A study in neotropical Pselaphidae

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NORTHWESTERN UNIVERSITY STUDIES IN THE
BIOLOGICAL SCIENCES AND MEDICINE

Number I

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NORTHWESTERN UNIVERSITY STUDIES IN THE
BIOLOGICAL SCIENCES AND MEDICINE

NUMBER I

A STUDY IN
NEOTROPICAL PSELAPHIDAE

BY
ORLANDO PARK

NORTHWESTERN UNIVERSITY

1942

NORTHWESTERN UNIVERSITY

EVANSTON AND CHICAGO

NORTHWESTERN UNIVERSITY STUDIES

Editor

JOHN Webster Spargo

Advisory Board

James Washington Bell Leslie Brainerd Arey

Thomas Moody Campbell Harold Thayer Davis

Fred Dow Fagg Melville J. Herskovits

Elmo Paul Hohman Paul A. Witty

COPYRIGHT, 1942

NORTHWESTERN UNIVERSITY

PRINTED IN THE UNITED STATES OF AMERICA

BY THE PANTAGRAPH PRESS, BLOOMINGTON. ILL.

AND PUBLISHED NOVEMBER 7, 1942

I DEDICATE THIS PAPER WITH SINCERE AFFECTION
TO PROFESSOR WARDER CLYDE ALLEE. WHO HAS TIME
TO CONSIDER THE SPECIES QUESTION WHILE DOING
RESEARCH UPON THE AGGREGATION OF INDIVIDUALS

Table of Contents

PAGE

Preface vii

General Considerations and the Collecting of Pselaphidae ... 1

Preparation of Pselaphidae for Study 8

Taxonomic and Morphological Considerations 12

Key to the Tribes of Neotropical Pselaphidae 31

Subfamily Pselaphinae 34

Division I. Brachyscelia 35

Tribe 1. Faronini 35

2. Pyxidicerini 37

3. Jubinini 38

4. Euplectini sensu latiore 63

5. Brachyglutini 122

6. Metopiini 204

7. Batrisini 214

8. Tychini 260

9. Goniacerini 283

Division II. Macroscelia 286

Tribe 10. Pselaphini 286

11. Holozodini 288

12. Hybocephalini 289

13. Ctenistini 291

14. Tyrini 295

15. Arhytodini 343

16. Attapseniini 348

Subfamily Clavigerinae : Tribe 17. Clavigerini 350

The Undescribed Species of Motschulsky 359

zoogeographic and statistical considerations 360

Abstract 378

Bibliography 381

General Index 389

Index to Plates 407

( vii )

56051

Preface

The scope of this paper is limited in two ways. The author has attempted
to coordinate and add to the information on the Pselaphidae which inhabit
the American tropics. This has never been coordinated, the nearest approach
being that of David Sharp, who gave a series of inadequate descriptions of
Central American species in 1887 in the Biologia Centrali Americana. Second,
this present paper, through the medium of a modified Rafifrayan system,
bridges the thirty odd years between the generic analysis of this family by
Raffray in 1908, in the Genera Insectorum, and 1941. During this time much
novel information has accumulated on the anatomy, taxonomy, species ecology
and zoogeography of these fascinating beetles.

For the past six years I have received much help from many people, and
this opportunity is taken to thank them. I am indebted to Mr. H. S. Barber
of the Bureau of Entomology for permission to study the types of neotropical
pselaphids described by F. C. Fletcher; to Dr. E. A. Chapin of the National
Museum for providing facilities to study at this institution; to Dr. Black-
welder of the same institution for reading and criticizing the section on com-
parative anatomy; to Mr. J, B. Calhoun of my Department for checking de-
scriptions; to Professor Alfred Emerson of the University of Chicago for the
gift of specimens from the Canal Zone and British Guiana, for identification
of host termites, and for a reading of the entire manuscript; to the late Mr.
H. C. Fall of Tyngsboro, Massachusetts for critical advice; to Mr. W. J.
Gerhard of the Field Museum for reading galley proof; to Miss Gloria Hilker
and Mr. Raymond Parker of my Department for secretarial aid ; to Dr. C. H.
Seevers of the Chicago Y.M.C.A. College for the gift of specimens from Mexico
and Colombia; to Mr. Henry Dybas of the University of Chicago for the gift
of specimens from Mexico; to Mr. J. D. Sherman, Jr. of Mt. Vernon, New
York for procuring essential literature; to Dr. H. F. Strohecker of Ohio Uni-
versity for the gift of specimens from Bolivia and Brazil ; to Dr. E. C. Williams
of the Chicago Academy of Sciences for the gift of specimens from the Canal
Zone; to Mr. Rupert Wenzel of the Field Museum for the gift of a specimen
from Paraguay; and to Mr. James Zetek, U.S. Department of Agriculture for
many facilities in the Panama Canal Zone.

To all of these I am deeply appreciative, but must point out that short-
comings in this paper are to be credited to the author.

This report is not a monograph of neotropical Pselaphidae. It is a sum-
mary of data preparatory to monographic study. Many genera are insuf-
ficiently known to key out all of the described forms; many type specimens
must be examined and redescribed; many species await description; the spe-
cies ecology and distribution of neotropical pselaphids are little understood.

(ix)

PREFACE

All of the types of the new species described in this paper are in the col-
lection of the author. Paratypes are to be distributed in those species described
on a large series. Eventually the author's collection of pselaphidae will be
deposited in a museum.

Twenty-one plates are included to illustrate pselaphid anatomy and
taxonomy. These have been drawn by the author. Although great care has
been exercised, some discrepancies may be found between a given figure and
the text. In all such cases the text is to be considered correct since the curva-
tures of parts makes the exact delineation difficult, or exact drawing may dis-
tort habitus. Where discrepancies exist between halves of a bilaterally sym-
metrical figure, the left side is to be considered in preference to the right side.

(X)

Si- /n*'- nQ

Studies in American Pselaphidae with Particular
Reference to the Tropical Areas

Orlando Park
Northwestern University

GENERAL CONSIDERATIONS AND THE COLLECTING OF
PSELAPHIDAE

Twenty years ago I collected my first pselaphid beetle. Since then my
general interest in Coleoptera has narrowed gradually, and although other
groups have held my attention, I invariably returned to a study of the "ant-
beetles". The last ten years have been spent in a rather constant study of
this family of beetles. The word constant is used in a relative sense, implying
devotion to these insects as much as feasible amidst the normal confusion of
academic duties.

Pselaphidae are difficult to collect. Their habitats are usually dark and
secluded. The species are inconspicuously colored, a yellowish or reddish brown
being the average color pattern. Pselaphids are of minute size and many
crouch when uncovered, often with the head, antennae, and legs more or less
concealed by the body. Some of the beetles letisimulate when touched {Tmesi-
phorus, Rhexidius, Melba).

In general, for the purposes of collecting, the family can be divided into
two sections. This division follows a rather basic separation of the family
with regard to their ecological requirements, e.g. those forms inhabiting de-
caying plant debris (the mold species) and secondly, those forms entering into
the complex society of ants (the myrmecocolous species). However, some
pselaphids appear to be equally at home in both niches, e.g. Tmesiphorus
costalis (Park, 1933), Batrisodes globosus (Park, 1929, 1932b, 1935a, b), and
again, pselaphids may be found less frequently in the nests of termites and
other habitats not enumerated.

I. The Mold Species. The majority of species of the family are found
in the various types of mold. The Euplectini and Trichonychini are especially
characteristic of plant debris, and with the exception of the Clavigerinae, most
of the other genera are found here at one time or another.

Plant mold can be imperfectly divided into two closely related categories:
the mold of decaying logs (particularly the more advanced stages of the log
decay cycle, in which the sapwood and heartwood have undergone consider-
able decay and can be easily crumbled with the fingers, although the early
stage where the bark is loose and the sapwood still firm and moist may be rich

(1)

2 NEOTROPICAL PSELAPHIDAE

in pselaphids, especially the larger species), and the leaf mold of the forest
floor. Within my experience I have found log mold to have a higher yield:
the mold should be moist but not wet; easily crumbled but not gritty, and
brown to black in color rather than red. The moist decaying vegetation of the
forest floor, particularly about the base of trees, is good collecting ground.
Hollow stumps with several inches of wood bounding the cavity and with a
quantity of fine, black mold within the latter are usually infested with micro-
coleoptera. Again, rotting stumps, with only portions of the heartwood left
and the roots rotted away, can be overthrown, and beneath the stump and
upon its upturned base pselaphids may be taken.

In other words, dense, heavily shaded forests with a deep leaf mold and
abundance of prostrate trees are productive, particularly the deciduous trees
such as ash, oak, elm, hickory, beech, and maple. Meadows or dry upland
oak-hickory forests are not so rich in pselaphids, but may yield uncommon
forms.

Flood plains which are subjected to an annual inundation make poorer
collecting ground, although near the top of the flood-line, in the piled debris,
some species are to be had, and the uplands of river valleys, especially north-
facing slopes, are good hunting. With experience, the pselaphids can be seen
and picked up. Two general methods yield the greatest numbers of individuals
— sifting and heating. Leaf or log mold can be sifted with great profit by
using screens, a practice proved valuable by generations of entomologists.
The wire basket with a handle, used for deep-fat frying, having a quarter-
inch mesh is neither too bulky nor inconvenient to use. With this or some other
suitable screen or sieve, several square feet of white cloth should be carried
so that the material sifted can fall upon the cloth and be easily seen. Sifting
has one great advantage: the mold can be sifted in situ, the specimens col-
lected and another sample tried. In this way unproductive leaves or debris
can be discarded, and on the other hand productive material can be worked
again and again. The second method for obtaining numbers of individuals is
by the application of a gradient of temperature to the contained sample: the
Berlese Method. I have used this method with great success. A simple modi-
fication of the famous original, which can be constructed easily and at little
expense, is as follows: One or more funnels should be made up of stout gal-
vanized iron. These can be of any size but I have found funnels measuring
ten to fourteen inches in diameter at the top and from ten to twenty inches
long very satisfactory. The spout of the funnel should taper to a tubular piece
several inches long and half an inch in diameter. Such a funnel is fixed up-
right over a finger bowl of 95 per cent ethyl alcohol. A series of circular screens
is made up of varying diameters and mesh. I have found three sizes useful,
(1) a small screen three inches in diameter with a sixteenth-inch mesh, (2) a
medium screen six inches in diameter with a quarter-inch mesh, and (3) a
large screen eight inches in diameter with a half-inch mesh. These screens are
placed in the funnel at bottom, middle and top thirds respectively. The sample
of mold is then inserted on top of the large screen and a heating unit laid

METHODS OF COLLECTING 3

over the mouth of the funnel above the sample. This heating device may be
an electric toaster, stove, or light bulb in the laboratory. In the field where
immediate assay of mold is necessary, a frying-pan of live coals or a Thermat
pad will give the desired heat. The heat from above will gradually drive the
mold animals deeper until they drop through the screens into the alcohol.
Although one or two hours will often provide a high yield, two or three days
may be necessary. Also, merely allowing the sample to dry in the funnel for a
week will give results without the application of artificial heat.

After berlesing a sample I have found that the yield may be augmented
by laying a small square of cloth on the now hot debris and putting several
drops of carbolic acid on the cloth and then covering the funnel.

The Berlese system, in its many ramifications, has one great advantage,
that of thoroughness. Where accurate quantitative data are desired it is in a
class by itself in making an assay of floor debris.

Collecting over a period of years has shown that the Pselaphidae are
constant constituents of mold. The adults hibernate through the winter in this
stratum, copulate therein during the spring and remain active residents during
the spring and summer seasons. They are largely nocturnal feeders. Their
chief food, at least of the common free-living forms, is the small game that
also lives in the mold in such imponderable myriads, insect larvae, the Collem-
bola, Acarina (chiefly Oribatidae, Hoplodermatidae and Parasitidae and other
minute mites described admirably by Jacot (1935, 1936a, b, c). This general
food habit was known to Denny as early as 1825. Since the mold stratum is
always at twilight during the day, the period of activity of pselaphids is not
circumscribed by intense illumination, although at night many species fly.

The majority of species of the family have well developed metathoracic
wings and fly well, e.g. Bibloplectus, Thesiastes, Rhexius, Rhexidius, Brachy-
gluta, Soalenarthrus, Reichenbachia, Decarthron, et cetera. Such forms usu-
ally have well-developed compound eyes. Others, such as Rhinoscepsis,
have rudimentary wings and rudimentary eyes. The deep mold forms with
rudimentary wings, of course, would not be more appreciably collected during
the night than through the day, but the night-flying forms can be collected by
lights. Light-traps, then, are also useful in obtaining pselaphids. Such traps may
be complex or simple. For example, the standard light suspended in front of a
sheet, or a lantern on a square of white cloth, will attract many pselaphids.
The yield is dependent upon such factors as the type of habitat, season, and
particular weather conditions. Both forests and clearings or meadows will
yield these insects. Innumerable species fly to lights at night in the tropics,
as descriptions of new species attest (Fletcher, 1928). Light collecting was
one of my surest methods in the rain forest of Panama. These mold forms
often are quite locally distributed. Thus to our perceptions, of two ecologically
equivalent, adjacent logs on the forest floor, one log will consistently yield
large numbers of Euplectini, whereas the other log berlesed the same length
of time may be barren of species. No general statement can be made as yet
concerning such local distribution. It may be coincidence; it may be some

4 NEOTROPICAL PSELAPHIDAE

more subtle but not necessarily more mysterious influence such as aggre-
gation; it may be undiscernible changes in rate or character of chemical de-
cay; some shift in food or water conditions. In such a welter of possibilities,
the best approach is calm resignation in the face of barren collecting, and an
inquiring state of mind.

Other, more isolated methods of taking free-living pselaphids are by
sweeping with a net the meadow grasses, especially bluegrass, inspecting the
under side of flat stones and sorting sphagnum moss.

11. The Myrmecocoles. Since many pselaphids are myrmecocolous, ant
nests are desirable hunting grounds. No collection of Pselaphidae may be con-
sidered complete without full representation of these often highly specialized
and always interesting species. Examination of the ant nest requires skill and
patience, chiefly the latter.

Although every log or stump may be potentially rich in mold species, few
of the many ant nests examined will yield pselaphid inquilines. This is not
because these beetles are rare, but rather because they are not so numerous
as their prolific hosts. Persistent search will gradually reward one by the ac-
cumulation of species to be taken nowhere else, e.g. all of the Clavigerinae
{Adranes, Fustiger), Ceo-phyllus, many species of Batrisodes, Cedius, Cerco-
cerus, et cetera.

The literature dealing with specific collecting records, hosts, and pertinent
ecology of these forms is taken up in detail under each species {vide infra),
but certain general suggestions can be made here. Some pselaphids are re-
stricted apparently to a single host ant, or to a group of closely related hosts;
but since others occur with a wide variety of unrelated hosts, all ant nests
should be examined. In general, the more restricted the beetle to a single host
or group of hosts, the more specific its requirements and accordingly the more
specialized its structural details; some species are found over a wide variety
of host ants, and may even lead a free-living existence in mold as well. These
are less specialized usually than their restricted cousins, and such a situation
bears upon their structure, taxonomy, and ecology, as will be indicated later.

The first general survey of ant and termite guests was that of the inde-
fatigable Wasmann, who described countless new forms, chiefly among Staphy-
linidae, Paussidae, and the clavigerine Pselaphidae, He was no less interested
in the ecology of these guests, and gave to the biology of his day the most
complete picture of host-guest interrelations, although he was less admirable
in certain of his theoretical interpretations. Wasmann's contributions may be
best gleaned from his publications of 1890, 1891, 1892, 1895, 1896, 1897a, b,
1904a, b, 1906, 1911, and 1913 of the bibliography. Wasmann (1894) lists over
twelve hundred inquilines of ants and termites, and his contribution is further
treated by Wheeler (1923, 1928). The origin of myrmecophily is discussed by
Wasmann (I.e.), Wheeler (I.e.) and Donisthorpe (1909, 1927). Donisthorpe
has reviewed (1927) the British ant guests, among which pselaphids are dis-
cussed.

METHODS OF COLLECTING 5

One of the contributions made by Wasmann bears upon the present work.
After prolonged study, he suggested a sufficiently elastic classification of guests
of social insects. This grouping was essentially ecological, and in the modified
form used by Wheeler (1910, 1923) may be outlined as follows, with respect
to Pselaphidae.

Synechthrans. Guests living within the nest but attacked and killed by
the hosts when possible; usually scavengers, or active predators of the host
workers, their brood or their food stores and other guests. Such forms are
especially numerous in examples among the Staphylinidae, but no bona fide
synechthran is known to me within the Pselaphidae. Synechthrans, by the very
nature of their role, are strong active species as a rule and are least specialized
for life within the nest biocoenose, of the guests.

Synoeketes. Guests living within the society without being actively perse-
cuted by the host; usually indifferently tolerated. Such forms are slower mov-
ing as a rule and more specialized for the social group than are the synech-
thrans. Wheeler subdivided this second type into six categories: (1) Neutral
Synoeketes "insects which pay no attention to the ants or their brood, but
live on the refuse or nest materials and spend their time seeking these on the
walls of the galleries and chambers." (2) Mimetic Synoeketes in which the
species show, to the human perceptions at least, structural or ecological char-
acteristics which are quite similar to the hosts. (3) Loricate Synoeketes in
which the body is flattened, rounded, and tapered. Usually the species are
relatively inconspicuous. (4) Symphiloid Synoeketes in which the species be-
comes more intimately adjusted to the host, approaching the true guests. (5)
Myrmecocleptics, a category formed for the Lepismid, Atelura formicaria,
by Janet (1896). This insect is of the loricate body form, but steals up to
two regurgitating ants and partakes of the liquid food passing between them.
(6) Strigilators, a term proposed by Wheeler (1910) for a group of diverse
insects which "lick the surfaces of ants and seem to feed very largely, if not
exclusively, on the cutaneous secretions and the thin coating of saliva with
which the ants cover one another."

The Pselaphidae number representatives in this second division of guests.
Tmesiphorus costalis may be said to be a facultative mimetic synoekete (Park,
1933), and Batrisodes globosus also falls in this type (Park, 1935b). Both
species can and do live in mold and under loose bark or stones on the floor,
but both are found with ants and are known to feed upon the host brood.
They are not persecuted by their hosts, nor are they cared for in any obvious
way. The species of Rybaxis, and possibly Ceophyllus and Cedius may also
be synoeketes in the strict sense of the word.

Symphiles. These are true guests of the social insects, and are found
among the Staphylinidae, Paussidae and Clavigerinae. As has been stated by
Wheeler, these are the elite of the guests. All of the clavigerids are symphiles
and agree in having certain "symphilic characters and behaviorisms" as far
as known, e.g., (1) the peculiar, oily integument, usually yellowish to reddish
brown in color, strikingly similar to their hosts; (2) the well-developed, oily.

6 NEOTROPICAL PSELAPHIDAE

golden trichomes or specialized tufts of setae developed frequently on the
elytra and abdomen. These trichomes are characteristic of the symphiles, in
particular of the clavigerines, and the trichome secretion is highly stimulating
to the ant host, the workers of the latter licking and sucking these hair tufts
assiduously. (3) The inconspicuous, modified mouth-parts, clothed with golden
pubescence fitted for scraping, licking, and sucking. (4) The inordinately
modified antennae. (5) The deliberate, rather clock-like precision of their
unhurried walk within the hurry of the nest. (6) The habit of twirling the
antennae when approached by a host worker. The ecology of the European
Claviger has been discussed rather fully by Donisthorpe (1927), Hetschko
(1896), Krueger (1910), Mueller (1818) and Wasmann (I.e.), and our own
Adranes has been investigated (Park, 1932) sufficiently to state that these
clavigerids are cared for by the host, e.g. fed regurgitated liquid food, licked,
and even transported back and forth in the nest.

These guest pselaphids have been the subject, then, of considerable re-
search; yet one may confidently state that only a minute part of this
fascinating field of comparative ecology has been explored. This is particularly
true of the many pselaphid synoeketes and the Clavigerinae. The careful study
of the many tropical species will richly repay the patience and ingenuity
necessary in this field. Even the tabulation of a complete check-list of Amer-
ican guest insects is lacking. The North American guests of ants, e.g. the
myrmecophiles (myrmecocoles in part) were listed by Hamilton (1888) and
much more completely by Schwarz (1890). Since then notable contributions
have been made by Wickham, one of the best students of our pselaphid fauna
(1892, 1896, 1898, 1900), and recently additional records have been given (Park,
1935a).

The collection of this second group of pselaphids, the guest species, re-
quires a great deal of time, since close examination is essential. Once the
nest is located, it must be examined with care and piece-meal. Rough handling
and breaking of many galleries will allow most if not all of the contained
beetles to escape. The latter may be found anywhere in the nest. In general,
the synoeketes such as Batrisodes may be more frequent in the superficial
galleries, but the symphiles {Adranes, Fustiger) and other synoeketes
(Ceophyllus) tend to haunt the brood chambers and must be sought for in
the depths of the nest. When the nest is first opened, the beetles are seldom dis-
covered immediately unless their infestation is very high. Rather they tend to
crouch against the walls of the galleries, or crawl slowly into intact areas. This
is in marked contrast to the hurry and bustle of the host workers. After the
latter have adjusted to the emergency and begin the orderly carrying away
of their aphids, brood, and food, and begin their normal routine of recon-
struction, the pselaphids should be sought for as smaller, much slower-moving
forms; their precise, peculiar method of walking will serve to distinguish them.
Smoke blown into the mouth of a gallery often drives the inmates forth. If
after an hour at a good-sized nest no pselaphids are apprehended, another

METHODS OF COLLECTING 7

nest should be opened, or the original one placed in a bag and reserved for
more detailed study.

One point should be emphasized. When the guest pselaphids are collected,
they should be accompanied by a goodly series of the host, and the guests and
host should be kept together with a note number so that later the observ^ations
recorded in the field can be allocated to the proper specimens. The host should
be mounted on the same pin as the beetle. Without this precaution the col-
lection cannot be said to be really complete.

Ant nests on hillsides, meadows, marginal nests in forest clearings, be-
neath road-side debris, about the borders of ponds and in rich forests will yield
interesting pselaphid guests. Nests beneath stones seem to be especially good,
as are also the large nests of Lasius aphidicola, flavus, and related forms. The
workers of the latter ants are honey yellow in color, numerous, tend aphids
and coccids and usually nest in rotting logs and the soil beneath decaying logs
and stumps. Their nests often have a characteristic, pleasingly aromatic odor.
In these nests Ceophyllus and Adranes are most frequently found.

The log-nesting Aphaenogaster tennesseensis harbors many species of
pselaphids {Batnsodes, Tmesiphorus, Cercocerus, Cedius) but the beetles are
not easy to obtain, since the host often tunnels in firm wood. The related
Aphaenogaster julva, often nesting in more rotten logs, although the occasional
host of Tmesiphorus, is not generally productive of pselaphids.

The clearing ants, building around and in upland forest clearings, e.g.
Formica exsectoides and Formica ulkei, hold many guests in their large
cone mounds, among which some species of Batrisodes are to be found.

A great variety of guest pselaphids are found, at infrequent intervals, in
the nests of the ubiquitous Losing niger americanus, e.g. Batrisodes, Ceophyllus,
Adranes. Details of host-guest relations, where available, are set down with
the taxonomic descriptions which follow, and the reader is also referred to the
list of hosts and their guests in the cases of certain genera.

Although pselaphids may be collected in cyanide bottles or other standard
killing jars, such jars usually allow these tiny insects to become dirty, or even
lost, and it is difficult to keep ant host and guest together. I have found num-
bered vials of 95 per cent ethyl alcohol to be the best collecting medium. The
pselaphids should not be picked up with forceps; a suction bottle is good, but
a small camel-hair paint brush is superior. Once the pselaphid is discovered,
it is the work of a few seconds to moisten the tip of the brush in the alcohol
and dab up the specimen. In this way specimens are kept segregated ecologic-
ally, clean and unbroken.

Pselaphid collecting equipment then is simple, e.g. a small brush, alcohol
vials with note number, several stout sacks for carrying home mold samples
or ant nest, a small sharp hatchet and a notebook. A good hand lens of ten
diameters' magnification, or better, a watch-maker's eye-glass or a Berger
Loop head-glass are helpful for the examination of small pieces of the habitat.
This latter is often facilitated by a small electric torch, especially in deep
forests or for collecting at dusk.

Preparation of Pselaphidae for Study

Once the catch has been returned to the laboratory it should be taken care
of promptly. Pselaphids brought in for study, either taken at random, or
with ants, must be placed in larger, more suitable containers. They may be
placed in one of the many excellent artificial nests described by Wheeler
(1910) and their fascinating behavior observed and experimented upon.

For isolated species, or for the particular study of their more intimate
relations and requirements with mold or nest co-inhabitants, small petri-dish
nests are satisfactory (Park, 1929, 1932a, 1933b). Such nests can be examined
under the dissecting binocular with ease, and at length. Far too little is known
concerning the life of our small mold insects, and it is a commentary upon
our use of the methods available, and our intellectual curiosity, that so much
priceless material is killed and identified — often without data of any kind —
before an effort is made to obtain information about the living animal. A
properly mounted dead specimen can yield up its taxonomic or morphologic
secrets for a span of years, but the chance to gain knowledge of its equally
important physiology and ecology has passed for ever.

Entire colonies of ants, or whole sections of logs, can be kept indefinitely
in the laboratory if the requisite moisture, temperature, and food are provided.

Since 1818 the problem has been challenged, but practically no data have
been collected upon the embryology and post-embryonic stages of Pselaphidae ;
in fact Mueller in this year discovered more than many recent workers. The
larval stages of the Clavigerinae are virtually unknown to science, and but few
Pselaphinae have had their larvae discovered {Batrisodes monstrosus LeConte
and Euplectus conjiuens LeConte) and properly keyed and figured (Boving
and Craighead, 1931), and this much accomplished in a family of over four
thousand species! The food of the pselaphids, their feeding behavior, drinking
behavior, breeding behavior, enemies, the place they occupy in the Darwinian
web-of-life, their genetics, their period of activity, the critical environmental
influences in their lives — these questions and many more are almost if not
quite untouched. This, of course, holds for the majority of our species of
animals, and must be faced in the light of our rapidly vanishing natural areas
in many parts of the world.

So much, then, for the opportunities afi'orded by the study of living ma-
terial. For the study of dead material three general methods are to be used:

(1) abundant material should be kept preserved in alcohol for study en masse,

(2) the bulk of the specimens should be mounted dry upon card points, and

(3) for examination of the minutiae of external and internal organization,
e.g. sclerites, setae, genitalia, and endoskeleton, microscopic slide-mounts must
be made.

(8)

PREPARATION FOR STUDY 9

When mounted dry, pselaphids fall into two groups. First, all "large"
species (1.5 to 4 mm. in length) should be mounted upon a stiff card triangle
of which the point is bent sharply for about a half millimeter (cf. Ross, 1934,
for general details). For the small species (1.5 to 0.6 mm.) the bent point of
the triangle is too broad. Such species should be mounted upon the point of an
unbent triangle or upon a bristle; in this case the specimen should not be
pushed into the mounting cement but allowed merely to adhere to the outer
convexity of the drop of cement.

Such triangle mounting is best done under the dissecting binocular to in-
sure clean work. When mounted, the left side, both ends, and the dorsal and
ventral surfaces should be clean of cement and are easily studied with mag-
nifications up to 100 diameters. With experience, the binocular mounting is as
rapid as good mounting without the aid of the microscope, and is far more
clean and accurate. The mounting can be varied to allow this or that genus
to be set in such a way that the essential differential characters can be seen
at the greatest advantage, e.g. the ventral face of the tenth antennal segment
in one group, the anterior tarsi or mesocoxae in another, and so on.

As to cementing fluid, either a good glue slightly thinned or Canada bal-
sam can be used, and the arrangement of the beetle on the triangle with the
cement is best done by specially ground needles. The tools I have found most
useful are a small paint brush with the hairs cut away save for a tuft of about
three or four bristles remaining; needles made from aluminum wire, sharpened
on emery-cloth under the binocular to give one straight needle and one sharply
bent needle, each with very slender shafts and as long and fine a point as
possible; a micro-dissection knife for genitalia, made by grinding a No. 1
insect pin on both sides near the point until a small, sharp blade is produced.

Length or other dimensions can be best obtained by using a crosslined
reticule in an eye-piece of the binocular dissecting microscope; the fine squares
of the reticule should have a length and width of between a tenth and a four-
teenth of a millimeter. Drawing the entire or a part of the specimen can be
greatly facilitated by the use of the reticule. Thus if lightly ruled paper is
used, the part to be drawn, whether a wholemount or a microscope slide, can
be accurately transferred, square by square, to the paper, from the image
covered by the net of lines in the reticule.

In the preparation of microscope slide mounts, which are essential for
many taxonomic studies, large pselaphids can be mounted in depression slides
or the cover glass held up by bits of glass or rubber; or the pselaphids can be
dissected and mounted in sections.

The exact method of mounting on slides depends upon the use for which
they are intended. For most taxonomic purposes, the beetles are allowed to
remain in 95 per cent ethyl alcohol for twenty-four hours, cleared in cedar-
wood oil for twenty-four hours, and then mounted in Canada balsam. Such
slides can be examined with ease at 400 diameters magnification, and both
dorsal and ventral surfaces are at one's disposal by turning the slide over. In
order to do this the slides should be very thin, else the higher magnifications

10 NEOTROPICAL PSELAPHIDAE

will not allow a focus of the reverse side of the slide; a wooden slide carriei
can be used to advantage which will hold the inverted slide in place without
danger to the cover slip.

When Euplectini are mounted in this manner, one is amazed at the de-
tail which has escaped observation of specimens on card points; the pores,
pubescence, foveae, sutures, and sensory areas take on a new significance.
However, the aspect and detail of depressions, grooves, or sulci are not well
shown in slide mounts, unless carefully stained while in the alcohol, and point
mounts are best for these and similar structural items. Therefore a combination
of alcoholics, triangle mounts, and slides is really necessary for complete
estimation of a specimen.

Mouth-parts, antennal structure, eye facets, tarsi, and detail of genitalia
of the larger species are also best studied under slides; I have become con-
vinced that future taxonomy will come to depend on slide mounts for taxonomic
details between closely related forms, and to this end the micro-coleoptera
lend themselves admirably.

Dark species can be bleached by hydrogen peroxide or Chlorox, and then
washed thoroughly in distilled water, dehydrated, and cleared as for the non-
bleached material.

Where the end is the study of the comparative external morphology of
the pselaphids I have found it convenient first to rid the specimens of internal
tissue and the following technique has proved satisfactory: either old and
dry specimens or fresh material are placed in a cold potassium or sodium
hydroxide solution of between 15 per cent and 30 per cent for twenty-four
hours. The action can be hastened by placing them in 10 per cent hydroxide
solution and boiling for ten minutes. After this the specimens must be washed
thoroughly and then can be passed into 95 per cent alcohol directly, or the
integument can be stained with eosin, methyl orange, or acid fuchsin. After
dehydration the technique is the same as for regular slide mounts. These
potashed specimens can be still further cleared by passing them through the
bleaching fluids mentioned above. Such mounts show the endoskeleton with
great clarity, and are invaluable for study of minute details under oil im-
mersion at 1000 diameters or more.

Genitalia. Specimens brought from the field in alcohol should always be
examined for extruded genitalia, especially the males. ^ Such material may be
treated differently, since the structure of the genitalia is hardly known in
Pselaphidae and comparative studies of these structures will undoubtedly be
valuable for a future, broader view of the taxonomy of the family as a whole.

The extruded genitalia of the male should first be studied in situ to show
the relation of the pygidium to penis, orientation of the latter with respect to
dorsal, ventral, lateral surfaces, and whether the species belongs to the type
in which the pygidium hinges on one side, or whether to the group having the
pygidium of two pieces, a right and a left pygidial plate (in the latter case

^ Or living material may be killed with carbon tetrachloride, followed by ether, as
suggested by Valentine (1934), or by ether alone, to initiate extrusion of aedeagus.

METHODS OF COLLECTING H

these two plates meet in a so-called pygidial carina), to allow the extrusion
of the copulatory apparatus.

After such preliminary study, the genitalia should be excised and run up
as slide mounts, where the observations on fresh material can be checked under
high magnification. Once on the slide, the type of penis should be discerned,
e.g. whether it is bilaterally symmetrical (some Reichenbachia, Batrisodes,
Cylindrarctus, Tmesiphorus, etc.) or asymmetrical (some Batrisodes, Pilopius,
Dalmosella, etc.).

Where the genitalia are not so extruded, they can be dissected out, work-
ing with the dissecting binocular and keeping the specimen under alcohol. Skill
acquired through practice in the handling of the small needles and knife is
necessar}^ here; after the genital apparatus is cut out it can be cleared and
made into a slide mount. Since the appartus is minute, the genitalia are easily
lost in the transfer to the slide; this can be overcome by using the brush, the
point of which has been dipped into balsam. The brush can then be touched
to the genitalia and lifted rapidly into the balsam on the slide.

Taxonomic and Morphological Considerations

Not many investigators have devoted their time wholly or in large part
to the Pselaphidae. However, this family has had the advantage of treatment
by a master's touch in the virtually unique work of Achille Raffray. His first
general survey of the pselaphids was his world catalogue (1903-1904). This
was followed by his exhaustive treatment of the genera of the world (1908)
and finally by a complete catalogue of the species (1911). The majority of
the now known species of Pselaphidae were described by Raffray in a long
series of papers; the outlines of present classification of the family, its com-
parative anatomy and most of our information on the zoogeography of the
group bear the imprint of his discerning mind.

This is not to say that others have not contributed brilliantly to a knowl-
edge of the family. Following the beginnings by Paykull (1789) and the recog-
nition of the pselaphids as a family by Herbst (1792) which resulted in the
description of three species, Tychus niger (Paykull), Pselaphus heisei Herbst,
and Pselaphus dresdensis Herbst, information slowly accumulated until 1816,
when Reichenbach monographed the family for the first time. This was fol-
lowed by a treatment of the group by Denny (1825) and by Aube (1833-34).
It was not until Reitter's new classification in 1881 that the number of sternit^s
was employed in the taxonomy of Pselaphidae, and the groups within the family
partially delimited. In 1890 Raflfray proposed the modem system based upon
the form and insertion of the mesothoracic coxae, trochanters, and femora,
Raffray was followed by Ganglbauer (1895) in his penetrating work, Kdfer
von Mittelewopa, and Raffray extended the system (1908) to embrace the
world fauna.

The Pselaphidae of North America, particularly those to be found within
the political boundaries of the United States, received monographic treatment
by John L. LeConte (1850) and little more was accomplished until the mono-
graph by Brendel and Wickham (1888-1890). Both of these studies were well
done for their particular era and served to set the stage for the taxonomic
genius of Thomas L. Casey.

Casey (1884, 1886, 1887, 1893, 1897, 1908) described many new North
American species and in his full descriptions added much to our general in-
formation of the anatomy of the family and its taxonomic possibilities. It is a
pity that Casey could not have monographed the North American species at a
time when he could have assayed and properly integrated the increase in
information since Brendel and Wickham's paper. The failure to do this left
our knowledge of Pselaphidae in this country highly unorganized. This was
demonstrated by the use of the early Brendel and Wickham treatise as the
basis for Pselaphidae in Blatchley's classic Coleoptera of Indiana (1910),

(12)

TAXONOMIC MORPHOLOGY 13

and also by the necessity of using Raff ray's keys to the world fauna in a com-
pilation of genera of pselaphids by Bradley (1930). Both Blatchley and Brad-
ley used the scattered work of Casey where feasible.

Monographically speaking, then, the pselaphids had not been coordinated
between 1890 and 1934, when John R. Bowman gathered the scattered literature
of the family, and drew up keys from descriptions of species.

Henshaw (1885) numbers 136 species and varieties of pselaphids, divided
among 29 genera. Leng (1920) in his admirable Catalogue numbers 364 spe-
cies and varieties, divided among 63 genera. This was an increase of 167 percent
species and 117 percent genera between 1885 and 1920. Taking the 1920 figures
of Leng, we find that LeConte described 81 species and 12 genera, Brendel 63
species and 8 genera, and Casey 181 species and 22 genera. Thus these three
students described 325 out of 364 species, and 42 out of 63 genera. Since virtually
all of the LeConte and Brendel species and genera were listed by Henshaw,
we note that the total increase to 1920 was largely a consequence of Casey's
taxonomic activity.

In addition our knowledge of North American Pselaphidae has been ma-
terially added to since 1900 by shorter contributions, among which may be
mentioned the revision of Adranes by Wickham (1901) ; addition of the tribe
Holozodini by Schaeffer (1906) to the pselaphid fauna of the United States in
the description of the new species Caccoplectus spinipes; the revision of
Rybaxis by Fall (1927) and of Rhexidius by Fletcher (1932). In this latter
paper, Fletcher described Hamotus {H amotoides) opimus from Florida. This
was the first time that a member of this large, typically neotropical aggregate
had been definitely recorded north of Mexico.

That portion of the Americas in which this study is especially concerned,
from the Rio Grande southward through Argentina, has received no mono-
graphic treatment, nor can any be contemplated for many years. Much of the
region is occupied by the neotropics, and the pselaphid fauna of the equatorial
rain forest and tropical savanna remains largely unknown. The most am-
bitious effort was that of David Sharp (1887) in the Biologia, covering the
area from the northern boundary of Mexico to Panama. Unfortunately the
lack of keys, the short and vague descriptions, and the generalized figures
render this study less valuable. Of much more practical worth are the short
generic studies and description of new species by Raffray (1891, 1896, 1897,
1903, 1904, 1909, 1911, 1917) and the modern work of Bruch, Reichensperger,
and Fletcher (1927, 1928, 1928a, 1930).

The extent to which the pselaphid fauna of the neotropics remains un-
known may be partially realized by considering the amount of new material
discovered in several expeditions. In the Biologia, Sharp (1887) listed 98
species, of which 70 were new. In an expedition to Venezuela, Simon found 39
species, of which 33 were new (Raffray, 1891). The Cornell University expe-
dition to South America returned with 11 species of Pselaphidae. Of these
two could not be identified beyond the genus, and of the nine which could be
identified, seven were new (Fletcher, 1928). In a study of Barro Colorado

14 NEOTROPICAL P3ELAPHIDAE

Island, Gatun Lake, in the Panama Canal Zone, to be discussed at length in
this report, this artificially isolated mountain peak of only a few square miles
yielded 44 species on three expeditions, and of this number 40 were new. From
these few instances it will be seen that the pselaphids of the American tropics
are incompletely known.

There is no single, qualitative criterion the application of which will
separate all pselaphids from all staphylinids. Such a condition is the rule in
studies on classification and is to be expected if we consider the species as
by-products of the evolutionary process.

It is apparent that Pselaphidae are highly evolved staphylinoid beetles
in which certain structural parts have attained a peculiar degree of speciali-
zation, presumably through a differential selection by the environment of genetic
combinations over a long period of time. Genetically, nothing is known of the
stability or lability of pselaphid structure and function. Therefore we may
not check the validity of a pselaphid species by experimental breeding, nor
map out the probable lines of taxonomic development with the degree of as-
surance done for the Drosophilidae (cf. Dobzhansky, 1937) or the Cynipidae
(Kinsey, 1936). Classification of Pselaphidae, then, must depend upon com-
parative anatomy (without the aid of comparative embryology) and the
ecological science of zoogeography.

The pselaphids are wholly brachyelytrous, the mesothoracic wings or
elytra being short and exposing part of the abdomen. This condition is shared
by other families, for example the Staphylinidae, part of Ptiliidae, et cetera.

Their size range is intermediate between staphylinids and ptiliids. The
largest pselaphid known to me is the Brazilian Hamotus (Hamotoides)
ecitophilus Raffray. This giant measures 5.5 millimeters in length and lives
in the society of Eciton army ants. A number of species are small, measuring
0.5 to 0.7 millimeter. The average length for the family is about 1.5 millimeters.

Pselaphidae have a more compact body plan than Staphylinidae. This
is one of the best criteria for separating the two families. In pselaphids the
head capsule is more solid, and the gular sutures, so well shown in Paederinae,
are absent or reduced. Secondly, this consolidation is shown in the prothorax,
where the lateral sclerites are generally shorter and of a more rigid con-
struction than in Staphylinidae. Staphylinids generally have six visible ster-
nites (morphologically segments III to VIII). According to Leng (1920) some
variation occurs, for example five segments {Micropeplus, Oligota), six seg-
ments (Euaesthetus) , seven segments (Oxytelini, Aleocharini) and eight seg-
ments visible and movable (Omalium). Blackwelder (1936) gives the total
number of abdominal segments in Staphylinidae as ten, of which the first is
represented by tergite; second by tergite usually and sternite in some species;
third, fourth, fifth, sixth, seventh and eight with normal tergite and sternite;
ninth and tenth segments variously modified and often considered with the
genitalia.

TAXONOMIC MORPHOLOGY 15

In Pselaphidae the great majority of species have the abdomen with from
five to six visible tergites and sternites. Exceptions occur, but these are a
consequence of the general consolidation of the body — a family trait. Thus,
Cyathigerini have two visible tergites and sternites; Clavigerinae have a
dorsum of three fused tergites, but five to six visible sternites. In other groups
the number of sternites varies with sex. In such forms, unevenly distributed
through many tribes, the males have a ventro-terminal piece, the penial plate
or pygidium. This appears to be a part of the seventh visible stemite. It may
be excessively minute or very large and conspicuous. The penial plate may be
a single plate {Actium, Bibloplectus, Cedius, Cylindrarotus, Dalmosella,
Melba, Ramecia, Thesiastes, Thesium, Tnmioplectus , Tyrogatunus, Tyrus),
varying in shape from narrow-transverse, through quadrate, circular, oval,
semi-circular, to narrow-oblong. The penial plate may be divided into two
parts, a right and a left piece {Rhinoscepsis, Euplectus) . In dried specimens
the males of these latter show the two plates as closely appressed, the line of
contact being then spoken of as the longitudinal penial or pygidial carina. In
Euplectus, the genus can be conveniently divided into two aggregates of sub-
genera, depending upon whether this carina is convex to the left or to the right.
Again, in Sonoma tolulae the males have a seventh stemite, which is divided
into three pieces, a right, a left, and a median plate.

The male genitalia and associated penial plate (Plates I, II, III) never
have been studied or applied to the classification of the family. This is strange
since the male copulatory organ (aedeagus or penis) is large, sclerotized, and
easily dissected in fresh or relaxed material. I have found the aedeagus to
offer qualitative characters in the separation of closely allied species, and to
give at least another criterion for the determination of generic limits as well
as the evolution of the family. Protected as it is from frequent contact with
the environment (in distinction to mouth-parts and tarsi which are in nealy
continual contact), and requiring close adjustment to the female genital tube
for successful continuance of the species, the male genital tube offers valuable
taxonomic characters.

The pselaphid aedeagus is a further specialization of the staphylinoid plan.
It seems to be derivable from the Oxytelinae. Typically, the pselaphid aedeagus
consists of a large, heavily sclerotized median lobe. The basal (morpho-
logical anterior) part of the median lobe swells into a basal bulb. The dorsal
surface of the median lobe quite generally bears two membranous diaphragms,
the basal diaphragm is larger, usually oval, and occupies the basal half to
two-thirds; the apical diaphragm is smaller, oval to triangular, and occupies
the apical part of the median lobe. The free apical end (mor|Dhological posterior)
of the median lobe is generally narrowed into a sharp-pointed lamina of diverse
length and shape. Lateral lobes are present less frequently and are regarded
as primitive. These latter are usually small or membranous and may be moved
latero-mesiad by bilaterally symmetrical bulbar muscles of the basal bulb, or
these muscles may be chiefly concerned in exserting and rotating the relatively
large aedeagus from the male genital orifice. Occasionally the median lobe

16 NEOTROPICAL PSELAPHIDAE

gives rise to what I have termed a ventral lobe. The ventral lobe may or may
not bear the lateral lobes, and its presence is regarded as a specialized con-
dition. The smaller apical diaphragm noted above is usually associated with
the median orifice. In a few cases the median lobe gives off a movable acces-
sory piece. This is a single, asymmetrically placed part and appears to be
moved by asymmetrically inserted bulbar muscles. These are the chief parts
of the pselaphid aedeagus to be observed at normal binocular magnification of
prepared specimens on points.^ Slide-mounts bring out a wealth of detail on
internal structure.

The median lobe is invariably present; all other parts noted above may be
absent or variously modified, as is brought out by a study of the illustrations.
Although the aedeagus gives evidence for (a) structural modification at differ-
ent rates within the same tribe, (b) convergence or parallelism between genera
of different tribes, and (c) divergence between species within the same genus,
there are two definite trends of specialization to be observed in its compara-
tive anatomy. These are (1) simplification through loss of parts, and (2)
progressive asymmetry.

The primitive pselaphid aedeagus has perfect bilateral symmetrj^ a well-
developed median lobe in which the diaphragms are invisible from above, a
right and left lateral lobe present as sclerotized parts, and no ventral lobe or
accessory piece.

The specialized pselaphid aedeagus has the median lobe bilaterally asym-
metrical, diaphragms well-formed and visible from above, lateral lobes absent,
ventral lobe present or absent, accessory piece present or absent.

Associated with these trends is the penial plate. Since it is considered
here as a remnant of the seventh visible sternite, and since we have shown
that the Pselaphidae tend towards a consolidated staphylinoid body plan, its
presence is primitive, and its absence specialized. Thus it is present as a twice-
divided plate (Sonoma tolulae) ; divided plate (Euplectus) ; a single plate
which must be asymmetrically moved during extrusion of the aedeagus, either
to the right (dextral penial plate) or to the left (sinistral penial plate) —
many genera previously noted belong here, and are either dextral or sinestral
while at least one genus (Cedius) has both dextral and sinestral species — and
finally this plate drops out in numerous genera.

The aedeagus of Reichenbachia is primitive among Brachyglutini, and is
very similar to the Oxytelinae; Pilopius among Ctenistini, and Cylindrarctus
among Tychini, are primitive. These three genera have lateral lobes but each
presents certain specializations, thus Reichenbachia has a poorly developed
basal diaphragm, Pilopius has a slight apical asymmetry, and Cylindrarctus
a ventral lobe. The Batrisini are highly specialized, and the dorsal surface of
the Pilopius aedeagus is strangely batrisine. Within the large genus Batrisodes
a reliable key can be made to species, based on the aedeagus. In the first place,

^ It will be remembered that when a specimen with exserted aedeagus is examined
under the binoculars, it is ventral surface uppermost and therefore the aedeagus, which
is exserted, lies with its apical end directed anteriorly and its dorsal surface uppermost.

TAXONOMIC MORPHOLOGY 17

no Batrisodes has a primitive aedeagus. This is a genus where reduction of parts
is strikingly developed.

Overlaid upon this superficial simplicity is a developing asymmetry.
Thus Batrisodes furcatus and riparius are bilaterally symmetrical while
globosus, denticollis and schaumi are progressively asymmetrical. The species
of this genus studied so far culminate in the aberrant monstrosus. In this latter
species the asymmetry is extreme and an accessory piece is developed. The
aedeagus of monstrosus is so far removed that it should serve to divide the
genus into two subgenera.

The Tyrini appear to have a very specialized penis, with some features
common to Batrisini and Ctenistini but little affinity with Brachyglutini and
Tychini. Among tyrines studies, Ceophyllus and Tmesiphorus are relatively
primitive, with reduced but symmetrical aedeagus; Tyrus is more specialized
in its pronounced asymmetry, but the presence of the penial plate is a primitive
feature; the system appears to culminate, thus far, in Cedius. In this latter
genus there is an extreme asymmetry which is directly correlated with the
penial plate. Thus in Cedius ziegleri the asymmetry is to the left and there
is a sinistral penial plat€ ; in spinosus the asymmetry is to the right and there
is a dextral penial plate.

The Clavigerinae {Fustiger veracruzensis) have an aedeagus which pre-
sents no novelties from the tyrine type, being apparently homologous with the
bilaterally symmetrical organ of Ceophyllus. This is further important evidence
in support of not more than subfamily rank for these symphilic pselaphids.

Contrary to most systems of classification, the Euplectini and Trichony-
chini are highly specialized as regards the aedeagus. The two genera studied
{Rhexidius and Dalmosella) have highly complex, asymmetrical male genitalia
— much less oxyteline than the brachyglutine aedeagus. Enough has been said
here, in this preliminary study, to demonstrate the importance of male genitalia
in the taxonomy of the family. A complete evaluation must await the study
of more genera.

The pselaphid abdomen apparently consists of ten segments, which agrees
with the opinion of Blackwelder for staphylinids, and of Tanner (1927) for
beetles in general. The first and second tergites are either wholly membranous,
or slightly sclerotized and more or less folded. The third tergite is usually
sclerotized. The first three tergites are generally not visible in dried specimens,
being retracted and hidden beneath the elytra in the living condition and re-
maining so nidden unless potashed preparations are made. The fourth, fifth,
sixth, seventh, and eighth are visible and are commonly termed the first to
the fifth dorsal segments; the third tergite may be visible, in which case siy
dorsal abdominal segments can be counted.

The first sternite is apparently absent as a general rule; the second ster-
nite is present as a membranous area articulating the metastemum to the third
sternite, and continuous with the membranous second tergite. The third sternite
may or may not be visible; if visible it is sclerotized and may be wholly
visible, or visible as a variously modified area between the posterior coxae.

18 NEOTROPICAL PSELAPHIDAE

The fourth, fifth, sixth, seventh, and eighth sternites are usually visible, and
are commonly termed the ventral abdominal segments. The ninth and tenth
segments are involved in the genitalia.

Therefore the pselaphid abdomen shows evidence for ten segments, but
the strongly sclerotized, normally visible segments are five to six dorsals and
ventrals, plus the pygidial plate in some males and some females. In the de-
scriptions of species {vide infra) these visible segments are counted from the
base of the abdomen apically, and their exact tergite and sternite origin is
not counted, unless specifically mentioned. Thus the "first abdominal seg-
ment" refers to the first visible segment, the "second ventral segment" refers
to the second ventrally visible segment, et cetera.

A physiological character, that of movability of the abdominal segments,
has been made the most of in separating the two families. This can be utilized,
however, with living material or relaxed specimens, and is relative. Thus within
the Staphylinidae some groups (Staphylininae, Aleocharinae, Paederinae) have
a highly mobile abdomen, and may carry the apex elevated or move it dorso-
ventrally in the typical staphylinid gesture; in Steninae this is not so greatly
developed as a rule; in the Trilobitideini, a tribe of staphylinids created by
Fauvel to hold the species Trilobitideus mirabilis, the abdominal segments are
said to be (Raffray, 1908) solidly immovable in appearance, although more
or less mobile in the living state. In the Pselaphidae the movability of the
abdomen is generally much less, and is antero-posterior in nature (retractile)
rather than freely movable in the dorso-ventral plane; however, this is also
relative. Thus the Clavigerinae have practicaly no abdominal movement; the
Tyrini and Batrisini are more intermediate in this respect; certain Euplectini
(the New Zealand Eleusomatus) have an abnormal abdomen for pselaphids,
constructed in general on the staphylinid plan: the abdomen is gradually and
strongly tapered posteriorly. In Eleusomatus the males have six sternites and
the females only five visible. The abdomen in this, and other euplectine genera,
as well as Sonoma among Faronini, may be as movable as that of some of the
staphylinids.

When everything is considered, however, this mobility of the abdomen
and the structural differences which make it possible or impossible, is one of
the most important criteria for separating the two families under discussion.

The Pselaphidae have the labial palpi either two-segmented (Pselaphinae)
or one-segmented (Clavigerinae). The Staphylinidae generally have three-
segmented labial palpi.

The Pselaphidae nearly always have the distal segment of the maxillary
palpi provided with an apical or subapical palpal cone; this structure is gen-
erally lacking in Staphylinidae. In general it may be said that Staphylinidae
have remarkably conservative maxillary palpi, usually four-segmented and
filiform although exceptions are known. On the other hand, Pselaphidae have
the most variable maxillary palpi known to the author, in fact the name of
the genus Pselaphus is derived from the Greek ("I feel my way") and refers
to these remarkable organs. The pselaphid palpus is usually four-segmented,

TAXONOMIC MORPHOLOGY 19

although it may have three segments in some Goniacerini, Attapseniini; it is
apparently one-segmented in Arhytodini and Clavigerinae. In some pselaphids
(Euphalepsus) the palpus, although fully formed, is very petite (Park, 1933)
and nearly every segment may be grotesquely modified, often forming the
most reliable separation of genera (the reader is especially urged to examine
the palpi of neotropical Tyrini in this respect, the phylogenetic derivation of
which has been attempted on pp. 340-342). The neotropical Ctenistini have
four-segmented palpi, but some ctenistine genera [Biotus, Atinus) have two-
segmented palpi, while Chennium and Chenniopsis have three-segmented palpi.
The nature and extent of palpal modification will become apparent in the
following pages and needs no further elaboration here.

In regard to number of tarsal segments the Staphylinidae is more variable
than the Pselaphidae. Staphylinidae may have a tarsus of three segments
{Micropeplus, Dinopsis, Oxytelini), four segments {Oligota, Euasthetinae),
anterior and intennediate with four and posterior tarsi with five (Bolitocharini) ,
anterior with four, intermediate and posterior with five (Myrmedoniini), five
segments (Aleocharini, Paederinae, Steninae). The Pselaphidae have three-
segmented tarsi, with the exception of the Dimerini which has two-segmented
tarsi. The Dimerini, however, holds but a single species, Dimerus staphy-
linoides Fiori of Italy.

The pselaphid tarsus is generally primitive, the chief variation being in
the relative size of the three tarsomeres. Two tribes have very specialized
tarsi: the third tarsomere is bilobed in the Schistodactylini and the second
tarsomere is bilobed in the Arhytodini. There is some sexual differentiation in
the tarsus. Thus the males of certain brachyglutines {Braxyda, Bryaxina,
Xybaris, Achillia) have the second anterior tarsomere laterally dilated, dorso-
ventrally flattened, and bearing a pad of setae on the ventral surface. Xybarida
nasicola has the second tarsomere relatively shorter and thicker on the anterior
tarsi than this segment of the other tarsi, and bears on the ventrally flattened
face stiff setae in the male sex. The female of this species has the normally
slender, unsetose tarsi. On the other hand both sexes of Raxyhis have the sec-
ond tarsomere of the anterior tarsi thicker than the third, and ventrally clothed
with long setae. There is considerable variation in the tarsal claws. In general
there may be a single claw, two unequally developed claws, or two equally de-
veloped claws, and this variation is discussed at length elsewhere.

Thus we may generalize by saying that the number of visible abdominal
segments and the number of tarsomeres are relatively variable in staphy-
linids and conservative in pselaphids; the maxillary palpi are variable in
pselaphids and conservative in staphylinids.

Relatively speaking, the antennae are also conservative in staphylinids
and notably variable in pselaphids. These appendages vie with the maxillary
palpi in extent of modification; they are more variable in pselaphids than in
any other family of beetles, with the possible exception of the Paussidae. They
range from two to eleven segments, and practically any antennomere can bear
sulci, foveae, spines or teeth, peculiar pubescence or specialized appendages.

20 NEOTROPICAL PSELAPHIDAE

This diversity is demonstrated by the plates and in the descriptions which
follow, and is not confined to a single subfamily, tribe or genus but extends
through the entire family. In many cases special antennal modification is re-
stricted to one sex, usually the male ; in many cases both sexes have the anten-
nae modified.

The method of articulation of the pselaphid antenna is notable, and has
been previously discussed by Casey, Raffray and other students but has not
been sufficiently appreciated by coleopterists as a whole. Pselaphidae have the
first antennomere flexed dorsad to articulate on the upper wall of the antennal
acetabulum, or where the acetabulum is functionally obsolete (as in the spe-
cies with contiguous antennae mounted on a median antennal tubercle) then
this segment is articulated on the ventral face of the tubercle. Hence the
pselaphid antennal articulation is restrictive as contrasted to the articulation
of staphylinids. The Staphylinidae show some variation, but quite generally
have antennae which do not articulate on the upper wall of the acetabulum
and do not have such pronounced antennal tubercles. This may be a prophetic
difference, that is, the pselaphid antennal-articulation plan is suggested here
and there in the staphylinids — giving yet another hint as to original stock of
the pselaphids.

The vertex of the pselaphid head capsule usually bears a pair of vertexal
foveae. These foveae are very characteristic of the entire family. They repre-
sent invaginations of the integument, and in slide mounts these foveae are
seen to have their floors attached to the arms of the V-shaped supratentorium
of the endoskeleton, the supratentoria continuing ventrad where the two oblique
arms unite ventro-posteriorly to attach to the floor of the median gular fovea.
This latter usually is present as an invagination of the integument near the
demarcation of the ventral surface of the head proper and the cervicum.
Rarely the arms of the supratentorium attach to the ventral surface of the
head without forming the gular fovea ; at times the single gular fovea bifurcates
internally to form two ventrally continuous foveae; in still other cases there
are two entirely separate but approximate gular foveae, each attaching to
one arm of the supratentorium.

The vertexal foveae are rarely absent {Adranes, Nisaxis), although they
may be very minute {Fustiger, Barrojuba, Trimiomelba, Ceophyllus) . In some
genera these foveae are highly specialized. Thus in Pselaphus they are drawn
forward to produce two voluminous subfrontal cavities, the orifices of which
are so far anteriad of the supratentorial anchorage that they may be over-
looked at first. It is as though in Pselaphus the forward attenuation of the
antennal tubercle had pulled the head capsule integument anteriorly between
the eyes while, the floor of the foveae being held by the supratentorium, the
walls were consequently stretched abnormally. The vertexal foveae as a gen-
eral rule are normally sized and placed but their walls may be wholly nude
or densely pubescent. In some genera {Euplectus, Batrisodes, Hamotus) the
foveae may be both nude and pubescent within the same genus, but this is not
a common condition. Rarely the foveae are wholly obscured by dense cephalic

TAXONOMIC MORPHOLOGY 21

pubescence or squamose areas (Arhytodes) . This wealth of detail is made much
of in the taxonomy of the family, especially in separating species within a
genus.

Staphylinidae do not present this picture, the vertexal foveae being of very
rare occurrence [Edaphiis).

No comparative treatment would be complete without a discussion of the
pubescence. The great range of pselaphid pubescence is suggested by exami-
nation of the plates, where a number of setal types are illustrated. These setae
vary about a norm, commonly found throughout the family, which may be
described as an elongate, aciculate seta which is circular in cross-section. Of
great use in pselaphid taxonomy are the extremes developed; the length, thick-
ness, stiffness, amount of taper, apical contour, amount, and degree of incli-
nation are all of value (cf. especially Plate IV).

One of the more striking modifications is the development of trichomes.
These are usually thick, tortuous bundles of golden setae which adorn the
apical elytral margins and the latero-basal angles of the dorsum and are not-
ably developed in Clavigerinae. Here the trichomes are specifically modified
for the conduction of a trichomal secretion which appears to be very stimu-
lating to their formicid hosts. Trichomes are variably developed in the Clavi-
gerinae, and may be absent. What appear to be homologues of clavigerid
trichomes, at a lower level of organization, are found in the Attapseniini,
also wholly myrmecophilous.

Trichomes occur upon the abdomen of certain symphilic staphylinids
{Xenodusa, Lomechusa, Atemeles). Therefore the trichomes may not be con-
sidered as a phylogenetic character of use in the separation of clavigerines
from pselaphines, since (1) they are not universal in Clavigerinae, (2) they
occur on non-clavigerine tribes (Attapseniini), (3) occur in certain symphilic
staphylinids. Rather I should regard trichomes as an ecological adjustment
to life with social insects.

Tufts of setae, not trichomoid in the symphilic sense but similar in ap-
pearance, may be found in other pselaphids, usually the male sex in some
Euplectus, Actium, Dalmosella or in the female sex of some Thesium. Such
setal tufts usually arise from a tuberculoid area and are usually abdominal.

Some genera are wholly glabrous (Eupsenitis) ; other are nearly glabrous
(Eupsenina) ; others scantily pubescent {Melba, Trimiomelba) ; many are
normally pubescent {Euplectus, Arthmms, Reichenbaohia) ; some are heavily
pubescent (many Hamotv^, Hamotocellus). In the genus Pselaphus the
pubescence is massed upon sterna and ventral face of the head into aggregations
of broad, thick, membranous scales more or less agglutinated. This has been
described by Casey (1893), and has been aptly described as "sugary" by
David Sharp.

Typically squamoid pubescence is found in the Ctenistini. Here the setae
are sparse, long, appressed scales. These scales are especially massed in pronotal
depressions, elytral apices and base of dorsum. These scales may be very
narrow (femora of Pilopius), or conspicuously spade-shaped (elytral apices of

22 NEOTROPICAL PSELAPHIDAE

Pilo-pius). The normal ctenistine scale is gradually broadened distally, and its
integumentary puncture is provided with a tubular extension into the chitin.
The Arhytodini and Hybocephalini also have squamous pubescence in part.

The setae may be normally inserted, or may be lodged on small asperities
(as on the antennal cones of Tychus), or may be placed upon relatively large
tubercles (asperate setae on the distal antennal face of Rybaxis clavata) . These
antennal cones are present in many of the Pselaphidae examined from various
parts of the world, and under oil at high magnification they can be differentiated
from the normal antennal setae. When we have more data concerning the an-
tennal cones, they may serve as a taxonomic aid (Park, 1935c), as has been
noted for the male genitalia previously. For examination of these cones see the
distal antennal segment of Melba, Dalmosella, Euplectus, Bibloplectus, Tychus,
Pilopiits, Rybaxis and Tmesiphorus among Illinois genera; Central American
species examined {Hamotus turalbus) have the antennal cones well developed.
In this species the cones are normally transparent and very difficult to see in
unstained preparations but appear to be articulated upon rounded asperities;
normal antennal setae are usually quite distinct and are smaller than cones and
placed in slightly recessed punctures. These cones may be homologous to the
distal setiform cone of the last segment of the pselaphid maxillary palpus; at
least they appear similarly under magnifications of 1000 diameters, and like
the palpal cone, may be sensory in function. It is interesting to note that such
cones are also developed upon the antennae of Thysanoptera, Chalcididae,
Proctotrupidae, et cetera.

The ventral face of the head may bear knobbed or capitulate setae [Melba,
Trimiomelba, Eupsenina) in a definite pattern; in some genera (Thesiastes)
these capitulates are few in number, strongly knobbed, and more or less spino-
form; in Bibloplectus these setae are truly spinoform processes of the integu-
ment. On the other hand the setae on the ventral surface of the head of Rhex-
idius are very long, very abundant, and only slightly capitulate, e.g. the setal
tips are gradual elongate-oval swellings, sometimes absent entirely; in Euplec-
tus, the same area bears sparse, recurved, noncapitate setae.

An extreme in the modification of the setal tip is seen in the maxillary palpi
of certain species, for example Pilopius lacustris, where the setae of the distal
segment are long, uniformly slender to the apex which flairs into a thin, flat plate
at right angles to the shaft. These setae may be termed umbrella-setae. Also
the distal palpal segment of Ephimia and Juxtahamotopsis have peculiar setae:
short, thick, rigid, blunted, translucent, and appear to be small spikes. In this
case we may have a transitional stage from seta to palpal cone.

Almost always one seta arises from a single puncture, but in Adranes the
setae of the head, pronotum and elytra appear to be doubled, that is, two di-
vergent setae arising from a single puncture. This is not true, species of Adranes
following the general rule, and under high magnification each seta is seen to
bifurcate a short distance beyond the puncture, to give two long processes.

The remaining features of this comparative review deal with the sternal
areas, the endoskeleton, and the sternal foveae. The Pselaphidae have the pros-

TAXONOMIC MORPHOLOGY 23

terum characteristically reduced between the coxae, so that the anterior coxal
cavities are large, confluent and opened posteriorly; the anterior coxae are
typically large, subconical and either contiguous or narrowly separated.

The mesosternum is characteristically short and wide. Anteriad of the coxal
cavities, it presents a highly diverse appearance of great convenience in sepa-
rating genera ; this variation can be appreciated only through concentrated com-
parative study. As in most beetles, the median portion of the ventral surface of
the mesothorax is composed of the unpaired mesosternum, usually wider than
long and in a varying degree bounding the coxal cavities posteriorly. It projects
in a varying degree between the coxal cavities as the mesostemal process. Lat-
erally the mesosternum is bounded by the epistemum. When the mesosternum
and epistemum are clearly separated, the dividing suture is the stemopleural
suture, but there is a varying degree of fusion between the two sclerites, this
line of fusion being marked at times by carinae or foveae. Similarly, the
epimeron may be present at a distinct sclerite ventrally, or may not be apparent
as a discrete element. Anteriorly the mesosternum presents a system of foveae,
carinae, ornamented depressions or pubescent areas which make this part of
the pselaphid body very different in appearance from the homologous region of
the staphylinid. The anteriorly narrowed, "neck-like" portion of the mesosternal
area articulates with the prothorax by a folded, extensive membrane ; and where
this membrane attaches to the mesosternum and mesoepistemum this region of
the sternum is elevated generally into a heavily sclerotized collar. This collar
may represent the prepectus of staphylinids, and for convenience here is termed
the prepectoid area. Since the prepectoid is discussed and figured, no more need
be said here save that often it is secondarily depressed or modified to hold the
tips of the reposed anterior coxae. The mesothoracic coxal cavities are large,
rounded, closed posteriorly by the metasternum, and are wholly confluent,
slightly confluent, narrowly separated by the intercoxal lamella, composed of
mesosternal and metastemal processes, or finally may be widely separated. The
coxae are, therefore, contiguous to separated and moderately distant as in
Adranes, for example.

The metasternum is characteristically large. It is often modified by tu-
bercles, spines, teeth, carinae, sulci and foveae. Such elaborations present both
specific and sexual differences and are consequently of great use in identifica-
tion. For example the males of Adranes have the metasternum greatly modified
by spines or spinoid tubercles in contrast to the females. This modification
reached a peak in Arhytodini where the males may have a pair of tubercles, or
a pair of small sharp, hooked spines, or both tubercles and spines in various
stages of development and position while the females have a simple metastemal
field. On the other hand both males and females of some Neotyrus, Tyrogatunus
and other genera have similarly modified metasteraa.

Degree of separation of the intermediate coxae is variable, and of impor-
tance in tribal separation. Thus Clavigerinae, Pselaphini, Batrisini and Brachy-
glutini have the coxae usually well separated, but the last mentioned tribe
shows several degrees of separation and hence groups of brachyglutine genera

24 NEOTROPICAL PSELAPHIDAE

can be isolated on this character. Tyrini also show considerable variation, but
as a tribe come under this first group, while Euplectini have these coxae approxi-
mate or contiguous.

The chitinous invaginations of the integument — the endoskeleton — are well
formed in pselaphids. We have previously noted the supratentorium of the
cephalic capsule, its intimate relationship with the vertexal foveae, and with
the gular fovea. The author has been at some pains to check the condition cited,
and this study has covered well over a hundred nearctic and neotropical species.
Earlier, Stickney (1923) recorded the supratentorial details for Pilopius
lacustris and Fustiger fuchsi.

The endoskeleton of pro-, meso-, and metathorax is less well understood.
The prosternum has a one-piece prosternal furoa of the U-type which extends
internally from the dorsal wall of the coxal cavities, one arm of the furca from
each cavity and the two arms broadly joined at their bases. The mesosternal
furca is composed of two discrete arms, one extending internally and anteriorly
from the dorsal wall of each coxal cavity. The metasternal furca if of the
Y-type, with a basal stem invaginating in the center of the posterior metasternal
field, and this basal piece bifurcating, with the arms extending dorsad into the
thoracic haemolumen and musculature.

Chitinous invaginations of the abdomen, associated with the spiracles, are
present in genera investigated, and are notable in certain Euphalepsus. From
certain points of view the sclerotized male copulatory apparatus could be con-
sidered invaginations, in view of their relation to the ninth and tenth abdominal
segments, but this is not involved in the endoskeleton.

Another general morphological subject to be examined here is the foveal
system of Pselaphidae. The integument is diversely and richly supplied with
small integumental invaginations. Possibly no other single feature is of such
use in the identification of genera and species as the foveae — their presence or
absence, number, type and distribution. The vertexal and gular foveae have
been previously discussed, and are only a few of the many foveae present. The
significance of foveae in Pselaphidae has been underestimated, and at least
two aspects need emphasis.

In the first place foveae often suggest a general sensory function. The rich
pubescence of many foveae lends credence to this hypothesis but careful experi-
ments are necessary before definite ideas can be held on this point.

In the second place, the morphology of foveae is easily studied by slide-
mount technique and a considerable amount of data are at hand for their
evaluation (cf. especially Plate V). The topographic position of many foveae
in Pselaphidae tends to indicate that they have arisen where sutures coalesce.
Therefore their presence is an indirect argument for the structural consolidation
of the body, so well shown in pselaphids, and so conspicuous by its absence in
the staphylinids. When a fovea is examined, it is seen to be a thimble-shaped
or cylindrical invagination of the hardened integument. Its walls are usually
either segmentally creased, or spirally whorled. Usually it is short and conical;
in other cases its lumen is long, tubular and sinuate.

TAXONOMIC MORPHOLOGY 25

The distribution is diverse. Cervical foveae may occur on the ventral face
of the cervicum or neck, where they may mark the posterior area of the gular
sclerite (Euplectus interruptus) ; or on the dorsal face of the cervicum (Melba)
where they form a part of the metatentoria of that region.

The prostemum with its ankylosed sidepieces usually presents from one to
five foveae, following the general plan of the sutural zones of the insect pro-
sternal area. The more numerous and well-developed the foveae, the more
primitive the species, other things being equal, and conversely, with the final
disappearance of foveae, leaving an apparently unmodified sheet of integument,
the more highly evolved the species. Such a generalized hypothesis must be care-
fully analyzed in the future to prove or disprove its worth. However, the general
idea of (1) developed sclerites, bounded by clean sutures, (2) sclerites becoming
consolidated, the sutures vestigial and their more resistant intersections or areas
persisting as foveae, and (3) eventual disappearance of foveae, leaving a solid
chitinous piece, may serve as a working plan. Obviously not all foveae are to
be viewed in the light of this idea, e.g. the elytral foveae and pronotal foveae
may have their origin too far removed in evolution to be considered. The fusion
of the pronotal sclerites into one pronotal piece is an ancient combination in
beetles, and the elytra or wing cases are also greatly modified from the meso-
thoracic functional wings of other insect stock. The sternal areas, however, offer
a promising field, especially when they can be compared with staphylinid areas,
admirably reviewed by Blackwelder (1936), whose comparative treatment of
the anatomy of the Staphylinidae should serve as a guide in future revisions
of the family.

The pselaphid prostemum consists of two sclerotic areas, which are some-
times primitively well defined, and at times fused into one piece. When both are
developed, the prostemum has two sclerites. The first is the basisternum and
is an anterior piece being bounded by the anterior foramen of prothorax into
which the head is inserted, anteriorly; laterally by the notostemal sutures of
each side ; posteriorly by the anterior coxal cavities in part and in part by the
second sclerite, the furcasternum. The jurcasternum is variously developed and
may be clearly visible under the anterior coxae, or virtually absent externally.
This last sclerite or division is chiefly concerned in the endoskeletal invagina-
tions, the diverging arms of which are anchored in the basal furcasternal area.

Returning to the prostemal foveae, we find that these are distributed as
follows: (1) Anterior Prostemal Foveae, one on each antero-lateral angle of
the basisternum, usually invaginated in the notostemal suture when it is clearly
formed. (2) Lateral Prostemal Foveae, one on each postero-lateral angle of
the basisternum, usually invaginated in the area where the notostemal suture
anastomoses with the stemacostal suture, the transverse suture separating the
two prostemal areas. However the lateral prostemal foveae may be located
far from this point, and lie, one above each coxal cavity in the sternacostal
suture, or, if this is not present or not in its normal position, in the posterior
margin of the basistemum above each coxa. Thus the lateral prostemal foveae
are essentially related to the anterior coxae, and form an anatomical land-

26 NEOTROPICAL PSELAPHIDAE

mark in the topography of the prosternum. When they are present, these foveae
can be seen to best advantage in potashed slide-mounts in which the coxae have
been removed. (3) Median Prostemal Fovea, when present, in the posteriorly
angulated portion of the basistemum where it forms a slight projection between
the anterior coxae, or invaginated in the sternacostal suture medianly between
the coxae.

It should be noted that all combinations may exist, from one, three to
five of the foveae present or absent, and the foveae may be well-formed in-
vaginations, deeply conical and with their walls segmentally creased or whorled
to foveoid depressions. The primitive Sonoma {Raj onus) tolulae has all five
present, and not very well developed; the anterior prosternals especially are
weak. Here the sutures are more clearly defined, but in Rhinoscepsis bistriatus
only the lateral prostemal foveae are present and these are strongly defined
and nude, and in Euplectus (Pycnoplectus) interruptus only the lateral pro-
sternals are present and these are pubescent. The figures and descriptions will
give other data on these foveae, and we should remember that this classification
of foveae is a tentative one upon which a complete picture may be erected
for the family as a whole.

Because the foveal system is being elaborated here as a taxonomic aid,
rather than as a detailed account of comparative anatomy, the foveae of the
meso- and metasterna are considered collectively, inasmuch as the student
examining the venter is confronted with a compact region holding the inter-
mediate and posterior coxae. In addition to certain rare or aberrantly placed
foveae, the meso- and metastemal field presents a varying number of foveae,
from one to eleven, which may be considered here.

I. Prepectoid Foveae. These are invaginations on the prepectoid area,
and are very rare. When they are present {Sonoma {Raj onus) tolulae) they
lie in a region which would be traversed by the stemopleural suture if it were
present, and appear as the most anterior pair of foveae. The prepectoid abounds
in complicated depressions; and foveoid depressions are suggested by the
topography of Euplectus {Pycnoplectus) interruptus and Adranes lecontei, to
name two extremes; true prepectoid foveae are known, however, only in
tolulae, among the species studied thus far. Their presence is regarded as a
primitive feature, since the prepectus apparently lost its identity, as a discrete
element, among pselaphids by fusing more or less with the sternum and epister-
num of the mesothorax.

II. Lateral Mesosternal Foveae. These are a pair of foveae which ap-
pear as invaginations of the sclerotized posterior wall of the prepectoid and
also in the region of the stemopleural suture when it is present. They are prac-
tically never absent, being the most constant of all the stemal foveae, and
traverse the prepectoid wall where it is elevated above the mesosternum. They
course medianly, and their apertures are usually difficult to locate in dry
triangle mounts because of pubescence in some groups (Ctenistini, Pselaphini,
Tmesiphoms, et cetera). In slide mounts, however, under high magnification,
they are quickly discerned.

TAXONOMIC MORPHOLOGY 27

III. Median Mesostebnal Foveae. These foveae also are usually present,
but may be widely separated, close together with a common aperture, or fused
as one fovea, the median mesostemal fovea. They appear as openings in the
mesosternum, just posterior to the prepectoid ridge, and between the usually
conspicuous coxal-prepectoid carinae, which run longitudinally on each side
of the mesosternum in most species. They penetrate also the prepectoid, in-
vaginating anteriorly. In cleared slide mounts they can be easily found when
present, but in dry triangle mounts they usually appear as one median fovea,
since many species have a common aperture for these foveae. They are shorter
than the lateral mesostemal foveae, and in a number of species the lateral
and median mesostemals cross each other on each side because of the median
course of the former and the anterior course of the latter.

IV. Lateral Mesocoxal Foveae. These appear as invaginations at the
lateral extremity of each mesothoracic coxal cavity. They vary in size from
huge invaginations to minute pores; they may lie a short distance from the
cavities or be partially lapped by the coxal rim ; they may be nude or pubescent,
circular to slit-like, and are present in about sixty per-cent of the species.
These lateral mesocoxals are important foveae since they invaginate at a
topographic area where a number of sclerites, or sclerotic regions, meet, e.g.
mesosternum, mesoepistemum, mesoepimeron, metaepisternum and metaster-
num. Three or more of these regions are usually involved in the formation of
the fovea on each side, so that each fovea appears as the hub of a wheel with
the sclerotic regions radiating spoke-wise from its cavity. Again, examination
of cleared slide mounts, in which one mesothoracic coxa has been removed to
show the coxal cavity, usually shows the fovea as a deep, conical, segmentally-
creased invagination which penetrates anteromedianly below the coxa. The
internal, blind end of the foveal lumen continues as a sclerotized fiber which
joins the arm of the mesostemal furca of the endoskeleton above each coxa,
and passes dorsal to the lateral articulation of the coxa. These foveae, then,
are important topographically and appear also to have a direct connection
with the endoskeleton (e.g. Tmesiphorus costalis), as was shown also for the
vertexal foveae.

V. Posterior Mesocoxal Foveae. These invaginations may or may not
be present. When they occur they should be looked for as a pair of openings
along the posterior margin of the coxae, one on each coxal border. The po-
sition of these foveae varies considerably. They may be approximate, in which
case they lie near the median end of the coxal cavity of each side and their
course is anterior into the heavily sclerotized metasternal process or lamina
between the coxae; or they may be widely separated, each appearing as an
invagination of the posterior coxal border of the metasternum near the lateral
mesocoxals noted above ; or they may occupy some intermediate position along
the posterior coxal margin.

VI. Median Metasternal Foveae or Fovea. These foveae are almost
always fused as one fovea which forms an invagination in the metasternal

28 NEOTROPICAL PSELAPHIDAE

process and courses anteriorly between the intermediate coxae. This fovea is
uncommon, but in many Tyrini (certain Hamotus, Neotyrus) is large.

The following table is given to show the range and distribution of the
foveae in a few representative pselaphids. This selected list is made up of
Nearctic species, but is applicable to any other faunal area.

Table I
MESO- AND METASTERNAL FOVEAE

Species I II III IV V VI Total

Sonoma (Rafonus) tolulae + + + + + f 11

Rhinoscepsis bistriatus 0 + + + + 0 8

Rhexidius canaliculatus 0 + + + + 0 8

Bibloplectus ruficeps 0 + f + + 0 7

Melba sulcatula 0 + f + + 0 7

Euplectus interruptus 0 + + + 0 0 6

Trimiomelba dubia 0 + f 0 + 0 5

Rhexius insculptus 0 + + + 0 0 6

Tmesiphorus costalis 0 + f + 0 0 5

Pilopius lacustris 0 + + 0 0 f 5

Adranes lecontei 0 + 0 0 0 0 2

Legend : + foveae present and paired

f foveae fused into a single fovea
0 foveae absent
See Plate V

In this table the meso- and metasternal foveal range is from eleven to
two. Primitiveness is directly proportional to the number of foveae, if the
assumptions set forth here are tenable. Since these eleven species were chosen
at random from slides of nearly one hundred species, the confirmation of other
lines of evidence is indicative of the phylogenetic value of foveae. Thus the
Faronini are the most staphylinoid pselaphids from many points of view, and
Sonoma tolulae has eleven out of a possible twelve foveae, whereas the highly
specialized Adranes lecontei has but two foveae. In Adranes even the vertexal
foveae are lacking; in fact, the dorsal arms of supratentorium do not even
reach the epicranium. Sternal foveae also check the relative position of genera
within tribes: Rhexidius canaliculatus is more primitive than Rhexius in-
sculptus; Melba more primitive than Trimiomelba; Bibloplectus more primitive
than Eupleotus. Thus the foveal system should prove phylogenetically sig-
nificant when it is more thoroughly studied.

There is one more structural item which should be mentioned, namely the
compound eyes. Rediscovery of Mendelism, followed by the establishment of
the gene theory, in the present century has placed at the disposal of biologists
a logical mechanism for heredity which can be experimentally attacked (Mor-
gan, 1919, 1926). Physiological genetics and cytogenetics have utilized insect
material to great advantage within recent years, and the insect eye has played
an important role in modern problems. Especially pertinent are the experiments
which attempt to explain the facet size and number, their heredity and the
role of ecological factors such as temperature (Hersh, 1934; Margolis, 1935;
Zeleny, 1915, 1917). Eventually the interrelation between environment and
heredity in the insect eye will be sufficiently understood to allow us to evaluate

TAXONOMIC MORPHOLOGY 29

these organs in our taxonomy. Certainly facet number is as good a character
as many others now in use.

In Pselaphidae the eye varies from circular, through ovoidal to strongly
reniform and its shape, relative position, amount of ocular setosity are all
quite constant for a species population except where the sexes have differently
formed eyes. The loss or reduction of eyes is considered as a specialized con-
dition, and primitive stocks, therefore, are thought to have the eyes well
developed. Often loss or reduction is correlated with loss or reduction of func-
tional metathoracic wings, or both with habitat such as the deep mold or
cavernicolous species, occasionally with sex but no invariable rule may be
set forth in this respect.

Nevertheless there has been considerable reduction or loss of compound
eyes in the Pselaphidae. Thus, in Euplectini, Mirus and Scotoplectus have no
eyes, Rhinoscepsis has reduced eyes in both sexes, and Autoplectios and
Eutyphlus have reduced eyes in the female sex. In Batrisini, Amaurops
(Troglamaurops) and Arianops have no eyes but replacing spines, Amaurops
{Amaurops) has neither eyes nor replacing spines, and Bergrothiella has re-
duced eyes. In Pselaphini, Pselaphiscnus has reduced eyes, and in Pselaphu^
the eyes vaiy among the species from well-developed to greatly reduced. In
Goniacerini, Bibrax has the eyes represented each by a single facet. In
Aletopiini, Barrometopia has reduced eyes of ten facets each. In the Clavi-
gerinae, Adranes and Claviger have no eyes.

Number of facets is much less well known, but offers great taxonomic pos-
sibilities. In Fustiger the species vary in number of ocular facets from 8 to 30 ;
in Hamotus the facet number varies among the species from 34 to 96. We are
at the threshold of our knowledge in this notable character. The new species
described in this paper have the facet number stated, but the implications
must await more examples.

A novel feature is the facet structure of a new genus of termitophilous
tyrines, Tyrogatunus. Here the reniform eye of 62 facets has the dorsal third
of the eye composed of about 22 very flat, significantly wider facets, whereas
the ventral two-thirds has the more normal strongly convex type of facet.

In the previous pages, certain salient structures have been discussed
comparatively. From this it is obvious that the pselaphids are most nearly
allied to Staphylinidae — in fact, they should be regarded as a specialized as-
semblage of an ancestral staphyliniform ancestor. The pselaphid tribe Faronini
is especially staphylinoid. As Casey noted (1893), the tarsus of Faronus is
quite similar to many Oxyteline staphylinids. Again, the first visible tergite of
Faronus has a transverse pubescent line which is found in some Omaline
staphylinids. The general resemblance of euplectines to Euasthetinae is also
suggestive. These euasthetine staphylinids have a distinctive pselaphoid habitus,
which goes beyond their small size and color, extending to the contour of the

30 NEOTROPICAL PSELAPHIDAE

body; the eleven-segmented antennae and well-developed vertexal foveae of
euasthetines are especially pselaphoid.

Finally, a summary of the pselaphid anatomy and ecology suggests the
following definition of the family: Pselaphidae is a consistent assemblage of
some 4700 described species of brachyelytrous beetles belonging to the super-
family Staphylinoidea ; the family has a cosmopolitan distribution, reaching a
maximum of speciation and complexity in the tropical regions; the stratum of
competition is chiefly the forest floor mold, although grassland and the so-
cieties of ants and termites have been invaded; as a group, the family is
predaceous, with well-developed mandibles; the active period is during the
night, especially the hours at and after dusk; they are characterized by a
compact body plan in which there is a tendency for sutures, especially gular
and sternal, to be reduced or absent, with foveae abundantly and diversely
developed ; the vertex almost always bears a pair of vertexal foveae ; antennae
are highly variable, usually clavicom, of from two to eleven segments, and
diverse in stmcture; form may be both specific and sexual; the articulation
of antennae to head is usually more restrictive than in allied families, being
by means of a flexure of the basal antennomere to the dorsal surface of the
acetabulum; labial palpi are small and conservative, of from one to two seg-
ments; maxillary palpi are peculiarly labile, usually four-segmented, and
usually with an apical palpal cone; the abdomen has little dorso-ventral play,
and typically has five visible tergites and six visible sternites; the aedeagus
is a specialized organ of oxyteline affinities, tending to reduction of parts and
bilateral asymmetry; the tarsi are three-segmented with the possible ex-
ception of two aberrant genera; the larval stage is staphyliniform, similar to
larvae of Bledius in the two species investigated by Boving and Craighead
(I.e.) ; the size range of pselaphid imagines varies from 0.6 to 5.5 millimeters.

Key to the Tribes of Neotropical Pselaphidae

At present there are twenty-two tribes of Pselaphidae. In the present
paper two tribes (Euplectini and Trichonychini) are united. The Western
Hemisphere is represented by seventeen tribes. Four tribes (Dimerini, Mirini,
Cyathigerini and Schistodactylini) have no known American species. Four
tribes (Jubinini, Metopiini, Arhytodini and Attapsenini) are exclusively Amer-
ican; some tribes are poorly represented in the Western Hemisphere (Faronini,
Pyxidicerini, Batrisini, Pselaphini, Ctenistini, Hybocephalini and the sub-
family Clavigerinae) . These facts of distribution are taken advantage of in
the key which follows.

This tribal key (Plates VI and VII), and all other keys in the present
study, are artificial in the sense that isolation of specimens is the goal, without
reference to evolutionary order. Consequently key characters of little phylo-
genetic weight may be employed, if by so doing tribes, or parts of tribes, can
be separated effectively. Again, this and the keys which follow relate spe-
cifically to the Neotropical Region (roughly the Americas south of the Tropic
of Cancer, and their associated island groups, to central Argentina) and should
not be expected to apply elsewhere.

All seventeen tribes of the Americas are known from this region, and
their neotropical components may be separated as follows:

Antennae of not more than three segments (PI. VI, 5)

CLAVIGERINI

(p. 350)

Antennae of more than three segments (PI. VI, 6, 7) 2

Tarsi with the second segment bilobed, the third segment cylindrical
and inserted between the lobes of the second; known only from

South America (PI. VI, 3) ARHYTODINI

(p. 343)
Tarsi with the second segment large or small, cylindrical, obconical,

compressed or flattened but never bilobed 3

Tarsi with the first two segments small and the third segment rela-
tively very large (PI. VI, 1 ) 4

Tarsi with the first segment small and the last two segments rela-
tively very large (PI. VI, 2) 6

Antennae of nine segments PYXIDICERINI

(p. 37)

Antennae of eleven segments 5

(31)

32 NEOTROPICAL PSELAPHIDAE

5. Trochanters of intermediate legs short, very obliquely articulated with

femora, so that the latter are near the coxae ; tarsi with two equal

claws (PI. VI, 9) FARONINI

(p. 35)
Trochanters of intermediate legs with the femora articulated at the
distal face, so that the femora are relatively distant from the coxae;

tarsi with a single claw (PL VI, 8) HOLOZODINI

(p. 288)

6. Trochanters of intermediate legs with the femora very obliquely

articulated, so that the femora are near the coxae (PI. VI, 9) . . . . 7
Trochanters of intermediate legs long, more or less clubbed or in-
flated distally, with the femora articulated at the distal face, so
that the femora are relatively distant from the coxae (PI. VI, 8) . . 13

7. Mentum very wide, covering mouth and mouth-parts in large part;

base (cardo) of each maxilla extended obliquely on outer face into
a long projection; ventral surface of head usually (but not in-
variably) provided with two strong carinae which converge basally

toward neck to form a Y or a V (PI. VII, I) JUBININI

(p. 38)
Mentum normally small; base of maxillae not so extended; ventral
surface of head variably modified but not with a Y or V-carinal
pattern (PI. IX, 1) 8

8. Posterior coxae with median face, which articulates with the tro-

chanter, either conical or conically produced (PI. VII, 7) (Euplec-

tini, sensu latiore) EUPLECTINI and TRICHONYCHINI

(p. 63)
Posterior coxae with median face, which articulates with the trochan-
ter, either broadly triangular or globular (PI. VII, 6) 9

9. First visible stemite relatively long: at least as long as the posterior

coxae, usually extending well beyond these coxae; this sternite al-
ways clearly visible for its entire width; with the first stemite

visible, at least six stemites can be counted 12

First visible sternite very short: either invisible, or visible laterally
but invisible medianly ; or visible laterally and also visible medianly
as a short plate or minute tubercle between the coxae ; with the first
sternite thus hidden, at least five sternites can be counted 10

10. Tarsi with a single claw BRACHYGLUTINI

(p 122)
Tarsi with two very unequally developed claws 11

11. Antennae with their articulations distant, and hence the head is not

suddenly and strongly constricted anterior of the eyes and not
swollen to form a median antennal tubercle; antennae diverse but
never having the first segment conspicuously long, hence antennae
never geniculate, or sharply bent between the first two segments

(PI. XIX, 1) BATRISINI

(p. 214)

KEY TO THE TRIBES 33

Antennae with their articulations contiguous to subcontiguous; in-
serted on a median, swollen, antennal tubercle; antennae with a
conspicuously elongated first segment, and strongly geniculated

(PI. XVIII, 4) METOPIINI

(p. 204)

12. Antennae straight, not geniculate TYCHINI

(p. 260)

Antennae strongly geniculate GONIACERINI

(p. 283)

13. Tarsi with a single claw PSELAPHINI

(p. 286)
Tarsi with two equal or unequal claws 14

14. Body pubescence in the form of scales (PI. IV, 6-8) . . CTENISTINI ^

(p. 291)
Body pubescence diverse but never in the form of scales 15

15. Pronotum always with one, two, or three basal foveae which may

be free or connected by a transverse, arcuate basal sulcus; elytra
usually with basal foveae; maxillary palpi usually large and very
conspicuous TYRINI ^

(p. 295)
Pronotum and elytra lacking foveae and sulci; the maxillary
palpi very minute; known only from the nests of leaf-cutting
ants ATTAPSENINI

(p. 348)

^ In the Western Hemisphere the Hybocephalini (p. 289) are limited to a single genus
{Ephimia). This rare genus is atypical of its tribe, and may belong in the Tyrini. Since
Ephimia may not be easily separated from Tyrini and Ctenistini, it is taken care of in
both of these tribes.

Subfamily Pselaphinae

Raffray (1908, p. 10) defines this large subfamily in general terms by
stating that the mouth-parts are well-developed for chewing; the abdomen
with from two to six tergites and six stemites ; antennae of from five to eleven
segments, with the last segment never having a wholly truncate, setose apex;
without trichomes or setose bundles at the base of the first visible tergite and
apical elytral margins.

For our purposes, the neotropical Pselaphinae can be separated by having
five or more antennal segments. It is possible that in time students may either
break the family into a number of subfamilies, or merge the Pselaphinae and
Clavigerinae, since the trend is to bridge the gap between these two sub-
families. Thus the Arhytodini and Attapsenini have mouth-parts intermediate
between primitive Pselaphinae and Clavigerinae; the Attapsenini have trich-
omoid setae at the base of the tergum. Therefore the Pselaphinae are with
certainty separated from Clavigerinae only by more primitive chewing man-
dibles, and conversely, the number of abdominal segments, number of anten-
nomeres, and presence of trichomes is of less value than formerly.

The neotropical Pselaphinae number sixteen out of seventeen tribes known
for the region, and this subfamily is divisible into two sections, the Brachyscelia
and Macroscelia (Raffray, 1908, p. 11). This separation is very consistent,
and, since the Clavigerinae are typically macrosceline, it might be more logical
to divide the family into two subfamilies, Brachyscelinae and Macroscelinae
— or if one prefers, the Pselaphinae (limited to brachyscelines) and the Macro-
scelinae. For more discussion of the status of clavigerines the student is re-
quested to see page 350.

DIVISION I. BRACHYSCELIA (Raffray, 1890)

In this division all of the trochanters are short, and the femora are very
obliquely articulated upon them, so that the femora are very close to their
respective coxae.

The neotropical area has nine brachysceline tribes which may be examined
as follows:

Tribe 1. Faronini

Raffray (1890, 1903, 1908)

Casey (1887, 1893, 1897)

Students of the family Pselaphidae are unanimous in regarding the Faronini
as a very primitive, generalized tribe, if not the most primitive existing section
of the family. The tribe is a small one, and has a wide, discontinuous distri-
bution, with New Zealand holding the large majority of described species. Of
some ten or eleven genera, only three are found in the region under discussion.
These three genera are all monotypic, and found only in Chile.

The primitive anatomy of the tribe is suggested by the morphology of
a North American form, Sonoma (Rafonus) tolulae (LeConte) , parts of which
are illustrated here (PI. V, 2, XIII, 4, 5, 7, 9). The body is usually flattened
and elongate. The antennae are not highly specialized, but gradually enlarged
distally to form a poorly delineated club. The large abdomen is strongly mar-
gined, with usually five visible tergites; the stemites visible are six in the
females and seven in the males. Casey, speaking of Sonoma {Sonoma), noted
that the secondary sexual modifications of the ventral, distal area of the
abdomen were bilaterally asymmetrical, and this is not a primitive arrange-
ment. On the other hand the tarsi of Faronus and near allies are quite similar
to Oxytelini of the Staphylinidae, with the first two segments small, subequal,
and the third segment large and having two equal claws. The conical middle
and posterior coxae are staphylinoid, and also euplectine. Casey (1893, p. 433)
thought the tribe intermediate between staphylinids and pselaphids, and in
addition to the oxyteline tarsus, pointed out that the transverse pubescent
line of the first visible tergite was not only a typical faronine condition, but
also was frequently seen in the staphylinid Homalini.

Key to the Genera

Pronotum with a median longitudinal sulcus 2

Pronotum with no median longitudinal sulcus GOLASA

2. First four tergites subequal in length PROSAGOLA

First three tergites subequal in length, fourth tergite much larger

SALAGOSA

(35)

36 NEOTROPICAL PSELAPHIDAE

GOLASA (Raffray, 1904)
microcephala (Reitter). 1883. Chile. (Sagola)

PROSAGOLA (Raffray, 1904)
elfridae (Reitter). 1885. Chile. (Sagola)

SALAGOSA (Raffray, 1904)
brevipennis (Reitter). 1885. Chile. (Sagola)

KYI:

\:
Tribe 2. Pyxidicerini

Raffray (1903, 1908)

This is a small tribe of four genera, one of which {Bythinoplectus) is
American. The American species have the body elongate and flattened, and
the integument is usually shining. The head has the usual pyxidicerine fossa
on each dorso-lateral face, in which repose the peculiar maxillary palpi. These
palpi are four-segmented, and the segments are closely articulated irregularly
so as to form an oval or elongate-spherical mass. First segment medium ; sec-
ond large, basally slender, and slightly clubbed apically; third articulating
on the lateral face of the second, smaller, variable in form, geniculate ventrally
and inflated dorsally, this dorsal face being sulcate to receive the fourth or
distal segment; fourth segment irregularly elongate transversely and articulat-
ing to the third segment by a short petiole on the lower of the two transverse
faces. In repose these segments tend to fit into or upon one another, and the
palpus lies in the large palpal fossa of the head.

The antennae are nine-segmented, with the distal segment enlarged to
form the antennal club; these organs are articulated on either side of the
elongate median antennal tubercle which is formed by the vertex and front.
The head is triangular, broad through the occiput and narrowing rapidly
anteriorly to the antennal insertion.

Abdomen elongate, strongly margined, with six visible sternites of which
the first is small and visible only between the diverging but contiguous conical
posterior coxae.

The tarsi are three-segmented, but this segmentation can be observed only
with difficulty. Dorsally, the tarsi are apparently two-segmented, since only
the first and third may be seen. The first segment is small, conical, and broadly
sulcate ventrally ; second segment minute, triangular, and articulates with the
first on its ventral face so that this second segment lies in the ventro-distal
cavity of the first; third segment is relatively very large, medianly slightly
inflated, bearing a single large claw.

BYTHINOPLECTUS (Reitter, 1881)

acutangulus Raffray. 1904. Granada, Windward Islands.

denticomis Raffray. 1896. Mexico.

formicetorum Raffray. 1912. Argentina, (con Atta lundi Guer.) Buenos

Aires, cf. Bruch, 1929.
foveatus Reitter. 1883. St. Thomas, Virgin Islands. Genotype.
impressifrons Raffray. 1896. Brazil.
transver Sleeps Raffray. 1904. Brazil.

(37)

Tribe 3. Jubinini

Raffray (1903, 1908)

The Jubinini are wholly American. The tribe contains eleven genera, and
all of these genera and all but one species are found south of the northern
border of Mexico. The single species found outside the region discussed here
was described by Schaufuss {Stratus ursinus Schaufuss, 1872) from Mexico and
with doubt from New Orleans, Louisiana. Inasmuch as no representative of
this species has since been reported from the United States, and there seems
to be some uncertainty about the Louisiana record, it is possible that ursinus
is Mexican and that the Jubinini are wholly neotropical. Certainly the tribe
is essentially a southern stock as evidenced by the type localities.

Morphologically the genera have certain features peculiarly developed
(PI. VII) and not found elsewhere in the family. This is especially true of the
ventral face of the head and the mouth-parts.

The body is usually elongate and flattened. There is considerable variation
in pubescence and in punctation of the integument. The head is generally
elongate and more or less triangular, with the insertion of the antennae sub-
contiguous. The ventral surface of the head is characteristically carinated in
most of the genera, and this is a diagnostic feature of great weight. In all but
three or possibly four genera, this lower surface of the head has two well-
developed oblique carinae, which arise on each side of the head, near the
mentum, and converge posteriorly. This convergence of the oblique carinae
may be anteriad of the neck to form a Y-shaped pattern, or the carinae may
converge at the neck to form a V-shaped pattern. In a few genera this pattern
is absent.

The jubine mentum — a very large, transverse plate which covers the mouth
and most of the mouth-parts — is characteristic of the species.

The maxillary cardo is prolonged on the external face into a long, oblique,
acute-to-obtuse spine. This projection of the cardo flanks the expanded mentum
on either side, and partially obscures the maxillary palpus. The development
of cardo and mentum led Raffray to separate the Jubinini into a separate tribe.

The maxillary palpus is typically four-segmented and primitive. The first
segment is medium in size; the second elongate and longer than the first; the
third segment usually smaller and transverse to triangular; the fourth segment
is relatively large, elongate-cylindrical or fusiform and terminates in the
usual palpal cone.

The antennae are eleven-segmented, without striking modijBcations seen
in more specialized tribes. The intermediate segments are simple and transverse
or quadrate as a rule, and either become gradually larger distally, or the distal
three to five segments form a club.

(38)

JUBININI 39

The pronotum is cordiform, narrowed on each side near the middle or
even strongly bilobed, with the marginal invagination at times toothed. In all
of the genera but one there is a transverse subbasal sulcus. Barrojuba lacks
this transverse sulcus entirely.

The elytra have an entire or subentire sutural stria, a poorly-developed-
to-vestigial dorsal stria, and often a longitudinal sulcus on the elytral flank.
Humeri are well formed, and at times dentate. Elytral base usually has a
transverse carina or raised surface. The elytra are often much shorter in the
females than in the males of a species, and the female sex often has less well
developed metathoracic wings. In some species the females have the wings
wholly vestigial.

This sexual difference sometimes seen in elytral size and wing development
is paralleled in the eyes. Thus in many species the short-elytral, reduced winged
females have conspicuously smaller eyes than males of the same species.

The abdomen is elongate, laterally margined, and has six visible sternites
in both sexes.

All three pairs of coxae are conical, and the trochantal-femoral articu-
lation is typically brachysceline, being oblique with the associated femur and
coxa relatively close to each other.

The tarsi depart from the oxyteline-faronine type, being more typical of
the pselaphids as a whole; that is, the first segment is small, whereas the
second and third segments are much larger than the first. Two claws are
present at the end of the third tarsomere, and are either equal or slightly
unequal in length.

These are more especially forest-floor mold species, and careful collecting
in this stratum will undoubtedly reveal many new genera and species.

Key to the Genera

Pronotum with a transverse subbasal sulcus 2

No transverse pronotal sulcus BARROJUBA, new genus

2. Antennal club large, distinct, compact and composed of from six to

seven segments ENDYTOCERA

Antennal club at most of five segments, usually indistinct 3

3. Ventral surface of the head with two oblique, converging, sharply

defined carinae 4

Ventral surface of the head with no oblique, converging carinae .... 9

4. Head suddenly constricted before the anterior end, and then dilated

to form a blunt, quadrate to rhomboidal tubercle 5

Head elongate, narrowing regularly to the anterior end, and without
the suddenly formed apical tubercle 6

5. Antennae elongate, with the segments much longer than wide; pro-

notum with two sharply-defined longitudinal sulci

PSELAPHOMORPHUS

Antennae very short, with the segments square to transverse; pro-
notum with two simple elongate depressions MACTA

40 NEOTROPICAL PSELAPHIDAE

6. Sides of the head with the ventro-lateral borders sharply defined or

carinated; ventral surface of the head with a long, median, longi-
tudinal carina which bifurcates anteriorly ARCTOPHYSIS

Sides of the head with the ventro-lateral borders smoothly or evenly
rounded both anteriorly and posteriorly of the eyes, or in some
genera {Sebaga) carinated between the eyes and the mentum but
evenly rounded posteriorly, behind the eyes ; ventral surface of the
head with converging carinae which begin near the outer anterior
angle of the mentum and unite from a point near the posterior
limits of the eyes to the neck, and consequently these carinae form
a conspicuous V or Y pattern 7

7. Head anteriorly truncate, with the antennae distant from each other

at their bases 8

Head subacutely narrowed or attenuated anteriorly, with the antennae
very close to each other at their bases, subcontiguous JUBUS

8. Fronto-antennal tubercle widely, deeply excavated or longitudinally

sulcate medianly JUBOMORPHUS

Fronto-antennal tubercle not medianly, longitudinally sulcate or
excavated SEBAGA

9. Ventral surface of the head with three longitudinal sulci, these consist

of an oblique lateral groove on each side, and a median groove; disc
of pronotum with a strong median longitudinal sulcus. . .BALEGA

Ventral surface of head with only a single median sulcus, or a median
fovea; pronotal disc with or without lateral longitudinal sulci, but

lacking a median longitudinal sulcus 10

10. Ventral surface of head with a median longitudinal sulcus; the
pubescence thick and abundant but not downy ; tarsi with two very
unequal claws ; sides of pronotum with three lobes, two lateral and
a basal lobe being more or less developed STRATUS

Ventral surface of head with an antebasal, large fovea placed medianly
and near the mentum; pubescence peculiar, being long, abundant,
soft and downy, that is appearing like the nap of a cloth ; sides of
pronotum constricted; tarsi with two equal claws. . . .PHAMISUS

PSELAPHOMORPHUS (Motschulsky, 1855)

brevipennis Raffray. 1917. Paraguay.

bruchi Raffray. 1909. Buenos Aires, Argentina, con Solenopsis rich-

teri Forel. cf. Bruch, 1929.
longiceps Raffray. 1890. Brazil.

microphthalmus Raffray. 1890. Venezuela, {muticus Raffray)
sculpturatus Motschulsky. 1855. Panama. Genotype.

MACTA (Raffray, 1890)
constricta Raffray. 1890. Brazil. Genotype.

JUBININI 41

ARCTOPHYSIS (Reitter, 1881)
gigantea Reitter. 1882. Colombia. Genotype.

JUBOMORPHUS (Rafifray, 1890)
simoni Raffray. 1890. Venezuela. Genotype.

SEBAGA (Rafifray, 1890)
Sebaga rafjrayi new species

In this description and those following, where width is given with length,
length is always given first. Head 0.34 x 0.36 mm. through eyes; pronotum
0.36 X 0.48 mm.; elytra 0.56 along suture x 0.71 to 0.73; abdomen 0.69 x 0.72
to 0.74 mm.; tergite I, 0.268; tergite II + III, 0.281. Total length 1.95 to 1.97
mm.; greatest width 0.72 to 0.75 mm. (PI. XV.)

General body color light red brown, with the antennae, palpi, and tarsi
paler; pubescence yellowish white, sparse, long, conspicuous. Average length
of body pubescence 0.067 to 0.107 mm. Integument shining, with setae arising
from subasperate punctures.

Head rounded-triangular, broadest through eyes, tapering gradually to
the broadly rounded front. Eyes large, composed of about 40 coarse facets.
Eyes slightly hairy. Occiput sinuate posteriorly, with a median notch; vertex
evenly rounded, vertexal foveae large. Intra-foveal distance about equal to
distance between an eye and nearest fovea. These vertexal foveae located
in the center of the vertex, equidistant from the posterior margin of the oc-
ciput and from the anterior margin of the antennal insertions. A broad, well
defined sulcus from each fovea to a point above each antennal insertion ; mar-
gins of the sulcus rounded ; sulcus broadest near fovea, not deepening anteriorly,
forming as a whole an elongate-oval impression; foveae nude. Front simple,
unmodified, evenly declivous. Antennae inserted on front without formation
of antennal tubercle, distant at their bases; eleven-segmented. Segment I
and II equal in length and width; I regularly ovate; II truncate apically;
III, IV, V, VI of about same width; III a little longer than IV, ovate; IV and
V moniliform, about same length; V as long as VI; VI subtriangular, asym-
metrically slightly produced at anterior basal face; VII about as long as VI,
slightly wider, subtriangular, produced more strongly at anterior basal face;
VIII, IX, X and XI forming the club; VIII, IX and X of same shape —
that is, the basal half of each segment is drum-shaped and the apical half
consists of a slender, slightly eccentric, tapering, narrower spindle; VIII
slightly shorter and narrower than IX; IX slightly narrower than X; IX and
X of about same length; XI truncate at base, widest through middle third,
tapering to subacute apex, slightly wider than X, twice as long as X. Maxillary
palpi four-segmented; first segment very minute; second segment elongate,
slender basally, gradually inflated apically; third segment much shorter than
second, but elongate, roughly elongate-rounded triangular in outline with
the inner face much more convex than outer face; fourth segment longest.

42 NEOTROPICAL PSELAPHIDAE

widest medianly, with the mesial face relatively convex and lateral face
relatively flat; a short, acute palpal cone inserted at apex of fourth segment.
Lower surface of head almost glabrous, shining. Occipital angles well-defined.
Sides of ventral face defined and carinated between eyes and mentum; sides
evenly and smoothly rounded posteriorly from eyes. Mentum characteristically
broad. Cardo of maxilla characteristically produced obliquely into a prominent
projection which tends to obscure first segment of maxillary palpi. Lower
surface of head with a pair of oblique, strong carinae. Each carina begins
near lateral union of mentum and gena, and converges obliquely to join its
fellow from the opposite side near the posterior margins of the eyes, forming
a long V-shaped pattern; enclosed surface of the V evenly concave.

Pronotum wider than long, widest medianly, above transverse sulcus.
This transverse sulcus is entire, biarcuate. Anterior to sulcus the pronotum
narrows evenly, to form a rounded-triangular apical half. Posterior to sulcus
the sides are almost straight for a short distance, then become abruptly nar-
rower in basal fifth, giving a highly irregular outline to the lateral margins.
No longitudinal sulci. Transverse sulcus with a lateral nude fovea in its floor,
near but not at the lateral margin. Disc of pronotum with a conspicuous,
regularly transversely oval antebasal platform or saucer. This peculiar plat-
form has the edges carinated, and is elevated above the pronotal disc so that
its posterior edge partially overhangs the transverse sulcus. Transverse sulcus
curves basally around the antebasal platform and tends to widen medianly,
so that from a certain point of view, this platform appears to form a raised,
undercut, isolated, transversely oval plateau within the expanded median
portion of the transverse sulcus.

Elytra transversely carinated at base. Laterally this carina is produced
so that the humeri are dentate. No dorsal stria. Sutural stria entire, deep, end-
ing basally in a sutural fovea. Sutural fovea recessed beneath transverse basal
carina. Transverse basal carina shortly arcuate to a point above the recessed
median basal fovea, and then straight to the humeral basal fovea, which is
recessed beneath the humeral tooth. Each elytron, therefore, has three nude
basal foveae. A longitudinal carina on the elytral flank, extending apically
from the humeral tooth. Median to the carina is a longitudinal sulcus which
extends apically from the humeral fovea. The floor of this sulcus is of un-
even depth and there is an accessory fovea in its floor at basal fifth, apical to
to the humeral fovea.

Abdomen with five visible tergites, which become gradually narrower to
apex. First tergite twice as long as second; second slightly longer than third;
third slightly longer than fourth; fifth quite small. Six stemites visible. First
sternite very short, largely obscured by the posterior coxae, the stemites
regularly narrower to apex; second twice as long as third; third and fourth
subequal in length; fifth medianly very short, about half as long as fourth,
with a small tubercle at its median, posterior margin; fifth sternite deeply and
regularly incised semicircularly to accomodate the large sixth sternite; sixth
sternite with a shallow, broad depression in basal half, this depression be-

JUBININI 43

coming more well-defined apically with the apical margin elevated obliquely
on each side of depression.

Prosternum medianly, longitudinally carinate for a short distance between
the anterior coxae, this longitudinal carina bifurcating obliquely to form an
arcuate, carinated edge as the anterior limit of each coxal cavity. Prosternum
not medianly, longitudinally carinate in anterior half. Mesosternum with a
longitudinal carina extending anteriorly from each middle coxal cavity to the
prepectoid area, the enclosed space between these mesosternal carinae being
very pubescent and concave. This concavity, however, is so obscured by
pubescence that it can be discerned only after careful manipulation. In the
center of the concavity is an elongate, rounded elevation. Middle coxae sub-
contiguous. Metasternum weakly concave medianly, with a median, longitudinal
carina. This carina is conspicuous because of its dark color, and extends from
between and posterior of middle coxae to the end of the medianly produced
posterior margin of the metasternum between the slightly separated posterior
coxae. Just ventral of the anterior end of the metastemal carina, the metaster-
num is produced into a thin tooth between the middle coxae.

Legs simple. Anterior and middle coxae strongly conical; posterior coxae
much shorter. Femora slightly inflated. Tibiae slightly arcuate and slightly
inflated. Tarsi very long and very slender, cylindrical, of even diameter
throughout. First tarsomere very minute; second very long; third long, about
two-thirds the length of second, and bearing two short arcuate slightly un-
equal claws.

Described from three male cotypes. Two taken at light at night on July
14, 1936; one at light at night on July 17, 1936. All collected by author on
Barro Colorado Island, Gatun Lake, Panama Canal Zone.

This species is more closely allied to Sebaga centralis than to any other
species of the genus so far known. From centralis it may be readily separated:
centralis has the pronotal antebasal platform perfectly circular in outline;
the apical half of the pronotum has the posterior lateral corners extended
basally and then abruptly apically to form a broad tooth-like extension; last
stemite with a simple, shallow fovea; length 1.0 millimeter; rafjrayi has the
pronotal antebasal platform transversely ovate; the apical half of the pro-
notum has the posterior lateral comers evenly produced and not extended
posteriorly; last sternite of male with depression as described above; length
1.95 millimeters.

Until more information accumulates upon tergite proportions in Sebaga,
Jubus, and allied aggregates, the relative lengths of the first and second tergites
should be dropped from generic keys. Sebaga centralis Raffray, Sebaga
scydmaenilla (Sharp), and the new species of this genus described in this
report have the first tergite longer than second. Raffray (1890, p. 300 and
fig. 3, Plate 6) shows centralis to have this condition. Raffray (1908, p. 26)
says that Sebaga has the first tergite not much larger than the second, and
Jubus has tergite one much larger than tergite two. The confusion is increased
by Raffray (1908, fig. 1, Plate 3) in which Jubus tetratomus Reitter is shown

44 NEOTROPICAL PSELAPHIDAE

having the j&rst tergite equal to or slightly shorter than the second, and this
does not check with generic diagnosis (Raffray, 1908, p. 30) . Distance between
antennal bases and the consequent narrowing of front is a much more constant
and reliable character in separating these two genera.

Sebaga notonoda new species

Length: 1.71 mm. Greatest width: 0.59 mm. Color as in raffrayi, with the
body pubescence shorter, average length of setae 0.054 to 0.067 mm.

Head rounded-triangular, broadest just posterior to the eyes, the eyes
medium in size, composed of about 25 very coarse facets. Occiput less sinuate
posteriorly than in raffrayi, with the occipital notch medianly much broader
and less pronounced. Vertexal foveae more anteriad in position than in rafjrayi,
placed on a line opposite the second tier of facets of the eyes, and instead of
being equidistant between the occiput and antennal insertions, the vertexal
foveae are three-fifths of this distance from the occiput. Antennae with seg-
ments I and II equal in length and width; I ovate; II truncate apically; III
and IV of the same length; VII a little longer than VI; VI and VII sub-
rhomboidal, slightly produced for entire anterior face; VIII as long and as
wide as IX; XI one and one-half times as long as X; otherwise as in rafjrayi.
Ventral surface of head with the typical V-shaped carinal pattern, but with
the V shorter than in rafjrayi, the two arms of the V and the posterior margin
of the mentum forming an equilateral triangle; these carinae converging
posterior of the V and enclosing an elongat€-oval gular fovea. Head otherwise
as in rafjrayi.

Pronotum with the biarcuate transverse sulcus much deeper than in
rajjrayi; posterior angles of the anterior rounded-triangular half of the pro-
notum not evenly rounded as in rafjrayi but posteriorly extended at the ex-
ternal-posterior angles to form a short cusp or tooth. Posterior to the trans-
verse sulcus the sides are sub-dentate and then narrow obliquely in basal
fifth. Lateral foveae in the transverse sulcus are vestigial, being represented
by an indented, darkened area on the sulcal floor, near but not at the edge
of the sulcus. Disc of the pronotum with the antebasal platform very different
from that described for rajjrayi. The antebasal platform, instead of being al-
most flush with the discal curve of the pronotum and more or less enclosed
in the transverse sulcus, projects from the anterior median wall of the sulcus,
and consequently the top of the platform is oblique with reference to the pro-
notal diac, and is parallel with the sharply sloping wall of the sulcus. Antebasal
platform (PI. XV, 10) twice as wide as long, slightly dumb-bell shaped, with
the median narrower part slightly sulcate; platform edges defined but not
projecting over the column of the platform, that is, the top and column of
platform not well differentiated; surface of platform slightly roughened,
slightly convex. Each latero-basal angle of pronotum with an obscure, tri-
angular fovea. Pronotum otherwise as in rafjrayi.

JUBININI 45

Elytra with the transverse basal carina not so irregular as in raffrayi,
but instead paralleling the basal elytral margin; the three basal foveae less
recessed beneath the transverse basal carina, and hence apparently larger
than in raffrayi. Elytra otherwise as in raffrayi.

Abdomen with first tergite almost twice as long as second; second longer
than third; third longer than fourth; fifth much larger than in raffrayi, two-
thirds as long as fourth segment. Third stemite somewhat longer than fourth;
fifth stemite medianly very short, one-fourth as long as fourth, and conse-
quently the rounded tubercle at middle extending for entire length of the fifth
stemite; sixth stemite smaller than in raffrayi, flattened medianly, this flattened
area extending for the length of the segment and for one-half of its width,
with a small median concavity in this flattened area ; posterior margin of sixth
stemite less sinuate than in raffrayi. Otherwise as in abdomen of raffrayi.

Prostemum not longitudinally carinated, and the anterior coxal cavities
not as sharply defined as in raffrayi. Mesostemum not examined. Metasteraum
evenly convex, with carina as in raffrayi. Posterior coxae slightly separated
at base, the separation a little more pronounced than in raffrayi. Ventral sur-
faces and legs otherwise as in raffrayi.

Described from one male type. Collected by the author on Barro Colorado
Island, Gatun Lake, Panama Canal Zone by sifting leaf mold of the forest
floor at Zetek 23. July 27, 1936. 10:00 A.M.

This unique specimen is quickly separated from the male raffrayi by many
characters enumerated above, but especially by the strikingly different ante-
basal platform. The species is also easily separated from the genotype, cen-
tralis Raffray, by the antebasal platform.

Sebaga scydmaenilla (Sharp). 1887. Guatemala. (Duciola) (PI. VII)

I have two specimens of what I believe to be scydmaenilla. In assigning
my specimens to this species, I feel a certain amount of doubt. Sharp (1887,
p. 44 and Fig. 24, Plate I) gives a few lines in Latin and a few sentences in
English, accompanied by a small, generalized drawing, as his description of
this species. These data agree, as far as they go, with my two specimens.
However, since scydmaenilla has not been recorded since the original citation
of the Guatemalan type, which was a single badly-preserved, doubtfully female
specimen, I have redescribed my material for future reference. As in the case
of notonoda, this redescription is a comparative account of the differences be-
tween scydmaenilla and raffrayi. Such treatment focuses attention on differ-
ences, does not waste space, and if the standard of comparison has been de-
scribed in the same paper there is no loss of accuracy. Redescription follows:

Length: 1.95 mm. (length given by Sharp, loc. cit., 1.5 mm.). Greatest
width 0.8 mm. Color as in raffrayi and notonoda, with the body pubescence
average length being intermediate between these species, 0.067 to 0.08 mm.

Head rounded-triangular, broadest through posterior third of eyes, the
eyes intermediate in size between raffrayi and notonoda, composed of about

46 NEOTROPICAL PSELAPHIDAE

32 facets (since my specimens are females, this eye size is unusual for the tribe,
Raffray (1908) having pointed out that the female jubine tends to have
smaller eyes than the males sex in the tribe, in the same species; since Sharp
had only a female type, no sexual comparison was possible for him in this
regard, and the male scydmaenilla may have eyes as large or larger than in
raffrayi; certainly my female scydmaenilla have fewer facets than the male
rafjrayi but more facets than the male notonoda). Antennae quite different
from raffrayi or notonoda, segments I and II equal in length and width; I
ovate; II truncate apically; III, IV and VI of about same width; V slightly
wider than IV or VI; IV, V and VI moniliform, V longer than IV or VI;
VII longer and wider than VI, irregularly subquadrate, slightly produced on
the anterior face; VIII, IX, X and XI forming a less distinct club than in
raffrayi or notonoda; IX and X of about same width ; XI nearly twice as long
as X. Ventral surface of the head with the typical V-shaped pattern formed
by oblique, converging carinae but with these converging carinae having their
origin more medianly than in raffrayi or notonoda, and fusing at a point op-
posite the anterior third of the eyes ; enclosed surface of the V evenly concave,
but then deepening centrally to form a clearly-defined, perfectly circular,
shallow and flat-bottomed fovea. Head otherwise as in raffrayi.

Pronotum with the transverse median sulcus well-defined and perfectly
straight for the median four-sixths of its width. Disc of pronotum with no
antebasal platform, which instantaneously separates the males of centralis,
notonoda, and raffrayi (females unknown) from the females of scydmaenilla
(males unknown). Pronotum otherwise as in raffrayi.

Elytra with the transverse basal carina paralleling the basal elytral mar-
gin, and the sutural fovea recessed less deeply than in raffrayi. In these re-
spects notonoda is similar to scydmaenilla. Elytra otherwise as in raffrayi.

Abdomen proportionately broader than in raffrayi and notonoda, which
may well be a secondary sexual, rather than a species character. First tergite a
little more than twice as long as second; fifth tergite small, one-half as long
as fourth. Third sternite slightly longer than fourth; fourth and fifth stemites
of equal length; no median tubercle on fifth sternite, and with its posterior
margin not deeply incised (this latter being typical for females in general) ;
sixth sternite one-fifth longer than the fifth, evenly convex, lacking a median
flattened area or a median concavity, and with the posterior margin slightly
produced medianly. Abdomen otherwise as in raffrayi.

Prostemum as in raffrayi. Metasternum much shorter than in raffrayi or
notonoda, evenly convex, rather granular near posterior coxal articulation
and also medianly in a longitudinal line, the effect being that of a subcarinate
condition. Posterior coxae short, but longer than in raffrayi or notonoda. Tibiae
less arcuate than in these two latter species, but slightly inflated ; tarsal claws
more unequal than in the two species named above. Ventral surface and legs
otherwise as in raffrayi, save that the mesosternum could not be examined.

Redescribed on two females, both taken on Barro Colorado Island, Gatun
Lake, Panama Canal Zone. One specimen was collected by the author from

JUBININI 47

beneath the loose bark of a prostrate log on the forest floor, on July 27, 1936.
The second specimen was taken by Dr. E. C. Williams, Jr., from a sample of
floor mold (No. 1433) on July 12, 1938.

The genus Sebaga is known imperfectly because the majority of the
descriptions are based on one sex, or the sexes are not differentiated. Such a
situation makes analysis difficult. Apparently the females have the sixth sternite
simple, evenly convex, whereas the males have this sternite variously concave.
Sharp described his single specimen in the genus Duciola, but Raffray (1908,
p. 29) placed scydmaenilla in Sebaga. This species does not have the con-
spicuous antebasal platform which was stated as characteristic of the genus
Sebaga by its author (Raffray, 1890, p. 300 and 1908, p. 29). RafTray must
have known that the antebasal platform was lacking in scydmaenilla when he
placed this species in Sebaga, and hence certain possibilities are available for
study: (1) Sebaga may include species with and without the antebasal plat-
form in both sexes, in which case subgeneric division would be admissable;
(2) the antebasal platform may be diagnostic for males and lacking in all
or some females; (3) the genus may have the antebasal platform in all
species and both sexes, in which case scydmaenilla (Sharp) is misplaced; (4)
the third possibility may be the true one, but Raffray studied the type of
scydmaenilla and found that it had the platform but that it was overlooked
by Sharp. This latter is hardly tenable, since Sharp would almost certainly
have noted in his figure the presence of such a prominent feature.

Key to the Species (PI. XV)

Pronotum with a median tubercle, antebasal platform or spinoid
process just anteriad of, or associated with the transverse sulcus. . . 2

Pronotum with no median tubercle, antebasal platform or spinoid
process scyd7naenilla (Sharp) (females known only) ^

2. Antebasal platform dorsally slightly concave, glabrous and shining,

with carinated edges which project beyond the supporting column. . 3
Antebasal platform not so formed, tuberculate, spinoid, or transverse
but without overhanging carinated margins 4

3. Antebasal platform perfectly circular from above

centralis Raffray (male known only)

Antebasal platform transversely ovate from above

raffrayi new species (male known only)

4. Antebasal platform a strong spinoid process or tooth

denticollis (Schaufuss) (sex of type unknown)

Antebasal platform not spinoid or tooth-like 5

* It is perfectly possible that the two females which I have identified as scydmaenilla
are in reality females of raffrayi, but I am loath to associate males with females arbitrarily
in the same species unless there is substantial data for such an allocation; it is definitely
certain that they are not females of notonoda in view of accumulative morphological
evidence on many characters.

48 NEOTROPICAL PSELAPHIDAE

5. Antebasal platform transverse and prominent 6

Antebasal platform a minute, transverse tubercle

dilatata Raffray (male known only)

6. Antebasal platform a prominent, transversely rhomboidal tubercle

lamellata Raffray (male known only)

Antebasal platform a prominent, transverse, amphidiscal or dumb-
bell shaped process, slightly narrower and sulcate medianly

notonoda new species (male known only)

The species of the genus Sebaga may be listed as follows:

centralis Raffray. 1890. Venezuela. Genotype.
denticollis (Schaufuss). 1872. Mexico. (Jubus)
dilatata Raffray. 1893. Brazil.
lamellata Raffray. 1893. Mexico.
notonoda new species. Panama Canal Zone.
raffrayi new species. Panama Canal Zone.

scydmaenilla (Sharp). 1887. Senahu, Guatemala (Sharp). Also from
Barro Colorado Island, Panama Canal Zone.

JUBUS (Schaufuss, 1872)

This the typical genus of the tribe; it has a very wide geographic distri-
bution and many species. Although the species vary in the details of antennal
segment proportion and shape, and in features of the pronotum and elytra,
the habitus is common to the genus as a whole. Jubus may be easily separated
from its ally, Sebaga, by the shape of the head and the amount of separation
of the bases of the antennae as set forth in the tribal key to genera. The mouth
parts of the genus have been described in some detail (Raffray, 1908, p. 25),
and various aggregates {Duciola Reitter, Gasola Reitter, Gamba Schaufuss)
have been incorporated in Jubv^ by Raffray (1903), so that the genus appears
to be a natural assemblage, in so far as one may determine such a thing by
assay of morphological details alone.

Sexes in Jubus are readily separated by a number of contrasting features.
For example, the eyes of the female are distinctly smaller, and are composed
of significantly fewer facets; the male generally has the ventral surface of
the abdomen variously modified and concave, whereas the female usually has
the abdomen simple and more or less evenly convex. Males may or may not
have the legs armed with teeth or spines, but the females as a general rule
have the legs simple.

Raffray (1903) has separated Jubus into seven groups of species, and this
separation I have modified in a few respects to divide the genus into the
Raffrayian categories, as follows:

First tergite very large, from one-third to twice as long as the second
tergite 2

JUBININI 49

First tergite equal or subequal in length to second tergite; if longer,
not more than one-fifth longer than second tergite 4

2. Vertex with the median sulci vestigial, absent or just perceptible

GROUP I.

Vertex with two well-defined sulci 3

3. Antennal club very distinct, clearly defined from rest of the antenna

GROUP 11.

Antennal club indistinct GROUP III.

4. Vertex with the sulci narrow, and with the vertexal foveae so small

that they are not obvious, and in consequence, the sulci appear to

arise de novo from the vertex 5

Vertex with the sulci and vertexal foveae well differentiated, the foveae
broader than the sulci, so that the latter are seen to leave the foveae
as a narrower channel 6

5. Antennal club distinct, composed of the last four segments, e.g. seg-

ments VIII, IX, X and XI GROUP IV.

Antennal club indistinct GROUP V.

6. Antennal club distinct, composed of the last five segments, e.g. seg-

ments VII, VIII, IX, X and XI GROUP VI.

Antennal club indistinct GROUP VII.

Jubus terranus new species

Head 0.328x0.335 mm.; pronotum 0.369x0.436 mm.; elytra 0.469x0.549
mm.; abdomen 0.657x0.643 mm.; total length 1.84 mm.

General body color light yellowish brown. Pubescence straw color, closely
appressed; average length of body pubescence 0.0335 to 0.0536 mm.

Head subtriangular, occiput strongly sinuate, broadly impressed at median
posterior margin, this depression forming a broad basal notch. Eyes medium in
size, composed of about 26 facets, not conspicuous. Vertexal foveae small, equi-
distant from the occipital margin and the anterior margin of antennal insertion
on the front; the foveae close together, each fovea being much closer to its com-
panion fovea than either is to its associated eye. A narrow sulcus proceeding
anteriorly from each vertexal fovea, this sulcus being about the same diameter
as the fovea, straight for the basal half of its length, then arcuate mesially to
unite with the companion sulcus to form a common sulcus which ends at the
center of the antennal tubercle. Front simple, almost vertical, greatly reduced
between the antennal insertions to form a thick lamina. Antennae close together
at base as typical for the genus, stout, eleven-segmented. Segment I very short
from above and subquadrate, because of the expansion of its apical articular
surface to the dorsal face; II not quite as wide as I, and from a certain point of
view shaped like a parallelogram; III to VII gradually increasing in width;
III obconic; IV to VII progressively more rhomboidal; VIII, IX, X and XI
forming the club, and conspicuous because of their length, the four of about the
same width; XI conical, truncate basally, subacute apically, the segment about
two and a half times longer than X. Maxillary palpi small, first segment minute;

50 NEOTROPICAL PSELAPHIDAE

second segment elongate, increasing in width to become clubbed at distal end ;
third segment wider than second, subtriangular; fourth and last segment largest
in length and width, symmetrically fusiform, distal end acute, bearing a very
short, blunt palpal cone. Lateral margins of head evenly rounded both anteriorly
and posteriorly from the eyes. Ventral surface of head subglabrous. Mentum
very wide, evenly concave. Cardo of maxilla produced into an elongate spinoid
process to obscure base of maxillary palpi. Ventral surface of head with a long
V formed by two converging carinae, which unite medianly far behind the eyes
and near the union of neck and gular-genal areas ; this V enclosing a triangular
space which is raised from the rest of the ventral face, and enclosing two dis-
tinct foveae, a gular fovea at the posterior acute end of the triangle between the
uniting carinae, and an apical fovea near the median posterior margin of the
mentum.

Pronotum more or less heptagonal, broadest anterior to middle. Just pos-
terior to middle, each lateral margin armed with a short but prominent acute
tooth. Lateral margins sinuate anteriorly to this tooth to the antero-lateral
angles of the pronotum, forming two sides of the heptagon. Apical pronotal mar-
gin, between these angles, in a broad, forwardly directed curve to form the two
anterior angles of the heptagon. Posterior to the lateral tooth, each side abruptly
narrower and sinuate to the rounded postero-extemal pronotal angles, forming
two sides of the heptagon. Basal margin of pronotum straight, forming the
seventh side of the heptagon. If the rounded anterior margin of the pronotum is
considered as one side, then the pronotum dorsally may be spoken of as hex-
agonal. Disc of pronotum fiat, with a well-developed sinuate transverse sulcus
posterior to disc, this sulcus ending on each side at the base of the lateral tooth.
Laterally, the transverse sulcus is expanded anteriorly, but lateral foveae are
not apparent. No median fovea in transverse sulcus, but the anterior median
margin of sulcus is differentiated into a slightly darker subtriangular area.
From a purely lateral point of view, the base of the pronotum has an elongate,
fusiform, obliquely-directed, well-defined depression.

Elytra with a transverse basal carina paralleling the basal margin. Sutural
stria entire, ending basally in the sutural fovea. Lateral to this basal fovea,
partially recessed beneath the transverse basal carina, are two more foveae, the
discal and humeral. These two latter foveae are mutually more close to each
other than are the discal and sutural foveae. No dorsal stria. Each elytron,
therefore, with three nude basal foveae. Flank of elytron with a subhumeral
fovea, from the edge of which arises a longitudinal carina ; mesiad to this carina
is a longitudinal sulcus which arises from the subhumeral fovea.

Abdomen with five visible tergites, decreasing in width to the subacute
apex. Segments strongly margined. First tergite slightly longer than second, in
the ratio of 3 to 2i/^ ; second tergite slightly longer than third ; third and fourth
subequally long; fifth shorter than fourth and triangular. Six stemites visible.
First sternite forming an elongate triangle between posterior coxae, and visible
shortly posterior to coxae and on each side of the coxae ; second sternite longer
than third in the ratio of 2I/2 to I14 ; third almost twice as long as fourth ; fourth

JUBININI 51

slightly longer than fifth ; sixth very large. Medianly the stemites are flattened,
this flattening becoming more pronounced apically, and culminating on the fifth
and sixth stemites. Fifth stemite short medianly, and deeply incised to contain
the base of sixth; median posterior margin of fifth slightly produced, and with
two transversely ovate foveoid depressions. Sixth stemite broadly and entirely
concave, about four times as long as fifth.

Prosternum long before the coxae, obtusely longitudinally carinate in the
anterior half. Anterior coxal cavities sharply defined. Mesostemum produced
between middle coxae in a long spinoid process; middle coxae subcontiguous.
Metasternum with a strong, longitudinal, median carina; the metasternum is
long.

Anterior legs with the coxae prominently conical, the femora strongly in-
flated. Intermediate legs with the coxae much shorter, conico-ovoidal, femora
less strongly inflated. Posterior legs with coxae conical, each trochanter armed
with a very slender, translucent, aciculate spine which arises from the mesio-
basal angle. Tarsi long, slender; segments of equal diameter; first tarsomere
short, second and third tarsomeres very long, the third ending in two unequal
claws. Above description of male holotype.

Female Allotype. Resembling the male holotype save for the following
secondary sexual differences: Eyes much smaller than in the male, consisting
of six coarse facets. These facets are arranged four in a ventral row and two in
a dorsal row. Stemites unmodified, convex. Second stemite long, longer than
first in the ratio of 2i/^ to l^^, and longer than the third in the ratio of 2i/^ to 1%.
Third stemite longer than fourth in the ratio of 1 to 0.8; fifth and sixth stemites
medianly of same length, simple; the sixth stemite sharply, semicircularly in-
cised in median third of hind margin. Femora moderately inflated but the pos-
terior trochanters are wholly simple and unarmed. Metasternum much shorter
than in the male, in the ratio of 2.8 for holotype metasternal length to 2 for
allotype metastemal length.

Described from six specimens, all collected by Dr. E. C. Williams, Jr. in
the floor mold of the rain forest on Barro Colorado Island, Gatun Lake, Panama
Canal Zone, as follows: Holotype male and paratype male in mold sample
No. 1118 on July 17, 1938. Allotype female in mold sample No. 1034 on July 19,
1938. Paratype female in mold sample No. 34 on July 24, 1938. Paratype male
in mold sample No. 103 on July 24, 1938. Paratype female in mold sample
No. 345 on July 29, 1938.

Jubus terranus is a member of Group IV, since I interpret this group as
having the vertexal foveae minute rather than absent, and hence the vertexal
foveae in Group IV are small, of the same diameter as the vertexal sulci, whereas
in Groups VI and VII they are conspicuously larger than the associated vertexal
foveae. Such an interpretation of Raffray's group key (I.e.) is entirely con-
sistent with the anatomy of the genus, and takes into account the less powerful
and less illuminated equipment of earlier days. If such an interpretation is not
made, then the suggestion arises that there are no vertexal foveae, or that such
foveae are not in any way associated with their vertexal sulci, and this view is

52 NEOTROPICAL PSELAPHIDAE

not at all consistent with the anatomy of the genus. Furthermore, if Juhus
terranus is not assigned to Group IV, then it would go to a new group, since the
presence of vertexal sulci, minute vertexal foveae, first two tergites subequal in
length, and a distinct antennal club of only four segments, bars the species from
Groups I, II, III, V, VI, and VII.

Much better data for its place in Group IV are obtained by checking its
similarities with the other species in this group. Juhus terranus is similar to
tetratomv^ (Reitter), caviventris Raffray, gracilicornis Raffray and related
species; it is distinct from all these forms on the described anatomy, especially
the male secondary sexual characters, antennal proportions and sternal features.

JuhiLS chickeringi new species

Total length 0.837 mm. Greatest width 0.295 mm.

Color light brown with the antennae, maxillary palpi and legs paler. Body
pubescence yellowish cream, short, appressed. Average length of body pubes-
cence 0.02 to 0.034 mm.

Head rounded-triangular, eyes large and prominent. Eyes composed of
about 36 small facets. Occiput sinuate with a clearly defined median notch.
Temporal angles rounded, their length less than the longitudinal diameter of
the eye from a dorsal view. Vertex evenly convex, conspicuously higher than
the eyes; vertexal foveae minute, nude, not wider than their associated sulci,
and situated on a line which passes through the middle of the eyes. Vertexal
sulci as in terranus. Antennal insertions close together at base, narrowing the
front as in the typical pattern for the genus. Front almost vertical, simple. An-
tennae eleven-segmented, segment I large, as wide as II; III, IV, V, VI, and VII
narrower than II ; III a little longer than IV, of equal width ; V, VI, VII pro-
gressively transverse, subrhomboidal, with their lateral basal angles progres-
sively reduced; VIII, IX, X, and XI forming a distinct club, these segments
progressively slightly wider; VIII wider than II; XI narrowly truncate at base,
broadening rapidly to basal third and then narrowing slowly to the subacute
apex. Maxillary palpi four-segmented, first segment minute; second elongate,
arcuate, slightly clubbed distally where it articulates with the third; third
shorter, triangular, wider than second; fourth large relatively, wider than third
segment, as long as other three segments, widest beyond base, then lengthily
acute to apex which has a small palpal cone. Ventral surface of the head typical
for the genus, with the wide mentum and produced cardo. Eyes prominent ven-
trally. Tempora long ventrally, their length distinctly greater than the longi-
tudinal diameter of the eyes from a ventral view. V-shaped pattern very clear,
the converging carinae fusing to form the apex of a triangle or V at a point near
the posterior limit of the eyes. Posterior to this fusion, the converged carinae
continue to the base of the head, where they are lost in a semicircular sulcus
which separates the neck from the head. Enclosed surface of the V regularly
arcuate in its longitudinal diameter, from a high point at the fusion of the

JUBININI 53

carinae, to a low point just back of the mentum. Sides of the head subearinate
anterior of the eyes, and evenly rounded posterior of the eyes.

Pronotum wider than the head, with the transverse arcuate sulcus dividing
the pronotum into two unequal portions ; anterior portion is more than twice as
long as the posterior portion, and a third wider. This anterior part is subrhom-
boidal, with the sides converging to the semicircular apical border on each side
from a very small acute tooth, this tooth arising opposite the transverse sulcus
on each side. Posterior to this lateral tooth, the basal portion of the pronotum
is formed by the sides becoming abruptly narrower. Transverse sulcus curves
posteriorly on each side and ends just below the marginal tooth.

Elytra with the base transversely carinate. Each elytron with three basal
foveae recessed beneath the transverse carina. Sutural fovea gives rise to an
entire sutural stria. There is no dorsal stria. The median and lateral foveae are
mutually closer than is the median to the sutural. The humeri are not dentate.
Flank of each elytron with a conspicuous longitudinal carina; this carina is
abruptly arcuate basally to recess the rather large subhumeral fovea. Each
elytron, then, with three basal foveae and a subhumeral fovea; an entire sutural
and epipleural stria but no dorsal stria.

Abdomen with five visible tergites, narrowing to a subtruncate apex. First
and second tergites subequal in length; third tergite shorter than second; third
and fourth tergites subequal in length; fifth tergite rounded triangular, about
as long as fourth. Six visible sternites; first sternite broadly triangular between
posterior coxae; second sternite as long as first; third sternite long, as long as
second; fourth sternite one-half as long as third; fifth very short medianly, a
third as long as fourth, deeply, semicircularly incised to contain the sixth ster-
nite; sixth large, medianly twice as long as the fourth sternite, and the median
posterior margin deeply incised. The ventral surface of the abdomen is conspic-
uously, medianly concave; all of the sternites are involved, with their median
halves flattened or concave and differentiated from the sloping sides. This con-
cavity is notable on the second and third sternites, where the limits of the con-
cavity are subearinate. The sixth sternite has a secondary median concavity.

Prostemum prominent anterior of the coxae, and medianly gibbous but
not carinate. Mesostemum laterally carinated. Metasternum very long, as long
as first and second sternites united, but not carinated medianly; it is medianly
concave. All coxae well-developed, the anterior coxae very prominently conical;
middle coxae apparently contiguous and elongate-ovoid; posterior coxae also
very prominent, conically produced mesially, and subcontiguous. The conical
portion of each posterior coxa is carinate on the mesial face, and the mesial-
posterior angle is produced in a sharp point. Trochanters not armed. Femora
slightly inflated, the anterior pair especially. Tarsi three-segmented, elongate,
cylindrical in the jubine pattern, first tarsomere minute; second and third much
longer, subequal in length, the third ending in two claws.

Described from one specimen, a male. This type was collected by the author
on July 25, 1936, on Barro Colorado Island, Gatun Lake, Panama Canal Zone,
from moist stage four log mold at Drayton 12.

54 NEOTROPICAL PSELAPHIDAE

I take pleasure in naming this distinct species for my young friend, Donald
Chickering, with whom I spent many happy hours in the Central American
forest. This species belongs to Group IV, and can be readily separated from
terranus on many characters, e.g. the posterior tronchanters are not spined,
metastemum not carinate medianly, entirely different pronotal outline, shorter
pubescence and much smaller size.

Jubus turneri new species

Total length 0.8 mm. Greatest width 0.29 mm. (PI. VII.)

Unless stated otherwise, the following details are drawn from the holotype
male ; certain details were obtained from slide mounts of male paratypes, where
magnifications of from 500 to 1000 diameters could be used. Such magnifications
are indicated.

Color light yellowish-brown, with the antennae, maxillary palpi and legs
paler. Body pubescence yellowish-cream, short, appressed. Average length of
body pubescence 0.02 to 0.035 mm.

Head rounded-triangular, eyes medium large, prominently semicircular
from the dorsal view, composed of about 30 moderately coarse facets. Occiput
is broadly sinuate but not medianly notched. Temporal angles rounded and
prominent, their length equal to the longitudinal diameter of the eye from a
dorsal view. Vertex evenly convex, conspicuously elevated above the eyes. Ver-
texal foveae minute, nude, of same diameter as the associated sulci, and placed
on a line passing through the middle of the eyes ; vertexal sulci straight in their
basal half, then medianly arcuate to form a common sulcus; this common sulcus
extends medianly between the antennal prominences, to medianly notch the
abruptly vertical front between the antennae. Antennae eleven-segmented ; close
together at insertions, narrowing the front in the typical genus pattern ; segment
I and II large, equal in width ; I quadrate ; II oval ; III and IV subequal in length
and width, subspherical ; V to VII narrower than II; V to VII progressively
wider, V transversely ovate, VI transversely ovate and subrhomboidal, VII
transversely rhomboidal; VII not as wide as VIII; VIII, IX, X and XI forming
a club, these segments progressively slightly wider, the club distinct from a
dorsal view and indistinct from a lateral view; XI slightly longer than VIII,
IX and X united, narrowly truncate at base, broadest at basal third then length-
ily narrowing to subacute apex.

Maxillary palpi out of the ordinary for the genus, the following taken from
slide mounts of four male paratypes. Four-segmented. First segment unusually
large, 0.013 mm. long, cylindrical, slightly wider at apex, sharply angulated at
middle so that the segment is bent nearly to a right angle. Second segment 0.018
mm. long by 0.018 mm. wide, strongly triangular, and very little longer than
large first segment. Third segment 0.018 mm. long by 0.018 mm. wide, pyra-
midal, with the narrow face basal, and the broad face apical. Fourth segment
0.054 mm. long by 0.027 mm. wide, significantly larger than other segments,
pedunculate-securiform, broadest medianly, tapering rapidly to base and slowly

JUBININI 55

to apex, apex armed with a relatively long, very aciculate palpal cone. The
palpi are unusual in that the first three segments, although differing in shape,
are more or less equal in length.

Ventral surface of head typical for genus. Mentum conspicuously concave.
Cardo produced from base and partially obscuring mouth-parts. Tempora with
their length equal to the longitudinal diameter of the eye from a ventral view.
Eyes prominently extended medianly from a ventral view, to narrow the genal-
gular field near the mentum. V-shaped pattern clear on lower face of head, the
converging carinae fusing to form the apex of a long triangle or V, the fusion
taking place at a line drawn through the posterior margins of the eyes ; basal
to this fusion, the carinae enclose a small, elongate gular fovea, and continue
to the neck. Enclosed surface of the V regularly arcuate in its longitudinal
diameter, from a point distinctly anterior to the fusion of the carinae, to a low
point just back of the wide mentum. Sides of head subcarinate anterior to the
eye and evenly rounded posterior to the eye.

Pronotum in two lobes, an anterior subrhomboidal and a posterior trans-
versely oblong lobe. These lobes separated by a clearly defined, arcuate, trans-
verse sulcus. Anterior lobe nearly four times as long as basal lobe, with the sides
evenly arcuate to the semicirculately produced apical margin, and obliquely
narrowed from this widest level, to the transverse sulcus. No sign of a tooth or
spine on the pronotal margins, in both triangle and slide-mounts. Basal or
posterior lobe nearly one-half narrower than anterior lobe, sides evenly and
slightly arcuate, from transverse sulcus to relatively straight basal margin.

Scutellum very minute, acute-triangular.

Elytra radically different from many species of genus: each elytron with
only two basal foveae. These foveae are relatively large, nude, and lie just pos-
terior to the biarcuate transverse basal carina. Sutural stria entire. No dorsal
stria. Humeri sub-dentate, this condition being due to the structure of the elytral
flank: each elytral flank has a longitudinal carina which is sharply bent, nearly
at a right angle, near the humerus, so that the humerus appears in relief from
rest of flank. Beneath this apical flexure of the carina is a large subhumeral
fovea.

Abdomen with five visible tergites: first tergite very large, as long as the
second and third tergites united; second tergite slightly longer than third; third
one-fourth shorter than the fourth, so that both the second and fourth tergites
are longer than the third; fifth is small, triangular and inconspicuous. Six stem-
ites visible, first sternite broadly triangular between the coxae; second stemite
very large, one-half longer than the first and medianly very gibbous or tumid,
with a transverse fossa at its base. In slide-mounts, under high magnification,
this transverse fossa is seen to have considerable depth, and to have carinate
edges. Third sternite simply convex, one-third as long as second ; fourth sternite
as long as third; fifth very short medianly, one-half as long as fourth, medianly
incised to hold the large, transversely ovate sixth stemite; sixth three times as
long as fifth, concave in median basal half, medianly slightly produced at pos-
terior margin.

56 NEOTROPICAL PSELAPHIDAE

Slide-mounts show the penis to be large, 0.126 mm., long; longer than the
third, fourth, and fifth sternites united, in four male paratypes.

General punctation of the dorsal body surface very minute, the punctules
each bearing a seta. In slide-mounts of four male paratypes, one female para-
type and female allotype, the following averages obtain: pronotal disc with
4 to 5 punctures per 0.04 sq. mm. ; elytral disc with 7 to 8 punctures per 0.04
sq. mm.; tergites with 3 to 4 punctures per 0.04 sq. mm.; these punctures small,
very isolated, not recessed.

Prostemum medianly gibbous anterior to coxae, but not carinate.

Mesostemum laterally carinate each side, to form the usual ante-coxal
plate between the middle coxae and prepectoid area.

Metasternum very large, twice as long as first stemite, or about one-fifth
shorter than first and second sternites united; medianly with a longitudinal
entire carina, this carina strong in basal two-thirds of its length.

In slide-mounts of both sexes, under high magnification, the following
sternal foveae are demonstrable: lateral prostemal foveae, one anteriad of each
of the anterior coxae in the basistemum; lateral mesosternal foveae well de-
veloped, in the prepectoidal wall just anteriad, and on each side of the meso-
sternal field or ante-coxal plate noted above; median mesosternal fovea, un-
paired, at anterior end of ante-coxal plate. This mesosternal fovea can be seen
in triangle mounts as well. Other foveae, e.g. vertexal, gular, etc. have been
previously noted. The second stemite has a well-developed pair of foveae, long,
cylindrical, whorled lumen. These are placed one just above each side of the
transverse fossa at base of second sternite, and hence parallel to the fossa, with
the orifice opening laterally, and the fovea ending medianly near the center of
the fossa. These foveae are present in both sexes.

Coxae shorter than in chickeringi. Anterior coxae conical, longest. Middle
coxae conico-ovoidal, in slightly confluent cavities, the mesosternal and meta-
stemal processes not quite meeting, the coxae subcontiguous. Posterior coxae
shortly conical, contiguous or very nearly so, with the metasternum just per-
ceptibly visible between them as a microscopically acute point.

Femora moderately inflated. Tarsi three-segmented, cylindrical, first tar-
somere minute, second and third very much longer, the second slightly longer
than third ; end of distal segment with two arcuate, equal claws.

Allotype female differs from the holotype male as follows: size, color,
pubescence, maxillary palpi, pronotum, elytra are not different. Eyes vestigial,
reduced to two facets on each side of the head, giving a long, evenly arcuate
and convergent aspect to the tempora. This great reduction of eye is typical of
the tribe, but in this species reaches a maximum expression.

Antennae like the male, save that the segments VIII, IX, and X are not so
asymmetrical, XI shorter, not quite so long as VIII, IX, and X united, and the
club is indistinctly formed as compared with the males.

Ventral surface of the head is different in that the converging carinae form
a very long triangle or V-shaped pattern, these carinae fusing where head and
neck meet, and enclosing a shorter gular fovea.

JUBININI 57

Metasternum very much shorter than that of the male, 0.09 mm. long,
about as long as the first stemite between the posterior coxae. The metasternum
is carinated longitudinally and medianly, however, as in the male.

Tergites with the first long, one-half longer than the second, but not so long
as in the male.

Sternites differing. First as in the male; second long, two-sevenths longer
than third, with a median transverse fossa at base. However, the fossa in the
female is less deep and slide-mounts show no carinate edges, although the
whorled ante-fossal foveae are well-developed. Third longer than fourth ; fourth
longer than fifth ; sixth also longer than fifth.

Comparison of the two sexes of this species bring out the interesting point
that while a concave ventral abdominal surface often designates a male, it is
not a universal rule since the male venter in this species is not concave as it is
in chickeringi. Secondly, the metasternum may be medianly carinate in the male
sex only, or in both sexes. On the other hand, the males have relatively large eyes
and a long metasternum, while the females have relatively small eyes and a
short metasternum.

Described from seven specimens as follows: Holotype male collected by
the author on July 25, 1936, from moist, stage four (wholly decayed) log mold
at Drayton 17, on Barro Colorado Island, Gatun Lake, Panama Canal Zone.
One male paratype with the same data.

Three male paratypes collected by the author, on the same island, July 29,
1936, from beneath the loose bark of a log at Pearson 4.

Allotype female and one paratype female collected by Dr. Eliot C. Wil-
liams, Jr., from the same island. The paratype on July 15, 1938 in mold sample
No. 1148, and the allotype on July 21, 1938 in mold sample No. 716.

I take pleasure in naming this distinct species for my colleague, Prof. C. L.
Turner, who spent part of a summer with me in the Canal Zone. This is another
minute species of Jubus, about the same size as chickeringi, but wholly different
in numerous particulars. Jubus turneri belongs in Group II by virtue of the
elongate first tergite in both sexes. Its other peculiarities include the two basal
elytral foveae, and differently constructed venter.

This is the first species to be recorded in Jubus between Mexico and South
America in Group II. Other species of this group are known from Brazil, Bolivia,
and Colombia on the south, and one from Acapulco, Mexico on the north. The
Mexican Jubus punctatus (Sharp) is so vaguely described that only a single
structural difference can be cited: Sharp notes that punctatu^ has the elytral
punctation strong and cribrate, whereas turneri has the elytral punctation very-
slight, sparse, and minute; quantitatively, these two species are easily separable
on size, punctatus being 2.33 mm. long and turneri significantly less than a
millimeter in length. Similarly turneri differs from others in the group by its
small size and described anatomy. It is distinct from such large species as brevis
Raffray of Bolivia, 1.7 mm. long with dentate humeri, and is more closely allied
to the small liliputanus Raffray of Brazil.

58 NEOTROPICAL PSELAPHIDAE

Including the three new species of Jubus, this neotropical genus has forty-
nine known species: in the catalogue which follows, the Roman numeral
designates the Raffrayian group, a key to which has been given previously.

I

laeviceps Rafifray. 1893. Brazil.

II

brevis Rafifray. 1903. Bolivia.

decipiens Raffray. 1893. Colombia.

liliputaniLS Raffray. 1893. Brazil.

punctatus (Sharp). 1887. Mexico. (Duciola)

spinicollis Schaufuss. 1872. Colombia, {schaujussi Raffray, 1883)

trouessarti Raffray. 1896. Brazil.

turneri new species. Panama Canal Zone.

vulpinus Raffray. 1893. Brazil.

Ill

argus Raffray. 1893. Brazil.

heterocerus Raffray. 1918. Paraguay. ;

lativentris Raffray. 1893. Brazil.

IV

alternans Raffray. 1918. Paraguay.
caviventris Raffray. 1890. Venezuela.
chickeringi new species. Panama Canal Zone.
gracilicornis Raffray. 1903. Mexico.
hetschkoi Raffray. 1893. Brazil.
inermis Schaufuss. 1887. Colombia.
insularis Raffray. 1908. Guadeloupe, Leeward Islands.
pallidus Raffray. 1893. Colombia.
laticollis Raffray. 1883. Venezuela.
longicornis Raffray. 1893. Brazil.
punctulatus Raffray. 1890. Venezuela.
semipunctatus Schaufuss. 1872. Colombia.
subopacus Schaufuss. 1872. Colombia.
terranus new species. Panama Canal Zone.

tetratomus (Reitter). 1882. Venezuela, {abbreviatus Raffray, 1890)
(Duciola)

V

aberrans (Sharp). 1887. Guatemala. (Duciola) (Placed in fifth group
with doubt)

JUBININI 59

ooeculus Raffray. 1896. Brazil. (Placed in sixth group in 1903, re-
placed in fifth group in 1908 by Raffray)
laetus Raffray. 1890. Venezuela.
longipennis Raffray. 1883. Colombia.

VI

clavatus Raffray. 1903. Grenada, Windward Islands.
grouvellei Raffray. 1893. Brazil.
intermedius Raffray. 1893. Brazil.

VII

bifossulatiLS Raffray. 1893. Brazil.

brasiliensis Raffray. 1893. Brazil.

crassipes Raffray. 1909. Brazil.

convexiiLSCulus Raffray. 1893. Brazil, [convexinscutus Raffray, 1908)

dominulus Raffray. 1893. Brazil.

gracilis Raffray. 1893. Brazil.

microcephalus Raffray. 1893. Brazil.

microphthalmus Raffray. 1893. Brazil.

quadratus Raffray. 1893. Brazil.

simoni (Reitter). 1882. Brazil. (Gasola)

sinuatiLS Raffray. 1893. Brazil,

suhrectus Raffray. 1893. Brazil.

Group Unknown

hrucki (Schaufuss). 1872. New Granada (Colombia?) (Gamba)
elongata (Schaufuss). 1872. Argentina. {Gamba)
rugicollis (Schaufuss). 1872. Argentina. {Gamba)

BARROJUBA new genus

Jubinini having: (1) large eyes, composed of coarse facets, in the male sex;
(2) vertexal foveae vestigial or absent; (3) eleven-segmented antennae with
the last four segments long, subequal in width, to form a club, the antennae
being close together at their insertion, narrowing the front; (4) typical carinated
pattern of ventral surface of head being Y-shaped, with a glabrous, unifoveate
enclosed area; (5) pronotum unidentate each side at basal third, and with no
transverse sulcus; (6) elytra with a single basal fovea (sutural) on each elytron,
no dorsal stria; well-developed subhumeral fovea and longitudinal carina on
elytral flank; (7) abdomen with five visible tergites, and six visible stemites;
(8) prostemum transverse, not medianly carinate anterior to coxae; (9) coxae
conical; anterior coxae separated, very long; middle coxae long, contiguous;
posterior coxae short, contiguous; (10) tarsi three-segmented, elongate, later-

60 NEOTROPICAL PSELAPHIDAE

ally compressed, second tarsomere very much longer than third, third tarsomere
ending in a pair of unequal claws.

Genotype: Barrojuba albertae new species

Barrojuba albertae new species

Measurements: Head 0.469 x 0.469 mm.; eyes 0.201 mm. long; antennae
0.904 mm. (club 0.569 mm.) long; cervicum 0.067 mm.; pronotum 0.482 x 0.603
mm.; elytra 0.683 at suture x 0.871 mm. at posterior third; abdomen 0.75 mm.
X 0.8 mm.; first tergite 0.24 mm., second tergite 0.19 mm., third tergite 0.16
mm., fourth tergite 0.10 mm., fifth tergite 0.05 mm.; hind tibiae 0.67 mm.; hind
tarsi 0.45 mm., first tarsomere 0.03 mm., second tarsomere 0.3 mm., third tarso-
mere 0.12 mm., tarsal claws 0.04 mm. long claw; total length 2.45 mm. x 0.87
mm. greatest width. (PI. XVIII.)

Color reddish-brown with maxillary palpi, antennae and legs yellowish-
brown. Pubescence abundant, long, golden; average length of body pubescence
0.067 to 0.12 mm.

Head rounded-triangular. Eyes very large, hirsute, much longer from a
dorsal view than sides of head either anterior or posterior of the eyes; com-
posed of about 56 very large, coarse facets. Tempora converging slightly behind
eyes, not prominent. Occiput medianly sinuate. Vertex simple, evenly convex,
not appreciable higher than eyes. Vertexal foveae very far forward, on a line
passing just posterior to posterior margin of first antennal segment, vestigial,
small and difiBcult to locate, appearing as a pair of minute, oblique scars, with-
out much depth, mutually close together (being separated by the width of two
eye facets) , as though they were the byproduct of the articulation of the first
antennal segment with the mesio-dorsal wall of its acetabulum. These scars may
not be true vertexal foveae, viz. they may not have a connection with the cep-
halic endoskeleton, in which case true vertexal foveae are lacking. Vertex and
front densely, cribrately, coarsely punctate (about 24 to 32 punctures per
.01 sq. mm.) ; front evenly and continuously declivous, simple, strongly nar-
rowed by antennal acetabula.

Antennae eleven-segmented, I and II large; I longer and wider than II;
I and II suboblong; III shorter and narrower than II, obconical; IV, V, VI, and
VII gradually and progressively wider than III; IV obconic; V subquadrate;
VI and VII progressively transverse and trapezoidal; VIII, IX, X and XI form-
ing a long, distinct club, abruptly longer than VII, subequal in width, slightly
wider than VII; VIII, IX, and X cylindrical; VIII twice as long as VII, and a
little longer than IX, and subequal in length to X; XI ovate-acuminate, twice
as long as X.

Maxillary palpi four-segmented ; first segment minute, cylindrical ; second
segment long, slender, pedunculate at base, broadening apically ; third segment
broader and shorter than second, pyriform, broadening apically; fourth segment
largest, broader than third and longer than second, ovate-acuminate, densely
clothed with very short setae and bearing apically a small palpal cone.

JUBININI 61

Ventral surface of the head typical of the tribe. Mentum large, transverse,
concave. Cardo with the base notably produced, this produced portion is espe-
cially thick, forming a large, equilateral triangular piece on each side of the
mentum. Two oblique, very sharp, high carinae fuse medianly at a point op-
posite the posterior third of the eyes, forming a thin, low common carina, to
give a Y-shaped pattern. The neck and head ventrally are separated by a well-
formed semicircular sulcus, and at the point where the common median carina
approaches this sulcus, the carina sharply bifurcates to enclose the gular fovea.
On both sides of the common carina the head is subopaque, clothed with shaggy
setae, but the enclosed triangular field, between the forks of the Y, is glabrous,
shining and concave, with a darkened, minute, pore-like fovea near base of
mentum.

Pronotum campanulate, similar to many species of Jubus in its contour,
but unique in the tribe by having no trace of a transverse basal sulcus. A strong
short, triangular, acutely-pointed tooth situated on each side at basal third.
Anterior to this tooth, each side is sinuate, then evenly arcuate to apex, to form
a transverse anterior portion which includes two-thirds of the pronotal length.
Posterior to this tooth, each side is immediately, semicircularly incised to form
a short, narrower basal portion, with subacute basal angles. A large, foveoid
depression on each side of the pronotum, mesiad of lateral tooth. Disc of pro-
notum covered largely by a conspicuous triangular glabrous area, which begins
near the anterior margin, and broadens regularly to include most of the basal
portion of the pronotum. The basal area of this triangular, glabrous region is
sparsely granulate. The sides of the disc, about this glabrous region, are punc-
tate and closed with long setae so that the shining area is very distinct. In the
middle of this triangular, glabrous field is a weakly elevated, fusiform area
which includes five large, raised punctures in the form of a V, with the median
basal puncture bearing a remarkably long, thick, spinoid seta. No trace of a
transverse sulcus.

Scutellum visible, triangular.

Elytra clothed with long pubescence, and evenly punctate; humeri sub-
dentate due to the strong transverse basal carina. Each elytron with an entire
sutural stria and a single basal fovea, the sutural, which lies at the origin of
the sutural stria, partially recessed by the transverse basal carina. No dorsal
stria, but a vague depressed area mesiad of each humerus. Elytral flank with a
strong, longitudinal carina which begins at the humerus, and a large, circular,
nude subhumeral fovea.

Abdomen with very strong margins, long, evenly tapering to rounded apex.
Five visible tergites, with proportions indicated by previous measurements,
densely pubescent. Six visible sternites; first stemite short, obscure between
the coxae; second stemite longest, slightly longer than third; third slightly
longer than fourth; fourth slightly longer than fifth; fifth weakly incised to
hold sixth; sixth stemite very transverse, shorter than fifth, and deeply concave
in median apical half. All sternites more or less flattened medianly. Third,
fourth and fifth sternites foveate on each side of median flattened area: these

62 NEOTROPICAL PSELAPHIDAE

foveae appear to be complex, and to open into short, transverse sulcoid depres-
sions. Second sternite with a pair of basal carinae on basal half, obscured by
the posterior trochanters.

Prosternum broad, flat, transverse, pubescent, not medianly carinate an-
terior to the coxae. Mesostemum relatively very elongate for the tribe, and
narrow and pubescent. Metasternum moderately elongate, medianly gibbous
and medianly longitudinally carinate. Anterior coxae very prominent, conical,
separated by a flat prostemal process which is medianly carinate. Middle coxae
prominent, conical, contiguous. Posterior coxae short, medianly conical, con-
tiguous. The legs are long, simple and unmodified, with long, compressed tarsi.
Tarsomeres with proportions as noted previously, ending in two arcuate, un-
equal claws.

Described on one male type, collected by Dr. Eliot C. Williams, Jr., from
Barro Colorado Island, Gatun Lake, Panama Canal Zone, in floor mold sample
No. 1438. July 6, 1938. It gives me pleasure to name this species for my wife,
who accompanied me on an expedition to the American tropics. The genus
Barrojuba has no near allies as a consequence of its described anatomy. It is
placed near Jubus, with which it has more affinities than with any other jubine
aggregate.

BALEGA (Reitter, 1881)

dentata Raffray. 1904. Mexico.

elegans Reitter. 1883. St. Thomas, Virgin Islands. Genotype.

PHAMISUS (Aube, 1844)

reichenbachi Aube. 1844. Colombia. Genotype.
reitteri (Raffray). 1883. Colombia. (Jubiis)
velutinus Raffray. 1904. Bolivia.

STRATUS (Schaufuss, 1872)

ursinus Schaufuss. 1872. Mexico. (Teapa) ; also New Orleans, Louis-
iana?

villosulus (Motschulsky). 1855. Panama. (Canthoderus) (generic
place doubtful, based on a sketch by Motschulsky).

ENDYTOCERA (Sharp, 1887)

oognata Sharp. 1887. Panama.

vestita Sharp. 1887. Panama. Genotype.

Tribe 4. Euplectini, sensu latiore

After considerable study of the American fauna I have combined the
Euplectini, sensu strictiore, and the Trichonychini into a single tribe.

Apparently the only character separating these two aggregates concerns the
tarsal claws. Thus Raffray (1903, 1908) says of Euplectini "tarsi with a single
or principal claw, and at times also an accessory, claw-like hair" and of Trich-
onychini "two unequal claws on each tarsus, the small or accessory claw is
curved, and not to be confused with a hair." Bowman (1934, p. 2) says of
Euplectini "inner tarsal claw absent or exceedingly minute" and of Trichony-
chini "inner tarsal claw very small but distinct, at least one-fifth as long as the
outer."

These differences are insufficient to separate two groups of genera which
inhabit much the same zoogeographic range, the same ecological niches, and
resemble each other in many basic morphological features. If the claw formula
was rigid, with one group having one claw and the other group having two
claws, the two aggregates could be separated for practical purposes; this still
would not demonstrate a fundamental arrangement. Leng (1920) followed
Raffray in using both tribes; such a course was proper, since Raffray 's opinion
held, will always hold, great authority, but as data accumulate such a course
becomes less advisable. American students of the family have not found the
employment of both tribes wholly profitable. Thus, early workers, such as
Brendel and Wickham (1890) and the brilliant Casey (1893, p. 442 and 1897,
p. 552) opposed such a course; recently Bowman (1934, p. 8) separated the two
groups with apparent reluctance, since he felt that a still further break-up of
the euplectines might be justifiable "especially if the Trichonychini be re-
moved."

Casey bitterly opposed separation of these two groups of genera, and his
remarks in one instance (1893) will bear quoting:

"The tribes or groups Euplectini and Trichonychini of Reitter and Raffray
cannot be maintained as distinct and natural aggregates of genera, and should
be united to form the single tribe Euplectini. The auxihary (tarsal) claw varies
by successive degrees in different genera and species otherwise closely related
so that it is impossible to draw any line of demarcation between two groups
founded upon this character or any other which it seems possible to discover.

The second tarsal claw is distinctly visible as a minute hair-like appendage
in at least several species of European Euplectus, in Trimiopsis, and also in
Actium, which was recently re-described by Mr. Raffray under the name
Proplectus and placed in the "Trichonychini". I have seen the second rudi-
mentary claw plainly in Bibloporics bicanalis and Euplectus calif omiciis.
Finally in {Ramecia crinita) the auxiliary claw becomes as large, conspicuous
and fully formed as in Trichonyx itself, and yet in general habitus and
details of structure crinita is unmistakably very closely allied to Euplectus,
and should be not widely separated from that genus.

(63)

64 NEOTROPICAL PSELAPHIDAE

The so-called second claw is always in the nature of an appendage, even
in Trichonyx, Oropits and other typical trichonychide genera. That is to say —
the large claw is in every case perfectly in the plane of the axis of the tarsus,
the auxiliary claw projecting laterally from its base."

I have the same feeling concerning the evaluation of the tarsal claws as
Casey, and consequently treat the two groups of genera as one tribe, Euplectini.
Without going into lengthy detail here, since species descriptions can be studied
by anyone interested in the problem, slide mounts of tarsi under high magnifica-
tion show the truth of the inapplicability of the secondary tarsal claw as a prime
character. Thus the North American specialized Rhinoscepsis histriatus Le-
Conte has a secondary claw over half as long and a third as thick as the primary
claw. Again, although one of the new species from Central America, Panara-
mecia williamsi, has a secondary claw fully half as long as the primary claw,
most of its anatomy indicates a position near such euplectine genera as Bib-
loplectus, Pteroplectus and Rameda.

The Euplectini is a very large tribe, with an average size which is small,
even for the family; they are very difficult to study. Of cosmopolitan distribu-
tion, the group has a combination of characters which almost always renders
tribal designation simple. Few pselaphid genera of other tribes are confused
with euplectines, although exceptions can be found; for example, Eupsenius of
the Brachyglutini has many characteristic euplectine features.

Euplectines have the typical three-segmented pselaphid tarsus, with the
first tarsomere very minute, and the second and third tarsomeres relatively very
much larger than the basal segment. The articulation of the trochanters with
the femora is typically brachysceline ; that is, the trochanter is short and not
clubbed apically but very obliquely articulated with the femur so that the latter
closely approaches the coxa. The mentum is not greatly expanded transversely
to cover the mouth-parts as in the Jubinini, but is normally small, and the
cardo of each maxillary palpus is also normally small and not externally pro-
duced at the base in a long spinoid process. Finally, the posterior (metatho-
racic) coxae are very transverse, save at the mesial face where they articulate
with the trochanter of the posterior legs; this mesial, articulating face is ab-
ruptly conical, or conically produced instead of being globular or broadly tri-
angular.

The maxillary palpi are relatively primitive for the great majority of the
species, being four-segmented with the first segment very minute; second seg-
ment elongate, slightly arcuate, narrow basally and slightly clubbed or inflated
apically; third segment shorter than second, globular, triangular or pyriform;
fourth segment largest, oval or fusiform, more or less rounded-truncate at base,
acuminate at apex, the latter bearing a small, usually aciculate palpal cone.

The dorsal surface of the head (vertex, front), antennal insertions, form
of the antennal segments, pronotum, abdomen and tarsal claws are diverse in
the tribe. Such variation is specific, but in many instances sexual, and this-
diversity is demonstrated in the keys, descriptions and illustrations which
follow.

EUPLECTINI 65

The abdomen is generally elongate, strongly margined, and of five to six
visible tergites ; ventrally there may be six visible stemites in both sexes, or six
in the females and seven in the males. In the latter case, the seventh stemite
may be in one piece, or longitudinally divided into a right and a left pygidial
plate. The male sex often has the sternites secondarily modified.

Euplectini offer a promising field for evolutionary study. Such an investi-
gation is not contemplated in the present paper, since the world fauna must be
taken into such calculations. The American euplectines appear to culminate in
the cluster of genera which includes Melba, Dalmosella, Basolum, Pseudo-
trimium, Trimiomelba, Actium, Actinoma, Trimiosella and their allies. In these
genera there is a general summation of morphological features away from the
staphylinid pattern. This is suggested by increasing glabrosity, consolidation
of sternal sutures and foveae, increasing prominence of the distal antennal seg-
ment, and in many of these genera the signal development of specialized capit-
ulate setae on the ventral surface of the head. These trimiforms or melbaforms
appear to have affinities with some of the Brachyglutini, for example Eupsenius
and Eupsenina.

If the assumption is made that pselaphids have evolved from staphylinoid
ancestors, and morphological evidence has been presented for such a view, then
development in the euplectines must be based on more and more remote organ-
ization from the staphylinid stem. For example, the following criteria may be
taken into brief consideration:

1. General consolidation of the body, including head, thorax and abdomen,
is considered a specialization of great weight, carrying the family from Staphy-
linidae, through Faronini, into Clavigerinae. Such consolidation leads to increas-
ing abdominal immobility, loss of sutures, reduction of sternal foveae and
finally loss of sternal foveae.

2. A general vestiture of simple setae is considered primitive, but either
a glabrous condition, or highly modified setae such as capitulate or scales, or
a combination of glabrosity with modified setae, is considered specialized.

3. Tarsi with two equal, simple claws are considered generalized. Bilater-
ally asymmetrical claws, reduction in the size of one claw, or presence of a
single claw are considered progressively specialized.

4. Tendency towards filiform or moniliform antennae with a loose weakly
developed club is considered primitive, but the development of a large antennal
club and the progressively larger distal segment of the club, is considered
specialized.

5. Simple four-segmented maxillary palpi are primitive, whereas increas-
ing specialization of the palpi is viewed as more highly evolved.

6. A penial plate, increasing the number of visible sternites in the male
sex to seven, is more primitive than six sternites visible. Where this plate is
longitudinally divided into a right and left piece by the pygidial carina, the
combination is more primitive than a single penial plate. This single penial plate
may move asymmetrically to the right, or to the left.

7. The bilaterally symmetrical aedeagus, with lateral lobes, is more primi-
tive than the asymmetrical aedeagus, with fewer parts.

66 NEOTROPICAL PSELAPHIDAE

We must be very cautious in using those structural features which may be
secondary adjustments, such as the reduction of mouth-parts for a specialized
diet, as in the Clavigerinae; or the reduction or loss of eyes and wings in one
or both sexes. It is quite possible that a genus may be primitive in its general
anatomy, but will have certain parts highly specialized. Thus Rhinoscepsis is
a primitive genus in many respects, but there is a reduction in eyes and wings.
Species living habitually in deep soil, caves, or the nests of ants and termites
are usually illustrations of this idea.

Key to the Genera

Prostemum with a median longitudinal carina (lateral straight or
oblique carinae may or may not be present separating the pro-
sternum from the pronotum, but these are not involved ; where the
prostemum is medianly carinate, the carina extends from a point
between the bases of the anterior coxae, across the sternum, ending

at or near the anterior margin) 2

Prostemum with no median longitudinal carina 6

2(1). Base of each elytron with four foveae (the basal foveae lie in
a line between the suture and the humeral angle ; these basal
foveae do not include a subhumeral fovea which may or may
not be present just posterior of the humerus and on the flank

of the elytron) 3

Base of each elytron with fewer than four foveae 4

3 ( 2 ). Ventral surface of head with a fine, median carina

PTERACMES

Ventral surface of head with a median sulcus

PTEROPLECTUS

4 ( 2 ) . Second tergite armed, a prominent tubercle on each side, in the

male (female unknown) FARONOMA

Second tergite not armed or laterally tuberculate in either sex 5

5 ( 4 ) . Disc of pronotum simple, with no central fovea or foveoid de-

pression BIBLOMIMUS

Disc of pronotum with a central depression which varies from
a small fovea to an elongate, fusiform, longitudinal foveoid

area THESIUM

6(1). Base of each elytron with four foveae 7

Base of each elytron with fewer than four foveae 10

7 ( 6 ) . Sides of pronotum with one or more distinct teeth^ 8

Sides of pronotum not dentate^ 39

* The presence or absence of teeth must be clearly understood. There are three basic
types of lateral pronotal margins involved in the Euplectini: entire, in which the margin
is a simple line; crenulate, in which the margin is thrown into a series of waves or undu-
lations, the period of the wave varying with the species, but the waves being continuous,
not discrete entities; dentate, in which the margin is periodically erected into discrete ele-
vations. These elevations are nearly always prominent, acute teeth or spines, with sharp-

EUPLECTINI 67

8(7). Pronotura with a small, subspherical to subcylindrical anterior
lobe, and a very large posterior lobe, the small anterior lobe
acting as a bearing for the equally small pedunculate neck

(PI. VIII, 7) RHEXIUS

Pronotum without such a small anterior, pedunculate lobe. ... 9
9(8). Lateral pronotal margins unidentate, each side bearing a single

tooth at middle of subbasal area 42

Lateral pronotal margins pluridentate, each side bearing five
to six teeth (PI. VIII, 10) EURHEXIUS (in part)

10 ( 6 ) . Base of each elytron with three foveae 11

Base of each elytron with two foveae 21

11 (10). Eyes invisible from above MITRACEPHALA

Eyes visible from above 12

12 (11). Disc of pronotum simple, with no trace of a fovea or a longi-

tudinal median sulcus 13

Disc of pronotum with either a median longitudinal sulcus, or
a central fovea or foveoid depression 15

13 (12). Sternite IV very short, much shorter than II and III which are

subequal in length LIOPLECTUS

Sternites II, III and IV subequal in length, or gradually de-
creasing in length 14

14 (13). Lateral pronotal margins entire; elytral base simply foveate,

having a transverse basal carina ACTIUM (in part)

Lateral pronotal margins with a small subbasal tooth, and
crenulate anterior to this tooth ; base of each elytron with a
multiarcuate, transverse, basal carina, the basal foveae be-
ing vestigial, and appearing as pits, one under each arc of
the transverse carina PANARAMECIA, new genus

15 (12). Disc of pronotum with either a central fovea, or a foveoid

depression 16

Disc of pronotum with a long, median, longitudinal sulcus. ... 17

16 (15). Ventral surface of head with a few stout, strongly capitate,

rather spiniform setae; basal tergites with no basal carinae
on disc THESIASTES

to-blunt ends; in several species the elevations are subdentate, minute and blunted denticles.
Thus a tooth may be distinct, but require high magnification to discern its form, this latter
condition is especially notable in the fifth group of Eurhexius with subdentate margins, as
contrasted with Aporhexius and Rhexinia with crenulate margins.

In some cases there is a combination of these features. Thus Panaramecia has a basal
tooth, and anterior to this tooth the margin is minutely crenulate. Again in Fletcherexitis
the margin is subentire, with the area opposite the lateral pronotal fovea slightly granular
so that the line of the pronotal margin appears similar to our North American Rhexidius
in part.

The above remarks refer to dry mounts on points. Microscope slides under high mag-
nification may show a crenulated margin to be composed of asperate tubercles, as in some
Thesium.

68 NEOTROPICAL PSELAPHIDAE

Ventral surface of head with no capitate setae, the setae present
being simple, acute, recurved; basal tergites with a pair of

short basal carinae on disc of segment

EUPLECTUS (in part)

17 (15) . Pronotum with both the transverse sulcus and the median longi-

tudinal sulcus rudimentary and just discernible. RHEXINIA
Pronotum with both transverse and longitudinal sulci strongly-
formed and clearly visible 18

18 (17). Lateral pronotal margins entire 19

Lateral pronotal margins either crenulate or dentate 20

19 (18). Pronotum as wide as head; first tergite very large, much longer

than second tergite ADROGASTER

Pronotum much wider than head; first tergite only a little
longer than second tergite ANARMODIUS

20 (18). Lateral pronotal margins crenulate APORHEXIUS

Lateral pronotal margins with five to six teeth (PI. VIII, 10)
EURHEXIUS (in part)

21 (10). Front of head prolonged into either (a) an elongate rostrum,

or (b) a median spinoid process, or (c) a dilated process

extending far beyond antennal insertions 22

Front of head not abnormally prolonged in any of these ways. . 23

22 (21). Restricted to termite nests; front irregular and abnormal, pro-

longed far beyond antennal insertions PHTEGNOMUS

Not inhabiting termite nests; front prolonged into a conspicu-
ous antennal rostrum, with antennae articulated at the distal
end of this tubercle, nearly contiguous; vextex and genae
with complex, tortuous sulci (PI. IX, 2) . . .RHINOSCEPSIS

23 (21). First three tergites highly abnormal in male sex (female un-

known), the lateral margins of first two tergites being deeply
concave and polished; sides of third sternite extending dor-
sally as an apically fimbriated, rounded lobe to clasp the pos-
terior angle of the second tergite; a tuft of scales in a slight
depression, above each lobe {ex Fletcher) ... .ALLOBROX
Tergites not so modified in either sex 24

24 (23). Pronotum with a median, obtuse but well developed, longi-

tudinal carina passing over the disc NEODALMUS

Pronotal disc simple and unmodified, or centrally foveate, or
longitudinally sulcate, but never with a median longitudinal
carina 25

25 (24). Pronotal disc simple, with no trace of fovea or sulcus 29

Pronotal disc either centrally foveate, or longitudinally medi-
anly sulcate 26

26 (25) . Pronotal disc with a median longitudinal sulcus 41

Pronotal disc centrally foveate or with a central foveoid de-
pression 27

EUPLECTINI 69

27 (26). Pronotal disc slightly flattened, and from an oblique point

of view there is a just discernible elongate depression

TRIMIOPSIS (in part)

Pronotal disc with a well formed central fovea or foveoid de-
pression 28

28 (27). Pronotum with a subbasal, transverse, arcuate sulcus

EUPLECTUS (in part)

Pronotum with two lateral foveae and a median foveoid de-
pression at base, these three areas not connected by a trans-
verse subbasal sulcus of any kind

BARROEUPLECTOIDES, new genus

29 (25). Posterior coxae not contiguous, either slightly or widely

separated 30

Posterior coxae contiguous, or so close that they are virtually so 31

30 (29) . Posterior coxae slightly separated 43

Posterior coxae widely separated, the first stemite appearing
between them as a transverse plate EUPSENINA (this genus
will key out here if the shape of the posterior coxae has
not been correctly diagnosed. It belongs in Brachyglutini).

31 (29). Each elytron with a long, sharply defined, nearly entire dorsal

stria on the disc, this stria extending for about three-fourths

of elytral length TOMOPLECTUS

Each elytron with either (a) a short dorsal stria, (b) a short
fusiform dorsal depression from discal median fovea, or (c) no
dorsal stria or depression 32

32 (31). Elytral humeri dentate to denticulate or acutely prominent. . . 33

Elytral humeri prominent or not, but never dentate or acute . . 34

33 (32). Base of elytra simply foveate, without a transverse basal

carina ACTIUM (in part)

Base of elytra with a transverse carina parallel to the basal
elytral margin ACTINOMA

34 (32). Pronotum with lateral foveae invisible from a strictly dorsal

point of view 35

Pronotum with the lateral foveae wholly or partially visible
from a strictly dorsal point of view 36

35 (34). Integument pubescent, punctate to punctulate; subbasal, trans-

verse sulcus continuing down flank of prothorax to end later-
ally each side in a fovea; these fovea are not visible from
above, and lie near or on the sides of the prosternum (PI. XI,

7, 8) MELBA

Integument glabrous, without punctures or pubescence; the
subbasal, transverse pronotal sulcus absent or represented
by a just discernible linear impression which ends on the

sides of the prothorax in a vague depression

EUPSENIUS (this genus

70 NEOTROPICAL PSELAPHIDAE

will key out here if the shape of the posterior coxae has not
been correctly diagnosed. It belongs in the Brachyglutini).
(PI. XIV)

36 (34). Tenth antennal segment symmetrical and lenticular (biconvex

or bean-shaped) 37

Tenth antennal segment asymmetrical and transversely tri-
angular 38

37 (36). Dorsal surface of head with a pair of deep, longitudinal sulci

which are parallel to each other, and do not unite anteriorly

TRIMIODINA

Dorsal surface of head without sulci, or the sulci very vestigial,
hardly perceptible 44

38 (36). Head small, triangular, distinctly narrower than pronotum

PSEUDOTRIMIUM

Head large, much wider than pronotum

TRIMIOPSIS (in part)

39 ( 7 ). Pronotum with a median, longitudinal sulcus which is nearly

entire and extends from near base to near apex, crossing
the transverse subbasal sulcus at right angles (PI. VIII,

11) FLETCHEREXIUS, new genus

Pronotum with disc either (a) wholly unmodified, or (b) with
a central median fovea 40

40 (39). Pronotal disc simple, not foveate; tenth and eleventh anten-

nal segments bilaterally asymmetrical; tenth segment much
wider and longer than the ninth, and of a rounded-triangular
shape, very asymmetrically articulated on the antero-mesial
face of the ninth, so that both ninth and eleventh segments
are in contact laterally and widely separated mesially by
the wedge of the tenth segment (PI. VI, 10) . .MELBAMIMA
Pronotal disc with a median fovea; tenth and eleventh anten-
nal segments bilaterally symmetrical; tenth segment normal,

transversely pyramidal, and normally articulated

VERABAROLUS, new genus

41 (26). Head small, much longer than wide; first two tergites of equal

length; tarsi with a single claw ACOTEBRA

Head large, more or less transverse; first tergite longer than
second; tarsi with two claws of nearly equal length, the inner

claw much thinner and slightly shorter

ANARMODIUS (in part)

42 ( 9 ) . Ventral surface of the head with a strong median sulcus ; pro-

notal margins with a strong tooth near the middle, on each
side ; base of elytra with four f oveae but no transverse basal

carina XHERIUS

Ventral surface of the head with a basal, circular gular fovea
but no median sulcus; each lateral pronotal margin with a

EUPLECTINI 71

small subbasal tooth and crenulate from the tooth to anterior
third; base of elytra with four small, rudimentary foveae
on each elytron, these foveae being apically margined by a

triarcuate or quadriarcuate transverse basal carina

PANARAMECIA, new genus

43 (30). Integument punctulate and pubescent DALMOPLECTUS

Integument glabrous, without punctures or pubescence

EUPSENIUS (this genus

will key out here if the shape of the posterior coxae has
been incorrectly diagnosed. It belongs in Brachyglutini).

44 (37) . Head with two vertexal foveae ; lateral margins of the pronotum

sharply defined, with the lateral fovea on each side wholly
within the margin, and wholly visible from a dorsal view

(female known only) TRIMIOSELLA

Head with four strongly formed foveae, two vertexal foveae
widely separated and on a line passing through the posterior
half of the eyes, and an anterior pair of foveae, closer to-
gether and near the frontal margin, one slightly behind and
mesiad of each antennal prominence; lateral pronotal mar-
gins smoothly rounded as in Melba, but the lateral subbasal

fovea visible on each side from a dorsal point of view

R AMELBID A, new genus

FARONOMA (Raffray, 1894)

cavangula (Reitter). 1894. Chile. Genotype. (Rybaxis)

The single species of this genus, originally described in Rybaxis of the
Brachyglutini, transferred to Faronini in the genus Faronoma by Rafifray,
and subsequently (1903) placed by Raffray in the Trichonychini, is here
placed in the enlarged Euplectini. It is one of two monotypic genera of
trichonoforms in which the male sex is known only, and in this sex the tergites
are remarkably modified. In this species the male has subequal tergites and
the second tergite has each lateral margin strongly tuberculate and armed.
Described from Valdivia, Chile, it has not been recorded since.

ALLOBROX (Fletcher, 1928)

dampfi Fletcher. 1928. Mexico. Genotype.

The author of this remarkable species has this to say regarding its
affinities: "Allobrox is without doubt more closely allied to the Chilian
Faronoma than to any other of the Trichonychini. These two genera are alone
in the tribe in possessing modifications of the dorsal abdominal segments re-
minding one of Brachygluta."

72 NEOTROPICAL PSELAPHIDAE

ANARMODIUS (Raffray, 1890)

Six visible sternites in male and female; male with femora more inflated,
and the anterior femora tuberculate.

Key to the Species

Each elytron with three basal foveae gibbus

Each elytron with two basal foveae bifoveatus

gibbus (Schaufuss). 1872. Brazil. {Trichonyx) Genotype.
bijoveatus Raffray. 1891. Venezuela.

FLETCHEREXIUS new genus

This genus is erected primarily for Eurhexius macrodactylus Fletcher
(1928). It appears to be more closely related to the eurhexiforms with edentate
pronotal margins {Anarmodius, Aporhexius, Rhexinia) than to the genera
having dentate margins {Xherius and Eurhexius as limited here), but war-
rants isolation on the remarkable tarsal claws, length of the eleventh antennal
segment, pronotal outline and elytral foveae.

Macrodactylus was described on three doubtfully male specimens col-
lected in 1925 from decaying log mold of Abies religiosa, between 3000 and
3200 meters near Mexico City.

Salient structural features are the shining punctate-granulate integument;
transverse head, but slightly narrower than pronotum; very small, oval eyes;
medianly placed vertexal foveae; a small, deep fovea behind each antennal
tubercle; occiput with a median longitudinal sulcus which passes forward to
just anteriad of the vertexal foveae; antennae eleven-segmented with segments
III, IV and V small and moniliform, VI, VII and VIII slightly increasingly
transverse, the XI slightly longer than VIII, IX and X combined. Ventral
surface of head with capitate setae. Pronotum distinctive. I examined a para-
type of macrodactylus in the National Museum (U.S.N.M. No. 44612) and
found the lateral pronotal outline (PI. VIII, 11) to strongly suggest our North
American Rhexidius (PI. VIII, 1), These outlines are subentire, widest slightly
posterior to the middle of the pronotum, strongly convex anterior of this point,
ending in a rounded obtuse apex, and slightly sinuate posterior to this widest
point to the subtruncate base with rounded posterior angles ; the lateral margin
in the basal third granulated so that, under high magnification the margin
gives the impression of being composed of about five very minute, blunted
denticles; median longitudinal sulcus deep and extending from basal margin
to apical sixth; transverse pronotal sulcus in basal third, crossing longitudinal
sulcus at right angles, the junction being broadened, and ending each side in an
ovate pubescent lateral fovea. Each elytron with a subepipleural carina and
subhumeral fovea on elytral flank, and four basal foveae. The first of these
foveae, the sutural, is the most apical and gives rise to the sutural stria; the

EUPLECTINI 73

second, or discal fovea is the most basal of the foveae and gives rise to a discal
stria; the third and fourth are close together and give a paired appearance
since their striae arise laterally and unite along the basal rims of the foveae,
as in Thesium. Abdomen with subequal tergites and six sternites, of which
latter the first is very short, shorter than posterior coxae; second, third and
fourth sternites subequally long, evenly convex; fifth broadly emarginate;
sixth transverse. Metastemum convex, medio-posteriorly slightly impressed.
Tarsal claws very unequal and distinctive. An accessory claw less than half
as long as primary claw, and about one-half as wide, that is, very thick for
its length. Primary claw large, over twice as long as the accessory claw, and
instead of becoming narrower to an attenuated apex, holds its width to the
distal fifth where it is abruptly and ventrally acute, thus being apically inflated.

macrodactylus (Fletcher). 1928. Mexico. Genotype. {Eurhexius)

The remarks about to be made on Eurhexius are also pertinent to Fletcher-
exius and any wholesale consolidation of the eurhexoid aggregates will in-
volve the above genus as well.

APORHEXIUS (Raffray, 1903)

Pronotum with the lateral margins distinctly crenulated, as in the North
American Rhexidvas Casey. This character serves to separate Aporhexius from
Fletcherexius where the lateral pronotal margins are subentire save for a
crenulate-granulate area opposite the lateral pronotal foveae.

Pronotum with the median longitudinal and transverse subbasal sulci
strongly formed, as in Fletcherexius and Eurhexius. This character separates
Aporhexius from Rhexinia, the only other neotropical eurhexiform genus with
distinctly crenulated pronotal margins.

Male metastemum slightly sulcate medianly and this sex with the last
stemite impressed and medianly glabrous.

Pubescence unusually dense.

pubescens Raffray, 1903. Bolivia. Genotype.

RHEXINIA (Raffray, 1890)

Pronotal margins laterally crenulate, and with the longitudinal and trans-
verse sulci virtually absent or so poorly developed as to be just perceptible.
Head and pronotum confluently punctate and granular. Six visible sternites.

angulata Raffray. 1890. New Grenada (Colombia?). Genotype.
versicolor Raffray. 1908. Guadeloupe, Leeward Islands.

XHERIUS (Raffray, 1890)
cordicollis Raffray. 1890. Venezuela. Genotype.

74 NEOTROPICAL PSELAPHIDAE

EURHEXIUS (Sharp, 1887)

This is the largest of American eurhexiform genera (Raffray's second
group of Trichonychini, 1908), containing about 25 species. Its central taxo-
nomic position (analogous to Jubus in Jubinini) in the eurhexi forms, numer-
ous species and wide distribution (Uruguay to Guatemala) make its exami-
nation necessary. The species all have a homogeneous habitus. Size range is
large, from one to nearly four millimeters, with a thick body and integument
more or less granulate and pubescent. The head is very transverse, subreni-
form, with prominent tempora. Maxillary palpi typically four-segmented, first
segment small, short; second longer than wide, slender basally, inflated apically,
sinuate; third small, much shorter but slightly wider than second; fourth
large, ovoid-acuminate to subsecuriform, heavily pubescent. Antennae eleven-
segmented as usual, slightly geniculate, first segment relatively long and
cylindrical; second globular; third to seventh submoniliform, narrower than
second, with some variation in the species as to length and width of seg-
ments; club foraied of the last three segments which gradually increase in
width and length as a rule, the last segment being much larger than the tenth
as a rule, acute-pyriform to obtuse-conical. Ventral surface of the head with
the sulciform fossa for reception of the maxillary palpus on each side, well
developed as typical for the eurhexiform genera. Pronotum (PI. VIII, 10)
cordiform, conspicuously narrowed anterior of the middle, but not forming a
small pedunculate lobe as in Rhexius; disc crossed by a narrow, deep, entire
longitudinal median sulcus and a subbasal transverse sulcus; lateral margins
always armed with teeth, usually six in number, these teeth varying in size
from very large spine-like projections {sexpunctatus Raffray) to minute teeth
{muticus Raffray), but always present and always discrete, not merging to
form a crenulate margin as in the North American Rhexidius and the neo-
tropical Rhexinia and Aporhexius. Elytra subquadrate, with rounded humeri;
each elytron with three or four basal foveae (usually four). Abdomen large,
usually longer than elytra, and strongly margined. Tergites subequal or slightly
shorter in progression. Six relatively simple sternites in both sexes, making
sexual differentiation difficult or very doubtful without dissection. Prosternum
flat, transverse, laterally carinated on each side. Tarsi three-segmented, first
tarsomere small, second and third much longer than the first, with the second
usually slightly thicker and much longer than third; two unequal claws, the
external claw large, over half as long as the inner claw.

With his usual acumen, Fletcher (1928) has observed that in setting up
the genus Eurhexius, Sharp (1887) did not specify lateral pronotal teeth in
vestitus, parviceps, ventralis, and trimiodes, nor show pronotal teeth in his
figure of vestitus. Such negligence on the part of Sharp has left some doubt as
to the composition of Eurhexius, and as Fletcher noted, if Sharp's species (of
which I have not seen the types) do not have pronotal teeth, then Rhexidius
Casey (August, 1887) of North America becomes a synonym of Eurhexius
Sharp (April, 1887) of the American tropics. I doubt this very much, especially
since Raffray (1903, 1908) definitely allocates Sharp's four species in Eur-

EUPLECTINI 75

hexius, along with many other species known to have well formed pronotal
teeth. It is a pity that such an important genus should have been so vaguely
described as to allow confusion in its composition. R affray (1903) cited Sharp's
four species and rugulosus (Reitter) as of doubtful status — a strange situation
in which the great majority of the genus could be placed, but the genotype
could not!

Raffray (1908), in his great generic treatment, defined Eurhexius as al-
ways having lateral pronotal teeth or tubercles, and incorporated rugulosus
(Reitter) and the four species of Sharp without any query. Raffray made so
few mistakes (an exception being application of the wrong priority with
Thesiuni and Apothinus) , that between 1903 and 1908 he must have seen the
Sharp types; at least that is a strong inference which would account for the
change in status of these doubtful species between these two dates.

There is another line of indirect evidence to substantiate the presence of
pronotal teeth for Eurhexius, in these doubtful species. In 1882 Reitter de-
scribed three species of Rhexius, namely simoni, rugulosus, and procerus. In
the case of simoni and procerus his descriptions state definitely that the lateral
pronotal margins are denticulate, whereas in rugulosus he states that the
pronotum has the lateral margin without denticulations. This is a definite
statement by a competent coleopterist. Sharp (1887), in erecting Eurhexius,
has no doubt that "Rhexius simonis and R. procerus, Reitter, belong to it."
Therefore Sharp included the two species of Reitter, knoivn to have pronotal
teeth, with his four species, and did not mention rugulosus of Reitter, which
was described in the same paper and did not have pronotal teeth. The inference
is that Sharp's four species, with vestitus as a probable genotype, have pronotal
teeth. Other Eurhexius by Raffray follow this position.

This consolidates the limits of Eurhexius, with the exception of Rhexius
rugulosus Reitter, which I am unable to place. This latter species may belong
in Anarmodiu^ or Fletcherexiu^ if the pronotal margins are not dentate, or in
Aporhexius if these margins are crenulate; or if Reitter did not correctly de-
scribe his specimen, and subsequent examination of the type by Raffray showed
pronotal teeth, it belongs in Eurhexius. I doubt the last assumption on the
basis of Reitter's reputation.

If Raffray (1908) is wrong as to Eurhexius, then at least seven related
genera will have to be reexamined comparatively from the types; for example,
Eurhexius may be found to contain Sharp's four species with vestitus as geno-
type, rugulosus (Reitter) and macrodactylus Fletcher. In this case the species
of Raffray, and others by Schaufuss, Reitter, and the author, probably belong
in a new genus.

Until further research can clear up the obscurity, my position is that of
the Raffray 1908 diagnosis. Raffray (1903) divided Eurhexius into five groups
of species, which I have had to modify slightly:

Each elytron with three basal foveae Group I

Each elytron with four basal foveae 2

76 NEOTROPICAL PSELAPHIDAE

2. Lateral pronotal margins with about six sharply defined, acute teeth. . 3
Lateral pronotal margins with about six very minute, blunted but

discrete denticles, of which one may be larger Group V

3. Tempora with the posterior angles pointed, subdentate. . . .Group II
Tempora with the posterior angles rounded, not subdentate 4

4. Antennae with segments IX and X at least as long as wide, if not

longer than wide Group III

Antennae with segments IX and X slightly or distinctly wider than
long, e.g. transverse 5

5. Antennae with segments III to VIII all transverse, wider than long

Group IV, first section.

Antennae with segments III to VI having length and width equal,

and segments VII and VIII slightly transverse

Group IV, new second section

The following keys to the species of Eurhexius are offered tentatively
with the exception of rugulosus Reitter, which appears to belong in some other
aggregate (vide supra) :

Key to the Group I Species

Species known from Central America. 1

Species known from Brazil 4

1. Basal antennal segment twice as long as second segment; first visible

tergite twice as long as second ventralis

(2.5 mm., 3000-4000 ft., Volcan de Chiriqui, Panama)
Basal antennal segment not twice the length of second; first two
tergites subequally long 2

2. Antennal segments VII and VIII slightly broader and shorter than

segments III to VI parvioeps

(2.12 mm., 8000 ft., Volcan de Chiriqui, Panama)
Antennal segments III to VIII of equal length and width, similar. . . 3

3. Integument polished, pubescence short trimiodes

(L5 mm., 8500-10500 ft., Totonicapan, Guatemala)
Integument not shining, more or less opaque, pubescence dense and

conspicuous vestitus

(2.12 mm., 2000-3000 ft., Volcan de Chiriqui, Panama)

4. Length 1 mm.; long, brown pubescence sexpunctatus

(Blumenau, Brazil)

Length 2 mm. ; shorter, sparse pubescence longicornis

(Blumenau, Brazil)
Group II
The second group contains but a single species, simoni (Reitter). In this
species, described from Sao Paulo, Brazil, at 3000 feet altitude, the length is
given at 3.0 millimeters and the pronotum is much more densely punctate than
the head or elytra. The acute temporal angle separates it from the rest of
the genus.

EUPLECTINI 77

Key to the Group III Species
Here belong six species, unusual for the length of the antennal segments.

Species known from south of 32 south latitude putzeysi

(Montevideo, Uruguay)
Species known from north of 22 south latitude 2

2. Third tergite with two short median spines near the apical margin,

the margin slightly depressed and emarginate between these pro-
jections laevis

(2.0 mm.; Bahia, Brazil)
Third tergite not so modified 3

3. Fourth tergite strongly, longitudinally carinate procerus

(3.0 mm.; 3000 ft.; Sao Paulo, Brazil)
Fourth tergite not so modified 4

4. Head relatively less transverse, one-third narrower than the pro-

notum megacephalus

(2.0 mm.; Matto Grosso, Brazil)
Head relatively very transverse, subequal to the pronotum in

width quadrifoveatus

(2.4 mm.; Brazil)
This key does not include majorinus (Schaufuss), of the Amazon river
system, Brazil.

Group IV
Key to Species of First Section

This key does not include two species, insignis (Schaufuss) and angustatus
(Schaufuss), of the first section.

Second antennal segment quadrate 3

Second antennal segment ovate 2

2. Antennal segments IX and X slightly larger than Ylll . sub acuminatus

(2.0 mm.; Blumenau, Brazil)
Antennal segments IX and X very abruptly larger than antennal

segment VIII ootopunctatus

(1.8 mm.; Blumenau, Brazil)

3. Elytra red, rest of body nigropiceus rubripennis

(2.2 mm. ; Argentina)
Coloration of body uniform rufous or ferrugineous 4

4. Head unusually small, distinctly more than one-fifth narrower than

the pronotal width reitteri

(1.9 mm. ; Blumenau, Brazil. Male with anterior femora briefly
bicarinate; dorsal stria evanescent before middle of elytra)
Head very transverse, not more than one-fifth narrower than the
pronotal width 5

5. Lateral pronotal margins with six teeth crassicornis

(1.95 mm.; San Esteban, Venezuela. Male with anterior
femora briefly carinate; dorsal stria wholly absent)

78 NEOTROPICAL PSELAPHIDAE

Lateral pronotal margins with five teeth ; first antennal segment three
times as long as second, or as long as III to VII inclusive, funicle
minute, moniliform, abruptly narrower than IX; IX and X three

times larger than VIII bicolor

(1.8 mm.; Alpine Bolivia)

The two species crassicornis Raffray and rubripennis Raffray are said to
closely resemble putzeysi (Schaufuss) of Uruguay, but differ from this species
in antennal structure, much thicker and shorter antennae, and much stronger
pronotal teeth.

Group IV

Second Section, new

This section of the genus has (a) each elytron with four basal foveae,
(b) lateral pronotal margins with six strong teeth, (c) rounded tempora, (d)
antennae with segments III to VI as long as wide and VII and VIII slightly
transverse. At the present time it includes one species:

Eurhexius zonalis new species

Male Holotype. Measurements in millimeters:

Head 0.24 (median) or 0.3 (through tempora) x 0.44 wide, through eyes;
cervicum 0.06 x 0.21; antennae 0.73 total; segment I 0.13, II 0.06, III to VIII
inclusive 0.24, club 0.28, XI only 0.13; pronotum 0.5 x 0.53, the spines from
0.03 to 0.01; elytra 0.5 (at suture) x 0.67; abdomen total 1.0, first tergite
0.3 X 0.77, second 0.2, third 0.2, fourth 0.16, fifth 0.13; sternites first 0.13,
second 0.2, third 0.13, fourth 0.11, fifth 0.03, sixth 0.16. Total length 2.31 x 0.77
greatest width. (PI. VIII.)

Reddish brown uniformly, integuments very shining; lightly but sub-
asperately and diffusely punctate with the following exceptions: the anterior
sixth of the pronotum and the basal marginal area are coarsely, deeply punctate
and the antennal prominence on each side of the head is very coarsely and
cribrately punctate while the cervicum is lightly alutaceous.

Head transverse, the eyes small but prominent and composed of about 28
small but prominent facets, the eyes not quite as long as tempora. Tempora
prominent and rounded. Vertexal foveae two, large, circular, nude, on a line
passing through the middle of eyes, widely separated, one being behind each
antennal prominence, connected by an entire, broadly arcuate sulcus. Occiput
medianly sulcate to just beyond vertexal foveae, with a short, conical, obtuse
but prominent spine on each side of this longitudinal sulcus at the occipital
margin of the head. Head dorso-ventrally flattened, the ventral surface very
broad, flat, glabrous, densely pubescent with long, non-capitate setae. These
setae are very long (0.13 to 0.18 mm.) in contrast to the body pubescence
(0.08 to 0.12 mm.). Medianly, the glabrous ventral surface has a very large
circular deep gular fovea at base, and a strong median carina from this fovea to

EUPLECTINI 79

mentum; laterally the ventral surface is sharply limited each side by a carina,
from eye to basal margin posteriorly and from eye to base of mandible
anteriorly. The cervicum is subcontinuous with the ventral surface of the
head, but dorsally is separated from head by an abrupt, deep, arcuate sulcus.

Maxillary palpi four-segmented, first segment short; second long, sinuate,
basally slender becoming strongly inflated apically ; third short, ovate-triangu-
lar, as wide as apex of second; fourth longer than second and wider than third,
fusiform, with mesial face inflated, and bearing a short palpal cone.

Antennae eleven-segmented, proportions as given above, I elongate-
cylindrical, II obconical. III to VIII submoniliform. III to VI with length and
width equal, VII and VIII slightly transverse, narrower than II; club (IX,
X, XI) large and conspicuous, IX trapezoidal, X transversely trapezoidal, XI
basally truncate, conical.

Pronotum (PI. VIII, 10) anteriorly narrowing and then suddenly obliquely
dilated to form a very short collar at the extreme anterior margin for the re-
ception of the broad cervicum; disc crossed by a deep, subentire, longitudinal
median sulcus and a deep, subentire transverse subbasal sulcus; a large
circular fovea athwart the transverse sulcus, on each side, about midway be-
tween margin and median pronotal point; sides each with six teeth, the first
basal, the second opposite the transverse sulcus, four more between transverse
sulcus and anterior fourth, decreasing in length and thickness from the third
spine on each side, sixth small, denticulate; basal margin thin, slightly raised,
with a median longitudinal carina for a short distance, this carina merging
with the longitudinal sulcus.

Each elytron with an entire sutural stria, the sutural angle being slightly
produced into an acute tooth; shorter along suture than along flank; base
with four large foveas, decreasing in diameter from sutural to lateral; two
vague, short dorsal depressions, not reaching middle of elytron; humeral angle
prominent, obliquely elevated but rounded, not dentate; a long carina parallel
to elytral margin, far down on the flank, but no subhumeral fovea.

Abdomen strongly margined, proportions of tergites and sternites as given
in measured lengths above. First tergite with a small but stout tubercle on
each side of the disc, well within the margin, near the base. First sternite
strongly produced and elevated between the posterior coxae, as a narrow,
elongate-triangular platform.

Prostemum flat, glabrous, separated from pronotum on each side by an
obtuse, arcuate carina; no median longitudinal carina; a pair of large, deep,
circular lateral prosternal foveae at base, between coxae. Mesosternum simple.
Metasternum medianly and weakly sulcate.

Anterior coxae long, conical, prominent, not contiguous; middle coxae
short, contiguous; posterior coxae short, massively conical, slightly separated.
Anterior femora strongly inflated, and with a high, thin, lamina-like carina
on the anterior- ventral face in the distal third; middle and posterior femora
not as strongly inflated. Tarsi three-segmented, with the first segment small
and other two tarsomeres much larger, the second being longer than the third.

80 NEOTROPICAL PSELAPHIDAE

Tarsal claws euplectine, very unequal; a very large, rapidly very acute primary
claw, and an accessory bristle-like claw one-sixth as thick and less than half
as long as primary claw.

Penis verj' large, bilaterally asymmetrical. Slide mount gives the length
as 0.126 mm., and 0.0504 mm. wide through the posterior muscular bulb.

Female Allotype: As for the holotype with the following exceptions:

Length 2.0 mm. x 0.85 mm. wide, that is shorter and broader. The eyes
are composed of 28 facets like the male, but the facets are very much smaller
so that the eyes are less prominent, and the tempora are twice the eye length.
Metasternum not medianly sulcate, but simply convex.

First sternite not elevated as a prominent triangular platform between
the posterior coxae. First, third, and fourth stemites equal in length, fifth
sternite one-third shorter than fourth, sixth sternite one-fourth longer than
fourth or twice as long as fifth; second sternite the longest, 0.16 mm., two-
fifths longer than first or third.

Tergites regularly decreasing in length, from first (0.26 mm.) to fifth
(0.1 mm.).

Described on four specimens, all collected by Dr. E. C. Williams, Jr.,
on Barro Colorado Island, Gatun Lake, Panama Canal Zone as follows:
Holotype male July 9, 1938 in floor mold sample No. 1342; Allotype female
July 29, 1938 in floor mold sample No. 345; Paratype male July 26, 1938 in
floor mold sample No. 285; Paratype male July 31, 1938 in floor mold sample
No. 1440.

It is notable that both male and female have the anterior femora carinate.
The less prominent eyes and evenly convex metasternum serve to quickly dif-
ferentiate the female. Eurhexius zonalis is quite distinct from all others of the
genus on the described anatomy. The antennal differences between the two
sections of the fourth group are not so important as might be imagined, but
serve to differentiate certain groups from each other; on the other hand the
many structural differences are notable.

Key to the Group V Species

These three species make a definite approach to Aporhexius, but the pro-
notal margins are not simply crenulate, but instead have very minute, discrete
blunted denticules evenly spaced on the lateral pronotal margins. They are
quickly separable from the first four groups of the genus on the same char-
acter. It is possible that this group also includes Rhexius rugulosus Reitter.

Size very large, in excess of four millimeters long; each lateral pronotal
margin with a minute tooth nearly opposite the transverse sulcus,
and five much smaller, blunted denticles evenly spaced between this
minute tooth and the apex; four elytral foveae arranged in two

basal pairs muticus

(Largest species of genus, 4.25 mm., and one of the
largest of the entire family; Bogota, Colombia)

EUPLECTINI 81

Size less than four millimeters in length; lateral pronotal margins with
minute blunted denticles of equal size and shape ; four basal elytral
foveae not in definite pairs 2

2. Antennae with segment III small, subobconic; IV to VIII transverse,

laterally crescentric; IX and X quadrate; XI subcylindrical, very

long cavifrons

(2.6 mm.; Sao Paulo, Brazil)
Antennae with segments III to VIII moniliform, equal, much smaller
than IX or X; IX and X abruptly larger, subquadrate; XI ovate. . 3

3. Metastemum medianly impressed; stemites with second medianly,

triangularly impressed; third stemite broadly transversely im-
pressed; fourth sternite deeply medianly exacavated, the excavation
with carinated lateral margins ; fifth triangularly elevated each side ;
sixth entirely concave and apically sinuate. .. .Male abdominalis

(3.7 mm.; Blumenau, Brazil)
Metasternum convex; sternites convex, with distal sternite apically

emarginate Female abdominalis

(2.9 mm.; Blumenau, Brazil. Note great size range!)
The excellent secondary sexual differences in abdominalis form a notable
exception for the genus.

One species of the genus, Eurhexius putzeysi has been taken with ants
(Bruch, 1929) in Argentina.

The species may be listed as follows:

I

longicornis Raffray. 1904. Brazil.

parviceps Sharp. 1887. Panama.

sexpunctatus Raffray. 1904. Brazil.

trimiodes Sharp. 1887. Guatemala, {nee trimioides)

ventralis Sharp. 1887. Panama.

vestitus Sharp. 1887. Panama. Genotype?

II

simoni (Reitter). 1882. Brazil. (Rhexius) {nee simonis)

III

laevis Raffray. 1904. Brazil.
majorinus (Schaufuss). 1872. Brazil?
megacephalus Raffray. 1904. Brazil.
proeerus (Reitter). 1882. Brazil. {Rhexius)

putzeysi (Schaufuss). 1879. Uruguay, (nee putzeisi, putzeitsi, etc.)
and Buenos Aires, Argentina con Solenopsis richteri

Forel (Bruch, 1929).
quadrifoveatus Raffray. 1904. Brazil.

82 NEOTROPICAL P3ELAPHIDAE

IV

angustatus (Schaufuss). 1882. French Guiana.

bicolor Raffray. 1904. Bolivia.

crassicornis Raffray. 1891. Venezuela.

insignis (Schaufuss). 1879. New Grenada (Colombia?) {semihyalinus

(Schaufuss), 1882).
octopunctatus Raffray. 1904. Brazil.
reitteri Raffray. 1904. Brazil.
rubripennis Raffray. 1908. Argentina.
subacuminatus Raffray. 1904. Brazil.
zonalis new species. Panama Canal Zone.

abdominalis Raffray. 1904. Brazil, (see also Raffray, 1911)
cavifrons Raffray. 1912. Brazil.

muticus (Raffray). 1883. Colombia, (see also Raffray, 1904)
This census does not list rugulosus of Reitter, vide supra.

RHEXIUS (LeConte, 1850)

LeConte (1850, 1878)
Sharp (1887)
Schaufuss (1872)
Brendel (1893)
Raffray (1903, 1908)
Casey (1908)
Bowman (1934)

This wholly American genus is better represented in North America (8
species) than in the neotropics (3 species), although the genotype insculptus
LeConte and a few other species have an essentially subtropical distribution.
Since all of the temperate species are distributed in the eastern part of the
United States, the distribution of the genus in the Americas follows the forested
areas, in a long curve from the drainage basin of the Amazon River, through
the Isthmus of Panama and into Louisiana, Mississippi, Missouri, Illinois,
Indiana, District of Columbia, Virginia, and Pennsylvania. The last complete
treatment of the North American forms was by Casey (1908, p. 278); the
neotropical forms have not been coordinated, and very probably will be found
to include many new species.

The neotropical species all have four basal foveae on each elytron, but
show considerable variation in the relative lengths of tergites, of the first
antennal segment, and the structure of the pronotum. It is notable that the
Panamanian optatus is very similar to the genotype insculptus in general
aspect, while the Amazonian species depart radically from the more northern
forms.

EUPLECTINI 83

All members of Rhexius have a common habitus (PI. VIII, 6-9) which af-
fects the antennae and articulation of the head to the pronotum. This is so
striking that once seen it is seldom forgotten. The eleven-segmented antennae
have the basal segment very elongate, varying from one-half of the total anten-
nal length to as long as segments II to VI inclusive. The antennae are typically
geniculate, the arc being between the first two segments.

The articulation of head and pronotum is especially diagnostic. The very
transverse head narrows abruptly to a small subcylindrical neck. This peduncle
is closely invested by the exceptionally small anterior lobe of the pronotum,
in the manner of a bearing, and the large posterior lobe of the pronotum seems
to constitute the pronotum as a whole, the anterior lobe appearing as a part
of the head. Sharp (1887, pp. 40-41) describes the condition succinctly, "the
structure of the prothorax is most remarkable, its anterior part being con-
stricted so as to form a short tube in which the head is inserted by a very
short neck; this thoracic tube has the appearance of being only a development,
rather greater than usual, of the neck of the head. . . ."

Six stemites in both sexes. The sixth stemite is usually medianly prominent
and sinuate in the male; rounded in the female. The males usually have the
anterior femora carinated on the internal face. Tarsi with two very unequal
claws, of which the first is very large, arcuate and acute, and the accessory
claw very thin, and not more than half as long.

Key to the Species

Antennae with first segment as long as II to X inclusive umied. elegans
(1.4 mm.; Sao Paulo, Brazil. Male metas-
ternum with a minute median impression)

Antennae with first segment not this long 2

2. First visible tergite very long, longer than second and third tergites

united brasiliensis

(Amazon basin, Brazil)
First visible tergite relatively short, about as long as the second

tergite optatus

(1.5 mm.; 4000-6000 ft., Volcan de Chiriqui, Panama)
The species of Rhexius inhabiting the neotropics are:

brasiliensis Schaufuss. 1872. Brazil.
elegans Raffray. 1909. Brazil.
optatus Sharp. 1887. Panama.

MITRACEPHALA (Raffray, 1890)

Raffray (1890, 1904)

This and the next genus are so specialized that they show little close af-
finity with others of the tribe. The present genus, founded on a single peculiar
species, may be generally described as follows:

84 NEOTROPICAL PSELAPHIDAE

The head is almost semicircular from a dorsal point of view, with an
almost straight occiput, and a semicircularly produced front, the surface of
the head being medianly, broadly concave. Although the eyes are large, they
are wholly invisible from above, as a consequence of the expanded top of the
head. The extended front covers the mouth-parts, labrum, and base of antennae.
The antennae are inserted on the antero-lateral sides of the front, beneath the
expanded dorsal wall, instead of at the extreme end of an elongate rostrum
as in Rhinoscepsis, and these organs are relatively short, and the segments
progressively thicker apically, so that the club is not apparent, although the
distal segment is large, about three times the length of the tenth segment.

Pronotum transverse, wider than head, with a strong bisinuate transverse
sulcus and a less developed longitudinal median sulcus.

Elytra with three basal foveae on each elytron.

Abdomen elongate-cylindrical, weakly margined; five tergites and six
sternites. Tarsi with two very unequal claws.

Raffray (1908, p. 128) thinks that the species may be an inhabitant of
the nests of social insects, either ants or termites.

longipennis Raffray. 1890. Brazil. Genotype.

PHTEGNOMUS (Raffray, 1890)
Raffray (1890, 1904)

This genus is also remarkable for the development of the head ; in fact it
may represent several genera and many undescribed species when it is more
fully understood. It is notable in that it is one of the very few genera of
pselaphids which are exclusively found in the nests of termites.

Head always greatly dilated laterally, but not obscuring the eyes from a
dorsal viewpoint, and the front is always expanded to cover the mouthparts;
the eleven-segmented antennae are inserted under the sides of the front, and
not at the end of the expanded portion ; these organs have a conspicuous three-
segmented club. Vertex excavated. Eyes placed near the posterior margin of
the head.

The front is variously formed; it may be expanded as an elongate tubercle,
with parallel sides and a truncate apex (naso) , or as a long median spur.

Pronotum not greatly wider than head, transversely ovate, with the longi-
tudinal and transverse sulci more or less vestigial.

Elytra with the base transversely carinated, and each elytron with two
foveoid depressions.

Abdomen with a wide, strong margin; five visible tergites, with the first
tergite hidden beneath the elytral apices as usual, but appearing laterally, so
that six tergites may be counted; six sternites.

inermis Wasmann. 1894. Venezuela, {con Eutermes meinerti Wasmann)
naso Wasmann. 1894. Venezuela, {con Eutermes meinerti Wasmann)
oberthuri Raffray. 1890. Brazil. Genotype.

EUPLECTINI 85

RHINOSCEPSIS (LeConte, 1878)

LeConte (1878)
ScHAUFuss (1888) (Rhinosceptis)
Raffray (1898) (Rhynoscepsis)
Raffray (1904, 1908) (Rhinoscepsis)
Bowman (1934)

As in the case of Rhexius, this is a genus of pselaphids which is found in
the subtropics of North America through the region of Florida, and again in
the Amazon basin and as far south as Argentina. Its dispersal is more discon-
tinuous, however, since no species is known from the whole of Central America.

The genus is primitive in its structure, but has several highly specialized
characters, as has already been noted (PI. IX and X). The genotype {bistriatus
LeConte) appears to be relatively abundant in the St^inhatchee river drainage
of Florida, and differs in many particulars from the South American congeners.
This species has been discussed, and its gross anatomy figured so that other
species of the genus can be contrasted with it.

All Rhinoscepsis have the head attenuated anteriorly to form a long rostrum
or antennal tubercle, with the antennae inserted subcontiguously at the apex of
this extension; again the vertex, sides of the head, and genae are usually crossed
by tortuous lateral sulci, as noted in the key to the tribe. The eyes are generally
small, almost rudimentary, in both sexes. The eleven-segmented antennae have
a moderately developed club, the distal segments of which are provided with
antennal cones.

The cordiform pronotum usually has four foveae at basal margin, two
large foveae or foveoid depressions connected by a transverse sulcus, and a
longitudinal median sulcus more or less entire. Prosternum is not medianly
carinate. Sternal foveae are well developed, usually including lateral pro-
sternals, and meso-metasternal foveae II, III, IV, and V on each side.

Each elytron has two basal foveae, entire sutural stria, subhumeral fovea ;
subepipleural carina and sulcus more or less developed. There may be a rudi-
mentary third basal fovea present. The dorsal stria is variable in extent. The
humeri are prominent, usually subdentate.

Abdomen large and well developed. Six tergites visible, and both sexes have
seven stemites. The male has the seventh sternite primitive, divided into a right
and left pygidial plate, so that when these plates are appressed, their mesial
margins form a straight or arcuate "pygidial carina", as in Euplectus and
Acolonia, etc. The penis is large and bilaterally symmetrical in the genotype.
The female has the seventh sternite transversely triangular and small, or ovate-
rhomboidal with two converging carinae. Some females, at least, have the third
tergite prominently spined at apical margin.

Prothoracic coxae primitive, elongate-conical and prominent; mesothoracic
and metathoracic coxae shorter, the former contiguous and the latter contiguous
or virtually so.

Tarsi primitive for the euplectines, with a well-developed secondary tarsal
claw.

86 NEOTROPICAL PSELAPHIDAE

I have had to modify Raffray's early key to the genus (1898) in order to
incorporate recently discovered species:

Pronotum nearly as long as wide 2

Pronotum transverse, at least one-fourth wider than long (PI. XVIII,
2) 3

2. Median longitudinal pronotal sulcus obsolete on disc; lateral pronotal

foveae not, or very slightly, incising lateral pronotal margins; 1.6

mm. long gracilis

Median longitudinal pronotal sulcus deep and entire ; lateral pronotal
foveae deeply incising lateral pronotal margins . . dybasi new species

3. Longitudinal, median pronotal sulcus very obsolete on the disc, form-

ing a deep anterior and a deep posterior sulciform fossa. . .militaris

(1.1 mm.; "Amazones", Brazil; antennae short, thick, with

fifth segment larger than either the fourth or sixth segments)

Longitudinal, median pronotal sulcus deep and entire for the whole

of its length (PI. XVIII, 2) 4

4. Fifth antennal segment subequal in size to fourth and sixth segments 5
Fifth antennal segment one-half wider, and slightly longer than either

fourth or sixth antennal segments ; third tergite with a very long and
prominent spine directed posteriorly from the median third of apical
margin falli new species

5. Lateral pronotal margins incised or notched each side opposite the

lateral pronotal fovea pubescens

(1.2-1.3 mm.; "Amazones", Brazil)
Lateral pronotal margins not incised each side opposite the lateral

pronotal fovea richteri

(1.5 mm.; Argentina)

Rhinoscepsis falli new species

Measurements: Head 0.27 x 0.27; antennae 0.47 total length, first segment
0.08, second segment 0.04, third to ninth united 0.16, tenth segment 0.04 x 0.05,
eleventh segment 0.13 x 0.07; pronotum 0.23 x 0.3; elytra 0.36 x 0.45; abdomen
0.45 including spine x 0.43 through second tergite; first tergite 0.13, second 0.13,
third 0.12 to base of spine, spine on third tergite 0.1 ; fourth 0.03, fifth 0.1. Total
length 1.4 x 0.45 mm. (PI. XVIII).

Dark yellowish-brown with paler legs and maxillary palpi; integument
moderately shining; pubescence very short (0.02 to 0.03 mm. long), sparse, pale.

Head with rounded temporal angles; the tempora nearly straight, longer
than the eyes. Eyes small, composed of 24 small facets, set obliquely on the
sloping anterior half of the head. Sides converging arcuately to form the long
antennal rostrum; distal end of this rostrum spherically expanded, bearing
apically the subcontiguously articulated antennae. Occiput medianly, longi-
tudinally carinate from base to the spherically enlarged end of rostrum. Vertex
and front granulate, two vertexal foveae on a line passing through the posterior

EUPLECTINI 87

margin of the eyes. Basal half of head with a sinuate sulcus on each side; this
sulcus arising on the occipital margin, extends obliquely mesiad to a point be-
hind the vertexal fovea, then turns sharply across the head behind the eye, to
the ventral surface of the head, where it expands abruptly into a deep ovate
fossa, half as large as eye and enclosing some of the ventral facets. Ventral
surface of head tumid between fossae, with a median basal gular fovea.

Labial palpi relatively long, two-segmented. Mentum longer than wide.
Cardo of maxilla prominently exposed. Maxillary palpi four-segmented, first
segment relatively large, that is, distinctly wider than base of second; second
segment about three times as long as first, slender basally and arcuate to in-
flated apex ; third short, ovate-triangular, wider than second ; fourth longer than
second and wider than third, fusiform, with a very small palpal cone at apex.
Mandibles long, arcuate and well developed, twice as long as the simple labrum.
Labrum hidden dorsally by antennal rostrum, but mandibles clearly visible.

Antennae long, about one-third of body length, eleven-segmented. Segment
I cylindrical, twice as long as II; II ovate; III to IX submoniliform; III,
IV, VI equal in length and width ; V half wider and slightly longer than either
IV or VI ; VII and VIII slightly larger than V, transversely moniliform ; IX
spherical, not as wide as VIII ; X transverse, drum-shaped ; XI ovate-acuminate.

Pronotum widest anterior of middle, apical margin nearly straight, the sides
curving evenly each side to an incised notch opposite to and in part containing
a large lateral fovea, the sides then abruptly expanding to an acute tooth, then
narrowing obliquely to basal margin. Base with four foveae; disc crossed by a
deep, entire median, longitudinal sulcus extending from base to apical seventh,
and a transverse submedian sulcus, equally deep, connecting the lateral foveae;
a median foveoid depression formed where these two sulci cross each other.

Elytra shorter than abdomen. Each elytron with two basal foveae, a sutural
at base of an entire sutural stria, and a discal at base of a deep dorsal stria
which extends to basal third of disc. Humeral angle prominent, with a sub-
humeral fovea on the elytral flank, recessed beneath a carina which extends
longitudinally parallel to margin, and turns mesiad at base just behind humerus.

Abdomen with five visible tergites, but only three are visible from a dorsal
view. Proportions as given above. Third tergite is notable, bearing a long,
basally broad, apically acute spine from the middle of the apical margin. From
a dorsal view the abdomen ends with this spine, giving a highly unique outline.
Fourth tergite very short, set obliquely under the end of the third, and invisible
from above. Fifth tergite wholly ventral in position, and invisible from above.
Stemites seven: first small, hidden largely by posterior coxae save for a de-
pressed triangle between them; second longest; third, fourth and fifth progres-
sively shorter; sixth semicircular, enclosed by the fifth, as long as third; seventh
sternite very small, transversely triangular, not carinated, and enclosed between
the sixth sternite and fifth tergite. All sternites convex and simple.

Prostemum not medianly carinate; granulated; lateral prosternal foveae
present. Anterior coxae long, conical. Middle coxae contiguous. Metasternum
long, longer than second and third sternites combined, with a deep median

88 NEOTROPICAL P3ELAPHIDAE

sulcus ; lateral mesocoxal foveae obvious ; metasternal foveae fused and median.
Posterior coxae shortly conical, subcontiguous.

Anterior femora and tibiae inflated ; anterior tibiae basally sinuate, with a
minutely serrated carina along the ventro-anterior face in basal half.

Tarsi three-segmented; first tarsomere small, second and third much larger;
second longest and much thicker than third, this thickness being due to the
dorso-ventral width, the segment being laterally compressed; third slightly
arcuate and thick; tarsal claws primitive, very unequal, with a large, thick,
arcuate, pointed primary claw and a very thin secondary claw which is half
as long as the first.

Described on a single female specimen, from Matto Grosso, near Corumba,
in Brazil. I dedicate this striking species to a lamented friend of long standing,
Mr. H. C. Fall.^

Rhinos cepsis dybasi new species

Type Male: Measurements: head 0.27 x 0.23 mm.; pronotum 0.25 x 0.28
mm.; elytra 0.30 x 0.40 mm.; abdomen 0.50 x 0.40; antennae 0.43 mm. long;
total length 1.3 mm.; greatest width 0.4 mm.

Yellowish brown, subopaque with flavous, abundant, short pubescence; the
distal segment of maxillary palpi swollen and light yellow.

Head with prominent, rounded tempora which are slightly convergent an-
teriorly, three times longer than the eyes, and slightly longer than wide; eyes
hardly visible from above, rudimentary, composed of 8 facets lying within the
cephalic sulcus. Apical end of rostrum transversely ovate. Cephalic sulcus hold-
ing the eye and the ovate genal fossa relatively larger, being more than twice
as large as eye. Head otherwise as in falli.

Maxillary palpi four-segmented, as in falli save for distal segment. This
latter segment tumid, yellow, ovate with rounded base and subacute apex, ven-
tral face flattened; veiy large for the genus, being slightly more than three times
as wide as third, and nearly four times as long. (In the male bistriatus of the
United States the fourth segment is about twice as wide as third, and in falli
the fourth is twice as wide as third.)

Antennae long, slightly more than one third the body length, eleven-seg-
mented ; segment I subconical with the ventral face strongly produced at base,
twice as long as second (this is very distinctive when contrasted with the cyl-
indrical flrst antennomere of males of bistriatus and falli); II ovate; III-VI
moniliform; VII-VIII transversely moniliform, longer and wider than eighth;
X transverse, drum-shaped ; XI ovate-acuminate.

'I owe much to Mr. Fall, who encouraged my work on Pselaphidae through examina-
tion of specimens and long, instructive letters. My earliest taxonomic attempt was on two
different families of Coleoptera, including a new genus of Cryptophagidae {Glyptophonis
mycetoecus Park, 1929). Mr. Fall subsequently examined the types, pronounced the species
valid, and found an undescribed specimen in his own collection which belonged to mycetoe-
cits. Such aid to a young taxonomist, and long correspondence concerning Rybaxis and other
pselaphids, were very stimulating, and I take this opportunity to express my gratitude.

EUPLECTINI 89

Pronotum as in falli with deep entire longitudinal and transverse sulci and
deeply incised lateral margins.

Elytra as in falli save that dorsal stria is subentire, extending to apical
ninth.

Abdomen with five visible tergites, first four subequally long, the fifth
shorter with broadly rounded apex; tergites simple; margins strong.

Seven stemites, the first four subequal in length, evenly and minutely gran-
ulate; fifth half as long as fourth, medianly and transversely tumid with tumid
region glabrous; sixth semicircular, enclosed by fifth, as long as fourth and
transversely foveate for apical third, with basal margin of foveation elevated
and densely pubescent, these setae recurved toward base of segment ; seventh
enclosed by sixth, obliquely divided into a right and left triangular plate.

Middle coxae contiguous; metasternum relatively short, as long as fourth
and fifth stemites united, not sulcate but medianly depressed at apex; posterior
coxae approximate. Femora simple; tibiae thick, especially the anterior pair
which are medianly inflated, very slightly contorted near base and excavated
apically ; tarsi as in falli.

Described on one male collected by Mr. Dybas, for whom this important
addition is named, on July 13, 1941, at San Juan, Vera Cruz, Mexico. The im-
portance of dybasi is zoogeographic. In structure dybasi shows definite affinities
with the genotype bistriatus of the southern United States, as well as the South
American species; it serv^es to bridge the gap which existed, no members of the
genus having been reported previously between Brazil and the United States.
Species are to be expected from Central America if northward spread from a
postulated Brazilian center is tenable.

The species of Rhinoscepsis are as follows:

falli new species. Brazil.

gracilis (Schaufuss). 1872. Brazil. (Panaphantus)

militaris (Schaufuss). 1872. Brazil. [Panaphantus)

pubescens (Raffray). 1898. Brazil. (Rhynoscepsis)

richteri (Raffray). 1908. Argentina. (Rhynoscepsis)

dybasi new species. Vera Cruz, Mexico.

THESIUM (Casey, 1884)

Casey (1884, 1893, 1908)

Sharp (1887) (Apothinus)

Brendel and Wickham (1890)

Raffray (1898, 1903, 1908) (Apothinus)

Leng (1920)

Bowman (1934) (Thesium cavifrons (LeConte) genotype, p. 144)

Of the nine known species of this genus, two are found north of the Rio
Grande river (including the genotype), one from Brazil, and six from what
appears to be the center of distribution. Central America. The genus, then, is
wholly American and extends from the Amazon basin through the Isthmus of

90 NEOTROPICAL PSELAPHIDAE

Panama, Guatemala, Mexico, and up the Mississippi and Ohio river valleys.

This genus is very well-marked. The eyes are well-formed, large and with
coarse facets as a rule. The eleven-segmented antennae have a large two to
three-segmented club, of which the distal segment is characteristic. This
eleventh segment is formed in two portions, as in Eutyphlus, but not so sharply
differentiated as the latter. The basal piece is large, more or less cylindrical,
but the apical piece is pyramidal or conical and much smaller, being set within
the circular distal face of the basal piece. The ninth and tenth obviously and
increasingly transverse, the eleventh much longer than wide, longer than ninth
and tenth combined, not much wider than tenth segment. Vertexal foveae large
and pubescent. Pronotum with lateral margins crenulated ; disc with a median,
longitudinal ovate puncture of varying proportions and size among the species;
base with a large pubescent lateral fovea each side, connected more or less
indefinitely with a median, nude impression by a transverse sulcus; basal margin
with a brief, longitudinal carina which does not reach the median impression.
The elytra have three basal pubescent foveae each, a sutural, median, and
lateral. The sutural and median foveae of each elytron are characteristically
enclosed by the strong sutural stria which passes anteriorly, parallel with the
mesial elytral margin, to a point anteriad of the sutural fovea, where it curves
laterally to pass above and over the anterior margins of the sutural and median
fovea, enclosing them, and then curving posteriorly, sharply, just lateral of the
median fovea, and ending before the middle of the elytra. The lateral basal
fovea is by itself and also more or less enclosed in a discal stria which ends
posteriorly before the middle of the elytron. In addition, the humeri are well
marked, set off by an oblique humeral line, and below this, on the subhumeral
flank, is a large pubescent subhumeral fovea and long stria which extend pos-
teriorly nearly to the apex of the flank. The prosternum is longitudinally and
medianly carinate. The abdomen has no apparent basal carinae, and is sexually
differentiated: males with seven sternites, the seventh being a circular, simple,
one-piece, asymmetrically articulated pygidium ; females with six sternites. The
metathoracic coxae are broadly subconical, and consequently the first sternite
is seen between them medianly as a triangular field, and laterally well shown
where the coxae narrow markedly near the elytral flanks.

Key to the Species
Vertex with three foveae across middle, between the eyes; size rela-
tively large, nearly two millimeters long impressifrons

(1.85 mm.; 4000-5000 ft., Cerro Zunil, Guatemala)
Vertex with two foveae on the middle of the vertex, between the eyes ;
size smaller, not longer than one and one-third millimeters 2

2. Head relatively large, as wide through the eyes as the pronotum .... 3
Head relatively small, including the eyes, distinctly narrower than the

pronotum; pronotum very transverse, about one-third wider than
long 5

3. Eighth antennal segment strongly transverse, almost as wide as ninth

antennal segment 4

EUPLECTINI 91

Eighth antennal segment not transverse, not wider than seventh, and

distinctly narrower than ninth segment sharpi

(1.1-1.2 mm.; Mexico)

4. Pronotum regularly suboval insignis

(1.1 mm.; Blumenau, Brazil)
Pronotum strongly cordiform, with the lateral margins angulated and

subincised anterior to middle clavatus

(1.3 mm.; Mexico)

5. Disc of pronotum with a small subapical fovea brevicollis

(1.1 mm.; Mexico)
Disc of pronotum with an elongate sulcoid or fusiform foveoid de-
pression 6

6. Depression on pronotal disc in the form of a deep, sulcoid, medianly

longitudinal depression, with the apical end of this depression
broadest and rounded; tempora long, longer than the eyes in both

sexes, the eyes relatively small obscurus

(1.25 mm.; San Geronimo and Capetillo, Guatemala)
Depression on pronotal disc in the form of an elongate, fusiform de-
pression, median, and with both ends tapered; tempora short, only
half as long as the eyes in the male (female unknown) , the eyes rela-
tively very large, two-fifths the length of the head

barrocoloradoensis new species

Thesiuni barrocoloradoensis new species

Measurements: Head 0.2 x 0.25 mm.; pronotum 0.2 x 0.3 mm.; elytra 0.36
X 0.4 mm. ; abdomen 0.5 x 0.4 mm. ; penis 0.18 x 0.1 mm. ; metastemum 0.2 mm. ;
antennae 0.4 mm. Total length 1.26 x greatest width 0.4 mm.

Yellowish-brown, with long sparse pubescence; head and pronotum asper-
ate, the asperities each bearing a seta.

Head trapezoidal, occiput with a short, median, longitudinal carina which
does not end on the vertex in a fovea; two vertexal foveae placed on a line
passing through the middle of the eyes, their orifices slightly anteriorly directed,
and with the floor of each fovea attached to an arm of the supratentorium.
Supratentorium massive. Eyes large, two-fifths as long as head. Tempora very
short, half as long as the eye. Front broad, with a short, blunt, median tubercle
at the beginning of the declivity, between the antennae. Ventral surface with a
small gular fovea, the floor of which is attached to the supratentorium.

Antennae eleven-segmented, rather widely separated, segment I a little
longer and half wider than second, oblong-obconic; H ovate; III obconic, half
the width of second; IV transverse, submoniliform, as wide as third but shorter;
V-VII slightly wider than fourth, about as long, transversely submoniliform;
VIII asymmetrically transverse, as wide and as long as seventh ; IX distinctly
wider and longer than eighth, transversely trapezoidal; X gradually wider than
ninth, longer, transversely trapezoidal; XI as wide as tenth, in two portions, a
basal cylindrical portion almost twice as long as the tenth segment, and a much

92 NEOTROPICAL PSELAPHIDAE

narrower pyramidal apical portion, about one-fourth as long as basal piece.

Maxillary palpi four-segmented, first segment short, thick, one-third as
long as second, and articulating obliquely with second; second segment short,
subconical with the basal width narrower than first segment; third segment
slightly wider than the inflated apical end of the second, and half as long as
second, subspherical ; fourth three and a half times longer than third and twice
as wide, ovate, with a truncate apex bearing a very long, blunt palpal cone.

Pronotum with simple apical and basal margins, the surface asperate-
tuberculate, especially the lateral margins which are strongly crenulate ; broad-
est at middle ; a short median carina extends from the basal margin to a large
subbasal, transversely fusiform fossa; three minute foveae on each side of the
basal carina, at basal margin; a deep lateral fovea on each side of this median
depression, the three connected by a transverse subbasal sulcus; anterior half
of disc with a median, longitudinal, fusiform foveoid depression.

Scutellum elongate-triangular, small.

Elytra lightly punctate; each elytron with prominent, oblique, subdentate
humeral angle, three basal foveae arranged in the typical form for the genus, as
noted previously; subhumeral fovea recessed beneath the humerus, and asso-
ciated with a long subepipleural sulcus on the flank.

Abdomen with six tergites visible, first very short and exposed at base of
elytra, one-fourth as long as second (normal first visible tergite for pselaphids) ;
second one-third longer than third; third and fourth and fifth subequal in
length; sixth very short, as long as first, and transversely triangular. Second
tergite with a transverse depression in basal half, and half the segmental width.
Seven sternites, of which the first is triangular between the coxae; second
longest, with a short, deep and wide depression in basal third; third sternite
one-third shorter than second; fourth slightly shorter than third; fifth medianly
short, one-half as long as fourth, the apical margin broadly concave; sixth with
basal margin broadly convex, fitting the fifth, but with apical margin medianly
deeply incised to contain the small, circular seventh; seventh sternite articulat-
ing with the abdomen on its right side, and swinging to the right to permit
extrusion of the penis, measurements of which have been given.

Prosternum with anterior margin strongly dentate, and with a strong
median, longitudinal carina from coxal cavity to apical margin, entire; lateral
prosternal foveae well formed.

Mesosternum with a median, longitudinal carina; prepectoid alutaceous.

Metastemum very long and broad. Sternal foveae of the raeso- and meta-
sternal fields well developed and all paired to give a high (primitive) number,
foveae II, III, IV and VI typical, and in addition a pair of foveae rarely found
(Posterior Mesosternal Foveae) which penetrate between the posterior-lateral
angle of the mesosternum and the mesocoxal cavity on each side. Thus barro-
coloradoensis has two prosternal, and ten meso-metasternal foveae.

Middle coxae distinctly separated by the union of a truncate process from
the mesosternum and metastemum. Posterior coxae very short, triangularly con-
ical, almost contiguous. Femora only moderately inflated. Tarsi relatively short

EUPLECTINI 93

and thick, with a first segment two-fifths as long as second; second inflated; a
single very long, arcuate claw.

Described on a single male, the type. Collected by the author on July 27,
1936, on Barro Colorado Island, Gatun Lake, Panama Canal Zone, from beneath
the bark of a log at Zetek 23. The type is a slide mount.

The genus may be listed as follows:

barrocoloradoensis new species. Panama Canal Zone.
brevicollis (Raffray). 1898. Mexico. {Apothinus)
clavatus (Raffray). 1898. Mexico. (Apothinus)
impressifrons (SharjD). 1887. Guatemala. {Apothinus)
insignis (Raffray). 1898. Brazil. (Apothimis)
ohscurus (Sharp). 1887. Guatemala. {Apothinus)
sharpi (Raffray). 1898. Mexico. (Apothinus)

BIBLOMIMUS (Raffray, 1903)

Raffray (1903) {Bihlomimus)
Raffray (1908a, b) [Ramecia)

Raffray erected this genus (p. 545, 1903) on a single species, minutus;
later he described a second species, impressa (1908a, p. 36), and placed both of
these in the North American genus Ramecia (Casey, 1893, p. 450). This sy-
nonymy was followed in the Genera Insectorum (1908b, p. 101). After giving
the matter some study, I feel that the two species of Raffray do not belong in
Ramecia, and reinstate Bihlomimus for them.

These two genera, Bihlomimus and Ramecia, are structurally similar save
that the former has the prosternum with a median, longitudinal carina, whereas
the latter has the prosternum simple and not carinate. The presence or absence
of the median prosternal carina is considered too fundamental to allow such an
association. Possibly Bihlomimus should be placed as a neotropical subgenus
of Ramecia, but generic isolation is considered preferable at this time. Both
genera are believed to be more primitive than their relative positions given by
Raffray (1908), and Casey (1893, p. 450-453 and 1897, p. 552) has discussed
the affinity of his genus with the trichonychide genera.

The species of Bihlomimus may be separated as follows:

Tenth antennal segment strongly transverse, twice as wide as the ninth

segment; head and pronotum about equally wide minutus

(1.0 mm.; female sex known only)
Tenth antennal segment twice as long as ninth segment, but not appre-
ciably wider; head narrower than pronotum 2

2. Six sternites present; sternites second to fifth subequal in length; sixth

sternite large, triangular impressa Female

(1.1 mm.)

Seven sternites present; sternites second to fourth progressively

shorter; fifth minute; sixth much larger, arcuate, deeply emarginate;

seventh large, briefly ovate impressa Male

94 NEOTROPICAL PSELAPHIDAE

Two species known:

impressa (Raffray). 1908. Guadeloupe, Leeward Islands. (Ramecia)
minutus Raffray. 1903. St. Vincent, Windward Islands. Genotype.

It will be noted that Biblomimus is restricted so far to the Lesser Antilles,
no species having been recorded from North, Central or South America; on the
other hand, Ramecia is unknown from Central or South America. This wide
geographic separation is additional evidence that the two genera are not
identical.

PANARAMECIA new genus

Euplectini having (1) vertex trifoveate; (2) eleven-segmented antennae
which are widely separated, and with a three-segmented club; (3) maxillary
palpi four-segmented, first minute, second long and apically inflated, third sub-
triangular, fourth wider than third and longer than second, bearing apically a
small palpal cone; (4) pronotum cordifonn, disc simple and unmodified, lateral
margins each with a small subbasal tooth and crenulate anterior to tooth, a
median fovea connected each side with a smaller lateral fovea by a biarcuate
transverse subbasal sulcus; (5) elytra with a transverse multiarcuate basal
carina, each arc sheltering a small vestigial basal fovea, the foveae usually
three with a vestigial fourth sometimes present, no subhumeral fovea but a well
developed longitudinal carina on elytral flank ; no dorsal stria or dorsal depres-
sion; (6) five visible tergites in both sexes, first four subequal; (7) six visible
sternites in both sexes, second, third and fourth subequal; (8) middle coxae
contiguous; (9) tarsi with a large primary claw and a very thin accessory claw
which is half as long as large claw and difficult to see on dry mounts, but readily
seen on cleared slide mounts; (10) prosternum simple, with no median, longi-
tudinal carina.

Genotype: Panaramecia williamsi new species.

Panaramecia williamsi new species

Male Holotype. Measurements: head 0.22 x 0.29 mm.; antennae 0.38 mm.;
pronotum 0.24 x 0.3 mm. ; elytra 0.33 x 0.45 mm. ; abdomen 0.5 x 0.4 mm. ; total
length 1.29 mm.; greatest width 0.45 mm. (PI. XV)

Reddish-brown, integument moderately shining; pubescence opaque, dense,
conspicuous (average length of body setae 0.03 to 0.05 mm.), and in addition
about twenty-five very much longer setae dispersed on the tergites, these setae
from 0.1 to 0.15 mm. long.

Head with tempora straight, and temporal angles broadly rounded, the
tempora longer than the eyes. Eyes relatively small, composed of about 26 to 28
very minute facets. Head dorso-ventrally flattened, the vertex only slightly
convex, the sides above the eyes carinated each side from the antennal insertion
to a point opposite the posterior eye margin. Occiput medianly with a very

EUPLECTINI 95

strong longitudinal carina which arises on the cervicum, crosses occiput and
ends just posterior, and between the vertexal foveae, this median carina ending
in a median vertexal foveae. Vertex, therefore, trifoveate including the paired
vertexal foveae which are on a line passing through middle of eyes. A long,
slightly oblique sulcus arises at each vertexal fovea and ends just mesiad of
each antennal insertion, not actually joining its fellow, but seeming to, as a
consequence of the raised frontal margin between antennae. Head between
lateral carina and sulcus moderately flat, slightly raised and slightly granu-
lated ; head between sulci slightly depressed and less punctate, not granulated.
Ventral surface of head coarsely, sparsely punctate, with a median basal gular
fovea; pubescence short, not capitate but is finely pointed and subprostrate ;
laterally carinated each side from base of mandible to posterior eye margin.

Maxillary palpi four-segmented, first minute; second four times as long as
first, equal to first in width at base, and inflated to width of third apically;
third short, subtriangular; fourth widest and longest, obliquely truncate at base,
subacute at apex, bearing a small palpal cone.

Antennae eleven-segmented, widely separated at bases, segments I and II
subequal in length, subquadrate, second narrower than first; III to VII narrower
than second, subequal in length and width; III obconic; IV, V, VI, VII, and
VIII submoniliform ; club gradual, of IX, X, and XI, these segments progres-
sively wider than eighth; IX and X transversely trapezoidal; X shorter but
much wider than second; XI as long as from eighth to tenth united, but not
forming the entire club.

Pronotum with a large, transversely expanded median foveoid depression
between disc and basal margin, and a smaller lateral fovea each side slightly
more anterior and well within margin, these three foveae connected by a weakly
developed biarcuate transverse subbasal sulcus. Disc not medianly foveate or
modified. Lateral margins narrowing obliquely to apex, and more sinuately to
base, lateral margin with a short acute tooth opposite each lateral fovea, and
anterior to this tooth the margin is very finely and irregularly crenulated.

Elytra with each elytron having a subbasal, transverse carina, this carina
being medianly briefly interrupted, the mesial half biarcuate and the lateral
half uniarcuate, so that the carina is triarcuate as a whole. Within each arc is
a shallow, rudimentary fovea, that is, a sutural, a discal, and a lateral fovea.
The lateral fovea under high magnification is seen to be in reality two vestigial
foveae, but this is difficult to discern. Flank with a strong longitudinal carina
which parallels the margin for apical three-fourths then turns mesiad abruptly
to end behind the humeral angle. No trace of a subhumeral fovea. Humeri
oblique and moderately prominent but not dentate. No dorsal stria of any kind.

Abdomen distinctly margined. Five visible tergites, first four are subequal
and very gradually and progressively shorter; fifth very small and triangular.
Six visible stemites, first triangular between coxae, slightly longer than coxae
or subequal in length; second one-fourth than first medianly; third slightly
shorter than second ; fourth slightly shorter than third ; fifth medianly half as
long as fourth, posterior margin concave to enclose sixth ; sixth transversely fusi-

96 NEOTROPICAL PSELAPHIDAE

form, as long as second, slightly impressed medianly and the posterior margin
nearly straight; all sternites little modified. Abdomen from a lateral view
ventrally concave in the antero-posterior axis.

Prosternum simple, with no longitudinal median carina. Metasternura long,
longer than second and third sternites united, with the basal half medianly
slightly sulcate. Middle coxae contiguous. Posterior coxae obliquely conical,
very short, and just perceptibly separated by the metasternum.

Femora slightly, equally inflated. Middle trochanters with the ventral face
shortly produced into a thin subcarinated crest. Middle tibiae with a prominent
rounded tubercle or uncus on the internal face at apical three- fourths. Tarsi
with two unequal claws, the first claw large and prominent, the second claw
half as long as first but very much thinner and not discernible at low magnifi-
cations since it is closely appressed to the first, the tarsi appearing to be single-
clawed.

Female Allotype. As in the male holotype, save that (a) the abdomen when
seen from a lateral view is not ventrally concave, but straight in the antero-
posterior axis, (b) sixth sternite strongly bisinuate at the posterior margin, the
median third extending as a short rounded lobe, (c) middle trochanters normally
rounded on ventral face, (d) middle tibiae normal, without prominent uncus
of male.

Described on six specimens all collected by Dr. E. C. Williams, Jr., on
Barro Colorado Island, Gatun Lake, Panama Canal Zone, as follows: Holotype
male, Paratype male and two Paratype females on July 25, 1938, from floor-
mold sample No. 164; Allotype female and Paratype male on July 25, 1938,
from floor-mold sample No. 134.

I am pleased to name this isolated species for my friend, Dr. Williams,
who spent a summer with me at the Institute for Research in Tropical America
at Barro Colorado Island. The series of specimens shows some variation in sev-
eral structural features: the median vertexal fovea varies in the paratypes
from a deep to a shallow fovea; the transverse carina at elytral base varies
from a triarcuate carina with three small foveal pits, to quadriarcuate with
four small foveal pits; the pronotal disc is perfectly simple, evenly convex in
five of the specimens, but in one male paratype the disc has a faint, vestigial,
median, longitudinal, depression rather like a stria. With more material, this
variant may prove to be a distinct variety. Otherwise the series is perfectly
homogeneous. The secondary sexual characters of the males are few but dis-
tinctive, the short laminoid tubercle of the middle tibiae being obvious and
constant.

In a slide mount of a paratype female certain additional features may be
noted: (a) the gular fovea resolves into two minute foveae, each with its floor
attached to the supratentorium, (b) the apical prosternal margin is dentate,
(c) the lateral prosternal foveae are present, and close to each other, and be-
tween them there is a very short, median, longitudinal carina for the basal fifth
of the prosternum, (d) the foveae of the meso- and metasternum are well
formed; II present on each side at union of prepectoid, mesoepistemum and

EUPLECTINI 97

mesosternum, each fovea having two whorled lumens opening at a common ori-
fice; III median and fused; IV and V paired, giving a total nine foveae for the
three sternal areas or seven foveae for the mesostemal and metasternal areas.
This is a relatively high number and places the species (Table I) in a more
primitive group.

Pararamecia shows certain structural affinities with several genera, for ex-
ample Pteroplectiis, Bibloplectus, Ramecia, and Adalmus. It appears to be most
related to Pteroplectus of Chile, but the latter genus has the prosternum entirely
carinated medianly and longitudinally, and the females have seven sternites.
Ramecia in North America, Panaramecia of the Canal Zone, and Biblomimus
of the Lesser Antilles have many things in common, and structurally there is
an interesting gradation in the prosternal carina, which is entire in the latter,
microscopically discoverable as a minute fold between the prosternal foveae in
Panaramecia, and absent in Ramecia. Panaramecia and Ramecia are related
through the development of the secondary tarsal claws, but Ramecia and
Biblomimus have seven sternites. Such comments are given to reemphasize the
lack of a complete tabulation of comparative structural details. Until more is
known the phylogenetic relationships will be poorly understood.

PTEROPLECTUS (Raffray, 1898)
grandicornis (Schaufuss). 1879. Chile. (Euplectus). Genotype.

THESIASTES (Casey, 1893)

Casey had the following to say regarding his genus (pp. 457-8) :

"In general organization the species of this genus resemble Euplectus,
but have the body much more minute, the head smaller and especially shorter,
the frontal truncature narrower, the eyes relatively larger and more prominent,
the tempera shorter and the abdomen completely devoid of dorsal carinae,
although deeply impressed at the base of the first two or three segments. In
spite of these differences I should have probably regarded them as one of the
subgeneric groups of Euplectus, had it not been for the fact that the male
sexual modifications at the apex of the venter were found to be of a com-
pletely different type. The large, rhomboidal, tumid and carinate seventh
ventral in the male Euplectus is here replaced by the oval, flat, laterally en-
closed pygidium so characteristic of Ramecia, Actium, and other more or less
widely separated genera; this indicates a real divergence from Euplectus far
more pronounced than might be inferred from the general organization. The
male sexual organs must indeed be remarkably different in structure."

I am in entire agreement with Casey that Euplectus may not logically con-
tain males with the seventh sternite in two valves, and with a single valve.
Thesiastes has many structural features shared by Euplectus, but is not to be
included in the latter genus. Thesiastes now holds some fourteen species, dis-
tributed over the world, including South America, Antilles, North America,
and Asia, and the East Indies. The species have a general resemblance to
Ramecia in habitus and pubescence, are similar to Euplectus in many ways,
and there is an odd resemblance to Thesium in outline. The tarsi have a large

98 NEOTROPICAL PSELAPHIDAE

primary claw and the accessory is little more than a bristle, visible under high
magnification. The eleventh antennal segment often has a distinct sensory
patch on the apico-lateral face. The ventral surface of the head bears a few
spiniform, strongly capitate setae, quite different from the simple aciculates
of Euplectus, or the simple capitulates of the melbaforms.

The neotropics have but two species:

argus (Reitter). 1883. Chile. (Euplectus)
liliputanus Raffray. 1904. Grenada, Windward Islands.
Both of these belong in Group I of Raffray (1904, p. 543) , having the head
as long as wide, relatively small, strongly narrowed apically; the antennal
club large with the ninth and tenth segments transverse ; the first two tergites
transversely impressed at base. It is of interest to point out that this first
generic group also includes the North American species [atratus Casey,
debilis (LeConte), fossulatus (Brendel), and pumilus (LeConte), indicating
that the American species as a whole have a common ancestry, with the
neotropical forms having migrated southward.

PTERACMES (Raffray, 1890)
schaufussi Raffray. 1890. Chile. Genotype.

LIOPLECTUS (Raffray, 1898)

This strange genus is confined to Argentina and since all of the species
have been described by Raffray, his 1908 key is given with slight modification:

Body very flat 2

Body more or less convex 4

2. Abdomen much longer than elytra; head much larger than wide;

antennal segments IV to VIII moniliform, IX transverse. . .nitidus
Abdomen slightly longer than elytra; head not longer than wide 3

3. Antennal segments IV to VII moniliform, VIII not much wider but

slightly transverse, IX similar to eighth but a little wider, X strongly
transverse and nearly concave, close to the eleventh; 1.8 mm. long

longulus

Antennal segments IV to VII moniliform but progressively more
transverse, IX and X very transverse and nearly lenticular; 1.9
mm. long lenticornis

4. Body elongate and parallel but slightly convex; length 1.8 mm.

simplex

Body less elongate, less parallel and much more convex 5

5. Head normal with a simple parabolic sulcus and the front not exca-

vated ; length 1.75 mm bicolor

Head very flat, occiput transversely impressed and the front of the
head (anterior of middle of vertex) slightly excavated; length 2.2
mm capitatus

EUPLECTINI 99

This key does not take into account myrmecophilus, 2 mm. long, erected
on the male sex and said by Raffray to be near nitidus but to have a shorter,
more anteriorly narrowed head and rounder tempora.

The species of the genus may be listed as follows:

bicolor Raffray. 1909. Argentina.

capitatus Raffray. 1909. Argentina.

lenticornis Raffray. 1909. Argentina.

longulus Raffray. 1909. Argentina.

myrmecophilus Raffray. 1912. Argentina, (con Atta hystrix)

nitidus Raffray. 1898. Argentina. Genotype.

simplex Raffray. 1909. Argentina.

EUPLECTUS (Leach, 1817)

Like Juhus and Eurhexius, this is an important genus in the grasping of a
generalized conception of the family (PI. XII, 5, 6; XIII, 8; V, 3). Not only
is it one of the older genera in the taxonomic literature, but it is one of the
largest genera in the family. It contains some 102 described species, and is
practically cosmopolitan in distribution. The taxonomy of the genus is in a
highly confused state, and much research needs to be done on the fauna, from
a world viewpoint, before subgeneric division can be thoroughly attacked, and
certain constituents placed in new genera to give a homogeneous assemblage.
Virtually all students of the family have had the genus under study and have
contributed to our sum of information.

The faunal area under discussion here, namely the American neotropics,
is much more easily handled, since Euplectus is relatively very poorly repre-
sented. This is oddly similar to the situation in Thesiastes, suggesting again
that Euplectus has had its center of dispersal elsewhere, and has spread slowly
from North America into the neotropics.

In this vast region being examined there are certainly five, possibly seven,
species of Euplectus, as contrasted with some twenty-three to twenty-seven
species known in North America north of the Rio Grande river. Despite this
small number of neotropical species, it is difficult to key out the species without
direct examination of the types, since descriptions of several are generic rather
than specific; the species are based on a specimen of unknown sex in some
cases, in one case on a single female, and the males of only four species are
known.

Sex in Euplectus is quickly diagnosed. The females have six visible ster-
nites; the males have seven visible sternites, of which the seventh is longi-
tudinally carinate. This carina may be median or slightly asymmetrically
placed ; it may be straight or oblique ; it may be convex to the right or convex
to the left. These variations of the carina of the seventh stemite are species
specific, and should form the basis for a reexamination of the genus. The carina
of the seventh stemite, as noted previously, is not in reality a true carina,
but marks the median union of a right and left pygidial plate or valve of the

100 NEOTROPICAL PSELAPHIDAE

seventh sternite, these valves swinging ventro-laterally to allow extrusion of
the male copulatory organ. The male sternites are variously secondarily modi-
fied by trichomoid setae, fossae, carinae, foveae, et cetera, and are rarely
perfectly simple and convex. The male legs may be variously modified.

The number of basal elytral foveae, the shape and extent of the pronotal
discal fovea, and whether or not the vertexal foveae are nude or pubescent, are
important characters, so that the genus does not lack taxonomic scope.

Key to the Known Males (incomplete)

Fourth sternite with a transverse fossa or f oveoid depression 2

Fourth sternite without such a transverse depression 3

2. Head slightly wider than pronotum inhonestus

(1.4-1.5 mm.; each elytron with three basal foveae; Colombia)

Pronotum slightly wider than head illepidus

(1.4 mm.; Grenada, Windward Islands)

3. First antennal segment cylindrical; second antennal segment ovate;

pronotal discal impression free and ovate insularis

(1.4 mm.; Guadeloupe, Leeward Islands)
First and second antennal segments quadrate; pronotal discal impres-
sion elongate-oblong, sulcoid exiguus

(1.0 mm.; St. Vincent, Windward Islands)

Tentative Key to the Seven Species Ascribed
Lateral pronotal margins not sinuate toward base, and not having a

tubercle or a tooth at the level of the lateral fovea on each side .... 2
Lateral pronotal margins slightly sinuate toward base, and each side
with a small tubercle or tooth at the level of the lateral pronotal
fovea 3

2. Known from the female sex only, and only from Venezuela, .signifera

(Size?; each elytron with three basal foveae)
Known from the male sex only, and only from the Lesser Antilles

eonguus

(See male key)

3. Impression of pronotal disc in the form of an elongate sulcoid depres-

sion which extends to the median subbasal fovea of the pronotum. . 4
Impression of pronotal disc variously shaped (sulcoid, foveoid or
ovate) but free, that is, not joining the median subbasal fovea of
the pronotum 5

4. Known only from Guatemala guatemalenus

(1.5 mm.; female?; Duenas, Guatemala)

Known only from Lesser Antilles illepidus

(See male key)

5. Head with the longitudinal sulci, arising in each case from a vertexal

fovea, connected anteriorly behind the frontal margin by a well-
developed transversely arcuate sulcus 6

EUPLECTINI 101

Head with the anterior union of the longitudinal vertexal sulci obso-
lete, rudimentary insularis

(1.2-1.4 mm.; both sexes known; Guadeloupe, Leeward Islands)
6. Base of each elytron with no foveae (?!) ; known only from Guate-
mala solitarius

(1.25 mm.; sex of unique type unknown) (Cerro Zunil, Guatemala)
Base of each elytron with three foveae; known only from Colombia

inhonestus

(See male key)

RafTray (1903, 1908) does not list guatemalenus Sharp, and thinks that
solitarius Sharp is probably not Euplectus. However Sharp (1887, p. 37)
compares his guatemalenus with Euplectus signatus Reichenbach of Europe, a
well known species. If Sharp's two doubtful species be included, the neotropical
forms may be listed:

exiguus Rafifray. 1904. Grenada, Windward Islands. (VIII)
guatemalenus Sharp. 1887. Guatemala. (Euplectus?) (X?)
illepidus Raffray. 1904. St. Vincent, Windward Islands. (X)
inhonestus Raffray. 1898. Colombia. (X)
insularis Raffray. 1908. Guadeloupe, Leeward Islands.
signifera Reitter. 1882. Venezuela, [nee signifer) (VII)
solitarius Sharp. 1887. Guatemala. [Euplectusl) (X?)

The Roman numerals denote the Raffray group number (1904), and it is
notable that the tenth group is wholly neotropical, and secondly that the
Antilles have the greatest number of species.

BARROEUPLECTOIDES new genus

Euplectini having (1) vertex 4-foveate; (2) eleven-segmented antennae
which are widely separated, and with a two-segmented club; (3) maxillary
palpi very small, four-segmented, first minute, second subtriangular; third
subspherical, nearly as long as second and of about same width; fourth seg-
ment as long as second and third united, ovate; (4) pronotum subquadrate,
lateral margin denticulate at basal third; lateral fovea each side at level of
marginal denticule; median fovea at basal third; no trace of transverse sub-
basal sulcus connecting the three subbasal foveae; disk with a median fovea;
(5) each elytron with two basal foveae; no subhumeral fovea but a well-
developed longitudinal subepipleural carina and sulcus; (6) abdomen five
visible tergites, of which the first three are subequal in length and the fourth
much longer than the preceding; six stemites in the female sex (male un-
known), second, third, fourth and fifth subequal; tergites with no basal
carinae; (7) middle coxae contiguous; (8) posterior coxae contiguous; (9)
prostemum not medianly, longitudinally carinate; (10) tarsi three-segmented,
small, euplectine, with last tarsomere bearing a large claw.

Genotype: Barroeuplectoides zeteki new species

102 NEOTROPICAL PSELAPHIDAE

Barroeuplectoides zeteki new species

Female Type. Measurements: head 0.17 x 0.24 mm.; pronotum 0.21 x 0.23
mm.; elytra 0.25 x 0.33 mm.; abdomen 0.34 x 0.33 mm.; antennae 0.25 mm.;
total length 0.97 mm.; greatest width 0.33 mm. (PI. XV).

Reddish-brown, moderately shining; pubescence uniform in length (0.03
mm. long), sparse on head, pronotum and elytra, but moderately abundant on
tergites.

Head transversely trapezoidal, widest through eyes; tempora slightly
convergent, long, almost twice as long as eyes. Eyes small, not prominent,
composed of about 24 very minute facets ; the eye almost circular from a lateral
view, and each facet being about the size of one of the coarse head punctures.
Occiput medianly, slightly sinuate, and with a feeble median notch. Vertex
with two small, circular, nude foveae on a line through the middle of the eyes,
each vertexal fovea being about twice as wide as one of the coarse head punc-
tures. From each vertexal fovea is a deep, slightly convergent longitudinal
sulcus which extends anteriorly to end in an anterior fovea as large as the
vertexal fovea. This anterior pair of foveae not united to each other by a
transverse arcuate sulcus. Surface of vertex between the longitudinal sulci
strongly vaulted into a subtriangular area which is not punctate, and this
impunctate condition continues anteriorly of the anterior pair of foveae to
the nearly straight, slightly elevated frontal line. Sides of vertex lateral to the
longitudinal sulci, from occiput to antennal prominences, coarsely and sub-
cribrately punctured. Therefore the vertex has four foveae, the normal posterior
pair and an anterior pair near the antennal prominences. Ventral surface of
head coarsely but sparsely punctate, convex; laterally limited by a strong,
short carina which extends each side from base of mandible to a point op-
posite the posterior margin of the eye, the lateral carina being parallel to,
but not diverging toward, the eye; a small basal circular nude gular fovea.
Ventral face of head without capitate setae; ventral surface of cervicum
polished, impunctate, with a well-defined median longitudinal stria extend-
ing from the gular fovea to prosternal margin. Front nearly vertical.

Maxillary palpi very minute, slightly longer than the eye, presumably
four-segmented; second segment subtriangular; third subspherical, almost as
long and about the same width as second ; fourth wider than third and as long
as second and third united, ovate, medianly inflated, apically subacute.

Antennae short and thick, eleven-segmented, rather widely separated at
base by the front, the separation equaling nearly one-half the width of the
head; segment I and II subquadrate, of same width and length; III to VIII
narrower than second, shorter than second, subquadrate, very closely articu-
lated; of approximate same length and width; IX subquadrate, very slightly
wider than eighth and about as long as eighth; club strongly formed of the
last two segments; X twice as wide and twice as long as ninth, nearly twice as
wide as long, transversely trapezoidal, with the apical half narrower so that
the eleventh segment is conspicuously articulated in distinction to the ap-
pressed articulation of the rest of the segments; XI peculiar in that it is as

EUPLECTINI 103

wide as long, almost spherical, being slightly more acute in apical fifth.

Pronotum subquadrate, slightly transverse, the lateral margins only
slightly convergent to base. Each lateral margin with a slight sinuation at
basal third, and at the bottom (most mesial point) of the sinuation is a small
but distinct tooth or denticule. Each side with a lateral nude fovea near but
wholly within the margin, and at the level of the denticule, as in certain neo-
tropical Ewplectus. Pronotal disc with a very small, deep, polished fovea near
the base of the disc. This circular discal fovea is about one-half the length of a
discal seta. Posteriorly this discal fovea is connected with the larger subbasal
fovea by a narrow, short canal or sulcus. The subbasal median fovea is also
deep and polished, but is not connected with the lateral subbasal foveae in
any way, viz. there is no transverse subbasal sulcus. The integument around
the subbasal median fovea, and the basal third of the pronotum is in general
coarsely and conspicuously punctate, whereas the anterior half of the pronotum
is less coarsely and more sparsely punctate.

Elytra with integument shining, only very finely punctulate. Each elytron
with two basal foveae. These basal foveae are very large, much larger than
the fovea of the pronotal disc. An entire deep sutural stria from the sutural
basal fovea, and a dorsal depression from the discal fovea extending to basal
third. Flank with a well-formed longitudinal carina paralleling elytral mar-
gin, and a subepipleural sulcus immediately mesiad of this carina, this sulcus
ends below the humerus, but there is no subhumeral fovea. Because of the
strongly formed, arched apical end of the longitudinal carina, the humeral
angle is slightly oblique and denticulate.

Abdomen strongly margined, with five visible tergites; first three tergites
subequal in length; fourth tergite distinctly longer than the first three as in
Euplectus; fifth tergite vertical, transversely fusiform, strongly convex and
shorter than the preceding segments. No basal carinae on disc of the basal
tergites. Six stemites visible, first very short; second, third, fourth, and fifth
sternites subequal in length with the second and fifth being slightly longer,
but this difference is difficult to discern; sixth stemite short, half as long as
fifth. All sternites convex and unmodified.

Prostemum, simple, not medianly, longitudinally carinate. Lateral pros-
temal foveae present, one anteriad of each anterior coxa. Anterior coxae short,
conical.

Metasternum long, as long as second and third sternites united, with a
very short, median, longitudinal carina between the middle coxae, this carina
only extending through basal seventh of metasternum. Middle coxae are
contiguous. Posterior coxae contiguous and shortly conical. Legs short with
simple femora, the tibiae similarly unmodified. Tarsi short, three-segmented,
the first tarsomere very minute, last two tarsomeres much longer, with the
second distinctly longer than third; third tarsomere bearing a large claw.

Described on a single female specimen, the type, collected by the author
on July 27, 1936, by sifting leaf mold on the forest floor of Barro Colorado
Island, Gatun Lake, Panama Canal Zone, near Zetek 23.

104 NEOTROPICAL PSELAPHIDAE

I take pleasure in naming this interesting species for my friend Mr.
James Zetek, resident custodian of the Barro Colorado Island Laboratory,
whose interest and aid made my trips to the Zone profitable and pleasant.
This species runs to the neighborhood of Acolonia Casey in the 1908 key to
genera of Raffray's great treatise. It is obviously not at all near to this genus.
On the other hand it is allied to Euplectus in many features, in general habitus,
pronotal outline, and tergite proportions, while differing from Euplectus in
having no transverse pronotal sulcus of any kind, lack of basal abdominal
carinae and other characteristics. Known so far by a single species, this genus
is very distinct:

zeteki new species. Panama Canal Zone.

VERABAROLUS neiv genus

Euplectini having (1) vertex bifoveate; (2) eleven-segmented antennae
which are widely separated at base, and with a three-segmented club; (3)
maxillary palpi well-formed, four-segmented, first short and cylindrical; sec-
ond arcuate, elongate, narrow at base and apically inflated; third short, trans-
versely triangular; fourth long, nearly twice as long as eye, subsecuriform ;
(4) pronotum obcordate, lateral margins not dentate; lateral fovea each side
at basal third, and a median subbasal fovea connected by a biarcuate, trans-
verse, subbasal sulcus ; disc with an elongate median fovea or linear groove, not
reaching apical margin or subbasal transverse sulcus; (5) each elytron with
four basal foveae, non-denticulate humeral angle; flank with subhumeral
fovea and a subepipleural carina which is parallel to elytral margin ; no dorsal
stria, but an entire sutural stria; (6) abdomen of five visible tergites, these
with no basal discal carinae, and subequal in length, being slightly progres-
sively shorter; six visible stemites in the female sex (male unknown), second
to fifth sternite progressively shorter; (7) middle coxae subcontiguous, allowing
the mesosternal and metastemal processes to be discerned between them;
(8) posterior coxae contiguous; (9) prostemum not medianly longitudinally
carinate, but medianly gibbous, this gibbous area being posteriorly prolonged
to form a short carinoid line in basal third, between lateral prosternal foveae;
(10) tarsi three-segmented, first minute, second and third much larger, second
longer and thicker than third, third with a single claw.

Genotype: Verabarolus subdendrus new species.

Verabarolus subdendrus new species

Female Type. Measurements: Head 0.18 x 0.23 mm.; antennae 0.33 mm.;
pronotum 0.23 x 0.24 mm.; elytra 0.26 x 0.33 mm.; abdomen 0.39 x 0.30;
total length 1.06 mm. x greatest width 0.33 mm.

Reddish-brown, the elytra slightly darker; pubescence abundant, rather
short (0.015 mm.) to longer (0.03 mm.) ; integument punctulate, moderately
shining.

EUPLECTINI 105

Head trapezoidal with rounded temporal angles; tempora rather long,
longer than eye; eyes small (0.04 mm. long), moderately prominent, composed
of about 22 small facets, the eye circular from a lateral view. Occiput broadly
arcuate with a median longitudinal carina extending from cervicum, across oc-
ciput, to a point posterior to a line passing through posterior margins of eyes.
Vertex with sides above eyes subgranulated ; two vertexal foveae which are
small, nude, circular, on a line through the posterior third of the eyes; vertexal
sulci beginning at a point lateral to and posterior of each vertexal fovea, and
converging in an arc to a point mesiad of each ant^nnal prominence, thence
being connected by a common transverse sulcus which passes posteriad of the
almost vertically declivous front. Head dorso-ventrally flattened from a lateral
point of view. Ventral surface of head nearly flat, subgranulated, with a large
nude circular gular fovea at middle of basal margin. Ventral surface with no
capitulate setae. Cervdcum ventrally polished and simple.

Maxillary palpi well developed, four-segmented, first segment short and
cylindrical ; second about three times longer than first, distinctly more narrow
than first at base and inflated in apical half, slightly arcuate; third short,
wider than second, transversely triangular; fourth long (0.07 mm.), almost
twice as long as eye, oblique at base, minutely truncate at apex, subsecuriform,
with a small apical, palpal cone.

Antennae eleven-segmented, widely separated at base by about one half
of the width of the head; segment I subquadrate; II ovate, as wide and as
long as first, first and second segments distinctly wider than third; second as
long as third and fourth united; III obconic; IV to VII subspherical, with the
sixth segment slightly smaller than either the fifth or seventh segment; VIII
subpyramidal ; club well-formed of last three segments as follows, IX pyra-
midal, transverse, slightly wider than eighth; X pyramidal, transverse, slightly
wider than ninth; XI relatively large, as long as eighth, ninth, and tenth united,
eylindrico-globose, apically not acute, but rounded slightly.

Pronotum obcordate, widest through middle, with the lateral margins
broadly rounded to apex and more angulated to base; each side with a large
subbasal fovea, and at middle a small rounded median subbasal fovea, these
three foveae connected by a transverse biarcuate subbasal sulcus; disk with a
free, deep, short, polished subcuneiform fovea.

Elytra with the humeri not denticulate ; each elytron with an entire sutural
stria, no dorsal stria, four basal foveae; a well-formed subhumeral fovea which
lies apical to a subepipleural carina on each flank, this carina being parallel
to the elytral lateral margin.

Abdomen with five visible tergites, but no basal discal carinae, the tergites
simple, subequal and very slightly diminishing in length, with the fifth slightly
shorter, and of a rounded-triangular form from a dorsal view. Six visible
sternites, the first short, triangular between the coxae, relatively heavily
pubescent; second to fifth progressively decreasing in length, with the fifth less
than one-half as long as the second; sixth sternite longer than fifth, subequal
in length to third, slightly flattened in median apical half, and sinuate to form

106 NEOTROPICAL PSELAPHIDAE

a rounded median lobe which fits into a ventral incisure of the posterior mar-
gin of the fifth tergite. Fifth sternite with a minute tubercle at middle of
apical margin.

Prosternum with the apical margin serrato-dentate ; medianly gibbous,
with the posterior portion of the gibbous area fonning a short carinated ele-
vation between the lateral prosternal foveae which are well-developed anteriad
of each coxa. No entire median longitudinal carina.

Mesostemum not carinated medianly, flat and shining.

Metasternum medianly tumid, with a short sulcoid area at extreme
posterior fifth; long, as long as third and fourth sternites united.

Anterior coxae short, conical; middle coxae subcontiguous, the meso- and
metasternum discernible between them as narrow, flat, acute extensions;
posterior coxae contiguous, shortly conical. Legs simple, with short three-
segmented, euplectine tarsi, the first tarsomere very small, the next two much
larger; second tarsomere very much larger than the third, the third bearing
a single claw.

The paratypes agree with the type, save that the median discal fovea of
the pronotum is more linear and longer; in one paratype the elytra have the
fourth (most lateral) basal fovea much smaller than the other three. From a
slide mount of a paratype the following morphological additions can be added:
(1) the sternal foveae are very well developed; in addition to the lateral
prosternal foveae noted previously, the meso- and metasternum have foveae II,
III, IV, and V paired and present. II are large, with a bifurcated whorled
lumen, one arm of which penetrates the prepectoid and one arm the mesoster-
num proper. Ill are small, with a single whorled lumen, one on each side of a
median longitudinal carina of the prepectoid. IV are relatively as large as
any I have encountered, and typically located, that is, at the lateral angle
of each middle coxal cavity, at the union of five sclerotic areas (mesosternum,
mesoepisternum, mesoepimeron, and metasternum). VI are small, one in the
center of the posterior margin of each middle coxal cavity. (2) Each of the
elytra has three asetose pores. These appear as very clear, perfectly circular
areas in strong relief against the yellow integument. They appear to be sensory,
and, although they have no relation to the setal punctures, are of almost the
same size. Two of these pores lie on the disc at the apical fourth. The third
lies in the basal third, posterior to a line drawn between the fourth and third
basal foveae. (3) There appears to be a peculiar mechanism between the
inner face of the elytra and the sides of the invisible first tergite. In life this
tergite, which is membranous, is tucked beneath the elytra. In the cleared speci-
men, there are about twelve short oblique striae on the lateral face (pleurite?)
of this membranous segment. In apposition are about eight transverse carinae
on the internal face of the elytron, near its apical external angle. Such a
mechanism suggests the possibility of a stridulatory mechanism, but no further
data concerning the possible function of this area are at hand.

Described on four females, collected by the author, beneath the bark of logs
on Barro Colorado Island, Gatun Lake, Panama Canal Zone, as follows: July

EUPLECTINI 107

26, 1936, at Armour 8; July 28, 1936, at Zetek 3; July 29, 1936, at Pearson 4;
July 30, 1936, at Armour 10.

This distinct species appears to be rather generally distributed in the center
of the island. It is near Euplectus, from which it is readily separable by the
subequal tergites, lack of basal tergite carinae, and other features. In Raffray's
1908 key, it runs to the neighborhood of the Chilean Pteroplectus, but cannot
be confused with this genus as the latter has a strong, entire prosternal carina
and seven stemites in the female. The genus as now constituted has but the
one species:

subdendrus new species. Panama Canal Zone.

ADROGASTER (Raffray, 1890)
longipennis Raffray. 1890. Brazil. Genotype.

ACOTEBRA (Reitter, 1881)
sinioni Reitter. 1893. Chile. Genotype.

TOMOPLECTUS (Raffray, 1898)
cordicollis Raffray. 1898. Mexico. Genotype.

ACTIUM (Casey, 1886)

Casey (1886, 1887, 1893, 1897, 1908)

Brendel and Wickham (1890)

Raffray (1898, 1904, 1908)

Bowman (1934) (genotype Actium pallidum Casey)

Proplectus Raffray, 1890 (Trichonychini) a synonym of Actium.

This is a large genus of some seventeen species, of which only three are
found south of the Rio Grande river. The center of distribution therefore ap-
pears to be in the United States, especially California, where some nine or ten
species are known. Raffray (1908) thinks that this genus replaces Trimium
(Aube, 1833) in the western hemisphere, the latter genus being abundant and
typical in the European palaearctic fauna. Actium seems to be rather centrally
located in the tribe, in general much more specialized than the Euplectoid
genera, and not so specialized as the Melboid genera. The three neotropical
species are neither known from the eastern regions of South America nor from
the Antilles, and hence it would seem probable that the species of Actium have
spread eastward from California into the eastern United States, and secondly
southward down the Rocky Mountain-Andean chain as far as Chile.

In general the eyes are well formed in both sexes. Vertexal foveae are
always present and may be nude or pubescent. Antennae are eleven-segmented,
with the club composed chiefly of the eleventh segment, although the length
of this segment varies in the subgenera from as long as the eighth to tenth
combined, to as long as the sixth to tenth combined. The maxillary palpi are

108 NEOTROPICAL PSELAPHIDAE

four-segmented, with the distal segment elongate-oval, rather thick and acum-
inate. Ventral surface of the head with capitulate setae (a melbaform trend).
Pronotum with the disc simple, not foveate or sulcate ; the base with a trans-
verse sulcus, usually arcuate or biarcuate, posteriorly angulated at middle, ex-
tending to a lateral fovea each side ; these lateral foveae are usually pubescent.
Prosternum not medianly longitudinally carinate. Elytra with two to three
basal foveae on each elytron, plus a subhumeral fovea and a longitudinal sub-
epipleural carina and sulcus. Abdomen with six sternites in the female, and
seven sternites in the male; male seventh sternite in the form of the simple,
asymmetrically articulated, one-plate pygidium found in Melba. First tergite
usually provided with a pair of short, basal, discal carinae.

Rafifray (1904) divided the then known species of this genus into four
groups, and since a neotropical species is known from each of the first three
only, this group key will serve to isolate the neotropical forms known at this
time:

First tergite with a pair of basal discal carinae, second tergite with

no basal discal carinae 2

First and second tergites each with a pair of basal discal carinae ; each

elytron with three basal foveae trimiiforme (Reitter) Group I

(Valdivia, Chile)

2. Each elytron with three basal foveae gracili Raffray, Group II

(Chile)

Each elytron with two basal foveae caviceps Raffray, Group III

(Mexico)

The three species of the region under examination may be listed as follows:

caviceps Raffray. 1898. Mexico.

gracili Raffray. 1898. Chile.

trimiiforme (Reitter). 1885. Chile. (Pseudoplectus)

ACTINOMA (Raffray, 1898)
obesum Raffray. 1898. Mexico. Genotype.

PSEUDOTRIMIUM (Raffray, 1898)
microcephalum Raffray. 1898. Probably Mexico. Genotype.

TRIMIODINA (Raffray, 1898)
concolor (Sharp). 1887. Guatemala. [Trimium). Genotype.

TRIMIOPSIS (Reitter, 1882)

This wholly neotropical genus has been strictly limited by Raffray (1908),
and now includes two species from Guatemala so inadequately described that

EUPLECTINI 109

their inclusion is doubtful, the genotype from Colombia and a new species
from the Panama Canal Zone.

These four species may be separated as follows:

Head not wider than pronotum ; clypeal margin "strongly raised and
connected on either side by a small process to the anterior acuminate
part of the convex vertex, so that the depressed space is (distinctly)
divided into a lateral portion on each side and a median portion

placed more anteriorly" [ex Sharp) femoralis Sharp

(1.25 mm.; male?; El Tumbador, Guatemala)

Head wider than pronotum; clypeal margin not so connected each
side with the vaulted vertex (PI. XIX, 7) 2

2. Vaulted median portion of the vertex extending anteriorly as a tri-

angular angle into the post-clypeal depression 3

Vaulted median portion of the vertex transversely divided into a basal
triangular portion which is separated by a transverse sulcus from an
anterior acute tubercle (PI. XIX, 7) furcalis new species

3. Known from Guatemala; 1.4 mm. long; rufocastaneus

clavicornis Sharp

Known from Colombia; 1.3-1.4 mm. long; testaceus

claviceps Reitter

Trimiopsis has a characteristic habitus, which includes the broad head,
strongly vaulted vertex, and the distinctly asymmetrically triangular tenth
antennal segment. The following species is new:

Trimiopsis furcalis new species

Holotype Male. Measurements: Head 0.20 x 0.24 mm.; pronotum 0.21 x
0.20 mm.; elytra 0.28 x 0.32 mm.; abdomen 0.40 x 0.30 mm.; total length 1.1
mm.; greatest width 0.32 mm. (PI. XIX, 7).

Reddish-brown, with the head and pronotum slightly darker; integument
moderately shining, pubescence short and inconspicuous.

Head with the tempora parallel, as long as eye; eyes prominent; temporal
angles prominent and squarely rounded; vertex with sides above each eye
flattened and granulated, medianly the vertex is conspicuously vaulted and
not granulated; vertexal foveae minute and punctiform (in contrast to the
large vertexal foveae of the genotype), situated on a line passing through
middle of eyes. Vertexal sulci complex: from each vertexal fovea there extends
a short longitudinal sulcus, which bifurcates near a point opposite the anterior
margin of the eye, into two arcuate sulci; these arcuate sulci are medianly
confluent with their homologous sulci from the other side, so that there are two
arcuate transverse sulci. This sulcation of the head divides the vaulted median
part of the vertex into a larger, posterior, subtriangular portion which begins
between the vertexal foveae and is limited anteriorly by the median transverse
sulcus, and a smaller, acute subpyramidal tubercle which lies between the two

110 NEOTROPICAL PSELAPHIDAE

transverse sulci. The posterior transverse sulcus lies at about the anterior
margin of the eyes, the anterior transverse sulcus extends semicircularly be-
hind the raised frontal margin. Front between the antennal bases arcuate.
Ventral surface of the head coarsely and conspicuously punctate, without
capitulate setae.

Maxillary palpi four-segmented, first segment minute and cylindrical;
second slender, arcuate, apically inflated; third asymmetrically subspherical;
fourth widest and longest, oblique at base, acute at apex, subconico-ovate,
with an apical palpal cone.

Antennae short, not longer than the head, separated by half the width
of the head, eleven-segmented, segment I and II relatively large, first incon-
spicuous because of the deep articulation beneath the front, and shorter and
narrower than second segment; second ovate; III to VIII very closely articu-
lated, of about same length and width, subequal, distinctly smaller than sec-
ond; third obconical; fourth to eighth are transversely moniliform; IX wider
than eighth, short and inconspicuously articulated to tenth; X much larger,
as wide as eleventh and strongly, asymmetrically triangular, the mesial face
being longer and tumified; XI truncate at base, closely appressed to tenth,
as long as fifth to tenth segments united, asymmetrically subacute. With minor
differences this is a typical Trimiopsis antennal pattern.

Pronotum trimiform, obcordate, each side with a small lateral fovea within
the margin at basal third, and a medial subbasal fovea connected by an entire,
biarcuate, transverse, subbasal sulcus; disc simple, slightly flattened (with an
oblique light and high magnification, a just discernible ovate depression can
be seen).

Elytra widest medianly, with rounded humeri; each elytron with two
conspicuously large basal foveae, the sutural fovea giving rise to a sutural stria
which is not entire, that is, it ends a short distance from the apical margin at
about apical seventh; the discal fovea gives rise to a short, triangular dorsal
depression in basal fourth; neither a subhumeral fovea nor a subepipleural
sulcus on the elytral flank.

Abdomen with a relatively narrow margin and five visible tergites. First
tergite with a pair of short, blunt, straight, parallel discal carinae separated
by about one-half of segmental width. First three tergites subequal in length,
fourth longer, fifth subequal to third and rounded-triangular from a dorsal
view. Seven stemites visible, first sternite shorter than second, and triangular
between the coxae; second slightly longer than third; third and fourth sub-
equally long; fifth shorter, with a small median tubercle at basal margin;
sixth as long as second, medianly flattened; seventh rounded-triangular, as
long as sixth.

Frostemum medianly, transversely gibbous, not medianly longitudinally
carinate. Middle coxae subcontiguous under high magnification. Posterior
coxae shortly conical and contiguous. Metasternum long, nearly as long as
first three stemites united, flattened and gently, medianly depressed. Sternal
foveae IV very large and conspicous at the lateral angle of each middle coxa.

EUPLECTINI 111

Legs with the femora distinctly inflated; middle femora ventrally strongly
sinuate, with a conspicuous blunt triangular tooth at base as a consequence
of this sinuosity; tarsi three-segmented, euplectine, first minute, second and
third much larger than first, second longer and thicker than third; third
tarsomere bearing a single, large, arcuate claw.

Allotype Female is similar throughout save that (1) the fourth tergite is
not much longer than the third, the five tergites being subequal in length;
(2) only six stemites, with the first very short, second longer than first and
third; third and fourth subequal; fifth one-half as long as fourth; sixth large,
as long as second and third united, subtriangular, with lateral margins sinuate
and apex rounded to fit into a deep ventral incisure of the ventral margin of
the fifth tergite; (3) femora not inflated, and middle femora simple.

Note that the female has the vaulted vertex and bifurcated sulcal pattern
present in the male.

Described upon a male and a female specimen, both collected at the same
time and niche, beneath the bark of a log at Armour 8, July 26, 1936, on Barro
Colorado Island, Gatun Lake, Panama Canal Zone, by the author. The species
of the genus are as follows:

claviceps Reitter. 1882. Colombia. Genotype, {nee caviceps auct.)
clavicornis Sharp. 1887. Guatemala.
femoralis Sharp. 1887. Guatemala.
furcalis new species. Panama Canal Zone.

NEODALMUS (R affray, 1890)

This is a melbaform, monotypic genus which is isolated by the pronotal
structure: the disc of the pronotum is crossed longitudinally by a median
carina, analogously to the brachyglutine Bunoderus. There is a single species:

carinatus Raffray. 1890. Venezuela. Genotype.

DALMOPLECTUS (Raffray, 1890)

This genus was created by Raffray to contain a melbaform species, known
only from the female sex, originally placed in the Tychini. The fact that the
posterior coxae are distinctly, although slightly, separated serves to differentiate
the genus from Melba.

batrisoides (Reitter). 1882. Brazil. (Dahnodes).

MELBAMIMA (Raffray, 1909)

This genus contains a single melbaform species, separated from Melba
chiefly on the structure of the antennae (PI. VI). These organs are eleven-
segmented, with the first two segments relatively ver>' large and subquadrate
and nearly three times as wide as segments III to VIII; the third segment is
obconical; fourth to eighth transverse and compactly articulated; IX of the

112 NEOTROPICAL PSELAPHIDAE

same general form, but slightly wider than the eighth segment; club formed
of the tenth and eleventh segments, of which the eleventh is conspicuously
large: segment X bilaterally very asymmetrical, much longer and wider than
ninth, of a rounded-triangular shape, and very asymmetrically articulated on
the antero-mesial face of the ninth segment. Because of this asymmetrical
articulation, the ninth and eleventh segments are in contact laterally, but
widely separated mesially because of the wedge of the tenth segment; segment
XI as long as the second to the seventh inclusive, asymmetrically subconical,
with the apex acute, lateral face slightly and sinuately concave and the
mesial face convex.

Melbamima clavicornis represents a divergent, specialized trend from
Melba, since most species of the latter genus have only slightly asymmetrical
tenth antennal segments, but certain species such as Melba clavata have this
segment much more asymmetrically formed. One species represents the genus
so far:

clavicornis Raffray. 1909. Brazil. Genotype.

TRIMIOSELLA (Raffray, 1898)

This also is a monotypic, melbaform genus, erected to contain a species
formally placed in the then expanded Trimiopsis. Such a course was necessary
following the restriction of Melba to contain only those species in which the
lateral pronotal foveae were placed far down on the sides of the prothorax and
hence invisible from above. In Trimiosella the lateral pronotal foveae are
within the lateral pronotal margins and hence fully visible from above. Tenth
antennal segment lenticular, and not asymmetrical. Males with seven sternites,
females with six sternites, the seventh male sternite being the one-plate, non-
carinated type of pygidium common to the melbaforms as a group.

anguina (Reitter). 1883. St. Thomas, Virgin Islands. Genotype.

RAMELBIDA new genus

This new genus is erected for Melba quadrijoveata Raffray (1904, p. 537).
Raffray (1898, 1904, 1908) restricted Melba to those species having the lateral
pronotal margins rounded, and the transverse subbasal sulcus continuing down
the sides of the prothorax, ending each side in a lateral fovea. Consequently
these lateral foveae lie in or near the prosternum, and are not visible from a
dorsal point of view. In 1898 Raffray erected Trimiosella for Trimiopsis
anguina Reitter, since the latter, although closely related to Melba, had lateral
pronotal foveae visible from above. Later, Raffray (1904) described quadri-
joveata as a species of Melba. This was a mistake, since the latter species has
the lateral pronotal foveae also visible from above, and in fact, is so shown
in a figure (fig. 8, p. 537, Raffray, 1904).

Melba quadrijoveata may be a Trimiosella, but at present the described
structure seems to be too divergent for this genus, and Ramelbida is erected
to contain the melbaforms having: (1) eleven-segmented antennae, the sec-

EUPLECTINI 113

ond segment of which is large and ovate; third to eighth moniliform and
slightly transverse; ninth and tenth segments progressively more transverse,
lenticular and symmetrical; eleventh segment ovate and as long as sixth to
tenth inclusive; (2) head wider than long, nearly as wide as pronotum; with
the vertex holding four foveae, one pair on a line through the posterior half of
the eyes, each nearer an eye than their mutual intrafoveal separation ; a second
pair of foveae placed near the subtruncate frontal margin, one on each side
at the base of the small first antennal segment; no vertexal sulci; (3) pronotum
with the biarcuate transverse subbasal sulcus terminating in a lateral fovea
each side, these foveae being visible from a dorsal point of view; (4) elytra
with obtuse humeri and each elytron having two large deep basal foveae.

Ramelbida has but two genera with which it may be confused, Melba and
Trimiosella. From both of these it may be readily separated by the complete
absence of vertexal sulci (these sulci being obsolete in Trimiosella) , four well-
developed vertexal foveae (approached in this only by Melba (?) temporalis) ,
and the visible pronotal foveae (which takes it from Melba). Many of the
species described in Melba may prove to belong in Ramelbida, but this may
not be ascertained until types are examined. At present there is but one:

quadrijoveata (Raffray). 1904. St. Thomas, Virgin Islands. (Melba).
Genotype.

MELBA (Casey, 1897)

Casey (1897)

Raffray (1898, 1904, 1908, 1908a, 1909, 1912, 1912a)

Leng (1920)

Bowman (1934) [Melba thoracioa (Brendel), p. 144, genotype)

Brendel and Wickham (1890) {Trimium in part)

Casey (1897) (Zolium)

Reitter (1883) (Trimiopsis in part)

Sharp (1887) [Trimiopsis in part)

Like Jubus, Eurhexius, and Euplectus, this is a large and important genus ;
unlike Euplectus, it is wholly American, and appears to be one of the most
highly specialized in the euplectine tribe. There are about eleven described
species north of the Rio Grande river, distributed from Arizona eastward to
the Atlantic coast, and from Louisiana and Florida to New York and Illinois.
The genus does not appear to have any species spreading into Canada. South
of the Rio Grande, there are about eighteen species, eleven of which are endemic
in the Antilles, and the other seven species are recorded from Mexico, through
Guatemala, French Guiana, Brazil, and Argentina. Such a distribution appears
to indicate a neotropical origin for the genus, especially since related melba-
forms [Ramelbida, Trimiosella) are antillean also, and the Lesser Antilles are
the present center of taxonomic diversity in the genus.

The habitus of Melba is fairly consistent (PI. XI, 7, 8). The species are
small (0.7 to 1.1 mm.), with a conspicuously large distal antennal segment,

114 NEOTROPICAL PSELAPHIDAE

and the cordiform pronotum has rounded lateral margins, with the lateral
foveae on each side not visible from a dorsal view.

Certain special features of their anatomy should be noted, and are figured
for the genotype and related North American species in the plates (PI. IV,
XI, XII). The head varies in outline from subtriangular, in which the sides
are oblique, to the attenuated anterior end with a subtruncate front, to sub-
quadrate. In the subquadrate head the males have the sides more or less sud-
denly dilated anteriorly [parmata, ventricosa) . Although the front is usually
not prolonged, in some species {clypeata and jleutiauxi) the front is prolonged
above the epistomal region, strongly in males and less strongly in females.
The eyes are large and prominent. Two vertexal foveae are present between
the eyes, these foveae being nude, circular, and connected by an arcuate sulcus
which is usually well formed but may be partially interrupted. The ventral
surface of the head is provided with distinct capitulate setae. Maxillar>' palpi
four-segmented; first minute; second arcuate, slender basally and inflated
apically; third short, transverse, subtriangular, as wide as or wider than sec-
ond; fourth longest and widest, elongate-oval to subsecuriform. Antennae
eleven-segmented, with the first two segments larger than the third to seventh,
the second larger than the first; third to tenth inclusive small, with some
variation in shape and relative size among the species ; tenth segment usually
transverse, lenticular and bilaterally symmetrical but may be transversely tri-
angular and asymmetrical {clavata) ; eleventh segment quite large, conoidal or
ovoid, acuminate, provided with antennal cones which can be discerned only
in slide mounts at high magnification.

Pronotum obcordate to cordiform, with rounded lateral margins, and the
basal third crossed transversely by an arcuate to biarcuate variably developed
sulcus; this sulcus continues down each pronotal flank to end in a lateral
fovea near or on the flanks of the prostemum, making the foveae invisible from
above; disc of pronotum simple.

Elytra with the humeri never dentate, usually rounded, but in some species
nearly square {parmata, ventricosa, eggersi) ; there is no subhumeral fovea and
no subepipleural sulcus on the elytral flank; on each elytral flank, however,
there is an important generic feature in the presence of a fine oblique line
which extends from near the middle of the lateral margin obliquely to the elytral
apex. (In the North American Dalmosella and Trimiomelba, this cariniform
line is not oblique, but is parallel to the elytral margin from its origin at basal
third to apex, and forms a good criterion for separation ; this feature was known
to Casey in the erection of his melbaform genera.) Each elytron with two
basal foveae; the sutural gives rise to a sutural stria, and the discal gives rise
to a short variable dorsal depression. The abdomen has five subequal tergites,
the first tergite not narrowed at base ; the stemites show sexual differentiation,
there being six sternites in the female and seven stemites in the male. The
male seventh stemite is a circular, simple, uncarinated one-piece pygidium
which is asymmetrically articulated.

Prosternum simple, with no median longitudinal carina. The mesosternum

EUPLECTINI 115

and metasternum have seven foveae developed (about parallel with the sternal
development of Bibloplectm) , foveae II, IV, and V are paired and III is
median and fused in the genotype and closely related forms. The metasternum
is usually simply convex in the female, and often sulcate or concave in the
male sex.

The legs are usually secondarily modified in the males. This is diverse in
the genus. The femora of the males are generally inflated. In dentipes the
mesothoracic tibiae are medially spined; in others these tibiae are obtusely
prominent and pubescent medially, angulate, swollen and bearing a copulatory
pad on the mesial face at apical third {thoracica, sulcatula). This pad, when
examined on slide mounts at high magnification, is seen to consist of minute
semispherical transparent padules, the number of padules varying in some
cases with the species. The swollen male middle femora may bear large punc-
tures, or sensory pores, and these pores may be present on the anterior femora
as well. The tarsi are euplectine, with a minute first and a relatively large
second and third tarsomere ; second slightly longer, and much thicker than the
third; third bearing a large curv^ed claw.

Although this present study is primarily concerned with the neotropical
Pselaphidae, I should like to take this opportunity to make up a brief for
Dalmosella of North America. Dalmosella (PI. IV, XII) was erected by Casey
(1897, p. 570) for a new species, tenuis, which I designate as the genotype, and
two doubtful inclusions, Trimium simplex LeConte and Trimium americanum
LeConte. Leng (1920) placed Dalmosella in Melba, and this course was fol-
lowed by Bowman (1934). I do not know simplex and americanum, but tenuis
is very distant from our present conception of Melba. Casey's original de-
scription of tenuis was based on a female, and the remarkable male characters
(PI. XII, 15, 16) were unknown to him. I have taken tenuis in copulation in
Illinois, and the male features have not been reported to my knowledge. The
following tabular comparison (Table II) between two genotypes will set forth
the striking differences between the two genera in question.

The genus Melba shows numerous radiating trends into other melbaform
and some brachyglutine genera. Thus the general habitus and contiguous pos-
terior coxae are similar to the glabrous Eupsenius with subcontiguous posterior
coxae and an even larger distal antennal segment. The subglabrous Eupsenina
with very distant posterior coxae seems much more remote, but the capitate
setae of the ventral surface of the head are melboid. Melba frontalis suggests
certain outlines of Dalmosella and Ramelbida. Melba clavata approaches Mel-
bamima. Melba parmata suggests Dalmoplectus. It is evident that this genus
has been an active evolutionary center in the past, and there are probably
many new species awaiting discovery.

Raffray (1904, p. 535) divided the genus Melba into four groups of species.
This grouping can no longer be maintained, since Group I of Raffray is Dal-
mosella, and the addition of many new species since this time, with increased
structural and zoogeographic information, makes a revision necessary. The
following key to subgenera is offered to bring our knowledge of this difficult
group up to date.

116

NEOTROPICAL PSELAPHIDAE

Table II

COMPARISON OF DALMOSELLA AND MELBA

Dalmosella tenuis Casey

Capitulate setae on ventral face of head.

Melba thoracica (Brendel) and
Melba sulcatula Casey-
Capitulate setae on ventral face of head.

Tenth antennal segment transversely tri-
angular and bilaterally asymmetrical.

Tenth antennal segment lenticular and prac-
tically bilaterally symmetrical.

Vertexal foveae large and pubescent.

Vertexal foveae smaller and nude.

Arcuate vertexal sulcus wide, coarse, distinc-
tive.

Arcuate vertexal sulcus simple, only mod-
erately developed.

Pronotum with a strong, biarcuate trans-
verse sulcus which cuts the lateral wall
near base each side, the resulting constric-
tion being distinctive. The anterior margin
at the lateral end of the sulcus is dis-
tinctly tufted with setae.

Pronotum with the biarcuate transverse sul-
cus near basal third, narrowing the pro-
notal outline but not cutting the lateral
margin in this manner, but passing simply
down each pronotal flank. The sulcus not
tufted laterally with setae.

Lateral pronotal foveae not visible from
above, but pubescent.

Lateral pronotal foveae not visible from
above, and nude.

Basal elytral foveae pubescent.

Basal elytral foveae nude.

Elytral flank with a cariniforra line which is
parallel to the margin from origin at basal
third to apex.

Elytral flank with an oblique line which
arises near middle of flank and extends
obliquely to apex. A striking structural
difference.

First tergite slightly constricted at base.

First tergite not constricted at base.

Males with seven, females with six ster-
nites. Seventh male stemite a simple oval,
asymmetrically articulated pygidium.

Males with seven, females with six ster-
nites. Seventh male sternite a simple, oval
to suboval, asymmetrical articulated
pygidium.

Male mesothoracic femora simple.

Male mesothoracic femora inflated and with
sensory pores, under high magnification.

Male tibiae simple.

Male second sternite very greatly modified:
integument extended into a broadly tri-
angular lobe which extends posteriorly
from basal two-thirds for the median fifth
of width; this lobe is heavily pubescent
and overhangs an equal depression pos-
teriorly. In lateral view this pubescent
lobe is distinctive. On each side of the
apical depression is a small, erect, obtuse
spine. (See plates).

Male mesothoracic tibiae with a copula-
tory pad on mesial face at apical third,
the pad being made up of a differential
number of padules, at high magnification.

EUPLECTINI 117

Key to the Subgenera

Tenth (penultimate) antennal segment transversely triangular and
bilaterally asymmetrical (approaching Dalmosella and Melba-

mima) known from Brazil and possibly Argentina

ASYMMELBA, new subgenus

Tenth antennal segment transverse, lenticular or practically bilater-
ally symmetrical 2

2. Vertex with four free foveae arranged in an anterior pair near anten-

nal bases and a posterior pair between the eyes; no vertexal sulci
connecting the foveae (approaching Ramelhida) known from

Antilles RAMELOIDEA, new subgenus

Vertex with a pair of vertexal foveae between the eyes, these foveae
more or less connected by an arcuate vertexal sulcus 3

3. Vertex with a large, deep, transverse excavation between the eyes,

this depression medianly tuberculate; known from French Guiana

VERTELBA, new subgenus

Vertex simply convex or flattened between the eyes 4

4. Head quadrate in outline, and in the males (seven sternites) anter-

iorly dilated; known from the Antilles (Raffray, Group IV)

QUADRELBA, new subgenus

Head narrowing anteriorly of the eyes 5

5. Front prolonged anteriorly above the epistomal area, this extension

more pronounced in the males (seven sternites) than in females (six
sternites), but distinct in both sexes; known from the Antilles and

possible Guatemala (Raffray, Group III)

FRONTELBA, new subgenus

Front normally subtruncate to gently arcuate between bases of anten-
nae; includes all North American species and the Antilles (Raffray,
Group II, and original Melba of Casey) MELBA, s.s.

Key to Asymmelba

Front transversely sulcate; tenth antennal segment strongly dilated
on mesial face and very asymmetrical; eleventh antennal segment

conical clavata

(0.9 mm.; Sao Paulo, Brazil)

Front rectilinear, and with two deep transverse sulci; tenth antennal

segment slightly asymmetrical; eleventh antennal segment ovate

impressifrons

(0.9 mm.; Sao Paulo, Brazil)
Melba impressifrons has aflBnities with both caviceps and temporalis.
Melba longicollis (Raffray, 1912), from Argentina may also belong in this
group, but the tenth antennomere is described as merely large and transverse.

118 NEOTROPICAL PSELAPHIDAE

Rameloidea

Only one species appears to belong here, Melba temporalis Raffray, from
Martinique (region of St. Pierre). By the four free vertexal foveae this species
approaches Ramelbida, but the lateral foveae are not visible from a dorsal
view ; the species also shows a relationship to impressifrons , but the tenth anten-
nal segment is simply transverse and symmetrical.

Vertelba

Here also belongs a single species, Melba caviceps Raffray, from French
Guiana. Described on a male, the tibiae are simple, and the length is given as
1.00 mm. long. The deep excavation of the head is approached only by Melba
impressifrons Raffray, but the tenth antennal segment is not asymmetrical,
although described as strongly transverse.

Key to Quadrelba

Head simply expanded on each side anterior of the eye; 0.8-0.9 mm.
long; St. Thomas and Puerto Rico, Antilles ventricosa

Head slightly expanded on each side anterior of the eye, and sub-
dentate; 0.8-0.9 mm. long; St. Thomas and Puerto Rico, Antilles
parmata

Key to Frontelba

The following key does not include Melba (Frontelba) fleutiauxi Raffray.
The inclusion of David Sharp's two Guatemalan species is questionable in
view of the inadequate descriptions and the geographic isolation of the two
groups of species. It is wholly possible that these two species belong in Melba
s.s. Sharp (1887, p. 38) says that mimula is closely related to clypeata; with
respect to his other species, minuta is said to have the head transverse-
quadrate (an approach to Quadrelba) but the figure of this species does not
show the quadrate head outline expanded anterior of the eyes, and does show
the anterior portion of the head expanded between the antennae. Examination
of tj'pes will have to resolve these questions.

Species known from Guatemala 2

Species known from the Lesser Antilles 3

2. Head distinctly longer than wide; 1.0 mm. long mimula

Head as wide or slightly wider than long; 0.8 mm. long minuta

3. Front produced between the antennae as a semicircular, fiat extension ;

0.75 mm. long ; St. Thomas clypeata

Front produced between the antennae, this extension with three
tubercles arranged in a triangular pattern; 0.9 mm. long; Gua-
deloupe frontalis

EUPLECTINI 119

Key to Melba s.s. Males

The following unsatisfactoiy key is based on the male sex only. The females
have only six sternites, whereas the males have seven sternites, the seventh
being in the form of a small oval subcircular, or more rarely subrhomboidal
plate. This plate (operculum, pygidium) is uncarinated medianly, asym-
metrically articulated, and enclosed by the incised sixth stemite and fifth
tergite. It should be noted that one species {longicollis Raffray) is a guest of
ants.

Third, fourth, and fifth sternites presumably simple, without tubercles,
foveae or conspicuous depressions (Raffray in describing these two
species discusses the male characters but makes no mention of such

sternal modifications ; types not seen) 2

Third, fourth, and fifth sternites with at least one segment secondarily
modified, often two segments modified by foveae, tubercles or de-
pressions 3

2. Metasternum longitudinally sulcate; sternites II to V subequal in

length; stemite VI medianly flattened; 0.9-1.0 mm. in length

crassipes

Metasternum flattened; sternites II to V progressively shorter; stemite
VI transversely impressed; 0.9-1.0 mm. in length grenadensis

3. Third sternite with a median transverse impression; fifth sternite with

two approximate transverse foveae; 0.6-0.7 mm. in length

inconspicua

Third sternite otherwise modified 4

4. Third sternite with a tubercle on each side; 0.75 mm. in length

specularis

Third sternite otherwise modified 5

5. Third sternite with an impression on each side, this depression sub-

tuberculate; metastemum not strongly impressed; 1.0 mm. in length

gibbula

Third sternite with an oblong, arcuate foveoid depression on each side ;
metasternum longitudinally impressed; length 1.0 mm eggersi

This key does not take into account a remarkable myrmecocolous species,
Melba longicollis Raffray from a nest of Atta lundi in Argentina. This species
is 1.10 mm. long and the male has the anterior and the intermediate femora in-
flated and the intermediate tibiae dentate. It is said to be near dentipes Raffray
of Pennsylvania but to have a more elongate-oval pronotal outline.

It is possible that both Sharj^'s species, which are placed in Frontelba,
belong in Melba s.s.

The species of the genus Melba may be listed as follows:

Melba s.s.

Tenth antennal segment not bilaterally asymmetrical ; vertex of head with
the vertexal foveae connected by an arcuate, more or less defined sulcus ; vertex

120 NEOTROPICAL PSELAPHIDAE

of head not modified between the eyes, usually simple, convex or flattened;
front of head simple between the bases of the antennae and tnmcate to gently
arcuate; head not dilated anteriad of the eyes, but narrowing from eye to
antennal insertion.

Melba of Casey (1897), and Group II of Raffray (1904).

crassipes Raffray. 1908. Guadeloupe, Leeward Islands.

eggersi (Reitter). 1883. Puerto Rico; St. Thomas, Virgin Islands.

(Trimiopsis)
gibbula (Reitter). 1883. St. Thomas, Virgin Islands. (Trimiopsis)
grenadensis Raffray. 1904. Grenada, Windward Islands.
inconspicua (Reitter). 1883. St. Thomas, Virgin Islands. {Trimiopsis)
specularis (Reitter). 1883. St. Thomas and Water Island, Virgin

Islands; Dominica, Leeward Islands. (Trimiopsis)
longicollis Raffray. 1912. Argentina, (con Atta lundi Guer.) cf.

Bruch, 1929.

Frontelba new subgenus

As for Melba, save that the front of the head is prolonged between the
antennal bases, above the epistomal area, as a flat or a multi-tuberculate, tri-
angular piece, more pronounced in the male sex.

Group III of Raffray (1904).

clypeata (Reitter). 1883. St. Thomas, Virgin Islands. (Trimiopsis)
fleutiauxi (Raffray). 1890. Guadeloupe, Leeward Islands. (Trimiopsis)
frontalis Raffray. 1908. Guadeloupe, Leeward Islands.
'f.mimula (Sharp). 1887. Guatemala. (Trimiopsis)
Iminuta (Shai-p). 1887. Guatemala. (Trimiopsis)

Vertelba new subgenus

Tenth antennal segment bilaterally symmetrical ; vertex of head with ver-
texal foveae between the eyes connected by an arcuate sulcus; vertex of head
with a large, deep, transverse excavation, the excavation being medianly tu-
berculate. Otherwise similar to Melba.

caviceps Raffray. 1909. French Guiana.

Quadrelba new subgenus

Tenth antennal segment bilaterally symmetrical ; vertex of head with ver-
texal foveae between the eyes connected by an arcuate sulcus; head quadrate
or square in outline, the sides being tumid, dilated or subdentate between the
eye and antennal base, this dilation being more pronounced in the male sex.

Group IV of Raffray (1904).

EUPLECTINI 121

pannata (Reitter). 1883. Puerto Rico; St. Thomas, Virgin Islands.

(Trimiopsis)
ventricosa (Reitter). 1883. Puerto Rico; St. Thomas, Virgin Islands.

{Tri7niopsis)

Ranieloidea new subgenus

Tenth antennal segment bilaterally symmetrical ; vertex of head with four
completely free vertexal foveae, an anterior pair between antennal bases, and a
posterior pair between eyes; no trace of connecting, arcuate vertexal sulcus
or sulci.

temporalis Rafifray. 1909. Martinique, Windward Islands.

Asymmelba new subgenus
Tenth antennal segment transversely triangular and bilaterally asymmet-

rical.

clavata Raffray. 1909. Brazil.
impressifrons Raffray. 1911. Brazil.

Tribe 5. Brachyglutini

The Brachyglutini is well represented in tropical America by twenty-eight
genera out of sixty odd for the world. As with the preceding tribe, following a
key to genera, these twenty-eight groups are arranged in linear form, although
few phylogenetic relationships can be demonstrated in this way. The arrange-
ment of these genera is almost the reverse of the order used by Raff ray (1908).
This eminent specialist placed the brachyglutines after the batrisines and
metopiines. From what has been said previously on the derivation of the
pselaphids from a staphylinoid stock, it appears that the batrisine genera are
much less staphylinoid than the Brachyglutini. This is especially obvious when
the tendency in Batrisini for the reduction or complete absence of the abdominal
margins is contrasted with the generally better developed margins of the
Brachyglutini.

On the other hand, the single tarsal claw of Brachyglutini is less staphy-
linoid than the two unequally developed claws of the Batrisini, although the
Euplectini have both tarsal claw patterns frequently developed. Again, the first
visible sternite in both brachyglutine and batrisine tribes is poorly developed,
but less invisible in the latter. Thus, although there are many exceptions in
both tribes, we feel that the batrisines are structurally more specialized than
brachyglutines. The twenty-eight genera alluded to are arranged here in a series
in which the species have progressively less contiguous posterior coxae, the
middle coxae are progressively less contiguous, and the abdominal margins are
progressively less developed. It should be noted that this is a tendency in the
arrangement, and not a complete application since, in many cases, other struc-
tural features have altered the relative position of genera in the series. For ex-
ample Drasinus and Decarthron are placed near each other, a course which I
adopted after examination of my material in both genera, and later discovered
that Fletcher (1928) had previously reached the same conclusion. Barada,
Eupsenius and Eupsenina begin the series as a consequence of their melbaform
affinities, and the approximate posterior coxae in the first two genera is common
in the Euplectini but very rare in the Brachyglutini. The remarkable glabrosity
of Eupsenius and Eupsenina however precludes considering them as very primi-
tive, but it is thought that these genera are more euplectine than many other
subglabrous genera and have arisen from euplectoid ancestors which have
evolved highly specialized species which exist today. The case for each genus
is more or less different, and involves summation of many values, thus the
almost marginless, subglobose body of Eupsenina is accompanied by capitate
setae on the ventral surface of the head, and many other instances could be cited.

The chief structural features which combine to distinguish this large tribe
are (1) oblique articulation of trochanter and femur of the middle legs, (2)
three-segmented tarsi, the first segment of which is relatively minute in con-

( 122 )

BRACHYGLUTINI 123

trast to the much larger last two segments, (3) third tarsal segment with only
a single claw, (4) generally globular posterior coxae, (5) abdomen with five
visible tergites and usually but five visible sternites. The first sternite is nearly
invisible between the posterior coxae with a few exceptions as in Eupsenius and
Eupsenina.

At present the Brachyglutini is the largest tribe in the family, is world wide
in distribution, and presents radiating lines of genera which appear to approach
Euplectini in some cases, Batrisini in others, and Tychini in still other cases.
Its central taxonomic position renders its study especially profitable for a
conceptual view of the family as a whole.

Key to the Genera

Posterior coxae contiguous or subcontiguous (PL XIV) 2

Posterior coxae distant 3

2(1). Ventral surface of head with a median, longitudinal carina;
maxillary palpi minute, with the first segment invisible ; pos-
terior coxae absolutely contiguous ; integument with brownish

pubescence ; known only from Venezuela BARADA

Ventral surface of head without any trace of a median, longi-
tudinal carina ; maxillary palpi normally developed ; posterior
coxae subcontiguous, with the first sternite visible between
them as a minute piece which is longer than wide; integument

glabrous, without punctures or pubescence (PI. XIV)

EUPSENIUS

3(1). Ventral surface of head with either a median, longitudinal

carina or a median fossa 4

Ventral surface of head without a median longitudinal carina
or fossa; habitus of Eupsenius, having the integument glab-
rous, with few punctures or pubescence, but posterior coxae
are widely separated, the first sternite beneath the meta-
sternal margin being a narrow, oblong piece, much wider than
long; each side of head from the ventral face is angulated in
the posterior half, the anterior portion being rounded and the
posterior half with the margin carinated EUPSENINA

4(3). Ventral surface of head with a large, median, oval fossa or
fovea, the borders of which are more or less carinated; anten-
nae always ten-segmented 5

Ventral surface of head with a median, longitudinal carina;
antennae either ten-segmented or eleven-segmented 7

5 (4). Third (penultimate) segment of maxillary palpi much longer

than wide EUTELEIA

Third (penultimate) segment of maxillary palpi transverse,
slightly or greatly wider than long, subtriangular, with the
external face rounded and the internal face angulated or sub-
acute 6

124 NEOTROPICAL PSELAPHIDAE

6(5). Base of each elytron with two foveae (PI. XVIII, 3)

DECARTHRON

Base of each elytron with three foveae ITAMUS

7(4). Antennae ten-segmented 8

Antennae eleven-segmented 9

8(7). Fourth (last) segment of maxillary palpi regularly ovoidal with

subacute apex ECTOPOCERUS

Fourth (last) segment of maxillary palpi with the internal face
either slightly concave or straight, and the external face con-
vex, the apex blunt DRASINUS

9(7). Maxillary palpi with the third (penultimate) segment lentic-
ular, with the long axis vertical, the external face concave and

bearing spongy pubescence BYTHINOGASTER

Maxillary palpi with the third segment not so formed 10

10 ( 9 ) . Abdomen with at least the first two tergites margined, the

margin may be narrow or wide, but is present 11

Abdomen with the tergites laterally limited by a single, simple
carina GLOBA

11 (10). Fourth (last) segment of maxillary palpi with a tooth or tu-

bercle on the external face, this tooth may be acute or blunt,

and may be at apical third or basal third (PL VII)

BERDURA

Fourth segment of maxillary palpi not so formed 12

12 (11). Middle coxae contiguous, the mesostemal and metasternal

processes not visible between them 13

Middle coxae either subcontiguous (in which case the meso-
stemum is visible between them as an acutely pointed, narrow
lamina), or distant (in which case the mesosternum is visible
between them as a more or less flattened plate with usually
a truncate end which is in contact with a flattened plate ex-
tending anteriorly from the metasternum) 18

13 (12) . Pronotum with the disc simply convex 14

Pronotum with the disc distinctly longitudinally gibbous or with
a median longitudinal carina, or with the disc deeply and
complexly excavated 17

14 (13). Lateral pronotal foveae relatively much larger than the median

subbasal pronotal fovea 15

Lateral pronotal foveae absent or vestigial, never larger than

the punctiform median subbasal fovea if present

PHOBERUS

15 (14). Elytra with a discal stria of variable length, but distinct 16

Elytra with no dorsal stria or striaform depression on disc. . .
EREMOMUS

16 (15). Epistomal region simple, or slightly expanded

REICHENBACHIA

BRACHYGLUTINI 125

Epistomal region remarkably dilated into a transverse plate
which extends apically beneath the antennae as far as the
second antennal segment, and laterally is almost as wide as
the head including the prominent eyes; known only from
Brazil NODULINA

17 (13). Disc of prontiim either with a strong, median, longitudinal

carina, or the disc is medianly, longitudinally gibbous

.' BUNODERUS

Disc of pronotum with a very large and deep excavation which
is trilobed, the large median lobe lies on the center of the disc
and is confluent with a smaller oblique lobe on each apico-
lateral angle of the disc, each of these oblique lobes being
more or less bilobed in themselves, giving a complex discal
picture ; this discal depression is in addition to the very large,
deep lateral fovea each side of pronotum in the anterior half,
and a small, circular subbasal fovea at middle; known only
from Panama PANABACHIA, new genus

18 (12). Middle coxae distant as previously described 19

Middle coxae subcontiguous as previously described 23

19 (18). Each elytron with either basal foveae, or with fine points re-

placing foveae 20

Elytra with no basal foveae, or replacing points of any kind; no
pronotal foveae, neither lateral nor median, but with the pro-
notal base wrinkled at margin PSELAPTUS

20 (19). Pronotum with no distinct foveae, neither lateral foveae nor a

median basal fovea; base of each elytron with four minute

points replacing the basal foveae SCALENARTHRUS

Pronotum with foveae, either two laterals and a median, or two
minute laterals and no median, or no laterals and a median
present 21

21 (20). Pronotum with a lateral fovea on each side and a median sub-

basal fovea present; base of each elytron with either two or

or four foveae XYBARIS

Pronotum with either the median fovea present and the lateral
foveae absent, or the median fovea absent and the lateral
foveae present 22

22 (21). Base of each elytron with four foveae; pronotum with the

median fovea present, and the lateral foveae absent ; pronotal

base transversely impressed MITONA

Base of each elytron with two foveae; pronotum with the
median fovea absent, and a minute lateral fovea present on
each side CRYPTORHINULA

23 (18). Pronotum with three subbasal foveae present, consisting of a

lateral fovea on each side and a median fovea, these foveae
distinct 24

126 NEOTROPICAL PSELAPHIDAE

Pronotum with lateral foveae lacking entirely, and the median
fovea may or may not be present, when present it is minute
and punctiform 27

24 (23). Fourth (last) segment of maxillary palpi briefly and regularly

ovoidal, very acuminate at apex 25

Fourth (last) segment of maxillaiy palpi ovoidal, but distinctly
sinuate near apex on external face 26

25 (24). Body short, subglobular with the habitus of Xybaris and

Scalenarthrus ; each elytron with three basal foveae; ab-
domen with the lateral margin very narrow; known only

from Brazil STROMBOPSIS

Body elongate, subparallel and flattened; each elytron with
either two or three basal foveae; abdomen with the lateral
margins normally developed; known only from Chile and
Cuba ACHILLIA

26 (24). Each elytron with two basal foveae RAXYBIS

Each elytron with either three or four basal foveae

BRYAXINA

27 (23). Each elytron with either four minute basal foveae, or four re-

placing points; median pronotal fovea may be absent or

present XYBARIDA

Each elytron with two basal foveae; median pronotal fovea
minute and punctiform but always present; habitus of
Bryaxina BRAXYDA

BARADA (Raffray, 1891)

The exceptionally small maxillary palpi, and absolutely contiguous pos-
terior coxae separate this genus from the rest of the tribe. The male sex has
sixth visible (seventh normal) stemite in the form of a small knob articulated
at the apical margin of the fifth visible sternite. A single species known, erected
on a single male (1.45 mm.), and to my knowledge the female has not been
discovered.

mucronata Raffray. 1891. Venezuela.

EUPSENIUS (LeConte, 1850)

LeConte (1850, 1863)

LeConte and Horn (1883)

Reitter (1883)

Brendel and Wickham (1890)

Brendel (1893)

SCHAUFUSS (1887)

Raffray (1896, 1904, 1908, 1909, 1911)

Leng (1920)

Bowman (1934)

BRACHYGLUTINI 127

The phylogenetic position of this genus is uncertain and many students
have had something to say regarding the species. Raffray (1896, p. 262) said
"The lack of suflfieient materials renders the characteristics of the genus erron-
eous up to the present", and now, some forty-five years later, the position is still
unsatisfactory. In 1850 LeConte erected the genus, based on Eupsenius glaber,
the genotype (PI. XIV) ; later this distinguished biologist described another
species rufus (1863). Since then seven species have been described from the
neotropics. Eupsenius appears to be very isolated in the northern part of its
range, has no near relatives in the morphological sense, and both its zoogeo-
graphic affinities and morphological affinities lie in the neotropics.

If Brachyglutini are limited by distant metathoracic coxae in part, and
Euplectini in part by contiguous to approximate coxae, then Eupsenius belongs
in the latter tribe. If, on the other hand, the Brachyglutini are chiefly limited
by triangular coxae and Euplectini by conical coxae, then Eupsenius belongs
in the former tribe. If Brachyglutini are said to have globular coxae, then it
becomes of interest to determine whether the triangular coxa is a globe or a
cone. Final emphasis on coxal shape is of value where one has worked in a group,
but is confusing and hardly practical otherwise since (a) exact coxal shape
varies between species, (b) a cone is more or less triangular while triangular
coxae are more or less conical if they have any length and thickness ; moreover
this descriptive term applies to the produced mesial end of each coxa and not
to the morphological whole which extends laterally nearly to the margin of the
metathorax.

The separation of the coxae has not been understood generally. Brendel and
Wickham (1890, Vol. I, p. 1) describe the coxae of Eupsenius as widely sepa-
rated. This is not correct, as pointed out by Raffray (1896, p. 262) , and Raffray
(1904, 1908) keyed out the genus as having the posterior coxae subcontiguous,
but placed it at the end of the tribe with Barada. However in the recent treat-
ment b}^ Bowman (1934, p. 2) Eupsenius will not key out since it is assigned
to the section of the tribal key having the coxae "very widely separated". In
his generic key, however, Eupsenius will key out perfectly (Bowman, 1934,
p. 76) on the Raffrayian characters affecting the ventral surface of the head.

In later years Raffray (1904, 1908) apparently had decided that this genus
was definitely Brachyglutine, but in his last discussion of the genus (1909, p. 36)
felt that Eupsenius and Eupsenina were very aberrant types of brachyglutine
stock which established a transition between the Brachyglutini and the Tychini.
It is readily seen that his earlier remarks (1896) are still available for adoption
now. It is even possible that this genus should form a new tribe or subtribe.

Regarding the antennae of glaber, LeConte originally stated that the
eleventh antennal segment was "wider in the middle than the tenth and one
half longer". He must have meant something else since the eleventh antennal
segment is much larger than the tenth segment, being longer than the third
to the tenth segments combined in glaber.

The two species of the United States are predominantly subtropical in
their distribution, having been recorded from South Carolina, Florida, and

128 NEOTROPICAL PSELAPHIDAE

Louisiana [glaber] and Alabama and Florida {rufus). It would be of interest
to study the types of all the species to see if glaber were more nearly related
to the Mexican species and rufus more nearly related to the Antillean species,
or if both arose from one or the other stem. Such data might throw light on
the possible migration route northward.

Apparently glaber is penetrating northward up the Mississippi valley, since
I have collected it near New Columbia, Illinois, the most northern record of the
genus to my knowledge.

Tentative Key to Neotropical Species

Posterior coxae slightly oblique mesially, the metasternum appearing
between them as a truncate edge, the coxae slightly separated 2

Posterior coxae not mesially oblique, the metasternum appearing be-
tween them as a minute, obtuse point, the coxae practically con-
tiguous 4

2. Ninth antennal segment as long as tenth antennal segment

niexicanus

(1.3-1.5 mm.; Mexico)
Ninth antennal segment shorter than tenth antennal segment 3

3. Tenth antennal segment two times as long as ninth segment . gibbicollis

(1.6-1.7 mm.; Mexico; eleventh antennal segment
as long as second to tenth inclusive combined)

Tenth antennal segment three times as long as ninth segment

longicollis

(Bogota, Colombia; 1.8 mm.)

4. Known only from Mexico grouvellei

(1.2-1.4 mm. long; Mexico; segments of antennae IX and X lentic-
ular, XI ovate, acuminate, shorter than in mexicanus ; male last
sternite lightly, longitudinally sulcate)
Known only from the Antilles 5

5. The last three described species are not separable with any certainty

without recourse t,o the types:

a. -polity^ Reitter. St. Thomas, Virgin Islands.

Ninth and tenth antennal segments less lenticular than in grou-
vellei; eleventh segment longer and less ovate than in grou-
vellei.

b. dominicanv^ Schaufuss. Hispaniola (probably Haiti as the citation

is Saint-Domingue)
Said to be similar to grouvellei and polity^ but the antennae are
lost from the type (only known specimen) according to
Raffray, 1896.

c. gracilis Raffray. Grenada, Windward Islands. 1.0-1.1 mm. long.

Near politus, but the ninth and tenth segments of antennae are

BRACHYGLUTINI 129

more transverse than in politus, and the eleventh segment
thicker than politus, and cited as being less than half the length
of the antenna. Antennal segment IX lenticular, X transverse
and twice as large as ninth, XI large and conical.

The general habitus and structural detail of the genotype, glaber, is de-
picted in the plates. Raffray (1908, 1909) has already remarked on the tychine
character of the fourth segment of the maxillary palpi, this segment being
slightly securiform.

The shining, glabrous, short and thick body, general lack of punctures and
setae on the integument, the yellowish to reddish-yellow color, the subcontig-
uous posterior coxae, slightly securiform and large distal segment of the max-
illary palpi, and the exceptionally large and melbaform eleventh antennal seg-
ment give a constant habitus to the genus.

The species may be listed as follows:

dominicanus Schaufuss. 1887. Hispaniola.

gibbicollis (Raffray). 1896. Mexico. {Euprenius Raffray nee LeConte)
gracilis Raffray. 1904. Grenada, Windward Islands.
grouvellei (Raffray). 1896. {Euprenius) Mexico.
longioollis (Raffray). 1896. (Euprenius) Colombia.
mexicanus (Raffray). 1896. (Euprenius) Mexico.
politus Reitter. 1883. St. Thomas, Virgin Islands and Guadeloupe,
Leeward Islands.

EUPSENINA (Raffray, 1909)

Eyes large, set in a trapezoidal head, the ventral surface of which is devoid
of longitudinal median carina or large median fossa. The maxillary palpi are
minute, the first segment very minute, second slender at base and swelling
apically where it is abruptly clavate, third small and globose, fourth subsecuri-
form, subovate. Eleven-segmented antennae with the first segment elongate
and cylindrical, the antennae subgeniculate between the long first and the
shorter second segment, which varies in shape between the species from globose
to triangular, third to eighth small, moniliform, ninth and tenth lenticular, cres-
centric, the eleventh segment relatively enormous. Pronotum subcordate. Elytra
relatively very wide. Abdomen with tergites subequal, and with six sternites.
Other differences are notable but are discussed in the description of a new
species.

The genus is not discussed in the Genera Insectorum, so a rather free trans-
lation of Raffrey's remarks is not out of order:

"This genus is very aberrant and extremely near Eupsenius, which it resembles
in habitus, and hardly differing at first sight with its geniculate antennae; but
differing from Eupsenius by the smaller palpi, of which the last segment is
more acuminate; ventral surface of the head does not have the lateral carina

130 NEOTROPICAL PSELAPHIDAE

of Eupsenius, the eyes are smaller, the posterior coxae are widely separated,
with the metasternum squarely truncate between them, uncovering the first
sternite which is short, not extending beyond the coxae, but really visible.
Among certain species of Eupsenius the first sternite is equally a little visible,
especially when the posterior coxae are more or less separated. The visibility
of the first sternite, coupled with the lack of a median longitudinal carina
on the ventral face of the head, renders the addition of this new genus very
embarrassing, and there is but little logic in placing Eupsenina in Tychini on
the basis of the visibility of the first sternite, but on the other hand, Eupsenina
resembles Eupsenius, where the latter's invisible first sternite (or nearly so)
places it in the Brachyglutini. It is impossible to isolate Eupsenius from
Eupsenina, each in a separate tribe since they resemble each other so much."

There are three species in the genus Eupsenina at present; they may be
rapidly separated as follows:

Second segment of the antennae spherical to ovate and simple 2

Second segment of the antennae conspicuously, transversely triangular,
the mesial or internal face being produced and subacute, the lateral

or external face simply convex patricia new species

2. Second antennal segment ovate ; vertexal sulci arising from the vertexal
foveae short, not uniting with the frontal depression anteriorly be-
tween the bases of antennae fracticornis

(1.1 mm.; described on female; meta-
sternum large and simply convex)
Second antennal segment spherical; vertexal sulci arising from the
vertexal foveae long, uniting with the frontal depression anteriorly

between the bases of antennae sulcifrons

(1.2 mm.; described on male; metasternum medianly foveate)

Eupsenina patricia new species

Type Male. Measurements: head 0.2 x 0.3 mm. through eyes; pronotum
0.28 X 0.26 mm.; elytra 0.43 x 0.49 mm.; abdomen 0.15 x 0.5 mm.; total length
1.06 X greatest width 0.5 mm.

Uniform yellowish-brown, the integument highly polished and subglabrous.
Under high magnification the integument is minutely punctulate, with very
sparse, just perceptible setae (0.01 mm. long), these setae being about five per
one-tenth square millimeter. At lower magnification the integument appears
to be glabrous.

Head subtriangular from a dorsal view if the eyes are not included. Eyes
large and prominent, being 0.087 mm. long, and composed of about 50 distinct
facets, subcircular from a lateral view, set in the anterior half of the head and
slightly longer than the tempora. Tempora 0.08 mm. subparallel, with rounded
posterior angles forming the subtruncate, inconspicuous occipital margin.
Vertex evenly, broadly convex with each side converging above the eye to form
a subacute, triangular extension between the bases of the antennae, and extend-

BRACHYGLUTINI 131

ing slightly beyond this line. This triangular extension simple with its apex
continuous with simple, strongly declivous front. Vertexal foveae minute,
placed on a line passing through the posterior margins of the eyes, and each
fovea directly posterior of the antennal base; this pair of vertexal foveae con-
nected by a pair of distinct, fine sulci which converge to unite near the anterior
fourth of the eyes, i.e. the vertexal sulci are short, and enclose a triangular area
of the vertex which is a smaller, more posterior replica of the frontal extension
alluded to above, the lateral margin of the vertex being paralleled by the nearest
vertexal sulcus. The ventral surface of the head is peculiar: it is fiat, glabrous
and medianly simple without median fossa or carina, and even the characteristic
basal gular fovea is absent. There is a transversely oblique, short depression
each side near the cephalic-cervical constriction; this depression on each side is
moderately deep and from an oblique view the apical wall of the depression is
strongly carinated so that the ventral surface of the head is deceptively flat
from a direct view, but strongly angulate-carinate in reality. Thus the carina
forming the wall of the short depression each side forms the transversely-oblique
carina so typical of the genus Eupsenina; anteriorly, this carina becomes obso-
lete, and is represented by a small tumulus near the postero-ventral angle of
each eye. The two transverse depressions noted above probably have their floors
attached to the base of the supratentorium, and if so, they are collectively
homologous to the gular fovea of other pselaphids. On each side of the ventral
surface of the head are three distinct, capitate setae, reminiscent of melbaform
euplectines. Anteriorly, the setae are on a line with a conspicuous, arcuate,
narrow process which arises near the base of each maxilla, between the eye and
the mentum ; this slender process extends anteriorly in a divergent arc nearly to
the level of the mandibles in repose, and each process bears six capitate setae.
At first sight these arcuate extensions appear to arise from the maxilla, and so
lend an allusion to the maxillaiy extension of the Jubinini.

Maxillae well-developed, the cardo and stipes large, the galea with a well-
developed brush of setae. Maxillar>'' palpi four-segmented, first segment
minute; second elongate, very slender basally, suddenly inflated apically ; third
subtriangular, short, not quite as wide as second, mesial face acute, lateral face
convex; fourth longer than second and twice as wide, obliquely truncate at base,
subacute at apex, bearing a palpal cone, the mesial face is much more convex
than the lateral face.

Antennae eleven-segmented, equal to the elytra in length (0.43 mm.), con-
spicuous; segment I elongate-cylindrical (0.08 mm. long x 0.04 mm. wide) ; II
conspicuously triangular (0.06 mm. long x 0.06 mm. wide), with lateral face
convex and mesial face acutely produced; III briefly obconical; IV-VII sub-
equal, as wide as third, closely articulated, submoniliform, conspicuously nar-
rower and shorter than second segment; VIII submoniliform, slightly larger
than seventh; IX transverse, larger than eighth; X very transverse, much wider
than ninth and nearly as wide as eleventh, but very short and not much longer
than ninth, rather disc-shaped from a direct dorsal view; XI exceptionally large
(0.2 mm. long x 0.067 mm. wide) , about as wide as second segment and clothed

132 NEOTROPICAL PSELAPHIDAE

with long setae (0.067 mm. long) which are distinctive since the rest of the body
is subglabrous save for the ventral capitates of the head, and the hirsute meta-
sternum noted later; this last segment is about one-half as long as the total
antennal length; simply truncate at base, slightly sinuate apically, the segment
being subsecuriform in outline with a straight lateral face becoming concave
or sinuate apically, and the mesial face straight in basal half and strongly
convex in apical half. The antennae are subgeniculate, as a consequence of the
elongate first segment ; moderately distant at base, being separated by the tri-
angular front, their separation being equal to the width of the eleventh segment.

Pronotum melbaform, simple, obcordate, with unmodified disc, and rounded
lateral margins ; no median basal fovea, but an indistinct transverse, subbasal
sulcus which is entire laterally but interrupted medianly; this sulcus or sulci-
form stria continues down each lateral flank of pronotum to end in a lateral
fovea on each side; this fovea is glabrous, shallow and distinct laterally but not
dorsally. Pronotal-prosternal coalescence demarcated by a carina which is
anteriorly continuous with the apical pronotal margin.

Scutellum distinct and sharply triangular.

Elytra with the humeri obliquely tumid ; each elytron with the sutural stria
turning obliquely near the scutellum and parallel to the basal margin, forming
a transverse basal carina reminiscent of Sebaga; two small, glabrous basal
foveas on each elytron, just posteriad of the transverse basal carina (which
separates this species from the unifoveate elytron of the other species of the
genus). No subhumeral fovea or subepipleural sulcus on elytral flank.

Abdomen exceptionally short, specialized, convex. Five visible tergites, first
tergite about twice as long as second medianly, and very closely fitted to the
elytra, with no basal discal carinae; second one-third longer than third; fourth
long, longer than second; fifth subtriangular, not visible from above, ventro-
declivous, long being about one-half longer than fourth tergite. Six sternites
clearly visible; first forming a short, very transverse plate, about four times
wider than long, closely fitted between posterior coxae and metasternum, and
also visible laterally as a gradually lengthening plate, ending beneath the
elytra; second sternite not quite twice as long as first, and with a prominent,
short, longitudinal, slightly arcuate carina from the basal margin on each side
between coxa and elytra, so that this carina must be looked for from an oblique
view; third sternite very short, half as long as second; fourth still shorter; fifth
longer, as long as third; sixth very large, transversely semilunar, with strongly
convex basal outline and slightly bisinuate apical outline, investing the apical
margin of the fifth tergite; this sixth sternite as long as fifth tergite, or as long
as the first to fifth sternites combined. The abdomen has a distinct Globa aspect.
Only a small portion of the fourth tergite and none of the fifth visible from
above. The abdomen has no margin at all, and consequently the abdomen is
formed of a series of unbroken rings ; the first tcrgite-second sternite forms the
first ring; second tergite-third sternite the second ring; third tergite-fourth
sternite the third ring. For these three rings the terms "tergite" and "sternite"
are used in a functional sense only. The fourth tergite and fifth sternite are

BRACHYGLUTINI 133

morphologically separated by an oblique suture. The fifth tergite and sixth
sternite are free to allow separation distally for the extrusion of the penis.

Prosternum very short before the anterior coxae, simple.

Mesosternum tumid, with carinoid margins, and medianly elevated into a
longitudinal carina. Middle coxae approximate but not contiguous.

Metasternum large and complex; glabrous laterally and pubescent me-
dianly. This sparsely pubescent area extends from the posterior coxae to an
acute angle posterior of the median metasternal process which enters between
the bases of the middle coxae, and the edges of this pubescent space are sharply
raised or carinoid. The arcuate lateral carinoid margins of the area bifurcate
anteriorly to send out an oblique carina posterior of each middle coxa, which
passes externally of the coxa and ends just above sternal fovea IV on each side.
Sternal foveae IV and V well-developed. Pubescent metasternal area depressed
and thin in the posterior, median third between the posterior coxae. Posterior
coxae very widely separated.

Anterior femora inflated; flattened on the ventral face in the apical half,
this flattened area oblique and glabrous and bearing at its basal external angle
a distinct foveoid scar. Tarsi very long and slender, first tarsomere minute, sec-
ond and third very much longer, the last tarsomere being shorter and thinner
than second. This third tarsomere bears a single claw. Under high magnification
on a slide mount this claw is seen to be distinctly bifid at apex!

Described on a single male specimen, collected by the author from decayed
log mold at Drayton 15 on Barro Colorado Island, Gatun Lake, Panama Canal
Zone.

This minute, distinctive species is easily separable from its congeners by
the triangular second antennal segment, sexual characters, and single fovea of
each elytron. Its anatomy is so divergent that it may warrant subgeneric isola-
tion with further accumulation of data.

fracticornis Raffray. 1909. Brazil. Genotype.
patricia new species. Panama Canal Zone.
sulcifrons Raffray. 1917. Paraguay.

EREMOMUS (Raffray, 1904)

This genus contains two South American species, closely allied to Reichen-
bachia. The head in both species has the vertex trifoveate, the foveae being large
and equal in size, a pair of vertexal foveae lie on the head between the eyes,
and a third fovea is on the anterior region of the head between the antennal
bases, just behind the nearly truncate front. The four-segmented maxillary
palpi have the usual minute first segment; second segment elongate, very slender
at base and suddenly globose in distal third of its length ; third segment trans-
versely triangular, with the mesial face acute and lateral face rounded convex;
fourth segment very much wider than third, ovate, base truncate, apex acute.

134 NEOTROPICAL PSELAPHIDAE

bearing a short palpal cone. Ventral surface of head with a single, median, longi-
tudinal carina. Pronotum with simple disc, and three foveae of unequal size, a
lateral fovea each side at basal third which are larger than the median, subbasal
fovea. Elytra with no dorsal stria, and each elytron with two basal foveae
(Raffray, 1904), not trifoveate as stated by Raffray (1908) ; elytra triangular.
Abdomen with first tergite with a pair of discal carinae, and much longer than
second. Female sex known; male unknown.

Key to the Species

Antennae with segments IV-VII cylindrical, VIII much shorter than
either seventh or ninth and quadrate; 2.3 mm. long; known only
from Bolivia obesus

Antennae with segments IV and V ovate; VI-VIII progressively
shorter and progressively wider; 2.0 mm. long; known only from
Brazil crassicornis

crassicornis Raffray. 1904. Brazil.
obesus Raffray. 1904. Bolivia. Genotype.

PHOBERUS (Raffray, 1904)

This is a monotypic genus known only from Bolivia. Ventral surface of
the head tricarinate, a median, and a lateral longitudinal carina each side of
head (in the male the lateral carinae are very strong, and are obsolete in the
female). Maxillary palpi four-segmented, first minute; second elongate cyl-
indrical, very gradually widening toward apex; third segment briefly obconical
(or vertically triangular and as long as wide, with the base acute and apex
broadly truncate) ; fourth elongate, regularly fusiform, subacute at base and
apex bearing a slender palpal cone. Pronotum subhexagonal, with a median
subbasal punctiform fovea, but no lateral foveae. Elytra with no dorsal stria;
each elytron with three slightly elongated basal foveae; humeri prominent,
nearly square in the male and rounded and obtuse in the female. First tergite
longer than second, and with a pair of divergent basal discal carinae. Abdominal
margin very strong, wide on the first two tergites.

Male with second antennal segment longer than first, cylindrical, with the
mesial-apical face produced internally into a tooth; ninth antennal segment
transverse, with the mesial-apical face triangularly produced into a large tooth ;
tenth segment distinctly shorter than ninth and drum-shaped. Head deeply
excavated medianly, between eyes and antennal bases, this excavation com-
plexly armed; epistome spinoid.

Female with antennae with segments II and IX not toothed ; the frontal
excavation of the head smaller, simpler. 2.0 mm. long.

armatus Raffray. 1904. Bolivia. Genotype.

BRACHYGLUTINI 135

REICHENBACHIA (Leach, 1826)
LeConte and Horn (1883) (Bryaxis)
Sharp (1887) {Bryaxis in part)
Brendel and Wickham (1890) {Bryaxis in part)
Casey (1897)

Raffray (1904, 1908, 1908a, 1908b, 1909, 1911, 1917)
Fletcher (1928, 1928a)
Bowman (1934)

Reichenbachia junoorum (Leach) of Europe and Algeria is the genotype.
Reichenbachia is the largest genus of the Pselaphidae, holding approximately
313 described species. Of this great number possibly twenty-one may belong to
other genera, but have been so briefly described that they may not be verified
without recourse to the types. These species are distributed over the world, the
genus being cosmopolitan with the exception of Australia and New Zeland. The
Americas have over a third of the species of the genus, there being sixty species
north of Mexico and seventy-eight species south of the Rio Grande river. The
North American species have not received original treatment since 1897 when
Casey keyed out these species ; the neotropical species have never been treated
as a f aunal unit. Both North and South American faunae need revision badly ;
many new species remain to be described, types must be examined to resolve
several complex taxonomic situations, synonyms need to be studied and a new
key developed; especially desirable is the formulation of a complete key on
characters common to both sexes. Such treatment can not be offered at this time.

Reichenbachia occupies an important taxonomic position for the Brachy-
glutini, and is structurally much more average than the genus Pselaphus which
has given the name to the family as a whole. The neotropical species have in
common the following characters: (1) distant posterior coxae, (2) ventral sur-
face of the head with a median, longitudinal carina or carinoid swelling, (3)
eleven-segmented antennae, the segments of which are nearly infinitely varied,
especially in the male sex (PL XVI, XVII) , (4) four-segmented maxillary palpi,
of relatively simple and generalized pattern as described later, (5) abdomen
with a distinct lateral margin, (6) middle coxae contiguous, (7) pronotum with
the disc simple, evenly convex and not sulcate, foveate or carinate, (8) pronotum
with three subbasal foveae, the lateral foveae relatively much larger than the
median fovea, these three foveae never connected by a transverse subbasal sulcus,
(9) each elytron with a distinct dorsal or discal stria, varying in length among
the species, and either two or three basal foveae, (10) the epistomal region gen-
erally simple and normal, sometimes slightly expanded laterally or vertically
elevated but never swollen to the width of the head.

Certain species are at least facultative synoeketes; the majority of the
species pass the day in floor mold of forests, becoming active at night. The large,
coarsely faceted eyes and well-developed metathoracic wings coincide with their
commonly observed reaction of flying to night lights. Both sexes come to lights
at night, in about equal proportions for most species observed. Their powers of

136 NEOTROPICAL PSELAPHIDAE

flight may have had a definite dispersal value, especially when their cosmopoli-
tan distribution is noted. Poor flght for one sex, as in the case of many Jubus,
would prove to be a restrictive factor in species dispersal as much as poor flight
for both sexes, and it is of interest to again point out the parallel development
of large eyes and wings in so many instances, or the converse of rudimentary^
eyes and wings in one or both sexes within the family. A few of the neotropical
species have a moderately wide distribution, sallaei being reported from
Mexico, Guatemala, and Panama, parviceps with the same general range, celata
from Mexico, Guatemala and Nicaragua, reichei from Guatemala and Co-
lombia. With wide geographic ranges known for certain species of the genus,
structural characters become of great importance in separating new species,
since similar specimens from relatively distant localities may represent either
the same species, or variations within the same species population.

The genus as a whole was separated into at least seven valid divisions and
sixty species groups by Raffray in 1904. The addition of new species since that
time has increased the number of groups holding neotropical species. Probably
a new group will have to be formed to hold femoralis Fletcher, and one species
has been placed in a new genus {vide infra). Three of Raffray's seven divisions,
and eighteen out of sixty species groups, contain neotropical representatives of
Reichenbachia. The following arrangement is based upon Raffray's 1904 treat-
ment, and deals only with these neotropical species groups. Unfortunately, such
keys place emphasis upon the male sex, and in most instances the females of
this genus must be assigned by association rather than by exact structural detail.
Among the neotropical species there are seven groups in which both sexes have
the head, mandibles, antennae, pronotum and legs simple and unmodified. In
these groups the males and females are difficult to separate. In such cases direct
dissection to expose the copulatory organs, or cleared slide mounts to examine
the latter, will settle the question of the sex of specimens; where a series is
available this method of direct examination of one or two specimens is necessary
to correlate minute structural differences with sex. These methods have been
fully discussed in the section on preparation of material for study. The fifth
visible (most distal) sternite is large in the genus, and subject to some varia-
tion. Such variation is especially found in the males and consequently proves
helpful in separation of sexes in the seven groups noted above; the male fifth
sternite is often laterally sinuate, or concave medianly, this concavity varying
from a simple, even depression to a longitudinal impression. The males of the
other groups are strikingly marked, with abnormal antennae, or front, or legs
in various combinations, often grotesque and frequently very^ similar in allied
species. In the following tentative key I have relied chiefly on structural char-
acters of the male sex; the Roman numerals refer to the 1904 Raffrayan group
number.

Key to the Neotropical Species Groups

Species in which both sexes are essentially normal in most particulars,
and agree in the following essential items: (1) the vertex has three

BRACHYGLUTINI 137

foveae, these are subequal in size and have a relatively constant
position, namely two placed between the eyes, and median fovea be-
tween the antennal bases; (2) vertex normally convex or flattened
between the eyes; (3) antennae with the segments normal; (4)

femora and tibiae normal 2

Species in which both sexes, or the male sex only, have at least one,
frequently two or more, of the following essentially abnormal items:
(1) anterior fovea of head normal in position between the antennal
bases, but minute in size as compared with the two foveae between
the eyes; (2) anterior fovea abnormally placed, incising the frontal
margin, or lodged entirely on the steeply declivous front; (3) an-
terior or frontal fovea wholly absent, in which case the head has but
two vertexal foveae; (4) vertex abnormal, either medianly vaulted
and swollen, or with a median longitudinal carina or obtuse eleva-
tion; (5) antennae with one or more segments very abnormal in
shape, size or bearing accessory foveae, spines or other deformities ;
(6) femora or tibiae or both, on one or more pair of legs, abnormally
swollen, dilated, compressed or excavated 7

2. Each elytron with three basal foveae 3

Each elytron wdth two basal foveae 5

3. Lateral pronotal foveae circular to subcircular 4

Lateral pronotal foveae transversely oval, or distinctly wider than

long Group X.

4. Basal discal carinae of first tergite relatively very long, at least one-

half of the segmental length Group VI.

Basal discal carinae of first tergite relatively very short, not more
than one-fifth of the segmental length Group IX.

5. Pronotum glossy and polished, very lightly punctulate; elytra dis-

tinctly punctate Group XVII.

Body glossy and polished, very lightly punctulate 6

6. Dorsal or discal stria of each elytron well-developed, long, extending

beyond the middle of the elytral length Group XX.

Dorsal or discal stria of each elytron shorter, not extending beyond
the middle of the elytral length Group XXI.

7. Dorsal surface of head with three subequal, normally placed foveae,

e.g. two between the eyes, and one between the bases of the antennae 8
Dorsal surface of head abnoniial in one of the following ways: (1)
vertex medianly, longitudinally carinate or obtusely elevated; (2)
vertex vaulated and swollen medianly; (3) the anterior or frontal
fovea minute but normally placed between antennal bases; (4) an-
terior fovea incising the frontal margin or wholly on the declivous
front; (5) the anterior or frontal fovea wholly absent 11

8. Posterior tibiae normal, neither dilated, nor flattened nor excavated. . 9
Males with the posterior tibiae abnormal, either dilated with a long

138 NEOTROPICAL PSELAPHIDAE

median depression on ventral face, or strongly swollen at apex

Group XLVII.

9. Antennal segment X abnormally large in both sexes, being as wide or
distinctly wider than the eleventh segment which is also very large.

(PI. XVII, 10) Group XXXV.

Antennae with the tenth and eleventh segments normal, but one or
more of the intermediate segments (fourth to ninth) abnormal 10

10. Antennal segment V abnormally large, distinctly larger than the fourth

or sixth segments, the sixth segment not abnormal. (PI. XVII,

11-15) Group XL.

Antennal segments V and VI simple in the females and very abnormal
in the males (PI. XVII, 16) Group XLI.

11. Antennae with segments normal in both sexes 12

Antennae with" one or more segments abnormal in the males, and

normal in the females 13

12. Head with the anterior, median fovea present and incising the frontal

margin so that it is abnormal in position Group LI.

Head with the anterior, median fovea wholly absent .... Group LIV.

13. Antennal segment V of the male (female unknown) slightly longer

than either fourth or sixth segments ; anterior, median fovea of head
present between antennal bases, but minute; middle tibiae armed
with a small spine near apex; posterior femora strongly dilated, with
the dilation broadly and entirely excavated on the posterior face;

known only from Peru Group LXIV, new group.

Anterior, median fovea of the head wholly absent, or if present ab-
normal in position or subequal in size to the two foveae between the
eyes, not minute as described above; legs in the male not so formed 14

14. Head with the vertex either (1) medianly swollen or vaulted between

the two inter-ocular foveae, or (2) medianly and longitudinally

carinate between the inter-ocular foveae 15

Head with the vertex normally convex to flattened between the inter-
ocular foveae 16

15. Head with the vertex simply but prominently swollen between the

two vertexal foveae in both sexes, this swelling does extend towards
the front, but does not reach the frontal margin ; males with meta-
sternum distinctly, medianly impressed and females with meta-

stemum flattened Group LIX.

Head with the vertex sharply, medianly, longitudinally carinated be-
tween the inter-ocular foveae, this carina especially well formed
posteriorly to occipital crest (male), or vertex with the carina not
sharp, but in the form of an obtuse elevation between the inter-
ocular foveae Group LV (in part).

16. Anterior median fovea of the head present but abnormally placed,

either incising the frontal margin, or wholly on the declivous front 17

BRACHYGLUTINI 139

Anterior median fovea wholly absent, the head, therefore, having only-
two foveae on the dorsal surface 18

17. Antennal segments V and VI very large and more or less abnormal

beneath Group LII.

Antennae with segments VI to X inclusive abnormal. . . .Group LIII.

18. Antennal segment V abnormal, being very long, often armed or other-

wise unusual; VI normal Group LV (in part) .

Antennal segments V and VI abnormal ; epistome may or may not be
prominently produced into a median, dorsal spine. . . .Group LVI.

Group VI

Only a single neotropical species belongs to this group, the other represen-
tatives being Asiatic. This neotropical species is unique in having very long
basal discal carinae on the first tergite, these being subparallel, separated by
one- third of segmental width, and two-thirds the segmental length, extending
to apical third of the first tergite. Described on a male specimen ; the trochanters
of the middle legs are armed with a sharp spine at middle of posterior margin.
Length 1.8 mm.

limpida Fletcher. 1928. Peru.

Group IX

Antennal segment V distinctly longer than the fourth or sixth seg-
ments boliviensis

(2.0 mm. ; known only from female)

Antennal segment V not so formed 2

2. Antennae relatively shorter and thicker; 1.8 mm.; known only from

the female grouvellei

Antennae relatively longer and more slender; known only from the
female pubescens

boliviensis Raffray. Bolivia. 1904
grouvellei Raffray, Mexico. 1904
pubescens Schaufuss. Mexico. 1879

Group X

Antennal segment IX subquadrate — obconical, only slightly larger
than eighth segment; segment X similar to the ninth segment in
form and somewhat larger; 2.15 mm. long aubeana

Antennal segment IX trapezoidal, slightly transverse, slightly larger
than eighth segment; segment X very much larger than ninth seg-
ment, truncate — obconical; 1.9 ram. long gounellei

aubeana (Raffray). 1890. Venezuela. {Bryaxis)
gounellei Raffray. 1909. Brazil.

140 NEOTROPICAL PSELAPHIDAE

Group XVII

There is but one species in this group. Antennae slender, with a two-
segmented club, segment VII subquadrate; VIII subquadrate, slightly trans-
verse; IX quadrate; X large, twice the size of ninth, subovate; XI moderate
in size in comparison to the eleventh segment of many other species, briefly
fusiform. Basal discal carinae of first tergite including one-third of segmental
width. Metasternum obsoletely, medianly carinate. Last sternite slightly im-
pressed, with apical margin medianly obtusely, triangularly produced, with
a slight sinuation on each side. 1.6 mm. The elytra are distinctive, being
cribrately, rugosely punctate. Known only from the male sex.

curvipes Raffray. 1904. Brazil.

Group XX

Antennal segments I and II elongate, cylindrical; III obconical; male
with metasternum widely impressed and last sternite large, strongly
oblique laterallj^, medianly truncate and with a subovate, distinctive
and large impression; the middle trochanters each with a small,
obtuse tooth; 1.8 mm. long irrita

Antennal segments I and II not elongate-cylindrical; male secondary
sexual characters (where known) not as above 2

2. Antennal segment I quadrate; II ovate; III minute and briefly ob-

conical; IV twice as long as third; V cylindrical, slightly wider than
fourth and much longer; VI much larger than fifth; VIII strongly
quadrate; IX large, truncate, obconical; X similar to ninth but
larger; XI moderate in size, ovate, truncate at base and acuminate
at apex; basal carinae of first tergite only including one-fourth of the
discal width. Known only from the female; 1.6 mm luteola

(When the male is found it may prove to have abnormal antennae
especially since the third segment of the female is rather excep-
tional; if this proves to be the case this species will go to another
group of the genus)

Antennal segment I large; II narrower and subcylindrical ; III-VII
small and oblong; VIII quadrate; IX obconical; X subquadrate;
XI large, ovate, acuminate 3

3. Metasternum unmodified, hardly depressed; last sternite widely exca-

vated, and ogival in shape (in the form of a pointed arch) ; 1.6

mm. long estebanensis Male

Metasternum similarly unmodified; last sternite transverse, medianly

with an obsolete fovea, apex sinuate; 1.6 mm. long

estebanensis Female

estebanensis (Raffray). 1890. Venezuela and Brazil. (Bryaxis)
irrita Raffray. 1904. Mexico.
luteola Raffray. 1904, Mexico.

BRACHYGLUTINI 141

Group XXI
This large group is not understood well enough at present to give a work-
able key.

goryi Aube. 1833. Colombia.

chevrolati Raffray. 1904. Brazil.

illepida Raffray. 1904. Brazil.

obesa Raffray. 1909. Brazil.

parviceps (Sharp). 1887. Mexico, Guatemala, Panama. (Bryaxis)

pilosa Raffray. 1904. Venezuela, {pilosella of Raffray, 1890, not the

pilosella of Schaufuss.)
pilosella Schaufuss. 1872. Venezuela.
rubra Aube. 1844. Brazil.
semisanguinea Schaufuss. 1887. Brazil, {minassanae Schaufuss,

female) 1887.
subfoveolata Schaufuss. 1872. Colombia. (However, see Group LIV)
subnitida Schaufuss. 1887. Brazil.
tenuicornis Schaufuss. 1887. Brazil.

Group XXXV

Antennal segments VII and VIII slightly transverse ; IX very trans-
verse, being only slightly longer than eighth but twice as wide as
eighth; 1.9 mm. long; not known north of Paraguay. .^Mbencorms

Antennae with segment IX transverse, but not twice as wide as the
eighth segment; not known south of the equator 2

2. Antennal segment X large, but not wider than eleventh segment;

segments VII, VIII and IX strongly transverse; known only from

Colombia and Venezuela lebasi

(middle trochanters spined in Male and simple in Female)
Antennal segment X large, slightly to distinctly wider than eleventh
segment; known only from the Antilles 3

3. Antennal segment X distinctly wider than the eleventh segment, dis-

tinctly obconical with the truncate base narrower than the truncate
apex, and the sides divergent from base to apex; known from

Grenada (PI. XVII, 10) grenadensis 4

Antennal segment X slightly wider than eleventh segment; known
from St. Vincent Island vincentiana 5

4. Antennal segment XI oblong, with truncate base and acute apex;

segments VII, VIII and IX very transverse, from one-third to one-
half wider than long; 2.0 mm. long Male (PI. XVII, 10)

Antennal segment XI ovate, with a much narrower base; segments
VII, VIII and IX much less transverse Female

5. Antennal segment X square, with the internal or mesial face rounded

Male

Antennal segment X nearly two times longer than ninth segment, and
only a little wider Female

142 NEOTROPICAL PSELAPHIDAE

grenadensis Raffray. 1904. Grenada, Windward Islands.
lebasi Aube. 1844. Colombia and Venezuela.
tubericornis Raffray. 1917. Paraguay.
vincentiana Raffray. 1904. St. Vincent, Windward Islands.

Group XL

The following key is unsatisfactory since it does not take into account
two of the species assigned to this group, pentachiroides (Schaufuss) of Brazil
and intacta (Sharp) of Guatemala. As to the latter species, I can make noth-
ing of the description which would effectually separate it from its congeners.
Sharp says that the fifth antennal segment is greatly enlarged and foveolate-
impressed in front. The large fifth segment is a group characteristic, and I do
not know what face of the segment is meant by the "front". This, like many
other species, must await examination of the types before proper allocation
can be made. Intacta has, according to Sharp, a length of two millimeters, is
known only from a male specimen which has the middle tibiae supplied with
an acute spine or mucro near the apex.

Antennal segment V transversely triangular, the lateral or external
face straight, the mesial or internal face prolonged into an obtuse
ogival dilation; known only from the male, the metasternum being
laterally convex, and medianly entirely concave, with subcarinated

margins; 1.9 mm. long globulosa (PI. XVII, 15)

Antennal segment V ovate, not mesially produced 2

2. Antennal segment V with the dorsal face distinctly and densely

punctate, and the ventral face with three irregular impressions;
1.9 mm. long; known from the male sex, with the metasternum and

last sternite flattened falsa (PI. XVII, 14)

Antennal segment V with the dorsal face glabrous, polished and the
ventral face with a large foveoid impression 3

3. Ventral face of fifth antennal segment with a large, median foveoid

excavation, half-oval in shape with the basal margin of the excava-
tion truncate, and the lateral margins converging apically to a very
rounded apex; 1.65 mm. long; known only from the male sex. . . .

callosa (PI. XVII, 13)

Ventral face of the fifth antennal segment with an elongate, sulci-
form excavation, this excavation being ovate medianly, with a much
narrower apical and basal continuance of the ovate portion, so that
the lateral margins present a subdentate appearance seen on looking
directly into the excavation sarcinaria (PI. XVII, 11, 12)

callosa (Raffray). 1890. Venezuela. (Bryaxis)

falsa Raffray. 1904. Mexico.

globulosa Raffray. 1904. Brazil.

intacta (Sharp). 1887. Guatemala. (Bryaxis)

pentachiroides (Schaufuss). 1887. Brazil.

sarcinaria (Schaufuss). 1887. Mexico.

BRACHYGLUTINI 143

Group XLI

In this group the females have the fifth and sixth antennal segments simple
and normal, while the males have these segments very irregular or abnormally
formed, being diversely expanded, foveate or spinose.

Key to the Males

Antennal segment V not excavated or foveate, but with one of its faces
produced, either as an oblique rounded process, or an acute spine,
or a blunted spine 6

Antennal segment V with the ventral, mesial, or ventro-mesial face
foveate or irregularly excavated ; spines may or may not be present 2

2. Antennal segment V obliquely subpyriform with the apical-mesial

angle produced into a rounded process ; segment VI transverse, with
the mesial face produced into a more slender, more acute, spinoid
process; ventral faces of both fifth and sixth segments excavated;
VII much smaller than sixth, wider than eighth, subquadrate but
with the mesial face produced into a short, blunt process; basal
discal carinae of first tergite separated by one-third of the discal
width; metasternum slightly, obsoletely impressed at middle; last

sternite simple, hardly impressed; legs simple; 1.8 mm. long

mexicana (PI. XVII, 16)

Antennal segments V, VI, VII not so formed 3

3. Antennal segment V subcircular, excavated on the ventral face in the

apical-internal half, and with two minute spines; VI subquadrate,
obconical; basal discal carinae of first tergite separated b}^ more

than one-third of the segmental width; 1.8 mm. long biclavata

Antennal segments V and VI not so formed 4

4. Antennal segment V elongate, about twice as long as wide, with the
ventral face polished and foveate; VI also large, but about half as long

as fifth, the length and width subequal ; VII transverse, much smaller
than sixth, with the internal-apical angle acute; metasternum medi-
anly concave with the lateral boundaries prominent and tuberculate;

2 mm. long sallaei

Antennal segment large, but differently formed, not elongate as de-
scribed 5

5. Antennal segment V in the form of an irregular triangle, and with the

ventral face excavated; VI transverse; 2.0 to 2.33 mm. long

diversicornis

(In this species the discal stria of each elytron is said to be wholly
absent!)
Antennal segment V very large, transversely quadrate, with the ventral
face bearing a transverse, irregularly biarcuate excavation; VI
transverse, with the ventral face obliquely flat and this flattened,
opaque surface studded with small asperities in sharp contrast to

144 NEOTROPICAL PSELAPHIDAE

the glabrous dorsal face; VII elongate-cylindrical, slightly longer
than sixth, much narrower, and distinctly longer than eighth segment
but of the same width ; middle coxae each with a broad, triangular

laminoid spine fovearthra new species (PL XVI, 13, 14)

*6. Antennal segment V irregularly semilunar, with a sharp spine on the
internal face; VI a little smaller than fifth, nearly ovoidal, with a

small tooth on the internal face eucera

Antennal segment V with lateral face strongly convex, and mesial face
greatly produced, this production being arcuate so that the ex-
tension is an acute production of the internal apical angle which
bears several short setae; VI with a very narrow base, and an ir-
regularly pyriform, swollen apical two-thirds, the lateral face being
very rounded, the mesial face being nearly straight, with this latter
face bearing a short, blunt spine which is also equipped with sev-
eral setae; 1.8 mm. long guadalupensis

Reichenbachia fovearthra new species

Holotype Male. Measurements: head 0.29 x 0.37 mm.; antennae 0.84 mm.;
pronotum 0.37 x 0.40 m,m.; elytra 0.62 x 0.73 mm.; abdomen 0.47 x 0.71 mm.;
total length 1.8 mm.; greatest width 0.73 mm. (PI. XVI, 13, 14).

Yellowish-brown, the integument shining, punctulate; pubescence moder-
ately abundant, longer (0.03 mm. long) on abdomen than on the elytra,
pronotum and head (0.02 mm. long). Head with the prominent eyes (34 large
facets) longer (0.107 mm.) than tempora (0.07 mm.). Vertex evenly convex,
with three large, subequal, pubescent foveae, each lying in a depression, two
being on a line through the middle of the eyes, mutually more distant than
each to the nearest eye, and a third median anterior fovea between the anten-
nal insertions. Front regularly declivous but not vertical; epistome simple;
labrum simple. Ventral surface of head flattened, with the usual longitudinal,
median, carinoid elevation typical of genus.

Maxillary palpi typical of genus, as for stroheckeri save that the fourth
segment is slightly obliquely truncate at apex.

Antennae abnormal, eleven-segmented, separated by a distance equal to
the mutual separation of the inter-ocular foveae; segment I irregularly elongate-
cylindrical, dorsal surface concave; II subspherical, as wide as first but
shorter; III much narrower and shorter than second, transversely obconical;

IV shorter and wider than third, transversely ovate, the mesial face subacute;

V very large and complex, transversely subquadrate, dorsal face strongly convex
longitudinally ; laterally this curvature gives a semilunar outline to the segment,
ventral face with a very large, densely setose, irregularly biarcuate excavation
occupying apical half from side to side; VI abnormal, much smaller than
fifth, excentrically articulated, transversely subovate dorsal face, ventral face

* These two species, eucera and guadalupensis, are the only two of this forty-first group
known to inhabit the Antilles, and are very closely related.

BRACHYGLUTINI 145

with an oblique, flat, oval, sharply-limited surface which is asperate and setose;
VII-XI inclusive longer than wide ; VII-X inclusive narrower than sixth ; VIII
distinctly shorter than either seventh or ninth; IX, X, and XI progressively
wider; IX and X subequal in length; XI slightly wider than sixth and as long
as ninth and tenth united, basally truncate and apically subacute.

Pronotum with disc simple ; a large pubescent lateral subbasal fovea each
side, and a minute median nude, punctiform fovea nearer base.

Scutellum acute — triangular, glabrous, distinct.

Each elytron with three circular nude, basal foveae — a sutural fovea at
origin of entire sutural stria, a median, and a lateral at origin of a well-
formed, arcuate discal stria which extends from fovea to far beyond middle to
apical fifth. Wings well-developed.

Abdomen with the usual large first tergite and strongly defined margins ;
first tergite with a pair of strong, slightly divergent, straight, basal carinae
one-third as long as segment, and separated by nearly one-half of segmental
width. Last sternite medianly flattened, the apical margin bisinuate and con-
sequently medianly slightly lobed, relatively long.

Sternal foveae II, III, IV, and VI well-developed and pubescent.

Metastemum laterally glabrous, medianly broadly concave and densely
pubescent.

Femora moderately inflated, especially the intermediate and posterior
pair; intermediate coxae each bearing a thin, triangular laminoid spine at
mesial angle; this spine is indistinct due to the surrounding pubescence, but
is quite large when dissected out; intermediate tibiae subtruncate apically, this
truncature with a minute internal tooth ; posterior tibiae thickened for apical
half of length, the mesial face of the thickened area bearing a brush of short,
dense, stiff, equal setae.

Allotype Female. As for holotype save that the antennae are simpler:
segment I elongate-cylindrical, dorsally concave; II narrower, ovate; III dis-
tinctly narrower and shorter than second, obconical; IV as wide as, and slightly
longer than third, subobconical; V and VII distinctly longer than VI and VIII,
these last four subequal in width, as wide as fourth; IX-XI progressively
wider and longer, forming the club. Secondly, the intermediate coxae are not
armed. Thirdly, the last sternite is very different from the male, being simple,
very transverse, relatively short, about as long as the two preceding sternites
united, with a simple, convex apical margin.

Described on seven specimens collected by the author at light at night
(9:00-10:30 p.m.), on Barro Colorado Island, Gatun Lake, Panama Canal
Zone; holotype, allotype, and one paratype male July 7, 1936; one paratype
female July 17, 1936; two paratype females July 28, 1936 and one paratype
female July 29, 1936.

This species is not closely related to any member of this group, but is more
allied with diversicornis (Sharp) from Guatemala than to the other species.

biclavata (Reitter). 1882. Colombia. {Bryaxis)

diversicornis (Sharp). 1887. Guatemala. (Bryaxis)

146 NEOTROPICAL PSELAPHIDAE

eucera (Aube). 1844. Puerto Rico. {Bryaxis)
fovearthra new species. Panama Canal Zone.
guadalupensis Raffray. 1908. Guadeloupe, Leeward Islands.
mexicana Raffray. 1904. Mexico.

sallaei (Sharp). 1887. Mexico, Guatemala, Panama. (Bryaxis)

(sallei Raffray, 1908, nee Sharp)

Group XLVII

The neotropical representatives of this group have been contributed by
Fletcher, and have few affinities with the rest of the group, the outstanding
parallel being the possession of swollen tibiae of the posterior legs. These two
neotropical species have the male sex characterized by (1) swollen hind tibiae,
and (2) mandibles with a tooth on the external face; the females have simple
hind tibiae and normal mandibles.

Mandibles each with a small tooth on the external face; posterior
tibiae swollen 2

Mandibles and tibiae simple Females

2. External mandibular tooth forming an acute angle with the mandibu-
lar curvature; posterior tibiae strongly dilated externally with an

elongate median depression beneath; length 1.6 mm

Male latipes (PI. XVI, 2)

External mandibular tooth forming an obtuse angle with the mandibu-
lar curvature ; posterior tibiae strongly dilated but lacking an elon-
gate median depression beneath; length 1.4 mm. (PI. XVI, 1)
Male guatemalensis

guatemalensis Fletcher. 1928. Guatemala.
latipes Fletcher. 1928. Mexico.

Group LI
The fifty-first group contains but one species:
nasalis (Reitter). 1900. Brazil. (Bryaxis). (nasuta Reitter, 1882).

Group LII

The fifty-second group contains two species, but the remarks anent the
fifty-sixth group should be considered for a more complete picture. The repre-
sentatives of this group are specialized with respect to the vertexal foveae:
the two foveae between the eyes are normal, but the third fovea, (which is
generally of the same size and located on the top of the head, between the
antennal bases, near the front) , is here much smaller and placed on the abruptly
declivous front, so that it occupies a plane at nearly right angles to the two
vertexal foveae. This foveal arrangement is common to both sexes, where the
female sex is known, and forms a transition to those species where this frontal
fovea is wholly absent.

BRACHYGLUTINI 147

Antennal segment VI elongate-cylindrical, three times as long as wide;
intermediate legs with the coxae and trochanters simple, not spinose
or acutely produced Female oberthiiri

Antennal segment VI abnormal and V also abnormal ; either the coxae
or trochanters of the intermediate legs spined or acutely produced. . 2
2. Antennal segment V twice the size of the fourth segment, circular in
form, with the dorsal face slightly convex and the ventral face gib-
bous; VI large, oblong-ovate, with dorsal face convex and ventral
face depressed and granulated ; intermediate coxae with the internal
angle produced into a long, triangular, acute and posteriorly directed
process; 1.6 mm. long Male oberthiiri

Antennal segment V oblong, the dorsal face reniform in outline, the
ventral face concave, and bearing a strong, acute, median ap-
pendage; VI with the dorsal face elongate-oval in outline, but the
ventral face very complex and abnormal ; biappendiculate, the first
appendage being near the base, elongate and slender, angulated at
its basal third so that its expanded apical end extends ventrally
beyond the second appendage ; second appendage arises in the basal
half of the ventral face as an acute tooth more or less covered by
the basal appendage; anterior half of the ventral face not appen-
diculate but quadrately produced, with the apical area narrowing
to form an angulated, subgeniculate articulation with the seventh
segment; VII and VIII with ventral faces narrowed and produced;
fifth and sixth segments articulated in an arc, to give the antennae
a distinctive appearance; intermediate trochanters armed at base

with a small spine; 1.8 mm. long (PI. XVI, 10, 11)

Male appendiculata (female not known)

appendiculata Raffray. 1904. Mexico, (may be a variation of di-

versula Raffray, vide infra)
oberthiiri Raffray. 1904. Colombia.

Group LIII

This fifty-third group contains but a single species:

reichei (Schaufuss). 1872. Colombia. (Bryaxis). (reicheiana Schau-
fuss) Guatemala (cf. Sharp, 1887, p. 27)

Group LIV

I am insuflficiently acquainted with this group to attempt a key to the
species :

bifoveata Fletcher. 1928. Mexico.

binodula (Schaufuss). 1872. Colombia. (Bryaxis)

celata (Sharp). 1887. Mexico, Guatemala, Nicaragua. (Bryaxis)

immodica Raffray. 1904. Colombia.

148 NEOTROPICAL PSELAPHIDAE

obnubila Raffray. 1904. Mexico.

stussineri (Reitter). 1882. Brazil. (Bryaxis)

subfoveolata (Schaufuss). 1872. Colombia. (Bryaxis). It should be
pointed out that this same species is also placed in Group XXI by
Raffray (1904). I have followed this since I am unfamiliar with
subfoveolata.

Group LV

This group is probably composite. It includes a species from Madagascar,
a species from Sumatra, and two neotropical species. One of these latter prob-
ably should be placed in a new group, since the vertex is sharply carinate
medianly in the male, and obtusely carinate in the female sex. This heterogene-
ous assemblage agrees in having the two vertexal foveae normally placed
between the eyes, but the median frontal fovea is wholly absent, in both males
and females. Males have the fifth antennal segment large, of relatively ab-
normal size. The two neotropical species may be separated as follows:

Vertex of the head normally convex nominata

(2.0 mm. long; known from the female only)
Vertex of the head with a median, longitudinal carina or an obtuse

carinoid elevation 2

2. Vertex with a strong, sharp, median longitudinal carina which anteri-
orly becomes an obtuse ridge; basal part of vertex and adjacent
occiput with a transverse, densely but finely granulated area cov-
ered with long, yellow, anteriorly directed setae; antennal segment
V very large, about three times longer than second segment, arcuate
externally, armed internally near apex with a strong, apically en-
larged spicule; 1.4 mm. long; metasternum medianly depressed.. .

carinifer Male (PI. XVII, 17)

Vertex with an obtuse carina between the vertexal foveae; antennal
segment V elongate-cylindrical, as long as third and fourth seg-
ments united, not spiculate on internal-apical face

carinifer Female (metasternum not depressed)

carinifer Fletcher. 1928. Mexico.

nominata (Sharp). 1887. Guatemala. (Bryaxis)

Group LVI

So far as known this group is purely American, and at present holds two
neotropical species. They are allied to the fifty-fifth group in having no trace
of a frontal fovea, and one of the species at least, has the epistomal area
prominently elevated. It is also possible that the taxonomy of this section of
the genus is very involved, and some changes may have to be made when
more information has accumulated.

This group is separated from the fifty-fifth group in that the males have
the fifth and sixth antennal segments abnormal, while the previous group had

BRACHYGLUTINI 149

the fifth segment only abnormally formed. The females have the antennae

normal. The two species may be separated as follows:

Each elytron with three basal foveae diversula

Each elytron with two basal foveae stroheckeri new species

Reichenbachia stroheckeri new species

Holotype Male. Measurements: head 0.22 x 0.36 mm.; antennae 0.87 mm.;
pronotum 0.31 x 0.38 mm.; elytra 0.53 x 0.7 mm.; abdomen 0.46 x 0.6 mm.;
first visible tergite 0.26 x 0.6 mm.; total length 1.52 mm.; greatest width
0.7 mm. (PI. XVI, 8, 9)

Integument yellowish-brown, shining, lightly punctulate with short (0.016
to 0.033 mm.), moderately abundant pubescence. Eyes prominent, three times
as long as tempora, with about 30 coarse facets. Tempora short, convergent,
with subtnmcate posterior angles. Vertex with two foveae between the eyes,
these foveae being pubescent and large, e.g. a diameter equal to two eye facets
united, free with no intrafoveal sulcus. Front almost vertically declivous be-
tween the antennal bases, the declivity glabrous, slightly concave. Absolutely
no trace of a frontal fovea, pit, or foveoid depression between frontal margin
and epistome. This total lack of a frontal fovea separates this species from
appendiculata Raffray and allies. Epistome erected into a prominent, obtuse,
glabrous, slightly recurved horn, forming a transverse sulcus or cleft between
the declivous front and the epistome. This epistomal structure effectually
separates this species from diversula Raffray and appendiculata Raffray as
described. The epistomal tubercle is probably a male secondary sex char-
acter. Labnim small, transverse, tumid, the anterior margin medianly con-
cave. Mandibles normal, not dilated and without external teeth or tubercles,
bases exposed each side of labrum. Ventral surface of head triangular, sub-
glabrous, with a median, longitudinal, poorly-defined carina. A minute gular
fovea on each side of this carina, at its extreme base.

Maxillary palpi normal for genus, four-segmented; first segment minute,
cylindrical; second elongate-pyriforra, arcuate, basally slender and gradually
expanded in apical half to apex; third short, subtriangular, mesial face sub-
acute, lateral face strongly convex, wider than second segment ; fourth segment
largest, longer than second and wider than third, obliquely truncate at base,
subacute at apex, bearing a short pelpal cone, mesial face nearly straight,
lateral face convex, cylindrico-conical in outline.

Antennae abnormal, eleven-segmented, longer than pronotum and elytra
united, rather widely separated by a distance equal to that from the center
of one vertexal fovea to the center of the other (0.134 mm.) ; segment I
oblong, dorsally concave; II longer than wide, narrower than first, sub-
obconical; III short, transversely obconical; IV as long as third but much
wider, twice as wide as long, slightly asymmetrical; V large, distinctly wider
than fourth and four times as long, the dorsal surface strongly biconvex or
dumb-bell shaped, the ventral face constricted in apical third, and bearing a

150 NEOTROPICAL PSELAPHIDAE

prominent, transverse, truncate lamina at center, just behind the constriction;
VI as large as fifth, articulated at an angle with fifth to give antennae a sub-
geniculate appearance, the dorsal face simple, elongate, the ventral face with
a long, slender, very capitate appendage extending from basal margin and
seeming to arise from the fifth segment unless observed with care, also a short,
acute, arcuate cusp arising from the ventral face just anterior to the capitate
appendage noted, and partially covered by the latter; anterior to this cusp
the ventral face is expanded ventrally and bears a median, arcuate, longi-
tudinal lamina; VII-X excentrically articulated; VII strongly and VIII
weakly narrowed mesially, of nearly equal length and width; IX slightly
longer than eighth, of same width, with the non-articular portion drum-shaped;
X subclindrical, as long as eighth and ninth united and slightly wider than
ninth; XI as long as ninth and tenth united, basally truncate, apically sub-
sinuate to bluntly narrower apex. The dorsal faces of the fifth and sixth seg-
ments are similar to those of diversula Raffray and appendiculata Raffray,
and the remarkable anatomy of the ventral faces of the fifth and sixth seg-
ments is strikingly like the condition in appendiculata Raffray.

Pronotum with form typical of genus; a large pubescent, subbasal fovea
on each side, and a minute, nude, punctiform median basal fovea, these foveae
wholly free and unconnected by transverse sulcus ; disc simple and unmodified.

Elytral form typical of genus; each elytron with but two basal foveae,
these foveae circular, large; the sutural fovea at base of the well-formed
sutural stria; the discal fovea at base of the long, arcuate discal stria which
extends to apical fifth. Scutellum distinct. Wings long and well-formed.

Sternal foveae II, III, IV, and VI well-formed and with their orifices
covered by long setae, foveae IV especially large and transverse. The metaster-
num medianly concave and pubescent, with the margins of the concave area
moderately prominent; lateral areas of metasternum are glabrous.

Abdomen with the first visible tergite bearing at base two straight, diver-
gent carinae; these basal carinae are short, being only one-fifth as long as
segment, and separated by one-third of the width of the segment. Last stemite
medianly slightly depressed.

Legs simple with exception of the intermediate coxae. Each of these coxae
bears a short, acute spine at its mesial-posterior angle.

Described on two male specimens, both collected by the author at light
on Barro Colorado Island, Gatun Lake, Panama Canal Zone. The holotype
male at 10:00 p.m., July 17, 1936, and the paratype male at 10:00 p.m.,
July 28, 1936. Named for my friend. Dr. Strohecker.

There is either a striking case of genetic parallelism of the antennal
abnormalities of the male sex, or a taxonomic imbroglio involving groups 52
and 56. After considerable thought I have decided the former condition exists,
at least to the extent that appendiculata Raffray and stroheckeri are dis-
tinct. However, certain remarks must be set down to aid future students.
David Sharp (1887, p. 29 and PI. I, fig. 14) described Bryaxis diversa from
Panama, based on seven examples taken from the sandy banks of streams

BRACHYGLUTINI 151

near San Feliz and Tole. This description is dated March, 1887. Raffray
described Bryaxis diversa from Cape Town, South Africa in January, 1887.
These "Bryaxis" are Reichenbachia and Sharp's name was preoccupied; Raf-
fray consequently named Sharp's species Reichenbachia diver sula (1904, p.
363).

In the next place the original description of diversula is so poor that only
a few items can be elicited: (1) pronotum with a minute median fovea, (2)
frontal fovea of head present on the anteriorly declivous front, this condition
being stated by Sharp and also shown in his figure; (3) each elytron with three
basal foveae; (4) dorsal faces of the fifth and sixth antennal segments are
well shown. This set of features, taken with other general characters, would
place diversula in Group 52 in which the frontal fovea is present but on the
declivous front, and the males have the fifth and sixth antennal segments
abnormal. However, Raffray (1904) put diversula in Group 56 which is char-
acterized by having no frontal fovea. Now it is obvious that either Raffray
incorrectly placed diversula, or examined Sharp's types and discovered that
Sharp incorrectly diagnosed the presence of the frontal fovea. Both assump-
tions are difficult to entertain and yet are mutually untenable. The matter is
further complicated in that Raffray (1904, p. 295) described from Mexico
Reichenbachia appendiculata. This latter species has a frontal fovea on the
strongly declivous front, and abnormal fifth and sixth antennal segments in
the male, and so belongs in Group 52. This appears to be a definite and correct
allocation. However, if diversula belongs in group 52 (and Sharp's words and
figure would seem to demonstrate this position), then we have appendiculata
and diversula in the same group, and the dorsal faces of the male fifth and
sixth antennal segments are slightly similar in form. The ventral faces of these
segments are not even hinted at by Sharp, and are well described in all their
abnormality by Raffray. However, appendiculata has each elytron with two
basal foveae and diversula has three basal foveae as near as I can determine.
This would definitely separate diversula from appendiculata.

In the next place, the new species, stroheckeri has the dorsal face outline
similar to diversula and appendiculata, similar abnormal features on the
ventral faces of the fifth and sixth antennal segments of appendiculata, agrees
with this latter species in having only two basal foveae on each elytron; differs
radically from appendiculata in having no frontal fovea at all and from both in
having the epistome erected into a horn-like tubercle. Raffray has nothing to
say on the epistome of appendiculata, and if this were abnormal in this species
he would have been sure to describe it; Sharp figures a normal epistome in
his diversa. It seems clear, then, that stroheckeri and appendiculata are not
even closely related, and equally clear that stroheckeri and diversula are even
more distantly separated.

diversula Raffray. Panama. {Bryaxis diversa Sharp, 1887, preoccu-
pied, cf. Raffray, 1904). (Group 52, vide supra'?)
stroheckeri new species. Panama Canal Zone.

152 NEOTROPICAL PSELAPHIDAE

Group LIX

This fifty-ninth group holds a single species in the neotropical area,
designata (Sharp), based on seven specimens from Las Mercedes, Guatemala.
The median frontal fovea is absent; both sexes have the fifth and sixth anten-
nal segments abnormal; male with a concave, and female with flattened,
metasternum; the vertex is medianly swollen or prominent between the inter-
ocular foveae, this extending anteriorly as an elevated area, but not reaching
the front. This prominent vertex is uncommon in the genus, and approached
in the neotropics only by carinifer Fletcher of Group 55.

designata (Sharp). 1887. Guatemala. (Bryaxis)

Group LXIV new group

This new group is erected for a single neotropical species, femoralis
Fletcher. Since the sixty-third group of Raffray has been elevated to a new
genus, femoralis could have been placed in this vacated spot, but the subse-
quent confusion would have been too great, and so Raffray 's groupings have
been left intact, there being no sixty-third group in the genus at present. The
essential features may be summated as follows: head with the vertex, front,
epistome, and mandibles normal for genus; the vertexal foveae not normal,
there being the usual two inter-ocular foveae, and the median anterior fovea
is very small on the depressed front between antennal bases, instead of being
subequal in size to the posterior pair; antennae normal; pronotum normal,
with a large, lateral, pubescent fovea each side and a smaller, nude fovea at
middle nearer base; each elytron with two basal foveae, and a discal stria not
reaching the middle; abdomen normal, first tergite with a pair of slightly
divergent basal carinae not reaching middle of segment and separated by one-
half the segmental width at base; metasternum flattened in male (only sex
known) ; legs not normal, intermediate tibiae armed with a strong spur on
the ventral face near apex, posterior femora greatly dilated, the dilation being
broadly and entirely excavated on the posterior face. As Fletcher pointed out
(1928) this species falls in Division V of Raffray (Groups 29-32) but does
not fit any of these on the character of the anterior cephalic fovea coupled
with the abnormality of the posterior femora.

femoralis Fletcher. 1928. Peru.

In addition to the species enumerated in the above groups, the following
species of Reichenbachia, known from the neotropics, are included without
group allocation:

argentina Raffray. 1909. Argentina.

biocellata (Schaufuss). 1887. Mexico. (Bryaxis)

bisinuata (Schaufuss). 1887. Cuba. (Bryaxis)

bythinoides (Sharp). 1887. Panama (Bryaxis). Group LIV?

crassipalpis (Sharp). 1887. Guatemala. (Bryaxis)

BRACHYGLUTINI 153

dorsopunctata (Schaufuss) . 1887. Brazil. (Bryaxis)

festina Raffray. 1909. Argentina.

fluviatilis (Schaufuss). 1887. Brazil. {Bryaxis)

griseopubescens Raffray. 1909. Argentina.

hippopotamus (Schaufuss). 1887. Brazil. (Bryaxis)

impressicollis (Sharp). 1887. Guatemala. (Bryaxis). (Reichenhachial)

impubis (Sharp). 1887. Guatemala. (Bryaxis). (Reichenbachiat)

impunctata (Schaufuss). 1887. Mexico. (Bryaxis)

lutea Raffray. 1909. Argentina.

penita (Schaufuss). 1887. Brazil. (Bryaxis)

pygmaea (Schaufuss). 1887. Brazil. (Bryaxis)

rubecula (Sharp). 1887. Panama. (Bryaxis)

spuria (Schaufuss). 1887. Brazil. (Bryaxis)

triangulifera (Schaufuss). 1887. Brazil. (Bryaxis). (Reichenbachial)

truncata (Schaufuss). 1887. Cuba. (Bryaxis)

PANABACHIA new genus

This genus is erected for Bryaxis vulnerata Sharp. Sharp (1887, p. 31)
has the following to say:

"Antennae short and slender, with rather large club; joints 4-8 minute, sub-
equal, the terminal three gradually forming a club. Head short, moderately
broad, the front of the clypeus a Httle raised and with a slight antennary
tubercle ; bifoveate between the eyes, the extreme vertex in the middle slightly
notched or depressed. Thorax broad and short, much narrowed behind; with a
very large and deep depression formed as it were of three depressions united,
the larger on the disc, the smaller one a little nearer the front on each side.
Elytra with a distinct sutural stria and a well-marked intrahumeral depres-
sion." 1.25 mm.

This species is figured by Sharp, showing the remarkable discal excavation
of the pronotum. Such pronotal structure is absent in the qualitative sense
from Reichenbachia, and Raffray (1904, p. 156) placed this species with doubt
in Reichenbachia as a new division, and felt that it warranted at least a new
subgenus.

I feel that the structure of the pronotum is sufficient for a generic di-
vergence. Based on a unique, it has not been reported since.

vulnerata (Sharp). 1887. Panama. Genotype.

NODULINA (Raffray, 1904)

This monotypic genus is allied closely to Reichenbachia, differing in the
anatomy of the head. The head is very wide, including the prominent eyes,
more than one-half wider than the length between the occipital margin and
frontal margin; both occipital margin and the frontal margin between the
antennal bases are truncate, with the angles rounded abruptly to give a trans-
versely-squared appearance. Beyond the frontal margin the epistome is greatly

154 NEOTROPICAL PSELAPHIDAE

expanded into a dilated plate extending apically beneath the antennae as far
as the second segment, and laterally nearly to the eye margin to give a width
subequal to the total head width through the eyes. This dilated epistomal area
is simple in the female and bears a median, apically setose, triangular horn
or tubercle in the male sex.

convexa (Schaufuss). 1879. (Bryaxis). Brazil; Dutch Guiana.

BUNODERUS (Raffray, 1904)

This genus, allied to Brachygluta and Reichenbachia, is distinct in the
neotropical part of the tribe by having the pronotum with the disc crossed
longitudinally by a median carina or carinoid gibbosity. In this it occupies an
analogous position to the Brachyglutini, that Neodalmus occupies in the
Euplectini.

Key to the Species

Disc of pronotum with a strong, entire, median longitudinal carina
carinicollis (1.6 mm. Based on Female)

Disc of pronotum with the median longitudinal carina obsolete, re-
placed by a carinoid, longitudinally gibbous swelling 2

2. Metasternum with a wide, entire longitudinal, median impression the
sides of which are carinated longipilis Male

Metasternum widely, less deeply sulcate, the sides not thrown into
carinae longipilis Female (species 1.5-1.7 mm. long)

carinicollis Raffray. 1904. Mexico.
longipilis Raffray. 1904. Brazil.

STROMBOPSIS (Raffray, 1904)

A monotypic genus allied to Xybaris, Xybarida, and Cryptorhinula on
the one hand but considered more primitive than this group of genera on
general anatomy as described.

breviventris Raffray. 1904. Brazil.

ACHILLIA (Reitter, 1890)

This large genus, named for Raffray by Reitter in 1890, has an odd distri-
bution. Out of twenty-five known species, twenty-four are found in Chile and
one in Cuba! In its concentration in Chile, this pattern reminds one of the
concentration of Ldoplectus in the Euplectini with seven species known, all
from Argentina.

The elytron has either two or three basal foveae (not two foveae as stated
by Raffray, 1908). The body is elongate, subparallel and flattened. The sub-
quadrate head has the front transversely sulcate and diversely impressed and
armed, especially in the male sex. In eljridae the vertexal foveae are on a
level with the anterior margin of the eyes, while in clavata the foveae are far

BRACHYGLUTINI 155

forward, one near each antennal base. Ventral face of the head with the usual
median, longitudinal carina. Antennae eleven-segmented, often irregular in
the male sex. Maxillary palpi four-segmented, first minute; second gradually,
strongly swollen apically; third transversely, often irregularly, triangular;
fourth irregularly ovoidal. Pronotum subcordiform, disc simple, three sub-
basal foveae. Elytra with each elytron with two or three (possibly four foveae
in valdiviensis?) basal foveae, dorsal stria present but shortened. Abdomen
normally margined, not abnormally formed. Middle coxae subcontiguous;
posterior coxae distant. Second tarsomere longer and thicker than the third,
and bearing beneath a brush of setae in the male anterior tarsus.

The synonymy in many of the species is complicated. Being quite unfa-
miliar with the genus, I have used the group key of Raffray (1904) to partially
separate the many species:

Antennae simple 2

Antennae different in the two sexes 11

2. Abdomen simple 3

Abdomen with first tergite modified (rare in genus as noted previ-
ously), with a strong, acute tubercle, set in a depression on each
side of segment; head with a fine, transverse frontal sulcus, and
between the eyes a large depression Group X

3. Head with no transverse frontal sulcus, but the head diversely sculp-

tured 4

Head with a transverse frontal sulcus 6

4. Head with a large frontal fovea and also a short longitudinal short

sulcus on each side Group IX

Head with a depression anterior of the eyes 5

5. Head with a strong, transverse depression anteriad of eyes; vertex

more or less prominent and produced above the eyes. . . .Group VII
Head with a sinuate depression anteriad of the eyes, the front pro-
longed anteriorly and head distinctate punctate Group VIII

6. Transverse frontal sulcus simple and deep 7

Transverse frontal sulcus present, and in addition, a very deep, wide,

transverse depression anterior of eyes Group VI

7. Head much longer than wide, with a very large triangular anterior

depression; last segment of antennae very large Group V

Head either square, or simply attenuated anteriorly 8

8. Head attenuated anteriorly and simple Group I

Head square 9

9. Club of antennae with eleventh segment conspicuously large 10

Club of antennae with the tenth segment large and transverse, eleventh

segment not wholly fonning the club Group II

10. Eleventh antennal segment very large, club practically one-segmented

Group III

Eleventh antennal segment larger than normal but ovoidal . . Group IV

156 NEOTROPICAL PSELAPHIDAE

11. First segments of the antennae abnormal; head armed; epistomal area

large Group XI

Last segments of the antennae abnormal 12

12. Segments VIII, IX, and X very abnormal; occiput gibbous; vertex

prominent and deeply excavated each side in the male; antennae
simple, but sinuate, head wide, flattened triangularly on front and

vertex and squamous in the female Group XII

Segments IX and X very large, abnormal, but not armed ; head deeply
excavated each side of vertex Group XIII

The species may be listed as follows, the roman numerals denoting the
Rafifrayian species groups:

I

approximatus (Reitter). 1885. Chile.
convexiceps Rafifray. 1904. Chile.

II

cordicollis Raffray. 1904. Chile.

Ill

clavata Raffray. 1904. Chile.
kindermanni (Reitter). 1883. Chile.

IV

blanchardi Raffray. 1904. Chile, {valdiviensis Reitter) 1883.

elfridae Raffray. 1904. Chile. (Reitter in. litt)

latifrons Raffray. 1904. Chile.

picea Rafifray. 1904. Chile.

quadriceps Raffray. 1904. Chile.

tripunctata (Reitter). 1885. Chile.

V

simulans (Reitter). 1885. Chile.

VI

brevicornis Raffray. 1904. Chile.
bifossifrons (Reitter). 1883. Chile.
humidula (Reitter). 1885. Chile.

VII

cosmoptera (Blanchard). 1852. Chile. (Pselaphus) {Aplodea, ReitieT)
{Tyropsis, Raffray). See Raffray, 1904. {chilensis, Reitter, 1883)
larvata (Reitter). 1885. Chile.

BRACHYGLUTINI 157

VIII

longiceps (Reitter). 1885. Chile.

IX

praeclara (Reitter) . 1885. Chile.

X

bituberculata (Reitter). 1885. Chile.

XI

monstrata (Reitter) . 1885. Chile.

valdiviensis (Blanchard). 1852. Chile. (Pselaphus) {Aplodea, Reit-
ter) {Tyropsis, Raffray). See Raffray, 1904. {anas Reitter, 1885)
(nasuta Reitter, 1885; nasina Reitter, 1893)

XII

puncticeps (Reitter). 1883. Chile.

XIII

excisa (Schaufuss). 1879. Cuba.
validicornis (Reitter). 1885. Chile.

RAXYBIS (Raffray, 1908)

This is an Argentine genus closely related to Braxyda and Bryaxina,
differentiated from them by the key characters. There is also a slight but
constant difference. Raxybis males have the second segment of the anterior
tarsi thicker than the third, but not dilated nor flattened, and the ventral
surface is clothed with long, dense setae; this tarsal condition is also found in
the females. On the other hand the males of Braxyda, Bryaxina, Xybaris,
Achillia have the second tarsomere dilated, flattened and with a pad of setae
beneath.

Length 2.4 mm nodosa

Length less than two millimeters 2

2, Front flat, obtusely angulated; epistome uncarinated

frontalis Female

Front medianly truncate, fasciculated and with a triangular tubercle ;

epistome strongly carinated frontalis Male

frontalis Raffray. 1908a. Buenos Aires, Argentina. (Male and female

known.)
nodosa Raffray. 1908a. Buenos Aires, Argentina. Genotype. (Male

known only.)

158 NEOTROPICAL PSEL APHID AE

BRYAXINA (Raffray, 1904)

This is a genus of moderate size, closely related to Achillia, and restricted
to Brazil. The males have the second tarsomere of the anterior tarsi greatly
expanded laterally, flattened, with the ventral surface setose. The maxillary
palpi are four-segmented with the fourth segment irregularly pyriform or ir-
regularly pyramidal, the base being rounded, widening rapidly to basal third,
then lengthily narrowing to an acute apex, which bears a palpal cone, however,
this narrowing is accompanied by a distinct sinuation on the external face, so
that the external-apical outline is concave and the internal-apical outline is
convex.

There are ten species known, and I have used Raffray's key (1904, pp.
262-263) for their separation since no new forms have been described.

Each elytron with three basal foveae 2

Each elytron with four basal foveae 4

2. Basal discal carinae of first tergite one-third of the segmental

length torticornis

Basal discal carinae of first tergite one-fourth of the segmental length 3

3. Antennae thick, with eighth segment strongly transverse, ninth less

transverse than eighth, tenth nearly square, eleventh elongate-oval;

head armed and excavated in the male sex armiceps

Antennae thicker, with segment eight slightly and nine and ten
strongly transverse, eleven briefly obconical; head simple in the female

sex (male unknown?) fraudatrix

4. Antennal segments all longer than wide, or most of the segments longer

than wide 5

Antennal segments as wide as long (subequal), or fourth, eighth,
ninth, and tenth square at least 6

5. Basal discal carinae of first tergite one-fourth of segmental length;

antennal segments four and eight square lucida

Basal discal carinae of first tergite one-third of segmental length;
antennal segments four and eight slightly longer than wide . . clavata

6. Antennae with segments five, six, seven much longer than wide, and

segments four, eight, nine, and ten square 7

Antennae thick, with the segments not much longer than wide 8

7. Basal discal carinae of first tergite one-third of segmental length

dimidiata

Basal discal carinae of first tergite one-fourth of segmental length
schaufussi

8. Antennae with segment eight square, nine and ten transverse; basal

discal carinae of first tergite one-fourth of the segmental length

cavifrons

Antennae with segments eight, nine, and ten transverse; basal discal
carinae of first tergite one-third of segmental length 9

9. Antennae with segments eight and nine very transverse, not much

BRACHYGLUTINI 159

larger than seventh, tenth less transverse; basal discal carinae of

first tergite one-third of segmental length foveifrons

Antennae with segments eight, nine, and ten less transverse, much
larger than seventh, forming a marked club; basal discal carinae
of first tergite one-third of the segmental length and divergent
crassicornis

The species are listed as follows:

armiceps Raffray. 1904. Brazil.

cavifrons (Schaufuss). 1879. {Bryaxis) Brazil.

clavata Raffray. 1904. Brazil.

crassicornis Raffray. 1904. Brazil.

dimidiata Raffray. 1904. Brazil.

foveifrons Raffray. 1904. Brazil.

fraudatrix (Schaufuss). 1879. (Bryaxis) Brazil. Genotype.

lucida Raffray. 1904. Brazil.

schaufussi Raffray. 1904. Brazil.

torticornis Raffray. 1904. Brazil.

BRAXYDA (Raffray, 1904)

This is a small genus of two Bolivian species, related to Bryaxina, and
separated by the key characters noted previously. The males have the second
tarsomere of the anterior tarsi expanded and supplied below with a brush of
setae. Pronotum with a minute, punctiform median fovea near base and no
lateral foveae. Elytra with a strong discal stria extending to the middle of
elytral length ; each elytron with two basal foveae, the sutural and discal. First
tergite much longer than second, with a pair of basal discal carinae one-fourth
of the segmental length and enclosing one-third of the segmental width. Male
pygidium very large, subhexagonal, curved ventrally. Fourth segment of
maxillary palpi truncate at base, regularly fusiform as in the genus Reichen-
bachia; third segment small, triangular. Middle coxae subcontiguous, allow-
ing the mesosternum to be seen between them as a thin lamina.

The two species may be separated as follows:

Key to the Species

Male with segments of antennae III, IV, and VI short; V three times
wider than long; VII two times wider than long; VIII quadrate;
IX and X obconical-truncate, wide, slightly crescentric, tenth two
times wider than long; XI fusiform; metasternum broadly concave;
middle legs with trochanters lunate, produced mesially into a thick,
acute tooth ; middle femora inflated, with the ventral face obliquely
notched to produce an apically directed tooth ; middle tibiae with a
large, strongly curved spine at internal-apical angle. Female with
antennal segments VIII, IX and X quadrate; metasternum not con-
cave; middle legs simple. 2.6 mm hamata

160 NEOTROPICAL PSELAPHIDAE

Male with segments of antennae III, IV, and VI two times longer than
wide ; V and VII three times longer than wide ; VIII one-half longer
than wide ; IX slightly longer than eighth ; X two times longer than
ninth; XI fusiform, slightly sinuate, truncate at base; middle legs
with trochanters more strongly lunate and mesially toothed ; middle
femora gibbous but not ventrally toothed at middle ; middle tibiae
slightly notched apically but not having the large, recurved spine
at apex. 2.6 mm. Female unknown crassipes

crassipes Raffray. 1904. Bolivia.

hamata Raffray. 1904. Bolivia. Genotype.

XYBARIDA (Raffray, 1896)
Raffray (1896, 1904, 1908)

This small brachyglutine genus of only four species is widely distributed
from southern Brazil, the Panama Canal Zone, into Yucatan. The species
agree in having a short, globiform body and one species at least may be a
facultative synoekete of a species of termite. The genus is structurally related
to Scalenarthrus, Xybaris and their allies. The four known species may be
isolated by the following key:

Antennal segment IX wider than long 2

Antennal segment IX longer than wide nasicola new species

2, Pronotum with a very minute, punctiform, median fovea at base. ... 3
Pronotum with no median pronotal fovea punctulum

3. Known only from southern Brazil clavata

Known only from Yucatan pusilla

Xybarida nasicola new species

Holotype Male. Measurements: head 0.23 x 0.30 mm.; antennae 0.67
mm.; pronotum 0.30 x 0.35 mm.; elytra 0.53 x 0.53 mm.; abdomen 0.33 x 0.50
mm.; total length 1.4 mm.; greatest width 0.53 mm. (PI. VII)

Body subglobular, light reddish-brown, moderately shining, and punctulate
with vertex and occiput more strongly punctate; pubescence short (0.02 mm.
long), sparse, golden. Eyes prominent, consisting of about 34 small facets
each, and 0.067 mm. long. Tempora one-half longer than eye, and convergent
to subtruncate occiput. Occiput, vertex, and epistome punctate and pubescent,
semi-shining and in strong contrast to the glabrous, shining cervicum. Vertex
convex between the vertexal foveae, which are small, about equal to an eye
facet in diameter, and nearer the eyes than to each other. No circumambient
interocular sulcus, but front between the antennal bases, and behind the
rounded frontal margin, broadly, shallowly concave. Front simple, gradually
declivous to epistome. Epistome elongate, roughly punctate and with longer
pubescence, its apical margin strongly rounded and convex. Labrum prominent
as a semilunar, subdetached plate. Mandibles conspicuous, left crossed over

BRACHYGLUTINI 161

right, in an arc the length of the labrum removed from the head. Ventral surface
of the head flattened, subglabrous, flask-shaped in outline and strongly marked
by: (1) a high, thin, median, longitudinal carina; (2) a strong lateral carina,
each side, which is straight and internally directed from base of mandible to
base of maxilla, then arcuate externally to a point beneath occiput and finally
internally arcuate to base of head; (3) a posteriorly arcuate, ocular carina
from near the anterior margin of each eye to the median part of the lateral
carina (PI. VII, 10).

Maxillary palpi relatively long and slender, four-segmented; first segment
minute; second strongly arcuate, basally slender, and apically inflated, slightly
compressed laterally ; third short, subtriangular, with the lateral face very con-
vex; fourth very long and slender, wider than third and longer than second,
obliquely truncate at base, narrowing gradually to acute apex, the apex bearing
a long, obtuse, obliquely placed palpal cone, and of especial note: this fourth
segment has an oblique, short, median scar or camiform line on the exteral face.

Antennae eleven-segmented, widely separated at base by almost the width
of the head, not including eyes; segment I subquadrate, obonical, wider and
slightly shorter than second; II elongate-cylindrical; III narrower and as long
as second, obconical ; IV, VI and VIII shorter than V or VII but subequal in
width, obconical to conical; IX elongate-obconical, distinctly longer than wide,
and longer than either seventh or tenth; X cylindrical, distinctly shorter than
ninth; XI forming the club, relatively large (0.17 x 0.08 mm.) and as long as
eighth, ninth, and tenth united, subasperate.

Pronotum simple, with neither lateral nor median foveae.

Elytra with obtusely elevated humeri ; each elytron with four, very minute,
shallow points replacing the foveae, and an obliquely transverse basal carina
just anteriad of these discrete foveal points, a faint sutural stria but no dorsal
stria. Elytral flank simple.

Abdomen with a distinct, but very narrow margin. Five visible tergites of
which the first is elongate (0.17 mm. long), as long as second and third united,
with two very small, inconspicuous, straight, parallel carinae at base which are
one-eighth as long as segment and separated by a little more than one-fourth
of the segmental width. Second tergite very slightly longer than third. Fourth
tergite about as long as third, vertical and not fully visible from above. Fifth
tergite obliquely ventral, wholly invisible from above, distinctly longer than
fourth, but not quite twice as long as fourth tergite, apical margin slightly
sinuate laterally and subtruncate at median fifth of width.

Five sternites visible medianly and six sternites visible laterally, the first
of these being invisible beneath the metasternum medianly between the distant
posterior coxae, but visible laterally near each elytron, as an elongate-acute
triangle. Second sternite very long laterally, becoming shorter medianly and
concave where it is as long as the third and fourth united, and bearing each side
at lateral third a longitudinally arcuate carina which arises on the basal half
of the first sternite and extends through apical half of second. Third sternite
medianly tumid, a little longer than fourth. Fourth sternite flattened and sub-

162 NEOTROPICAL PSELAPHIDAE

truncate medianly. Fifth sternite as long as fourth and modified: excavated in
median third and laterally the side of the excavation is erected into a prominent,
triangular, setose cusp. Sixth sternite as long as fourth and fifth sternites united,
granular, with the median third triangularly excavated and almost vertical,
that is, this excavation is at right angles to the excavation of the fifth sternite,
and covered with very short, dense setae forming a setose pad.

Metasternum glabrous laterally and pubescent medianly ; medianly broadly
concave with tumid margins.

Anterior femora inflated, flattened on ventral face, with a longitudinal
sulcus partially developed on this flattened surface; intermediate femora less
inflated, simply flattened ventrally; posterior femora norm,al.

Anterior legs with each trochanter bearing a thin, arcuate spine about
as long as the trochanter.

Tarsi three-segmented; first tarsomere very short; second and third much
longer, with the second very long on the intermediate and posterior legs, where
it is twice as long as third tarsomere ; third bearing distally a claw one-third as
long as tarsomere. The anterior tarsi are secondarily modified : the second tar-
somere is relatively shorter, and much thicker than this segment in the other
legs, and the ventral face is flattened and bears stiff setae. This thickened con-
dition is not to be confused with the wider second tarsomere of males of related
genera. In the latter the segment is wide and thin ; here it is thick and not much
wider than the third, and the setae of the ventral face do not form a dense,
short, setose pad.

Allotype Female. As for holotype with the following differences:

Integument uniformly lightly punctulate.

Eye relatively a little larger, about equal to the tempora in length, but of
the same number of facets, the facets a little coarser. Mandibles smaller. Ventral
surface of head and maxillary palpi as in holotype.

Antennae a little shorter and thicker, segments III to VIII subequal in
width ; IV slightly shorter than third or fifth ; V, VI, and VII subequal in length ;
IX elongate-obconical, longer than eighth or tenth ; X distinctly shorter than
ninth, obconical; XI relatively large, as long as eighth, ninth, and tenth united,
subasperate.

Pronotum and elytra as in holotype.

Fifth tergite relatively shorter, about one-third longer than fourth and
subtriangular in outline.

Second sternite (first visible medianly) relatively longer, longer than the
next three united, these latter simple, convex, very short. Last sternite (fifth
visible medianly) long, almost as long as first visible, transversely semilunar,
with basal margin convex and apical margin concave, investing the convex
apical margin of fifth tergite, more coarsely punctate than other sternites and
medianly tumid.

Legs with femora not inflated, and trochanters simple, not armed. Second
tarsomere of anterior tarsi not thickened and not ventrally setose.

Metasternum not medianly concave, but distinctly tumid medianly.

BRACHYGLUTINI 163

Described on two specimens, collected by the author on Barro Colorado
Island, Gatun Lake, Panama Canal Zone. Holotype male on July 5, 1936, in
the gallery of the termite, Nasutitermes ephratae (Holmgren) in a log at
Armour 8. Allotype female on June 30, 1936, at a light at 10:00 p.m.

I associate the female with the male on the very close agreement in nu-
merous structural details, including the peculiar modification of the distal seg-
ment of the maxillary palpi. The two sexes are readily told apart by the an-
tennae, last sternite and male armature of the trochanters, anterior tarsi,
metastemum and numerous other points.

Since the male was taken within the darkness of the termite nest (4:00
p.m.), while the female was taken at night, there is indirect evidence that (1)
the species may be a facultative synoekete, and (2) the species follows the
family rule of nocturnality. With respect to the former, the beetle was not seen
to be molested by the termites in any way. Regarding this species, Professor
Emerson, who identified all host termites in this study, has the following com-
munication on the possible host:

"Nasutitermes ephratae (Holmgren) and Nasutitermes corniger (Motschul-
sky) are the two most commonly collected termites on Barro Colorado Island,
not because they are the most abundant, although they are actually numerous,
but because they also build conspicuous nests and covered tunnels, so they
stand out a little more in the general landscape than some other species which
are actually more numerous, but live in relatively concealed places.

Two other species of the same genus also occur on the island, Nasutiter-
mes columbicus and Nasutitermes nigriceps. N. ephratae was originally de-
scribed from Surinam and is common throughout South and Central America
from the Amazon region north. N.corniger was originally described from
Panama and is common on the Pacific coast of South America, and Central
America on both coasts. It has a very closely related species, N.costalis in
the West Indies and northern South America, east of the Andes and from
the Amazon valley north."

Xybarida nasicola does not appear to have the behavior, or the peculiar
morphological extravagances of symphilic beetles, but on the other hand appears
to be perfectly at home, and tolerated by the termites so that we may assign it
the role of a synoekete pending further information.

This species does not appear to be even closely related to other species of
the genus. The genus may be listed as follows:

clavata Raffray. 1896. Brazil. Genotype.
nasicola new species. Panama Canal Zone.
punctulum Raffray. 1904. Brazil.
pusilla (Schaufuss). 1879. Mexico. (Bryaxis)

BERDURA (Reitter, 1881)

This is a small genus with abnormal maxillary palpi, found in the Antilles
and the Panama Canal Zone. It has affinities with Scalenarthrus of the neo-
tropical fauna on the one hand, and also with the monotypic Berlara crassi-
palpis Reitter of Java. The combination of distant posterior coxae, ventral

164 NEOTROPICAL PSELAPHIDAE

surface of head with a median longitudinal carina, eleven-segmented antennae,
first two tergites distinctly margined, and the distal segment of maxillary palpi
provided with a tooth on the external face separate the two species from other
neotropical genera in this tribe.

The two species may be quickly separated as follows (PI. VII, 4, 5) :
Distal (fourth) segment of maxillary palpi with a minute, acute tooth

on external face at apical third exdsula

Distal (fourth) segment of maxillary palpi with a minute, rounded
tubercle on external face at basal third. . . .dentipalpa new species

Berdura dentipalpa new species

Type. Measurements: head 0.20 x 0.26 mm.; antennae 0.335 mm.; pro-
notum 0.23 x 0.30 mm.; elytra 0.40 x 0.44 mm.; abdomen 0.15 x 0.43 mm.; total
length 1.0 mm.; greatest width 0.44 mm. (PI. VII)

Body subglobular, shining, reddish-brown; integument lightly punctulate,
with short pubescence (0.017 to 0.022 mm.). Eyes below level of vertex, sub-
circular from lateral view, of twenty-eight coarse facets, 0.067 mm. through long
diameter, longer than tempora; tempora slightly convergent to occiput; occiput
truncate and slightly swollen to level of vertex; vertex slightly, evenly convex,
with two foveae on a line through middle of the eyes ; vertexal foveae small but
distinct, equal in diameter to an eye facet, not connected by any sulcus ; front
angularly produced but declivous between antennal bases, no elevated frontal
rim or margin ; epistome unmodified, pubescent. Ventral surface of head and ven-
tral surface of cervicum finely alutaceous. Dorsal surface of cervicum glabrous.
Ventral surface of head medianly concave, and with stout carinae as follows:
(1) a median, longitudinal, laminoid carina; (2) a strong, biarcuate lateral
carina each side from base of maxilla to posterior area of head; (3) a short,
strong, obliquely vertical carina which arises at the middle of the ventral margin
of each eye (PI. VII, 12) and drops in a straight line to join the lateral carina
at its most external arc, quite different to the homologous carina of Xybarida
nasicola in its course.

Maxillary palpi four-segmented ; first segment minute and obconical ; sec-
ond elongate, arcuate, basally slender and only moderately inflated apically;
third short, subtriangular; fourth longer than second and wider than third,
conical-ovate in outline, with the base rounded and apex very rapidly acute
and bearing a long, obtuse, obliquely inserted palpal cone. The external face of
this distal segment bears a small, rounded tubercle as basal third (PI. VII, 4).

Antennae eleven-segmented, rather short, widely separated at bases; seg-
ment I arcuate cylindrical; II ovate, as long and as wide as first from dorsal
view, but shorter from lateral view due to the overhang of the antennal acetab-
ulum; III obconical, much smaller than second; IV to VIII subequal in size,
submoniliform, small and closely articulated; IX transverse, as long as eighth
but wider; X wider than ninth and slightly longer; XI relatively large, twice as
wide as tenth and nearly as long as fifth to tenth segments inclusive united, very

BRACHYGLUTINI 165

hirsute, flattened dorso-ventrally when seen from the side, and with a distinct
sinuation on the internal face at apical third.

Pronotum with neither subbasal lateral, nor basal median foveae.

Each elytron with an obtusely elevated humerus, an entire sutural stria,
no trace of a dorsal stria, flank simple, base transversely carinate with four
minute basal foveal points just posteriad of the basal transverse carina.

Abdomen with five visible tergites, only the first two being fully visible
from above, the next two more or less vertical and the last ventral in position.
Lateral margins narrow, but well-developed on the first three segments. First
tergite twice as long as second, with a pair of straight, parallel basal carinae
almost half as long as the segment and separated by one-fourth the segmental
width. Second a little longer than third; third and fourth subequal in length.
Fifth tergite twice as long as fourth, nearly semicircular, tumid, rather coarsely
punctate.

Abdomen with five stemites visible medianly ; first long, one-fourth longer
than the next three united, the latter short, subequal in length. First visible with
a lateral fovea on each side immediately posterior to the mesial angle of the
posterior coxae, and with its orifice directed toward the lateral margin. Fifth
visible (last) sternite one-half the length of the first visible sternite, trans-
versely tumid, rather coarsely punctate and closely in contact with the apical
margin of the fifth tergite.

Mesosternum very transversely elevated at middle into an angulated cari-
noid wing above each middle coxa; mesosternum broadly introduced between
the middle coxae as a truncate plate ; middle coxae distant.

Metasternum slightly longer than first visible ventral, simple, not concave ;
produced medianly into a broad, truncate plate between the very distant pos-
terior coxae.

Legs simple.

Described from a single female specimen, the type, collected by the author
on Barro Colorado Island, Gatun Lake, Panama Canal Zone, at a light at night,
on July 7, 1936.

excisula Reitter. 1883. St. Thomas, Virgin Islands. Genotype.

dentipalpa new species. Panama Canal Zone.

SCALENARTHRUS (LeConte, 1880)
LeConte (1880)
LeConte and Horn (1883)
Brendel and Wickham (1890)
Raffray (1904, 1908, 1911, 1912)

Fletcher (1928) ,., ^ . r.

Bowman (1934)

ScHAUFUSS (1887) {Cylindremboliis; Bryaxis in part)
ScHAUFUSS (1879) (Bryaxis)
Raffray (1890) (Abryxis)
Raffray (1896) (Eupines)

166 NEOTROPICAL PSELAPHIDAE

From the above references it will be seen that this genus has been given
considerable attention, and second, that between the original description of the
genus by LeConte in 1880 and the final congeneric elucidation by Raffray in
1904, the genus in its modern sense was not understood, the neotropical species
being known under some four different names; as late as 1896, Raffray placed
a Mexican species, clavicornis, in the purely Australo-Asiatic Eupines.

At the present time this important genus includes American species only,
having in common: (1) short, globular to subglobular body, (2) ventral surface
of head with a median, longitudinal carina, (3) maxillary palpi not abnormally
formed, but simple and regular, (4) antennae eleven-segmented, often ab-
normal, (5) pronotum with neither lateral nor median foveae, in rare cases a
minute, indistinct punctiform basal impression (injlatus), (6) each elytron with
four punctiform foveal points replacing the basal foveae, and with no trace of
a dorsal stria, (7) abdomen with a relatively long first tergite, and the first two
to three tergites distinctly, but narrowly margined, (8) first sternite invisible
medianly, and wholly covered at this point by the metasternum, (9) inter-
mediate coxae distant, the mesosternum advanced between them as a flat, trun-
cate plate, (10) posterior coxae very distant.

The males generally have the epistome diversely elevated and anned, but
this is not an absolute criterion since some species have the epistome simple in
the male, and in other species only the male sex is known. The antennae are
usually abnormal in the male sex, but again this is not an absolute criterion.
In one group the males have the second segment of the anterior tarsi expanded.
Sex, then, is best determined by either direct dissection, or by examination of
the genital structures in cleared microscope slide-mounts. On triangle-mounts
specimens having the epistome or antennae abnormal, or both, are probably
males. The metasternum may be either concave or convex in the males.

The genus is of interest to the zoogeographer. At present there are eighteen
known species. The genotype, horni LeConte, is North American, distributed
from southern California to Arizona, and is presumably derived from the Mex-
ican fauna. Of the remaining seventeen species, three inhabit the Lesser Antilles,
three inhabit South America from the Amazon drainage basin to high elevations
in Bolivia, one at the cross-roads in the Panama Canal Zone, and the remaining
ten are found from Guatemala and British Honduras to Vera Cruz, Mexico. If
these species are all really congeneric, then Mexico, especially Yucatan with
at least four species, would seem to be the center of distribution, with one migra-
tion route to the north-west into the arid southwestern United States, a second
through the Canal Zone into South America, and a third over a now submerged
connection with the Antilles. Much expeditionary work needs to be done before
a clear picture can be presented. It should be noted that the related Berdura, as
well as the Hybocephaline Ephimia among others, have species found in the
Lesser Antilles and the Canal Zone. In Scalenarthrus the genus in general is
Central American, with Antillean as well as South American and North Amer-
ican exponents.

BRACHYGLUTINI 167

Raffray (1904) divided the genus into four groups, and his key to these
groups has been followed, save that its expansion by the addition of a new group
for a remarkable new species, necessitated some alteration:

Key to the Groups, based on males

Eleventh antennal segment simple, ovate to elongate-ovate in form,
or at most slightly sinuate on interal face near apex, often as long as
the preceding three or four segments united 2

Eleventh, tenth, and ninth antennal segments abnormal in shape or
structure, this abnormality marked 4

2. Eleventh antennal segment regularly ovoidal 3

Eleventh antennal segment irregularly ovoidal, and very obliquely

truncate at base Group III

3. First visible tergite with two thin, short basal carinae separated by

one-fourth the segmental width Group I

First visible tergite with no basal carinae visible Group II

4. Ninth antennal segment not as large as tenth Group IV

Ninth antennal segment much larger than tenth . . Group V, new group

Alternative group key based on males

Eleventh antennal segment simple, ovate to elongate-ovate in form,
and never abnormal in either sex save a slight sinuation on internal
face near apex (concavus) or a very slightly oblique base (simplex) 2

Ninth, Tenth, and Eleventh antennal segments distinctly abnormal
in structure or outline 3

2. First visible tergite with two thin, short basal carinae separated by

one-fourth the segmental width Group I

First visible tergite with no basal carinae Group II

3. Eleventh antennal segment very obliquely and arcuately truncate at

base, this obliquity paralleling the convex, arcuate apical margin of
the tenth segment, and the eleventh segment, therefore, having an
acutely produced basal external angle, with the external face of the
segment being longer than the internal face; known only from Mex-
ico; female with regularly ovate distal antennal segment

Group III

Abnormality of the antennal club very pronounced, but not identical
with the above 4

4. Ninth antennal segment not as large as tenth segment. . . .Group IV
Ninth antennal segment very much larger than tenth antennal seg-
ment; known from the Panama Canal Zone. . .Group V, new group

Group I

Known only from Brazil marginalis

Distributed north of the equator 2

168 NEOTROPICAL PSELAPHIDAE

2. Antennal segment III subconical, IV-VIII quadrate, IX transverse,
X trapezoidal, less transverse than ninth, XI short, ovate; known

only from Yucatan subcarinatus

Antennal segment III-VIII moniliform, IX quadrate, X transversely-
oblique and triangular and wider internally, XI large, ovate; known
only from the Lesser Antilles guadelupensis

Group II

First visible sternite between the posterior coxae minutely carinate;
frontal sulcus obsolete or quite shallow medianly 2

First visible sternite between the posterior coxae not at all carinate,
but broadly concave ; the transverse frontal sulcus equally deep for

its entire length concavus

2. Antennal segment IX briefly obconical, IX ovate-elongate, as long as
the preceding four segments united schaufussi

Antennal segment IX transverse, IX large, ovate, the base very slightly
subobliquely truncate (showing an affinity for Group III in this fea-
ture), and as long as the five preceding segments united. . . .simplex

Group III

Known only from a single species, obliquus, from Guanajuato, Mexico,
but fortunately both sexes have been described. Length L2-1.25 mm. The female
has the eleventh antennal segment relatively small, as long as the four preceding
segments united, and regularly ovate in shape. The male has the last three seg-
ments abnormal in shape, and appears to the author to be misplaced in RafTray's
key, since the abnormalities of the antennal club would seem to place the group
under step "4" of our key, rather than step "2"; however the degree of abnor-
mality is much less than in the fourth and fifth groups. The male obliquus has
the ninth antennal segment broadly transverse, with the mesial face simply
convex and the lateral face narrowly acute at the distal angle; tenth segment
very much more transverse and shorter than ninth, with the mesial face convex
and the lateral face very narrowly produced and acute ; eleventh antennal seg-
ment as long as the preceding five segments united, with a very obliquely trun-
cate base, this obliquity following the arc of the distal margin of the tenth seg-
ment, and with the external basal angle of the segment very acute, thus the
lateral face of the segment is distinctly longer than the subsinuate mesial face.
Because of this abnormal club an alternative key to the groups of Scalenarthrus
is given which departs still further from the Raffrayan pattern, but may serve
to check one's group allocations.

Group IV

This the largest group in the genus and holds many remarkable antennal
modifications. The following key to males, unless otherwise stated, does not

BRACHYGLUTINI 169

take into account two species, separabilis (Schaufuss) and adparatus (Schau-
fuss), both from Yucatan.

Known only from the Lesser Antilles, and separable from the other

species by remarkable male antennae described below 2

Not known from the Antilles, and male antennal modifications of a
much different character, as described below 3

2. Eleventh antennal segment longer than segments I to X inclusive

united, and over twice as wide as first segment; this eleventh seg-
ment with an oblique, ovate fovea at basal third, and of a unique
shape, obliquely truncate at base, obtusely rounded at apex, strongly
sinuate medianly, with the internal face broadly concave and the
external face angulate-convex; 1.0 mm. long; known from Grenada

clavatiLS

Eleventh antennal segment ovate, slightly sinuate, base rounded-
truncate, apex acute, as long as the four preceding segments united ;
segment X as wide as eleventh, very transverse with the external
face straight and the internal face obliquely produced to form an
acut€ apical internal angle; IX much smaller than either tenth or
eighth, with the internal face acute; VII and VIII subspherical, each
with a long appendage or spine arising from the internal face; 1.25
mm. long; known from Grenada pectinicornis

3. The vertexal foveae free, not connected in any way with the transverse

frontal sulcus 4

The vertexal foveae connected with the transverse frontal sulcus or
impression by a fine, shallow arcuate inter- foveal sulcus 5

4. Antennal segment III obconic; IV to VII more transverse; VIII-XI

abruptly wider to form the antennal club ; X with a distinct blunt
tooth which arises from the internal apical angle of segment and
extends distally, almost reaching the excavation of the eleventh seg-
ment; XI longer than the four preceding segments united, lateral
face straight for basal two-thirds and then very oblique to the obtuse
apex, the internal face irregularly convex, surface with a deep trans-
verse excavation which lies in a part of the basal half, this excava-
tion with a small acute tooth on the inner basal edge provided with
a dense brush of setae; length 1.0 mm.; known from Guatemala and

British Honduras globosus

Antennal segment III-VII moniliform, not transverse; VIII slightly
transverse; IX slightly wider, lenticular; X strongly transverse and
slightly oblique, not toothed; XI very large, almost as long as the
third to tenth segments inclusive united, wide, with lateral face con-
vex to internally oblique, subacute apex and mesial face distinctly
sinuate at apical third, the entire basal half of the dorsal surface of
the segment deeply excavated; length 1.2 mm.; known from Mexico
cavicornis

5. Antennal segment XI almost as long as the six preceding segments

170 NEOTROPICAL PSEL APHID AE

united, with outer basal angle forming a tooth which projects pos-
teriorly to slightly overlap the tenth segment; this eleventh segment
remarkable for the extent of excavation, the entire surface is exca-
vated save for an elongate area at mesial apical face; 1.2 mm. long;
Vera Cruz, Ver., Mexico inflatus

Antennal segment XI with a transverse excavation which occupies

much less than the basal half of segment 6

6. Antennal segment XI with a distinct subbasal tooth; known from
Yucatan denticornis

Antennal segment XI with no tooth, but with the basal margin of
excavation sharply defined and provided with a long, dense tuft of
inwardly directed setae on the inner basal angle; 1.0 mm. long;
known from British Honduras ventricosus

Group V New Group

This new group has been erected for a remarkable new species of the
Panama Canal Zone. The key character given for the separation of this species,
undedmtympus, is simply a convenient structural feature for rapid separation
from the other species in Group IV, and does not by any means indicate the
divergence between these two groups. This Panamanian species has the male
second tarsomere of the anterior tarsi swollen, flattened below, and provided
with a brush of setae, as in the males of Xybaris, Achillia, Bryaxina, Braxyda.
This secondary sexual character is not common to Scalenarthrus, and it is pos-
sible that the new species belongs in a separate subgenus or even a new genus.
It is of interest in this precise connection to point out the parallel in another
subglobose, related genus Cryptorhinula, where the anterior tarsi of the males
are not dilated save in oedipus (Sharp) , where the second tarsomere is peculiarly
swollen.

In the essential key characters undecimtypus is Scalenarthrus, with affini-
ties with Pselaptus and Xybaris. Numerous peculiarities will be found in the
description which follows, especially the male antennal club and the remark-
able air-filled tube on each side of the head.

Scalenarthrus undedmtympus new species

Holotype Male. Measurements: Head 0.20 x 0.26 mm.; antennae 0.335
mm.; pronotum 0.23 x 0.30 mm.; elytra 0.40 x 0.47 mm.; abdomen 0.13 x 0.40
mm.; total length 1.00 mm.; greatest width 0.47 mm. (PL VII, 2, 3, 12)

Body subglobular, light yellowish-brown, moderately shining, very lightly
punctulate; pubescence rather short (0.01 mm. on pronotum and 0.022 mm. on
elytra) , inconspicuous save under high magnification but rather abundant. Head
subquadrate from a dorsal view, with prominent eyes. Eyes with about twenty-
four coarse facets, relatively long (0.09 mm.), more than twice as long as the
convergent tempora which are short (0.04 mm.). Vertex flattened, higher than

BRACHYGLUTINI 171

eyes, with a pair of small, distinct vertexal foveae, each nearer an eye than to
each other and distinctly less in diameter than an eye facet. No circumambient
sulcus connecting the vertexal foveae. Front between antennal bases indistinctly
impressed, and anterior to antennal bases triangularly declivous to the simple,
nearly vertical, hirsute epistome. Labrum rather small and simple. Mandibles
conspicuous, each with a distinct, obliquely truncate tooth or boss at base on
the external face. Ventral face of head with a median, longitudinal carina, a
biarcuate lateral carina on each side, and a short, straight carina from middle
of ventral margin of each eye to lateral carina, joining the latter at a right
angle. (PI. VII, 12)

Maxillary palpi four-segmented, normal, first segment minute and cylin-
drical; second elongate, arcuate, basally slender and inflated in distal third;
third short, one-third as long as second and slightly wider than second, subtri-
angular; fourth longer than second and wider than third, elongate-ovate, ob-
liquely truncate at base, apex subtruncate slightly, with a palpal cone at apex.

Antennae widely separated at base, eleven-segmented, abnormal, segments
I and II subovate, relatively large, subequal from dorsal view; III obconical,
shorter and narrower than second; IV to VII subequal in width, transverse,
shorter than third, closely articulated; VIII subtrapezoidal, a little wider than
seventh ; IX transverse, asymmetrically triangular from a dorsal view and quad-
rate from a posterior view, distinctly wider and longer than tenth, the quadrate
posterior face with a broad, shallow fovea; X small and inconspicuous, very
transverse, much narrower and shorter than ninth, asymmetrically trapezoidal;
XI one-half wider than ninth and as long as fourth to ninth inclusive united,
0.107 mm. long, truncate at base, subovate with a short, blunt apex, nearly as
wide as long. This eleventh segment is excavated on the internal face at apical
third and on the dorsal face near the base is a conspicuous, circular, raised table
or drum-shaped tubercle.

Pronotum slightly wider than long; basal margin slightly medianly pro-
duced or sinuate; base of pronotum with no foveae, neither lateral nor basal.
The positions usually occupied by lateral and median foveae are indicated by
darkened areas of the integument.

Elytra with humeri obliquely elevated ; each elytron with an entire sutural
stria, no trace of a dorsal stria, flank simple, the base with four small basal
foveae.

Abdomen with five visible tergites, only the first two of which are to be
seen from a dorsal view; first three tergites narrowly but distinctly margined.
First tergite as long as second and third united, with a pair of straight, parallel
basal carinae separated by one-fourth of the segmental width and almost one-
half as long as segment. Second tergite and fourth subequal in length, longer
than third. Fifth as long as the third and fourth united, apical margin rounded-
triangular in outline.

Five stemites visible medianly, the first of these as long as the second to
the fifth inclusive united; second, third, and fourth very short and inconspic-
uous; fifth relatively large, three- fourths the length of the first visible stemite.

172 NEOTROPICAL PSELAPHIDAE

slightly tumid with a deep, subtriangular excavation in basal half occupying
one-sixth of the segmental width.

Mesostemum advanced between the distant intermediate coxae as a sub-
truncate plate, this plate densely pubescent.

Metasternum slightly longer than first visible sternite, evenly and simply
convex, posteriorly truncate between the very widely separated posterior coxae.
Sternal foveae IV well developed, one at each lateral angle of an intermediate
coxal cavity, the mesial wall of the fovea recessed by a longitudinally arcuate
carina which extends from this point posteriorly for almost one-half the meta-
sternal length. The metasternum medianly advanced between the intermediate
coxae, meeting the mesosternal process, and like the latter pubescent in this re-
stricted area. This pubescent intercoxal region is elevated above the plane of
the metasternum and the paired sternal foveae VI lie just posterior to the ele-
vation. The posterior walls of the intermediate coxal cavities are strongly
beaded, this bead forming the anterior margin of the metasternum at this point
and continuous with the intercoxal extension mesially and continuous with the
longitudinal metasternal carina laterally.

Anterior femora strongly inflated; intermediate and posterior femora not
inflated. Anterior and intermediate tibiae normal ; posterior tibiae thickened in
apical half and strongly arcuate internally. Trochanters and coxae not armed.
Anterior tarsi with second tarsomere dilated and flattened, the ventral face pro-
vided with a brush of short oblique setae ; intermediate and posterior tarsi nor-
mally developed and slender.

Examination of a male paratype, cleared and mounted in balsam, reveals
additional structural details not appreciable in a triangle mount: (1) The
labrum is seen to have two minute acute teeth which arise from the ventral sur-
face and extend anteriorly slightly beyond the distal margin; (2) The obliquely
truncate tooth at external base of each mandible has several convergent pore
canals which extend into the integument as fine invaginations. These canals sug-
gest a sensory function for this mandibular boss; (3) On each side of the head,
between the antennal base and the eye, the integument is invaginated obliquely
to form a long subpyramidal tube. This air-filled tube courses beneath the ver-
texal integument to end blindly near each vertexal fovea. As far as I know,
this tubular extension is unique. It does not have any discernible connection
with the vertexal fovea, nor with the arm of the supratentorium which connects
the floor of the vertexal fovea with the floor of the gular fovea of each side;

(4) The gular foveae are two in number and widely separated, one on each side
of the extreme base of the longitudinal median carina of the ventral surface of
the head, and clearly connected with the vertexal foveae by the supratentorium ;

(5) The circular, flat-topped, drum-shaped boss of the eleventh antennal seg-
ment is seen to have thin walls and apparently extends deeply into the sub-
stance of this segment; (6) The four basal elytral foveae are seen as minute,
deep cylindrical foveae penetrating the elytral integument; (7) The true first
sternite of other tribes is visible as a narrow, wide membranous sclerite between
the posterior coxae, and wholly covered by the metasternum; (8) The penis is

BRACHYGLUTINI 173

relatively large, bilaterally asymmetrical and in repose lies with its base at the
base of the abdomen and its long axis parallel with the long axis of the body.
The penis is as long as visible sternites I to V inclusive united. In actual size it
is 0.25 mm. long by 0.06 mm. wide through the rounded basal bulb; (9) The
tarsal pad consists of eight rows of oblique setae, with fourteen setae per row
or one hundred and twelve setae in all.

Described from two male specimens collected by the author at light at
night, on Barro Colorado Island, Gatun Lake, Panama Canal Zone as follows:
holotype July 17, 1936, and paratype July 7, 1936. The many novel structural
features readily separate this new species from others of the genus. The species
of the genus may be listed as follows:

Group I

guadelupensis Raffray. 1912. Guadeloupe, Leeward Islands.
marginalis (Schaufuss). 1887. Brazil. (Bryaxis)
subcarinatus Raffray. 1904. Mexico.

Group II

concavus Fletcher. 1928. British Honduras and Guatemala.
schaufussi Raffray. 1904. Brazil.
simplex Raffray. 1904. Bolivia.

Group III
obliquus Raffray. 1904. Mexico.

Group IV

adparatus (Schaufuss). 1887. Mexico.

cavicornis (Raffray). 1896. Mexico. (Eupines) {clavicornis of Rafiray,

1904, 1908)
clavatus Raffray. 1904. Grenada, Windward Islands.
denticornis (Schaufuss). Mexico. {Bryaxis, 1879) {Abryxis of Raffray)
globosus Fletcher. 1928. British Honduras and Guatemala.
inflatus Fletcher. 1928. Mexico.

Pectinicornis Raffray. 1904. St. Vincent, Windward Islands.
separabilis (Schaufuss). 1887. Mexico. (Bryaxis) (Abryxis of Raffray)
ventricosus Fletcher. 1928. British Honduras.

Group V new group
undedmtympus new species. Panama Canal Zone.

PSELAPTUS (LeConte, 1880)

LeConte (1880)

Sharp (1887)

Brendel and Wickham (1890)

174 NEOTROPICAL PSELAPHIDAE

Casey (1897)

Raffray (1891, 1896, 1900, 1904, 1908, 1911, 1912)

Leng (1920)

Bowman (1934)

This is a genus of moderate size, holding eleven species. The group is wholly
neotropical with the exception of the genotype, Pselaptus belfragei LeConte
which is distributed sparingly from central Texas to southern California. This
latter species has apparently evolved from the Central American group, as the
center of the genus appears to be in northern South America, the species hav-
ing radiated south into Brazil and Argentina, north-east via the Lesser Antilles
into Cuba, westward into Venezuela and Columbia and from this point up
the Isthmus into Guatemala and Mexico.

The genus is specialized and belongs to a section of the tribe {Xybarida,
Berdura, Scalenarthrus, Pselaptus, Mitona, Xybaris, Cryptorhinula) holding
species which have many features in common, and very difficult to separate
effectually. Pselaptus has been isolated in the key by certain structural char-
acters, from its allies. The size is small (1.0 to 1.4 mm. in length), with smooth
integuments which are usually glabrous and shining, but may be dull and un-
polished in some species. The metasternum is large and usually concave in
the male sex, variously formed. Thus the male politissimus has the metasternum
elevated and triangular ; in the male sternalis and cristatus the metasternum is
concave, and in sternalis at least this concavity is wide, squamous. The females
have the metasternum flattened (grouvellei) .

The key is both tentative and incomplete, although it will serve to isolate
the majority of the known species. I have found that the group of genera
clustering about Scalenarthrus is one of the more difficult taxonomic areas
in the family, generic limits not being too well drawn and many new species
undoubtedly awaiting discovery.

Species known only from the Antilles 2

Species of Central and South America 3

2. Male metasternum large, entirely and deeply concave, with carinoid

lateral margins, the concavity provided with squamous pubescence ;
1.4 mm. long; known only from the southeastern end of the Antilles

(Grenada) sternalis

Metasternum not of this character; known only from Cuba, .longiclava

3. Base of pronotum with a fine crest anteriad of scutellum; area of pro-

notum occupied by lateral subbasal foveae of other genera here oc-
cupied by confluent punctures; 1.25 mm. long; known from Mexico
and said by Raffray (1904, p. 250) to resemble the Grenadine

sternalis! cristatus

Pronotum without these features 4

4. Species known only from Guatemala 5

Species known south of the Isthmus of Panama 6

5. Antennal segments III-VIII small; IX slightly wider than eighth,

quadrate, as long as wide; X similarly quadrate but larger than

BRACHYGLUTINI 175

ninth; known from a single specimen of unspecified sex, probably

female; 1.5 mm. long; El Reposo, Guatemala batrisoides

Antennal segments III-X small, similar; 1.33 mm. long; based on a
male with concave metastemum simulatrix ^

6. Antennae with segments III-VIII slightly progressively shorter; IX

and X subtransverse, slightly larger than eighth and crescentric in
form; metasternum slightly flattened; 1.7 mm. long; known from a

female from Bahia, Brazil grouvellei

Antennae not so formed 7

7. Antennal segment I with the dorso-intemal angle produced into a

tuberculate tooth in the male sex tuber culijer

Antennal segment I not so formed 8

8. Antennal segments III obconical; IV-VIII subelongate-quadrate ; IX

obconical, twice as long as eighth; X slightly quadrate; male from

San Esteban, Venezuela; 1.5 mm. long caloaratus

Antennal segments III-VIII longer than wide; IX elongate-obconical;

X slightly transverse ; metasternum elevated and triangular in form ;

male from Blumenau, Brazil; 1.4 mm. long politissimus

This key does not take into account formicarius of Colombia. The species
may be listed as follows:

batrisoides Sharp. 1887. Guatemala.
calcaratus Raffray. 1891. Venezuela.
cristatus (Schaufuss). 1897. Mexico. (Bryaxis) {Eutrichites by Raffray

in error, cf. 1904, p. 209).
formicarius Raffray. 1900. Colombia.
grouvellei Raffray. 1896. Brazil.
longiclava (Schaufuss). 1887. Cuba. (Bryaxis)
-politissimus Raffray. 1904. Brazil.
simulatrix (Sharp). 1887. (Bryaxis). Guatemala.
sternalis Raffray. 1904. Grenada, Windward Islands.
tuberculifer Raffray. 1912, Argentina, (con Atta lundi Guer.)

Buenos Aires, Argentina (Bruch, 1929)

MITONA (Raffray, 1904)

This genus, allied to the North American Anchylarthron, as well as
Xybaris, Pselaptus, and allies, is found in northern and northwestern South
America. The mesost^mum is bicarinated, and advanced between the middle
coxae as a short, flat plate, these coxae distant. Metasternum wide and flat-
tened. The short, subquadrate, slightly convex body, and narrow, slightly
elevated abdominal margin is similar to Pselaptus. The complete lack of
lateral pronotal foveae separate it from Xybaris.

The species may be separated as follows:

^ This species, described by Sharp from Paraiso, Guatemala, may not be Pselaptus at
all. Raffray (1908) places it in Pselaptus and states of the genus that there are no pronotal
foveae of any kind. Sharp (1887, p. 31) says that the pronotal base is produced in front
of scutellum and has a very minute fovea in middle close to the base !

176 NEOTROPICAL PSELAPHIDAE

Antennae with segments V and VI subcylindrical, distinctly longer

than wide quadraticeps

(1.1 mm.; antennal segments I short, quadrate;
II elongate-ovate ; III-VII subcylindrical ; VIII
quadrate; IX larger and quadrate; X twice as
large as ninth; XI briefly ovate)

Antennae with segments V and VI moniliform 2

2. First tergite with the two basal, discal carinae divergent, approximate,

their apical ends separated by about the distance between the two
sutural striae of the elytra, these striae of the first tergite distinct,

about one-third of tergite length bisulciceps

(1.1 mm.; close to quadraticeps)
First tergite with the two basal, discal carinae very short and in-
conspicuous 3

3. Antennae segments VII and VIII moniliform and of same size; IX

transverse, slightly wider than eighth; X twice as large as ninth,

subquadrate-transverse. Metastemum flattened mniszechi

(1.3 mm. close to nigra)

Antennae with segment VII moniliform, VIII hardly larger than

seventh, transverse; IX slightly larger, transverse, slightly acute

internally ; X twice as large as IX, slightly transverse. Metasternum

posteriorly and widely, subtriangularly impressed nigra

(1.4 mm. close to mniszechi)

quadraticeps Raffray. 1904. Bolivia. Genotype.
bisulciceps RafTray. 1904. Bolivia.
mniszechi Raffray. 1904. Colombia.
nigra Raffray. 1904. Venezuela.

XYBARIS (Reitter, 1882)

This is a genus of pselaphids confined to the neotropics. It contains seven
species from Brazil and one from the Panama Canal Zone. These eight species
all agree in the following: (1) normal maxillary palpi, (2) a median longi-
tudinal carina on the ventral surface of the head, (3) base of pronotum with
a lateral fovea each side and a median fovea, (4) two or four well formed
foveae at the base of each elytron, (5) the dorsal elytral stria represented
by a very faint intrahumeral impression, (6) a narrow abdominal margin,
(7) mesostemum produced posteriorly between the mesothoracic coxae as a
distinct and truncate plate, (8) metathoracic coxae not conical; and distant
from each other, (9) five visible tergites and sternites, the true first sternite
invisible between the posterior coxae. These characters separate the members
of the genus from all other brachyglutine aggregates.

The sexes may be readily distinguished. The males have the second tar-
somere of the anterior tarsi laterally dilated and slightly flattened dorso-
ventrally and with a conspicuous brush of setae on this flattened ventral sur-

BRACHYGLUTINI 177

face; the females have this tarsomere normally formed and not brushy be-
neath. In addition most of the species have the males with special modifications
of the head.

The following species is new. It is the first species of the genus known
outside of Brazil, and may form the type of a new genus although I have not
followed this latter course as both of the specimens at hand are females.

Xybaris funiculis new species

Cotype Females. Measurements: Head 0.20 x 0.268 mm.; antennae 0.40
mm.; pronotum 0.23 x 0.288 mm.; elytra 0.41 x 0.536 mm.; abdomen from
dorsal view only 0.134 mm., in reality the first visible tergite, but the true
total abdominal length 0.422 mm.; total length from strict dorsal view 0.974
mm.; greatest width 0.536 mm. (PI. VII)

Body subglobose, yellowish-brown, moderately shining, unifonnly punc-
tulate. Pubescence long (setae 0.033 mm.) on elytra and abdomen, stout and
yellowish in color; setae slightly shorter on head and pronotum. Pubescence
on the whole conspicuous when compared to Scalenarthrus, Berdura, Xybarida
with very indistinct pubescence. Head in dorsal outline subtrapezoidal, with
the eyes 0.087 mm. long, 0.03 mm. in diameter, and composed of about twenty-
four very coarse facets. Tempora 0.033 mm. long. Vertex evenly subconvex,
with two large and deep vertexal foveae on a line through the anterior third
of the eyes. Each vertexal fovea has the diameter of an eye facet, with nude,
cylindrical walls, and separated from the adjacent eye by the foveal diameter.
These foveae free, not connected to each other or to the front by a sulcus. A
conspicuous transverse cleft arising just posterior to the anterior prominence
of each antero-lateral corner of the vertex, and extending medianly to a point
opposite each vertexal fovea. Front simple, steeply declivous to the simple,
nude epistome. Labrum simple. Mandible simple, left crossed dorsal to right;
no external basal tooth. Bases of maxillae relatively wide, and mentum
relatively long and narrow. Ventral surface of the head with a high median,
longitudinal carina; a biarcuate lateral carina each side; an ocular carina
which arises at the anterior margin of the eye, and remains in contact with
the eye, to join the lateral carina beneath the middle of each eye. (PI. VII, 11)

Maxillary palpi normal, four-segmented; first segment minute; second
elongate, arcuate, slender at base and inflated apically; third short, subtri-
angular; fourth longest and widest, obliquely truncate at base, subacute at
apex, conico-ovate, bearing an apical palpal cone.

Antennae normal, eleven-segmented, widely separated at base; segments
I and II subconical, relatively large; III obconical, smaller than second; IV
to VIII closely articulated, subequal, shorter than third; IX transverse, wider
than eighth, about as long as eighth; X wider and longer than ninth, sub-
trapezoidal; XI relatively large, subasperate, twice as wide as tenth and
as long as fourth to tenth inclusive, subovate with a bluntly rounded apex.

Pronotum obcordate with a subbasal lateral fovea on each side and a

178 NEOTROPICAL PSELAPHIDAE

median fovea nearer base, all three foveae distinct and subequal in size, with
the median deeper than laterals; base with a row of about twenty coarse
punctures just posterior to the median fovea.

Elytra with obliquely prominent humeri; each elytron with the flank
simple, an entire sutural stria, and no dorsal stria; base of each elytron with
four distinct foveae, each about the size of the median pronotal fovea. Meta-
thoracic wings well developed, translucent, the membranous surface appearing
minutely granular in dry specimens; each wing fringed with long setae, the
setae being 0.047 mm. in length.

Abdomen with five visible tergites and stemites medianly. Tergite one
nearly four times as long as second; third as long as second; fourth about
as long as third; fifth transversely, irregularly ovate and not visible from
above, with a prominent median longitudinal tubercle on the basal half of
length, and with the apical half of the tergite irregularly and medianly de-
pressed near the junction with apical margin of last stemite, its surface more
coarsely punctate.

First stemite wholly invisible between the posterior coxae ; second stemite
(first visible medianly) long, longer than the remaining stemites united; sec-
ond, third, and fourth visible stemites very short, subequal ; fifth visible ster-
nite (true sixth) as long as the two preceding united, with its apical margin
medianly produced or emarginate.

Metasternum with a very long, longitudinal carina on each side, arising
at the lateral margin of the mesothoracic coxal cavity and extending poster-
iorly half the distance to the apical margin of the metasternum. This metaster-
nal carina is a very conspicuous feature of the species. Legs simple, typical
of genus and of the female sex, with the second tarsomere of the anterior tarsi
not dilated and flattened and not bearing a setal brush beneath. The first tarso-
mere is minute, the second large, the third relatively large but not as long
as the second, and bearing a single tarsal claw.

Described from two female specimens, cotypes, collected by the author at
light at night, on Barro Colorado Island, Gatun Lake, Panama Canal Zone.
One specimen collected the night of July 7, 1936 and one the night of July
17, 1936.

This is a very distinct species. At first these females were thought to be
associated with the two males of Scalenarthrus undecimtympiis. This asso-
ciation in the field was found to be purely fortuitous when they were analyzed
as the conspicuous pubescence, radically different ocular carinae of the ventral
surface of the head, and presence of well developed basal pronotal foveae of
Xybaris funiculis preclude such a point of view.

The genera clustering around Xybaris are both difficult to separate
and not fully appreciated zoogeographically. The carinae of the ventral surface
of the head offer excellent material for future study. Thus the lower face of
the head, the region bounded by the mandibular bases and mentum apically,
the posterior margin of the tempora, and laterally by the eyes is seen to be
roughly trapezoidal in outline. On the field are five carinae: a median, longi-

BRACHYGLUTINI 179

tudinal carina of varying height, marking the fusion of the mesial margins
of the genal sclerites, the primitive gular sclerite not being in evidence; on
each side of the median carina is a more or less biarcuate lateral carina which
arises near the base of a mandible and extends to the posterior margin of the
head; finally, there is a pair of ocular carinae. It is with these ocular carinae
that we are especially concerned. They appear to be constant for a species,
but show no discernible sexual modification and hence should serve in the
separation of closely allied genera. For example (1) in Xybarida nasicola
the ocular carina arises anterior to each eye, passes post^ro-ventrally, and
unites with the lateral carina without touching the eye at any point (PI. VII,
10) ; (2) in Xybaris funiculis the ocular carina arises at the anterior margin
of the eye, passes postero-ventrally, and unites with the lateral carina; this
ocular carina is in contact with the eye for most of its course (PI. VII, 11) ;
(3) In Berdura dentipalpa and Scalenarthrus undecimtympus the ocular carina
arises from the median-ventral margin of the eye and passes ventrally to
join the lateral carina at nearly a right angle (PI. VII, 12).

The eight species of the genus Xybaris may be listed as follows:

spiniceps Reitter. 1882. Sao Paulo, Brazil. Genotype.

triangulifera (Schaufuss). 1887. Minas Geraes, Brazil. (Bryaxis)

sahlbergi Reitter. 1882. Petropolis, Brazil.

quadraticeps Raffray. 1904. Brazil.

atomaria Raffray. 1904. Blumenau, Brazil.

troglocera Reitter. 1882. Brazil.

excisa Raffray. 1909. Sao Paulo, Brazil.

funiculis new species. Panama Canal Zone.

CRYPTORHINULA (Schaufuss, 1887)

This specialized, wholly neotropical genus is closely allied to Xybaris.
The center appears to be in Brazil, the species also being found in Venezuela
and as far north as Guatemala.

The head is relatively large, subquadrate, with vertex simple and flattened
to slightly vaulted; vertex separated from the front by a transverse, entire
sulcus; front usually simple, truncate, and usually transversely elevated be-
tween the antennal bases (in some males the front has a median setose tubercle) ;
the two vertexal foveae vary from minute to small and are free ; ventral surface
of the head with a median, and on each side a lateral, longitudinal carina.
Maxillary palpi as in Xybaris. Antennae as in Xybaris save that (a) the second
segment is not swollen in Cryptorhinula males and is often swollen or dilated
in Xybaris males, and (b) the eleventh antennal segment in the males of some
Cryptorhinula is of irregular form and may be toothed at base.

The tarsi are elongate, slender, with the second tarsomere slight]}'- longer
than the third, and a little thicker (in oedipu^, which may not belong in this
genus, the anterior tarsi of the male (?) sex is said to be peculiarly swollen).
This condition is normal for the male Xybaris, among other genera, but not
typical for Cryptorhinula.

180 NEOTROPICAL PSELAPHIDAE

Other characters, of generic import, are stated in the key to genera.
The species of this genus (with the exception of longidava) may be tenta-
tively separated as follows:

Key to the Species

Head with the front having a setose tubercle between the bases of

the antennae 2

Head with no median setose frontal tubercle 3

2. Discal stria of each elytron distinct; head not distinctly and closely

punctate nodifera Schaufuss, Male

(Antennae lacking from the unique type)
Discal stria of each elytron obsolete and very short; head not dis-
tinctly punctate longiceps Raflray, Male

(Antennal segment XI large and oval; 1.2 mm. long)

3. Antennae with the last segment (XI) oblong, apex obtuse, base com-

pressed and minutely toothed ; head distinctly and densely punctate

schaufussi Raffray , Male

(1.4 mm. long)
Antennae with last segment not so formed 4

4. Known only from Guatemala 5

Known from South America 6

5. First tergite slightly longer than second ; 1.3 mm. long ; eleventh anten-

nal segment subacuminate and about as long as sixth to tenth seg-
ments combined trimioides (Sharp)

First tergite nearly twice as long as second; 1.5 mm. long; eleventh
antennal segment "very large and acuminate". . . .oedipus (Sharp)

6. Antennae with segment III obconical, IV-VII moniliform, VIII trans-

verse, IX and X transversely subquadrate; first tergite with the
basal discal carinae slender, slightly divergent, separated by one-
fourth of the discal width; 1.2 mm. long

longiceps Raffray, Female

Antennae with segments hardly crescentric (III-VIII) ; segment III
slightly wider than long, VIII slightly transverse, IX and X slightly
transverse, larger than eighth and crescentric ; first tergite with the
basal discal carinae short, parallel, including slightly less than one-
third of discal width; 1.2 mm. long xybaridoides Raffray

The species may be listed as follows:
longiceps Raffray. 1890. Venezuela.
longidava Raffray. 1890. Brazil.
nodifera Schaufuss. 1887. Brazil. Genotype.
f oedipus (Sharp). 1887. Guatemala. (Bryaxis)
schaufussi Raffray. 1896. Brazil.
f trimioides (Sharp). 1887. Guatemala. (Bryaxis)
xybaridoides Raffray. 1904. Brazil, {nee xybaroides Raffray, 1904,
1908)

BRACHYGLUTINI 181

DRASINUS (Raffray, 1904)

Raffray (1904) {Drasinm, p. 148 and Euteleia in part, p. 183)

Raffray (1908) (Drasinus)

Fletcher (1928) (Drasinus)

This genus is restricted to the neotropics. It contains at present four species
which may be characterized as follows: (1) ventral surface of the head with
a strong median, longitudinal carina; (2) antennae with ten segments; (3)
maxillary palpi with four segments, of which the last has the external face
convex, the internal face slightly concave to straight, and the apex bluntly
rounded; (4) mesothoracic coxae slightly but distinctly separated, the meso-
stemum extending between them as a truncate plate; (5) metathoracic coxae
distant from each other; (6) abdomen with the first tergite having a narrow
but strongly formed margin; (7) first stemite hidden beneath the coxae and
metasternum so that the first visible stemite is morphologically the second.

Raffray (1904, p. 148) in erecting Drasinus states that the intermediate
(mesothoracic) coxae are slightly distant; in his generic key (1908, p. 196)
Raffray places Drasinus in a group having contiguous intermediate coxae, and
later in the same paper (1908, p. 226) in discussing the genus notes that the
intermediate coxae are slightly distant. The 1908 generic key of Raffray is
incorrect and the generic diagnosis of 1904 and 1908 must be followed.

I have placed Drasinus and Decarthron much nearer together than the
relative positions given them by Raffray, despite the difference in the ventral
surface of the head. This opinion was reached after a study of my own ma-
terial in both genera and it was a source of satisfaction to discover that Fletcher
(1928, p. 211) independently had reached the same conclusion.

Key to the Species

Bluntly rounded apex of fourth segment of maxillary palpus meeting
the slightly concave internal face of the segment in an acute angle,

the segment being widest near apex (apical fifth)

Subgenus Drasinus 2

Bluntly rounded apex of fourth segment of maxillary palpus meeting
the straight to slightly convex face of the segment in a perfectly
rounded, non-angulate contour, the segment being widest nearer
the middle (apical four-sevenths of total length) and externally
rounded in apical fourth; this segment with a distinct terminal
palpal cone Subgenus Paradrasinus, new subgenus 3

2. Known only from Mexico; 1.3-1.4 mm. long; antennal segments III

to VII decreasing in length with the seventh quadrate .... binodulus

Known only from Brazil; 1.2 mm. long; antennal segments IV to IX

quadrate lewisi

3. Known only from Mexico; 1.5 mm. long; male with the third visible

stemite (morphological fourth) medianly tumid, the small tumulus
very transverse and simple, provided with a sparse fringe of setae

182 NEOTROPICAL PSELAPHIDAE

(U.S.N.M. paratype, No. 44604) hirsutus

Known only from Panama Canal Zone; 1.2-1.3 mm. long; male with
the third visible sternite (morphological fourth) highly modified:
four protuberances, two lateral which are relatively low and broad
and lightly pubescent, and two median which are relatively high

and narrow and each heavily tufted with setae

cisinsularis new species

Subgenus Drasinus

I have given some thought to the composition of Drasinus and am still
very dissatisfied. This is largely the result of mistakes and lack of fullness of
species descriptions rather than with the original generic concept. As at present
organized, all four species would appear to agree well in general habitus, in
being closely related to Decarthron, and in having both sexes (as far as de-
scribed) having the metastemum modified and the posterior tibiae inflated and
slightly arcuate in posterior half or third of their length.

In addition to the confusion arising from the incorrect generic key of
Raffray (1908) previously alluded to, the chief difficulty appears to lie in the
shape of the distal segment of the maxillary palpi. When Raffray described
the genus Drasinus (1904, p. 148) he gave a clear figure of the maxillary palpus
of the genotype hinodulus and I have used this as the shape of the palpus in
the key to subgenera given above. However, in the same paper (1904, p. 183)
Raffray described Euteleia and gave an equally clear figure of the palpus of
recens (Schaufuss) the Brazilian genotype. In this second genus Raffray de-
scribed three new species, Euteleia lewisi, trifoveata and nodosa. In 1908
Raffray took his Euteleia lewisi from this genus and placed it in his Drasinus.
Now the cited figure of the fourth segment of the palpus of Euteleia recens
(Schaufuss) is radically different from that of Drasinus hinodulus Raffray
and hence the distinguished French author must have subsequently discovered
this error and reassigned lewisi to Drasinus. But the original description of
lewisi (1904, pp. 183-184) cites the fourth segment of the palpus as fusiform,
which agrees perfectly with that of recens and does not agree with hinodulus
at all.

I have not seen the genotypes of either of these Raffrayan genera and
hence place lewisi Raffray in Drasinus on the assumption that the 1908 po-
sition is the true one and that both hinodulus and lewisi have similar maxillary
palpi.

Subgenus Paradrasinus new subgenus

I am perfectly satisfied with the composition of this section of Drasinus.
I have had the opportunity to study a paratype (U.S.N.M. No. 44604) of the
well-described hirsutus Fletcher and this species is wholy congeneric with
cisinsularis. Both have similar terminal segments of the maxillary palpi, as
described in erecting this new subgenus ; both have the male sex with modified
sternites. The many differences are of specific, rather than subgeneric rank.

BRACHYGLUTINI 183

Drasinus cisinsularis new species

Holotype Male. Measurements: Head 0.189 x 0.308 through the eyes;
antennae 0.569 mm.; pronotum 0.276 x 0.335 mm.; elytra 0.469 v 0.57 mm.;
abdomen from a dorsal view 0.268 x 0.53 mm.; first tergite 0.201 x 0.53 mm.;
total length 1.2 mm.; greatest width 0.57 mm.

Body yellowish-brown, moderately shining, clothed with long, flavous,
subdecumbent pubescence, very indistinctly punctulate. Head with prominent,
large eyes (0.1 x .053 mm.) of about 32 very coarse facets. Occipital portion
of the vertex simply and transversely gibbous, not medianly carinate. Occipito-
cervical field transversely sulcate with a sharp but minute longitudinal median
carina which does not extend to vertex. Center of vertex very slightly de-
pressed. Two vertexal foveae in a line with the second transverse row of ocular
facets; each fovea nude, sharply defined and of the diameter of an ocular facet,
neither connected with each other nor with the front by sulci. Sides of head
sharply incised by a short, slightly oblique, subpubescent cut just anterior to
each eye and hence near the lateral base of each antennal prominence. At the
mesial base of each antennal prominence is a small, nude, foveaform pit. These
pits, then, form a second, more anterior pair of vertexal foveae and presumably
are consequences of the antennal articulation. Front between antennal bases
simple and declivous to the clypeus. Clypeus simple, not rugose. Labrum simple,
its apical margin slightly concave. Ventral surface of the head subtriangular,
with the lateral margins carinated and with a strong median, longitudinal
carina, the latter enclosing at its anterior tenth a small subcircular fovea.

Maxillary palpi four-segmented. First segment minute and cylindrical;
second long, arcuate, swollen distally ; third rounded-triangular with the outer
face evenly convex and inner face angulate-convex, short, only about a third
as long as second, and as wide as distal portion of second; fourth slightly
longer than second, wider than other segments, obliquely truncate at base,
outer face convex, inner face nearly straight, apex rounded and obtuse, bear-
ing a small palpal cone.

Antennae ten-segmented; segment I subcylindrical; II subcylindrical with
rounded, tapered ends, narrower and shorter than first; III-VII subcylindrical
to submoniliform, gradually shorter and gradually slightly narrower; VIII-X
forming the club, eighth and ninth of the same subtrapezoidal form with trun-
cate base, oblique divergent sides and subtriangular apex, the eighth larger
than seventh and smaller than ninth; distal (tenth) segment about as long
as preceding two united and wider than ninth, base truncate, sides convex,
apex gradually rounded.

Pronotum wider than head, similar in shape to hirsutus, with three circular
subbasal, free, nude foveae, a lateral on each side and a median. Basal margin
with a row of coarse punctures.

Elytra with two deep, circular, nude, subbasal foveae on each elytron, the
sutural fovea at the origin of the well-marked, entire sutural stria and the
discal fovea at the origin of the well-marked discal stria which reaches slightly

184 NEOTROPICAL PSELAPHIDAE

beyond middle of elytral length. Humeri prominent and rounded. Elytral
flanks with no subhumeral fovea and no longitudinal carina or stria.

Abdomen with five tergites visible, first with a narrow but strong lateral
margin. First tergite as long as other four united, with a pair of slightly
divergent discal carinae two-thirds as long as segment and separated by one-
half the segmental width. Five sternit^s medianly visible, the true first being
hidden by the posterior coxae and the metastemum. First visible stemite twice
as long as the remaining sternites united; second visible laterally but not
medianly; third visible sternite (morphologically the fourth) strongly modi-
fied as follows: the segment has four elevations, a lateral pair which are
relatively low and broad and lightly pubescent, and a median pair of elevated
protuberances which are relatively high and narrow, each of these median
elevations bearing a tuft of long setae; fourth visible stemite very short and
medianly flattened; fifth visible (last sternite) with the apical margin medianly
produced into a rounded lobe and medianly flattened, save at the middle of the
basal margin which bears a minute, rounded tubercle.

Mesostemum extended between the intermediate coxae as a subtruncate
plate, these coxae therefore clearly separated. Metasternum large, extending
between the intermediate coxae as a subtruncate plate to reach the mesostemal
extension. Sternal foveae IV and V large and pubescent. Metasternum between
pair V slightly tumid and in the shape of a spear-head, with the apex of the
spear continuing posteriorly as a median longitudinal striaform depression.
The area just anteriad and mesiad of the articulation of the posterior legs
also slightly tumid. Metaepistemal-metastemal sutures and metaepistemal
sclerites well-formed. Posterior coxae distant.

Anterior and intermediate legs simple; posterior tibiae slightly swollen
and slightly arcuate in apical third, with the ventral surface flattened and
bearing a patch of dense pubescence at apical sixth.

Allotype Female. Similar to holotype male save that the sternites are
simply convex and not modified in any way, consequently it is much easier to
count the five visible ventral segments.

Described on seven specimens collected by the author at light at night
on Barro Colorado Island, Gatun Lake, Panama Canal Zone. The holotype
male, allotype female, one male and one female paratype on July 7, 1936, at
10:30 p.m.; one female paratype on July 8, 1936; one male paratype on July
17, 1936; one male paratype on July 28, 1936. All were taken near the island
laboratory save the female of July 8 which was taken at the south-eastern end
of the island, near Bangs Casa.

This distinct species is allied only to hirsutus, from which it may be dis-
tinguished by the non-rugose clypeus and wholly different modifications of
the male sternites.

The species may be listed as follows:

Subgenus Drasinus s.s. (Raff ray, 1904)

binodulus Raffray. 1904. Mexico. Genotype, {nodicornis Fletcher,
1928, nee Raffray)

lewisi (Raffray). 1904. Brazil. (Euteleia)

BRACHYGLUTINI 185

Subgenus Paradrasinus new subgenus

cisinsularis new species. Panama Canal Zone.

hirsutus Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico; Rio Azul,
British Honduras.

ECTOPOCERUS (Raffray, 1904)

This is a monotypic genus, known by the male sex only, limited to Chile,
and allied to Drasinus and Decarthron in having antennae of but ten segments.
The antennae are irregular: segment I ovate, large, as long as second and
third united ; II also large, but short, the segment being very transverse, evenly
convex in the lateral face and produced on the mesial face into an elongate,
subacute, apically flexed point, this mesial extension being half the width of
the segment; III to VIII transverse, with the third about one-half as wide
as the second segment and fourth to eighth progressively narrower, so that the
eighth is just barely transverse, small and inconspicuous; IX very peculiar,
very long but the articulation to the eighth segment is far forward, near the
fourth of the segment, and consequently two-thirds to three-fourths of the ninth
segment lies posteriorly, over the dorsal faces of the eighth, seventh, sixth, and
fifth segments; the lateral face of the ninth segment is elongate-semicircular
in outline, while the mesial face is bisinuate; X large and conspicuous in size,
being wider than the ninth, and as long as first to seventh segments united,
but simple in outline, elongate-oval, with both ends rounded.

Maxillary palpi four-segmented, first, minute; second elongate, basally
slender and suddenly thicker apically; third, short, transversely subtriangular,
acute mesially, convex laterally; fourth, largest, almost fusiform, slightly,
obliquely truncate at base, very pointed apically, with a small palpal cone.

Ventral face of head convex, with a median, longitudinal carina.

Easily separated from Drasinus on the fourth segment of the maxillary
palpi, and separated from Decarthron by the lack of the median oval fossa
on the ventral surface of the head. This genus, then, is intermediate between
these two genera just mentioned. One species:

verticicornis (Reitter). 1885. Chile. (Decarthron) . Genotype.

DECARTHRON (Brendel, 1865)

Brendel (1865)

Brendel and Wickham (1890)

ScHAUFUss (1879, 1882) (Bryaxis in part)

LeContb and Horn (1883)

Raffray (1904, 1908 a, b, 1909 a, b, 1911)

Fletcher (1928 a, b)

Bowman (1934)

The genus Decarthron is limited to those species having the following
characters: (1) Ventral surface of the head with a median, oval fossa or fovea
of large size, the borders of which are well-defined or carinated; (2) Antennae

186 NEOTROPICAL PSELAPHIDAE

of ten segments; (3) Third segment of the maxillary palpi transverse, sub-
triangular, with the external face rounded-convex and the internal face sub-
acute-convex or angulated; (4) Base of each elytron with two foveae; (5)
Distant metathoracic coxae.

As at present constituted, the genus holds 71 species of which 13 are
known from the United States and Canada and 58 from the neotropics.
Decarthron formiceti (LeConte), distributed from Pennsylvania and New
Jersey south into the States bordering the Gulf of Mexico, has been designated
as the genotype by Bowman (1934, p. 144).

The genus is essentially a neotropical aggregate: Mexico (18) from the
coastal extension of the tropical rain forest in southern Tamaulipas southward ;
Mexico and Guatemala (2) ; Guatemala (2) ; Panama Canal Zone (4) ; Vene-
zuela and Colombia (1); Colombia (2); Dutch Guiana (2); Brazil (13);
Peru (1); Bolivia (1); Paraguay (1); Chile (1); Argentina (8); Grenada,
Windward Islands (2) and Cuba (1).

The species in general have well-developed eyes and wings and fly well,
coming to lights at night. This dusk flight may extend well into the night but
I have not found the insects active by day. Many are synoeketes within the
society of ants, one of the new species being adjusted to life with the rapacious
army ants to cite but one example.

This is a very specialized genus of pselaphids and belongs near the
limits of the Brachyglutini. It has few relatives. The secondary sexual modi-
fications affect the male sex and may be partially outlined as follows. The
front of the head may be prolonged beyond the bases of the antennae into a
short truncated plate or into a long, conical, spiniform horn. The epistome
or clypeal region may be variously armed. The antennae, from the third to
the tenth segment, may be highly abnormal. The anterior tibiae may be dilated
and bear a ventral sulcus and the anterior femora may be dorsally excavated.
The intermediate femora are generally variously flattened and granulated or
excavated dorsally, the excavation being of diverse shapes and bearing spines,
tubercles, or contorted carinae. The posterior tibiae may be strongly inflated.
In contrast, the females are usually much less variable among the species, the
body and appendages being simple in form. For this reason the keys have
employed the male sex in large part and females are difficult to determine in
most cases.

The following key has been modified from Raffray's group key of 1904
and is prepared for the male sex unless otherwise stated :

Key to Neotropical Groups of Decarthron, Based Chiefly on Males

Front of head prolonged anteriorly between antennal bases 2

Front of head simply declivous or truncate between the antennal

bases, never prolonged anteriorly 3

2. Frontal extension in the form of a short, anteriorly truncated process

Group XIV

BRACHYGLUTINI 187

Frontal extension in the form of a long, conical, subacute spine or
horn Group XV

3. Pronotum with three subbasal foveae, a median and a lateral each side 4
Pronotum with a single subbasal fovea, the median 6

4. Front more or less truncate ; epistome armed Group I

Front more or less declivous ; epistome simple 5

5. Anterior tibiae simple Group II

Anterior tibiae dilated apically and ventrally sulcate Group III

6. Base of pronotum with a row of small but sharply cut and well de-

fined punctures Group V

Base of pronotum lacking a row of punctures 7

7. Antennae abnormal Group VI

Antennae normal in both sexes 8

8. All antennal segments much longer than wide Group XIII

Antennal segments not all longer than wide 9

9. Intermediate antennal segments cylindrical to obconic 10

Intermediate antennal segments ovoidal, globular or moniliform 11

10. Antennal segments III, IV, and V much longer than wide. . .Group X
Antennal segments III, IV, V, and VI much longer than wide

Group XI

11. Posterior tibiae strongly inflated; anterior and intermediate femora

of males simple Group VII

Posterior tibiae at most slightly thickened in apical half; inter-
mediate femora of males always inflated, excavated, and more or
less armed 12

12. Intermediate antennal segments globular Group VIII

Intermediate antennal segments ovoidal, a little longer than wide

Group IX

It will be noted that there are no neotropical species known at present
from Groups IV and XII of the genus.

The above key follows Raffray (1904) in separating Decarthron into
fifteen groups of species. This is only a convenient way of separating the species,
without any necessarily implied evolutionary order. To my mind the separa-
tion of, for example, groups X and XI does not rank with the separation of
group XV. From the viewpoint of structural development it appears necessary
to divide the genus into two subgenera, Decarthron s.s. holding the first four-
teen Raffrayan groups, and a new subgenus Decarfuss holding the fifteenth
group. This latter group is very isolated, not only in the remarkable frontal
horn, but in swollen maxillary palpi, and is as unrelated to the general con-
cept of Decarthron as Drasinus or Euteleia. The fourteenth group, holding
Decarthron frontale Raffray alone, is not an annectant link between the rest
of the genus and the fifteenth group, viz: frontale is typical Decarthron s.s.
with excavated middle femora in the male sex, and the frontal prolongation
in this species is simply a quantitatively more pronounced development of
the front such as may seen in chichion at a much lower level of integration.

188 NEOTROPICAL PSELAPHIDAE

On the other hand the swollen maxillary palpi and long conical, spiniform
horn of euspinifrons appear to separate the fifteenth group of the genus in a
qualitative sense. In the following treatment of the species, therefore, the
reliable grouping of Raff ray is divided into two subgeneric aggregates:

Subgenus Decarthron s.s. (Brendel, 1865)

Groups I to XIV inclusive of Raffray, 1904. Characterized by a simple
front, either declivous from interantennal baseline to apical clypeal margin,
or truncate and declivous, or produced as a truncated triangle between inter-
antennal baseline and then declivous. Front never produced into an anteriorly-
directed, long, cylindrical, spiniform horn between antennae.

Although some of the species of this subgenus have simple intermediate
femora, the insignia of the majority are found in the abnormal intermediate
femora. The femur may be considered as a subfusiform segment of the leg,
having four faces and two ends: dorsal face, ventral face, anterior face,
posterior face, basal end (articulating with the trochanter) and apical or distal
end (articulating with the tibia). The apical end is usually subtruncate and
may be gradually narrowed or abruptly narrowed and pedunculate. The basal
end is almost always simply and acutely narrowed. The dorsal face of the
male femur, when modified, is greatly swollen (inflated or tumid) and presents
many different outlines but is usually triangular with the highest point of the
tumidity forming the apex of an obtuse angle near the middle third of the
femoral length. This swelling is usually excavated and the excavation almost
infinitely varies between species and within the species population. Usually the
excavation is a deep, broad fossa with glabrous floor but it may be a very narrow
sinuate or arcuate sulcus involving the posterior face as well. The excavation
often has the floor secondarily modified by thin lamellae or carinae or teeth or
spines. The outline of the excavation has two ends, an apical and a basal end.
The basal end often has the edge ornamented by a single spine or tooth which
points apically ; this spine may point dorsally or there may be two basal spines.
The apical end very seldom carries a spine or tooth, but it may do so and the
tooth may point basally and be straight or recurved.

In this first subgenus, keys to the species are given in those groups holding
hitherto undescribed species (VI and VIII). Before passing to these matters, I
should like to give a brief note in regard to Decarthron tropicum Fletcher
(Group XI). This species was described on nineteen specimens collected at light
at night on December 19, 1926, at Vera Cruz, Vera Cruz, Mexico. I have four
males of this species collected on August 24, 1936, at light at night by Dr.
Charles Seevers at Villa Juarez, Tamaulipas, Mexico. My specimens extend the
northward range of tropicum to near the northward end of the coastal extension
of the tropical rain forest. I have compared my males with a male paratype
of tropicum (USNM No. 44599) and am satisfied that they are conspecific.
They may represent a more northern race of tropicum since the oval impression
of the anterior femora is lightly punctulate-granulate in comparison with the
same area of the paratype and the depression of the intermediate femora is a

BRACHYGLUTINI 189

little smaller and more truncate-ovoidal in outline in contrast to the larger,
irregularly ovoidal depression of the paratype. These differences do not seem
to warrant specific rank.

Key to Males of Group VI

Fourth antennal segment very swollen on mesial face and much wider
than either third or fifth segments 2

Fourth antennal segment not conspicuously wider than the third and
fifth segments 4

2. Known only from Brazil 3

Known only from Panama Canal Zone chichion new species

3. Intermediate femora greatly dilated dorsally, with the dilation bearing

an apically directed tooth and abruptly excavated, this excavation
having two strong, parallel carinae, apical to the excavation the
femora are suddenly obconically pedunculate; antennal segments

VII and VIII short and transverse, slightly produced on mesial
face; length 1.4 mm torticorne

Intermediate femora differently modified ; antennal segments VII and

VIII more 'transverse ; not as long nanum

4. Fourth antennal segment with the mesial face produced suddenly at

middle into a truncated process rugulosum

Fourth antennal segment not produced mesially or if so, the mesial
face of the segment is evenly developed 5

5. Known only from Grenada, Windward Islands insulare

Known either from Mexico or Guatemala 6

6. Third antennal segment relatively very large, longer than any anten-

nal segment save the tenth, obtusely prominent mesially

punctatum

Third antennal segment never longer than ninth segment 7

7. Seventh antennal segment quadrate to transverse, lateral face never

produced, mesial face produced or not 8

Seventh antennal segment transverse, very obliquely truncate at apex,
lateral face produced, much larger than mesial face. . . .squamosum

8. Seventh antennal segment with the mesial face produced

quadrifoveatum

Seventh antennal segment with mesial face not produced 9

9. Intermediate femora swollen, but the swelling evenly developed on the

dorsal face, this face slightly emarginate with the edge of the
emargination bidentate and a recurved, narrow sulcus below the

emarginated edge; 1.6 mm. long quadraticeps

Intermediate femora otherwise modified 10

10. Intermediate femora triangularly swollen in the middle of the dorsal
face, this dilation bearing at dorsal apex an apically directed spine
and the swelling bearing a broadly semilunar excavation ; the apical
fourth of femur set apart from basal three-fourths by a sudden

190 NEOTROPICAL PSELAPHIDAE

annular constriction at base of swelling; length 1.5 mm

arthriticum

Intermediate femora otherwise modified 11

11. Intermediate femora greatly swollen, deeply emarginate and im-
pressed; basal edge of emargination prolonged into a tooth in the
same plane, apical margin continued within the emargination on
the outer edge by a transparent lamella; bottom of emargination
provided with an oblique lamella not connected with the sides;
1 .2 mm. long complicatum

This key covers the species of the sixth group with the exception of
curticorne (Schaufuss) from Yucatan, Mexico. This species, unknown to me,
is said by Raffray (1904, p. 189) to be close to arthriticum Raffray, but
differs from Raffray's species in an entirely different structure of the male
intermediate femora and much larger third, fourth and fifth antennal seg-
ments.

Decarthron chichion new species

Holotype Male. Measurements: Head 0.2 x 0.3 mm. through eyes; pro-
notum 0.268 x 0.3 mm.; elytra 0.4 x 0.57 mm.; abdomen 0.28 x 0.56 mm. from
a strictly vertical view; total length 1.3 mm.; greatest width 0.57 mm. (PI.
VI, XVI)

Light reddish-brown, shining, integument clothed with moderately long,
orange, subdecumbent pubescence; head, pronotum and abdomen lightly
punctulate, elytra more heavily punctate (the elytral integument is thrown
into semitransverse subscabroid wrinkles in one of the paratypes, probably a
consequence of preservation too soon after pupation) .

Head with large, prominent eyes (0.107 long x 0.067 mm. wide from a
vertical view) composed of about 32 very convex, coarse facets; the eye is
sharply reniform from a lateral view. Vertex not medianly carinate but trans-
versely swollen posteriorly and flattened anteriorly; with two free, nude, minute
vertexal foveae, each smaller than an ocular facet but set in the bottom of a
gently sloping depression so that they appear superficially larger, each fovea
nearer an eye than to each other and on a line with the third transverse row of
ocular facets; each side of vertex with a short, subarcuate incision at base of
antennal area. Front medianly and triangularly truncate between antennal
bases and then dropping abruptly in an anteriorly oblique plane as a narrow,
suboblong with nearly parallel sides, to the anterior margin of the epistome.
This declivous surface roughly punctate or subscabroid. Apical margin of
labrum concave. Left mandible crossed dorsal to right mandible. Ventral sur-
face of head with a large, sharply-defined, deep ovoid fossa (described from
male paratype).

Antennae ten-segmented, distantly inserted beneath antero-lateral angles
of head. The fourth, seventh, and eighth segments very abnormally formed

BRACHYGLUTINI 191

and fourth to eighth segments inclusive articulated to form an arc. These
striking abnormalities and the segmental proportions as illustrated.

Maxillary palpi four-segmented. First segment minute, longitudinally
ovoid; second arcuate, with a cylindrical basal peduncle which is narrower
than first segment but which gradually at first and then rapidly widens to
from a swollen apical third ; third segment short, transversely triangular with
an evenly convex external face and a short subacute internal face ; fourth seg-
ment obliquely truncate at base, both external and internal faces evenly con-
verging to subacute apex, this segment longer than second and wider than
third, with an apical palpal cone.

Pronotum rounded-hexagonal, wider than long. No lateral foveae but with
a median, free, small, circular, nude fovea at basal third. Basal pronotal margin
simple.

Elytra each with two small, perforate, circular, nude basal foveae. The
sutural fovea at origin of deep, entire sutural stria. Discal fovea at origin of
deep discal stria which extends four-sevenths of elytral length (length of elytra
measured from the acute-triangular scutellum). Elytral flank with no sub-
humeral fovea, no carina and no stria.

Wings long (nearly three times as long as elytra when fully extended),
strong, finely pubescent with margins having much longer setae (in dry speci-
mens the membranous surface granular and iridescent) .

Abdomen with first tergite nearly twice as long as remainder of abdomen
from a strictly dorsal view, with a pair of strong, slightly arcuate apically and
therefore slightly divergent, discal striae which are separated by one-half total
tergite width and one-half as long as the segment (discal striae measured from
a male paratype). Abdominal margin narrow but well-developed. Five visible
tergites. Five visible sternites but these made out with difficulty because of
their construction: first visible very long, medianly more than three times as
long as the remaining four sternites combined, the apical margin of this first
sternite gradually produced so as to vault over the second and third visible
sternites; second, third, and fourth very narrow medianly; fifth (terminal)
sternite also medianly produced posteriorly to fit into concave apical margin
of terminal tergite.

Intermediate coxae separated by an oblong, truncate extension of the
mesosternum. Posterior coxae distant. Sternal foveae IV and V, metaepistema
and associated sutures as in Drasinus cisinsularis. Metasternum tumid above
the articulation of each posterior leg and medianly concave.

Posterior tarsi elongate, slender, subcylindrical; two-thirds as long as
tibiae; first tarsomere minute, one-sixth as long as second; second tarsomere
elongate-subcylindrical, longer than third; third tarsomere elongate-cylindrical,
bearing apically a single long, arcuate, sharp claw one-third as long as tarso-
mere. Anterior and posterior tibiae bearing an apical pubescent process. Inter-
mediate (mesothoracic) femora very complexly modified, the dilation, arma-
ture and excavation as illustrated. Tibiae of all legs, anterior and posterior

192 NEOTROPICAL PSELAPHIDAE

femora not abnormally swollen. All tibiae pubescent in apical fifth at ventral
face.

Allotype Female. Similar to holotype and paratypes save that (1) the
declivous frontal area is slightly tumid and not scabroid; (2) antennae not
abnormally formed; (3) intermediate femora simple; (4) first visible sternite
not quite so produced and fourth sternite relatively longer.

Described on six specimens all collected by the author at lights between
9 and 11 p.m., on Barro Colorado Island, Gatun Lake, Panama Canal Zone,
in July, 1936. Male paratype (July 14), male paratype (July 16), male holo-
type and female allotype (July 17) at island laboratory; two male paratypes
(July 8) at Burrunga Point.

This is a clearly defined species. In antennal abnormality it approaches
torticorne Raffray and nanum (Schaufuss) of Brazil. In complexity of male
intermediate femora it approaches coniplicatum Fletcher of Guatemala. This
large sixth group of the genus would seem to have a Brazilian and a Mexican
focus, with the two rather satisfactorily united by coniplicatum and chichion
of Central America.

Key to the Males of Group VIII

Head strongly narrowed anteriorly ; vertexal f oveae united by oblique
sulci which unite near the frontal margin; intermediate femora with
inflated dorsal area ending in an unspined obtuse angle, a long and
narrow sinuate sulcus arising on posterior face from just below this
angle and extending ventro-apically to apical eighth, the sulcus hold-
ing at its dorso-basal end a spine; length 1.3-1.4 mm.; known only
from Grenada, Windward Islands spinosum

Head slightly narrowed anteriorly to square; males with the inter-
mediate femora otherwise modified; not known from the Antilles. . 2

2. Head square with a flattened vertex; known from Brazil and Argen-

tina 3

Head with occipito-vertexal area convex to tumid; known from neo-
tropics north of Brazil 4

3. Intermediate tibiae with a small, apically directed spine at four-fifths;

antennal segments II-V subquadrate and subequal, VI-VII slightly
smaller, VIII larger and transverse, IX much larger and slightly
transverse; anterior femora with dorso-posterior face with a trans-
versely oval, lightly punctulate, well-defined area; intermediate
femora with dorsal excavation in apical half, with a very large,
slightly recurved and blunted spine at basal end of excavation, floor
of excavation deeply notched on posterior face near apical end of
excavation; 1.7 mm. long; known only from Argentina, .rubripenne
Intermediate tibiae without tibial spine on ventral face at apical four-
fifths ; spine at basal end of excavation of intermediate femora much
smaller; vertexal f oveae very shallow and superficial; known only
from Brazil externedens

BRACHYGLUTINI 193

4. Excavation of int€rmediate femora with the apical edge erected into

a blunt recurved tooth; 1.4 mm. long; Mexico denticulatum

Excavation of intermediate femora without an apical tooth 5

5. Apical end of intermediate femora with a deep, narrow notch or con-

striction on the dorsal face just distal to the apical end of the ex-
cavation ; 1.6 mm. long planiceps

Apical end of intermediate femora with no notch on dorsal face distal
to excavation 6

6. Excavation of intermediate femora with the spine of the basal edge

arcuate and aciculate, excavation deep on dorsal face beneath the
spine and narrowing and becoming shallow on posterior face; 1.7

mm. long; known from Cuernavaca, Morelos, Mexico schmitti

Excavation of intermediate femora with the spine of the basal edge
straight and bluntly truncate, excavation very broad and deep, semi-
lunar in shape and extending broadly over the posterior face; 1.35

mm. long; known from Panama Canal Zone

noctiphoton new species

Decarthron noctiphoton new species

Holotype Male. Measurements: Head 0.221 x 0.335 mm. through the eyes;
pronotum 0.30 x 0.335 mm.; elytra 0.469 x 0.67 mm.; abdomen from a dorsal
view 0.368 x 0.58 mm. (first tergite 0.30 x 0.58 mm.) ; total length 1.35 mm.;
greatest width 0.67 mm. (PI. XVI)

Color, pubescence and punctation as in chichion.

Head as in chichion save that the eyes are larger (0.11 x 0.067 mm. from a
dorsal view) and composed of about 40 coarse facets, the eyes more conical and
less reniform. Vertex less flattened anteriorly, more tumid between vertexal
foveae; vertexal foveae larger, of the diameter of an ocular facet, otherwise
similar. Front evenly truncate between antennal bases and dropping vertically,
obliquely to anterior margin of epistome ; fronto-clypeal slope nearly glabrous,
not scabroid. Labrum as in chichion. Ventral surface of head as in chichion.

Antennae ten-segmented, distantly inserted as in chichion, but "normal",
of the form and proportions as illustrated. The only structural feature to be
noted in addition is a finely pubescent, sharply-defined depression occupying
the apical third of the ventral face of the distal (tenth) segment.

Maxillary palpi as in chichion save that the second segment is quite dif-
ferent: thicker in peduncle, more gradually enlarged apically to the apical third
where it is then more suddenly and subacutely dilated ; fourth segment thicker
than in chichion.

Pronotum as in chichion.

Elytra as in chichion save that discal stria is half as long as elytra.

Wings long and well-developed.

194 NEOTROPICAL PSELAPHIDAE

Abdomen with five tergites visible, the first very long as usual and with
discal striae as in chichion. Five visible sternites clearly visible (combined
median length 0.381 mm.) ; first stemite long (0.268 mm.), apical margin pro-
duced in median third of width to partially cover second; second, short; third,
produced into a sharp cusp at middle of apical margin, this tooth partially
covering the fourth; fourth, short and simple; fifth (terminal) longer than the
preceding three united, punctulated, apical margin broadly produced to fit
concave apical margin of fifth tergite.

Mesostemum, intermediate coxae, posterior coxae, sternal foveae, meta-
episternal and associated sutures and the metasternum as in chichion.

All tibiae normally slender at base, slightly thickened apically, bearing the
usual setose area apically at ventral face ; posterior tibiae slightly arcuate dis-
tally as usual. Anterior femora swollen dorsally, the swelling bearing a trans-
versely oval depression on the dorso-posterior part of swelling, this depression
punctulate-granulate and its dorsal edge strongly carinated as illustrated. Inter-
mediate femora complexly excavated and armed as illustrated. Posterior femora
simple.

Allotype Female. As for holotype and paratypes save that (1) the distal
margin of labrum is less concave, (2) third visible stemite not medianly cusped,
(3) apical margin of fourth and basal margin of fifth sternites involved in a
small but distinct median depression, (4) fifth stemite with apical margin less
convex, nearly straight but more definitely punctate than in the male.

Described on thirteen specimens all collected on Barro Colorado Island,
Qatun Lake, Panama Canal Zone, at lights at night. Paratype female May 19,
1935, by Alfred Emerson. Paratype male August 31, 1935, by Alfred Emerson.
Paratype males on July 6, July 7, July 14, July 15, 1936, by author. Holotype
male and allotype female on July 7, 1936, by author.

Subgenus Decarfuss new subgenus

Group XV of Raffray, 1904. Characterized by the front between the an-
tennae being produced into a long, conical and spiniform horn, directed an-
teriorly.

Key to the Males of Group XV

Antennae simple monoceros

Antennae very abnormally formed as described

euspinifrons new species

Decarthron euspinifrons new species

Holotype Male. Measurements: Head 0.234 x 0.361 mm. through the eyes;
pronotum 0.321 x 0.375 mm.; elytra 0.53 x 0.602 mm.; abdomen 0.335 x 0.556
mm. from a dorsal view; total length 1.48 mm.; greatest width 0.602 mm.
(PI. XVIII)

BRACHYGLUTINI 195

Integument light reddish-brown clothed in subdecumbent rufoflavous pu-
bescence; occipito-vertexal area very lightly punctulate, vertex anteriorly dis-
tinctly punctate, pronotum very lightly punctulate, elytra and abdomen more
distinctly punctate.

Head with prominent eyes (0.120 x .046 mm. from a dorsal view) of about
36 coarse facets, the eye rounded from a dorsal view, nearly circular from a
lateral view with only a small triangular genal wedge incising the posterior
margin, occupying the area of three facets.

Entire vertex convex save for a faint triangular flattened space between
and behind the vertexal foveae. Vertexal foveae each separated from an adja-
cent eye by the space of three facets, free with no suggestion of sulci, nude,
deep, a diameter slightly more than an ocular facet. Vertex not medianly cari-
nated. Each side of the head between eye and antenna entirely involved in a
large, pubescent, pyriform fovea which is not wholly visible from above. This
fovea appears to be a specialized homologue of the subarcuate pubescent in-
cision of the same area in other species of the genus {chichion, noctiphoton for
example), and is another argument for subgeneric isolation of euspinifrons.
Front produced between antennal bases into a horn (0.10 mm. long from inter-
antennal base to apex), extending beyond the labrum. This horn, from a dorsal
view, narrowing to an acute angle at apex, the apex bluntly rounded. From a
lateral view this horn is seen to have a wide base, arising from the middle of
the clypeus up to the interantennal line ; narrowing rapidly from this base ; near
the apex the horn is suddenly and angulately constricted so that from this lateral
view the apex is in two steps and sharp-pointed. The horn is provided at the apex
with two laterally divergent, dorsally upcurved and prominent setae. Labrum
tumid, with a concave distal margin. Left mandible crossed dorsal to right;
base of each mandible notably tumid on dorsal face.

Antennae ten-segmented, distantly articulated. Segment I very long (as
long as next two united) and with the middle of the ventral face bearing a con-
spicuous, rounded, fiat-topped tubercle or drum-shaped tumulus; II long (as
long as next two united) subcylindrical; III strongly obconic; IV- VI inclusive
subequal, subquadrate, slightly narrower than third and much shorter; VII and
VIII subtrapezoidal, gradually wider than sixth; IX and X distinctly more pu-
bescent, the ninth larger than eighth, obtrapezoidal with a much narrower ar-
ticular peduncle at center of anterior face; tenth segment only slightly wider
than ninth, squarely truncate at base, rounded at apex. Ventral face of tenth
sharply and deeply incised in apical third, the basal rim of this excavation
densely set with a fringe of whitish setae.

Maxillary palpi in comparison with chichion and noctiphoton conspicuously
swollen; four-segmented. First segment small but clearly visible; second arcuate
and pyriform with a rapidly expanding width to the broad apex; third trans-
versely triangular, outer face convex, inner face acute, this segment swollen;
fourth longer and wider than other segments, obliquely truncate at base, swollen,
the sides rapidly converging to subacute apex which bears a terminal cone.

196 NEOTROPICAL PSELAPHIDAE

Ventral surface of head with a deep, ovate fossa with carinated edges
typical of the genus.

Pronotum with basal margin strongly beaded, the bead continuous, flat and
expanded anteriorly at middle into a blunt, triangular cusp. Median fovea free,
nude, sharply cut. A deep, pubescent lateral fovea each side at bottom of an
ovate depression.

Elytra each with the usual two basal, nude foveae, entire sutural stria and
discal stria. The discal stria extends slightly beyond the middle of elytral length
(0.288 mm.). No subhumeral fovea and flanks lacking stria or carina.

Wings well-developed.

Abdomen with five tergites. First tergite long, strongly and narrowly mar-
gined, with two strong, slightly divergent, straight discal striae; these striae
separated by one-half the segmental width, and one-half the segmental length.
Five visible sternites. First morphological stemite invisible, covered by meta-
stemum and coxae but can be seen by dissection to be a narrow, very transverse
plate medianly, this plate punctate. First visible stemite (second morphological)
recessed each side to hold a posterior coxa, each coxal depression densely pu-
bescent, the segment very long (four times as long as other sternites united,
e.g. 0.268 mm.) with apical margin medianly produced to cover the second and
most of the third visible sternites; fourth stemite narrow; fifth (terminal)
stemite twice as long as fourth, distinctly punctate, apical margin strongly pro-
duced to fit the subacutely concave apical margin of fifth (terminal) tergite.
First visible stemite flattened medianly and last stemite tumid medianly.

Intermediate and posterior coxae, mesostemum, sternal foveae, metaepi-
stema and associated sutures as in chichion.

Metasternum medianly clothed with appressed, posteriorly-directed setae;
medianly tumid and this raised area flattened and the center of the flattened
area longitudinally sulcate. This sulcation is not deep but is clearly defined as
the consequence of two striaform sulci. Each sulcus arises near one of the fifth
sternal foveae, courses in an arc medianly, then laterally to end near each
stemal-metacoxal border.

Anterior and intermediate trochanters with posterior face strongly flattened
to form an ovate table ; this tabular surface has a ctenoid appearance because
of a single row of equally long, closely set, stiff setae.

Femora nornial, neither swollen, excavated nor armed.

Anterior tibiae with the distal half of ventral face flattened and bearing a
pad of short setae. Pubescence of the distal fourth to sixth of the ventral tibial
face is typical for Decarthron but in euspinifrons the anterior tibial pubescence
is quantitatively exaggerated.

Intermediate tibiae with a strong, lamelliform tooth, one-fourth as long
as tibia, arising from the ventral face at apical three-fourths.

Allotype Female. Similar to holotype save that (1) front is simply decliv-
ous and simply formed, (2) first antennal segment simple, (3) second and third
visible stemites clearly discernible because the first visible is not so produced

BRACHYGLUTINI 197

medianly, (4) first visible stemite evenly convex, not flattened, (5) anterior
and intermediate trochanters simple, (6) tibiae simple.

Described on eight specimens, all collected on Barro Colorado Island, Gatun
Lake, Panama Canal Zone. Female paratype collected at light at night on
August 2, 1935, by Alfred Emerson; holotype male, allotype female and two
paratype females (July 7, 1936), paratype female (July 15, 1936), paratype
female (July 17, 1936) collected at night at light by the author; paratype male
collected July 29, 1936, at night from overnight nest of Eciton burchelli Westw.
by the author.

With reference to this last paratype, the host ants were very kindly iden-
tified by Dr. Neal Weber. Regarding the host, I quote from my field notes:
Wednesday, July 29, 1936

"At about Snyder-Molino trail 4, Dr. Chickering and I saw a column of army
ants moving along a log late in afternoon — the column was about ten ants
wide. We followed column to large tree on trail fifty feet away and there, be-
tween two plank-buttresses the ants were forming nest of their own bodies,
hanging in festoons 6 to 12 inches long, and the trunk and ground covered
with them. We estimated that the nest was eight square feet and two inches
deep (2305 cubic inches). Allowing 173 ants to a cubic inch and a conservative
army ant volume of 90 cubic millimeters each, the population worked out at

about 388,000 army ants. Collected quart of ants returned at 9:30 P.M.

to find ants on the march, with pupae and larvae, the soldiers guarding column

of ten ants wide as before. Nest about gone Thursday, July 30, 1936. By

9:30 A.M. ants had entirely disappeared."

The rapacious habits of these ants are well known and their autecology
has been reported recently (Schneirla, 1940) from this island. With this par-
ticular colony of Eciton burchelli Westw. there also occurred the limuloids
Cephaloplectus mus Mann and Limulodes brachyscelis Seevers and Dybas.

With respect to Decarthron euspinifrons, I am inclined to place this
pselaphid as a synoekete of burchelli, as the male collected was in the midst
of a long festoon of ants and certainly would be quickly destroyed unless it was
a tolerated guest. Since other specimens were collected at light at night, the
pselaphid is probably a facultative synoekete enjoying its nocturnal pselaphoid
heritage.

Euspinifrons is structurally very isolated in the genus, having its nearest
relative in monoceros (Schaufuss) of Dutch Guiana, and its zoogeographic
affinities seem to be South American rather than Central American.

Two species are worthy of additional note.

Bryaxis denticornis Schaufuss (1880, p. 15) of Yucatan, Mexico, was placed
by Sharp (1887, p. 24) as Decarthron denticorne (Schaufuss), and in this allo-
cation was doubtful, since Schaufuss did not describe the thorax of the species.
Not listed by Raffray (1904, 1908) in genus.

Batrisus monoceros Sharp (1887, p. 14), based on one male from 7000 to
9000 feet in the Quiche Mountains of Guatemala, but not figured, is not listed
by Raffray (1904, 1908) in Batrisini. I am struck with the similarity of Sharp's

198 NEOTROPICAL PSELAPHIDAE

inadequate description and my Decarthron euspinifrons. If monoceros Sharp
turns out to be a Decarthron, then it will have to have another name due to
monoceros (Schaufuss), 1882, of Dutch Guiana. Sharp's species is undoubtedly
valid and monoceros (Sharp), monoceros (Schaufuss), and euspinifrons new
species are quite obviously all distinct on many structural features. The ques-
tion turns on whether Sharp's species is Decarthron or not. The question can
not be settled without recourse to the type but I am inclined to place monoceros
Sharp as non-brachyglutine on the strength of his reputation since, in order to
make the mistake he would have to: (1) count eleven antennal segments for ten,
(2) find a transverse pronotal sulcus (his species was in the subgenus Arthmius
of "Batrisus" and Decarthron has no such sulcus, a fact which was known to
Sharp), (3) fail to see the abdominal margin, and many other obvious features,
involving tarsal claws, ventral surface of head, et cetera.

Just what monoceros Sharp is I do not know. It is certainly not Batrisus
as now limited; probably not Decarthron for reasons just stated. If in the
Batrisini it may form the type of a new neotropical genus. For the present we
must leave it unplaced.

The species of Decarthron may be listed as follows:

Subgenus Decarthron

I

bicolor Raffray. 1904. Chile.

binodosum Raffray. 1908. Argentina.

corpulentum (Schaufuss). 1887. Minas Geraes, Brazil. {Bryaxis)

fractifrons Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.

hetschkoi Raffray. 1904. Blumenau, Brazil.

fmacrocephalum (Schaufuss). 1887. Brazil. (Bryaxis)

simplex Raffray. 1908. Argentina.

II

cochlearifer (Schaufuss). 1879. Mexico. (Bryaxis). Also Guatemala

teste Sharp, 1887.
dimissionis (Schaufuss). 1887. Brazil. (Bryaxis)
hirsutum Raffray. 1908. Argentina.
soror (Schaufuss). 1887. Mexico.

Ill

sulcipes Raffray. 1904. Yuracaris, Bolivia.

V

tritomum Raffray. 1904. Blumenau, Brazil.

VI

arthriticum Raffray. 1904. Sierra de Durango, Mexico.
chichion new species. Panama Canal Zone.

BRACHYGLUTINI 199

complicatum Fletcher. 1928. San Miguil, Guatemala.
curticorne (Schaufuss). 1872. Yucatan, Mexico. (Bryaxis)
insulare Raffray. 1904. Grenada, Windward Islands.
nanuni (Schaufuss). 1887. Amazonas, Brazil. (Bryaxis)
punctatum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
quadraticeps Raffray. 1904. Cuantla, Mexico.
quadrijoveatum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
rugulosum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
squamosum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
torticorne Raffray. 1909. Sao Paulo, Brazil.

VII

laevicolle (Aube). 1844. Male: Venezuela and Colombia. {Bryaxis)
(Female: bipunctatum Reitter, teste Raffray, 1904)

VIII

denticulatum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
externedens Reitter. 1882. Petropolis, Brazil.
noctiphoton new species. Panama Canal Zone.
planiceps Raffray. 1904. Colombia.
rubripenne Raffray. 1908. Argentina.
schmitti Raffray. 1904. Cuemavaca, Morelos, Mexico.
spinosum Raffray. 1904. Grenada, Windward Islands, {spinosus
Raffray, 1904, p. 186)

IX

brasilianum Raffray. 1904. Matto Grosso, Brazil.
cearae (Schaufuss). 1879. Matto Grosso, Brazil.
minutum Raffray. 1904. Matto Grosso, Brazil.
nigricans Raffray. 1911. Sao Pallo, Brazil.
unifoveolatum (Schaufuss). 1887. Cuba. (Bryaxis)
vulneratum Raffray. 1904. Mexico.

X

restitutum Sharp. 1887. Guatemala (Rio Naranjo, Rio Maria Linda,
Torola, San Geronimo) ; Cordova, Mexico?; Nicaragua?; Amazonas,
Brazil?

similars Sharp. 1887. Champerico, Guatemala.

tomentosum Raffray. 1904. Colombia.

XI

bruchi Raffray. 1911. Argentina.

jallaciosum Sharp. 1887. Cordova, Mexico and Cahabon, Guatemala.

lamellipes Fletcher. 1928. Rio Pichis, Peru.

planifrons Raffray. 1904. Yucatan, Mexico.

200 NEOTROPICAL PSELAPHIDAE

schaufussi Raffray. 1904. Santarem, Amazonas, Brazil.
suturale (Schaufuss). 1879. Mexico.

tropicum Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico, and Ta-
maulipas, Mexico.

XIII

gracilicorne Fletcher. 1928. Vera Cruz, Vera Cruz, Mexico.
longicorne Raffray. 1904. Amazonas, Brazil.

XIV

frontale Raffray. 1904. Colombia.

Subgenus Decafuss new subgenus

euspinifrons new species. Panama Canal Zone, con Eciton burchelli

Westw.
monoceros (Schaufuss). 1882. Paramaribo, Dutch Guiana. (Bryaxis)

Unplaced

aurivillii (Schaufuss). 1882. Dutch Guiana. (Bryaxis)

Identicorne (Schaufuss). 1880. Yucatan, Mexico. {Bryaxis denticornis)

saucium Raffray. 1908. Paraguay.

Before taking up the few remaining brachyglutine genera, I have drawn up
a key to the three new species of Decarthron and the new species of Drasinus.
This is done since they are the only brachyglutines with ten-segmented antennae
reported from Barro Colorado Island and form a group with superficially sim-
ilar facies:

Key to both sexes of Barro Colorado Decarthron and Drasinus

Ventral surface of head with median longitudinal carina 2

Ventral surface of head with median ovate fossa 3

2. Third visible stemite with four elevations, a lateral pair relatively

low, broad and lightly pubescent and a median pair relatively high,

narrow and densely tufted Drasinus cisinsularis Male

Third visible sternite simply convex .... Drasinus cisinsularis Female

3. Front produced into an anteriorly directed horn between antennal

bases Decarthron euspinifrons Male

Front not produced into a horn 4

4. Maxillary palpi swollen ; pronotum with three subbasal foveae

Decarthron euspinifrons Female

Maxillary palpi normal; pronotum with a single median fovea, no
lateral foveae 5

5. Intermediate femora swollen, excavated on dorsal and posterior faces 6

BRACHYGLUTINI 201

Intermediate femora simple, not excavated 7

6. Antennal segments IV, V, VI, VII, VIII forming an arc; IV very-

swollen and much larger than third or fifth; VII and VIII trans-
verse, mesially produced Decarthron chichion Male

Antennae simple, not as above Decarthron noctiphoton Male

7. Apical margin of fourth and basal margin of fifth visible stemites in-

volved in a small, distinct median depression

Decarthron noctiphoton Female

Apical margin of fourth visible sternite simple

Decarthron chichion Female

EUTELEIA (Raffray, 1904)

This is a small genus of three known species, two known from Brazil and
one from Mexico, allied to Decarthron by having on the ventral face of the head
a large, oval fossa with sharply defined or carinate borders, and in having an-
tennae of only ten segments. It is easly separated from Decarthron on the third
segment of the maxillary palpi. In Euteleia this third segment of the maxillary
palpi is subconical to ovoidal, much longer than wide, subacute apically and
almost pedunculate to acute at base; the second segment is similarly very long,
slender basally, gradually widening apically to form a rounded apex which is
as wide to slightly wider than the third segment; fourth segment longer than
third segment, shorter than second segment, similarly stream-lined with rounded
apex and subpedunculate, subacute base, and bearing a long, slender palpal cone
at apex. This distinctive palpus quickly separates this genus from Decarthron,
Drasinus and Ectopocerus.

Key to the Species

Third segment of the maxillary palpi relatively very long, distinctly
more than half the length of the fourth (last) segment) recens

Third segment of the maxillary palpi shorter, not more than half the

length of the fourth segment 2

(However, see Raffray, 1904, pp. 304-306)
2. Antennae with the segments longer than wide; 1.6 mm.; metasternum
sulcate, with two setose bundles between the middle coxae at their
posterior margins nodosa

Antennae with segments III-VII moniliform, VIII a little larger, and
nearly square, IX much larger and square; 1.2 mm trifoveata

nodosa Raffray. 1904. Mexico.

recens (Schaufuss). 1879. Brazil. (Bryaxis). Genotype.

trifoveata Raffray. 1904. Brazil.

ITAMUS (Raffray, 1904)

This is a monotypic genus, limited to Brazil, and closely related to Decar-
thron in the ten-segmented antennae, ventral surface of the head with a median

202 NEOTROPICAL PSELAPHIDAE

oval fossa with sharply defined edges, and general shape of the segments of
the maxillary palpi. It differs from Decarthron in the anatomy of the head.
The head is transversely square from a dorsal view, with the front abruptly
truncate between the bases of the antennae; the front is separated from the
epistomal region by a deep, transverse sulcus (this sulcus is about as deep as
half of the eye length, and therefore conspicuous) on the anterior end of
the head below the level of the basal antennal segments ; laterally this frontal
sulcus continues along each side of the head, incorporating the antennal
acetabulum, and extending posteriorly over each gena to end near the occipital
margin beneath the posterior margin of the eye; this posterior portion of the
circumcephalic sulcus is filled with pubescence which by its appearance sug-
gests some secretory or sensory function.

Antennae with segment I as wide as tenth, subquadrate, medianly and
transversely creased or impressed; II narrower than first, cylindrical, three
times as long as wide ; III obconic ; IV-VI ovate ; VII-VIII transverse, slightly
produced or subacuminate on mesial face; IX subquadrate, transverse, sub-
equal to width of eighth; X (last) ovate with a very truncate base.

laticeps Raffray. 1904. Brazil.

GLOBA (Raffray, 1887)

This genus is restricted so far to South America. It is highly specialized
in that the abdomen is exceptionally short, convex, declivous, rounded apically,
with the abdominal "margin" formed by a single thin carina. In this char-
acter Globa departs from the majority of Staphylinidae, from the Euplectini
and on the other hand, approaches the Batrisini.

Antennae eleven-segmented, stout, generally simple in construction, with
a three-segmented club.

Maxillary palpi four-segmented, first segment minute; second elongate,
slender save for the usual apical inflation; third very small, transversely tri-
angular as usual; fourth largest, oval, slightly flattened, acuminate with a
palpal cone.

Ventral surface of the head tricarinate, a median straight carina and a
sinuous lateral carina each side, all three longitudinal.

Pronotum cordiform, simple.

Elytra subglobular, without basal foveae, and neither a sutural nor a
dorsal stria on either elytron.

Abdomen previously noted, the first tergite much longer than second or
third; fourth and fifth longer than third, and diversely armed or irregular
in the male. sex; fifth tergite not visible from above. Six sternites, of which
the first is visible beneath the metasternum, and the sixth is semicircular to
invest the ventral margin of the fifth tergite.

Middle coxae distant; posterior coxae distant.

The three species may be separated as follows:

BRACHYGLUTINI 203

Antennae with ninth segment large, obconical, the length of the seg-
ment equalling its apical width at least laevis

(1.4 mm.; known only from Bolivia)

Antennae with the ninth segment strongly transverse 2

2. Known only from Venezuela; male with the fourth tergite transversely
and obliquely foveate on each side, and with a median tubercle;

1.0 mm brevicornis

Known only from Colombia; male fourth tergite not armed in this
manner longipes

brevicornis Raffray. 1890. Venezuela.

laevis Raffray. 1904. Bolivia.

longipes Raffray. 1887. Colombia. Genotype.

BYTHINOGASTER (Schaufuss, 1887)

This is a highly specialized monotypic genus, known so far only from
Hispaniola (probably Haiti as the citation is "Saint-Domingue") .

The abdomen is short, convex with an exceptionally narrow margin for the
Brachyglutini, and like Globa, presents certain batrisine features. The maxil-
lary palpi, however, are very different from those of Globa, the first segment
is minute; second segment elongate, arcuate, apically swollen; third segment
peculiar, lenticular with the long axis of the segment vertical, that is longer
than wide, the external (lateral as opposed to mesial) face is concave and
this concavity is supplied with spongy pubescence; fourth large, oval, acumi-
nate, bearing a palpal cone. Ventral surface of the head, flat and unsculptured
(Raffray, 1908, p. 203) with exception of a median, longitudinal carina (Raf-
fray, 1908, key, p. 192). Middle coxae slightly separated. This odd genus is
said by Raffray to resemble the Australo-Asiatic genus Eupines. I am un-
familiar with either of these genera.

simplex Schaufuss. 1887. Hispaniola. Genotype.

Tribe 6. Metopiini

This tribe was isolated by Raffray (1904, p. 106) to contain pselaphids
having the following combination of characters: (1) head with antennae
contiguous or subcontiguous, articulated on a prominent median antenna!
tubercle, the head constricted behind the tubercle and then expanded poster-
iorly; (2) eleven-segmented, long, slender antennae which are always con-
spicuously geniculate (PL XVIII) as a consequence of the inordinately long
first segment; (3) mentum normal, not expanded to cover the mouth and
mouth-parts; (4) first sternite small but visible between the posterior coxae
as a plate which is not longer than these coxae; (5) medial faces of posterior
coxae, articulating with the trochanters, subtriangular to subglobular; (6)
intermediate trochanters short, very obliquely articulated with the femora so
that the latter are near their respective coxae; (7) three-segmented tarsi hav-
ing the first segment short and the last two long, the last segment bearing
two very unequal tarsal claws.

Few tribes have such a characteristic facies. Their long, slender legs, long
and geniculate antennae, and contiguous antennal insertion make a picture
seldom forgotten. Within the neotropics the only pselaphids they remotely re-
semble are Goniacerini, also with a strong antennal tubercle and geniculated
antennae [Bibrax) , but with the first sternite very long, clearly visible from
side to side and longer than the posterior coxae.

Sex in Metopiini can be quickly and infallibly diagnosed: the females
have six sternites; the males have seven stemites, of which the seventh is in
two plates, a right and a left as in the males of some euplectine genera. As
in these latter, these two subtriangular valves move laterally at copulation,
to allow extrusion of the penis; in repose, these plates meet medianly to form
a median, longitudinal carina or sulcus with carinated edges.

The Metopiini are exclusively neotropical, centering in the rain forest of
the Amazon River basin. From here the species extend with decreasing fre-
quency south into Argentina and north to Panama. They are apparently
nocturnal, spending the day beneath bark of fallen logs or leaf mold of forest
floors, and flying at dusk. Some come to lights at night. Many species live
with ants. One of the new species has been found with termites.

The following key to genera has been modified from Raffray, 1908.

Key to the Geneea

Each side of pronotum bearing a long spine (PI. XVIII)

METOPIOXYS

Sides of pronotum not spinose (PI. XVIII) 2

2. Third antennal segment subequal to the second segment in length,

or very much longer METOPIAS

(204)

METOPIINI 205

Third antennal segment always very much shorter than the second . . 3

3. Posterior coxae contiguous or nearly so METOPIELLUS

Posterior coxae distant 4

4. Elytra with no sutural striae METOPIOSOMA

Elytra each with a well-defined sutural stria (PL XVIII)

BARROMETOPIA new genus

METOPIAS (Gory, 1832)

Gory (1832)
AuBE (1833)
SCHAUFUSS (1872)
Sharp (1887)
Raffray (1904, 1908)

This is the type genus of the tribe, and one of the first strictly neotropical
genera to be delineated. As now restricted it holds the following species:

carinipes Rafifray. 1904. Yuracaris, Bolivia.

curculionoides Gory. 1832. Cayenne, French Guiana. Genotype.

elegans Sharp. 1887. Volcan de Chiriqui, Panama.

elongatus Schaufuss. 1872. Amazonas, Brazil; Yuracaris, Bolivia.

METOPIELLUS (Raffray, 1908)

aglenus (Reitter). 1895. Blumenau, Brazil, con Tetratomium reitteri

Mayr.
hirtus (Reitter). 1895. Sao Paulo, Brazil. Genotype. (Metopias)
silvaticus Bruch. 1933. Loreto, Misiones, Argentina, con ants.

METOPIOSOMA (Raffray, 1908)

pacificus (Westwood). 1856. Santarem, Brazil. (Metopias) Genotype.
barretoi Bruch. 1924. Sante Fe, Argentina, con Solenopsis richteri
Forel. cf. Bruch, 1929.

METOPIOXYS (Reitter, 1885)

The following key has been drawn up to separate the more numerous
species of this genus, two of which are new. The genus is unique in the tribe
in having the lateral pronotal margins spinose. Of the twelve known species,
ten are from Brazil, one from Argentina and one as far north as Colombia.
The genus is unknown from Central America or the Antilles.

Key to the Species

Large species, 2.3 to 3.3 mm. long 5

Small species, 1.9 to 1.5 mm. long 2

206 NEOTROPICAL PSELAPHIDAE

2. Elytra humeri spined 3

Elytra may have prominent humeri, but humeri never spined 4

3. Antennal segment IX spherical, X spherical; known only from Brazil;

1.66 mm. long trabeculatus

Antennal segment IX elongate-oval, X trapezoidal from a dorsal view,
asymmetrically transverse from a lateral view with the dorsal face
produced dorso-anteriorly ; known only from Colombia; 1.7 mm.
long seeversi new species

4. Integument shining; elytral humeri not prominent; 1.87 mm. long;

antennal segment IX spherical, X quadrate subcarinatus

Integument strongly granulate between the eyes ; elytral humeri prom-
inently oblong; 1.5 mm. long (smallest species known) . .spiculatus

5. Pronotum trispinose, a large straight spine on each side anterior of

the middle, and a single smaller spine at middle of the apical mar-
gin; 2.6 mm. long; integument lightly punctulate and polished;
humeri of elytra obtusely prominent but not spined; antennal seg-
ment VIII briefly ovate, IX transversely trapezoidal, XI conical;
male metastemum slightly transverse and depressed; male last

sternite obtuse and depressed tricuspidatus

Pronotum bispinose as usual 6

6. Very large, in excess of three millimeters long; integument entirely and

cribrately punctate (largest species of the genus) bellicosus

Smaller, not longer than 2.7 millimeters ; integuments variously shin-
ing, lightly granulate to locally strongly alutaceous 7

7. Elytra humeri spined 8

Elytra may or may not have prominent humeri but these never spined 11

8. Integument entirely granulated, the granules small but abundant, semi-

shining; 2.3 mm. long; antennal segment VIII obconical, IX

subovate, X subglobular and slightly transverse gallardoi

Integument of elytra and abdomen semishining to strongly shining;
integument of head and pronotum either weakly or locally strongly
alutaceous 9

9. Male with metastemum simply tumid on either side of a median im-

pression mattogrossoensis new species

Male with the metastemum on each side of a median impression either
subcarinately tumid or tuberculat€ with the tubercular swelling

carinated 10

10. Alutaceous punctation of head and pronotum very strong; antennal
segment VIII and IX oblong, X transverse ; male metastemum with
a strongly compressed, sharply carinated tubercle on each side; male
with sixth sternite entirely and circularly excavated with the apical
angles extended as the approximate arms of a forceps; 2.5 to 2.7

mm. long gladiator

Alutaceous punctation of head and pronotum much weaker, with ely-
tra and abdomen shining; antennal segment VIII oblong, IX ovate.

METOPIINI 207

X quadrate; male metasternum strongly concave, with each side
rounded into an obtuse but subcarinated swelling; male with sixth
stemite depressed, transversely emarginate apically, the apical
angles being prolonged as divaricate spines; 2.5 to 2.6 mm. long

hamatus

11. Elytral humeri not strong; integument shining; antennae with seg-
ment VIII small, IX larger and spherical, X quadrate; 2.5 mm.

long longipennis

Elytral humeri strongly formed, prominently and oblongly elevated;
integument shining also; antennal segments VIII and IX sub-
spehrical, X quadrate; 2.33 mm. long reichei

Metopioxys seeversi new species

Type. Measurements: Head 0.368 from apex of antennal tubercle to
cervicum x 0.30 mm. through tempora; cervicum 0.067 mm.; pronotum 0.30
X 0.335 mm.; elytra 0.53 x 0.60 mm.; abdomen 0.40 x 0.53 mm.; total length
1.7 mm.; greatest width 0.60 mm.

Yellowish-brown; head and pronotum subgranular; elytra semishining
and sparsely but distinctly granulate, each granule bearing an erect seta;
abdomen semishining. Pubescence very sparse.

Head pyriform; tempora long (0.13 mm.), nearly twice as long as the
eyes, rounded. Eyes 0.08 x 0.067 mm. from a dorsal view, composed of 20
coarse facets, circular from a lateral view. Head widest through tempora, nar-
rowing rapidly before eyes to a prominent, slightly upturned antennal tubercle;
vertex deeply and broadly sulcate between the eyes; two vertexal foveae
placed very near the posterior margin of the head, each fovea in line with
the first longitudinal row of ocular facets and each fovea less than the diameter
of an ocular facet. Cervicum finely, transversely alutaceous. Ventral surface
of the head tumid laterally, with a median longitudinal depression in anterior
half and a large, deep, circular median fossa in posterior half. Mentum minutely
granulate.

Antennae eleven-segmented, contiguous on the prominent antennal
tubercle; segment I very long (0.70 mm.), nearly as long as rest of antennae
(second to eleventh segments inclusive 0.90 mm.), the antennae strongly
geniculate and nearly as long as body; the first segment swollen in basal
fourth, minutely granular, with a double row of erect setae on ventral face;
II elongate (0.12 mm.), slenderly obconical; III elongate-cylindrical (0.23
mm.), almost twice as long as second; IV, VI and VIII elongate-oval and
distinctly shorter than V and VII which are elongate-subcylindrical ; third
to eighth inclusive subequal in width ; club formed of last three segments, IX
regularly oval ; X trapezoidal from a dorsal view but in reality asymmetrically
transverse in the dorso-ventral axis, the ventral face evenly rounded and the
dorsal face longer than the ventral face and produced dorso-anteriorly; XI
slightly excentrically articulated toward the ventral face, as long as the pre-

208 NEOTROPICAL PSELAPHIDAE

ceding two united, about as wide as tenth, subacute apex, rounded base, dorsal
face sinuate, ventral face evenly convex.

Maxillary palpi small, four-segmented, first segment minute; second
elongate, arcuate, basally slender, widest at distal three-fourths, narrowing
at distal fourth; third elongate, shorter than second, pedunculate at base,
swelling from distal three-fourths to apex, and about as wide as second; fourth
much wider than third but shorter than second, external face slightly, evenly
convex, internal face strongly arcuate-convex to blunted apex. No palpal cone
discernible.

Pronotum with a sharp, obliquely dorsal spine (0.1 mm. long) arising
from a swelling at middle of each lateral margin; a broad, rather poorly de-
fined longitudinal sulcus mesial to each spine, from the anterior fourth to the
basal bead; disc with a still broader and less well-defined median longitudinal
sulcus from apical third to basal bead; a narrower, more clearly defined
biarcuate transverse subbasal sulcus from side to side ; the longitudinal median
sulcus and the transverse sulcus divide the disc into four tumidities, a sub-
oblong apical pair and a subquadrate basal pair.

Elytra with sloping humeri, each humerus armed with a sharp, erect
spine; each elytron obliquely subplicate from base of humeral spine; each
elytron with two vestigial foveae beneath a strong transverse basal bead and
a poorly-defined sutural stria which is not entire, extending to apical six-
sevenths where it ends abruptly in a foveaform depression.

Abdomen with five visible tergites of which the first is nearly as long as
second and third united, these latter subequal; fourth longer than third; fifth
longer than fourth, as long as first, longitudinally slightly tumid in middle.
Lateral abdominal margins carinoid. Six visible sternites of which the first is
seen as an oblong, depressed plate between the mesial ends of the posterior
coxae, about half as long as the latter; second longest; third, fourth, and fifth
subequal; sixth (last) longer than fifth. Sternites simple and convex.

Metastemum medianly tumid, this tumid area flattened.

Anterior coxae subcontiguous, narrowly separated by a prosternal lamina.
Intermediate coxae approximate, their cavities confluent at the level of the
sterna. Posterior coxae very widely separated.

Femora long and slender. Anterior femora gradually swollen at middle;
intermediate more definitely swollen at apical three- fourths; posterior still
more abruptly swollen at apical three-fourths.

Anterior tibiae thick, slightly contorted, with a long glabrous sulcoid
scar on antero-ventral face for basal half, the upper margin of the scar
strongly carinated. Intermediate and posterior tibiae long and slender.

Tarsi of usual pattern with two very unequal tarsal claws.

Described from a single female specimen, collected from a log on July
25, 1938, at Villavicencio, Meta, Colombia by Dr. Charles H. Seevers for
whom the species is named.

This species has no close relatives. It is the only species of the genus
known north of Brazil and structurally is best contrasted with trabeculatus
of about the same size from Amazonas.

METOPIINI 209

Metopioxys mattogrossoensis new species

Type. Measurements: Head 0.522 from apex of antennal tubercle to
cervicum x 0.40 mm. through tempora; cervicum 0.08 mm.; pronotum 0.435 x
0.50 mm.; elytra 0.70 x 0.737 mm.; abdomen 0.563 x 0.70 mm.; total length
2.3 mm.; greatest width 0.737 mm. (PI. XVIII).

Reddish-brown. Head, including long antennal tubercle, entirely minutely
granulate save for two glabrous oblong areas, one obliquely antero-median of
each eye. Cervicum transversely alutaceous. Pronotum entirely, minutely
granulate save for the lateral spines and their associated basal prominence.
Elytra and abdomen strongly shining. Pubescence very sparse.

Head pyriform; tempora long (0.167 mm.) but relatively shorter than
in seeversi, not being much longer than the eyes. Eyes 0.134 x 0.08 mm. from
a dorsal view, composed of about 24 coarse facets, circular from a lateral
view. Head widest through tempora, narrowing rapidly anterior of eyes to a
prominent, upturned antennal tubercle, this tubercle relatively longer than in
seeversi. Vertex deeply, broadly, ovately sulcate between the eyes. Vertexal
foveae as in seeversi save that (1) they are more median, each fovea placed
mesiad of the mesial edge of the eye, and (2) larger, each fovea twice the
diameter of an ocular facet. Ventral surface of head and mentum as in
seeversi.

Antennae eleven-segmented, contiguous; segment I very long (1.07 mm.)
nearly as long as rest of antennae (second to eleventh inclusive 1.34 mm.),
the antennae strongly geniculate and longer than body; first segment as in
seeversi; II elongate-obconical (0.167 mm.) ; III elongate-cylindrical (0.335
mm.) twice as long as second; IV, VI, and VIII distinctly shorter than V
and VII, fourth and eighth elongate-oval; fifth, sixth, and seventh elongate-
cylindrical; third to eighth subequal in width. Club of last three segments,
IX regularly oval, X circular from ventral view, transverse from dorsal view,
very asymmetrically transverse from lateral view, the dorsal face being
strongly produced; XI as in seeversi.

Maxillary palpi as in seeversi save that the fourth segment is slightly
longer than second.

Pronotum with a sharp, obliquely dorsal spine (0.187 mm. long), other-
wise as in seeversi save that (1) lateral longitudinal sulci and transverse sulcus
are more sharply defined and (2) the basal bead is vestigial and (3) the trans-
verse sulcus deepens medianly to form a distinct, glabrous fovea.

Elytra as in seeversi save that (1) humeral spine is shorter and more
inclined, (2) basal elytral foveae relatively larger and deeper, (3) sutural
stria ends simply at apical nine-tenths.

Abdomen with five visible tergites of which the first is as long as next
two united, these last two subequally long; fourth as long as first; fifth
slightly longer than first, rounded subtriangular.

Seven stemites clearly visible. First as in seeversi; second longer than
third; third and fourth subequally long; fifth shortest; sixth and seventh sub-
equal medianly and both longer than second. The third, fourth and fifth are

210 NEOTROPICAL PSELAPHIDAE

medianly strongly and minutely granulate; second and seventh not granulate.
Third and fourth slightly medianly depressed. Sixth deeply excavated medianly
to form a large circular glabrous fossa with sloping sides, the stemite is strongly
minutely granulate about this fossa and has each lateral-posterior angle pro-
duced into a wide, arcuate, truncate horn. Seventh composed of two separate
plates, a right and a left piece which meet medianly to give the stemite an
elongate-triangular outline with rounded apex.

Metastemum medianly tumid, this tumid area slightly depressed, the
depression gradually deepening posteriorly to broadly separate each side into
two simple swellings which are neither tuberculate-compressed (as in gladi-
ator), nor subcarinated (as in hamatus).

Coxae as in seeversi. Femora swollen, but not as abruptly as in seeversi.
Tibiae as in seeversi save that the scar of anterior tibiae is longer, occupying
nearly two-thirds of tibial length. Tarsi as in seeversi.

Described from a single male specimen from Corumba, Matto Grosso,
Brazil. The only close relatives would seem to be two Brazilian species,
gladiator and hamatus from both of which it differs in male metastemum,
antennae and other morphological features.

The species of Metopioxys may be listed as follows:

gladiator Reitter. 1885. Blumenau, Brazil. Genotype.

bellicosus (Westwood). 1856. Brazil. (Metopias)

gallardoi Bruch. 1917. Buenos Aires, Argentina, con Solenopsis rich-

teri Forel. cf. Bmch, 1929.
hamatus Raffray. 1896. Cavallo Cocho, Amazonas, Brazil.
longipennis (Schaufuss). 1872. Santarem, Brazil. {Metopias)
mattogrossoensis new species. Matto Grosso, Brazil.
reichei (Schaufuss). 1872. Iquitos, Brazil. (Metopias)
seeversi new species. Villavicencio, Meta, Colombia.
spiculatu^ (Schaufuss). 1886. Amazonas, Brazil.
subcarinatus (Schaufuss). 1872. Santarem, Brazil.
trabeculatus (Schaufuss). 1872. Amazonas, Brazil.
tricuspidatus Raffray. 1896. Iquitos, Amazonas, Brazil.

BARROMETOPIA new genus

Metopiini having (1) long, bristling, erect pubescence recurved distally;
(2) eyes reduced in size and number of facets; (3) tempora long, four times
the eye length; (4) vertex trisulcate between the eyes and the prominent, T-
shaped antennal tubercle, and with two nude, posteriorly-placed vertexal fo-
veae; (5) eleven-segmented, subcontiguous, strongly geniculated antennae in
which the first segment is nearly as long as the other ten segments united, the
second segment about twice the length of the third segment and a club formed
of the last three segments; (6) short maxillary palpi of four segments; (7)
pronotum with a median longitudinal sulcus but no lateral longitudinal sulci
and no transverse sulcus; lateral margins not spinose; (8) elytra with humeri

METOPIINI 211

not spinose, each elytron with a single basal fovea, no dorsal stria but with
a subentire, well-formed sutural stria; (9) five tergites with lateral margins
carinoid; (10) males with seven sternites and females with six sternites; (11)
posterior coxae widely separated.

Genotype: Barrometopia quasimoda new species.

Barrometopia quasimoda new species

Holotype Male. Measurements: Head 0.3 (from distal margin of antennal
tubercle to occipito-cervical sulcus) x 0.3 through tempora; cervicum 0.053
mm.; pronotum 0.27 x 0.28 mm.; elytra 0.502 x 0.53 mm.; abdomen 0.23 x 0.47
mm.; length 1.4 mm.; width 0.53 mm. (PI. XVIII).

Uniform light reddish-brown with yellow palpi; integument very lightly,
very sparesly and minutely granulate, strongly shining; the pubescence con-
spicuous, consisting of moderately long, moderately dense, flavous setae which
are bristling and erect, with their ends sharply recurved on head, pronotum
and elytra but more subdecumbent on abdomen.

Head subpyriform, widest through tempora, narrowing rapidly anterior
of the eyes to form the prominent antennal tubercle which is T-shaped in
outline; tempora long (0.16 mm.) about half the head length and four times
the eye length; eyes small (0.04 x 0.04 mm.), circular, composed of 10 facets.
Vertex with a narrow moderately deep, longitudinal sulcus from the base of
the antennal tubercle to just posterior of the posterior eye margins; between
the eyes, and on either side of the posterior part of this longitudinal sulcus,
are two flavous, slightly elevated, quadrate, glabrous areas; each of these
quadrate areas is extended anteriorly to the base of the antennal tubercle in a
less elevated acute-triangular extension, and each of these triangular areas is
bounded mesially by a sharply limited, narrow sulcus so that the head anterior
of the eyes is trisulcate; two vertexal foveae placed on the posterior third of
vertex, each fovea nude, conspicuous and obliquely oval in shape, larger than
an ocular facet and in line with the lateral margin of the quadrate areas
noted above.

Transverse occipito-cervical sulcus minutely, longitudinally sculptured;
rest of cervicum lightly alutaceous to glabrous.

Mentum glabrous. Ventral surface of head tumid, with a weakly formed,
subquadrate depression at middle of base. Ventral surface of cervicum granu-
lated.

Antennae eleven-segmented, subcontiguous, strongly geniculated; segment
I long (0.8 mm.), nearly as long as rest of antennae (1.0 mm.), the total
antennal length longer than body length, the first segment slightly contorted,
granulate, broader in basal third, narrowing to apex where it is dilated, with
a foveaform depression on the ventral face of this expanded apex; II, III
obconical (second 0.2 mm. long, third 0.1 mm. long) ; IV subobconical, shorter
than third; V as long as fourth, wider than fourth or sixth; VII as wide as

212 NEOTROPICAL PSELAPHIDAE

fifth; VIII distinctly shorter and narrower than seventh. Club of last three
segments, jointly forming an arc so that they have a secondary geniculation ;
IX longer than seventh and eighth united, asymmetrically suboblong with
obliquely truncate base and rounded apex; X from a lateral view strongly tri-
angular, with the ventral face narrow and acute and the dorsal face long,
strongly produced in an arcuate, truncated tooth from the antero-dorsal angle
of segment; XI subcorneal with subsinuate dorsal face and subacute apex.

Maxillary palpi short and four-segmented, the fourth segment carried in a
forward arc, strikingly similar to the way in which the antennal club is car-
ried; first segment minute; second elongate-arcuate, gradually thicker in
distal three-fourths; third short and obconical, half as long as second and
about as wide; fourth only slightly longer than second and about three times
as wide, apex rapidly formed and briefly acute, with no discernible palpal cone.

Pronotum relatively simple, not spinose; disc with a deep, narrow but
well-defined median longitudinal sulcus from apical six-sevenths to basal two-
sevenths, each side evenly tumid lateral to this sulcus. No lateral longitudinal
sulci and no transverse basal sulcus. Basal two-sevenths constricted and more
densely granulate with about six feeble impressions.

Elytra relatively simple with unarmed humeri, no dorsal sulcus or stria;
each elytron with a well-formed, subentire sutural stria and a single basal
fovea.

Wings well-developed, three times as long as elytra when fully extended,
closely and minutely setose.

Abdomen with five tergites; first as long as next two united, these last
two subequal; fourth nearly as long as first; fifth rounded subtriangular, about
twice as long as first. Lateral margins of the abdomen very narrow and
carinoid save at base of first tergite.

Seven sternites; first a subtrapezoidal, depressed plate between posterior
coxae and nearly as long as these coxae medianly, clearly visible laterally;
second slightly longer than first; third, fourth, and fifth progressively shorter;
sixth long, as long as second to fifth inclusive united, flattened medianly with
a deep V-shaped incision for apical half of length; seventh, three-fourths as
long as sixth, obliquely and longitudinally divided into a right and a left tri-
angular plate.

Metastemum broadly flattened and depressed medianly, with each side
elevated into a well-defined, obtuse tubercular swelling; the posterior margin
of metasternum medianly truncate and laterally near each posterior coxa ex-
tended posteriorly into an obtuse projection.

Posterior coxae widely separated. Femora simply inflated. Anterior
trochanters each armed with a long, lamellate, narrow and truncate spine on
the ventral face; other trochanters simple. Anterior tibiae with an elongate
sulcoid scar with carinated margins extending from base to apical two-thirds
on antero-ventral face; other tibiae simple. Tarsi of regular metopiine pro-
portions with two very unequal tarsal claws.

Allotype Female. Similar to holotype save (1) integuments are very light

METOPIINI 213

fiavous, the specimen having apparently just pupated, (2) six sternites only,

(3) fifth sternite short and subequal to fourth; sixth s^ernite long, as long as
second to fifth inclusive united and evenly convex, transversely acute-ovate,

(4) metasternum simple and evenly tumid, (5) anterior trochanters simple,
not armed.

Described from two specimens collected from Barro Colorado Island,
Gatun Lake, Panama Canal Zone. Holotype male collected by the author in
the morning of July 25, 1936, from stage four log mold at Drayton 12. Allotype
female collected by Alfred Emerson on May 4, 1935, from a cell in the nest of
the termite Termes panamaensis (Snyder).

This is the only metopiine recorded with Isoptera. Its peculiar appearance
is largely that shared by the tribe as a whole but it may well prove to be a
synoekete of the termite noted above and the reduced eyes and complicated
cephalic sulci lend some credence to this view. The well-developed wings and
sharp, typically pselaphoid mandibles mitigate against a symphilic role in
the termite society.

Taxonomically it is only related to Metopiosoma of Brazil and Argentina.

Superficially it has the aspect of the goniacerine Bibrax of Barro Colorado
Island, but is readily separable as Bibrax bradleyi Fletcher has six sternites
in both sexes, strong and broad abdominal margins, eye composed of only a
single facet, no median pronotal sulcus and the first sternite long and clearly
visible from side to side, being longer than the posterior coxae. This similarity
in habitus between Goniacerini and Metopiini has been alluded to by students
previously (Fletcher, 1927) but the two tribes are basically very unrelated
as will be seen later.

Tribe 7. Batrisini

The Batrisini, in contrast with the neotropical Brachyglutini, are gen-
erically impoverished. The tribe at present contains eight neotropical genera
which have in common (1) antennae distantly inserted on the head, never
subcontiguously articulated on a common, median antennal tubercle. (2)
Mentum normal, never expanded to cover the mouth and mouth-parts. (3)
First stemite very small, nearly hidden between the posterior coxae and
median apical margin of metasternum but not invisible as in the Brachy-
glutini. (4) Lateral abdominal margins absent or represented by one, or at
most two, carinae; never wide and strongly formed. (5) Trochanters of inter-
mediate legs always obliquely articulated on the femora so that each femur
and coxa are close together. (6) Posterior coxae with their mesial ends form-
ing a subtriangular articulating area for the posterior legs. (7) Tarsi three-
segmented, with the first segment minute and the last two segments relatively
much longer and elongate-cylindrical to elongate-obconical, the distal segment
bearing apically two very unequally developed tarsal claws.

The Batrisini are in reality a very highly specialized tribe. Subfamily
status could be advocated for them without too much diflSculty. Numerically
the tribe is only exceeded by the Brachyglutini in species from the viewpoint of
the world fauna. Raffray (1908) finds the batrisines to be best developed in
the Indo-Malayan region, poorly represented in Africa, New Zealand, Aus-
tralia, and Madagascar. From an Indo-Malayan center they appear to have
spread chiefly north into the Palarctic and Nearctic areas, chiefly by means
of the great genus Batrisodes and its allies, and from these two northern realms
to have penetrated into the African region and into the Neotropical region.

The Batrisini are approached in their carinoid abdominal margin by a few
genera of Brachyglutini and some Metopiini, and by the Metopiini in the
construction of the first stemite and tarsal claws.

Many batrisines are synoeketes of the ant society, especially within the
genus Batrisodes, where they eat the eggs and larvae of the host while more
or less tolerated by the host workers. The palarctic synoeketes have been dis-
cussed by Donisthorpe (1927) and the nearctic synoeketes in Batrisodes have
been cited with their host ants by Blatchley (1910), Fall (1912), Holmquist
(1928), Mann (1911), Park (1929, 1932, 1935a, 1935b), Schwarz (1890, 1896),
and by Wickham (1894, 1896, 1898, 1900). Food, habits, and ecological re-
lations within the ant nest have been reported less abundantly (Park, 1929,
1932, 1935b). Virtually nothing is known of the neotropical inquilines among
the Batrisini.

In general the majority of the Batrisini is free-living, inhabiting the floor
stratum of forests, in moist leaf and log mold. Here they are strictly pre-
daceous, feeding on mold mites (Oribatidae) or even attacking larger injured

(214)

BATRISINI 215

animals (earthworms) and some species may be facultative myrmecophiles,
living freely in floor mold and the nest of ants (Park, 1932, 1935b). Many
species of neotropical areas come to lights at night, as will be noted later.

Key to the Neotropical Genera

Body short, thick and globular (PI. XVIII) 2

Body elongate-cylindrical (PI. XVIII) 3

2. Humerus of elytron produced into a distinct callus ; metasternum never

medianly carinated EUPHALEPSUS (PI. XV, XVIII)

Humerus of elytron without a callus or swelling ; metasternum always
medianly carinated PHALEPSOIDES

3. Lateral margins of first tergite with both an external and an internal

carina as the margin of the segment; other tergites with only a single

lateral carina or no carina (PI. XIX, 1) 4

Lateral margins of the first three or four tergites with both an ex-
ternal and an internal carina (PI. XVIII) BATOCTENUS

4. Elytron with a well marked dorsal stria ITETICUS

Elytron with no dorsal stria or replacing dorsal depression 5

5. Pronotum with a subbasal transverse sulcus, and without antebasal

spines 6

Pronotum with no subbasal transverse sulcus, but with two large ante-
basal spines, and at times with a smaller spine on each side of the
pronotum anterior of middle OXARTHRIUS

6. Pronotum with the lateral margins entire 7

Pronotum with each lateral margin distinctly incised or gashed. . . .

SYRMOCERUS (PI. XIX)

7. Pronotum with a lateral longitudinal sulcus on each side . . SYRBATUS
Pronotum without lateral longitudinal sulci ARTHMIUS

ARTHMIUS (LeConte, 1850)

LeConte (1850) (Arthmius)

LeConte and Horn (1883) {Batrisus)

ScHAUFuss (1872, 1879) {Batrisus, Bryaxis)

Raffray (1890) (Batrisus)

Raffray (1897, 1904, 1908, 1911) (Arthmius)

Sharp (1887) (Batrisus)

Fletcher (1928, 1930) (Arthmius)

In 1850, John L. LeConte erected the genus Arthmius and the genotype,
Arthmius globicollis LeConte, for a small batrisine whose range is now known
to cover the eastern third of the United States (Florida and Georgia north-
wards into Pennsylvania). Few genera were destined to be more important
taxonomically. Thirty-three years later LeConte and Horn placed globicollis
into Batrisus, since the species had been described as having a single tarsal
claw but later study "with a powerful microscope" demonstrated two unequal

216 NEOTROPICAL PSELAPHIDAE

tarsal claws. Sharp (1887) and Raff ray (1890) followed this lead, describing
their new species in subgenus Arthmius of Batrisus.

In 1897 Raffray, in an important paper, reaffirmed his earlier belief
of 1894, that Arthmius of LeConte was suflBciently distinct to warrant
generaic status, and divided the genus into three subgenera: Syrbatus Reitter,
Arthmius ss. of LeConte, and Syrmocerus Raffray. These three subgenera
are now recognized as distinct genera, and as such are treated separately in
this paper as I have been unable to find species which intergrade in their
pronotal anatomy to allow bridging the gap between one genus and another,
although all three show an arthmioid habitus.

The neotropical batrisines become numerically important by virtue of
Arthmius. Although the genotype is nearctic, the genus as a whole is over-
whelmingly neotropical. At present there are five species known north of
Mexico, of which four are distributed east of the Rocky Mountains and one
from Oak Creek Canyon, Arizona, at 6000 feet [morsus Fletcher, 1932). In
contrast the neotropics have at present 94 species distributed: Mexico (12),
Guatemala (3), Panama (2), Canal Zone (1), Colombia (5), Venezuela (2),
Bolivia (10), Peru (5), Chili (1), Paraguay (2) and Brazil (51). Brazil,
especially the drainage basin of the Amazon river, would seem to be the
center of taxonomic diversity, and many new species remain to be discovered
before our information can be considered complete enough for any generalized
statement. At present I am inclined to view Arthmius as a typical neotropical
genus of the rain forest, spreading with difficulty into drier or cooler areas. I
should be surprised if species of the genus were found north of the deciduous
forest biome or above the deciduous forest montane zone.

Their sharp mandibles presuppose an adherence to the predaceous family
habit, and they do not appear to have adjusted to a life with ants and termites.
Their natural habitat is the forest floor mold. New evidence presented later
seems to prove that they inhabit this stratum by day and fly by night. Their
large eyes and long wings support this view.

Sex is readily ascertained. The males have six stemites fully visible (not
counting the morphological first sternite) , of which the last is quite minute as
a rule, placed as an ovate-transverse plate between the very large last tergite
and next to the last sternite. This fifth visible sternite is usually large and
variously ornamented or formed. The antennae, legs, and especially the dorsal
surface of the head may be highly abnormal.

The females have simple legs, antennae, and head as a rule and always
only five stemites fully visible (not counting the morphological first sternite),
of which the last is large.

I have attempted to key out the species of Arthmius. This would have
been impossible but for the work of Raffray since the types are not at hand in
most instances. In 1897 Raffray keyed out the species of the genus then known,
and this was especially good since he had direct access to most of the types
of the early species of Schaufuss, Sharp, and Reitter. In the following keys
this 1897 background is integrated with the more recent work.

BATRISINI 217

Key to Groups of Arthmius, Based on the Male Sex
(After Raflfray, 1904)

Pronotum laterally flattened, and the disk medianly elevated into a
definite but obtuse longitudinal median carina or strongly longi-
tudinally gibbous 2

Pronotum with sides and disk normally convex 3

2. Fourth antennal segment distinctly larger than either the third or

fifth segments, or antennae thick or otherwise abnormal I

Antennae long, slender, simple II

3. Antennae abnormal 4

Antennae normal 5

4. Legs abnormal Ill

Legs normal IV

5. Legs abnormal V

Legs normal 6

6. Dorsal surface of head abnormally excavated or armed 7

Dorsal surface of head normal VIII

7. Clypeus (epistome) normal VI

Clypeus (epistome) abnormally excavated, tuberculated or otherwise

armed VII

Key to Species of Group I

Six sternites fully visible (Males) 2

Five sternites fully visible (Females) 4

2. Distal margin of clypeus truncate, with rounded apical angle, and

dorsal surface strongly elevated into a wide median longitudinal
biconcave carina ; antennal segment IV three times as long as third,
cylindrical but much wider than either third or fifth with the mesial

face uniformly produced; 2.1 mm. long plicicollis

Clypeus and antennae not as above 3

3. Distal margin of clypeus medianly produced into a long horn with its

subacuate apex tufted with setae; antennal segment IV ovate; 1.5

mm. long barhiellinii

Distal margin of clypeus strongly, evenly rounded and with the dorsal
surface tumid to end basally in a small pubescent horn; antennal
segment IV twice as long as third, with the mesial face strongly

produced medianly, much wider than third or fifth ; 2 mm

primariits

4. Vertex with a strong median fossa; 2 mm. long crassicornis

Vertex without a median fossa 5

5. Known only from Mexico plicicollis

Known only from Brazil 6

6. North of Tropic of Capricorn barbiellinii

South of Tropic of Capricorn primarius

218 NEOTROPICAL PSELAPHIDAE

Group II

This second group holds a single species, dichrous, known from a single
male from Blumenau, Brazil.

Key to the Species of Group III

Six stemites fully visible (Males) 2

Five stemites fully visible (Females) 13

2. Antennal segment I very abnormal with the mesio-apical angle

strongly produced 3

Antennal segment I simple, not as above 4

3. Antennal segment I with the mesio-apical angle produced into a long,

flattened tooth with obtuse summit; dorsal surface of head simple,
square, slightly convex through vertex with two pair of foveae, an
anterior oblong pair and a posterior punctiform pair; 1.7 mm.

bubalus

Antennal segment I obtrapezoidal, wider than the eleventh segment,
longer than second and third united, with the mesio-apical angle
produced into a short, subconical, subacute extension; dorsal sur-
face of head strongly transversely excavated and toothed as de-
scribed below; 1.6 mm. long sabomba new species

4. Antennae with the intermediate segments articulated to form an arc. . 5
Antennae with the intermediate segments not forming an arc 10

5. Arc confined to antennal segments III, IV, and V, with the fifth seg-

ment with the ventro-apical face produced and projecting ventro-

apically ; 1.8 mm truncaticeps

Arc confined to antennal segments distal to III 6

6. Arc confined to antennal segments IV, V, VI, VII and VIII; VI and

VII slightly longer than wide with squamous pubescence on ventral
faces; VIII slightly transverse with the apical angle acute; 1.7
mm curvicornis

7. Arc beginning with segment V and ending with VII or VIII 8

Arc extending from segment V to segment IX, all of these segments of

normal shape; posterior trochanters enlarged with the posterior face
concave, the concavity densely pubescent; 1.6 mm. scaphiger

8. Antennal segment V not much larger than IV; 1.8 mm simplicior

Antennal segment V much larger than IV 9

9. Segment V cylindrical-ovate, much wider than IV or VI ; VI elongate,

very slender, slightly arcuate; VII arcuate-triangular with apical
face wide, truncate and the latero-apical angle produced; 1.9 mm.

pedestrianus

Segment V strongly dilated toward the base; VI and VII thick and
less than twice as long as wide, the seventh segment not arcuate-
triangular and the apical-external angle not produced; 1.6 mm.
geniculatus

BATRISINI 219

10. Antennal segment IV very transverse, dilated, one-half wider than

II, the inner surface somewhat concave and notably pubescent; V of
same general form but wider and slightly produced on external face,
surface also pubescent; VI greatly expanded on external face, au-
riculate, twice as broad as II, the edge fringed with dense white
setae; VII subquadrate, narrower and not wider than II; 1.6 mm.

SUhjlLSUS

Antennae not as described above 11

11. Antennal segment III much larger than I or II and swollen ; II square ;

IV to VIII oval ; 2.2 mm inflatipes

Antennae not as described above 12

12. First four antennal segments simple. III and IV obconical; V to X

progressively larger, slightly flattened and lightly, squamosely
pubescent; V obconical, VI subglobular, VII square, VIII slightly

transverse; 1.7 mm platycerus

Antennal segment V at least twice as long as III ; VI slightly shorter
than VIII; VII nearly as long as V, slightly clubbed in form;
1.8 mm articularis

13. Head and pronotum black; elytra and abdomen chestnut red. .bicolor
Body uniform reddish-brown 14

14. Abdomen with apex mucronate or pointed 15

Abdomen with apex rounded, not mucronate. . . .sabomba new species

15. Median depressions at base of first tergite very transverse, nearly con-

fluent medianly; intermediate tibiae notched on the external face

beyond the middle of their length singularis

Median depressions at base of first tergite simply ovate and very dis-
tant from each other; intermediate tibiae not notched or grooved
on the external face articularis

In this key singularis and bicolor have been described on the female sex
only, each from a single specimen. It is possible that bicolor belongs in Group
I and the discovery of the males in both species may change their positions.

Arthmiu^ sabomba new species

Holotype Male. Measurements: Head 0.368 including apex of clypeus
to occiput x 0.469 mm. through eyes; pronotum 0.368 x 0.368; elytra 0.55 x
0.76 mm.; abdomen 0.335 x 0.67 mm.; total length 1.6 mm.; greatest width
0.76 mm. (PI. VI).

Reddish-brown, semishining with conspicuous semierect pubescence. Head
with very short, right-angled tempora about the length of an ocular facet.
Eyes large (0.12 x 0.067 mm. from dorsal view), composed of about 24 very
coarse facets; subreniform from a lateral view. Occiput with a short median
longitudinal carina. Vertex with two foveae; each fovea nude, separated from
an eye by the length of three ocular facets, deep and with a diameter of an
ocular facet. Vertex very transverse, with square corners, the sides slightly

220 NEOTROPICAL PSELAPHIDAE

divergent to the antero-lateral angles which are coarsely punctate; anterior
half of vertex medianly excavated to form a deep glabrous fossa. Frontal
margin evenly concave between antennal bases with two short, contiguous,
triangular teeth at middle; front densely pubescent and declivous between
antennae, the median portion of this declivity produced into an obconical,
glabrous tubercle from the base of which arises on each side a tuft of con-
spicuous setae. Clypeus greatly elongated and strongly tumid; the apical
margin is a black bead strongly produced in an obtuse angle; surface with
erect pubescence and granulate-punctate, the tumidity ascending dorso-
posteriorly in an obtuse angle. Considering the clypeus as a whole, therefore,
the angulate apical and basal margins give it a symmetrical parallelogram
outline. The median angle of elevated basal margin is strongly carinated and
elevated to partially obscure the obconical appressed tubercle of the front.

Maxillary palpi four-segmented and simple ; first segment minute ; second
sharply arcuate at base, elongate, slender for basal three-fourths and expanded
in apical fourth ; third short, rounded triangular with the usual convex external,
and short subangulate internal, faces; fourth longer than second, twice as
wide as third, base lengthily oblique, apex subacute, convex external face,
sinuate-convex internal face; palpal cone short, thick, conical.

Antennae eleven-segmented, coarsely punctate, distant, abnormal; seg-
ment I obtrapezoidal, wider than the eleventh segment, longer than second and
third united, with the mesio-apical angle strongly produced; II and III sub-
equally wide, second moniliform, third slightly shorter and transversely asym-
metrical; IV large, longer than any other segment save the eleventh, and
wider than any other segment save the first and last three, asymmetrically
elongate with the basal end much wider than apical end and the mesio-basal
angle produced; V, VI, VII, VIII subcylindrical, fifth longest of these four,
next two subequal, eighth shortest; IX elongate hexagonal; X transverse
hexagonal; XI as long as preceding two united, with truncate base and sub-
acute apex.

Pronotum rounded hexagonal in outline, widest in anterior third, with
evenly convex disk; basal third with an arcuate-transverse glabrous sulcus,
the median posterior margin of which is produced anteriorly into a short, acute
cusp; sulcus ends on each side in an obscure fovea.

Elytra with prominent, obliquely elevated humeri ; each elytron with three
large nude basal foveae and an entire sutural stria.

Wings long and well-formed.

Abdomen with five tergites; first with a strong lateral margin for the
basal two-thirds as a consequence of an external and an internal carina, apical
third of segment not margined and not carinated; this first segment two and
a half times longer than next two united; second and third subequal and with-
out lateral margins; fourth half the length of first; fifth shorter than fourth,
rounded subtri angular.

Abdomen with six sternites fully visible. Fifth (next to last) large,
glabrous, as long as first four united, with a conspicuous median depression

BATRISINI 221

which is very broad and deepens apically, the apical margin abruptly erected
to form a posterior wall of the depression and this apical margin medianly
slightly concave; basal-external angles of depression subserrately elevated
into three or four minute blackened obtuse denticles, each denticle bearing a
long coarse, flavous, decumbent seta which is directed medio-posteriorly for
one-third or more of the depression. Sixth (last) sternite minute, transversely
fusiform, granulate-punctate, and lies between the median apical margins of
the last tergite and next to last sternite.

Intermediate trochanters conspicuously abnormal, with the ventral face
flat and ovate, this surface crowded with short, uniform setae and in addition
a single, very long seta which arises from the anterior margin of the pad
(examination of the numerous male paratypes, both dry and microscope slide-
mounts, attests to the complete constancy of this single erect seta set in the
pad of short setae) . Anterior and posterior trochanters, all femora and anterior
tibiae simple. Intermediate and posterior tibiae with a strong uncus near apex.
Tarsi normal for tribe.

Allotype Female. Similar to holotype save that (1) eyes are slightly
smaller and tempora slightly longer; (2) occipital carina not as strongly
formed; (3) vertex simple, semicircularly impressed between antennal tubercles,
with an evenly declivous front which lacks teeth and tubercle; (4) clypeus
simple, declivous, evenly convex; (5) antennae simple; (6) first tergite
relatively shorter; (7) only five fully visible sternites, of which the last is
large, distinctly longer than preceding three united, semilunar in outline with
a concave apical margin; (8) intermediate trochanters simple; (9) tibiae not
apically armed.

Described on 15 specimens, all collected on Barro Colorado Island, Gatun
Lake, Panama Canal Zone. Male paratype (July 7, 1936) ; three male para-
types (July 15, 1936) ; male paratype (July 16, 1936) ; male holotype (July
22, 1936) ; three male paratypes (July 24, 1936) ; male paratype (July 29,
1936) all collected at light at night after 9 P.M. and before midnight, and
all collected by the author. Two male paratypes (July 17, 1938) , one male and
one female paratype (July 19, 1938) and allotype female (July 23, 1938) all
collected from leaf mold of the rain forest floor by Dr. Eliot Williams.

From these data it should be noted that although ten were taken at light
at night, only five were collected during the day. Of these taken at light all
were males, but the diurnal catch was of nearly equal sex ratio (3 males, 2
females). This is either coincidence or an indication that the males fly to
light more than females.

Second, it seems clear that the species is nocturnal. This is a general rule
for the family but heretofore has lacked definite substantiation. Thus careful,
quantitative quadrat samples of the forest leaf mold discovered sabomba in
the floor by day and not by night; the same species, in the same locality, was
taken on the wing only after dusk. For a full statement of the analysis the
work of Williams (1941) should be examined.

Third, a male (July 17, 1938) and a female (July 19, 1938) had evidently

222 NEOTROPICAL PSELAPHIDAE

only recently pupated. This checks with similar data on other species so that
there seems to be a general period of pselaphid pupation in the rain forest
floor in the rainy season, during the first half of July. Other periods are to
be expected (May 4, 1935 for Barrometopia quasimoda in the nest of its host
termite at the end of the dry season is of interest as the dark, humid nest en-
vironment is in contrast with the dry season) and it is quite possible that life
cycles are begun and completed for the duration of the protracted wet period
in the tropics.

Arthmius sabomba is unrelated to other groups in the genus save the third,
and within this group is distantly associated with bubalus. Both sexes promptly
diverge from Raffray's 1897 key to males and females, and the recent species
of Raffray and Fletcher are equally different.

In this connection a word should be said as to the identity of unique
specimens in the genus. Since many species are known only from one sex, the
keys to Arthmius in the present paper will serve to identify males or species
represented by both sexes but students with an isolated female will have to
take the specimen through each group key, and then consult Raffray's notes
of 1897. Even then there is an element of doubt since early descriptions are
not complete.

Key to the Species of Group IV

Six stemites fully visible (Males) 2

Five sternites fully visible (Females) 7

2. Antennal segment I very large, inflated on the ventral face, other

antennal segments simple ; 2.1 mm bison

Antennal segment I simple, not conspicuously large and ventrally
produced 3

3. Antennal segment II abnormally large 4

Antennal segment II not abnormally large 6

4. Antennal segment II with the dorsal face dilated and with the internal

face flattened 5

Antennal segment II not armed or dilated but more than three times
longer than segment III, with the internal face rounded, and dorsal
face depressed and squamously pubescent; 2.5 mm orion

5. Antennal segments III, IV, and VI not much longer than wide; V

and VII much longer; VIII square; IX and X much larger and

orbicular; 1.8 mm bythinoceros

Antennal segments IV, V, and VI nearly three times longer than wide ;

VII much longer than wide; IX and X oval; 2.2-2.4 mm reitteri

6. Antennal segments V, VI, VII with internal faces slightly rounded,

slightly larger than IV or VIII; IV and VI square; VIII trans-
verse ; 1.8 mm quadripunctatus

Antennal segment V much larger than IV or VI; VII cylindrical;

VIII square; 2 mm bituberculatus

BATRISINI 223

Abdomen mucronate or apically pointed; intermediate tibiae simple;
antennal segments V and VII much longer and thicker than IV,
VI, and VIII quadripunctatus

Abdomen not mucronate 8

Head with a small longitudinal carina at middle of the front; anten-
nal segment II much larger than I or III orion

Head without a median longitudinal frontal carina but with a small
longitudinal median carina on occiput bythinoceros

Key to the Species of Group V

Six sternites fully visible (Males) 2

Five sternites fully visible (Females) 14

Anterior femora abnormal 3

Anterior femora simple 10

Anterior femora with a deep transverse sulcus on the dorsal face, this
sulcus limited anteriorly by a strong transversely flattened and
obtuse tubercle, and limited posteriorly by a much smaller, obtuse
tubercle ; intermediate trochanters with a small sharp median spine ;

1.8 mm hydropicus

Anterior femora with different modifications 4

Antennal tubercles very rugosely punctate and swollen; 1.6 mm

manifestus

Antennal tubercles smooth and either flat or only slightly elevated ... 5
Anterior femora with a median deep transverse sulcus on the dorsal
face, the borders of the sulcus carinated and densely pubescent, and
posterior (basal) to this sulcus a wide impression, and anterior

(apical) to the sulcus a flattened squamous area; 1.9 mm

femoratus

Anterior femora with different modifications 6

Anterior femora with a shallow median depression on the dorsal face,
the anterior margin of this depression is slightly pubescent and
lightly carinated ; apical to this carinated margin is a minute trans-
verse sulcus ; 2 mm cruralis

Anterior femora with different modifications 7

Anterior femora with a deep oval fovea at apical third of dorsal face,
the margins of this fovea lacking a pubescent carina; external to
the apical fovea the femora are incised by a transverse notch;

1.4 mm rubriculus

Anterior femora with different modifications 8

Fovea of dorsal surface of anterior femora oblong 9

Anterior femora with a perfectly circular fovea and a high crenulated

longitudinal crest; 1.9 mm extraneus

Intermediate trochanters with a light brush of setae; 1.9 mm

cicatricosus

224 NEOTROPICAL PSELAPHIDAE

Intermediate trochanters absolutely devoid of a pubescent brush;

2.2 mm brevicollis

10. All trochanters simple 11

Anterior trochanters with a short apical spine; intermediate trochan-
ters with a slender, sharp pointed, erect, very long median spine;

2.3 mm tibialis

11. Anterior tibiae absolutely simple; metastemum with a deep median

oblong fovea; first fully visible sternite with a thin, posteriorly-
directed ligula; 1.4 mm mancus

Anterior tibiae abnormal 12

12. Anterior tibiae not dilated on external face, but short and thick, with

the internal face thicker and rounded at middle, these tibiae not

apically sinuate ; 2.3 mm bicornis

Anterior tibiae with different modifications 13

13. Anterior tibiae with an abrupt, pointed dilation near the middle of

the dorso-external face; 2 mm simplicicornis

Anterior tibiae nearly entirely dilated on the external face, this
dilation slightly rounded and flattened; 1.4-1.5 mm latipes

14. First apparent sternite (second morphological) with a median longi-

tudinal carina near base hydropicus

First apparent sternite (second morphological) with no median longi-
tudinal carina manifestus

Key to the Species of Group VI

Six stemites fully visible (Males) 2

Five sternites fully visible (Females) 14

2. Head not excavated 3

Head variously excavated 4

3. Margin of front between antennal bases simply concave or poster-

iorly arcuate, with a pair of short conical approximate and anteriorly

inclined truncated tubercles; 2.8 mm rhinoceros

Margin of front between antennal bases biarcuate with the median
area, joining the arcuations, produced anteriorly into a subacute,
triangular extension; 2.3-2.4 mm sus

4. Species unknown south of Panama 5

Species unknown north of Brazil 6

5. Lateral margin of the vertex above each eye erected into a strong but

obtuse, slightly arcuate carina; 2.0-2.2 mm vividus

Lateral margin of the vertex above each eye not at all carinated;
2 mm armatellus

6. Head much longer than wide not including the eyes, or as long as

wide including the eyes; lateral margins of the vertex concave or
sinuate, the head widening to the prominent laterally everted anten-
nal tubercles ; vertex broadly excavated from eyes to frontal margin,
this depression bearing an elongate carina in the shape of a narrow

BATRISINI 225

staple with abruptly everted ends (this odd structure may also
be likened to a single heavy carina which is medianly and longi-
tudinally sulcate, with this narrow sulcus closed apically and ex-
panded basally ) ; 2 mm aubei

Head with different modifications 7

7. Vertex and occiput more or less distinctly excavated, the excavation

simple or complexly spined, tuberculated, sulcate or carinate.... 8
Head between the eyes to the occiput simply convex or slightly tumid,
never armed as noted above 9

8. Metasternum with the apical margin medianly erected between the

posterior coxae into a transverse lamella which is inclined anteriorly

(basally) ; 2.4 mm edithae

Metasternum not modified as noted above 10

9. Vertex simply convex between the eyes and the occiput, anteriorly there

are three obsolete impressions, an apical transverse and two sub-
circular; 1.9 mm areolatus

Vertex from the eyes to the occiput simple, slightly transversely gib-
bous; anterior half of vertex simply and deeply depressed, this ex-
cavation strongly rounded posteriorly, occupying the median third
of the head width and extending in an arc for median third of the
inter-antennal margin; 1.6 mm cinnamomeus

10. Head subquadrate to longer than wide 12

Head strongly transverse 11

11. Head with a slightly arcuate, deep, entire sulcus which extends from

just above and behind each eye transversely over the vertex, this
conspicuous excavation extended posteriorly at middle in a second-
ary subtriangular excavation ; in the center of this transverse sulcus

is a small tubercle; metasternum sulcate; 1.25 mm transversalis

Head more strongly transverse; vertex with a suboval depression at
middle between the eyes, with an elongate oval tubercle at center of
this depression; just apical to this median depression is an arcuate,
transverse sulcus occupying median third of the vertex ; metasternum
sulcate with a strong compressed tubercle on each side; 2.3-2.4 mm.
vulneratus

12. Head subquadrate, about as long as wide 13

Head much longer than wide; 2.1 mm cornutus

13. Metasternum simple ; 2.1 mm cerastes

Metasternum broadly concave, with a deep and narrow sulcus in the

concavity, armed on each side behind the middle by a sharp spine;
1 .5 mm elegantulus

14. Head with either a small tubercle near middle of the front, or a slender

carina on the vertex 15

Head without a frontal tubercle and without a vertexal carina 17

15. Head with a small tubercle 16

226 NEOTROPICAL PSELAPHIDAE

Head with a slender carina on the anterior part of the vertex; front
with two circular, sharply delimited foveae sus

16. Posterior frontal area with a small, median tubercle; antennal tu-

bercles rounded, not prominent edithae

Anterior frontal area with a small, median tubercle; anterior tubercles
strongly formed and more pointed; 2 mm patruelis

17. Vertex with a median fossa 18

Vertex without a median fossa ; front lacking a transverse frontal im-
pression; head with four foveae, the posterior pair being placed be-
tween the eyes; a small rugose and squamously pubescent patch on
each antennal tubercle vividus

18. Head very strongly transverse vulneratus

Head only slightly wider than long, or quadrate 19

19. Vertexal fossa round, and either very shallow or deep 20

Vertexal fossa oblong, very deep cornutus

20. Vertexal fossa deep and well-formed armatellus

Vertexal fossa wide but very superficial, being in reality a shallow

depression aubei

Key to the Species of Group VII

Six sternites fully visible (Males) 2

Five sternites fully visible (Females) 16

2. Clypeus (epistoma) abnormal 3

Clypeus (epistoma) normally formed but the front having a median

tubercle; this frontal tubercle separated from the inter- antennal
frontal margin by a transverse depression so that the obtusely
pointed and slightly suberect tubercle appears to be a part of the
clypeus proper carinatus

3. Head very transverse, with dilated and externally auriculated antennal

tubercles, these tubercles expanded laterally beyond the eyes so that
the head is widest through the antennal bases; vertex with a deep,
sharply formed and regularly trapezoidal excavation between the
eyes; intermediate trochanters simple but intermediate tibiae with
a very strong spine; metasternum flat, with a nearly entire sulcus;

2.4 mm auriculatus

Head only slightly wider than long, or quadrate 4

4. Vertex concave 5

Vertex either simply convex or prominently elevated but not concave 6

5. Head between the eyes concave for nearly the entire head width, with

a small tubercle each side between the eyes ; intermediate trochanters
armed medianly with a small tubercle; intermediate tibiae with a

long spine ; 2.2-2.5 mm boliviensis

Head with a median elongate-triangular shallow concavity ; trochan-
ters simple; intermediate tibiae with a strong spine germaini

BATRISINI 227

6. Vertex prominently elevated 7

Vertex simply convex to flattened 8

7. Vertex becoming prominently triangularly elevated apically, this ele-

vation with an apical ciliated border and apical to this a very small
median fovea; anterior and intermediate trochanters armed each

with a small, pointed tubercle; 1.9 mm triangularis

Vertex becoming prominently triangularly elevated apically, the
summit of this elevation acutely incised or notched, with a large
oblique fovea on each side entering on the front; intermediate tro-
chanters sparsely pubescent; 1.55 mm elevatus

8. Front more or less tuberculated 9

Front without a tubercle, but excavated or incised 11

9. Front with a very short, median, wide, strongly truncated tubercle,

with the truncated face of the tubercle rugose; antennal tubercles

flattened and rounded; the trochanters simple; 1.9 mm

circumscriptus

Front with a median tubercle which is more or less shai-p-pointed ; an-
tennal tubercle strongly formed, especially prominent laterally;
therefore the frontal margin of head appears trituberculate 10

10. Head some longer than wide, with a strong, thick, median triangular

spinoid tubercle on the front and very prominent antennal tubercles;

trochanters simple; metastemum deeply sulcate; 2.1 mm

peniculus

Head slightly transverse, with a frontal tubercle in the form of a
medianly-placed, erect, straight horn; intermediate and posterior
trochanters with a small brush of setae; 1.9 mm erectus

11. Front simply depressed and broadly bifoveate; metastemum broadly

sulcate; intermediate trochanters slightly pubescent; 1.7 mm

labiatus

Front diversely notched, incised or excavated 12

12. Frontal incisure large and quadrangular; trochanters simple; meta-

stemum with an entire but shallow median sulcus; 1.4-1.6 mm

honestus

Frontal incisure deep to very shallow, and of various shapes but not
quadrangular 13

13. Frontal incisure triangular, deep, with an excavated area within the

borders of the incised area 14

Frontal incisure not triangular, and not as deep 15

14. Deep triangular notch of the front regular in outline, with a transverse

carina placed near the bottom of the incisure and apically ; clypeus
with a conspicuously large, basally compressed, transverse horn, this
horn being dorsally swollen, rugose and slightly pointed posteriorly;
trochanters simple; metastemum with a broad, entire sulcus more
or less carinated apically ; 2 mm elephas

228 NEOTROPICAL PSELAPHIDAE

Frontal incisure less deep, less wide, more ogival-triangular, prolonged
posteriorly in a sulcus which disappears on the vertex; clypeus tri-
angularly gibbous; trochanters simple; metasternum with short
setae; 1.7-1.9 mm melanocephalus

15. Frontal incisure transverse, medianly angulate, with long setae, and a

slender carina disappearing posteriorly on the vertex; epistome
(clypeus) with a strong, erect, triangular, pointed horn which is

densely pubescent; trochanters simple; 2.5 mm ciliatus

Frontal incisure very wide, medianly circular and in the center of this
incisure is a rudimentary tubercle or swelling; front and clypeus
separated by a deep, slightly transverse excavation; clypeus with a
strong, thick, triangular, flattened and slightly recurved horn; tro-
chanters simple ; 1.8 mm rufipes

16. Anterior part of vertex with a slender median carina; antennae elon-

gate, slender with segments at least twice as long as wide ; front with

two transverse, vaguely limited foveae carinatus

Vertex without carina, either medianly excavated or simply convex. . 17

17. Vertex with a median fovea, and lateral margins of head each with a

small tooth or cusp germaini

Vertex with or without a median fovea or impression but the sides of
the head not toothed 18

18. Vertex with a median foveaform depression; head slightly transverse

with antennal tubercles slightly prominent laterally, large, flattened,

obliquely cut and subcarinated at summit auriculatus

Vertex with neither a median carina nor fovea 19

19. Front with an entire, transverse impression just posterior of a hypo-

thetical line passing through the antennal tubercles, .drcumscriptus
Front without a transverse post-tubercular impression ; head with four
free foveae, of which the posterior pair lie between the eyes and are
punctiform, relatively small and shallow, while the anterior pair are
slightly oblong and obliquely placed between the antennal tubercles
elevatus

Key to the Species of Group VIII

Six sternites fully visible (Males) 2

Five sternites fully visible (Females) 7

2. Head quadrate (that is, the width of the head not including the eyes,
is equal to the head length), with tempora more rounded than the
antennal tubercles; vertex perfectly simple from occiput to eyes
with the usual pair of vertexal foveae ; anterior of the eyes the vertex
is transversely, narrowly impressed in an entire striaform line which
broadens and deepens at middle, this median depression in reality

foiTned by a pair of foveae; 2.4 mm jauveli

Head more or less transverse (that is, the width of the head not in-
cluding the eyes, is greater than the head length) 3

BATRISINI 229

3. Head with three vertexal foveae 4

Head with either two vertexal foveae and a median carina, or two

vertexal foveae only ; vertex never with three foveae 5

4. Head with three vertexal foveae, two between the eyes as usual and a

smaller median fovea which is circular in outline; intermediate tro-
chanters with a small setaform spine; 1.8 mm planijrons

Head with the usual pair of inter-ocular vertexal foveae and a median
oblong fovea; anterior and intermediate trochanters angularly di-
lated but not spined; 1.6 mm trifoveolatus

5. Vertex with a median longitudinal carina between the vertexal foveae 6
Vertex simple, with the normal pair of vertexal foveae but no median

longitudinal carina; trochanters simple; 1.7 mm resectus

6. Vertexal carina long; intermediate trochanters slightly pubescent;

tibiae simple; 1.7 mm modestus

Vertexal carina very short; intermediate trochanters not pubescent;
intermediate tibiae with a strong spine; 2 mm edmundi

7. Abdomen mucronate apically (this acute to subacute contour is caused

by the last tergite being either obtusely prominent or having a blunt,
obtusely prominent apical tubercle which may or may not be visible

from above) 8

Abdomen not apically mucronate 9

8. Vertex without a median fovea or depression of any kind; 2.2 mm

peruvianus

Vertex with an obsolete median depression placed posterior to the

vertexal foveae productus

Vertex with a large transverse depression which extends from the an-

tennal tubercles to behind the eyes, with the vertexal foveae within

this depressed area ; 2.6 mm magnus

9. First fully visible sternite (second morphological) with a median

longitudinal carina at base 10

First fully visible sternite (second morphological) not medianly cari-
nate at base 14

10. Head very transverse, nearly twice as wide as long breviceps

Head only slightly wider than long or quadrate to elongate 11

11. Front evenly declivous and without foveae or paired depressions 12

Front with a pair of obsolete depressions or a pair of deep oblique

sulciform foveae 13

12. Known only from Argentina; vertex evenly convex and without a

median fovea ; 1.5 mm delicatus

Known only from Peru; vertex trifoveate, with a large deep median
fovea in addition to the usual pair of inter-ocular foveae; 1.8 mm.
, laevipennis

13. Front broadly flattened with a pair of obsolete foveaform depressions

planijrons

230 NEOTROPICAL PSELAPHIDAE

Front medianly slightly elevated with a deep, oblique and sulciform
fovea on each side trifoveolatus

14. Vertex with a median carina 15

Vertex without a median carina 17

15. Vertex with the median carina very short 16

Vertex with the median carina long, extending over the vertex ; front

with a transverse impression which is widely interrupted at middle
infirmus

16. Front with a transverse impression which is wide, shallow and does

not reach margins modestus

Front with a transverse impression which extends from side to side of
front and is deep and sulciform humilior

17. Vertex with a median fovea or foveaform depression 18

Vertex without any median depression 19

18. Median vertexal fovea very small and punctiform adulator

Median vertexal fovea not of this form ; body very much more elongate

and cylindrical, with parallel sides; 2.6 mm parallelus

19. Abdomen and posterior portion of elytra punctate to punctulated;

1.7 mm punctatus

Body absolutely impunctate fauveli

The species of Arthmius known to inhabit the neotropics are listed by
groups as follows:

I

barbiellinii Raffray. 1909. Sao Paulo, Brazil.

crassicornis Raffray. 1897. Mexico.

plidcollis Reitter. 1882. Mexico.

primarius Reitter. 1888. Blumenau, Brazil, {rostellatus Reitter)

II

dichrous Reitter. 1888. Blumenau, Brazil.

Ill

articularis Raffray. 1897. Yuracaris, Bolivia.

bicolor Ritter. 1882. Sao Paulo, Brazil, (or in Group I?)

bubalus Raffray. 1897. Mexico.

curvicornis (Schaufuss). 1872. Yucatan, Mexico. (Batrisus)

geniculatus (Sharp). 1887. Jalapa, Mexico. (Batrisus)

infiatipes Raffray. 1897. Brazil.

pedestrianus Raffray. 1904. Sierra de Durango, Mexico.

platycerus Reitter. 1888. Blumenau, Brazil.

sabomba new species. Panama Canal Zone.

scaphiger (Sharp). 1887. Jalapa, Mexico. (Batrisus). (Fletcher, 1930)

simplicior Raffray. 1897. Yucatan, Mexico.

BATRISINI 231

singularis (Schaufuss). 1879. Chile? (Bryaxis)
subfusus Fletcher, 1930. Jalapa, Mexico.
truncaticeps (Sharp). 1887. Guatemala. (Batrisus)

IV

bison Raffray. 1897. Brazil.

bituberculatus Reitter. 1888. Blumenaii, Brazil.

bythinoceros Reitter. 1888. Blumenau, Brazil, [quinquefoveolatus

Reitter, nee Schaufuss teste Raffray, 1904)
lamellatus Raffray. 1890. San Esteban, Venezuela.
orion (Schaufuss). 1872. New Friburg, Brazil. (Batrisus) [carinatus

Schaufuss)
quadripunctatus (Schaufuss). 1872. Yucatan, Mexico. (Batrisus)
reitteri Raffray. 1897. Blumenau, Brazil.

bicornis Raffray. 1897. Brazil.

brevicollis Raffray. 1897. Brazil.

castaneus (Sharp). 1887. San Juan, Vera Paz, Guatemala. (Batrisus)

cicatricosus Raffray. 1897. Paraguay.

cristulatus Reitter. 1889. Brazil.

cruralis Raffray. 1897. Matto Grosso, Brazil.

extranev^ Fletcher. 1930. Corumba, Matto Grosso, Brazil.

femoratus Raffray. 1897. Brazil.

hydropicus Raffray. 1897. Brazil.

latipes Raffray. 1897. Mexico.

mancus Fletcher. 1930. Corumba, Matto Grosso, Brazil.

manifestus Reitter. 1888. Blumenau, Brazil, (lubricus Reitter)

rubriculus Fletcher. 1930. Corumba, Matto Grosso, Brazil.

simplicicornis (Sharp). 1887. Guatemala. (Batrisus)

tibialis Raffray. Yuracaris, Bolivia.

VI

areolatus Raffray. 1897. Brazil.

armatellus (Sharp). 1887. Volcan de Chiriqui, Panama at from 2000

to 4000 feet. ( Batrisus)
aubei (Schaufuss). 1872. Rio de Janeiro, Petropolis, New Friburg,

Minas Geraes, Brazil, (quinquefoveatus Schaufuss). (Batrisus)
cerastes Raffray. 1897. Petropolis, Brazil, (cornutus Reitter nee

Schaufuss teste Raffray 1904).
einnamomeus (Schaufuss). 1887. Minas Geraes, Brazil. (Batrisus)
eornutus (Schaufuss). 1872. Minas Geraes, Brazil. (Batrisus) (stultor

Schaufuss)
edithae Reitter. 1888. Blumenau, Brazil, (minax Reitter)

232 NEOTROPICAL PSELAPHIDAE

elegantulus Fletcher. 1928. Perene, Peru.

patruelis Reitter. 1888. Blumenau, Brazil.

rhinoceros (Schaufuss). 1872. Macahe, Brazil. (Batrisus)

sus (Schaufuss). 1872. Petropolis, Minas Geraes, Brazil. (BatrisiLs)

transversalis Rafifray. 1904. Petropolis, Brazil.

vividus (Schaufuss). 1872. Panama. (Batrisus)

vulneratus Raffray. 1897. Yuracaris, Bolivia.

wasmanni Raffray. 1898. Rio Grande del Sol, Brazil.

VII

auriculatus Raffray. 1897. Yuracaris, Bolivia.
boliviensis Raffray. 1897. Yuracaris, Bolivia.
carinatus (Schaufuss). 1872. Theresopolis, Petropolis, Rio de Janeiro,

New Friburg, Minas Geraes, Brazil. (Batrisus)
ciliatus Raffray. 1897. Brazil.
circumscriptus Raffray. 1897. Blumenau, Brazil,
cristatifrons Reitter. 1889. Brazil.
elephas Raffray. 1897. Brazil.
elevatus Raffray. 1890. Tovar Colony, Venezuela.
erectus Raffray. 1897. Brazil.
germaini Raffray. 1897. Yuracaris, Bolivia.

honestus (Schaufuss). 1872. Petropolis, New Friburg, Brazil. (Batrisus)
labiatus Raffray. 1904. Theresopolis, Brazil.
melanocephalu^ Reitter. 1888. Blumenau, Rio Grande, Brazil.
peniculus (Schaufuss). 1872. New Friburg, Brazil. (Batrisus)
rufipes Raffray. 1897. Theresopolis, Brazil.
triangularis Raffray. 1897. Bogota, Colombia.

VIII

adulator Reitter. 1888. Sao Paulo, Brazil.

breviceps Raffray. 1897. Yuracaris, Bolivia.

delicatus Fletcher. 1928. Tucuman, Argentina.

edmundi Raffray. 1904. Petropolis, Brazil, (carinatus Reitter, 1888,

nee Schaufuss; reitteri Raffray, 1897)
fauveli Raffray. 1897. Yuracaris, Bolivia.
humilior Reitter. 1888. Blumenau, Brazil.
infirmus Raffray. 1897. Brazil.
laevipennis Fletcher. 1928. Iquitos, Peru.
luzerae Reitter. 1882. Colombia.

macro cephalus (Schaufuss). 1872. New Friburg, Brazil. (Batrisus)
magnus Fletcher. 1928. Iquitos, Peru.
modestus Raffray. 1897. Theresopolis, Brazil.
parallelus Raffray. 1897. Yuracaris, Bolivia.
peruvianus Raffray. 1882. Peru. (Batrisus)

BATRISINI 233

planifrons (Schaufuss). 1872. Bogota, Colombia. (Batrisus) {tri-

punctatus Reitter, 1882)
productus Raffray. 1897. Yuracaris, Bolivia.
punctatus Raffray. 1897. Mexico.
resectus Raffray. 1897. Brazil.
trijoveolatus (Schaufuss). 1872. Bogota, Colombia. (Batrisus)

Unplaced

coronatus (Westwood). 1870. Brazil. (Bryaxis)

concolor Raffray. 1908. Paraguay

rugiceps (Schaufuss). 1872. Bogota, Colombia. (Batrisus)

SYRBATUS (Reitter, 1881)

Reitter (1881, 1882, 1885, 1888) (Syrbatus, Arthmius)
Raffray (1897, 1904, 1908, 1908a) (Arthmius)
Raffray (1917) (Syrbatus)

This genus was treated as a subgenus of Arthmius until recent years. It is
undoubtedly closely related to Arthmius but generically distinct on pronotal
structure. All Syrbatus have a longitudinal sulcus on each side of the pro-
notum, and these sulci are absent in Arthmius; the present genus may be re-
garded as intermediate between Arthmius and Syrmocerus.

With one questionable exception, it is a South American genus: Brazil (25) ;
Paraguay (3); Argentina (2). In addition to these thirty species Raffray
(1897a) described mashona from Salisbury, Southern Rhodesia, Africa as
belonging to the genus!

I have reorganized the key to males (1897) and key to groups (1904)
of Raffray to include recent work:

Key to the Groups of Syrbatus Males

Sides of head (genal-temporal area) simple, neither ridged nor cari-

nated 2

Sides of head (genal-temporal area) longitudinally carinated 5

2. Antennae more or less abnormal in the male sex Group I

Antennae simple, similar to the female 3

3. Head dorsally excavated Group II

Head not excavated or infossate on dorsal surface 4

4. Epistome (clypeus) armed or abnormal Group III

Epistome (clypeus) simple Group IV

5. Antennae abnormal Group V

Antennae simple Group VI

Group I

Represented by a single species, antennator, in which the male has the
third antennal segment much longer than wide and the latero-apical angle

234 NEOTROPICAL PSELAPHIDAE

swollen, fourth segment irregularly transversely flattened at base on dorsal face
and the external face angulate-produced at middle ; clypeus extended apically
in an acute-pyriform outline with sharp apex; interantennal line medianly
concave, with a small cusp just posterior to the concave area, a pair of small
median tubercles in a depression between the eyes.

Group II

Head as long or much longer than wide 2

Head distinctly much wider than long, and distinctly wider than pro-

notum 6

2. Clypeus with a posteriorly curved, pointed horn 3

Clypeus with either a simple tubercle or a carina 5

3. Interocular excavation not limited apically by a carina; 2.4 mm

hiatusus

Interocular excavation sharply limited apically by an elevated carina
or carinated ridge 4

4. The limiting carina entire and simple between the antennal bases;

2.1 mm bubalus

(Not to be confused with Arthmius bubalus, s.s.)
The limiting carina between antennal bases strongly ciliated and
medianly interrupted ; 2.4 mm grouvellei

5. Clypeus with a simple tubercle; 2.3 mm centralis

Clypeus with an obtuse carina brevispinus

6. Head, including eyes, one-fourth longer than head from occiput to

apex of clypeus, and because the antennal tubercles are externally
produced, the head through the tubercles is distinctly wider than
total head length; vertex with a deep, transverse excavation in the
shape of a dumbbell, with a small acute median horn at center of
excavation which opens apically as the deeply arcuate inter-
antennal line; 1.8 mm. intermediate trochanters simple, .hetschkoi
Intermediate trochanters provided with a dense brush of short setae;
2.4 mm transversalis

Transversalis and hetschkoi are separable on a number of points in addi-
tion to the intermediate trochanters. The former has obtuse but well developed
apical pronotal angles, sides of pronotum nearly straight posterior to the ab-
ruptly formed apex and deep lateral pronotal sulci. The latter has a cordiform
pronotum with insensibly formed apical angles, rounded sides and poorly formed
lateral sulci.

The ambiguously isolated mashona Raffray of Southern Rhodesia is placed
by Raffray (1897) next to hetschkoi.

There is another species which is placed in this group. Raffray (1908a)
described Arthmius bruchi as belonging to the subgenus Syrbatus, but stated
that it was nesLr Arthmius sits (Schaufuss) and Arthmius carinatus (Schaufuss).
Both of the latter are true Arthmius without lateral pronotal sulci, the former

BATRISINI 235

in Group VI and the latter in Group VII. The male bruchi is described as
having the vertex deeply and transversely impressed, and this feature with the
simple, uncarinated tempora and normal antennae would place bruchi in
Syrbatus Group II if the pronotum is Syrbatus.

Group III

Vertex with a semicircular patch of squamous pubescence just above
(mesiad) of each eye, these areas sharply defined and conspicuous

so as to give the impression of a double eye each side; 2.1 mm

quadrioculatus

Vertex not as above 2

2. Clypeus with either a strong obtuse carina or an elevated tubercle ... 3
Clypeus not carinate or tuberculate 4

3. Clypeus with a strongly developed obtuse median, longitudinal carina ;

clypeus excavated on each side and apically in the form of a pointed

arch (ogival) ; 1.8 mm sublaminatus

Clypeus excavated each side near base and medianly an elongate tu-
bercle which is flattened on top and may be described as an "ele-
vated plaque", squamous; 2 mm scitus

4. Clypeus prominent, wholly concave with a ciliated margin; 1.7-1.8

mm curvispina

Clypeus prominent, flattened and ogival in form (that is acute-

pyriform or in the form of an apically pointed arch) ; 1.7 mm

phantasma

Group IV

Intermediate trochanters dilated and truncate, with a brush of short
setae; 1.6-1.7 mm calcarifer

Intermediate trochanters each with a strong tooth or spur at apex;
2.3 mm simpUcifrons

Also in this group belongs marthae Reitter, but described on the female
sex only; 1.7 mm. long, and said by Raff ray to closely resemble calcarifer
Reitter.

Group V

First antennal segment simple, not abnormally large or irregularly

dilated mirabilis

First antennal abnormal, large, irregularly dilated 2

2. Pronotum abruptly narrowed apically so that the apical angles are

accentuated, and the sides only slightly rounded in contour to nearly

straight 3

Pronotum gradually narrowed apically so that the apical angles are
obsolete and the sides arcuate 8

3. Clypeus with apical margin square and truncate 4

236 NEOTROPICAL PSELAPHIDAE

Clypeus with apical margin rounded 7

4. Antennae short and thick, segments not twice as long as wide, VIII

and IX quadrate, X slightly transverse; 2.05 mm spathulatus

Antennae elongate and slender, segments III to VII at least three times
as long as wide, VIII twice as long as wide, IX and X ovoidal 5

5. First antennal segment strongly dilated, subcircular in dorsal outline

and deeply concave in mesio-apical half 6

First antennal segment with mesio-apical angle obliquely prolonged,
with the prolonged point recurved bidenticulatus

6. Second antennal segment strongly globose; 1.4-1.7 mm caudatus

Second antennal segment elongate-cylindrical; 2.3 mm divergens

7. Antennal segments III-VII elongate but less than twice as long as

wide, VIII quadrate, IX briefly oval ; 2 mm clypeatus

Antennal segments III quadrate; IV slightly smaller and transverse,
V-VIII quadrate; 1.2-1.3 mm naso

8. Clypeus bifid at apex ; 2.2 mm bifurcatus

Clypeus subtruncate at apex, not bifid; 2.15 mm nasutus

To this relatively large fifth group must be added sublyratus Reitter,
described on both male and female. This species is easily recognized by the
cephalic architecture. Sublyratus has a more triangular outline of the head
than any other species. The head is as long, from clypeal apex to occiput, as
wide if the eyes are not included ; or two-fifths wider than long if the eyes are
included. The clypeo- frontal area is in the form of a rounded-triangular plate
which is longer from apex to interantennal line than the rest of the head from
interantennal line to occiput. In addition the first antennal segment is as ab-
normal as the same segment of many males in the genus, being cordate in dorsal
outline, as wide apically as half the clypeal width, with the subcylindrical sec-
ond segment articulated in a slight median notch of its apical margin. I am
unable to place the species in the key as I am ignorant of the shape of the thorax.

Group VI

There is only one species at present in this group, demoniacus Raffray,
based on a single male specimen, 1.5 mm. long, with unique cephalic architec-
ture. The sides of the head are evenly, strongly arcuate, with the eyes placed
at the lowest part of the arc and not projecting much beyond a line drawn
through the antennal tubercle and tempora on each side; this outline is ap-
proached in other species but the tempora are everted and sharply, obliquely
truncate behind each eye so that the apical corner of each tempora is in the
form of a cusp; between the eyes the vertex is broadly excavated, limited
laterally by a double carina.

The species of Syrbatus may be listed as follows:

I
antennator (Reitter). 1888. Blumenau, Brazil. (Arthmius)

BATRISINI 237

II

brevispina (Reitter). 1882, Sao Paulo, Brazil, {brevispinus) (Geno-
type?)

bruchi (Raffray). 1908. Argentina. [Arthmius]

bubalus (Raffray). 1897. Bahia, Brazil. (Arthmius)

centralis (Raffray). 1897. Blumenau, Brazil. (Arthmius)

grouvellei (Raffray). 1897. Bahia, Brazil. (Arthmius)

hetschkoi (Reitter). 1888. Blumenau, Brazil.

hiatusus (Reitter). 1888. Blumenau, Brazil.

transversalis (Raffray). 1897. Sao Antonio, Brazil. (Arthmius) (7i«c
Group III of Raffray, 1904)

III

auritulus (Westwood). 1870. Brazil. (Bryaxis)

curvispina (Reitter). 1888. Blumenau, Brazil.

phantasma (Reitter). 1882. Sao Paulo, Brazil, (soror Reitter)

quadrioculatus (Reitter) . 1888. Blumenau, Brazil, (atricapillus Reitter)

scitus (Reitter). 1888. Blumenau, Brazil, (solivagu^ Reitter)

sublaminatus (Reitter). 1888. Sao Paulo, Brazil.

IV

calcarifer (Reitter). 1882. Blumenau, Sao Paulo, Brazil.

marthae (Reitter). 1882. Blumenau, Colonia Alpina, Brazil, (martha)

simplicifrons (Reitter). 1882. Blumenau, Colonia Alpina, Brazil.

bidenticulatus Raffray. 1917. Asuncion, Paraguay.
bifurcatus (Raffray). 1908. Argentina. (Arthmius)
caudatus Raffray. 1917. Asuncion, Paraguay.
clypeatus (Reitter). 1882. Brazil.
divergens (Reitter). 1888. Blumenau, Brazil.
mirabilis (Reitter). 1885. Blumenau, Brazil.
naso Raffray. 1917. Asuncion, Paraguay.
nasutus (Reitter). 1888. Blumenau, Brazil.
spathulatus (Raffray). 1897. Brazil. (Arthmius)
sublyratus (Reitter). 1882. Sao Paulo, Brazil.

VI

demoniacus (Raffray). 1897. Bahia, Brazil. (Arthmius)

Unplaced
trinodulus (Schaufuss). 1887. Minas Geraes, Brazil, (vide Raffray, 1904)

238 NEOTROPICAL PSELAPHIDAE

SYRMOCERUS (Rafifray, 1897)

Raffray (1897) (Arthmius) (1904, 1908, 1911)

This is a Brazilian genus of five species having many structural affinities
with Arthmius. It was originally erected as a subgenus of the latter but has
been recognized as distinct since 1904. The genus is quite disparate from its
nearest ally, Syrbatus, by the key character. The three genera, Arthmius,
Syrbatus and Syrmocerus form one evolutional line within the neotropical
batrisines, in which Arthmius with many species and a wide range has entire
pronotal margins and no longitudinal sulci, Syrbatus with about one third as
many species and the lateral pronotal depressions expanded apically into longi-
tudinally developed sulci, and Syrmocerus with sharply incised lateral pronotal
margins, the incisure caused by the development of a shorter, more arcuate,
heavily pubescent sulcoid fovea. The last two genera are entirely South Amer-
ican, and Syrbatus with a range which includes Brazil, Paraguay, and Argen-
tina, seems less highly specialized than Syrmocerus with five species limited
as far as known to the Brazilian rain forest.

The following key, based on the male sex, will separate the known species:

Key to the Males of Syemocerus

Antennal segment I normally developed, subobconical to subcylindri-
cal, with the apical angles mutually developed and regularly acute 2

Antennal segment I very abnormally developed, with the mesio-apical
or internal angle formed as a long spine or greatly expanded 4

2. Dorsal surface of head with an entire, broad, obtuse, median longi-

tudinal carina and the surface entirely and roughly granulated; 2.8

mm rugiceps

Dorsal surface of head with a short median longitudinal carina which
crosses occiput and extends apically for a short distance on the pos-
terior part of the vertex; dorsal surface of head not roughly granu-
lated but the area of the antennal tubercles is coarsely punctate ... 3

3. Antennal segment III quadrate; V longer than IV, VI, or VII; an-

tennal tubercles flattened ; head tuberculated posterior and ventral
to the eyes; vertex with a median, transverse, arcuate tubercle;

2.8 mm dama

Antennal segment III elongate-obconical ; III, V, and VII longer than
IV or VI ; antennal tubercles tumid ; head not tuberculated on lateral
or ventral surface; vertex with a median, subconical, erect tubercle;
1.8 mm guarinus new species

4. Antennal segment I with the mesio-apical angle extended apically into

a conspicuous, flattened, sinuo-arcuate tooth which reaches the apex

of the third antennal segment; 3 mm cervus

Antennal segment I with the mesio-apical angle extended mesio-pos-
teriorly in an abrupt, apically rounded, lamellate plate, the axis of

the plate being at right angles to the segmental axis ; 2.9 mm

gazella

BATRISINI 239

Syrmocerus guarinus new species

Type Male. 1.8 mm. long x 0.7 mm. wide through elytra. Chestnut brown,
semishining with coarse flavous sparse long semibristling pubescence. (PI. XIX)

Head, including eyes, subtriangular with short tempora half as long as
eyes ; eyes large, composed of about 24 coarse facets. Occiput and posterior part
of vertex with a median, longitudinal carina. Vertex and occiput subglabrous t-o
the antennal tubercles, with a pair of deep, circular, nude vertexal foveae be-
tween the eyes. These foveae connected by an arcuate sulcus which widens and
deepens apically to form a large, median depression between the antennal tu-
bercles. Antennal tubercles large, tumid, subtriangular and very coarsely punc-
tate, sparsely pubescent. Between and just anterior to the vertexal foveae is a
median vertexal tubercle; this tubercle is subconical, coarsely punctate dorsally
and with its width, length, and height equal and obliquely truncate at apex.
Front entirely concerned with the excavation noted above, the inter-antennal
line being entirely concave. Clypeus triangular with a sharp apical angle; medi-
anly strongly elevated into a high laminoid longitudinal crest, the crest being
dorsally flat and pubescent and abruptly cut off posteriorly at the frontal ex-
cavation ; a very small tubercle each side of crest. Therefore from a dorsal view
the head appears quadrituberculate, with the vertexo-frontal excavation being
bounded anteriorly by the clypeal crest, laterally by the antennal tubercles and
posteriorly by the vertexal tubercle. Ventral surface of the head transversely
tumid in apical third; very coarsely punctate, without tubercles, and with the
punctures becoming more sparse and strigose medianly.

Maxillary palpi as in Arthmius.

Antennae eleven-segmented, distant, coarsely punctate; segment I simple,
elongate obconical; II elongate, narrower than first; III elongate-obconical;
III, V, and VII longer than IV, VI, and VIII; III to VI subequal in width;
VII obtrapezoidal ; VIII smaller than either VII or IX.

Pronotum characteristic of genus ; widest through apical three-fourths, with
prominent apical and nearly rectangular basal angles. Disc strongly medianly
elevated in the form of an obsolete carinoid crest as in Group I Arthmius.
An entire transverse sulcus at basal fourth, with the discal tumidity abruptly
falling to base basal to sulcus; posterior wall of sulcus beaded, the bead ex-
panded and angulated laterally into a tumid area to lateral margin. Each
lateral margin sharply incised, the incisure continued apico-medianly as a large,
oval, pubescent fovea typical of genus, and the incisure abruptly limited pos-
teriorly by the bead of the transverse sulcus, Pronotal integument subglabrous.

Each elytron with an entire sutural stria, no dorsal stria or impression, the
humeral angle obliquely well-defined, and with three deep, nude, circular foveae.
Integument sparsely punctulate.

Five tergites, the first large, the last subtriangular with rounded, non-
tuberculate apical profile; margins as in Arthmius.

Six clearly visible stemites (morphologically II to VII), of which the first
four are progressively shorter; fourth medianly, transverely creased or narrowly

240 NEOTROPICAL PSELAPHIDAE

sulcata and with the apical margin medianly minutely tuberculate; fifth large,
sparsely but distinctly punctate, transversely semilunar in shape, two-thirds as
long as first four united, basal third tumid, apical two-thirds semilunarly im-
pressed, apex with the margin raised and medianly sharply, triangularly incised;
sixth (last) sternite minute, tumid, coarsely punctate, transversely subfusiform
in shape, lying between the concave median apex of the last tergite and the
incised margin of the fifth sternite.

Metasternum subglabrous, with a deep median, longitudinal sulcus; this
sulcus is sharply defined but with rounded lateral margins, and is not entire,
being abruptly limited at apical third.

Tarsi as in Arthmius. Anterior femora compressed at apical fourth on ven-
tral face to give a subcarinoid appearance at this point; other femora simple.
Anterior tibiae with a highly specialized spur, this spur being nearly half tibial
length, inserted just beneath base of first tarsomere, flat, angulate medianly,
and with a spatulate tip; intermediate tibiae with a strong, acute, simple spur
of regular length ; posterior tibiae simple. Intermediate trochanters with the pos-
terior face flattened and bearing a pad of short, dense setae; other trochanters
simple.

Described on one male, the type, from Corumba, Matto Grosso, Brazil.
Most closely related to dama, from which it is distinct on antennal propor-
tions, vertexal tubercle, genal structure and sternite structure.

In the original diagnosis of Syrmocerus (Raffray, 1897, p. 459) it is clearly
stated that a transverse pronotal sulcus is present. Raffray (1904, p. 125 and
1908, p. 134) in his keys states that the transverse pronotal sulcus is present;
in the 1908 discussion of the genus, Raffray states (p. 153) that the transverse
pronotal sulcus is absent. I have followed the original diagnosis in order not to
create a new genus.

The species of this genus follow:

cervus (Raffray). 1897. Minas Geraes, Brazil. (Arthmius)

dama (Raffray). 1897. Brazil. [Arthmius) (Genotype)

gazella (Raffray). 1897. Brazil. [Arthmius)

guarinus new species. Corumba, Matto Grosso, Brazil.

rugiceps (Raffray). 1897. Brazil. [Arthmius)

OXARTHRIUS (Reitter, 1882)

Reitter (1882)

Sharp (1887) [Batrisus)

Raffray (1897) [Batrisus) (1904) [Ozarthrius) (1908, 1911, 1917)

Fletcher (1928)

Bruch (1933)

This is an entirely neotropical genus of twelve species: Guatemala (1),
Panama (1), Panama Canal Zone (2), Brazil (2), Peru and Bolivia (4), Para-
guay (1) and Argentina (1). It is not known north of Guatemala and the spe-
cies appear to be rather thinly distributed over a great area and uniformly un-
common.

BATRISINI 241

Structurally the species have a common habitus. The truncated cordate
pronotum, lacking sulci, and provided with a pair of large conspicuous ante-
basal spines is typical of the genus. In addition some species have a pair of
smaller spines, one on each lateral margin of the pronotum between the middle
and apical third. The body is usually large, always elongate-cylindrical. In com-
mon with the arthmioid genera, the abdominal margin of the first tergite is
strongly formed by both an external and an oblique internal carina, and the
following tergites have the "margin" formed by a very short basal external
carina on each side. The elytra are simple with a single large basal fovea and
sutural stria on each elytron in the majority of the species, while in a new
subgenus there are no basal foveae.

The males have the antennae, metasternum, and intermediate legs abnor-
mally modified in most of the species; where both sexes are known the females
have relatively unmodified antennae, metasternum and intermediate legs.

Oxarthrius was considered a subgenus of Batrisus until 1904. The genus is
more allied to Iteticus than to other neotropical aggregates, from which it is
distinct in lacking any dorsal elytral stria and the possession of antebasal
pronotal spines.

The following arrangement of the genus is necessitated by the accumulation
of novel data:

Key to Subgenera {both sexes)

Each elytron with a single basal fovea; distal segment of maxillary

palpi with simple, unscarred external face

SUBGENUS OXARTHRIUS, s.s.

Elytra without basal foveae; distal segment of maxillary palpi with a

distinctive scar on the external face near middle

SUBGENUS BAROXARTHRIUS, new subgenus

Subgenus Oxarthrius, s.s.

Key to Species {both sexes)
(Modified from Rafifray, 1897)
The following key is complete with the exception of Oxarthrius attaphilus
Bruch.

Pronotum, in addition to the large antebasal spines, with a small spine

or tooth on each lateral margin between middle and apex 2

Pronotum with lateral margins not armed 7

2. Pronotum conspicuously rugose and granular 3

Pronotum nearly glabrous, at least shining and lightly punctulate ... 5

3. Antebasal spines of pronotum long, compressed, sharp-pointed; lateral

spines relatively large; 1.76 mm rugosicollis Male

Antebasal spines of pronotum relatively shorter, less pointed, and di-
rected posteriorly; lateral spines relatively small; 2.8 mm 4

4. Intermediate femur with a small pubescent tubercle near base ; inter-

mediate tibia with an apical spur rugosus Male

242 NEOTROPICAL PSELAPHIDAE

Intermediate legs not armed as described rugosus Female

5. Intermediate and posterior tibiae mucronate or spined at apex; ver-

texal foveae small and obscure; supraocular carina indistinct; lateral

pronotal spines relatively large and triangular; 2.25 mm

hamaticollis Male

Intermediate and posterior tibiae not mucronate or spined at apex, the
apex simply pubescent; vertexal foveae deep, large and distinct;
supraocular carina strong and distinct; lateral pronotal spines small;
1.7 mm 6

6. Antennal segments VIII, IX, and X abnormally produced on the ven-

tral face ; metasternum with a large, erect spine at middle of apical
margin ; intermediate femur with a lamellate spine at basal third and
a sharp conical spine at center of ventral face; intermediate tibia

contorted and with a large tooth at apical three-fourths

sternadens Male, new species

Antennae, metasternum and intermediate legs simple

sternadens Female, new species

7. Pronotum rugose and granular; 2.7 mm anthicoides Female

Pronotum varying from shining and lightly punctulate to slightly

granular 8

8. Antennal segments VIII, IX, and X progressively transverse; 2 mm.

rivularis Female

Antennal segments VIII and IX either much longer than wide or
quadrate 9

9. Lateral pronotal fovea large, elongate, nearly sulciform ; vertex tumid,

with sharply defined fovea and sulci; 2.5-2.7 mm 10

Lateral pronotal fovea small, circular, never sulciform; vertex flat-
tened, with punctiform vertexal foveae and obsolete sulci 11

10. Intermediate femur with a small spine at base; intermediate tibia with

a strong triangular tooth beyond middle on ventro-posterior face. .

bispinosus Male

Intermediate legs not as described bispinosus Female

11. Head much longer than wide 12

Head either quadrate or much wider than long 13

12. Intermediate trochanters with a very long, biarcuate spine

armatus Male 2.4. mm.

Intermediate trochanters not armed armatus Female 2.6.mm.

13. Pubescence fine in quality and very short; vertexal sulci almost in-

visible ; 2 mm simplex Female

Pubescence long and coarse; vertexal sulci relatively developed; 2.8
mm forticornis Female

Oxarthrius sternadens new species

Holotype Male. Measurements: head 0.268 x 0.435 through eyes; cervicum
0.033 mm. ; pronotum 0.4 x 0.4 mm. ; elytra 0.53 x 0.67 mm. ; abdomen from a

BATRISINI 243

dorsal view 0.469 x 0.55 mm. (in reality the abdomen is 0.737 mm. long but this
length is not visible from above; the tergites are I (0.335), II (0.067), III
(0.067), IV (0.201) and V (0.067 mm.) long, or in a ratio of 5/1/1/3/1. Total
length 1.7 mm. Greatest width 0.67 mm.

Rich chestnut brown with palpi, antennae, and legs paler; the integument
polished and shining; sparsely but distinctly punctulate, each puncture raised
and bearing a long seta.

Head transverse with long, rounded tempora so that the head has a semi-
circular occipito-genal contour; eyes prominent, medianly placed, each com-
posed of about 72 very minute facets. Head abruptly narrowed apical of eyes,
the sides slightly convergent, with obliquely truncate antennal tubercles, thus
the head has a transversely oblong vertexo-frontal contour. Front concave be-
tween antennae, declivous, apically subtuberculate. Vertex medianly vaulted
and surmounted by a prominent median, longitudinal carina extending from
occiput to a line drawn through bases of antennal tubercles. Vertex lightly
punctulate posteriorly, coarsely punctate on antennal tubercles, glabrous at an-
terior center. A deep, circular, nude vertexal fovea each side on a line through
middle of eyes and mesiad of antennal tubercle, mutually connected by a U-
shaped sulcus with obsolete inner and strong outer wall, the sulcus communi-
cating broadly with the frontal depression. Therefore the vertex has an in-
verted Y sulcus with the long vertexal carina entering between the fovea!
arms. Each side of head with a prominent oblique carina from tempora, above
eye, to lateral margin of antennal tubercle; from a lateral view there is a
second angulated carina which arises at middle of anterior margin of eye and
extends apically to form the bead of the clypeal margin. Genae furnished with
a beard of bristling setae. Labrum remarkably transverse, short, deeply, and
entirely concave along margin, with each lateral angle produced sharply as a
sharp cusp. Ventral surface of head anteriorly densely set with small, crowded
punctures.

Maxillary palpi four-segmented; first segment minute; second elongate-
conical, apically three times wider than base ; third short, in the shape of an
elongate triangle, longer than wide, apically twice as wide as base, wider than
second; fourth longest and widest, obliquely narrowed at base, lengthily nar-
rowed to apex, subsinuate ventrally.

Antennae eleven-segmented, distant, elongate, subgeniculate because of
the strong four-segmented club; segment I oblong; II subcylindrical, much
narrowed; III-VII elongate-obconical; last four segments as long as second
to seventh inclusive, distinctly wider and the eighth, ninth, and tenth ab-
normal: VIII with the ventral face produced apicolaterally, IX and X with
ventral faces strongly produced to form a triangular crest, this crest foveate
on mesial face of IX and foveate on lateral face of X.

Pronotum typical of genus, truncate-cordate. A pair of strong, conico-
pyramidal, sharp-pointed antebasal spines; disk simple; no sulci; a large tri-
angular foveaform depression lateral to each antebasal spine, a smaller fovea-
form depression far down on pronotal flank and lateral to the lateral fovea,

244 NEOTROPICAL PSELAPHIDAE

not visible from above ; base with a pair of small foveae on each side ; a second
pair of small horns or teeth on lateral margins, one of these small cusps being
near middle of each side.

Elytra typical of genus with very oblique humeri; each elytron with a
single, large, circular, deep, nude basal fovea and an entire sutural stria.

Abdomen elongate with five tergites having proportions as noted above;
first tergite with a straight external and an oblique internal carina each side;
second and third with a very short, straight carina each side at base; last
tergite distinctly, transversely impressed at base. Five clearly visible sternites
(morphological II-VI) without abnormalities, and of normal proportions.

Metastemum with a very prominent spine at middle of apical margin,
this spine nearly as large as antebasal pronotal spines, laterally compressed,
with a sharp, slightly recurved apex.

Intermediate trochanter with apex sharpened into a prostrate, acute tooth;
intermediate femur excavated in basal half of ventral face and with two con-
spicuous spines: a long, narrow, aciculate, erect spine at middle, and a lamel-
late, subtruncate spine at basal third; intermediate tibia contorted, apically
slightly inflated, basally flattened, with a short, strong tooth at apical three-
fourths of length, this tooth appressed and apically directed.

Allotype Female. Similar to holotype male save that (1) antennae are
simple, (2) the tooth at pronotal margin each side is larger than in the male,
(3) metastemum not spined, and (4) intermediate legs not armed or abnormal.

Described on a male and a female, collected by the author on Barro
Colorado Island, Gatun Lake, Panama Canal Zone. Holotype male on July
25, 1936, in stage 4 log mold at Drayton 12; allotype female on July 27, 1936,
beneath bark of a log at Zetek 23.

Oddly enough this new species has little in common with rivularis of
Panama, and is more nearly allied with hamaticollis of Guatemala; from the
latter it differs in numerous structural details noted in the key. Among other
differences between the latter two species is a qualitative difference in the
armature of the intermediate legs of the males: hamaticollis has a single spine
on the femur, while sternadens has the femur strongly bispinose, and the
former has apparently simple tibiae which are apically cusped while the latter
has contorted tibiae with a strong appressed tooth at apical three-fourths.

Subgenus Baroxarthrius new subgenus
This new subgenus is erected for the new species which follows, and is
characterized by (1) the distal segment of the maxillary palpi having a foveoid
scar on the external face; (2) elytra without a trace of basal foveae; (3) the
male sex having the lateral wings of the pronotum and the prosternum sec-
ondarily modified.

Oxarthrius escharus new species

Holotype Male. Measurements: Size and general proportions as in ster-
nadens, being slightly larger; total length 1.8 mm. Uniform reddish-brown with
palpi paler. Pubescence abundant, long, bristling, and rufous.

BATRISINI 245

Head with occiput, vertex and front with the punctures elevated so that
the integument is minutely but distinctly granulate; clypeus subrugose. A
very long, median longitudinal carina extending from the occiput across the
vertex to a line drawn through the bases of the antennal tubercles ; this carina
abruptly limited apically by the interfoveal sulcus. Interfoveal sulcus is entire,
connecting the vertexal foveae, and does not extend down the front as in
sternadens; floor of the sulcus glabrous; external wall of sulcus more sharply
defined than internal wall in the region of the eyes, and less sharply defined than
internal wall anteriorly; sulcus transversely ovoid between antennal tubercles,
very sharply defined basally so that the long vertexal carina has its apical end
bifurcated. Supraocular lateral carina as in sternadens. Ocular-clypeal carina
not angulate as in sternadens but broadly arcuate. Eyes with about 64 facets,
the facets being fewer and larger than in sternadens. Fronto-clypeal area
declivous, the front between antennae in the form of a triangular field with
laterally carinated edges. Ventral surface of head sparsely granulated. Labrum
as in sternadens save that the produced apical comers are more obtuse.

Maxillary palpi with first three segments typical of the genus, the distal
(fourth) segment with a small, oblique, foveoid scar at the middle of the ex-
ternal face. This distinctive feature is equally well-developed in the allotype
female, and in the paratypes of both sexes.

Antennae eleven-segmented, distant, integument granular; segments all
simple, all longer than wide, without foveae, dilations or other abnormalities.

Pronotum truncate-cordate, integument with sparse, elevated punctures
which are smaller than those of the head. Disc simple. Lateral margins not
spined. Two strong conical, sharp, antebasal spines at basal two-fifths, with
an elongate-oval, subsulcoid median fovea between these spines, and a deep,
circular lateral fovea between each spine and the lateral margin. Base of pro-
notum with a pair of small foveae each side, that is, a fovea basal to each spine
and a fovea basal to each lateral fovea.

Ventral surface of prothorax highly abnormal. In the first place, the flank
of the pronotum is a glabrous, triangular plate with carinated edges which
extends ventrally on each side as a free process. This is best appreciated from
a lateral view. From a ventral view each of the pronotal wings is seen to give
rise to an oblong lamella on its mesial face, this lamella extending obliquely
mesio-posteriorly. Between these oblique lamellae the prosternum is erected
into two abnormal processes: (1) an acutely arcuate, subtruncate lamella at
center, and (2) a fusiform spinoid process between the anterior coxae, this
process strongly arcuate anteriorly, with its sides fringed with stiff setae. This
pronotal-prosternal modification equally well developed in the male paratype.

Elytra with sparse elongated punctures and prominent oblique humeri;
each elytron with a sutural stria, the interstrial space elevated and the punc-
tures subtuberculate. No dorsal stria and no trace of basal foveae.

Abdomen with five tergites with proportions as in sternadens; lateral mar-
gins weaker than in sternadens, and last tergite not transversely impressed at
but simple convex with a strongly concave apical margin. Five fully

246 NEOTROPICAL PSELAPHIDAE

visible stemites (morphological II-VI), with the last entirely, circularly im-
pressed for median third of segmental width.

Metastemum simply, slightly, longitudinally impressed in apical half.

Coxae, trochanters, femora, tibiae and tarsi normal, save for the inter-
mediate femora. Each of the latter with a spine at base of the ventral face.
This mesofemoral spine is long (one-fourth as long as femur), apically in-
clined instead of erect, and very conspicuous.

Allotype Female. Similar to holotype, save that (1) pronotum laterally
is normal, lightly punctulate, and closely invests the anterior coxae and proster-
num; (2) prosternum simple; (3) last tergite and last stemite simply tumid
and punctate; (4) legs not armed.

Described on five specimens collected on Barro Colorado Island, Gatun
Lake, Panama Canal Zone. Holotype male (July 25, 1936) collected by the
author from decayed log mold at Drayton 15; one male paratype and two
female paratypes (May 2, 1935) collected by Alfred Emerson from the galleries
of a termite nest, probably Coptotermes niger Snyder, in a fallen tree ; allotype
female (August 15, 1935) collected by Alfred Em,erson from decaying log mold.

The species of Oxarthrius may be listed as follows:

Subgenus Oxarthrius, s.s.

anthiooides (Schaufuss). 1887. Brazil. (Batrisus)

armatus (Raffray). 1897. Yuracaris, Bolivia. (Batrisus)

attaphilus Bruch. 1933. Loreto, Misiones, Argentina, con Atta

sexdens L.
bispinosus Reitter. 1882. Blumenau, Santa Rita, Brazil. (Genotype)
forticornis (Raffray). 1897. Yuracaris, Bolivia. (Batrisus)
hamaticollis (Sharp). 1887. Las Mercedes, Guatemala (3000 feet).
(Batrisus) nee hamatus of Raffray key, p. 437, 1897.
rivularis (Schaufuss). 1872. Panama. (Batrisus)
rugosicollis Raffray. 1917. Asuncion, Paraguay.
rugosus (Raffray). 1897. Yuracaris, Bolivia. (Batrisus)
simplex (Raffray). 1897. Yuracaris, Bolivia. (Batrisus); and from

Perene Colony, El Campamiento,
Peru at 2000 feet (Fletcher, 1928).
sternadens new species. Panama Canal Zone.

Subgenus Baroxarthrius new subgenus
escharus new species. Panama Canal Zone.

ITETICUS (Raffray, 1904)

Raffray (1897) (Batrisus)
Raffray (1904, 1908, 1909, 1911)

This is a purely South American genus of eight species found so far only
in Brazil and Bolivia. It was erected in 1904 (p. 140) for seven species described

BATRISINI 247

under the old generic name of Batrisus, a genus unknown in the western
hemisphere and, as at present restricted, limited to four species. This is of
interest since the great genus Batrisodes, although abundant in the United
States, is unknown from Mexico southwards and Raffray, in erecting Iteticus,
states that the latter replaces Batrisodes in the neotropics. If this is true, and
the morphological differences between these two genera are not great, then
there is a gap between Batrisodes and Iteticus of over 4000 miles. Iteticus is
quite isolated in the neotropical batrisines by the key characters, especially
the well developed dorsal stria on each elytron. This latter structural feature
separates the genus at once from the three arthmioid genera and the peculiar
Oxarthrius. Iteticus is quickly distinguished from Batrisodes by having the last
segment of the maxillary palpi regularly ovoidal, only slightly elongated and
slightly subacute at apex, and not much wider near middle than at base, and
in having lateral margins as described in the generic key; whereas Batrisodes
and the specialized Batoctenu^ have the lateral margins of the first several ter-
gites clearly formed by both an internal and an external carina, and the last
segment of the maxillary palpi is wider at base and with a much more acute
apex.

The following key to species has been based on the 1897 key of Raffray
with recent work integrated to bring our knowledge up to date :

Key to the Males of Iteticus

Head and pronotum cribrate, the punctures coarse and very crowded ;

3 mm semipunctatus

Head and pronotum not cribrate 2

2. Vertex with a median longitudinal carina, this carina may be strong

or weak but is never broken up 3

Vertex with no median longitudinal carina, but in some species there
are several, more or less irregularly separated points or cusps which
may appear as an interrupted carina 4

3. Intermediate trochanters armed near the middle with a short, blunted

spinoid tubercle; posterior trochanters armed at middle with a
tubercle shaped like a toad-stool fungus, being basally columnar

and apically flattened and expanded princeps

Intermediate trochanters armed at middle with a long, strong, erect,
pointed spine; posterior trochanters armed near base by a thick,
short, blunt horn longispina

4. Anterior tibiae simple 5

Anterior tibiae inflated at middle of internal face, and notched apically,

this incisure being pubescent and terminating in a minute spur just
before the apex ; 2.7 mm laeviceps

5. Intermediate trochanters simple; posterior trochanters apically ex-

tended, with a very long, obtuse tooth; 3.6 mm imperialis

Intermediate trochanters armed with a tooth, spine or tubercle 6

248 NEOTROPICAL PSELAPHIDAE

6. Intermediate trochanters bearing at middle a tubercle which in turn

bears a trichome of long setae ; posterior trochanters bearing at mid-
dle a short tubercle which bears in turn a trichome of long setae,
and apically these trochanters are recurved with the apex in the form

of a small hook with a very sharp point; 3.2 mm hiarmatus

Intermediate trochanters bearing at middle a small tooth 7

7. Posterior trochanters with the apex extended in a long, strong, com-

pressed spine which is recurved and truncate germari

Posterior trochanters bearing at apical third a hook-shaped spine, this
spine is broad, flattened, slightly spiral with a truncate apex and
bearing near base a trichome regius

Species of Itetiaus may be listed as follows:

hiarmatus (Raffray). 1897. Bahia, Brazil. {Batrisus)
germari (Aube). 1844. New Friburg, Brazil. (Batrisus)
imperialis (Raffray). 1897. Yuracaris, Bolivia. (Batrisus)
laeviceps (Raffray). 1897. Yuracaris, Bolivia. (Batrisus)
longispina (Raffray). 1897. Minas Geraes, Brazil. (Batrisus)
princeps (Reitter). 1882. Petropolis, New Friburg, Constancia, and
Theresopolis, Brazil. (Syrbatus) (Genotype)
regius (Raffray). 1896. Caraca, Minas Geraes, Brazil. (Batrisus)
semipunctatus Raffray. 1908 and 1909. Serra de Baturite, Ceara,
Brazil. (First species described as Iteticus)

At this place in the tribe Batrisini a few words may be said regarding
three very puzzling species:

Schaufuss described Batrisus asteriscus from Bogota, Colombia in 1887.
Raffray (1897) examined and reported on the type of this insect, placing it
with doubt in the neotropical species of Batrisus. In this paper he felt that
asteriscus was quite apart from other neotropical members of the genus
since it had three cephalic sulci and five pronotal sulci, placing it near
Batrisus quinquesulcatus Raffray of Singapore. In 1904 Raffray erected Iteticus
for all of the neotropical Batrisus listed in his 1897 paper, save asteriscus.
The type of asteriscus was imperfect, but Raffray concluded that it could not
be Iteticus as this genus, among other things, lacks any trace of a median
longitudinal sulcus. In the structure of the abdominal margins asteriscus is
Batrisodes, unknown in the neotropics. If asteriscus turns out to be in the
latter genus, it becomes very important as a link with Iteticus, for reasons
given above, but since the species has not been recorded since 1887, little more
can be said now save to point out its affinities with Group 40 of Batrisodes
holding quinquesulcatus Raffray of Singapore and Sumatra, and spinicollis
Motschulsky of Ceylon ! This highly doubtful assignment is doubly questioned
by Raffray (1908) and I feel that there is insufficient data to cita Batrisodes
as present in the neotropical region on the assumption that asteriscus might
belong to the genus.

BATRISINI 249

David Sharp described two similarly unplaced species in 1887, Batrisus
crassipes and Batrisus lamellipes from Bugaba, Panama. Without recourse to
the types I am unable to place either in a genus: (1) their body shapes take
them from Phalepsoides and Euphalepsus, and Sharp was familiar with the
latter genus; (2) they are not Batoctenus on the integumental punctation, and
Sharp erected this genus in 1887 so that this preclusion is assured; (3) they
are not Iteticus as both of Sharp's species lack spines, longitudinal and trans-
verse pronotal sulci; (4) they are not Arthmius, Syrbatus or Syrmocerus as
they lack a transverse pronotal sulcus and do have a short dorsal striaform
depression. Therefore they are not members of any neotropical genus known.
Raffray left them unplaced in his revision (1897), left them without definite
generic assignment (1904) and in 1908 left them as unplaced but near Iteticus.

BATOCTENUS (Sharp, 1887)

Sharp (1887)
Raffray (1904, 1908)

This is a neotropical genus of five species, two from Panama and three
from South America (Bolivia 1 and Brazil 2).

Morphologically it is very isolated from the other neotropical genera, and
the species of the genus have an unusually striking similarity in habitus. The
body is very elongate-cylindrical, with an elongate head which is always
coarsely, rugosely punctate, with a relatively simple vertex, indistinct vertexal
foveae, very large eyes and flat antennal tubercles. The pronotum is similarly
rugosely punctate with the exception of the genotype, and lacks longitudinal
and transverse sulci. Elytra elongate, with prominent, usually subcarinoid
humeri; each elytron with four basal foveae and a well-formed sutural and
dorsal stria. Abdomen with five tergites, of which the first is laterally margined
by an external and an internal carina and the next two tergites have the mar-
gins less distinctly formed by two carinae which tend to form between them a
minute longitudinal fold of the integument near tergite base. Seven sternites in
the male and six sternites in the female sex, the first five subequally long,
sixth relatively very large; seventh sternite of the male small, indistinctly
lodged between the last tergite and sixth sternite. The males have the distal
(eleventh) antennal segment, metasternum, legs and prosternum variously
ornamented, modified or armed.

Maxillary palpi four-segmented, relatively short in comparison to Oxar-
thrius, Iteticus and the arthmioid genera, but not minute as in Euphalepsus;
first segment minute; second elongate-arcuate, distally wider; third short, sub-
triangular, nearly as wide as long; fourth longer than the preceding two seg-
ments but relatively short when contrasted with Oxarthrius, ovate to sub-
conical, with a very acute apex and a minute palpal cone.

The cribrate, elongate vertex; large eyes; depressed antennal tubercles;
relatively short distal palpomere and better devloped abdominal margins
readily isolate the genus.

250 NEOTROPICAL PSELAPHIDAE

Key to the Species

Pronotum nearly impunctate ; 2.12 mm 2

Pronotum rugosely and cribrately punctate 3

2. Antennal segment VIII oblong, much larger than VII ; X shorter than

IX; intermediate tibiae with an apical spur simplex Male

Antennal segment VIII only slightly larger than VII ; X larger than
IX; intermediate tibiae simple simplex Female

3. Known only from northern Panama ; 2 mm 4

Known only from South America south of the Equator 5

4. Anterior tibiae slightly dilated on internal face for median third of

length, tapering towards both base and apex; intermediate tibiae

with an apical spur puncticollis Male

Anterior and intermediate tibiae simple puncticollis Female

5. Antennal segments II-VIII longer than wide

barberi new species, Male

Antennal segments III and IV wider than long 6

6. Antennal segment V quadrate, VI quadrate; 2.2 mm. known only

from Brazil incertus Female

Antennal segment V slightly transverse, VI quadrate; 2.5 mm. known
only from Bolivia 7

7. Antennal segment XI with internal (mesial) face incised or notched

at base and toothed at middle dimidiatus Male

Antennal segment XI simple, ovate with a truncate base

dimidiatus Female

Batoctenus barberi new species

Type Male. Measurements: Head 0.40 x 0.40 mm. including eyes, or 0.167
mm. wide not including eyes; cervicum 0.134 mm.; pronotum 0.43 x 0.40 mm.;
elytra 0.67 x 0.72 mm.; abdomen 0.60 x 0.53 mm.; tergites in the following
proportional length: I (4), II (2), III (iVs), IV (2), V (1); total length
2.2 mm.; greatest width is through elytra, 0.72 mm. (PI. XVIII).

Body very elongate-cylindrical, reddish-brown; head both above and
below completely, rugosely, cribrately punctate, the punctures becoming
elongate-oval to substrigose between eyes; pronotum both above and laterally,
and prosternum completely, rugosely and cribrately punctate save for apical
eighth of pronotal disc; elytra subglabrous and shining; abdomen subim-
punctate and shining. Pubescence short, sparse and subappressed on head and
pronotum; shorter and sparser on elytra; relatively abundant, longer and ap-
pressed on abdomen.

Head much longer than wide if the eyes are not included, with an arcuate,
abruptly vertical and glabrous occipital wall; tempora short, oblique and
sharp-angled; vertex long, longitudinally convex, simple, extending as a sub-
quadrate area apical to eyes. Eyes very large (0.18 mm. long x 0.12 mm. wide

BATRISINI 251

from a dorsal view) composed of 32 enormous facets, each 0.02 mm. in
diameter, which are high and conical. The head outline reminds one of a
large-eyed Fustiger. The long cervicum is in shai-p contrast to the cribrate
head and pronotum as it is subglabrous, evenly arcuate and has a strong
median, longitudinal carina. Occiput abruptly higher than cervicum and
medianly slightly notched. Vertex with a pair of foveae on a line through
posterior third of eyes, these vertexal foveae absolutely free, circular, nude,
and as wide as an ocular facet but difficult to discern because of the cribrated
integument. Anterior sixth of vertex medianly, longitudinally sulcate, the sul-
coid area apically incising the inter-antennal line broadly. Front and clypeus
narrow, directed obliquely ventrad so that the labrum is beneath the antennal
tubercles. These latter flattened, rounded in outline and being merely the areas
of antennal articulation. Ventral surface of head tumid medianly and strongly
depressed and narrowed each side of base.

Maxillary palpi four-segmented; first segment small, of same diameter
as base of second, obconical; second elongated arcuate-conical as usual with
inflated apical end; third subtriangular, wider than second, less than half as
long as second, with a short subtruncate internal face and a long convex ex-
ternal face, nearly as wide as long; fourth longer than preceding two pal-
pomeres but relatively shorter than in Oxarthrius, one-third wider than third,
obliquely truncate base and an acute apex bearing apically an excessively
minute, truncated palpal cone.

Antennae eleven-segmented, distant; segment I arcuate-cylindrical from
a dorsal view, as wide as tenth; II-VIII subequal in width, all longer than,
wide, obconical to cylindrical (this character separates barberi from all other
known species of the genus of both sexes) ; IX slightly wider than eighth,
subcylindrical in dorsal outline; X distinctly shorter than ninth, subtrapezoidal ;
XI large, as long as preceding three segments united and much wider. Club
formed chiefly of this distal segment. Ventrally the eighth and ninths segments
are abnormal, having their ventral faces produced strongly; the ventral face
of the eleventh segment is very abnormal : longitudinally biconcave or bifossate
with the two excavations separated medianly by an oblique, transverse ele-
vation, the basal excavation shallow, devoid of coarse antennal setae, the
apical excavation asymmetrically deepened into a pyramidal fovea.

Pronotum cribrate as described, with no other markings save an elongate-
triangular lateral fovea each side just behind the middle, the apex of the tri-
angle sulcoid; pronotum longer than wide, sides parallel in basal half and
slightly convergent in apical half.

Elytra complex; each elytron elongate, with (1) a subhumeral fovea at
apical end of a long, strong, subepipleural carina on elytral flank; (2) humerus
tumid, with apex transversely carinated above the subhumeral fovea, this
carina turning abruptly apically as a long entire carina on the edge of elytral
disc (this gives to the humeral angle the carinated callus aspect of Group I
Euphalepsus) ; (3) base with four deep circular nude foveae, the integument
arched over the orifices of the foveae; (4) a long entire discal carina arising

252 NEOTROPICAL PSELAPHIDAE

between the orifices of the second and third basal foveae; (5) sutural stria entire,
arising from the most mesial basal fovea. The elytron, therefore, has three
entire carinae in addition to the sutural stria.

Abdomen with five tergites with proportions as given above; first nar-
rowed at base, with a strong lateral margin formed of an external and an
internal carinae which converge apically but do not join; second and third
tergites with the two carinae very short; fourth tergite with a short, con-
spicuous horn arising each side near base and partially covered by the lateral
margin of the corresponding sternite. First tergite deeply, transversely de-
pressed at base, this depression primarily divided into three subequal cham-
bers by a pair of long, parallel basal carinae which extend to apical third;
second and third tergites also with a pair of long basal carinae.

Abdomen with seven stemites, with complex modifications: first sternite
clearly visible laterad of coxal-trochantal articulation, and between coxae as a
short, longitudinally carinated and glabrous area. Second not longer than first,
but visible from side to side. Third as long as second, medianly glabrous and
bearing medianly a very large, erect, subcylindrical spine; this spine is
obliquely truncate and holds a small tube, the orifice being seen on the
posterior portion of the truncate apex. Fourth sternite as long as third, medianly
glabrous and bearing a tubercle in apical third. Fifth sternite medianly as long
as fourth, but with the apical margin semicircular; medianly glabrous. Sixth
sternite semicircular, fitting into the apical outline of the fifth, wholly
glabrous, medianly tumid and as long as the preceding three stemites united,
and with two projections: first a strong tubercle at center of tumid disc, this
tubercle bearing apically two strongly divergent tufts of setae so that the
tubercle appears bifurcated; second, a strongly recurved or rolled, lamelloid,
truncate plate from center of apical margin. Seventh sternite is a small,
medianly tuberculated plate between the last tergite and the sixth sternite.

Tarsi normal for the tribe.

Anterior trochanters with a short spine at base of ventral face.

Anterior tibiae highly modified: middle third of length dorso-ventrally
flattened and widened; apical fourth of length laterally flattened; entire tibiae
dorsally concave so that the wide middle portion is at a lower level than both
ends; anterior edge with two strongly formed and broadly triangular teeth,
one tooth at middle and one tooth near apical fourth just basal to laterally
flattened apical area, both teeth in the plane of the dorso-ventral flattened
portion; a small conical tooth projecting ventrally from ventral face, just
apical of first triangular tooth.

Intermediate femora inflated, with the ventral face flattened and arcuate.

Intermediate tibiae inflated medianly, with the ventral face flattened and
sinuate.

Metastemum medianly glabrous and tumid, with a subentire median
longitudinal sulcus which deepens apically to terminate in a subapical fovea.

Described on two males (type and paratype) from Corumba, Matto
Grosso, Brazil. Named for my friend, H. S. Barber.

BATRISINI 253

This is a bizarre representative of a fauna notable for its morphological
diversity. It is very distinct from other members of the genus in many details.
Of the five species, three {dimidiatus, puncticollis and simplex) have both sexes
known, and the proportions of the third to sixth ant^nnal segments are similar
for both sexes of a species. The fourth species {incertus) is known only from
the female sex, and barberi only from the male sex but barberi is the only one
of the five having segments II to VIII longer than wide and I assume that
the female, when discovered, will have elongate antennal segments. The
genotype, simplex, unfortunately does not represent the genus morphologically,
it being the only species without a cribrate pronotum.

The species may be listed as follows:

simplex Sharp. 1887. Volcan de Chiriqui (2000-4000 feet), Panama.

Genotype.
puyicticollis Sharp. 1887. As for genotype.
dimidiatus Raffray. 1904. Yuracaris, Bolivia.
incertus Raffray. 1904. Amazonas, Brazil.
barberi new species. Corumba, Matto Grosso, Brazil.

EUPHALEPSUS (Reitter, 1883)

Reitter (1883, 1885, 1888)

Sharp (1887)

Raffray (1887, 1890, 1904, 1908, 1909, 1911, 1917)

Fletcher (1927)

Park (1933)

This is an exclusively neotropical genus with the exception of a single
doubtful record, namely Euphalepsus dentipes Raffray (1904, p. 184) ques-
tionably cited from Louisiana. With this exception there are 24 species: Mexico
(2), Guatemala (1), Costa Rica (1), Panama Canal Zone (1), Panama (1),
Colombia (1), Venezuela (2), Brazil (13) and Paraguay (2). As in so many
neotropical aggregates Brazil appears to be the center of speciation.

This is a genus of large, highly specialized species. The species are easily
recognized, their size, globular form, uncarinated metasternum and especially
the callus at each elytral humerus differentiate them from other pselaphids.
As yet nothing is known concerning their ecology.

Raffray (1904) has divided the genus into groups and this plan is fol-
lowed here:

Key to Neotropical Groups

Humeral callus very pronounced, abruptly formed and extending on
the elytra beyond the humeral margin (PI. XVIII) 2

Humeral callus much less pronounced, apically narrowed, less abinjptly

formed and restricted to the humeral margin Group V

2. Humeral callus apically extended on the elytra as an acute triangular
wedge or a carina Group I (PI. XV) .

254 NEOTROPICAL PSELAPHIDAE

Humeral callus simple, abruptly and bluntly terminated (PI. XVIII) 3

3. Pronotum gibbous (by gibbous in this genus is meant a pronounced

swelling of the pronotal disc, so that at least 50 per cent of the dorso-
ventral height of the pronotum proper is dorsal to a line drawn
through the basal and apical pronotal margins at their median
points; some species {globipennis) have the pronotum gibbosity
very pronounced, approaching the carinoid disc of Group I of
Arthmius and some Syrmocerus; other species {liljebladi and pana-

mensis) have a simple gibbous condition as described) 4

Pronotum not gibbous, the disc simply and evenly convex. . .Group IV

4. Pronotum as long as wide or very slightly longer than wide . . Group II
Pronotum much longer than wide Group III

In the following keys to species the male sex only is used. The majority
of species of Euphalepsus is known from this sex, few females having been
recorded. The secondary sex characteristics of females are correspondingly
poorly known. The female of centralis Sharp is described as having a conical
projection on the dorsal surface of the last tergite. The male secondary sex
characteristics are much better known, and in this sex the intermediate and
the posterior femora and tibiae are generally modified. A common pattern is a
spine or tooth on the ventral face of the intermediate femur and a spine or
tooth on the ventral face of the intermediate tibia, these spines varying specif-
ically in size, shape and exact position between closely related species.

Partial Key to Group I

Antennae with segments I to VIII inclusive forming one-half the total
antennal length, with IX, X, and XI forming a very elongate club,
these last three segments being very cylindrical ; head and pronotum
densely punctate, the punctures being subconfiuent; 2.24-2.44 mm.
pilicornis

Antennae not as above 2

2. Base of pronotum with three longitudinal carinae which extend from

the basal margin to the transverse sulcus, one median and a sub-
median carina each side between the median carina and the lateral

margin 3

Base of pronotum not as described 4

3. Antennal segments IX and X slightly transverse; 2.4 mm., .gounellei
Antennal segments IX and X elongate-oval, distinctly longer than

wide ; 2 mm tricarinatus

4. Here belong three Brazilian species, .bilineatus, bistriatus, longicornis

Key to Group II, After Park (1933)

Vertex strongly canaliculated ; a deep interantennal sulcus, commun-
icating laterally with a pair of anterior sulci which curve between
median frontal process and the antennal tubercle each side, and

BATRISINI 255

communicating laterally with a pair of posterior sulci which curve
between occiput and antennal tubercles, each posterior sulcus termi-
nating basally in a deep glabrous fovea; 2.88 mm liljebladi

Vertex not canaliculated as described 2

2. Antennal segments IX and X oblong, longer than wide; no small

pore-like foveae on sides of head behind eyes 3

Antennal segments IX and X transverse ; each side of head with two
approximate, minute, pore-like foveae behind each eye; 1.6 mm.
panamensis

3. Base of each elytron trifoveate; 2 mm globipennis

Base of each elytron quadrifoveate 4

4. Antennal segments II to VIII subquadrate to quadrate; 2 mm

humeralis

Antennal segments elongate; 2.25 mm rugipes

Group III

Only one species known in this group, fasciculatus Raffray 1.6 mm.
long from Bahia, Brazil, described on a male specimen with each elytron
trifoveate, simply convex pronotal disc and the pronotum distinctly longer
than wide.

Group IV

This is the largest, least understood group of the genus, containing ten
species. It is possible that centralis Sharp and reitteri Sharp belong in
Group II. Raffray (1904, p. 63) stated that he was unfamiliar with centralis
and (p. 104) placed Sharp's species in Group IV with simply convex pronotal
disc. I have followed Raffray in this designation although Sharp's figure of
reitteri might be construed as gibbous, in which case both Sharp's species
would have to be placed in Group II. A second suggestion for this transfer
is the parallel development of vertexal sulci between reitteri and liljebladi;
although the two species differ in numerous details one cannot help feeling
that Sharp's species are out of place with such forms as cavifrons, dentipes
and tibialis. Until Sharp's types can be examined I have left the original Raffray
list unchanged save for integration of new work.

The following partial key to the species of this group follows:
Anterior part of vertex and front abruptly depressed, this depression
holding three large foveaform impressions arranged so that each

impression forms one angle of a triangle; 1.5 mm cavifrons

Anterior part of vertex and front not as described 2

2. Base of each elytron with three foveae 3

Base of each elytron with four foveae 4

3. Intermediate femur not spined; 1.4 mm tibialis

Intermediate femur with a curved spine near base on ventral face;

1.5 mm ovipennis

256 NEOTROPICAL PSELAPHIDAE

4. Intermediate femur with ventral face lacking spines, serrations or

angulate extensions 5

Intermediate femur not as described 6

5. Intermediate femur with a minute pubescent patch near base of ventral

face; intermediate tibia with a very small tooth near middle of

ventral face ; 2 mm centralis

Intermediate femur lacking pubescent patch ; intermediate tibia with
a very small tooth near apex ; 2.5 mm reitteri

6. Intermediate femur very strongly arcuate, with the ventral face exca-

vated, very thick near trochanter where ventral face is extended

in a pronounced acute, aciculate angle; 1.8 mm cruralis

Intermediate femur not as described 7

7. Intermediate femur with a serrate line of small teeth or spines on

base of ventral face ; 2 mm fuscocapillus

Intermediate femur with very long spine before the middle of ventral
face ; 1 .2 mm hetschkoi

Of the eight species assigned to this group in the neotropics, the female of
but one (centralis) has been described. Second, of these eight species only one
is known north of Panama [centralis from Guatemala). The following species,
based on four females, is very distinct from the female centralis and has been
found with ants. This is the first myrmecocolous record of the genus, although
it was previously suggested (Park, 1933) that at least some species of the genus
might be myrmecophilous. The description of this new species follows:

Euphalepsus myrmecocolus new species

Type Female. Measurements: Head 0.30 x 0.40 mm.; pronotum 0.43 x 0.43
mm.; elytra 0.80 x 0.87 mm.; abdomen 0.47 x 0.80 mm.; total length 2.0 mm.;
greatest width 0.87 mm. (PL XVIII).

Body, femora, and first eight antennomeres dark red; tarsi, both ends of
tibiae and palpi tan; antennal club coal black. The pubescence dark brown,
abundant, recurved to subappressed. Integument moderately shining and lightly
punctate.

Head with rounded tempora not quite as long as eyes but distinctly longer
than wide; eyes very large and prominent, composed of about 80 small facets,
ovate in lateral view, placed obliquely on sides nearer to ventral than dorsal
surface. Head in dorsal outline regularly trapezoidal, converging simply to
antennal tubercle at each antero-lateral angle ; vertex simple, rather flattened,
with a pair of large, deep, nude vertexal foveae. Front and clypeus simply
declivous between antennal tubercles. Labrum simple. Ventral surface of head
with a conical tubercle each side, between eye and cardo of maxilla, this
tubercle surmounted by a very long, thick, translucent spiniform process.
Genal-gular area bearing about 16 long, bristling, strongly capitate setae,
reminiscent of certain euplectine genera.

BATRISINI 257

Maxillary palpi four-segmented and quite small in keeping with genus;
first segment minute, elongate-cylindrical; second three times as long, arcuate,
pedunculate for basal third then expanded in apical two-thirds; third as wide
as second, one-half as long, triangular from ventral view, broadly obconical
from lateral view; fourth as long as preceding two united, wider than third,
subfusiform, with a minute apical truncature bearing a palpal cone. Fourth
segment 0.10 mm. long x 0.03 mm. wide.

Antennae 0.93 mm. long, eleven-segmented, distant, simple; first segment
rounded-oblong; II similar but smaller; III smaller, obconical; IV-VIII
moniliform; club large (0.40 mm. long), composed of last three segments,
integument rugose, black, the last segment as long as ninth and tenth united
(0.20 mm.).

Pronotum with length equal to width, widest near middle; disc strongly
and simply convex but not gibbous (33 per cent elevated above the critical
line given in Group key) ; transverse antebasal sulcus connecting a lateral
fovea each side ; longitudinal sulcus extending apically from each lateral fovea,
between disc and margin, and becoming evanescent at middle; basal bead ex-
tended medianly in a short, narrow carina for half the distance between bead
and transverse sulcus.

Scutellum large for pselaphids, equilaterally triangular.

Each elytron with a prominent humeral callus; a subhumeral fovea; an
entire longitudinal carina on flank, from subhumeral fovea to apical margin;
four large, deep, nude basal foveae of which the sutural is set apart; sutural
stria strong and entire.

Wings present.

Abdomen with five visible tergites in a length ratio of 3/1.3/1.3/2.5/3,
with margins as follows: first each side with a strong, entire external and
internal carina; second and third each side with a single, entire carina. First
four tergites with a pubescent fovea in each latero-basal corner (by microdis-
section these foveae were found to extend deeply into the abdominal cavity as
conical invaginations. They appear to be spiracular, and if so then the setae
at orifice may be guard hairs.) Base of first tergite with a pair of minute, distant,
blunt cusps separated by one-third the discal width of segment. Last tergite
simple, flattened, vertical, and transversely fusiform.

Six sternites in a length ratio of 1/1.5/1/.5/.5/3 at middle. First in the form
of a circular platform with concave, rugulose upper surface, between posterior
coxae. Second with a longitudinal median carina. Sixth transversely semilunar,
with a broad, black apical bead.

Metasternum simple, convex, medianly foveate at apex.

Legs neither toothed nor inflated. In addition to the usual patch of setae
at apex of ventral face, each intermediate tibia has a sharply defined, longi-
tudinally ovate, densely pubescent fovea or depression on the antero-dorsal
face for apical third of length. Tarsi long, slender, three-segmented; first
tarsomere short and triangular; next two much longer, third longer than sec-

258 NEOTROPICAL PSELAPHIDAE

ond and bearing a very long, slender primary and a much shorter, slender
secondary claw, typical of genus.

Erected on one type and three paratype females, collected with ants at
5500 feet, on June 30, 1941, at Las Vigas, Vera Cruz, Mexico, by Mr. Dybas.
The host ants have been sent away for identification. The sex was determined
by dissection.^

The female of centralis and of myrmecocolus are rapidly differentiated.
Sharp (1887, p. 20) states that the female centralis "is remarkable on account
of the existence of a conical projection of the dorsal surface of the hind body
at the extremity." As seen from the description of myrmecocolus there is
nothing analogous to this condition.

Group V

I am unfamiliar with this group of three Brazilian species, all described
by Reitter.

The species may be listed as follows:

I

bilineatus Reitter. 1888. Blumenau, Brazil.

bistriatus Reitter. 1883. Brazil.

gounellei Raffray. 1917. Pemambuco, Brazil. (Male known only)

longicornis Reitter. 1885. Blumenau, Brazil.

pilicornis Raffray. 1917. Asuncion, Paraguay. (Male known only)

tricarinatus Raffray. 1904. Bahia, Brazil. (Male known only)

II

humeralis Raffray. 1887. Bogota, Colombia.
globipennis Reitter. 1883. San Marcos, Mexico. (Genotype)
liljebladi Park. 1933. Turrialba, Costa Rica. (Male known only)
panamensis Fletcher. 1927. Barro Colorado Island, Gatun Lake,

Panama Canal Zone. (Female known only)
rugipes Raffray. 1890. Tovar Colony, Venezuela. (Female known only)

III

jasciculatus Raffray. 1904. Bahia, Brazil. (Male known only)

IV

cavifrons Raffray. 1909. Sao Paulo, Brazil. (Male known only)
centralis Sharp. 1887. San Geronimo and Quiche Mountains (7000
to 9000 feet) Guatemala. (Both sexes known)

^ This dissection is easily performed on Euphalepsus. The abdomen is large and conical
and can be cut off without injury to legs. Then the abdomen is held firmly, lumen up, by
the spread hairs of a small brush. If this is done in 95 per cent alcohol, under a binocular
dissecting microscope, the penis can be picked out with a fine micro-hook if a male, or the
absence of penis confirmed if a female.

BATRISINI 259

cruralis Raffray. 1890. Tover Colony, Venezuela. (Male known only)

fuscocapillus Reitter. 1888. Blumenau, Brazil. (Male)

hetschkoi Reitter. 1888. Blumenau, Brazil. (Male)

ovipennis Reitter. 1883. Brazil. (Male)

reitteri Sharp. 1887. Volcan de Chiriqui (2500 to 4000 feet) , Panama.

(Male known only)
tibialis Raffray. 1904. Amazonas, Brazil. (Male known only)
myrmecocolus new species. Vera Cruz, Mexico. (Female known only)

laevicollis Reitter. 1888. Blumenau, Brazil.
lothari Reitter. 1888. Blumenau, Brazil.
puncticollis Reitter. 1888. Blumenau, Brazil.

PHALEPSOIDES (Rafifray, 1890)

Reitter (1888) (Euphalepsus)
Raffray (1890, 1904, 1908, 1909)

This is small genus of four species known to inhabit Brazil. Three of the
species were described as Euphalepsus, and Raffray two years later emended
this genus, erecting the present genus to hold those neotropical batrisines
having (1) no humeral callus and (2) the metastemum as strongly, medianly,
longitudinally carinated. It should be noted that Group V of Euphalepsus
forms a transition to Phalepsoides with respect to the humeral callus.

The species may be listed as follows:

punctatissimus (Reitter). 1888. Blumenau, Brazil. (Genotype)

{Euphalepsus)
laevissimu^ (Reitter). 1888. Blumenau, Brazil. (Euphalepsus)
longiceps (Reitter). 1888. Blumenau, Brazil. (Euphalepsus)
vagepunctatus Raffray. 1909. Sao Paulo, Brazil,

Tribe 8. Tychini

The Tychini are delineated by the following combination of characters:
(1) the neotropical species have eleven-segmented antennae which are never
geniculate, and are always widely separated at their bases. This particular
character tends to make neotropical tychines unfamiliar in habitus to the
student of nearctic Tychini, since such genera as Tychus, Cylindrarctus and
their North American and European allies have the antennae approximate at
base, the head correspondingly narrowed into more or less of an antennal
tubercle, and therefore imparting to the whole animal a distinctive facies.
The neotropical tychines, on the other hand, never have the antennae close
together upon a common median antennal tubercle and hence the head has a
broad, unfamiliar outline approaching Batrisini in many genera; (2) Mentum
normal, never expanded to cover the mouth and mouth-parts; (3) Abdomen
with five visible tergites. The first tergite is margined each side by an external
and an internal carina and the second and third tergites are also usually
margined each side by at least a single, short carina. This pattern holds for
all neotropical genera with the exception of one genus, Dalmophysis, which
has no marginal carinae on the first tergite or any succeeding tergites and is
wholly marginless. Some genera have the lateral margins well-developed
{Iniocyphus, Dalnwdes, Dalmomima, Batriphysis) although narrow and vari-
ously foiTned. Other genera (Buris) have the margin indistinct, limited to the
base of the first tergite; (4) Abdomen with the first stemite as long or much
longer than the posterior coxae and always continuously visible from side to
side. Females always with six sternites. Males with six stemites in all but
three neotropical genera. These latter {Buris, Dalmoburis, Dalmophysis)
have seven sternites in the male sex. Dalmophysis has a small, transversely
triangular seventh sternite; Buris and Dalmoburis have the seventh stemite
relatively large and longitudinally divided into a right and a left plate. It
should be added that in a few genera only a single sex is known, thus Iniocyphus
and Batriphysis are known only from males, and Bythinophysis from the female
sex alone; (5) Posterior coxae have their mesial faces globular; (6) Femora
obliquely articulated with their trochanters, so that coxa and femur, of the
intermediate legs at least, are close together; (7) Three-segmented tarsi with
the first tarsomere very small, and the last two relatively very long, the distal
tarsomere bearing either a single large claw, or a large claw and an accessory
bristle-like claw.

In contrast to Batrisini, neotropical Tychini are represented by a relatively
large number of genera, but few species. Thus, there are fourteen genera and
only thirty spcies. The neotropical genera may be artificially separated as fol-
lows :

(260)

TYCHINI 261

Key to the Neotropical Genera

Base of each elytron with at least three foveae DALMODES

Base of each elytron with at most two foveae 2

2. Base of each elytron with two foveae 3

Base of each elytron simple, without foveae, and at most with a

vague impression 6

3. Flank of each elytron with a longitudinal sulcus 4

Flank of each elytron with no trace of a longitudinal sulcus, but with

a strong longitudinal carina on the posterior (apical) half of elytral
flank DALMONEXUS, new genus

4. Pronotum with a longitudinal sulcus on each side. . HARMOPHOLA
Pronotum without lateral longitudinal sulci 5

5. Pronotum with three free antebasal foveae but no trace of a trans-

verse antebasal sulcus HARMOMIMA

Pronotum with a lateral fovea each side connected by a transverse
antebasal sulcus HARMOPHORUS

6. Flank of each elytron with a longitudinal sulcus 7

Flank of each elytron without any trace of a longitudinal sulcus ; the

elytral flank may be variously modified: (1) perfectly simple, (2)
an entire longitudinal carina of varying thickness, which may or
may not arise in a subhumeral fovea, or (3) a carina developed
only on the posterior (apical) third of the elytral length 8

7. Posterior coxae widely separated by the metasternum

BYTHINOPHYSIS

Posterior coxae very slightly separated DALMOMIMA

8. Flank of each elytron with a subhumeral fovea BURIS

Flank of each elytron without a subhumeral fovea 9

9. Flank of each elytron with an entire longitudinal carina from near

humeral angle to apical eighth of length 10

Flank of each elytron either perfectly simple and noncarinated, or
with a longitudinal carina for the apical third of elytral length. ... 11

10. Occiput and vertex longitudinally, medianly carinate

BATRIPHYSIS, new genus

Occiput and vertex not medianly, longitudinally carinate

DALMOBURIS, new genus

11. Flank of each elytron with a fine longitudinal carina for the apical

third, the basal two-thirds of length being perfectly simple

PHYBYTHARSIS, new genus

Flank of elytra without any trace of longitudinal carinae 12

12. Abdomen absolutely immarginate, lacking even an external carina at

base of first tergite on each side DALMOPHYSIS

Abdomen with at least the first tergite narrowly but distinctly mar-
gined with an external and an internal carina each side 13

262 NEOTROPICAL PSELAPHIDAE

13. Posterior coxae separated by appreciably more than half the median

metastemal length, usually by as much as three-fourths this dis-
tance; sutural striae of elytra indistinct or rudimentary 14

Posterior coxae separated by not more than half the median metaster-
nal length, usually by as little as one-third this distance; sutural
striae of elytra distinct and strongly formed BATRYBRAXIS

14, Head slightly longer than wide through eyes; vertex convex, un-

carinated with vertexal foveae not apparent; front very long, ogival
between antennal bases; each side of head with a narrow longi-
tudinal sulcus extending from antennal insertion posteriorly above
each eye; antennae simple, slender, much more than half as long

as body; legs long and slender INIOCYPHUS

Head much wider through eyes than long; vertex with a thick, short,
median longitudinal carina at base ; front sharply declivous beyond
inter-antennal line; each side of head with an obliquely mesio-
posteriad incisure and vertexal fovea ; antennae highly abnormal in
the male sex, not more than half of body length; legs normally

inflated ; known only from nest of termites

ANOPLOBRAXIS, new genus

DALMODES (Reitter, 1882)

Reitter (1882)

Sharp (1887)

Raffray (1896, 1904, 1908, 1908a, 1911, 1911a)

As limited here, Dalmodes is a neotropical genus of tychines, the species
of which have the base of each elytron quadrifoveate with one exception,
gracilipes, in which the elytron base has three foveae; the flank of the elytron
has a longitudinal sulcus; the pronotum has a transverse subbasal sulcus but
no lateral longitudinal sulci; the posterior coxae are widely separated; the
abdomen has the first tergite narrowly but distinctly margined each side with
an external and an internal carina, the second and third tergites much less
sharply margined; six stemites in male and female, the sixth being relatively
large and more or less rounded at apical margin.

This is a tentative restriction, placing several species in other genera.
Early descriptions are vague and types usually not available for study so
that the exact limits of the genus will remain unknown for some time to come.
Five species are considered as belonging in Dalmodes, but of these one may
be misplaced.

Key to the Species

Known only from Mexico rybaxoides

Known only from Brazil 2

2. Base of each elytron with three foveae gracilipes

Base of each elytron with four foveae 3

TYCHINI 263

3. Total length more than two millimeters infossus

Total length less than two millimeters 4

4. Antennal segments III-VIII regularly moniliform; head as long as

wide pullus

Antennal segments III-VIII not all moniliform; head shorter, not as
long as wide labialis

The species of Dalmodes may be listed as follows:

gracilipes Raffray. 1904. Blumenau, Brazil.

infossus Raffray. 1911. Sierra de Baturite, Brazil.

labialis (Schaufuss). 1887. Rio de Janeiro, Matto Grosso, Brazil.

[Batrisohryaxis) . Genotype.
pullus Raffray. 1911. Matto Grosso, Brazil.
rybaxoides Reitter. 1882. Mexico. {Dalmodes as emended?)

BYTHINOPHYSIS (Raffray, 1908)

This genus was erected on a single species from French Guiana {puncti-
pennis). Originally the genus was separated from Dalmodes by having the
first tergite longer than the second, elytral margins slightly dilated, and distal
palpomere sharply securiform, whereas Dalmodes has the first tergite sub-
equal to second, elytral margins not dilated and distal palpomere only slightly
securiform. These two genera agree in such basic features as widely separated
posterior coxae and flank of each elytron with a longitudinal sulcus, so that
they are quite close together. Bythinophysis has no basal elytral foveae and
consequently I have placed several species, formerly in Dalmodes, in this
genus as the qualitative character of no basal elytral foveae seems more funda-
mental than a quantitative length of the first tergite, amount of flair of elytra
and degree of securiformity of the last maxillary palpal segment. In this I
may be in error but more morphological research is indicated before the ques-
tion may be laid aside arbitrarily. It is possible that the two genera will have
to be combined under Dalmodes. In the present state of our knowledge the fol-
lowing key may help to separate the species with the exception of plicatulus.

First tergite distinctly longer than second tergite; antennal segments
III obconical, IV-VI quadrate, VII-VIII slightly transverse, IX-X
crescentric and transverse; 1.5 mm.; known from female only. . . .
punctipennis

First and second tergites subequal 2

2. Pronotum with the transverse sulcus entire and connecting the lateral

foveae each side 3

Pronotum with the transverse sulcus abbreviated so that the median
fovea is transversely dilated; known from male only: sternites
longitudinally excavated; fourth sternite strongly toothed on each
side; intermediate trochanters compressed and toothed at base of
ventral face; posterior tibiae bisinuate, with a small tooth at mid-
dle of internal face ; 1.65 mm ensipes

264 NEOTROPICAL PSELAPHIDAE

3. Antennal segments III-VII simple, similar, moniliform 4

Antennal segments III-VII not mutually similar 6

4. Known only from Guadeloupe, and only from female sex; 1.3 mm.

humilis

Known only from Guatemala; 1.66 mm 5

5. Posterior tibiae with a very large, triangular, sharp tooth on internal

face just above middle of length brevicollis Male

Posterior tibiae simple, not armed brevicollis Female

6. Antennal segment II quadrate, III moniliform, IV-V slightly trans-

verse, VI-VII transverse and slightly crescentric with the internal
face slightly serrate; VIII-IX very transverse and internal face

produced; anterior femora broadly foveate; 1.5 mm

venustulus Male

Antennal segment II briefly ovate, III-VII moniliform but progres-
sively slightly decreasing in width; VIII-IX wider and lenticular;
1.2 mm schaufussi Male

The species may be listed as follows:

^brevicollis (Sharp). 1887. Coatepeque, 1300 feet, Guatemala.
(Dalmodes)

ensipes (Raffray). 1890. San Esteban, Venezuela. [Dalmodes)

(May be the type of a new genus)

humilis (Raffray). 1908. Guadeloupe, Leeward Islands. (Dalmodes)

plicatulus (Schaufuss). 1882. Cayenne, French Guiana. (Trichonyx)

punctipennis Raffray. 1908. Cayenne, French Guiana. Genotype.

schaufussi (Raffray). 1896. Teapa, Mexico. [Dalmodes.) (Also
recorded with doubt from New Orleans,
Louisiana, and Yucatan, Mexico)

venustulus (Schaufuss). 1872. Teapa, Mexico. [Trichonyx)

HARMOPHOLA (Raffray, 1896)

This is a monotypic genus in which the elytral flank has a longitudinal
sulcus and two basal elytral foveae and the pronotum has both a transverse sub-
basal sulcus and a lateral longitudinal sulcus on each side. The lateral pronotal
sulci differentiate the genus from its allies.

clavata Raffray. 1896. Colonia Alpina, Brazil. Genotype.

HARMOPHORUS (Schaufuss, 1886)

This is a monotypic genus in which the elytra are similar to Harmophola,
but the pronotum lacks the longitudinal lateral sulci and has a well-formed
transverse subbasal sulcus. The eyes are very large but not visible from a dorsal
viewpoint because the sides of the head are dilated. The integuments are
strongly punctate.

manticoroides Schaufuss. 1886. Brazil. Genotype.
* However, see Dalmoburis.

TYCHINI 265

HARMOMIMA (Raffray, 1904)

This neotropical genus holds two species of montane Bolivia. It is related to
Harmophorus, having two basal foveae and a subepipleural sulcus on each
elytron, but is readily distinguished from the allied genera by having the median
pronotal fovea transversely dilated only, lacking a transverse subbasal sulcus
and therefore the pronotal base has three free foveae. The two species may be
separated as follows:

Antennal segment II briefly ovate, III-VIII moniliform, with the
seventh slightly larger than sixth, and the eighth slight transverse,
IX and X strongly transverse and with the lateral face slightly cres-
centric ; XI ovate ; 1.2 mm grandiceps

Antennal segment II globose, III-X moniliform with the third to
eighth globose, ninth and tenth slightly transverse ; XI oblong-ovate ;
1 mm impressicollis

grandiceps Raffray. 1904, Yuracaris, Bolivia. Genotype.
impressicollis Raffray. 1904. Yuracaris, Bolivia.

DALMOMIMA (Raffray, 1908)

This is a monotypic genus which has a habitus veiy similar to Batrybraxis
but differs from this genus in having the flanks of the elytra longitudinally
sulcate ; Dalmomima is similar to the five preceding genera in having the elytral
flanks longitudinally sulcate, but of these five only Dalmomima and Bythino-
physis have no basal elytral foveae; it is distinct from Bythinophysis in that
the latter genus has widely separated posterior coxae, whereas Dalmomima has
the posterior coxae only slightly separated.

The male has the head with the dorsal surface excavated anteriorly and
elevated and subauriculate laterally, while the female lacks this modification.

caviceps (Raffray). 1896. Colonia Alpina, Brazil. (Batrybraxis) . Geno-
type.

This concludes the section of neotropical Tychini having the flank of each
elytron longitudinally sulcate. The next section holds five neotropical genera in
which the flank of each elytron has either (1) a subhumeral fovea and an entire
longitudinal carina (Buris) ; (2) no subhumeral fovea but an entire longitudinal
carina (Batriphysis, Dalmoburis) ; (3) no subhumeral fovea but the apical half
of each elytron with a longitudinal carina, or (4) no subhumeral fovea, but with
each elytron having a longitudinal carina for the apical third of its length. This
is not a proposed evolutionary arrangement, and the differences between these
genera are many and basic, as will be noted, but is given here as a convenient
grouping in which neotropical tychines are divided into three sections, the
sulcate group, the carinate group, and the unmodified group with respect to the
flanks of the elytra.

266 NEOTROPICAL PSELAPHIDAE

BURIS (Fletcher, 1928)

This is a monotypic genus which is unique among neotropical tychines in
having each elytral flank with a subhumeral fovea from which extends an entire,
broad, strong longitudinal carina. The base of the elytra have no foveae. The
pronotum has a transverse subbasal sulcus connecting a small lateral fovea of
each side. The males have seven sternites, of which the seventh is longitudinally
divided into a right and left plate; females have six sternites. This stemite
number is shared by only two other neotropical genera, Dalmoburis and Dalmo-
physis. The abdominal margin is limited to the base of the first tergite. Posterior
coxae widely separated, the separation equal to the distance between the inter-
mediate and the posterior coxae.

brunneus Fletcher. 1928. In rotten trunk of Coco palm. Vera Cruz,
Vera Cruz, Mexico. Genotype.

I have a good series of Buris brunneus Fletcher as follows: four males
Cordoba, Vera Cruz, collected in log mold July 20, 1936, by Dr. Charles Seevers;
two males from Huichihuyan, San Louis Potosi, in log mold June 18, 1941;
one male and two females from Tamazunchale, San Louis Potosi in log mold
June 22, 1941, by Mr. Dybas.

These nine specimens check the ecological niche of the types and extend
the Mexican range of the species.

DALMOBURIS new genus

This new genus is distinct from other Tychini on the following combination
of characters: (1) Pronotum without lateral longitudinal sulci, but with a trans-
verse subbasal sulcus connecting a small lateral fovea on each side; (2) Elytra
with no basal foveae, but each elytron with a sutural stria and on the flank an
entire, narrow, longitudinal carina; flank with no subhumeral fovea and no
longitudinal sulcus; (3) Six sternites in the female sex; seven sternites in the
male sex, the seventh stemite being longitudinally divided into a right and left
triangular plate; (4) First tergite strongly margined each side by a short ex-
ternal carina half the segmental length, and a longer, arcuate internal carina
three- fourths the segmental length ; second and third tergites with a short basal
carina each side at base; (5) Posterior coxae widely separated by a distance
equal to the metastemal length ; (6) Head transverse, with simple, eleven-seg-
mented antennae widely separated at base on the antero-lateral comers of the
front; (7) Maxillary palpi four-segmented, moderately long, slender and simple.

Dalmoburis petrunkevitchii new species

Holotype Male. 1.0-1.2 mm. long x 0.5.-0.55 mm. greatest width.

Shining, light reddish-brown when mature. Head subglabrous; pronotum
lightly punctulate, with unusually short, sparse, appressed setae; elytra dis-
tinctly punctate, with long coarse subappressed setae; abdomen lightly punc-

TYCHINI 267

tulate, with pubescence intermediate in length between that of pronotum and
elytra.

Head transverse, with long rounded tempora twice as long as eyes; eyes
small (0.05 mm. long x 0.03 mm. wide from a dorsal view) , not prominent, com-
posed of about 28 small facets, reniform in lateral view^ the eye being .073 mm.
in the dorso-ventral diameter. Occiput and associated portion of vertex strongly,
medianly tuberculate ; this tubercular elevation is evenly convex and not longi-
tudinally carinate. Vertex tumid in posterior half to between the eyes, depressed
in anterior half, with a pair of vertexal foveae distantly placed, one behind each
antennal insertion on a line running through middle of eyes; vertexal foveae
small, nude, about the diameter of an ocular facet, and connected by a well-
formed circumambient sulcus. This sulcus apically reaching the arcuate, me-
dianly concave, but entirely elevated frontal margin between antennal bases.
No longitudinal median carina on vertex. Fronto-clypeal area short, simply
declivous. Labrum relatively large, with a biarcuate apical margin. Ventral
surface of head simple.

Maxillary palpi similar to Buris, relatively long and slender, four-seg-
mented; first segment minute, subcylindrical ; second, arcuate, elongate, as wide
as first for basal half then gradually inflated to apex; third not quite half as
long as second, obconical from a lateral view and triangular from a ventral view,
slightly wider than second; fourth only slightly wider than third, but as long
as preceding three segments, obliquely truncate at base, gradually narrowed to
apex, apex narrowly truncate with a short, conical palpal cone occupying the
apical truncature.

Antennae eleven-segmented, distant, simple; first segment dorso-ventrally
compressed and arcuate, longer than second and as wide as ninth ; II regularly
elongate-oval, longer than third; III obconical; IV and V slightly shorter than
third, elongate-oval; VI moniliform, shorter than fifth; V, VIII, and IX pro-
gressively wider and pyramidal, the ninth wider than long; X distinctly trans-
verse, trapezoidal; XI as long as preceding four united, regularly truncate at
base, sides subparallel and widest apart in basal two-fifths, narrowing to a
conical, obtuse apex for apical three-fifths.

Pronotum with rounded apical comers; strongly evenly convex on disc;
straight, convergent sides ; a small lateral nude fovea each side near base con-
nected by a nude, biarcuate, medianly expanded subbasal sulcus.

Elytra with evenly convex, nodular humeri; each elytron with an entire
sutural stria; no basal foveae; no subhumeral fovea; flank with an entire longi-
tudinal carina arising just ventrad of the nodular humerus and continuing to
apex as a fine, but distinct carina.

Abdomen with five tergites with a length ratio of l/l/l/li^/li/^ ; first
tergite each side with a margin formed by a straight external carina half the
segmental length, and a strongly arcuate internal carina which reaches apical
three-fourths of segment; second and third tergites each with a very short,
straight carina each side near base ; last tergite broadly rounded-triangular in
outline.

268 NEOTROPICAL PSELAPHIDAE

Abdomen with seven sternites with a length ratio of 11/2/1/-33/.33:
.2/1.33/1.33. First five simple and convex; sixth with an erect, transversely
oblong lamina arising medianly at apical four-fifths. On using high magnifica-
tion this peculiar plate is seen to consist of erect, slender, sharp teeth so that
the plate in reality, is a comb; seventh as long as sixth, in two parts, a right and
a left subtriangular plate. In the holotype and some paratypes, these plates are
widely separated and the partially extruded penis protruded between them ; in
some paratypes the plates are closed, the line of junction forming a median,
longitudinally arcuate carina.

Intermediate trochanters with a small, blunt tooth near base on ventral
face. Femora simply inflated. Tibiae gradually thicker to apex and apically pu-
bescent on ventral face; posterior tibiae with a short apical spur. Tarsi relatively
short and thick, first segment small, triangular; second and third much longer,
second twice as long as third; third with a long, thick primary claw and an
accessory bristle. Posterior coxae widely separated, their separation equal to
the metasternal length.

Metasternum medianly, simply and broadly concave.

Allotype Female. Similar to male save that (1) occiput is not medianly
tuberculate, (2) six sternites only, all unmodified, (3) femora not inflated,
(4) intermediate trochanters unarmed.

Described on nineteen specimens, all collected from soft, moist, decayed
log mold or sifted from leaf mold of the rain forest floor at Barro Colorado
Island, Gatun Lake, Panama Canal Zone, during the day. One female paratype
and two males paratypes collected July 20, 1935, by Alfred Emerson. The rest
collected by the author during the summer of 1936 by the author as follows:
female paratype at Drayton 16 (July 25) ; holotype at Zetek 23 and allotype
at Zetek 23 (July 27) ; two male paratypes at Zetek 3 (July 28) ; one male and
two female paratypes at Zetek 17 (July 28) ; two female and two male para-
types at Pearson 2 (July 29) ; one male and three female paratypes at Armour
10 (July 30).

Because of its relatively wide insular distribution and abundance, I am
inclined to consider this species as a characteristic constitutent of the rain forest
log mold. It is strange that none were taken at night at lights. It is of interest
also that of nineteen specimens, nine were males and ten females, attesting a
normal sex ratio.

One male collected July 20, 1935, had just pupated.

I take pleasure in naming this distinctive species for my friend, Professor
Alexander Petrunkevitch, with whom I spent many a happy hour collecting
in the rain forest.

At first glance Dalmoburis petrunkevitchii and Buris brunneus appear very
similar. Both have the same indefinable habitus of close taxonomic relationship,
and at first I had thought that petrunkevitchii could be placed in Buris. Mature
consideration of paratypes of Buris brunneus in the U. S. National Museum and
direct comparison of these with the present species, showed such a course to be
both impracticable and unjustifiable. Both genera agree in such fundamentals

TYCHINI 269

as habitus, posterior coxal separation, antennal separation, sternite number and
longitudinally divided seventh male stemite, in pronotal structure and other
characters. Both genera disagree on such fundamentals as abdominal margina-
tion and elytral structure, so a new genus had to be erected in keeping with the
separation of genera in Tychini.

As species, brunneus and petrunkevitchii are widely different on many char-
acters, in addition to generic differences, such as the very abnonnal and special-
ized male antennae of brunneus, radically different character of the male vertex
and male stemite modification.

I have also included Dalmodes brevicoUis Sharp in this genus. My series
consists of five specimens as follows: three males from log mold on July 20,
1936, collected by Dr. Charles Seevers in Cordoba, Vera Cruz; one female on
June 18, 1941, by Mr. Dybas from Huichihuyan, San Louis Potosi; one male on
July 10, 1941, by Dr. Seevers from Penuela, Vera Cruz. These specimens were
mounted on points or cleared and slide-mounts prepared. On careful study they
appear to agree with Sharp's description and figure of brevicoUis from Guate-
mala, in so far as these go. However, the males have seven sternites with the
seventh sternite longitudinally divided; the females have six sternites and this
is not Dalmodes where both sexes have six simple sternites. In the next place
the males have the last tergite strongly produced into a sharp, conical spine
whereas the female has a rudimentary spine. Sharp stated that the abdominal
spine was strong in the female and rudimentary in the male, although his ob-
servation that the male hind tibiae are spined while the females have unarmed
tibiae agrees with my series. Finally the elytral flanks are ornamented with a
long, strong carina which Sharp might have interpreted as a sulcus.

The penis of the males of my material is very large (0.45 mm. long x 0.27
mm. wide) through the basal bulb, extending nearly to the second sternite, and
of typical tychine pattern, so that the sex is not in question.

In the following key both sexes are included and Buris added since these
three species, although very different, have the same habitus:

Seven sternites present, the seventh longitudinally divided into two

pieces Males 2

Six sternites present Females 4

2. Elytral flank with a longitudinal carina ending near humeral angle in

a fovea Buris brunneus

Elytral flank with a longitudinal carina ending near humeral angle but
lacking a subhumeral fovea 3

3. Posterior tibiae with a large, triangular, acute spine on internal face

at basal third Dalnioburis brevicoUis

Posterior tibiae without tooth at basal third and with a minute spur
at apex Dalmoburis petrunkevitchii

4. Elytral flank with a longitudinal carina and subhumeral fovea

Buris brunneus

Elytral flank with a longitudinal carina but without a subhumeral
fovea 5

270 NEOTROPICAL PSELAPHIDAE

5. Last stemite ogival, very long, nearly as long as wide

Dalmoburis brevicoUis

Last stemite transversely fusiform with apical margin nearly straight,

much wider than long Dalmoburis petrunkevitchii

I have keyed brevicoUis Sharp in both Bythinophysis and Dalmoburis until
the type can be studied, although the latter genus appears to be a more suitable
vehicle. The species of Dalmoburis may be listed as follows:

brevicoUis (Sharp). 1887. Coatepeque, 1300 feet, Guatemala; Cordoba,
Vera Cruz, Mexico; Penuela, Vera Cruz, Mexico; Huichihuyan, San
Louis Potosi, Mexico.

petrunkevitchii new species. Panama Canal Zone. Genotype.

BATRIPHYSIS new genus

This new genus is distinct from other Tychini on the following combination
of characters: (1) Head subquadrate with simple, eleven-segmented antennae
widely separated at base on the antero-lateral corners of the front; eyes reni-
form, not prominent, placed far below the convex, longitudinally medianly cari-
nate vertex; (2) Vertexal foveae absent; (3) Maxillary palpi simple, four-
segmented, moderately slender and elongate; (4) Integuments of dorsal and
ventral surfaces roughtly punctate to granular; (5) Pronotum lacking lateral
longitudinal sulci and lacking lateral foveae, but with a long transverse ante-
basal sulcus; (6) Elytra lacking basal foveae, sutural stria vestigial, but each
elytron with an entire, longitudinal carina on the flank; (7) Six sternites in the
male sex (female sex unknown) ; (8) Five visible tergites, the first three later-
ally margined each side; (9) Posterior coxae moderately separated by a distance
equal to one-third the metastemal length; (10) Tarsi with a large, broad, acute
primary claw and a much shorter, narrow accessory claw.

Batriphysis epicranis new species

Type Male. 1.6 mm. long x 0.6 mm. wide.

Light reddish-brown ; punctation heavy as described below ; the pubescence
moderately abundant and subappressed ; body elongate-cylindrical as in Dalmo-
physis, the habitus batrisoid.

Head subquadrate, slightly wider through the eyes than long; tempora
short, one- fourth the head length, strongly arcuate, and only slightly longer than
the eyes. Eyes appear very small from above (0.05 mm. long x 0.02 mm. wide)
but in reality elongate-reniform, with a dorso-ventral depth of 0.1 mm. placed
far below vertex, on the sides of head, and composed of about 32 small facets.
Occipital margin subtruncate. Vertex high, convex, coarsely granulate, with an
entire, high, median, longitudinal carina from occiput to a point just apical of
anterior eye margin; here this median vertexal carina bifurcates and becomes
vestigial and interrupted. Vertexal foveae absent, their homologues present as
a pair of circular tumuli with blackened periphery, each elevation fonned by

TYCHINI 271

the anchorage of one arm of the supratentorium, each tumulus just beyond an
arm of the bifurcated median carina. A median triangular portion of the anterior
vertex (bounded by the interantennal line and an oblique line from antennal
insertion to bifurcated arm of median carina) subglabrous, with few scattered
granules; this triangular area transversely depressed just posterior to inter-
antennal line, and with a transversely suboblong tumulus with blackened peri-
phery placed just posterior of this depression and just apical of median carinal
bifurcation. Frontoclypeal surface long, nearly vertical, convex and simple save
for a small median tuberculation on interantennal line. Labrum short but un-
usually wide, with a simple, truncate margin. Ventral surface of head trans-
versely tumid, coarsely punctate, not medianly carinate.

Maxillary palpi distinctly paler, four-segmented ; first segment very short,
triangular, wider apically than base of second; second sharply arcuate at base,
slender and cylindrical in basal half, gradually inflated in apical half, about five
times longer than first; third globose-triangular in lateral outline, slightly wider
than second but one-third as long as second ; fourth relatively short, one-fourth
longer than second, subsecuriform-conical in outline with blunted apex bearing
a long, slender palpal cone.

Antennae eleven-segmented, widely separated, absolutely simple; segment I
cylindrical, longer and wider than second; II subcylindrical, longer and wider
than third; III subobconical ; IV-VII moniliform; VIII transversely monili-
form, slightly wider; IX transversely ovate-moniliform, wider than eighth; X
subquadrate-submoniliform, much wider and longer than ninth; XI as in
Dalmoburis.

Pronotum subquadrate, one-tenth wider than long, widest in apical two-
fifths, sides converging apical and basal of this point; disc evenly convex. Integ-
ument granulate. No lateral longitudinal sulci or lateral foveae. Subbasal trans-
verse sulcus strongly angulate medianly, continuing lat€rally where sulcus is
expanded, then narrowing and passing far down pronotal flanks.

Elytra simply punctate, with angulate humeri ; each elytron with a vestigial
sutural stria which is discernible only at apex, and lacking basal foveae ; each
elytral flank with a strong, entire longitudinal carina but lacking subhumeral
fovea or longitudinal sulcus.

Abdomen with five visible tergites having a length ratio of 2.5/1.5/1/1.5/1.
First tergite, in addition to its much greater length, is roughly punctate, the
punctures very large, shallow, elongate-oval whereas the remaining tergites are
simply punctate. Margins as follows: first tergite with an exceptionally high,
entire external carina which continues the line of the elytral-flank carina, and a
short oblique internal carina for basal third (the triangular area between carinae
obliquely elevated with the orifice of a large fovea seen beneath this oblique
elevation) ; second, third, and fourth tergites with a short, thick, straight carina
each side at base.

Abdomen with six stemites; the first four rugosely punctate with large,
oval, crowded punctures ; sixth simply punctate ; six stemites with a length ratio
of 1.8/1.8/.7/.6/.5/2. First and second stemites subequal, the first much longer

272 NEOTROPICAL PSELAPHIDAE

than posterior coxae. No abnormal modifications; sixth the longest, and trans-
versely oval. In the type the large penis is partially extruded between apical
sternite and tergite.

Prosternum simple, subglabrous, with a fovea apical of each coxa. Meso-
sternum rugose with a strong median longitudinal carina for apical half. Meta-
sternum coarsely punctate, slightly medianly sulcate. Posterior coxae separated
by a distance equal to about one-third the metasternal length. Legs simple and
unarmed except that the anterior femora are slightly inflated with a flattened
ventral face. Tarsi batrisine, thick; first segment short, triangular: second four
times as long as first; third (distal) half as long as second, with two distinct
claws, a large, acute primary claw and a much shorter, slender accessor^' claw.

Erected on a single type male, collected by the author on Barro Colorado
Island, Gatun Lake, Panama Canal Zone, July 28, 1936, in log mold at Zetek 3.

This is a difficult species to analyse. It has the general cylindrical outline
of Dalmophysis, from which it differs in many basic generic characters such as
abdominal margin, relative tergite length, et cetera. In general epicranis appears
like a heavily punctate batrisine, and the tarsal claw aids this illusion whereas
the elongate first sternite precludes such association. Taxonomically the species
is near Batrybraxis. It agrees with Batrybraxis in tergite and sternite lengths
and separation of posterior coxae, but cannot be placed in this genus as (1) it
lacks vertexal foveae, lateral pronotal foveae per se and has a vestigial sutural
stria, and (2) has an entire longitudinal carina on elytral flank.

DALMONEXUS new genus

This new genus is distinct from other Tychini on the following combination
of characters: (1) Head with vertex, front and clypeus highly modified in the
male, but the occiput and vertex strongly, medianly, longitudinally carinate in
both sexes; (2) Eleven-segmented, simple antennae widely separated on the
antero-lateral angles of the front; (3) Maxillary palpi simple, four-segmented,
elongate and moderate in size; (4) Pronotum wider than long, abruptly nar-
rowed in basal third; subbasal sulcus connecting a lateral fovea each side; (5)
Each elytron with entire sutural stria, but lacking basal foveae; flank with a
strong, longitudinal carina for apical half of length; (6) Six stemites in both
sexes; (7) Five visible tergites, the first three laterally margined each side; (8)
Posterior coxae widely separated by a distance equaling three-fourths the meta-
sternal length.

Dalmonexus seeversi new species

Holotype Male. L20 mm. long x 0.60 mm. wide.

Moderately shining dark red when mature, palpi and legs paler. Flavous
pubescence moderately abundant, long and bristling on head, pronotum and
elytra; pubescence sparse and subappressed on abdomen. Integuments lightly
punctulate.

Head distinctly wider through eyes than long; tempora very short, very

TYCHINI 273

wide and rounded; eyes short and inconspicuous from above, but reniform and
conspicuous from a lateral view, composed of about 32 medium-sized facets.
Head with a strong median longitudinal carina bisecting cervicum, occiput and
vertex to a point opposite the anterior margin of the eyes. This posterior half of
the vertex evenly vaulted above the eye level. Anterior half of vertex rapidly,
evenly declivous to front and also medianly longitudinally carinate. Therefore,
only the median third of length is not carinated. Sides of head anterior of the
eyes convergent and erected into a conspicuous, suboblong crest or marginal
wing from anterior third of eye to apex of first antennal segment. This marginal
crest deeply, obliquely incised just posterior to antennal articulation, with a
small vertexal fovea just mesiad of the incisure. These vertexal foveae nude and
entirely free. Interantennal line conspicuously bicornuate each side as a conse-
quence of the extension of each lateral crest past the antennal articulation as a
rounded horn ; deeply arcuate between these frontal horns, with the median point
of arcuation sharply, narrowly incised (this median incisure just apical to origin
of anterior median carina) , and with a coarsely setose, acute spine on each side
of incisure. Front deeply and transversely recessed below these median spines.
Clypeus complex: produced into a transversely obconical elevation which has its
anterior face medianly elevated into a longitudinally lamelloid carina which
continues dorsally to end in a short median tooth of dorsal margin, this tooth
bearing a pair of divergent pencils of setae; a lateral tooth at each dorsal angle
of the clypear elevation so that this obconical process is dorsally tridentate.
Labrum simple, transverse, with concave apical margin. Ventral surface of head
simple, evenly flattened, without median longitudinal carina.

Maxillary palpi four-segmented ; first segment minute ; second strongly ar-
cuate near base, elongate, basally pedunculate, gradually expanding to apex;
third short, one-third the length of second and slightly wider, subquadrate with
evenly convex external and angulate internal face; fourth large, one-fourth
longer than second, twice as wide as third, obliquely truncate at base, apically
becoming subconical and subsinuate with the apex minutely truncate and bear-
ing a small but distinct palpal cone.

Antennae eleven-segmented, simple; segment I subcylindrical, as wide as
tenth; II ovoidal, shorter than first and as wide as ninth; III-VII small, monili-
form; VIII transversely moniliform, slightly wider; IX and X trapezoidal, pro-
gresively transverse; XI slightly wider than tenth, as long as distal segment of
maxillary palpus or slightly longer than preceding three segments united, basally
truncate, convergent in apical half to blunt apex.

Pronotum one-fifth wider than long, widest through basal third, with a sub-
semicircular apical outline and then sides abruptly and angulately narrowed in
basal third, the sides subparallel basal to the constriction; transverse subbasal
sulcus in basal fourth connecting a lateral fovea each side, the foveae placed
beneath the overhang of the lateral margins.

Each elytron with an entire sutural stria, two large basal foveae and the
posterior (apical) half of flank decorated with a strong, longitudinal, blackened
carina which continues the arc of the external carina of the first tergite.

274 NEOTROPICAL PSELAPHIDAE

Abdomen with jBve visible tergites in the length ratio of 3/1.8/1/1/1, simple.
Margins as follows: first tergite each side with two parallel, subentire carinae
with the internal carina strongly Y-shaped (a rounded cusp of elytral apex
fitting into the bifurcation) ; second, third, and fourth tergites each side with a
straight, short internal carina and second and third with a rudiment of an ex-
ternal carina at base.

Six stemites in the length ratio of 1.3/1.5/.6/.5/.5/1.2. First sternite visible
side to side, separated from second by a deep pubescent trough ; sixth sternite
with a suberect, transvesely arcuate, lamelliform carina at middle and one-fifth
the segmental length from apical margin.

Metastemum medianly, longitudinally sulcate.

Posterior coxae distant, separated by a distance equal to three-fourths the
median metastemal length. Legs simple save posterior tibiae. Each posterior
tibia thickened in apical half, the thickened portion sharply arcuate. A tuft of
long setae at start of arcuation on internal face, and apex with a dense pad of
short setae and a stout, arcuate tooth. Tarsi three-segmented; first tarsomere
very short, last two relatively long, second longer than third ; third with a long
tarsal claw.

Allotype Female. Similar to holotype save that (1) longitudinal median
carina of posterior half of head much longer, extending to a point opposite an-
tennal bases; (2) anterior median longitudinal carina not present; (3) sides of
head anterior to eye elevated, but in the form of a wide flattened margin, not
produced apically as horns, but simply converging between and below antennae
as a narrow continuous, carinoid arc; (4) front evenly declivous and entirely
simple save for the union of the marginal elevation just noted; (5) clypeus
simply declivous; (6) sixth sternite not modified; (7) posterior tibiae slightly
arcuate through apical half, without basal tuft and lacking terminal tooth.

Described on twenty-three specimens, all collected on Barro Colorado
Island, Gatun Lake, Panama Canal Zone. One female paratype collected August
15, 1935, by Alfred Emerson in nest of the termite, Cornitermes (C.) acignathus
walkeri Snyder. Rest collected by the author as follows: Two male and two
female paratypes July 25, 1936, in rotten log mold at Drayton 15; holotype,
allotype, seven male, and two female paratypes sifting floor mold at Zetek 23
on July 27, 1936, and three male and four female paratypes same place and
date in log mold.

The record with the termite is probably accidental.

It should be noted that the sex ratio is nearly 1/1 and that the August 15
specimen and five taken in floor debris had just pupated.

This isolated form is named for my friend. Dr. Charles H. Seevers. The
genus is nearest Dalmodes and Bythinophysis in Raffray's 1908 arrangement,
but is obviously distant from these genera on the absence of a longitudinal sulcus
on elytral flank, and an entirely different pronotum among other basic features.

PHYBYTHARSIS new genm
This new genus is distinct from other Tychini on the following combination
of characters: (1) Head with vertex, front and clypeus highly modified in the

TYCHINI 275

male, but occiput and vertex strongly, medianly and longitudinally carinate in
both sexes; (2) Eleven-segmented, simple antennae widely separated on the
antero-lateral angles of the front; (3) Maxillary palpi simple, four-segmented,
elongate and moderate in size; (4) Pronotum wider than long, abruptly nar-
rowed in basal fourth; no median and no lateral foveae; a transverse sulcus
which receives an oblique accessory sulcus from basal margin each side; (5)
Each elytron with entire sutural stria, but lacking basal foveae ; flank with a
longitudinal carina for apical third to apical half of elytral length; (6) Six
sternites in both sexes; (7) Five visible tergites, the first three laterally mar-
gined each side; (8) Posterior coxae only moderately separated by a distance
equaling one-half the metasternal length.

Phybytharsis gambosis new species

Holotype Male. 1.14 mm. long x 0.60 mm. wide.

Moderately shining, dark red when mature. Pubescence flavous, moderately
abundant, long and bristling. Integument sparsely, lightly punctulate.

Head one-ninth wider than long with eyes included ; tempora short, as long
as eyes but very wide and gradually rounded. Eyes subreniform, central, of
about 30 medium-sized facets. Cervicum not carinate. Occiput and vertex bi-
sected by a thick, longitudinal median carina which extends to a point opposite
anterior third of eyes. Vertex vaulted above eye level. Sides of head anterior of
eyes with a deep, glabrous, rounded-triangular incisure. This incisure conspic-
uously developed in contrast to the narrow, oblique homologue of Dalmonexus.
A pair of minute, shallow vertexal foveae, each fovea nude and placed mesio-
posteriad of lateral incisure. Anterior half of vertex, between vertexal foveae
and interantennal line, glabrous, simple, declivous. Front very complex: the
anterior glabrous vertexal area is entirely separated from the front by a prom-
inent cylindrical antennal tubercle on each side, and by an interantennal crest
which is abruptly elevated medianly into a high, thin, transverse lamella. Just
anterior to this lamella the front is very deeply, transversely excavated, and
this wide, deep, short excavation is in turn walled in by the clypeus. The clypeus
is equally complex, elevated into a high thin lamella; this clypeal lamella ex-
tends from one antennal acetabulum to the other, and medianly is thickened
into a triangular, apically setose column, while laterally the walls are very thin
and translucent. Labrum simple. Ventral surface of the head uncarinated.

Maxillary palpi paler, pubescent, four-segmented, first two segments as in
Dalmonexus; third quadrate with a slightly convex external, and a straight,
shorter internal face, slightly wider than second and one-third as long; fourth
one-half wider than third, four times as long, obliquely truncate at base, apically
narrowed, with a small palpal cone.

Antennae eleven-segmented, widely separated at base, perfectly simple;
segments as in Dalmonexus.

Pronotum transverse, apical three-fourths transversely ovate; basal fourth
suddenly narrower; these two portions separated by a deep, arcuate, transverse
sulcus. This antebasal sulcus becomes broader laterally where it is overhung

276 NEOTROPICAL PSELAPHIDAE

with a brush of long setae, and then extends down each pronotal flank. Neither
median nor lateral foveae discernible. A unique feature is a short accessory
sulcus, each side near lateral margin, which arises from the basal margin and
extends obliquely mesiad to enter the transverse sulcus.

Each elytron with an entire sutural stria ; no basal foveae but with a faint
intrahumeral impression ; flank with a longitudinal carina extending from apical
margin and continues as a strong feature to apical third of elytral length, grad-
ually fading out between apical third and apical half; basal half of flank per-
fectly simple.

Metathoracic wings well developed.

Five visible tergites in a length ratio of 2/1/1/1/1 with margins as follows:
first three each side with a subentire, subparallel external and internal carina,
these carinae well-formed, the external following the arc of the elytral carina.
Internal carina of first basally bifurcated.

Six sternites in a length ratio of 1/1/.4/.3/.3/1.5. First visible from side to
side, and with a large circular, pubescent fovea between posterior coxae. Sixth
sternite with apical margin produced. Penis partially extruded in holotype.

Metasternum with a median longitudinal sulcus.

Intermediate coxae narrowly separated by an unusually long and narrow
mesosternal process. Posterior coxae moderately separated by a distance equal
to half the median metasternal length. Intermediate trochanters triangular, with
a spine at center of ventral face. Posterior tibiae entirely arcuate. Tarsi thick,
tarsomeres of usual length proportions, with a large tarsal claw.

Allotype Female. Similar to holotype save that (1) the head is simple, the
lateral incisure narrow, oblique and pubescent; vertexal foveae simple con-
nected by a narrow, anteriorly arcuate sulcus which is bounded apically by the
arcuate, tumid interantennal line of the simple front; clypeus simply declivous;
(2) tergite ratio 3/1/1/1/1; (3) sternite ratio 1/1.2/.5/.3/.5/1.2; (4) inter-
mediate trochanters unarmed.

Erected on three specimens (holotype, allotype, male paratype) from rotten
log mold at Miller 3, by the author on July 29, 1936, on Barro Colorado Island,
Gatun Lake, Panama Canal Zone. The allotype and paratype had recently
pupated.

By the 1908 arrangement of Raffray, Phybytharsis is nearest Batrybraxis.
It differs from Batrybraxis in numerous ways, among which may be noted:
pronotum with accessory, oblique sulci between basal margin and transverse
sulcus, and lacking lateral foveae; elytral flank with longitudinal carina in
apical third; it is also related to Dalmonexus but is distinct in lacking basal
elytral foveae and on posterior coxal separation.

The remaining four tychine genera are distantly related by the essential
tribal characters and have little in common save the perfectly simple elytra.

DALMOPHYSIS (Raffray, 1896)

This is a monotypic Mexican genus with no nearly allied relatives, as
demonstrated by the following combination of characters: (1) Vertexal foveae

TYCHINI 277

well-formed, on a line which passes through the posterior margin of the eyes,
and placed on the simply convex, wholly unmodified head; (2) Antennae simple;
(3) Pronotum ovoidal with the usual antebasal, transverse sulcus; (4) Elytra
perfectly simple, lacking basal foveae, with wholly unmodified flanks and lack-
ing a satural stria; (5) Abdomen without any traces of marginal carinae, which
in itself is unique among neotropical genera; (6) Second tergite conspicuously
longer than first or third; (7) Six sternites in the female sex; seven sternites in
the male sex, this seventh sternite being very small, triangular, and not longi-
tudinally divided.

cylindrica Raffray. 1896. Mexico. Genotype.

INIOCYPHUS (Raffray, 1911)

This is a monotypic Brasilian genus known only from the male sex, and
equally unrelated to other Tychini as indicated by the characters set forth in
the generic key. In addition to these it should be mentioned that the male sex
has six sternites only ; the abdomen is conical with the first three tergites nar-
rowly, but distinctly margined.

iheringi Raffray. 1911. Sao Paulo, Brazil. Genotype.

ANOPLOBRAXIS new genus

This genus is distinct from other Tychini on the following combination of
characters: (1) Head transverse, with prominent eyes placed at middle of head;
(2) Ventral surface of head simple, lacking median longitudinal carina; (3)
Antennae widely separated beneath distinct ovoidal tubercles, eleven-seg-
mented, highly abnormal in the male sex; (4) Maxillary palpi simple, elongate,
and slender, four-segmented, with distal segment bearing a palpal cone; (5)
Pronotum nearly as long as wide, disc simple, with an antebasal, transverse
sulcus connecting a large, deep, pubescent fovea each side; (6) Each elytron
perfectly simple, lacking any modification of the flank, lacking basal foveae
and with rudimentary sutural stria; (7) Abdomen with first three tergites dis-
tinctly margined each side and male with six sternites; (8) Posterior coxae dis-
tant, separated by a distance equal to three-fourths of the median metasternal
length.

Its novelty is enhanced by living with termites.

Anoplobraxis guianensis new species

Type Male. Measurements: Head 0.26 x 0.361 mm. through eyes; pronotum
0.335 X 0.35 mm.; elytra 0.56 x 0.737 mm.; abdomen 0.388 x 0.53 mm. Total
length 1.54 mm. Greatest width 0.74 mm. (PI. XIX, 2).

Brownish-yellow with flavous, long shaggy pubescence; integument lightly
punctulate.

Head transverse with rounded tempora which are as long as wide; eyes
prominent, at middle of head, as long as tempora, with about 24 rather large
facets ; vertex evenly convex, bisected at base by a short, low, thick carina which

278 NEOTROPICAL PSELAPHIDAE

is recessed in the integument. Sides of head sharply narrowed and angulated just
anterior of eye, the angle continued mesio-obliquely as a deep, pubescent in-
cisure, and then elevated into an ovoidal, distinct antennal tubercle each side.
A small vertexal fovea lies as the end of each incisure. Front between antennal
tubercles flat, with a drum-shaped platform or circular tumulus at middle of
flattened inter-antennal line. Front below int^rantennal line, and clypeus decliv-
ous and perfectly simple; labrum simple; ventral surface of head simple. Tem-
poral beard well-developed.

Maxillary palpi yellow, four-segmented, moderately elongate and slender;
first segment short, slightly wider than base of second; second elongate, slender
and arcuate in basal two-thirds, gradually broader in apical third; third one-
third as long and subequal in width to second, elongate-triangular; fourth one-
fourth longer than second and distinctly wider than third, subtruncate at base,
broadening to middle, thence narrowing to acute, minutely truncate apex which
bears a distinct palpal cone.

Antennae half as long as body (0.74 mm.), distant, eleven-segmented, very
abnormal; segment I large, elongate-cylindrical, as long as next three united
(0.134 mm.) and as wide as sixth; II elongate-ovoidal; III-VI subequal in
length, third briefly obconical, fourth moniliform, fifth transverse-moniliform,
sixth slightly wider with mesial face narrowly, subacutely produced ; VII longer
and wider, transverse-pyramidal, with mesial face also strongly produced ; club
distinctly formed of next four segments; VIII, IX and X very irregularly but
strongly transverse, with their ventral faces deeply and completely excavated,
each excavated face at a different plane than the other two, and the eighth also
with a pubescent, laminoid horn on its dorso-mesial face; XI much narrower
than any of the preceding three but as long as preceding four united (0.19 mm.) ,
base circular and regularly truncate, segment in two parts, a basal subcylindri-
cal half and a conical half set within the circular distant rim of the wider basal
portion reminiscent of the condition in Thesium.

Pronotum subquadrate with evenly convex disc and gradually diverging
sides to basal fourth where the margins become obliquely narrowed ; base crossed
by an arcuate antebasal sulcus at this point, the sulcus deepening laterally to
end in a large, very deep, pubescent fovea each side.

Scutellum small, acute-triangular.

Elytra entirely simple, lacking basal foveae and with unmodified flanks;
sutural stria rudimentary.

Wings present and moderately well-developed.

Abdomen with five visible tergites in a length ratio of 2.5/1/1/1.5/.8 and
margins well-formed as follows: first each side with a pair of strong, arcuate,
parallel, subentire carinae; second and third with a single, straight carina for
basal half on each side.

Six stemites in a length ratio of 1.2/1.2/.7/.5/.4/1.2 and all simple and
convex; first visible from side to side, with a large circular, pubescent fovea
between posterior coxae as in Phybytharsis ; sixth with apical margin simply
rounded.

TYCHINI 279

Posterior coxae widely separated by a distance equal to three-fourths the
median metasternal length as in Dalmodes and Bythinophysis.

Intermediate trochanters each with a long, oblique, translucent spine on
ventral face. Femora not inflated, but tibiae, especially the posterior pair, ar-
cuate. Tarsi long (posterior pair nearly two-thirds as long as their tibiae) , three-
segmented ; first tarsomere short, obconical-triangular ; last two relatively very
long as usual, with the second longest and the third bearing a long, acute tarsal
claw.

Described on a single male specimen, collected April 20, 1924, at Kartabo,
British Guiana, in the nest of a new species of Anoplotermes (Anoplotermes)
by Alfred Emerson. Professor Emerson's field notes disclose that the beetle was
collected unnoticed with tennites of the colony and discovered later in the vial.
There are no ecological data to show this species is a definite termitophile but
the fact that it was collected with the termites indicates toleration by the host
and hence we can suggest that guianensis is a synoekete. On the other hand, the
well-formed eyes and wings as well as the normally formed mandibles and max-
illae suggest a nonsymphilic role. These latter characteristics are to be treated
with reserve since some true symphiles (Fustiger) have both eyes and wings,
although the mouth-parts are reduced, while other pselaphids live a nonsym-
philic, predaceous life, but are blind and wingless.

The new genus and species is a welcome addition since it adds a species to
the few pselaphids associated with Isoptera, and is one of the very few psel-
aphids recorded from British Guiana. In the 1908 Raffrayan arrangement
Anoplobraxis becomes associated with Dalmodes and Bythinophysis in the
tribal key but is rapidly separated from these two aggregates since they have
the elytral flanks longitudinally sulcate.

BATRYBRAXIS (Reitter, 1882)

This is an important genus of neotropical Tychini, organized on the follow-
ing combination of characters: (1) The head is large, more or less transverse
and the vertex, front and ventral surface of the head are often very complex,
armed, excavated or fasciculated in the male sex whereas the females are gen-
erally conservative and appear very differently from males of the same species;
(2) Antennae eleven-segmented, widely separated on the antero-lateral angles
of the head, and often highly abnormal in the male sex, this range of abnormal-
ity varying greatly among the species; (3) Maxillary palpi four-segmented,
moderately elongate and slender; first segment always very small, obconical to
subcylindrical; second much longer, elongate, slender and arcuate in basal half
and strongly inflated near apex; third obconical, about as wide as second, but
from a third to a fourth as long, much longer than wide; fourth widest and
longest, varying from cuneiform to securiform, with the apex bearing a palpal
cone; (4) Pronotum transverse, with evenly convex, simple disc and transverse
antebasal sulcus connecting a lateral fovea each side ; at this level the pronotum
is usually suddenly naiTower, or the pronotal outline may be subcordiform;
(5) Elytra are simple, they lack basal foveae, although faint dorsal depressions

280 NEOTROPICAL PSELAPHIDAE

may be present, and the elytral flanks lack f oveae, sulci or carinae ; the sutural
stria of each elytron, however, is strongly developed; (6) Abdomen with five
visible tergites and six sternites in both sexes ; first tergite conspicuously longer
than second ; first two sternites long, the second varying from slightly longer to
much longer than the first; (7) The posterior coxae are only moderately sepa-
rated by a distance which varies from one-third to nearly one-half the median
metasternal length; (8) Three-segmented tarsi with the first tarsomere very
short; next two relatively elongate, the second longest and elongate-obconical
while the third is thinner, cylindrical and bears a large, acute claw and an
accessory bristle.

The size is small and the body typically thick, convex, and more or less
ovoidal. They appear to inhabit the forest floor mold by day and the species are
probably much more numerous and widely spread than our meagre knowledge
indicates.

The following species are new:

Batrybraxis panamaensis new species

Holotype Male. 0.93 mm. long; 0.50 mm. wide; antennae 0.4 mm. long.

Light brown with legs, maxillary palpi, and swollen seventh antennal seg-
ment yellow; integument shining, uniformly but minutely punctulate; pubes-
cence flavous, moderately long, abundant, and semierect on body save abdomen
where it is subappressed. Temporal beard well-developed.

Head transverse and structurally very complex; tempora very short and
wide, only half as long as eyes; eyes small, far down on sides of head but promi-
nent, placed in basal third, and composed of about 32 small facets. Occiput me-
dianly, longitudinally sulcate. Vertex high, transversely vaulted from occiput
to opposite anterior eye margins, and at this point the vaulted area is abruptly
and vertically declivous. This transverse declivity forms a crest which is modi-
fied as follows: the median third of the crest is lower than the lateral thirds and
holds a pair of erect, oblong, truncate horns while each lateral third of the crest
is in the form of a laminoid plate which becomes lower nearer each eye. The head
is laterally excavated anterior to the eye as usual by a narrow, pubescent, deep
and parallel-sided incisure. The vertexal f oveae are not discernible as such. The
vertex just anterior to the transverse crest (in line with the lateral incisures)
is ornamented by a median, semi-circular crest whose posterior edge is roundly
elevated into a subcornuate pubescent process which nestles against the median
horns of the transverse crest. What I take to be the homologues of the vertexal
foveae are two roughened depressions, one at each end of the just noted semi-
circular crest, these indentures probably mark the anchorage of the supra-
tentorium to vertex. The inter-antennal line of the front is marginally tumid
and semi-circular in outline, with a small foveoid indenture each side which
marks the articulation of the first antennomere. Clypeus simply vertical. Ventral
surface of the head perfectly simple.

Maxillary palpi as described for genus.

Antennae eleven-segmented, distant, abnormal; segment I elongate-cyl-

TYCHINI 281

indrical, only shorter than eleventh ; II ovate, smaller than first but only shorter
than first, tenth or eleventh; III minute, obconical; IV-VI gradually, slightly
wider but subequal in length to third, transversely moniliform; VII abnormal,
very transverse, wider than any segment save last two, with the mesial face pro-
duced, of a yellow color (glandular?) ; VIII and IX pyramidal; X trapezoidal;
XI not much wider than tenth but almost as long as preceding four united,
shaped as in Anoplobraxis.

Pronotum obviously transverse, formed as in Dalmonexus.

Elytra perfectly simple, as in Anoplobraxis save that the sutural striae are
strongly developed.

Wings long, well-developed, iridescent, fringed with long setae.

Abdomen with five visible tergites in a length ratio of 2/.6/.5/1/.6 with
margins well-formed on sides of first tergite, consisting of two high, parallel,
straight, subentire carinae.

Six sternites in a length ratio of .6/1.3/.3/.3/.4/1 and unmodified save that
first sternite has a circular pubescent fovea between posterior coxae.

Posterior coxae not distant, separated by a distance equal to one-third of
the median metasternal length. Intermediate and posterior trochanters each
armed with a long translucent spine on the ventral face. Tarsi as described for
genus.

Allotype Female. Similar to holotype save that (1) occiput is simply me-
dianly indented instead of sulcate; (2) vaulted vertex simply declivous to a
point opposite the lateral incisures and wholly unarmed. Despite this simplified
field the vertexal foveae are not discernible as such; (3) Antennae perfectly
simple, the seventh segment small and intermediate in size between the sixth
and eighth and the distal segment much more ovoidal; (4) Trochanters un-
armed.

Described on two specimens collected by the author on Barro Colorado
Island, Gatun Lake, Panama Canal Zone, from beneath bark. The holotype on
July 27, 1936, at Zetek 23 and the allotype on July 26, 1936, at Zetek 0.

Batrybraxis bowmani new species

Type Male: 0.90 mm. long; 0.47 mm. wide; antennae 0.43 mm.

Yellow with shining, sparsely punctulate integument; pubescence short and
erect on head, long and semierect on pronotum and elytra, subappressed on
abdomen; no temporal beard.

Head one-fourth wider than long; tempora prominent, longer than wide,
nearly rectangular; eyes as long as tempora, median, much less convex and
prominent than in panamaensis, reniform, composed of 28 facets. Occiput
broadly, medianly indented but not sulcate. Vertex vaulted above eye-line, the
tumidity being deeply, simply, medianly excavated with each side of the ex-
cavation erected into a strongly arcuate cornuate cusp, and the vaulted area
sharply declivous each side at antennal base. At this latter point each lateral
margin is obliquely, deeply, narrowly incised in the usual pubescent, parallp'

282 NEOTROPICAL PSELAPHIDAE

sided furrow. Anterior to this line (which passes well beyond eyes, skirting the
vertexal declivity and ending each side in the lateral incisure), the front is di-
vided by two longitudinal depressions into three areas: a lateral tumidity above
each antennal base, and a median elevation which posteriorly bifurcates into a
pair of teeth. These median, sharp teeth lie just opposite the median vertexal
excavation, and therefore are framed by the larger vertexal cusps. As in pana-
maensis, I could not discern vertexal foveae. The inter-antennal area just de-
scribed is perfectly semicircular in outline, and ventrally merges with the
clypeus in a simple vertical descent. Labrum simple. Ventral surface of the head
perfectly simple and unmodified.

Maxillary palpi as described for genus.

Antennae eleven-segmented, distant, normal; segment I elongate-oval, half
as long as eleventh but longer than any other segment; II nearly as wide and
half as long as first, quadrate; III-VII small, third obconical, others moniliform;
VIII and IX subpyramidal, increasingly transverse, the ninth about as wide as
second; X is asymmetrically trapezoidal, wider than first; XI as in panama-
ensis.

Pronotum as in Dalmonexus.

Elytra as in panamaensis.

Wings present.

Abdomen with five visible tergites in a length ratio of 1.5/.6/.6/1/.6 and
with margins as in panamaensis. Six sternites in a length ratio of .6/1.4/.3/
.4/.5/1 with first stemite visible from side to side and with the usual pubescent
fovea between posterior coxae.

Posterior coxae approximate, separated by a distance equal to one-fourth
the median metasternal length. Intermediate and posterior coxae each armed
with a long translucent spine on the ventral face. Tarsi as described for genus.

Described on a single male collected by the author on July 28, 1936, from
log mold at Zetek 17 on Barro Colorado Island, Gatun Lake, Panama Canal
Zone, and named in honor of Dr. John R. Bowman in recognition of the labor
involved in bringing the descriptions of North American pselaphids between
two covers.

Bowmani is congeneric with panamaensis but is quickly separated by the
simple male antennae, wholly different head and more narrowly separated pos-
terior coxae. It is possible that additional information will cause us to place
these two species in a new genus because of the lack of vertexal foveae per se.

The species of Batrybraxis may be listed as follows:

bowmani new species. Panama Canal Zone.

curtula Reitter. 1882. Blumenau, Sao Paulo, Brazil. Genotype.

jortis Reitter. 1882. Sao Paulo, Brazil.

infiexa Schaufuss. 1887. Mexico.

longipennis (Raffray). 1890. Tovar Colony, Venezuela. {Batrisus:
Arthmius)

panamaensis new species. Panama Canal Zone.

punctipennis Reitter. 1882. Petropolis, Brazil.

Tribe 9. Goniacerini

The Goniacerini are highly evolved brachysceline pselaphids, representing
one of the apices of specialization in the family. The tribe has few genera and
few species. Its zoogeographic penetration is limited to tropical Africa and tropi-
cal America, with the latter region being more abundantly represented in both
genera and species.

Taxonomically, Goniacerini are differentiated from other pselaphids by the
following combination of characters: (1) head narrowed anterior to the eyes
to form a prominent, median frontal antennal tubercle; (2) antennae subcon-
tiguously articulated on this tubercle, with a long first segment and strongly
geniculate (as in the Metopiini), and with the genera varying in number of an-
tennal segments from five to eleven; (3) abdomen with five visible tergites,
and six sternites in both sexes ; first stemite longer than posterior coxae, clearly
visible from side to side (as in the Tychini) ; abdomen with strongly formed,
flattened abdominal margins; (4) trochanters short, with the femora obliquely
articulated on them so that the corresponding coxa and femur are subcontig-
uous; (5) posterior coxae with their mesial articulating faces subtriangular, not
conically produced; (6) tarsus three-segmented, strong, first segment small and
triangular, second and third segments relatively much longer than first ; third
segment bearing a large tarsal claw and in some groups an accessory bristle-like
claw; (7) maxillary palpi short, small, and always appear three-segmented.
However, this will probably prove erroneous when all of the genera have been
fully investigated. Fletcher (1927) found that the maxillary palpi of Bibrax
bradleyi have four segments, but that the first was very minute and visible only
after dissection; second strongly arcuate, apically inflated; third ovate-elon-
gate; fourth ovate-elongate with an obtusely pointed apex, obliquely truncate
at base, with a short thick palpal cone. Raffray (1890) found that the appar-
ently three-segmented maxillary palpi of Goniacerus perforatus were in reality
four-segmented on dissection, the first relatively large and sharply arcuate.
Raffray (1908, p. 295) states that the maxillary palpi are three-segmented for
the tribe, (p. 297) demonstrates only three segments for Ogmocerus giganteus
of Abyssinia, and later (1908, pi. 8, fig. 55) figures only three segments for this
species, although Fletcher (1927) thought that this Raffrayan figure showed
four segments. From such data it appears that a great deal of morphological
work, especially with prepared microscope slides, needs to be done on the gon-
iacerine mouth-parts.

The individuals of this tribe seem to be very uncommon, and nothing is
known of their ecology. The neotropical genera may be separated by the follow-
ing key:

(283)

284 NEOTROPICAL PSELAPHIDAE

Antennae of eleven segments BIBRAX

Antennae with less than eleven segments 2

2. Antennae of six segments 3

Antennae of five segments 4

3. Antennal segment I convex on dorsal face, concave on ventral face,

with the face margined for its entire length by a thin, denticulated

lamella LISTRIOPHORUS

Antennal segment I cylindrical, gradually thickened and slightly
sinuate to apex GONIACERUS

4. Antennal segment I strongly elongate, slightly sulcate mesially; II

subquadrate; III oblong in females and obconical in males; IV
quadrate; V oblong-cylindrical, with an acute apex; wide abdominal
margins limited externally and internally by carinae; known only

from Paraguay GONIACEROIDES

Antennae not as described ; abdominal margins narrower, in the form
of a flattened, narrow, sharply cut lamina ; known only from Brazil 5

5. Antennal segment I elongate, deeply sulcate on dorsal face, with the

internal face having a thin denticulated marginal lamina as in
Ldstriophorus ; II slightly transverse; III cylindrical; IV slightly
longer than wide, cylindrical; V ovoidal-acuminate. .GONIASTES
Antennal segment I elongate, convex on dorsal face, concave on ventral
face, slightly sinuate; II small, transversely triangular; III large,
strongly obconical and with the ventral face excavated; IV trans-
verse, slightly wider at apex than third; V slightly narrower than
fourth, slightly longer than wide ADROCERUS

BIBRAX (Fletcher, 1927)

This monotypic genus has its nearest apparent ally in the Ethiopian Ogmo-
cerus because of its eleven-segmented antennae and strong abdominal margins.
Its aspect is similar to the Metopiini with non-spinose pronotum (Metopiellus,
Metopiosoma, Barrometopia) . Males have the fourth stemite medianly flattened
and shining; fifth with a large transverse depression; sixth (last) stemite with
a deep circular apical fovea. Females with sternites simply, evenly convex. Eyes
composed of a single facet. Maxillary palpi four-segmented.

bradleyi Fletcher, 1927. Barro Colorado Island, Gatun Lake, Panama
Canal Zone. Genotype.

LISTRIOPHORUS (Schaufuss, 1872)

This is a monotypic genus with three-segmented maxillary palpi, and bril-
liantly shining integuments. The six-segmented antennae separate it from other
neotropical aggregates with the exception of Goniacerus, from which it is
quickly diagnosed by the remarkable first antennal segment and an entirely
different integumental structure.

felix Schaufuss. 1872. Mexico. Genotype.

GONIACERINI 285

GONIACERUS (Motschulsky, 1855)

This is the largest neotropical genus. The six-segmented antennae have an
entirely different first segment than that of Listriophorus, as noted in the generic
key. The palpi apparently three-segmented. The integument is distinctive, con-
sisting usually of an anastomosing lattice of minute carinules to give a sub-
opaque alutaceous surface. The six stemites are subequal but notable in that
the first and second sternites are fused medianly, although laterally distinct.
As Raffray (1908) has pointed out, this is an interesting approach to the
Cyathigerini, a remarkably specialized tribe holding a single large genus
(Cyathiger) of the Indo-Malayan rain-forest. It is possible that the Cyathi-
gerini are ecological equivalents in the last-named tropical region, of the Gonia-
cerini of the other two great tropical areas.

gibbus (Motschulsky). 1851. Obispo, Panama. Genotype.
setifer (Schaufuss). 1872. Brazil. (Metopioides)
anophthalmus Raffray. 1890. Blumenau, Brazil.
perforatus Raffray. 1890. Caracas and San Esteban, Venezuela, [nee
perforatue of Raffray, 1908)

GONIACEROIDES (Raffray, 1917)
umbilicatus Raffray. 1917. Asuncion, Paraguay, Genotype.

GONIASTES (Westwood, 1870) ;

sulcijrons Westwood. 1870. Brazil. Genotype.
westwoodi Raffray. 1890. Brazil.

ADROCERUS (Raffray, 1890)
cavicornis Raffray. 1890. Brazil. Genotype.

DIVISION II. MACROSCELIA (Raffray, 1890)

The preceding nine tribes form the first division of the subfamily Psel-
aphinae, all having the coxae subcontiguous to their respective femora as a
consequence of the short, obliquely articulated trochanter.

The Macroscelia have the intermediate trochanters elongate obconical
to clubbed apically, with the articulation of the respective femur distinctly
apical, and consequently the intermediate coxa and femur are relatively distant.
This division holds fewer tribes, genera and species.

Tribe 10. Pselaphini

The Pselaphini are poorly represented in the neotropics by two genera
and eight species. They may be differentiated from other macrosceline tribes
by (1) fourth (distal) segment of the maxillary palpi is very long, slender
and pedunculate at base, inflated and clubbed at apex, and (2) the tarsi are
normally formed, with the second tarsomere never bilobed, the third (distal)
tarsomere having only a single large claw. The two genera may be separated
as follows:

Distal segment of the maxillary palpi without a sulcus on the external
face, or if present it is very short and restricted to the apex; vertex
with a deep, median, longitudinal sulcus from near anterior margin
of eyes to apex of antennal tubercle; abdomen relatively long, nearly

as long as elytra PSELAPHUS

Distal segment of the maxillary palpi with an entire longitudinal sul-
cus on the external face from base to apex; vertex with no longi-
tudinal sulcus, at most the apical margin of antennal tubercle in-
cised; abdomen relatively short, much shorter than elytra

PSELAPHELLUS

PSELAPHUS (Herbst, 1792)

Heebst (1792)

Denny (1825)

AuBE (1833)

Reitter (1881)

Raffray (1890, 1904, 1908, 1911)

Ganglbauer (1895)

LeConte (1850)

LeConte and Horn (1883)

Brendel and Wickham (1890)

(286)

PSELAPHINI 287

Casey (1893)
Blatchley (1910)
Bradley (1930)
Bowman (1934)

This genus was the first genus recognized as a pselaphid aggregate, and
historically, therefore, is of great importance. Obviously it is highly specialized,
and far from the norm of the family. Out of more than eighty species of
Pselaphus, distributed over the entire world, the Western Hemisphere is poorly
represented, with five species in the United States and a single species of the
Amazon drainage basin in Brazil.

bizonatus Schaufuss. 1886. Brazil.

PSELAPHELLUS (Raffray, 1908)
Raffray (1908, 1908a, 1911)

The remaining genus of neotropical Pselaphini is restricted to the area,
extending from Guatemala to Argentina. It is closely allied to Pselaphus.
No ke}^ is attempted as I am unfamiliar with the genus save for a single species.

bicolor Raffray. 1911. Buenos Aires, Argentina.
convexus Raffray. 1908. Buenos Aires, Argentina.
elegantissimus (Schaufuss). 1886. Brazil. (Pselaphus)
longiceps (Sharp). 1887. Paso Antonio, Guatemala. {Pselaphus)

{laeviceps Raffray, 1904; laviceps Raffray, 1908)
opacus (Schaufuss). 1886. Brazil. (Pselaphus)
pallipes Raffray. 1908. Buenos Aires, Argentina.
vestitus Raffray. 1908. Buenos Aires, Argentina.

Tribe 11. Holozodini

This is a small tribe of macroscelines holding two specialized genera, one
of which [Holozodus) occurs in Madagascar, while the other is known from
the neotropics. This tribe, then, has a parallel zoogeography to the Goniacerini,
in that both are confined to two out of three of the world's great tropical and
subtropical regions.

As in Pselaphini, the tarsi have a single tarsal claw and the second
tarsomere is not bilobed; they differ from Pselaphini in that the ventral
surface of the head is flattened, rather than gibbous, and the maxillary palpi
are radically different. These palpi are very small. Sharp (1887, p. 22) in
erecting Caccoplectus stated that the maxillary palpi "are unusually minute,
so that I can only with difficulty obtain a sight of the terminal joint." Raffray
(1908, p. 316) describes these palpi as follows: segment I invisible, II slightly
arcuate and slightly inflated apically. III very small and slightly triangular,
IV hardly as long as the preceding two united, briefly ovoidal and apically
obtuse.

CACCOPLECTUS (Sharp, 1887)

There are two species in this genus, the genotype, and a second species,
spinipes Schaeffer (1906) known from Texas.

celatus Sharp. 1887. Zapote, Guatemala and Mexico. Genotype.

(288)

Tribe 12. Hybocephalini

In a regional study such as the present paper, this tribe is difficult to
integrate. There is a single hybocephaline genus in the neotropics (Ephimia) ,
and this genus differs from other genera of the tribe in having two equal tarsal
claws. This tribal abnormality taken together with the nonbilobed and simple
second tarsal segment, and general habitus and pubescence runs an example
either to the Ctenistini or Tyrini — never to the Hybocephalini!

The species are very uncommon and the distribution peculiar, so that a
close comparison of a specimen with the generic characters will serve to isolate
a member of this genus in the neotropics.

EPHIMIA (Reitter, 1882)

Reitter (1882, 1883)
Sharp (1887)
Raffray (1904, 1908)

One of the strangest facts concerning Ephimia is its distribution. It is
entirely insular, with two species in the West Indies and the third species in
the Pearl Islands. Thus both sides of Central America are inhabited, without
any species yet described from the mainland.

Head longer than wide, with prominent eyes placed behind the middle,
very short oblique tempora; narrowed anterior of the eyes to form a long
truncate vertex terminating in an antennal tubercle. The antennae are sub-
contiguous, eleven-segmented, the segments closely articulated with the inter-
mediate segments transverse and a three-segmented club. Maxillary palpi four-
segmented: first small, visible, subglobular; second arcuate, slender at base,
elongate and apically inflated ; third obconical, about as wide as second ; fourth
much larger, ovoidal, apically acuminate, with stiff pubescence and a minute
palpal cone.

Pronotum slightly longer than wide, convex, with three large, free, densely
pubescent basal foveae of which the median is very visible from a dorsal
view but the laterals far down on the sides.

Elytra each with a large basal pubescent fovea, and sutural stria but with-
out definite humeral angle and no dorsal stria.

Abdomen with five visible tergites, the lateral margins very widely and
strongly margined as in Tyrini; six stemites in both sexes. Intermediate, and
posterior, coxae widely separated. Intermediate legs macrosceline, the legs
thick and long; tarsi thick and short, three-segmented, with the first segment
small, last two relatively larger, but the second is only about half as long
as the third, the third bearing two short equal claws.

(289)

290 NEOTROPICAL PSELAPHIDAE

The integument is shining where it is not densely pubescent ; the pubescence
complex. Thus the tempora, sides of head and the area anterior of the eyes
have squamous setae; antennal segments densely pubescent, obscuring the
articulation; distal segment of maxillary palpi has the apical half covered with
short, spike-like setae; pronotal foveae have spongy pubescence; basal elytral
fovea and apical area densely pubescent; general body pubescence dense and
in the form of subappressed to appressed, thick-shafted setae.

To the author, this genus presents one of the most perplexing taxonomic
problems in the neotropics, and it is possible that Ephimia will have to be
taken from the Hybocephalini entirely, in which case the tribe will not be a
neotropically represented group. The reader is requested to study the remarks
made under the genus Juxtahamotopsis of the Tyrini for further discussion.

Key to the Species

Known only from the Antilles; length less than two millimeters. ... 2

Known only from Pearl Islands ; length two millimeters

crassicornis

2. Antennal segments III to VIII strongly transverse, only slightly

lenticular; known only from the Windward Islands 3

Antennal segments III to VIII strongly, transversely lenticular; known
only from the Virgin Islands simoni

3. Antennal segments IX and X of equal length; 1.6 mm

subnitida Male

Antennal segment X nearly twice as long as IX. .subnitida Female

crassicornis Sharp. 1887. San Miguel, Isla del Rey, Pearl Islands.
simoni Reitter. 1882-1883. St. Thomas, Virgin Islands. Genotype.
subnitida Raffray. 1904. Grenada, Windward Islands.

Tribe 13. Gtenistini

In the neotropics this tribe is poorly represented by four genera and twelve
species, one genus and species of which may be incorrectly assigned to the
region.

These are clearly separated from other macrosceline tribes by the key
characters: second tarsomere normal, not bilobed; tarsi with two large, equal
to subequal claws; pubescence always in the forai of scales. This scaley
pubescence has a characteristic structure, as illustrated (PI. IV, 6-11), and
is never entirely absent; it is especially dense in the temporal areas, in sulci
and foveae of the pronotum and elytra, and at articular surfaces of the ab-
dominal segments. In addition, the Gtenistini are separable from the Tyrini
by the form of the epistome. In Gtenistini the epistome is relatively very large
and expanded or tumid between the labrum and the frontal tubercle, and this
tumidity may be so pronounced that the lateral margins of the clypeus are
auriculate; in Tyrini the epistome is large but is never laterally expanded or
auriculate, never conspicuously tumid between labrum and frontal tubercle.
The Gtenistini may be separated from the hybocephaline Ephimia with greater
difficulty, although the latter genus never has the greatly expanded epistome.

The three-segmented tarsi have the last two tarsomeres much larger than
the first, but the second is never as long as the third; tarsi have two large
equal claws.

A number of Gtenistini inhabit the society of ants (Bruch, 1929; Gasey,
1893; Mann, 1911, 1914, 1924; Wickham, 1889, 1892, 1900).

Key to the Genera ^

Second (apparent first) segment of maxillary palpus with a lateral
appendage on external face, this appendage may be long or short,
and terminates in a bundle of setae (PI. IV, 22) 2

Second (apparent first) segment with the external face without trace
of tubercle or appendage ENOPTOSTOMUS

2. Third and fourth segments of maxillary palpus always wider than

long, transversely ovoidal to transversely triangular 3

Third and fourth segments always longer than wide, elongate tri-
angular to acuminate-fusiform GTENISIS

3. Fourth segment of maxillary palpus with the apical face rounded,

and without a terminal palpal cone (not to be confused with an
appendage of the external face) (PI. IV, 22) PILOPIUS

*If the specimen has run to Gtenistini in the tribal key (p. 31), and none of the seg-
ments of the maxillary palpi have conspicuous lateral appendages, it is either an unrecorded
neotropical genus of Gtenistini or belongs to Ephimia of the Hybocephalini (p. 289).

(291)

292 NEOTROPICAL PSELAPHIDAE

Fourth segment with apical face angulate and bearing at angulate
apex a slender palpal cone, in addtion to the appendage of the
external face CTENISODES

In the above generic key I have material in all four genera so that I am
confident of the larger taxonomic aggregates but less so of the limits of many
of the species. In two cases I have assigned my specimens to species previously
described. These species were named many years ago and the structural detail
is very incompletely set forth. The sympathetic reader will understand the risk
taken in such cases, yet without the types for direct comparison I am unable
to state positively that the material is new to science in these two particular
instances.

ENOPTOSTOMUS (Schaum, 1864)

This fairly large genus is found in Africa, Asia Minor, and as far north
as Portugal and Greece, and as far east as Sumatra. In addition a single species
is placed here with doubt by Raffray from the neotropics. I share Raffray's
apprehension that it may belong to some other genus but do not know the
species. My material in the genus belongs to Enoptostomus aubei (Rosen-
hauer) collected by Simon at Algeciras, Cadiz, Spain, and identified by the
illustrious Reitter. The maxillary palpi are so different from other genera that
should another specimen of clandestinus be found the question of generic
status can be quickly answered.

clandestinus Schaufuss. 1886. Brazil, (cf. Raffray, 1904, 1908)

CTENISIS (Raffray, 1890)

Raffray (1890, 1896, 1904, 1908, 1908a)
Sharp (1874) (Tetrads), (1887) {Desimia)
Casey (1893)
Bowman (1934)

In this genus, where both sexes are known for the same species, the sex
can be diagnosed by the antennal proportions. The males have a prominent
club formed by the last four segments (VIII-XI) which are generally elongate-
cylindrical; the eighth segment is conspicuously larger than the seventh, and
segments IV-VII very small. The females have segments IV- VII relatively
larger than the same segments of the male, the eighth segment is similar to the
seventh, and the club is more or less composed of the last three segments.

Key to the Males

Segment VIII as long as the four preceding united 2

Segment VIII as long as the five preceding united 4

2. Not known south of Mexico rajjrayi

Not known north of the Amazon basin 3

CTENISTINI 293

3. Head with a very long, recurved infraocular spine amazonica

Head without an infraocular spine, but with a small pencil of setae

below each eye nasuta

4. Not known south of Guatemala dispar

Not known north of Colombia 5

5. Head with a very long, recurved infraocular spine aequinoctialis

Head with a very thin, nearly straight infraocular spine . . . angustata

Key to the Females

Not known south of Guatemala dispar

Not known north of Colombia 2

2. Apparently indistinguishable on the described characters:

aequinoctialis
amazonica

Only three of the above six species have known females, and this key
does not include fasciculata and gracilis. The species may be listed as follows:

aequinoctialis (Aube). 1844. Matto Grosso, Brazil and Valencia,

Colombia. (Also recorded from Amazon basin)
amazonica Raffray. 1896. Amazon basin, Brazil.
angustata Raffray. 1896. Argentina.

dispar (Sharp). 1887. Cordova, Mexico and Paraiso (300 feet),
Guatemala, {brevicollis Raffray, 1896)
Genotype. (Desimia) .

I have a female of what I consider dispar from Sabinas Hidalgo,

Nuevo Leon, Mexico, collected June 14, 1941, by Charles Seevers.

This locality is in northern Mexico, is not rain forest, and extends

the range of Sharp's species materially.

fasciculata Raffray. 1908. Buenos Aires, Argentina, con Solenopsis

richteri Forel, cf. Bruch, 1929.
gracilis Raffray. 1908. Argentina.
nasuta Raffray. 1896. Amazon basin, Brazil.
raffrayi Casey. 1893. Tucson, Arizona, and Mexico, {dispar Raffray,

1896, nee Sharp.)

PILOPIUS (Casey, 1897)
Casey (1897)
Bowman (1934)

This genus is typical of the nearctic fauna. Out of sixteen species, thirteen
are found within the United States, including the genotype Pilopius lacustris
Casey; one species is reported from Japan (Pilopius discedens (Sharp), 1883;
cf. Raffray, 1904, 1908) ; one species, Pilopius zimmermani (LeConte) has a
remarkable range for a pselaphid if the species population is truly homogen-
eous; and one species is reported from the neotropics.

294 NEOTROPICAL PSELAPHIDAE

This generic distribution pattern is exceptional in pselaphids, and indi-
cates that the genus has dispersed southward from a nearctic center. A com-
moner pattern is the reverse situation, with species dispersing northward from
a neotropical center. The scant representation of Ctenistini in the neotropics
is additional indirect evidence that this tribe originated elsewhere.

major Mann. 1914. San Miguel, Mexico, con Prenolepis (Nylanderia)

mexicana Forel.

zimmermani (LeConte). 1850. {Ctenistes auct. nee Reichenbach)
United States (Indiana south to Florida,
Georgia and Louisiana) ; Mexico; Colombia;
Amazon basin, Brazil!?

CTENISODES (Raffray, 1897)

Raffray (1897, 1904, 1908)

Erected on a female specimen, 1.6 mm. long, with unique maxillary palpi.
The genus approaches Ctenisis. Unfortunately the male sex is unknown. It
has not been recorded for forty-four years and I am happy to report another
specimen of this genus and what I consider the same species. The new record
indicates that the genus may be a synoekete in the ant society.

laticeps Raffray. 1897. Mexico. Genotype.

I have a single female from Montemorelos, Nuevo
Leon, Mexico, taken June 16, 1941, by Charles Seevers
with ants. The host is being determined.

Tribe 14. Tyrini

This is an extensive tribe of elegant, large-sized pselaphids distributed
over the world, and notable for the generic diversity of the maxillary palpi.
The tribe reaches a peak in species and individuals in the tropical forests,
and the neotropical forms may be characterized as follows: (1) Pubescence
normally long, abundant, and setiform; never in the form of scales, but at
times very sparse, short, and thick-shafted (this separates the tyrines from
the ctenistines) ; (2) head generally with prominent, multi-faceted eyes placed
medianly or postmedianly; the head generally longer than wide, usually nar-
rowed anterior to eyes, then more or less widened to form a prominent, median,
usually bilobed antennal tubercle. However, in H amotocellus the head is
squarely truncate anterior to the eyes, not narrowed, and the widely separated
antennae are placed on the angles of the subrectangular front; (3) antennae
eleven-segmented, approximate save for H amotocellus, and do not show the
startling specific and sexual abnormalities of Batrisini, Brachyglutini, and
other assemblages previously covered although some exceptions to this will
be encountered in the diagnoses which follow; (4) maxillar\^ palpi four-seg-
mented and generically of the utmost value, showing an almost infinite range
of variation; (5) the pronotum usually cordiform to ovate, usually with three
antebasal foveae which are highly variable in themselves and may or may
not be connected by a sulcus ; disc usually simply convex but may be strongly
gibbous and medianly spinoid (Neotyrus) ; (6) abdomen with a strong margin
each side of the first three visible tergites as a rule ; the tergite length ratio is
of importance both generically and specifically; the neotropical genera have
six stemites in both sexes, and show little sexual diversity as compared to
many other tribes already studied; (7) the trochanters of the intermediate
legs are typically macrosceline, elongate and distally enlarged to articulate
the femora distally so that femur and coxa are not approximate; (8) tarsi
three-segmented, large, the first tarsomere short, the next two relatively much
longer of which the third is always the longest and bears two long, equal claws
(save for Phalepsus, where the tarsal claws are very unequal).

Ephimia of the hybocephalines and Ctenistini are the only neotropical
pselaphids liable to be confused with this tribe. Ephimia has the two equal
tarsal claws very short, and Ctenistini are distinctive as a consequence of
their scaly pubescence and the conformation of the epistomal area previously
alluded to.

The general habitat of Tyrini is the leaf and log mold of the forest floor,
although many species are exquisitely adjusted synoeketes of the ant society
(Park, 1932), or are facultative synoeketes (Park, 1933) and numerous records
are extant of their common occurrence with ants (Blatchley, 1910; Dury,
1898; Hamilton, 1886; McCook, 1877; Park, 1935; Raffray, 1908; Schwarz,

(295)

296 NEOTROPICAL PSELAPHIDAE

1890, 1896, and Wickham, 1894, 1900) . Several of the new species subsequently
described have been discovered with termites.

The neotropical genera may be separated by the following key:

Key to the Neotropical Geneea (PI. XX)

Tarsi each with long equal to subequal claws 2

Tarsi each with two short and very unequal claws. . . .PHALEPSUS

2. Internal face of distal segment of maxillary palpi longitudinally

sulcate (this sulcus may be broad or narrow; entire or only ex-
tending for the apical third) 7

Internal face never sulcate in any part 3

3. Distal segment of maxillary palpus widest near apex which is broadly

convex; this segment has the internal face produced near the apex
into a pointed and pubescent process at right angles to the long axis
of the segment, and from this point the segment narrows rapidly

to the base LETHENOMUS

Distal segment not as above 4

4. Distal segment of maxillary palpi covered with short, bristling,

spike-like setae JUXTAHAMOTOPSIS, new genus

Distal segment nude or with pubescence minute, appressed and in-
conspicuous if discernible 5

5. Distal segment of maxillary palpi with a broad and shallow longi-

tudinal sulcus for the apical fourth of the dorsal face; pubescence
very long and thin with the apical ends of the setae curving in

various directions to intertwine or mat

TYROGATUNUS, new genus

Distal segment and pubescence not as above 6

6. Pronotum with three free antebasal foveae ; first tergite only slightly

longer than second TYROPSIS

Pronotum with antebasal foveae connected by an arcuate transverse

antebasal sulcus ; first tergite longer than next three united

NEOTYRUS

7. Pronotum with an entire transverse antebasal sulcus 8

Pronotum without a transverse antebasal sulcus 12

8. Distal segment of maxillary palpus less than half as wide as long. ... 9
Distal segment nearly three-fourths as wide as long, semicircular in

outline PSEUDOHAMOTUS

9. Third (next to last) segment of maxillary palpus perfectly globular

APLODERINA

Third segment not globular 10

10. Head squarely truncate anterior of eyes, with no antennal tubercle
and the antennae widely separated at the corners of the sub-
rectangular front HAMOTOCELLUS

Head narrowed anterior of eyes, with antennae articulated upon a
more or less bilobed and median frontal tubercle 11

TYRINI 297

11. Tergites I, II, III subequal or decreasing in length

HAMOTOIDES (subgenus of Hamotus)

Tergites I, II, III increasing in length PHAMISULUS

12. Sulcus of distal segment of maxillary palpus confined to apical

half 13

Sulcus of distal segment of maxillary palpus extending beyond apical
half 14

13. Distal segment of maxillary palpus ovate-cylindrical, obliquely

truncate at base, with sulcus extending as an elongate fovea on

apical half of internal face APHARUS

Distal segment gourd-shaped, narrowed basally, ovate in median two-
fifths, and very narrow and elongate-cylindrical in apical half,
with a very narrow and striaform sulcus on apical half of internal
face CERCOCERULUS

14. Apex of distal segment of maxillary palpus lengthily very acute to
aciculate, with a palpal cone one-third the segmental length set in

apex and continuing the long axis of the latter

PSELAPHOCOMPSUS

Apex of segment obtuse, with a palpal cone set obliquely within the
apex of the sulcus of internal face 15

15. Distal segment of maxillary palpus very elongate-cylindrical, nar-

row and subfiliform, with the sulcus of internal face deep but very

narrow 16

Distal segment ovate-fusiform to ovate-conical, obliquely truncate
at base, with a broad sulcus of variable shape, length and depth
HAMOTUS ss.

16. First tergite much longer than other tergites united

CERCOCEROPSIS

First tergite varying from slightly longer to distinctly longer than
second tergite, but never as long as second and third united. . . .
CERCOCEROIDES

PHALEPSUS (Westwood, 1870)

This is a moderately large genus of eight elegant species known from
Brazil and Paraguay. They are of average size (1.3 to 2.0 mm.) with an
elongate-oval, strongly convex outline, very attenuated anteriorly and broadly
rounded posteriorly. They bear somewhat the same relation to the other
neotropical tyrines as Ephimia does to the other hybocephalines, that is they
are aberrant in having the tarsal claws short and very unequal.

The genus, although highly specialized, clearly belongs to the first division
of neotropical tyrines — those having the maxillary palpi nonsulcate. The
maxillary palpi are four-segmented, long and slender; the first segment is
very small and subcylindrical; second very long, subsinuate and pedunculate
through the basal half, becoming inflated apically, with the apical internal
face obtusely angulate; third similar in form to second, but much shorter,

298 NEOTROPICAL PSELAPHIDAE

somewhat narrower, subtriangular, with the internal apical face obtusely
angulate, segment slightly longer than wide; fourth as long or as much as
one-third longer than second, subfusiform, wider than second, very narrow
towards base and apex, the apex more or less lengthily aciculate, and without
a discernible palpal cone. (PI. XX).

The species may be listed as follows:

ampliventris Schaufuss. 1879. Amazon basin, Brazil.

batesellus Westwood. 1870. Amazon basin, Brazil.

cavicornis Raffray. 1904. Matto Grosso, Brazil.

fluminicola Schaufuss. Amazon basin, Brazil.

marelloides Reitter. 1888. Blumenau, Brazil.

nanus Schaufuss. 1879. Amazon basin, Brazil.

subglobosus Westwood. 1870. Amazon basin, Brazil. Genotype.

vulgaris Raffray. 1904. Central Paraguay.

TYROPSIS (Saulcy, cf. Raffray, 1908)

This neotropical genus holds seven species from Chile and two from
Brazil. Since I am unfamiliar with any of the species, I have followed the
1908 treatment of Raffray. It would appear that the taxonomy of the genus
is involved and partially lost in the early records of the family. Blanchard
described Pselaphus castanea (led no doubt to place it in this genus because
of its large maxillary palpi). Reitter, recognizing castanea as not related to the
Pselaphus of Herbst, included Blanchard's species in a new genus, Aplodea.
Previously, however, Saulcy had erected the genus Tyropsis for a beetle in
Chevrolet's collection, and which was supposed to belong to the Mediterranean
fauna but in reality was identical with castanea. Some order was attained
when Raffray was able to examine the Blanchard type in the Museum of
Paris.

Structurally, Tyropsis is homogeneous and typically tyrine. The sexes
are well marked. The males have the last three to five antennomeres variously
excavated or spined as a rule, while the three-segmented antennal club is
simple in the females. The sixth sternite is laterally sinuate and medianly
lobed or produced in the males, and simply transverse in the females. The
last (fifth visible) tergite is gibbous in the males and flat in the females.

Its closest relatives are to be found in Neotyrus, both genera having
similar maxillary palpi and differing in pronotal and tergite structure as
previously set forth in the tribal key.

The maxillary palpi are four-segmented, large and conspicuous; first seg-
ment very small; second and third similar in form, elongate with a slender
base swelling in a rounded apical inflation, the third much shorter and as
wide to slightly narrower than the second segment (the amount of apical in-
flation in both palpomeres subject to specific variation) ; fourth segment
elongate-fusiform, slender at both base and apex, the apex is minutely truncate
with a setiform palpal cone set within this truncature. (PI. XX).

TYRINI 299

Raffray (1904) divided the genus into three groups as follows:

Antennae similar in both sexes Group I

Antennae dissimilar in the sexes 2

2. Head not excavated Group II

Head excavated Group III

The species of Tyropsis have not been increased since 1908 and may be
listed as follows:

I

castanea (Blanchard). Chile. Genotype. [Pselaphus]

(chevrolati Saulcy; elsbethae Reitter;
cosmoptera Schaufuss, nee Blanchard)

hirta Reitter. 1888. Blumenau, Brazil.

pilifera Reitter. 1888. Sao Paulo, Brazil.

valdiviensis Reitter. 1885. Chile.

II

adumbrata Reitter. 1885. Chile.

difformis Schaufuss. 1879. Chile.

palpalis Reitter. 1883. Chile, {praeses Schaufuss, female)

spinula Reitter. 1885. Chile.

Ill

cavifrons Raffray. 1895. Chile, {valdiviensis Schaufuss, 1886, nee
Reitter)

NEOTYRUS (Raffray, 1895)
This is a small neotropical genus of four species, two of which are
termitocolous, related to Tyropsis by the maxillary palpi, but distinct from
this genus on pronotal and tergite differences, as indicated in the tribal key
to genera.

Neotyrus coptocolus new species

Type Male. Measurements: Head 0.43 x 0.47 through eyes; pronotum
0.53 X 0.49 mm.; elytra 0.76 x 1.00 mm.; abdomen 0.62 x 0.87 mm.; total
length 2.4 mm.; greatest width 1.00 mm. (PI. XX).

Reddish-brown with very short, stiff, inconspicuous, and wholly appressed
setae; integument subopaque and coarsely granulate-asperate on antennae,
legs, head, pronotum, and elytral costae; slightly shining, with small and
sparse asperities on abdomen; palpi, vertexal foveae, transverse pronotal
sulcus and elytral intervals glabrous and shining.

Head with rounded tempora as long as eyes ; eyes prominent, placed slightly
behind middle and composed of about 76 very small facets. Vertex and occiput

300 NEOTROPICAL PSELAPHIDAE

vaulted posteriorly with a pair of very small, nude vertexal foveae on a line
through center of eyes, nearer each other than either from an eye, and on the
highest part of the vertex; anteriorly from this point the vertex slopes to the
front. Sides of head suddenly narrowed anterior of the eyes, then suddenly ex-
pand to form a conspicuous antennal tubercle on each side. These tubercles are
deeply and widely separated by a trough-like sulcus which arises just anterior
of the vertexal foveae and extends to the inter-antennal line of front. Front
suddenly declivous at end of this sulcus. Clypeus simple, lower than front and
longitudinally medianly elevated; clypeus hirsute with long, apically-directed
setae in contrast to the general body pubescence. Labrum simple. Genae with a
broad, triangular, infra-ocular spine. Maxillary palpi as described for Tyropsis
save that the apex of the distal segment is thin, more acute, and with palpal cone
set within a very small truncature.

Antennae eleven-segmented, 1.3 mm. long; simple; segment I elongate-
cylindrical; II-VIII subequal in width, slightly narrower than first; second and
third subquadrate, subequal; fourth to eighth submoniliform, slightly decreasing
in length; club distinctly of last three segments; IX longer than eighth, trans-
verse, trapezoidal; X very transverse, trapezoidal, much wider and shorter
than ninth; XI very large and coarsely asperate, wider than tenth and nearly
as long as preceding three segments united, truncate at base, broadly rounded
at apex.

Pronotum hexagonal, with a straight apical margin and two short oblique
sides which continue into two long, straight sides, which in turn abruptly unite
to form the wide, straight basal margin. Disc strongly gibbous, the gibbosity
culminating in an acute spinoid tubercle near base ; antebasal transverse sulcus
nearly semicircular, curving below the discal gibbosity apically each side to
end in a circular, perforate lateral fovea; a minute median fovea lies just apical
of transverse sulcus, at base of discal spine, and a longitudinal carina extends
from basal bead, crossing sulcus, to median fovea.

Scutellum large, triangular, with apex sinuate-acute.

Elytra each with sloping humerus ; five strong and asperate costae between
lateral and sutural margins; five wide glabrous intervals; two perforate pu-
bescent basal foveae, one at base of each of the two innermost intervals, with
inner fovea smaller.

Abdomen large, of five visible tergites with a length ratio of 8/1/.8/1.6/2,
only the first tergite visible from above and strongly margined. First tergite
medianly, longitudinally elevated into a high carina, this bisecting carina also
continued over the next three tergites; last tergite transversely suboval.

Six stemites in a length ratio of 1/2/.5/.5/.8/1.5, simple, save that the
first is heavily pubescent.

Metastemum glabrous, conspicuously and triangularly elevated into a tu-
bercle each side of a wide median sulcoid depression; a tremendous, pubescent
fovea at base of median depression. Both intermediate and posterior coxae
widely separated. Anterior legs with glabrous trochanters which are compressed
and extend apically in a long, thin spine; femora inflated, with a large elongate-

TYRINI 301

oval glabrous field on the basal half of ventral face, the posterior margin of this
field carinoid, and the whole is sharp contrast to the asperate femoral integu-
ment. Intermediate legs with the trochanters glabrous, compressed and carinoid;
femore inflated and asperate. Posterior legs wholly asperate. Tibiae simple. Tarsi
as for tribe with two large, slightly unequal, tarsal claws.

Described on a single male specimen collected on Barro Colorado Island,
Gatun Lake, Panama Canal Zone, by Dr. Laura Hare on May 13, 1935, from
a nest of Coptotermes niger Snyder in a decaying log.

Although there are no data on the ecology of coptocolus, I unhesitatingly
assign a role of synoekete to this pselaphid until definite observations between
termite host and beetle prove otherwise. This seems justifiable on assaying its
remarkable external anatomy. Coptocolus is geographically isolated from the
other species of the genus, as well as by its habitat with termites.

The pubescence of coptocolus allies it with vestitus of Argentina rather
than gibbicollis of central Brazil. From vestitus it is very distinct on tibiae,
antennal club and numerous other points. It differs from both in the distal seg-
ment of the maxillary palpi: in vestitus and gibbicollis the apex of this palpo-
mere is narrowly but distinctly truncate ; in coptocolus the apical truncature is
so small as to be nearly absent, hardly larger than the base of the palpal cone.
I prefer to assign to Neotyrus a variably developed apical truncature of the
distal palpomere, rather than erect a new genus at this time.

Neotyrus harem new species

Holotype Male. 2.4 mm. long x 1.0 mm. wide. Reddish-brown with mod-
erately long, stiff, subappressed, and conspicuous setae of a bright golden color.
Integument bright and shining throughout with sparse, subasperate punctation
save for legs which are coarsely asperate-punctate.

Head with tempora as in coptocolus. Eyes large, prominent, median, each
composed of about 120 small facets. Vertex rounded into convex occiput, and
glabrous and flattened between the eyes ; on each side of this elongate glabrous
area is a vague, glabrous depression on a line with the posterior margins of the
eyes. The bottom of this depression holds a minute vestigial vertexal fovea. The
median glabrous area extends anteriorly, deepening to form a median, fusiform,
inter-antennal sulcus which separates the poorly developed antennal tubercles,
and then curves ventrally over the inter-antennal line of the front. At this point
the sulcus has much higher and sharper walls which terminate at the clypeus.
Clypeus granulate-punctate. Ventral surface of head flat, glabrous, with a large
median basal fovea. Genae with a large, triangular, laminoid infra-ocular spine.

Maxillary palpi four-segmented, of Tyropsis-N eotyrus construction; first
segment small ; second elongate-arcuate, strongly pedunculate for basal half and
expanding to form an obliquely truncate, pyriform apical half; third smaller but
similar in form to second, with the basal peduncle for basal fourth and pyriform
area extending for apical three-fourths, also obliquely truncate; fourth (distal)
elongate-fusiform as in coptocolus, with apical end dorso-ventrally flattened and

302 NEOTROPICAL PSELAPHIDAE

minutely truncate, this truncature scariform and oblique, bearing a small palpal
cone.

Antennae with segment I elongate-cylindrical; II quadrate, smaller; III as
long as second, longer than wide, obconical; IV-VIII submoniliform, slightly
decreasing in length and slightly increasing in width ; IX larger, quadrate-trape-
zoidal; X as long but wider than ninth, transverse-trapezoidal; XI as in cop-
tocolus.

Pronotum with lateral contour, spinoid discal gibbosity, and arcuate basal
sulcus as in coptocolus. The arcuate sulcus ends each side in a circular pubescent
fovea, and in addition there also extends from each lateral fovea a straight,
oblique sulcus to basal margin. That is, two sulci leave each lateral fovea: the
arcuate interfoveal sulcus, and an oblique fovea-basal bead sulcus. Median basal
fovea minute. Flanks of pronotum glabrous.

Scutellum large, elongate-triangular, alutaceous.

Elytra with obtuse humeri. Each elytron with two, equal, circular, pubes-
cent foveae. From the inner fovea extends a strong, entire sutural stria. The
outer fovea has a subentire discal stria. The inner wall of the discal stria is ele-
vated to form a single, strong costa.

Abdomen with five visible tergites in a length ratio of 8/1.5/1/2.5/2. First
tergite strongly margined; last tergite truncate-triangular. All tergites evenly
convex, lacking the median bisecting carina of coptocolus.

Six stemites in a length ratio of 2/3/1/.5/1/1. First stemite medianly ele-
vated between posterior coxae into a large alutaceous rhomboidal tubercle ; first
two stemites deeply separated, with the trough densely pubescent; last stemite
medianly deeply incised or notched. A discoid process of the male copulatory
apparatus fits into this notch, when the penis is not exserted, so that the truncate
apex of the last tergite is flush with the last stemite.

Metastemum glabrous laterally and sharply elevated into two longitud-
inally carinate tubercles which are separated by a sparsely pubescent and
broadly concave median region.

Anterior legs: trochanter glabrous; femur with a glabrous ovoidal field oc-
cupying the basal four-fifths of femoral length, with the posterior margin of
the field strongly carinated, this area on the antero-ventral face; tibia arcuate,
apically setose on ventral face.

Intermediate legs: trochanter glabrous, ventrally carinate and extended at
apex into a triangular tooth ; femur with a much smaller, fusiform, glabrous field
on antero-ventral face; tibia as above.

Posterior legs: simple, wholly granulate-puntate with straight tibiae.

Tarsi as for tribe, with two large, arcuate, slightly unequal tarsal claws,
one claw being slightly shorter and thicker.

Allotype Female. As for holotype save that (1) last tergite transversely
rhomboidal, with a longer subtruncate apical margin; (2) first stemite only
normally elevated between coxae; (3) sixth (last) stemite with the apical
margin simply rounded, lacking any median incisure or discoid process.

Described on two specimens collected from nests of the termite Coptotermes

TYRINI 303

niger Snyder by Alfred Emerson on Barro Colorado Island, Gatun Lake, Pan-
ama Canal Zone. Holotype on April 30, 1935, and allotype on April 30, 1935.

The maxillary palpi and slightly unequal tarsal claws are intermediate be-
tween Phalepsus and Neotyrus s.s. on the one hand while the oblique scariform
truncature of the dorsal apex of the distal palpomere tends towards Tyro-
gatunus. This distinctive species also approaches Tyrogatunus and the nearctic
Tyrus in common trochantal and femoral modification of both sexes as well as
sexual differences in the form of the last sternite. This genus may have to be
broken up, but for the present the species of Neotyrus may be listed as follows:

coptocolus new species. Panama Canal Zone (con Coptotermes niger).

gibbicollis (Schaufuss) . 1886. Amazon basin, Brazil (Aplodea) Geno-
type.

harem new species. Panama Canal Zone (con Coptotermes niger),

vestitus Raffray. 1908. Buenos Aires, Argentina.

JUXTAHAMOTOPSIS new genus

This new genus is distinct from other Tyrini on the following combination
of characters: (1) head elongate-subtriangular with prominent post-median
eyes, a pair of small vertexal foveae, and a long narrow, medianly sulcate ver-
texal-frontal field ending in a small bilobed antennal tubercle; (2) antennae
nongeniculate, eleven-segmented, with an inconspicuous club composed of the
last three segments which are very elongate-cylindrical and as long as the pre-
ceding eight segments united; (3) maxillary palpi (PI. XX) short, four-seg-
mented, with the last segument non-sulcate but covered with short, spike-like
setae; (4) pronotum with strongly convex disc, and lateral margins biconvex as
a consequence of a large triangular fovea, large circular median basal fovea,
no sulci ; (5) elytra with two large basal foveae, a dorsal depression, and an en-
tire sutural stria on each elytron; (6) abdomen with five visible tergites and six
sternites, margins very strongly developed and broadened, tergites progressively
shorter, second and third sternites longer than others; (7) intermediate legs
strongly macrosceline; (8) pubescence thick-shafted, setiform, not scaly; (9)
tarsi three-segmented, not bilobed, third tarsomere much longer than second,
second much longer than first; two long, equal tarsal claws; (10) male sex with
anterior legs greatly modified as described in genotype; female sex unknown.

Juxtahamotopsis bardeni new species

Type Male. Measurements: Head 0.44 x 0.35 mm.; pronotum 0.47 x 0.47
mm.; elytra 0.53 x 0.93 mm.; abdomen 0.84 x 0.97 mm.; total length 2.3 mm.;
greatest width 0.97 mm. (PI. XX)

Body reddish-brown, shining, pyriform contour as a whole, being progres-
sively wider to first visible tergite. Punctation diverse: antennal tubercle with
a few very coarse punctures, and the rest of the head, pronotum, and abdomen
nearly impunctate; elytra very sparsely asperate; antennal club and femora

304 NEOTROPICAL PSELAPHIDAE

scabroid to asperate. Pubescence long, thick-shafted, appressed, and golden in
color on the body ; anterior femora, anterior tibiae, vertexal, pronotal, elytral
and sternal foveae, sides of head anterior and posterior of eyes, sides of pro-
notum and apical elytral margin densely pubescent.

Head elongate-subtriangular, with simple rounded tempora as long as eyes ;
eyes prominent, composed of 50 large facets, placed just behind the middle of
head and appearing to lie in a bed of pubescence. Vertex highest near occiput,
simple, sloping evenly to inter-antennal line; a pair of small vertexal foveae on
a line through posterior ocular margins ; sides of head anterior of eyes gradually
concave to form a median antennal tubercle, this latter medianly longitudinally
sulcate, forming a bilobed front, to a point on a line through anterior ocular
margins. Clypeus deeply recessed beneath overhanging frontal antennal tu-
bercle, simple, and erected near apex into a semicircular carina. Labrum
minutely granulose. Ventral surface of head simple.

Maxillary palpi four-segmented, as long as distal antennal segment; first
segment short, oblong; second four times as long as first, as wide as first for basal
half, then slightly wider and arcuate in apical half but not inflated, with a
rounded apex; third distinctly wider and half as long as second, asymmetrically
ovoidal; fourth as long as first three united, twice as wide as third, with the ex-
ternal face nearly straight, and the internal face broadly convex to narrow but
rounded apex. This distal segment is conspicuous because it is clothed in short,
stiff, apically-directed, spike-like setae.

Antennae closely articulated, approximate, eleven-segmented, long (1.6
mm.), being two-thirds the body length, with the first eight antennomeres
(0.8 mm.) as long united as the last three (0.8 mm.) united. Segment I elongate-
cylindrical; II as wide but shorter and obconical, with the articular surface be-
tween these two being obvious (as in Attapseniini) in contrast to the other
articulations; III- VIII as wide as second; third very short and transverse, disc-
shaped; fourth one-half longer, transverse and drum-shaped; fifth to eighth
gradually longer, from quadrate to obconical; club of the last three segments,
inconspicuous but in reality strongly formed; IX very elongate-cylindrical, not
wider than eighth; X very elongate-subobconical ; XI very elongate and slightly
wider, apically rounded. The antennal club has a notable ornamentation: the
integument is studded with small, separate asperities which are so arranged in
lines that these segments appear to have the surface separated into oblong com-
partments.

Pronotum with strongly convex disc which is steeply declivous in basal
fourth; sides biconvex; a large circular fovea at middle of basal fourth, on the
discal declivity just noted; each side provided with an enormous triangular
fovea which incises the side at basal third as noted above.

Each elytron with sloping humeri, two large basal foveae, an entire sutural
stria and a broad but shallow dorsal depression to middle of length.

Abdomen large, with simple segments. Five visible tergites in a length ratio
or 3.8/3.5/3.0/2.0/1.5 and the first three with broad, flat margins. Six sternites
in a length ratio of 1/2.5/2.5/2/1/0.5.

TYRINI 305

Metasternum long, elevated into a flattened surface which is sulcate in
apical half.

Inteimediate coxae widely separated by a space equivalent to trochanter
width at apex. Posterior coxae widely separated by a space one half the median
metasternal length.

The intermediate and posterior legs- simple.

Tarsi three-segmented, relatively short; first segment short and triangular;
second twice as long as first; third nearly twice as long as second and obconical,
bearing a pair of long, strong, equal claws.

The anterior legs are profoundly modified: they measure 1.8 mm. in length,
well over two-thirds the body length (femur 0.73, tibia 0.8 and tarsus 0.27 mm.)
and are in an arc. The femur is greatly inflated dorso-ventrally and flattened
laterally, with the narrow inner face densely setose. The tibia is longer than the
femur, strongly arcuate and very thin in contrast to the large femur; it is cari-
nated along the concave inner face, which also is densely pubescent. The rela-
tively short tarsus articulates basal of the tibial apex so that the latter extends
nearly to the apex of the second tarsal segment.

Described upon a single male specimen, collected by Dr. Williams in leaf
mold (Sample 1118) of the rain forest of Barro Colorado Island, Gatun Lake,
Panama Canal Zone, on July 17, 1938.

In its essential structural features this genus is tyrine, in the development
of the antennal club it is allied to the ctenistine and hybocephaline stems; the
maxillary palpi agree with Ephimia with respect to the stiff setae but not the
shape of the distal palpomere. This is another instance which suggests that the
hybocephaline Ephimia, unknown from the American mainland, belongs in the
Tyrini near Juxtahamotopsis.

LETHENOMUS (Raffray, 1895)

This is a monotypic Chilean genus equally isolated as Juxtahamotopsis by
virtue of its maxillary palpi. These latter organs are four segmented, with an
extremely small first segment; second elongate, slender in basal half, gradually
broader to apex where the segment is nearly four times as wide as base, with a
rounded apex; third similar in form to the second, two-thirds as long, and as
wide, with the internal apical face subangulate ; fourth segment unique in the
tribe, much longer than second and much wider, with a slender base and a
swollen, perfectly rounded apex. This apex lacks a palpal cone and its contour
is unbroken ; however, the internal face near apex is produced into an acute tooth
which is pubescent. (PI. XX)

villosus (Schaufuss). 1886. (Aplodea) Chile. Genotype.

APHARUS (Reitter, 1882)

This genus holds four species, all of which are South American. The group
is closely related to the subgenus Hamotus, differing in having a narrower ab-
dominal margin, a very long first visible tergite, and in having the sulcus of the
internal face of the distal palpomere limited to the apical half. All three of these

306 NEOTROPICAL PSELAPHIDAE

features are approached by Hamotus: the abdominal margin, the relative
lengths of the first two tergites, and the extent of the palpal sulcus vary among
the species and, as will be seen, this variation is taken advantage of in the keys
to species. The development of the palpal sulcus seems to be the best criterion:
in Apharus this sulcus never extends for more than the apical half of the internal
face, while in those Hamotus with a shortened sulcus, this latter extends into
the basal third of the internal face.

The maxillary palpi of Apharus are four-segmented; first segment very
small as usual among Tyrini; second elongate, basally slender and arcuate, grad-
ually expanding to an oblique apex; third short, triangular; fourth much the
longest and widest, elongate-ovoidal, obliquely truncate at base, rounded at
apex, the internal face with an elongate-oval fovea or sulcus occupying the an-
terior half of the segment, with the palpal cone set within the apex of this palpal
sulcus at an oblique angle (PL XX).

The males, where known, have the anterior trochanters each armed with a
tooth. Both sexes have the metastemum variously sulcate, impressed and tu-
berculate. The posterior tibiae are without spurs in the male of mulleri and
armipes, have the spurs well developed in the female of armipes and lacking in
the female of colombiensis.

The following key to species does not account for clavicornis Raffray with
which I am unfamiliar, and the reference to which I have been unable to check.

Anterior trochanters armed with a tooth .... Males 2

Anterior trochanters unarmed. . . .Females 3

2. Metasternum simply impressed at apex; occiput gradually formed;

pronotum with length and width subequal ; length 2.0 mm. . . mulleri
Metasternum medianly sulcate, with a large tuberculate tooth each

side; occiput abruptly and sharply formed; length 1.85 mm

armipes

3. Posterior tibiae without spurs ; occiput abruptly and sharply formed ;

pronotum transversely subglobose, being one-third wider than long;
disc of elytron with a dorsal depression for basal third ; metastemum

medianly sulcate and tuberculate each side; length 1.20 mm

colombiensis new species

Posterior tibiae each with a strong arcuate spur; pronotum subglobose;
disc of elytron lacking a dorsal depression; occiput and metasternum
as above ; length 1.85 mm armipes

Apharus colombiensis new species

Type Female. 1.20 mm. long x 0.60 mm. wide through elytra. Shining
reddish-brown, convex, 40 per cent smaller than the allied armipes, and with
long, coarse, semierect, flavous pubescence. Head, pronotum and abdomen
lightly punctulate; elytra with a few very large coarse punctures; femora and
antennal club scabroid.

TYRINI 307

Head as in armipes, with the occiput abruptly and vertically formed from
the occipital-cervical sulcus, the occipital crest carinoid; however, in contrast
to armipes, the front is distinctly narrowed anterior of the eyes and then ex-
panded to form a larger ant^nnal tubercle.
Maxillary palpi as for genus.

Antennae short, thick, eleven-segmented; I elongate-cylindrical; II shorter,
slightly narrower, quadrate; III-VI subequal, very short and transverse; VII
transversely triangular with the internal or median face acute, wider than sixth ;
VIII slightly wider and longer than seventh, transversely trapezoidal; IX-XI
forming a club; ninth much larger than eighth, transverse, with median face
subacute; tenth subequal to ninth, regularly trapezoidal; eleventh very large,
truncate at base, asymmetrically narrowed at rounded apex, much wider than
tenth and as long as preceding four segments united.

Pronotum transversely subglobose, one-third wider than long in contrast
to mulleri; a very large lateral fovea each side at basal fifth and a small, punc-
tiform median fovea at basal fourth.

Each elytron with two circular basal foveae; an entire sutural stria from
inner fovea ; a broad triangular dorsal impression from outer fovea to basal third
of elytron, in contrast to armipes.

Abdomen with five visible tergites in a length ratio of 3.5/2/.6/1.5/1.2.
From a dorsal view only the first two tergites can be entirely seen, and the first
appears, therefore, much larger than the rest of the abdomen. First with a
narrow but distinct margin, this marginal field being longitudinally triangular,
and the disc of the segment is medianly tumid and strongly depressed at each
latero-basal comer. Second tergite with a conspicuous transverse sulcus from
side to side at base; lateral margins carinoid.

Six stemites in a length ratio of 1/2/1/.5/.2/.5, with the first deeply exca-
vated and densely pubescent, and the second very tumid.

Intermediate coxae widely separated. Posterior coxae separated by no
greater distance than the intermediate coxal separation. Legs all simple, un-
armed, uninflated and not arcuate. Tibial spurs entirely absent in contrast to
the female armipes. Tarsi of the usual tyrine proportions, with two long, ar-
cuate, equal claws.

Metasternum broadly medianly sulcate, with a tubercular swelling each
side.

Described on one female, collected by C. H. Seevers on August 1, 1938,
from beneath bark, at Puerto Salgar, Cundinamarca, Colombia.

The species of the genus may be listed as follows:

armipes Raffray. 1891. Caracas, Venezuela, (both sexes known)

clavicomis Raffray. 1891? Ceara, Brazil.

colomhiensis new species. Puerto Salgar, Cundinamarca, Colombia.

(female known only)
muZZen Reitter. 1882. Sao Paulo, Brazil. Genotype, (male known only)

Taken at 2600 feet.

308 NEOTROPICAL PSELAPHIDAE

HAMOTUS (Aube, 1844)

AuBE (1844)

Reitter (1882)

Sharp (1887)

SCHAUFUSS (1887)

Raffray (1904, 1908)

Fletcher (1932)

Park (1935)

Hamotus was erected by Aube on three species in 1844: the genotype
lateritius (p. 92), bryaxoides (p. 93), and hunieralis (p. 93). The last named
species was misplaced by Aube, and was early assigned to Tyrus. Tyrus was a
genus erected by Aube in 1833 and its genotype is mucronatus (Panzer).
LeConte and Horn (1883, p. 87) correctly placed Tyrus hunieralis (Aube) and
this course has been uniformly followed by American students. Tyrus humeralis
is widespread in the Nearctic Region, from Canada south into Florida, and west
to the Mississippi drainage basin. I have satisfied myself that humeralis (Aube)
is perfectly congeneric with mucronatus (Panzer) of Europe. My material in
the latter species comes from Germany and has been identified by Edmund
Reitter. Both species have the typical distal segment of the maxillary palpus,
that is, pedunculate-ovoidal in outline, with no longitudinal sulcus and with the
palpal cone set in the acuminate apex of the segment.

The other two species of Aube, lateritius and bryaxoides, are typical
Hamotus. Both species have the distal segment of the maxillary palpus cyl-
indrico-ovoidal in outline, with the base obliquely truncate and the internal face
conspicuously longitudinally sulcate, with the palpal cone set obliquely within
the apex of the sulcus.

Hamotus has received much attention from three distinguished students of
the family, Reitter, Schaufuss, and Raffray. The substantial increase in infor-
mation since 1904 has rendered a new treatment desirable. At the present time
the genus contains eighty-nine species and as a homogeneous aggregate of large
size ranks with Reichenbachia, Decarthron, Arthmius, and a few other genera
in the region under examination.

Taxonomically it is one of the most important neotropical genera. It is dis-
tributed over the Neotropical Region from the tropic of Cancer to the tropic of
Capricorn, and its restriction to this fauna is complete with one exception,
Hamotus opimus Fletcher discovered in 1932 in peninsular Florida. Such a dis-
persal pattern is presumptive evidence of neotropical origin and, since there has
been great speciation in the genus, its confinement to this area indicates physio-
logical intolerance of extra-tropical environment rather than inability to dis-
perse or to compete with nearctic species.

There is but one other species about which doubt can be entertained.
Brendel described Tyrus elongatus (Brendel and Wickham, 1890, p. 239) from
a male from Williams, Arizona. Leng (1920, p. 132) placed it doubtfully in
Cercocerus. Bowman (1934, p. 136) placed it in Hamotus. I agree with Bowman
that elongatus cannot be Cercocerus — a glance at Brendel's figure precludes such

TYRINI 309

an association. As to whether elongatus is Hamotus or Tyrus cannot be ascer-
tained from the original description, but a single glance at the palpi of the type
will settle the question as the two genera are wholly distinct, with no overlap.
Presumably this has been done by Bowman. The habitat is too arid for Hamotus
but I do not know this species.

America north of the tropic of Cancer has but one ally of Hamotus. This
relative is the myrmecophilous, monotypic Cercoceru^ batrisoides Leconte
(1861, p. 57). This species is in entire agreement with the subgenus Hamotoides
of Hamotus. In fact it could be placed in Hamotus with no great difficulty as
the only differential between Cercocerus and Hamotus is the relative size of the
eleventh antennomere. In Cercocerus this distal segment forms the antennal club
and is about seven times longer than the tenth segment. In Hamotus the last
three antennomeres form the club but there is great variation in the relative size
of these segments, thus in some species the ninth and tenth segments are small
and the eleventh is longer than the preceding five united.

Otherwise these two genera are congeneric, Cercocerus having the typical
hamotine palpi. ^ Cercocerus batrisoides is a remarkable pselaphid, with un-
usually strong secondary sexual characters as indicated in the plates. Its ap-
parent rarity in collections is probably a consequence of its being represented
by a stray specimen from log mold. It is an habitual synoekete of ants, being
perfectly unmolested by its host. I have usually taken it from nests of Aphaeno-
gaster tennesseensis Mayr. Leng (1920) lists it from Pennsylvania, Indiana,
and Louisiana. My series comes from Cincinnati, Ohio; Smith, Indiana; Topeka,
Kansas, all with the ant host noted (Park, 1935) . From these few data it appears
that the species does not occur south of New Orleans. It is a nearctic extension
of Hamotus, distributed through the Mississippi basin from the subtropics, east-
ward to Pennsylvania and westward to Kansas. Thus this species and Hamotus
opimus become of great zoogeographic importance. The distribution of batri-
soides is linked with its formicid hosts and we await more collecting records as
well as its detailed ecology.

Within the neotropical region Hamotus has also many specialized relatives.
It is closely allied with Apharus through Hamotus alleei in a phylogenetic
shortening of the palpal sulcus and lengthening of the first tergite ; it is allied
to Pseudohamotus with its semi-circularly swollen distal palpomere but typical
palpal sulcus; it is allied to a long series of genera in which the distal palpomere
becomes elongate-cylindrical and the palpal sulcus very narrow {Cercoceropsis,
Cercocer aides) ; and more remotly allied to Pselaphocompsus and Cercocerulus.

In other words, Hamotus is a stem genus which has one close ally in the
nearctic, and many allies in the neotropical region. Throughout its neotropical
range, the species seem to be a part of the rain forest fauna. They are especially

'In Bowman's recent treatise (1934, p. 132) the genus Cercocerus will not key out.
In this key to tyrine genera Hamotus is given an apical palpal cone along with Tyrus, while
Cercocerus is given no palpal cone.

This was probably a typographical error, as Tyrus is the only one of the three with a
terminal palpal cone while both Hamotus and Cercocerus have a distinct palpal cone set
obliquely within the apex of the longitudinal palpal sulcus.

310 NEOTROPICAL PSELAPHIDAE

typical of moist, well-decayed log mold and there are few records of their
being taken at lights at night; some species have adjusted to the rapacious
army ant society (ecitophilus), others live with termites as noted later.

The largest pselaphid known to the author belongs in this genus. This
giant is Hamotus (Hamotoides) ecitophilus Raffray of Brazil which measures
5.5 mm. in length and lives with Eciton.

The comparative anatomy of the genus is not given here as the numerous
descriptions of new species which follow serve to give the range of structural
diversity. It should be pointed out, nevertheless, that, although the diversity
is extensive, the central habitus of Hamotus is unmistakable and the species
vary in the quantitative development of such features as the length of the
palpal sulcus, length ratio of tergites, color of pubescence, proportions of the
antennomeres, development of the pronotal foveae, and sulcus.

Sex is poorly differentiated by secondary characters. Only rarely are the
males distinctive from the females on clear cut modification of the antennae,
tibiae, or metasternum. Much more commonly the secondary sexual differences
are subtle differences in the proportions of the antennal club or abdominal
contour. Therefore long series of a species are greatly to be desired in the
genus, and direct dissection necessary.

On the other hand, what at first appear to be slight differences in anten-
nomeres of insufficient value for species separation, prove to be relatively
stable in a long series of specimens. Raffray (1904) stated that these slight
antennal differences were quite reliable for species separation. I have been at
some pains to check this view. Having at hand several species represented by
both sexes in series of a dozen or more, I used an ocular micrometer at high
magnification to measure the length and width of the last three antennal seg-
ments. A summary of these data are given later under the species concerned,
but it should be said here that the reliance of Raffray, Reitter, and Schaufuss
on antennal segments has been justified in my own work.

Finally, it is pleasing to find at least a tenth of the known species are
known from several adjacent countries, that is, the genus is becoming suf-
ficiently known to have the distribution of its components partially delineated.
Some species have a great range. Thus monachus is known from Costa Rica to
Mexico; tritomus from Colombia to Mexico; hirtus from Grenada, St. Vincent,
and Guadeloupe; bryaxoides from Colombia, Venezuela, and Brazil. In time
such information, it is to be hoped, will appear comparatively scanty; this
calls for much expeditionary labor and taxonomic discrimination.

As late as 1908 Raffray recognized Hamotus of Aube and Hamotoides
(Schaufuss, 1887) as subgenera, but between 1909 and 1917 Raffray treated
them as genera. I feel that this latter treatment is a mistake. Hamotus and
Hamotoides differ in several ways but the differences are gradual, lacking any
precise break in a qualitative sense. The chief character for their separation
is the presence or absence of the transverse pronotal sulcus. Now the transition
between having or lacking this sulcus is fully bridged by lateritius, decipiens,
longepilosus, micans, longiceps and alleei. In these species, which are placed

TYRINI 311

in Hamotus s.s. but could just as easily be allocated to Hamotoides, we run
the gamut from a transversely oval median fovea with a vestigial sulcus present
for a short distance on each side, through an entire shallow depression not quite
reaching the lateral foveae, to an entire but interrupted sulcus. Furthermore,
the genotype, lateritius, is just such a midway species. It stands at about the
center of the genus with respect to sulcus development, and if the subgenera
were made separate entities then great confusion might arise. Finally, the clean
break between Arthmius, Syrbatus, and Syrmocerus in the pronotal outline
and associated foveae is a good example of how a genus may be fragmented
at the hands of taxonomists, whereas the breaking up of Hamotus would not
result in such a practical arrangement.

Key to the Subgenera of Hamotus

Pronotum with three perfectly free, circular antebasal foveae and with
no trace of a connecting sulcus, or rarely with the median fovea
transversely oval or with the foveae connected by an interrupted
vestigial sulcus, or a broad, shallow vestigial depression. (PI. XIX, 3)
HAMOTUS s.s.

Pronotum with a deep, entire transverse antebasal sulcus connecting
the lateral foveae. (PI. XIX, 4) HAMOTOIDES

Key to the Subgeneric Groups of Hamotus, s.s.

Median pronotal fovea connected to the lateral foveae by an inter-
rupted sulcus, or the sulcus represented by a wide, very superficial
impression Group XI

Median pronotal fovea lacking any connection with the lateral foveae 2

2. Median pronotal fovea transversely oval, with a short vestige of a

transverse sulcus entering the foveal lumen on each side. .Group X
Median pronotal fovea large, circular and entirely free 3

3. Antennal segments IX and X much longer than wide Group I

Antennal segments IX and X with width equal to length, or much

wider than long, never longer than wide 4

4. First visible tergite subequal in length to second, or the tergites very

gradually shorter 5

First visible tergite distinctly much longer than the second tergite .... 8

5. Antennal segments IV-VIII quadrate Group II

Antennal segments IV-VIII not all quadrate, some being transverse . . 6

6. Antennal segments IV and V quadrate Group III

Antennal segments IV-VIII all transverse 7

7. General body pubescence varying from a clear light yellow, through

golden to a reddish-yellow Group IV

General body pubescence varying from a dark brown to nearly
black Group V

8. Antennal segment XI with a large, shallow foveiform depression on

ventral face near base Group VI

312 NEOTROPICAL PSELAPHIDAE

Antennal segment XI lacking such a foveiform depression 9

9. Elytra punctate, the flanks wrinkled and the punctures granulose on

the sides Group VII

Elytra either lightly punctulate or impunctate 10

10. General body pubescence deep brown Group VIII

General body pubescence tawny to yellowish-brown Group IX

Key to the Subgeneric Groups of Hamotoides

Median pronotal fovea very large and strongly formed, with the trans-
verse sulcus seen from each side of the foveal lumen as a sharply

narrower groove. (PI. XVII, 5) Group XII

Median pronotal fovea either very small, or formed by a slight
arcuation of the walls of the transverse sulcus or wholly absent.

(PI. XVII, 4) 2

2. General body pubescence deep brown Group XIII

General body pubescence varying from yellow to yellowish-brown or

tawny Group XIV ^

This organization is an extension of the 1904 arrangement of Raffray,
and divides the genus into fourteen groups of species. In the following keys
to species the term "palpal sulcus" refers to the longitudinal sulcus of the
internal face of the distal segment of the maxillary palpus, and the Roman
numerals refer to antennal segments.

Key to Species of Group I

V, VI, VII three times longer than wide 2

V, VI, VII quadrate to transverse 6

2. Metasternum tuberculate or spined 3

Metasternum simple 5

3. Metasternum with a pair of long spinoid processes at base, these

processes compressed and curved near apex; 3.4 mm.; Bolivia

sternalis Male

Metasternum with two strong tubercles 4

4. XI not twice as long as wide; 3.0 mm.; Panama rostratus Male

XI slightly more than twice as long as wide ; 3.5 mm. ; Panama ....

grandipalpis Male

5. 3.4 mm. ; Bolivia sternalis Female

6. First visible tergite distinctly longer than second 7

First and second tergites subequal in length 9

7. Known from Buenos Aires, Argentina ; 3.3 mm argentinus

Known from Blumenau, Brazil northwards 8

8. XI regularly ovoidal, longer than the preceding two united; Brazil

and Colombia gracilicornis

XI elongate, longer than the three preceding united ; Colombia . . badius

Rarely the pubescence is a silvery gray.

TYRINI 313

9. Median pronotal fovea much smaller than lateral pronotal foveae;

3 mm. ; Bolivia boUviensis

Three pronotal foveae subequal in size; 3.5 mm.; Brazil iheringi

Key to Species of Group II

IX and X subequal in length and width; XI briefly ovoidal, slightly
longer than preceding two united; Blumenau, Brazil. . . .parviceps

X about one-half longer than IX; XI as long as the three preceding
united; Minas Geraes, Brazil subtilis

Key to Species of Group III
Elytral flanks roughly punctate, disc nearly impunctate ; Brazil . .

inaequalis

Elytra wholly impunctate 2

2. IX and X subequal in size, slightly transverse 3

X one-half wider than IX, very transverse ; 2.5 mm. ; Brazil . . globulifer

3. XI with parallel sides and rounded apex, as long as preceding four

united ; 2.6 mm. ; Brazil aubeanus

XI much wider in apical third, apex obtusely acuminate, not much
longer than three preceding united; 2.1 mm.; Brazil. . appendicularis

Key to Species of Group IV

This is a large group of nineteen species notable for their bright golden
pubescence. The center of the group seems to be the northern rain forests of
South Amrica, especially Venezuela and Colombia. This key does not include
furcifer and claviger.

Body dorso-ventrally flattened ; very attenuated anteriorly ; elytra and
abdomen with lateral outlines oblique to second tergite ; I unusually

elongate-cylindrical; 2 mm. ; Brazil deplanatus

Body of normal convexity and outline ; I of normal proportions 2

2. Male with posterior tibiae swollen and with the mesial face very

abnormal, bearing either a large fovea or a prominent truncated

tubercle 3

Males and females with tibiae not abnormal at middle of mesial face. . 4

3. Posterior tibiae with a large, elongate-oval, pubescent fovea at center

of mesial face; 2.9 mm.; Mexico. (PI. XVII, 8) tibialis

Posterior tibiae with a conspicuous, drum-shaped tubercle at center
of mesial face, the apex of the elevation pubescent; 2.6 mm.; Costa
Rica. (PI. XVII, 9) turalbus

4. Antennae very slender, III-VIII transversely spheroidal; Colombia

brunneus

Antennae short and thick 5

5. VI, VII, VIII abruptly more transverse than III, IV, V 6

III-VIII all very transverse or very gradually more and more trans-
verse 9

314 NEOTROPICAL PSELAPHIDAE

6. XI acuminate at apex; vertexal foveae as near to each other as either

is to the adjacent eye; 2.1 mm.; Venezuela frontalis

XI obtusely rounded at apex; vertexal foveae mutually more distant
than either from the adjacent eye 7

7. Palpal sulcus shortened, not reaching base 8

Palpal sulcus entire; 2.3 mm.; Venezuela vesiculifer

8. XI as long as four preceding united ; Venezuela clavicornis

XI as long as five preceding united; 2.3 mm.; Colombia, .punctipennis

9. Posterior tibia with a distinct apical spur of setae (this is not a sexual

character) 10

Posterior tibia without an apical spur; pubescence a rich yellow-gold
color, long and appressed; 2.2 mm.; Colombia bryaxoides

10. Posterior tibial spur short, thick and obtuse; 3.1 mm.; Venezuela

globifer

Posterior tibial spur fine, aciculate, usually sharply angulate or
recurved 11

11. IX and X very short and so transverse that they appear as disks;

head much wider than pronotum; Colombia barbatus

IX and X of variable width but never in the form of thin disks 12

12. Palpal sulcus entire; 2.5 mm.; Venezuela auricapillus

Palpal sulcus not entire 13

13. XI not as long as four preceding united 14

XI as long or longer than four preceding united 15

14. XI short, thick, sides subparallel, rounded at apex; 2.2 mm.;

Venezuela and Colombia robustus

XI very narrow at base, nearly globular; 2.25 mm.; Venezuela..
in flatus

15. Pronotum slightly longer than wide 16

Pronotum distinctly wider than long sandersoni new species

16. XI as long as four preceding united; 2.1 mm.; Colombia. . . .bulbifer
XI as long as five preceding united; 2.1 mm.; Colombia, .transversalis

Key to Species of Group V

Palpal sulcus entire 2

Palpal sulcus not entire; 2.7 mm.; Ecuador juscopilosus

2. Antennal club not well developed, IX and X only slightly trans-

verse, subequal, and not much wider than VIII 3

Antennal club strong, very abruptly formed, IX at least twice as
wide as VIII 4

3. Pubescence long; Brazil impunctatus

Pubescence short; 2.4 mm.; Venezuela crassipalpus

4. XI very large, as long as six preceding united; 1.9 mm.; Paraguay

laetus

XI not much longer than four preceding; 2.2 mm.; Brazil, .gracilipes

TYRINI 315

Group VI contains a single remarkable species, cavicornis Raffray of
Guatemala. The species has long, semierect, brown pubescence, is 2.4 mm.
long and owes its isolation to the foveoid eleventh antennomere. As stated
earlier in the genus treatment, this latter character probably refers to the
male sex only and is remarkable in Hamotus where few species have abnormal
antennal modifications.

Group VII contains a single species, rugosus Raffray of Bolivia. This
species also has long brown pubescence, is 2 mm. long and owes its isolation
to the elytral punctation. The elytral flanks have the integument strongly
punctate-granular.

Key to Species of Groups VIII and IX

I have reorganized these two groups into one key since the color of
pubescence, varying from tawny to deep brown, may prove confusing.

Palpal sulcus entire, reaching and dividing basal margin 9

Palpal sulcus not entire, not reaching base 2

2. Apical spur of posterior tibia long, fine and acuminate 3

Apical spur of posterior tibia blunt to truncate 4

3. XI equal to the five preceding segments united; 2.4 mm.; Brazil

grouvellei

XI equal to only slightly longer than the three preceding united;
Peru brevimarginatus

4. Ill distinctly longer than wide 5

III distinctly wider than long, or at most with width and length equal 6

5. Known only from Mexico; 2.3 mm ursulus

Known only from Brazil ; 2.3 mm simplex

6. Known only from Brazil centralis

Not known south of Panama 7

7. Pubescence fine in texture, long and abundant 8

Pubescence stiff, very short and sparse costaricensis new species

8. Known only from Mexico aztekus new species

Known only from the Canal Zone castanalus new species

9. Not known south of Mexico ; 2.6 mm singularis

Not known north of Panama 10

10. Ill much longer than wide to slightly longer 11

III very transverse to width equaling length 13

11. Known only from Bolivia 12

Known only from Panama ; 3 mm setipes

12. Ill, IV, V, and VI much longer than wide; 2.6 mm bicolor

III slightly longer than wide, IV and V quadrate, VI transverse;

2.4 mm fauveli

13. Posterior tibia without tibial spur (?) (Sharp states that his species

is closely allied to singularis of Reitter. Raffray had difficulty in
placing this Sharp species, described on two imperfect specimens
without any detail given); 2.5 mm.; brown pubescence; Panama
parvipalpis

316 NEOTROPICAL PSELAPHIDAE

(If parvipalpis has III longer than wide it will run to setipes of
Sharp which is better known: the latter has lighter pubescence and
is larger)
Posterior tibia with an apical spur 14

14. Pronotum longer than wide 15

Pronotum wider than long; 2.4 mm.; Venezuela soror

15. III-X progressively more transverse; Brazil vulpinus

III-VIII regularly transverse; not known from Brazil 16

16. Body elongate; XI much longer than four preceding; posterior tibial

spur long; 2.4 mm. ; Venezuela cavipalpus

Body short and thick ; XI as long as or slightly longer than four pre-
ceding; posterior tibial spur much shorter; 2.1 mm.; Bolivia

sulcipalpus

Key to Species of Group X

Intel-mediate trochanters each strongly spined; Venezuela and
Colombia lateritius Male

Intermediate trochanters not spined; 2.9 mm.; Colombia

decipiens Male

Apparently Raffray had access to the type of lateritius Aube, and since
this species is the genotype, the following data have been translated from
Raffray (1904) to give a rough word picture of this key form. The head has
an antennal tubercle nearly as long as the rest of the head and the two vertexal
foveae are separated by a distance nearly twice as great as that separating
either from its adjacent eye. Distal palpomere is subcylindrical, with sub-
acuminate apex, and an entire longitudinal sulcus on the internal face. The
long antennae have III longer than wide, obconical; IV-VII square; VIII
slightly transverse; IX and X large, gradually transverse; XI regularly oblong-
oval. The pronotum is longer than wide, subconical; the median fovea is free
but transversely oval, with a short vestige of the transverse sulcus extending
from each side. The male has each posterior tibia supplied with a short,
straight, obtuse apical spur and the intermediate trochanters each prolonged into
a strong, obtuse spine; metastemum flattened and medianly slightly im-
pressed.

Key to Species of Group XI

III to VI longer than wide 2

III to VI quadrate, as wide as long 3

2. II twice as long as wide, IX and X with length and width equal;

pubescence subappressed, brown; 3.4 mm.; Bolivia. . . .longepilosus

II slightly longer than wide, IX and X much longer than wide;

pubescence bristling, yellow ; 3.6 mm. ; Brazil longiceps

3. IX and X very large, much larger than VIII; head slightly longer

than wide; 2.3 mm.; Venezuela and Colombia micans

TYRINI 317

IX and X small; ninth with width and length equal, not much larger
than VIII; tenth with width and length equal, not much larger

than ninth ; head very long, one-third longer than wide

alleei new species

Key to Species of Group XII

Lateral pronotal margins tuberculate and sinuate above the lateral
pronotal foveae which incise the lateral contour; Mexico, .nodicollis

Lateral pronotal margins simple; lateral pronotal foveae not incising
the lateral contour 2

2. Distal palpomere of a peculiar form, being curved internally near

apex which is acuminate; 3.5 mm.; Nicaragua pubiventris

Distal palpomere not as above 3

3. IX and X subglobular with all angles rounded; 2.5 mm.; Brazil..

appendiculatus

IX and X not subglobular 4

4. X subquadrate, either as long as wide or slightly longer than wide. ... 5

X wider than long 6

5. IX twice as large as VIII, X quadrate with length and width equal,

twice the size of ninth but of nearly the same length ; XI very large,
oblique and ovoidal; 1.6 mm.; French Guiana sanguinipes

IX twice as large as VIII, as wide as long, trapezoidal; X slightly
larger than ninth, trapezoidal, slightly longer than wide; XI of
normal size, as long as the preceding two united; 2.3 mm.; Mexico. .
electrae new species

6. Intrahumeral impression strioid, clearly defined and one-half the

elytral length; 2.3-2.5 mm.; Mexico, Guatemala and Costa Rica. .

monachus

Intrahumeral impression very short 7

7. First two visible tergites of equal length; 2.33 mm.; Guatemala. . . .

difficilis

First tergite shorter than second (!) ; 2.33 mm.; Guatemala, .vicinus
This key does not include emeryi Wasmann, of Brazil.

Key to Species of Groups XIII and XIV

These two groups have been reorganized to accommodate new material
and the species incorporated into one key to avoid possible confusion in the
color of pubescence which, with one exception, varies from yellowish-brown
to brown.

Pubescence a silvery gray; body length in excess of five millimeters;

known only from colonies of anny ants ; Brazil ecitophilus

Pubescence tawny to deep brown; body length less than three milli-
meters 2

2. X longer than wide 3

X with length and width equal, or much wider than long 6

318 NEOTROPICAL PSELAPHIDAE

3. General body pubescence varying from deep brown to black 4

General body pubescence varying from light yellow to reddish-gold . . 5

4. X very large and cylindrical, nearly twice as long as IX; Colombia

to Mexico tritomus

X trapezoidal, not nearly twice as long as IX; 2 mm.; Brazil. . . .
nigropilosus

5. IX quadrate, length and width equal; X obconical, much longer than

wide ; IX briefly and regularly ovoidal ; Mexico suturalis

IX slightly longer than wide; X slightly longer than wide, with an
arcuate tooth at center of ventro-external face; XI as long as
preceding two united, with a porous tubercle at apico-internal face
and a sharp spicular tooth at center of ventro-external face;
Mexico veracruzensis new species

6. IX distinctly longer than wide thomasi new species

IX with length and width equal or much wider than long 7

7. Large, at least 2.8 mm. long; known only from Mexico; elytra with

sparse, strong, rugose punctures commodus

Smaller; not known north of Panama or Lesser Antilles 8

8. X distinctly transverse; 2 mm.; Windward and Leeward Islands..

hirtus

X very slightly transverse or with length and width equal; known
only from the mainland 9

9. Known from Argentina, Paraguay and Brazil 10

Known from Panama Canal Zone, Venezuela and Colombia 11

10. Pubescence inserted in minute granulations; male with anterior

trochanter spined and anterior femur with an obtuse tooth at

base; 2.3 mm.; Argentina punctulatus

Pubescence not inserted in minute granulations; male with anterior
trochanter spined but the anterior femur simple, not toothed;
2.0-2.2 mm.; Brazil and Paraguay bellus

11. Elytra impunctate; 1.75 mm.; Colombia hilaris

Elytra with subasperate punctation 12

12. IV-VIII all subequal in size and all transverse; 2.5 mm.; Venezuela

jlavopilosus

IV and V quadrate-moniliform to slightly transverse, VI-VIII very
transverse-moniliform 13

13. IV-VI transverse, VII and VIII lenticular; IX slightly transverse,

X quadrate, much larger than ninth; XI briefly, regularly ovoidal,
very large, obtuse at apex; pubescence short, appressed and flavous;

2.1 mm. ; Venezuela reichei

rV and V quadrate-moniliform, VI-VIII gradually transverse-monili-
form ; IX and X quadrate, tenth with a tooth on the ventro-lateral
face in the male sex; XI as long as preceding two united, also with a
tooth at center of ventro-lateral face in male sex; male with anterior
trochanters toothed ; females with simple quadrate ninth and tenth

TYRINI 319

segments, eleventh not toothed, anterior trochanters not toothed;

pubescence dark brownish-yellow

veracruzensis jletcheri new subspecies

This group key is complete with the exception of rossii described from
Paraguay. Rossii measures 1.96 mm. in length and is said to be near hirtus
but has a larger head, more transverse antennal tubercles, antennal segments
V-VIII more transverse, IX more transverse and X much longer than hirtus.
Rossii has the first two visible tergites subequal in length and a simple
metasternum.

Hamotus (Hamotus) costaricensis new species

Type. Measurements: Head 0.45 x 0.43 mm.; pronotum 0.47 x 0.50 mm.;
elytra 0.60 x 0.87 mm.; abdomen 0.60 x 0.90 mm. Total length 2.12 mm.

Shining brownish-yellow. Pubescence light tan color, sparse, very short
and stiff. Integument lightly punctulate.

Head slightly elongate with long tempora, much longer than wide and
longer than eyes. Eyes strongly reniform, composed of about 92 small facets.
Vertex and occiput simply convex, with three foveae: a pair of small vertexal
foveae, each about the size of an ocular facet, nude, punctiform, on a line
through posterior third of eyes and equidistantly placed; a third fovea even
smaller, punctiform, nude, on a line through anterior third of eyes in center
of head. Front narrowed to form two small antennal tubercles separated
medianly by a shallow sulcoid impression which extends posteriorly to median
vertexal fovea; front very narrow and vertical from inter-antennal depression
to clypeus. Clypeus simple, with a strong semi-circular carina just posterior
of apical margin, extending from side to side as in Juxtahamotopsis. Labrum
very transverse. Right mandible crossed dorsad to left; jaws strong with large
teeth. Ventral surface of head broad and very flat, with a large circular, nude
fovea at middle of base.

Maxillary palpi four-segmented; first minute, cylindrical; second elongate,
base pedunculate and no wider than first, arcuate, becoming strongly inflated
at apex; third short, triangular with angulate internal and convex external
face, less than half as long as second, nearly twice as wide as second; fourth
one-third longer than second, nearly twice as wide as third, elongate-oval with
base obliquely truncate base and rounded apex, internal face nearly straight,
external face convex; palpal sulcus of internal face elongate-oval, extending
obliquely from apex to basal fourth, the basal fourth of the segment, there-
fore, not sulcate; palpal cone strong and blunt, set obliquely in the apical
end of the sulcus.

Antennae eleven-segmented; I elongate-cylindrical; II shorter, slightly
narrower and quadrate; III asymmetrically narrowed at base, but with length
equal to apical width; IV-VIII moniliform, becoming very slightly transverse;
IX slightly longer and wider, slightly transverse, subtrapezoidal; X similar,
slightly larger; XI large, truncate at base, twice as wide as tenth, as long

320 NEOTROPICAL PSELAPHIDAE

as the preceding four segments united, apex rounded, external face strongly
convex, internal face slightly convex. Antennae 0.94 mm. long.

Pronotum slightly transverse, with simple disc and sides which slightly
diverge from base to near apex and then become broadly rounded to apical
margin; base with three large, subequal, circular pubescent foveae.

Elytra with rounded humeri. Each elytron with two circular, pubescent
basal foveae, a deep and entire sutural stria and a very short discal impression
for basal fifth of length.

Abdomen with five visible tergites in a length ratio of 6/3.5/1/. 5/1. 5 with
the first three strongly margined. Six simple sternites in a length ratio of
1/2.5/1.5/.8/.5/1.5.

Metasternum medianly with a broad longitudinal depression and each
side with a rounded tumidity. Legs simple save that the posterior tibiae are
apically spurred. This spur is long, oblong, angulated at base, truncated at
apex. Tarsi slightly more than one-half the tibial length ; first tarsomere short
and triangular; second three times as long as first; third longer than second,
with a pair of long arcuate, aciculate tarsal claws.

One specimen from Turrialba, Costa Rica. Probably a female.

In Raffray's 1904 treatment costaricensis runs off the key near centralis
Reitter with which it has little in common, and it would appear to have no
close relatives.

Hamotus (Hamotus) alleei new species

Type. Measurements: Head 0.37 x 0.23 mm.; pronotum 0.33 x 0.40 mm.;
elytra 0.53 x 0.74 mm.; abdomen 0.53 x 0.74 mm. Total length 1.8 mm.

Shining reddish-brown when mature; pubescence long, silky and golden;
integument strongly punctate with base of pronotum cribrate, the femora and
tibiae scabroid, but the antennal club nearly smooth.

Head elongate, one-third longer than wide, with long converging tempora
which are bearded. Eyes shorter than tempora, not prominent, medianly placed,
semilunar in lateral view and each of 56 moderately sized facets. Occipital
margin subretuse. Vertex elevated but dorsally flattened, with a pair of small
punctiform nude vertexal foveae between the eyes. Each vertexal fovea lies
in a pyramidal impression, and mutually closer than either to adjacent eye.
Front with inconspicuous antennal tubercles which are separated by a short
but deep longitudinal sulcus; this sulcus terminates posteriorly in a median
punctiform fovea. Front and clypeus as in costaricensis. Ventral surface of
head complex and nonhamotine: transversely tumid between eyes, the tumidity
mounted by an arcuate carina; this transverse carina connected to oral cavity
(submental boundary) by a longitudinal median carina; below each eye at
its ventral angle, the transverse carina forms an infraocular tubercle and this
tubercle is connected with posterior boundary of head by a longitudinal lateral
carina; enclosed surface between these three carinae flattened, with a trans-
versely oblong fovea at middle of base.

TYRINI 321

Maxillary palpi large; first three segments as in costaricensis. Fourth
(distal) palpomere obliquely truncate at base, internal face straight, external
face convex to rounded apex to form the usual elongate-oval outline. Internal
face with an entire, longitudinal sulcus and a large palpal cone inserted within
apex of sulcus as usual. This distal segment 0.19 mm. long by 0.09 mm. wide.
It is covered with a thin pearly secretion which became hardened after im-
mersion in alcohol. This palpal secretion has been not^d on many species of
Hamotus and suggests a sensory function.

Antennae one-half the body length (0.9 mm.) and simple; I elongate-
cylindrical; II similar but smaller; III-VIII subequal, monilifomi; IX and X
as in key; XI much longer than wide, subconical, not quite as long as three
preceding united.

Pronotum shorter and wider than head, slightly transverse, subglobose.
Base with small distinct median fovea and large lateral fovea each side ; foveae
nude and connected by a rudimentary transverse sulcoid depression of varying
breadth and depth, at no time cleanly cut and always difficult to follow.

Abdomen with five visible tergites in a length ratio of 6/1/1/1/1.5 with
first two with strong lateral margins. Base of first with a pair of strong,
straight, slightly divergent basal carinae which are two-fifths as long as seg-
ment and separated by one-half the segmental width. Six simple sternites in a
length ratio of 1/2.5/1/1/1/.5.

Metasternum elongate, tumid each side of a subglabrous broadly concave
depression ; apical margin finely incised at middle.

Posterior coxae and intermediate coxae separated by one-third the median
metasternal length. Legs simple and the posterior tibiae are not spined or
spurred. Tarsi of typical Hamotus proportions, with two large, equal claws.

Described on two specimens of doubtful sex, both collected by the author
in decayed log mold in rain forest of Barro Colorado Island, Gatun Lake,
Panama Canal Zone. Type July 25, 1936, at Drayton 13; paratype July 29,
1936, at Zetek 3. The paratype had recently pupated.

Alleei runs to Group XI but has little affinity with other species. With
more time it may form the type of a new genus. The general habitus,
pubescence, head from above, antennae, pronotum and elytra, and especially
the maxillary palpi are Hamotus. The very long first tergite is Apharus. The
vestigial pronotal sulcus places the species near the genotype lateritius rather
than the extremes of Hamotus but lack of tibial spurs and nude foveae incline
it to Hamotoides. The ventral surface of the head, punctation, and basal ab-
dominal carinae are nonhamotine. It is a pleasure to name this distinctive
pselaphid for my friend. Professor Warder Clyde Allee.

Hamotus (Hamotus) sandersoni new species

Type. Measurements: Head 0.37 x 0.38 mm.; pronotum 0.37 x 0.43 mm.;
elytra 0.47 x 0.80 mm.; abdomen 0.63 x 0.80 mm.; total length 1.84 mm.

Uniform light brownish-yellow. Pubescence abundant, fine in texture, sub-
appressed, dark golden in color. Integument lightly punctulate.

322 NEOTROPICAL PSELAPHIDAE

Head with length and width subequal, of the usual form, with long con-
vergent tempora. Eyes moderately prominent, median, reniform, with about
96 very minute facets. Vertex with three relatively large nude foveae ar-
ranged in a triangle: a pair placed on a line through eye centers and as near
each other as either is to its adjacent eye — each of these foveae lies in the
apical margin of a definite ovate depression, which gives a peculiarly double
aspect to these interocular foveae; the third fovea is median and anterior,
placed at the base of the narrow longitudinal sulcus separating the small
antennal tubercles. Front, clypeus, and labrum as in costaricensis. Ventral
surface of the head is flattened, with a longitudinal lateral carina each side
below the eye — which is an approach to the condition in alleei — and a tri-
angular gular fovea at middle of base.

Maxillary palpi of usual hamotine form ; fourth palpomere with the longi-
tudinal sulcus of the internal face not entire, reaching to three-fourths of length,
slightly oblique, narrow with an expanded apical end in which is inserted
the very oblique palpal cone.

Antennae short and thick; I elongate-cylindrical; II less elongate, but
longer than wide, smaller than first; III-VIII all transverse; IX larger, asym-
metrically trapezoidal, transverse, mesial face shorter than lateral face; X
still larger and very transverse, also asymmetrically trapezoidal; XI as long
as four preceding united, as wide as long, with very round apex.

Pronotum distinctly transverse; form as in costaricensis; three pubescent
antebasal foveae of which the median is distinctly smaller than the lateral.

Elytra as in costaricensis.

Wings well developed.

Abdomen with five visible tergites in a length ratio of 3/3/2/2/1.5 and
the first three strongly margined. Six simple stemites in a length ratio of
1/3/.8/.5/.4/.4.

Metastemum, posterior coxae, and intennediate coxae as in alleei.
Posterior tibiae slightly arcuate in apical fourth, and bearing an apical spur
of setae. This apical spur is moderately long, very slender, strongly angulate,
aciculate. Tarsi as for genus.

Named on three specimens collected by the author on Barro Colorado
Island, Panama Canal Zone, from decaying log mold of the forest floor. Sex not
determined with certainty from external anatomy. Type on July 6, 1936, at
Armour 7 and two paratypes on July 26, 1936, at Armour 8. Named for one
of the younger students of Pselaphidae, Dr. Sanderson. This species is dis-
tinctive in its morphology. It is typical of Raffray's fourth group and ap-
pears to be closest to bulbifer of Colombia from which it is quickly separated
on pronotal dimensions.

Hamotus (Hamotus) castanalus new species

Type. Measurements: Head 0.40 x 0.43 mm.; pronotum 0.47 x 0.49 mm.;
elytra 0.60 x 0.94 mm.; abdomen 0.74 x 0.87 mm.; total length 2.21 mm.

Integument shining reddish-chestnut; almost impunctate save for legs

TYRINI 323

and antennal club which are subscabroid. Pubescence long, silky, abundant,
and yellowish-brown.

Head with width and length subequal with long oblique tempora. Eyes
medianly placed, reniform in lateral view, moderately prominent and com-
posed of about 58 moderately large facets. Vertex high, prominently and evenly
vaulted into a dome between the eyes. A pair of very small, nude, punctiform,
vertexal foveae on a line through anterior third of eyes, mutually separated
by a distance greater than either from its adjacent eye. Antennal tubercles
small and separated by a simple median depression, at the bottom of which
is the small median fovea. Front, clypeus, labrum, ventral surface of head
and maxillary palpi as in costaricensis.

Antennae short and thick; I subelongate-subcylindrical, being shorter than
usual; II smaller and subquadrate; III-VIII transverse, moniliform to trapezoi-
dal; IX and X gradually larger, transverse, trapezoidal; XI truncate at base,
very rounded at apex, one-third longer than wide, as long as preceding four
united.

Pronotum and elytra as in costaricensis.

Abdomen with five visible tergites in a length ratio of 5/3.5/2/2.5/2
with the first three strongly margined as usual. Four tergite with a large
circular, pubescent fovea in each latero-basal angle. Fifth tergite distinctive:
transversely flattened in basal half and slightly tumid in apical half, with a
short blunt dentoid tubercle at center of apical margin.

Six simple sternites in a length ratio of 2.5/3/1. 8/1/1/.8 and since the
last four are slightly flattened medianly the sex is probable male.

Metastemum as in alleei. Posterior coxae separated by one-half, and inter-
mediate coxae separated by one-fourth the median metasternal length. Legs
simple save that the posterior tibiae each bears an apical spur. These spurs
consist of about six long, thick, truncate setae arranged in an angulated,
truncate bundle. Tarsi as for genus.

Described on a single specimen collected by the author on Barro Colorado
Island, Gatun Lake, Panama Canal Zone, from beneath the bark of a log at
Armour 8 on July 26, 1936.

This species is readily separated from its allies. The domed vertex, long
silky pubescence, conspicuously fewer ocular facets and the terminal tergite
distinguish castanalus from costaricensis. The shorter terminal antennomere
separates it from aztekus among other characters noted. The only other near
relative is centralis of Brazil which has the pronotum distinctly longer than
wide, while castanalus has the pronotum slightly transverse.

Hamotus (Hamotus) aztekus new species

Type Male. Measurements: Head 0.40 x 0.40 mm.; pronotum 0.40 x 0.50

mm.; elytra 0.50 x 0.78 mm.; abdomen 0.70 x 0.84 mm.; total length 2.00 mm.

Shining reddish-brown; integument subimpunctate save for elytra which

324 NEOTROPICAL PSELAPHIDAE

are lightly punctulate and antennal club which is subgranulate. Pubescence
yellowish-brown, long, silky, and abundant.

Head as in castanalus save for the following: vertex not unusually vaulted
but is medianly depressed; the small antennal tubercles are distinctly separated
by a longitudinal sulcus instead of a median depression ; eyes of about 88 facets.
Front, clypeus, labrum, ventral surface of head, and maxillary palpi as in
costaricensis.

Antennae 0.87 mm. long; I to X as in castanalus; XI distinctive, being
three-fourths as wide as long, and as long as the preceding five segments united.

Pronotum slightly transverse with the sides nearly parallel ; three antebasal
pubescent foveae, of which the median is slightly smaller and more circular.

Each elytron with two large, circular, pubescent basal foveae; an un-
usually broad, deep, sulcoid sutural stria; a relatively long dorsal sulcoid
impression extending from outer fovea through basal third of elytral length.

Wings long and well-developed.

Abdomen with five visible tergites in a length ratio of 5/3.5/2/1.5/2
having the first three margined as usual. The last tergite is sexually dis-
tinctive, being broadly subtriangular.

Six sternites in a length ratio of 1/3/2.5/1/.8/.8 with the last four slightly
flattened. The penis is exserted between the last sternite and tergite, establish-
ing the sex of the type.

Metastemum as in alleei. Intermediate coxae separated by less than one-
third, and posterior coxae separated by slightly more than one-half, the median
metasternal length. Legs as for genus; posterior tibiae each with an apical
spur. This spur is sharply angulate at base, thick, subtruncate, and composed
of six very stout setae.

Described on nine specimens, all from Vera Cruz, Mexico, as follows:
type male and four paratypes from Tezonapa, one paratype from Penuela;
two paratypes from Tuxpango collected by Henry Dybas in July and August,
1941, and one male paratype from Cordoba on July 20, 1936, collected by
C. H. Seevers.

The female sex has the eleventh antennal segment as long as the preced-
ing four united; the sternites normally convex; the last tergite broadly
trapezoidal with the apical margin concave. The form of the terminal tergite
rapidly sexes the species, while the sexual variation in the distal antennomere
is a good illustration of a quantitative differential, in contrast to the qualitative
differences in the club of veracruzensis. There is some variation in the third
antennal segment, some specimens having this segment as long as wide and
others wider than long, but never longer than wide, which, therefore, quickly
separates aztekus from ursulus, simplex and other species with a distinctive
elongate third antennomere. From its nearest allies aztekus differs in the long
distal antennal segment of the male. The relatively short second sternite and
elytra are also diagnostic.

In the following descriptions of three new species of the subgenus
Hamotoides I have given a tolerably full account of one species and contrasted

TYRINI 325

the others with this and previously recognized species. Such a course not only
saves space but it introduces the comparative method more strongly. This is
valuable in itself since the subgenus as a whole has a deceptively common
habitus, as demonstrated by Schaufuss, Reitter, and Raffray and therefore the
several species populations must be separated with great care to avoid con-
fusion.

Hamotus (Hamotoides) veracruzensis new species

Holotype Male. Measurements: Head 0.40 x 0.40 mm.; pronotum 0.38
X 0.43 mm.; elytra 0.56 x 0.80 mm.; abdomen 0.70 x 0.77 mm. Total length
2.04 mm. (PI. VI, XVII)

Elongate, graceful body of a shining reddish-brown color. Integument
uniformly and distinctly punctate, with the elytra having the punctures
asperate and the antennal club granulate. Pubescence an opaque reddish-yellow
color, moderately short, subappressed, and not unusually sparse or abundant.

Head with oblique tempora slightly longer than the eyes. Eyes median,
very large and prominent, convex and subreniform, each composed of about
48 large facets. Occiput and posterior half of vertex convex; a pair of very
large, deep vertexal foveae placed on a line passing through eye-centers. Each
vertexal fovea is close to an eye, separated from the eye by the united
diameters of two ocular facets, and each with a diameter of three facets. Just
anterior to each eye the side of the head is abruptly narrowed by an angulation
which then expands to form an antennal tubercle. The antennal tubercles are
separated by a deep longitudinal sulcus, the posterior end of which forms
the median fovea. This pubescent circular fovea thus has its lumen directed
apically instead of dorsally. Front narrow and vertical between antennae,
descending to the simple clypeus. Clypeus and labrum as in costaricensis.
Base of mandibles with abundant golden setae; left mandible crossed dorsal
to right. Ventral surface of head simple and flattened.

Maxillary palpi large; first segment minute; second elongate, gently
arcuate and slightly obconical, the base much thicker and the apex much less
inflated than usual in the genus, apex not twice as wide as base and with the
internal face longitudinally sulcoid (for repose of distal palpomere?) ; third
segment as usual short and triangular, wider than second and about one-
third as long, with an acute-angular internal and a longitudinally convex outer
face. Fourth (distal) segment as long as eleventh antennal segment (0.234
mm.), one-fourth longer than second, slightly more than twice as wide as
second, elongate-oval, with a very obliquely truncate base and blunt apex.
The internal face of this last segment is entirely sulcate ; this palpal sulcus is
narrow, apically its margin circles the apex, enclosing the unusually apical
palpal cone, and basally the sulcus margins flair along the truncate base to
form its basal margin and hence enclose the peduncle or articular neck of the
segment. The palpal cone is exceptionally thick, blunt, translucent, slightly

326 NEOTROPICAL PSELAPHIDAE

arcuate. This last segment is in reality covered with excessively fine, appressed
pubescence which gives a micro-strigoid appearance. Over the surface is spread
the flaky, dehydrated, pearly secretion noted previously.

Antennae 0.87 mm. long; sexually modified in a qualitative sense; I
elongate-cylindrical; II smaller, elongate-cylindrical; III obconical, longer
than wide; IV and V shorter than third, quadrate-monilif orm ; VI-VIII grad-
ually transverse-moniliform ; last three segments forming a distinct club; IX
slightly longer than wide, rounded-trapezoidal; X larger, also slightly longer
than wide, obconical-trapezoidal, with an apically arcuate tooth at middle of
latero-ventral face; XI subovate, as long as the preceding two united or as
long as distal palpomere, having a straight sharp, apically directed spicule at
center of latero-ventral face, and a porous tubercle at apico-mesial face. Club
granular in addition to these sexual modifications.

Pronotum simple with evenly convex disc; sides subparallel in basal half,
then converging to rounded apex; base with a strong arcuate transverse sulcus
which connects a large lateral fovea each side with the poorly formed median
fovea. This latter is small and deep and lies in a widening of the sulcus.

Elytra each with two circular basal foveae, an entire sutural stria and a
broad discal impression extending for the basal half of elytral length.

Abdomen with five visible tergites in a length ratio of 4/3.5/2.3/1.6/1.5
and the first three strongly margined. Last tergite tranversely trapezoidal,
with a nearly straight apical margin.

Six stemites in a length ratio of 1.5/2.5/2. 5/1.8/1/.5 these being distinctly
concave medianly. The penis is exserted between terminal tergite and stemite,
assuring the sex of the holotype.

Metastemum strongly tumid each side of a longitudinal sulcoid impression
and the apical margin is deeply, narrowly incised to enclose a narrow, cross-
striated tubercle of the first sternite.

Intermediate coxae separated by one-fifth, and posterior coxae separated
by two-fifths the median metastemal length.

Anterior trochanters each apically prolonged into a short, black, triangular
tooth ; posterior tibiae not spurred. Tarsi as for genus.

Allotype Female. Substantially as for holotype save that (1) the tenth
and eleventh antennomeres are not toothed; (2) right mandible crossed dorsal
to left; (3) sternites more convex medianly; (5) anterior trochanters simple,
not dentate.

Described on thirty specimens from Vera Cruz, Mexico, as follows: holo-
type, allotype, three male and two female paratypes from Cordoba (July 11,
1941, Henry Dybas) ; two male paratypes from Cordoba (July 20, 1936, C.
H. Seevers) ; two female paratypes from San Juan, 20 miles east of Cordoba at
1750 feet elevation (July 18, 1941, Henry Dybas) ; nine male and eight female
paratypes at Penuela (July 10, 1941, C. H. Seevers) ; one male and one female
paratype at Tezonapa (August 8, 1941, Henry Dybas).

TYRINI 327

This very distinctive species, with clear-cut qualitatively different sexual
characters, is a member of Group XIV by virtue of its tawny pubescence.

Hamotus (Hamotoides) veracruzensis jietcheri new subspecies (PI. XVII)

I have set aside the following Panamanian population as a subspecies of
veracruzensis, although it may prove to have full specific rank. It agrees with
veracruzensis save for the following: (1) Pubescence a darker brownish-yellow;
(2) ninth antennal segment as wide as long; (3) tenth antennal segment as
wide as long; (4) eleventh antennal segment relatively longer; (5) antennal
club of same length but distinctly less asperate; (6) terminal tergite of male
transversely subfusiform; (7) terminal tergite of female transversely sub-
trapezoidal.

The secondary sexual characters are the same and this appears to be an
excellent opportunity to study the male copulatoiy apparatus of veracruzensis
s.s. and of jietcheri for information on the specific value of the penis between
two widely separated populations geographically, but with so many structural
features in common. Such a study, involving other neotropical pselaphids, is
now in progress.

This subspecies described on eighteen specimens collected by the author
on the rain forest floor of Barro Colorado Island, Gatun Lake, Panama Canal
Zone, as follows: one female paratype (July 1, 1936) in a termite gallery of a
decayed log at Bang's Casa; one male paratype (July 1, 1936) in log mold
at Bang's Casa; one male and two female paratypes in log mold at Zetek 3
(July 28, 1936) ; five male and eight female paratypes beneath loose bark at
Zet€k 15 (July 28, 1936) . Named in honor of Frank C. Fletcher.

Hamotus {Hamotoides) electrae new species

Type Male. 2.3 mm. long x 0.87 mm. wide. Shining reddish-brown with
the integument distinctly subasperately punctate and the antennal club granu-
late. Pubescence bright yellow-gold, long, semibristling and abundant. Head
as in veracruzensis save that the eyes have about 38 even coarser facets and
the clypeus is roughly asperate. (PI. XVII)

Antennae 0.94 mm.; I elongate-cylindrical; II subquadrate; III as long
as second but narrower, obconical; IV and V subequal, quadrate-moniliform,
as wide as third; VI and VII transverse-moniliform, as wide as fifth but
shorter; VIII very slightly wider than seventh, of same length, subtrapezoidal ;
distinct club of last three segments ; IX as wide as long, trapezoidal ; X slightly
longer than ninth, trapezoidal, slightly longer than wide; XI as long as preced-
ing two united, granulo-asperate as usual, with the poroid tubercle of apico-
intemal area well-developed. Last two segments not toothed.

Pronotum as in veracruzensis save that the median pronotal fovea is very
large, deep, cleanly cut and conspicuous, slightly larger than in monachus and
about five times larger than in veracruzensis.

328 NEOTROPICAL PSELAPHIDAE

Elytra as in veracruzensis.

Tergites margined as usual, in a length ratio of 3.5/3.5/2.5/2.5/2 with the
last tergite rounded-triangular.

Stemites in a length ratio of 1.5/2.5/2/1.5/1/1.5 with the last five much
more concave medianly to form an elongate-oval depression. The sixth sternite
is notably large, trapezoidal, coarsely punctate and deeply depressed medianly.
The penis is partially extruded so that the sex of the type is verifiable.

Metastemum, coxal separation and legs as in veracruzensis save that the
anterior trochanters are not toothed but instead the ventral face is compressed
into a longitudinal blackened carina.

Described from a single male specimen from San Juan, Vera Cruz,
Mexico, collected by C. H. Seevers on July 13, 1941.

In the Raffray 1904 key this species becomes associated with sanguinipes
Rafifray of French Guiana, with which it has little affinity save common
position in Group XII.

Hamotus {Hamotoides) thomasi new species

Type. Measurements: 2.11 mm. long x 0.80 mm. wide. Shining reddish-
brown; pubescence and punctation as in electrae. (PI. VI, XVII)

Head as in electrae save that the eyes have about 34 facets each and are
distinctly hirsute; median cephalic fovea more distinctly pubescent and with
the lumen obliquely dorsal, rather than apical as in veracruzensis.

Antennae with segment I elongate-cylindrical ; II subquadrate ; III shorter
and narrower, longer than wide, obconical; IV-VIII as in electrae; club well-
formed: granulate-asperate as usual with IX trapezoidal, longer than wide;
X trapezoidal, wider than ninth and wider than long; XI as long as the two
preceding united, distinctly flattened so that the dorso-ventral diameter is
much greater than the latero-mesial diameter, and with the poroid tubercle
of its apico-mesial face well developed.

Pronotum as in veracruzensis with a very small median fovea not much
larger than the transverse sulcus, but with the latter almost straight in the
median third of its course instead of sharply arcuate as in veracruzensis.

Elytra as in veracruzensis.

Abdomen with five visible tergites in a length ratio of 4/4/2.8/2.2/2 of
which the first three are margined as usual and the last tergite is transversely
trapezoidal.

Six sternites in a length ratio of 1.5/2.5/2. 5/1. 8/1/.5 with the stemites
deeply separated, convex antero-posteriorly and slightly flattened medianly.
Metastemum as usual. Legs simple; trochanters simple, posterior tibiae not
spurred.

The sex of the single specimen is unknown. It was collected from log
mold by C. H. Seevers on August 1, 1938 near Puerto Salgar, Cundinamarca,
Colombia. This species is a member of Group XIV, and within this assemblage

TYRINI 329

is distinctive in having the combination of elongate ninth and transverse
tenth antennomeres and golden pubescence. Named in honor of my brother.

The species of Hamotus may be listed as follows:

Subgenus Hamotus s.s. (Aube, 1844)
I

argentinus Raffray. 1908. Buenos Aires, Argentina.

badius Schaufuss. 1887. Colombia.

boliviensis Raffra3^ 1904. Yuracaris, Bolivia.

gracilicorms Reitter. 1882. Blumenau, Brazil; Colombia.

grandipalpis Sharp. 1887. Volcan de Chiriqui (2000-3000 feet), Panama.

iheringi Raffray. 1911. Sao Paulo, Brazil.

rostratus Sharp. 1887. Bugaba, Panama.

sternalis Raffray. 1904. Yuracaris, Bolivia.

II

parviceps Reitter. 1888. Blumenau, Brazil.
subtilis Schaufuss. 1887. Minas Geraes, Brazil.

Ill

appendicularis Schaufuss. 1887. Brazil.

aubeanus Reitter. 1882. Brazil.

globulifer Raffray. 1904. Brazil.

inaequalis Reitter. 1882. Petropolis and Blumenau, Brazil.

IV

auricapillus Reitter. 1882. Tovar Colony, Venezuela.

barbatus Schaufuss. 1887. Colombia; San Esteban, Venezuela.

brunneus Schaufuss. 1887. Colombia.

bryaxoides Aube. 1844. Caracas and San Esteban, Venezuela;

Colombia; Bahia, Brazil.
{subpunctatus Reitter, 1882)

bulbifer Raffray. 1904. Colombia.

davicornis Reitter. 1882. Venezuela.

claviger Schaufuss. 1887. Colombia.

deplanatus Raffray. 1909. Serra de Baturite, Ceara, Brazil.

frontalis Reitter. 1882. Venezuela.

furcifer Schaufuss. 1887. Brazil.

globifer Reitter. 1882. Venezuela.

inflatus Raffray. 1891. San Esteban, Venezuela.

punctipennis Raffray. 1904. Colombia.

robustus Schaufuss. 1887. Caracas, Venezuela; Colombia.

ifrater Schaufuss, 1887 and bryaxoides
Schaufuss, 1887 nee Aube, 1844)

330 NEOTROPICAL PSELAPHIDAE

sandersoni new species. Panama Canal Zone.
tibialis Rafifray. 1904. Mexico.
transversalis Reitter. 1882. Colombia.
turalbus Park. 1935. Turrialba, Costa Rica.
vesiculifer Rafifray. 1891. Cumana, Venezuela.

crassipalpus Rafifray. 1891. Tovar Colony, Venezuela.

fuscopilosus Reitter. 1888. Tambillo, Ecuador.

gracilipes Reitter. 1888. Blumenau, Brazil.

{brevicornis Reitter, 1888)
(or reversed synonomy?)

impunctatus Reitter. 1888. Blumenau, Brazil.

laetus Rafifray. 1904. Paraguay (central area).

VI

cavicornis Rafifray. 1904. Guatemala.

VII

rugosus Rafifray. 1904. Yuracaris, Bolivia.

VIII

bicolor Rafifray. 1904. Yuracaris, Bolivia.
castanalus new species. Panama Canal Zone.
cavipalpus Rafifray. 1891. Caracas and San Esteban, Venezuela.
jauveli Rafifray. 1904. Yuracaris, Bolivia.
grouvellei Rafifray. 1904. Bahia, Brazil.

parvipalpis Sharp. 1887. Bugaba and Volcan de Chiriqui (2500 to

4000 feet) , Panama.
sulcipalpus Rafifray. 1904. Yuracaris, Bolivia.

IX

aztektis new species. Vera Cruz, Mexico.

brevimarginatus Schaufuss. 1887. Pozuzu, Peru.

centralis Reitter. 1888. Blumenau, Brazil.

costaricensis new species. Turrialba, Costa Rica.

setipes Sharp. 1887. Bugaba (800 to 1500 feet), and Volcan de

Chiriqui (2000 to 4000 feet), Panama.
simplex Raffray. 1904. Theresopolis, Brazil.
singularis Reitter. 1882. Mexico. Sharp (1887): Cordoba, Vera
Cruz, Mexico; Guatemala; Panama.
soror Rafifray. 1904. Caracas, Venezuela.

TYRINI 331

ursulus Schaufuss. 1887. This was described from Mexico without
a definite locality. I am glad to be able to
extend the range. I have a series from
Tezonapa and Penuela, Vera Cruz.

vulpinus Reitter. 1888. Blumenau, Brazil.

X

decipiens Raffray. 1904. Colombia.

lateritius Aube. 1844. GENOTYPE. Venezuela; Colombia.

(tenuicornis Reitter, 1882 cf. Raffray, 1891)

XI

alleei new species. Panama Canal Zone.

longepilosus Raffray. 1904. Yuracaris, Bolivia. I have this species

from Coroico, Bolivia.
longiceps Raffray. 1904. Minas Geraes, Brazil.
micans Reitter. 1882. Venezuela; Colombia.

Subgenus Hamotoides (Schaufuss, 1887)

XII

appendiculatus Reitter. 1888. Blumenau, Brazil.

difficilis Sharp. 1887. Zapote, Guatemala.

electrae new species. Vera Cruz, Mexico.

emeryi Wasmann. 1894. Joinville, Brazil.

monachus Reitter. 1882. One of the better known species.

Described from Yucatan, Mexico. Sharp (1887)
lists it from El Reposo and Zapote, Guatemala,
and Park (1935) lists it from Turrialba, Costa
Rica.

nodicollis Raffray. 1883. Mexico.

pubiventris Sharp. 1887. Chontales, Nicaragua.

sanguinipes Schaufuss. 1887. Cayenne, French Guiana, {sanguinifer
of Raffray, 1904; sanguinipes in Raffray, 1908)

vicinus Sharp. 1887. Capetillo, Guatemala.

XIII

nigropilosus Raffray. 1904. Para, Brazil.

tritomus Reitter. 1882. This is a widely distributed species. Described
from Colombia; Sharp (1887) records it from
Mexico (Jalapa?) ; El Reposo, Zapote, San
Isidro, Cahabon, San Juan in Vera Paz, Tele-
man, Panzos and La Tinta, Guatemala; Gran-
ada and Chontales, Nicaragua; Bugaba, Volcan
de Chiriqui, David, Panama.

332 NEOTROPICAL PSELAPHIDAE

XIV

bellus (Shaufuss). 1886. (Phamisulus) . Sao Paulo and Matte Grosso,
Brazil; Paraguay (central area). Raffray (1908) lists
it also from Pemambuco and Para, Brazil.

commodus Schaufuss. 1879. Yucatan, Mexico. Teapa, Tabasco, Mexico.

ecitophilus Raffray. 1909. Largest pselaphid reported to my knowl-
ledge. San Jose dos Campos, Brazil, con Eciton.

flavopilosus Raffray. 1891. San Esteban, Venezuela.

hilaris Schaufuss. 1887. Colombia.

hirtus Raffray. 1904. Only Antillean member of the genus so far re-
ported. Described on the female from Grenada,
Windward Islands. Raffray (1908) described
the male and reported the species from St.
Vincent, Windward Islands and Guadeloupe,
Leeward Islands.

punctulatus Raffray. 1912. Argentina.

reichei Raffray. 1891. Cumana, Venezuela.

rossii Raffray. 1917. Asuncion, Paraguay.

thomasi new species. Puerto Salgar, Cundinamarca, Colombia.

suturalis Schaufuss. 1879. Yucatan and Teapa, Tabasco, Mexico.

veracruzensis new species. Vera Cruz, Mexico.

veracruzensis jietcheri new subspecies. Panama Canal Zone.

APLODERINA (Raffray, 1904)

This is a monotypic Bolivian genus closely allied to Hamotoides. Its dis-
tinction lies in a perfectly globular third palpomere and a remarkably developed
male antennal club. The illustrations serve to isolate this hamotine better than
verbal description (PI. XX).

sulcicornis Raffray. 1904. Yuracaris, Bolivia. Genotype.

PHAMISULUS (Reitter, 1888)

This is a monotypic Brazilian genus, also closely allied to Hamotoides. The
last (fourth) segment of the maxillary palpi is elongate-conical, very acuminate
at apex, and with the internal face entirely sulcate. It is readily distinguished
by the increasing length of the first three visible tergites.

The complex taxonomic history of this genus is cited by Raffray (1908,
p. 401).

horroris (Schaufuss). 1886. Brazil. Genotype. {Phamisus Schaufuss,
nee Aube). {Neophamisus hetschkoi Reitter,
1888).

TYRINI 333

HAMOTOCELLUS (Raffray, 1911)

This is a monotypic Brazilian genus with no close allies in the Tyrini.
Raffray in erecting the genus places it near Phamisulus, but there is little quali-
tative affinity. The maxillary palpi are four-segment€d with the first segment
minute; second elongate-sinuate and subcylindrical; third short, triangular;
fourth very long, subfusiform with an acuminate apex and the internal face
entirely sulcate (PI. XX).

The head is unique among neotropical tyrines, being wholly devoid of a
common antennal tubercle. The front is perfectly truncate and rectilinear, with
an antenna distantly articulated at each apico-lateral angle.

Pronotum with disc moderately gibbous, laterally the contour is concave to
give a modified cordate outline ; there is no median ant€basal fovea, and on each
side is a sinuation in which lies the lateral fovea ; lateral foveae connected by a
transverse antebasal sulcus which is medianly expanded.

Each elytron is subtriangular, without any striae or foveae.

The abdomen is very similar to Phamisulus, broad, tapering rapidly, first
three tergites however subequal to slightly decreasing in length, but with a
strong, high and narrow margin on the first three visible tergites.

Cinnamon red with short, abundant, rigid, obtuse setae. Length given as
four millimeters so that it ranks as one of our large pselaphids.

hirsutus Raffray. 1911. Sao Paulo, Brazil. Genotype.

CERCOCEROPSIS (Raffray, 1904)

At present there are only two species in this genus, occupying a relatively
restricted area of the neotropical region — the Matto Grosso swamp of south-
western Brazil, southwards into the Paraguay river drainage to Asuncion, Para-
guay.

In general organization the genus is a specialization of the hamotine plan,
especially the antennae, head, pronotum, and elytra suggest Hamotus s.s. while
the very elongate first visible tergite suggests Apharus as noted by Raffray
(1904), this segment being longer than the other four tergites united. The
maxillary palpi are well-developed and indicate parallelism or affinity with
Cercoceroides.

The maxillary palpi have the first segment very small as usual in the tribe ;
second segment elongate, slender basally and apically gradually inflated to a
rounded apex; third segment short, triangular, slightly longer than wide, the
apex of this triangle inserting into the second, and the base of the triangle ar-
ticulating with the fourth, segment; fourth (distal) segment very elongate, sub-
filiform or narrowly subfusiform, subcylindrical, with both base and apex sub-
acuminate, and the internal face entirely but narrowly sulcate, with the usual
oblique palpal cone set near apex within the sulcus (PI. XX).

The species may be separated as follows:

Third palpomere regularly obconical, as long as wide; fourth palpo-
mere regularly fusiform, slender; 1.6-1.8 mm.; Brazil longipes

334 NEOTROPICAL PSELAPHIDAE

Third palpomere much longer than wide, gradually wider to apex
which is obliquely truncate ; fourth palpomere not so regularly sym-
metrical, slightly cultriform or knife-shaped, with external face sub-
rectilinear, internal face suboblique and slightly thicker at obtuse
basal angle; 1.54 mm.; Paraguay rugicornis

longipes Raffray. 1904. Matto Grosso, Brazil. Genotype.
rugicornis Raffray. 1917. Asuncion, Paraguay.

CERCOCEROIDES (Raffray, 1896)

This genus at present holds six species, all residents of the South American
rain forest, with the swampy jungle of Matto Grosso appearing to be the center
of dispersal with four species.

It is hamotine in form, allied to the subgenus Hamotus in major structural
features of head, pronotum, elytra, and tergites. The maxillary palpi are re-
markably similar to Cercoceropsis, while the metastemum is diversely tuber-
culate in the male sex and this latter character is fully utilized in the following
key to species:

Metasternum with at least one pair of recurved or otherwise modified
tubercles, and the metastemum always medianly and longitudinally
sulcate or concave Males 4

Metastemum not tuberculate Females 2

2. Metasternum medianly, longitudinally impressed 3

Metasternum simple, slightly elevated and not longitudinally im-
pressed ; 2.4 mm simplex Female

3. Known from Matto Grosso ; 2.3 mm germaini Female

Known from Paraguay; 2.3 mm.; head larger and less narrowed an-
teriorly; eleventh antennomere of same length (as long as three
preceding united in my material) , but thicker and more rounded on

external face; fourth palpomere longer and more slender

laticeps Female

4. Ill slightly obconical, slightly longer than wide; IV and V quadrate;

VI-VIII transverse 6

Antennae not as above 5

5. Ill, IV, V longer than wide; VI quadrate; VII and VIII transverse;

metasternum very deeply and very broadly concave, with a very
strong, acute, compressed and recurved tubercle adjacent to each

posterior coxa; Venezuela; 2.6 mm pectoralis Male

Not known north of Paraguay river basin; III much longer than wide;
IV-VII quadrate; VIII slightly transverse; metasternum broadly
concave, with a microtubercle each side, this tubercle being acute,
recurved or hook-shaped; 2.5 mm tuberculatus Male

6. Metasternum medianly narrowly sulcate, with a strong hook-shaped

process each side; stemites strongly impressed longitudinally; 2.3
mm germaini Male

TYRINI 335

Metastemum broadly concave, with two pair of tubercles: one elon-
gate, subcarinoid tubercle immediately anteromesiad of each pos-
terior coxa and at the center of metastemal length a microtubercle

which is sharply curved anteriorly ; 2 mm

sternalis Male, new species

Cercoceroides sternalis new species

Type Male. 2.0 mm. long x 0.94 mm. wide. Dark reddish-brown with the
elytra red and palpi and tarsi brownish-yellow. Integument shining, lightly
punctulate. Pubescence long, thin, semi-bristling and shaggy (PI. XX).

Generally hamotine in form with tempora shorter than the eyes ; eyes large,
convex, very prominent and each composed of about 46 facets which are coarse
and convex. Occiput and posterior half of vertex strongly, evenly convex. A pair
of large and deep vertexal foveae on a line through anterior third of eyes and
each closer to an adjacent eye than to each other. Head subangulately narrowed
anterior of eyes, then expanded to form the well-developed antennal tubercles.
These latter separated by a deep longitudinal sulcus which arises on the inter-
antennal line and ends in a median foveoid depression opposite posterior margins
of antennal tubercles. Narrow front vertical to the subgranulate clypeus. Ventral
surface of head in great contrast to rest of body — roughly granulate-punctate,
with the usual gular fovea having alutaceous walls.

Maxillary palpi prominent; first segment short, obconic-cylindrical; second
elongate-pedunculate for basal half, gradually inflated to rounded-oblique apex ;
third short, triangular, longer than wide, internal face acute, external face gently
convex, with second and fourth segments articulating at each end of the external
face; fourth very long (0.3 mm.), longer than second, very narrow (one-third
wider than third), slightly wider at basal four-fifths, base and apex narrower,
internal face entirely, narrowly sulcate, this sulcus bearing a palpal cone set
obliquely below apex, and the sulcus basally sinuate.

Antennae I elongate-cylindrical ; II smaller, slightly longer than wide ; III
slightly longer than wide, obconical; IV and V quadrate; VI-VIII progressively
transverse; IX and X slightly transverse, trapezoidal, progressively larger; XI
as long as the preceding three united but shorter than distal palpomere, sub-
obconical with truncate base and rounded apex.

Pronotum with three large, free, pubescent, circular, antebasal foveae and
simple convex disc.

Elytra each with two large pubescent, circular, basal foveae, the inner of
which at base of a deep, entire, sutural stria and the outer at base of a well-
developed dorsal impression half the elytral length.

Abdomen with five visible tergites in a length ratio of 5/4/2.5/2.5/2 with
first three margined as usual. Last tergite recessed beneath fourth, vertical, in-
visible from above, very convex or longitudinally tumid at middle.

Six stemites in a length ratio of 1/3/2/.5/.7/1 with the second, third, and
fourth attractively bicolored, their apical margins being bright yellow. These

336 NEOTROPICAL PSELAPHIDAE

segments not longitudinally impressed as in germaini but very slightly flattened.
Penis partially exserted to assure sex of type.

Metasternum 0.335 mm. long, medianly broadly concave. Immediately an-
tero-mesiad of each posterior coxa is an elongate subcarinoid tubercle, and in
the exact center of the metasternal length, on each sloping wall of the concavity,
is a minute hook-shaped process or an anteriorly directed microtubercle ; apical
margin medianly incised as usual to accommodate intercoxal tubercle of first
sternite.

Legs simple save that the posterior tibiae are spurred. This spur arises quite
basad of apex; for quite a distance the coarse setae emerge to give a straight,
thick, very obliquely truncate bundle.

Described on a single male from Corumba, Matto Grosso, Brazil.

This new species has the antennae of germaini and the metasternal micro-
tubercles of tuberculatus in addition to a pair of juxtacoxal tubercles. It is pos-
sible that the variation in antennomeres and male characters is great within the
genus, in which case tuberculatus and sternalis may be varities of germaini, and
simplex the female of one of these male variations. Such a condition is not prob-
able. Study of antennomeres in Reichenbachia, Arthmius, and both subgenera
of Hamotus suggest a genetic ratio between length and width of a segment in
the same sex of a given species of pselaphid. That is, the third antennomere for
example, if obconical will vary in length but is never wider than long; or if this
segment is more or less transverse, it will vary in width but is never longer than
wide. Such study requires long series of specimens. Since Cercoceroides is not
common in collections, this approach must be delayed.

The species may be tabulated as follows:

germaini (Raffray). 1890. Matto Grosso, Brazil. Genotype. (Cerco-

cerus)
laticeps Raffray. 1917. Asuncion, Paraguay.*
pectoralis Raffray. 1911. Merida, Los Andes, Venezuela.
simplex Raffray. 1904. Matto Grosso, Brazil.
sternalis new species. Corumba, Matto Grosso, Brazil,
tuberculatus Raffray. 1904. Matto Grosso, Brazil.

PSEUDOHAMOTUS (Raffrey, 1890)

This neotropical genus holds five species having many notable affinities with
Hamotoides but distinctive in the form of the last segment of the maxillary
palpi (PI. XX).

This distal palpomere is more or less semicircular in outline, nearly as broad
as long, with external face consequently very convex; the internal face is sub-
rectilinear and bears an entire but very narrow sulcus ; as usual in the hamotine
stem, the palpal cone is obliquely inserted at the apex of this sulcus.

' I have recently received a female of this species from Horqueta, Paraguay, collected
December, 1935, by A. Schulze. This checks with Raffray's description and has not since
been reported.

TYRINI 337

The species may be tentatively separated as follows :

First visible tergite shorter than second; 2.33 mm.; known only from
Guatemala latipalpis

First two tergites subequal or first slightly longer than second; not
known north of Panama 2

2. Known only from Panama ; 2.33 mm curtipalpis

Known only from Brazil 3

3. Antennomere VI quadrate, as long as wide; not more than 2.6 mm. in

length 4

Antennomere VI regularly transverse, distinctly wider than long; 2.8
mm planiceps

4. Antennomere III much longer than wide; antennal tubercles promi-

nent, deeply separated and obviously constricted at base; 2.3-2.6

mm inflatipalpus

Antennomere III slightly longer than wide; antennal tubercles less
marked ; 2.5 mm conjunctus

The species may be listed as follows :

conjunctus (Reitter). 1882. Petropolis, Rio de Janeiro, Brazil.

(Hamotus) Genotype.
curtipalpis (Sharp). 1887. Bugaba, David, Panama. (Hamotus)
inflatipalpus (Reitter). 1888. Blumenau, Brazil. (Hamotus)
latipalpis (Sharp). 1887. Zapote, Guatemala. (Hamotus)
planiceps Raffray. 1904. Brazil.

PSELAPHOCOMPSUS (Raffray, 1908)

This is an aberrant, monotypic Brazilian genus. Although erected in 1908
(p. 403), both genus and species were redescribed by Raffray in 1911 (pp.
447-449) .

The maxillary palpi are unique among neotropical tyrines but are strikingly
similar to these organs in Pseudophanias of the Indo-Malayan rain forest. The
first segment is minute and inconspicuous as usual; second arcuate, very long
and slender, becoming gradually wider to the rounded apex; third wider than
long, slightly wider at apex than second, truncate at base and apex. Fourth one-
third shorter than second, not much wider at base than third, then slightly
broadening near base and then gradually narrowing to a long, acuminate apex;
this gives a conical outline which is slightly sinuate internally near apex; the
internal face bears a very slender, entire, slightly oblique palpal sulcus, with a
very long apical palpal cone set within the sulcus. Raffray states that this palpal
cone is one-third the segmental length (PI. XX) .

The infra-ocular spine is very strongly developed as a tubercle from the
posterior genal angle to the middle of the eye, and suggests parallelism with
some species of Neotyrus, Tyrogatunus, as well as non-neotropical genera as
Tmesiphorus. The small size of the maxillary palpi and other features led

338 NEOTROPICAL PSELAPHIDAE

Raffray to suggest some approach to Pseudotychus of South Africa and
Eudranes of Australia. Finally the general form suggests the subgenus
Hamotoides but the nonsulcate pronotum suggests Hamotus proper.

punctatus Raffray. 1908. Nouveau-Fribourg, Rio de Janeiro, Brazil.
Genotype.

CERCOCERULUS (Raffray, 1904)

This is a monotypic Brazilian genus. Originally placed in Phalepsus, the
genotype was removed by Raffray because of its large, equal tarsal claws. Struc-
turally it shows many affinities with the subgenus Hamotus but is unique among
neotropical tyrines on the basis of its maxillary palpi.

These organs are similar to those of the Australian Rytus. The large maxil-
lary palpi have a minute first segment, which however, is slightly wider than
the base of the second; second segment about three-fourths as long as fourth,
slightly arcuate and very slender for basal two-thirds then inflated to the
rounded apex; third obconical, longer than wide, less than one-third as long as
fourth; fourth distinctively shaped, gourd-like, with a wide ovoidal basal half
and a subulate spinoid apical half, with the internal face having a striaform
longitudinal sulcus from near apex to middle of segment (PI. XX).

hirsutus (Schaufuss). 1886. Amazon basin, Brazil. Genotype.

TYROGATUNUS new genus

This new genus is distinct from other Tyrini on the key characters pre-
viously given, but several morphological features necessitate further elabora-
tion. The t€rmitocolous members of Tyrogatunus have a novel eye structure, an
unusual distal palpomere, and peculiar pubescence.

The eyes are slightly postmedian in position, reniform in lateral view as
customary in the tribe, and are flanked with a strong infraocular spine; each
eye is composed of about 62 facets. These facets are not uniform in size or shape.
The dorsal third of each eye holds some 22 facets which are very flat, and signi-
ficantly greater in diameter while the ventral two-thirds holds much smaller,
normally convex facets. This striking condition is found in both sexes (PI.
XVII, 1).

The pubescence is very long (0.20 mm.), moderately abundant (about 5
setae per 0.005 sq. mm.), bristling and golden. These setae are thin-shafted with
the distal third to fourth excessively thin and tending to curl (PL III, 6) in
various directions, so that from an optical view the setal tips present a variably
developed mat.

The maxillary palpi (PI. XX) are large with the first three segments formed
as in Tyropsis and Neotyru^ in general and their detail can be seen in the illus-
trations. The fourth or distal palpomere is distinctive. It is long (0.22 mm.) and
is a fusiform shape, with the base subpedunculate and the apex rounded. The
unique feature is a longitudinal sulcus on the dorsal face, that is, when the
specimen is seen from above the sulcus is in full view, the internal face being

TYRINI 339

devoid of any trace of sulcation. Such a condition is nonhamotine on the one
hand, and yet the presence of a sulcus is nonneotyrine so that this sulcus, alone,
serves to isolate the genus. The sulcus is very broad and shallow, but the margins
are sharply defined. The long, truncate palpal cone is set within the apex of the
sulcus, which latter occupies the apical fourth of the segment. In a paratype the
distal palpomere is coated with the pearly palpal secretion noted for other
genera.

The males and females resemble each other in coxal spines, trochantal
spines, and carinate anterior femora, reminding one of similar nonsexual leg
abnormalities in Tyrus. Sex is quickly diagnosed by the shape of the terminal
(sixth) sternite, which is a narrow, very short and simple segment in the female;
in the male this sternite is deeply incised at the middle of the apical margin to
accommodate a discoid penial plate, as in Tyrus. At first I thought that the
female sex had the notched terminal sternite but subsequent dissection of a
paratype demonstrated the sex and served to impress the author with the ne-
cessity for such direct methods.

Tyrogatunus zeteki new species

Holotype Male. Measurements: Head 0.47 x 0.43 mm.; pronotum 0.50 x
0.50 mm.; elytra 0.67 x 0.94 mm.; abdomen 0.63 x 0.97 mm. Total length (in-
cluding cervicum) 2.4 mm. (PI. Ill, XVII, XX).

Dark reddish-brown, shining and lightly punctulate with the elytra slightly
more punctate. Pubescence as described above.

Head with long oblique tempora which are longer than the eyes. Eyes as
described above. Vertex smoothly rounded, with a pair of small, deep, nude
fovea on a line through eye centers, and slightly closer to eyes than to each
other. Each fovea lies in a depression and the latter is faintly connected with the
frontal fovea by a rudimentary, oblique impression. Frontal fovea is larger, pu-
bescent, and occupies the apex of a triangular interantennal sulcus. The antennal
tubercles, therefore, are oblique. Below each eye is a broad, triangular infra-
ocular spine. The ventral surface of the head is simply flattened, with the usual
median gular fovea at middle of base.

Maxillary palpi as described above.

Antennae half the body length (1.27 mm.) slender: segment I elongate-
cylindrical; II smaller, similar; III-VIII obconical, third to sixth longer than
wide, seventh and eighth as long as wide ; club poorly differentiated and progres-
sively asperate, with IX longer than wide, elongate-trapezoidal; X as long as
wide, trapezoidal; XI not as long as preceding two united, with rounded apex
and truncate base.

Pronotum with the hexagonal outline of Neotyrus coptocolus; disc evenly
convex; a large pubescent lateral fovea each side and a smaller nude median
fovea, these three foveae being connected by an arcuate antebasal sulcus ; basal
bead medianly extended as a longitudinal cuneiform carina which reaches lumen
of median fovea.

340 NEOTROPICAL PSELAPHIDAE

Elytra with obtuse humeri. Each elytron with two large, circular, pubescent
basal foveae, an entire sutural stria and a long dorsal stria, at bottom of dorsal
impression, which extends beyond the middle of elytral length.

Abdomen with five visible tergites in a length ratio of 7/2.5/1.5/1/2 with
first three margined as usual.

Six stemites with proportions and shape as illustrated. The sixth stemite
is deeply incised at middle of apical margin to hold a discoid penial plate.

Metastemum deeply, broadly sulcate with each sulcal wall forming a prom-
inent tumidity.

Anterior legs: trochanter with a short, stout triangular tooth at apex of
ventral face ; femur with a sharp, high longitudinal carina which occupies the
median half of the ventral face ; tibia arcuate.

Intermediate legs: coxa with a densely setose spinoid tubercle at ventro-
posterior face; trochanter with a very long, thin spine at apex of ventral face;
tibia arcuate.

Legs otherwise simple and normal for tribe, with the tarsi having two large,
arcuate, equal tarsal claws.

Allotype Female. Similar to holotype save that (1) the abdomen is slightly
broader and shorter; (2) elytra more punctate; (3) stemite ratio differing, as
illustrated, with the terminal (sixth) stemite short and simple.

Erected on three specimens collected from nest or galleries of the termite,
Coptotermes niger Snyder, on Barro Colorado Island, Panama Canal Zone.
Holotype and allotype collected by the author at Armour 7 (July 6, 1936) and
paratype female collected by Alfred Emerson on September 6, 1935. Named for
my friend James Zetek, resident custodian of the B.C.I, laboratory.

* * * » *

In closing this section on neotropical Tyrini the author is tempted to write
a few words regarding the maxillary palpi as indicators of speciation. This is
done in full recognition of the possibility that structural features of the oral and
tarsal areas may not be the best regions for this purpose, and also that one struc-
ture is necessarily limited in its bearing. On the other hand these palpi offer such
a range of generically limited characters that proper examination must have
some value.

There appear to be two basic types of neotropical maxillary palpi in the
Tyrini (PI. XX) : the tyrine type in which the second and third palpomeres are
similar in shape, pedunculate, with the fourth or distal segment subfusiform and
nonsulcate; and the hamotine type in which the third palpomere is short, tri-
angular and the distal segment is obliquely truncate at base and with a longi-
tudinal sulcus on the internal face. In the former case the palpal cone is more
or less apical and inserted in a variably developed apical tmncature. In the
latter case the palpal cone is set very obliquely within the apex of the palpal
sulcus. Virtually all palpomeres vary among the genera, and within generic lim-
its there is considerable variation among the species. Few and minor are the
sexual variations of the palpi, and within the species population there is no
significant variation.

TYRINI 341

In general the first two palpomeres are relatively stable, the first usually
very short, cylindrical, and inconspicuous; the second very long, more or less
arcuate, slender basally and more or less inflated apically. The third shows much
more variation, being arcuate-pedunculate, obconical, triangular, or spherical.
The fourth varies the most, being one of the most labile regions of the tyrine
body, as may be seen in the illustrations. Thus we find that in both the tyrine
and hamotine types, the degree of variation is in direct proportion to the dis-
tality of the palpomere.

Under the dissecting binoculars I have observed pselaphids feeding upon
oribatid mites and small staphylinid larvae, as well as the larval and pupal
brood of host ants, and in these cases the maxillary palpi were continually in
use, being twirled about and especially the distal palpomere being used to rap-
idly, lightly touch the food in a continuous tapping. Such exploratory behavior
suggests a sensory function, and the demonstrable secretion of the distal palpo-
mere of many tyrines supports this view. Real progress would be achieved by
making a study of serial sections of these organs.

I regard the tyrine type of palpus as primitive and the hamotine type as
highly derived. Thus if we assume a fusiform distal palpomere with a simple,
acute apex as a hypothetical basis for evolution, the neotropical genera may be
arranged as follows:

A. Development of the tyrine type.

1. Phalepsus with a very primitive, fusiform distal palpomere.

2. Development of three tyrine modifications of the distal palpomere,
but with the first three palpomeres primitive:

a. Lethenomus in which the fusiformity is lost and the segment be-
comes obconical-pyriform and the internal face, near the apex, becomes pointed
and pubescent.

b. Tyropsis, Neotyrus, Tyrogatunus in which the apex becomes more
or less truncate, with an apical palpal cone set within the truncature in the first
two genera, and secondly this truncature moves basad over the dorsal face to
form a sulcus in the last genus.

c. Juxtahamotopsis with the shortening of the third and fourth seg-
ments, and the development of many subpalpal cones.

These three lines are quite unrelated to each other.

B. Development of the hamotine type.

This appears most feasible from the lower end of 2b {Neotyrus-Tyropsis
stock), in which certain tendencies are assumed: the shortening of the long axis
of the third palpomere from elongate-pedunculate to triangular; second, loss of
fusiformity of the fourth palpomere which involves increasing width and in-
creasing basal obliquity; third, the apical truncature of fourth palpomere moves
basad over the internal face to form a longitudinal sulcus; fourth, as the sulcus

342 NEOTROPICAL PSELAPHIDAE

develops, the terminal cone is pulled basad so that it becomes obliquely set
within the apex of the sulcus.

Several lines of development are possible:

a. The main line would appear to include Apharus (with the sulcus
limited to the apical half), Hamotus s.s. (with the sulcus gradually lengthening,
but varying from short in which only the apical two-thirds of the segment are
sulcate, through a sulcus four-fifths segmental length, to entire in which the
sulcus divides the oblique basal margin and therefore radically alters the in-
ternal face since the basal margin is now continuous with the sulcal margin) ,
Hamotoides (in which the tendency is for an entire sulcus of narrowing width).
At this point there appears to be a basic divergence in length-width ratio of
the segment:

b. The fourth palpomere becomes very wide in proportion to its length,
as in Pseudohamotus with a very narrow, entire sulcus and a semicircular
outline.

c. The fourth palpomere becomes very narrow in proportion to its
length, also with a narrowing of the entire sulcus: Hamotocellus, Cercoceroides,
Cercoceropsis.

d. An aberrant line shows the palpal sulcus narrowed to striaform pro-
portions, and the distal palpomere becoming very narrow apically: Pselapho-
compsus, Cercocerulus.

e. Another line would seem to diverge from Ba, in which the third
palpomere is spherical, and the simply ovoidal fourth palpomere is entirely
sulcate. The base of this segment is simple, and the sulcus is broad and fusiform.
Such a condition is approached by Aploderina.

This system is but one of many possible. It should be integrated with the
tergite ratio, cephalic sutures, and sternal foveae as well as the pronotal sulcus
and elytral striae-costae complex.

Of these structural criteria I should regard the sternal foveae, and espe-
cially the male copulatory apparatus as basic. These require prepared slides
and are being studied at the present time.

Tribe 15. Arhytodini

This is a monogeneric tribe of eleven species confined to South America.
Structurally it is of great importance as the following points will demonstrate.

The body is elongate, ovoidal, with the abdomen broad, and the body dorso-
ventrally flattened. The pubescence is of two types: the general body setae are
moderately elongate, arcuate, and more or less sparse and semierect; in addition
foveae, sulci, many sutures and other areas, as described later, are filled with
very short, appressed, matted scales which have a surgary appearance and make
a direct approach to the Ctenistini.

Head elongate, flattened, with clearly marked antennal tubercles which are
separated by a short frontal sulcus; the vertex bears a Y or V-shaped sulcus;
postmedian eyes of large facets. The antennae are eleven-segmented, with the
last three antennomeres forming a poorly marked club. The shape and size of
the antennomeres offers an excellent separation of the species.

The mouth-parts are peculiar. The large submentum-mentum is nearly
vertical, almost wholly covering the oral aperture. The maxillary palpi are
minute, apparently of one segment which is thin, pedunculate, basally arcuate,
apically inflated to present a rounded apex holding a terminal seta. This latter
may be the homologue of the palpal cone of other tribes. The mandibles are
well-developed, elongate, with four or five teeth. The labrum is excessively
transverse and short as a rule. Thus the rudimentary maxillary palpi and the
occluding mentum form a direct approach to the rudimentary mouth-parts of
Clavigerinae, while the long and narrow, but well-toothed mandibles, suggest
the primitive predaceous habit of the family. Since at least one species is known
to be myrmecophilous we may have here a group of species well on the road to
social parasitism, in which case the obviously primitive (mandibles) , and highly
specialized (mentum, labium, maxillae, and associated palpi) mouth-parts are
nicely balanced.

Pronotum usually wider than long, with the disc usually longitudinally
gibbous and subcarinoid as in some Euplectini and Batrisini; antebasal, strongly
biarcuate to V-shaped sulcus present.

Elytra with two basal foveae, and several striae some of which vary in
length among the species.

Abdomen with wide, flattened margins; five visible tergites and six stemites.
Tergites often gibbous or diversely tuberculate.

Metastemum more or less longitudinally sulcate. Anterior femora with the
antero-ventral face more or less carinoid and produced, especially in the male
sex. The long, slender, typically macrosceline legs have tarsi which are unique
in the Pselaphidae. The three-segmented tarsi have a short first tarsomere ; sec-
ond much longer, thick, arcuate-obconical, with the apical face very oblique,
as is the first segment, and ventrally bilobed; third tarsomere short, conical,

(343)

344 NEOTROPICAL PSELAPHIDAE

articulated deeply into the oblique apex of second, between the two lobes and
bears a single, very large, arcuate and shaip claw.

From this resume it will be seen that Arhytodini offer affinities with
Ctenistini in pubescence, and Clavigerinae in oral structure, but have unique
tarsi.

I have expanded and modified the 1909 key of Raffray to include later
species :

ARHYTODES (Reitter 1881)
Reitter (1881)
Raffray (1890, 1891, 1904, 1909)

The genus is sufficiently summarized above. The species may be separated
as follows:

Dorsal striae of elytra entire ; disc of pronotum more or less longitudi-
nally elevated into a subcarinoid tumidity 2

Dorsal elytral striae either absent, or if present not beyond the middle
of elytral length 7

2. Antennomeres II, III, IV, V, and VII transverse; VI and VIII elon-

gate; 2.7 mm. long; Argentina myrmecophilus

Antennae not as above 3

3. Antennomere III quadrate, as wide as long 4

Antennomere III elongate, longer than wide 5

4. IV three times longer than wide; V quadrate; VI three times longer

than wide ; VII quadrate ; VIII three times longer than wide ; Brazil ;

1.9 mm. long oberthuri

IV-XI all longer than wide achillei new species

5. IV transverse ; V-XI elongate ; Brazil brevicornis

IV longer than wide 6

6. All antennomeres cylindrical; dorsal elytral stria geminate or paired

only at base ; Brazil ; 2 mm. long vestitus

VIII, IX, and X obconical; dorsal elytral stria geminate for the entire
elytral length ; Brazil gounellei

7. Elytra with dorsal striae , 8

Elytra with no dorsal striae; pronotum with disc simply convex, not

longitudinally gibbous; tergites not medianly gibbous; antennae
very long, nearly as long as body: I large and cylindrical; II quad-
rate; III, IV, V, and VII slightly, VI and VIII twice as long, as wide;
Argentina bruchi

8. Dorsal elytral stria geminate and extending for half the elytral

length; antennomere II quadrate; III-VIII about twice as long as
wide ; IX and X three times as long as wide ; tergites weakly gibbous
medianly ; pronotal disc strongly longitudinally carinoid ; Brazil . . .

semisulcatus

Dorsal elytral stria very short, not extending to middle of disc 9

ARHYTODINI 345

9. Known only from Bolivia; Male with II quadrate, III-VIII gradually
increasing in length ; 2.7 mm boliviensis

Known only from Venezuela 10

10. VI and VIII nearly two times longer than wide, IX and X nearly four
times longer than wide in the Male; antennomeres much shorter
with IX and X only three times longer than wide in the Female;
2.25 mm margaritaceus

VI and VIII nearly two times longer than wide, IX and X about three
times longer than wide in the Male; VI and VIII slightly longer
than wide, IX and X about two times longer than wide in the
Female; 2.25 mm rubripennis

Arhytodes achillei new species

Type. Measurements: head 0.49 x 0.45 mm.; pronotum 0.43 x 0.52 mm.;
elytra 0.74 x 0.94 mm.; abdomen 0.67 x 1.07 mm. Total length 2.33 mm.
(PI. VI, XIX)

Shining reddish-brown ; antennae and legs densely granulate-punctate ; ver-
tex and front sparsely, coarsely granulate; pronotum sparsely asperate-punc-
tate ; elytra subglabrous ; abdomen very sparsely asperate-punctate. Pubescence
as described above, with body setae golden and squamose setae white.

Head with straight, oblique tempora nearly as long as eyes and meeting the
occiput at nearly a right angle; occipital margin deeply, semi-circularly incised
for median half of width. Vertex with sides subparallel and subcarinoid from
posterior angles to middle of eyes; vertex flat, with a broad, squamose V-shaped
sulcus, from occipital incisure one arm of this sulcus passes obliquely anteriad,
filling the space between eye and antennal tubercle. Eyes postmedian, promi-
nent, each composed of 26 veiy convex facets. The ovoidal eye does not have
the facets in rows but irregularly placed and in the type before me, the facets
are oddly bicolored, with the pigment sharply concentrated distad and the lower
two-thirds of the facets a translucent amber. Antennal tubercles separated by a
broad, short, squamose frontal sulcus, which does not extend posteriorly to join
the V-shaped vertexal sulcus. Mouth-parts as described above. Ventral surface
of head flattened, with a large triangular squamose patch each side. Cervicum
alutaceous.

Antennae long (1.87 mm.) reaching well beyond posterior elytral margin;
segment I elongate cylindrical, about three times longer than wide; II slightly
longer than wide, narrower than first; III very short and quadrate; IV-VI
elongate-cylindrical, fourth one-third longer than third segment, fourth to sixth
progressively greatly increasing in length; VII elongate-cylindrical, subequal
to fourth; VIII elongate-cylindrical, subequal to sixth. These first eight are all
longer than wide, save for the quadrate third antennomere, and measure 1.07
mm. united. Club of last three segments measures 0.80 mm. united; IX elongate-
cylindrical, slightly longer than first, about as wide as first, two times longer
than eighth; X subobconical, longer than ninth; XI as long as eighth, slightly

346 NEOTROPICAL PSELAPHIDAE

wider than first, slightly longer than wide, with truncate base and rounded apex.

Pronotum with disc longitudinally gibbous and subcarinoid; base with a
broad, squamose, biarcuate, V-shaped sulcus.

Elytra with oblique humeri. Each elytron with two squamose basal foveae,
an entire sutural stria, two entire dorsal striae, and a short humeral stria ; aris-
ing between the basal foveae is an entire, wide, flat costa which is limited each
side by an entire dorsal stria so that the elytral disc has one costa and two in-
tervals ; the outer interval is incomplete externally since the short humeral stria
is obsolete beyond the humeral elevation; the inner interval is complete being
bounded by the inner of the two dorsal striae and the sutural stria.

Abdomen with five visible tergites in a length ratio of 3.5/3/2.5/1.5/2 with
the first three having wide, flat margins. The tergites are simple, not medianly
gibbous and without tubercles. Base of first and elytral margin, as well as lateral
articulations of first-second and second-third tergites, densely squamose.

Six sternites in a length ratio of 2/3/2/1. 5/.5/1 with sternites well sepa-
rated. First wholly, and lateral articulations of second-third and third-fourth
sternites, densely squamose.

Metastemum 0.335 mm. long, medianly sulcate, sulcal walls tumid. All
sternal foveae, the prosternum, the mesostemum, and lateral sternal sclerites
squamose. Intermediate coxae separated by one-fifth, and posterior coxae sepa-
rated by two-fifths, of the median metasternal length.

Legs very long and slender, with the tarsi as described for tribe. The an-
terior femora are modified: each femur has the basal third of the anterior face
semi-circularly produced into a carinoid and stiffly setose lamina.

Described from a single specimen from Corumba, Matto Grosso, Brazil. The
sex is probably male. This distinctive species is named in honor of the great
French expert, Achille Raffray.

Achillei belongs in the first section of the genus by virtue of its entire dorsal
elytral striae, but has few afiinities with the species of the genus. The subcarinoid
pronotal disc, strial elytral pattern, simple tergites and antennomere proportions
at once separate it from others in the genus. To the author's mind it most closely
approaches gounellei of Brazil but the antennae of these two species are very
different, as well as the tergites. Thus gounellei has antennomere III, IV, and V
only slightly longer than wide, and VI twice as long as wide; achillei has III
quadrate, IV, V, and VI rapidly increasing in length. Gounellei has the tergites
obtusely gibbous medianly, and provided with three bundles of scales ; achillei
has simple tergites.

The species may be listed as follows:

achillei new species. Corumba, Matto Grosso, Brazil.
boliviensis Raffray. 1904. Yuracaris, Bolivia.
brevicomis Raffray. 1904. Minas Geraes, Brazil.
bruchi Raffray. 1908. Argentina.
gounellei Raffray. 1909. Rio de Janeiro, Brazil.
margaritaceus Raffray. 1891. San Esteban, Venezuela

ARHYTODINI 347

myrmecophilus Bruch. 1918. Cordoba, Argentina. Con Wasmannia

auropunctata australis Em.
oberthuri Raffray. 1891. Cavallo Cocho, Amazonas, Brazil.
rubripennis Raffray. 1891. Caracas and San Esteban, Venezuela.
semisulcatus Raffray. 1909. Ceara, Sierra de Baturite, Brazil.
vestitus (Westwood). 1870. Genotype. Brazil: Petropolis, Theresopolis,

Blumenau, Nouveau-Fribourg (?Novo-Riborgo), and Rio de Janeiro.

Tribe 16. Attapseniini

This is a recently recognized, monogeneric, wholly myrmecophilous tribe.
At present it holds two species, one from Brazil and one from Argentina. Since
both species are adjusted to the society of leaf-cutting ants {Atta sexdens L.)
there is the possibility that the exact ecology of these species can be worked out,
and also that additional species can be discovered with other kinds of leaf-
cutting ants.

The chief structural points may be summarized as follows:

Head subhexagonal with short, oblique tempora; eyes large, reniform in
lateral view, composed of large facets; vertex with the usual pair of vertexal
foveae; a short antennal tubercle on each side of the narrowed front. In the
genotype the front is sharply, longitudinally bicarinate from the vertexal foveae
to the antennal tubercles, with the intervening space between the carinae sulcoid.

Mandibles with five to six teeth.

Maxillary palpi presumably only three-segmented ; first segment elongate-
cylindrical (true second palpomere?), obliquely truncate; second slightly obcon-
ical and not much longer than wide, slightly longer and distinctly wider than
first; third (distal segment) subovoidal, slightly more than one-fourth longer,
and distinctly wider, than second, with a short, blunt, palpal cone at apex. The
maxillary palpus is not as long as the maxillary cardo! Such reduced mouth-
parts are intermediate between the Arhytodini and Tyrini, and the myrme-
cophilous habitat suggests a parallel with Clavigerinae. In the latter case, how-
ever, the rudimentary clavigerine mandible suggests a much more complete ad-
justment to the society of the host ant, while the toothed attapsenine mandible
suggests the primitive predatism of pselaphids. Such speculation, in the absence
of direct ecological experiments, leads to the conclusion that this new tribe plays
the role of the synoekete in the Atta society.

The antennae are eleven-segmented, with a compact funicle and poorly de-
veloped club. This condition is approached by Endytocera and Barrojuba in
the Jubinini, and to a less extent by Ephiinia of the Hybocephalini and Juxta-
hamoto'psis of the Tyrini.

Pronotum lacking either basal foveae or sulci.

Elytra inclined towards the abdominal impression noted later ; each elytron
with a sutural stria but lacking basal foveae, discal striae, sulci, and impressions.

This total absence of pronotal and elytral foveae and sulci is a very spe-
cialized feature for pselaphids.

The abdomen is also specialized in the direction of the Clavigerinae. The
abdomen, as a whole, forms a perfect oval with the elytra, and has a deep,
subelliptical basal depression. An oblique carina limits the sides of this depres-
sion, giving a sharp and triangular wall ; the basal fourth of the lateral carina,

(348)

ATTAPSENIINI 349

each side, is furnished with a row of ten to twelve long, trichomatous, setae
which project into the depression and, therefore, appear to be analogous to
the trichomes of Fustiger, Adranes, and other clavigerid aggregates. This basal
depression occupies more or less of the first two tergites, and the remaining
tergites are convex, short, and without lateral margins. Six sternites.

Mesosternum trapezoidal-subrectangular. Metasternum obconical in opti-
cal outline, medianly excavated, and with the posterior margin medianly and
deeply incised. Anterior coxal cavities confluent, their coxae subtriangular.
Intermediate coxal cavities confluent, their coxae large and globose; inter-
mediate legs typically macrosceline. Posterior coxae subtriangular.

Femora and tibiae arcuate; the tibiae dilated and compressed for basal
third to half of length. Tarsi three-segmented; first short; second and third
very elongate (about three times longer than first tarsomere, with the third
slightly longer than second) ; two long, subequal, tarsal claws.

ATTAPSENIUS (Bruch, 1933)
Bruch (1933)
Reichensperger (1936)

This genus is described above, it being the only genus of the tribe.

The two species may be separated as follows:

Antennomere I straight, cylindrical, longer than next two united;
II-X subquadrate, progressively slightly wider, very closely
articulated; XI oblong-oval, as long as the preceding three or
four segments united; 2.3 mm. long chernosvitovi

Antennomere I elongate-cylindrical; II-VI smaller, one and one-half
times longer than wide ; VII very short ; VIII quadrate ; IX and X
broader and longer; XI elongate-cylindrical, longer than the three
preceding segments united; 3.2 mm. long (or 4 mm. long if the
curvature of the abdomen is taken into consideration) . .eicfmawm

These two remarkable species may be listed:

chernosvitovi Bruch. 1933. Loreto, Misiones, Argentina. Genotype.
eidmanni Reichensperger. 1936. Mendes, Est. Rio, Brazil.
Both from the nests of the leaf-cutting ant, Atta sexdens L.

Subfamily Glavigerinae

The Glavigerinae usually have the following combination of characters.
The head is longer, much longer than wide, and subcylindrical; very rarely
is the head subquadrate, or as wide as long. A median gular fovea is present;
the pair of vertexal foveae is present, often small, but at times absent
(Adranes). The eyes may be well-developed to rudimentary in the same genus
(Fustiger) , or absent {Adranes, Claviger) . The mouth-parts are always rudi-
mentary— in fact, this is one of the best characters in defining the subfamily.
The mandibles are usually slender, terminating in a blunt point, and lacking
teeth. The maxillae are vestigial, provided with a distinct brush of setae, used
m scraping their specialized food. The maxillary palpi appear to be of a single
segment, or at most two segments, with the distal piece usually pedunculate,
and terminating in setae rather than a palpal cone. This palpomere is elongate-
truncate (Claviger) or subspherical to ovoidal [Claviger odes) . Mentum very
large. Labrum very large. Thus these small mouth-parts (mandibles, maxillae,
labium) are only studied with precision from slide-mounts of dissected parts.
In life these oral organs are relatively hidden by the mentum and labrum, the
oral aperture being often a transversely oval, sharply delimited area with the
mouth-parts somewhat recessed. This means that apprehension of living and
struggling prey by toothed mandibles is impossible, rather the food must
be passive, and nourishment obtained either by piercing with the mandibles,
then sucking and licking the exuded liquids, or scraping, brushing, and licking
a surface.

The antennae have but one feature in common, namely the distal anten-
nomere is, as far as I know, more or less sharply truncate, with the circular to
oval truncation provided with erect setae. This is not usual in the Pselaphinae.
The number of antennomeres is highly variable. Thus the antennae have two
segments {Mastiger, Articerus, Disarthricerus) , three (Adranes, Fustiger,
Apoderiger), four (Rhynchoclaviger, Radama, Diartiger), five (Claviger odes,
Paussiger, Microclaviger) or six (Claviger, Claviger opsis, Pseudacerus) to
mention but three genera in each type. This variation in antennomeres is an
excellent character for separation of groups of genera within the subfamily,
but is not valuable as a phylogenetic feature for separating Glavigerinae from
Pselaphinae, since this variation is surpassed in Goniacerini. Thus clavigerines
have a variation of from two to six segments, while Goniacerini has a variation
of from five to eleven segments. The first clavigerine antennomere is invisible
from above, deeply inserted into the acetabulum at each side of the front.

Elytra with the apical margins bearing a trichome of long, tortuous, golden
setae near each external angle; only rarely are these trichomes absent — they
are badges of the symphile.

(350)

CLAVIGERINAE 351

The large abdomen has six sternites, the typical Pselaphid number, but
the tergites are specialized: the general tergite pattern is a tergum or dorsum
of three fused tergites, and two terminal tergites. The fused dorsum shows
its lineage along the lateral margins, where the component tergites have not
been wholly fused ; medianly the tergum presents a glabrous expanse which is
usually deeply depressed at the base. The antero-lateral angles of the margin
of the tergum also usually bears trichomes. Thus the elytral and abdominal
trichomes ornament the base of the abdomen. This dorsum, with its trichomes,
is paralleled in the less complicated but similar abdomen of the myniiecophilous
Attaseniini, so that it is not purely clavigerine. The actual reduction in ab-
dominal segments is not peculiar to Clavigerinae, in fact this reduction is
suipassed in the Cyathigerini, where Cyathiger has the segments fused to give
only two tergites and two sternites. Thus the abdominal features are not unique,
and may not be used to separate the two subfamilies.

The legs are definitely macrosceline; the tarsi are three-segmented, with
the first two tarsomeres small and the third tarsomere much larger, elongate-
cylindrical, subarcuate, and bearing a single tarsal claw.

Integumental modification is very diverse, glabrous, punctulate, punctate,
granulate, cribrate, alutaceous, or striate. Pubescence is similarly diverse, the
setae being elongate-aciculate, subsquamoid, bifurcated (Adranes) , or apically
plurifurcate {Claviger, in part).

Sex is best discovered by direct dissection. The aedeagus is of the tyrine
type, with a narrowly oval basal bulb which is bifenestrated, and which
terminates apically in a rapidly narrowing, arcuate, sperm-conducting apex.
The males often have the sternites longitudinally concave, giving a distinctive
lateral profile ; the abdomen is more tapering from a dorsal view, the metaster-
num is often secondarily modified by tubercles or cusps, and the legs usually
armed by spines or teeth, but not always. Thus males may bear prominent
femoral spines, or femoral and tibial spines, or lack spines entirely, in the
same genus. Females have the sternites longitudinally convex in profile, the
abdomen much more rounded apically from a dorsal view, and the metasternum
and legs are simple, or relatively so.

It is obvious that the clavigerines are, at most, of subfamily rank. The
elevation of these species to family status in the Leng (1920, p. 132) catalogue
is not tenable unless the Staphylinidae are broken into numerous families
and the Pselaphidae are similarly separated into at least five families. Al-
though my opinion is derived independently from the comparative morphology
of the pselaphids, it should be noted that students of the family give the clavi-
gerids subfamily rank (LeConte and Horn, 1883; Brendel and Wickham, 1890,
p. 218; Ganglbauer, 1895; Raffray, 1904, 1908, 1911; Mann, 1921; Bruch, 1933;
Bowman, 1934; Meixner, in Kukenthal, 1936).

The comparative ecology of Clavigerinae is in much need of study. They
are an example of adaptive speciation within a particular niche, namely the
society of ants. They are never free-living — indeed, their rudimentary mouth-
parts make it probable that they would be unable to compete with the predators

352 NEOTROPICAL PSELAPHIDAE

of the floor mold described so well by Jacot (1935). Their ornamented integu-
ment, oily trichomes, unhurried walk, reduced oral equipment, and specialized
antennae and dorsum are hall-marks of the true guest or symphile.

Their presence with ants has long been known (Mueller, 1818; Dury,
1884, 1898; Schwarz, 1890, 1896; Wickham, 1889, 1892, 1894, 1900, 1901;
Hetschko, 1896; Raffray, 1908; Knaus, 1908; Krueger, 1910; Wheeler, 1910
[including much data on ant guests as a group and the early work of Was-
mann]; Blatchley, 1910; Mann, 1911, 1915, 1918; Crawley, 1916; Gallardo,
1916; Donisthorpe, 1927; Bruch, 1929, 1931; Park, 1932, 1935; Reichensperger,
1931, 1933). From this imposing array little more is known than that the
clavigerines are always with ants, and are unmolested by their hosts.

Two species have been studied: Claviger testaceus of Europe by Mueller,
Hetschko and Krueger; Adranes lecontei of North America by Park.

Summarizing what is known of these two species we arrive at the fol-
lowing generalities:

1. Lecontei and testaceus are wholly unmolested by their hosts. They
stalk about the dark, moist galleries, haunting the brood chambers, and when
approached by an ant do not hurry away but either pass on, stop and twirl
the antennae, or crouch so that the worker must pass around or over the
beetle.

2. The host ant workers assiduously suck the beetle's trichomes, lick
their integuments, at all hours of the day and night in this arhythmic social
medium (Park, 1941). I have seen lecontei licked for two minutes at a time,
by several ants together.

3. The beetles ride about upon the gaster of the ant. This phorecy has
been seen repeatedly in lecontei. The author has watched a lecontei riding on
its host {Lasius aphidicola Walsh) for ninety consecutive minutes before the
ant was relieved of its heavy burden.

4. The beetles are fed regurgitated liquid food by the host workers, in
the same manner as one worker will feed her sisters.

5. When not being fed, or transported, by the workers, the beetles strike
at the society by scraping, puncturing, and sucking, the eggs, larvae, and
pupae of the host. Scavengerism is not their metier although they may scrape
at a shred of cast pupal membrane — this work is carried out by the more
primitive synoeketes and synechthrans of the nest, chiefly the former.

6. The juvenile mites {Antennophorus wasmanni) which balance upon
the aphidicola workers also climb upon the lecontei.

These exquisite adjustments of the blind testaceus and lecontei suggest
long association with their hosts, with selection pressures very different from
free-living pselaphines and it is to be expected that the modern clavigerids ex-
hibit many specializations of their pselaphid organization.

The forty-two genera of Clavigerinae have been eagerly sought by col-
lectors and consequently the distribution has been fairly well outlined, as a
by-product of the collection. It seems clear that the clavigerines have followed
their hosts, and are known over all major faunal regions save New Zealand.

CLAVIGERINAE 353

According to the work of R affray and Wasmann, these insects are most diversi-
fied and abundant in Madagascar, that anciently separated home of so many
strange animals. Europe and the Western Hemisphere have an impoverished
clavigerine fauna.

The neotropical region contains three genera. Unfortunately the author
is entirely unfamiliar with either specimens or the original description of
one of these genera {Neofustiger) and consequently the following key is in-
complete.

Key to Genera of Neotropical Clavigerinae

Third (distal) antennal segment with a transverse suture near middle

of length; known only from the Antilles PSEUDOFUSTIGER

Third (distal) antennal segment entire, with no suture. . .FUSTIGER

NEOFUSTIGER (Bruch, 1929)

cochlearis Bruch. 1929. Misiones, Argentina. Genotype, con Para-

trechina fulva fumata For.

PSEUDOFUSTIGER (Reitter, 1884)

This interesting monotypic genus is important in that it represents a stage
in the consolidation of the clavigerine antenna from four to three segments.

stricticornis (Reitter). 1883. St. Thomas, Virgin Islands. Genotype.

(Articerus) .

FUSTIGER (Brendel, 1866)

Brendel (1866) (Fustiger) (1889)

Raffray (1882) iCommatocerus) (1904, 1908, 1909, 1911)

LeConte and Horn (1883)

WiCKHAM (1889, 1892)

Brendel and Wickham (1890) {Articerus Brendel, nee Dalman, 1825)

SCHWARZ (1896)

Wasmann (1897) (Commatocerinus)

Schaeffer (1906)

Knaus (1908)

Blatchley (1910)

Mann (1915, 1918, 1921)

Gallardo (1916)

Bruch (1929, 1931)

Reichensperger (1931, 1933)

Bowman (1934)

Park (1935)

This is a very important genus and by its numerous species, centering in
Brazil, signalizes neotropical clavigerines in somewhat the same way that
Arthmius contributes to neotropical batrisines.

354 NEOTROPICAL PSELAPHIDAE

The genotype, fuchsi Brendel, has been found with Cremastogaster
lineolata and Cremastogaster leviuscula; other hosts are listed for the species
later, but it should be noted that the species ecology has not been worked
out, as it has for Adranes and Claviger. Gallardo is the only one to have
written on the host-beetle relationship, finding the species elegans completely
tolerated by its host.

The general construction of the genus may be understood from the fol-
lowing description of a new species:

Fustiger veracruzensis new species

Holotype Male. Measurements: Head 0.36 x 0.32 mm.; pronotum 0.31
X 0.47 mm.; elytra 0.60 x 0.77 mm.; abdomen 0.76 x 0.79 mm. Total length
2.03 mm. Greatest width 0.79 mm. (PI. II, VI, VII, XVII, XIX).

Shining reddish-yellow brown. Integument of antennae asperate-strigose ;
legs lightly, sparsely subasperate; head and pronotum strongly sculptured with
crowded, longitudinally ovate, glabrous cells having strong, common, carinate
walls; elytra with sparse, uniformly distributed, subasperate punctures, and
the posterior third medianly strigose; abdomen subglabrous. Pubescence long,
monaxon, very fine and apically directed on antennae; short, strongly arcuate,
subsquamoid on head and pronotum; elytra with more slender, subappressed
setae more or less arranged in rows on flanks and disc, and in addition a very
rudimentary trichome of about twelve very long setae at postero-apical angle;
abdomen with fully formed trichome on the lateral margin of first visible tergite.
This trichome is in two parts, a basal tubercle is surmounted by a brush
of long golden setae which are directed posteriorly; second, an apical tubercle
is surmounted by a brush of long golden setae which fan out mesio-basally.
The dorsum of the fused first three visible tergites has about twenty-six very
long, slender, erect setae in about three transverse rows, the apical half of
each seta directed anteriorly towards basal depression. In addition, the
dorsum and last two tergites are sparsely supplied with excessively minute,
prostrate setae.

Head subquadrate, being only 12 per cent longer than wide through eyes.
Tempora long, subparallel, nearly as long as eyes. Eyes median, subreniform,
each of 30 prominent facets. Occiput and subrectangular temporal angles
clearly set off from alutaceous cervicum. A pair of minute, poroid vertexal
foveae on a line through posterior eye margins. Antennal acetabulum, each
side, long, arcuate, and glabrous, extending from anterior eye margin to
vertical, narrow, frontal lamina separating acetabulae. Clypeus subquadrate,
extensively involved with front in acetabulae; transversely triangular when
seen in optical apical view. Labrum very transverse and granular. Oral aperture,
framed by clypeus, genae, and mentum, nearly as wide as head but very nar-
row, being elongate-elliptical, arcuate. Maxillary palpi with a minute sub-
spherical basal segment or piece, and a much larger, strongly pedunculate-
obconical distal segment or portion — the palpi are minute and lie wholly

CLAVIGERINAE 355

within the frame of the oral aperture. Mandibles minute, simple, elongate-
triangular, not toothed, also wholly within the oral frame. Ventral surface of
head with a large, median gular fovea.

Antennae long (0.64 mm.), the visible portion three-fourths as long as
head, cervicum and pronotum united; three-segmented; segment I invisible
from above, as usual, subquadrate (0.046 mm. long) ; II very obconical but
as wide as long (0.046 mm. long); III elongate-obconical (0.55 mm. long),
slightly arcuate, with circularly truncate and setose apex, this apical surface
relatively narrow, being only slightly more than one-third the width of the head.

Pronotum transversely suboval with a large, shallow, glabrous, foveoid
depression at middle of base.

Elytra with oblique humeri. Each elytron with an entire sutural stria;
then a row of setae; then an entire juxtasutural stria; then a row of setae;
then two discal striae which converge and do not extend beyond middle of
disc, and which enclose one or two rows of setae; then about three poorly
defined rows of setae; then a short, shallow, intrahumeral depression; then
about ten rows of setae to lateral elytral margin.

Abdomen with first tergite partially membranous and hidden beneath
elytra for the most part. Five visible tergites of which the first three are visible
on the lateral margins by their sutures, but wholly fused between margins to
form a prominent dorsum. Dorsum deeply depressed in basal half and tumid-
convex in apical half. Fourth tergite with a small but prominent conical
tubercle at each latero-basal angle. Fifth (distal) tergite is vertical, sub-
triangular. Length ratio: 12 (dorsum)/2 (fourth)/2.5 (fifth tergite).

Sixth sternites in a length ratio of 2/3/3/.8/.5/2 with the first and last
more pubescent and in lateral view the sternites form a slight arc, that is,
they are longitudinally concave. Sixth transversely reniform to accommodate
last tergite, medianly depressed near apex.

Abdomen from a dorsal view with broadly rounded apex, which is in con-
trast to many clavigerine males having a tapering apex.

Aedeagus dissected: 0.368 mm. long x 0.107 mm. wide, strongly sclerotized,
yellowish-brown, stream-lined. The basal portion is oval, and this tapers
rapidly to form the arcuate, elongate-triangular, apical portion. Dorsal surface
of basal portion with the oval fenestra covered by a semi-membranous, ex-
pansible roof. Dorsal surface of apical portion with the triangular fenestra
similarly covered, but medianly with a longitudinally shallow sulcus towards
arcuate apex. This perfectly bilaterally symmetrical penis is entirely similar
to the penis of Tyrini {Ceophyllus, Tmesiphorus) and is not similar to the
ctenistine penis. It suggests either remarkable coincidence, or relationship
despite the different tarsomere ratio.

Metastemum very large and strongly tumid, without any median modi-
fications save that there is a pyriform patch of pubescence which projects
over first sternite.

Legs all strongly macrosceline, with very long and subobconical trochan-
ters; short, inflated femora; long, subarcuate tibiae; tarsi with two minute,

356 NEOTROPICAL PSELAPHIDAE

subequal basal tarsomeres and the third (distal) tarsomere is very long,
arcuate, cylindrical and bears a short, sharp tarsal claw. The legs are perfectly
simple and unarmed.

Allotype Female. Similar to holotype save that: (1) the body is longer
and broader (2.31 x 0.94 mm.) ; (2) abdomen from a dorsal view with a taper-
ing apex; (3) sternite ratio entirely different, the six sternites having a length
ratio of 1/6/5/1. 5/.5/1. 3. This is a notable differential when the two sexes
are present. The male not only has a shorter, more blunt abdomen which is
ventrally concave, but the subequal second and third sternites are only half
as long as these sternites of the female. The female has the larger, more taper-
ing abdomen ventrally convex.

Described on 60 specimens (56 males and 4 females). All were collected
from the nests of a cremastogastrine ant which is now being identified. Further,
this abundant material was taken in a single afternoon (June 30, 1941) at
5500 feet elevation near Las Vigas, Vera Cruz, Mexico, by C. H. Seevers
and Henry Dybas.

Fustiger veracruzensis is a very distinct species. In the first place, it is
the first clavigerid from Mexico and serves to bridge the zoogeographic gap
between the United States species, and the Costa Rican species which have
been so well studied by Reichensperger.

In the second place, veracruzensis is isolated from all other species by the
following combination of characters:

1. Eyes with 30 ocular facets. This separates all United States species,
which never have more than 10 facets, and also clavipilis with 15 facets.

2. Head very brachycephalic, being only about one-tenth longer than
wide. This separates the majority of the genus Fustiger which typically has
the head much longer than wide. For example schmidti, clavipilis, haytiana,
have head twice as long as wide and schwarzi has head three times as long
as wide, etc.

3. Elytra uniformly punctate. This separates smithi with base of elytra
rugosely punctate.

4. Males with unarmed legs. This separates many species. For example
oglobini, gounellei, insignis, haytiana, henrici, etc. have the male sex with
conspicuously spined or modified intermediate legs.

5. Head and pronotum coarsely sculptured. This separates elegans which
has no integumental sculpture.

Fustiger veracruzensis is most closely related to cornicen Reichensperger,
from the forest floor of Costa Rica. It differs from cornicen in many ways:
cornicen is much smaller, being 1.5 mm. long; the pronotum is as long as wide;
the antennae are little longer than the head, but more arcuate, much broader
distally, the last antennomere, in a photograph of the type, being half as wide
as the head.

One thing of zoogeographic interest is that the host of this new species is
definitely a cremastogastrine ant, and although the southern species of Fustiger

CLAVIGERINAE 357

have a variety of hosts, the species of the United States usually live with
Creynastog aster.

The distribution of this genus of beetles is very broad, and the species
may be listed as follows:

The following catalogue of the genus Fustiger is an exception to the usual
plan of this paper in that it attempts to list the genus as a whole rather than
the neotropical species.

Africa and Madagascar

1. elegantulus (Rafifray). 1882. Massouah, Abyssinia (Ethiopia)

(Commatocerus)

2. ranavalonae (Wasmann). 1897. St. Marie, Madagascar.

(Commatocerinus)

3. laevis (Raffray). 1899. Suberbieville, Madagascar.

( Commatocerinus )

India

4. indicus Wasmann. 1917. India.

North America

5. fuchsii Brendel. 1866. Genotype. United States: Tennessee; Missis-

sippi {Cremastogaster leviuscula Mayr) ; Indiana; Arizona (Cre-
mastogaster lineolata). See Blatchley, 1910; Park, 1935; Wickham,
1889, 1892.

6. calif ornicus Brendel. 1889. United States: Los Angeles, California

{Cremastogaster lineolata). See Schwarz, 1896.

7. knausii Schaeffer. 1906. United States: Cloudcroft, New Mexico.

9000 feet, in Sacramento Mountains. [Lasius americanusl). See
Knaus, 1908.

8. veracruzensis new species. Vera Cruz, Mexico. (Host ants now being

determined)

Antilles

9. smithi Raffray. 1904. St. Vincent, Windward Islands.

10. haytiana Mann. 1915. Diquini, Hayti. (Aphaenogaster relicta)

11. schivarzi Mann. 1918. Cayamas, Cuba. (Host unknown).

Central America

12. insignis Reichensperger. 1931. Vara Blanca, Costa Rica. At about

6000 feet, between Barba and Poas. (Pheidole).

13. schmidti Reichensperger. 1931. Vara Blanca, Costa Rica. At about

6000 feet, between Barba and Poas. (Pheidole).

358 NEOTROPICAL PSELAPHIDAE

14. cornicen Reichensperger. 1933. Salvadora Farm, Parisminafluss, Costa

Rica. [Ponera).

15. henrici Reichensperger. 1933. San Jose, Costa Rica. {Pheidole innupta

Menozzi).

16. clavipilis Mann. 1921. Lombardia, Honduras. {Wasmannia auro-

punctata Roger).

South America

17. brasiliensis (Westwood). 1856. New Friburg, Brazil.

18. amazonicus Westwood. 1869. Upper Amazon Basin, Brazil,

19. festivus Schaufuss. 1879. Amazon Basin, Brazil.

20. testudineus Schaufuss. 1882. Pozuzu, Peru.

21. hetschkoi Reitter. 1888. Blumenau, Brazil.

22. reitteri Wasmann. 1893. Blumenau, Brazil.

23. fauveli Raffray. 1898. Yuracaris, Bolivia.

24. elegans Raffray. 1908. Buenos Aires, Argentina.

Brazil.

{Solenopsis pylades Forel, Gallardo 1915, 1916).

{Solenopsis richteri Forel, Bruch 1929).

25. gounellei Raffray. 1909. New Friburg, Brazil.

26. nitidus Bryant. 1915. Brazil.

27. oglobini Bruch. 1931. Loreto, Misiones, Argentina.

{Paratrechina silvestrii Em.)

Fiji Islands

28. cribratus Mann. 1920. Fiji.

29. levuanus Mann. 1920. Fiji.

30. rafjrayi Mann. 1920. Fiji.

31. vitiensis Mann. 1920. Fiji.

32. wasmanni Mann. 1920. Fiji.

The Undescribed Species of Motschulsky

The Russian entomologist, Victor de Motschulsky, published a letter in
the Etudes entomologiques, pp. 8-25, in 1855. This letter was a description
of a collecting trip he had made in the area about Obispo, Panama. In the
several weeks of his stay he found about thirty kinds of Pselaphidae, practically
all new since virtually nothing was known of the pselaphid fauna of the region.
These "new species" were listed by Motschulsky, but save for a few words or
a sketch, were not further treated, and Motschulsky never published their
description.

Since the majority of these Motschulsky names have no description, they
have no status at all. Even if these specimens could be located, and their
authenticity proven (which is practically impossible now), subsequent de-
scription by some one else could not establish priority by Motschulsky. There-
fore these names are of historical, but not of taxonomic, importance. David
Sharp (1887, pp. 1-2) sums up the view of Reitter and himself in a cogent
manner:

These names have no claim to be adopted, and I mention them only be-
cause they have been given as "pubhshed" in the list of Motschulsky's genera
and species issued by the Entomological Society of Russia in 1868. In the case
of three or four genera rude outline figures were given, and as these enable
us to form an imperfect idea of what Motschulsky intended, their names have
been adopted by Reitter and are also included in our list. It is certainly un-
fortunate that this letter of Motschulsky's should never have been followed
by any proper description of the objects mentioned and named therein. It is
quite clear that he could not have made a proper study of these minute
creatures on board ship between Colon and New Orleans, where his letter was
written; and, so far as we know, he never returned to their study except
to sketch the rude outline figures I have alluded to. Although some of these
insects have become disseminated to a small extent under Motschulsky's
names, but little value can be attached to these "typical" examples. In the
case of two of these names Reitter has had an opportunity of testing them,
and finds they were incorrectly applied by Motschulsky; in short, Motschulsky
not only failed to describe the species he gave names to, but actually did not
even discriminate them. For these reasons I think the authors of the Munich
Catalogue did right in refusing to recognize these names, and certainly Reitter
has done all that courtesy and consideration demand when he treated those
that were accompanied by figures as entitled to vahdity.

I have listed the Motschulsky names of Panama pselaphids:

Batrisus collaris Cercocerus perplexus Eupsenius aequatorialis

Batrisus cylindricus Ctenistes aequatorialis Metaxis robustus

Batrisus frontalis Euplectus adustus Trichonyx aequinoctialis

Bryaxis consanguinea Euplectus antennatus Trichonyx canaliculatus

Bryaxis cornigera Euplectus cordicollis Trimicerus pacificus

Bryaxis glabrella Euplectus robustus Trimicerus rivalis

Bryaxis macrura Euplectus tropicalis Tychus pilosus
Bryaxis nitida

(359)

Zobgeographic and Statistical Considerations

A complete analysis of the distribution of Pselaphidae in the neotropics
involves the Nearctic Region, and eventually all faunal regions since the
analysis would be global in its many implications. Moreover, we should need
some information on the palaeontology, ecology, and genetics of pselaphids
as well as data on palaeogeography. Only a small portion of this is available.

Such an analysis is impossible in this paper for the reason that the neo-
tropical pselaphid fauna is imperfectly known, and its distribution even less
understood. Therefore my purpose here is to tabulate some suggestive data,
and suggest some problems for future solution.

Table III
COMPARISON OF NEARCTIC AND NEOTROPICAL PSELAPHIDAE

Tribe

Faronini

Pyxidicerini

Jubinini

Euplectini (s.l.) . . .
Brachyglutini ....

Metopiini

Batrisini

Tychini

Goniacerini

Pselaphini

Holozodini

Hybocephalini . . .

Ctenistini

Tyrini

Arhytodini

Attapseniini

Clavigerini

Totals: 11 tribes 65 384

17 tribes 141 895

From this table it will be seen that the neotropics have all nearctic tribes
plus six tribes not found in the nearctic, over twice as many genera and over
twice as many species. Only the Faronini, Euplectini and Ctenistini are better
represented in the nearctic areas. Of these three, the ctenistines are possibly
truly better adjusted to the lower mean temperatures and lower annual rain-
fall, but the euplectine's slight superiority in nearctic species number is un-
doubtedly apparent rather than real. That is, the average minute size of
euplectine units makes their collection difficult. While the United States has
been very well collected relatively, floor sifting and Berlese sampling is just
beginning in the neotropics. The vastness of the unexplored areas, their slow

(360)

Nearctic
Genera

Species

Neotropical
Genera

Species

2

10

0

1

131

113

0

59

22

0

5

1

0

19

14

0

0

9

3

1

11

36

28
5
8

14
6
2
1
1
4

16
1
1
3

3

0

6

1

74

26

10

0

114

260

22

4

185

7

30

0

10

1

8

1

1

0

3

5

12

6

132

0

11

0

2

2

22

ZOOGEOGRAPHY 361

penetration, limited to coastal zones, river systems and populated places, has
served to sample the neotropical fauna, rather than cover the territory.

Table IV

Genera common to Genera common to Nearctic, Neotropic

Nearctic and Neotropic Regions Regions, and distributed outside the

Western Hemisphere

Thesium Euplectus

Rhinoscepsis Thesiastes

Pseudotrimium (?) Reichenbachia

Actium Pselaphus

Melba Fustiger

Euplectus

Thesiastes

Rhexius

Arthmius

Euphalepsus (?)

Scalenarthrus

Pselaptus

Reichenbachia

Decarthron

Pselaphus

Pilopius

Ctenisis

Hamotus

Fustiger

From this table we observe that there are 19 genera of pselaphids com-
mon to the two American faunal regions, and only five genera common to
these two regions and having in addition species distributed outside of the
Western Hemisphere. Of these 19 common genera, practically all have more
neotropical than nearctic species. This gives a total of 17 tribes, 187 genera and
1279 species for the Western Hemisphere. Of these genera of American
pselaphids, 46 are found only in the Nearctic, and 122 are found only in the
Neotropic area. In terms of percentages, the Neotropical Region holds 64
per cent, and the Nearctic Region 36 per cent of all genera inhabiting the
Americas. This shows that the former region is much more endemic, and sug-
gests a much greater isolation. This conclusion is confirmed by the geological
evidence available on separation of the Americas via the Panamanian Isthmus,
and is also supported by the much greater resemblance between the Nearctic
and Palaearctic Regions than between the Neotropical and Palaearctic Regions.
In terms of species the neotropics are nearly, if not wholly, 100 per cent
endemic. The nearctic pselaphid fauna is intermediate in composition, then,
between the neotropical areas and the rest of the world. This suggests penetra-
tion from one or more northern connections between Asia or Europe, during
favorable climate for terrestrial poikilotherms, dispersal southward into South
America, either via the Central American or Antillean highway or both, and,
under the relatively warm and moist tropical climate, evolution of a diverse
and pecuhar neotropical pselaphid fauna, with secondary dispersal northward
of some faunal elements.

362 NEOTROPICAL PSELAPHIDAE

Thus Euplectus, Reichenbachia, and Pselaphus would appear to have
entered North America from the Palaearctic long ago. Reichenbachia,
especially, seems to have great vagility. On the other hand Hamotus appears
certainly to have evolved within the neotropics, and to have spread in all di-
rections, reaching into the northern limit of the neotropics in Mexico and into
peninsular Florida via the Antilles. In this connection a general hypothesis
may be proposed regarding dispersal between the two American faunal areas.
The change in climatic and associated biotic conditions is quite abrupt in the
Mexican arm of the continent, between the arid southwestern United States
and Mexico on the one hand, and the northern extension of the rain forest in
Mexico. This faunal break appears to develop along the Tropic of Cancer.
The eastern or Antillean arm, from Venezuela to Florida, offers much less
change in climate and biotic conditions.

In other words, on the west the change is relatively abrupt from neotropical
rain forest to nearctic semidesert; on the east the change is from neotropical
rain forest to nearctic subtropical forest. The western highway offers continuous
dispersal surface, with a good north-south highway in the Rocky Mountains-
Andes chain which allows vertical movements to compensate for changes in
latitude; but the climatic-biotic change is marked. The eastern highway is
subjected to frequent insular discontinuity, plus the vicissitudes of insular
climate; but the climatic-biotic overall change is much more gradual. It would
seem that these two dispersal paths have had to bear the north-south faunal
interchange over a long period of time, and a careful analysis should demon-
strate which path has been most successfully used. This requires a more
complete knowledge of pselaphid distribution than we now possess.

The actual facts are meager. Separate cases can be made out for each
highway, largely depending upon the genus involved, which must mean that,
granting a sound taxonomy, both routes have been used by Pselaphidae. At
present we have not enough data to espouse either the Mexican or the Antillean
bridge as a major influence.

Thus the wholly American genus Melba has about twenty-nine species.
Eleven species are nearctic, distributed north of the Rio Grande, from Arizona
to the Atlantic coast, and from Florida to New York. The preponderant num-
ber of these, however, is east of the grassland biome. The neotropics have
eighteen species, seven of which extend from central Mexico, through Guate-
mala, French Guiana, Brazil, and into northern Argentina; eleven Melba are
endemic to the Antilles. The genus Melba then, appears to have used both routes,
with a slight preponderance for the Antillean route.

On the other hand, the important genus Hamotus, with eighty-nine species,
is distributed over the entire Neotropical Region and extends northwards to
the limit of the rain forest in Vera Cruz. Here the genus breaks off short, with
at least three species in Vera Cruz. The only non-neotropical species is
Hamotus opimus of southern Florida, which suggests colonization from the
Antilles. The difiiculty here is lack of facts because the Antilles have but one
species, Hamotus hirtus, of the Windward and Leeward Islands. This is a

ZOOGEOGRAPHY 363

typically exasperating example — there is no doubt that other hamoti are living
on the Antillean chain — we simply do not know enough.

Countless examples could be cited but many of these have been already
stated in the preceding pages, and need not be restated here. There are numer-
ous genera which appear to have moved up the Central American route
{Eurhexius), others to have used the Antillean route, others both routes.

In the examples of genera using the Mexican route, they nearly always
dwindle or stop at the northern limit of the rain forest and therefore aid in
delimiting the Neotropical Region. My data show this limit to be just south
of the Tropic of Cancer on the Atlantic side (southern Tamaulipas — northern
Vera Cruz), as the description of new species attest. In so far as these data go,
they confirm the work of Smith (1940) on the zoogeography of Mexico,
especially with respect to the lizard genus, Sceloporus.

The northward extent on the Pacific side is unknown.

Thus, to sum up this first aspect, a major problem for the future is to
ascertain the relative usage of the Antillean versus the Mexican highway be-
tween the Nearctic and Neotropical Regions. Emerging as subproblems are
the (1) extent of neotropical species on the Pacific side of Mexico; (2) the
ratio of nearctic to neotropical elements in the southern third of peninsular
Florida; (3) the ratio of Central American to South American elements at
several points through Central America, especially the shift between Panama
and Guatemala. This requires much expeditionary work, followed by difiicult
taxonomic research. The regions in which materials are critically needed appear
to be two: the Antilles as a whole; and the Pacific slope of Mexico, especially
from Mazatlan to Manzanillo.

It must be pointed out that two influences may obscure the relationships
present. These are chiefly intra-tropical. The first of these is altitude. Most of
the vast neotropical area lies below 3000 feet, but the species may penetrate at
different latitudes to different elevations, following the well known relationship
between altitude, climate and biome from pole to equator. We have no informa-
tion on this point either, at least nothing comparable to Schmidt's study of
vertical distribution of the salamanders of the genus Oedipus in Guatemala
(1936). We know that pselaphids can penetrate to moderately high altitudes:

Table V
SELECTED ALTITUDE RECORDS OF PSELAPHIDAE

Species Elevation Country Source

in feet

Hamotus setipes 800- 1500 Bugaba, Panama Sharp, 1887

2000- 4000 Chiriqui, Panama Sharp

Metopias elegans 3000- 4000 Chiriqui, Panama Sharp

Arthmius armatellus 2000- 4000 Chiriqui, Panama Sharp

Oxarthrius hamaticollis 3000 Las Mercedes, Guatemala Sharp

Batoctenus simplex 2000- 4000 Chiriqui, Panama Sharp

Batoctenus puncticollis 2000- 4000 Chiriqui, Panama Sharp

Euphalepsus centralis 7000- 9000 San Geronimo, Guatemala Sharp

Euphalepsus reitteri 2500- 4000 Chiriqui, Panama Sharp

364 NEOTROPICAL PSELAPHIDAE

Table V {Continued)
SELECTED ALTITUDE RECORDS OF PSELAPHIDAE

Species Elevation Country Source

in feet

Reichenbachia sallaei 4000- 5000 Cerro Zunil, Guatemala Sharp

2000- 3000 Chiriqui, Panama Sharp

Reichenbachia intacta 1000 Cahabon, Guatemala Sharp

Thesium impressifrons 4000- 5000 Cerro Zunil, Guatemala Sharp

Trimiodina concolor 8500-10000 Totonicapam, Guatemala Sharp

Rhexius optatus 4000- 6000 Chiriqui, Panama Sharp

Eurhexius vestitus 2000- 3000 Chiriqui, Panama Sharp

Eurhexius parviceps 8000 Chiriqui, Panama Sharp

Eurhexius ventralis 3000- 4000 Chiriqui, Panama Sharp

Eurhexius trimiodes 8500-10500 Totonicapam, Guatemala Sharp

Endytocera vestita 2500- 4000 Chiriqui, Panama Sharp

Endytocera cognata 800- 1500 Bugaba, Panama Sharp

I have used here the records of Sharp's ancient work. Although his de-
scriptions are not complete, his locality data are much better than the more
recent work of Raffray. From this table we find the greatest elevation at-
tained by neotropical pselaphids to be Totonicapam, Guatemala (Eurhexius
trimiodes) at 10,500 feet, and the greatest known vertical range that of
Hamotus setipes, from 800 to 4000 feet in Panama. The few data make pre-
diction rather hazardous but the situation in Eurhexius is suggestive, with
vestitus at 2000-3000 in northern Panama, ventralis at 3000-4000 in the same
forest, parviceps at 8000 in the same forest extension, and northwards trimiodes
at 8500-10500 in Guatemala. There are many species described from "Haute-
Bolivie, Yuracaris" which suggest considerable altitudes, and a third critical
area for study would be the Bolivian Andes from the northeastern corner up the
Madeira drainage to tree-line. This should throw much light on altitude strati-
fication from the Amazon floor to the limit of penetration; this compared with
a similar transect in the Panamanian Chiriqui, Guatemala, and Central Mexico
would be especially desirable. Of course these remarks refer to the free-living
species. The symphiles, and to a less extent the synoeketes, live in the relatively
stable, dark, humid nest of their host and their distribution becomes the host's
distribution. In such cases the oxygen available and the barometric pressure
would be the two influences varying with altitude, while food, shelter, lack of
light and relative humidity would remain more or less constant; temperature,
especially nocturnal temperatures, in and out of the ant and termite nest in a
restricted altitude range have not been sufficiently studied in this respect.
Some information is at hand on one genus of symphiles: Fustiger insignis and
schmidti occur at 6000 feet in Costa Rica, while Fustiger veracruzensis occurs
at 5500-5000 in Vera Cruz, Mexico.

Since pselaphids are poikilothermal this problem of vertical distribution
probably has a profound effect upon their distribution and is taken into ac-
count later in the discussion of taxonomic density. At least four zones are
recognized for the Andes (Chapman, 1933; Cutright, 1940): tropical (sea
level to 3,500-5,000 feet); subtropical (3,500-5,000 to 8,000-9,000 feet);

ZOOGEOGRAPHY 365

temperate (8,000-9,000 to 11,000-12,000 feet) ; paramo or puna (11,000-12,000
to lower snow limit at 15,000-16,000 feet) . Chapman found relatively abrupt
changes in bird species between zones and there is no reason to suppose that
the pselaphids would not be even more limited. So far definite neotropical
altitude records show pselaphids to be in the first three zones but no data are
available to show increasing relationship with the nearctic fauna with in-
creasing elevation. This should be interesting to work out since (Humboldt,
1850) from pole to equator mean temperature increases about one degree
Fahrenheit with each degree latitude, and ascent of the Andes (Outright,
1940) shows a decrease in the mean air temperature of about one degree
Fahrenheit for each 300 feet — that is, 300 feet elevation in the Andes is
equivalent to about 67 miles of latitude. The importance of mountains, both as
barriers to dispersal and as dispersal highways, is summarized in general terms
in Hesse, Allee and Schmidt (1937) and is too well known to prolong this dis-
cussion without specific information.

The second intra-tropical influence relates more especially to the Antillean
area and is concerned with the possibility of dispersal of pselaphids by natural
rafts or floating masses of vegetation (Wallace, 1880) . Any such debris from
the mouths of the Amazon, Essequibo, or Orinoco rivers might move north-
ward on the arm of the South Equatorial Current that develops north of
Pernambuco, passing between Trinidad and Martinique, and if it withstood the
passage might secondarily colonize the Lesser Antilles. Again, drift would tend
to move from the Lesser Antilles west by north to the Yucatan coast. Finally,
drift from between Nicaragua to Yucatan would tend to eventually attain the
Gulf Stream and pass through the Straits of Florida. These remote possibilities
should be kept in mind since rafts have been sited far at sea, and a few minute
oribatid mites in a handful of leaf mold could support a pselaphid population
for a long time.

To continue the analysis, some remarks are desirable on the horizontal
range of pselaphids. In the first place the great majority of the 895 neotropical
species listed in this paper are valid, that is, contain few synonyms which
might give a necessarily imperfect idea of species range. The sound condition
of this taxonomy is due to two chief reasons. The majority of the species were
described prior to 1904 by four Europeans, Sharp, Schaufuss, Reitter and
Raffray ; Raffray was able to examine practically all of the Reitter and Schau-
fuss types, and at least some of the Sharp types, and hence could discover
synonyms of his own and others. This placed the pselaphids of the neotropics
on a fairly firm, if limited foundation, upon which the modern school could
build.

The debt we owe to these four workers is easily measured by their taxo-
nomic activity. In the following table, it will be seen that eighteen men have
described 897 species in the Americas south of the United States (this figure
includes two northern Mexican species, not properly neotropical). Of these
the first four, mentioned above, have described 751 species, while Raffray has
described nearly half of the entire number!

366 NEOTROPICAL PSELAPHIDAE

Table VI

SPECIES OF NEOTROPICAL PSELAPHIDAE
BY AUTHORS

Student Species Described

L Raffray 416

2. Reitter 135

3. Schaufuss 132

4. Sharp 68

5. Park 60

6. Fletcher 34

7. Aube 10

8. Westwood 10

9. Bruch 8

10. Reichensperger 5

11. Motschulsky 4

12. Wasmann 4

13. Mann 4

14. Blanchard 3

15. Gory 1

16. LeConte 1

17. Bryant 1

18. Casey 1

In the second place, the very vastness of the area already noted, has
served to isolate the collecting localities. This has had an advantageous effect
upon the validity of species but has not been beneficial to zoogeography. In
the following table the several political portions of the neotropics are analyzed
with respect to number of species.

The next table shows the Pselaphidae broken down into as many separate
political areas as possible. The sum of the tribal totals (969 species) compared
with the actual number of species present (895 species) indicates how few of
the species have been reported from more than one country. The majority of
species have been reported at the time of their description, and have not been
heard of since that time. In the present paper a number are reported for the first
time in fifty years. This simply means that until local lists are present, the range
of species is too inadequately known for careful zoogeographic analysis. It also
means that, in addition to species already described, hundreds of undescribed
species await discoveiy if the long columns of zero in Table VII are to be
properly changed.

On the other hand, some progress is being made through the years. About
one out of eleven species is known from two countries. Some pselaphids are
known to have an extensive geographic range. These cases lie especially in forms
which fly readily to lights at night {Arthmius, Reichenbachia) or are large-sized
and more or less abundant (Hamotus) . The Tyrini especially have ranges better
understood. For example Hamotus hirtus is known from both sexes and in three
islands in the Antilles; Hamotus monachus from Mexico to Costa Rica; Hamo-
tus tritomus from Mexico to Colombia; Reichenbachia celata from Mexico to
Nicaragua ; Reichenbachia sallaei from Mexico to Panama, and numerous addi-
tional examples could be added.

ZOOGEOGRAPHY

367

Table VII
SPECIES OF PSELAPHIDAE IN NEOTROPICAL COUNTRIES

Tribes

Countries

Ph

Si

a

3

W

pa

P

6

£

>,

H

<

<

a

Argentina

0

1

3

10

13

3

3

0

0

4

0

0

3

3

2

1

3

Bolivia

0

0

2

2

10

2

17

2

0

0

0

0

0

8

1

0

1

Brazil

0

2

26

28

73

14

128

11

5

3

0

0

4

47

6

1

8

British Guiana

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

British Honduras

0

0

0

0

4

0

0

0

0

0

0

0

0

0

0

0

0

Chile

3

0

0

7

26

0

1

0

0

0

0

0

0

8

0

0

0

Colombia

0

0

11

5

17

1

6

0

0

0

0

0

2

17

0

0

0

Costa Rica

0

0

0

0

0

0

1

0

0

0

0

0

0

3

0

0

4

Cuba

0

0

0

0

5

0

0

0

0

0

0

0

0

0

0

0

1

Dominica

(Leeward Isl.)

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

Dutch Guiana

0

0

0

0

3

0

0

0

0

0

0

0

0

0

0

0

0

Ecuador

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

French Guiana

0

0

0

2

0

1

0

2

0

0

0

0

0

1

0

0

0

Granada

(Windward Isl.)

0

1

1

3

6

0

0

0

0

0

0

1

0

1

0

0

0

Guadeloupe
(Leeward Isl.)

0

0

1

6

3

0

0

1

0

0

0

0

0

1

0

0

0

Guatemala

0

0

2

10

22

0

5

2

0

1

1

0

0

7

0

0

0

Haiti

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

Hispaniola
(cf . Haiti)

0

0

0

0

2

0

0

0

0

0

0

0

0

0

0

0

0

Honduras

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

Martinique

(Windward Isl.)

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

Mexico

0

1

6

10

53

0

15

7

1

0

1

0

5

11

0

0

1

Nicaragua

0

0

0

0

2

0

0

0

0

0

0

0

0

2

0

0

0

Panama

0

0

4

4

6

1

8

0

1

0

0

0

0

7

0

0

0

Panama Canal Zone 0
(Barro Colo. Isl.)

0

6

6

15

1

4

6

1

0

0

0

0

8

0

0

0

Paraquay

0

0

3

0

3

0

8

0

1

0

0

0

0

6

0

0

0

Pearl Islands
(Panama)

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

Peru

0

0

0

0

3

0

5

0

0

0

0

0

0

1

0

0

1

Puerto Rico

0

0

0

3

1

0

0

0

0

0

0

0

0

0

0

0

0

St. Thomas

(Virgin Isl.)

0

1

1

9

2

0

0

0

0

0

0

1

0

0

0

0

1

St. Vincent
(Windward Isl.

0

0

0

1

2

0

0

0

0

0

0

0

0

1

0

0

1

Uruguay

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

Venezuela

0

0

8

7

12

0

4

2

1

0

0

0

0

18

2

0

0

Water Island
(Virgin Isl.)

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

Totals

3

6

74

117

283

23

205

34

10

8

2

3

14

151

11

2

23

Certain areas are better known than others. For example there are increas-
ing data showing considerable similarity of the pselaphid fauna of southern
Brazil and northern Argentina ; of northwestern Brazil and Colombia and Vene-
zuela; of Colombia and Panama; of southern Mexico and Guatemala.

The discussion may be furthered by bringing horizontal area into the prob-
lems which beset us.

368 NEOTROPICAL PSELAPHIDAE

Table VIII

Country Approximate area Species of

in square miles Pselaphidae

Argentina 1,153,000 49

Bolivia 514,000 45

Brazil 3,293,000 356

British Guiana 89,500 1

British Honduras 8,600 4

Chile 289,800 45

Colombia 440,800 59

Costa Rica 23,000 8

Cuba 44,000 6

Dutch Guiana 46,000 3

Ecuador 116,000 1

French Guiana 32,000 6

Guatemala 48,200 50

Hispaniola 28200 3

Honduras 44,200 1

Leeward Islands 700 13

Mexico 767,000 HI

Nicaragua 49,200 4

Panama 32,400 79

Paraguay 97,700 21

Peru 709,800 10

Puerto Rico 3,400 4

Uruguay 72,000 1

Virgin Islands 100 16

Venezuela 398,600 54

Windward Islands 500 19

All three columns have been adjusted. Some areas, notably Jamaica (4200
square miles) have no Pselaphidae reported! Haiti and the Dominican Republic
are combined under the older name of Hispaniola because of doubt of the orig-
inal type localities in two of the three species. The Pearl Islands, Panama Canal
Zone, and the Republic of Panama are united. The area data are atlas simplifi-
cations, with fractions of one hundred square miles not used ; furthermore, recent
boundary settlements are not integrated as exact data are lacking. The third
column represents the species reported, in all save a few cases where overlap
was taken into account. These faunal figures represent the situation to the best
of my ability but are not necessarily exact as there is always the possibility of
overlooking a paper. The only large regional study is that of Sharp (1887) for
Central America. We have nothing comparable to Bequaert (1940) on the
Tabanidae of the Antilles, or a modern faunal analysis of a limited area such
as Wetmore and Swales (1931) or Cochran (1941) on the birds and herpetology,
respectively, of Hispaniola.

This eighth table brings out some correlations of interest. Thus we find
that the United States, with an area of about 3,026,700 square miles has had the
advantage of relatively very intensive study, and lists 384 species of Psel-
aphidae; Brazil, with an area of about 3,293,000 square miles, of relatively very
little studied territory, lists 356 species of Pselaphidae! This latter figure repre-
sents nearly half the described neotropical species, and attests to the amount of
work to be done. That is, it is not as though the pselaphid fauna of the United
States were poorly known. Even as early as 1850, LeConte, in his classical paper

ZOOGEOGRAPHY 369

on the pselaphid fauna of the United States, shows that the then known fauna
compared very favorably with the even far better known pselaphid fauna of
Europe. Also, this is not to say that a great deal has been done in Nearctic
pselaphids — there are many new species undiscovered, no thorough zoogeog-
raphy— the large size of the Brazilian fauna simply means that the neotropics
abound in these beetles.

The lowest taxonomic density (area divided by species) is in Ecuador,
1 species per 116,000 square miles. The highest t.d. is in the Isthmus of Panama,
1 species per 410 square miles, as far as the mainland is concerned. As seen in
the following table, certain Antillean groups have a higher taxonomic density.

Table IX

TAXONOMIC DENSITY OF NEOTROPICAL PSELAPHIDAE

Country

Taxonomic Density-

Virgin Islands . . .
Windward Islands
Leeward Islands . .

Panama

Puerto Rico

Guatemala

British Honduras .

Costa Rica

Paraguay

French Guiana . . .

Chile

Mexico

Cuba

Venezuela

Colombia

Brazil

Hispaniola

Bolivia

Nicaragua

Dutch Guiana . . .

Argentina

Honduras

Peru ,

Uruguay

British Guiana . . .
Ecuador

26
53

410

850

964

2,150

2,875

4,652

5,333

6,440

6.909

7,333

7,381

7,471

9,221

9,400

11,422

12,300

15,333

23,530

44,200

70,980

72,000

89,500

116,000

These ratios merely reflect our present state of information, and show no
relation to size of range, but when we consider that much of the Neotropical
Region is occupied by a single biome, namely the Rain Forest, with abundant
moisture, food and vegetation, it is clear that the taxonomic densities, at least
between the Tropics of Cancer and Capricorn, should approach each other at
last. That is, a unifonn biome should have a uniform taxonomic density, other
conditions remaining favorable.

But what is this maximum taxonomic density? To reach an approximate
answer we must return to the best known area. This is a rocky, little mountain
peak, Barro Colorado Island, cut off when the Chagres River was dammed in
1914 to form the Panama Canal. It lies in Gatun Lake, athwart the north-south

370 NEOTROPICAL P3ELAPHIDAE

dispersal highway between Central and South America, and although it has
about forty miles of shore-line, contains but six odd square miles of surface.
About half of this area is in relatively untouched rain forest, and the island
houses the Institute for Research in Tropical America. The climate, flora, fauna,
ecology have been often and well studied (Allee, 1926, 1926a; Carpenter, 1934;
Chapman, 1929; Dunn, 1931; Enders, 1935; Gross, 1930; Kenoyer, 1929; Park,
1938; Park, Barden and WilHams, 1940; Rau, 1933; Schneirla, 1938; Standley,
1927, will serve to open the bibliography for those unfamiliar with work done
on the region) .

Now Barro Colorado Island has been subjected to two summers of collect-
ing Pselaphidae by the author, and in addition I have worked over the forest
floor and termitophilous pselaphids of Dr. Alfred Emerson and Dr. Laura Hare
from this forest, as well as the pselaphids obtained by quadrat and Berlese
sample of Dr. EHot Williams on the island forest floor; finally Dr. Bradley col-
lected here and these pselaphids have been described by Fletcher (1927) . I men-
tion this in detail as the point is important. That is, the pselaphid fauna of this
six square miles may be said to be fairly well known, and thus will serve as a
guide to taxonomic density. I have little doubt that many other species await
discovery here, but there are at present forty-five species of Pselaphidae known
from the island. Therefore the taxonomic density of Barro Colorado Island is
about 1 species per one-tenth square mile.

When this ratio of 1 : 0.12 is contrasted with the densities in Table IX,
the gaps in our knowledge are better appreciated. A density of less than
1 : 10,000 in Pselaphidae represents practically unexplored territory, and hence
Peru, Uruguay, British Guiana, and Ecuador are areas where collections are
desirable.

Having the Barro Colorado Island figures to use as a basis for estimation,
some effort should be made to give a speculative figure of the actual (described
and undescribed) number of species of neotropical Pselaphidae.

Table X
SUBREGIONS OF NEOTROPICAL PSELAPHIDAE

Subregion

Approximate area
in square miles

Reported species
of Pselaphidae

Taxonomic
Density

Central American . . . .
Antillean

600,000

90,000

6,600,000

257

61

651

1 : 2,334
1 : 1,476
1 : 10,138

It will be noted that the South American area is not divided into a Chilean
and a Brazilian subregion of Wallace (1876). We have insufficient information
on pselaphids of Peru and Ecuador for such a division. The three subregions rec-
ognized have a sufficiently distinct pselaphid fauna to warrant their existence.
These three areas have an average taxonomic density of 1 : 4649, which by
coincidence is nearly that of Paraguay.

ZOOGEOGRAPHY 371

The Central American subregion includes Salvador, from which no psel-
aphids are known. The northern part of Mexico is nearctic, as is also an inland
extension southwards involving the Rocky Mountain-Andean Cordillera. This
part of Mexico has been subtracted to give the 600,000 square miles for the sub-
region. In general terms, from the Tropic of Cancer to South America. This area
holds many endemic genera and is exposed to dispersal from the South American
subregion on the south and possibly from the Nearctic Region on the north. This
is to be discussed in detail shortly.

The Antillean subregion now consists of a chain of islands which begins
near the mouth of the Orinoco River and extends northwestward nearly to Flor-
ida. Therefore it is discontinuous and its insular units collectively have consider-
able variation in local weather and terrain. The taxonomic density of 1 : 1476
is superficially impressive. Actually the pselaphid fauna is poorly known. Two
local studies would be of interest: a comparative analysis of Trinidad and the
Orinoco delta; a similar study of the pselaphids of three areas, namely extreme
southern Florida, northwestern Cuba, and eastern Yucatan. From purely faunal
needs, specimens from Jamaica are greatly to be desired. The figure of 90,000
square miles includes Jamaica, Trinidad, Barbados, and the Bahamas from
which no pselaphids are known.

The third is the South American Subregion, with a density of 1 : 10,138
for the whole. The figure of 6,600,000 is arrived at by subtracting the southern
half of Argentina and southern Chile. At this early stage there appear to be at
least two centers of speciation. The Matto Grosso area of southwestern Brazil,
eastern Bolivia, and northern Paraguay; the upper reaches of the Amazon in
northwestern Brazil, southern Colombia, and southern Venezuela.

The three subregions having been outlined, it is possible to examine the
affinities of Barro Colorado Island. This small locality is well known in Psel-
aphidae, and such an analysis is profitable since the Panamanian Isthmus sepa-
rates two of the three subregions.

On this island there are thirty-one genera, and forty-four or possibly
forty-five, species. Of these genera, eleven are found nowhere else; of the
species, only two are found elsewhere. This high degree of endemism is un-
doubtedly a consequence of lack of information in large measure. It is not
even a peculiar situation in neotropical pselaphids, as we know them. That
is, an area thoroughly worked will present the same picture, whether it be in
Mexico, or Brazil.

Taking the situation on the island as we find it today, the genera Sebaga,
Jubus, Eurhexius, Eupsenina, Xybarida, Xybaris, Arthmius, Oxarthrius,
Euphalepsus, Batrybraxis, Neotyrus, and Hamotus are predominantly South
American.

The genera Thesium, Trimiopsis, Scalenarthrus, Drasinus, Dahnoburis
predominantly Central American — not taking into account the eleven endemic
genera, which may prove to be either northern or southern in distribution.

The genus Berdura is Antillean.

The genus Reichenbachia is cosmopolitan and the genus Decarthron al-

372 NEOTROPICAL PSELAPHIDAE

Table XI
FAUNAL AFFINITIES OF BARRO COLORADO ISLAND

Genus and Species
of B.C.I.

Genus
Endemic

Species of Genus in:

Central Am.
Subregion
(Including

BC.I./
Excluding)

South Am.
Subregion

Antillean
Subregion

Sebaga raffrayi "j

Sebaga notonoda /-No

Sebaga scydmaenilla }

Jubus terranus \

Jubus chickeringi > No

Jubus tumeri j

Barrojuba albertae Yes

Eurhexius zonalis No

Thesiura barrocoloradoensis No

Panaramecia williamsi Yes

Barroeuplectoides zeteki Yes

Verabarolus subdendrus Yes

Trimiopsis furcalis No

Eupsenina patricia No

Reichenbachia fovearthra ) xt

Reichenbachia stroheckeri j

Xybarida nasicola No

Berdura dentipalpa No

Scalenarthrus undecimtympus No

Xybaris funiculis No

Drasinus cisinsularis No

Decarthron chichion "^

Decarthron noctiphoton > No

Decarthron euspinifrons /

Barrometopia quasimoda Yes

Arthmius sabomba No

Oxarthrius sternadens \ -h^

Oxarthrius escharus j

Euphalepsus panamensis No

Dalmoburis petrunkevitchii No

Batriphysis epicranis Yes

Dalmonexus seeversi Yes

Phybytharsis gambosis Yes

Batrybraxis panamaensis | -kt

Batrybraxis bowmani |

Bibrax bradleyi Yes

Neotyrus coptocolus I -kt

Neotyrus harem j

Juxtahamotopsis bardeni Yes

Hamotus alleei 1

Hamotus sandersoni ( j^^

Hamotus castanalus i

Hamotus veracruzensis subsp. fletcheri. '
Tyrogatunus zeteki Yes

3/1

5/2

42

1/0

0

0

5/4

21

0

6/5

1

0

1/0

0

0

1/0

0

0

1/0

0

0

3/2

1

0

1/0

2

0

29/27

41

6

2/1

2

0

1/0

0

1

11/16

3

3

1/0

7

0

3/2

1

0

25/22

29

3

1/0

0

0

18/17

76

0

4/2

8

0

6/5

18

0

2/1

0

0

1/0

0

0

1/0

0

0

1/0

0

0

3/1

4

0

1/0

0

0

2/0

2

0

1/0

0

0

25/21

62

1

1/0

0

0

though American, is seemingly evenly distributed between the northern and
southern subregions of the neotropics.

From these considerations we conclude that the pselaphid fauna of Barro
Colorado Island is generically thirty per cent novel. By allowing 3 per cent
to each genus, then the fauna may be stated:

ZOOGEOGRAPHY 373

Endemic 33%

South American 36%

Central American 15%

Antillean 3%

Cosmopolitan 3%

Unattached 3%

Six genera have nearctic species [Thesium, Arthmius, Scalenarthms,
Reichenbachia, Decarthron, and Hamotus). None of these genera are pre-
ponderantly nearctic; all save Reichenbachia are neotropical in proportion of
species, yet the island holds six out of nineteen genera common to the nearctic
and neotropical regions. It holds one of the five genera {Reichenbachia) found
in the neotropics, nearctic, and also with species outside the Western
Hemisphere.

Since this analysis was possible only after the taxonomic work was finished
in the preceding pages, the author feels that the above discussion is without
bias, and consequently represents the situation as far as is known. If this is
so, the Panamanian Isthmus is represented as just such a cross-roads as theory
would expect, with considerable local speciation and a marked South American
element the outstanding characteristics.

Professor Dunn (1940) finds the rich herpetological fauna of Nicaragua,
Costa Rica, and Panama to be relatively homogeneous and to have a high
percentage of endemic species. From our survey of Barro Colorado we find
this high endemism coinciding with the high endemism of Pselaphidae.

With these data before us we are in a position to estimate the total num-
ber of species of neotropical Pselaphidae (PI. XXI). In the first place, the
total area of this region is placed at 7,290,000 square miles. If the B.C.I.
index of ten species per square mile be used, then the fantastic total of 72,-
900,000 faunal units is obtained as a starting point. Let us examine the problem
with as much care as possible. Such an assumption would infer that:

1. There were no subspecies.

2. There was a maximum taxonomic density for the entire neotropical
area.

3. There was no competition for food.

4. Within the range of a species there was equal population density.

5. There was no overlapping in range between species.

*****
1. If there were 72,900,000 taxonomic units, this large number would
presuppose a highly developed taxonomy with all ranges mapped. If this were
so, these units would not be species but subspecies. The most advanced
taxonomy is probably that of the ornithologists. Taking one of the largest
families of American birds, the warblers, we find about 50 species and 150
subspecies.^ Assuming that the Pselaphidae subspeciate no more than three

^ These figures on species and subspecies of warblers are taken from Pearson's Birds
of America (1936). It should be noted that they do not agree with the 1935 Abridged
Checklist of North American Birds of the American Ornithologists' Union. Other sub-
speciation studies, within Coleoptera, attest the probability of this general process, for
example the work of Valentine (1935, 1936).

374 NEOTROPICAL PSELAPHIDAE

subspecies on the average to one species, this gives us 24,300,000 species popu-
lations. In our speculative argument this first step may be characterized as
the Subspeciation Factor. (PI. XXI).

2. It is obvious that the number of species is subject to great variation
over such a large area. Area always covered by water (lakes, river systems,
water of swamps) would be wholly uninhabited. Grasslands have a much lower
yield in species. The periodically inundated forests (Haviland, 1926) and
swamps would have a lower yield than moist higher lying forests. Palm
swamps where the floor is thigh-deep mud. Mangrove areas, and all coastal
zones periodically invaded by tides, and brackish water communities, would
have very few species. Dissected rocky terrain, or areas with little or no
humus, would be almost barren of species. Montane zones above the tree-
line would be similarly almost barren, and the impoverishment above the
rain forest proper would be notable and progressive.

If this is so then the fixed subspeciation rate may not be employed as
the process does not take into account the distinctive communities involved.
Unfortunately exact information is lacking for most pselaphid records, for
example, exact altitude in feet, whether the collection was from the plains of
southern Brazil or the brazilian rain forest. Grassland or pampas of Argentina,
plains of Paraguay or Uruguay, these and their many gradations may be
reflected in the sum total of subspecies selection pressure and, without in-
formation, a purely artificial but logical reduction must be made.

Let us assume one-tenth of the area has maximum density, that is one-
tenth the area has one-tenth of 24,300,000 or 2,430,000; one-tenth of the area
has nine-tenths maximum density, and so on:

One tenth 2,430,000

One tenth 2,187,000

One tenth 1,944,000

One tenth 1,701,000

One tenth 1,458,000

One tenth 1,215,000

One tenth 972,000

One tenth 729,000

One tenth 486,000

One tenth 243,000

13,365.000

This revised total does not take into account the probability that some
portions could not support any pselaphids. This should allow for at least some
reduction and at a conservative figure would reduce the total to 13,000,000
species. This second step may be characterized as the Community Factor.
(PI. XXI).

3. Species are populations of individuals and these latter must eat. Since,
with few exceptions, predaceous species feed upon animals smaller than them-
selves, they are ecologically fixed by their size within one of the horizontal
strata of the Eltonian pyramid (Elton, 1927; Park, Allee and Shelford, 1939;

ZOOGEOGRAPHY 375

Williams, 1941). This means that there is competition for the smaller food ani-
mals between the species of predators in the same size class. To use a hypotheti-
cal example in which only food is used: if there are ten pounds of food in X time,
and the predators require one pound each in X time, then the number of
species of predators will lie between ten (monoecious or parthenogenetic)
species each consisting of one individual, or one species with ten individuals.

The 13,000,000 species derived above assumed optimal food and no compe-
tition within the community. This is patently not the case. The only study in
which neotropical Pselaphidae have been quantitatively collected in relation
to all other animals of their size range is that of Williams (1941) on the forest
floor of Barro Colorado Island. Williams analysed eighteen small quadrats
twenty-five centimeters square and eleven large quadrats one meter square,
both manually and with Berlese samples. This analysis produced 498 speci-
mens of Coleoptera, including 26 specimens of Pselaphidae. These beetles were
of small size, averaging between one to two millimeters. They belonged chiefly
to seven characteristic families (Carabidae, Staphylinidae, Pselaphidae, His-
teridae, Ptilliidae, Tenebrionidae, and Scarabaeidae). The first five families
are either wholly or partially carnivorous and compete for the same food in all
probability. Not all of these beetles were identified by experts in time for
publication so the number of competing species of beetles must be arrived
at in some other way. There were eight species of pselaphids with an average
length of 1.7 millimeters. If we reorganize the Williams data, then the simple
proportion of 498 : 26 as X : 8 gives 153 species of possible coleopterous
competitors.

In addition to these beetles there were numerous animals present in the
leaf mold, many of which were predaceous. These included species in the same
size range of one to three millimeters, small Oniscidae, Araneida, Chilopoda,
Dermaptera, Reduviidae, and ants. The ants are characteristic, abundant,
omnivorous and at least some species are arhythmic (Park, 1941, 1941a).
These and the other animals are important competitors. Williams' tables list
about 102 possible competing species other than beetles. This brings the num-
ber of competitors to 255 species.

In addition another hundred were not identified. Assuming thirty of
these small forms to compete, the total possible competing species is 285 to 8
species of Pselaphidae, or 35 species to one pselaphid species.

This gives a competing ratio within the community but does not take
into account inequalities in intra-community distribution within the same
stratum, namely the forest floor. Both in this and the nearctic region I have
found some nights to have a high yield to lights while other nights produced
no pselaphids; some logs on Berlesing a sample have a high yield, nearby
logs few or no pselaphids. This must be taken into account. Williams found
that pselaphids occurred on 60 per cent of all quadrats.

Therefore: 13,000,000 x 60% gives 222,857 species.
35

376 NEOTROPICAL PSELAPHIDAE

This figure of 222,857 species may be said to be adjusted for interfamily
competition within the community and this third step (PI. XXI) may be char-
acterized as the Competitive Factor. It assumes a more or less perfect equili-
bration between food and feeders, and attempts to compensate for the third
and fourth postulates previously listed.

4. This does not take cognizance of the fact that species of Pselaphidae
have overlapping ranges. Intrafamily competition should be more severe than
interfamily competition since pselaphids would tend to have similar predators
and parasites; and their food and niche requirements are satisfied during the
same period of the twenty-four hour cycle. Here I have no rule to guide specu-
lation. The present maximum of one species per one-tenth square mile may
represent one-fifteenth to one-thirtieth the fauna without intrafamily competi-
tion. This would postulate 7000 to 15,000 neotropical species adjusted for total
competition at this level of integration.

What has been said here refers to the Range Factor, and all of these in-
fluences (PI. XXI) have been treated as operating independently. This is
undoubtedly false, as they probably operate jointly at every part of the argu-
ment. Furthermore, there is no information upon the effects of human activity
upon pselaphids. Such effects obviously exist in populated areas. These effects
are certainly adverse and there is every reason to believe that this adverse
influence will increase in magnitude.

Similarly there are no data on the net evolution of pselaphids, that is
the relation between the establishment of successful mutants and the ex-
tinction of species.

Nor are the guests of ants and termites properly treated since selection
pressures within the nest of the host must be very different from those in the
forest floor or tropical grassland.

The author is aware that different methods of treatment, or rearrange-
ment of the same treatment, might be more desirable ; that different values can
be set up. The considered maximum of 14,000 to 15,000 species may seem high
when not quite 1000 are described, but the figure appears reasonable when
we realize how little is actually known of the area estimated. When all insects
have been described, the one and a half million described between 1758 and
1940 (Metcalf, 1940) will not appear nearly as imposing to us as it does now,
when the tropics are just revealing their richness.

A second question to be asked is, what is the total population of indi-
viduals? This is much more readily answered as we have at least one quanti-
tative figure. Williams found 26 specimens in thirteen square meters, or one
per square meter of leaf mold in the Barro Colorado forest. This works out
roughly at 300,000 per square mile. This must be reduced by half to allow
for that part of the floor covered by tree trunks, et cetera, but is trebled by the
log mold species, the majority of which do not inhabit the leaf duff, but pass
the day beneath the loose bark of trees fallen on the ground, and this does not
include the ant and termite nest forms which work out at five per cent. This
gives a conservative estimate of 465,000 per square mile, for maximum forest

ZOOGEOGRAPHY 377

cover under optimal conditions. Applying the scale for varying density of
species population previously used, the total estimated population may be
derived proportionally:

465,000 : 10 as a: : 14,000

maximum maximum total

population species estimated

per sq. mi. per sq. mi. species

This utilizes the precautionary steps taken in estimating number of
species, since it has been held that species populations are populations of
competing individuals. Therefore the estimated population of neotropical
Pselaphidae is 651,000,000.

Naturally many species are uncommon, others very abundant, but these
figures enable us to set the average population at 46,500 individuals per
species. This brings up a picture of many species with relatively small popu-
lations, annually maintained, competing in a relatively densely populated,
relatively uniform biome.

There remains the biomass (Pickles, 1937), or living weight per unit of
area. Weight data are at hand for the Chicago area only. These are the un-
published thesis figures of one of my students, Dr. Elizabeth Lunn, since
used by Williams (1941), in which the average weights were obtained by
weighing numbers of animals in a chemical balance. These were of beetles of
the forest floor beyond the size range of pselaphids, as well as leaf and log mold
oribatid mites and collembolans upon which pselaphids feed. Dr. Lunn's data
were of organisms from a rich forest in the Chicago area. The beetles averaged
0.03 gram, the mites and collembolans 0.000025 gram. They are frankly aver-
age weights and in using them here we have to assume that beetles of the
same general size have the same general weight. This Chicago figure is about
seven times too heavy for pselaphids. If the figure of .004 gram is used, then
the 651,000,000 neotropical pselaphids have a biomass of 2,604 kilograms.

These ideas on the population may be summarized:

Table XII

THE NEOTROPICAL PSELAPHID POPULATION

Number of described species 895

Number of species estimated to exist 7000 to 14,000

Number of individuals estimated 651,000,000

Biomass estimated in kilograms 2,604

Average species population 46,500

Abstract

The methods of collecting both free-living and inquilinous Pselaphidae are
discussed.

The preparation of these organisms for study is outlined with respect to
pinned specimens on points, whole-mounts for microscopic study, and special
techniques suggested for the study of special structures, such as foveae or
genitalia under very high magnification.

The historical development of pselaphid taxonomy is sketched, with
especial emphasis on the Western Hemisphere.

The comparative morphology of Pselaphidae is discussed with reference
to taxonomic and phylogenetic problems, especially emphasizing the paral-
lelisms and divergences between Pselaphidae and Staphylinidae. Special refer-
ence is made to the following: number and flexibility of abdominal segments;
male genitalia; maxillary palpi; tarsal segments and tarsal claws; antennae;
pubescence; foveae, especially vertexal, gular and sternal; a system of number-
ing sternal foveae is suggested and its phylogenetic significance discussed;
endoskeleton ; compound eyes. This section concludes with a definition of
Pselaphidae.

A key to the seventeen tribes of neotropical pselaphids is given, follow-
ing which, each tribe is treated by a key to genera. The genera are variously
discussed, a key to species is given in each genus where feasible, and each
genus concludes with a catalogue of its species in which author, date of
description, geographic range, synonymy and genotype are listed.

The several changes in the system of neotropical pselaphids, and new
genera and species follow:

Juhinini

Sebaga rafifrayi, S. notonoda new species, Panama Canal Zone.

Sebaga scydmaenilla (Sharp) redescribed.

Jubus terranus, J. chickeringi, J. turneri new species, Panama Canal Zone.

Barrojuba albertae, new genus and new species, Panama Canal Zone.

Euplectini (including Trichonychini)

Fletcherexius new genus for macrodactylus (Fletcher).

Group IV of Eurhexius divided into two sections.

Eurhexius zonalis new species, Panama Canal Zone.

Rhinoscepsis falli new species, Brazil.

Rhinoscepsis dybasi new species, Mexico.

Thesium barrocoloradoensis new species, Panama Canal Zone.

Panaramecia williamsi, new genus and new species, Panama Canal Zone.

Barroeuplectoides zeteki new genus and new species, Panama Canal Zone.

Verabarolus subdendrus new genus and new species, Panama Canal Zone.

Trimiopsis furcahs new species, Panama Canal Zone.

(378)

ABSTRACT 379

Ramelbida new genus for quadrifoveata (Raffray).

Melba divided into Melba s.s., and the following new subgenera: Asymmelba,
Rameloidea, Vertelba, Quadrelba and Frontelba.

Brachyglutini

Eupsenina patricia new species, Panama Canal Zone.

Group LXIV, new group, added to Reichenbachia.

Reichenbachia fovearthra, R. stroheckeri, new species, Panama Canal Zone.

Panabachia new genus for vulnerata (Sharp).

Xybarida nasicola new species, Panama Canal Zone.

Berdura dentipalpa new species, Panama Canal Zone.

Group V, new group, added to Scalenarthrus.

Scalenarthrus undecimtympus new species, Panama Canal Zone.

Xybaris funiculis new species, Panama Canal Zone.

Drasinus divided into Drasinus s.s., and Paradrasinus new subgenus.

Drasinus cisinsularis new species, Panama Canal Zone.

Decarthron divided into Decarthron s.s., and Decarfuss new subgenus.

Decarthron chichion, D. noctiphoton new species, Panama Canal Zone.

Decarthron euspinifrons new species, Panama Canal Zone.

Metopiini

Metopioxys seeversi new species, Colombia.

Metopioxys mattogrossoensis new species, Brazil.

Barrometopia quasimoda new genus and new species, Panama Canal Zone.

Batrisini

Arthius sabomba new species, Panama Canal Zone.

Syrmocerus guarinus new species, Brazil.

Oxarthrius divided into Oxarthrius s.s., and Baroxarthrius new subgenus.

Oxarthrius stemadens, O. escharus new species, Panama Canal Zone.

Batoctenus barberi new species, Brazil.

Euphalepsus myrmecocolus new species, Mexico.

Tychini

Dalmodes emended.
Bythinophysis emended.

Dalmoburis petrunkevitchi new genus and new species, Panama Canal Zone.
Batriphysis epicranis new genus and new species, Panama Canal Zone.
Dalmonexus seeversi new genus and new species, Panama Canal Zone.
Phybytharsis gambosis new genus and new species, Panama Canal Zone.
Anoplobraxis guianensis new genus and new species, British Guiana.
Batrybraxis panamaensis, B. Bowmani new species, Panama Canal Zone.

Tyrini

Phylogeny of neotropical genera suggested, based on maxillary palpi.

Neotyrus coptocolus new species, Panama Canal Zone.

Neotyrus harem new species, Panama Canal Zone.

Juxtahamotopsis bardeni new genus and new species, Panama Canal Zone.

Apharus colombiensis new species, Colombia.

Hamotoides a subgenus of Hamotus, not a separate genus.

380 NEOTROPICAL PSELAPHIDAE

Hamotus costaricensis, new species, Costa Rica.

Hamotus alleei new species, Panama Canal Zone.

Hamotus sandersoni new species, Panama Canal Zone.

Hamotus castanalus new species, Panama Canal Zone.

Hamotus aztekus new species, Mexico.

Hamotus veracruzensis new species, Mexico.

Hamotus veracruzensis fletcheri, new subspecies, Panama Canal Zone.

Hamotus electrae, new species, Mexico.

Hamotus thomasi new species, Colombia.

Cercoceroides sternalis new species, Brazil.

Tyrogatunus zeteki new genus and new species, Panama Canal Zone.

Arhytodini

Arhytodes achillei new species, Brazil.

Clavigerinae

Clavigerinae a subfamily of Pselaphidae, not a separate family.
Fustiger veracruzensis new species, Mexico.

The names of undescribed species of Motschulsky are listed but have no
validity.

There are 17 tribes, 141 genera, and 895 species of neotropical Pselaphidae.
These are discussed zoogeographically. The neotropics have over twice the
number of both genera and species as the nearctic region. Nineteen genera
are common to the Nearctic and Neotropical Regions ; five genera have species
outside the Western Hemisphere.

The Neotropical Region is outlined with respect to Pselaphidae, and the
area placed at about 7,290,000 square miles, with three subregions: Central
American, Antillean, and South American.

Vertical distribution and population by floating rafts are discussed.

The number of species in each tribe, for each country of the neotropics
is given in tabular form. These data are combined with square miles of area to
work out Taxonomic Density.

The fauna of Barro Colorado Island, Panama Canal Zone, is discussed
in detail and shown to have the highest taxonomic density known for the
neotropics, with its pselaphid elements showing much endemism and also a
strong South American influence.

By means of a theoretical approach, involving a subspeciation factor,
community factor, competitive factor and a range factor, the total number of
species of neotropical Pselaphidae is estimated to be between 7000 and 14,000.

The total neotropical population of individual pselaphids is estimated at
651,000,000 with a biomass of 2,604 kilograms.

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384 NEOTROPICAL PSELAPHIDAE

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General Index

Names of new genera, subgenera, species and subspecies are italicized. Valid species of
neotropical Pselaphidae are followed by the genera in parentheses. Species not so treated
refer to synonyms, or are not species of Pselaphidae, or are pselaphids not knowTi from the
neotropical region.

abbreviatus 58

abdomen 15-18

abdominalis (Eurhexius) 82

aberrans (Jubus) 58

Abies 72

Abr3'xis 165, 173

Acarina 3

achillei (Arhytodes) 345-346

Achillia 19, 154-157

acignathus 274

Acotebra 107

Actinoma 65, 108

Actium 63, 65, 97, 107-108

acutangulus (Bythinoplectus) 37

Adalmus 97

adparatus (Scalenarthrus) 173

Adranes 4, 6, 7, 13, 20, 22, 23, 26, 28, 29,

349, 350, 351, 352
Adrocerus 285
Adrogaster 107
adulator (Arthmius) 232
adumbrata (Tyropsis) 299
aedeagus, see genitalia
aequinoctialis (Ctenisis) 293
Africa 214, 233, 283, 284, 292, 338
aglenus (Metopiellus) 205
albertae ( Barroj-itba) 60-62
Aleocharinae 18
Aleocharini 14, 19
Algeria 135

alleei (Hamotus) 309, 310, 320-321, 331
Allobrox 71
alternans (Jubus) 58
altitude 363-365
Amaurops 29
amazonica (Ctenisis) 293
amazonicus (Fustiger) 358
americanus 7

ampliventris (Phalepsus) 298
Anarmodius 72, 73, 75
anas 157

anatomy, see morphology
Anchylarthron 176
Andes 364, 371
anguina (Trimiosella) 112
angulata (Rhexinia) 73
angustata (Ctenisis) 293
angustatus (Eurhexius) 82

anophthalmus (Goniacerus) 2S5
Anoplobraxis 277-279
Anoplotermes 279

antennae 19-20, 135, 185, 204, 283, 350
antennator (Syrbatus) 236
Antennophorus 352
anthicoides (Oxarthrius) 246
Antilles 362, 363, 367

subregion 370-371
ants 7, 37, 40, 81, 99, 120, 175, 197, 205,

210, 215, 246, 291, 293, 294, 295, 309,

310, 332, 347, 348, 349, 350-352, 353, 354,

356, 357-358, 376
Aphaenogaster 7, 309, 357
Apharus 305-307
aphidicola 7, 352
Aplodea 156, 157, 298, 303, 305
Aploderina 332
Apoderiger 350
Aporhexius 67, 72, 73, 74
Apothinus 89, 93
appendicularis (Hamotus) 329
appendiculata (Reichenbachia) 147
appendiculatus (Hamotus) 331
approximatus (Achillia) 156
Araneida 375
Arctophysis 41
area 368

areolatus (Arthmius) 231
Argentina 31, 362, 367, 368, 369, 371
argentina (Reichenbachia) 152
argentinus (Hamotus) 329
argus (Jubus) 58
argus (Thesiastes) 98
Arhytodes 21, 344, 347
Arhytodini 19, 23, 31, 34, 343-347
Arianops 29

armatellus (Arthmius) 231
armatus (Oxarthrius) 246
armatus (Phoberus) 134
armiceps (Bryaxina) 159
armipes (Apharus) 307
Arthmius 21, 215-233, 236, 237, 238, 240
arthriticum (Decarthron) 198
Articerus 350, 353
articularis (Arthmius) 230
asteriscus 248
Asymmelba 121
Atelura 4

390

NEOTROPICAL PSELAPHIDAE

Atemeles 21

Atinus 19

atomaria (Xybaris) 179

atratus 98

atricapillus 237

Atta 37, 99, 120, 175, 246, 348, 349

attaphilus (Oxarthrius) 246

Attapseniini 19, 21, 31, 33, 34, 348-349, 351

Attapsenius 349

aubeana (Reichenbachia) 139

aubeanus (Hamotus) 329

aubei 292

aubei (Arthmius) 231

auricapillus (Hamotus) 329

auriculatus (Arthmius) 232

auritulus (Syrbatus) 237

aurivillii (Decarthron) 200

auropunctata 347

Australia 135, 214, 338

australis 347

Autoplectus 29

aztekus (Hamotus) 323-324, 330

B

badius (Hamotus) 329

Bahamas 371

Balega 62

Barada 122, 126

Barbados 371

barbatus (Hamotus) 329

barberi (Batoctenus) 250-253

barbiellinii (Arthmius) 230

bardeni ( Juxtahamotopsis ) 303-305

Baroxarthrius 241, 244, 246

barretoi (Metopiosoma) 205

barrocoloradoensis (Thesium) 91-93

Barro Colorado Island 367, 369, 370, 371,

372-373
Barrojuba 20, 39, 59-62
Barroeuplectoides 101-104
Barrometopia 29, 210-213, 284.
basisternum 25
Basolum 65

batesellus (Phalepsus) 298
Batoctenus 249-253
Batnphysis 270-272
Batrisobryaxis 263
Batrisodes 4, 5, 6, 7, 8, 11, 16, 17, 20, 214,

246, 248
batrisoides 309

batrisoides (Dalmoplectus) 111
batrisoides (Pselaptus) 175
Batrisini 17, 18, 23, 29, 31, 32, 214-259
Batrisus 215, 216, 230, 231, 232, 233, 240,

246, 248, 282
Batrybraxis 265, 279-282
belfragei 174

bellicosus (Metopioxys) 210
bellus (Hamotus) 332

Berdura 163-165, 174

Bergrothiella 29

Berlara 163

Berlese method 2, 3

Biblomimus 93-94, 97

Bibloplectus 3, 15, 22, 28, 64, 97

Bibloporus 63

Bibrax 29, 204, 213, 283, 284

biarmatus (Iteticus) 248

biclavata (Reichenbachia) 145

bicolor (Arthmius) 230

bicolor (Decarthron) 198

bicolor (Eurhexius) 82

bicolor (Hamotus) 330

bicolor (Lioplectus) 99

bicolor (Pselaphellus) 287

bicomis (Arthmius) 231

bidenticulatus (Syrbatus) 237

bifossifrons (Achillia) 156

bifossulatus (Jubus) 59

bifoveata (Reichenbachia) 147

bifoveatus (Anarmodius) 72

bifurcatus (Syrbatus) 237

bilineatus (Eu phalepsus) 258

binodosum (Decarthron) 198

binodula (Reichenbachia) 147

binodulus (Drasinus) 184

biocellata (Reichenbachia) 152

biomass 377

Biotus 19

bipunctatum 199

bisinuata (Reichenbachia) 152

bison (Arthmius) 231

bispinosus (Oxarthrius) 246

bistriatus 26

bistriatus (Euphalepsus) 258

bisulciceps (Mitona) 176

bituberculata (Achillia) 157

bituberculatus (Arthmius) 231

bizonatus (Pselaphus) 287

blanchardi (Achillia) 156

Bledius 30

Bolitocharini 19

Bolivia 364, 367, 368, 369, 371

boliviensis (Arhytodes) 346

boliviensis (Arthmius) 232

boliviensis (Hamotus) 329

boliviensis (Reichenbachia) 139

boivmani (Batrybraxis) 281-282

Brachygluta 3, 71, 154

Brachyglutini 16, 17, 23, 32, 122-203, 214

Brachyscelia 34, 35-285

brachyscelis 197

bradleyi (Bibrax) 284

brasilianum (Decarthron) 199

brasiliensis (Fustiger) 358

brasiliensis (Jubus) 59

brasiliensis (Rhexius) 83

Braxyda 19, 157, 159-160

GENERAL INDEX

391

Brazil 362, 364, 367, 368, 369, 371

oreviceps (Arthmius) 232

brevicollis 293

brevicollis (Arthmius) 231

brevicollis (Bythinophysis) 264

brevicollis (Dalmoburis) 270

brevicollis (Thesium) 93

brevicornis (Achillia) 156

brevicornis (Arh5^todes) 346

brevicornis (Globa) 203

brevimarginatus (Hamotus) 330

brevipennis (Pselaphomorphus) 40

brevipennis (Salagosa) 36

brevis (Jubus) 58

brevispina (Syrbatus) 237

brevispinus 237

breviventris (Strombopsis) 154

British Guiana 367, 368, 369, 370

British Honduras 367, 368, 369

bruchi (Arhytodes) 346

bruchi (Decarthron) 199

bruchi (Pselaphomorphus) 40

bruchi (Syrbatus) 237

brucki (Jubus) 59

brunneus (Buris) 266, 269

brunneus (Hamotus) 329

Bryaxina 19, 157, 158-159

Bryaxis 135, 139, 141, 142, 145, 146, 147,
i48, 151, 152, 153, 154, 159, 165, 173, 175,
179, 180, 185, 197, 198, 199, 200, 201, 214,
231, 233

bryaxoides (Hamotus) 308, 329

bubalus (Arthmius) 230

bubalus (Syrbatus) 237

bulbifer (Hamotus) 329

Bunoderus 111, 154

burchelli 197

Buris 266, 269

bythinoceros (Arthmius) 231

Bythinogaster 203

bythinoides (Reichenbachia) 152

Bythinophysis 263-264

Bythinoplectus 37

Caccoplectus 13, 288

calcaratus (Pselaptus) 175

calcarifer (Syrbatus) 237

californicus 357

callosa (Reichenbachia) 142

Canthoderus 62

capitatus (Lioplectus) 99

Carabidae 375

carinae, ocular 179

carinatus 232

carinatus (Arthmius) 232

carinatus (Neodalmus) 111

carinicollis (Bunoderus) 154

carinifer (Reichenbachia) 148

carinipes (Metopias) 205
carnivores 3

castanalus (Hamotus) 322-323, 330
castanea (Tyropsis) 298, 299
castaneus (Arthmius) 231
caudatus (Syrbatus) 237
cavangula (Faronoma) 71
caviceps 111
caviceps (Actium) 108
caviceps (Dalmomima) 265
caviceps (Melba) 120
cavicornis (Adrocerus) 285
cavicornis (Hamotus) 330
cavicornis (Phalepsus) 298
cavicornis (Scalenarthrus) 173
cavifrons 89

cavifrons (Bryaxina) 159
cavifrons (Euphalepsus) 258
cavifrons (Eurhexius) 82
cavifrons (Tyropsis) 299
cavipalpus (Hamotus) 330
caviventris (Jubus) 58
Cayenne, see French Guiana
cearae (Decarthron) 199
Cedius 4, 5, 7, 15, 16, 17
celata (Reichenbachia) 147
celatus (Caccoplectus) 288
Central America 363, 368, 370

subregion 370-371
centralis (Euphalepsus) 258
centralis (Hamotus) 330
centralis (Sebaga) 48
centralis (Syrbatus) 237
Ceophyllus 4, 5, 6, 7, 17, 20
Cephaloplectus 197
cerastes (Arthmius) 231
Cercoceroides 334-336
Cercoceropsis 333-334
Cercocerulus 338
Cercocerus 4, 7, 308, 309
cervical foveae 25
cervus (Syrbatus) 240
Chalcididae 22
Chenniopsis 19
Chennium 19

chernosvitovi (Attapsenius) 349
chevrolati 299

chevrolati (Reichenbachia) 141
chichion (Decarthron) 190-192, 198, 201
chickeringi (Jubus) 52-54, 58
Chile 35, 367, 368, 369, 371
chilensis 156
Chilopoda 375
cicatricosus (Arthmius) 231
cinnamomeus (Arthmius) 231
circumscriptus (Arthmius) 232
cisinsularis (Drasinus) 183-184, 185, 200
clandestinus (Enoptostomus) 292
clavata 22

392

NEOTROPICAL PSELAPHIDAE

clavata (Achillia) 156

clavata (Bryaxina) 159

clavata (Harraophola) 264

clavata (Melba) 121

clavata (Xybarida) 163

clavatus (Jubus) 59

clavatus (Scalenarthrus) 173

clavatus (Thesium) 93

claviceps (Trimiopsis) HI

clavicornis 173

clavicornis (Apharus) 307

clavicornis (Hamotus) 329

clavicornis (Melbamima) 112

clavicornis (Trimiopsis) 111

Claviger 29, 350, 351, 352

claviger (Hamotus) 329

Clavigerinae 1, 4, 5, 8, 15, 17, 18, 19, 21,

23, 29, 31, 343, 344, 348, 349, 350-358
Clavigerini, see Clavigerinae
Clavigerodes 350
Clavigeropsis 350
clavipilis (Fustiger) 358
clypeata (Melba) 120
clypeatus (Syrbatus) 237
cochlearifer (Decarthron) 198
cochlearis (Neofustiger) 353
coeculus (Jubus) 59
cognata (Endytocera) 62
collecting 1-7
Collembola 3

Colombia 366, 367, 368, 369, 371
colombiensis (Apharus) 306-307
Commatocerinus 353, 357
Commatocerus 353, 357
commodus (Hamotus) 332
community factor 374
competition 374-376
complicatum (Decarthron) 199
concavus (Scalenarthrus) 173
concolor (Arthmius) 233
concolor (Trimiodina) 108
confluens 8

conjunctus (Pseudohamotus) 337
constricta (Macta) 40
convexa (Nodulina) 154
convexiceps (Achillia) 156
convexiusculus (Jubus) 59
convexinscutus 59
convexus (Pselaphellus) 287
coptocolus (Neotyrus) 299-301, 303
Coptotermes 246, 301, 302, 303, 340
copulation 3, 115
cordicollis (Achillia) 156
cordicollis (Tomoplectus) 107
cordicollis (Xherius) 73
cornicen (Fustiger) 358
Cornitermes 274
cornutus 231
comutus (Arthmius) 231

coronatus (Arthmius) 233

corpulentum (Decarthron) 198

cosmoptera 299

cosmoptera (Achillia) 156

costalis 1. 5, 27

Costa Rica 364, 366, 367, 368, 369, 373

costaricensis (Hamotus) 319-320, 330

crassicornis (Arthmius) 230

crassicornis (Bryaxina) 159

crassicornis (Ephimia) 290

crassicornis (Eremomus) 134

crassicornis (Eurhexius) 82

crassipalpis (Reichenbachia) 152

crassipalpus (Hamotus) 330

crassipes 249

crassipes (Braxyda) 160

crassipes (Jubus) 59

crassipes (Melba) 120

Cremastogaster 354, 357

cribratus 358

cristatifrons (Arthmius) 232

critstatus (Pselaptus) 175

cristulatus (Arthmius) 231

cruralis (Arthmius) 231

cruralis (Euphalepsus) 259

Cryptophagidae 88

Cryptorhinula 154, 174, 179-180

Ctenisis 292-293

Ctenisodes 294

Ctenistes 294

Ctenistini 16, 17, 19, 21, 26, 31, 33, 2

291-294, 343, 344, 348

Cuba 367, 368, 369, 371

curculionoides (Metopias) 205

current

Florida 365

Gulf Stream 365

South Equatorial 365
curticorne (Decarthron) 199
curtipalpis (Pseudohamotus) 337
curtula (Batrybraxis) 282
curvicornis (Arthmius) 230
curvipes (Reichenbachia) 140
curvispina (Syrbatus) 237
Cyathiger 285, 351
Cyathigerini 15, 31, 285, 351
Cylindrarctus 11, 15, 16, 260
Cylindrembolus 165
cylindrica (Dalmophysis) 277
Cynipidae 14

Dalmohuris 266-270

Dalmodes 111, 262-263, 264

Dalmomima 265

Dalmonexus 272-274

Dalmophysis 276-277

Dalmoplectus 111

Dalmosella 11, 15. 17, 21, 22, 65, 11

GENERAL INDEX

393

dama (Syrmocerus) 240

dampfi (Allobrox) 71

debilis 98

Decarfuss 187, 194, 200, 201

Decarthron 3, 122, 185-201, 202

decipiens (Hamotus) 331

decipiens (Jubiis) 58

delicatus (Arthmius) 232

Demerara, see British Guiana

demoniacus (Syrbatus) 237

dentata (Balega) 62

denticollis 17

denticollis (Sebaga) 48

denticorne 197

denticorne (Decarthron) 200

denticornis 197

denticornis (Bythinoplectus) 37

denticornis (Scalenarthrus) 173

denticulatum (Decarthron) 199

dentipalpa (Berdura) 164-165

dentipes 253

deplanatus (Hamotus) 329

Dermaptera 375

designata (Reichenbachia) 152

Desimia 292, 293

Diartiger 350

dichrous (Arthmius) 230

difficilis (Hamotus) 331

difformis (Tyropsis) 299

dilatata (Sebaga) 48

Dimerini 19, 31

Dimenis 19

dimidiata (Bryaxina) 159

dimidiatus (Batoctenus) 253

dimissionis (Decarthron) 198

Dinopsis 19

Disarthricerus 350

discedens 293

dispar 293

dispar (Ctenisis) 293

divergens (Syrbatus) 237

diversa 151

diversicomis (Reichenbachia) 145

diversula (Reichenbachia) 151

Dominica 367

dominicanus (Eupsenius) 129

dominulus (Jubus) 59

dorsopunctata (Reichenbachia) 153

Drasinus 122, 181-185, 187

dresdensis 12

Drosophilidae 14

Duciola 45, 48, 58

Dutch Guiana 367, 368, 369

dybasi (Rhinoscepsis) 88-89

Eciton 197, 310
ecitophihis 14, 310
ecitophilus (Hamotus) 332

Ectopocerus 185

Ecuador 367, 368, 369, 370

Edaphus 21

edithae (Arthmius) 231

edmundi (Arthmius) 232

eggersi (Melba) 120

eidmanni (Attapsenius) 349

electrae (Hamotus) 327-328, 331

elegans (Balega) 62

elegans (Fustiger) 358

elegans (Metopias) 205

elegans (Rhexius) 83

elegantissimus (Pselaphellus) 287

elegantulus 357

elegantulus (Arthmius) 232

elephas (Arthmius) 232

Eleusomatus 18

elevatus (Arthmius) 232

elfridae (Achillia) 156

elfridae (Prosagola) 36

elongata (Jubus) 59

elongatus 308

elongatus (Metopias) 205

elsbethae 299

Eltonian pyramid 374

elytral foveae 25

emeryi (Hamotus) 331

endoskeleton 20, 24

Endytocera 62

Enoptostomus 292

ensipes (Bythinophysis) 264

Ephimia 22, 33, 289-290, 291, 295, 297, 305,

348
epicranis (Batriphysis) 270
equator 365
erectus (Arthmius) 232
Eremomus 133-134
escharus (Oxarthrius) 244-246, 247
estebanensis (Reichenbachia) 140
Euasthetinae 19, 29
Euasthetus 14
eucera (Reichenbachia) 146
Eudranes 338

Euphalepsus 19, 24, 253-259
Eupines 165, 166, 173, 203
Euplectini 1, 3, 17, 18, 24, 29, 31, 32, 63-

121
Euplectus 8, 15, 16, 20, 21, 22, 24, 26, 28,

63. 97, 98, 99-101, 362
Euprenius 129

Eupsenina 21, 22, 65, 122, 129-133
Eupsenius 21, 65, 122, 126-129
Eurhexius 67, 72, 73, 74-82, 363, 364
Europe 101, 135, 352
empinifrons (Decarthron) 194-197, 200
Euteleia 181, 184, 187, 201
Eutermes 84
Eutrichites 175
Eutyphlus 29, 90

394

NEOTROPICAL PSELAPHIDAE

excisa (Achillia) 157
excisa (Xybaris) 179
excisula (Berdura) 165
exiguus (Euplectus) 101
exsectoides 7

externedens (Decarthron) 199
extraneus (Arthmius) 231
eye 28-29, 338

fallaciosum (Decarthron) 199

falli (Rhinoscepsis) 86-88, 89

falsa (Reichenbachia) 142

Faronoma 71

Faronus 29, 35

Faronini 18, 29, 31, 32, 35-36

fasciculata (Ctenisis) 293

fasciculatus (Euphalepsus) 258

fauveli (Arthmius) 232

fauveli (Fustiger) 358

fauveli (Hamotus) 330

felix (Listriophorus) 284

femoralis (Reichenbachia) 152

femoralis (Trimiopsis) 111

femoratus (Arthmius) 231

festina (Reichenbachia) 153

festivus (Fustiger) 358

fiavopilosus (Hamotus) 332

flavus 7

Fletcherexim 67, 72-73, 75

fletcheri (Hamotus) 327, 332

fleutiauxi (Melba) 120

flight, see lights, 3, 276

Florida 362, 363, 371

flumincola (Phalepsus) 298

fluviatilis (Reichenbachia) 153

food, see habitat, 3, 214

Formica 7

formicaria 4

formicarius (Pselaptus) 175

formiceti 186

formicetorura (Bythinoplectus) 37

forticornis (Oxarthrius) 246

fortis (Batrybraxis) 282

fossulatus 98

foveae, see

cervical, elytral, frontal,
gular, phylogenesis, pronotal,
sternal, vertexal

fovearthra (Reichenbachia) 144-145, 146

foveatus (Bythinoplectus) 37

foveifrons (Bryaxina) 159

fracticornis (Eupsenina) 133

fractifrons (Decarthron) 198

frater 329

fraudatrix (Bryaxina) 159

French Guiana 362, 367, 368, 369

frontale (Decarthron) 200

frontalis (Hamotus) 329

frontalis (Melba) 120
frontalis (Raxybis) 157
Frontelba 120
fuchsi 24, 354, 357
fulva 7

funiculis (Xybaris) 177-179
furcalis (Trimiopsis) 109-111
furcasternum 25
furcatus 17

furcifer (Hamotus) 329
fuscocapillus (Euphalepsus) 259
fuscopilosus (Hamotus) 330
Fustiger 4, 6, 17, 20, 24, 29, 279, 349, 350,
353-358

gallardoi (Metopioxys) 210

Gamba 48, 59

gambosis (Phybytharsis) 275-276

Gasola 48, 59

Gatun Lake 369

gazella (Syrmocerus) 240

geniculatus (Arthmius) 230

genitalia 10-11, 15-17, 269, 272, 327, 351,

355
geographic range 366
germaini (Arthmius) 232
germaini (Cercoceroides) 336
germari (Iteticus) 248
gibbicollis (Eupsenius) 129
gibbicollis (Neotyrus) 303
gibbous pronotum defined 254
gibbula (Melba) 120
gibbus (Anarmodius) 72
gibbus (Goniacerus) 285
gigantea (Arctophysis) 41
giganteus 283
glaber 127

gladiator (Metopioxys) 210
Globa 202-203
globicollis 215
globifer (Hamotus) 329
globipennis (Euphalepsus) 258
globulifer (Hamotus) 329
globulosa (Reichenbachia) 142
globosus 1, 5, 17
globosus (Scalenarthrus) 173
Glyptophorus 88
Golasa 36
Goniacerini 19, 29, 33, 204, 213, 283-285,

288, 350, 351
Goniaceroides 285
Goniacerus 283, 285
Goniastes 285
goryi (Reichenbachia) 141
gounellei (Arhytodes) 346
gounellei (Euphalepsus) 258
gounellei (Fustiger) 358
gounellei (Reichenbachia) 139

GENERAL INDEX

395

gracili (Actium) 108
gracilicorne (Decarthron) 200
gracilicornis (Hamotus) 329
gracilicornis (Jubus) 58
gracilipes (Dalmodes) 263
gracilipes (Hamotus) 330
gracilis (Ctenisis) 293
gracilis (Euphalepsus) 129
gracilis (Jubus) 59
gracilis (Rhinoscepsis) 89
grandiceps (Harmomima) 265
grandicornis (Pteroplectus) 97
grandipalpis (Hamotus) 329
Grenada 367
grenadensis (Melba) 120
grenadensis (Reichenbachia) 142
griseopubescens (Reichenbachia) 153
grouvellei (Eupsenius) 129
grouvellei (Hamotus) 330
grouvellei (Jubus) 59
grouvellei (Pselaptus) 175
grouvellei (Reichenbachia) 139
grouvellei (Syrbatus) 237
Guadeloupe 367

guadelupensis (Reichenbachia) 146
guadelupensis (Scalenarthrus) 173
guarinus (Syrmocerus) 239-240
Guatemala 362, 363, 364, 367, 368, 369
guatemalensis (Reichenbachia) 146
guatemalenus (Euplectus) 101
guianensis (Anoplobraxis) 277-279
gular foveae 20

hetschkoi (Fustiger) 358

hetschkoi (Jubus) 58

hetschkoi (Syrbatus) 237

hiatusus (Syrbatus) 237

hibernation 3

hilaris (Hamotus) 332

hippopotamus (Reichenbachia) 153

hirsutum (Decarthron) 198

hirsutus (Cercocerulus) 338

hirsutus (Drasinus) 185

hirsutus (Hamotocellus) 333

hirta (Tyropsis) 299

hirtus (Hamotus) 332

hirtus (Metopiellus) 205

Hispaniola 367, 368, 369

Histeridae 375

Holzodini 32, 288

Holozodus 288

Honduras 367, 368, 369

Homalini 35

honestus (Arthmius) 232

Hoplodermatidae 3

horni 166

horroris (Phamisulus) 332

humeralis 308

humeralis (Euphalepsus) 258

humidula (Achillia) 156

humilior (Arthmius) 232

humilis (Bythinophysis) 264

Hybocephalini 31, 33, 289-290

hydropicus (Arthmius) 231

hystrix 99

habitat 1-7, 197, 204, 214, 216, 295, 350-352
see nocturnalism

myrmecophiles

termitophiles
Haiti 367

hamata (Braxyda) 160
hamaticollis (Oxarthrius) 246
hamatus 246

hamatus (Metopioxys) 210
Hamotocellus 21, 295, 333
Hamotoides 13, 14, 21, 309, 310, 331-332
Hamotus 13, 14, 20, 21, 22, 28, 29, 305,

308-332, 362, 364, 366
Harmomima 265
Harmophola 264
Harmophorus 264
Hayti, see Haiti
haytiana (Fustiger) 357
harem (Neotyrus) 301-303
heisei 12

henrici (Fustiger) 358
heterocerus (Jubus) 58
hetschkoi 332

hetschkoi (Decarthron) 198
hetschkoi (Euphalepsus) 259

iheringi (Hamotus) 329
iheringi (Iniocyphus) 277
illepida (Reichenbachia) 141
illepidus (Euplectus) 101
immodica (Reichenbachia) 147
imperialis (Iteticus) 248
impressa (Biblomimus) 94
impressicollis (Harmomima) 265
impressicollis (Reichenbachia) 153
impressifrons (Bythinoplectus) 37
impressifrons (Melba) 121
impressifrons (Thesium) 93
impubis (Reichenbachia) 153
impunctata (Reichenbachia) 153
impunctatus (Hamotus) 330
inaequalis (Hamotus) 329
incertus (Batoctenus) 253
inconspicua (Melba) 120
indicus 357

Indo-Malay 214, 285, 337
inermis (Jubus) 58
inermis (Phtegnomus) 84
infirmus (Arthmius) 232
inflatus (Hamotus) 329
inflatipalpus (Pseudohamotus) 337

396

NEOTROPICAL PSELAPHIDAE

inflatipes (Arthmius) 230
inflatus (Scalenarthrus) 173
inflexa (Batrybraxis) 282
infossus (Dalmodes) 263
inhonestus (Euplectus) 101
Iniocyphus 277
inquilines, see

myrmecophiles

termitophiles
insculptus 82
insignis (Fustiger) 357
insignis (Eurhexius) 82
insignis (Thesium) 93
insulare (Decarthron) 199
insulario (Euplectus) 101
insularis (Jubus) 58
intacta (Reichenbachia) 142
intermedins (Jubus) 59
interruptus 25, 26
irrita (Reichenbachia) 140
Isoptera, see termites
Italy 19
Itamus 201-202
Iteticus 246-248, 249

Jamaica 368, 371

Japan 293

Java 163

Jubinini 31, 32, 38-62

Jubomorphus 41

Jubus 48-59, 62, 74

juncorum 135

Juxtahamotopsis 22, 290, 303-305, 348

K

kindermanni (Achillia) 156
knausii 357

labialis (Dalmodes) 263
labial palpi 18
labiatus (Arthmius) 232
lacustris 22, 24, 293
laetus (Hamotus) 330
laetus (Jubus) 59
laeviceps 287
laeviceps (Iteticus) 248
laeviceps (Jubus) 58
laevicolle (Decarthron) 199
laevicollis (Euphalepsus) 259
laevipennis (Arthmius) 232
laevis 357
laevis (Globa) 203
laevis (Eurhexius) 81
laevissimus (Phalepsoides) 259
lamellata (Sebaga) 48
lamellatus (Arthmius) 231

lamellipes 249

lamellipes (Decarthron) 199

larvae 8, 30

larvata (Achillia) 156

Lasius 7, 352, 357

lateritius (Hamotus) 308, 310, 316, 331

laticeps (Cercoceroides) 336

laticeps (Ctenisodes) 294

laticeps (Itamus) 202

laticollis (Jubus) 58

latifrons (Achillia) 156

latipalpis (Pseudohamotus) 337

latipes (Arthmius) 231

latipes (Reichenbachia) 146

lativentris (Jubus) 58

laviceps 287

lebasi (Reichenbachia) 142

lecontei 26, 352

Leeward Islands 362, 367, 368, 369

lenticornis (Lioplectus) 99

Lesser Antilles 365

Lethenomus 305

letisimulation 1

levuanus 358

lewisi (Drasinus) 184

lights, flying to, 3, 43, 135, 145, 150, 163,
165, 172, 178, 184, 186, 188, 192, 194, 197,
204, 216, 221, 276, 278, 281, 282, 366

liliputanus (Jubus) 58

liliputanus (Thesiastes) 98

liljebladi (Euphalepsus) 258

limpida (Reichenbachia) 139

Limulodes 197

limuloids 197

Lioplectus 98-99

Listriophorus 284

Lomechusa 21

longepilosus (Hamotus) 331

longiceps (Achillia) 157

longiceps (Cryptorhinula) 180

longiceps (Hamotus) 331

longiceps (Phalepsoides) 259

longiceps (Pselaphellus) 287

longiceps (Pselaphomorphus) 40

longiclava (Cryptorhinula) 180

longiclava (Pselaptus) 175

longicollis (Eupsenius) 129

longicollis (Melba) 120

longicorne (Decarthron) 200

longicornis (Euphalepsus) 258

longicornis (Eurhexius) 81

longicornis (Jubus) 58

longipennis (Adrogaster) 107

longipennis (Batrybraxis) 282

longipennis (Jubus) 59

longipennis (Metopioxys) 210

longipennis (Mitracephala) 84

longipes (Cercoceropsis) 334

longipes (Globa) 203

GENERAL INDEX

397

longipilis (Bunoderus) 154
longispina (Iteticus) 248
longulus (Lioplectus) 99
loricate synoeketes 4
lothari (Euphalepsus) 259
lucida (Bryaxina) 159
lundi 37, 120, 175
lutea (Reichenbachia) 153
luteola (Reichenbachia) 140
luzerae (Arthmius) 232

M

macrocephalum (Decarthron) 198

macrocephalus (Arthmius) 232

macrodactylus (Fletcherexius) 72-73

Macroscelia 34, 286-349

Macta 40

Madagascar 214, 288, 353

magnus (Arthmius) 232

major (Pilopius) 294

majorinus (Eurhexius) 81

mancus (Arthmius) 231

manifestus (Arthmius) 231

manticoroides (Harmophorus) 264

Manzanillo 363

marelloides (Phalepsus) 298

margaritaceus (Arhytodes) 346

marginalis (Scalenarthrus) 173

martha 237

marthae (Syrbatus) 237

Martinique 365, 367

mashona 233

Mastiger 350

Matto Grosso 371

mattogrossoensis (Metopioxys) 209-210

maxillary palpi 18-19, 164, 195, 245, 283,

284, 286, 289, 295, ff, 340-342, 343, 350
Mazatlan 363

megacephalus (Eurhexius) 81
meinerti 84

melanocephalus (Arthmius) 232
Melba 1, 15, 21, 22, 25, 28, 65, 111, 112,

113-121, 362
Melbamima 111
mesosternum 23
metasternum 23
Metopias 205, 210
Metopiellus 205

Metopiini 29, 31, 33, 204-213, 214, 283, 284
Metopioides 285
Metopiosoma 205, 213
Metopioxys 205-210
mexicana 294

mexicana (Reichenbachia) 146
mexicanus (Eupsenius) 129
Mexico 362, 363, 364, 365, 366, 367, 368,

369, 370
micans (Hamotus) 331
microcephala (Golasa) 36

microcephalum (Pseudotrimium) 108

microcephalus (Jubus) 59

Microclaviger 350

Micropeplus 14, 19

microphthalmus (Jubus) 59

microphthalmus (Pselaphomorphus) 40

militaris (Rhinoscepsis) 89

mimetic synoeketes 4

mimula (Melba) 120

minassanae 141

minax 231

minuta (Melba) 120

minutum (Decarthron) 199

minutus (Biblomimus) 94

mirabilis 18

mirabilis (Syrbatus) 237

Mirini 31

Mirus 29

mites 352

Mitona 174, 175-176

Mitracephala 83-84

mniszechi (Mitona) 176

modestus (Arthmius) 232

monachus (Hamotus) 331

monoceros 197

monoceros (Decarthron) 200

monstrata (Achillia) 157

monstrosus 8, 17

morphology 12-30

morsus 216

Motschulsky 359

mucronata (Barada) 126

mucronatus 308

miilleri (Apharus) 307

mus 197

muticus 40 %;

muticus (Eurhexius) 82

mycetoecus 88

myrmecocleptics 4

myrmecocoles, see myrmecophiles

myrmecocolus (Euphalepsus) 256-259

myrmecophiles 4-7, 14, 37, 40, 81, 99, 120,
135, 175, 197, 204, 205, 210, 214, 215, 246
291, 293, 294, 295, 309, 310, 332, 347, 348-
349, 350-353, 354, 356, 357-358, 376

myrmecophilus (Arhytodes) 347

myrmecophilus (Lioplectus) 99

Myrmedoniini 19

N

nanum (Decarthron) 199
nanus (Phalepsus) 298
nasalis (Reichenbachia) 146
nasicola (Xybarida) 19, 160-163
nasina 157

naso (Phtegnomus) 84
naso (Syrbatus) 237
nasuta 146, 157
nasuta (Ctenisis) 293

398

NEOTROPICAL PSELAPHIDAE

Nasutitermes 163
nasutus (Syrbatus) 237
natural rafts 365
Neodalmus 111
Neofustiger 353
Neophamisus 332
Neotropical Region 31,

see zoogeography
Neotyrus 23, 28, 295, 298, 299-303
neutral synoeketes 4
New Grenada, see Colombia
New Zealand 18, 35, 135, 214, 352
Nicaragua 366, 367, 368, 369, 370
niger 12, 246, 301, 303, 340
nigra (Mitona) 76
nigricans (Decarthron) 199
nigropilosus (Hamotus) 331
Nisaxis 20

nitidus (Fustiger) 358
nitidus (Lioplectus) 99
noctiphoton (Decarthron) 193-194, 199, 201
nocturnalism 3, 43, 135, 145, 150, 163, 165,

172, 178, 184, 186, 188, 192, 194, 197, 204,

215, 216, 221, 366
nodicoUis (Hamotus) 331
nodicornis 184

nodifera (Cryptorhinula) 180
nodosa (Euteleia) 201
nodosa (Raxybis) 157
Nodulina 153

nominata (Reichenbachia) 148
notonoda (Sebaga) 44-45, 48
Nylanderia 294

oberthiiri (Arhytodes) 347
oberthiiri (Phtegnomus) 84
oberthiiri (Reichenbachia) 147
obesa (Reichenbachia) 141
obesum (Actinoma) 108
obesus (Eremomus) 134
obliquus (Scalenarthrus) 173
obnubila (Reichenbachia) 148
obscurus (Thesium) 93
octopunctatus (Eurhexius) 82
Oedipus 363

Oedipus (Cryptorhinula) 180
oglobini (Fustiger) 358
Ogmocerus 283, 284
Oligota 14, 19
Omalinae 29
Omalium 14
Oniscidae 375
opacus (Pselaphellus) 287
opimus 13, 308
optatus (Rhexius) 83
Oribatidae 3, 214
orion (Arthmius) 231
Oropus 63

ovipennis (Euphalepsus) 259
Oxarthrius 240-246, 249
Oxytelinae 15, 16
Oxytelini 14, 19, 29, 35

pacificus (Metopiosoma) 205

Paederinae 18, 19

pallidum 107

pallidus (Jubus) 58

pallipes (Pselaphellus) 287

papal cone 18

palpalis (Tyropsis) 299

palpi, see labial, maxillary

Panabachia 153

Panama 3, 362, 363, 364, 366, 367, 368, 369,

373
Panama Canal Zone 367,

see Barro Colorado
panamaensis 213

panamaensis (Batrybraxis) 280-282
panamensis (Euphalepsus) 258
Panaphantus 89
Panaramecia 63, 67, 94-97
Paradrasinus 181-182, 185
Paraguay 367, 368, 369, 370, 371
parallelus (Arthmius) 232
paramo 365
Parasitidae 3
Paratrechina 353, 358
parmata (Melba) 121

parviceps (Eurhexius) 81

parviceps (Hamotus) 329

parviceps (Reichenbachia) 141

parvipalpis (Hamotus) 330

pallida (Eupsenina) 130-133

patruelis (Arthmius) 232

Paussidae 5, 19

Paussiger 350

Pearl Islands 367

pectinicornis (Scalenarthrus) 173

pectoralis (Cercoceroides) 336

pedestrianus (Arthmius) 230

penis, see genitalia

peniculus (Arthmius) 232

penita (Reichenbachia) 153

pentachiroides (Reichenbachia) 142

perforatue 285

perforatus 283

perforatus (Goniacerus) 285

Pernambuco 365

Peru 367, 368, 369, 370

peruvianus (Arthmius) 232

petrunkevitchii (Dalmoburis) 266-270

Phalepsoides 259

Phalepsus 295, 297-298

Phamisus 62, 332

Phamisulus 332

phantasma (Syrbatus) 237

GENERAL INDEX

399

Pheidole 357
Phoberus 134
phorecy 352
Phtegnomus 84
Phybytharsis 274-276
phylogenesis

aedeageal 15-17

clavigerine 350-356

euplectine 65-66

foveal 24-28

tyrine 350-356
picea (Achillia) 156
pilicornis (Euphalepsus) 258
pilifera (Tyropsis) 299
pilopius 11, 16, 21, 22, 24, 28, 293-294
pilosa (Reichenbachia) 141
pilosella 141

pilosella (Reichenbachia) 141
planiceps (Decarthron) 199
planiceps (Pseudohamotus) 337
planifrons (Arthmius) 233
planifrons (Decarthron) 199
platycerus (Arthmius) 230
plicatulus (Bythinophysis) 264
plicicollis (Arthmius) 230
politissimus (Pselaptus) 175
politus (Eupsenius) 129
Ponera 358
population 373-377
praeclara (Achillia) 157
praeses 299
Prenolepis 294
preparation 8-11
prepectoid area 23, 26
primarius (Arthmius) 230
princeps (Iteticus) 248
Proctotrupidae 22
productus (Arthmius) 233
pronotal foveae 25
Proplectus 63, 107
Prosagola 36

prosternum 22-23, 24, 25
Pselaphellus 287
Pselaphidae, definition of 29-30

phylogenesis, see

species, see
Pselaphinae 8, 18, 34-349
Pselaphini 23, 26, 29, 31, 33, 286-287
Pselaphiscnus 29
Pselaphocompsus 337-338
Pselaphomorphus 40
Pselaphus 12, 18, 20, 21, 29, 156, 157, 286-

287, 298, 362
Pselaptus 173-175
Pseudacerus 350
Pseudofustiger 353
Pseudohamotus 336-337
Pseudophanius 337
Pseudoplectus 108

Pseudotrimium 65, 108
Pseudotychus 338
Pteracmes 98
Pteroplectus 64, 97
Ptiliidae 14, 375
pubescence 21-22, 338, 350, 351
pubescens (Aporhexius) 73
pubescens (Reichenbachia) 139
pubescens (Rhinoscepsis) 89
pubiventris (Hamotus) 331
Puerto Rico 367, 368, 369
pullus (Dalmodes) 263
pumilus 98
puna 365

punctatissimus (Phalepsoides) 259
punctatum (Decarthron) 199
punctatus (Arthmius) 233
punctatus (Pselaphocompsus) 338
punctatus (Jubus) 58
puncticeps (Achillia) 157
puncticollis (Batoctenus) 253
puncticollis (Euphalepsus) 259
punctipennis (Batrybraxis) 282
punctipennis (Bythinophysis) 264
punctipennis (Hamotus) 329
punctulatus (Hamotus) 332
punctulatus (Jubus) 58
punctulum (Xybarida) 163
pupation 22, 268, 274, 276, 321
pusilla (Xybarida) 163
putzeisi 81
putzeitsi 81

putzeysi (Eurhexius) 81
Pycnoplectus 26
pygmaea (Reichenbachia) 153
Pyxidicerini 31, 37

Q
quadraticeps (Decarthron) 199
quadraticeps (Mitona) 176
quadraticeps (Xybaris) 179
quadratus (Jubus) 59
Quadrelba 120
quadriceps (Achillia) 156
quadrifoveatum (Decarthron) 199
quadrifoveatus (Eurhexius) 81
quadrifoveata {Ramelbida) 113
quadrioculatus (Syrbatus) 237
quadripunctatus (Arthmius) 231
quasimoda (Barrometopia) 211-213
quinquefoveolatus 231
quinquesulcatus 248

Radama 350

raffrayi 358

raffrayi (Ctenisis) 293

raffrayi (Sebaga) 41-44, 48

400

NEOTROPICAL PSELAPHIDAE

Rafonus 26

rain forest 369

Ramecia 15, 64, 93, 97

Ramelhida 112-113

Rajneloidea 121

ranavalonae 357

range factor 376

Raxybis 19, 157

recens (Euteleia) 201

Reduviidae 375

regius (Iteticus) 248

reichei (Hamotus) 332

reichei (Metopioxys) 210

reichei (Reichenbachia) 147

reicheiana 147

reichenbachi (Phamisus) 62

Reichenbachia 3, 11, 16, 21, 133, 135-153,

154, 159, 362, 366
reitteri 205, 232
reitteri (Arthmius) 231
reitteri (Eurhexius) 82
reitteri (Euphalepsus) 259
reitteri (Fustiger) 358
reitteri (Phamisus) 62
resectus (Arthmius) 233
restitutum (Decarthron) 199
Rhexidius 1, 3, 13, 17, 22, 28, 67, 73, 74
Rhexinia 67, 72, 73, 74
Rhexius 3, 28, 74, 81, 81-83, 88
rhinoceros (Arthmius) 232
Rhinoscepsis 3, 15, 26, 28, 29, 63, 66, 85-89
Rhinosceptis 85
Rhynchoclaviger 350
Rhynoscepsis 85, 89
richteri 40, 81, 210, 293
richteri (Rhinoscepsis) 89
riparius 17
river

Amazon 365, 371

Chagres 369

Esequibo 365

Madeira 364

Orinoco 365, 371
rivularis (Oxarthrius) 246
robustus (Hamotus) 329
rossii (Hamotus) 332
rostellatus 230
rostratus (Hamotus) 329
rubecula (Reichenbachia) 153
rubra (Reichenbachia) 141
rubriculus (Arthmius) 231
rubripenne (Decarthron) 199
rubripennis (Arhytodes) 347
rubripennis (Eurhexius) 82
rufipes (Arthmius) 232
rufus 127

rugiceps (Arthmius) 233
rugiceps (Syrmocerus) 240
rugicollis (Jubus) 59

rugicornis (Cercoceropsis) 334
rugipes (Euphalepsus) 258
rugosicollis (Oxarthrius) 246
nigosus (Hamotus) 330
rugosus (Oxarthrius) 246
rugulosum (Decarthron) 199
rugulosus (Eurhexius) 82
Rybaxis 5, 13, 22, 88
rybaxoides (Dalmodes) 263
Rytus 338

sabomba (Arthmius) 219-222, 230

Sagola 36

sahlbergi (Xybaris) 179

Salagosa 36

sallaei (Reichenbachia) 146

sallei 146

sandersoni (Hamotus) 321-322, 330

sanguinifer 331

sanguinipes (Hamotus) 331

sarcinaria (Reichenbachia) 142

saucium (Decarthron) 200

Scalenarthrus 3, 160, 163, 165-173, 174

scaphiger (Arthmius) 230

Scarabaeidae 375

Sceloporus 363

schaufussi 58

schaufussi (Bryaxina) 159

schaufussi (Bythinophysis) 264

schaufussi (Cryptorhinula) 180

schaufussi (Decarthron) 200

schaufussi (Pteracmes) 98

schaufussi (Scalenarthrus) 173

schaumi 17

Schistodactylini 19, 31

schmidti (Fustiger) 357

schmitti (Decarthron) 199

schwarzi (Fustiger) 357

scitus (Syrbatus) 237

Scotoplectus 29

sculpturatus (Pselaphomorphus) 40

scydmaenilla (Sebaga) 45, 48

Sebaga 41-48

secondary sexual characters 29, 39, 47, 48,
51, 57,'80, 81, 83, 96, 99, 136, ff. 158, 159,
162, 166, 172, 176, 186, 192, 194, 196, 204,
212, 215, 216, 221, 244, 246, 268-269, 274,
276, 281, 284, 302, 306, 310, 324, 326, 327,
340, 351. 356

seeversi {Dalmonexus) 272-274

seeversi (Metopioxys) 207-208, 210

semihyalinus 82

semipunctatus (Iteticus) 248

semipunctatus (Jubus) 58

semisanguinea (Reichenbachia) 141

semisulcatus (Arhytodes) 347

separabilis (Scalenarthrus) 173

setifer (Goniacerus) 285

GENERAL INDEX

401

setipes (Hamotus) 330
sexdens 246, 348, 349
sexpunctatus (Eurhexius) 81
sharpi (Thesium) 93
signatus 101
signifer 101

signifera (Euplectus) 101
silvaticus (Metopiellus) 205
similare (Decarthron) 199
simoni (Acotebra) 107
simoni (Ephimia) 290
simoni (Eurhexius) 81
simoni (Jubomorphus) 41
simoni (Jubus) 59
simonis 81

simplex (Batoctenus) 253
simplex (Bythinogaster) 203
simplex (Cercoceroides) 336
simplex (Decarthron) 198
simplex (Hamotus) 330
simplex (Lioplectus) 99
simplex (Oxarthrius) 246
simplex (Scalenarthrus) 173
simplicicornis (Arthmius) 231
simplicifrons (Syrbatus) 237
simplicior (Arthmius) 230
simulans (Achillia) 156
simulatrix (Pselaptus) 175
singularis (Arthmius) 231
singularis (Hamotus) 330
sinuatus (Jubus) 59
size 14

smithi (Fustiger) 357
social arhythmicity 352
Solenopsis 40, 81, 210, 293, 3oS
solitarius (Euplectus) 101
Solivagus 237

Sonoma 15, 16, 18, 26, 28, 35
soror 237

soror (Decarthron) 198
soror (Hamotus) 330
South America 363, 370

subregion 370, 371, 373
Spain 292

spathulatus (Syrbatus) 237
species

by authors 366

by neotropical countries 367

estimated in neotropics 376

in mold 1-4

nearctic 360

neotropical 360

new 378-380

on Barro Colorado 372

phj'logenesis, see

myrmecophilous, see

termitophilous, see
specularis (Melba) 120
spiculatus (Metopioxys) 210

spiniceps (Xybaris) 179

spinicollis 248

spinicoUis (Jubus) 58

spinipes 13, 288

spinosum (Decarthron) 199

spinosus 17, 199

spinula (Tyropsis) 299

spuria (Reichenbachia) 153

squamosus (Decarthron) 199

Staphylininae 18

Staphylinidae 5, 14, 18, 19, 20, 21, 25, 29,

375
staphylinoides 19
Steninae 18, 19

sternadens (Oxarthrius) 242-244, 246
sternal foveae 25-28
sternalis (Cercoceroides) 335-336
sternalis (Hamotus) 329
sternalis (Pselaptus) 175
Stratus 38, 62

strictocornis (Pseudofustiger) 353
strigilators 4

stroheckeri (Reichenbachia) 149-151
Strombopsis 154
St. Thomas 367
stultor 231

stussineri (Reichenbachia) 148
St. Vincent 367
subacuminatus (Eurhexius) 82
subcarinatus (Metopioxys) 210
subcarinatus (Scalenarthrus) 173
subdendrus (Verabolus) 104-107
subfoveolatus (Reichenbachia) 141, 148
subfusus (Arthmius) 231
subglobosus (Phalepsus) 298
sublaminatus (Syrbatus) 237
sublyratus (Syrbatus) 237
subnitida (Ephimia) 290
subnitida (Reichenbachia) 141
subopacus (Jubus) 58
subrectus (Jubus) 59
subspeciation factor 374
subtilis (Hamotus) 329
sulcatula 116

sulcicornis (Aploderina) 332
sulcifrons (Eupsenina) 133
sulcifrons (Goniastes) 285
sulcipalpus (Hamotus) 330
sulcipes (Decarthron) 198
supratentorium 20
sus (Arthmius) 232
suturale (Decarthron) 200
Surinam, see Dutch Guiana
symphiles 5

symphiloid synoeketes 4
synechthrans 4
synoeketes 4

Syrbatus 216, 233-237, 238, 248
Syrmocerus 216, 233, 238-240

402

NEOTROPICAL PSELAPHIDAE

Tabanidae 368

Tamaulipas 363

tarsi 19, 63, 157, 158, 176, 343, 351

taxonomic density 369, 370

temporalis (Melba) 121

Tenebrionidae 375

tennesseensis 7

tenuicornis (Reichenbachia) 141

tenuis 116

Termes 213

termites 84, 163, 213, 246, 274, 279, 301, 303,

338, 340, 376
termitocoles, see termitophiles
termitophiles, as for termites
terranus (Jubus) 49-52, 58
testaceus 352

testudineus (Fustiger) 358
Tetracis 292
Tetratomium 205
tetratomus (Jubus) 58
Thesiastes 3, 15, 22, 97-98, 99
Thesium 15, 21, 67, 89-93, 278
thomasi (Hamotus) 328-329, 332
thoracica 113, 116
Thysanoptera 22
tibialis (Arthmius) 231
tibialis (Euphalepsus) 259
tibialis (Hamotus) 330
Tmesiphorus 1, 5, 7, 11, 17, 22, 26, 27, 28
tolulae 15, 16, 26
tomentosum (Decarthron) 199
Tomoplectus 107
torticorne (Decarthron) 199
torticornis (Bryaxina) 159
trabeculatus (Metopioxys) 210
transversalis (Arthmius) 232
transversalis (Hamotus) 330
transversalis (Syrbatus) 237
transversiceps (Bythinoplectus) 37
triangularis (Arthmius) 232
triangulifera (Reichenbachia) 153
triangulifera (Xybaris) 179
tricarinatus (Euphalepsus) 258
trichomas 6, 21

Trichonychini 1, 17, 31, 32, 63-64, 107
Trichonyx 63, 72, 264
tricuspidatus (Metopioxys) 210
trifoveata (Euteleia) 201
trifoveatus (Arthmius) 233
Trilobitideini 18
Trilobitideus 18
trimiiforme (Actium) 108
trimiodes (Eurhexius) 81
Trimiodina 108
trimioides 81

trimioides (Cryptorhinula) 180
Trimiomelba 20, 21, 22, 28, 65
Trimioplectus 15

Trimiopsis 63, 108-111, 113, 120, 121

Trimiosella 65, 112

Trimium 108, 113

Trinidad 365, 371

trinodulus (Syrbatus) 237

tripunctata (Achillia) 156

tripunctatus 233

tritomum (Decarthron) 198

tritomus (Hamotus) 331

Troglamaurops 29

troglocera (Xybaris) 179

Tropic of

cancer 31, 308, 309, 362, 369, 370

Capricorn 308, 369
tropicum (Decarthron) 200
trouessarti (Jubus) 58
truncata (Reichenbachia) 153
truncaticeps (Arthmius) 231
tuberculatus (Cercoceroides) 336
tuberculifer (Pselaptus) 175
tubericornis (Reichenbachia) 142
turalbus (Hamotus) 22, 330
turneri (Jubus) 54-58
Tychini 16, 17, 33, 111, 260-282, 283
Tychus 12, 22, 260

Tyrini 17, 18, 19, 24, 33, 289, 295-342, 348
Tyrogatunus 15, 23, 29, 303, 338-340
Tyropsis 156, 157, 298-299
Tyrus 15, 17, 303, 308

U

ulkei 7

umbilicatus (Goniaceroides) 285

undecimtymjms (Scalenarthrus) 170-173

unifoveolatum (Decarthron) 199

United States 368, 369

ursinus 38, 62

ursulus (Hamotus) 331

Uruguay 367, 368, 369, 370

vagepunctatus (Phalepsoides) 259
validicornis (Achillia) 157
valdiviensis (Achillia) 157
valdiviensis (Tyropsis) 299
Venezuela 362, 367, 368, 369, 371
ventralis (Eurhexius) 81
ventricosa (Melba) 121
ventricosus (Scalenarthrus) 173
venustulus (Bythinophysis) 264
Verahohis 104-107
Vera Cruz 362, 363, 364
veracruzensis (Fustiger) 17, 354-357
veracruzensis (Hamotus) 325-326, 332
versicolor (Rhexinia) 73
Vertelha 120

vertexal foveae 20-21, 270, 280, 281
verticicornis (Ectopocerus) 185

GENERAL INDEX

403

vesiculifer (Hamotus) 330
vestita (Endytocera) 62
vestitus (Arhytodes) 347
vestitus (Eiirhexius) 81
vestitus (Neotyrus) 303
vestitus (Pselaphellus) 287
vicinus (Hamotus) 331
villosulus (Stratus) 62
villosus (Lethenomus) 305
vincentiana (Reichenbachia)
Virgin Islands 367, 368, 369
vitiensis 358
vividus (Arthmius) 232
vulgaris (Phalepsus) 298
vulnerata (Panabachia) 153
vulneratum (Decarthron) 199
vulneratus (Arthmius) 232
vulpinus (Hamotus) 331
vulpinus (Jubus) 58

W

walkeri 274
warblers 373
wasmanni 352, 358
Wasmannia 347
wasmanni (Arthmius) 232
Water Island 367
westwoodi (Goniastes) 285
williamsi {Panaramecia) 94-97

142

Windward Islands 362, 367, 368, 369
wings, see lights

X

Xenodusa 21

Xherius 72, 73

Xybarida 19, 154, 160-163, 174

xybaridoides (Cryptorhinula) 180

Xybaris 19, 154, 160, 174, 175, 176-179

xybaroides 180

Yucatan 365, 371

zeteki (Barroeuplectoides) 102-104

zeteki (Tyrogatunus) 339-340

ziegleri 17

zimraermani (Pilopius) 293, 294

Zolium 113

zonalis (Eurhexius) 78-80, 82

zones, see altitude

zoogeography 89, 97, 99, 113, 127, 135-136,
154, 166, 176, 186, 188, 204, 214, 216, 233,
238, 240, 246-247, 253, 283, 285, 288, 289,
291, 294, 308, 309, 310, 330, 331, 332, 352,
356
general 360-377

Plates

Index to Plates

Adranes lecontei, IV

Anoplobraxis guianensis, XIX

Apharus. XX

Aploderina, XX

Arhytodes achillei, VI, XIX

Arthmiiis sabomba. VI

Barroeuplectoides zeteki, XV

BaiTOJuba albertae, XVIII

Barrometopia quasimoda, XVIII

Batoctenus barberi, XVIII

Batrisodes denticollis, II

Batrisodes furcatus, I

Batrisodes globosus, I

Batrisodes monstrosus, II

Batrisodes schaumi. II

Batrisodes riparius, I

Berdiira dentipalpa, VII

Berdura excisula, VII

Bibloplectus ruficeps, XI, XII

Cedius cruralis. Ill

Cedius spinosus. III

Cedius ziegleri, III, IV

Ceophyllus monilis, II, IV

Cercoceroides, XX

Cercoceroides laticeps, VI

Cercoceropsis, XX

Cercocerulus, XX

Cercocerus batrisoides, IV

Cylindrarctus americaniis, I

Cvlindrarctus longipalpis, I, XVII

Dalmosella, XII

Dalmosella tenuis, IV, XI, XII

Decarthron chichion, VI. XVI

Decarthron euspinifrons, XVIII

Decarthron noctiphoton, XVI

Decarthron tropicum, VII

Euphalepus, XV

Euphalepsus myrmecocolus, XVIII

Euplectus difiicilis, XII

Euplectus interruptus. V, XII, XIII

Eupsenius glaber, XIII, XIV

Eurhoxius zonalis, VIII

Eutyphlus prominens, XII

Fletcherexius macrodactykis, VIII

Fustiger clavipilis, XV

Fustiger haytiana, XV

Fustiger veracruzensis, II, VI, VII, XVII,

XIX
Hamotocellus, XX
Hamotus, XX
Hamotus electrae, XVII
Hamotus fletcheri, XVII
Hamotus monachus. XVII. XIX
Hamotus thomasi. VI. XVII
Hamotus tibialis. XVII
Hamotus turalbus, XVII. XIX
Hamotus veracruzensis, VI, XVII '

Jubus turneri, VII
Juxtahamotopsis. XX
Lethenomus. XX
Melba. XII

Melba thoracica, IV. XI. XII
Melba sulcatula. XI
Melbamima clavicornis. VI
Metopioxys mattogrossoensis, XVIII
Panaramecia williamsi. XV
Phalepsus. XX
Phloeocharis subtilissima, I
Pilopius lacustris. IV, V
Pilopius piceus, I
Pselaphocompsus, XX
Pselaphus bellax, IV
Pselaphus erichsonii. IV
Pselaphus fustifer, IV
Pselaphus longiclavus, IV
Pseudohamotus, XX
Reichenbachia appendiculata. XVI
Reichenbachia diversula. XVI
Reichenbachia callosa, XVII
Reichenbachia carinifer, XVII
Reichenbachia falsa. XVII
Reichenbachia foveartlira, XVI
Reichenbachia glolmldsa. XVII
Reichenbachia grenaden-i.'^. XVII
Reichenbachia guatemalensis, XVI
Reichenbachia latipes, XVI
Reichenbachia mexicana, XVII
Reichenbachia jiluridcntata. I
Reichenbachia sarcinaria. XVII
Reichenbachia stroheckeri. XVI
Rhexidius canaliculatus. V. VIII
Rhexius inscid]3tus. VIII
Rhinoscepsis bistriatus. IX, X
Rhinoscepsis falli. XVIII
Rybaxis clavata. IV
Scalenarthrus undecimtympus. VII
Sebaga centralis. XV
Sebaga notonoda. XV
Sebaga raff ray i, XV
Sebaga scvdmaenilla, VII
Sonoma tolulae, V, VI, XIII
Svrmocerus guarinus. XIX
Tmesiphorus costalis. II. IV. V
Trimiomelba dubia. V, XI. XII. XIII
Trimioplectus obsoletus. XII
Trimiopsis furcalis. XIX
Tychus minor. IV
Tyrogatunus, XX
Tyrogatunus zeteki. III. XVII
Tyropsis. XX
Tyrus humeralis, III
Xybaris funiculis, VII
Xybarida nasicola, VII

Plate I

INTRAFAMILY VARIATION OF THE PSELAPHID AEDEAGUS

a (accessory piece) ; ad (apical diaphragm) ; bb (basal bulb of median
lobe) ; bd (basal diaphragm) ; bm (bulbar muscles) ; 11 (lateral lobes) ;
ml (median lobe) ; vl (ventral lobe) ; pp (penial plate).

Fig. I. A staphylinid aedeagus, Phloeocharis subtilissima Mann, subfamily
Oxytelinae, tribe Phloeocharini. Redrawn from Blackwelder, 1936.
Lateral view. Included for comparison ; see text.

Fig. 2. Reichenbachia pluridentata Park. Lateral view.

Fig. 3. Reichenbachia pluridentata Park. Dorsal view. 0.475 x 0.225 mm.

Fig. 4. Pilopius piceus (LeConte). Lateral view. This and subsequent lateral
views have the morphological dorsal side uppermost, and the apical
(morphological posterior) end to the right.

Fig. 5. Pilopius piceus (LeConte). Last sternite, with minute penial plate par-
tially exserted.

Fig. 6. Pilopius piceus (LeConte). Aedeagus, dorsal view. 0.225 x 0.1 mm.

Fig. 7. Pilopius piceus (LeConte). Apical view.

Fig. 8. Cylindrarctus longipalpis (LeConte). Dorsal view. 0.389 x 0.201 mm.
Note penial plate exserted to right, the bilaterally symmetrical
bulbar muscles, and the ventral lobe.

Fig. 9. Cylindrarctus americanu^ Schaufuss. Dorsal view similar save for dif-
ference in apical end of ventral lobe.

Fig. 10. Cylindrarctus americanus Schaufuss. Lateral view.

Fig. 11. Batrisodes furcatus (Brendel). Dorsal view. 0.28 x 0.08 mm.

Fig. 12. Batrisodes riparius (Say). Dorsal view. 0.201 x 0.134 mm.

Fig. 13. Batrisodes globosus (LeConte). Dorsal view. 0.233 x 0.133 mm.

Fig. 14. Batrisodes globosus (LeConte). Lateral view.

Plate I

(po-rk

Plate II

INTRAFAMILY VARIATION OF THE PSELAPHID AEDEAGUS

(Continued)

Fig. 1. Batrisodes denticollis (Casey). Lateral view.

Fig. 2. Batrisodes denticollis (Casey). Dorsal view. 0.275 x 0.15 mm.

Fig. 3. Batrisodes schaumi (Aube). Lateral view. Note membranous lateral
lobe.

Fig. 4. Batrisodes schaumi (Aube). Dorsal view. 0.435 x 0.167 mm.

Fig. 5. Batrisodes monstrosus (LeConte). Dorsal view. 0.49 x 0.268 mm. Note
extreme asymmetry; the accessory piece which moves to the right
on contraction of the asymmetrical bulbar muscles; the arcuate,
bifurcated extension of the median lobe; the membranous lateral
lobes.

Fig. 6. Fustiger veracruzensis Park. Dorsal view, from paratype. 0.39 x 0.134
mm. Note homologies with ceophylline aedeagus.

Fig. 7. Ceophyllus monilis LeConte. Dorsal view.

Fig. 8. Ceophyllus monilis LeConte. Lateral view.

Fig. 9. Tmesiphorus costalis LeConte. Lateral view.

Fig. 10. Tmesiphorus costalis LeConte. Dorsal view. 0.4 x 0.25 mm.

Fig. 11. Tmesiphorus costalis LeConte. Apical view.

Plate II

Plate III

INTRAFAMILY VARIATION OF THE PSELAPHID AEDEAGUS
{Continued) AND THE PENIAL PLATE

Fig. 1. Tyrus humeralis (Aube). Male pygidial area. S6 (sixtli sternite); To
(fifth tergite) ; pp (penial plate).
Tyrus humeralis (Aube ) . Female pygidial area.

Tyrus humeralis (AubeL Aedeagus, dorsal view. 0.381 x 0.167 mm.
Tyrus humeralis (Aube). Right lateral view. (Reversed drawing)
Tyrus humeralis (Aube). Left lateral view. (Normal orientation)
Tyrogatunus zeteki Park. Ventral abdominal surface: female on left;
male on right. Drawn from types. Note remarkable long, matted
pubescence, shown on right, pp (penial plate, note the homology
with Tyrus ) .
Fig. 7. Cedius ziegleri LeConte. Aedeagus, dorsal view. 0.502 x 0.167 mm.
Note that the asymmetrv is to the left. The penial plate swings
to the left.
Fig. 8. Cedius spinosus LeConte. Dorsal view. 0.361 x 0.124 mm. Note that
the asymmetry is to the right. The penial plate swings to the right.
Fig. 9. Cedius cruralis Park. Dorsal view. 0.335 x 0.134 mm. Note that the
asymmetry is to the left. The penial plate swings to the left.

Fig.

2.

Fig.

3.

Fig.

4.

Fig.

5.

Fig.

6.

Plate III

Plate IV

I. PUBESCENCE

Adranes lecontei Brendel
Fig. 1. Abdominal trichome. 0.25 mm.
Fig. 2. Bifurcated seta from disk of elytron. 0.09 mm.
Fig. 3. Bifurcated seta from disk of elytron. 0.09 mm.
Fig. 4. Seta from apical margin of elytron. 0.072 mm.
Fig. 5. Elytral trichome. 0.198 mm.

Pilopius lacustris Casey
Fig. 6. General integumental scale of body and legs. 0.03 mm.
Fig. 7. Scale with recurved tip, from posterior elytral margin. 0.07 mm.
Fig. 8. Spade scale found on posterior elytral margin, basal elytral foveae^
sternal foveae and depressions, ventro-posterior area of head and
mesial faces of prothoracic coxae. 0.31 mm.
Fig. 9. Asperate scale. A form of scale which is set on an asperity found on

ventral faces of prothoracic trochanter and femur. 0.041 mm.
Fig. 10. Umbrella seta, on processes of maxillary palpi. 0.072 mm.
Fig. 11. Type of very minute seta on segments of maxillary palpi. 0.009 mm.

Tmesiphorus costalis LeConte
Fig. 12. Capitate seta on processes of maxillary palpi. 0.009 to 0.01 mm.

Tychus minor LeConte
Fig. 13. Normal seta of eleventh antennal segment. 0.04 to 0.07 mm.
Fig. 14. Antennal cone of eleventh antennal segment. 0.54 to 0.72 mm.

Rybaxis clavata Brendel
Fig. 15. Asperate setae from mesio-ventral face of eleventh antennal segment

of male. 0.54 to 0.07 mm.
Fig. 16. Normal seta of antenna. 0.04 to 0.05 mm.

Dalmosella tenuis Casey
Fig. 17. Distal cone on fourth segment of maxillar\" palpi. 0.009 to 0.01 mm.
Fig. 18. Antennal cone on eleventh segment of antenna. 0.01 to 0.04 mm.

Melba thoracica (Brendel)
Fig. 19. Antennal cone on eleventh antennal segment. 0.04 to 0.05 mm.
Fig. 20. Normal seta of antenna. 0.01 mm.
Fig. 21. Capitulate seta of ventral area of head.

II. MAXILLARY PALPI

Fig. 22. Pilopius lacustris Casey. Note the remarkable development of umbrella
setae on the processes of segments II, III, IV. Slide mount, 450
diameters.

Fig. 23. Pselaphus longiclavus LeConte. Fourth segment, lacking normal pu-
bescence in figure.

Fig. 24. Pselaphus Justifer Casey. Fourth segment, lacking normal inibesccnce
in figure.

Fig. 25. Pselaphus erichsonii LeConte. Fourth segment, lacking normal pubes-
cence in figure. Note distal groove at base of palpal cone.

Fig. 26. Pselaphus bellax Casey. Fourth segment, lacking normal pubescence.
Note characteristic asperities of segment.

Fig. 27. Ceophyllus monilis LeConte.

Fig. 28. Cedius ziegleri LeConte.

Fig. 29. Cercocerus batrisoides LeConte. Note that the palpal cone is set ob-
liquely within the apex of the fourth segment, and in a broad shallow
groove on the mesial face. This arrangement is rare among tem-
perate, but common in tropical tyrine pselaphids.

Fig. 30. Tmesiphorus costalis LeConte.

Fig. 31. Tychus minor LeConte.

Plate IV

10

O I

^4

^ 5

ctCD

^

9 i=
12 &-

14

27

25
24
25
26

Plate V

Fig. 1. Primitive Generalized Diagram of Pselaphid mesosternal and meta-
sternal field. P, prepectoid area; MOS, mesosterniim ; MOES, meso-
episternum; MOEP, mesoepimeron ; MOCC, mesosternal ooxal cavi-
ties; MES. metasternum; MEES, metaepisternum.
I, Prepectoid foveae. IV. Lateral mesocoxal foveae.

II, Lateral mesosternal fovene. V, Posterior mesocoxal foveae.
Ill, Median mesosternal foveae. VI, Metasternal foveae.

Fig. 2. Sonoma iRafonus) tolulae (LeConte).

Mesosternal and metasternal field. Legend as in Fig. L Note that
this species has eleven foveae, that is, all are present save the meta-
sternal foveae, which are medianly fused into one fovea.

Fig. 3. Euplectus iPycnoplectus) interruptus LeConte.

Mesosternal and metasternal field. Legend as in Fig. 1. Of the three
pair of foveae present (II, III, IV), note that two are pubescent
(II, IV), indicated diagrammatically by short straight lines in the
mouth of the fovea. Foveae III externally might pass unnoticed, the
foveal mouth is so inconspicuous. Fig. 3a. Shows Foveae II and III
in a transparent integument, to illustrate the characteristic whorling
of the walls of the foveae. Note (a) in Fig. 3, of attachment to
mesothoracic wing.

Fig. 4. Trimiomelba diibici (LeConte). Male.

Mesosternal and metasternal field. Legend as in Fig. L Two pair of
foveae present (II, V) , while III is median and unpaired. The foveae
are all represented as transparent, so that the whorling of their walls
can be observed ; II are remarkable in size, and in cleared slides these
foveae meet in the midline, above median III, but do not inter-
communicate. Note the metasternal furca (MEF) indicated by
dotted lines.

Fig. 5. Tmesiphorus costalis LeConte.

Mesosternal and metasternal field. Right side of figure presented
with transparent integument (cold KOH 50% for 14 hours, 700 di-
ameters magnification) to show the mesosternal furca (MOF) and
metasternal furca ( MEF ) , as well as the whorled tubes of the foveae
II and IV. Note relation of mesosternal furca to fovea IV. Fovea III
is median and unpaired. All foveae (II, III, IV) and pubescent.

Fig. 6. Rhexidius canaliculatus (LeConte) and Rhexius insculptus LeConte.
In these two trichonychine species fovea II of the mesosternal field
is large but typical of Pselaphidae. However, in fovea III on each
side the fovea in reality is bifurcated into two foveae with a common
orifice. This condition is shown in the figure. Slide mount, 4(!0 di-
ameters.

Fig. 7. Pilopius lacustris Casey.

Mesosternal and metasternal fields. Legend as in Fig. 1. MOF, meso-
sternal furca; MEF, metasternal furca; MOC, mesothoracic coxa;
T, mesothoracic trochanter; F, mesothoracic femur; MEC, meta-
thoracic coxa. Note that foveae II and III are paired, while fovea VI
is median and unpaired. All foveae are nude. Fovea VI is shown with
transparent integument to show whorling of fovea. The character-
istic scale pubescence (a) is enlarged to show its elongate, thin
paddle-shape, the deep puncture in which it is set, and the long tube
or air space which runs from its tij) through the base of the bulb of
the scale into the integument where it expands into what appears
to be a sac.

Fig. 7a. Foveae II and III of Fig. 7, enlarged at 700 diameters to show whorled
walls in the prepectoid area.

Plate V

4 P i-l

-I

s.

Ez:

'"■"^xn""^

/^OEP^/f /

7° s\

MO 5

*^

7

:2r T

M

-nEES

MEEsJ

^V^

/

ME5

J

2

MEEP?

MtES

Plate VI

TRIBAL KEY CHARACTERS

Fig. 1. Sonoma tolulae (LeConte). Anterior tarsus.

Fig. 2. Hamotus thomasi Park. Posterior tarsus, from type.

Fig. 3. Arhytodes achillei Park. Posterior tarsus, lateral view, from type.

Fig. 4. Arhytodes achillei Park. Posterior tarsus, dorsal view, from type.

Fig. 5. Fustiger veracruzensis Park. Three-segmented antenna (only the last

two are visible from above). Drawn from female paratype.
Fig. 6. Dccarthron chichion Park. Ten-segmented antenna. Drawn from male

paratype.
Fig. 7. Hamotus veracruzensis Park. Eleven-segmented antenna. Drawn from

male 1 olotype.
Fig. 8. Cercoceroides laticeps Raffray. Intermediate troclianter-femur artic-

ultion. Drawn from the female.
Fig. 9. Arthmius sabomha Park. Intermediate trochanter-femur articulation.

Drawn from female paratype.
Fig. 10. Melhamima clavicornis Raffray. An eleven-segmented antenna with

asvmmetricallv articulated tenth antcnnomere. Modified after

Raffrav, 1909.'

Plate VI

J

ffil

%^

Plate VII
MISCELLANEOUS CHARACTERS

Fig. 1. Jubus turneri Park. Ventral aspect of head. Note especially the V-
shaped jubine carina, and the expanded mentum with its jubine side-
pieces (stippled). Paratype male from a slide at 700 diameters.

Fig. 2. Scalenarthrus undecimtympus Park. Dorsal aspect of head. The left
side shown as opaque, from point-mount. Note the tubercle at ex-
ternal mandibular base. The right side from slide-mount at 400
diameters; the antennal acetabulum is shown as transparent to indi-
cate the pselaphoid method of antennal articulation; the funnel-
shaped fovea is shown as a stippled invagination; the tentorial arm
is shown connecting the vertexal and gular foveae.

Fig. 3. Scalenarthrus undecimtympus Park. Antenna. Slide at 400 diameters.

Fig. 4. Berdura dentipalpa Park. Maxillary palpus, type, from slide at 400
diameters.

Fig. 5. Berdura excisula Reitter. Maxillary palpus, after Raffray, 1908.

Fig. 6. Decarthron tropicum Fletcher. Posterior coxal articulation.

Fig. 7. Sebaga scydmaenilla (Sharp). Posterior coxal articulation.

Fig. 8. Fustiger veracruzensis Park. Ventral aspect of abdomen of female,
from paratype.

Fig. 9. Fustiger veracruzensis Park. Ventral aspect of abdomen of male, from
liaratype. Drawn on same scale as fig. 8.

Fig. 10. Xybarida nasicola Park. Carinal pattern of ventral surface of head.

Fig. 11. Xybaris funiculis Park. Carinal pattern of ventral surface of head.

Fig. 12. Scalenarthrus undecimtyynpus Park and Berdura dentipalpa Park.
Carinal pattern of ventral surface of head.

Plate VII

Plate VIII

MISCELLANEOUS TRICHONIFORMS

Fig. 1. Rhexidius canaliculatus (LeConte). Dorsal aspect.

Fig. 2. Rhexidius canaliculatus (LeConte). Head, lateral aspect.

Fig. 3. Rhexidius canalicidatus (LeConte). Head of male, note median

frontal cusp.
Fig. 4. Rhexidius canaliculatus (LeConte). Head of female, cusp absent.
Fig. 5. Rhexidius canaliculatus (LeConte). Penis. Note structural similarity

with penis of Dalmosella tenuis Casey, Plate XII.
Fig. 6. Rhexius insculptus LeConte. Sternites.
Fig. 7. Rhexius insculptus LeConte. Dorsal aspect.
Fig. 8. Rhexius insculptus LeConte. Prothoracic tarsus, 700 diameters.
Fig. 9. Rhexius insculptus LeConte. Maxillary palpus, 400 diameters.
Fig. 10. Eurhexius zonalis Park. Pronotum. From male paratypc.
Fig. 11. Fletcher exius macrodactylus (Fletcher). Pronotum. From paratvjie

U.S.N.M. No. 44612.

Plate VIII

Plate IX

Rhinoscepsis bistriatus LeConte

Fig. 1. Ventral view of head of female. Note the character of the mandible -
crenulate labrum; labium with labial palpus, mentum and sub-
mentum, maxillary palpus with cardo, stipes, lacinia and first seg-
ment of palpus; rudimentary, large-faceted eye, partially set in the
rudder-shaped ventral portion of the cephalic groove; right gular
fovea at point where gulo-genal suture disappears anteriorly, the
fovea representing externally the attachment of the right arm of
the supratentoriura where it joins the ventral surface of the head,
and this indicated by a pair of dotted lines; the broad "gular field.""

Fig. 2. Dorsal surface of head of female. Note anteriorly the approximate first
or basal antennal segments, with their dorsal articulation to the
front indicated by dotted circles ; the rough character of the integu-
ment; median longitudinal oval sulcus and strong longitudinal
median carina; the right vertexal fovea, with its attachment to the
right arm of the supratentorium indicated by dotted lines; the
rudimentary, large-faceted eye, partially set in the sigmoid dorsal
portion of the cephalic groove which ends posteriorly on each oc-
ciput; the medianly notched and posteriorly striulated character
of the base of the head.

Fig. 3. Seta found on the ventral surface of the head.

Fig. 4. Last four segments of right antenna of female.

Fig. 5. Distal (fourth) segment of right maxillary palpus showing the palpal
cone on the apex.

Fig. 6. Right lateral aspect of female, after treatment in cold 5% KOH for
two hours to soften the integument. Reading from right to left is
noted the typical pselaphid antenna of eleven segments with a
three-segmented club and the characteristic dorsal articulation of
the antenna to the head; beneath the excavated fronto-clypeal area
is seen the horizontally directed labrum and below the labrum the
long, arcuate mandible; the complex cephalic groove of the right
side is shown passing obliquely ventral to the right vertexal fovea
and turning abruptly ventral anteriad of the rudimentary eye,
which lies partly in the groove, and then passing anteriorly for a
short distance and expanding posteriorly, ending near the back of
the head; the compact prothorax with its large prothoracic coxa;
the rudimentary metathoracic wings; the elytron represented by a
straight line above the wing; the meso- and metathoracic coxae;
the abdomen with eight tergites discernible, of which the first two
are membranous and the last six are visible and sclerotized; six
pleurites and spiracles are present and nine sternites are indicated.

Fig. 7. Ventral aspect of prothorax of female showing the large basisternum
and confluent prothoracic coxal cavities (FCC). Note the well-
developed lateral prosternal foveae (LPF).

Fig. 8. Detail of the left Lateral Prosternal Fovea. Note the characteristic
whorling of the course of the fovea, when seen in slide mounts at
high magnification.

Fif. 9. Dorsal surface of mesothorax of female under high magnification, a.
mesoscutum; b. and c. elytral articulations on the scutellum and
side pieces; d. axillary cord of right elytron; e. small posterior por-
tion of mesoscutellum ("scutellum") which is visible between closed
elytra; f. mesoscutellum, showing the characteristic striulation;
g. mesoprescutum.

Plate IX

Q

7

Plate X

Rhinoscepsis bistriatus LeConte

Fig. 1. Metanotum of female, under high magnification, a.b. metascutum;
c.d. metascutelkmi ; e. rudimentary left metathoracic wing.

Fig. 2. Right elytron of female. Note characteristic striulation of the integu-
ment on the articular anterior surface, and the posterior margin. The
three basal foveae, named from left to right the sutural, discal and
humeral, are drawn under high magnification to bring out the char-
acteristic whorling of the lumen of the fovea into the integument,
a. The lock-notch which fits over the first visible pleurite and
sternite.

Fig. 2a. Right metathoracic leg of female, a. Coxa; b. Trochanter; c. Femur;
d. Tibia and e. The three-segmented Tarsus.

Fig. 2b. Third tarsal segment to show detail of the tarsal claw and accessory
claw.

Fig 2c. Detail of integumental surface of metathoracic coxa along the line x
in 2a above, under high magnification, to show striulation.

Fig. 3. Mesosternal and metasternal field of female. MOS, mesosternum;
MOES, mesoepisternum ; MOCC, confluent mesocoxal cavities;
MES, metasternum ; MESS, metaepisternum ; P, prepectoid area ;
II, lateral mesosternal fovea; III, median mesosternal fovea; IV,
lateral mesocoxal fovea and V, posterior mesocoxal fovea. Note that
these foveae are shown as though the integument was transparent,
to bring out the characteristic whorling of their walls. These sternal
fovea are important structures (see p. 24ff).

Fig. 4. Ventral aspect of abdomen, female. Sl-7, visible sternites; T6, sixth
visible tergite.

Fig. 5. Ventral aspect of abdomen, male. Sl-7, visible sternites, with the
seventh, the "pygidium," with the arcuate longitudinal "carina";
T6, sixth visible tergite.

Fig. 6. Ventral aspect of posterior sternites of male abdomen showing the
penis being exserted between the right and left pygidial plates,
which together make up the seventh sternite, and when closed, their
line of union forms the longitudinal median "carina."

Plate X

MES

Plate XI
MISCELLANEOUS EUPLECTINI

Fig. 1. Trimiomelha dubia (LeConte). Male head and j^ronotiim, dorsal
aspect. 400 diameters. Note minute vertexal foveae, coarse punc-
tation and vertexal tubercle.

Fig. 2. Dalmosella tenuis Casey. Male head and pronotum, dorsal aspect.
400 diameters. Note large pubescent vertexal foveae, associated
sulcus and the distinctive character of the transverse basal pronotal
sulcus.

Fig. 3. Bibloplectus ruficeps (LeConte). Head, dorsal aspect. 700 diameters.

Fig. 4. Bibloplectus ruficeps (LeConte). Head, ventral aspect. 700 diameters.
Note spiniform setoid processes.

Fig. 5. Melba thoracica (Brendel) and Melba sulcatula Casey. Dorsal aspect
of head, 400 diameters. 25% KOH for 24 hours. Note relation of
vertexal foveae to supratentoria, and the metatentoria of the cervical
region.

Fig. 6. Melba thoracica (Brendel). Ventral aspect of head, 400 diameters.
25% KOH for 24 hours. Note capitulate setae.

Fig. 7. Melba thoracica (Brendel). Head and pronotum, dorsal aspect, 100
diameters. Note asperate punctation. Male mesothoracic femur and
tibia, 100 diameters. Male mesothoracic tibia, distal end, 700 diam-
eters to show padules.

Fig. 8. Melba sulcatula (Casey). Head and pronotum, dorsal aspect, 100 diam-
eters. Note normal punctulation. Male mesothoracic femur and tibia,
100 diameters. Male mesothoracic tibia, distal end, 700 diameters
to show padules.

Plate XI

Plate XII

MISCELLANEOUS EUPLECTINI

Fig. 1. Trimioplectus obsoletus Brendel. Genal seta, 700 diameters.

Fig. 2. Eutyphlus prominens Casey. Genal setae, 700 diameters. Abundant

in this species but very scarce in E. similis LeConte.
Fig. 3. Bibloplectus ruficeps (LeConte) . Male metathoracic leg, 400 diameters.
Fig. 4. Bibloplectus ruficeps (LeConte). Male metathoracic tibial spur and

tarsus, 700 diameters.
Fig. 5. Euplectus interruptus LeConte. Male prothoracic tarsus, 700 diameters,

mesial face. Note primary and secondaiT claws and contrast with

Fig. 4.
Fig. 6. Euplectus difficilis LeConte. Maxillary palpus, 700 diameters.
Fig. 7. Trimiomelba dubia (LeConte). Male maxillary palpus, 700 diameters.
Fig. 8. Trimiomelba dubia (LeConte). Male metathoracic leg, 400 diameters.
Fig. 9. Trimiomelba dubia (LeConte). Male metathoracic tarsal claws, 700

diameters. Note minute secondary claw and contrast with Figs.

4 and 5.
Fig. 10. Melba thoracica (Brendel) and Melba sulcatula Casey. Mesothoracic

tarsus, 400 diameters.
Fig. IL Melba thoracica (Brendel). Mesothoracic leg, 150 diameters.
Fig. 12. Melba thoracica (Brendel). Metathoracic leg, 150 diameters.
Fig. 13. Melba thoracica (Brendel). Prothorax, anterior face.
Fig. 14. Melba thoracica (Brendel). Prothorax, posterior face. Note the endo-

skeleton, conical coxae, brachyscelid articulation, and sensory pores

on the femora. 700 diameters.
Fig. 15. Dalmosella tenuis Casey. Male sternites (0.3 x 0.3 mm.) showing

peculiar secondary sexual modification of second sternite. Note

exserted penis and pygidium asymmetrically articulated to the

right. Penis 0.12 x 0.07 mm.
Fig. 16. Dalmosella tenuis Casey. Male sexual modification of second sternite,

lateral view.
Fig. 17. Melba thoracica (Brendel). Head, lateral view.
Fig. 18. Trimio7nelba dubia (LeConte). Head of male, lateral view.
Fig. 19. Euplectus interruptus LeConte. Head, lateral view.
Fig. 20. Melba. Right elytron, lateral face. Note oblique pleural line.
Fig. 21. Dalmosella. Right elytron, lateral face. Note parallel pleural line.

Plate XII

Plate XIII

Fig. 1. Trimiomelba dubia (LeContel. Right eye, male, 40 to 45 facets, ant.,
anterior; ven., ventral. Slide mount, 700 diameters.

Fig. 2. Eupsenius glaber LeConte. Head, antennae and pronotum from dorsal
face.

Fig. 3. Trimiomelba dubia (LeConte). Toadstool-shaped vertexal spine on
the head of male. Pubescence not shown. Note coarse, shallow
integumental punctures around pedicel of spine. Slide mount, 700
diameters.

Fig. 4. Sonoma (Rafonus) tolulae (LeConte). Ventral aspect of prothorax.
PS, prosternum; PCC, prothoracic coxal cavities; APF, anterior
prosternal foveae; LPF, lateral prosternal foveae; MPF, median
prosternal fovea (unpaired). This is a generalized, primitive pros-
ternal field with five out of a theoretical six foveae.

Fig. 5. Sonoma (Rafonus) tolulae (LeConte). Right elytron, male. This is a
primitive elytron with a row of foveae on the flange fitting under
the pronotum, and ten rows of punctures on the integument. The
small foveae near the sutural margin may vary from 2 to 5 in
number, the first basal fovea may be present or absent, the second
row of discal foveae is more constant.

Fig. 6. Euplectus (Pycnoplectus) interruptus LeConte. Ventral aspect of
prothorax, female. PS, prosternum; PCC, prothoracic coxal cavi-
ties; LPF, pubescent lateral prosternal foveae.

Fig. 7. Sonoma (Rafonus) tolulae (LeConte). Lateral aspect of abdomen,
male. MCA, metathoracic coxal acetabulum in first sternite. Seven
sternites shown (Sl-71 and six tergites shown (Tl-6), however in
dry mounts only five tergites are visible.

Fig. 8. Euplectus (Pycnoplectus) interruptus LeConte. Right elytron, female.
Note four large foveae, one sutural and three discal. The subhumeral
fovea does not show from this view, but is indicated in Fig. 8a, a
lateral view of the elytron. Note that the subhumeral fovea is
pubescent and almost surrounded by a cariniform line.

Fig. 9. Sonoma (Rafonus) tolulae (LeConte). Ventral aspect of abdomen,
male. MCA, metathoracic coxal acetabulum on each side the first
visible sternite. Seven visible sternites (Sl-7). Note that the seventh
is composed of three asymmetrical pieces, a right and left lateral
and a median, pygidial plate.

Plate XIII

Plate XIV

Fig. 1. Eupsenius glaber LeConte. Ventral aspect on the left; dorsal aspect
on the right. For discussion see text.

Plate XIV

Plate XV

Fig. 1. Barroeuplectoides zeteki Park. Antenna in silhoiitte. Drawn from type.
Fig. 2. Panaramecia williamsi Park. Apical portion of intermediate tibia and

tarsus. Drawn from holotype.
Fig. 3. Elytra of Euphalepsus, in which the humeral calus of each elytron is

extended posteriorly as a carina. Contrast with Fig. 7, Plate XVIII.
Fig. 4. Outline sketch of Fusiiger clavipilis Mann, showing a common outline

in the genus. Contrast with Fig. 5. (After Mann, 1921 1
Fig. 5. Outline sketch of Fustiger haytiana Mann, showing a rare outline in

the genus. Contrast with Fig. 4. (After Mann, 1915)
Fig. 6. Fustiger haytiana Mann. Male intermediate femur and trochanter,

with the unusually long, blunt femoral spine. (After Mann, 1915)
Fig. 7. Outline sketch of pronotum of Sebaga centralis Raffray, after Raffray,

1891.
Fig. 8. Sebaga centralis Raffray. Antebasal pronotal platform.
Fig. 9. Sebaga raffrayi Park. Antebasal pronotal platform.
Fig. 10. Sebaga notonoda Park. Antebasal pronotal platform.

Plate XV

Plate XVI

Fig. 1. Reichenbachia giiatemalensis Fletcher. Right mandible, drawn from

male paratype (U.S.N.M., No. 44608).
Fig. 2. Reichenbachia latipes Fletcher. Right mandible, drawn from male

paratype (U.S.N.M., No. 44605).
Fig. 3. Decarthron chichion Park. Intermediate femur. Male type.
Fig. 4. Decarthron noctiphoton Park. Intermediate femur. Male type. a.

Proximal spine; b. carinoid crest on floor of excavation. Note the

complete absence of a spine at the apical end of excavation; D.

denticulatum Fletcher has the apical spine developed.
Fig. 5. Decarthron noctiphoton Park. Detail of male inteimediate femoral

excavation, slide mount at 700 diameters. Note a, proximal spine

is tubular, with secondar\^ striations (canals?) radiating from base;

b, the carinoid ridge is bifurcated, and "feathered" by secondary

striations.
Fig. 6. Decarthron noctiphoton Park. Anterior femur. Male type.
Fig. 7. Decarthron noctiphoton Park. Antenna. Male type.
Fig. 8. Reichenbachia stroheckeri Park. Distal nine antennomeres, from male

paratype. Dorsal aspect.
Fig. 9. Reichenbachia stroheckeri Park. Lateral aspect of the fifth and sixth

antennomeres, from male paratype.
Fig. 10. Reichenbachia appendiculata Raffray. Lateral aspect of the fifth and

sixth antennomeres of male. Modified after Raffray, 1904.
Fig. 11. Reichenbachia appendiculata Raffray. Dorsal aspect of the fifth and

sixth antennomeres of male. Modified after Raffray, 1904.
Fig. 12. Reichenbachia diversula Raffray. Dorsal aspect of the fifth and sixth

antennomeres of male. Modified after Sharp, 1887.
Fig. 13. Reichenbachia fovearthra Park. Dorsal aspect of the third, fourth,

fifth and sixth antennomeres of male, from holotype.
Fig. 14. Reichenbachia fovearthra Park. Ventral aspect of the fifth and sixth

antennomeres of male, from holotype.

Plate XVI

Plate XVII

Fig. 1. Tyrogatunus zeteki Park. Left eye, from holotyi^e male. Stippled
facets represent pigment present, or expanded; white facets repre-
sent pigment absent, or contracted. See text for detail.

Fig. 2. Fustiger veracruzensis Park. Left eye, from holotype male.

Fig. 3. Cylindrarctus longipalpis (LeConte). Right side of head. I, first
antennomere; a, flattened sensory area; b, antennal acetabulum;
c, translucent window between acetabulae; d, clypeus; e, labiiun;
f, mandible; g, stipes-palpifer of maxilla; h, first and second maxil-
lary palpomeres; i, gena; j, cervdcal constriction; k, occiput; 1,
vertex; m, front; n, vertexal fovea; o, antennal tubercle; p, com-
pound eye; q, vertexal spicule.

Fig. 4. Hamotus (Hamotoides) : small median pronotal fovea, as found in
thomasi, veracruzensis, and jletcheri.

Fig. 5. Hamotus {Hamotoides) : large median pronotal fovea, as found in
monachus and ejiectrae.

Fig. 6. Hamotus {Hamotoides) ^/lomasi Park. Distal four antennomeres, from
male type.

Fig. 7. Hamotus (Hamotoides) i^eracruzensis fletche7^i FRrk.Dii^tnliour Rnten-
nomeres. Contrast with Fig. 7, Plate. VI.

Fig. 8. Hamotus [Hamotus] tibialis Raffray. Male, posterior femur. Modi-
fied from Raffray, 1904.

Fig. 9. Hamotus (Hamotus) turalbus Park. Male, posterior femur. Modified
from Park, 1935.

Intrageneric variation of male antennae in Neotropical Reichenbachia.
Figs. 10 to 16 after Raffray, 1904; Fig. 17 after Fletcher, 1928.

Fig. 10. Reichenbachia grenadensis Raffray.

Fig. 11. Reichenbachia sarcinaria Schaufuss.

Fig. 12. Ventral surface of fifth antennomere, sarcinaria Schaufuss.

Fig. 13. Ventral surface of fifth antennomere, callosa Raffray.

Fig. 14. Ventral surface of fifth antennomere, falsa Raffray.

Fig. 15. Reichenbachia globulosa Raffray.

Fig. 16. Reichenbachia mexicana Raffray.

Fig. 17. Reichenbachia carinifer Fletcher.

Plate XVII

?^J^?^^^

8

4

Plate XVIII

INTRAFAMILY VARIATION OF HABITUS IN NEOTROPICAL
PSELAPHIDAE

Fig. 1. Barrojuba albertae Park, Panama Canal Zone. Dorsal aspect, from

male type. Note complete absence of vertexal foveae.
Fig. 2. Rhinoscepsis falli Park, Brazil. Dorsal aspect, from type.
Pig. 3. Decarthron euspinijrons Park, an ecitophile from the Panama Canal

Zone. The frontal horn is novel in the genus. Dorsal aspect from

male type.
Pig. 4. Metopioxys mattogrossoensis Park, Brazil. Dorsal aspect, from male

type. Note geniculate antenna.
Pig. 5. Barrometopia quasimoda Park, a termitophile from the Panama Canal

Zone. The pronotum is strongly gibbous on either side of the median

sulcus. Dorsal aspect, male type.
Fig. 6. Batoctenus barberi Park, Brazil. Dorsal aspect, male type.
Pig. 7. Euphalepsus myrmeco coins Park, Mexico. Dorsal aspect, female type.

Plate XVIII

Plate XIX

INTRAFAMILY VARIATION OF HABITUS IN NEOTROPICAL
PSELAPHIDAE (Continued)

Fig. 1. Syr7nocerns guarinus Park, Brazil. Dorsal aspect, male type.

Fig. 2. Anoplobraxis guianensis Park, a termitophile from British Guiana.

Dorsal aspect, male type.
Fig. 3. Haniotus iHamotus) turalbus Park, Costa Rica. Redrawn from Park,

1935.
Fig. 4. Hamotus (Hamotoides) riwnachus Reitter, Costa Rica. Dorsal aspect.
Fig. 5. Arhytodes achillei Park, Brazil. Dorsal aspect, from type.
Fig. 6. Fustiger- veracruzensis Park, a symphile from Mexico. Dorsal aspect,

male paratype.
Fig. 7. Trmiiopsis jurcalis Park, Panama Canal Zone. Dorsal aspect, male

holotypc.

ro

Plate XX

GENERIC VARIATION OF MAXILLARY PALPI IN
NEOTROPICAL TYRINI

Palpi are in sillioutte to facilitate generic diagnosis. All normal
pubescence and species differences omitted. The figures are of left
palpi as seen from the dorsal surface. For evolution please see text.

Fig. L Phalepsus Westwood (Redrawn after Raffray, 1908)

Fig. 2. Lethenomus Raffray (Redrawn after Raffray, 1908)

Fig. 3. Tyropsis Saulcy and Neotyrus Raffray (Original)

Fig. 4. Tyrogatunus Park (Original)

Fig. 5. Juxtahamotopsis Park (Original)

Fig. 6. Apharus Reitter (Original I

Fig. 7. Hamotus Aube (Original)

Fig. 8. i/amo^w.s Aube (Original)

Fig. 9. Aploderina Raffray (Redrawn after Raffray, 1904)

Fig. 10. Pseudohamotus Raffray (Redrawn after Raffray, 1908)

Fig. 11. Cercoceropsis Raffray (Redrawn after Raffray, 1904, 1908)

Fig. 12. Cercoceroides Raffray (Original)

Fig. 13. Hamotocellus Raffray (Redrawn after Raffray, 1911)

Fig. 14. Pselaphocompsus Raffray (Redrawn after Raffray, 1908, 1911)

Fig. 15. Cercocerulus Raffray (Redrawn after Raffray, 1904)

Plate XX

Plate XXI

SOME INFLUENCES PROBABLY OPERATING UPON PSELAPHIDAE

(For documentation please see text)

Fig. 1. Theoretical, evenly distributed, taxonomic units at maximum density.

Fig. 2. Operation of the Subspeciation Factor. The numerous taxonomic units
are in reality subspecies of a relatively few species populations.

Fig. 3. Operation of the Community Factor. The differential biotic potential
of the several communities imposes differential distribution and re-
duces the number of species populations for the whole area.

Fig. 4. Operation of the Competitive Factor. Predators in the same stratum
of the Eltonian Pyramid compete with pselaphid species popu-
lations, for food and shelter, greatly reducing the number of species.

Fig. 5. Operation of the Range Factor. Species populations of pselaphids over-
lap within a given biome. This sets up intra-family competition
and may or may not reduce the number of species, depending upon
overlap in activity pattern, extra-family competition, et cetera.

Plate XXI

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