fort ofver Sv. Podur. p. 149.

18/2. Sira buskii. Tullberg, Sver. Podur. p. 41.

1873. Seira buskii. Lubbock, Monogr. Coll. and Thys. p. 145. PI. XXII.

1890. Sira buskii. Uzel, Thys. Bohemias, p. 54.

1893. Sira buskii. Schott, Palsearct. Coll. p. 52.

1895. Sira buskii. Reuter, Finl. Coll. p. 23.

1896. Sira buskii. Lie-Pettersen, Norges Coll. p. is

1896. Sira buskii. Schaffer, Coll. v. Hamburg, p. 203.

1897. Sira buskii. Poppe & Schaffer, Coll. v. Bremen, p. 271.

Lubbock thus describes the species: "Dark violet with
metallic reflections. Head, legs and base of antennae yelowish.
Eyes on a black patch, and connected by a black band. Spines
yellowish at base, colorless towards the extremnity. Length,
one-fifteenth of an inch. The basal (antennal) segment is rather
shorter than the second or third, which, again, are, though very
little, shorter than the apical. The small claw is without teeth.
The large one has three teeth on the inner, and one on the outer
margin."

Our specimens agree pretty closely with the above de-
scription and with the colored figure given by Lubbock in his
"Monograph." I have not been able to satisfy myself as to the
presence of the above-mentioned outer tooth on the superior
claw. If present it must be very small in our specimens.
Ant. I is never more than half the length of Ant. II, which is
slightly longer than III. Ant. IV usually equals II. The distal
parts of tibia and femur show a decidedly blue color. As to
the form of the feet and furcula, it is almost exactly the same
as S. nigromaculata (see figures). The two species are not liable

84 COLLEMBOLA OF MINNESOTA

to be inter-mistaken, however, owing to the decided difference
in color. S. buskii is also much more hairy and has the ocelli
larger in proportion to the size of the eyespot. Collected under
boards and paper in dark places, sometimes dry, sometimes wet.
Taken once in the basement of Pillsbury Hall at the University.
A very active species ; living solitary, so far as my observation
goes. Not abundant. Hitherto it has been found in England,
Finland, Norway, Germany, Austria, Hungaria, Bohemia, the
Tirol and Italy. Dr. Folsom also mentions it as one of the spe-
cies "apparently restricted to the eastern part of the United
States," and which may be a recent importation from over the
ocean.

Seira nigromaculata Lubb.
PI. VIII, Figs. 1-7.

1873. Seira nigromaculata. Lubbock, Monogr. Coll. and Thys. p. 146.

1872. Sira elongata. Tullberg, Sveriges Podurider. p. 41. PI. VI, 22-35.

1895. Sira nigromaculata. Reuter, Finl. Coll. p. 23.

1896. Sira nigromaculata. Schaffer, Coll. von Hamburg, p. 202.

"Gray; the scales give it a mottled appearance. The eyes
are on dark patches. There is a dark band running along the
side of the body, on the front margin of the mesothorax. and
on the posterior edge of the third, fourth and fifth abdominal
segments. The third abdominal segment has also a transverse
dark band in the middle, interrupted at the center. The sixth
abdominal segment is black. The legs are annulated ; the an-
tennas iron grey, the segments being paler towards the base.
The spring reaches forwards as far as the ventral tube. The
clubbed hairs are numerous. The markings on the scales are
peculiarly bold. Length one-twelfth of an inch."

Tullberg has tried to identify this species with Degeeria
elongata Nicolet, but without foundation. He mentions and
figures five pairs of specialized touch hairs (kansel har). The su-
perior claw bears three inner teeth, and, according to Tullberg,
one outer tooth in addition, though I have failed to find it on
my specimens. He gives the length as one and one-half milli-
metre.

I have taken the species but once. On Sept. 19, 1899, a
dozen specimens were found on the outer stone window sill of

COLLEMBOLA OF MINNESOTA 85

a third-story window of Pillsbury Hall at the University, under
jars where a little moisture remained untouched by the sun.

Lepidocyrtus albicans Reut.
PL VII, Figs 6a-8.

1895. Lepidocyrtus albicans. Reuter, Finl. Coll. p. 20.

1896. Lepidocyrtus albicans. Schaffer, Coll. von Hamburg, p. 200.

The species is described as : "Silvery, without the scales,
entirely white, with only the eye spots and a spot between the
bases of the antennas black, Ant. IV and the distal end of III
pale blue, Ant. I, II and III together about as long as the
head, IV shorter than II and III taken together; dentes equal
to the manubrium in length; or a little longer; mesonotum
slightly prominent. Length 1-1.5 mm."

The above description fits well excepting that Ant. HI
and IV and the tip of II are pale blue, which accords with the
description given by Schaffer; and the mesonotum, which seems
to me quite prominent. Possibly I am mistaken in my identifi-
cation of this species. It is rather common, living solitary un-
der sticks and stones.

Lepidocyrtus decemoculatus n. sp.
PI. VII, Fig. 14.

Entirely white, or with a yellowish or brownish cast, ex-
cepting the antennae which are entirely blue, the black eye spots
with a slight blue shading off at their posterior borders, and a
dark brown line connecting the anterior ends of the eye spots.
Ocelli reduced, 10 in number, six to each eye spot. Antennae
short, stout, the segments proportioned about as in L. pur-
pureus, but more hairy. Claws with a single tenent hair and two
inner teeth on the superior claw, as usual in the genus. Man-
ubrium equal in length to the combined length of the mucrones
and dentes. Mucrones of the usual form.

Probably the smallest species yet described, being but .8 mm.
in length. In color it agrees pretty closely with L. albicans,
but is a much stouter-bodied species, and has the mesothorax
more massive, even, than in L. purpureus. The scales are sil-
ver}' white. This little insect is extremely agile and difficult to

86 COLLEMBpLA OF MINNESOTA

capture. Apparently social in their habits. I have taken them
but seldom, but where found, under a stone or board in a moist
situation, they were in considerable numbers. The number of
ocelli in this species would seem to place it near Reuter's genus
Calistella, but, inasmuch as this is the only essential point of
difference from others of the short bodied Lepidocyrtus, and as
it is probable that the Calistella is rather a reduced Seira-like
form with its more rangy body and long antennae, I believe this
species should be retained in the genus Lepidocyrtus. Isotoma
has a species with but four ocelli, and another in which ocelli
are entirely lacking ; Sminthurus has a species which is eyeless ;
why not then regard the present genus as embracing species in
which the partial reduction of eyes has taken place. I believe that
this must ultimately lead to the reabsorption of the eyeless spe-
cies of Lepidocyrtus which are now referred to the separate genus
Cyphodeirus Nicolet. We certainly have precedent for uniting
two or more genera in one when species are found which prove
to be their connecting links.

Lepidocyrtus sexoculatus n. sp.
PI. VII, Fig. 13.

Entirely white, excepting the eye spots, which are four in
number, and are black. The two anterior eye spots each con-
tain two ocelli, situated in a line. transverse to the head, the, pos-
terior eye spots each contain a single ocellus. The body is well
covered with scales, which seem to give sometimes a yellowish
tint. The mesothorax projects less than in any other species I have
seen. Head large, antennas hairy, not much longer than the head.
Ant. IV shorter than II and III together. The legs are long and
bear claws of the usual form. The outer claw is slender and has
two teeth, the inner one straight and lanceolate. There is a
single tenent hair. The manubrium and dentes are about equal
in length, and the mucrones is essentially like that figured for
L. albicans. Length, I mm.

It is rare, and is found chiefly under bark and stones, where
I have taken it with L. lo-oculatus, Cyphodeirus albinus, Isot-
oma fimetaria and other such white forms. It much resembles
L. lo-oculatus, but is rather larger and lacks the blue color

COLLEMBOLA OF MINNESOTA 87

of antennae, and the dark line connecting the eyes, and, most no-
ticeable of all, it has four small black eye spots in place of two
larger ones. The species is to the genus Lepidocyrtus prac-
tically what the genus Sinella is to the genus Entomobrya, only
the ocellar reduction is less advanced. Probably this .six-eyed
species, in connection with the ten-eyed one, will form a bridge
over which we may bring back the eyeless Cyphodeirus to the
genus from which it was taken.

Lepidocyrtus purpureus Lubb.
PI. VII, Figs. 9-12.

1873. Lepidocyrtus purpureus. Lubbock, Monogr. Coll. and Thys. p. 155.

PI. XXX.

1890. Lepidocyrtus purpureus. Uzel, Thys. Bohemise. p. 51.

1895. Lepidocyrtus purpureus. Reuter, Finl. Coll. p. 18.

1896. Lepidocyrtus purpureus. Schaffer, Coll. von Hamburg, p. 201

The original description reads : "Intensely deep blue with
beautiful, purple reflections. Legs' and basal segment of an-
tennae yellow. Third segment of the antennae shorter than the
second. Thorax with an upright fringe and a central tuft of
short setae. Length, .045 of an inch; breadth, .013."

Schaffer's description speaks of the thickly set, iridescent
scales and says that "Ant. Ill is at least one-third shorter than
II. The first three antennal segments are shorter than the head,
Ant. IV as long as II and III together. Dentes little longer
than the manubrium. Dark blue. Ant. I and II (excepting
the blue end), legs and dentes whitish or yellowish. Length,

i mm.'

The coloration in our specimens exhibits a peculiarity which
is noticeably different from those described. The top of the
head is quite yellowish, even bright yellow in many specimens.
The coxae of the legs, and the ventral tube are blue, the remain-
der of the legs usually brownish yellow. The manubrium is
usually of a diffuse blue, the dentes clear. The mucrones is as
in L. albicans, with the "basaldorn" very slender and even some-
times lacking, owing, perhaps, to accidental breakage. The an-
tennae are short and comparatively stouter than in L. albicans.
As to the relative lengths of the various antennal segments
there is more or less of variation, so that they hardly merit the

88 COLLEMBOLA OF MINNESOTA

importance once attached to them. The mesonotum projects but
little, and is more massive than in the preceding species. Some
of the specimens attain even 1.5 mm. in length. Abundant under
logs and stones.

Lepidocyrtus pusillus (L.).

1767. Podura pusilla. Linn. Syst. Nat. Ed. XII. II, 2. p. 1014.

1788. Podura lanuginosa. Gmel. Linnaeus Syst. Nat. I, 6. p. 2911

1871. Lepidocyrtus seneus. Tullberg, Fort, ofver. Sv. Podur. p. 150.

1862. Lepidocyrtus lanuginosus. Tullberg, Sver. Podur. p. 38. PI. VI, i 7.

1871. Lepidocyrtus aeneus. Lubbock, Monogr. Coll. and Thys. p. 154.

PI. XXIX.

1871. Lepidocyrtus pusillus. Lubbock, Monogr. Coll. and Thys. p. 156

1890. Lepidocyrtus lanuginosus. Uzel, Thys. Bohemias, p. 52.

1893. Lepidocyrtus lanuginosus. Schott, Palaearct. Coll. p. 45.

1895. Lepidocyrtus lanuginosus. Renter, Finl. Coll. p. 19.

1896. Lepidocyrtus lanuginosus. Schaffer, Coll. von Hamburg, p. 200.

1897. Lepidocyrtus lanuginosus. Lie-Pettersen, Norg. Coll. p. 12.

1897. Lepidocyrtus lanuginosus. Poppe & Schaffer, Coll. v. Bremen, p.
271.

The species is associated with so many insufficient and vary-
ing descriptions that it is not easy of determination. However,
if I have assigned my specimens rightly to this species, the fol-
lowing description may be ventured, — Color rather a clear blue,
of about uniform tint throughout the body. Head somewhat
lightei and more purplish in tint, with the posterior part, and
a spot mediad to each eye spot nearly colorless. Antennae short,
little longer than the head, entirely blue, growing darker toward
the apex. Ventral tube blue. Coxae and femurs purplish blue,
tibiae and feet colorless. Manubrium faint blue, dentes color-
less.

About like L. purpureus in form, but without the brownish-
yellow legs and basal parts of the antennas. The figures given
for the claw, mucrones and mesothorax of L. purpureus would
apply about equally well to this species. The antennas, however,
are shorter in proportion to length of head. When the body is
straight, the white, inter-segmental bands are not apparent, ex-
cept slightly at the anterior ends of Th. Ill and Abd. IV.

Length, i mm. Taken under loose bark, etc.

COLLEMBOLA OF MINNESOTA 89

Lepidocyrtus aenescens n. sp.

A blue species with five white cross-bands. Antennae en-
tirely white, legs the same, down to the distal end of the tibiae,
beyond that pale. Mantibrium tinted but slightly with blue,
dentes with a pale yellowish cast. Mesothorax massive, pro-
jecting but slightly over base of head. Antennae short and stout,
hardly longer than the head. Ant. IV about equal to the two
preceding segments. Ant. Ill shorter than II. Dorsal parts
rather heavily scaled in life, but the scales apparently loosely
fastened, as they are very often absent in preserved specimens.
The scales are of a light brown color, the blue of the body is
rather blackish, and presents more of a granular appearance than
in L. purpureus or L. pusillus, where the pigment is more uni-
formly spread. In general form, the three species are much alike.
The same figures of mucrones and claw would answer for all,
yet the species seems distinct from all yet described in the blue
tibiae, the entirely concolorous dark blue antennae, head entirely
blue, blue manubrium, presence of "basaJdorn" on mucrones,
and the white cross-bands on the body. Not that it is unique in
the possession of any one of these characters, but in their combi-
nation. Length, 1.25 mm. One of our commonest collembolan
forms. Found under sticks and stones throughout the summer.

Achorutes boletivorus Pack.
Plate X, Figs. 13, 14.

1873. Achorutes boletivorus. Packard, Thys. Essex Co., Mass.

"A much smaller species than A. nivicola, being about half
the size, with a rather thicker body, and the head a little smaller
in proportion to the body. Antennae shorter, the joints shorter,
sub-spherical, terminal joints ovate, much shorter than in the
other species. Eyes conspicuously black. Legs proportioned
same as in A. nivicola, ending in long, sharp claws ; elater as
well developed as in A. nivicola. Pale gray above with a slight
greenish tinge, on the under side of the body lined with white,
with scattered gray specks on side of body. Supra-anal spines
rather longer than in A. nivicola. Length, .O5-.O7 inch. Sept. 10,
very abundant on under side between lamellae of Boleti and

90 COLLEMBOLA OF MINNESOTA

Agaricus, hundreds on one plant, Brunswick, Maine. Salem
(Mass.), under a heap of horse manure, Aug. 15."

It is difficult to point out the differences between this spe-
cies and that which I have identified as A. longispinus Tullb.
In figuring the antennae, the claws or the anal spines, one figure
would answer for either, though I doubt if A. boletivorus has
any tenent hair. The tenent hair is so slightly clavate on A.
Longispinus as to be scarcely noticeable. It appears, however,
that A. boletivorus is rather the thicker bodied of the two species,
and it is slightly smaller and far lighter in color. My specimens
reach one and one-third millimeters in length. Have taken them
often and in large numbers among the gills of mushrooms of
various kinds, and in tunnels which they had evidently bored
in the flesh of the caps. Several hundreds have been taken
from a single agaric. When the cap is broken up, and their hid-
ing places brought to light, they leap out and usually make a
bee-line for some overhanging fragment of mushroom, or other
place of shelter. They are very lively, usually running about half
an inch, then jumping nearly an inch, then alternating again.
The larger specimens can jump two inches when disturbed, but
when forced to take their largest leap they overdo themselves
and usually turn around, or turn a summersault in the air. so
that they alight 'tail end to," and begin running toward their
starting point., Usually under normal conditions they alight on
their feet, but when hurried will occasionally come down on
their backs. They prefer mushrooms which are beginning to
get stale and decay.

Achorutes longispinus Tullb.
PI. X, Figs. 15-16; XI, Fig. 5.

1876. Achorutes longispinus. Tullberg, Coll. Borealia. p. 37. PI. X, 31-34.
1896. Achorutes longispinus. Schaffer, Coll. v. Hamburg, p. 171. PI. IT,

45-

"Upper claw present. Mucrones of the furcula thick, con-
vergent. Anal spines large, about as long as the upper claw;
papillae separated at their bases. Length, 2 mm." Schaffer adds
"Keulenhaare der Tibien undeutlich" and "Der dunkelblaue Pig-
ment gleichmassig verteilt."

COLLEMBOLA OF MINNESOTA 91

I think there is little doubt that the identification is correct,
though there seems to be a great disparity in size, mine meas-
uring hardly more than I mm.

The fairly uniform dark bluish color, the "undeutlich"
tenent hair, and the similarity of the parts of the specimens to
the figures given by Tullberg and Schaffer convince one that
either our variety is smaller than that from Nova Zembla, or that
I have only immature specimens. As I have taken it but once,
the latter may be true. They were found by hundreds in a little
bunch on the surface of a little pool at the edge of wave-marks
at Lake Pepin, in the latter part of August, 1899. This water
habit, alone, would seem to separate them from their closest
neighbor A. boletivorus, which nearly always occurs in mush-
rooms or occasionallly under bark or rubbish. I have never
found it near the water. In this form, which is the slenderer of
the two, the manubrium narrows greatly before its union with
the dentes, while in A. boletivorus the manubrium broadens rap-
idly basal-wards from its very end. For further comparison, see
A. boletivorus.

Achorutes schneideri Schaffer.
PL X, Figs. 9-12; XI, Figs. 1-2.

1896. Achorutes schneideri. Schaffer, Coll. v. Hamburg, p. 173. PI. Ill,

49-

1897. Achorutes schneideri. Poppe & Schaffer, Coll. v. Bremen, p. 266.

"Dark blue, very short haired. Outer claw bearing in the
middle a very small, often hardly noticeable tooth. Inner claw
suddenly contracted at the middle to a mere bristle. Tibia with
one clavate hair, the .swelling at its end not very pronounced.
Dentes and mucrones together about as long as the manubrium.
Mucrones with narrow plate, end of the edge bowed and pro-
jecting out. Dentes three to four times as long as the mucrones.
Anal spines small, on very small papillae which are not in contact
with each other. Length, 1.7 mm."

The clavate hair on this species is especially large, reaching
out nearly as far as the tip of the superior claw, when bent down
that way, but habitually carried out at a wide angle from the claw.
The hair is nearly straight. The inner edge of the superior claw

92 COLLEMBOLA OF MINNESOTA

has a very minute tooth. The color is exceedingly dark, appear-
ing a dead black to the naked eye. They live socially, as is com-
monly the case among the Achorutes, and often occur in great
numbers on the under surface of boards and in other moist sit-
uations. Once I found scores of them in the crevices of an
axe-wound in a living tree, where the sap was exuding enough to
supply the needed moisture. This is probably the most numer-
ous species of the genus in our locality. My specimens seem con-
siderably larger than those of the description, measuring 2.25mm.
in length, yet perhaps this is not surprising, as many of our col-
lembolans are somewhat larger than European specimens of the
same species.

Achorutes socialis Uzel.
PI. X, Figs. 20-23; XI. Fig- 3-

1890. Achorutes socialis. Uzel, Thys. Bohemias, p. 69. PI. II, 16-19.
1893. Achorutes socialis. Schott, Palsearct. Coll. p. 81. PI. VII, 6-8.
1896. Achorutes socialis. Schaffer, Coll. v. Hamburg, p. 172.

"Lower claw present. Upper claw large, slightly curved,
an acute tooth not far from the apex. Clavate hair over the claw.
Tibia set with long hairs, the clavate hair being longest of all.
Mucrones oblong, attenuate toward the end, blunt. Dentes less
than three times the length of the manubrium, thick, three times
longer than the mucrones. Five acute conical teeth on the
lower side of the dentes. Anal spines strong, about equalling
the papillae in length, slightly curved, obtuse. Antennae as long
as the manubrium, the segments successively increasing in
length, Ant. II truncate at the apex, III and IV less distinctly
separated. Body swollen, narrowed behind, the final segment
cylindrical. Dark blue, pruinose, feet, antennae and furcula pur-
ple. Length, 1-1.5 mm."

Uzel mentions their living in very large colonies in low,
loamy ground and sometimes being found on snow. So far it
has been taken here but once, and that time by Mr. O. W.
Oestlund about the middle of April. Though there is no record
with the date, yet it is probable that they were in considerable
numbers as nearly thirty specimens were secured. The zigzag
row of five or six chitinous teeth on the dentes serves well to
distinguish it from any of the other species with which I am

COLLEMBOLA OF MINNESOTA 93

acquainted, and the anal horns are much smaller than in any
other of our species.

Achorutes schbtti Reut.
PI. X, Figs. 17-19; XI, Fig. 4.

1895. Achorutes schotti. Renter, Finl. Coll. p. 31. PI. II, 8.

1896. Achorutes schotti. Schaffer, Coll. v. Hamburg, p. 171. PI. Ill, 57.

"Blue or grayish blue, short haired; tibia with a single cla-
vate hair over the large claw ; large claw slightly curved, rather
stout, smaller claw very slender, subuliform or almost bristle-like,
reaching about to the middle of the large claw. Furcula with
the dcntes shorter than the manubrium, somewhat thick, slightly
narrow at the apex, a long hair behind, near its base, mucrones
aboutt 1/3 to 2/5 shorter than the dentes, slender, its apex
acuminate and slightly curved ; anal papillae minute, spines
small, straight, about the length of the papillae. Length, I mm."

It will be noticed that Reuter does not mention the tooth
on the inner margin of the large claw, yet he shows in his figure
that it is not very large. The antennae are of the short type,
much like that which I have figured for A. boletivorus. The
body is rather short and heavily built. Some of the specimens
show hardly any of the bluish tint, but are a rather light gray.
The tenent hair is much shorter and more slender in my spec-
imens than in either A. schneideri or A. socialis, though it seems
long in Renter's figure. I have only taken the species twice,
and then sparingly. Under stones in moist places. Length, I
mm. Rather a sluggish form.

Podura aquatica Linn.
PL XI, Figs. 6-1 1.

1740. Podura aquatica nigra. DeGreer, Acta Soc. Reg. Sc. Upsal.

1746. Podura aquatica nigra. Linne, Fauna Suec. Ed. I. p. 343.

1758. Podura aquatica. Linnaeus, Syst. Nat. Ed. X. p. 609.

1762. La Podure noire aquarique. Geoff roy, Ins. Env. Paris. II. p. 690.

J77S- Podura aquatica. Fabricius, Syst. Ent.

1776. Podura aquatica. Miiller, Zool. Prod.

1780. Podura aquatica. O. Fabricius, Fauna Groenl. p. 211.

1781. Podura aquatica. Schrank, En. Ins. Austria;.
1804. Podura aquatica. Latreille, Hist. Nat. Crust, et Ins.

1835. Podura aquatica. Boisduville & Lacordaire, Faun. Ent. Env. Paris.

94 COLLEMBOLA OF MINNESOTA

1838. Achorutes aquatica. Burmeister, Handb. d. Entom.

1838. Hypogastrura aquatica. Bourlet, Mem. sur les Podures. p. 31.

1839. Achorutes aquatica. Gervais, in Walckenser. Ins. Apt. III. p. 4.36.
1841. Podura aquatica. Nicolet, 1'Histoire d. Podur. p. 55.

1841. Podura aquatica. Lucas, Hist. Nat. des. anim. Art. p. 565.

1842. Hypogastrura aquatica. Bourlet, Mem. Soc. Roy. Douai.
1847. Podura aquatica. Nicolet, Ann. Soc. Ent. France.
1867. Podura aquatica. Lubbock, Trans. Linn. Soc.

1871. Podura aquatica. Tullberg, Fort ofv. Sv. Podur. p. 153.

1871. Podura aquatica. Lubbock, Monogr. Coll. and Thys. p. 185. PI.

XLII.

1872. Podura aquatica. Tullberg, Sv. Podur. p. 50. PI. X, 1-6.

1873. Podura aquatica. Packard, Thys. from Essex Co., Mass. p. 35
1890. Podura aquatica. Uzel, Thys. Bohemiae. p. 73.

1893. Podura aquatica. Schott, Paljearct. Coll. p. 76.

1895. Podura aquatica. Reuter, Finl. Coll. p. 29.

1895. Podura aquatica. Reuter, Coll. pa Sno och is. p. 121.

1896. Podura aquatica. Schaffer, Coll. v. Hamburg, p. 171. PI. II, 38.

1896. Podura aquatica. Lie-Pettersen, Norg. Coll. p. 19.

1897. Podura aquatica. Poppe & Schaffer, Coll. v. Bremen, p. 266.

Opaque, blackish-blue; antennae and legs reddish brown.
Body broadly fusiform. Furcula reaching beyond second pair
of legs ; mucrones thick, short and nearly straight. Dentes ar-
cuate, with an incipient joint at the bend; the distal ends cov-
ered with transverse rows of small, chitinous tubercles. Mucrones
short, somewhat spear-like, with an outer tooth. Claw long and
slender, slightly curved, without teeth. Projecting over the claw
from the tibia is a long hair, which is not, however, swollen at the
end. Antennae about the length of the head, appearing more slen-
der from a side than from a dorsal view, as they are slightly flat-
tened. The length generally given for this species is I mm.
though Nicolet says "i millimetre et demi a 2." Our full grown
specimens measure about 1.5 mm.

One of the most widely spread species of the Collembola,
being reported from almost every place where this group has been
studied. With us it seems very abundant. It is found among
rubbish on the edge of lakes where the waves dash up so that
part of the time the insects are on the weeds and stones, and
again they are jumping about on the surface of the water. Some-
times they may be taken in great numbers from the surface of
stagnant pools. It is of interest to compare the furcula with
the water-leapers among the Sminthuri, which they somewhat

COLLEMBOLA OF MINNESOTA 95

resemble in form. In both cases the furcula is dorso-ventrally,
instead of laterally flattened.

Xenylla gracilis n. sp.
PI. XI, Figs. 12-15.

Rather dark blue above, paler beneath. Body slender, fu-
siform, head narrow in front, becoming broader between the
eyes and then narrowing again. Thorax narrower than the head.
Abdomen gradually broadening posteriorly till the fourth seg-
ment, after that narrowing rather abruptly, the fifth and sixth
segments being much narrower. The sixth is blunt on the end,
and bears two supra-anal spines on separated papillae, the spines
not longer than the papillae themselves. Claws short, unarmed,
tibiae with two clavate hairs. Ocelli placed as usual in this genus.
Antennae hardly longer than the head. The second, third and
fourth segments about equal and somewhat longer than the first.
The third and fourth are broad. The mucrones is of a different
form from any described or figured so far, the recurved hook at
its end being quite characteristic of the species. The dentes and
mucrones together are about one-third longer than the claw.
Length, .9 mm. Taken rather rarely in damp places under boards
along the Mississippi bottom lands, where they live socially.

Friesia caldaria n. sp.
PI. XI, Figs. 16-18.

Purplish blue above, paler beneath. Eye spots conspicu-
ously black. Body short and thick, with antennae, legs and fur-
cula to correspond. Head triangular in outline as seen from the
side. Claw rather short and stout, tibiae with two clavate hairs
nearly as long as the claw. The fifth and sixth segments of the
abdomen bear dorsally several clavate hairs. The furcula is
more rudimentary than in any other genus, the manubrium being
very short and broad, the mucrones hooked at the end, and two-
thirds as long as the dentes. Dentes and mucrones together are
but little longer than the larger anal horns. The three anal horns
are situated in a triangle, the hindmost one being median, and
somewhat smaller than the other two. Each one is set on a short
papilla. There is present a well-developed tenaculum, with two-

96 COLLEMBOLA OF MINNESOTA

toothed blades much as an Achorutes. The skin is thickly cov-
ered with small conical, chitinous tubercles. Length, .75 mm.

Under boxes and plant jars in University greenhouse, where
the dirt is quite moist. They are quite rare, and have been taken
withe Isotoma minima and I. fimetaria. As I have never taken it
out of doors, it is possibly an exotic species. Hitherto, the
genus has been, so far as I know, represented by but one type
species, F. mirabilis (Tullberg). From that species F. caldaria
differs in the possession of clavate hairs on the tibia, and in the
better development of the furcula. Whether F. mirabilis has the
clavate hairs on the final abdominal segments, it is impossible to
determine from any literature at hand, but it is improbable, in-
asmuch as Brook mentions some strong hairs on the fifth seg-
ment, "which, unless accurately focussed, look broad enough at
the base to be taken for spines," and yet he says nothing about
their ends being clubbed. Probably Tullberg's species is consid-
erably larger, as he gives the length as 1.5 mm. ; though my num-
ber of specimens of F. calderia is so limited that it is possible none
of them are mature. I believe this is the first record of this
genus in America.

Aphorura inermis (Tullberg).

1872. Lipura inermis. Tullberg, Sver. Podur. p. 55.

1873. Lipura inermis. Lubbock, Monogr. Coll. and Thys. p. 194.
1873. Lipura fimetaria. Packard, Thys. Essex Co., Mass. p. 28.

1890. Lipura inermis. Reuter, Coll. in Cald. viv. p. 20.

1891. Lipura inermis. Schott, Kaliforn. Coll. p. 24.
1893. Lipura inermis. Schott, Palsearct. Coll. p. 88.

1895. Lipura inermis. Reuter, Finl. Coll. p. 33.

1896. Lipura inermis. Lie-Pettersen, Norg. Coll. p. 21.

1896. Aphorura inermis. Schaffer, Coll. v. Hamburg, p. 161. PI. II, 18 19.

The species is described as: "Post-antennal organ with four-
teen elevations. Two ocelliform punctures at the base of each
antenna. No anal spines. Length, i mm."

The claws are unarmed, the lower one very slender, and, in
fact, little different from that figured for A. ambulans. The an-
tennae are comparatively shorter than in A. ambulans, and the
whole body seems not only shorter, but less slender than in that
species. The absence of anal horns in A. inermis separates it
easily from the species of Linne, which it otherwise so closely re-

COLLEMBOLA OF MINNESOTA 97

sembles, both being entirely white and eyeless. Schott found this
spcies in California and, in referring to Packard's record of L.
fimetaria, he says: "Ohne Zweifel meint Packard mit L. fimetaria
obige Art wenn er in seiner Beschreibung sagt : "It may be
known from L. ambulans, with which at first it may easily be
confounded, by wanting the hooks at the end of the abdomen."
I have taken but few specimens of this species. They were
found in damp places, on the under side of stones, and were
not very active.

Aphorura ambulans (L., Nicolet).
PI. XII, Figs. 3-7.

1758. Podura ambulans. Linne, Syst. Nat. Ed. X. p. 609.

1847. Anurophorus ambulans. Nicolet, Essai Classif. 1'Ord. Thys. p. 384.

PI. VI, 14.

1862. Lipura ambulans. Lubbock, Notes on the Thys. Pt. II. p. 600.

1869. Lipura ambulans. Tullberg, Skand. Podur. af. Underf. Lipur. p. 17.

1871. Lipura ambulans. Tullberg, Fort. ofv. Sver. Podur. p. 154.

1872. Lipura ambulans. Tullberg, Sver. Podur. p. 55. PI. XI, 16-29.

1873. Lipura ambulans. Packard, Thys. Essex Co., Mass. p. 29.

1873. Lipura ambulans. Lubbock, Monogr. Coll. and Thys. p. 189 PI.

XLIII.
1893. Lipura ambulans. Schott, Palaearct. Coll. p. 87.

1895. Lipura ambulans. Reuter, Finl. Coll. p. 33.

1896. Lipura ambulans. Lie-Pettersen, Norg. Coll. p. 20.
1896. Aphorura ambulans. Schaffer, Coll. v. Hamburg, p. 161.

"Elevations of each post-antennal organ 12-14. Ocelliform
punctures at the base of each antenna 2. Anal spines large, ar-
cuate. Length, 2 mm.," says Tullberg.

Body entirely white^ with a few scattered hairs. Protho-
rax short, but visible from above. The skin is finely granular.
The post-antennal organs are not easy to make out ; they are elon-
gate, consisting each of a double row of elevations. The antennae
are quite peculiar in form, as may be seen by referring to the
figures. The species is quite abundant, under bark and sticks
in damp places. They are often found in colonies so that one may
take many at once. I have taken them with our other albino
collembolans : Cyphodeirus albinus and Isotoma fimetaria.

98 COLLEMBOLA OF MINNESOTA

Anurophorus laricis Nic.
PI. XII, Figs. 1-2.

1842. Anurophorus laricis. Nicolet, Hist. les. Podur. p. 53. PI. Ill, 3.

1844. Anurophorus laricis. Gervais, Ins. Apt. in Walckenser. Vol. III.

p. 442.

1847. Anurophorus laricis. Nicolet, Ann. Soc. Ent. France.

1862. Lipura corticina. Lubbock, Notes on the Thys. Pt. II. p. 600.

1871. Anurophorus laricis. Tullberg, Fort. ofv. Sv. Podur. p. 164.

1872. Anurophorus laricis. Tullberg, Sver. Podur. p. 53. PI. XII, 1-2.

1873. Lipura corticina. Lubbock, Monogr. Coll. and Thys. p IQI PI

XLV.

1890. Anurophorus laricis. Uzel, Thys. Bohemia, p. 74.
1893. Anurophorus laricis. Schott, Pal?earct. ColL p. 86.

1895. Anurophorus laricis. Reuter, Finl. Coll. p. 33.

1896. Anurophorus laricis. Schaffer, Coll. v. Hamburg, p. 164.

1896. Anurophorus laricis. Lie-Pettersen, Norg. Coll. p. 20.

1897. Anurophorus laricis. Poppe & Schaffer, Coll. v. Bremen, p. 266.

This widely distributed species is described by Nicolet as
"Smaller and more compressed than the preceding- (Aphorura
fimetaria). Body irregularly dotted, quite brilliant metallic black,
paler beneath, with a few short hairs ; Posterior borders of the
segments slightly raised; two transverse depressions at the an-
terior border of each segment near the midline of the
back. Antennae paler than the body; a slight depression
on top of the head between the eyes, which are black and
only 1 6 in number, placed in each lunule-like eyespot; the eye-
spots situated behind the antennae. Legs pale yellow (fauve).
Ventral tube large and deep ; no anal horns at the tip of the ab-
domen. Length, i.5mm. First found under the bark of Larix
europea DG."

Later writers speak of it as "without anal spines, post-an-
tennal organ, lower claw and furcula," though these are generic
rather than specific characters. The body is broadest at the
posterior part of the abdomen, which is broadly rounded off at
the end. The color of my specimens is dark blue, which is the
color given by most authors. The legs are pale blue, the claw
short, stout and unarmed, and at the tip of the tibia are borne
two long hairs which seem to me slightly clavate. Tullberg
figures but one such hair, and labels it "pilis apice arcuatus."
The antennae are longer than the head; Ant. I being about two-

COLLEMBOLA OF MINNESOTA 99

thirds as long as II, which equals III, IV is about as long as I
and II together. The genus has never been reported from North
America before, so far as I know ; and certainly the species never
has. They live socially, but must be rare in the localities where
I have collected, as I have taken them but once. They were found
under bark or under chips and boards in damp .situations near the
shore of Lake Pepin.

Anurida tullbergi Schott.

PI. XII, Figs. 8-9.

1891. Anurida tullbergi. Schott, Nya Nordiska Coll. Ent. Tidsk. XII.

p. 192.
1893. Anurida tullbergi. Schott, Plsearct. Coll. p. 91. PL VII, 17-18.

1895. Anurida tullbergi. Renter, Finl. Coll. p. 33.

1896. Anurida tullbergi. Coll. v. Hamburg, p. 164. PI. II, 23.

"Post-antennal organs irregular. Elevations (tumores) in
each organ 24-28. Ocelli 10, 5 on each side of the head. Length.
2-2.5 mm."

The claws are without teeth. The dark blue color of the in-
sect is laid on rather irregularly over a darker ground, giving
a somewhat netted appearance, the dark color far over-weighing
the light, which is more in evidence on the ventral side than on
the dorsal.

Schott, from whom the substance of the above is taken, also
remarks that it lives like A. maritima Laboulb. except that he had
never taken A. maritima in fresh water, while A. tullbergi is
found on the surface of ponds.

Evidently these species are very closely related, but the
shape of the post-antennal organ, as well as the much larger num-
ber of elevations composing the ring, will serve to separate it
from A. maritima which has but seven or eight, and these situated
in a circle. I have taken but two specimens of this species.
These were taken with a colony of Achorutes longispinus Tullb.
in a little pool at the edge of the wave-marks at Lake Pepin,
Minn.

ioo COLLEMBOLA OF MINNESOTA

Neanura muscorum (Tempi.).

PI. XII, Figs. 12-14.

1834. Achorutes muscorum. lempleton, Thys. Hib. p. 97.

1838. Achorutes muscorum. Burmeister, Handb. d. Entomol.

1840. Achorutes muscorum. Lucas, Hist. Nat. Crus. Ar. et. Myr.

1842. Achorutes tuberculatus. Nicolet, Mem, Soc. Helv .

1844. Anoura tuberculata. Gervais, Hist. Ins. Apt. Walckenser. p. 443.

Vol. III.

1847. Anoura muscorum. Nicolet, Mem. Soc. Ent. France, p. 338.

1862. Anoura muscorum. Lubbock, Notes on the Thys. Pt. II. p. 600.

1869. Anura muscorum. Tullberg, Skand. Podur. af Underf. Lipur.

p. 21.

1869. Achorutes tuberculatus. Porath, Of. af k. Vetensk.-Akad. Forh.

1871. Anura muscorum. Tullberg, Fort. ofv. Sv. Podur. p. 155.

1872. Anura muscorum. Tullberg, Sver. Podur. p. 58. PI. XII, 18-24

1873. Anoura muscorum. Lubbock, Monogr. Coll. and Thys. p. 197. PI.

LVI, 27-29.

1873. Anura gibbosa. Packard, Thys. of Essex Co., Mass. p. 27.
1876. Anura muscorum. Tullberg, Coll. Borealia. p. 41.
1890. Anura muscorum. Uzel, Thys. Bohemia?, p. 76.
1890. Anura muscorum. Reuter, Coll. in Caldar. viv. p. 20.
1893. Anura muscorum. Schott, Palaearct. Coll. p. 93.
1893. Neanura muscorum. MacGillivray, North. Am. Thys. Pt. IV. Can.

Ent. XXV. p. 314.

1895. Anura muscorum. Reuter, Finl. Coll. p. 34.

1896. Anura muscorum. Lie-Pettersen, Norg. Coll. p. 21.

1897. Neanura muscorum. Poppe & Schaffer, Coll. v. Bremen, p. 266.
1900. Neanura muscorum. Absolon, Aphoruriden aus d. Hohlen d. Mahr,

Karstes. Zool. Anzeiger. XXIII. p. 406.

Lubbock's description is : "Body subcylindrical, turned pos-
teriorly, and ending with two mammillae; dark purplish. Head
short, triangular. Eyes not remote from the base of the an-
tennae, which are very .short and have the first joint very large,
succeeding necessarily diminishing in size, last acuminate. Legs
pale blue. Rings with long, spiny hairs in rows along the back ;
hairs usually arising in pairs. Length, .07 of an inch."

In the young the color is lighter, as the pigment is not so
dense. The eyes are three on each side of the head, and in the
young each eye patch is divided into two parts which are sep-
arated from each other, the anterior bearing two ocelli, the pos-
terior but one. The sense kernel at the tip of the antennae is single
and nearly globular. From most positions the antennae appear

COLLEMBOLA OF MINNESOTA 101

but three-jointed, the joint between Ant. Ill and IV being hardly
noticeable. There is little danger of confusing this species with
any other species found here. The large tubercles on the back
and at the posterior end of the body, which caused Nicolet to
name it "tuberculatus" ; the presence of but three eyes on each
side ; the thick body noted by Packard when he named it "gib-
bosa" ; all help to distinguish it.

The mouth cone is sharp in front, and projects front of the
head. A very common species in Minnesota, and has been re-
ported as well from many other parts of the United States. It
lives in roten wood and in other moist, protected places. It
seems to prefer wood that is in an advanced stage of decay, and
pretty juicy, where it is to be found in the cracks and worm
holes.

Neanura quadrioculata n. sp.
PI. XII, Fig. 15.

Entirely white except the two black eye patches on each side
of the head, each eye patch containing a single ocellus. An-
tennae as long as the head. Tubercles not so prominent as in N.
muscorum, and bearing long sense hairs. Length, .8 mm., and
possibly more.

This might easily be mistaken for the young of the preceding
species had it a pigmented skin, but I believe the young of N.
muscorum always show more or less of the bluish pigment dots
which are entirely absent in this species. The color is white,
with a yellowish cast. The buccal cone is sharp and projects as
far forwards as in N. muscorum ; while the antennae are rather
larger, comparatively, than in that species, though of the same
form. This is what we would expect in an albino species. The
presence of but four eyes instead of six is, however, the distin-
guishing feature, though not very easy of determination. N.
muscorum, when young has two eye patches on each side of the
head, but the front one always bears two ocelli. They are rare
and occur under sticks in damp places.

102 COLLEMBOLA OF MINNESOTA

Aphoromma granaria (Nic.).

PI. XII, Figs. lo-n.

1847. Anoura granaria. Nicolet, Ann. Soc. Ent. France.

1862. Anoura granaria. Lubbock, Notes on the Thys. Pt. II. p. 601.

1871. Anurida granaria. Tullberg, Fort. ofv. Sv. Podur. p. 155.

1872. Anurida granaria. Tullberg, Sver. Podur. p. 56. PI. XII, 13-17.

1873. Anoura granaria. Lubbock, Monogr. Coll. and Thys. p. 198. PI.

XLIX.

1890. Anurida granaria. Uzel, Thys. Bohem. p. 76.

1891. Anoura granaria. MacGillivray, Cat. Thys. of N. Amer. Can. Ent.

XXIII. p. 276.

1893. Aphoromma granaria. MacGillivray, Can. Ent. XXV.
1893. Anurida granaria. Schott, Palsearct. Coll. p. 92.

1895. Anurida granaria. Renter, Finl. Coll. p. 33.

1896. Anurida granaria. Lie-Pettersen, Norg. Coll. p. 21.
1896. Anurida granaria. Schaffer, Coll. v. Hamburg, p. 167.

"Entirely white. Body, antennae and legs finely granular.
Length, 2mm. Entirely of a uniform, opaque, alabaster white,
excepting the median part of the back, which is slightly tinted
with dark yellow and rather transparent. The bodv is clothed
with short hairs, more numerous on the antennse ; the whole sur-
face above and below, as well as the antennse and legs, covered
with a granulation, very fine and regular ; the granules in rounded
cones. The buccal cone is large, short, rounded at the tip, its
opening indicated by a very distinct little transverse slit; the
feet bear a single rather long claw : finally, the anal segment is
composed of three hemispherical tubercles (mamelons), a superior
and two inferior, at the center of which is the anus." I think
no one has mentioned the sense knobs on the antennal tips.
They are much as in Anurida tullbergi. The post-antennal or-
gans are situated rather high up on the head, instead of more lat-
erally as in the Aphoruras, and are rounded in outline, consist-
ing of 12 to 14 "tumores" of triangular shape, their longest points
extending inward toward the center of the ring. Nicolet remarks
a yellow tint down the middle of the back. Tullberg says most
of his specimens were entirely white, but a few found among
some rubbish thrown up by the sea were yellowish. The speci-
mens are so colorless that any yellow food matter in the intes-
tinal tract shows through very plainly, and may possibly have

COLLEMBOLA OF MINNESOTA 103

given rise to the above observations. I have but three specimens,
which were taken under the bark of a pine log on Gray Cloud
Island, in the Mississippi River below St. Paul. The log came
down from the northern pineries, and posibly the specimens
came down with it. MacGillivray records the species from
Ohio.

LIST OF NEW SPECIES

The figure immediately following the name of the species
refers to the text page; the others refer to the plate and
figures.

Sminthurus curvisetis, 50; III, 1-7.
" longisetis, 51; III, 8-i3b.

" minnesotensis, 52; II, 10-16 and XIV.

Orchesella albosa, 61; I, 14, 15.

zebra, 61; I, 8-13 and XVI, i.
Isotoma minima, 63; IX, 17-19 and X, I.
" bidenticula, 66; X, 2-4.
" catena, 69; IX, i5-i6b.
" caeruleatra, 70; IX, 11-14.
" muskegis, 72; XIII.
Entomobrya bicolor, 73; XVI, 2.

clitellaria, 75; XV.

Lepidocyrtus decemoculatus, 85; VII, 14.
" sexoculatus, 86; VII, 13.

" aenescens, 89.

Xenylla gracilis, 95; XI, 12-15.
Friesia caldaria, 95; XI, 16-18.
Neanura quadrioculata, 101; XII, 15.

INDEX

Names and figures in boldface indicate respectively full descriptions
and the pages on which the descriptions begin. Roman numerals indicate
plates.

Abd. I, Abd. II 23.

Abdomen of the Collembola. ... 7.

Abdominal appendages 7, 8.

ACHORUTES..38, 6, 7, 40, 72, 96.

aquatica 94.

boletivorus 89, X. 91, 93.

longispinus 90, X, XL 99.

muscorum 100.

nivicola 89.

schneideri 91, X, XI. 93.

schotti 93, X. XL

socialis 92, X, XL 93.

tuberculatus 100.

Aetheocerus aquaticus 71.

Anal horns 8, 23.

Anal organs 23.

Anal papilla 23.

Anal tubercle 23.

Anoura

granaria 102.

muscorum 100.

tuberculata 100.

Ant. I, Ant. II 23.

Antennae 6.

Antennal organs 6, 23.

Anura

gibbosa 100.

granaria 102.

muscorum 100.

ANURIDA 42.

granaria

102.

maritima 5, 99.

tullbergi 99, 102.

ANUROPHORUS 42.

ambulans 9"-

laricis 98.

Anus 8.

APHOROMMA 42.

granaria

102.

APHORURA 41.

ambulans 97, XII. 65, 96.

fimetaria '

inermis 96.

APHORURIDAE 40, S.

Apterygogenea 9, 25.

Appendages, of the abdomen... 7.

biramus 9, 10.

of the head 5.

of the thorax 6.

Beckia albinos 82.

Bibliography 15.

Biramus appendages 10.

Bittacus 8.

Boreus 8.

Calistella 86.

Campodea 9.

Catch 8, 23.

Caudal appendage 8.

Characters of the Collembola. . 5.

Clavate hairs 23.

Claws 7, 10, 23.

inferior 23.

inner 23.

outer 23.

superior 23.

Clubbed hairs 7, 23.

Collecting Collembola 13.

Collembola, Key to the order of 25.

Coxa 7.

Crystalpoduren 82.

CYPHODEIRUS 35, 34, 86, 87.

albinus 82, 65, 86, 97.

Cyphoderus

albinos 82.

albinus . 82.

Degeeria 33.

arborea 77.

corticalis 77.

cyanea 83.

decemfasciata 78.

disjuncta 77.

lanuginosa 77.

marginata 78.

multifasciata 77.

muscorum 77.

nicoletii 77.

nivalis 77.

pulchella 78.

purpurascens 76.

io8

INDEX

Denies 8, 23.

Denticles of the claws 7.

Desoria

annulata 68.

cylindrica 68.

ebriosa 68.

fusca 68.

pallida 68.

viatica 68.

Distribution of the Collembola, 11.

Economic importance of the

Collembola 3.

Entognatha 5.

ENTOMOBRYA 33, 35, 87.

bicolor 73, XVI. 76.

clitellaria 75, XV. 34.

dorsalis 74, 76.

multifasciata 77, 34.

orcheselloides 74.

purpurascens 76.

spectabilis 77, VIII.

ENTOMOBRYiDAE 29, 26, 37.

Eyepatches 5.

Eyes 5, 10, 11, 12.

Femur 7.

FRIESIA 40.

caldaria 95, XL

mirabilis 40, 96.

Furcula 8, 10, 23.

General characters of the Col-
lembola 5.

Genital papilla 8, 23.

Habits of the Collembola 11.

Hairs

clavate 23.

clubbed 7, 23.

tactile 6.

tenent 7, 23.

Halthaken 8.

Head of the Collembola 5.

Heterotoma chlorata 68.

Hypogastrura aquatica 94.

Inferior claws 23.

Inner claws 23.

ISOTOMA 31, 33, 86.

alba 64.

anglicana 68.

bidenticula 66, X. 64.

catena 69, IX.

cseruleatra 70, IX.

fimetaria 64, X. 86, 96, 97.

grandiceps 70.

hiemalis 70.

leonina 67, IX.

lineata 6,8.

minima 63, IX, X. 66, 96.

minuta 63.

muskegis 72, XIII.

palustris 70, IX. 68, 69.

palustris var. fucicola 69.

quadrioculata 65, X. 64.

sensibilis 67, IX.

tricolor 68.

viridis 68, IX. 69.

Key to the: —

Family Aphoruridse 41.

Entomobryidse .... 29.

Poduridse 38.

Sminthuridse 25.

Genus Achorutes 39.

Aphorura 41.

" Entomobrya 34.

Isotoma 32.

" Lepidocyrtus 36.

Neanura 42.

Qrchesella 30.

Papirius 26.

Seira 36.

Sminthurus 27.

" Tomocerus 35.

Order Collembola 25.

La Podure brune enfumee.... 53.

La Podure brune ronde 53.

La Podure noire aquarique. . . . 93.

Legs 7.

Length 23.

LEPIDOCYRTUS 36, 34, 87.

senescens 89.

aeneus 88.

albicans 85, VII 87.

albinos 82.

decemoculatus 85, VII. 86.

lanuginosus 88.

purpureus 87, VII. 85, 88, 89.

pusillus 88, 89.

sexoculatus 86, VII.

Lipura

ambulans 97.

corticina 98.

fimetaria 96.

inermis 96.

Literature consulted 15.

List of new species 105.

Machilis , 6, 8, 9, 10, 11.

Macrotoma

celer 80.

ferruginosa 80.

lepida 80.

nigra 80.

vulgaris 81.

Manubrium 10, 23.

INDEX

109

Mesothorax 6

Metathorax 6

Mouthparts

Mucrones

23.

NEANURA .............. 42, 6, 7.

muscorum ........ 100, XII. 101.

quadrioculata .......... 101, XII.

Neuroptera ................... 8-

New species, List of .......... 105.

Ocelli ................ 5, 10, 11, 12.

ORCHESELLA .............. 30.

albosa ......... . ........... 61, I.

cincta. Regeneration of an-
tennse .................... 62.

zebra ................ 61, I, XVI.

Orthoptera .................... 5.

Outer claws ................... 23.

Ovipositor .................... 8.

Panorpa ...................... 8.

PAPIRIUS ............... 26, 6, 7.

ater ........................ 58-

maculosus ........... 58, I, 5, 52.

marmoratus ................ 53.

unicolor .................... 59.

Pediculidse ................... 10.

Phylogeny of the Collembola. . 9.
Pilosi ........................ 27-

PODURA .................. 39, 38.

ambulans .................. 97.

aquatica ............. 93, XI. 58.

cinerea ............ 70-

nigra ............... 93.

atra ........................ 53.

fasciata .................... 77-

fimetaria ................... 64-

fusca ...................... 53.

fusco-nigra ................ 53.

globosa fusca ............... 53.

lanuginosa ................. 88.

palustris ................ 70, 71.

psi

pusilla ..................... 88.

p- o

signata ....................

simplex .................... ??•

striata ..................... ??•

terrestris ................... 64.

variegata .................. 77-

viridis ...................... 68.

PODURIDAE .............. 37, 31.

Postantennal organs ........ 6, 23.

Preserving Collembola ........ 13.

Prothorax ..................... 6.

Pterygota ..................... 9.

Regeneration of antennae ...... 62.

Relationships of the Collem-

bola ..................... 9-

Saltatory organ 8, 23.

Scales 9, 36, 85.

SEIRA 35, 34.

buskii 83, VIII.

nigromaculata 84, VIII. 83.

Setosi 27.

Sinella 87.

Sira

buskii 83.

elongata 84.

nigromaculata 84.

SMINTHURIDAE 25, 5, 6, 38.

SMINTHURUS 27, 6, 86.

aquaticus 56.

arvalis •' • • 4.

aureus 43, V. 46, 48.

bimaculatus 46, 47.

csecus 49, IV, V.

coecus 49.

curvisetis 50, III. 51.

fuse us 53, II.

longisetis 51, III.

malmgrenii 56.

minnesotensis 52, II, XIV. 51, 59.

minutus 44, V. 46, 47, 48.

multifasciatus 53.

niger 47, V. 46.

novemlineatus 57, 58.

penicillifer 55, IV. 39, 56, 58.

pruinosus 48, III.

quadrimaculatus. . . 45, V. 47, 48.

spinatus 57, IV. 39.

Smynthurus

ater 47, 53.

aureus 43.

benitus 49.

bourletii 46.

buskii 53.

frontalis 48.

fuliginosus 47.

f uscus 53, 54.

minutus 44.

niger 47.

quadrimaculata 45, 46.

6 — maculata 45.

signatus 53.

Spring 8, 23.

Springgabel 8.

Superior claws 23.

Tactile hairs 6.

Tactile organs 6.

Tail 8.

Tarsus ?•

Teeth of claws 7.

Tenaculum 8» 1°. 23.

Tenent hairs ?• 23.

Tergum 12.

Terms, technical 23.

no

INDEX

Th. I, Th. II 23.

Thorax of the Collembola 6.

THYSANURA 25, 9, 10.

Tibia 7.

TOMOCERUS 35, 6, 11, 29.

arcticus 79, VI, VII. 81.

celer 80.

lepida 81.

niger 80, VI, VII.

plumbeus 81.

vulgaris 81.

Trochanter 7.

Tullbergia immaculata 82.

Ventral tube 7, 11, 23.

Vesicles, exsertile 11.

Wings 10.

XENYLLA 40.

gracilis 95, XI.

EXPLANATION OF PLATE I.

Papirius maculosus Schott.

Fig.

1. Antenna

2. Foot of 3d pair

3. Foot of ist pair

4. Right eye patch

5a. Mucrones, dorsal view
5b. Mucrones, lateral view
5c. Notched hair from 53

6. Tenaculum

7. Dorsal bristle

Orchesella zebra n. sp.

8. Left eye patch

9. Claw

10. End of Furcula, lateral view

11. Antenna.

I2a and b. Pair of antennae, one showing mutilation

13. Pinnate hair from dorsal thoracic fringe

Orchesella albosa n. sp.

14. Right eye patch

15. Antenna.

COLLEMBOLA < > F M I N X K S ( > T A

PI. I

J.E.-G.del.

EXPLANATION OF PLATE II.

*

Sminthurus fuscus (L.).

Fig.

i. Furcula, lateral view
2a. Genital papilla, lateral view
2b. Genital papilla, ventral view
33. Tenaculum, lateral view
3b. Tenaculum, seen from behind
4. Mucrones

53. Anal organ, seen from above
5b. Anal organ seen laterally

6. Left eye patch.

7. Foot, ist pair

8. Antenna of 3 young individual

9. Antenna of a mature individual

Sminthurus minnesotensis n. sp.

10. Antenna

11. A dorsal bristle

12. Mucrones

13. Right eye patch

14. Foot, 3d pair

15. Foot, 2nd pair

16. Vertex of head, oblique lateral view

COLLEMBO L A OF M I N N E S ( ) T A

PI. II

J. E.G. del.

EXPLANATION OF PLATE III.

Sminthurus curvisetis n. sp.

Fig.

1. Antenna

2. Left eye patch

3. Dorsal bristle

4. Anal segment; a, anal organ; b, genital papilla

5. Mucrones

6. Claw

7. Tenaculum, lateral view

Sminthurus longisetis n. sp.

8. Furcula

9. Antenna

10. Mucrones

11. Anal organ, seen flat

12. Claw

133. Dorsal bristle

I3b. End of 133 enlarged

Sminthurus pruinosus Tullb.

14. End of furcula

15. Foot

COLLEMBOLA OF MINNESOTA

PI. Ill

.I.E. G. del.

EXPLANATION OF PLATE IV.

Sminthurus spinatus AlacG.

Fig.

1. Foot, ist pair

2. Foot, 3d pair

3. Furcula, ventral view

4. Right eye patch

5. Anal segment of female

6. Anal segment of male

7. Antenna of male

8. Antenna of female

Sminthurus penicillifer Schaff.
Fig.

9. Foot, ist pair

10. Right eye patch

11. Antenna

12. Mucrones

Sminthurus caecus Tullb.

13. Antenna

COLLEMBOLA <>F .MINNESOTA

PI. IV

J. E. (i. del.

EXPLANATION OF PLATE V.

Sminthurus caecus Tullb.

Fig.

1. Anal organ and its papilla

2. Furcula, lateral view
33. Mucrones, ventral view
3b. mucrones, lateral view

4. Foot, ist pair

Sminthurus aureus Lubb.

5. foot, 3d pair

6. Furcula, ventral view
73. Mucrones, oblique view
7b. Mucrones, lateral view

8. Antenna.

9. Left eye patch

Sminthurus quadrimaculatus Ryd.

loa. Anal organ, seen flat

lob. Anal organ, seen laterally.

Sminthurus minutus MacG.

1 1 a. Anal organ seen laterally

nb. Anal organ median section through papilla

12. Left eye patch

13. Foot, ist pair

14. Foot, 3d pair

15. Mucrones

Sminthurus niger Lubb.

16. Left eye patch

17. Mucrones, lateral view

18. Antenna

C 0 L L K M B OLA OF M I N N E 8 () T A

PI. V

.1. E.G. del.

EXPLANATION OF PLATE VI.

Tomocerus arcticus Schott.

Fig.

1. Dentes, showing spines

2. Mandible

3. Tips of the two mandibles

4. Maxilla

5. Palp

6. Labrum

7. Mucrones

8. Mutilated antenna

9. Tip of normal antenna

Tomocerus niger Bourl.

10. Dentes, showing spines

11. Left eye patch

12. Mucrones

COLLEMBOLA ( > F M I X X K S ( ) T A

PI. VI

.1. K.I;, del.

EXPLANATION OF PLATE VII.

Tomocerus arcticus Schott.

Fig.

1. Scale.

2. Scale

33. Claw, seen from above

3b. Claw, lateral view

43. Clavate hair of tibia, lateral view

4b. Clavate hair of tibia, flat view

Tomocerus niger Bourl.

5. Claw, lateral view
Lepidocyrtus albicans Reut.

6a. Mucrones, lateral view
6b. Mucrones, ventral view

7. Thorax, lateral view

8. Antenna

Lepidocyrtus purpureus Lubb.

9. Thorax, lateral view

10. Foot

1 1. Antenna

12. Right eye patch

Lepidocyrtus sexoculatus n. sp.

13. Left eye patch
Lepidocyrtus decemoculatus n. sp.

1 4. Left eye patch

0 O I, L K .M B O LA OF MINXES () T A

PL VII

.1. E.G. del.

EXPLANATION OF PLATE VIII.

Seira nigromaculata Lubb.

Fig.

1. Foot

2. Scale

3. Mucrones

4. Right eye patch

5. Furcula, lateral view

6. Dorsal bristle

7. Antenna

Seira buskii Lubb.

8. Right eye patch
Cyphodeirus albinus Nic.

9. Foot

10. Antenna

11. Mucrones

Entomobrya spectabilis Reut.

12. Foot

13. Right eye patch

14. Antenna

15. Furcula, prone

16. Mucrones, lateral view

C O L L E M B () L A OF M I N N E S ( ) T A

PI. VIII

II

J. E. G. del.

EXPLANATION OF PLATE IX.

Isotoma leonina Pack.

Fig.

1. Dorsal view of the head

2. Right eye patch and post-antenna! organ

3. End of furcula

4. Claw

Isotoma viridis Bourl.

5. Left eye patch

6. Tenaculum

7. Antenna

Isotoma palustris Miiller.

8. Antenna

9. Right eye patch

10. End of furcula
Isotoma caeruleatra n. sp.

1 1. Antenna

12. Foot

13. End of furcula

14. Right eye patch

Isotoma catena n. sp.

15. Foot.

i6a. End of furcula, lateral view
i6b. End of furcula, ventral view

Isotoma minima n. sp.

17. Furcula, lateral view

1 8. Mucrones, lateral view

19. Antenna

Isotoma sensibilis Tullb.

20. Mucrones

COLLEMBOLA OF MINNESOTA

PI. IX

J. E.G. del.

EXPLANATION OF PLATE X.

Isotoma minima n. sp.

Fig.

1. Right eye patch and post-antennal organ

Isotoma bidenticula n. sp.

2. Furcula

3. Mucrones

4. Right eye patch and post-antennal organ

Isotoma fimetaria (L.), Tullb.

5. Foot

6. Furcula

Isotoma quadrioculata Tullb.

7. Right eye patch and post-antennal organ

8. Foot

Achorutes schneideri Schaff.

9. Antenna.

10. Posterior abdominal segments

11. Furcula

12. Dentes and mucrones

Achorutes boletivorus Pack.

13. Antenna

14. Furcula

Achorutes longispinus Tullb.

15. Posterior abdominal segments

1 6. Anal horn

Achorutes schbtti Reut.

17. Posterior abdominal segments

1 8. Furcula

19. Dentes and mucrones

Achorutes socialis Uzel.

20. Anal horn

21. Posterior abdominal segments

22. Furcula

23. End of furcula

COLL K M B OLA ( ) F M I N N E S ( ) T A

PI. X

J. E.G. del.

EXPLANATION OF PLATE XL

Achorutes schneideri Schaff.
Fig.

1. Foot

2. Right eye patch
Achorutes socialis Uzel.

3. Foot
Achorutes schotti Rent.

4. Foot

Achorutes longispinus Tullb.

5. Foot
Podura aquatica Linn.

6. Foot

7. Tenacnlum

8. Furcula, extended, seen from above

9. Furcula, lateral view

10. End of furcula, ventral view

11. Antenna

Xenylla gracilis n. sp.

12. Right eye patch

13. Posterior abdominal segments

14. Anal horns, seen from above

15. Furcula

Friesia caldaria n. sp.

16. One of the anal horns

17. Lateral view of posterior part of the abdomen

1 8. Furcula

C ( ) L L E M B ( ) L A OF M I N N E S ( ) T A

PL X]

(o

II

J. E.G. del.

EXPLANATION OF PLATE XII.

Anurophorus laricis Nic.

Fig.

1. Antenna

2. Foot

Aphorura ambulans (L., Nic.)t

3. Antenna, lateral view

4. Antenna, ventral view

5. Foot

6. Posterior end of abdomen

7. Posterior end of abdomen, ventral view

Anurida tullbergi Schott.

8. Tip of antenna showing sense organ

9. Right eye spot and post-antennal organ

Aphoromma granaria (Tempi.).

10. Posterior end of abdomen, lateral view

11. Post-antennal organ

Neanura muscorum (Tempi.).

12. Foot

13. Antenna

14. Right eye patch

Neanura quadrioculata n. sp.

15. Right eye

C O L L E M B 0 L A O F MINNESOTA

PI. XII

,1. E.G. del.

EXPLANATION OF PLATE XIII.

Isotoma muskegis n. sp.
Fig.

1. Dorsal view of male

2. Dorsal view of female

3. Lateral view of female

4a. Distal end of furcula, lateral view
4b. Distal end of furcula, ventral view

5. Left eye patch

6. Foot of male

7. Tenaculum

8 — n. Sensory tubercles of male

COL L K M B O LA ( ) F M I N N K S ( ) T A

]']. XIII

4

4b

a.

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J. E.G. del.

EXPLANATION OF PLATE XIV.

Sminthurus minnesotensis n. sp.
Dorsal and lateral views

Figures made by Charlotte M. King.

C O L L E M H ( ) I, A OF MlNNESOT A

PI. X 1 V

\ Ov

Sminthurus minnesotervsis

EXPLANATION OF PLATE XV.

Entomobrya clitellaria n. sp.

Dorsal and lateral views

Figures made by Charlotte M. King.

C OLLEMBOL A O F M I N N E S ( ) T A

PI. XV

Entomobrya clitellaria

EXPLANATION OF PLATE XVI,

Fig.

1. Orchesella zebra n. sp.

2. Entomobrya bicolor n. sp.

Figures made by Charlotte M. King.

(' O L L K M 150 L A O F MINNESOTA

PL XVI

i/

1

\

1

Orchesella zebra

Entomobrya bicolor