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CONTENTS
PAGE
No.* 1. — The Ant Genus Strumigenys Fred. Smith in
the Ethiopian and Malagasy Regions. By Wil-
liam L. Brown, Jr. August, 1954 1
No. 2. — Deep Water Elasmobranchs and Chimaeroids
from the Northwestern Atlantic Slope. By
Henry B. Bigelow and William C. Sehroeder. Sep-
tember, 1954 35
No. 3. — Status op Invertebrate Paleontology, 1953.
By Bernhard Kummel, Editor. October, 1954 . 89
No. 4. — Revision op the Chrysomelid Subfamily Aiila-
coscelinae. By P. Monros. November, 1954 . . 319
No. 5. — The Comparative Biology of Reproduction in
the Wood-Boring Isopod Crustacean Limnoria.
By Robert J. Menzies. December, 1954 . . 361
No. 6. — The Genus Eustala (Araneae, Argiopidae) in
Central America. By Arthur M. Chickering.
March, 1955 ..." 389
Bulletin of the Museum of Comparative Zoology
AT HAEVARD COLLEGE
Vol. 112, No. 1
THE ANT GENUS STRUMIGENYS FRED. SMITH IN
THE ETHIOPIAN AND MALAGASY REGIONS
By
William L. Brown, Je.
Museum of Comparative Zoology, Harvard University
CAMBRIDGE, MASS., U.S.A.
PRINTED FOR THE MUSEUM
August, 1954
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Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 1
THE ANT GENUS STRUMIGENYS FRED. SMITH IN
THE ETHIOPIAN AND MALAGASY REGIONS
By
William L. Brown, Jr.
.Museum of Comparative Zoology, Harvard University
CAMBRIDGE, MASS., U.S.A.
PRINTED FOR THE MUSEUM
August, 1954
No. 1. — The Ant Genus Strumigenys Fred. Smith
in the Ethiopian and Malagasy Regions
By William L. Brown, Jr.
This is a part of my revision of the dacetine ant genus
Strumigenys Fred. Smith, planned to include the entire Strumi-
genys world fauna. For information concerning the characters
and relationships of Strumigenys, the reader should consult my
recent general references on tribe Dacetini (Brown, 1948, 1953).
The 1953 reference also contains a detailed discussion of the
standard measurements most useful in dacetine studies and the
indices derived from these measurements. To recapitulate briefly :
TL or "total length" is the sum of the exposed lengths of the
head with mandibles, alitrunk, petiole, postpetiole and gaster.
HL is the maximum measurable length of the head proper, seen
in perfect dorsal full-face view, including all of occipital lobes
and clypeus. ML is the exposed length of the closed mandibles
from dorsal view (same position from which HL is measured).
WL, or Weber's length of alitrunk, is the diagonal distance from
base of cervix to metapleural angles, as seen from the side.
CI is the cephalic index, or HL/maximum width of headXlOO.
MI, mandibulo-cephalic index, is HL/MLXlOO. Error of
measurement for the head and mandibles should not normally
exceed ±0.01 mm.; errors of indices as calculated from raw
measurement units should not exceed ±1.
The cooperation of numerous individuals in the entire dace-
tine project is cited in detail in my 1953 reference, but I
should like to acknowledge here the most valuable loans of
material and other aid rendered by the following : Dr. George
Arnold, of Bulawayo ; Prof. Francis Bernard, of the Universite
d'Alger; Dr. Ch. Ferriere, of the Museum d'Histoire Naturelle,
Geneva ; Prof. Guido Grandi, of the University of Bologna ;
Prof. Ed. Handschin, of the Naturhistorisches Museum of Basel ;
Dr. Harlow B. Mills, of the Illinois Natural History Survey;
Dr. E. S. Ross, of the California Academy of Sciences; Dr.
George Salt, of Cambridge University ; and Dr. Neal A. Weber,
of Swarthmore College, Pennsylvania.
Aside from a handful of obscure species in Microdaceton Sant-
schi, Smithistruma Brown, Miccostruma Brown, Cocliomyrmex
Wheeler, and perhaps one or two other small genera at present
4 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
known from North Africa, the Ethiopian-Malagasy clacetines
fall into two distinct, relatively common, and presumably dom-
inant genera : Strumigenys and Serrastruma Brown. Serra-
struma underwent drastic preliminary revision in a recent paper
(Brown, 1952), and it now appears that the number of species
may have to be reduced still further by synonymy, since only
four to six of those names appear to represent distinct entities.
These few Serrastnima species are all very much alike, and all
are exceptionally variable in a tribe which is otherwise outstand-
ing in the constancy of species characteristics. Serrastnima
appears to be a relatively recently evolved group of Ethiopian
origin; its ancestors are probably to be looked for in Smithi-
struma species like those of the alberti group. Serrastrama is
easily the commonest, and apparently the dominating African
dacetine genus, and it seems likely (on the assumption that it
competes for the same food as other clacetines, namely collembola
and a few other small cryptobiotic arthropods) that its presence
is the chief cause of the scarcity of other dacetine groups below
the Sahara.
The other genus fairly well developed in Africa is Strumi-
genys, which survives as fourteen known, valid species in the
Ethiopian Region, plus one in Madagascar. Two of the Ethiopian
species have become established as tramps outside Africa-
Madagascar (rogeri and scotti), and these will be discussed be-
low. All of the African Strumigenys species clearly belong to
one ancestral stock, of which the most generalized known species
is S. grandidieri of Madagascar, although the close interrelation-
ship of these specie.s is masked by extensive morphological radia-
tion and might not therefore be guessed at without one 's having
the complete series of forms in intergrading array. Undoubtedly,
other species from these regions remain undescribed and uncol-
lected, but in spite of the incompleteness of the record, it seems
clear that the Afro-Madagascan Strumigenys fauna is a very
limited one compared to the two other distinct faunas of the
genus. The New World and Indo-Australian faunas share,
roughly equally, at least 100 described and undescribed species
that I have been able to verify to date, leaving out those that
are clearly synonyms.
The reason for the paucity of the African Strumige?iys fauna
brown : ant genus Strumigenys FRED. SMITH 5
is not entirely clear, especially in the absence of detailed ecologi-
cal data, but it seems probable that competition between Strum-
igenys and Serrastruma is at least partly responsible. In the
other tropical dacetine faunas, Strumigenys is usually clearly
the dominant genus, though Smith istruma is abundant in some
of these regions and competes for much the same food (chiefly
or entirely collembola of entomobryoid and isotomoid affinities).
Strumigenys and Smithistruma differ, however, in the basic
form of the mandibles, and to a certain extent also in details of
predatory behavior (Wilson, 1954; Brown, 1954; unpublished
data of both authors), so that competition between the two
groups is probably only partial. On the basis of evidence I
have given elsewhere (especially in the 1953 reference), it seems
very likely that the long-mandibulate life-form (Strumigenys)
is ancestral to the short-mandibulate, or smithistrumiform type.
The long-mandibulate type is better fitted for foraging in the
open, while the short-mandibulate forms are more suited to
cryptic hunting; the former tends to concentrate more toward
the tropics, while the latter is predominant, in the Northern
Hemisphere, at least, in the warm temperate belts.
In Africa, however, the chief short-mandibulate genus is Ser-
rastruma, which exists successfully through most of the con-
tinent from South Africa to the Sahara, avoiding only extreme
montane and desert habitats. The Serrastruma mandibles, a
modified and somewhat elongate version of those of Smithistruma,
may be a very efficient prey-catching instrument, but there is
probably more than this behind the success of Serrastruma.
Probably ecological tolerances and fertility are involved strongly
here, as suggested by the extreme morphological variability of
the species and the rather larger-than-average nest populations,
of which accurate estimates are just beginning to come in.
As mentioned already, the Afro-Madagascan Strumigenys so
far described all belong to a single group (the rogeri group, here
so named) representing a common stock. This group, excepting
the two probably historically-migrant tramp species, is restricted
to Africa and Madagascar, and its relationships with groups of
other faunas are not particularly close. With the single excep-
tion of S. rufobrunea, a widespread and very variable species,
the African Strumigenys show the narrow ranges of intraspecific
b BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
variation usually expected of members of the genus, and ecologi-
cal specialization, so far as known, follows morphological varia-
tion. Strumigenys in Africa, as elsewhere, seems to tend to fill
the available niches by speciating to specialized types, which then
stabilize and become relatively constant and therefore are easily
separable one from another. Serrastruma, on the other hand,
fills many or all of the same niches by producing only a few, but
very plastic species.
It is interesting to note that the three truly widespread tramp
dacetines [Strumigenys rogeri Emery, Trichoscapa membrani-
fera Emery and Quadristruma emmae (Emery)] are all either
certainly or very likely of African origin. In fact, Quadristruma
emmae, though not yet recorded from Africa proper, is now
seen, through the discovery of the intergradient Strumigenys
tetraphcmes (q.v. infra), to be a direct offshoot of the S. rogeri
group and hardly separable from that group except by the
detail of the loss of the two smallest antennal segments. In a
similar way, Trichoscapa membranifera seems close to certain old
African stocks of short-mandibulate genera (Smithistruma, Cod-
iomyrmex loveridgci Brown, Miccostruma), and this species is
actually known from various humanly-disturbed areas in Egypt
and elsewhere in North Africa. S. rogeri is widespread in the
West Indies, the Pacific, and in the hothouses of the British
Isles, and it has long been thought to be a native Neotropical ant,
but I can now show that it is African as its morphological relatives
are ; the West African S. sidfurea proves to be its synonym.
The findings in the Dacetini are in agreement, as concerns
tramping ability, with the patterns of colonization now emerging
for the ants in general. It would seem, despite certain outstand-
ing exceptions to the contrary, and taking into account the
chaotic state of the taxonomy of ants, that the worldwide "tramp
habitats" in the tropics and subtropics are occupied mainly by
species and genera of African origin. The degree to which this
is true will only be surely revealed after much difficult basic
taxonomic labor, involving the synonymy of many species and
varieties described originally on a purely geographical basis. The
origins will be made known chiefly by analyzing group relation-
ships, and then searching for the particular species concerned in
its presumed native area, for it is frequently true that in its native
brown : ant genus Strumigenys FRED. SMITH 7
range, an ant elsewhere common as a tramp will be diffusely
distributed, or even rare. At present writing, this appears to be
the case with all the dacetines mentioned above.
The stages of tramping through the agency of human com-
merce appear to be fairly obvious. The critical step involves the
chance transplantation of a continental propagule to a favorable
offshore island with a limited native fauna. If such an island is
not already "saturated" with competing tramps, the chances
greatly favor the establishment of a very dense population there
within a relatively short time. With the pressures of normal
continental extraspecific competition, predation and parasitism
removed or greatly lessened at the new insular habitat, a dense
population is virtually inevitable. From an insular colony, small
in area by geographic restriction, but dense in structure, and
exposed to intensive contacts with commercial transportation,
the probability that new propagules will be transported to new
colonial sites is enormously increased over what it originally
was in the continental distribution. It seems likely that this
is the usual pattern of dispersal of potent tramp species among
the smaller insects and certain other invertebrates (the notorious
and well-studied giant snail, Achat ina fulica, for instance; Be-
quaert, 1950). The study of this problem in the ants is a fascin-
ating one, but very difficult due to the present very great pro-
portion of unrecognized synonyms among the tramp species.
From the fragmentary information we have at present, the
tramp ants of the tropics and subtropics seem, as has already
been mentioned, to be predominantly African in origin. Perhaps,
as seems very likely in the better-known but restricted case of
the dacetines, this apparent predominance of African forms
reflects a relatively potent evolutionary situation centering in
the Dark Continent. In the case of the dacetines, Africa cer-
tainly would appear to have been the chief center of major-
group evolution, at least during the more recent geologic past,
as well as the present.
The largest and most generalized member of the rogeri group
is S. grandidieri Forel, from Madagascar. This species shows
many similarities in general habitus (as well as in details like
the median longitudinal cephalic sulcus, the antennal scrobe
posteriorly limited near the compound eye, the preocular notch,
8 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the size, and general head shape) to generalized members of the
Indo- Australian fauna (chyzeri group) and to American species
like 8. mandibular).* Fr. Smith and S. precava Brown. The
closest relationships of 8. grcmdidieri are, however, clearly with
the African members of the genus. The generalized rogcri group
characters include well developed preocular notches combined
with rather large eyes, fairly long mandibles with the usual
pair of apical teeth forming a fork, and two additional preapical
teeth, and a rather strikingly depressed posterior part of the
mesonotum.
Important tendencies of specialization within the group in-
clude, in different lines, reduction of eye size and loss of the
preocular notch, reduction of body size, shortening of mandibles
and antennae, and reduction even to loss of the more distal of
the two preapical teeth. The reduction of the distal preapical
tooth is unique among dacetines in that it takes place asym-
metrically, with the tooth on the left mandible diminishing more
strongly than that on the right. The tooth on the left may even
disappear entirely, while that on the right persists in a more or
less reduced state in all but one species (irrorata) . All stages in
the reduction of the distal preapical teeth are found among
rogcri group species, and each stage furnishes a useful species-
constant character.
The eye-notch character and the dentitional asymmetry have
received scant attention from most authors, especially Santschi,
and in consequence these features are frequently not even men-
tioned in past descriptions. The published figures of African
Strumigenys, as well as the mensural citations, are also largely
untrustworthy. In the matter to follow, I have not tried to
correct by specific mention all of the numerous published errors
of detail. Instead, there are emphasized below the essential
characters, and especially the measurements, of all species
studied at first hand. Special attention has been given to the
construction of the key. Type material of all species treated
has been directly examined unless otherwise specifically men-
tioned.
The species included here that were described prior to 1922
have been catalogued (under Strumigenys s. str.) in the follow-
ing references: Emery, 1922, Genera Insectorum, Fasc. 174, pp.
brown : ant genus Strumigenys fred. smith 9
320, 322; Wheeler, 1922, Bull. Amer. Mus. Nat. Hist., 45: 917-
918, 1034.
In these lists are included Strumigenys reticulata Stitz and
S. ludovici Forel, both of which have since been transferred to
Serrastruma (Brown, 1952). S. reticulata is a synonym of Ser-
rastruma lujae (Forel), while ludovici is perhaps a prior name
for Serrastruma alluaucli (Santschi).
Key to the Species of Strumigenys of the Ethiopian and
Malagasy Regions, Based on the Worker Caste
Notes on the use of the key. Since most of the species are still
known only from scanty material, this key should be taken only
as a preliminary guide. Larger series may well reveal that
the allowances I have made for potential infraspecific variation,
while generous, may in some cases be transgressed. It should
also be emphasized that the mere fact that a given specimen
does not readily run out in the couplets below is no assurance
that the would-be identifier has discovered an undescribed
species. It is regrettable that past authors have described in
error certain "new" forms solely on the basis that they would
not run out in the existing keys. On the other hand, it does
seem likely that additional species of Strumigenys beyond those
here treated occur in Africa.
The identifier using this key must be prepared to measure the
dimensions of the head and exposed mandibles to a satisfactory
degree of precision. The tolerances of error for these measure-
ments are about ±0.01 mm. A good-quality manipulator set in
a mechanical stage, under magnification of not less than 60
diameters, is recommended for these measurements. It is also
advisable to consult a full discussion of dacetine measuring
techniques (Brown, 1953).
It goes almost without saying that specimens must be clean
and undamaged. Dirt or adhesive lodged in the preocular notches
or mandibles can cause serious error, especially at couplets 1, 3
and 10. Furthermore, at couplets 3 and 10 in cases where any
doubt occurs, the mandibles should be opened in order to see the
dentition properly in at least a portion of any nest series.
At couplet 1, the eye-notches should not be confused with the
10 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
antennal scrobes ; the latter are broad, usually elongate sulci
running for some distance along the sides of the head in such
a position as to readily receive the retracted antennae, while the
preocular notches run more or less vertically, perpendicular to
the long axis of the head, immediately in front of the compound
eyes. Specimens should not be mounted flat on the surface of
cards; card mounts obscure the details of periocular structure
and mandibular dentition, and hence have been the greatest
single source of confusion visiting this genus to date. Point
mounts, utilizing fine pennant-shaped pieces of card, are by far
preferable.
At couplets 3 and 10, the possibility must be considered that
rare atavistic specimens may preserve the minute vestige of a
left preapical tooth close to the base of the dorsal apical tooth
where this (distal) preapical tooth is normally absent in a given
species. I have seen one specimen possibly belonging to this
category (Bernard ms. new species, couplet 4 and p. 16 ). Such
specimens can usually be detected if a part of a normal series,
but uniques will always be difficult, and must be checked by
means of dimensions and proportions and other characters given
in the descriptions.
1. Ventrolateral border of the head receding sharply at the anterior
margin of the eye to form a distinct preocular notch or groove; eye
oriented more or less anteriorly and usually more or less detached and
narrowly rounded in front 2
Ventrolateral border of head not or at most extremely feebly impressed
at the anterior margin of the eye; eye oriented entirely laterally, the
facets forming a flat or gently convex disc, or the eye reduced to a
very few minute facets 7
2. Larger, length of head proper over 1.0 mm.; each mandible with two
short, oblique, truncate preapical teeth (Madagascar) . grandidieri Forel
Smaller, length of head proper under 1.0 mm.; preapical teeth acute. . .3
3. Left mandible with a single preapical tooth, the distal preapical tooth
normally completely lacking (see note above on use of key) 4
Left mandible with two preapical teeth, the distal tooth smaller than
the proximal, but still quite distinct and acute 5
4. Larger, length of head proper > 0.70 mm.; CI > 72, MI < 54; upper
angles of propodeal lamellae low and more or less rounded (Kenya) ....
londianensis (Patrizi)
brown : ant genus Strumigenys feed, smith 11
Smaller, length of head proper < 0.60 mm. ; CI < 72, MI > 54 ; upper
angles of propodeal lamellae normally dentiform and acute (Congo
N. Angola) new species, Bernard ms.
5. Larger, length of head proper > 0.65 mm. ; MI < 42 ; compound eyes
exceptionally large and prominent (Transvaal) pretoriae Arnold
Smaller, length of head proper < 0.65 mm.; MI 42 or more; compound
eyes smaller to moderate in size and prominence 6
6. MI 43-49; mandibular shafts distinctly arcuate (W. Africa to Natal
and Angola) rufobrunea Santschi
MI 51 or more; mandibular shafts nearly straight (W. Africa; wide-
spread in tropics of both hemispheres, especially in the Pacific and W.
Indies ; also British greenhouses) rog.eri Emery
7. Normally exposed portions of the antennal scapes very broad, less than
three times as long as their greatest width; CI about 90 or slightly
more (Uganda) t.etraphanes new species
Normally exposed portions of antennal scapes more than three times
as long as wide ; CI well under 90, and usually less than 85 8
8. Greatest diameter of compound eye distinctly greater than greatest
width of antennal scape 9
Compound eye very small, its greatest diameter less than, or at least
not greater than, greatest width of antennal scape 10
9. Head narrower, CI < 73; mandibles longer, MI > 45 (Seychelles Is.;
Sao Tome I.) sootti Forel
Head broader, CI > 73 ; mandibles shorter, MI < 40 (Natal)
marleyi Arnold
10. Left mandible with only a single preapical tooth, the distal preapical
tooth normally completely lacking 11
Both mandibles each with two preapical teeth, though in some cases, the
distal preapical tooth on one or both sides may be reduced to a minute
denticle 1-
11. Right mandible with two preapical teeth, the distal tooth small and
normally covered by the dorsal apical tooth of the left mandible at full
closure; CI between 70 and 80 (Uganda to Angola) . .dextra new species
Eight mandible with only one preapical tooth, the distal preapical teeth
of both mandibles lacking; CI > 80 (Zululand) irrorata Santschi
12. Combined length of head and mandibles when closed > 0.85 mm.; CI
< 75 ; MI 50 or slightly more (Natal) liavilandi Forel
Combined length of head and closed mandibles < 0.85 mm. ; CI > 75 ;
MI usually under 50 13
12 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
13. Combined length of head and mandibles 0.70 mm. or less; CI ca. 81;
MI ca. 37-38; most hairs on dorsum of head nearly or quite obicular,
appearing like round, shining, convex scales or studs (British E. Africa)
stygia Santsclii
Combined length of head and closed mandibles more than 0.70 mm.,
usually 0.75 mm. or slightly more; CI 77-80± ; MI usually > 38; hairs
on dorsum of head more or less broadened apically, but not orbicular. 14
14. MI > 43; each humerus with a flagellate hair; HL 0.53 mm. or less.
(E. and S. Africa) tragaordlii Santschi
MI < 43, usually 41 or less; humeri without flagellate hairs; HL usually
greater than 0.53 mm. (E. and S. Africa) arnoldi Forel
SYSTEMATIC TREATMENT BY SPECIES
Stbumigenys grandidieri Forel
Strumigenys Grandidieri Forel, 1892, Ann. Soc. Ent. Belg., 36: 517, worker.
Type locality: Andrangoloaka Forest, Madagascar. Syntypes: Mus.
Hist. Nat., Geneva ; Mus. Comp. Zool. Harvard University.
Worker. Descriptive notes are based on two very similar syn-
types in the Museum of Comparative Zoology, one of which was
measured: TL 5.02, HL 1.33, ML 0.69, WL 1.30 mm. ; CI 76, MI
52. Because of its size, this species could hardly be confused
with any other African-Malagasy Strumigenys.
Head massive, deeply and broadly excised behind, with a
distinct, narrow median dorsal sulcus running from clypeus to
posterior excision. Antennal scrobes ending, or at least becoming
extremely indistinct, at about the level of the eyes. Eyes large,
but not so large relatively as in pretoriae, convex, prospicient;
preocular notch broad and deep, involving the dorsolateral
cephalic border.
Mandibles broad, robust, slightly depressed, inserted close
together and slightly diverging at full closure. Apical fork of
two stout acute subequal teeth, without intercalary tooth or
denticle. Each mandible with two short, truncate preapical teeth,
directed obliquely anteriorly, subequal in size and scarcely longer
than broad, very close to the apex and to each other.
Alitrunk slender, pronotum convex, its anterior margin nar-
rowly rounded and sharply marginate, without humeral angles.
Mesonotum reasonably distinct, although the promesonotal suture
is obsolescent ; posterior mesonotum forming a long slope down
BROWN : ANT GENUS StrumigemjS FRED. SMITH 13
to the strong metanotal groove, from which the nearly plane,
platform-like propodeal dorsum rises slightly but rather
abruptly; dorsum and declivity of propodeum meeting at ap-
proximately a right angle. Propodeal teeth long, spiniform,
strongly elevated and divergent ; lateral borders of declivity
without infradental lamellae, but with three or four fine vertical
rugules on each side.
Petiolar node shorter than its slender peduncle, about as
broad as long seen from above and narrowly rounded above as
seen in lateral view profile ; petiolar appendages reduced to in-
significant vestiges. Postpetiole transversely elliptical, strongly
convex, half again as broad as the petiolar node and less than
half as broad as the gaster, with only strongly reduced ventral
appendages. Gaster with 9-13 widely spaced, distinct basal
costulae extending about 1/5 the length of the basal segment.
Gaster otherwise and most of mandibles smooth and shining.
Remainder of body, including pleura and both nodes, densely
punctulate, opaque. Pine superimposed regulation on dorsum
of head and alitrunk, most distinct on anterior pronotal margin.
Ground pilosity sparse, short, very narrowly spatulate and
subappressed on head ; available specimens may be partially
rubbed. Row of 4 (or 6) longer, suberect, apically very feebly
spatulate hairs bordering occipital excision; another pair on
vertex. Scape hairs fine, curved apicad; clypeal border hairs
narrowly spatulate, curved mesad. A pair of long, erect, very
weakly clavate hairs on postpetiole, and a few on posterior half
of gaster. Color light ferruginous (possibly somewhat faded) ;
mandibles and head lighter and more yellowish; vertex trans-
versely, nodes and gaster slightly darker than the rest.
Female and male unknown to me.
As already mentioned in my introductory remarks, 8. grand-
idieri appears to be the most generalized and most primitive
member of the rogeri group. Furthermore, it has a "primitive
look" backed by size, head structure, form of alitrunk and
propodeal armament having much in common with presumed
primitive forms of other faunal groups. The species remains
known only from the Madagascan type collection, and is the only
species of the genus so far recorded from Madagascar proper.
14 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Strumigenys londianensis (Patrizi)
Prosoopomyrmex londianensis Patrizi, 1946, Boll. 1st. Ent. Univ. Bologna,
15: 295, figs. 1, 2, worker. Type locality: Londiani, Kenya (by tau-
tonymy). Additional orig. loc. : Mau Forest, Kenya. Holotype and para-
types: 1st. Ent. Univ. Bologna; paratypes in Brit. Mus. (Nat. Hist.).
Strumigenys (Proscopomyrmex) londianensis, Arnold, 1948, Occas. Pap. Nat.
Mus. S. Bhodesia, 2 (14) : 227.
Proscopomyrmex? londianensis, Brown, 1948, Trans. Amer. Ent. Soc., 74: 128.
Strumigenys londianensis, Brown, 1949, Mushi, 20: 15.
Worker. Notes based on a single paratype from Londiani, by
courtesy of Prof. Grandi. TL 4.2, HL 0.88, ML 0.45, WL 0.88
ram. ; CI 75, MI 51. Patrizi gave a short description and large,
detailed figures in dorsal and lateral views. In addition to
marked contradictions involving dimensions and proportions
between the description and figures, and between these and the
paratype before me, I note the following :
1. In the paratype, the mandibles are shorter and heavier
than as figured, not so strongly arcuate, and the teeth shorter
and thicker and set more nearly at a right angle to the shafts.
On the right mandible, a short distal preapical tooth is present,
but is small and partly covered by the dorsal apical tooth of the
left mandible at full closure. The left mandible lacks a distal
preapical tooth, but the proximal preapical tooth is well de-
veloped on both mandibles.
2. In the paratype, the compound eyes are rounded anteriorly
as seen from above, and are not pointed ; from lateral view, the
eyes appear roughly circular. In front of the eyes is a well-
marked vertical groove, extending even into the dorsolateral
cephalic borders above and well across the postbuccal surface
below. Greatest diameter of eye (ca. 0.07 mm.) greater than
maximum width of scape (ca. 0.05 mm.).
3. In the paratype, the posterior descending mesonotal slope
is gently and evenly concave, not interrupted by a suture-like
impression as shown in Patrizi 's figure 2.
4. In the same figure, the propodeal lamella is much too
abruptly terminated ventrally, as is clear even without reference
to a specimen. In the paratype, the dorsal angle of the lamella
brown : ant genus Strumigenys fred. smith 15
is lower and more blunt than as shown in the figure, and the
excision between upper and lower angles is concavely rounded,
not subangular.
5. In the paratype, numerous short, spaced basal costulae
meet the anterior border of the first gastric segment. Also,
the petiole of the paratype bears feeble vestiges of posterolateral
spongiform appendages left out in the figure, and there are
small, inconspicuous, reclinate-spatulate hairs on the dorsum
of the head of the paratype. The postpetiolar disc is smooth and
shining, but dirty.
This species is closely related to 8. rufobrunea and Strumi-
genys new species of Bernard ms., but is larger than either of
these and differs in numerous details, especially the very different
propodeal lamellae. It is a forest species still known only from
the two original Kenyan collections.
Strumigenys pretoriae Arnold
Strumigenys (Proscopomyrmex) pretoriae Arnold, 1949, Oecas. Pap. Nat.
Mus. S. Bhodesia, 2 (15): 267, fig. 8, worker. Type locality: Pretoria,
Transvaal. Holotype : Nat. Mus. S. Rhodesia, Bulawayo ; paratype in
Agric. Res. Inst., Univ. Pretoria.
Worker. Notes based on the single paratype worker, sent
through the courtesy of Prof. J. C. Faure for my study. TL 2.8,
HL 0.73, ML 0.29, WL 0.70 mm. ; CI 73, MI 39. Mandibles stout,
gently arcuate, with dentition as in Figure la. Eyes exception-
ally large and convex, narrowly rounded anteriorly and sep-
arated here from the head by a deep, narrow preocular notch
as shown in Figure lb. Posterior mesonotum depressed below
level of propodeal dorsum; propodeal lamella with a short but
acute, elevated tooth above, convex below (Figure lc). Petiole
with a long, narrow peduncle having a spongiform border be-
neath ; node broader than long, with moderate posterior spongi-
form fringe. Postpetiolar node transverse, smooth and shining
at least in the middle. Basigastric costulae distinct, fanning
from bilateral sources and extending almost to the midlength
of the basal segment. Head and promesonotum with moderately
abundant small, reclinate spoon-shaped hairs ; gastric dorsum
with sparse erect remiform hairs in transverse rows. Color
light ferruginous.
16 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The very large eyes mark this form at once among the Old
World Strwmigenys, and rival those of the Amazonian S. tococae
Wheeler. E. K. Hartwig collected the types while "beating for
thrips, " so it is possible that, like S. tococae, the eye develop-
ment may be correlated with strongly epigaeic foraging habits, or
perhaps even a snbarboreal mode of life. Such a correlation holds
well for a number of neotropical dacetine ants.
Figure 1. Strumigewys pretoriae Arnold, paratype worker; a. apex of
mandible; b, eye and periocular region, dorsal view; c, outline of propodeum,
lateral view; all to same scale.
Strumigenys new species, Bernard ms.
Worker. Notes based on two workers collected at different
localities in the Belgian Congo by N. A. Weber (see below).
This distinctive little species is widespread in the Congo drain-
age system and is apparently common in the southern part of this
region, as shown by several small series loaned by Prof. Bernard
from the Machado Angolan collections. Prof. Bernard has in-
dicated a desire to describe this species from his more abundant
material in his forthcoming work on the Angola ant fauna.
TL 1.9-2.0, HL 0.52, ML 0.29-0.31, WL 0.44-0.45 mm.; CI
69-70, MI 57-60. This very slender species has long, narrow,
gently arcuate mandibles and small compound eyes with deep,
narrow preocular notches, marking its close relationship to
rogeri, rufobrimea and lo?idianensis. The apical teeth are long
and slender, longer than in rogeri and rufobrunea, and the
proximal preapical teeth of both mandibles are also quite well
developed. In the case of the distal preapical tooth, however,
only that of the right mandible is normally present, and even
this is difficult to see at full closure because it is then covered
by the dorsal apical tooth of the left mandible. In one of the
brown : ant genus Strumigenys FRED. SMITH 17
specimens I have seen, the left mandible bears an extremely
minute projection at the proximal side of the base of the dorsal
apical tooth, and this projection may be an artifact, a structural
defect, or the vestige of a distal preapical tooth. I do not think
it wise to mount this specimen for examination by transmitted
light until further material is available, as this is one of only
two taken by Dr. Weber and deposited in American museums.
In any case, the projection is so very small as to be insignificant,
and it was not present in any of the remaining samples I have
examined.
Localities for material examined : BELGIAN CONGO : 10
miles E. Stanleyville, 1 worker (Weber, No. 2225). Beni to
Irumu, Ituri Forest, 1 worker (Weber, No. 2129B). ANGOLA:
Collections by A. de Barros Machado, all from vegetable debris
of the soil in gallery forest of various river tributaries of the
Congo system; Nos. 54-5, 1130-29, 1195-24, forest of Luachimo
R., near Dundo; No. 408-1, forest of R. Sanga, branch of R.
Luachimo, near Dundo ; No. 403-2, forest of R. Tchimana, branch
of R, Tchikapa ; No. 1430-20, left bank of R, Kasai, NE corner
of Angola.
This form is most like S. londianensis, from which it differs
very markedly in size, form of propodeal lamellae, and other
features.
Strumigenys rufobrunea Santschi
Strumigenys rufobrunea Santschi, 1914, Boll Lab. Zool. Portici, 8: 373,
worker, female. Type locality: Conakry, French Guinea, by present
selection. Additional orig. loc. : Olokomeji, Nigeria. Lectotype, by
present selection, the female from Conakry in Naturhist. Mus., Basel ;
other original syntypes deposited with lectotype.
Strumigenys (Proscopomyrmex) faurei Arnold, 1948, Occas. Pap. Nat. Mus.
S. Ehodesia, 2 (14) : 226, figs. 12, 12a, worker, female. Type locality
(orig. designation): Sordwana, Zululand. Other orig. Iocs.: Richards
Bay and St. Lucia Lake, Zululand. Holotype and paratypes: Nat. Mus.
S. Rhodesia, Bulawayo. Paratypes: Agric. Res. Inst., Univ. Pretoria;
Mus. Comp. Zool. Harvard Univ., etc. NEW SYNONYMY.
Strumigenys petiolata Bernard, 1953 (1952), Mem. Inst. Fr. Afr. Noire, 19
(1): 254, fig. 14 H, I, J, worker. Type locality: Mt. Nimba, French
Guinea, 700 M, in termitary in forest. Holotype: Mus. Hist. Nat.
Paris. NEW SYNONYMY.
18 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
8. rufobrunea is a common and highly variable species ranging
widely in tropical Africa. When Santschi first described the
species, he overlooked the important eye notches, thus mislead-
ing Arnold, who described the same form more accurately
under the name faurei. The recent description and figures of
8. petiolata Bernard are in several respects incomplete and self-
contradictory, and also fail to show eye notches. I believe this
omission is due to the deplorably poor method of card-mounting
practiced on ant specimens in many European museums; many
of the choice samples sent me from the Old World have been
rendered worthless by semi-immersion in adhesive that is virtu-
ally impossible to remove in any solvent without damage to
pilosity and other important details. One is frequently aston-
ished at the gross inaccuracy of what are supposed to be scientific
descriptions, but this astonishment is both explained and magni-
fied anew when the slovenly preparations upon which these de-
scriptions are so coolly based become available for re-examina-
tion. It must also be admitted that some American preparations
on the more desirable point mounts are so poorly done as to be
equally worthless. In my opinion, no descriptive myrmecological
work, however pretentious, can be trusted if the material upon
which it is based is improperly prepared.
To return to S. petiolata : Bernard considered this form closely
related to 8. reticulata Stitz (actually a synonym of Serrastruma
lujae), to S. hindenburgi Forel (an Argentinian species as dis-
similar from petiolata as its geographical remoteness suggests),
and to 8. grandidieri. Nothing is said about the really closely
related forms like londianensis, rogeri, and the senior synonyms
rufobrunea and faurei. Though I have not seen the petiolata
type, and in spite of the confused circumstances surrounding its
description, I believe that it is only a fairly large specimen of
rufobrunea well within the variation outlined below. I have
been able to compare directly the type of S. rufobrunea, work-
ers and females of the type series of S. faurei, and a large amount
of other material from diverse localities, and the notes below
summarize the specific characters of the two female castes.
Special emphasis is placed on variation within the species.
Worker. Measurements are based on 25 workers from at least
11 separate colonies from 8 localities listed below, excepting
brown : ant genus Strumigenys fred. smith 19
the Angola samples. HL 0.50-0.62, ML 0.22-0.30 mm.; CI 75-81,
MI 43-49. Examples from single collections : Khor Aba, Anglo-
Egyptian Sudan (Weber, 1470), HL 0.62, ML 0.30 mm.; CI 81,
MI 48, one worker. Gross Batanga, Cameroon (Schwab), HL
0.60, ML 0.30 mm. ; CI 80, MI 49, one worker. 8. faurei type
series, St. Lucia Lake and Richards Bay, Zululand, HL 0.52-0.56,
ML 0.25-0.26 mm. ; CI 75-79, MI 45-48, 12 workers. Ituri Forest,
Belgian Congo (Weber, 2124, 2129A), HL 0.50-0.51, ML 0.22-
0.24 mm.; CI 76, MI 43-47, 4 workers. Haut Mbomu, French
Equatorial Africa (Weber, 2187, 2192), HL 0.50, ML 0.24 mm.;
CI 76-77, MI 48, two workers. Same locality (Weber, 2188), HL
0.60, ML 0.28 mm.; CI 76, MI 47, one worker. Fort Portal,
Uganda (Weber, 2095), HL 0.55, ML 0.25 mm.; CI 76, MI 45,
one worker. Although none was measured from the six series
collected by Machado in the Congo and Angola (see below), the
workers here show a similar range of variation so far as can be
determined by simple inspection.
The larger workers often have broader heads and deeper,
narrower, more distinct eye notches, but exceptions occur both
ways. Larger workers also frequently have the pronotum evenly
punctulate, while smaller ones usually have feeble longitudinal
rugulation predominating on the pronotum ; all intergrades occur.
The postpetiolar disc varies from smooth and shining in most
series to finely longitudinally striate in the faurei types and
certain Angolan samples; here again, intergrades are found.
The proximal and distal preapical teeth are present on both
mandibles, the distal being considerably smaller than the proxi-
mal. The shafts of the mandibles are gently but very distinctly
arcuate, clearly more strongly so than in rogeri. Color varies
from light to deep ferruginous, and certain Angolan samples
are nearly black.
Female. Lectotype, HL 0.52, ML 0.23 mm. ; CI 73, MI 44. A
single dealate specimen from Kawanda Experiment Station, near
Kampala, Uganda (soil sample under elephant grass, Pennisetum
purpureum (G. Salt), HL 0.60, ML 0.28 mm.; CI 78, MI 47.
Two dealates from faurei type series, allonidal, HL 0.57-0.58,
ML 0.27-0.28 mm.; CI 80-81, MI 46-47. Total ranges for the
above 4 females; HL 0.52-0.60, ML 0.23-0.28 mm.; CI 78-81,
MI 44-47. Variation in these and a few Angolan females parallels
that of the workers.
20 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Male unknown.
In addition to the localities cited above, six series have arrived
after the main work on this species was completed, sent by Prof.
Bernard from the collections of Machado, all taken in vegetable
detritus in gallery forest in the southern Congo drainage area :
BELGIAN CONGO, between Tchikapa and Luluabourg, 100 km.
east of Tchikapa. Gallery forests of the rivers Luachimo,
Tchimana and Sanga, mostly near Dundo, ANGOLA ; Machado
Nos. 180-19, 403-2, 408-1, 1195-24, 1210-12, 1248-29.
From the available ecological data, it would seem that 8.
rufobrunea can occupy a great range of habitats, but it appears
most often to be found in rainforest or gallery forest, or tree-
shaded parts of the savannah. It is the commonest member of
the genus in Africa, if collection frequency is any guide. This
species could be confused only with 8. rogeri, but rogeri has
longer, straighter mandibles and differs in other ways also.
Strumigenys rogeri Emery
Pyiamica giindlachi Roger, 1862, Berlin, ent. Zeitschr., 6: 253, fig. 18a,
female, nee worker. Type locality: Cuba. Types in Zool. Mus. Univ.,
Berlin.
Strumigenys rogeri Emery, 1890, Bull. Soc. Ent. Ital., 22: 68, pi. 7, fig. 6,
worker. Type locality : St. Thomas, West Indies. Holotype : Mus. Civ.
Stor. Nat., Genoa. Forel, 1893, Trans. Ent. Soc. Loud., p. 378, worker,
female, St. Vincent, W.I., biology. Wheeler, 1908, Bull. Amer. Mus. Nat.
Hist., 24: 145, pi. 12, fig. 13, worker, Puerto Rico. 1913, Bull. Mus.
Comp. Zool., 54: 496. Wheeler and Mann, 1914, Bull. Amer. Mus. Nat.
Hist,, 33: 40, Haiti. Menozzi and Russo, 1930, Boll. Lab. Zool. Portici,
24: 163, Moca, Dominican Republic. Santschi, 1931, Rev. Ent., Rio de
Janeiro, 1: 275, Pinar del Rio, Cuba. M. R. Smith, 1936, Jour. Agr.
Univ. Puerto Rico, 20: 856, fig. 12, Puerto Rico, ecology. Donisthorpe,
1915, British Ants, p. 341 (1927, 2nd ed., p. 393), synonymy and refs.,
summary records from greenhouses in British Isles. Brown, 1948,
Trans. Amer. Ent. Soc, 74: 113, Fiji, Hawaii. Other locality records
from West Indies occur in the literature, but are repetitious and will
not be cited here.
Strumigenys incisa Godfrey, 1907, Notes R. Bot. Garden Edinburgh, 17: 102,
fig., worker. Type locality: Hothouse, R. Bot. Garden, Edinburgh.
Types: locality unknown. Synonymy teste Donisthorpe, 1915, loo. cit.
Strumigenys sulfurea Santschi, 1915, Ann. Soc, Ent. France, 84: 261, worker.
Type locality: Samkita, Gabon. Syntypes: Naturh. Mus., Basel. NEW
SYNONYMY.
brown : ant genus Strumigenys fred. smith 21
Worker. One syntype had an HL of 0.57 mm. ; CT 72, MI 53.
Ten workers from various West Indian and Hawaiian localities :
HL 0.58-0.62 mm., ML 0.30-0.34 mm. ; CI 70-74, MI 55. Except
for the very slightly smaller size, the syntype agrees very well
with abundant material available to me from the West Indies
and various Pacific islands. The extra-African material, as
would be expected of a tramp species stemming from a single
female, or at least from a restricted-locality stock, is unusually
uniform. There can be little doubt of the origin of S. rogeri
in Africa. It has no close relatives in the New World endemic
fauna, and it is clearly very close to 8. rufobrunea, S. londian-
ensis and other African species, previous accounts to the con-
trary notwithstanding.
8. rogeri is so well known, and so frequently described and
figured in the literature, that no new description is required
here. To emphasize a few points : the eyes are small, but the
preocular notches are distinct, deep and narrow. Mandibles
robust, very nearly straight, lying very close together when
closed, the preapical teeth two on each mandible, stout and
moderate in length, close to apex, the distal tooth much the
shorter of the two. Body and head slender; ground pilosity
arranged as in related species, inconspicuous. A pair of slender,
erect remiform hairs on vertex, a transverse row of four on
occiput, one on each side of the mesonotum, and several on the
nodes and gastric dorsum ; humeral angles each with a contorted
flagellate hair. Mesonotum sharply depressed posteriorly, the
low portion forming a continuous convexity with the propodeal
dorsum. Propodeal lamellae distinct, with short, acute teeth above.
Postpetiole more or less smooth and shining. Gastric dorsum
with 5 or 6 coarse but not long costulae on each side at base.
Color uniform light or yellowish ferruginous.
The female of S. rogeri differs from its worker in the usual
ways, and the compound eyes are unusually large. It can be dis-
tinguished from the 8. rufobrunea female by means of its slightly
narrower head and longer, straighter mandibles, which are a
little more than half as long as the head proper. In addition to
specimens from most of the localities cited in the synonymy, I
have seen material from Micronesia (H. S. Dybas), Jamaica
(H. B. Mills), Trinidad (N. A. Weber).
22 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
I am fortunate also in having important notes on the biology
of 8. rogeri made by E. 0. Wilson during his stay in Cuba in
the summer of 1953 ; these have been turned over to me in their
entirety, and I have abstracted them for use here so that the
habits of at least one member of the group should be illuminated
along with the routine revisionary data. It should be borne in
mind that the following notes were made in a habitat other than
the native one for the species, and that the majority of feeding
notes of this kind necessarily come from observations made in
artificial circumstances.
Wilson took his observation colony at San Vicente, Pinar del
Rio, Cuba, from a small nest under a rotten limb lying on well
shaded ground. The galleries extended into the wood itself.
Transferred to a small plaster observation nest, the workers
readily captured numbers of entomobryoid collembolans prof-
fered ; campodeids up to four times the length of the ants were
also always accepted and, like the entomobryoids, were fed to
the larvae. Also observed to be chewed by the larvae after cap-
ture were a small psocopteran, a small ichneumonid wasp, and a
small, injured embiopteran that had previously been ignored by
a colony of Smithistrwna nigrescens Wheeler. A symphylan
and a pseudoscorpion, one each, were accepted and eaten by the
larvae, but only after lengthy contact with the ants. Other
specimens of these last two groups seem to have been refused
by the larvae after capture on some occasions. A small polydes-
mid millipede was also captured, but soon rejected by larvae
and workers. Consistently avoided or ignored when offered in
the intimate confines of the observation nest were mites, nasute
and other termites, small isopods, poduroid collembolans, adult
staphylinid and sylvanid beetles of small size, a small campodei-
form beetle larva, and dead mosquitoes, though the beetles
mentioned disappeared from the nest and may possibly have
been eaten. Drosophila adults were caught by the adults, but
later discarded.
Entomobryoid collembolans seemed to be the usual and pre-
ferred prey fed to the larvae, although campodeids were never
refused. In feeding habits, therefore, 8. rogeri follows the
generic habit of collembolan predation but, like some other wide-
spread dacetine species, it will also accept a variety of other
brown : ant genus Strumigenys fred. smith 23
small arthropods, particularly campodeids, when available. In
hunting, or when disturbed, the workers and females open the
mandibles to slightly more than 180°.
In view of the fact that collembolan preclation is now known
to furnish the basic food supply for widely differing Strumigenys
species in all three of the major faunas of the world, it seems
reasonable to assume that it is general for the genus and also
that it is a primitive habit for the genus in the phylogenetic
sense. The cases in which the exclusive diet of entomobryoids,
isotomoids and symphypleonans is exceeded, show an erratic
choice of additional prey, and it does not seem possible at the
moment to predict for a given species just what additional kinds
of arthropods may be taken over and above the collembolan
groups named. This circumstance suggests that widened prey
preferences may be secondarily acquired. Relatively common
and successful species seem to accept a wider variety of non-
collembolan prey than do the ants which are rarer and ecolog-
ically more restricted. The rejection of poduroids as prey seems,
however, to be nearly or quite universal among Strumigenys and
the other dacetine genera so far studied. The generality of
collembolan predation can probably be extended to all the
African-Malagasy species of Strumigenys.
Strumigenys scotti Forel
Strumigenys scotti Forel, 1912, Trans. Linn. Soc. Lond., Zool., (2) 15: 159,
worker. Type locality: Mare aus Cochons, ca. 1000 ft., Silhouette, Sey-
chelles Is. Syntypes: Mus. Hist. Nat., Geneva.
Worker. One syntype examined through the courtesy of Dr.
Ch. Ferriere: TL 2.6, HL 0.67, ML 0.31, WL 0.66 mm.; CI 66,
MI 47 ; scape L 0.40 mm. Twelve workers selected from two large
nest series from Makambrera, ea. 1300 M., Sao Tome Island
(B. Malkin) : HL 0.59-0.63, ML 0.30-0.32 mm.; CI 68-71, MI
49-51.
The differences in size and proportions between the two
samples available are not excessive when one considers that
the first is limited to a single example ; furthermore, the localities,
one on an island in the Gulf of Guinea and the other in the
Indian Ocean, are probably secondary ones populated within
recent times from the African mainland. As in the case of
24 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
S. rogo-i, such insular populations are at once more limited in
their variability and denser in their structure than the hypo-
thetical parent continental stock, the latter remaining uncollected
to the present day. Though I was not able to compare directly
the syntype of 8. scotti with the Sao Tome sample because the
latter arrived after the type had been returned to Switzerland,
my extensive notes on the type reveal no significant differences of
the sort that usually distinguish species in this group. In this
case offshore colonization may well have proceeded from two dif-
ferent segments of the mainland population.
8. scotti is a medium-sized species without preocular notches.
It is similar to S. havilandi in general size and appearance, but
differs in a number of details, the most readily apparent being
the much larger eyes in scotti, especially as compared to the more
slender antennal scapes (see key). The mandibles are incurved
at their bases and have well developed distal and proximal pre-
apical teeth, though the distals are shorter than the proximals.
Posterior mesonotum depressed, continuous with plane or feebly
convex propodeal dorsum except for a feebly marked metanotal
groove. Propodeal teeth sharp, strongly elevated, with narrow,
concave lamellae beneath.
Petiole with a rather long peduncle having a narrow ventral
spongiform strip ; posterior appendages of node nearly obsolete.
Postpetiole transverse-elliptical, convex above, smooth and shin-
ing, its ventral spongiform appendages moderate in bulk. Basi-
gastric costulae short, indistinct, grouped bilaterally. Ground
pilosity of head composed of inconspicuous narrow spatulate
reclinate hairs, generally distributed except for the occipital 2/5,
where they are much reduced and partly replaced by 6 slender,
erect, blunt or subclavate specialized hairs, of which there are
also a pair on the mesonotum, a smaller pair on the posterior
mesonotum, and groups becoming more numerous on the nodes
and gaster. Humeri each with a long, finely flagelliform hair.
A female from one of the Makambrera colonies : HL 0.61, ML
0.31, forewing L 2.3 mm. ; CI 72, MI 50. Eyes very large.
Strumigenys marleyi Arnold
Strumigenys havilandi race marleyi Arnold, 1914, Proc. Ehodcsia Sci. Assoc,
13: 31, pi., fig. 10, worker. Type locality. Durban, Natal. Syntypes:
brown : ant genus Strumigenys fred. smith 25
Nat. Mus. S. Rhodesia, Bulawayo. 1917, Ann. S. Afr. Mus., 14: 378,
worker.
Strumigenys marleyi Arnold, 1926, Ann. S. Afr. Mus., 23: 286, worker.
Worker. Two syntypes, TL 2.4-2.5, IIL 0.62, ML 0.22, WL
0.60 mm. ; CI 76-77, MI 35-36. Related to 8. scotti, but mandibles
much shorter and more broadened at the base, recalling-, in less
extreme version, certain species of the Labidogenys complex of
the Indo-Australian Region (S. biroi Emery, 8. emdeni Forel) ;
the trend is surely a convergent one. Distal preapical teeth
much smaller than the proximals, the right slightly larger than
the left. Apical fork with ventral tooth slightly shorter than
dorsal and bearing on its ventral basal surface a small acute
adventitious tooth and a minute intermediate denticle. Arnold's
figure is highly diagrammatic, and shows a small median clypeal
protuberance corresponding to the approximate position of the
projecting labral lobes. Eyes weakly convex, with 6-7 facets in
the greatest diameter, the diameter being distinctly greater than
the maximum width of the scape.
Head and promesonotum covered with small inverted-spoon-
shaped hairs, generally distributed dorsally, but no specialized
erect hairs. Sparse, short, posteriorly inclined remiform hairs
arranged symmetrically on nodes and gastric dorsum.
S. marleyi is known only from the type collection, made by
Arnold in a nest of Pheidole punctulata Mayr. This Strumigenys
is similar to S. scotti in overall size and form, and in the size
of the eyes ; on the other side, it seems related by tendencies in
the development of mandibles and pilosity to the smaller form,
S. arnoldi.
Strumigenys havtlandi Forel
Strumigenys havilandi Forel, 1905, Mitt, naturh. Mus., Hamburg, 22: 13,
nota, worker. Type locality: "Natal, 5300 feet." Syntypes: Mus. Hist.
Nat., Geneva ; Natal Mus., Durban ; Mus. C'omp. Zool. Harvard Univ.
Santschi, 1913, Bull. Soc. Ent. France, p. 1257, worker, in key. Arnold,
1917, Ann. S. Afr. Mus., 14: 377, worker
Worker. Two syntypes, TL 2.5-2.8, HL 0.62-0.65, ML 0.33-0.34,
WL 0.67-0.70 mm. ; CI 71-73, MI 52-53. Mandibles very feebly
arcuate, their shafts noticeably tapered apicad ; both preapical
26 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
teeth of each mandible very slender, long- and acute, only a little
shorter than dorsal apical tooth. Compound eye minute, scarcely
half as wide as the maximum width of the robust antennal scape.
Alitrunk in profile very shallowly concave in the posterior
mesonotal region, its outline almost straight. Hairs shorter,
broader at apices, more numerous and more generally distributed
on posterior cephalic dorsum than in 8. scotti. In addition to the
usual sparse erect spatulate hairs, the gastric dorsum bears
sparsely distributed short, linear-spatulate appressed hairs. I
have not seen the sexual forms of this species, or records other
than the original one.
Strumigenys arnoloi Forel
Strumigenys Arnoldi Forel, 1U13, Ann. Soc. Ent. Belg., 57: 114, worker.
• Type Locality: Bulawayo, S. Rhodesia. Syntypes: Nat. Mus. S. Rho-
desia, Bulawayo; Mus. Hist. Nat., Geneva'?
Strvmigenys avnoldi Arnold, 1917, Ann. S. At'r. Mus., 14: 376, pi. 8, figs.
117, 117 ad, worker.
I have not seen type material, but have examined a specimen
from Pretoria (J. C. Faure), determined by Dr. Arnold, the
original collector, and thus presumed authentic. Also available
are 3 workers and a dealate female, preserved rather poorly,
from Eldoret, Kenya (S. Patrizi). Tbese two samples are closely
similar despite the geographical separation. Worker: TL 2.1-2.2,
HL 0.54-0.55, ML 0.21-0.22, WL 0.54-0.55 mm.; CI 77-78, MI
38-41. Female: HL 0.60, ML 0.24 mm.; CI 76, MI 39.
S. arnoldi is similar to #. tragaordhi, but differs in having a
longer, slightly narrower head proper, while its mandibles are
both relatively and absolutely shorter. The spoon-shaped pilosity
of the anterior cephalic dorsum is broader and more conspicu-
ous, and extends more abundantly to the promesonotum. In
these samples of arnoldi, the only specialized erect hairs of the
alitrunk are one clavate pair astride the mesonotum ; no special-
ized humeral hairs.
Dr. Arnold took the types of this species under a stone in a
nest of Bothroponera krugeri Forel.
Strumigenys tragaordhi Santschi
Strvmigenys Tragaordhi Santschi, li)13, Bull. Soc. Ent. France, p. 2.17,
worker, original diagnosis in key.
brown : ant genus Strumigenys fred. smith 27
Strumigenys traegaordhi Santsehi, 1914, Medd. GSteborgs Mus. Zool. Afd.,
3: 28, fig. 4, worker. Type locality: Pietermaritzburg, Natal, by present
selection. Additional orig. loc: Sweetwaters, Natal. Syntypes : Naturh.
Mus., Basel.
Worker. Two lectotopic syntypes, courtesy of Prof. Ed.
Handschin, HL 0.51-0.52, ML 0.23-0.25 mm. ; CI 79-80, MI 45-48.
This is a rather " average-looking" small Strumigenys. Mandi-
hles weakly arcuate, somewhat broader than as shown in Sant-
sehi 's figure and gently tapered from base toward apex, enclosing
a large oval space at full closure. Distal preapical teeth of both
mandibles very small, that of the right slightly larger. Ground
pilosity of head composed of narrow inverted-spoon-shaped hairs
distributed over the entire dorsal surface, but becoming small
and inconspicuous on the extreme occiput. Vertex with a pair
of slender, curved, erect, remiform hairs, and a transverse row
of four of these on the posterior occiput. Exposed scape L 0.29
mm. ; funiculus L 0.44 in the larger of the two syntypes.
Alitrunk slender, resembling that of stygia, but promesonotum
slightly more convex, propodeal dorsum straight in profile. A
flagellate hair on each humeral angle ; mesonotum straddled by
two pairs of erect remiform hairs, and the usual sparse remi-
form pilosity on nodes and gaster. Postpetiolar disc smooth and
shining. Color light ferruginous, head very slightly darker.
Various authors have recorded this species from widely sep-
arated East African localities, but the determinations remain
unconfirmed.
Strumigenys dextra new species
Holotype worker. TL 1.6, HL 0.41, ML 0.17, WL 0.40 mm.;
CI 76, MI 42. In general size and appearance resembling S.
amolcli and 8. tragaordhi, but a little smaller even than the
latter. Eyes very small, almost but not quite as wide as the
maximum width of the antennal scape, feebly convex and
laterospicient, without a preocular notch or groove. Mandibles
gently arcuate, gradually and weakly tapered from base toward
apex; dorsal apical tooth decidedly longer than ventral apical
and proximal preapical ; all of these teeth well developed, slender
and acute. Distal preapical tooth present on the right mandible
only, small, concealed at full closure by the dorsal apical tooth
28 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
of the engaged left mandible ; no trace of distal preapical tooth
on left mandible. Scape (L 0.63 mm.) gently curved at base,
feebly and gradually incrassate at midlength; funiculus (L
0.90 mm.; apical segment L. 0.61 mm.) with greatly reduced,
indistinct second and third segments.
Alitrunk in profile gently convex above, with a feeble im-
pression in the region of the posterior mesonotum ; metanotal
groove virtually obsolete. Propodeum with small but acutely
triangular teeth, continued below as feebly concave infradental
lamellae. Petiole distinctly and robustly pedunculate ; node with
gently sloping, bicarinulate anterior face, rounded above, its
spongiform appendages reduced to cariniform vestiges. Post-
petiole convex, smooth and shining above, with fairly well de-
veloped ventral appendages. Gastric dorsum smooth, with a
few coarse costulae extending over about the basal quarter of
the first segment. Dorsum of head, mesonotum, propodeum and
petiole coarsely retieulopunctate, opaque. Pronotum rather
coarsely longitudinally rugulose, with broad interspaces weakly
shining; posterior sides of alitrunk smooth, shining; appendages,
including mandibles, finely and superficially sculptured, more or
less opaque.
Ground pilosity of head reduced and inconspicuous, except
for a triple row of anteriorly curved spoon-shaped hairs along
each dorsolateral cephalic margin from frontal lobe to posterior
limit of scrobe. A similar single row, curved apicad, on the
anterior border of each scape, and a few hairs forming a clypeal
fringe. Ground pilosity reduced, scanty and inconspicuous.
Specialized erect hairs remiform to claviform : one pair on ver-
tex ; a curved row of 4 along occipital border ; one pair straddling
mesonotum; a pair on each node; about six transverse rows of
4 each on gastric dorsum, smaller toward gastric apex. Legs
and gula with fine, short, flattened reclinate pilosity. Color
yellowish ferruginous throughout.
Holotype taken with 6 paratype workers in a soil sample
under elephant grass (Pennisetum purpureum) at Kawanda Ex-
periment Station, 5 miles north of Kampala, Uganda (G. Salt,
No. SS 30). In the same and adjacent samples were taken other
presumably hypogaeic ant species {P oner a coeca Santschi, Sole-
nopsist sp., and Strumigenys tetraphanes new species).
BROWN: ant genus Si nt migenys fred. smith 29
Two additional workers, not paratypes, were seen from Bnsnia,
at the Kenya-Uganda boundary (N. A. Weber, No. 2080) and
a single worker from Haut Mbomn, Ubangi Shari, French Equa-
torial Africa (Weber, No. 2177). Combined measurements for
the Kawanda and Bnsnia series, 9 workers, TL 1.5-1.6, IIL 0.39-
0.43, ML 0.17-0.18, WL 0,38-0.43 mm.; CI 71-76, MI 40-43.
Internidal variation only very slight. Busnia series with slightly
broader hairs on the lateral cephalic borders than in the type
series. In addition, I have belatedly examined four small series
from among the material collected by A. de Barros Machado in
Angola, all from the vegetable detritus of the soil of gallery
forests of various tributaries of the Congo system : Camissombo,
87 km. south of Dundo, 850 M. (rain forest), No. 1419-6. Lua-
chimo Forest, near Dundo, No. 1248-29. R. Sanga, Dundo, No.
408-1. Left bank R. Kasai, NE corner of Angola, No. 1430-20.
This little species, related to arnoldi and the other small forms
without eye notches, can be distinguished readily by means of
the asymmetrical mandibular dentition, the lateralized develop-
ment of the cephalic ground pilosity, and the proportions and
relatively coarse sculpture. It is widely distributed and ap-
parently rather common in central Africa.
Strumigenys stygia Santschi
Strumigenys stygia Santschi, 1013, Bull. Soe. Ent. France, p. 257, worker,
original diagnosis in key. 1914, Voy. Alluaud et Jeannel Afr. Or., Hym.,
2: 113, fig. 20, worker. Type locality: Cave A at Shimoni, coastal
British E. Africa. Syntypes : Naturh. Mus., Basel.
Worker. Two syntypes, courtesy of Prof. Handschin, HL 0.49-
0.50, ML 0.18-0.19 mm.; CI 81, MI 37-38. See key. Mandibles
short, stout, feebly arcuate ; dorsal apical and proximal preapical
teeth long and slender ; distal preapical teeth small, that on right
larger than the one on the left. Head broad, and set with broadly
suborbicular to orbicular, shining, pale whitish, stud-like hairs
over its entire dorsal surface. A row of 4 stubby curved suberect
hairs along the occipital margin. Promesonotum broad, de-
pressed, with an indistinct median carinula ; farther posteriad.
mesonotum narrowed and dorsally weakly impressed, forming
with propodeal dorsum a gentle convexity, at the summit of
30 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
which is the feebly marked metanotal groove. Each side of
mesonotum with a stout clavate hair. Postpetiole superficially
sculptured, subopaque to opaque.
Anteunal scape (exposed L 0.26 mm.) distinctly broadened
at about midlength, its greatest width about 0.05 to 0.06 mm.;
sharply narrowed just before apex ; funiculus L 0.36 mm. Color
rather uniform yellowish-ferruginous. This species is known
to me only from the type series.
Strumigenys tetraphanes new species
Holotype worker. TL 2.15, HL 0.54, ML 0.19, WL 0.50 mm. ;
CI 91, MI 36.
Head broad, in general form like that of Quadristruma eury-
cera (Emery) (1897, Term. Fiizetek, 20: pi. 14, fig. 17) of New
Guinea ; dorsum depressed, only feebly convex. Posterior ex-
cision rather deep ; occipital lobes rounded, produced laterally
at greatest breadth of head bluntly and subangularly ; anterior
to this, the lateral borders converging strongly; preocular
laminae feebly converging, almost parallel. Eyes small, only
very feebly convex and without preocular notch, situated on
ventral scrobe borders at about cephalic midlength. Clypeus
much broader than long, obtusely angulate behind, free border
broadly rounded, but feebly emarginate and faintly impressed
in the center.
Mandibles short, robust, resembling those of Strumigenys
mocsdryi Emery (loc. cit., fig. 15) in size, form and position at
full closure, but not in dentition. Dorsal apical tooth about
0.13 mm. long, very slender, sharp, feebly recurved; ventral
apical tooth straight, slender, more than half as long as the
dorsal tooth and feebly diverging from it ; no intercalary teeth
or denticles. The large spiniform preapical tooth, situated a
little distad of midlength of mandible, is about % the length
of the dorsal apical tooth and similar in shape and feeble re-
curvature. About midway between apical and preapical teeth is a
minute but acute denticle (=distal preapical tooth), between
0.01 and 0.02 mm. long, that of the right mandible slightly larger
than that of the left.
Antennal scape 0.27 mm. long, broadly expanded anteriad,
brown : ant genus Strumigenys fred. smith 31
in shape like a naval cocked hat or the space enclosed by a low
normal curve and its baseline. The scapal expansion is not so
extreme as in Quadristruma curycera, but is considerably more
so than in Q. emmae (Emery) or any species of Strumigenys so
far described. Maximum breadth of scape about 0.11 mm. ;
expanded portion feebly convex dorsally. Funiculus 0.34 mm.
long, of which the apical segment occupies slightly more than
3/5 ; basal segment longer than broad, II, III and IV very short,
broader than long; IV as long as or slightly longer than II— {-III.
Alitrunk distinctive in form. Pronotum and anterior mesono-
tum together forming an almost perfect circle as seen from above,
this surface rather strongly depressed dorsally and with blunt,
overhanging lateral pronotal margins; humeral angles not de-
veloped. The surface of this promesonotal disc is divided by the
feeble, sulciform, semi-circular promesonotal suture ; pronotum
with an anteromedian and bilateral, and the mesonotum with
an anterior, dorsal convex area. Behind the promesonotal disc,
posterior mesonotum immediately and strongly depressed and
narrowed, and as seen from above continued posteriad by pro-
podeum to form with it an oblong, parallel-sided section slightly
shorter than the promesonotal disc and less than half as broad ;
this section as seen from the side forming one continuous,
convex dorsal outline, and without lateral margins as seen from
above. Metanotal groove visible on dorsum as a darkened line.
Propodeal declivity steep ; teeth short, half as long as the distance
between the centers of their bases and only moderately acute,
continued below by feebly concave infradental lamellae which
are almost as broad as the height of the teeth.
Petiolar peduncle laterally compressed and longer than its
node. Node small, anteroventrally compressed, broader than
long; as seen from the side high and narrowly rounded at the
dorsal apex. Petiolar appendages reduced to fine vestiges, mid-
ventral strip represented only as a low, non-spongiform carina.
Postpetiole forming a transverse ellipse, about twice as broad as
long and nearly twice as broad as the petiolar node; strongly
convex dorsally ; appendages fairly veil developed, but largely
restricted to the venter. Gaster slightly narrower than head,
somewhat depressed ; anterior spongiform margin medially
emarginate.
32 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
Gastric costulae coarse, radiating from bilateral origins, about
7 or 8 on each side, those nearest the middle oblique, enclosing a
free narrow median triangular area ; longest costulae extending
nearly 1/3 the length of the long basal tergite ; gastric dorsum
otherwise appearing very finely and superficially reticulate
(perhaps due in part to a film of secretion), but still very
strongly shining. Sides of posterior alitrunk shining, but feebly
roughened as on the gastric surface. Mandibular teeth shining.
Remainder of body densely punctulate, opaque ; postpetiole with
very feeble superimposed longitudinal rugulosity.
Dorsum of head from about midlength to posterior clypeal
border thickly set with conspicuous, heavy, suborbicular, sub-
appressed, inverted-spoon-shaped hairs ; a double row of the
same extends posteriad along each dorsolateral cephalic border
as far as the blunt lateral occipital angles, and a single row of the
same, large and very conspicuous (6-7 hairs) lines the anterior
border of each scape. Similar, but very much smaller and less
conspicuous hairs on the clypeus and posterior half of the
cephalic dorsum; contrast between the pilosity of anterior and
posterior parts of head quite striking, as in certain other species
of the S. rogeri group (e.g., scotti). Hairs on anterior clypeal
border similar to the foregoing, intermediate in size, subap-
pressed, 4 on each side of the middle. Alitrunk with a sparse
and altogether insignificant complement of minute appressed
hairs, the surface appearing nude except for a prominent pair of
short, erect, strongly clavate mesonotal hairs. A pair of the
same is directed posteriorly from the postpetiole, and there are
about twelve (some possibly broken off) on the gastric dorsum,
diminishing in size apicad. Legs and scapes with small ap-
pressed spatulate hairs. Underside of head with fine subap-
pressed pubescence ; inner borders of mandibles with a few long
fine hairs. «
Color ferruginous yellow, dorsal surfaces a trifle darker.
Holotype a unique worker taken in a soil sample from under
elephant grass at Kawanda Experiment Station, 5 miles north of
Kampala, Uganda, on Feb. 15, 1949 (G. Salt) with Strumigenys
dextra new species (q.v.) and other ants. Holotype deposited
in Museum of Comparative Zoology, Harvard University.
This aberrant member of the rogeri group is of more than
brown : ant genus Strumig eny 's fred. smith 33
usual interest because it shows affinities to the tropicopolitan
tramp species Quadristruma emmae (Emery), and in fact nicely
links this little form to the rogeri group, and thus to genus
Strumig enys. The fact that Q. emmae has only four segments in
the antennae still separates it from Strumigenys, but the ex-
treme reduction of the second and third funicular segments in
S. tetraphanes makes this difference largely an academic one.
A reappraisal of the genera of subtribe Strumigeniti may well
reveal that Quadristruma Brown (1949) should be merged with
Strumigenys, but whatever the eventual decision, it seems plain
now that emmae is African, not Papuasian, in origin, and that
the rogeri group is directly ancestral. The other Quadristruma
species, Q. eurycera (Emery), may not belong to the same stock
as emmae, and its resemblances to emmae and tetraphanes may
well be convergent ones. The final generic review of the Dacetini
will see this relationship altered in some manner.
S. tetraphanes is readily separated from the other members
of the rogeri group by means of its broad head and short mandi-
bles, and above all by means of its very broad antennal scapes.
Strumigenys irrorata Santschi
Strumigenys irrorata Santschi, 1913, Bull. Soc. Ent. France, p. 257, worker,
original diagnosis in key. 1914, Medd. Goteborgs Mus. Zool. Af'd., 3: .
29, fig. 5, worker. Type locality: Lake Sibayi, Zululand. Holotype:
Naturh. Mus., Basel.
I have not been able to view the unique worker type directly,
but Prof. Handschin has very kindly sent me pencil sketches in
answer to my inquiries. These confirm that both mandibles lack
the distal preapical tooth, although both mandibles are shown
as having long proximal preapical teeth. The compound eye is
portrayed as small, its greatest diameter less than the greatest
scape width ; the drawing shows no obvious trace of a preocular
notch. As measured from Santschi 's figure (loc. Git.), which
may or may not be accurate in showing proportions, the CI
would be about 84 and the MI about 41. Santschi gave the
length as 1.5 mm. total, which is probably too low.
34 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
REFERENCES
Bequaert, J. C.
1950. Studies in the Achatininae, a group of African land snails.
Bull. Mus. Comp. Zool., 105: 1-216, 81 pis. (cf. pp. 50-94).
Brown, W. L., Jr.
1948. A preliminary revision of the higher Daeetini (Hymenoptera:
Formicidae) . Trans. Amer. Ent. Soc, 74: 101-129, 2 figs.
1952. Revision of the ant genus Serrastruma. Bull. Mus. Comp. Zool.,
107: 65-86.
1953. Revisionary studies in the ant tribe Daeetini. Amer. Midi.
Naturalist, 50: 1-137, 10 text-figs., 3 pis. (cf. pp. 3-4, 7-15, 16).
1954 (1953). A preliminary report on dacetine ant studies in Aus-
tralia. Ann. Ent. Soc. Amer., 46: 465-471.
Wilson, E. O.
1954 (1953). The ecology of some North American dacetine ants. Ann.
Ent. Soc, Amer., 46: 479-495.
Publications Issued by or in ( "onnection
with THE
MUSEUM OF COMPARATIVE ZOOLOGY
AT HARVARD COLLEGE
Bulletin (octavo) 1863 -- The current volume is Vol. 112.
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Memoirs (quarto) 1864-1938 — Publication was terminated with Vol. 55.
Johnsonia (quarto) 1941 -- A publication of the Department of Mollusks.
Vol. 3, no. 33 is current.
Occasional Papers of the Department of Mollusks (octavo) 1945 -
Vol. 1, no. 17 is current.
Proceedings of the New England Zoological Club (octavo) 1899-
1948 -- Published in connection with the Museum. Publication terminated
with Vol. 24.
These publications issued at irregular intervals in numbers which may
be purchased separately. Prices and lists may be obtained on application
to the Director of the Museum of ( 'omparative Zoology, ( 'ambridge 38,
Massachusetts.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 2
DEEP WATER ELASMOBRANCHS AND CHIMAEROIDS
FROM THE NORTHWESTERN ATLANTIC SLOPE
by
Henry B. Bigelow
and
William C. Schroeder
CAMBRIDGE, MASS., U.8.A.
PRINTED FOR THE MUSEUM
September, 1954
No. 2 — Deep Water Elasmobranehs and Chimaeroids
From the Northwestern Atlantic Slope1
By Henry B. Bigelow and William C. Schroeder
CONTENTS
PAGE
Introduction 38
Elasmobranehs
Sharks 40
Family Scyliorhinidae, Cat Sharks 40
Apristurus profundorum 40
Family Squalidae, Spiny Dogfishes 40
Centroscyllhim fabricii, Black Dogfish .... 40
Etmopterus princeps 46
Centroscymnus coelolepis, Portuguese Shark 47
Batoids
Family Rajidae, Skates 52
Raja bathyphila 52
Raja fyllae 54
Raja jenseni 60
Raja laevis, Barn Door Skate 62
Raja mollis 63
Raja radiata, Thorny Skate 64
Raja senta 65
Raja spinicauda 66
Chimaeroids
Family Chimaeridae 70
Hydrolagus affinis, Deep Water Chimaera . 70
Family Rhinochimaeridae 71
Rhinochimaera and Harriotta 71
Rhinochimaera atlantica 72
Harriotta raleighana 81
References 84
1 Contribution No. 692 from the Woods Hole Oceanographic Institution.
38 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
INTRODUCTION
The slope of the bottom is so steep from the edge of the
continent at the 150-200 fathom level down to the 800-900 fathom
level off the northeastern United States and off Nova Scotia that
the intervening zone is not wider than about 25 miles, anywhere
between the offing of Chesapeake Bay and the Laurentian Chan-
nel, with a minimum breadth of only 7-10 miles. Nevertheless
this zone, narrow though it be, is of great interest ecolog-
ically, because it is the site of the transition from the bottom-
dwelling animals of the shallow waters of the continental shelf,
to those of the Atlantic abyss.
The explorations by the "Blake," and especially those by the
"Albatross" in the 1880 's, yielded a wide variety of bottom-liv-
ing fishes from the lower part of the slope at depths of 800 fath-
oms and more; they also sampled the bathypelagic communities
of the overlying waters, many additional members of which have
been brought to light subsequently. The fishes, too, of the north-
eastern American shelf have been studied intensively at many
hands for many years, not only from the descriptive-taxonomic
standpoint, but also from the standpoint of the commercial fish-
eries.
But the "Albatross" and "Fish HaAvk" devoted less attention
to the middle part of the slope. (They made only 63 trawl hauls
at 250-500 fathoms, contrasted with 117 hauls deeper than 700
fathoms). And no subsequent attempt has been made to con-
tinue the scientific investigation of the bottom-living fishes in
deep water in the northwestern Atlantic since 1887 when the
"Albatross" was transferred to the Pacific, whether because of
the expense that would have been involved, or because of a shift
of interest to other subjects. And very little commercial fishing,
either with hook and line or with the trawl, has ever been at-
tempted deeper than about 250 fathoms along the slope with
which we are concerned, partly because of the difficulty and
expense of operating commercial gear in greater depths, and
partly because it has not seemed likely that saleable food fishes
would be found on bottom there in worthwhile quantities.
Consequently, while it seemed safe to forecast, from the fish
faunae of shallow water and of deeper, what species of bottom
fishes might be expected along the mid zone of the slope, the
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 39
belt in question was a mare ineognitum, to all intents and
purposes, as regards the quantities of any species to be found
there.
In the hope of filling this gap in our knowledge, trawling
campaigns were carried out by the Woods Hole Oceanographic
Institution along the slope between the offings of southern New
England and of La Have Bank, Nova Scotia, on the "Caryn"
in June and September 1949; between the offings of Montauk,
Long Island, New York, and of La Have Bank from the dragger
"Cap'n Bill II" in June and July 1952; and between the offings
of Virginia and of La Have Bank on "Cap'n Bill II" in June
and July 1953. Otter trawls 35 feet wide were used in 1949,
35 and 50 ft. trawls in 1952, and 60 ft. trawls in 1953. One
hundred and forty-three successful hauls were made in the
three summers combined, dragging on bottom for 30-60 minutes,
between 200 fathoms and 730 fathoms. And a total catch of
about 25,000 bottom fishes in all the hauls combined seems good
evidence that the nets worked with at least moderate efficiency.
The present report deals with the catches of elasmobranchs
and of chimaeroids.
The following species of sharks and skates had been reported,
through 1953, from depths greater than 200 fathoms on the
American Atlantic slope north of Chesapeake Bay: Apristurus
profundorum Goode and Bean 1895; Centroscyllium fabricii
(Reinhardt) 1825; Etmopterus princeps Collett 1904; Centro-
scymnus coelolepis Bocage and Capello 1864; Raja bathyphila
Holt and Byrne 1908 ; Raja jenseni Bigelow and Schroeder 1950 ;
R. mollis Bigelow and Schroeder, 1950 ; R. laevis Mitchill 1817 ;
R. senta Garman 1885 ; and R. spinicauda Jensen 1914. On the
other hand, one species — Scymnodon melas — described by Big-
elow, Schroeder and Springer (1953, p. 233) as new must now be
relegated to synonymy (p. 51).
The trawling operations of "Cap'n Bill II" add R. fyllae Liit-
ken 1887 to this list. And it is likely that R. hyperborea Collett
1878 will be found off Labrador or off Newfoundland sooner or
later. But the number of trawl-hauls that have been made along
the 300-550 fathom zone between the Hudson Canyon and the
offing of La Have Bank, Nova Scotia, is now so large that the list
of elasmobranchs to be found on the bottom there is not likely
to be increased much in the future.
40 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
SHARKS
Family SCYLIORHINIDAE
Cat Sharks
Apristurus propundorum (Goode and Bean) 1895
This deep-water shark had been known from two specimens
only, both of them from the offing of Delaware Bay, until the
summer of 1952 when "Cap'n Bill II" trawled it at 7 stations
(8 specimens) scattered along the slope from the offing of New
York (Lat. 39°46'N, Long. 71°35'W) to the offing of southern
Nova Scotia (Lat. 42°39'N, Long. 63°54'W). And with 8 more,
taken in 1953 at 6 stations, the records for it are numerous
enough now and distributed widely enough to show that it is to be
found generally, though sparsely, along the slope from the offing
of Nova Scotia to that of Virginia (most southerly station, Lat.
37°39'N, Long. 74°06,W; most northerly, Lat. 42°40'N, Long.
63°52'W) . The depths of capture range between 360-420 fathoms
and 640-720 fathoms for the two years combined. The tempera-
ture on bottom, at the stations where it was taken, was 3.7° to 4.5 °C
in 1953, and presumably was about the same in 1952, though no
bottom readings were taken that year at the particular localities
in question.
Points of taxonomic interest are discussed in our earlier paper
(Bigelow, Schroecler and Springer, 1953, p. 214).
Family SQUALIDAE
Spiny Dogfishes
Centroscyllium fabricii (Reinhardt) 1825
Black Dogfish
Earlier captures of the black dogfish on the slopes of the Nova
Scotian Banks, and of Georges Bank, had not been numerous
enough to suggest the existence of more than a sparse population
there, though a widespread one as had been known for many years.
[n fact, only two specimens had come into our hands, in the Museum
of Comparative Zoology, at the time when our earlier discussion
of its occurrence in the western Atlantic was written (Bigelow
and Schroeder, 1948a, p. 486). But catches of 69 black dogfishes
by "Caryn" in 1949, and of 715 and 371 of them by "Cap'n
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 41
Bill II" in 1952 and 1953 respectively, show that our previous
estimate of its numbers off Nova Scotia and off Georges Bank
must be revised upward. This seems, indeed, to be the most
plentiful shark there at depths greater than those frequented by
the common spiny dogfish (Squalus acanthias).
No doubt the reason for the quantitative discrepancy between
the older records for the species in Nova Scotia slope waters, and
the catches of it made there in 1949, 1952 and 1953 is that all of
the former were based on fish taken with hook and line by the
halibut fleet which did not fish much below 200 fathoms, i.e. not
deep enough to sample more than the uppermost fringe of the
population of this deep-water shark.
The number of specimens at hand is now large enough to throw
some light on the quantitative occurrence of the species, both
geographic and bathymetric. The average catches, per successful
haul,1 within the depth range where fabricii was taken at all, were
about 24 specimens to the eastward of longitude 66 °W for the
years 1949, 1952 and 1953 combined (49 hauls) ; between 4 and
5 specimens from longitude 66° to longitude 69°59'W (26 hauls) ;
2 specimens from longitude 70° to longitude 71°59' (10 hauls) ;
and about 1 specimen westward and southward thence to the
offing of Virginia (12 hauls). Similarly, the largest catches made
in any one haul were 92 and 95 specimens east of longitude 66° ;
29 between longitudes 66° and 69°59'W; 8 between longitudes
70° and 71°59,W; and 3 farther to the west and south. The
regularity, too, with which fabricii was taken shows a correspond-
ing gradient from northeast to southwest, for while 97 per cent
of the hauls made in 1952 and 1953, within its preferred depth
zone, yielded it to the eastward of longitude 66°, only 65 per cent
did so along the slope off Georges Bank (longitudes 66° to
69°59') ; 60 per cent in the offing of southern New England
(longitudes 70° to 71°59') ; and 50 per cent farther westward
and southward.
Evidently, then, the center of abundance for fabricii, in
American waters, lies at least as far to the eastward and north-
ward as the offing of western Nova Scotia, perhaps farther still
in that direction. Even here, however, the black dogfish — like
other fishes — vary widely in numbers from place to place within
1 We take no account of such of the hauls as obviously were unsuccessful for
one reason or another.
42
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
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BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 43
sliort distances, independent of the precise depth, as is illustrated
by catches ranging from 3 to 92 per haul within a distance of about
5 miles along the 340 to 520 fathom zone between longitudes
63°58' and 64°06' in 1952; from 15 to 95 per haul within about
10 miles in that same general region in 310 to 625 fathoms be-
tween 63°50' an 64°00' in 1953 ; and from 5 to 40 within a few
miles to the southwestward (longitudes 64°10' to 64°17' ; 280 to
475 fathoms) that same summer. But a plot of the catches made
per haul (Fig. 1) shows that these were not haphazard, for in
each year there was a definite center of abundance, concentrating
at about longitudes 63° 50' to 64° 10', extending for something
like 30 miles along the slope between 310 and 545 fathoms, with
the bottom less productive both to the northeastward and to the
southwestward. And a similar concentration was encountered
some 35-40 miles to the southwestward (longitude 65° to 65°10/)
in 1952 at about that same depth (310-490 fathoms). This
precise locality was not revisited in 1953. The discovery of these
rather definite centers of population is of general interest as
evidence that the relative productivity of the bottom, in fishes,
may vary as widely from place to place, far down the slope, as
every fisherman knows that it does on the great fishing banks on
the continental shelf.
It may be worth adding that an average catch of 21 specimens
per haul, with the trawls used, would work out at about 4 speci-
mens per acre, the richest catches (92 and 95 per haul) at about
18 per acre — if the trawls caught all the specimens lying in
their path, which they certainly did not; how much to add for
failure in this respect would be sheer guesswork.
If the catches can be taken at face value, fabricii is only about
Yq-Yq as numerous along the slope of Georges Bank and off
southern New England as it is off Nova Scotia, and still less
numerous farther to the west and south.
Nevertheless, captures of five specimens off Delaware Bay in 3
hauls (Lat. 38°41'N-38°47'N), of one off the coast of Maryland
(Lat. 38°05'N), and of one off the coast of Virginia (Lat.
' 37°39'N) show that fabricii ranges farther to the southward,
along the American Atlantic slope, than had been known previ-
ously.
Off Nova Scotia, the shoalest capture of fabricii was in a haul at
44
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
185-220 fathoms (3 specimens) ; the largest catches (92 and 95
specimens) were made between 310 and 360 fathoms; and the
species seems to have been distributed rather uniformly down
to about 600 fathoms, to judge from average catches of about 28
per haul at 301-400 fathoms, of 22 at 401-500 fathoms, and of
33 at 501-600 fathoms. But catches of only 15 in a haul at 610-
625 fathoms, and 6 in one made at 660-705 fathoms1 suggest
that fabricii is less plentiful deeper than 550 fathoms than
shoaler. But average numbers of specimens taken per haul at
different depths may be deceptive, if taken by themselves, for they
conceal the fact that the numbers caught, in individual hauls,
varied about as widely within representative depth zones as they
did geographically (Fig. 1), no doubt for the same reason.
Maximum and minimum numbers caught per haul, east of
longitude 66°W, in 1949, 1952 and 1953 combined, at depths
greater than 300 fathoms, are as follows :
Depth in
Number of
Fabricii caught
fathoms
hauls
per haul
301-350
12
3-95
351-400
6
4-71
401 - 450
7
0-59
451 - 500
6
1-40
501 - 550
4
3-62
551-600
1
5
601 - 650
1
15
651 - 700
1
6
Farther to the west and south fabricii is not only less numer-
ous, but the upper boundary to its vertical range lies deeper down
the slope, progressively. Thus the shoalest hauls in which it was
taken were at 355-400 fathoms (1 specimen) and 360-420 fathoms
(2 specimens) along the slope of Georges Bank, at 390-460 fath-
oms (3 specimens in 3 hauls) in the offing of southern Massa-
chusetts, and 485-520 fathoms, southward from the offing of
New York.
i These were the only hauls to the eastward of longitude C6C
deep as 600 fathoms, either in 1952 or in 1953.
that worked as
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 45
The deepest catches were made at 660-705 fathoms off Nova
Scotia (6 specimens in one haul) ; at 600-670 fathoms off Georges
Bank (5 specimens in 1 haul) ; at 710-730 fathoms off southern
Massachusetts (5 specimens in 1 haul) ; at 630-675 fathoms (3
specimens in 1 haul) and at 640-720 fathoms (2 specimens in
1 haul) farther to the westward and southward. As these were
the deepest successful hauls, with one exception, that were made
in the respective sectors of the slope, it is a question for the
future how much deeper the range of fabricii may extend.
In 1953, when the temperature was taken on bottom with
maximum-minimum thermometers at almost all the stations
where trawl hauls were made, all the captures of fabricii
occurred where bottom temperatures ranged between about 4.5°C,
and about 3.3°C, the great majority between 4.5° and 3.9°. And
even if the range of fabricii reaches down as deep, say, as 1200
fathoms — of which there is no evidence — its lower thermal
boundary along the American slope would not be colder than
about 2.5°C. At the other extreme, specimens that work their
way up the Nova Scotian slope to 200 fathoms or so, such as were
brought in by the halibut fleet years ago, are likely to meet water
at least as warm as 6-7 °C. Thus, the range of temperature within
which it occurs in greatest numbers in American waters is only
about 2°C, the extreme range there perhaps 4-5 °C for the entire
population.
Consequent on the steepness of the slope, the maximum breadth
of the zone where fabricii occurs the most regularly is only some-
thing like 25-30 miles off the Grand Banks and off Nova Scotia,
even if it ranges down to 1000 fathoms there ; 10-12 miles along
Georges Bank and off southern New England; and perhaps 15
miles in the offing of Maryland and of Virginia.
The catches of fabricii made east of longitude 66 °W averaged
considerably larger in 1952 than in 1953 as tabulated below.
But with the catches in individual hauls ranging from 1 to up-
wards of 90 in each of the two years, the discrepancy may not be
wider than can be credited to what we may call "fisherman's
luck," for want of a better name.
46 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Catches east of longitude 66 °W, at depths
greater than 300 fathoms
Percentage
of hauls Average
Successful Hauls with with Total per Maximum
hauls fabricii fabricii catches haul catch
1952 19 19 100% 610 32 92
1953 15 14 93% 333 22 95
Among 25 specimens that were opened in 1953, 10 were empty;
the others contained remains of fishes, decapod crustaceans,
(shrimps), schizopod or euphausiid, squids, and octopus.1
Etmopterus princeps Collett 1904
We have already reported (with description) the capture of
47 specimens of this deep-water shark along the slope between
the offings of southern New England and western Nova Scotia
(Bigelow, Schroeder and Springer, 1953, p. 47). Earlier records
for princeps had been from the Faroes-Hebrides region (Collett,
1904, p. 3; 1905, p. 28) and from the offing of the Straits of
Gibraltar (Koefoed, 1927, p. 21). The trawlings of 1953 yielded
7 more, all of them from the offing of western Nova Scotia. The
largest numbers taken were 9 (once), 8 (once) and 7 (once)
while 1 was the number taken the most often (fourteen times).
The hauls that took princeps, in the three seasons, were at
depths ranging from 310-320 fathoms down to 490-540 fathoms,
with the largest catches (7, 8 and 9) at 480-520 fathoms, 420-
480 fathoms, and 390-440 fathoms respectively, which suggests
that princeps is about equally plentiful, downward, across the
depth zone along which it occurs off our coasts. And it is to be
expected considerably deeper there as well, for it has been taken
at 1134 fathoms off the Straits of Gibraltar.
The 18 hauls that yielded it in 1949 and 1952 were scattered
all along from the offing of La Have Bank (longitude 63°38/W)
to the offing of Cape Cod (longitude 70°05'W), with the largest
catches (3, 7, 8 and 9 individuals) off Nova Scotia. Similarly, 5
of the 7 specimens taken in 1953 were from the general offing of
La Have Bank, only 2 off the eastern part of Georges Bank,
although many successful hauls were made there and to the
i Stomach contents identified by Dr. Benjamin Laevitt.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 47
westward along the 300-550 fathom zone that summer. It is a
question for the future whether this difference is evidence of a
corresponding fluctuation in the western boundary of princeps,
in numbers large enough for the trawl to pick it up, or whether
we are dealing with a matter of pure chance. In either case, there
is nothing to suggest that this shark ranges westward beyond the
offing of Cape Cod, a limitation we cannot explain as due to
temperature, for readings taken by "Cap'n Bill II" in 1953 on
bottom along the 300-550 fathom zone were very nearly the same
to the westward of longitude 70° W (3.5°-4.8°) as to the eastward
(3.3°-4.5°).
Centroscymnus coelolepis Bocage and Capello 1864
Portuguese shark
The trawlings of 1953 yielded three specimens of this species :
two juvenile males, 565 mm. and 690 mm. long, and an adult
female of 1035 mm. which gave premature birth on deck to 15
embryos 266-282 mm. long, 5 of them males and 10 females. The
number of embryos is in line with Vaillant's (1888, p. 66) record
of 13 to 15 for this species. Moreau (1891, p. 9), it is true, has
reported only 5 for a Mediterranean female, identified as
coelolepis, but her small size (599 mm.) suggests that she be-
longed to some other species in reality.
It has been a tacit assumption, until recently, among students
of sharks, that the denticles which develop on any given part of
the body at different stages of growth are similar in shape ; hence,
that the shape of the denticles is a more or less reliable specific
character — or even a generic one. But Radcliffe (1916, p. 267)
has pointed out that the denticles to be seen on specimens of
different ages differ somewhat in shape in some species of the
genus Carcharhinus. Tortonese, too, (1952, p. 386, fig. 1; p. 387)
has recently found that the denticles on the sides of a juvenile
male, 270 mm. long, seemingly referable to Centroscymnus
coelolepis by other characters, were strongly tridentate, whereas
those on the adult coelolepis have evenly rounded edges, as has
been known for many years. And the "Cap'n Bill II" series of
that species enables us to corroborate his very interesting finding.
Thus those on the body of our adult female 1035 mm. long are
48
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
evenly ovoid in outline, with concave crowns, and regularly over-
lapping (Fig. 2D) ; they have been pictured and described simi-
larly for this species by Bocage and Capello (1866, pi. 3, fig. 3), by
Vaillant (1888, pp. 64-65), by Garman (1913, pi. 14, fig. 8), and
by us (1948a, p. 495, fig. 94A). But the denticles on the embryos
to which she gave birth1 are tridentate, weakly so on the top of
the head, where they are moderately widely spaced, but much
more strongly tridentate on the sides of the body where they are
more widely spaced as well (Fig. 2A).
Fig. 2. Centroscymnus coelolepis. Dermal denticles from side of trunk
below first dorsal fin. A, Embryo male, 282 mm. long, from adult female of
1035 mm., about 13 x. B, Juvenile male, 565 mm. long, about 8 x. C, Juvenile
male, 690 mm. long, about 6 x. B, Adult female 1035 mm. long (mother of
embryo shown in A), about 5 x.
i Embryos well formed, but with only the tips of the teeth exposed, while the
denticles had not yet erupted through the skin.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROms 49
It is evident, too, from partly grown specimens of different
sizes that the margins of the denticles that are developed succes-
sively, during growth, are less and less dentate. The smaller of
the denticles, for example, on the flanks and belly of a juvenile
male 565 mm. long are strongly tridentate still, but the larger
(i.e. younger) ones only Aveakly so, and with one overlapping the
next more or less widely in most cases (Pig. 2.6). At this stage the
denticles on the sides below the first dorsal fin range from about
1.2 mm. to about 2 mm. in length.
At a slightly more advanced stage, as represented by a male of
690 mm., the smallest (i.e. the oldest) of the denticles on the
trunk are tridentate (Fig. 20), but many of the larger (i.e.
younger) ones now have entire margins, though with pointed tips
still, while denticles of intermediate sizes show various inter-
mediate stages and the denticles on the body now overlap so
regularly that they hide the skin.
Up to this stage the denticles vary considerably in size from
one to the next, with those on the sides below the first dorsal fin
ranging from about 1 mm. to about 2.4 mm. in length. But those
on the adult female of 1035 mm. (Fig. 2/)) are all about equal
in size over any given region of the body. And they no longer
include any tridentate forms except near the tips of the pectoral
fins.
This seems an appropriate place to remind the reader that on
adult coelolepis (females, at least; adult males have not been
seen) the denticles are largest (about 3-3.5 mm. long) on the
mid sector of the trunk, belly as well as sides and back, and are
progressively smaller not only forward, but rearward as well, with
those on the caudal peduncle on the average only about 70 per
cent as long as those on the sides below the first dorsal fin.
The discovery that the denticles are of one shape on young
specimens of this particular species of shark, but of a strikingly
different shape on adults, opens vistas that are interesting from
the standpoint of elasmobranch morphology in general, as well
as from that of taxonomy.
To begin with, it poses the question, how long is the normal
life span of a dermal denticle in relation to the life of the
individual ? So far as we can learn, no special attention has been
paid to this point, nor is it safe to reach any conclusion a priori
50 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
here, for while the teeth of sharks, which correspond in all
essentials with the placoid scales or dermal denticles, are replaced
periodically, the dorsal fin spines — equally homologous with
the denticles — are retained throughout life in such sharks as
have them. Among bony fishes, the general rule is that a scale,
once formed, persists throughout the life of the fish, growing in
size meantime, at a rate that keeps pace (more or less) with the
rate of growth of the fish. In fact, the determination of the ages
of fishes by the markings on their scales, a familiar procedure in
fisheries biology nowadays, is based on belief in the validity of
this rule. But Hertwig's (1874, p. 358) observation that new
dermal denticles are formed between pre-existing ones in some
sharks,1 not only during embryonic development but during later
life as well, shows that the situation is not so simple for elasmo-
branchs.
Counts of about twice as many denticles within a given per-
centage of the total length of a specimen, below the first dorsal fin,
of C. coelolepis 565 mm., 690 mm., and 1035 mm. long as on an
embryo of 277 mm. (for details, see p. 49) show that the final
number is developed, in this particular species, by the time a
given specimen is about half grown — how much earlier is not
known. It also seems evident, from the shapes and relative sizes
of the denticles, and from their irregular arrangement, that
several generations of them are represented on small examples
as illustrated by our specimens of 565 and 690 mm. (Pig. 2, B, C).
But the uniformity in size and shape of the denticles on adults,
and the regularity with which they are arranged, suggest that
the ovoid ones that first develop on specimens a little more than
half grown represent the final generation, which persists through-
out the later life of the individual concerned. We can go no
farther than this from information available up until this time.
We think it probable, too, that a similar succession in the shapes
of the denticles takes place between young specimens and adults,
in the case of Centroscymnus owstoni Garman 1906, from Japan,
a near relative of the North Atlantic C. coelolepis. When adult,
its denticles resemble those of adult coelolepis very closely in
shape. But they are tridentate over the trunk as a whole on two
i It is not clear, from the context, whether Ilertwig made these particular
observations on Mustelus, on Acanthias, on Dalatias or on Heptranchias.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 51
Japanese squalids, 260 mm. and 287 mm. long-, in the Museum
of Comparative Zoology, which agree very closely in all other
respects (including very minute denticles, very oblique lower
teeth, and no median tooth in the lower jaw) with two adult
males of owstoni, 785 mm. and 805 mm. long, in the Museum.
Incidentally, the two small specimens just mentioned came from
Japan labelled Scymnodon squamulosus. But they differ sharply
from squamulosus as pictured by its describer (Giinther, 1878,
pi. 2, fig. B) both in their very oblique lower teeth, and in
pectorals reaching back as far as the level of the origin of the
first dorsal fin, for the lower teeth of squamulosus are shown as
nearly erect, and the tips of its pectorals as falling short of the
level of the origin of the first dorsal by a distance about as great
as the length of the snout in front of the mouth.
On the other hand, the successional history of the denticles of
Centroscymnus coelolepis strengthens the specific validity of G.
cryptacanthus Regan 1906, from Madeira, the denticles on the
type specimen of which (about 700 mm. long) were tridentate
with 3 parallel keels on the trunk anterior to the first dorsal,
but "the others smooth, with rounded edges and with a rounded
depression on the free surface of each" (Regan, 1906, p. 437).
Present realization that it is not safe to define species of sharks
by the shape of their denticles — unless the ages of the specimens
in question be taken into account — forces us, next, to conclude
that the juvenile squalids, 330-462 mm. long on which Bigelow,
Schroeder and Springer (1953, p. 233) based the new species
Scymnodon melas actually represent nothing more than an early
stage in the growth of Centroscymnus coelolepis. Thus their
denticles correspond very closely to the smallest and most tri-
dentate of those of our 565 mm. coelolepis (p. 49, Fig. 2B), though
they contrast so strongly with the rounded denticles of the adult
that we would never have guessed that they belonged to the same
genus, much less to the same species, had it not been proven that
the denticles of the young of coelolepis are similarly tridentate,
to be replaced by ovoid ones later. The somewhat wider spacing
of the denticles on the supposed melas than on partly grown
coelolepis points merely to an earlier stage in the growth of the
individuals. Neither can we find any better excuse for retaining
the species, whether in proportional dimensions, in the fins, or
52 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
in the shapes and number of teeth. And while we had thought
its black color distinctive, as contrasted with the chocolate hue
of the adult coelolepis, embryos of the latter, of proven parentage,
are a very deep blue, while half-grown males are black, with
only a faint tinge of chocolate to forecast the color of the adult.
The previous records for this species for the western Atlantic
have been scattered along the slope, from the Grand Banks of
Newfoundland to the offing of Nantucket. It is therefore inter-
esting — as it was unexpected — that the three caught by ' ' Cap 'n
Bill II" were all taken between the offings of New York and
Delaware Bay, as follows:
Length
in mm.
1035
Sex
5
Lat.
38°41'N
Long.
73°01'W
Depth
in fathoms
570-610
690
$
39°09'N
72°21'W
485-520
555
S
38°43'N
72°56'W
630-675
Our failure to take coelolepis off Georges Bank, or off Nova
Scotia, where it was reported so often by the halibut fishermen
3rears ago (Bigelow and Schroeder, 1948a, p. 498), and where
about 90 successful hauls were made in 1949, 1952 and 1953 at
depths greater than 200 fathoms, including about 40 hauls deeper
than 400 fathoms, is something we cannot explain.
Earlier captures of coelolepis in American waters were from
depths of 150-250 fathoms — all of them made with hook and line.
But we have already noted the likelihood that it would be found
much farther down the slope in the western side of the ocean,
as it is in the eastern, if fished for there with suitable gear. And
the "Cap'n Bill II ' trawlings bear out this expectation, by
extending its known range in American waters down to 630
fathoms at least.
BATOIDS
Family RAJIDAE
Skates
Raja bathyphila Holt and Byrne 1908
The capture by "Cap'n Bill II" of a female R. bathyphila,
360 mm. long, on the seaward slope of Georges Bank (Lat.
40°04'N, Long. 68°34'W), at 370-450 fathoms in 1952, and of a
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 53
juvenile male of 370 mm. at a neighboring- station (Lat. 40°10'N,
Long. 68°16'W) at 490 fathoms, added to earlier locality records
for it at one station off Chesapeake Bay, at 3 stations off southern
New England, and at one station off Brawns Bank, in depths of
885 to 1188 fathoms,1 show that this deep water skate is generally
distributed along the mid zone of the continental slope, between
the offings of Chesapeake Bay and of southern Nova Scotia.
Knowledge as to its status farther to the northeastward along
the American slope is to be desired to tell us how wide the gap
may be between the geographic ranges occupied by it in the
western side of the Atlantic, and in the eastern, where it is known
only from the Irish slope (type specimen), so far as we are aware.
The depths of capture recorded for it so far (370-1188 fathoms
on the American slope, 673 fathoms on the Irish) suggest that
its center of population lies deeper than 400-500 fathoms, with
the upper limit little shoaler, if at all, than 350 fathoms.
The most distinctive character of bathyphila is that its entire
lower surface is darker than the upper surface. Indeed, it is
unique in this respect, among the skates that are known from
the North Atlantic outside of the Gulf of Mexico. Within the
Gulf it is paralleled in this respect by the newly described R.
fuliginea Bigelow and Schroeder 1954. But the latter differs from
bathyphila so sharply in a more convex anterior outline as well
as in the prickliness of the lower surface of its tail and of the
upper sides of its pelvic fins that there is little likelihood that
the one species could be taken for the other. For a comparison
of bathyphila with the several skates of the Pacific and Indian
Oceans that are similarly dark colored below, see Bigelow and
Schroeder 1953, p. 161.
A character, almost equally diagnostic for bathyphila among
skates of its geographic province, but one that has not been
stressed previously, is the narrowness of its mouth. In the four
specimens that we have measured2 the breadth of the mouth
ranges from 4.9 to 5.9 per cent as great as the total length. The
only other skates known from the northwestern Atlantic, outside
of the Gulf of Mexico, that approach it closely in this respect are
Raja garmani Whitley 1939 (about 5.7-5.9 per cent) ; R. fyllae
i For details, see Bigelow and Schroeder, 1953, p. 159.
- The two "Ciip'n Bill II" specimens, and two others, the proportional dimen-
sions of which are given in Bigelow and Schroeder 1953, p. 161.
54 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
Liitken 1887 (5.8 per cent in eastern Atlantic specimen, 6.1-7.0
per cent in four of the ' ' Cap 'n Bill II ' ' specimens, 397-497 mm.
long) ; and Breviraja plutonia (Garman) 1881 (5.1, 5.6 per cent,
in two specimens taken off Jacksonville, Florida). And there is
no likelihood of confusing baihijphila with any of these, quite apart
from its coloration. Thus the anterior contour of the disc of bathy-
phila, half-grown and larger, differs widely from that of
fyllae, and the arrangement of thorns and prickles is noticeably
different in the two species, as we have pointed out elsewhere
(1953, p. 159). The plain coloration of the upper surface of
bathyphila contrasts as strikingly with the pattern of dark
rosettes on garmani as does the dark lower surface of bathyphila
with the pale lower surface of garmani. And no one, we fancy,
would be likely to mistake a bathyphila, wedge shaped in front,
with tail only moderately long, and a hard snout, for a plutonia,
with its much more convex anterior outline, much longer tail
and soft snout.
The male bathyphila taken in 1953 has six large thorns along
the mid line of the back from the scapular region to the level of
the axils of the pectorals, with the single median row reaching
back as far as the axils of the pelvics ; the female has seven large
medians between scapular region and level of axils of pelvics,
rearward from which there are 2-3 less regular rows. Thus these
specimens, 370 and 360 mm. long, respectively, represent a stage
in development between the 463 mm. female pictured by us in
Part 2 of Fishes of the Western North Atlantic and the somewhat
smaller (323 mm.) male (1953, Figs. 30, 31A). They agree so
closely with our earlier account of this species in all other
respects that no further discussion of them seems needful from
the taxonomic standpoint.
Raja fyllae Liitken 1887
This skate was included in our general survey of the raj ids
of the western North Atlantic (Bigelow and Schroeder, 1953, p.
194) because of its presence in west Greenland waters, where
it has been known for many years, as it has in boreal and subarctic
latitudes in the eastern side of the Atlantic. The cruises of
"Cap'n Bill II" have now extended the known range of fyllae
to the Nova Scotian slope, and even to the southwestern slope of
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CfllMAEROIDS 55
Georges Bank, in depths of 290-600 fathoms. It must, indeed,
be very generally distributed (though in small numbers) along
this depth zone between the offing of Halifax and the seaward
slope of Browns Bank (longitudes 63°47'W to 65°06'W) for it
was taken in 8 of the 19 successful hauls that were made there
in 1952 (16 specimens) as well as in 8 of the 16 successful hauls
Fig. 3. Raja fi/llae. Left, male, 505 mm. long, off La Have Bank,
M.C.Z. No. 37905; and right, female, 430 mm. long, same general locality,
M.C.Z. No. 37898.
made there in 1953 (13 specimens). And we may expect it to
prove equally widespread around the Newfoundland Banks when
the 300-600 fathom depth zone has been explored there more
fully. But it seems to be much less numerous farther to the
westward — unless at a considerably greater depth — for only
56 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
three hauls (3 specimens) yielded it on the Georges Bank slope
(longitudes 67°02'W to 68°54'W), out of the 24 successful hauls
that were made in 1952 and 1953, combined, at depths greater
than 300 fathoms, between longitudes 66°W and 70°W. And it
was not taken at all in the many hauls made farther to the west-
ward and southward.
The Nova Scotian-Georges slope specimens (Fig. 3) agree so
closely with the specimen from southwest of Ireland, figured by
us (Bigelow and Schroeder, 1953, Fig. 39), both in shape of disc,
in proportional dimensions including length of tail, and in dermal
armature, that no cleavage is apparent between the populations
inhabiting North American and north European waters. But
the additional material allows us to expand our earlier descrip-
tion of the species in the following particulars.
A — Length of tail. In 7 of the larger specimens, 407-505 mm.
long, including 2 mature males, the tail, measured from the
center of the cloaca, occupies 58-61 per cent of the total length,
and the ratio between length of tail and length of body is between
1.35 and 1.56. In 5 juveniles of both sexes, 198-272 mm., this ratio
is 1.69-1.80. In B. erinacea and in B. ocellata (only skates with
which fyllae might be confused in American waters) the ratio,
length of tail to length of body, is about 1.00-1.35.
B — Shape of disc. The anterior contour of an adult male
505 mm. long, in the "Cap'n Bill II" series (Fig. 3) parallels
closely that of a somewhat larger male (555 mm. long) from
West Greenland that was pictured first by Liitken (1898, PI. 2),
and subsequently by Clark (1926, PI. 22, fig. a) in being deeply
concave on each side, abreast of the spiracles, a point worth
mentioning since these are the largest males that have yet been
seen, so far as we are aware. Females from off Nova Scotia, 397
and 430 mm. long, agree very closely in the shape of their discs
with a female of 452 mm. taken southwest of Ireland that we
have pictured elsewhere (Bigelow and Schroeder, 1953, p. 195,
Fig. 39).
Students of skates have learned, long since, to expect con-
siderable variation in dermal armature from specimen to speci-
men in nearly every species, both for the larger thorns and for
the smaller prickles as well, though each species shows a basic
arrangement that is characteristic of it. Our predecessors have
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 57
observed, already, that fyllae is no exception to this ride ; and
the Nova Scotian specimens afford an additional illustration.
Thus the areas bare of prickles that tend to develop on the upper
surface of its disc, as this skate grows, vary considerably in
their extent among- the females, independently of the sizes of
the latter. In one, 430 mm. long, there is a bare area behind
each spiracle, reaching rearward to the shoulder region, and
there are no prickles on the upper surface of the pelvics. But
the regions rearward from the spiracles are prickly on another
female of 397 mm., and also the upper surface of the posterior
lobe of each pelvic fin, much as they are on a female of about
this same size taken off Ireland (Bigelow and Schroeder, 1953,
Fig. 39), and in all of the smaller specimens of both sexes taken
off Nova Scotia.
The males, as they mature, tend to lose any prickles they may
have had earlier on the pelvics, and also to lose part of the larger
thorns from the mid-dorsal belt of the disc between the levels
of the pectoral girdle and of the axils of the pectorals.
It was known, previously, that the upper surface of the tail,
which is set with prickles (besides the thorns) on small specimens,
loses most of these prickles with growth. It now seems that this
alteration is a more regular one than previous observations had
suggested, for while the tail is uniformly and densely prickly
above on the Nova Scotian juveniles, to 270 mm. long, it is wholly
bare of prickles along a definite median band throughout its
length back to the first dorsal fin on the larger Nova Scotian
specimens of 397-505 mm. The shape, too, of the tail alters in
fyllae with growth, from arched above in the young to flat above
in adults, along the median band that has become bare of prickles.
A feature which seems to have escaped scientific attention is
that the mucous pores on the nuchal region of fyllae are arranged
in a pattern that is conspicuous on small specimens as well as on
large. The only other skate of the western North Atlantic in which
the pores in this region are noticeable is R. laevis, but they are
black pigmented in the latter, whereas they are pale in fyllae.
Thirty to thirty-eight series of teeth have been recorded for
fyllae. In the larger of the Nova Scotian specimens, 397-505 mm.
long, the number of series varies more widely in the upper jaw
(30-38) than in the lower jaw (30-32). It is not known whether
58 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
this same disparity obtains for the European population of this
species.
The northeastern Atlantic and west Greenland representatives
of fyllae so far seen have been ashy gray to chocolate brown
above, the adults uniform, the young marked more or less dis-
tinctly with darker spots. One of the larger of the Nova Scotian
females 430 mm. long, and 2 others half to three-quarters grown,
are similarly of a uniform ashy gray tint above. But 5 other
females are conspicuously marked, above, with an oblong whitish
blotch, longer than wide, between the eyes, and with a similar
but vaguely outlined pale blotch on the inner posterior part of
each pectoral fin, a pattern of which we find no previous report
for fyllae. One large male and 1 half grown lack these blotches
but 1 large and 2 half to three-quarters grown males are so
marked for R. fyllae. The lower surface is uniformly grayish
white on the largest Nova Scotian male (505 mm.) both on tail
and on disc. But the lower surface of other large specimens is
more or less smoky around the outer posterior edges of the
pectorals, in the region of the cloaca, and on the anterior parts of
the pelvics; their tails are variously dark-blotched or mottled
below ; the region of the gill openings is smoky on one of them ;
and there is a smoky prepelvic blotch on three of them. Thus
the dark markings on the lower surface vary as widely from
specimen to specimen in extent and in arrangement among the
Nova Scotian population as among the Greenland and eastern
Atlantic populations.
The fact that the claspers are small, still, on one "Cap'n Bill
II" male of 442 mm., but seem ready to function on another of
505 mm., on which the alar thorns have also developed in 2-3 rows,
suggests that males of the Nova Scotian population mature,
sexually, at a length of perhaps 475-500 mm.
The only other western North Atlantic skates that fyllae re-
sembles closely in shape of disc, and in the general arrangement
of its dermal armature, are R. erinacea Mitchill 1825, and R. ocel-
lata Mitchill 1815. We have pointed out already (1953, p. 196)
that it differs from both of these in a longer tail. But the measure-
ments of the fyllae that we now have at hand show that the
distance from the axils of the pelvics to the first dorsal fin as
employed in our key (1953, p. 150) is not as reliable a criterion
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 59
as it seemed. Thus, while this distance is greater than from axils
of pelvics to fronts of orbits in most of our fyllae, it is only about
as great as to the mid levels of the orbits in a few, and is some-
what shorter than to the rear edge of the orbits in one adult
male,1 as it is in erinacca and ocellata also. And while the total
length of the tail (measured from center of cloaca) is the greater
relative to the length of the body in fyllae, there is virtually no
discontinuity in this respect, as appears from the following table.
Ratio, total length of tail (from center of cloaca) to
length of body
number of
total lengths
max.
min.
average
specimens
mm.
fyllae
1.80
1.35
1.57
12
198—505
erinacea
1.35
1.06
1.22
9
209—505
ocellata
1.10
0.97
1.05
4
414—809
The distance, however, from the origin of the first dorsal fin
to the center of cloaca is longer than from the cloaca to the tip
of the snout in all the specimens of fyllae that we have measured,
but shorter than from cloaca to snout both in erinacea and in
ocellata, as follows:
Ratio, distance from first dorsal to cloaca relative
to distance, cloaca to tip of snout
number of total lengths
max.
min.
average
specimens
mm.
fyllae
1.36
1.03
1.19
10
202—505
erinacea
0.97
0.81
0.88
5
209—505
ocellata
0.79
0.71
0.74
5
423—641
The interorbital space is narrower on fyllae, averaging 6.73
per cent (6.12-7.30) of the width of disc on 13 specimens ex-
amined, than it is on erinacea with an average of 8.01 per cent
(7.32-8.50) on 11 specimens, or ocellata with an average of 9.12
per cent (8.82-9.32) on 4 specimens.
For specimens that cannot be identified, positively, by length
of tail alone, the teeth should usually prove diagnostic, for there
are only 30 to 38 series in the upper jaw in fyllae contrasted with
i Abnormal ?
60 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
38 to 64 in erinacea, and 72 to 110 in ocellata. And the arrange-
ment of the thorns on the tail usually is distinctive for large
specimens, and in most cases for half grown, for ocellata and
erinacea of these sizes usually have a narrow naked band along
the mid line which has not been the case in any fyllae we have
seen. But we must admit that specimens might come to hand
for which depth of capture would be the only reliable criterion
for identification that we have been able to discover.
In any case there is little danger of confusing fyllae either with
erinacea or with ocellata in the field, for it has never been taken
in North American waters shoaler than 290 fathoms, and neither
of the others deeper than 85-87 fathoms (two erinacea trawled by
"Cap'n Bill II" off the southern edge of Georges Bank in July
1953).
Raja jenseni Bigelow and Schroeder 1950
The captures of a female jenseni, 625 mm. long and in good
condition, by "Cap'n Bill II" on the slope of Browns Bank,
Lat. 42°19'N, Long. 64°59'W, in a trawl haul at 390-440 fathoms,
and of a second female, of 695 mm., off Delaware Bay (Lat.
38°47'N, Long. 72°54'W) at 585-595 fathoms, call for mention,
for the only specimens of this deep water skate that had been
reported previously were a male, of 223 mm. from the slope of
Georges Bank, 1255 fathoms; a female (the type) of 541 mm. off
southern New England, 1043 fathoms; and a female of 850 mm.
(now fragmentary) from off Halifax, Nova Scotia, brought in
by a fisherman from 200 fathoms;1 all are now in the U. S. Na-
tional Museum, and all were taken many years ago.
The "Cap'n Bill II" specimens agree so closely with the type
specimen (Bigelow and Schroeder, 1950, PI. 1; 1953, Fig. 45)
that their specific identity is evident at a glance. There are 29
large thorns in the mid dorsal row on the 625 mm. female, 8 of
them anterior to the level of the axils of the pectorals. On the
695 mm. specimen, the total number in the median row is 26,
6 of which are anterior to the level of the axils of the pectorals,
so spaced as to suggest that 3 or 4 others had been lost. These
counts contrast with a total of 24 or 25 on the type (7 anterior to
i For the nomenclatural history of jenseni, description, and illustrations, see
Bigelow and Schroeder, 1950, p. 385, PI. 1 ; 1953, p. 213. Figs. 45, 40.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 61
the axils of the pectorals) and with a total of 31 on the smaller
male (8 anterior to the axils of the pectorals). Evidently there is
a small variation in number from specimen to specimen, inde-
pendent of the sizes of the latter. Enough specimens have been
seen to show that it is characteristic of jenseni for the mid-dorsal
thorns to be widely spaced anterior to the pelvic girdle, but
increasingly closely spaced thence rearward onto the tail. On
the 625 mm. female the thorns on the disc are about 20 mm.
apart; those abreast of the axils of the pelvics about 10 mm.
apart. The next 8 thorns along the tail are in contact at their
bases, but the thorns thence rearward are separated, one from
the next, by short interspaces. Also, the thorns are successively
smaller, rearward along the posterior third of the tail. As on the
type, there is no thorn in the interspace between the two dorsal
fins on either of the "Cap'n Bill II" specimens, but only a few
prickles.
The presence, on each side, of 3 or 4 thorns on the scapular
region on the small male of 223 mm., and of 3 on the type, 541 mm.
long, but of 2, only, on both of the "Cap'n Bill II" specimens
of 625 mm. and 695 mm. indicates that one or two of the thorns
in this group are lost with growth. There may be either two post-
ocular thorns or three on different specimens,1 but every specimen
that has been seen has had one preocular thorn, only, on each side.
The tip of the snout and the rostral ridge are about as rough on
the "Cap'n Bill II" specimens as on the type, and the small
prickles are about as densely distributed and cover about the
same areas. A point worth emphasis is that while the sides of
the tail of jenseni are densely prickly there are no prickles on
the lower surface of its tail below the level of the lateral folds.
The lower surface of the disc is naked everywhere.
Fifty-eight and sixty-six series of upper teeth have been
reported previously, for the two specimens for which they have
been counted. The "Cap'n Bill II" female 625 mm. long has 60,
but the 695 mm. specimen has only 51. Evidently the number
is widely variable on this species, irrespective of size, much as in
R. erinacea, and in R. ocellata. The teeth resemble those of the
type specimen closely (Bigelow and Schroeder, 1953, Fig. 46D)
both in shape and in arrangement.
i Three on the 850 mm. female ; two on each of the other specimens that have
been examined.
62 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
We have forecast already that the dark markings on the lower
surface of the disc, in jenseni, would prove widely variable (Bige-
low and Shroeder, 1953, p. 216), and the "Cap'n Bill II" speci-
mens corroborate this expectation. The ground-tint in both cases
is yellowish white. On the 625 mm. specimen this is clouded with
ashy gray around the posterior marginal zone of the pectorals and
on the outer posterior parts of the pelvics; in the region of the
cloaca and forward on either side of the abdomen; also over an
irregular area on each side close behind the mouth. On the 695
mm. female the lower surfaces of the pelvics, the abdominal
region in general, the lower surfaces of the pectorals, an irregular
area on either side inward and forward from the gill region,
and another smaller, inward from the nostril, are dark sooty
gray. This pattern simulates, rather closely, the dark markings
on some specimens of R. hyperborea (Bigelow and Schroeder,
1953, p. 209, Fig. 44), from which jenseni differs quite sharply by
having a more simple dermal armature and fewer teeth (Bigelow
and Schroeder, 1953, p. 213). The lower surface of the tail has
been plain dark ashy gray on all the specimens of jenseni that
have been seen thus far.
The localities whence jenseni has been reported (see above) are
scattered sufficiently to show that it is generally distributed along
the upper part of the slope between the offings of middle Nova
Scotia and of Delaware Bay. But we have yet to learn how much
farther its geographic range may extend in either direction. And
the paucity of captures, with the great depths at which the
"Albatross" specimens were taken, suggests that while a sparse
population exists as shoal as 200-600 fathoms, the center of
abundance for this species lies deeper down the slope than has
been sampled yet by adequate methods of fishing.
Raja laevis Mitchill 1817
Barn Door Skate
This skate has been recorded as deep as 235 fathoms, but it
occurs most regularly, and in greatest numbers on the continental
shelf in depths shoaler than 70-80 fathoms. Hence captures of
it by "Cap'n Bill II" at 265-305 fathoms off Nova Scotia (2
specimens in 2 hauls, Lat. 42°23'— 42°28'N; Long. 64°31'—
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 63
64°52'W), and at 300-410 fathoms off Nantucket (1 specimen in
1 haul, Lat. 39°54'N, Long. G9°56'W) are of interest, as extend-
ing the known depth-range of the species downward, somewhat.
Other records of it, from the traAvlings of 1952 and 1953 were
from 220-255 fathoms on the seaward slope of Georges Bank (1
specimen, Lat, 40°11'N, Long. 68°20'W), and from 175-225
fathoms off southern New England (1 specimen, Lat. 40°04'N,
Long. 72°12'W, 190-225 fathoms, and 2 specimens in 1 haul,
Lat. 39°56'N, Long. 71°22'W, 175-200 fathoms).
Raja mollis Bigelow and Schroecler 1950
The type — and only known — specimen of this species, trawled
on the slope off southern Nova Scotia, Lat. 41°53'N, Long.
65°35'W, at a depth of 858 fathoms by the "Albatross" in 1883,
had rested, unnoticed, in the IT. S. National Museum until 1950.
We can now add three more records for mollis from that same
general region, namely, a juvenile male, in the neighborhood of
195 mm. long (tip of tail lost) taken by the "Caryn" in June
1949, at Lat. 41°25'N, Long. 65°54'W, in a trawl fishing between
415 and 490 fathoms ; a second male, of 267 mm. taken by " Cap'n
Bill II," July 26, 1952, at Lat, 42°40'N, Long. 63°51'W, from
465-480 fathoms; and a third, 298 mm. long, July 12, 1953,
from Lat, 42°40'N, Long. 63°52'W, at 415-420 fathoms.
The fact that "Caryn" and "Cap'n Bill II" took only three
specimens of mollis in the 39 hauls they made at depths deeper
than 300 fathoms in the Nova Scotian sector during the three
summers combined, coupled with the depth (850 fathoms) at
which the type specimen was trawled, makes it likely that the
center of population for this species is along the lower part of
the continental slope. But it is anyone's guess how far its geo-
graphic range may extend, either to the northeastward, or to the
southwestward.
Mollis falls in the moderately short-tailed subdivision of the
genus, the distance from the level of the axils of its pelvics to the
first dorsal fin being much shorter than from the axils of the
pelvics to the tip of the snout, and the total length of its tail from
the cloaca being only about 1.1 times as long as the body from
center of cloaca to tip of snout. Its most noticeable external
characteristics are that it has no large thorns anywhere, posterior
64 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
to the scapular region, but that the upper surface of its disc and tail
are densely prickly, except close along the outer posterior edges
of the pectorals, and that the entire breadth of the lower surface
of its tail is also densely prickly, except for the extreme tip.1
The only slight differences worthy of mention between the larger
of the two "Cap'n Bill II" specimens and the type is that the
former has two minute thorns close in front of each eye (only one
in front of each eye on the type) ; and that while there is a
very small postocular thorn (as on the type) on one side of its
head, none is to be seen on the other side among the close-set
prickles that roughen the skin there. There are 54 series of
teeth in the upper jaw of the "Caryn" specimen about 195
mm. long, 60 in both the ''Cap'n Bill II" specimens of 267
and 298 mm., and 60 on the type specimen.
On the type specimen, the rostral projection from the cranium,
reaching nearly to the tip of the snout (easily felt) is soft
throughout its length. It is soft on the ' ' Cap 'n Bill II ' ' specimens
also and this state is so unusual, among the members of the gen-
era Raja and Breviraja, that we considered it as perhaps the
outstanding feature of the species mollis, in our earlier discussion
(1953, p. 237). But the rostral cartilage of the very small
specimen (195 mm. long) collected by "Caryn" in 1949 is rather
stiff to the touch, raising the question as to whether its degree
of firmness is a matter of the stage in growth, or whether it
perhaps is affected by preservation.
Eaja radiata Donovan 1807
Thorny Skate
Previous knowledge of the range of the thorny skate, and the
numbers in which it has been taken on the Newfoundland Banks,
in the inner parts of the Gulf of Maine, and on Georges Bank
(Bigelow and Schroeder, 1953, p. 262) had led us to expect a
plentiful representation of this species among the catches that
were made off Nova Scotia, and along the seaward edge and slope
of Georges Bank by the "Cap'n Bill II" in 1952 and 1953. But
the results proved otherwise for it was taken in 10 hauls, only,
in these two sectors combined, out of a total of 51 hauls that fished
i For detailed comparison with other species of Raja, see our earlier account
(1953, p. 237).
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 65
successfully there between 120 fathoms and 400 fathoms and none
was caught in 34 deeper hauls. The total number of specimens,
too, was only 12, the maximum catch in one haul only 2. This,
contrasted with the large catches that have been made on the
Newfoundland Banks, on Georges, and in the western side of
the Gulf of Maine (Bigelow and Schroeder, 1953, p. 262) is evi-
dence that while it has been taken as deep as 430-490 fathoms
off New York by "Cap'n Bill II" (Lat. 39°26'N, Long. 72°12'W,
July 1953) and at 459 fathoms near Spitsbergen, its center of
abundance lies shoaler than the zone along which the great ma-
jority of the "Cap'n Bill II" hauls were made. But the sizes of
the specimens taken at different depths make it likely that the
thorny skate reproduces itself, indifferently, down to the greatest
depth to which it occurs, for those taken shoaler than 300 fathoms
ranged from 196 mm. to about 860 mm. in length, those taken
deeper, from 145 mm. to about 865 mm. And while one from
240-270 fathoms contained an e^ about ready for deposition, an-
other from 400-460 fathoms contained a mass of immature eggs.
This skate was taken at 8 stations out of 44 along the 120-400
fathom depth zone off southern New England in the two years
combined; but, again, the largest catch was only 2 specimens,
the total catch 11 and only 1 was caught in 26 stations deeper
than 400 fathoms. Five specimens, also, Avere taken in 3 hauls
fishing between 253 and 490 fathoms off Long Island, New York
(longitudes 72°12'-72°19') in June-July 1953 (it had been re-
ported nearer land there, previously). But it seems that the so-
called "Hudson Trough" off New York about marks the bound-
ary to its regular occurrence in that direction at any depth, for
"Cap'n Bill II" did not take it in any of the hauls that she
made southward thence to the offing of Virginia in the summer
of 1953, though we have seen a specimen from 74 fathoms off
Charleston, South Carolina (Bigelow and Schroeder, 1953, p.
263).
Raja senta Garman 1885
This skate, ranging from the Newfoundland Banks and the
inner part of the Gulf of St. Lawrence to the offing of South
Carolina, was already known to occur widespread, though in small
numbers, from the offing of western Nova Scotia to the offing of
66 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
New Jersey; chiefly between 50 fathoms and 250 fathoms, but
recorded as deep as 478 fathoms off South Carolina. Therefore,
it was no surprise to take 1-2 specimens in each of 6 hauls at
125-340 fathoms along the slope of Georges Bank (Long. 66°51'W
and 69°43'W), 1 or 2 in each of 7 hauls at 150-225 fathoms off
southern New England (Long. 70°-72°01'W), 1 off Maryland
(Lat. 38°38'N, Long. 73°10'W), at 190-200 fathoms, and 1 off
Virginia (Lat. 37°38'N, Long. 74°14'W) in 1952 and 1953. The
series ranges from 120 mm. in length to about 577 mm. ; the larg-
est is a male with well developed claspers.
Raja spinicauda Jensen 1914
Definite locality records for this cold-water skate had been
limited, previously, to Barents Sea, to the waters east of Iceland,
to southwestern Greenland and the Greenland side of Davis
Strait, to the continental slope off eastern Newfoundland, and to
Hermitage Bay on the southern Newfoundland coast. But the
fact that an egg case, apparently of this species to judge from its
external sculpture and from the embryo contained within it,
had been brought in from Banquereau Bank, and that a similar
case (empty) had been trawled on the southwestern slope of
Georges Bank,1 had made it likely that the range of spinicauda
extended southward and westward along the upper part of the
continental slope as far as the general offing of Cape Cod. And
this likelihood has now been corroborated by the capture of a
juvenile male 392 mm. long by "Cap'n Bill II" on the slope of
Georges Bank (Lat. 42°17'N, Long. 65°06'W) at 320-360 fathoms,
besides two egg cases (one with identifiable embryo) off southern
Nova Scotia (Lat. 42°44'N, Long. 63°17'W, 410-420 fathoms)
in 1952, and of a third egg case, with well advanced embryo, on
the slope of Georges (Lat. 40°43'N, Long. 66°42'W, 405-430
fathoms) in 1953.
Spinicauda had been recorded previously from 77-88 fathoms
(140-160 meters) off Iceland, 120-404 fathoms off west Green-
land, and 120-140 fathoms in Newfoundland waters. The depths
recorded for the partly grown male taken by "Cap'n Bill II"
in 1952 (320-360 fathoms), as well as for the egg cases taken
i See Jensen (1948, pp. 50-52, and 53, Fig. 3) for records far Barents Sea,
Iceland and Greenland; Bigelow and Schroeder (1953, p. 272, 276) for those for
American waters.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 67
by "Caryn" in 1949 (260-350 fathoms) and by the "Cap'n Bill
II" in 1952 and 1953 (405-430 fathoms) suggest that spinicauda
occupies a somewhat deeper zone in the southernmost part of its
range than in the northern part.
The bottom temperature was 3.3° in 1953, at the only locality
where spinicauda was taken (egg case with embryo) that summer,
and 3.9°-4.4° along the general depth zone where either free-living
spinicauda, or its egg case, was taken in 1949 or in 1952, years
when the temperature was not recorded. These values suggest
that the upper limit to its thermal range may be slightly higher
off Georges Bank and off Nova Scotia than off the east coast of
Newfoundland, where the bottom water, at the depth where it was
taken (91-127 fathoms) was between -1.5° and +0.65°, or in
west Greenland and Icelandic waters where it has been found in
temperatures of 1.7° to 3.8°.
Spinicauda is given so distinctive an aspect by its wedge shaped
anterior contour with very long snout, and by a generally prickly
upper surface, but with larger thorns confined to a single row
of 21-26 (three examined by us had 22, 23 and 24 thorns, re-
spectively) along the mid line of the tail with one between the
first and second dorsal fins, that it could hardly be mistaken
for any other skate known from the western North Atlantic.
The only noticeable respect in which our juvenile male differs
from the adult is in a somewhat longer tail, a growth feature
that also is known for several other skates. More in detail, the
distance from the center of the cloaca to the first dorsal fin,
relative to the distance from center of cloaca to tip of snout, is
about 1.2 times as great on the "Cap'n Bill II" juvenile male,
as on the mature male, 1,236 mm. long, from Newfoundland, the
proportional dimensions of which are given in Part 2 of The
Fishes of the Western North Atlantic" (Bigelow and Schroeder,
1953, p. 272). And this divergence between small specimens and
large is about what might have been expected ; the correspond-
ing ratio, for example, in length of tail between young and
adult (measured similarly) is about 1.2-1.3 for R. erinacea; about
1.2 for R. fyllae; about 1.1 for R. laevis; 1.1-1.3 for R. radiata;
and 1.1-1.3 for R. senta.
In the adult spinicauda the rostral projection from the front
of the cranium (reaching very nearly to the tip of the snout)
68 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
is slender and rodlike along the anterior % of its length, and its
cartilaginous nature is evident, if the skin above it be slit, and
its sheath of fibrous tissue be spread apart. It is of the same
shape in our juvenile male. But in this case the histologic nature
of its anterior part remains to be learned, for it is only close to the
cranium that it is visible on an X-ray photograph. And we have
not felt free to dissect the single specimen, or to treat it with a
stain selective for cartilage.
Ishiyama (1952, p. 2) has already pointed out that X-rays must
be used with caution as tests for cartilaginous skeletal elements
in rajids. We have found, for example, that while the outlines
of the cranium, of the jaw cartilages, of the vertebral column,
and of the basal cartilages of the paired fins show clearly in our
X-rays of various skates and rays, those of the pectoral fins
may, or may not. Thus, the pectoral radialia are sharply outlined
on our X-rays of Gymnura, but the only visible evidence of them
on X-rays we have studied of various species of Raja, Breviraja,
Cruriraja, Psammobatis and Sympterygia is along the narrow
axial strands of calcification. Consequently, X-ray photographs
can be relied on as tests for the length of the rostral cartilage
only if they show its anterior termination sharply.1
The egg cases trawled by "Cap'n Bill II" in 1952 and 1953 —
identity established by the embryos contained in them — resemble
those referred provisionally to this species by Jensen (1914, p.
33 ; 1948, pp. 55, 56) and by us (1953, p. 272) very closely. They
are unique so far as known, among the egg cases of Atlantic
skates, in the sculpture of their surfaces with a large number of
low, longitudinal ridges, each close-set with a single series of
several hundred stiff rod-like structures with complexly dissected
tips (Fig. 4).
The three egg cases we have examined measure about 90 by
130 mm. ; about 92 by 135 mm. ; and about 86 by 136 mm., not
counting the terminal horns. The embryo that one of them
contained, 185 mm. long to its first dorsal fin, and 242 mm. to the
tip of its tail, still bears the large yolk sac. But it is so nearly
ready for birth that its identity as spinicauda is obvious. Embry-
onic characters — still persisting — apart from the yolk sac
are that only the tips of the single line of caudal thorns (22 in
i See, for example, Bigelow and Schroeder, 1948, Figs. 1, 2 ; 1953, Fig. 62.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 69
number) show through the skin; that the length of the tail, from
center of cloaca to first dorsal fin, relative to the distance from
center of cloaca to snout, is about 1.2 times as great as in the
fe^^tf^l^^-tyt^fr^yr^:,^^
Fig. 4. Raja spinioauda. Portion of egg ease trawled on the Nova
Scotian slope in 410-420 fathoms, Lat. 42°44'N, Long. 63°17'W, M.C.Z. No.
37691, to show sculpture; above, about 7 x, below, about 11 x.
juvenile male of 390 mm. ; that the tip of the tail still carries the
embryonic filament which with the caudal fin fold extends 35 mm.
from the rear base of the second dorsal; and that the thorn is
not yet visible between the two dorsal fins.
70 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
CHIMAEROIDS
Family CHIMAERIDAE
Hydrolagus affinis (Brito-Capello) 1867
Deep Water Chimaera
This chimaera was described originally from deep water off
Portugal. The first report of it, on our side of the Atlantic, was
by Gill in 1878 (as Chimaera plumb ea n. sp.), from one brought
in from 350 fathoms off La Have Bank. So many of them were
brought in during the next few years, by schooners long-lining
for halibut, that Goode and Bean (1895, p. 31) characterized it
eighteen years later as "very common in the deep water on the
outer edge of the banks north of Georges Banks."1 And while
one specimen, only, is known to have been taken on the American
slope during the past quarter century, we have risked the pre-
diction that "it would be found on the offshore slopes in un-
diminished numbers if it were sought at the proper depth" (Bige-
low and Schroeder, 1953, p. 544). This, then, was one of the
fishes we expected the trawlings of "Caryn" and of "Cap'n Bill
II" to yield. But they did not catch a single specimen. The
failure to take this particular species can hardly be blamed on
insufficient coverage of the zone explored, for 38 successful hauls
reaching deeper than 200 fathoms were made along the slope
of Georges Bank, 26 of which fished deeper than 300 fathoms, 19
deeper than 400 fathoms and 3 deeper than 500 fathoms; 49
hauls reaching deeper than 200 fathoms along the Nova Scotian
slope, 39 of them deeper than 300 fathoms ; 21 deeper than 400
fathoms and 7 hauls deeper than 500 fathoms, in the summers of
1949, 1952, and 1953 combined.
The fact that all reports of affinis, for the western side of
the Atlantic, have been based on specimens caught with hook
and line might suggest that our method of fishing was at fault.
But the otter trawl is so efficient an apparatus that we think
it more likely that affinis actually is far less numerous along the
Georges Bank and Nova Scotian slopes today than it was, there,
50-70 years ago.
i For reports of it, in the Western Atlantic previous to 1953, see Bigelow and
Schroeder, 1953, p. 544.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 71
Family RHINOCHIMAERIDAE
Rhinochimaera and Harriotta
The most striking feature of these bizarre chimaeroids is their
very long pointed snout, supported chiefly by the correspondingly
long upper rostral cartilage. This cartilage follows the same
course in Harriotta as is pictured for it in Rhinochimaera by
Garman (1904, PL 1, fig. 2) and by Dean (1904, PI. 1, fig. 4).
We may add to our earlier account (1953, p. 549) that it is sep-
arated from the skin along the inner part of the snout by a mass
of white, semigelatinous, pulpy tissue. The cartilage is in close
contact with the overlying skin toward the tip of the snout for a
short distance in Rhinochimaera of both sexes, also in females
and young males of Harriotta, and for a longer distance in mature
males of the latter, the tips of the snouts of which are hard.
The cartilage as we have pointed out (1953, p. 549) is more
flexible in the vertical plane around the crest of its curvature
than elsewliere, so that it is easily bent down there mechanically,
even on preserved specimens. But we have yet to learn whether
the fish can direct the outer part of the snout upward or down-
ward voluntarily.
Three genera of rhinochimaerids are known: Neoharriotta
Bigelow and Schroeder 1950, type species N. pinnata (Schnaken-
beck) 1929 1 (West Africa south of the equator), with separate
anal fin ; Harriotta Goode and Bean 1895 (North Atlantic, Japan,
and off lower California) and Rhinochimaera Garman 1901
(North Atlantic and Japan), without separate anal. Characters
that we have accepted previously (1953, p. 549) as alternative
between Harriotta and Rhinochimaera are the nature of the
dental plates (smooth in Rhinochimaera but with grinding ridges
and knobs in Harriotta), and whether the upper margin of the
caudal fin is smooth (Harriotta) or is armed with a longitudinal
row of denticulate structures (Rhinochimaera) . Examination of
the representatives of each that were taken during the recent
trawling trips of "Caryn" and of "Cap'n Bill II" shows that
the first of these criteria can be relied upon, except for newly
hatched specimens, the dental plates of which are smooth, or very
nearly so in Harriotta as well as in Rhinochimaera. In fact we
iGiven erroneously as 1931 in Bigelow and Schroeder 1953, p. 550.
72 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
have found no reliable feature to separate newly hatched speci-
mens of the North Atlantic representatives of Harriotta and of
Rhinochimaera generically, though it is easy to do so specifically.
It proves, also, that the presence of denticulations along the upper
side of the caudal fin is reliable as a distinctive criterion for adult
males of Rhinochimaera, as contrasted with Harriotta, but not
for young males, or for females, as is pointed out below (p. 80).
And it must remain an open question, until growth series of
Rhinochimaera can be studied, as to how early these denticula-
tions develop. All we can say, in this regard, is that while the
upper margin of the caudal is so thick and fleshy in adult Rhino-
chimaera of both sexes that the horny rays are entirely concealed,
it is so thin on a female R. atlantica 457 mm. long that these rays
are clearly visible. The development, also, of a double series of
hard knobs along the terminal %-% of the snout of maturing
males in Harriotta raleighana and in its close relative H. chaeti-
rhamphus (Tanaka) 1909, of Japan,1 but not in Rhinochimaera
seems more properly a generic character than a specific. Another
character, not proposed previously as alternative, between Har-
riotta and Rhinochimaera, but which seems to be so, is the shape
of the outer part of the long upper rostral cartilage which is sub-
triangular (base uppermost) in cross section in Harriotta but is
nearly as thick along its lower side as along its upper side in
Rhinochimaera.
Rhinochimaera atlantica Holt and Byrne 1909
This chimaeroid, previously known from the type specimen
only, from the Irish Atlantic slope, and from a few empty egg
cases presumably referable to it, was represented by 8 specimens
in the "Cap'n Bill II" collections. These range from a newly
hatched male, 151 mm. in total length, to large adults of both
sexes 1060-1315 mm. long. According to Holt and Byrne (1910,
p. 19, PI. 3) atlantica differs from pacifica (Mitsukuri) 1895, of
Japan, in a relatively shorter second dorsal fin, which they
picture as shorter than the distance from the gill openings to
the origins of the pelvic fins, but which they characterize as longer
i The illustration of the only other member of the genus, H. ctirtis-jamesi
Townsend and Nichols 192."). from off lower California (Townsend and Nichols,
11)25, Fig. 2) suggests that the specimen was a female; and in any case it was
too small (G inches) to show this character, even if actually a male.
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 73
than that distance in pacifiea, as it is shown on Dean's (1904, PI.
1, fig. 1) illustration. But the second dorsal of pacifiea is shown
as only about as long as from gill opening to pelvic origin by
Mitsukuri (3 895, PI. 1), and as shorter than that distance by
Garman (1904, PI. 1, fig. 1). The ratios, tabulated below, between
length of base of second dorsal and distance from gill opening to
pelvics, for the "Cap'n Bill II" series of atlantica, and for two
specimens of pacifiea in the Museum of Comparative Zoology
(one of these was the basis of Garman 's illustration) are further
evidence that the Atlantic population cannot be separated from
the Japanese on this basis. And we may note, in passing, that the
point of origin cannot be located with precision either for the
second dorsal, or for the pelvics because of the shapes of these
fins.
Species
atlantica
Length, to
rear base of
2nd dorsal
mm.
727
Sex
Ratio, base 2nd
dorsal to distance
gill opening to
pelvics
1.0 : 0.98
< i
755
$
1.0
: 1.09
1 1
770
9
1.0
: 1.0
1 1
825
9
1.0
: 1.08
i i
856
9
1.0
: 1.0
1 1
.880
9
1.0
: 1.0
pacifiea
< 1
575
590
1.0
1.0
: 1.0
: 1.0
According to Holt and Byrne (1910, p. 19, Fig. 3, and Footnote)
a second difference between atlantica and pacifiea is that the
"posterior limbs" of the forked canal that runs rearward along
the lower surface of the snout, end blind in atlantica, but join
the median anterior loop of the angular canal1 in pacifiea. Ex-
amination, however, of the two specimens of pacifiea in the
Museum of Comparative Zoology shows that they actually end
blind in that form, as they do in atlantica, though the blind
termination may lie ver}' close to the median loop of the angular
canal, on one side of the head or the other, on some specimens,
both of pacifiea and of atlantica, perhaps on both sides in some
cases. Garman 's (1904, PI. 2, fig. 2) illustration of the lower
i Nomenclature according to Garman (1SS8) and Bigelow and Schroeder (1953,
p. 530, Fig. 119A).
74
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
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BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 75
surface of the snout of pacifica is not clear in this respect.
Neither have we found anything- to differentiate the Atlantic
form (Fig. 5) from the Japanese, either in proportional dimen-
sions, in the shapes, sizes or relative positions of the fins, in the
nature of the dorsal spine (described for atlantica on p. 76), or in
the shapes of the dental plates, which are as free from any trace
of grinding prominences in the one as in the other. But our
specimens do suggest that the caudal filament may average
significantly longer on Japanese specimens than on Atlantic.
Thus it is almost as long as the second dorsal fin in one of our
pacifica and is pictured as about 70 per cent as long as that fin
by Dean (1904, PI. 1, fig. 4), whereas it is only about 10
per cent as long as the base of the second dorsal on one of our
atlantica specimens on which it seems to be intact, while it is
pictured as very short, indeed, by Holt and Byrne (1910, PI. 3)
for the type specimen. It seems, too, that the denticulations
(single or paired) with which the upper margin of the caudal
fin is armed, on large specimens, are not only more numerous
on the Japanese form than on the Atlantic, but that they are
regularly present on the females of the former, as well as on the
males, but only on some of the females of the latter. Thus there
are 47 and 52 series, respectively, on the two adult males of
pacifica that we have examined, with ' ' over fifty ' ' reported for it
by Dean (1904, p. 6), while his illustrations of an adult female
(Dean, 1904, PI. 1, figs. 1, 4) show them as rather prominent
and as distributed continuously all along the caudal. But they
number only 25 and 30, respectively, on our two adult Atlantic
males ; only one of our four large Atlantic females shows traces
of them all along the caudal; the caudals of two of them are
perfectly smooth ; and they are much smaller on females where
they are to be detected at all than they are on adult males.
On the other hand, they are larger, relatively, on the large
Atlantic males (Fig. 5) than on the Japanese.
In estimating the taxonomic significance of these differences, we
face the puzzling fact that the caudal denticulations of one of
the Japanese males resemble those of the Atlantic males in their
low, rounded form, with the interspaces smooth edged between
them. But they are sharp pointed (whether single or in pairs) on
the other Japanese male of about the same size, with the interven-
76 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
ing spaces interrupted, in most eases, by 1-3 much smaller,
pointed denticles, as pictured by Garman (1904, PI. 4, fig. 2)
many years ago for this same specimen, and by us more recently
(1953, Fig. 122).
It must remain an open question, until half-grown males can
be examined, whether this difference between two specimens,
both of which seem to be mature, represents two extremes of
individual variation, or whether one of these conditions (and if
so, which of them) precedes the other, as a given male becomes
active, sexually.
To sum up, the North Atlantic population of Rhinoehimaera
seems to differ certainly from the Japanese only in a secondary
sexual character that is subject to considerable variation from
specimen to specimen, and perhaps in the proportional length of
a structure (caudal filament) so susceptible to damage that
estimates of its length are largely a matter of guesswork for a
large proportion of the specimens that have come to hand. Were
we facing the question de novo we would hesitate to separate the
Atlantic form from the Pacific, specifically, on such slender
bases. However, since the name atlantica is in use already, we
are content to let it stand for the time being. Reduction to the
rank of subspecies may be its ultimate fate.
The general morphology of Rhinoehimaera pacifica, internal
as well as external, was made well known by Garman 's (1904)
and Dean's (1904) studies, accompanied by beautiful illustra-
tions. The following details for atlantica, additional to Holt
and Byrne's (1910) account, are based on the "Cap'n Bill II"
specimens.
The rear edges of the dorsal fin-spine are perfectly smooth on
all the large specimens, as noted by Holt and Byrne (1910, p. 18) .
But they are rough with minute serrations along the outer third
of their length on a female 457 mm. long ; evidently they are lost
during later growth. Holt and Byrne's illustration (1910, PI. 3)
suggests, further, that the spine is attached to the fin right out
to its tip (they do not comment on this), not free toward the tip
as it is in Harriotta (p. 83). And this seems to be the normal
state, being true of one of our large females, and of the largest
male as well. But the union must be a feeble one, for the
membrane is free from the fin along its outer %-% on all our
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 77
Fig. 6. Diagrams showing pattern of mucous canals on head. A, Ehino-
chimaera atlantioa, same specimen as in Figure 5, left side. B, Same speci-
men, right side. C, Dorsal view of male, 1034, mm. long to upper termination
of caudal fin, M.C.Z. No. 38243. D, Earriotta raleighana, female, 840 mm.
long to upper termination of caudal fin, M.C.Z. No. 38247, left side. E,
Same specimen, right side. F, Same specimen, dorsal view.
78 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
other specimens, including a female only 450 mm. long, without
any clear sign that the separation had been a forcible one.
Our specimens corroborate Holt and Byrne's (1910, p. 21)
suggestion that the pattern of mucous canals on the sides of
the head is a variable character, as it is in Harriotta (p. 83). It
seems usual for the jugular canal and the oral canal to branch
off separately from the orbital canal below the eye, with the two
separated by a longer or shorter interspace. But it is only on one
side of the head that this is the case on one of the large females,
and on one of the large males ; on the other side of the head of
each of these individuals the jugular canal and the oral canal
branch from the orbital as a single trunk which bifurcates some
little distance outward from its point of departure from the
orbital (Fig. 6A, B). It proves, too, that the canal pattern on the
crown is variable, also. Normally, the cranial canals of the
two sides are connected across the back of the head by a cross-
canal known as the aural.1 But the aural is interrupted, midway,
both on one of our specimens of pacifica (see Garman, 1904, PL
2, fig. 1) and on our 457 mm. female of atlantica, with its two
parts overlapping. And one of the large males of atlantica shows
a still more aberrant state, with the left-hand cranial canal re-
curving forward toward the mid line of the head to end blind,
with the aural canal interrupted (Pig. 6C). The large pores,
also, on the sides of the head, vary in number, not only from
specimen to specimen, but between the two sides of the
head on some specimens. A count of 13 below the cranial
canal on the left-hand side of the head of our largest male
atlantica, in the region between eye and frontal tenaculum, but
of 10 on the right-hand side, may serve as an illustration. The
presence of a few sharp denticles on the mid line of the back
between second dorsal fin and caudal, also on the nape, on an
atlantica so small (151 mm. long) as evidently to have been
hatched recently, deserves mention, also.
Rhinochimaera atlantica resembles its relative Harriotta ra-
leighana so closely in general appearance that the one might
be mistaken for the other on cursory examination, especially
since the two are likely to be taken together in trawl hauls at
appropriate depths on the slope, as happened on "Cap'n Bill II"
i Nomenclature according to Garman (1888, Pis. 1, 2, 4) and Bigelow and
Schroeder (1953, p. 530, Fig. 119).
BIGBLOW AND SCHROEDER : ELASMOBRANCHS AND OHIMAEROIDS 79
on four occasions off southwestern Nova Scotia. But it is easy to
tell partly grown specimens apart, on closer inspection. Thus the
glossy smoothness of the dental plates of Rhinochimaera con-
Fig. 7. Tracings of pectoral fins, adjusted to equal lengths along outer
margin, to show difference in shape ; solid line, Harriotta ralcighana, female
about 908 mm. long to upper termination of caudal fin, M.C.Z. No. 37726;
broken line, Rhinodhimaera atlantica, female about 1282 mm. to upper
termination of caudal fin, M.C.Z. No. 37735.
trasts strongly with the grinding ridges and
on the dental plates of Harriotta, soon after
eyes of Rhinochimaera are noticeably sma
Harriotta at all stages in growth as appears
comparative table :
Length, to
termination of
upper caudal1
knobs that develop
hatching ; also, the
Her than those of
from the following
Species
Rhinochimaera atlantica
Harriotta ralcighana
mm.
1034
1130
1184
1282
1290
1295
283
447
758
840
885
908
Sex
$
Ratio, horizontal
diameter of eye to
distance eye to
base of dorsal spine
1.0 : 2.80
s
1.0 :
2.66
9
1.0 :
3.17
9
1.0 :
2.43
9
1.0 :
3.03
9
1.0 :
3.07
9
1.0 :
1.78
S
1.0 :
1.65
2
1.0 :
1.63
9
1.0 :
2.00
9
1.0 :
1.85
9
1.0 :
2.13
1 Approximate measurement
80
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The pectoral fins are noticeably narrower toward the base in
Rhinochimaera than in Harriott a but with more broadly rounded
tip (Fig. 7). The rear edges of the dorsal fin-spine, which are
serrate in small specimens of both fish, and are serrate to maturity
in Harriotta, are perfectly smooth on large examples of Rhino-
chimaera, male as well as female. And the lateral mucous canal,
which runs nearly straight rearward from its point of departure
from the occipital canal in Rhinochimaera, or slopes slightly
downward (Fig. 5A), bows upward at first, then turns downward
— rearward in Harriotta.
More conspicuous differences between specimens of the two
fish that are nearing sexual maturity are that the upper margin
of the caudal fin thickens in Rhinochimaera, while developing a
row of prominent denticulate structures in the males (also in
some ffmales), but with the tip of the snout continuing smooth
and soft, whereas in Harriotta the upper caudal continues thin
and smooth-edged in both sexes, but the tip of the snout stiffens
in the males (not in females), bends upward, and develops a
double series of rounded knobs.
It is probable that R. atlantica is more widespread and more
plentiful in the eastern side of the Atlantic than the paucity of
the previous records (one adult specimen and a few egg cases from
the Irish Atlantic slope) might suggest, for this is certainly the
case in the west, where "Cap'n Bill II" took it at 6 stations off
southwestern Nova Scotia, at 1 station on the slope of Georges
Bank, and at 1 station in the offing of New York. A table follows
of localities, depths, and number, size and sex of the specimens :
Length to
termination
of upper
caudal1
Total
length
Sex
Lat.
N.
Long.
W.
Depth
in fathoms
Date
1512
1.11
$
42'
'22'
64 c
) — '
.i.i
290-340
7/15/53
436
4;") 7
9
42'
'40'
63'
'51'
465-480
7/26/52
1034
1060
S
38'
'52'
72c
'51'
415-440
6/27/53
1130-
1130
$
42c
'40'
63 c
'54'
520-545
7/12/53
1184
1202
9
40'
'07'
68'
'30'
420-480
7/13/52
1282
1315
9
42'
'14'
65'
'10'
490-530
7/28/52
1290
1315
9
40'
'11'
68'
'16'
480-490
7/14/52
1295
1315
9
42'
'38'
64c
'10'
460-475
7/13/53
i Approximate measurement
2 Filament lost
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS SI
It seems that Rhinochimacra is considerably less plentiful than
Harriotta off Nova Scotia and off New England judging from
the fact that four times as many specimens of Harriotta (32) as
of Rhinochimaera (8) were taken by "Cap'n Bill II."
Harriotta raleighana Goode and Bean 1895
Nine specimens of this long-nosed chimaeroid had been re-
ported previously from the western side of the Atlantic, from
the trawlings made by the "Albatross" in the 1880 's (Goode
and Bean, 1895, p. 33) , by the Prince of Monaco in 1913 (Koule and
Angel, 1933, p. 75) and by "Caryn" of the Woods Hole Oceano-
graphic Institution in 1949 (Bigelow and Schroeder, 1953, pp.
551, 552) at localities scattered along the continental slope from
the offing of Chesapeake Bay to the offing of Halifax, Nova
Scotia. Three specimens, also, were taken in the eastern side of
the Atlantic by the "Michael Sars" in 1910 (Koefoed, 1927, p.
29), one of them near the Canaries, the other two west of Scot-
land. We can now report the capture, by "Cap'n Bill II," of
26 specimens of both sexes in 1952, and of 6 more in 1953, ranging
from partly grown to adults.
Specimens of Harriotta taken by "Caryn" in 1949,
and by "Cap'n Bill II" in 1952 and 1953,
arranged in latitudinal sequence, south to north
Length in mm.
Lat.
N.
38°43'
Long.
W.
72°56'
Depth
fath.
630-675
Date
June 30,
1953
No.
1
Sex
9
to termina-
tion of
upper
caudal1
256
to tip
of fila-
ment
329
39°49'
70°05'
710-730
July
28,
1953
1
$
375
456
40°07'
68°30'
420-480
July
13,
1952
1
9
850
900
40°10'
68° 16'
490
July
14,
1952
3
$
702-748
742-837
41°25'
65° 54'
415-490
June
19,
1949
2
$ 9
126-730
155-770
42°14'
65°10'
490-530
July
28,
1952
5
$ 9
157-447
283-550
42°16'
65°08'
370-420
July
28,
1952
2
9
885-925
9462
42°22'
64°55'
290-340
July
15,
1953
1
9
840
948
42°38'
64°04'
440-460
June
17,
1949
1
$
735
773
42°38'
64°10'
460-475
July
13,
1953
1
$
758
836
42°39'
63° 58'
520
July
26,
1952
5
S 9
283-756
373-870
42°39'
64°00'
610-625
July
12,
1953
1
9
865
1025
42°40'
63°51'
465-480 •
July
26,
1952
3
S 9
188-716
249-792
42°40'
63°54'
520-545
July
12,
1953
1
$
?
775
42°40'
64°00'
440-450
June
17,
1949
1
$
705
818
42°41'
63°49'
465-480
July
26,
1952
4
S
250-721
295-815
42°41'
64°02'
385-400
July
27,
1952
3
S 9
741-908
832-935
i Approximate measurement
- Tail lost on 925 mm. specimen
82 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The fact that 30 of the total of 36 specimens were taken in the
offing of southwestern Nova Scotia, and that 6 of the 12 success-
ful hauls that were made there in 1952, at the appropriate depths,
yielded Harriotta, shows that this chimaeroid is more plentiful
along this part of the slope than earlier records for it might
have suggested. The proportion of hauls yielding it in this
region was somewhat lower in 1953 (4 out of a total of 10) , though
the trawlings of that summer seem to have heen equally successful
in general, to judge from the catches of fishes of other kinds. It
appears to be less plentiful to the westward of longitude about
66°W than to the eastward, for "Cap'n Bill II" took it in only
4 hauls (6 specimens) along the slope of Georges Bank, and to the
westward, out of a total of 41 hauls that she made there at
400 to 730 fathoms, in the summers of 1952 and 1953 combined.
On the Nova Scotian slope the upper limit to the regular
occurrence of Harriotta appears to lie at about 400 fathoms
although a few specimens were taken as shoal at about 340 fath-
oms. "Cap'n Bill II" took ralcighana down to 710-730 fathoms,
the Prince of Monaco at 728 fathoms (1332 meters, Boule and
Angel, 1933, p. 75), the "Albatross" trawled it at 1081 fathoms
off Marthas Vineyard, at 991 fathoms off New York, at 707
fathoms off New Jersey and at 781 fathoms off Chesapeake Bay.
Depth records for it in the eastern Atlantic are 1014 fathoms
(1853 meters) west of Scotland, and 1423 fathoms (2603 meters)
near the Canaries (Koefoed, 1927, p. 29).
The external aspect of H. ralcighana has been made well known
by the successive studies of Goode and Bean (1895, p. 32),
Koefoed (1927, p. 29), Roule and Angel (1933, p. 75), and
Bigelow and Schroeder (1953, p. 551). Examination of the
"Cap'n Bill II" series adds the following details.
A — Dermal denticles and dorsal fin-spine. No trace of the
juvenile dermal denticles is to be seen (or felt) on specimens
more than about 485 mm. long to the rearmost visible rays of the
upper side of the caudal fin. A female of 300 mm. (measured
similarly), still has one pair of supra-oculars, one pair on the mid-
line of the back in the space between the first and second dorsal
fins, and 4 pairs between the second dorsal and the caudal.
The increase in the size of the dorsal fin-spine with growth is
not accompanied by a corresponding increase in the size of the
BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 83
serrations along the rear margin of the spine, hence the latter
does not feel any rougher, to the touch, on large specimens than
on those of medium size. And the serrations may be partly
obliterated by maturity, on some individuals, perhaps wholly
so. The "Cap'n Bill II" series also verify earlier accounts of
the spine as free from the margin of the fin along at least its
outer half. This contrasts with the condition in Rhinochimaera
atlantica, where the spine is smooth edged from a very early
stage in growth, and where it is attached to the fin-margin,
right out to its tip, or nearly so (p. 76).
B — Caudal filament. When intact, the caudal filament may be
as much as 33-44 per cent as long as from snout to last visible
caudal fin-ray among the smaller specimens (191-263 mm., total
length) . On three of our larger males (680-750 mm., total length)
the filament is 111-116 mm. long, and 160 mm. on our largest
female (1025 mm., total length). But it is so thread-like toward
its tip that there is always a possibility that part of it may have
been lost, even on specimens on which it seems to be intact.
C — Pattern of mucous canals on head. Cumulative evidence
is conclusive, that the pattern of mucous canals on the head varies
too widely to have much significance in taxonomy, not only be-
tween different individuals, but even between the two sides of
the head of a single individual in many cases. On three of the
larger males, for example, the jugular canal and the oral diverge
jointly from the orbital canal on one side of the head, but
separately on the other side with an interspace between them
(Fig. 6D, E). When they arise jointly they may separate at
once or they may run for a longer distance or a shorter as
a joint trunk before they diverge, one from the other. On one
specimen of each sex the jugular canal fails to connect with the
orbital on either side of the head, while on one male it ends
blind on the right-hand side but connects with the orbital on the
left-hand side.
D — Snout, and sexual tenacula. In H. raleighana the snouts
of the males are similar to those of the females, up to a length of
450 mm. or so (to last visible caudal rays) ; and no trace is to be
seen of the frontal tenaculum, or of the prepelvic tenacula,
although the prepelvic pockets are already formed on newly
hatched specimens. But the tip of the snout has begun to curve
84 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
upward, its terminal knobs have formed, the sexual tenacula
have developed in the males, and the claspers seem to be ready to
function by the time a length of about 650 mm. (to last caudal
rays) has been reached.
The largest male yet recorded is about 836 mm. in total length
(758 mm. to last visible caudal ray). A female 990 mm. in total
length including a caudal filament of about 125 mm. as scaled from
Roule and Angel's (1933, PI. 4, figs. 34-34a) illustration, and
another 1025 mm. in total length, including caudal filament of
160 mm. (Cap'n Bill II" specimen) are the largest yet seen
of that sex.
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Bigelow, Henry B., William C. Schroeder, and Stewart Springer
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BIGELOW AND SCHROEDER : ELASMOBRANCHS AND CHIMAEROIDS 85
Clark, Eobert S.
1926. Eays and skates . . . Sci. Invest. Fisher. Board Scotland, 1926,
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COLLETT, R.
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Vidensk. Selsk. Christiania, Forhand. (1878) 1S79, no. 14, 106
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1904. Diagnoses of four hitherto undescribed fishes from the depths
south of the Faroe Islands. Videns. Selskabs. Forhand.
Christiania, 1904, no. 9, 7 pp.
1905. Fiske . . . "Michael Sars" togter i Nordhavet 1900-1902. Rept.
Norwegian Fisher, and Marine Invest., vol. 2, part 2, no. 3,
147 pp., 2 pis.
Dean, Bashford
1904. Notes on the long snouted chimaeroid of Japan. Journ. Coll.
Sci. Imp. Univ. Tokyo, vol. 19, art. 4, 20 pp., 2 pis.
Donovan, Edward
1807. The natural history of British fishes ... 5 vols., 120 pis., London.
Garman, Samuel
1881. Report on the selachians. Bull. Mus. Comp. Zool., vol. 8, pp.
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1885. Notes and descriptions taken from selachians in the U. S. Na-
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1888. On the lateral canal system of the Selachia and Holocephala.
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1901. Genera and families of the chimaeroids. Proc. New England Zool.
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1904. The chimaeroids . . . Bull. Mus. Comp. Zool., vol. 41, pp. 245-272,
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1906. New Plagiostomia. Bull. Mus. Comp. Zool., vol. 46, pp. 201-208.
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Gill, Theodore
1878. A new species of chimaera found in American waters. Bull.
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Goode, G. B., and T. H. Bean
1895. Oceanic Ichthyology . . . Smithsonian Contrib. Knowl., vol. 30,
xxxv+26*+553 pp.; vol. 31, Atlas, 123 pis.
Gunther, Albert
1878. Report on the deep sea fishes. "Challenger" Rept. Zool., vol.
22, part 57, lxv+268 pp., 66 pis.
86 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Hertwig, Oscar
1874. Ueber Bau unci Entwickelung der Placoidschuppen und der Zahne
der Selaehier. Jena Zeitschr. Naturw., vol. 8, pp. 331-404, pis.
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Holt, E. W. L., and L. W. Byrne
1908. Second report on the fishes of the Irish Atlantic slope. Fisheries
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1909. Preliminary note on some fishes from the Irish Atlantic slope.
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1910. Third report on the fishes of the Irish Atlantic slope. Fisheries
Ireland Sci. Invest. (1908), no. 4, 26 pp., 4 pis.
ISHIYAMA, EEIZO
1952. Studies on the skates and rays . . . found in Japan and adjacent
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Jensen, A. S.
1914. The selachians of Greenland. Mindeskr. Jap. Steenstrup, vol. 2,
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KOEFOED, ElNAR
1927. Fishes from the sea bottom. Bept. Sci. Bes. "Michael Sars." N.
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LUtken, Chr.
1887. Korte Bidrag til Nordisk ichthyographi. 4. Vidensk. Medd.
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1898. The ichthyological results of the expeditions of the "Ingolf".
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Mitchill, S. L.
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Mitsukuri, K.
1895. On a new genus of the chimaeroid group Harriotta. Zool. Mag.,
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BIGELOW AND SCHROEDER: ELASMOBRANCHS AND CHIMAEROLDS 87
MOREAU, EMILE
1891. Histoire naturelle des poissons de la France. Supplement, 144 pp.
Paris.
Radclitfe, Lewis
1916. The sharks and rays of Beaufort, North Carolina. Bull. U. S.
Bur. Fisher., vol. 34, pp. 239-284, pis. 38-49.
Regan, C. T.
1906. Descriptions of some new sharks in the British Museum col-
lection. Ann. Mag. Nat. Hist., ser. 7, vol. 18, pp. 435-440.
Reinhardt, Johannes
1825. Ichthyologiske Bidrag . . . Overs. Dansk. Vidensk. Selsk. Forh.
Kabenhavn (1824-1825), pp. 2-3.
Roule, Louis, and Fernand Angel
1933. Poissons provenant des campagnes du Prince Albert I de Monaco.
Result, camp. Sci. . . . Albert Ier, Prince Souverain de Monaco
. . . Fasc. 86, pp. 1-78, 4 pis.
SOHNAKENBECK, W.
1929. Uber einige Meeresfische aua Siidwestafrika. Mitt. Zool. Staats-
inst. Zool. Mus. Hamburg, vol. 44, pp. 23-45.
Tanaka, Shigeto
1909. Descriptions of one new genus and ten new species of Japanese
fishes. Journ. Coll. Sci. Tokyo, vol. 27, art. 8, 27 pp., 1 pi.
Tortonese, Enrico
1952. Studi sui Plagiostomi . . . Arch. Zool. Ital., vol. 37, pp. 383-
398.
Townsend, C. H., and J. T. Nichols
1925. Deep sea fishes of the ' ' Albatross ' ' Lower California expeditions.
Bull. Amer. Mus. Nat. Hist., vol. 52, pp. 1-20, pis. 1-4.
VArLLANT, L.
1888. Expeditions scientifiques du " Travailleur " et du "Talisman"
pendant les annees 1880-1883, Poissons, part 1, 406 pp., 28 pis.
Paris.
Whitley, Gilbert P.
1939. Taxonomic notes on sharks and rays. Australian Zool., vol. 9,
part 3, pp. 227-262.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3
STATUS OF INVERTEBRATE
PALEONTOLOGY, 1953
Bernhard Kummel, Editor
CAMBRIDGE, MASS., U. S. A.
PRINTED FOR THE MUSEUM
October, 1954
Publications Issued by or in Connection
with THE
MUSEUM OF COMPARATIVE ZOOLOGY
AT HARVARD COLLEGE
Bulletin (octavo) 1863 - - The current volume is Vol. 112.
Breviora (octavo) 1952 — No. 35 is current.
Memoirs (quarto) 1864-1938 — Publication was terminated with Vol. 55.
Johnsonia (quarto) 1941 - - A publication of the Department of Mollusks.
Vol. 3, no. 33 is current.
Occasional Papers of the Department of Mollusks (octavo) 1945 -
Vol. 1, no. 17 is current.
Proceedings of the New England Zoological Club (octavo) 1899-
1948 -- Published in connection with the Museum. Publication terminated
with Vol. 24.
These publications issued at irregular intervals in numbers which may
be purchased separately. Prices and lists may be obtained on application
to the Director of the Museum of Comparative Zoology. Cambridge 38,
Massachusetts.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3
STATUS OF INVERTEBRATE
PALEONTOLOGY, 1953
Bernhard Kummel, Editor
CAMBRIDGE, MASS., U.S.A.
PRINTED FOR THE MUSEUM
October, 1954
No. 3. Status of Invertebrate Paleontology, 1953
Bernhard Kummel, Editor
Documentation and interpretation of data on fossil inverte-
brates have actively engaged many scientists for more than a
hundred years. The historical development and methods of
documentation can be divided into four phases, (a) Description
of the faunas of a region; Sowerby's Mineral Conchology and
d'Orbigny's Paleontologie Francaise are classic examples of this
type, (b) Monographs of zoological groups by stratigraphic
horizons, (c) Extensive monographs of animal lineages through
all or part of their history, (d) Condensed works or phylogenies
covering whole classes or phyla. Needless to say, contributions
falling in categories (a) and (b) are primarily documentary,
hence must occupy much of the attention of our profession. All
interpretation of fossil invertebrates must ultimately stem from
this type of work. Contributions in categories (c) and (d) are
fewer in number and more difficult to attain. It is in these broad
syntheses that we seek ultimate meaning in paleozoology, evolu-
tion, and geologic history.
Great advances in recent years in genetics and neontology
have broadened understanding of population structures, processes
of isolation, and intraspecific variation. Whereas the paleontolo-
gist can contribute little towards the understanding of the mech-
anism of evolution, he can and does contribute the dimension of
time and thus supplies substantial evidence for the interpretation
of evolutionary patterns. Current taxonomic arrangements of
the invertebrates have been built up by many individual special-
ists working generally with small and geologically restricted
groups.
The projected Treatise on Invertebrate Paleontology under the
editorship of Raymond C. Moore represents the largest organized
effort in the history of our science to summarize knowledge of
fossil invertebrate animals. The Treatise will contain data on
the morphology, systematics, and evolution of all of the inverte-
brate phyla known to paleontology, and it will provide a sub-
stantial foundation for further advances.
The purpose of the present symposium is to assess in broad
perspective the status of invertebrate paleontology. It brings
together specialists who will present thumb-nail summaries on the
92 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
status and problems of taxonomy, evolutionary patterns, and
geologic history of many of the invertebrate phyla, especially for
the non-specialist. The total sum of these contributions is a
partial review of current thought and interpretation of fossil
invertebrates.
These papers were presented orally at the annual meeting of
The Paleontological Society in Toronto, Canada, November 10,
11, 1953.
Symposium Committee
J. Wyatt Durham
N. D. Newell
B. Kummel, Chairman
CONTENTS
PAGE
I. Toward a more ample invertebrate paleontology. N. D. Newell 93
II. Protozoa. H. E. Thalmann 99
III. Coelenterata. J. W. Wells 109
IV. Echinodermata
Pelmatozoa. E. C. Moore 12"
Eleutherozoa. J. W. Durham 15
V. Mollusca
Pelecypoda. N. D. Newell 161
Gastropoda. J. B. Knight, E. L. Batten and E. L. Yochelson 173
Cephalopoda. B. Kummel 181
VI. Arthropoda
Trilobita. H. B. Whittington 193
VII. Graptolithina. O. M. B. Bulman 201
VIII. On development, evolution and terminology of ammonoid suture
line. O. H. Schindewolf 217
IX. Macroevolution and the problem of missing links. A. Petrunke-
vitch 239
X. Evolution of late Paleozoic invertebrates in response to major
oscillations of shallow seas. E. C. Moore 259
XI. Systematic, paleoecologic and evolutionary aspects of skeletal
building materials. H. A. Lowenstam 287
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
I. Toward a More Ample Invertebrate Paleontology
By Norman D. Newell
The American Museum of Natural History
and Columbia University, New York
It is essential in any assessment of invertebrate paleontology
to keep in mind that it originated, and to a large extent has
developed, as a stratigraphic tool. In North America, particu-
larly, we have tended to be concerned with the uses of inverte-
brate fossils in the solution of geologic problems rather than with
the meaning, in the broadest sense, of the fossils. The emphasis
has been that of an applied rather than a pure science. Let it be
granted that the discovery of the useful attributes of fossils forms
one of the grand chapters in the early history of geology, leading
directly to the chronological classification of the geological record
and all that this implies in the story of life. Although this is,
indeed, a tremendous contribution to human knowledge, there is
much more to be learned from fossils.
Fossil invertebrates, because of their ubiquity, convenient size,
and relative ease of recognition, have always been favored over
other fossils by field geologists, and it is not surprising that the
study of their distribution has become an essential part of
stratigraphy. Without the data from these fossils our knowledge
of the details of geologic succession, correlation, and past geog-
raphies would indeed be very sketchy. The debt which strati-
graphic geology owes to paleontology, especially invertebrate
paleontology, is great, and the debt which paleontology owes to
stratigraphy is equally great. However, it is too often implied
that chronology is the chief or the only contribution to human
knowledge that our science can make. Nothing can be farther
from the truth.
The scope of our subject is vast, covering the enumeration,
history, distribution and ecology of a score of animal phyla and
a hundred or so orders, many of which have not yet really been
subjected to intensive inquiry. The literature is diffuse and the
numbers of genera are legion. Since the total number of investiga-
94 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
tors is woefully inadequate as compared with the size of the
task, there has inevitably been a tendency toward extreme spe-
cialization along taxonomic, stratigraphic, and even provincial
lines. Under the circumstances, our work has not, in general,
been characterized by broad syntheses.
There are, however, many signs that we have begun the ascent
from an intellectual plateau in our subject since the second
World War. Increasing effort to sharpen the utility of fossil
invertebrates as stratigraphic guides is leading competent investi-
gators to recognize some of the blind alleys where the labors are
not rewarded by commensurate returns. Many are beginning to
attack problems of broader significance. In the development of
commercial micropaleontology by the petroleum industry, we very
probably are witnessing the final stage in maturing of theories
of paleontologic correlation. The continuous growth of knowledge
in this subject has not resulted in revolutionary new develop-
ments since the general recognition of the importance of biologic
facies. Increasing numbers of stratigraphers are impressed by
the fact that stratigraphic relationships of separate outcrops
within a sedimentary basin are sometimes more readily deter-
mined by simple tracing and matching of strata than by com-
parison of suites of fossils. Many of these investigators are giving
more attention to fossils as indicators of environment, a field rich
in unexploited possibilities. In many cases the evolutionary
changes within a fauna during deposition of a stratigraphic
sequence are so slight that for all practical considerations the
fauna ranges without appreciable change from bottom to top
of a succession. The application of statistical methods in the
analysis of such a faunal sequence promises to permit further
refinement of paleontological zonation. However, in a majority
of cases successive modifications induced by shifting environment
may be more conspicuous than changes resulting from evolution.
Although statistical methods will certainly aid in the recognition
of subspecies and in study of obscure trends, the evaluation of
these trends, of course, must remain largely subjective. Mathe-
matical treatment of fossils does not offer a general solution of
our problems.
Occasionally the field geologist, on submitting his collection of
fossils to the paleontologist for study, is disappointed because
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
95
the material fails to elicit the desired information as to geologic
age. It may be that the collection is poorly preserved or frag-
mentary or, more commonly, the most distinctive guide fossils
are lacking in the material. This may seem to reflect on the
competence of the paleontologist or to cast doubt on the whole
principle of paleontologic zonation. In very many cases the
geologist in search of refinement of zonation of a stratigraphic
sequence makes demands that cannot be satisfied by the materials
at hand. So-called facies fossils, on the other hand, may lead
to valuable inferences with respect to past environments. We
suspect that often the wrong answers are sought from the ma-
terials at hand.
If the signs of change in emphasis are correctly read, I venture
to prophesy that developments in invertebrate paleontology dur-
ing the next few years will be characterized by increasing empha-
sis on the more biological aspects of invertebrate paleontology.
Even now, it is hardly appropriate to describe paleontology as
the "hand-maiden of geology". Its role in earth sciences is at
least as significant as those of petrology or structural geology,
PALEOZOOLOGY
Zoogeography
Geological Emphasis
Biological Emphasil
Fig. 1. Biological and physical aspects of paleozoology.
96 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
neither of which is primarily esteemed for useful applications
to other disciplines.
Paleontology is constituted of diverse matters (Fig. 1) many
of which have little to do with geologic problems, per se. Evolu-
tion, ecology, systematics, comparative anatomy, and zoogeog-
raphy of fossil invertebrates offer a wide range of fields of
investigation outside the usual scope of stratigraphic geology.
Geology can and does benefit from the more biological branches
of paleontology; and, of course, the stratigraphic aspects of
paleontology are absolutely fundamental for the establishment
of chronological sequence and correlation in the history of life ;
but balance must be sought in the application of our energies
if we are to achieve the most complete understanding of the his-
tory of life on earth. The biological aspects of invertebrate
paleontology, which have not received as much attention as the
physical aspects, now offer the greatest opportunities for investi-
gation. By general agreement, paleontology is a full member of
the family of earth sciences. It must be stressed, however, that
it really involves much more of biological than physical sciences.
Tangible evidence of a strong trend in our profession toward
a general broadening of the field of interest is manifest in two
great group projects of incalculable importance to invertebrate
paleontology. They involve active collaboration of more than 150
investigators. They are : The Treatise on Marine Ecology and
Paleoecology under the leadership of Harry S. Ladd, and The
Treatise of Invertebrate Paleontology under the leadership of
Raymond C. Moore. These two modern syntheses will open new
vistas to students of invertebrate paleontology. They will provide
inspiration and rich sources of information in the quest for a
broader understanding of fossil invertebrates.
We are in the midst of a new flowering of interest in organic
evolution in which genetics, systematics, and paleontology join
hands, and the vitality of this movement is making a deep im-
pression on our own science.
In these notable efforts we see evidence of a gradual widening
of appreciation and interest in many of the fundamental prob-
lems of invertebrate paleontology. These are exciting develop-
ments in which attention is increasingly focused on the fact that
fossils are the remains of organisms rather than being simply
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 97
stratigraphic tools. The new emphasis inevitably will lead to a
more ample science. The symposium of The Paleontological So-
ciety, planned and organized by Dr. Bernhard Kummel, clearly
indicates interest in the fundamental problems of our science.
If we must limit our attention to the strictly "practical"
points of view, many fundamental problems of paleontology may
seem utterly esoteric. Many of us, however, give at least lip
service to the thesis that pure science is also intensely practical.
' ' The whole of man 's experience has demonstrated that the prac-
tical results required for tomorrow depend essentially on the
'impractical' free curiosity of today." The broad problems of
paleontology are important to us, if I may paraphrase Warren
Weaver (1953), because they have "depth and sweep, because
they are esthetically attractive, because they are instances of
man's mind seeking to meet the challenge of the universe."
reference
Weaver, Warren
1953. Fundamental questions in science. Sci. Amer., vol. 189, pp. 47-51.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
II. Protozoa
By Hans E. Thalmann
Stanford University, Stanford, California
In the field of fossil Protozoa great advances have been achieved
during the past hundred years. At that time it was relatively
easy for a paleontologist to overlook, singly, the different branches
of the modern science of micropaleontology. Today even a spe-
cialist will have to devote his time either to a single class of
microfossils or, as is more often the case, to a selected group
within this class. The doctrine of mechanism, Darwin's ideas on
natural selection and organic evolution, improvement of optical
instruments from the simple microscope to the modern electron-
microscope, refinement of methods and techniques and last, but
not least, the paleontologist's incurable curiosity to penetrate
deeper into the secrets of Nature, have contributed to the accu-
mulation of knowledge of the most primitive forms of life buried
in sediments since pre-Cambrian time. Truly enough, we are
not yet standing on top of the pyramid of knowledge, but each
new contribution adds another stone that broadens the foundation
on which we build up understanding^ and intelligently the sci-
ence of fossil Protozoa, by unraveling their geologic history, their
trend of evolution and phylogenetic relationships, and by solving
the problems of paleoecology and paleogeography.
In the following pages an attempt is made to summarize the
status quo of our knowledge of the fossil Protozoa. The limited
space available for such a thumb-nail summary does not permit
one to give full credit to the legion of authors to whom every
paleontologist is indebted for his contributions, small or large.
Phytomonadina. So far only one representative, Chlamydomo-
nas, is known from the Upper Eocene, plus Phacotus which is
known from the Upper Miocene and forms limestones in the
Pleistocene, thanks to its calcareous tegument.
Xanthomonadina. Although forming siliceous cysts, this group
100 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
is not yet definitely known as fossil. With the help of modern
optical instruments, however, there is every possibility that they
might turn up when searched for in bituminous deposits.
Euglenida. Phacus and Lepocinclis are known from bitumi-
nous sediments of Eocene age, and Traehelomonas has been found
in the same habitat of Pliocene age.
Dinoflagellata. Great progress has been made during the last
two decades thanks to the intensive research work by G. Deflandre
and 0. Wetzel. Nearly half a hundred genera, three-quarters of
which are exclusively fossil, are presently known, most of them
organically conserved thanks to the fossilization of their cellulose
thecae. They are now traced back to the Jurassic, but their
phylogenetic relationships are still only vaguely known. The
question of whether the siliceous Dinoflagellata might be an-
cestral to the Radiolaria, and the calcareous Dinoflagellata to the
Foraminifera, is not yet settled.
Ebriidea. These marine planktonic flagellates with siliceous
endoskeleton have only recently become known as fossils, appear-
ing suddenly in the lower Tertiary. They are already represented
by about 20 genera, and more representatives are likely to be
found in pre-Tertiary beds with the help of modern optical in-
struments and more refined techniques.
Silicoflagellata. Relatively little progress has been made in
silicoflagellate research. It is an open field for investigation, and
the question, whether animal or plant, has not been settled. These
marine flagellates with siliceous tests of only a few microns are
known since Middle Cretaceous. Curiously enough, fossil Silico-
flagellata are at present better known than the Recent ones, and
definitely show evolutionary tendencies from geologically older
to younger forms. Recent work by G. D. Hanna and Y. T.
Mandra, although concerned only with a few Californian sedi-
ments already indicates that the Silicoflagellata might have
future use as stratigraphic tools and ecologic indicators.
C occolithophoridea. Although known as fossils since Ehren-
berg (1836), the true nature of these extremely minute, rock-
forming, planktonic, calcareous flagellates ("coccospheres" or
"coccoliths") was only recognized about 50 years ago by Loh-
mann (1902). They still are obscure as to their origin, appearing
since Liassic time, but modern research work with the help of
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 101
the polarization- and electron-microscope will certainly enhance
our knowledge of this class of Protozoa, which today are grouped
into the orders of Heliolithae (3 families with 25 genera), and
Ortholithae (3 families with 6 genera). Recent studies indicate
their possible stratigraphic value. Some "Problematica" : Cera-
tolithus Kamptner, Nannoconus Kamptner, Lithostromatium
Deflandre and Peritrachelina Deflandre, all about 12-20 microns,
are still not taxonomically pigeon-holed (Flagellata incertae
sedis).
Chrysomonadina. Formerly assigned to the C occolithophori-
dea, they are now separated as a distinct group. Minute siliceous
cysts belonging to Archaesphaeridium Deflandre and Micram-
pulla G. D. Hanna are knoAvn from Cretaceous beds, others from
Eocene lignites, Miocene fresh-water diatomites and Pleistocene
peats. The taxonomic position of Palaeostomocystis Deflandre,
a planktonic flagellate in Jurassic and Cretaceous beds is not yet
settled.
Chitinozoa. Discovered in insoluble residues of Ordovician and
Silurian limestones by Eisenack, the Chitinozoa are also of un-
known systematic position. Their youngest representatives so
far are reported from the Middle Devonian but more intensive
studies are necessary before their true nature and taxonomic
place are fully understood.
Thecamoebina. Fossil Thecamoebina have been reported to
occur in Middle Eocene deposits, but recent studies by Bolli and
Saunders (1954) indicate that most, if not all, so-called fossil
forms might in fact be Recent representatives, often erroneously
attributed to the Foraminifera. Similarity between tests of The-
camoebina and certain genera of the Saccamminidae (Foramini-
fera) seems to be responsible for this error. The presence of
thecamoebian forms as "fossils" apparently is due to contami-
nation from fresh-water rivers, lakes and swamps. "Fossil"
representatives of the "foraminiferal" genera Leptodermella
and Milletella should now be allocated to the Recent thecamoebian
C entropy xis, Lagunculina and TJmulina to Difflugia, and some
species of Proteonina to either Pontigulasia or Difflugia. Bolli
and Saunders' studies rule out the Thecamoebina as fossils.
Tintinnoidea (Calpionellidae) . Great progress has been made
in the recognition of the true systematic position of these lori-
102 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
cated oligotrichous Infusoria, which as planktonic microfos-
sils were populating the seas during Upper Jurassic and Lower
Cretaceous. G. Colom (1948) has excellently summarised our
present knowledge of these tiny marine, pelagic and free-swim-
ming, therefore widely distributed, organisms of the old Tethys
region. They suddenly appear at the base of the Tithonian and
persist as rock-formers associated with Nannoconus, coccoliths,
and radiolarians, into the Barremian where they abruptly disap-
pear. Their presence in sublithographic limestones, where the
calcified loricae appear brightly white in a dense grey ground-
mass, indicates a warm tropical environment. Few, if any, fossil
tintinnoids have been reported from the "Western Hemisphere
but a search for them in beds of Jurasso-Cretaceous age will
undoubtedly reveal their presence and might help to correlate
dense sublithographic limestones when megafossils or Foramini-
fera are scarce or absent.
Radiolaria. The taxonomy of the Radiolaria, based on the
composition of their siliceous skeleton, has recently been sum-
marized by A. S. Campbell (1952). These wonderful microscopic
animals of the seas have for a hundred years been the object
of study for their beauty and multiformity, although still prac-
tically nothing is known regarding the formation of the test in
these sarcodine Rhizopoda. For the geologist and paleontologist
there are only two of the four groups of Radiolaria regarded as
fossils of importance, the peripylean Spumellina and the monopy-
lean Nassellina, occurring as microfossils in all types of siliceous
rocks from Cambrian to Recent all the world over. Their ex-
clusively marine planktonic mode of life, although passively
transported by currents, is responsible for their world-wide distri-
bution, from littoral to deep-sea sediments. They are excellent
indicators of paleoecological conditions if and when properly
evaluated. Their stratigraphic use is at present confined to local
correlations, but further research indicates that many radiolarian
genera and species might become good guide-fossils and help out,
as in the case of calpionellids and coccolithophorids, when mega-
fossils or other microfossils are absent or of little value.
Foraminifera. Without any doubt the greatest advances made
in the study of fossil Protozoa have been made in the order of
the Foraminifera during the last hundred years or so. This prog-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 103
ress is evident when d'Orbigny's classification of 1852 is com-
pared with the modern taxonomic treatment of the testaceous
rhizopods in the modern handbooks of Galloway (1933), Glaess-
ner (1945), Cushman (1948), and Sigal (1952).
Sigal's and Glaessner's classification seems at present to be
the most comprehensive and logical one, grouping the order of
Foraminifera conveniently into three suborders : the Uniloculini-
dea (gelatinous, chitinous or slightly agglutinated tests, not yet
found fossil), the Biloculinidea (globular proloculus followed by
a tubular chamber), and the Pluriloculinidea (uni- or plurilocu-
lar proloculus followed immediately by a series of simple or
complicated chambers). These three suborders include seven
superfamilies with altogether 61 families and many subfamilies
comprising approximately 1200 valid genera and subgenera —
thus contrasting strikingly with the seven "orders", few families
and less than 100 genera of d'Orbigny in 1852. The tendency in
modern foraminiferal taxonomy is overwhelmingly in the direc-
tion of a natural classification. For such an end the Foraminifera
are excellently suited, thanks to their abundance in all sediments
of the geological column which allows morphogenetic and phylo-
genetic studies of their evolutionary pattern and geologic distri-
bution. It has to be admitted, however, that the ultimate goal in
every branch of paleontology has not yet been reached in the
Foraminifera : a true natural classification. But at least one
important principle is now settled, namely, that the primitive
forms were non-septate, and thus precede geologically as well as
phylogenetically the cohorts of septate, and especially septate-
spirally-coiled, more highly developed forms.
Much research work will have to be done with regard to the
more complex families in order to understand their phylogenetic
relationships. This is evident in Hofker's new attempt at a
natural classification (1951), that is by using micro-anatomical
studies of the tiny tests in order to establish the phylogenetic
concatenation of the genera and families of Foraminifera, fossil
and Recent. In establishing true natural relationships it is of
utmost importance, according to Hofker, to study and follow in
time sequence, the nature and behavior of the dentate buccal
apparatus or "toothplate" and its connection either with the
protoforamen or with the deuteroforamen in the chambers of
104 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
the foraminiferal test, and the pattern and distribution of the
pores in the test-walls. Glaessner (1954) has summarized the
new aspect of foraminiferal morphology and taxonomy initiated
and so strongly advocated by Hofker. Studies by Arnold (1954)
on the evolution of the Foraminifera, stressing their variation
and isomorphism, will also shed new light on taxonomy of the
group, as will Wood's (1948) interesting investigations of the
structure of the wall of the foraminiferal test. A new field of
study is now opened with the use of the electron-microscope where
magnifications up to 4000 times reveal highly interesting morpho-
logical characters (Jahn, 1953).
The principle of phylo-morphogenetic analysis, initiated by
the late Tan Sin Hok on Cycloclypeus and other larger Foramini-
fera, is gaining more and more ground leading to many hitherto
unsuspected genetic relationships in different groups of smaller
and larger Foraminifera, and will become increasingly more im-
portant for stratigraphic correlation purposes. The abundance
of material for such studies and for biometrical analysis, and the
relatively easy technical preparation of it, is hardly surpassed
by any other group of fossils.
The geologic history of the Foraminifera dates from the Cam-
brian. Presence of calcareous forms in Cambrian time has now
definitely been disproved, and it is not before the beginning of
Middle Devonian that the first calcareous genera appear. The
Lower Paleozoic is the time of the arenaceous genera and species
(Ordovician, Silurian and Devonian). "With the sudden evolution
and development of the calcareo-arenaceous endothyroids and
fusulinids at the end of the Mississippian and throughout the
Pennsylvanian, the development of calcareous perforate tests in
Foraminifera increases rapidly, especially when the Triassic-
Jurassic boundary is reached ; here more than half of the families
of Foraminifera have their origin, and persist, with few excep-
tions (Orbitolinidae, Spirocyclinidae, Stomiosphaeridae, Gumbe-
linidae, Meandropsinidae, Hantkeninidae, Orbitoididae, Discocy-
clinidae, Victoriellidae and Miogypsinidae) to Recent time.
The spectacular explosive and sudden evolution and develop-
ment of the rock-forming Fusulinidae during Pennsylvanian and
Permian, and their complete extinction at the end of the Permian
is a unique feature of the younger Paleozoic, repeated again, to a
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 105
lesser degree, by the Alveolinidae during Upper Cretaceous to
Oligocene times, the Orbitolinidae during Cretaceous, the Orbi-
toididae from Upper Cretaceous to Miocene, the Discocyclinidae
during Eocene, and the Nummulitidae during the Paleogene.
Wide lacunae of knowledge of the Foraminifera (excepting
Fusulinidae) still exist generally for the whole of the Paleozoic,
Triassic, Jurassic and Lower Cretaceous periods. Many of the
pluriloculinid families have their roots in either Triassic or Juras-
sic beds and unless we can learn more about the assemblages and
faunal composition of these periods the phylogeny of the Fora-
minifera will remain incomplete. The large families of Lagenidae
and Rotaliidae play an important role during the older Mesozoic,
aside from some prominent arenaceous families, and many ances-
tral genera will still have to be detected in years to come. Future
foraminiferal studies will have to emphasize the importance of
the Lower Paleozoic and Lower Mesozoic Foraminifera, and it is
a healthy sign that recent monographs are devoted, in increasing
numbers, to these so-far neglected faunas.
Since a great share of the total crude oil production in the
world is found in Upper Cretaceous and Tertiary formations,
much more attention has been paid to the foraminiferal assem-
blages of these beds in practically every country where oil wells
are drilled or exploration for hydrocarbons is under way. Much
more is, therefore, known about smaller and larger Foraminifera
(except for the Paleozoic Fusulinidae) of the last sixty or seventy
millions of years in our geologic history than of the preceding
five hundred millions. During the Cretaceous the important
planktonic Foraminifera, especially Globigerinidae, appear and
these widely distributed "Ammonites of the Tertiary" have since
proved to be of enormous stratigraphic value (Globigerina,
Globorotalia, Hantkenina, Orbulina, Pseudotcxtularia, etc.) for
interregional and intercontinental correlation of contemporaneous
beds and formations or, as is the case especially for Pliocene and
Pleistocene sediments, for interpreting paleoclimatic and paleo-
ecologic conditions. The value of orbitoids and nummulites for
world-wide correlations has been known for a long time and the
number of benthonic forms, as Globotruncana, Bolivinoides,
Flabellina, certain Rotalia species, etc., as time-markers is ever
increasing. The Globotruncanae with their short-lived and explo-
106 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
sive development are at present one of the most useful tools for
world-wide stratigraphic correlation of Upper Cretaceous sedi-
ments from Cenomanian to the end of Maestrichtian.
In applied micropaleontology, nowadays, the paleoecologic
significance of the Foraminifera is of great importance in recon-
structing the bionomics of former habitats and, most valuable of
all, in elucidating lateral and vertical facies changes in the sedi-
ments. Studies on Recent faunal assemblages in different habi-
tats, nekrocoenosis as well as biocoenosis, demonstrate the depend-
ance of most of the Foraminifera on varied biological factors
ranging from depth and temperature, light penetration, food
supply, salinity, calcium carbonate content, nutritious salts, etc.
to factors regulating the rate and mode of sedimentation, nature
of bottom sediments and influence of litho-f acies of the embedding
sediments.
In order to establish biochronological zones and paleoecological
conditions, each sedimentary basin has to be studied as a unit,
covering for each formation present, all facies and habitats from
reef and near-shore to deep-sea environment. Only after adjoin-
ing basins have been treated similarly as a unit, will it become
permissible to generalize or to make inter-basinal or inter-regional
correlations and paleogeographic deductions about the individual
formations. Up to now quite a few basins have been studied in
such a way, and future progress in everything concerned with
Foraminifera will be dependent on the amount of team work
undertaken, in cooperation with specialists in other fields of
paleontology, and thus shall the geologic history of the earth
become fully understood and the documents which Nature pro-
vides us in the form of large and small fossils shall be intelligently
deciphered. Likewise, concerted efforts of every micropaleontol-
ogist to reach and achieve a natural classification of the Foram-
inifera and other classes of Protozoa, and a purification of their
nomenclature will be a conditio sine qua non for the next hundred
years.
As Albert Gaudry said in 1890 : . . . "nous ne devons desesperer
de rien ; peu a peu nous decouvrirons dans les couches terrestres
les ancetres des creatures qui nous entourent, si dedicates qu'elles
soient."
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 107
SELECTED BIBLIOGEAPHY
Arnold, Z. M.
1954. Variation and isomorphism in Allogromia laticollaris: a clue to
foraminiferal evolution. Cushman Found. Foram. Research,
Contr., vol. 5, pt. 2, pp. 78-87.
Bolli, H. M., and J. B. Saunders
1954. Discussion of some Thecamoebina described erroneously as Fo-
raminifera. Ibid., vol. 5, pt. 2, pp. 45-52.
Campbell, A. S.
1952. An introduction to the study of the Radiolaria. The Micro-
paleontologist, vol. 6, no. 2, pp. 29-44.
Colom, G.
1948. Fossil tintinnids: loricated Infusoria of the order of the Oligo-
trichia. Jour. Paleontology, vol. 22, pp. 233-263.
Cushman, J. A.
1948. Foraminifera, their classification and economic use. 4th edit.,
Cambridge (Harvard Univ. Press). 605 pp.
Deplandre, G.
1952a. in: Grasse, P.-P., Traite de Zoologie, tome I, premier fascicule.
Paris (Masson).
1952b. in: Piveteau, J., Traite de Paleontologie, tome premier. Paris
(Masson).
Ehrenberg, C. G.
1838. Die Infusorienthierchen als vollkommene Organismen. Leipzig.
548 pp.
Galloway, J. J.
1933. A manual of Foraminifera. Bloomington (Principia Press). 483
pp.
Gaudry, A.
1890. Fossiles secondaires, vol. 2, Paris, p. 37.
Glaessner, M. F.
1945. Principles of micropaleontology. Melbourne (Univ. Press).
1954. New aspects of foraminiferal morphology and taxonomy. Cush-
man Found. Foram. Research, Contr., vol. 5, pt. 1, pp. 21-25.
Hofker, J.
1951. The Foraminifera of the Siboga-Expedition. Part III. Leiden
(Brill).
108 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
JAHN, B.
1953. Elektronenmikroskopische Untersuchungen an Foraminiferen-
sehalen. Zeitschr. f. wiss. Mikroskopie u. f. mikrosk. Technik,
Bd. 61, Heft 5, pp. 294-297.
LOHMANN, H.
1902. Die Coccolithophoridae, etc. Arch. f. Protistenkunde, vol. 1, pp.
89-165.
SlGAL, J.
1952. Ordre des Foraminifera, in: Piveteau, J., Traite de Paleontolo-
gie, vol. 1, pp. 133-178; 192-301.
Wood, A.
1948. The structure of the wall of the test in the Foraminifera; its
value in classification. Quart. Jour. Geol. Soc. London, vol. 104,
pt. 2, pp. 229-255.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
III. Coelenterata
By John W. Wells
Cornell University, Ithaca, N. Y.
These remarks are admittedly somewhat subjective, and some
points are to be taken as stimulants to cast light in still dark
places. I have divided my time amongst three aspects of coelen-
terate paleontology : classification, evolution, and paleoecology.
The classification (Fig. 1) as a whole is in no better shape than
that of most other phyla. Even the name of the phylum is not
wholly free from question. The coelenterated animals are obvi-
ously divisible into two distinct groups: (1) the Cnidaria (which
most people mean when they say Coelenterata), and (2) the
Ctenophora. Opinion favors recognition of two phyla (Hyman,
1940), and my comments are wholly confined to the Phylum
Cnidaria, divided by tradition and on morphological grounds
into three geologically ancient classes: (1) Hydrozoa, (2) Scy-
phozoa, and (3) Anthozoa. It is, of course, in the ranks below
the classes that we find divergent ideas of classification, and the
deeper we go the more we have a feeling of working our way
through a dark cellar full of cobwebs, a feeling not peculiar to
the Cnidaria.
In the Hydrozoa only the order (or class?) Stromatoporoidea
has much of a chronological record, but rather than being thereby
on firm ground, this extinct group of reef dwellers has given the
most trouble at the highest systematic level. They have been
claimed for the Foraminifera (Hickson, 1934; Parks, 1935), and
sponges (Heinrich, 1914; Twitchell, 1929) as well as for the
Cnidaria. The sum of morphological characters favors strongly
a hydrozoan connection (Lecompte, 1951), but evidence of this
position is largely negative, except that the fundamentally tra-
becular structure of the coenosteum is like unto only that of
cnidarians.
The pelagic siphonophores are best left to the neontologists.
Their only fossil representatives are vellelids and porpitids from
110
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the Paleozoic (Caster, 1942), significant only as being indicative
of the antiquity of this group.
The Scyphozoa, like the siphonophores, are notorious amongst
paleontologists for their lack of hard parts. They appear here
and there in the geologic column as stray and aggravatingly
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Fig. 1. Classification and chronology of the Cnidaria.
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 111
vague impressions from the Precambrian on, but the fossil mate-
rial signifies little in the systematics of the jellyfish. Perhaps I
may mention here the conulariids, another perplexing group,
possessed of a thin, phosphatic skeleton, whose tetrameral sym-
metry has suggested to some workers a scyphozoan relationship.
Indeed, it is hard to think that such a form as the Ordovician
Conchopeltis, the only conulariid for which traces of the tentacles
have been found, was not a jellyfish. But then, Conchopeltis may
not have been a conulariid.
In the Anthozoa we find a really significant chronological rec-
ord, and it is on the tabulate, rugose ("tetracorals"), and scler-
actinian ("hexacorals") corals that the most work has been done.
These are all clearly anthozoan cnidarians. The scleractinians
are clearly from the same stock as the corallimorph anemones
rather than directly from actiniarian anemones, as indicated
lately by studies of nematocysts (Carlgren, 1940, 1943, 1945).
But the relations of the extinct tabulates and rugosans to skele-
tonless stocks are still speculative ; both are cryptogenic and prob-
ably polyphyletic groups appearing first in the Ordovician with-
out any known phyletic past.
In the corals, as in other organic groups, the systematic value
of morphological characters is the chief classificatory problem.
Modern classifications are, or ought to be, phylogenetic, and to
discover the bases for such classifications, characters must be
found which show a certain degree of constancy and which also
reflect the fundamental organic plan of the animal. In the rugose
and scleractinian corals these characters are to be found in the
septa, which reflect the mesenteries, which in turn are the primary
structures of the anthozoan polyp. The mode of insertion, devel-
opment, and microstructure of the septa are thus of basic signifi-
cance. This was first recognized some time since for the
scleractinian corals (Pratz, 1882; Vaughan and Wells, 1943) and
is now finally being found to lie at the roots of rugosan system-
atics (Wang, 1950; Lecompte, 1952). The structure of the septa,
when more thoroughly understood than at present, will enable
us to thread our way through dense overgrowth of homeomorphs,
"morphic equivalents," "radicals," morphogenetic trends, and
confusion due to ecologic plasticity. The tabulates have not yet
revealed such constant but truly basic structures, a situation
112
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 113
reflected in their chaotic systematica, wherein strongly differing
forms are artificially lumped together by homeomorphy rather
than phylogeny, on the feeble basis of negative characters (Le-
compte, 1952). Thorough analysis of their microstructures, a
very difficult task in all Paleozoic corals, should help to clear up
the taxonomy of the tabulate group or groups, and may or may
not sustain the often-made suggestion of a relationship with the
alcyonarians (Hickson, 1924, int. at.).
The general evolutionary pattern of the major cnidarian
groups is only hinted at in the structural series of living forms,
and has found little or no actual confirmation from the fossil
forms. It should be remembered that a calcareous skeleton, some-
times calcific, sometimes aragonitic, is an evolutionary develop-
ment which has appeared at different times in different cnidarian
lines, each time being a secondary acquisition consequent on
sedentary habits. This scattering appearance of a major struc-
tural type seems peculiar to the Cnidaria, in which it has
occurred on widely-differing plans, in about half of the major
groups.
As shown by Figure 2, it appears, solely from the living struc-
tural and ontogenetic series, that the hydrozoans are the most
primitive cnidarians and hence presumably appeared first, that
the scyphozoans came next, followed by the structurally advanced
anthozoans. The fossil record does indicate, at least, that the
three classes were probably differentiated by the beginning of
the Cambrian. Supposed jellyfish occur in Precambrian rocks,
and reputed skeletonless zoanthactiniarians are reported from
the Cambrian (Clark, 1913; Dollfus, 1875). It is otherwise in
the groups with a respectable paleontological record.
The evolutionary pattern of the stromatoporoids and tabulates
is extremely obscure, partly because they have not really been
thoroughly studied, and partly because they seem to have been
remarkably self-satisfied organisms. The Milleporina and Stylas-
terina have as yet too few known fossil forms to allow any gener-
alizations on their history, except that they are a relatively recent
development.
Of all the cnidarian groups, only two have an abundant fossil
record nearly from their first inception — the Rugosa and the
Seleractinia. Only the latter is represented by any living forms,
114
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
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STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
115
which is a fortunate situation, for it sheds some light on the gen-
eral evolution of the other anthozoan corals. The principle which
serves in the classification of the Scleractinia — that the septal
structure is constant within a group and that it is progressively
modified in each group, often in more than one direction with the
passage of time — is also the guide to the broad evolutionary
history of the group (Fig. 3). The concept of morphogenetic
trends (Lang, 1917, 1923, 1938; Vaughan and Wells, 1943) also
sheds light on the evolution of lesser categories, especially at the
generic level. Here, while septal structures remain relatively
constant, the form of the corallum changes systematically, often
in several directions and on two levels (first-order and second-
fSSB\
ME ANDROID
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Fig. 4. First-order morphogenetic trends in scleraetinian corals, condi-
tioned by modes of colony-formation.
116 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
order trends), from solitary to colonial, from relatively simple
to fairly complex colonial structures, the latter being the termina-
tion of trends from which little more than mere survival may be
expected. Figure 4 shows some of the potential first-order trends
in colony formation from a solitary founder polyp. But, if we
add to these such seemingly genetic, second-order trends as the
encrusting, massive, ramose, and foliate habits, which may oper-
ate on nearly all of the first-order forms, something like 45
distinct colonial forms are possible, and the discouraging specter
of homeomorphy looms ever and ever larger. For instance,
Montlivaltia, a common Mesozoic genus of solitary forms, now
stands revealed as a monostomatous progenitor from which, by
various first- and second-order trends, many homeomorphic
colonial types arose at different times from different species, and
many good species of Montlivaltia are known from the late Trias-
sic well into the Cretaceous. At present the colonial montlival-
tians are generically divided on the basis of modes of colony-
formation, but it is obvious that these "genera" are no more
than form-genera, and the tracing of polyphyletic developments
in this subfamily alone will require very large collections, much
time, and painstaking study.
One of the most debated questions in the evolution of the
anthozoan corals is the relation of the scleractinians to the rugo-
sans. It boils down to whether the scleractinians were filiated
from the rugosans (Schindewolf, 1942), or whether they were
independently derived from skeletonless anemone stocks : the
scleractinians from the stock which led to the living corallimorphs
and actiniarians (Carlgren, 1918; Stephenson, 1921), and the
rugosans from earlier stocks leading to the zoanthids (Duerden,
1902, Hyman, 1940). Chronologically and to some extent eco-
logically, the scleractinians succeeded the rugose corals and it is
tempting to see in them revivified rugosans. It would seem that
the ancestral stock should be found in the late Paleozoic corals,
but it is generally admitted that the rugose corals of the Permian
are the specialized end-forms of a long-lived line of solitary forms
(Schindewolf, 1942). To derive the Scleractinia from these, we
have to assume (1) a possible change in skeletal substance from
calcite to aragonite, (2) a complete change in the microstructure
of the septa, and (3) a change in the mode of mesenterial and
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
117
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118 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
septal insertion. Further, this necessitates acceptance of a mono-
phyletic derivation by typostrophic proterogenesis from some
early ontogenetic stage of the tylolytic late Permian corals. All
of this is assuredly a large order, even for typostrophism. In
addition, the Scleractinia, like the Rugosa, are apparently not
monophyletic (Fig. 5). At the earliest appearance of both orders,
we perceive that each already contains widely divergent groups
on the subordinal level, such as the columnariids in the Rugosa,
and the astrocoeniids in the Scleractinia. Survival of aspects of
the rugosan mode of septal insertion in seleractinians (Schinde-
wolf, 1942; whence Cloud, 1948, and Moore et at., 1952), indica-
tive of transitional characters, seems to be more apparent than
real, even more curious modifications in scleractinian septal
insertion being overlooked. The question is not likely to be
settled for some time.
In recent years the ceaseless search for petroleum has resulted
in the discovery of more and more ancient reef structures, espe-
cially in the Paleozoic rocks. This has focused attention on the
natural history of bioherms and biostromes as organic associa-
tions. Some indication of the extent of work on ancient and
modern reefs is given by a recent bibliography (Pugh, 1950)
which, although incomplete, still lists some 1200 titles. While
relatively few of these contribute much to real ecological under-
standing of reefs, from them emerges the realization that Paleo-
zoic rugose corals were not important as reef constructors, and
that the real reefs of the Paleozoic were largely the work of algal
and algoid organisms (mostly of uncertain affinities), aided to
some extent by tabulate and stromatoporoid corals. Further, few
of these structures had the wave-resistant qualities of modern
oceanic reefs, possibly because few, if any, of the known Paleo-
zoic reefs were oceanic.
This understanding results from closer paleoecological and
sediment logical studies of Paleozoic reefs and from the extensive
ecological work done on Recent corals during the past 25 years
(Yonge, 1940). Earlier analyses (Vaughan, 1911, int. al.) of
ancient reef associations drew conclusions that were somewhat
too broad. This does not mean that ecological principles devel-
oped from the study of living corals are not applicable to Paleo-
zoic forms. Indeed, such studies show rather clearly why some
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
119
Paleozoic corals were significant on reefs and why others were
not. Simple comparison of the growth-forms of rngose and scler-
actinian corals suggests that the rugose corals were unfitted for
the turbulent environment of reef structures in the cumatic zone.
They lacked adhesiveness, and the rootlets developed in some
forms were only poor makeshifts, whereas the tabulates and
stromatoporoids, found in genuine reef communities, gained
stability from their encrusting or strongly adherent habit, just
as all important Recent hermatypic corals are stoutly adherent
basally to their substrates. Further comparison shows definite
superiority in colony-formation and compactness in modern
hermatypic corals, as well as in the extinct stromatoporoids and
SALINITY (PPM)
TEMPERATURE PC.)
ILLUMINATION (LUXES)
(CLEAREST WATERS)
oo DEPTH (METERS)
Fig. 6. Some ecological restrictions of the hermatypic corals.
tabulates. A few rugose corals were colonial, but their colonies
never amounted to much. This requires some explanation beyond
the limited range of modes of colony-formation available to rugo-
sans by extratentacular budding, and their failure to develop
edge-zone. Much of the answer is found in the ecological differ-
ences between living reef (hermatypic) and non-reef (aherma-
typie) corals. Modern reef corals owe most of their success on
reefs to an acquired symbiosis (Yonge, 1931), probably developed
during the Mesozoic, with unicellular algae (zooxanthellae), a
120
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
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STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 121
curious relationship which has conferred on the corals advantages
of increased metabolism or faster growth, with the concomitant
potential for immensely larger colonies or populations within a
given area — this to forms already structurally better fitted to
the reef environment, with, however, restriction to the better-
illuminated sites in warmer sea climates (Fig. 6). Recent non-
reef corals lack zooxanthellae, their colonies are small, they are
widespread even in temperate to cold sea climates, and are
restricted mainly by sediment controls. The rugosans are ana-
logous to the ahermatypic corals to a considerable degree.
Comparisons of some eeologic factors are suggested by the
chart (Fig. 7), ].iartly speculative and indicative of areas for
further application of ecological principles. It may be suggested
that the concept of warm, shallow, clear, well-illuminated tropical
seas as the environment of Paleozoic corals in general, by closer
analogy with the ecology of Recent corals, applies largely to the
stromatoporoids and tabulates, and that the major requirements
of the rugose corals were satisfied by temperate to warm (8°-
18°C.) waters and not -too-rapid accumulation of sediments. But
there is still much to be learned about the "ecological structure"
of corals, living and fossil.
REFERENCES
Carlgren, 0.
193 8. Die Mesenterienanordnung der Halcuriiden. Lunds Univ.,
Arsskr., N.F., Avd. 2, vol. 14, 37 pp., 25 figs., 1 pi.
1940. A contribution to the knowledge of the structure and distribution
of the cnidae in the Anthozoa. Idem, vol. 36, 62 pp., 16 figs.
1943. East-Asiatic Corallimorpharia and Actiniaria. Kungl. Svenska
Vetenskapsakad., Handl., 3rd ser. vol. 20, pp. 3-43, 32 figs. pis.
1,2.
1945. Further contributions to the knowledge of the cnidom in the
Anthozoa, especially in the Actiniaria. Lunds Univ., Arsskr.,
N.F., Avd. 2, vol. 41, 24 pp.
1949. A survey of the Ptychodactiaria, Corallimorpharia, and Acti-
niaria. Kungl. Svenska Vetenskapsakad., Handl., 4th ser., vol. 1,
121 pp., 4 pis.
122 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Caster, K. E.
1942. Two siphonophores from the Paleozoic. Paleontographica Ameri-
cana, vol. 3, pp. 57-90, 7 figs., pis. 4, 5.
Clark, A. H.
1913. Cambrian holothurians. Amer. Nat., vol. 47, pp. 488-507.
Cloud, P. E.
1948. Some problems and patterns of evolution exemplified by fossil
invertebrates. Evolution, vol. 2, pp. 324-350, 4 figs.
Dollfus, G.
1875. Note sur des empreintes attribuables a une actinie (?Palaeactis
vetula) dans les schistes cambriens des Moitiers-d 'Allonne. Mem.
Soc. nat. Sci. natur.-math. Cherbourg., 2e ser., vol. 9, pp.
224-232, pi. 3.
DUBRDEN, J. E.
1902. Eelationships of the Rugosa (Tetracoralla) to the living Zoan-
theae. Ann. Mag. Nat. Hist., 7th ser., vol. 9, pp. 381-398, 12 figs.
Heinrich, M.
1914. TJeber den Bau und das System der Stromatoporoidea. Centralbl.
Min., pp. 732-736.
HlCKSON, S. J.
1924. An introduction to the study of recent corals. Univ. Manchester
Pub., Biol. Ser. No. 4, vii + 257 pp., 110 figs.
1934. On Gypsina plana, and on the systematic position of the stroma-
toporoids. Quart. Jour. Micr. Sci., vol. 76, pp. 433-480, pis. 26,
27, 13 figs.
Htman, L. H.
1940. The invertebrates: Protozoa through Ctenophora: New York, xii
+ 726 pp., 221 figs.
Lang, W. D.
1917. Homoeomorphy in fossil corals. Proe. Geol. Assoc, vol. 28, pp.
85-94.
1923. Trends in British Carboniferous corals. Proc Geol. Assoc, vol.
34, pp. 120-136, figs. 15, 16.
1938. Some further considerations on trends in corals. Proc. Geol.
Assoc, vol. 49, pp. 148-159, figs. 25-28, pi. 7.
Leoompte, M.
1951. Les stromatoporoides du Devonien Moyen et Superieur du bassin
de Dinant. Premiere Partie. Mem. Inst. Roy. Sci. Nat. Belgique,
vol. 116, 215 pp., 35 pis.
1952. Madreporaires paleozoiques. In: Trait e de Paleontologie, ed. by
J. Piveteau, vol. 1, pp. 419-538, 229 figs.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 123
Moore, R. C, C. G. Lalicker, and A. G. Fischer
1952. Invertebrate fossils. New York, xiii + 766 pp.
Parks, W. A.
1935. Systematic position of the Stromatoporoidea. Jour. Paleont.,
vol. 9, pp. 18-29, pla. 6, 7.
Pratz, E.
1882. Ueber die verwandtschaftlicher Beziehungen einiger Korallen-
gattungen mit hauptsachlicher Berucksiehtikung ihrer Septal-
Struktur. Palaeontographica, vol. 29, pp. 81-122, 1 pi.
Pugh, W. E.
1950. Bibliography of organic reefs, bioherms, and biostromes. Seis-
mograph Service Corp., xxxi -f- 139 pp.
SOHINDEWOLF, 0. H.
1942. Zur Kenntniss der Polycoelien und Plerophyllen ; eine Studie
ueber den Bau der "Tetrakorallen" und ihre Beziehungen zu
den Madreporarien. Abh. Reichsamt Bodenforsch., N.F., heft
204, 324 pp., 155 figs., 36 pis.
Stephenson-, T. A.
1921. On the classification of Actiniaria. Quart. Jour. Micr. Sci., vol.
65, pp. 493-576, 20 figs.
TWITCHELL, G. B.
1929. The structure and relationships of the true stromatoporoids.
Amer. Midi. Nat., vol. 11, pp. 270-306, 2 figs., 9 pis.
Vatjghan, T. W.
1911. Physical conditions under which Palaeozoic coral reefs were
formed. Bull. Geol. Soc, Amer., vol. 22, pp. 238-252.
Vaughan, T. W., and J. W. Wells
1943. Revision of the suborders, families, and genera of the Sclerac-
tinia. Geol. Soc. Amer., Spec. Paper No. 44, xv 4- 363 pp., 39
figs., 51 pis.
Wang, H. C.
1950. A revision of the Zoantharia Rugosa in the light of their minute
skeletal structures. Phil. Trans. Roy. Soc. London, vol. 234B, pp.
175-246, 4 figs., pis. 4-9.
Yonge, C. M.
1931. The significance of the relationship between corals and zooxan-
thellae. Nature, Aug. 22, pp. 1-7.
1940. The biology of reef -building corals. Brit. Mus. (N.H.), Great
Barrier Reef Exped., 1928-29, Sci. Repts., vol. 1, no. 13, pp. 353-
391, 6 pis.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
IV. Echinodermata: Pelmatozoa
By Raymond C. Moore
University of Kansas, Lawrence, Kansas
INTRODUCTION
The purpose of this paper is to assess the present status of
knowledge concerning fossil pelmatozoans, taking into account
various important contributions which have been published dur-
ing the past half century. In 1900 Bather organized his own and
others' studies on all main groups of echinoderms in a well-
illustrated volume of Lankester's "Treatise on Zoology"; this
furnishes a very convenient starting point. Bather's lucid de-
scriptions of morphological characters and concise outline of
classification as then conceived have served during subsequent
decades as an indispensable reference and, although a revision
which might incorporate work done since 1900 never was pre-
pared, the book has been reprinted again and again. Appropri-
ately titled sections of the present paper contain brief statements
of what seem to be the significant features in Bather 's discussion
and furnish records of various contributions which have appeared
in later years.
In 1900, as generally now, echinoderms were divided into the
two main groups called Pelmatozoa (more or less permanently
fixed during life) and Eleutherozoa (free-moving) ; it is unim-
portant that Bather designated these assemblages as "grades,"
rather than subphyla or superclasses. The Pelmatozoa were dis-
tributed in four classes, respectively named Edrioasteroidea,
Cystidea, Blastoidea, and Crinoidea. Jaekel's (1899) proposal
to remove from among cystoids the peculiarly flattened forms
which he named Carpoidea was not considered by Bather until
after 1900 but the group was accepted by Schuchert (1904) and
others as an independent class and now generally is so treated
(although the name Heterostelea Jaekel, 1899, is used by some).
Other classes called Eocrinoidea (Jaekel, 1913) and Paracri-
126
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
noidea (Regnell, 1945) have been introduced also. The relegation
of blastoids to rank as a subclass of the cystoids, as recently pro-
posed by Regnell (1945), is a backward step which is not
accepted.
CARPOIDEA
The carpoids, which include ovoid to unevenly angular primi-
tive echinoderms having a dorso-ventrally much flattened theca
composed of few to many plates and generally a very peculiar
Fig. 1. Analysis of thecal structure of regular eoerinoids and rhombiferan
cystoids. In upward order, the alternately disposed circlets commonly are
designated as basals, infralaterals (outlined by heavy black lines), laterals,
radials (outlined by heavy black dots), and orals. Numbers for identification
of individual plates are indicated according to the system of Forbes (1848),
based on Ehombifera. The exterior of plates other than the orals typically
(or primitively) bears a pattern of ridges which is confluent across mid-
points of suture lines with the markings on adjacent plates, and among
rhombiferan cystoids the pore rhombs are similarly arranged.
STATUS OF INVERTEBRATE PALEONTOLOGY, 105.°,
127
tail-like stem appendage that narrows to a point, are chiefly
Cambrian and Ordovician fossils but some specimens assigned to
this group occur in rocks as young as Devonian. Typical genera
include Trochocystites, Mitrocystites, Anomalocystites, Placocyst-
ites, Cothurnocystis, Lagynocystis, Ceratocystis, and Dendrocyst-
ites. All of these forms known to Bather in 1000 were assigned
to two families of an order of eystoids called Amphoridea, a
heterogeneous assemblage which no longer is recognized. The
Carpoidea contain such strange, peculiarly modified echinoderms
of several sorts that interpretation of them as representatives of
a lineage standing widely separated from other groups is inescap-
able. Important additions to knowledge of them have been made
by Bather (1913), Chauvel (1939-41) and Hecker (1940), but
in general they remain poorly known and not at all adequately
understood. Gislen (1927) has published on some carpoids but
also has undescribed specimens.
Fig. 2. Plate arrangement of regular eoerinoids. A, Macrocystella, Trema-
docian (?U.Cam.), England; position of anus indicated by "A"; arrows
denote brachioles attached to radials. B, Lichenoides, Middle Cambrian,
Czechoslovakia, showing proximal parts of brachioles on both radials and
laterals and epispires along sutures; basals are very small, irregular, and
their exact number unknown; position of anus not determined. (After
Ubaghs.)
128 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
EOCRINOIDEA
The Class Bocrinoidea (Jaekel, 1918) was distinguished on the
basis of noncystidean features of the theca associated with the
occurrence of biserial brachioles such as characterize the cystoids.
A typical example is Cryptocrinus, which has an ovoid theca com-
posed of three circlets of plates below the small tegmen where five
pairs of brachiole facets are found. Because neither pore rhombs
nor diplopores penetrate the plates, this echinoderm was placed
by Bather in an order called Aporita and classed with the cyst-
oids. Detailed studies of Cryptocrinus by Yakovlev (1917-27)
led him to conclude that it was derived from rhombiferan cystoids
but assignable to a primitive group of crinoids. Regnell (1945)
refers Macrocystella and other genera of the Macrocystellidae to
the Eocrinoidea, whereas Bather thought that, despite lack of
pore rhombs, they belonged in the order Rhombifera of the
cystoids. The plates are imperforate but their outer surface bears
ridges and grooves disposed approximately normal to suture lines
between the plates and so spaced that the surface markings are
confluent from one plate to another (Figs. 1, 2A) . Another
genus, Lichenoides, which was included in the Macrocystellidae
by Bather but now separated in a family of its own, is a remark-
able eocrinoid that recently has been studied carefully and
described by Ubaghs (1953). Unlike other known early pelmato-
zoans, Lichenoides is demonstrated to have possessed two circlets
of brachiole-bearing plates near the summit of the theca (Fig.
2B). The restoration of this fossil by Jaekel (1918), copied in
various textbooks, is erroneous in showing only a single circlet of
such plates with five brachioles all together, and there are other
important inaccuracies. Margins of the thecal plates carry sur-
fieial canals that lead to pores located along the suture lines ; they
constitute so-called epispires (Hudson, 1915) which superficially
resemble cystoidean pore rhombs but differ in the lack of internal
canals or sacs. It is noteworthy that primitive crinoids such as
Palaeocrinus and Carabocrinus among inadunates and Cleiocrinus
among camerates have seemingly identical structures. The eocrin-
oids have a known range from Lower Cambrian to Middle
Ordovician.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 129
PARACRINOTDEA
Regnell (1945) introduced the Paracrinoidea as a class of
pelmatozoans which is denned by lack of polymeric symmetry of
their generally numerous thecal plates, absence of distinction
between dorsal and ventral parts of the theca, and the occurrence
of uniserial armlike appendages. Typical genera are Comarocyst-
ites, considered by Bather as a representative of the cystoids
(Rhombifera), and Canadocystis; a number of other forms are
doubtfully included in the group. Clearly, these fossils, all of
Middle Ordovician age in so far as known, differ markedly from
crinoids and they seem to be distinct from true cystoids. The
pore-rhomb structures that characterize all thecal plates of
Comarocystites are highly developed but unusual.
EDRIOASTEROIDEA
The edrioasteroids are distinctive, somewhat aberrant pelmato-
zoans, characterized by the many-plated flexible nature of their
upper surface which bears the mouth, anus, and generally curved
ambulacra. They first appear in Cambrian rocks and persist into
the Carboniferous. Most of them are discoid, but a few, such as
Pyrgocystis, have a stalklike cylindrical form. One genus, Astro-
cystites, rather strikingly simulates a blastoid in appearance.
First described by Billings in 1854, a dozen genera had become
known by 1900 and since that time some 15 additional ones have
been defined. They are currently divided among seven families.
Chief publications on the edrioasteroids since 1900 are a series of
papers by Bather (1915), Bassler (1935-36), and Cuenot (1948).
CYSTOIDEA
The early Paleozoic pelmatozoans called cystoids were under-
stood in 1900 to embrace a wide variety of supposedly most
primitive thecate echinoderms. A majority of them are charac-
terized by very large numbers of irregularly arranged plates and
associated lack of well-defined symmetry. Also, the plates com-
monly are perforated by rounded pores or indented by slits that
open on the interior of the theca or communicate with thin-walled
saclike canals. Slender armlike appendages, which are almost
130 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
exclusively biserial in structure and unbranched, may arise from
the tegminal area, or subvective systems leading to the mouth may
extend across the surface of thecal plates. Bather divided this
assemblage into orders called Amphoridea, Aporita, Diploporita,
and Rhombifera and he arranged among them genera which now
are removed to the classes called Carpoidea, Eocrinoidea, and
Paracrinoidea. Many forms that remain classified as cystoids
exhibit constancy of plate arrangement but not well-developed
radial symmetry. A few are both regular and symmetrical and
among these some offer problems in classificatory assignment.
Now known genera of cystoids are approximately 90 in num-
ber, of which some 40 belong to the order Diploporita, character-
ized by abundance of relatively small plates pierced by almost
universally paired pores, and the remainder are assigned to the
order Rhombifera. The latter mostly have larger and far fewer
plates, which in many genera exhibit a regularity of arrangement
that permits application of a scheme of individual plate designa-
tions, and determination of homologous thecal elements. Instead
of pores, the rhombiferan cystoids possess slitlike openings or
internal parallel canaliculate structures that cross sutures be-
tween the plates approximately at right angles ; in simplest form,
the groups of slits or canals occupy rhomb-shaped areas located
half on one plate and half on an adjoining plate but the external
appearance of specialized pore rhombs (as in pectinirhombs) is
considerably modified. An evident trend in evolution is toward
reduction in the total number of pore rhombs and their localiza-
tion on particular parts of the theca. Advance in knowledge of
kinds of cystoids, during the last half century, is indicated by
tabulation of genera recorded in 1900 (25 diploporites and 32
rhombiferans) as compared with present-day numbers (approxi-
mately 40 and 50, respectively). The most important published
studies since 1900 are papers by Bather (1913) on Middle and
Upper Ordovician cystoids of the Girvan district, southern Scot-
land; Jaekel (1918) on general structure and taxonomy; Chauvel
(1939-41) on Ordovician forms from France; Hecker (1940) on
fossils from northwestern Russia; and Regnell (1945-51) on
Ordovician and Silurian cystoids from Sweden and Belgium.
Diploporita. Some of the diploporite cystoids display note-
worthy resemblance to other groups of echinoderms, for example,
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 131
the five spirally curved subvective pathways on the summit of
Gomphocystis, which is strikingly like the pattern on the upper
surface of various edrioasteroids ; also Proteroblastus and Astero-
blastus which rather closely simulate Mastoids. Bather actually
classified Asteroblastus as a primitive sort of Mastoid, in spite of
the presence of diplopores and occurrence of an indefinite number
of irregularly arranged plates. The recently published Traite de
Paleontologie (tome 3, 1953) conveniently but ambiguously
places this genus and the family Asteroblastidae both in the chap-
ter on cystoids and in that on Mastoids. Actually, the diploporite
group of cystoids seems to comprise an assemblage that disap-
peared without issue. Their known range is from lower Middle
Ordovician to Devonian.
Rhombifera. The rhombiferan cystoids merit special notice
because many of {hem have features closely similar to regular
eocrinoids, suggesting genetic relationship to various groups of
crinoids, on one hand, and to Mastoids, on the other. Although
homologies of several sorts have been noted by several workers
between pore-rhomb structures and the hydrospires of Mastoids,
neither Bather nor anyone else seems seriously to have explored
the possibilities that beginnings of evolutionary differentiation
leading to typical eublastoids and to such diverse crinoids as
dicyclic inadunates like Palaeocrinus and Porocrinus, and all
kinds of dicyclic and monocyclic camerates, may exist within this
type of cystoids or the eocrinoids. One purpose of this paper is
to point out what seems to be previously overlooked ways in
which several puzzling characters of plate arrangements which
are diagnostic features of these noncystoid pelmatozoans may be
explained. Accordingly, the organization of several representa-
tive rhombiferan genera will be illustrated and discussed briefly.
Rhombiferans of the family Echinosphaeritidae are judged to
be the most archaic representatives of the order both because
they are among the oldest known and because they have the most
numerous thecal plates, virtually all of which are occupied com-
pletely by an unspecialized type of pore rhombs. The exterior of
unusually well-preserved specimens may be nearly smooth, as in
Echinosphaerites, or very strongly marked ridges running trans-
verse to plate sutures may form a distinctive pattern over all of
the theca, as in Caryocystites, Orocystites, and Heliocrinitet.
132
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Forms like some of these genera may very well correspond to
ancestors of the Cheirocrinidae and other families having more
stable structures, which also are more specialized, but because
c aTal^h
OXAj&^&fo
E 4\__/' ' ' " 2 " 7 ~^ p
Fig. 3. Plate arrangement of rhombiferan cystoids (laterals and radials
differentiated as in Figure 1 and position of anus marked by "A"). The
diagrams illustrate stability in placement of pore rhombs on plates 1+5.
12 + 18, and 14 + 15 and they demonstrate tendency of various plates to
change in shape and position. A, EcMnoenorinites, M.Ord.; B, Callocystites,
M.Sil. ; C, Schizocystis, MJSil.; D, Lepadocystis, U.Ord.; E, Cheiroorinits,
M.Ord. ; F, Glyptocystites, MLOrd. (All modified from Bather.)
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
133
homologous elements of these latter are better recognizable, atten-
tion will be confined to them.
The most regular, simply constructed sort of cheirocrinid has
a.theca composed of four 5-plate circlets disposed in alternating
position beneath a tegmen formed of five small plates correspond-
ing to orals. The arrangement of these elements and the system
of numbers for designation of them introduced by Forbes (1848)
are illustrated in Figures 3 and 4. Pore rhombs of unspeeialized
sort occur on a majority of the plates in the most primitive
genera, as for example in Glyptocystites (Fig. 3F), but they are
progressively reduced in number and increasingly modified in
type as seen in genera which must be interpreted as advanced.
4 1
OTO
B
Fig. 4. Plate arrangement of rhombiferan cystoids (laterals and radials
differentiated as in Figure 1 and position of anus marked by "A"). -4,
Pleurocystites, M.Ord.; B, Lovenicystis, U.Sil.; C, Proctocystis, M.Ord.
(Modified from Bather, A, and Regnell, B, C.)
134 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The most persistent pore rhombs are those located on plates
1 -f- 5, 12 + 18, and 14 -f- 15. In several genera of this group,
such as Ecliinoencrinites, Glyptocystites, Cheirocrinns, Pleuro-
cystites, and Proctocystis, thecal plates are marked externally by
parallel ridges and grooves that meet suture lines transversely
in such a manner as to be confluent with similar markings on
neighboring plates. Their pattern exactly corresponds to that of
simple pore rhombs in forms like Echinosphaerites and they
closely resemble the plates of the eocrinoid Macrocystella, also.
It is altogether reasonable to interpret them as traces or deriva-
tives of once-functional pore rhombs. They may dwindle into
marginal corrugations and along suture lines be represented by
regularly spaced pits that hold bundles of ligamentous fibers.
They may disappear entirely. These observations of plate fea-
tures in rhombiferan cystoids, and likewise in eocrinoids, prob-
ably have significance in understanding the more or less identical
characters of many crinoid plates.
Another important generalization derivable from comparative
study of these cystoids relates to placement of the food-gathering
subvective structures. In several genera they lie recumbent on
the thecal plates radiating from the tegminal region, becoming
rather closely similar to blastoids in such forms as Lepocrinites,
Proteroblastas, and Cystoblastus. The brachioles also may be
free appendages rising from the summit part of the theca.
In spite of stability expressed by the almost invariable enlarge-
ment of plate 3 in the lowermost circlet and constancy in place-
ment of pore rhombs, various genera show noteworthy downward
and upward shifts in position of some thecal plates along with
change in the plate outlines. In this way, the complement of
plates in a given circlet may be enlarged or reduced and the
latter sort of change may be effected also by complete disappear-
ance of thecal plates. Thus, modifications in the architectural
pattern of the whole theca are introduced. It is interesting to
learn that the position of the anal opening is almost invariably
above or between plates 7 and 8 of the next-to-lowermost (infra-
lateral) circlet.
Before leaving the cystoids, it is desirable to notice forms which
are grouped in the family Caryocrinitidae, for these have mostly
very regularly arranged plates in three circlets below the tegmen
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
135
and they exhibit distinct trimerous (or hexamerous) symmetry.
Hemicosmites and Caryocrinites are examples (Fig. 5). Pore-
rhomb canals, which are well developed on the inner side of
plates, do not appear externally, although their presence is
* 13 19 *- /
' \ "*--»
Fig. 5. Plate arrangement of hexamerally symmetrical rhombiferan cys-
toids showing inferred correlation with elements of other regular rhom-
biferans (as illustrated in Figs. 3 and 4) ; arrows mark location of
brachiole facets. A, Hemicosmites, M.Ord. ; B, Caryocrimtes, M.Ord.-M.Sil.
(Modified from Bather.)
136 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
marked by rows of tubercles running from the center to angles
of the plates; these tubercles comprise the thin covering of
slightly produced pores at borders of the rhombs. Bather applied
nomenclature of dicyclic crinoids to these cystoids, designating
the lowermost circlet as infrabasals, the intermediate one as
basals, and that next to tbe tegmen as radials and interradials
(although neither distribution of brachioles, or arms, nor disposi-
tion of plates in this third circlet furnish basis for distinction of
radials from interradials). The Avhole pattern of thecal structure
is explainable readily by downward migration of one plate from
the circlet of "laterals" (probably no. 13) in the 4-circlet regular
Rhombifera and upward migration of the others. A feature that
suggests affinity with camerate crinoids (as noted by Bather) is
the subtegminal placement of the proximal part of food passage-
ways leading to the mouth. Caryocrinites possesses typical pin-
nulate biserial arms of camerate type (Springer, 1926, pi. 33,
fig. 37).
BLASTOIDEA
The Class Blastoidea is generally distinguished from cystoids
by the very regular pentameral symmetry of the budlike theca
composed of plates which ordinarily are reckoned to be reduced
in number to 13 (three basals, five radials, and five interradially
disposed deltoids). Actually five lancet plates occur also, placed
along the midline of each radial, but they are concealed by numer-
ous small side plates of the recumbent ambulacra. Abundant
threadlike brachioles are joined to edges of the ambulacra. Bather
divided the group into "grades" called Protoblastoidea and
Eublastoidea, the former including Blastoidocrinus, Asteroblas-
tus, and Asterocystis, whereas the latter comprises all others.
Although Bassler (1938), and Bassler and Moodey (1943) have
followed this classification, adding Mesocystis to the Protoblast-
oidea, most students assign all of these named genera, except
Blastoidocrinus, to the cystoids and generally thejT do not recog-
nize a division (order) called Protoblastoidea. Probably the most
noteworthy contributions to the knowledge of blastoids during
the last half century are the studies of Hudson (1907), who
defined the order Parablastoidea ; Jaekel (1918), Avho recognized
the importance of hydrospire openings in classifying the Eublast-
Fig. 6. A, plate arrangement of a regular rhombiferan cystoid, Cystoblas-
tus, M.Ord. B, hypothetical evolutionary derivative of a ^re-Cystoblastus
type and C, a typical eublastoid in which correlation with elements of pre-
sumed rhombiferan ancestral stock is indicated by differentiation of circlets
as in Figure 1. Arrows denote position of ambulacra and "A" location of
the anus. The Mastoid radials are identified as rhombiferan infralaterals,
lancet plates as rhombiferan radials, and deltoids as rhombiferan laterals.
138 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
oidea by introducing suborders called Fissiculata and Spiracul-
ata; Wanner (1924-49), who described many remarkable Mas-
toids from Permian rocks of Timor; Cline (1936-44), who spe-
cially studied some Mississippian genera ; and Bergounioux
(1953), who surveyed morphology and taxonomy of the class.
On the whole, however, advance in this period is considerably
smaller than one might expect.
An absorbing problem on which no real progress has been made
for a very long time relates to the origin of the Mastoids. That
the group has strong cystidean affinities is very evident — so
much so, indeed, that Regnell (1945) ill-advisedly proposed to
rank the Blastoidea as a subclass of the cystoids. Yet no one
thinks that evolution leading to the eublastoids can be traced
from such blastoid-like cystoids as Proteroblastus, Asteroblastus,
or Cystoblastus. What then are the roots of Mastoids? Observa-
tion of the structure and evolutionary trends shown by the regu-
lar rhombiferan cystoids leads me to suggest a previously
unexplored line of attack. Remembering that thecal elements of
the 4-eirclet cheirocrinids show tendencies to shift positions and
shapes, as clearly illustrated by Cystoblastus (Fig. 6A), is it
conceivable that the ultimately very stable features of eublastoid
structure may be derived from this source? A postulate in this
direction is offered diagrammatically by Figures 6B and 6C, in
which a hypothetical intermediate cystoid-blastoid, descended
from a somewhat C y sto blast 'us -like ancestor, is succeeded by a
form having all of the structural characters typical of the true
blastoids. If this concept accords with the actual course of evolu-
tionary change, it becomes evident that such elements as the
lancet plates are fundamental parts of blastoid anatomy, being
derived from the uppermost circlet (so-called radials, nos. 15-19)
of the regular rhombiferans, whereas the deltoids are upwardly
moved laterals (nos. 10-14) in interradial position. Fusion of
two pairs of lowermost-circlet plates of the presumed rhombiferan
ancestor yields the characteristic basal circlet pattern of the
eublastoids, with the small (azygous) basal in the antero-right
position. The hydrospires, as perhaps most simply shown in
Codaster, are strictly homologous to the pore rhombs in the
Rhombifera, transecting the sutures between radials and deltoids
approximately at right angles, and study of them in thin sections
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 139
under polarized light demonstrates crystallographic continuity
of different parts of each hydrospire with thecal plates which they
adjoin. Thus, derivation of the blastoids from rhombiferan cys-
toids of seemingly very unlike thecal organization becomes a
rational hypothesis.
CRINOIDEA
By far the largest and most varied division of the Pelmatozoa
consists of the crinoids. Without doubt, also, this class contains
the most highly evolved members of the subphylum, as well as the
only representatives found in post-Paleozoic deposits. More than
5,000 species of fossil crinoids have been described, which is sev-
eral times the number of all other pelmatozoans combined.
Naturally, therefore, the Crinoidea have preeminent importance
in paleontological study of fixed echinoderms.
Crinoids are distinguished by almost universal well-developed
symmetry of the theca (calyx), and presence almost without
exception of relatively strong, prominent arms which may be
many-branched and very commonly provided also with innumer-
able branchlets (pinnules). A more or less elongate stem com-
posed of generally discoid, centrally pierced plates (columnals)
serves as a means of attachment, although many crinoids (espe-
cially modern comatulids) are stemless in adult life. Strati-
graphic range of the class is from Tremadocian ( ?Upper
Cambrian) to Recent.
In 1900, all main kinds of crinoids were fairly well known but
the classification accepted by Bather and generally adopted by
other workers of the time is radically different from that prevail-
ing now. Of course, much new information has been gained
from study of innumerable genera which then were unknown and
the interpretation of various morphological features has changed.
Crinoid genera known in 1900 numbered about 250, whereas
additional genera described since 1900 are about 500. Bather
divided all crinoids into subclasses called Monocyclica (having
only a single circlet of plates below the radials) and Dicyclica
(having two circlets below the radials). The monocyclic group
contained orders named Inadunata, Camerata, and Adunata,
whereas the dicyclic group contained orders named Inadunata,
Camerata, and Flexibilia, thus duplicating some of the ordinal
140 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
designations. Not only by this classification but by Bather's
discussions the conclusion is expressed that monocyclic inadun-
ates (like Pisocrinus) and monocyclic camerates (like Actino-
crinites) are much more closely related to one another than
respectively to dicyclic inadunates (like Cyathocrinites) and
dicyclic camerates (like Bhodocrinites) . This was denied by
Springer (1913) and has come almost universally to be rejected.
Wachsmuth and Springer (1885) divided the Inadunata into
assemblages called Larviformia (dominantly monocyclic) and
Fistulata (dominantly dicyclic) which, although widely accepted
in publications as late as 1943 (Bassler and Moodey), have been
displaced by differently defined orders named Disparida, Hybo-
crinida, and Cladida (Moore and Laudon, 1943; Jaekel, 1918;
Regnell, 1948; Ubaghs, 1953). The Camerata are divided into
orders called Diplobathrida and Monobathrida (Moore and Lau-
don, 1943 ; Ubaghs, 1953). Post-Paleozoic crinoids are grouped in
the Subclass Articulata.
It is impractical to review here the voluminous literature on
crinoids which has appeared during the past half century and
accordingly mere mention of selected contributions that seem to
have most significance must suffice. These include in foremost
place: (1) many long and short papers by Frank Springer
(1900-26), especially his monographs on the Flexibilia and
American Silurian crinoids which not only furnish organization
of a vast amount of accumulated studies but importantly extend
the frontiers of knowledge; (2) A. H. Clark's (1908-41) addi-
tions to understanding of the morphology and classification of
articulate crinoids, especially in monographs on living forms;
(3) Kirk's (1911-50) discussion of eleutherozoic crinoids and
numerous short papers on various genera; (4) James Wright's
(1913-53) comprehensive studies of British Carboniferous cri-
noids, including description of many new forms; (5) Wanner 's
(1916-49) invaluable enrichment of information pertaining to
Permian crinoids and penetrating interpretation of their rela-
tionships; (6) Jaekel's (1918) taxonomic survey and discussion
of the phylogeny of all pelmatozoans ; (7) Goldring's (1923)
large memoir on Devonian crinoids of New York; (8) Gislen's
(1924-38) work on fossil and living articulates; (9) Sieverts-
Doreck's (1927-52) numerous papers; (10) W. E. Schmidt's
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 141
(1930-42) studies of Devonian and Carboniferous crinoids of
Germany; (11) work by Moore (1940-52), Moore and Laudon
(1943-44), and Moore and Plummer (1937-40) describing many
late Paleozoic crinoids and revising classification ; (12) Teichert's
(1949) report on Australian Calceolispongia; (13) Termier and
Termier's (1949) effort to correlate structural characters of cri-
noid groups; and (14) Ubagh's (1943-53) thorough investigation
of some European genera and able general account of crinoids
representing all types. Collectively, these and the work of many
not mentioned may be accounted at least to have matched the
progress made in the investigation of crinoids from the time of
J. S. Miller's (1821) "Natural History of the Crinoidea, or
Lily-shaped Animals" down to 1900.
Origin of some crinoid stocks. The oldest known crinoid seems
to be a rather poorly described inadunate (called Dendrocrinus
cambriensis Hicks) from Tremadocian rocks of England, vari-
ously assigned to uppermost Cambrian or lowermost Ordovician.
Very little later and almost coincidentally, many representatives
of the Inadunata, Camerata, and some Flexibilia made their
appearance. The origin and interrelationships of these crinoid
groups have been studied again and again without arriving at any
firm conclusions but it is agreed that in each group various stable
features are distinguishable from the very beginning. For ex-
ample, among flexible crinoids this applies to the peculiarities of
ray structure and constant arrangement of infrabasal plates
(two large and one small, the latter invariably in right posterior
position except in rare aberrant individuals). In the monocyclic
camerate group called Tanaocrinina, the insertion of an anal
plate (tergal) in the circlet of radials and the hexagonal outline
of the basal circlet, which very predominantly consists of three
equal plates, are constant distinguishing features, whereas radials
in contact with one another all around and a pentagonal basal
circlet are similarly constant attributes of remaining monocyclic
camerates (Glyptocrinina). The phylogenetic significance of
these things, not to mention many others, remains almost wholly
conjectural.
Bather gave detailed attention to homologies observed between
various seemingly little related crinoids and to correspondence
in structures of some crinoids and cystoids, but he rejected the
142
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Fig. 7. Plate arrangement of lower part of cup in dicyclic camerate
crinoids showing inferred correlation with thecal elements of eocrinoids
and rhombiferan cystoids as differentiated in Figures 1-4. A, Archaeocrinidae
and Ehodocrinitidae, M.Ord.-Miss. ; B, Ptychocrinidae, Dimerocrinitidae, and
Lampterocrinidae, M.Ord.-L.Dev. If derivation here suggested is correct,
the brachials of each ray are developed in series with plates corresponding
to laterals (as in Lichenoides) ; also, the plan of plates shown in A is the
more advanced, which is contrary to opinion expressed by Moore and
LaudoD (1943).
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
18* ^ U9
143
Fig. 8. Plate arrangement of lower part of cup in monocyclic camerate
crinoids showing inferred correlation with thecal elements of eocrinoids and
rhombiferan cystoids as differentiated in Figures 1-5. A, Glyptoerinina,
U.Ord.-Perm. ; B, Tanaocrinidae, U.Ord.; C, Actinocrinitidae, Miss.-Perm. ;
D, Plan of basal circlet in all families of Tanaocrinina except Tanaocrinidae,
Dichocrinidae, and Acrocrinidae, showing orientation of pentastellate lumen
and (by dotted lines) position of sutures between plates in a 5-plate circlet.
If derivation here suggested is correct, the brachials of each ray are de-
veloped in series with plates corresponding to infralaterals of eocrinoids and
rhombiferan cystoids; also, the ancestral stock that gave rise to the Tanao-
crinina (Figs. B-D) must have developed the hexameral organization of
caryocrinitids, whereas the Glyptoerinina descended from a normal penta-
meral type of eocrinoid.
144 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
postulate that rhorabiferan cystoids (or pelmatozoans of this t3^pe,
including forms now classed as eocrinoids) could be ancestral to
any crinoid group. I undertake here to demonstrate by diagrams
(Figs. 7, 8) that the respective dorsal cup patterns of all types
of camerate crinoids are directly derivable from eocrinoids or
conceivably from regular rhombiferan cystoids of sorts that be-
long either to the Cheirocrinidae or Caryocrinitidae ; this calls
merely for longitudinal shifting of thecal plates in a manner
clearly shown within the cystoid assemblage. It is interesting to
observe that, whatever the ultimate stable arrangement of cup
plates in the crinoids may be, the orientation of the pentagonal or
pentastellate lumen at the center of the lowermost circlet (con-
tinuous with the stem) remains constant, although where this
opening is circular, orientation of the chambered organ cannot
be detected. A radical innovation which is introduced by this
approach to explaining camerate cup architecture is the deduc-
tion that infrabasal plates of dicyclic cups are identical to basal
plates of monocyclic forms and not elements of originally dif-
ferent circlets. It follows that monocyclic camerates are not
descendants of dicyclic camerates produced by diminution and
ultimate disappearance of the lowermost circlet (so-called infra-
basals). It is pertinent to call attention to the persistence of
stereom folds or ridge patterns on cup plates of very many of the
camerates, both dicyclic and monocyclic, reflecting the arrange-
ment of pore rhombs belonging to their presumed eocrinoid or
cystoid ancestors.
Much more lengthy discussion than can be given in this paper
is needed in order to analyze the many implications of homologies
which are newly suggested here. Such discussion may be under-
taken in later writing. For the present, I assert only that the
postulates now offered cannot plausibly be extended to embrace
any of the Flexibilia nor possibly more than a very few kinds
of inadunates (perhaps Hybocrinida, Carabocrinidae, Palaeo
crinidae, and some others). No trace of affinities with any cys-
toids, eocrinoids, paracrinoids, or carpoids is recognized in the
many kinds of flexible crinoids, disparid inadunates, or most of
the cladids. If all camerates are descended from eocrinoid- or
cystoid-like ancestors, whereas most other crinoids are not, the
Class Crinoidea is polyphyletic.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 145
REFERENCES
Bassler, R. S.
1935. Classification of the Edrioasteroidea. Smithson. Misc. Coll.,
vol. 93, no. 8, pp. 1-11, pi. 11.
1936. New species of American Edrioasteroidea. Ibid., vol. 95, no. 6,
pp. 1-33, pis. 1-7.
1938. Pelmatozoa Palaeozoica. Fossilium Catalogus, pt. 83, W. Junk,
'S Gravenhage.
Bassler, R. S., and M. W. Moodey
1943. Bibliographic and faunal index of Paleozoic pelmatozoan echino-
derms. Spec. Paper Geol. Soc. America, no. 45, pp. 1-734.
Bather, F. A.
1900. Echinoderma. in Lankester, E. R., Treatise on zoology, A. & C.
Black, London, pt. 3, pp. 1-344, illus.
1908. Jiingeres Palaozoicum von Timor, genus Schisoblastus. Neues
Jahrb. Min. Pal., Beil.-Bd., vol. 25, pp. 303-319, pi. 10.
1912. Notes on Hydreionocrinus. Trans. Edinburgh Geol. Soc, vol. 10,
pp. 61-76, pi. 8, figs. 1-14.
1913. The Trenton crinoid, Ottawacrinus. Canada Geol. Survey, Bull.
Victoria Mus., vol. 1, pp. 1-16, pi. 1.
1913. Caradocian Cystidea from Girvan. Trans. Roy. Soc. Edinburgh,
vol. 49, pt, 2, pp. 359-529, pis. 1-6, figs. 1-80.
1915. Studies in Edrioasteroidea, I-LX. Collected reprints from Geol.
Mag., Wimbledon, Eng.
1917. The base in the camerate monocyclic crinoids. Geol. Mag., dee.
6, vol. 4, pp. 206-212, figs. 1-9.
Bergounioux, F. M.
1953. Classe des blastoides. Traite de Paleontologie, ed. J. Piveteau,
Masson, Paris, vol. 3, pp. 629-650, figs. 1-36.
Chauvel, J.
1939- Recherches sur les cystoi'des et les carpoides armoricains. Soc.
1941. geol. et miner. Bretagne, vol. 5.
Clark, A. H.
1908- Numerous short papers on crinoid morphology and taxonomy.
1914.
1915- Monograph of the existing crinoids. Bull. U. S. Nat. Mus., vol.
1941. 82, pts. l-4a.
Cline, L. M.
1936- Blastoids of the Osage group, Mississippian. Jour. Paleont.,
1937. vol. 10, pp. 260-281, pis. 44, 45 ; vol. 11, pp. 634-649, pis. 87, 88.
1944. Class Blastoidea, in Shimer, H. W. and R. R. Shrock, Index
fossils of North America. Wiley, New York, pp. 133-137, pis.
50, 51.
146 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
CUENOT, L.
1948. Anatomie, ethologie, et systematique des echinodermes ; Traits
de Zoologie, ed. P. Grasse, Masson, Paris, vol. 11, pp. 3-275,
figs. 1-312.
1953. Classe des heterosteles, classe des cystides. Traite de Paleontolo-
gie, ed. J. Piveteau, Masson, Paris, vol. 3, pp. 599-628, figs. 1-12,
1 31.
Forbes, E.
1848. On the Cystidae of the Silurian rocks of the British Islands.
Mem. Geol. Survey Great Britain, vol. 2, pp. 483-534, pis. 11-23.
GlSLEN, T.
1924. Echinoderm studies. Zool. Bidr. Uppsala, vol. 9, pp. 1-316, figs.
1-351.
1927. A new Spanish carpoid. Ark. Zool., vol. 19, pt. 2, pp. 1-3.
1934. A reconstruction problem. Lunds Univ. Arsskr., n. f., avd. 2,
vol. 45, no. 11.
1938. A revision of the Recent Bathyerinidae. Ibid., vol. 34, no. 10.
GOLDRING, W.
1923. Devonian crinoids of New York. Mem. New York State Mus.,
vol. 16, pp. 1-670, pis. 1-60.
Heoker, R.
1940. Carpoidea, Eocrinoidea, und Ophiocistia des Ordovmums des
Leningrader Gebietes und Estlands. Acad. Sci. U.R.S.S., Trav.
Inst. Paleont., vol. 9, pt. 4, pp. 5-82, pis. 1-10.
Hudson, G. H.
1907. On some Pelmatozoa from the Chazy limestone of New York.
Bull. N. Y. State Mus., vol. 107, pp. 97-152, pis. 1-10.
1911. Studies of some early Siluric Pelmatozoa. Ibid., vol. 149, pp.
195-272.
1915. Some fundamental types of hydrospires with notes on Porocrinus
smithi Grant. Ibid., vol. 177, pp. 163-165.
Jaekel, O.
1899. Stamingesehichte der Pelmatozoen, 1, Thecoidea und Cystoidea,
Berlin, pp. i-x, 1-442, pis. 1-18.
1900. Ueber Carpoideen, eine neue Klasse von Pelmatozoen. Zeitschr.
deutseh. geol. Gesell., vol. 52, pp. 661-677.
1918. Phylogenie und System der Pelmatozoen. Palaont. Zeitschr., vol.
3, pp. 1-128, figs. 1-114.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 147
Kirk, E.
1911. The structure and relationships of certain eleutherozoic Pelma-
tozoa. Proc. U. S. Nat. Mus., vol. 41, pp. 1-137, pis. 1-11.
1929- Numerous short papers on crinoids in various journals.
1950.
Moore, R. C.
1940. Relationships of the family Allageerinidae. Bull. Denison Univ.
Sci. Lab., vol. 35, pp. 55-137, pis. 2, 3, figs. 1-14.
1950. Evolution of the Crinoidea in relation to major paleogeographic
changes in earth history. Internat. Geol. Congr., Rept. 18th Sess.,
London, pt. 12, pp. 27-52, figs. 1-18.
Moore, R C, and L. R. Laudon
1943. Evolution and classification of Paleozoic crinoids. Spec. Paper
Geol. Soc. America, no. 46, pp. 1-153, pis. 1-14, figs. 1-18.
1944. Class Crinoidea. in Shimer, H. W., and R. R. Shrock, North
American Index fossils, Wiley, New York, pp. 137-209, pis. 52-79.
Moore, R. C, and F. B. Plummer
1937. Upper Carboniferous crinoids from the Morrow subseries of
Arkansas, Oklahoma, and Texas. Bull. Denison Univ. Sci. Lab.,
vol. 32, pp. 209-313, pis. 12-16, figs. 1-37.
1940. Crinoids from the Upper Carboniferous and Permian strata in
Texas: Bull. Univ. Texas, no. 3945, pp. 1-468, pis. 1-21, figs.
1-78.
PrVETEATJ, J.
1953. Classe des edrioasteriodes. Traite de Paleontologie, ed. J. Pive-
teau. Masson, Paris, vol. 3, pp. 651-657, figs. 1-10.
Regnell, G.
1945. Non crinoid Pelmatozoa from the Paleozoic of Sweden. Lunds
Geol. Miner. Inst., Medd. 108, pp. 1-255, pis. 1-15, figs. 1 30.
1948. Swedish Hybocrinida. Arkiv f. zoologi, vol. 40A, no. 9.
1951. Caradocian-Ashgillian cystoid fauna of Belgium. Mem. Inst.
Roy. Sci. Nat. Belgique, vol. 120, pp. 1-47, illus.
Schmidt, W. E.
1930. Die Echinodermen des deutsches Unterkarbons. Jahrb. Preuss.
geol. Landesanst., pp. 1-92, pis. 1-3, figs. 1-20.
1934- Die Crinoiden des rheinischen Devons, Teil 1. Ibid., Abh., n. f.,
1942. Heft 163, pp. 1-149, pis. 1-34; Teil 2. Abh. Reichanst, f. Boden-
forschung, n. f., H. 182, pp. 1-253, pis. 1-26.
SOHUCHERT, C.
1904. Siluric and Devonic Cystidea. Smithson. Misc. Coll., vol. 27, pp.
201-272, pis. 34-44.
1913. Cystoidea. Maryland Geol. Survey, Lower Devonian, pp. 227-248,
ols. 32-36.
148 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
SlEVERTS (DOREOK.), H.
1927. Ueber die Crinoidengattung Marsupites. Abh. Preuss. geol.
Landesanst., n. f., heft 108, pp. 1-73, pis. 1-5.
1934- Numerous papers on crinoids, blastoids, etc., in various journals.
1952.
Springer, Frank
1901. Uintacrinus, its structure and relations. Mem. Mus. Comp. Zool.,
Harvard Coll., vol. 25, no. 1.
1911. On a Trenton echinoderm fauna at Kirkfield, Ontario. Mem.
Geol. Survey Canada, no. 15P, pp. 1-68, pis. 1-5.
1913. Crinoidea. in Zittel-Eastman, Textbook of Palaeontology, Mac-
Millan, London, 2d ed., vol. 1, pp. 173-243, figs. 267-346.
1920. Crinoidea Flexibilia. Smithson. Inst. Pub. 2501, pp. 1-486, pis.
A-C, 1-75, figs. 1-51.
1921. Dolatocrinus and its allies. Bull. U. S. Nat. Mus., vol. 115, pp.
1-78, pis. 1-16.
1923. On the fossil crinoid family Catillocrinidae. Smithson. Misc.
Coll., vol. 76, no. 3, pp. 1-41, pis. 1-5.
1926. Unusual fossil crinoids. Proc. U. S. Nat. Mus., vol. 67, art. 9,
pp. 1-137, pis. 1-26.
1926. American Silurian crinoids. Smithson. Inst. Pub. 2871, pp.
1-239, pis. 1-33 ; numerous other short papers.
Teiohert, Curt
1949. Permian crinoid Calceolispongia. Mem. Geol. Soc. America,
vol. 34, pp. 1-132, pis. 1-26, figs. 1-24.
Termier, H., and G. Termier
1948. Les echinodermes du Paleozoique inferieur. Revue Sci, Paris,
no. 3298.
1949. Hierarchie et correlations des caracteres chez les crinoides fos-
siles. Bull. Service Carte Geol. de 1 'Algerie, ser. 1 (Paleont.), no.
10, pp. 1-69, pis. 1-8.
Ubaghs, Georges
1943. Note sur la morphologie, le biologie, et la systematique du genre
Mespiloorinus. Bull. Mus. Nat. Hist. Belg., vol. 19; no. 15.
1945- Contribution a la connaissance des crinoides de l'Eodevonien de
1947. la Belgique. Ibid., vol. 21, no. 16; vol. 23, no. 4.
1950. Le genre Spyridiocrinus. Ann. Paleont., vol. 36.
1953. Classe des crinoides. Traite de Paleontologie, ed. J. Piveteau,
Masson, Paris, vol. 3, pp. 658-773, figs. 1-166.
1953. Notes sur Lichenoides priscus Barrande, eocrinoide du Cambrien
moyen de la Tchecoslovaquie. Bull. Inst. Roy. Sci. Nat. Belgique,
vol. 29, no. 34, pp. 1-24, figs. 1-12.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 149
Waohsmuth, Charles, and Frank Springer
1885. Revision of the Palaeoerinoidea. Proc. Philadelphia Acad. Sci.
Wanner, Johannes
1916. Die permischen Echinodermen von Timor, Teil 1. Palaont. von
Timor, Lief. 6, Teil 11, pp. 1-329, pis. 96-114, figs. 1-88.
1924. Die permischen Krinoiden von Timor. Mijn. nederl. Oost-Indie,
Jahrb., Verhandel. 1921, Gedeelte 3, pp. 1-34-8, pis. 1-22, figs.
1-61.
1924. Die permischen Echinodermen von Timor, Teil 2. Palaont. von
Timor, Lief. 14, Abh. 23, pp. 1-81, pis. 1-8, figs. 1-31.
1930. Neue Beitrage zur Kenntnis der permischen Echinodermen von
Timor, IV. Flexibilia. Dienst Mijnb. nederl. -Indie, Wetensch.
Mededeel. 14, pp. 1-52, pis. 1-4.
1937. Ibid., VIII-XIII. Palaeontographica Suppl.-Bd. 4, Abt. 4, Lief.
2, pp. 57-212, pis. 5-14, figs. 1-82.
1949. Ibid., XVI. Palaeontographica Suppl. Bd. 4, pp. 1-56, pis. 1-3.
Wright, James
1913- Numerous papers on British crinoids, incl. 1939, Scottish Car-
1953. boniferous Crinoidea. Trans. Roy. Soc. Edinburgh, vol. 60, pt. 1,
pp. 1-78, pis. 1-12, figs. 1-86.
1949- A monograph of the British Carboniferous Crinoidea. Mon.
1953. Palaeontograph. Soc, London.
Yakovlev, N. N.
1917- Some new data on Cryptocrinus and the connection between the
1918. Crinoidea and Cystoidea. Ann. Soc. Pal. Russia, vol. 2.
1927. Sur l'homologie dans la structure de la face ventrale du calice
de Cystoidea et de Crinoidea. C. R. (Dokladi) Acad. Sci.
U.R.S.S.;
1930. Le genre Petschoraorinus et le passage des crinoides dicycliques
aux crinoides monocycliques. Ibid.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 195-1
TV. Echinodermata: Eleutherozoa1
By
J. Wyatt Durham
Museum of Paleontology, University of California
Berkeley 4, California.
Inasmuch as all classes of eleutherozoan Echinodermata are
well represented in the Recent faunas, a realistic appraisal of
our knowledge of fossil Eleutherozoa requires a comparison with
the living fauna. According to A. H. Clark (1948) there are
about 1500 species of Asteroidea, the same number of Ophiuroi-
dea, and 771 species of Echinoidea in the Recent fauna (no
estimate for Holothuroidea). Mortensen (1928-1951) in his
comprehensive work lists 867 species and 88 varieties of living
Echinoidea. Pratt (1935) lists 1100 species of Asteroidea, 1600
species of Ophiuroidea, 600 species of Echinoidea, and 650
species of Holothuroidea as the approximate numbers of these
organisms that occur in the Recent faunas. Because of his greater
familiarity with the Echinodermata it seems probable that
Clark's estimates are more nearly correct than those of Pratt.
Clark also indicates that most of the species are inhabitants of
shallow water areas, from low tide down to depths of about 1500
feet. Thus the occurrences of most living Eleutherozoa would
compare favorably with the depth facies of much of the fossil
record. A general survey of the literature (not exhaustive) indi-
cates that as of 1952 there were described from the fossil record
at least 300 species of Asteroidea (first record in the Ordovician),
at least 179 species of Ophiuroidea (first record in the Ordovi-
cian, including about 74 species referable to the Auluroidea
auct.), at least 3 species of Somasteroidea (restricted to Ordo-
vician), and about 7200 species (about 4500 Trregularia) of
Echinoidea (first record in the Ordovician). D. L. Frizzel (per-
sonal communication, June 19, 1953) states that he recognizes
i A contribution from the Museum of Paleontology of the University of Cali-
fornia, Berkeley 4, California.
152
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
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STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
153
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154
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
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Eleutherozoaa Echmodmuata
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From; Clark, 1946.
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 155
117 species of fossil Holothuroidea, beginning in the Devonian
(he recognizes no pre-Devonian records as referable to the Holo-
thuroidea). The above data are summarized in graphic form in
Figures 1 and 2.
From the above data on Recent and fossil Eleutherozoa it is
apparent, considering the many "turnovers" in fossil faunas
that must have occurred from the early Paleozoic to Recent, that
the described fossil representatives of the various classes, ex-
cepting the Echinoidea, are an extremely inadequate sample of
the faunas that must have existed.
For more detailed comparisons of fossil and living faunas,
data regarding occurrences within faunal provinces are illumi-
nating. In the Australian area (Clark, 1946), there are recorded
(Fig. 3) 189 living and 17 fossil asteroid species, 223 living and
14 fossil ophiuroid species, 135 living and 56 fossil echinoid
species, and 158 living and one fossil holothurian species. It is
obvious that in this region the fossil record is very incomplete.
On the Pacific Coast of North America (Fisher, 1911-1930;
Grant and Hertlein, 1938; Clark, 1948), the present-day fauna
includes about 149 species of asteroids, and about 52 species of
echinoids in the region from Alaska to the Isthmus of Tehuante-
pec. Similar data for the Ophiuroidea and Holothuroidea is not
readily available, but by analogy with the world-wide fauna and
the Australian area it may be assumed that they are approxi-
mately equal in numbers to the Asteroidea and Echinoidea respec-
tively. In the fossil record (Durham, 1950; Durham and Roberts,
1948 ; Eaton, Grant, and Allen, 1941 ; Grant and Hertlein, 1938 ;
and other sources), about 4 species of asteroids, 10 of ophiuroids,
186 (species and subspecies) of echinoids, and no holothurians
have been reported along the Pacific Coast from Alaska to the
Isthmus of Tehuantepec. When these occurrences are compared
(Fig. 4) with the living fauna of the same area it is readily ap-
parent that only the echinoids are at all adequately represented
in the reported fossil record.
A more detailed comparison may be made (Fig. 5) between
the Recent and recorded Tertiary and Pleistocene echinoids of
the Pacific Coast when the records are sorted into epochs and
the scutellid echinoids segregated. Among the non-scutellid
echinoids no one epoch has a recorded species representation
156
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Eleutherozoan EcHriodermata
of Pacific Coast.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
157
equivalent to that of the Recent, but the Pliocene with 26 species
approaches the Recent fauna (39 non-scutellids). The scutellid
echinoids with several extinct and short-ranged genera (Astro-
dapsis, Merriamaster, Scutaster, and Scutellaster [=Anorthoscu-
tum auct.]) as well as somewhat longer-ranging genera such as
Echinarachnius, were obviously evolving rapidly in this area.
However this apparent rapid evolution is possibly affected by a
3 Number of Species
Or
O
o
O
a.
G o
e e
o
51
to
o
o
■
&
o
— 1_
^1
o
—i—
Pa /eocene
Eocene
vcene
Miocene
Pliocene
Pleistocene
Recent
refinement of systematics not apparent in the non-scutellid group :
for instance, the 37 new specific and subspecific unit names pro-
posed in the paper by Eaton, Grant and Allen (1941) for the
upper Miocene scutellids of a small area. Of the 37 names, 36
are applied within the genus Astrodapsis alone. Nevertheless,
despite doubts that may be raised by the systematics involved,
the rapid and varied diversification of the scutellids in the
158 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Pacific Coast Neogene testifies to the evolutionary potential pres-
ent in some irregular echinoid stocks under favorable conditions.
Some of these scutellids are fairly widespread and common in
the Neogene of the California area and serve as excellent in-
dex fossils.
Despite the apparent sparsity of their fossil record both the
Asteroidea and Ophiuroidea appear to be represented in the
Lower Ordovician (Spencer, 1951). Because of the excellent pres-
ervation of detail of some of the Lower Ordovician material and
from theoretical considerations of the significance of some of
the structures present in these early stelleroids, Spencer (op.
cit.) has presented a new classification of this group, in part
cutting across that used by Schuchert (1915). In addition to
the commonly recognized subclasses Asteroidea and Ophiuroidea,
Spencer proposed the new Subclass Somasteroidea for primitive
starfish with the "arms" merely differentiated portions of the
oral surface, with no ambulacral groove, and with a well defined
oral interambulacral skeleton only in early members. Insofar as
now known, the somasteroids are confined to the Lower Ordovi-
cian. The Auluroidea of Schondorf and Schuchert as well as the
Family Stenasteridae of Schuchert, which was considered to be
an asteroid, are included within the Order Stenurida of the
Ophiuroidea in Spencer's new classification. Spencer's orders
Stenurida and Ophiurida are differentiated on the basis of
whether or not the ambulacralia are modified into vertebrae
(Ophiurida). On this basis the Ophiurida are also present in
the Lower Ordovician.
The lack of an ambulacral groove in the somasteroids, the group
including the earliest starfish known so far, causes Spencer to
question the primitiveness of the groove and its significance in
the search for ancestors of the group. Because of its absence,
he feels that Cambrian Edrioasteroidea cannot have given rise
to the starfish as has been suggested, but that some ciliary feeding
echinoderm must have been their ancestor.
Among the Holothuroidea, D. L. Frizzell (personal communi-
cation, June 19, 1953) states that 9 families and 23 genera, with
117 species, can be recognized from the published records of
fossil members of the group. Three species and 2 genera have
been described from complete specimens from the Solenhofen
STATUS OP INVERTEBRATE PALEONTOLOGY, 195.*>, 159
limestone. All other records are based on sclerites. All authenti-
cated records of fossil holothurians are from Devonian or younger
rocks. The supposed pre-Devonian records cannot be referred
to the group.
Mortensen (1928-1951; esp. vol. 5, pt. 2, pp. 565-573) has sum-
marized data on fossil echinoids as well as that derived from
the living echinoids and presented a number of important con-
clusions on their phylogeny. The first of these is that Bothrioci-
daris, considered by Jackson and others to be the ancestral stock
of the Echinoidea is not a true echinoid, but more probably a
cystoid. The lack of an open ambulacral furrow in the Middle
Ordovician Bothriocidaris and its occurrence in the Middle Ordo-
vician Myriastiches and Upper Ordovician Aulechinus (which
Mortensen considers as ancestral to later echinoids), as well as
other morphological reasons, militate against Bothriocidaris being
considered the ancestor of the echinoids or even being considered
a member of the Class Echinoidea.
Mortensen further points out that the Paleozoic arehaeocidarids
and lepidocentrids have living descendants and that there is no
sharp distinction between the Paleozoic and later echinoids. He
also notes, although he does not recognize it in his classification,
that the Irregular echinoids are derived from several, perhaps
3 or 4, sources among the Regular echinoids. Mortensen also
indicates that the Order Camarodonta (and perhaps others)
among the Regular Echinoids is polyphyletic and thus an un-
natural group, although he continues to use it. These facts, as
well as others not noted here, point to the need for a revision
of the currently used major classification of the Echinoidea.
Of considerable significance is the establishment of the pres-
ence of growth lines (Durham, 1951; Zoeke, 1952) in the plates
of several different kinds of echinoids (and presumably, there-
fore, in all). The growth lines show the changes in shape the
plates have undergone during ontogeny, and inasmuch as they
are complete and not interrupted in all cases observed, they ap-
pear to cast considerable doubt on the occurrence of resorbtion
as a factor in growth and change of shape in the various plates of
the test (however this is not evidence against the complete re-
sorbtion of plates around the peristome).
160 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
LITERATURE CITED
Clark, A. H.
1948. Animals Alive. 472 pp., ill., New York (D. Van Nostrand Co.)
Clark, H. L.
1946. The echinoderm fauna of Australia, its composition and its
origin. Carnegie Inst. Wash., Publ. 566, pp. 1-567.
1948. A report on the Echini of the warmer Eastern Pacific, based
on the collections of the Velero III. Univ. S. Calif. Publ., Allan
Hancock Pacific Exped., vol. 8, no. 5, pp. 225-352, pis. 35-71.
Durham, J. W.
1950. 1940 E. W. Scripps Cruise to the Gulf of California. Part II.
Megascopic, paleontology and marine stratigraphy. Mem. Geol.
Soc. Amer., vol. 43, pt. II, pp. 1-216, pis. 1-48.
1951. Mode of growth in some echinoids. Bull. Geol. Soc. Amer., vol.
62, p. 1434 (abstract).
Durham, J. W., and W. A. Roberts
1948. Cretaceous asteroids from California. Jour. Pajeont., vol. 22,
pp. 432-439, pis. 65-66.
Eaton, J. E., U. S. Grant, IV, and H. B. Allen
1941. Miocene of Caliente Range and environs, California. Bull.
Amer. Assoc. Petrol. Geol., vol. 25, pp. 193-262, pis. 1-9.
Fisher, W. K.
1911- Asteroidea of the North Pacific and adjacent waters. Bull. U. S.
1930. Nat. Mus., vol. 76, pt. 1 (1911), pp. 1-419, pis. 1-122; pt. 2
(1928), pp. 1-245, pis. 1-81; pt. 3 (1930), pp. 1-356, pis. 1-93.
Grant, U. S., IV, and L. G. Hertlein
1938. The west American Cenozoie Echinoidea. Univ. Calif., Los
Angeles, Publ. Math. Phys. Sci., vol. 2, pp. 1-226, pis. 1-30.
MORTENSEN, Th.
1928- A monograph of the Echinoidea. 5 vols, in 17, Copenhagen (C. A.
1951 Reitzel).
Pratt, H. S.
1935. A manual of the common invertebrate animals. Pp. 1-854, figs.
1-974, Philadelphia (P. Blakiston's Son and Co., Inc.).
ScmJCHERT, C.
1915. Revision of Paleozoic Stelleroidea with special reference to
North American Asteroidea. Bull. U. S. Nat. Mus., vol. 88, pp.
1-311, pis. 1-38.
Spencer, W. K.
1951. Early Paleozoic starfish. Philos. Trans. Roy. Soc. London, Ser.
B, vol. 235, pp. 87-130, pis. 2-8.
Zoeke, M. E.
1952. Sur la croissance du squelette des Clypeaster fossiles. Compt.
Rend. Acad. Sci. Paris, vol. 234, pp. 1999-2002.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Statics of Invertebrate Paleontology, 1953
V. Mollusca: Pelecypoda
By Norman D. Newell
The American Museum of Natural History
and Columbia University, New York
The pelecypods form a truly diverse group of invertebrates
of great geological antiquity for which more than 7500 generic
and subgeneric names have been proposed, some 2000 to 3000
of which may prove to be useful after elimination of homonyms,
synonyms and unrecognizable categories.
Classification of the fossil forms involves special difficulties
because knowledge of internal shell characters is required, espe-
cially details of the hinge and muscle insertions which generally
are not clearly visible. The majority of pelecypod shells are,
and apparently have always been, formed mainly of the unstable
mineral aragonite, hence shell characters of examples from forma-
tions older than the Tertiary commonly are obscured or destroyed
as a result of recrystallization, solution and other diagenetic
changes. Therefore, an understanding of morphological details
in the older pelecypods is dependent on exceptionally well-pre-
served specimens which are even more essential for the pelecypods
than for other molluscs. For this, and for other reasons, existing
classifications of pelecypods have not adequately taken into
account the early geological history of the group, and many of
the current views with respect to pelecypod taxonomy are only
crude inferences based mainly or solely on comparative morphol-
ogy of living forms and therefore are not applicable to the greater
part of the history of the class.
Many diverse classifications of the bivalves have been proposed
by both paleontologists and neontologists and each has stressed
one or another line of evidence. None really has taken full ad-
vantage of existing knowledge.1 Classifications in which higher
categories are based primarily on soft anatomy have been some-
i Haas (1938) and Iredale (1939) have reviewed the voluminous literature on
the most significant attempts to develop a satisfactory classification of the
pelecypods.
162 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
what favored by zoologists as compared with those based on
skeletal characters. It has frequently been assumed that muscles
and organs are somehow more fundamental than skeletal parts,
and hence are the best indicators of relationship. On the con-
trarj-, all lines of evidence must be considered, anatomy, morphol-
ogy, ontogeny, and paleontology, and of these the evolutionary
records of the stratigraphic succession provide, after all, the
most valuable clues in the search for phylogeny. Although this
will seem obvious nowadays to many systematists, there are still
a few who are not acquainted with the richness of the fossil
record and who are not impressed by the vastness of geologic
time.
After the pioneer efforts of Linnaeus and Lamarck, the group-
ing of the bivalves followed expediency for many decades. Then,
with remarkable insight, the great Viennese paleontologist,
Neumayr, developed a comprehensive classification in 1883 based
primarily on features of the pelecypod hinge (Neumayr, 1883,
1891). His conclusions soon gained wide recognition and adop-
tion, partly because of Neumayr 's great personal prestige, but
even more because of the practical value of his results which
have to some extent influenced all subsequent work on the group.
Six years after the appearance of Neumayr 's first work on
pelecypod systematics, Dall (1889) introduced an outline of his
classification which was to prove influential, particularly in
America. Fundamentally, his work, which was not fully devel-
oped until 1895 (Dall, 1895), was not radically different from
that of the Austrian paleontologist, but it incorporated many
improvements. Dall followed Neumayr 's lead in emphasizing
the importance of the pelecypod hinge in classification of the
group. He also recognized the value of shell form and structure,
adductor asymmetry, and development of siphons as taxonomi-
cally very significant. Unfortunately, he was somewhat intolerant
of the pioneer contribution of Neumayr and he produced some
confusion by the introduction of several new terms for approxi-
mately the same groups recognized in the earlier work. While
Neumayr and Dall were working on pelecypod systematics, Pel-
seneer (1889), a French zoologist, proposed a wholly new classi-
fication in which the higher categories were based on details of
gill structure, but unlike Neumayr and Dall he gave practically
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 163
no consideration to the succession of fossil forms and he relegated
shell characters to a subordinate place among bases of classifica-
tion. Consequently, his conclusions were at considerable variance
with previous arrangements and they tended to bring together
many dissimilar kinds of shells. This classification, with minor
alterations, is still favored by a few neontologists, but a majority
now use a somewhat uncritical and heterogeneous synthesis by
Thiele (1934) of the works of Neumayr, Pelseneer, and Dall.
In 1895 Dall, considering the work of Neumayr and Pelseneer,
arrived at a taxonomic arrangement which, with but little modi-
fication, is embodied in the final edition of the Eastman-Zittel
Textbook of Paleontology published in 1913 and has been gen-
erally followed by American paleontologists. However, this clas-
sification, since it appeared half a century ago in essentially its
final form, does not agree in many respects with the conclusions
of many investigators about phylogeny.
The last really notable attempt to build a classification of
pelecypods (founded on somewhat new lines) was that of Douville
(1912). Douville was one of the leading paleontologists of the
time and he made use of much more ample paleontological data
than were available in the earlier efforts. Although very imper-
fect and incomplete, his classification represents a real advance
and has been widely used by British and French paleontologists.
Neumayr, Pelseneer, and Dall did not have access to sufficient
data on the succession of pelecypod faunas to enable them to
arrange their higher categories in a temporal sequence. Further-
more, none of these students displayed any considerable under-
standing of the principles of animal evolution. Their conclusions
were based mainly on comparative morphology with only general
recourse to the faunal sequence. In no sense were they based on
phylogenetic analyses.
In his work on the pelecypods, Douville took advantage of the
principle of adaptive radiation which already had become a
basic aspect of vertebrate phylogeny. He also took into account
valuable ontogenetic data worked out by the French paleontolo-
gist, Bernard (1895-1897), but generally not appreciated by other
investigators. It is unfortunate that the American and German
students of pelecypods have tended to overlook Douville 's con-
tribution.
164
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The fundamental general studies over pelecypod taxonomy-
were mainly between 1889 and 1912, and later general classifica-
tions are based in one way or another on the earlier efforts ;
hence they are not really new. Since they do not make use of
steadily accumulating paleontologic evidence, they do not repre-
sent very much progress toward an understanding of the general
Areas
Scallops
Oysters
Actinodonfs
Fig. 1. Probable phylogeny of the Arcacean pelecypods and their aniao-
myanian relativea since the Ordovician period, illustrating marked parallel-
ism in the development of hinge characters. This is the ' ' sedentary ' ' branch
of Douville. Representation is generalized; particular genera are not in-
tended.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 165
phylogeny of the Pelecypoda. It now seems clear that the ma-
jority of existing families and superfamilies of pelecypods origi-
nated before the Jurassic period. The faunas of older times,
although still poorly known, are much better understood today
than they were in Douville's time, and it is probable that the
origins of many of the higher categories will be worked out when
available data on the older pelecypod faunas are evaluated.
Parallel evolution is common in the pelecypods where separate
but related lines pass through closely similar morphological
stages. Convergence between more distantly related groups is
also a complicating factor which may result in an artificial
association of basically unlike groups. Attention to the strati-
graphic sequence of forms enables us in many cases to discrim-
inate between convergent and parallel trends (Fig. 1). For
example, some of the Recent Arcaceans possess taxodont denti-
tion and because of this have been placed by most students
close to the nuculoids. However, as pointed out by Douville, the
Mesozoic and Paleozoic ancestors of the Arcaceans are not at all
like the nuculoids. They possess a very different dentition of
the type (cyrtodont-parallelodont) which characterizes many
primitive Pteriaceans, Mytilaceans, and allied pelecypods. The
taxodont dentition of the Recent Arcaceans represents a very late
convergence toward the basically unlike nuculoids.
The Arcaceans and their ancestors possess a distinctive com-
plex ligament type which I have termed duplivincular (Newell,
1937, 1942). This is found in living pelecypods only among
Arcacea, and in the ancestry of Pteriaceans, scallops, and the
marine mussels. In all but the Arcacea the duplivincular liga-
ment was replaced before the Jurassic by other kinds of liga-
ments. Ligament evolution in these groups has followed parallel
trends. In the majority of living Pteriidae the ligament is similar
to that of living oysters, but as shown by the sequence of fossils,
it was developed separately in the two lines from different ances-
tors that possessed the duplivincular ligament. This is a trend
which has independently characterized several lineages.
Attention to ligament characteristics, almost completely ig-
nored by pelecypod systematists in the past, promises to provide
additional clues to phylogeny. For example, in both the pterioids
and the scallops the ancestral duplivincular ligament is replaced
1G6 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
by a so-called external ligament possessing one or more resilia.
In the former this change occurred during the Permian, in the
latter during the De\ronian. These grades of ligament structure,
arrived at independently through selection and parallel adapta-
tion,1 certainly are useful in recognition of higher categories, but
they may not be of equal value in different groups. The same
applies to many other characters of pelecypods, among which may
be enumerated the structure of gills, respiratory siphons, size and
distribution of adductor muscles, possession of a byssus, shell
microstructure, and dentition.
The experience of the majority of students since Neumayr
has tended to confirm his conclusions with respect to the relative
conservatism of pelecypod dentition, and the emphasis given
hinge teeth and sockets in classification of pelecypods probably
has been justified, even though other characteristics must also be
given weight. Independent development in separate stocks
of closely similar dentitions, as in the Nuculaceans and Arcaceans
cited above, probably is not common and in any case can be
evaluated by reference to the temporal sequence of forms.
The teeth and sockets of the pelecypod hinge lie below the
hinge axis. They do not serve as fulcral points, hence they are
not closely analogous to similar convergent structures in brachio-
pods and ostracodes. Their main function in pelecypods is to
guide the valves as they close so that they will always fit snugly
at the margins. Obviously a good marginal fit between the valves
is of high selection value in those pelecypods that are not buried
and protected by the substratum.
R. Anthony (1905) has shown that the position of the hinge
axis within the ligament is not permanently fixed. By means of
a smoked paper and a stylus cemented to one valve of a living
pelecypod (Fig. 2), he was enabled to record the successive, often
erratic, wandering of the hinge axis during opening and closing
of the valves. In the first two examples of Figure 2, dental articu-
lation is loose and the ligament flexible, hence the valves deviate
laterally in the sagittal plane. These forms normally are bur-
rowers so that a truly efficient hinge is not needed. In the other
i E. R. Truenian, who is systematically investigating pelecypod ligaments, has
shown experimentally that there is a direct correlation between mechanical
efficiency of the ligament and the mode of life (Truenian, 1953). Hence it seems
practically certain that variations in ligament structure are adaptive and that
the observed evolutionary trends in ligaments are also adaptive.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
167
R. Anthony, 1905.
II
ScUifO-ttt6&u*>*>
Iff
IV.
Mniil*t<i
VI.
6ti*e* Peden
Fig. 2. Erratic migration of hinge axis within the ligament during open-
ing and closing the valves in some living pelecypods. (Modified from
Anthony.)
168 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
examples, even though teeth and sockets are poorly developed or
lacking, the ligament is sufficiently strong and efficient to prevent
lateral slippage of the valves and displacement of the axis of
motion. Additional experimental evidence might be sought, but
it seems clear that the function of the teeth and sockets is to
supplement the ligament which is the true hinge. Adaptation
to mechanical stresses in different lines has resulted in the ob-
served multiplicity of dental patterns and ligament types, which
together make up the hinge complex of the pelecypods.
Examination of the record of fossil pelecypods shows that many
groups exhibit a strong ' ' family resemblance ' ' in general expres-
sion, and it is on these general resemblances that many of the
families and superfamilies of existing classifications rest. In
some cases the categories so distinguished seem to be natural
units. For example, the oysters and their near relatives, which
became clearly separate in the Triassic, comprise a compact and
well-defined group. The Pteriaceans, comprising somewhat less
distinctive groups with very ancient origins (in the Ordovician),
almost certainly are polyphyletic. The Trigonias clearly are a
separate line as far back as the Devonian, beyond which the
evidence is obscure. The scallops likewise form a major adaptive
group which is quite distinctive in general expression. It can
readily be followed back into the Silurian (Newell, 1938). How-
ever, in all of these groups there was considerable progressive
evolution in hinge characters and in composition and microstruc-
ture of the shell. These evolutionary changes have provided the
criteria by which families, genera and species are recognized. The
faunal sequence suggests that the true scallops probably are
monophyletic if we exclude the Amussiidae (Pernopecten) and
Limas which were independent long before (Devonian) the Pec-
tinidae appeared in the Triassic. In terms of morphologic dis-
tinctness and separation for hundreds of millions of years, there
are sound arguments for recognition here of at least three major
categories.
The conclusion that can be drawn from the literature on pele-
cypods is that several classifications in use tend to stress different
characters and are not in general agreement. Furthermore, none
is in harmony with the known facts of the paleontological succes-
sion, and to this extent certainly they cannot be regarded as
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
169
phylogenetic. In general, the relationships among the higher
categories have not been subjected to extended inquiry in the past
40 years, and insufficient attention has been given to rather wide-
spread parallel tendencies in evolution.
PELSENEER
Septibronchio
Eulamelli bronchia
Filibranchia
TELEODESMACEA pail
Heterodonta
Praeastgjtacea
My'acea.::..Adesmaeea
ANOMALODESMACEA
DALL
Poromyacea
Anatinocea
Naiodaceg.::::"
r-.-i i\±\X-Jv
•■^Trigoniqcea
Ostreacea Limidae Pinnjdae
liiiiilll
Actinodontacea
Arc'acea
Pectinacea Mytilaceo
/ •' pteriocea
: . Sedentary Branch DOUVILLE
....?.
Protobranchia
Nuculdcea Palaeoconcha
Normal Branch DOUVILLE Burrowing Branch DOUVILLE
PRIONODESMACEA dall
Nacreous
Crossed-Lamellar
Calcite
Fig. 3. Diagrammatic representation of bivalve classifications of Pel-
seneer, Dall, and Douville. Douville 's arrangement, although subject to many
improvements, in some respects corresponds more closely to the evidence of
fossil succession than do the others. (Modified from Davies.)
The chart of Figure 3, modified from G. Morley Davies (1933),
is an oversimplified comparison of the taxonomic schemes of
Pelseneer, Dall, and Douville, all of whom have borrowed from
Neumayr. Superimposed on this is shown the taxonomic distribu-
tion of a few kinds of shell structure. In Pelseneer 's classifica-
tion, four orders are recognized based chiefly on gill types. Since
a single gill type is found in quite dissimilar animals (Fig. 3),
and different types of gills in groups which on structural and
paleontological grounds seem to be homogeneous, it seems clear
that modifications of the gills have followed a simple adaptive
trend.
170 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Elaboration of the microscopic structure of the shell seems also
to have followed a characteristic trend observable in several
groups. Students of molluscs generally are agreed that nacreous
structure is a primitive character. The so-called porcellanous
(crossed-lamellar) structure, as pointed out by Dall, character-
izes the more specialized members of each major group with an
outstanding exception, the Arcacea, which although primitive in
most respects, possess crossed-lamellar shells (Fig. 3). Domi-
nantly calcite shells are found in only post-Paleozoic Limas,
oysters and scallops which on most counts seem to be closely
related. As shown elsewhere (Newell, 1937), the Paleozoic scal-
lops possessed both nacreous and crossed-lamellar shells unknown
in Recent forms. On the other hand, calcite shells, characteristic
of modern scallops, are unknown in the Paleozoic forms. It seems
that crossed-lamellar shells have developed several times in the
pelecypods from nacreous shells.1 The use of calcite throughout
is clearly a mark of specialization in this group and probably was
achieved more than once. For example, the most probable Paleo-
zoic ancestors of oysters (Pseudomonotinae) and scallops (Avi-
culopectininae) had diverged widely during the Permian period
but had not yet acquired calcite shells.
Dall based his three orders mainly on types of dentition, but
he tried also to equate other lines of evidence. Douville was able
to correct a few of the more outstanding errors of Dall's classifica-
tion ; for example, the unnatural association of the Arcaceans and
Nuculaceans. He separated three major groups according to
general mode of life. One of these includes most (but not all) of
the byssate and heteromyarian forms under a so-called fixed or
sedentary branch. The majority (but not all) of the burrowing
forms, provided with siphons and a weak hinge, form a second
division and all other pelecypods were placed in his "normal
branch ' '. It is now clear from the fossil record that the sedentary
branch of Douville in broad outline constitutes a natural group
(Fig. 1), although it cannot be simply defined in terms of gill
structure, hinge characters, or shell structure. The other two
branches probably are polyphyletic.
Obviously, comparative morphology of living forms alone can-
not give us a phyletic classification. The matter will not be
i Probably this has also occurred in the gastropods where crossed-lamellar
shells are regarded as an indication of specialization.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 171
resolved until succession in time of the fossil forms is understood
and given very high rank among the various lines of evidence.
REFERENCES
Anthontt, R.
1905. Influence pleurothetique sur la morphologie des mollusques
acephales dimyaires. Ann. Sci. Nat. Zool., vol. 1, pp. 165-396.
Bernard, Felix
1895- Note sur le developpement et la morphologie de la eoquille chez
1897. les Lamellibranches. Bull. Soc. Geol. France, vol. 23, pp. 104-154;
vol. 24, pp. 54-82, 412-449; vol. 25, pp. 559-566.
Dall, William H.
1889. Preliminary catalogue of the shell-bearing marine mollusks and
brachiopods of the southeastern coast of the United States. Bull.
TJ. S. National Museum, vol. 37, 221 pp.
1895. Contributions to the Tertiary fauna of Florida, Part III. A new
classification of the Pelecypoda. Wagner Free Institute Sci.,
Philadelphia, pp. 474-570.
1899. Pelecypoda, in Eastman-Zittel, Textbook of Paleontology, vol.
1, Invertebrata, pp. 422-507.
Davtes, G. M.
1933. The bases of classification of the Lamellibranchia. Proc. Malac.
Soc, vol. 20, pp. 322-326.
Dodvtllb, Henri
1912. Classification des Lamellibranches. Bull. Soc. Geol. France, vol.
12, pp. 419-467.
Haas, Fritz
1938. Bivalvia, in Bronns Klassen und Ordnungen des Tierreichs, vol.
3, part 2, pp. 248-322.
Iredale, Tom
1939. Mollusca, Great Barrier Reef Expedition, 1928-1929. Vol. 5,
no. 6, pp. 209-425.
Neumayr, M.
1883. Zur Morphologie des Bivalvenschlosses. Sitzungsber. Akad. Wiss.
Wien., vol. 88, pp. 385-419.
1891. Beitrage zu einer morphologischen Eintheilung der Bivalven.
Denkschr., Akad. Wiss. Wien., vol. 58, pp. 701-801.
172 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Newei*l, Norman D.
1937. Late Paleozoic peleeypods: Pectinacea. Kansas Geol. Survey,
vol. 10, pt. 1, 123 pp.
1942. Late Paleozoic peleeypods: Mytilacea. Kansas Geol. Survey,
vol. 10, pt. 2, 115 pp.
Pelseneer, P.
1889. Sur la classification phylogenetique de Pelecypodes. Bull. Sci.
Nat. France et Belg., ser. 3, vol. 20, pp. 27-52.
Thiele, J.
1934. Handbuch der systematischen Weichtierkunde, Teil III, Classis
Bivalvia, Jena, G. Fischer.
Trueman, E. R.
1953. Observations on certain mechanical properties of the ligament of
Pecten. Jour. Exper. Biol., vol. 30, pp. 453-467.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
V. Mollusca: Gastropoda1
By J. Brookes Knight2, Roger L. Batten3, and
Ellis L. Yochelson4
During the past several years, Dr. J. Brookes Knight, with the
junior authors, has been studying the morphology and system-
atics of the Paleozoic gastropods for the Treatise on Invertebrate
Paleontology. Recently we have spent some months in an effort
to integrate systematically our findings on Paleozoic genera with
those of other workers on post-Paleozoic forms. From these
studies we have constructed a classification that embodies ideas
and principles taken from an examination of living and fossil
gastropods. This classification, given in Figure 1, is still tentative,
and its full meaning will not become evident until the families
and genera in the superfamilies are given in the completed
Treatise.
We have used the anatomy of the soft parts as the basis for
constructing this classification. By coordinating information
about the anatomy of living forms and their shell features, it has
been possible to make an estimate of the probable soft anatomy of
many fossil gastropods — at least in broad outline. Actually the
shell can be brought to yield, with a reasonable degree of proba-
bility, much more anatomical information than has been generally
thought. If applied with due consideration for the order in which
animals appear in time, for ecological differences, and for simi-
larities due to convergence, inferences based on this information
lead to results in classification that seem more plausible than
those constructed by using other methods. Of course, like all at-
tempts at phylogenetic classification this one is hypothetical, and
additional information or different interpretations may later
alter it.
i Publication authorized by the Secretary of the Smithsonian Institution and
the Director, U. S. Geological Survey.
2 Research Associate, Smithsonian Institution, Washington 25, D. C.
3 Columbia University, New York, New York.
4 Geologist, U. S. Geological Survey, Washington 25, D. C.
174
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
From the time of Lamarck, the construction of phylogenies
and classifications was chiefly the work of neontologists. They
based most of their conclusions on studies of the comparative
anatomy of a relatively few living species. Much of their interest
pre-
cambrian
CAMBRIAN ORDOVICIAN SIL. DEVONIAN CAPS.
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Fig. 1. Proposed phylogeny of the Gastropoda.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 175
was concentrated in the attempt to discover missing links and to
construct hypothetical ancestral types, all with little attention to
or understanding of fossils.
Paleontologists, on the other hand, busy describing genera and
species, were seldom concerned with supra-familial categories and
were content to have their fossils placed in divisions erected for
living species. Paleozoic gastropods suffered the most from this
haphazard treatment because they differ most from the living
forms. Mesozoic species were generally classified more rationally.
Those of Cenozoic age, which differ little from those living today,
were for the most part correctly classified but placed without
roots into the past.
The great difference in Paleozoic gastropods as compared with
living ones can be seen by observing the distribution of the major
categories in time as shown in Figure 1. Note the concentration of
Archaeogastropoda in the Paleozoic era and the Mesogastropoda
and Neogastropoda together with the Opisthobranchia and Pul-
monata in the late Mesozoic and Cenozoic eras.
It has only been within the past decade that sufficient informa-
tion about the anatomy, embryology, and physiology of critical
living species has been available. This information combined with
previous observations — and above all with a deeper understand-
ing of the more ancient fossils — has made possible the recogni-
tion of the probable ancestral groups of the major ordinal cate-
gories and some understanding of the evolution among them.
Let us turn to an example of what can be done by correlating
the anatomy of the soft parts with conchology. Among the Mono-
placophora, which range from early Cambrian to Devonian, is a
group of cap-shaped shells, the Tryblidiidae. For many years
they were considered to be primitive patellids, which they do
resemble superficially in shape. In 1938, Wenz made the sugges-
tion that those ancient forms were actually very primitive bilat-
erally symmetrical animals. He based this idea on the presence
of symmetrically paired dorsal muscle scars as contrasted with
the horseshoe-shaped muscle scar of the patellid shell. If Wenz
was correct, as we believe he was, it follows that these primitive
forms did not undergo torsion of the soft parts as do the patellids
but were quite similar in internal organization to the chitons
(Polyplacophora) .
176 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
This was a revolutionary idea in gastropod systematics. It was
arrived at by discounting superficial shell resemblances and con-
centrating on what might be learned from the record of the soft
parts that was preserved in the shell. In this case it was merely
the scars left by the pedal muscles, but it was enough to give a
clue to the probable internal anatomy of monoplacophorans. The
cap-shaped shell of Patella and patellid like forms has been
achieved by many unrelated rock-clinging gastropods ; it is most
often an ecological adaptation and does not necessarily point to
relationships. Unfortunately, except in cap-shaped shells, muscle
scars are extremely difficult to observe, even in Recent gastropods.
Other features in the shell often correlate with specific features
of the anatomy. One of the most important shell features that
can be correlated with anatomical characters is the emargination
or channel that marks the position of the anal tube. Since the
ctenidia (primary gills) and other pallial organs have fairly
definite relationships to the position of the anus, this may give
information as to whether there was the primitive pair of gills
or only a single gill. An anterior canal or notch accompanied by
certain related features commonly indicates an inhalent siphon.
A heterostrophic nucleus has been shown to characterize certain
opisthobranchs inhabiting the present-day plankton. These ex-
amples indicate the type of inferential data that is important
in the estimation of the anatomy of extinct gastropods.
If we then reconstruct the soft anatomy of our early gastropods
inferentially, we can discuss their probable evolution in terms of
three principal adjustments : flexibility in the Isopleura and in-
creased motility and enhanced sanitation in the Anisopleura.
To return to the monoplacophoran, we have inferred that it
had the anatomy of a bilaterally symmetrical organism, much like
that of the chiton. The major evolutionary advance within the
Isopleura was the replacement of the single monoplacophoran
shell by a series of eight transverse plates. This gave the animal
greater flexibility and permitted it to cling closer to the irregular
surfaces of the rocks. So successful was this adjustment to its
narrow environment that the chitons, appearing for the first time
in the late Cambrian, survive today with very little change and
virtually no adaptive radiation.
It may be appropriate to say at this point that most zoologists
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
177
who are unfamiliar with the fossil record and who may not be
aware of the existence of the Monoplacophora regard the chitons
as a separate class reflecting characters of the ancestors of the
gastropods, if not all mollusks. As paleontologists we prefer to
be guided by the fossil record and suggest the Monoplacophora
for the ancestral role. Whether the Isopleura be regarded as a
subclass or a separate class from the Anisopleura is relatively
unimportant; if the current separation is maintained, we feel
that the Monoplacophora should be included with the chitons
(see Figure 1).
Stomach-
Muscle^
scars
Mouth
-A/entricle
-Auricle
Ctenidium
Anus
A.
Primitive
Isopleuran
(left side view)
Stomach
Ventricle
—Auricle
B.
Primitive
Anisopleuran
(right side view)
Reconstructions from Knight (1952).
Fig. 2. Schematic reconstructions of two gastropods.
The introduction of the phenomenon of torsion gave rise to
the Anisopleura with greatly increased motility and a newly
important problem of sanitation. Figure 2A represents the left
side of a primitive monoplacophoran restored with an organiza-
tion similar to that of a chiton, shown with the shell transparent.
Note that the anus lies in a posterior mantle cavity between a pair
of ctenidia. As in the chiton, the posterior position of the anus
obviates the need of any elaborate provisions for sanitation. Note
178 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
also that the broad, low shell with its equally broad, low foot and
its rather complex muscle attachment, permit little movement of
the shell and probably allowed only very sluggish progression.
Figure 2B represents a restoration of a gastropod-like mollusk
of the early Cambrian that is thought to be a primitive bellero-
phont, an advanced, relatively tall monoplacophoran, so to speak,
that has undergone torsion. This is a view of the right side and
is also drawn as being transparent. As is well known, torsion
takes place in an early stage of the trochophore larva. This tor-
sion occurs in such a way that the primitively posterior mantle
cavity, with the anus lying between a pair of ctenidia, develops
in a forward position over the head, just as if the shell with the
visceral hump and contained organs had been twisted 180° in a
counterclockwise direction relative to the head and foot.
Note that the broad, low shell in Figure 2A has become an ele-
vated one with the curvature that must have initiated coiling.
The elevated shell may have provided for a long, slender neck
such as that possessed by most living Anisopleura, which — com-
bined with the reduction of the shell muscles to a single pair —
would have permitted free movement of the shell relative to the
foot. The anterior mantle cavity now permits the withdrawal of
the body headfirst into the shell. Surely the traditionally slow-
moving snail has become an active race horse as compared with
the probably almost stationary monoplacophoran.
But the problem of keeping the ctenidia free from fecal matter
is now more difficult. Let us now consider briefly the series of
solutions that gave those gastropods which possessed them com-
petitive advantage.
The first solution was the development of an anal emargination
(a sinus or slit) for the egress of fouled ciliary currents without
contaminating the ctenidia that lay on each side. This solution
was used by the bellerophonts and pleurotomarians. Next —
after the introduction of asymmetrical coiling — came the sup-
pression of the right-hand ctenidium and associated organs. As
a result the ciliary currents entered the mantle cavity from the
left anterior side and departed by the right posterior immediately
after passing over the anus, which had migrated to that position
after the loss of the right ctenidium. Such a development oc-
curred several times within the archaeogastropods and led to the
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 179
origin of other orders. Still further adaptations, also leading in
part to the origin of new orders, were the gradual return of the
anus to a posterior position in the adult of many opisthobranchs
and — the last step — loss of the shell with almost full bilateral
symmetry in the adult.
A final adjustment not discussed here is the adaptation for
life on the land with conversion of the mantle cavity into a lung
and the loss of ctenidia in the pulmonates.
In summary, this classification shows that while the living Iso-
pleura have undergone very little change since late Cambrian
time, the Anisopleura have radiated outward to become one of
the most successful animal groups. Living snails have become
extremely numerous and varied and have invaded all habitats
and all environments from high mountains to the depths of the
oceans.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
V. Mollusca: Cephalopoda
By Bernhard Kummel
Museum of Comparative Zoology, Cambridge, Mass.
Few invertebrate classes possess (or are plagued with) the
volume of literature and diversity of interpretation, or are so
susceptible as media of philosophical speculation as the fossil
cephalopods. A complete review of the literature and progress in
the study of fossil cephalopods is beyond the scope of this paper.
Therefore I will center attention on the geologic distribution of
fossil cephalopods and current ideas on classification and evolu-
tion. The extent and degree of cooperation towards a uniformity
of nomenclature — both morphological and taxonomic — that has
prevailed in the past few years among the European and Ameri-
can authors responsible for the Cephalopoda for the Treatise has
been truly inspiring. The results of this labor will place the
study of these animals on a new threshold. It is a pleasure to
acknowledge the data on Jurassic ammonoids furnished by W. J.
Arkell ; the data on Cretaceous ammonoids furnished by C. W.
Wright ; the data on Paleozoic ammonoids furnished by A. K.
Miller; the data on the Dibranchiata furnished by L. Bairstow;
and data on nautiloid genera by Curt Teichert. Of the three
major groups of Cephalopoda, I will confine most of my remarks
to the Ammonoidea. Recent tabulations indicate that there are
approximately 3000 valid genera of fossil cephalopods with more
than an additional thousand generic names which go into
synonomy.
Within the Nautiloidea there are now recognized approxi-
mately 700 genera. Their evolutionary pattern is one of intense
radiation in the Ordovician during the initial phases of their
evolution, followed by a rapid and steady decline until the present
day with our one remaining relic genus. The main pattern of
distribution of nautiloid genera as illustrated on Figure 1 has
been known for a long time. Morphologically the nautiloids are
a highly diversified group but many of the orders that made their
182
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
appearance in the Ordovician became extinct by the Silurian and
Devonian. During the latter half of the Paleozoic the evolutionary
rate of the nautiloids was greatly diminished. A second surge
occurred in the Upper Triassic which has a diversified nautiloid
275
vvwvww
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
NAUTILOID
GENERA
i
i
1-
111
k::v :v::::^:
[
u.-e
0RD.
SIL
DEV.
MISS
PENN PERM
JURA.
CRET.
Pa E. QM.PLR
Cenozoic
Fig. 1. Bar graph showing number of nautiloid genera in each geologic
period. (Data from C. Teichert, personal communication.)
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 183
fauna, but nothing compared to that of the early Paleozoic. The
evolutionary pattern of the nautiloids in the Triassic is merely a
culmination of trends begun back in the Carboniferous. The Per-
mian was not a period of crisis for the nautiloids as it was for the
ammonoids, but in the late Triassic (Rhaetian) there was almost
complete extinction of the nautiloids. No "Rhaetian nautiloids are
known, but a single specimen from the Carnian of Now Zealand
offers strong evidence that an offshoot of the Syringonautilidae
survived into the Lias (Spath, 1927, p. 23 ; Kummel. 1953) ; from
this family all post-Triassic nautiloids are derived. Tho Jurassic
to Recent history of the nautiloids duplicates the general pattern
shown by the Paleozoic forms; that is, there is an initial experi-
mental phase of extensive radiation from which arose several
more stable stocks, none of which, however, was long lived. In
the Cenozoic only three new genera appear, of which only
Nautilus survives.
Up until recently the classification of nautiloids has been com-
pletely dominated by the scheme proposed by Hyatt in the 1900
edition of the Zittel-Eastman Textbook of Paleontology. Today
there is no doubt in anyone 's mind that Hyatt 's scheme is unten-
able. The rejection of Hyatt's classification is the rejection of a
systematic arrangement based on a single character. The tenta-
tive scheme recently proposed by Flower and Kummel (1950)
summarizing existing thinking can unquestionably be improved
but it has had the very desirable effect of crystallizing attention
on the more critical problems. There is wide agreement among
nautiloid specialists that the number of orders proposed by
Flower and Kummel should be reduced, but no agreement as yet
as to how this should be done. Of the 13 orders recognized by
these authors the Ellesmeroceratida, Endoceratida, Michelino-
ceratida, Ascoceratida, Discosorida, and Oncoceratida are gen-
erally accepted as well defined groups and appear to need only
minor revisions. The recognition of an Upper Triassic Bisiphytes
(Family Nautilidae) which shows clear affinities to the Syringo-
nautilidae changes the derivation of all post-Triassic nautiloids
to the Triassic Syringonautilidae rather than the Paranautilidae
as previously proposed (Kummel, 1953). This change necessi-
tates the suppression of the Centroceratida and the joining of
these families into the Nautilida. The Rutoceratida can most
184 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
probably also be included in the Nautilida but clear evidence of
this relationship is not available (R. H. Flower, personal com-
munication). Flower (1952) would derive the Rutoceratida from
the Oncoceratida, The Liroceratidae, Ephippioceratidae, Para-
nautilidae, Clydonautilidae, and Gonionautilidae, all formerly
placed in the Nautilida, may now need to be placed in a new order.
At first it would seem that they would be logically included in the
Barrandeoceratida ; however, connecting forms from the Devon-
ian have not been recognized as yet. The status of the Solenoch-
ilida, Tarphyceratida, Barrandeoceratida, and Bassleroceratida
is a source of disagreement among specialists. The crux of the
difficulties and confusion in nautiloid systematics and evolution
lies in the great host of early Paleozoic families. Taxonomic sta-
bility of these forms will be approached as our knowledge and
understanding of their complex morphology and modes of adap-
tation is increased. Agreement on the systematics of early Paleo-
zoic nautiloids is near but is not quite yet a reality. Because of
this no phylogenetic chart is presented.
It is significant to note that in the past few years very few new
genera have been established in spite of the fact that several large
new faunas have been described. It would be pleasant to think
that possibly we are near the limit of the total number of genera
in this order. This observation is encouraging in that maybe now
more effort and thought can be concentrated on critical paleo-
biological problems.
Ever since William Smith's great discovery of the usefulness
of fossils for correlation and geochronology, the ammonites have
played a leading role as a stratigraphic tool. The pioneer work
of d'Orbigny, Oppel, Quenstedt, Mojsisovics, Waagen, Neumayr
and many others firmly established the ammonites as the leading
actor in the drama of Mesozoic stratigraphy. Likewise the nature
of the ammonoid shell and its manner of growth has lent itself
beautifully to the pliable minds of evolutionary theorizers. Few
people have had more influence on the study of fossil cephalopods
than Alpheus Hyatt whose whole philosophy revolved around
the recapitulation doctrine — a principle not accepted today by
most cephalopod students. However, few text books of zoology
or geology fail to illustrate some of Hyatt's cephalopods demon-
strating recapitulation in action.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
185
The recent taxonomic house cleaning of ammonoid genera
enables the construction of the bar graph (Figure 2) on the
geologic distribution of ammonoid genera. There is a total of
approximately 1800 genera of ammonoids; of these 172 are from
140
130
AMMONOID
GENERA
199
Fig. 2. Bar graph showing number of ammonoid genera in each geologic
period. (Data on Paleozoic ammonoids from A. K. Miller, that on Jurassic
ammonoids from W. J. Arkell, and that on Cretaceous ammonoids from
C. W. Wright, personal communications.)
186 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
the Paleozoic, 370 from the Triassic, 735 from the Jurassic and
493 from the Cretaceous. There are an additional 1000 generic
names that fall into synonomy. The largest number of these
involve Jurassic ammonites.
The overall distribution of genera confirm commonly held
views. In spite of specific instances of "monographic highs" and
lack of record, it is the opinion of the Treatise ammonoid authors
that the data reasonably reflect the history of this group of ani-
mals. In fact, C. W. Wright (personal communication), who
compiled the list of Cretaceous ammonites, found his data most
illuminating as a commentary on the validity of the Cretaceous
stages. The most unusual aspects of the evolutionary history of
the ammonoids are the three periods of crisis ; during the first
two such crises the group nearly became extinct and from but
few surviving stocks even larger radiations developed until the
final extinction of the group in the late Cretaceous. The two
earlier periods of crisis are in the late Permian and in the late
Triassic.
Several important aspects in the history of the study of am-
monoids have greatly influenced our interpretation of ammonoid
phylogeny and taxonomy. It is indeed remarkable that not until
the 1860 's did the splitting of the genus Ammonites really begin.
The recognition of generic categories among the ammonoids de-
veloped rapidly after that date. Since this early period there have
been proposed many taxonomic schemes for the Ammonoidea.
Most of these, however, were based on a single character; the
suture, sculpture, siphuncle, and length of body chamber have all
been used in various manners with little success. Unit systems of
classification invariably ended up by bringing together hetero-
chronous homeomorphs.
Present interpretation of the relationships of Permian and
Triassic ammonoids illustrates this point well. Figure 3 is a bar
graph of total genera and new genera (dark stipple) of Permian
and Triassic ammonoids. The average evolutionary tempo of
Permian ammonoids is only slightly higher than that of the
Carboniferous. The most striking feature is the presence of only
seven genera in the Upper Permian. It should be kept in mind
that the number of known fossiliferous Upper Permian deposits
is indeed few. The ammonoid faunas of such classic areas as the
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 187
Salt Range, Djulfa, Timor, the Alps, Madagascar, and East
Greenland are not abundant, The radiation of the ammonoids
in the Lower Triassic is well demonstrated with its 128 genera.
This radiation was not a sudden affair. Lowermost Triassic de-
posits, that is, those of Otoceratan age, are as scarce as marine
Upper Permian strata. The smaller bar graph of Figure 3 shows
the total genera and new genera for the six ages of the Lower
Triassic. Only one genus carries on into the Triassic from the
Upper Permian. It is not until the middle Scythian that a really
large diversified fauna is encountered.
Figure 4 is a diagrammatic interpretation of the phylogenetic
relationships of Permian and Triassic ammonoids. Of the two
main groups of Paleozoic ammonoids, the goniatitids are repre-
sented by seven families in the Permian and the prolecanitids by
five families. It has long been thought that many Middle and
Upper Triassic ammonoids had their ancestry among these
goniatitid families. However, the extensive researches of L. F.
Spath over the past 30 years have demonstrated in a convincing
manner the improbability of any of these goniatitid families be-
ing ancestral to any Triassic stocks. There are numerous cases of
homeomorphy between many of these goniatitid genera and Mid-
dle and Upper Triassic genera. Permian ammonoids of the
prolecanitid stock are included in two superfamilies. One of
these — the Pronoritaceae — continues into the Triassic with a
very modest development but did not give rise to any new stock.
The ancestry of Triassic ammonoids is to be found in the
Xenodiscaceae.
The most common and abundant lowermost Triassic ammonoids
are the ophiceraticls which show a wide range of variability in
conch form. From this extremely variable ophiceratid stock arose
directly or indirectly more than a dozen families of Lower Trias-
sic ammonoids. This radiation is a continuation of that started
at the base of the Triassic with the ophiceratids, and represents
the height of the experimental phase in the eruptive comeback
of the ammonoids after their near extinction in the late Permian.
Most of the genera and families of this eruptive phase are short-
lived but from a few of them arose the eight long-lived super-
families that include most of the Middle and Upper Triassic
ammonoids. Thus with the Anisian begins the stabilized phase
in the evolutionary history of Triassic ammonoids.
188
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
The great decline and near extinction of the ammonoids in
the Rhaetian has been known for a long time. From a peak of
140 genera in the Carnian there are left only a few species of 5
genera in the Rhaetian. There is a sharp decline in evolutionary
development already in the Norian.
O
(/)
CO
<
IT
q:
Q-
_L
c
o
o
CO
Prohungaritan
!.*::;::#*:':::'::C;::;:
m i
Columbitan
1
■i .1
Owenitan
mm i
Flemingitan
, 1
Gyronitan
i
20
Otoceratan
—iiio
30 40
10 20 30 40 50 60 70 80 90 100 110 120 130 140
Fig. 3. Bar graph showing total number of ammonoid genera and new
genera (dark stipple) in each stage of the Permian and Triassic.
A single stock carries through into the Lias to give rise to the
great host of Jurassic and Cretaceous ammonoids. The evolu-
tionary patterns of the ammonoids in these two periods is quite
unlike that in the Paleozoic or Triassic. Two persisting, slowly
evolving, root-stocks - - the Lytoceratina and the Phylloceratina
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
189
— are the evolutionary reservoirs from which the great host of
Jurassic and Cretaceous ammonoids are derived. The Lytocera-
tina and Phylloceratina are characteristic of the ancient Tethys ;
they are the leiostracous or smooth shelled forms. The trachyos-
tracous or ornamented genera are most abundant in the epicon-
Fig. 4. Diagram showing inferred phylogeny and geologic distribution
of Permian and Triassic ammonoids.
tinental seas adjoining the Tethys. Some 30 years ago Salfeld
proposed his theory of Iterative Evolution in which he inter-
preted the innumerable throngs of the Ammonitina as arising
through repeated radiations of offshoots from the conservative
190
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
stocks. Deciphering the countless threads connecting the Am-
monitina and these conservative stocks is still evasive. More
Pig. 5. Diagram showing inferred phylogeny and geologic distribution
of Mesozoic ammonoids. (Adapted from Arkell 1950, Wright 1952, and
Kummel 1952).
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
191
progress has been made with Cretaceous ammonites than with
those of the Jurassic. When and if the various Jurassic and
Cretaceous superfamilies can be more definitely tied to one or
the other of the conservative root-stocks there will be need for
modification of the suborder Ammonitina.
The Dibranchiata cephalopods have not received as wide atten-
tion as the nautiloids and ammonoids. Mr. Leslie Bairstow
kindly furnished tentative and approximate data on the time
141
100
90
80
70
60
50
40
30
20
10
DIBRANCHIATE
GENERA
LM.U
PERM.
L
M.I U.
RIAS.
L.
M. U.
LIRA.
U.
CRET.
PdeoEoOM. PJIR
CENOZOIC
Fig. 6. Bar graph showing number of dibranch genera in each geologic
period. (Data from L. Bairstow, personal communication.)
distribution of genera of Dibranchiata. The most striking feature
of the bar diagram of Figure 6 is the great number of Recent
genera ; of the approximately 250 genera of Dibranchiata, 138 are
known only from the Recent. The great diversity of Recent
fauna, and the fact that many of the genera are very different
from the nearest fossil forms known, imply the previous existence
of many genera that are not actually known as fossils (L. Bair-
stow, personal communication). The incompleteness of the fossil
192 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
record of the dibranchs does not make them a suitable group for
the study of evolutionary rates.
The present status of our knowledge of the fossil Cephalopoda
presents an encouraging framework to direct and guide future
research. The great success to which the cephalopods, especially
ammonoids, have been used in stratigraphy has resulted in the
major emphasis being placed on them as "tools" of stratigraphy.
It is becoming more and more clear that a greater understanding
of the animal and its ecology and adaptive range will add greatly
to the value of the Cephalopoda as "tools" of stratigraphy and
as "tools" for study of evolutionary processes.
REFERENCES
Arkell, W. J.
1950. A classification of the Jurassic ammonites. Jour. Paleontology,
vol. 24, pp. 354-364.
Flower, R. H.
1952. The ontogeny of Centroceras, with remarks on the phylogeny
of the Centroceratidae. Jour. Paleontology, vol. 26, pp. 519-528.
Flower, R. H., and B. Kummel
1950. A classification of the nautiloids. Jour. Paleontology, vol. 24,
pp. 604-616.
Kummel, B.
1952. A classification of the Triassic ammonoids. Jour. Paleontology,
vol. 26, pp. 847-853.
1953. The ancestry of the family Nautilidae. Breviora, No. 21, pp. 1-8.
Spath, L. F.
1927. Revision of the Jurassic cephalopod fauna of Kachh (Cutch).
Mem. India Geol. Survey (Palaeontologia Indica), n. ser., vol. 9,
mem. 2, pp. 1-84, pis. 1-7.
Wright, C. W.
1952. A classification of the Cretaceous ammonites. Jour. Paleontology,
vol. 26, pp. 213-222.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
VI. Arthropoda: Trilobita
By Harry B. Whittington
Museum of Comparative Zoology, Cambridge, Masa.
The following notes express my own views and some that W. R.
Evitt and I have developed jointly, and are not necessarily those
of others working on Trilobita for the Treatise of Invertebrate
Paleontology. I acknowledge with thanks the helpful discussions
I have had with many friends, especially Drs. A. R. Palmer, C.
Poulsen, F. Rasetti, and C. J. Stubblefield.
Many articles have been written on the classification of trilo-
bites, but there is still no satisfactory arrangement. Major diffi-
culties are : (1) About half of the 600 or so Cambrian genera are
incompletely known or based on poor material, and many have
never been placed in any family. In particular the Upper
Cambrian forms grade into each other and are hard to separate.
Specialist or not, one welters in a morass of names and concepts.
(2) Post- Cambrian trilobites seem to fall readily into families
and higher groups, but there is a great gap between them and
their late Cambrian predecessors. This gap seems to be real,
and not merely because many students have worked on either
Cambrian or later trilobites, but rarely both. (3) There is a
lack of knowledge of the entire, and especially the ventral exo-
skeleton, and of the ontogeny of representatives of many families.
Attempts were made to base major divisions in trilobite classi-
fication on the number of thoracic segments or the size and
segmentation of the pygidium. The latter has been used recently
by Hupe (1953). Beecher's (1897) classification, using the
cephalic sutures, depended on an interpretation that accepted
Haeckel's theory of recapitulation. I know of no example in
trilobites of ontogeny recapitulating phylogeny, i.e., I know of
no ontogenetic stage that resembles a geologically older adult.
The use of part of a single morphological character as a basis
for an ordinal classification seems unwise (cf. Stubblefield 1936,
p. 432, etc.) and in this case has been shown to be unworkable.
194 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
It is to be hoped that this classification will no longer be used
or taught in the classroom.
In 1936 Stubblefield suggested that many proparian trilobites
might be permanently neotenous forms. Stormer (1942) took up
this suggestion vigorously, and considered that three orders of
trilobites (modifications of those of Beecher) were derived from
the supposedly primitive olenellids by arrested development (a
partial neoteny) of the anterior cephalic segments. In addition
to rejecting Beecher 's orders, I consider that certain of Stormer 's
premises are possibly erroneous, and his classification is no more
usable than Beecher 's. Hupe (1950) has claimed that partial
neoteny is general in trilobites. His evidence is drawn from
the study of representatives of two groups, proparia and opis-
thoparia, each of which is here regarded as being comprised of
genetically unrelated genera. Broad morphological trends of
change in the cephalon during the Palaeozoic are revealed, but
scarcely seem to me to admit of the conclusions arrived at. We
do not yet know a single line of evolution with data on the on-
togenies of successive genera, and are in no position to assess the
importance of neoteny as a process in trilobite evolution. I sus-
pect that adaptation to particular ecological niches (depth, bot-
tom conditions, food supply, etc.) is a far more important factor
in trilobite evolution, but to discern its operation is difficult.
If we can avoid being mesmerized by the importance that has
so far been attached to cephalic sutures in classification, a dif-
ferent approach is possible, i.e., to consider all the exoskeletal
characters (including ventral, and especially axial characters, as
Stubblefield [1936] urged), ontogeny (as Stormer [1942] did),
and the distribution of genera in space and time. Henningsmoen
(1951) has recently made suggestions along these lines and they
appear promising.
The Cambrian superfamilies shown in Figure 1 are those
used recently by Hupe (1953). The superfamilies outside the
stippled area are agreed upon by most students. The ptycho-
parioid and allied superfamilies, included within the more heavily
stippled area, seem to constitute a major natural group of trilo-
bites, but the subdivisions of this group, adopted for convenience
here, are not generally agreed upon (cf. Rasetti, 1951, pp. 198-
202). The post-Cambrian superfamilies of Figure 1 are the
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
195
Fig. 1. Eange in time of superfamilies of trilobites. Each black area
varies in width in proportion to the number of genera recorded at any one
time. Total number of genera in each superfamily is given. Data on
Cambrian trilobites largely from Hupe (1953). Tremadoc is included in the
Ordovician, and Lower, Middle, and Upper divisions of this period and of
the Cambrian are indicated. Proportions of length of periods after Newell
(1952). Correlations of strata and ranges of genera necessarily generalized.
The Ptychoparioidae and allied superfamilies of the Cambrian are included
in the more heavily stippled area, and post-Cambrian superfamilies possibly
derived from them in the lighter, diagonally stippled area.
196 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
groups of families indicated by the shading in Figure 2. In
making these superfamilies, besides using axial and ventral char-
acters of adult exoskeletons, W. R. Evitt and I here suggest, as
a result of our unpublished studies of protaspids of Ordovician
trilobites, that one might group together those families in which
early ontogenetic stages have the same general characters, al-
though the adults are distinctly different. This leads, for example,
to grouping together as the Cheiruroidae the calymenids, homalo-
notids, phacopids, encrinurids, cheirurids, and pliomerids. Per-
haps more striking is the Asaphoidae, here regarded as including
the asaphids and remopleuridids, and possibly nileids, telephinids
and cyclopygids. The lichids and odontopleurids — distinctive
groups, the origin and relationships of each of which is uncertain
— are shown in Figure 1, though they are here regarded as of
family, and not superfamily, rank.
The trilobites were marine animals and apparently dominated
Cambrian seas. Olenelloids appear first, and are confined to the
Lower Cambrian. Other groups occur in the later Lower Cam-
brian, and some extend only into the Middle Cambrian. These are
replaced by the more varied and numerous Upper Cambrian
forms, derivatives of the Middle Cambrian Ptychoparioids.
"Spindle", "burst", and "truncated burst" patterns, shown
by Cooper and Williams (1952) to characterize brachiopod evo-
lution, are equally evident in the trilobites. A lengthy pre-
Cambrian history evidently precedes the known history, and the
seemingly abrupt appearance of trilobites is apparently owing
to their becoming able to form a mineralized exoskeleton. This
Cambrian picture is very generalized, owing to difficulties of
correlation, and the extinctions may not be as sudden as they
appear to be.
There is a marked gap after the end of Cambrian time, only
four Cambrian superfamilies ranging into the Ordovician in
greatly reduced numbers. Following this great extinction, a
number of new superfamilies arise suddenly in the Lower Ordo-
vician, but no new ones arise after this time. Only one Ordovician
superfamily, here called the Asaphoidae, is known to arise in
the Upper Cambrian. The picture in the Ordovician is one of a
last evolutionary burst before new classes, e.g., of Mollusca and
Vertebrata, arise to crowd out the trilobites, and the post-Ordo-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
197
CAMBtoRDOVICIAN
DEVON. 1 GARB. PBM
HYSTRICURIDAEl
PLETHOPELTIMci
CERATO-
PYGIDAE'
KOMASPIDAE,
LEIOST-
EGIIDAE
ENDYMIONIIDAE
SCUTELLIDAE
LICKIOAE
ODONTOPLEURIDi
PLIOMERIDAE
— SHUMARDIIDA
Fig. 2. Range in time of families of post-Cambrian trilobites. Con-
structed in the same manner as Figure 1. Tremadoe, Lower, Middle and
Upper subdivisions of the Ordovician are indicated separately. The shading
links those families that have been combined into a superfamily in Figure 1.
Leiostegiidae is used in the sense of Whittington, 1953, and Lecanopygidac
Lochman, 1953, is not shown.
198 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
vician history is one of lingering survival.
Figure 2, composed in the same manner as Figure 1, indicates
the range in time of post-Cambrian families. The gap at the base
of the Ordovician is more clearly shown, and only in four cases
do we, know possible Cambrian ancestors of dominantly Ordo-
vician families. Striking is the asaphid "burst", probably occur-
ring simultaneously in unrelated groups in Baltoscandia,
America, and Asia. "Bursts" of this type may have taken place
in other trilobite families. The great "burst" of new proparian
forms begins in early Canadian (i.e. Tremadoc) time and ex-
tends into the Champlainian, and we have as yet no notion of
the ancestral stocks. Equally puzzling are the Lichidae and
Odontopleuridae, arising suddenly, "ready made", apparently
unrelated to each other or to other families. The possibility that
groups hitherto soft-shelled were acquiring the power to mineral-
ize the exoskeleton cannot be overlooked. The general decline
of trilobites from the mid-Ordovician onwards is evident, though
inadequate knowledge of Silurian trilobites may falsify the pic-
ture. The diversification of certain groups in the Devonian is
real, but perhaps over-emphasized as a result of the intensive
systematic work of Drs. R. and E. Richter. Undoubtedly, other
"bursts" are in part "monographic", and new ones will inevi-
tably be added.
It seems reasonable to suggest that a natural classification
should attempt to make orders from groups of related super-
families. If the superfamilies as shown in Figure 1 are accepted
tentatively, the chief stumbling block in the way of the erection
of orders is the lack of known connections between the super-
families. At least four orders might be suggested : one to include
eodiscoids and agnostoids, which are perhaps more like each other
than either resembles any other trilobite group ; a second to
include olenelloids and redlichioids ; a third for the corynexo-
choids ; and the fourth including the group of ptychoparioids
and allied superfamilies included in the heavily stippled area of
Figure 1. A lighter, diagonally stippled area includes the post-
Cambrian superfamilies which may be derived from ptycho-
parioids and their allies, and which consequently may be regarded
as belonging to the same order. A separate order may be neces-
sary for the cheiruroids, the post-Cambrian proparian trilobites,
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 199
the origins of which are at present obscure. Omitted from these
groups are lichids, odontopleurids, and various isolated genera
and small families of uncertain affinities. It does not seem ap-
propriate to formally propose such orders at the present time,
my intention being merely to outline what seems to be a promis-
ing line of approach. This approach emphasizes our lack of
knowledge in critical areas, and it is this lack which, in my
opinion, precludes any satisfactory classification of trilobites at
this time.
REFERENCES
Beechbr, C. E.
1897. Outline of a natural classification of the trilobites. Am. Jour.
Sci., ser. 4, vol. 3, pp. 89-106, 181-207, pi. 3.
Cooper, G. A., and A. Williams
1952. Significance of the stratigraphic distribution of brachiopods.
Jour. Paleont., vol. 26, pp. 326-337.
Henningsmoen, G.
1951. Remarks on the classification of trilobites. Norsk, geol. tidskr.,
vol. 29, pp. 174-217.
Hupe, P.
1950. Etude statistique de 1 'evolution du cephalon chez les trilobites
Proparia et Opistoparia. Bull. Soc. Geol. France, ser. 5, vol. 20,
pp. 9-24.
1953. Classe des Trilobites, in Traits de Paleontologie, vol. 3, pp.
44-246, ed. J. Piveteau. Paris.
LOCHMAN, C.
1953. Analysis and discussion of nine Cambrian trilobite families.
Jour. Paleont., vol. 27, pp. 889-896.
Newell, N. D.
1952. Periodicity in invertebrate evolution. Jour. Paleont., vol. 26,
pp. 371-385.
Rasetti, F.
1951. Middle Cambrian stratigraphy and faunas of the Canadian
Rocky Mountains. Smith. Misc. Coll., vol. 116, no. 5, pp. 1-277,
pis. 1-34.
200 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
ST0RMER, L.
1942. Studies on trilobite morphology. Part II. Norsk geol. tidskr.,
vol. 21, pp. 49-164, pis. 1, 2.
Stubblbfibld, C. J.
1936. Cephalic sutures and their bearing on current classifications of
trilobites. Biol. Rev., vol. 11, pp. 407-440.
Whittington, H. B.
1953. North American Bathyuridae and Leiostegiidae. Jour. Paleont.,
vol. 27, pp. 647-678, pis. 65-69.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
VII. frraptolithina1
By 0. M. B. Bulman
Sedgwick Museum, Cambridge, England
Graptolites are extinct colonial organisms, and graptolite
phylogeny is expressed in the complicated relations of a succes-
sion of colonies. Not only has every individual theca a complete
ontogeny (accurately recorded in its growth-lines) but each
adult represents a stage in the development of the astogenic
unit. Despite the stratigraphical importance of the group, precise
knowledge of graptolite phylogeny is disappointingly slight. The
general succession of graptolite faunas is, however, well-estab-
lished, and it reveals a fairly steady process of simplification in
the colony and reduction in number of constituent individuals,
with phases of elaboration in the skeleton of individual zooids.
Only recently have we begun to get sufficiently exact details
concerning structure and mode of growth to afford a basis for
investigation of the complex problems presented.
These notes are confined to the order Graptoloidea, or true
graptolites, but to understand their structure some preliminary
reference to the ancestral order Dendroidea is necessary. Here
the three types of thecae recognized by Wiman have been shown
by Kozlowski to be related to an internal stolon system and
probably to have been secreted by only two kinds of individual
(plausibly interpreted as male and female). Thus the term
"stolotheca" ( Wiman 's "budding-individual") really desig-
nates no more than the proximal, immature portion of the auto-
theca, since continuity of growth-lines demonstrates that each
stolotheca is part of a unit which includes the succeeding auto-
theca (Fig. 1 A, B) . Consideration of the growth-lines and the
stolon system also indicates that there was not (as there is in
Rhabdopleura, Fig. 1 E) a terminal "leading bud" behind
which successive individuals are proliferated; but that each
i I am grateful to Professor L. Sterrner of the University of Oslo for permis-
sion to publish this material which is based on a lecture given in Oslo in December
1951.
202
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
theca (a6)
gymn (si)
pect(st)
11"// / D
Pig. 1. Comparison of organization and method of budding in a dendroid
(A,B), a graptoloid (C,D) and Btobdopleura (E). al, a2 etc., autothecae;
b2, b3 etc., bithecae; si, s2 etc., stolothecae; st, stolon; gymn., gymnocaulus;
pect., pectocaulus.
In A, B and D, one complete unit (including stolotheca and protheca) is
shaded. Fig. A represents the growing end of a branch, and a3, b3 and sS
are all incompletely developed.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
203
autotheea in turn has represented the terminal bud of its branch,
and at a certain stage in its development there are produced
from back on its stolon two buds, male bitheca and female auto-
theea (Fig. 1 A, B). The budding processes in Bhab do pleura,
on the one hand, and the graptolites on the other, exactly parallel
the monopodial budding with terminal growing points, and the
sympodial budding, described (L. Hyman) in calyptoblastean
hydroids.
In the Graptoloidea, branch organisation is considerably sim-
plified by the loss of bithecae (the autothecal zooid, on Koz-
lowski's interpretation, becoming hermaphrodite), but the stolon
Fig. 2. Mode of branching in a dendroid (D. flabelliforme) . A, branching
division with production of two stolothecae (s4 and s'4) in place of stolo-
theca and bitheca. B, approximate zones of branching in the rhabdosome
of D. flabelliforme. xl.
system may be considered to persist to a limited extent in an
unchitinised condition. The occurrence of a small "unconform-
ity" between the growth-lines of adjacent thecae (Fig. 10) even
in early stages of colonial development, and the dual construction
of each interthecal septum, indicates that each theca buds from
the preceding theca as a slightly modified inheritance of the
dendroid method of budding (Fig. ID).
Bifurcation in a dendroid branch results from the formation
of two stolothecae in place of the normal stolotheca and bitheca
204 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
(Fig. 2A). Branching is often very regular; more so in Dit-
ty onema than in most dendroids and in D. flabelliforme than in
other species of that genus (Fig. 2J3). In the Graptoloidea,
branching is generally strikingly regular, but since only one
type of individual is present in the colony, it clearly results
from the formation of two buds in place of one under some
periodic stimulus. In relation to the Dendroidea, there is a break
here in the evolutionary sequence for which we still lack the
material to investigate.
The differences among branched dichograptid colonies are
largely due to the spacing and timing of these double buds.
There seems to be a general tendency towards reduction in the
number of branches in a colony, though few lineages are well
established and the recent work of Australian paleontologists
suggests that the phyletic relations of the Dichograptidae are
much more involved than has generally been recognized. Cer-
tainly the two-stiped Didymograptus is the successful type,
judged by its increasing preponderance in the upward succes-
sion; but branch reduction may have taken place either proxi-
mally or distally — i.e., Didymograptus may be either neotenic
or gerontomorphic, if one may use such terms of colonial proc-
esses.
Reduction in number of branches implies a reduction in total
number of individuals in a colony, which over the whole series
may be extreme. A large rhabdosome of Dictyonema flabelliforme
may have comprised the astonishing total of not less than 35,000
individuals (autothecal and bithecal) ; a large dichograptid might
have 3000 individuals (all of one kind) ; most leptograptids,
dicellograptids and diplograptids have from 100 to 200 individ-
uals (usually nearer the lower limit) ; while the Silurian Mono-
graptus averages about 50 and the late M. leintwardinensis
consists of only 10 to 17 individuals in a colony.
With the establishment of the simplified autothecal and pauci-
ramous rhabdosome of the typical graptoloid, several structural
features make their appearance — some rhabdosomal and some
thecal.
Rhabdosomal changes, apart from stipe-reduction, are most
conspicuously concerned with orientation relative to the sicula
(which itself remains strikingly constant) and the nema suspen-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
205
Oncogr
Cryptogr.
22 2'
Fig. 3. Progressive changes in the proximal end of the rhabdosome in
dichograptids, Ieptograptids and dicellograptids, showing progressive delay
in formation of the ' ' double bud ' \
206
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
sion; the rhabdosome passes from pendent through horizontal
to reclined and eventually scandent. This change in direction
of growth is an intermittently expressed tendency which affects
all graptolites ever since D. flabelliforme reversed the normal
orientation of a Dictyonema rhabdosome to begin the story of
graptoloid evolution. It proceeds side by side with a sequence
of changes in the development of the proximal end of the rhab-
Fig. 4. Monograptus argenteus (Nicholson) x2 showing change in thecal
character from hooked (proximal end) to straight (distal end) ; growth-
lines on enlargements xlO of selected thecae are partly conjectural, and are
inserted to illustrate the form and development of the thecae.
dosome which may be expressed as a progressive delay in the
formation of the two buds from which any bilateral rhabdosome
develops (didymograptid, leptograptid, dicellograptid or diplo-
graptid). A temporarily stable condition is reached when the
first four thecae of the rhabdosome alternate in origin and there
are three crossing eanals (as is very usual in dicellograptids and
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 207
diplograptids), the two buds being carried on th21 (Fig. 3).
Further evolution to aseptate and uniserial rhabdosomes is men-
tioned later.
Thecal changes include many types of elaboration and what
may be termed "thecal differentiation." The simplest expression
of the latter is a distal increase in size, the thecae remaining
constant in shape. Even the Dichograptidae show such a distal
increase, which contrasts with the uniformity in size of dendroid
thecae throughout a rhabdosome. In its extreme expression, it
is coupled with thecal elaboration, and successive thecae may
undergo progressive change in size and form, as in the many
bi-form monograptids (Fig. 4). The available evidence suggests
that new types spread gradually along the rhabdosome with
time. The linear propagation of buds in one of the simplified
Graptoloidea makes such changes more regular than comparable
changes in, for example, a compound coral ; and it has been com-
pared with the introduction of new characters in a metamerically
segmented animal. Less commonly does a new character seem
to operate throughout the life of a colony at its first appearance ;
and occasionally the distal thecae of a rhabdosome may show new
features which did not originate proximally, though such features
seem rarely conspicuous.
In seeking to attach significance to these thecal changes, it
may be added that so far as we are aware, they reflect no dif-
ference in habitat ; all graptolites are believed to be epiplanktonic,
and the remains of many different types occur side-by-side in
the rocks. As regards their transmission, it may be noted that
whatever modifications the first and subsequent thecae may show,
the sicula (the first individual of the colony) remains throughout
the Order almost as constant in form as it is in orientation.
Every subsequent zooid is produced by asexual budding, the
colony being subject to a common genetic control.
In stipe-reduction, change in direction of growth (from pend-
ent to scandent) and the various thecal changes (especially among
monograptids), the graptolites furnish numerous instances of
"programme evolution", for parallel changes undoubtedly occur
independently in many different lines of descent, though few
detailed phylogenies have as yet been established by which this
assertion can be illustrated.
208 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
There seem to have been three major events in the geological
history of the Graptoloidea :
I. Derivation of the Graptoloidea from the Dendroidea in
late Tremadocian times.
II. Origin of the biserial scandent rhabdosome early in the
Ordovician.
III. Origin of the uniserial scandent rhabdosome slightly but
appreciably above the base of the Silurian.
I. Derivation of the Graptoloidea. This involves loss of dis-
sepiments and bithecae, and was preceded by a change in mode
of life, the benthonic rooted habit giving place to a nema-attach-
ment to floating weeds. Such a change had in fact occurred in
Dictyonema flaoelli forme and that varied collection of its im-
mediate descendants the Anisograptidae. Of these, the best
known are Clonograptus (Fig. 5 A, B) and Bryograptus (Fig.
5 C, D), but Anisograptus (Fig. 5 F), Adelograptus (Fig. 5 E)
and Staurograptus (Fig. 5 H) are also important. They vary in
attitude of branches from pendent to reclined, and in number of
primary stipes from two to four; but all are united in the pos-
session of a nema attachment along with typical dendroid branch
structure, and they differ from Dictyonema flabelliforme chiefly
in loss of dissepiments.
The change from anisograptids to true dichograptids requires
the loss of bithecae and is usually accompanied by some reduction
in number of branches. Stipe-reduction may come first — Aniso-
graptus itself in one of its varieties has only four branches and
leads to the triradiate, unbranched Triograptus (Fig. 5 0) while
apparently retaining the dendroid branch structure. Or bithecae
may be lost while the number of branches shows little change
and may even increase — for there is much to suggest that the
Ordovician Clonograptus and Bryograptus species have a simpli-
fied graptoloid branch while retaining the rhabdosome form of
their Tremadoc ancestors. The transition from dendroids to
graptoloids is clearly a gradual one (in contrast to the other two
episodes) and the Graptoloidea may well be polyphyletic, though
all seem ultimately traceable (through various anisograptids) to
Dictyonema flaoelli forme.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
209
By the middle of the Lower Ordovician the dominant grapto-
loid type had become the two-stiped, horizontal or reclined
didymograptid. Then progressive delay in the origin of the two
buds from which the two separate stipes develop (Fig. 3) leads
to the proximal end characteristic of most leptograptids and all
dieellograptids of the Middle Ordovician, wherein the first four
thecae of the rhabdosome alternate and there are three crossing-
canals. Further, these leptograptids and dieellograptids show
the substitution of a new type of theca — the sigmoid leptograp-
Fig. 5. Representative members of the family Anisograptidae. A, B,
Clonograptus (flexilis and tenellus) ; C, D, Bryograptus (Tcjerulfi and
patens) ; E, Adelograptus (hunnebergensis) ; F, Anisograptus (matanensis) ;
G, Triograptus (canadensis); H, Staurograptus (dichotomus) . x% approx.
tid type — for the simple straight dichograptid type. In Dicello-
graptus and Dicranograptus this may become further modified
in a distinctive manner, the distal end becoming isolated and
introverted (Fig. 6 B, C).
With the development of the leptograptids, branched colonies
210
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
reappear (Pleurograptus, Nemagraptus and Amphigraptus) . No
satisfactory explanation of this has yet been given. Since the
details of branch formation are still unknown, parallel descent
from multiramous dichograptid ancestors cannot be altogether
excluded, nor even some kind of " pseudobranching " analogous
to the monograptid cladia; but an atavistic interpretation is the
one most usually accepted.
D E
Fig. 6. Selected types of graptoloid thecae. A, leptograptid ; B, dicello-
graptid (simple) ; C, dicellograptid and dicranograptid (more complex) ;
D, E, extreme types of monograptid (triangulate and lobate). Growth-lines,
mainly conjectural, inserted for greater clarity.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 211
II. Origin of the biserial scandent rhabdosome. The Dicello-
graptus — Dicranograptus series had reached a condition as re-
gards their proximal end (in the alternating origin of the first
four thecae) which is practically identical with that of the diplo-
graptids. Moreover, Dicranograptus (with its Y-shaped rhab-
dosome) has long been suggested as an intermediate between
Dicellograptus and the biserial graptolites. Nevertheless, the
diplograptids are the earlier group, and if Dicranograptus has
any significance in this story it can only be as a contributory fac-
tor in a polyphyletic ancestry.
The earliest diplograptid known is Glyptograptus dentatus
from the Extensus Zone in Britain ; by Upper Arenig times it is
found in Scandinavia, and by the beginning of the Llanvirn
(Bifidus Zone) it had reached Australia and America. Against
a background of Lower Ordovician graptolites, its appearance
is quite startling ; and its structure is so novel that it must surely
represent an unusually large but successful mutation. It pos-
sesses certain distinctive features in its proximal end which are
gradually lost in its descendants (but curiously enough reappear
in the only Dicranograptus of which we have as yet any detailed
knowledge). The significance of these features (the --'-shaped
thl2 with its initially upward growth, and the long downward-
growing initial part of th21) is unknown, but somewhat similar
features are recognizable in the nearly contemporaneous Lasio-
graptus hystrix and to a less extent in early Climacograptus
scharenbergi. In fact, the bulk of the true diplograptids may
well have a monophyletic origin in G. dentatus (using the term
diplograptid to include Diplograptus sensu lato, Climacograptus,
and some as yet undetermined portion of the lasiograptids).
So long as the rhabdosome consisted of two separate uniserial
stipes, it was not mechanically possible for the formation of the
two buds representing the bases of the two stipes to be much
delayed — in fact, the presence of three crossing-canals and the
alternating origin of the first four thecae is about as far as this
trend can proceed. But there is no such necessary limitation in
the scandent biserial rhabdosome, where the septum separating
the two stipes may arise at any point along the rhabdosome (Fig.
1 C,D). Its earliest appearance is between th22 and th22 (Fig.
IB) and the septum is then said to be "complete"; but it is
212
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Cryptograptus
?Glossograptus
Generalized Diplogr-
(complete septum")
Glyptogr.
dentatus
Oncograptus
PCardiograptus
? Skiagraptus
Fig. 7. Progressive changes in the proximal end of biserial scandent
graptolites. A-D, diplograptids illustrating further delay in production of
the "double bud"; E, F, proximal end of other scandent biserial graptolites.
Precise relations of the thecae in retiolitids remain unknown.
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 213
progressively deferred as more and more of the proximal thecae
alternate in origin, and may never occur at all if the thecae
alternate throughout the rhabdosome.
It may be noted that the thecae in diplograptids, though vari-
ously modified, never show the extremes that we encounter among
the Dicellograptus — Dicranograptus series; in particular, no
diplograptid so far as I am aware shows any trace of apertural
isolation. Thecae remain for the most part fairly generalised
and the angularly sigmoidal thecae of Ample rograpt us and
Climacograptus represent the most extreme modifications. It is
from the more conservative stock (which persists into the Silurian
system) that the great wealth of monograptids must be derived.
In addition to the diplograptids proper, there are numerous
other scandent biserial forms, such as Cardiograptus, Skiagrap-
tus, Cryptograptus, Glossograptus, Trigonograptus, Gymnograp-
tus and the retiolitids, which are all very imperfectly understood
as yet. Many of these appear to have been side lines (some even
from the dichograptids) incidental to the main evolutionary
story ; the retiolitids, however, are probably derived from diplo-
graptids (perhaps more than once), though the chitinous skeleton
is so extensively reduced, often to a few structural rods and
girders, that it is practically impossible to interpret their proxi-
mal end in terms of zooidal succession and development.
III. Origin of the uniserial scandent rhabdosome . Failure to
produce the pair of buds, or rather, the production of a single
bud in place of the pair, cannot by itself convert a diplograptid
rhabdosome into Monograptus, for even in the simplest and most
generalised diplograptid the first four thecae of the rhabdosome
are alternating in origin (Fig. 8A). This is beautifully illus-
trated by a form discovered by Dr. Strachan but not yet de-
scribed, which comprises a uniserial rhabdosome yet possesses
thl2 in its normal diplograptid relation. The change can only
effectively come after these proximal thecae have substituted a
linear serial arrangement for the alternating proximal arrange-
ment of their ancestor, either by reduction or loss of thl2 and
any later "second-order" thecae (Fig. 8C), or perhaps more
probably by a "merging" of the thecae of the two series (Fig.
8D) as postulated by Wiman. Such merging may be combined
with the pronounced tendency to an upward direction of growth
214
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
which affects the biserial Petalograptus and Cephalograptus.
Starting from a diplograptid with the most generalised proxi-
mal end (a complete septum) it would only be necessary to lose
one theca, or to get thl2 into series between thl1 and th2x, for
subsequent failure of the "double bud" to result immediately
in a monograptid (Fig. 8C, D). From such an ancestor, there-
2 ,'\
3"<
Generalized
Diplogr. type
Cephalogr.
type
reduction
and loss
of thl2
"merging'
of ih.\f
Fig. 8. Diagram illustrating the problem of monograptid origin.
fore, the origin of Monograptus is essentially a question of the
disposal of thl2; rearrangement (or loss) of numerous proximal
thecae in a form with a delayed septum is more difficult to under-
stand. Yet the well-defined species groups of Dimorphograptus
suggest that, if this was their origin, the change must have
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 215
occurred independently in several lines of descent. It may there-
fore be thought that Dimorphograptus (with a uniserial portion
often of considerable length) is less likely to be an intermediate
stage than an atavistic form (as Wiman suggested) or a short-
lived side line. But it must be admitted that Dimorphograptus
is essentially pre-monograptid in its range, and its significance
in relation to Diplograptus and Monograptus remains uncertain.
With the origin of the monograptids only a little more than
halfway through the evolutionary history of the Graptoloidea,
the major phases of structural evolution of the graptolite rhab-
dosome are passed, and for the next thirty million years the
uniserial scandent rhabdosome remains the dominant graptolite
form. Thecal elaboration begins anew1 and may lead to extremes
exceeding anything known from the Ordovician. The sequence
of thecal elaboration and the structure of ' ' pseudobranched "
rhabdosomes of genera like Cyrtograptus present many unsolved
problems ; but the basic form of the colony had in its very sim-
plicity attained a complete stability persisting to the extinction
of the Graptoloidea.
i In these monograptid elaborations there is an exaggerated development of the
dorsal margin of the theca leading to extroverted thecal forms, in contrast to the
dominant development of the ventral lip which produces the introverted Ordovi-
cian type of elaboration. Compare Fig. 6 B,C, with 6 D,E.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
VIII. On Development, Evolution, and Terminology
of Ammonoid Suture Line
By 0. H. Schindewolp
University of Tubingen, Germany
INTRODUCTION
In comparative anatomy it is a matter of course to use a termi-
nology that is based on the homology of organs. In osteology of
vertebrates, for instance, elements of the same origin and de-
velopment, but often of quite unlike shape receive the same
designations. Elements of different origin, however, i.e., merely
analogous organs, are sharply distinguished in terminology.
These principles are not yet sufficiently established in the
terminology of ammonoid suture line. Here the denominations
mostly have been based on the mature sutures, without regard
to, or at least without fully utilizing their ontogenetic de-
velopment. There are, however, several different modes in the
development of suture lines, so that it is impossible to base the
designations of the lobes merely on their position and shape in
the adult suture. This of course would be much simpler, but it
would veil the existing differences and thus the natural relations
of the forms exhibiting these different suture lines. This method,
therefore, is not feasible.
The first authors realizing these failings and initiating a ra-
tional terminology of suture line based' on its individual develop-
ment were F. Noetling (1905, 1906) and R. Wedekind (1913
a,b ; 1916; 1918). The attempt of Noetling, though ingenious in
itself, was a failure, since it involved two wrong suppositions :
(1) The foundation, on which the ontogenetic development and
phylogenetic evolution of suture line rise, is the primary suture
(i.e., the first genuine suture line following the prosuture), but
not the prosuture, a larval organ with widely different features.
(2) A genetic terminology of suture line cannot be based, as
Noetling proposed, on highly differentiated ammonites; it has to
218
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
start from the basic structures of the earliest ammonoids, the
undifferentiated goniatites.
Wedekind has wisely avoided these two mistakes and has estab-
lished a terminology unsurpassed until now in consistency and
simplicity. I have further elaborated the principles introduced
by him, and in this paper I shall discuss in a summary form some
general questions concerning the suture line and certain related
topics.
Agoniatites
Mimagoniat.
Oyroceratites
Lobobactrites
Bactrites
Fig. 1. Suture lines (partly adolescent and adult) and shell shapes of
the earliest representatives of goniatites. (Adapted from Schindewolf
1933.)
ACKNOWLEDGMENTS
The writer is deeply indebted to the Geological Society of
America for a very generous invitation to attend its 1953 Annual
Meeting at Toronto. This gave him the welcome opportunity to
deliver this lecture in the symposium of the Paleontological
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 219
Society. Dr. B. Kummel very kindly undertook the laborious
task of revising the manuscript and of bringing it into the present
form. The author wishes to render him sincerest thanks for his
trouble and for his stimulating interest.
THE EARLIEST GONIATITES
According to my conviction, the ammonoids descend from
straight orthocone nautiloids via Bactrites, Lobobactrites, Gyro-
ceratites, and Mimagoniatites (Schindewolf 1932, 1933, 1935,
1939a). The Michelinoceratida are an old root stock giving rise
to many other groups of nautiloids, to belemnoids and, as it seems
to me, also to ammonoids. It may be debated whether Bactrites
and Lob o~b act rites are to be included in nautiloids or in am-
monoids. I prefer to place them in the ammonoids on account
of the extreme ventral position of their thin siphuncle and its
connection with a ventral lobe, which are important diagnostic
features of ammonoids.
Bactrites and Lobobactrites (Fig. 1) thus would be the earliest
and most primitive representatives of goniatites, still retaining
the straight orthocone shell of Michelinoceratidae. The suture
line of Bactrites is characterized by the possession of a small
ventral lobe; otherwise, it is simply straight. In Lobobactrites
the shell is laterally compressed and on each of the flattened
sides a broadly rounded lateral lobe is added, while the dorsum
is occupied by a dorsal saddle.
Gyroceratites (Fig. 1), in my opinion a descendant of Lobo-
bactrites, has a loosely coiled shell with egg-shaped protoconch
and a large umbilical perforation. The dorsal side of the whorls
is still without an impressed concave zone. The suture line is the
same as in Lobobactrites. Mimagoniatites (Fig. 1) continues this
trend of evolution. In the beginning of its shell it resembles
Gyroceratites, but soon the whorls begin to cover each other and
to develop a concave zone at the dorsal side. The primary suture
and the next sutures in the region of the umbilical perforation
still retain the dorsal saddle, which in later developmental stages,
as soon as the concave zone appears, is replaced by a dorsal or
internal lobe. By the inception of this lobe the typical trilobate
goniatitic suture line is completed.
The earliest goniatites with tightly coiled shells are Agoniatites
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BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
J U, U,U+U2 L £ M
f
JUL A. AtA}E
f
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 221
(Fig-. 1) and Werneroceras (Pig. 3). In them the protoconch is
spirally coiled, the umbilical perforation is lacking, and the
whorls from the very beginning possess a concave dorsal zone.
As a further progress of evolution the primary suture already is
of the type exhibited by the later and adult sutures of Mima-
goniatites: it is characterized by a dorsal lobe.
It seems to me that this gradual perfection of suture line and
of involution is a strong argument in favour of a derivation of the
coiled ammonoids from uncoiled orthocone nautiloids. This
theory was first advocated by A. Hyatt (1884) and then sup-
ported and further elaborated by myself. Having corrected Hy-
att's misconception of the protoconch in nautiloids and ammo-
noids I was able to prove that the small egg-shaped protoconch
of michelinoceratids, bactritids, and all ammonoids is the exact
homologue of the coarse conical initial chamber of coiled nauti-
loids.
This statement is incompatible with the view held by L. F.
Spath (1933, 1936), that the coiled or typical goniatites evolved
Fig. 2. Suture lines of Anarcestes (Anarcestes) lateseptatus (Beyr.)
from the lower Middle Devonian (a, b), Subanarcestes macro cephalus
Schdwf. from the lower Middle Devonian (c), and Raymondiceras simplex
(Raym.) from the Upper Devonian (d, e). (Adapted from Schindewolf
1933 and 1934.)
Fig. 3. Development of suture line of Werneroceras ruppachense (Kays.)
from the lower Middle Devonian. (Adapted from Schindewolf 1933.)
Fig. 4. Development of suture line of Foordites platypleura (Freeh) from
the lower Middle Devonian. (Adapted from Schindewolf 1933.)
Fig. 5. Phylogenetic evolution of suture line in Manticoceratidse (and
its predecessor Archoceras) from the lower Upper Devonian, a, Archoceras
— b, Ponticeras — c, Manticoceras — d, Koenenites — e, Timanites — /,
Pharciceras. (After Wedekind 1913b and Schindewolf 1951.)
Fig. 6. Development of suture line of Cheiloceras sp. from the Upper
Devonian. (Adapted from Schindewolf 1929.)
Fig. 7. Development of suture line of Eeticuloceras reticulatum (Phill.)
from the Lower Pennsylvanian. (Adapted from Schindewolf 1929.)
Fig. 8. a-e, Development of suture line of Sporadoceras miinsteri (v.B.)
from the Upper Devonian. (Partly after Perna 1914.) /, Adult suture of
Discoclymenia cucullata (v.B.) from the Upper Devonian. (After Schinde-
wolf 1951.)
222 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
from coiled Silurian and Ordovician nautiloids of the general
type of Barrandeoceras, Tarphyceras or Paleonautilus. The cup-
shaped initial chamber, the rapidly expanding first whorls, the
mode of involution, the position of the siphuncle and other char-
acters of Barrandeoceras and related coiled nautiloids are so
profoundly different from those in coiled ammonoids, that such
a derivation is impossible. On the other hand, there is in every
respect a gradual transition from michelinoceratids through
bactritids to the coiled ammonoids. The progressive reduction
of the umbilical perforation and the transformation of the proto-
conch to be observed from Lower Devonian to Middle Devonian
species of Anarcestes and from them to the Middle Devonian
Werneroceras definitely postulate such forerunners as Mimago-
niatites and Gyroceratites.
The only difficulty so far was that this evolutionary trend
could not exactly be proved by the geological distribution of
the respective genera. But since H. K. Erben (1953) recently
recorded the occurrence of Lobobactrites, Gyroceratites, and
Mimagoniatites in the Lower Devonian of the Hartz Mountains,
these difficulties are eliminated, so that there are no more ob-
stacles to regarding Lobobactrites etc. as being the ancestors of
the typically coiled goniatites. As a matter of fact the tightly
coiled genera Agoniatites and Werneroceras are geologically
younger, and Anarcestes, at least, is not known from beds older
than those containing Lobobactrites, Gyroceratites, and Mimagon-
iatites. The interpretation by Spath, who considered these genera
as uncoiled derivatives of Anarcestes, is thus no longer tenable.
But these controversies do not affect the question of our suture
line. We repeat that all the earlier normally coiled goniatites
are characterized by a trilobate suture consisting of the ventral
or external lobe (E), the lateral lobe (L), the dorsal or internal
lobe (I), and the two saddles E/L and I/L separating them.
This elementary suture is the basis from which all the more dif-
ferentiated sutures of the later ammonoids can be derived. I
have termed the three lobes composing this suture the basic lobes
or protolobes, since they and they alone are common to all the
host of goniatites, clymenoids, ceratites, and ammonites. In the
later representatives of ammonoids these primary lobes are sup-
plemented by a varying number of additional lobes which may
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 223
be called secondary or metalobes.
The ventral lobe B and the dorsal lobe I are fixed in the plane
of symmetry of the conch ; their position is invariable. The lobe
E is connected with the ventrally arranged siphuncle ; the lobe I
is combined with the impressed zone of the whorls.
Variable, however, is the position of the lateral lobe, which
has no such limitations. In a few forms (Gyroceratites, Mimago-
niatites, Agoniatites) it occupies, as a broadly rounded lobe, the
middle of the flanks from the very beginning, i.e., from the
primary suture. It then shows a position commonly taken as
characteristic for the lateral lobe in a stricter morphologic
sense. In most cases, however, the lateral lobe is situated in the
primary suture on or at the umbilical seam. Usually small and
shallow, it is separated from the external lobe by a broadly
vaulted saddle on the flanks. Then, in later ontogenetic stages
this lobe mostly is broadened and shifted to the middle of the
flanks (e.g., Werner oceras, Fig. 3).
In some few genera (Anarcestes, Fig. 2a, b; Subanarcestes,
Fig. 2c; Raymondiceras, Fig. 2d, e; Arckoceras, Fig. 5a), how-
ever, it may retain the primary position next to the umbilicus up
to the mature suture. Its position thus is not, strictly speaking,
lateral. But the gradual shifting of the lateral lobe in related
goniatites proves that this lobe at the umbilicus is homologous
with the lateral lobe of the adult stages in other genera. It may
likewise be termed lateral in the somewhat broader sense that
it is the protolobe lying laterally from the plane of bilateral
symmetry, indicated by the ventral and dorsal lobe. In any case
the characteristic lateral position of this lobe on the flanks is
nearly always a secondary one.
THE DIFFERENTIATED GONIATITES
The further elaboration of the suture line consists of the in-
sertion of new lobes. The main process is that of subdividing
the saddles. In the apex of a saddle a new lobe appears, shallow
in the beginning and then gradually deepening. In the simple
trilobate suture of early goniatites and in the likewise trilobate
primary suture of the more advanced goniatites two saddles are
present: the internal saddle (I/L) and the external saddle
(L/E). Each of these saddles may be subdivided and thus give
rise to new lobes.
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BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
JUL
JUL A E
J U, U3 U2 L E
J U, Uz L £
14
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 225
The lobes which are derived from the internal saddle are
termed umbilical lobes (abbreviated U), since they are formed in
the region of the umbilicus; the lobes originating by the sub-
division of the external saddle are called adventitious lobes (A).
These lobes arise in a very definite order. The umbilical lobes
are formed alternately, U2 follows Ui at the ventral side, U3
comes in dorsally to U2, and so on. The adventitious lobes are
inserted in a simple ventrad sequence.
In these differentiated goniatites again the fate of the lateral
lobe is different. In the same manner as in most of the early
goniatites, it is situated in the primary suture immediately next
to the umbilicus and is crossed by the umbilical seam. It retains
this position throughout its ontogeny in the case that one or more
adventitious lobes are formed. Then the middle of the flanks
is occupied by the adventitious lobes. This case is by far the most
common among late Paleozoic goniatites. Some examples are
shown in Figures 6-10.
On the other hand, if no formation of adventitious lobes takes
place, usually a larger number of umbilical lobes arise which
displace the lateral lobe from its original position. The second
or third umbilical lobe, respectively, is then situated on the um-
bilical seam and the lateral lobe is shifted to the middle of the
flanks or still more outwards. This type of suture line is realized
in only a few groups of goniatites, as for instance the Mantico-
Fig. 9. Development of suture line of Anthracoceras paucilobus (Phill.)
from the Lower Pennsylvanian. (After Schindewolf 1951.)
Fig. 10. Development of suture line of Imitoceras sp. from the Lower
Mississippian. (After Schindewolf 1951.)
Fig. 11. Development of suture line of Merocanites applanatus (Freeh)
(and asiaticus [Karp.]) from the Mississippian. (Adapted from Karpinsky
1896 and Schindewolf 1929.)
Fig. 12. Development of suture line of KonincTcites sp. from the Lower
Triassic of the Salt Range (Pakistan). Geol. Dept. Tubingen Ce 1043/3.
Fig. 13. Development of suture line of Strenoceras (Strenoceras) sub-
furcatum (Ziet.) from the Middle Jurassic. (Adapted from Schindewolf
1953.)
Fig. 14. Development of suture line of Spiroceras bifurcati (Qu.) from
the Middle Jurassic. (After Schindewolf 1951.)
226
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
ceratidae (Fig. 5), the Prolobitidae, and the Prolecanitidae (Fig.
11).
The adult sutures of such goniatites, though they originated
in two profoundly different ways, may sometimes be very similar
in shape and formal composition (Fig. 15). But owing to their
different origin the homology of lobes is quite different. What
is the lateral lobe in the one suture is an adventitious lobe in
the other, and the lateral lobe of the latter suture corresponds
to an umbilical lobe of the first one. It is therefore necessary to
regard the actual development of suture line in order to deter-
mine the true homologies and to gain a proper designation of the
U-Type
A -Type
u, u2
Fig. 15. Diagrammatic confrontation of the U- and A-type of suture
development.
lobe elements. This is the more necessary since the two trends of
lobe formation are significant for definite groups of goniatites and
thus obviously are important for tracing the phylogenetic rela-
tions.
For brevity, we will call the type with adventitious lobes the
A-type (Fig. 15). Its main characteristics are: One or more
adventitious lobes are formed, but only one umbilical lobe is
present ; the lateral lobe retains the initial umbilical position
it held in the primary suture. The other type may be termed
the U-type (Fig. 15) : A larger number of umbilical lobes, but
no adventitious lobes are formed; the lateral lobe is removed
outwards from its original position. The U-type is limited to a
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 227
small stem of goniatites, while by far the majority of late Paleo-
zoic forms, the Tornoceratidae, Cheiloceratidae, the Goniatitidae
with all their derivatives, follow the A-type.
THE MESOZOIC AMMONOIDS
Differing from the Paleozoic goniatites (Fig. 12), the primary
suture in Triassic ceratites is quadrilobate, i.e., it contains one
element more than that of the former. It is to be interpreted in
such a manner, that by accelerated development a first umbilical
lobe (Uj) (which in Devonian and Carboniferous goniatites, if
at all, was inserted in a much later stage of development) has
been added , to the three protolobes. The lateral lobe is, from
the beginning, situated on the middle of the flanks and afterwards
is shifted still more outwards. The primary suture of such a
Triassic ceratite (Fig. 12a) corresponds thus in every detail to
a later developmental stage of e.g. Merocanites (Fig. lie).
The further elaboration of the suture line proceeds exactly in
the same way by the addition of two other umbilical lobes (U2
and U3). In later stages a crinkling of the lobes comes in. The
umbilical lobes Ui and U3, situated around the umbilical seam,
sometimes are strongly enlarged and unevenly differentiated by
serration. They may thus simulate a more or less large series of
"auxiliary" lobes, which are nothing else than parts of the two
umbilical lobes, produced by digitation.
The suture line of the Triassic ceratites follows the U-type,
and it can only be derived from goniatitic sutures representing
the same type of lobe development, as is the case, for instance,
in the Prolecanitidae. Now it is the general conviction, which
can be supported by my own studies of Triassic and Permian
ammonoids, that the Lower Triassic ceratites are descendants of
the Permian Xenodiscidae, which on their part go back to the
Carboniferous Prolecanitidae. So our observations and interpre-
tations of suture line lead to the same conclusions as those drawn
from other morphological features. They can be used to reinforce
and to define more exactly our phylogenetic conceptions.
So far as I can see, all the Triassic ceratites represent the U-type
of lobe formation; I have never observed a case of the A-type.
It seems to me, therefore, that the A-type prevalent in the Paleo-
zoic was extinguished at the Permian-Triassic boundary and left
228
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
no descendants in the Mesozoic (except, at most, some few surviv-
ing forms in the Lower Triassic). In the Triassic and, as we will
see, also in the Jurassic and Cretaceous the U-type alone is
dominant.
The evolutionary cycle of Jurassic and Cretaceous ammonites
originates in one of the lineages of Triassic ceratites. So it is
to be expected that the same type of lobe formation will be con-
tinued by them, and that indeed is the case. The primary suture
fi ^
-<
<*J
£
Ammon.
">
«>»
<«J
^
^>
*<»
^
I Cera t. \
£
s
f-\
£
Pro/.
Gon.
d
<>
U-Type
A -Type
CS
«5
i.
k4£o/7.>J — "
C*
Fig. 16. Diagrammatic representation of the phylogenetie relations of
ammonoids.
of these forms (Figs. 13, 14) is quinquelobate ; by a further
acceleration of development, two umbilical lobes are represented
in it besides the three protolobes. Their primary suture is thus
equivalent to a more advanced stage in the development of the
Triassic forerunners. The lateral lobe is situated on the flanks;
no adventitious lobes are formed between it and the external lobe.
Summarizing these observations on the suture line we gain a
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
229
very simple picture of the broad phylogenetic relationships
among ammonoids represented in Figure 16. Of course, this is
only a rough scheme, omitting all details, and needing further
refinement.
PRIMARY SUTURE AND PROSUTURE
The evolution of the first genuine or primary suture and of
its further ontogenetic differentiation shows a definite trend as
summed up on the right side of Figure 17. In Devonian am-
monoids, the fully coiled goniatites and the clymenoids, the
primary suture is trilobate ; it consists of the three protolobes I,
Manticoceras
Sudeticeras
Schlotheimia Oxynoticeras
Fig. 17. Comparison of prosutures (Pro) and primary sutures (Pri) of
various ammonoid genera. (Adapted from Schindewolf 1929 and 1942.)
L, and E only. This simple type of suture is retained until the
adult stage in early Devonian ammonoids ; the lobes only may
become deeper. In more advanced Devonian forms one or more
metalobes are added during development, The insertion of a
first umbilical lobe by subdividing the internal saddle usually
takes place between the 20th and the 25th suture.
In Carboniferous goniatites the initial suture is of the same
type as that of Devonian forms, but by acceleration of develop-
ment the umbilical lobe already appears in the next suture or
the one immediately following. This quadrilobate stage becomes
permanent as the primary suture in Triassic ceratites, and a
second umbilical lobe is added in about the 12th to the 16th
230 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
suture. Finally, by acceleration, this quinquelobate stage be-
comes the primary suture of Jurassic and Cretaceous ammonoids.
It may be further differentiated by the insertion of a third um-
bilical lobe in the 12th to the 15th suture line. This is a very
impressive example of the acceleration of development, the skip-
ping of old developmental stages and the insertion of new ones
into increasingly earlier stages of ontogeny.
The primary suture, however, is not the absolutely first suture
line ; in the development of every ammonoid it is preceded by
another suture belonging to the septum closing the protoconch.
It is totally different from the primary suture and has been
termed the prosuture (Schindewolf 1928, 1929). In its ventral
and dorsal parts it is characterized by having saddles instead of
the external and internal lobe so highly significant for the normal
ammonitic suture. Often the differences between the prosuture
and the primary suture are so great that the one in nearly all
cases has lobes, whereas the other shows saddles. The primary
suture then may look like a reversed prosuture. Furthermore,
the number of elements between the ventral and the dorsal side of
the two sutures is quite independent. It may be the same (Fig.
17, Manticoceras, Oxynoticeras), or it may be larger (Fig. 17,
Schlotheimia) or even smaller in the primary suture as compared
with that in the prosuture (Fig. 17, Sudcticeras) .
Finally, the phylogenetic evolution of the prosuture from
Devonian to Jurassic and Cretaceous ammonoids (Fig. 18, left
side) is entirely different from that of the primary suture. It is
not necessary to go into the details here, since I have given full
descriptions in my earlier papers (Schindewolf 1929, 1942). It
may suffice to state that the special character of the prosuture
is maintained throughout the whole history of ammonoids, and
that the sequence of the newly inserted lobes is quite different
from that of the later sutures.
Because of these manifold differences in shape and evolution,
it is impossible to deduce the primary suture from the prosuture,
whereas the former is closely connected with the following suture
lines and forms the basis for their further differentiation. There
is a definite break between the two sutures; the morphological
features of the prosuture do not find a continuation in the indi-
vidual development. It is therefore considered as an ephemeral
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
231
Prosufuren
Sufuren
Ju
ra
Trias
Karbon
Devon
J U,U3U2 L E
Fig. 18. Phylogenetie evolution of the prosuture and primary suture in
ammonoids. (After Schindewolf 1942.)
larval organ and we have to assume that the animal must have
undergone a kind of metamorphosis between the secretion of
the first and the second individual suture line. Only the latter,
Fig. 19. Median dorsoventral sections through the initial shells of Gonia-
tites (Paragoniatites) newsomi Smith from the Mississippian (a), and
Polyptychites sp. from the Lower Cretaceous (&). (After Schindewolf
1939a.)
232 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
our primary suture, is a genuine suture line in the usual sense.
A similar difference, like that between the prosuture and the
primary suture, is also expressed in the shape of the two respec-
tive septa. This may be illustrated by the two median dorso-
ventral sections in Figures 19a and b. In Goniatites newsomi
(Fig. 19a) the proseptum delimiting the protoconch differs from
the second septum by (1) its greater thickness, (2) its concave
instead of convex curvature, and (3) above all by the shape of
the ventral part of the septum, which is represented by a minute
dent of the shell wall only. The second septum, however, in its
ventral part is well developed and bears a hammer-like siphonal
funnel of exactly the same nature as in the following septa.
There is thus a distinct break between the first and the second
septum, whereas the latter is closely connected morphologically
with the following ones. The only difference is the adoral spur
at the dorsal side of the siphonal funnel in contrast to the retro-
fleeted funnels of the next following septa. It may be due to
the lack of room ; a backward extension of the siphonal funnel
is prevented by the immediate neighbourhood of the proseptum.
Polyptychites (Fig. 19b) from the Lower Cretaceous exhibits a
similar profound difference between the first septum and the
second septum. Further median sections of goniatites, ceratites,
and ammonites, all showing the same phenomena, have been
figured by Schindewolf (1939a and 1942).
I cannot agree, therefore, with J. C. A. Bohmers (1936), who
assumes two prosepta which are said to be different from the re-
maining septa. It may be that in some cases the second septum
shows a somewhat intermediate character between the first and
the third. The main break, however, seems to occur from the
first to the second septum, thus coinciding with the differences
between the prosuture and the primary suture.
PARTITION OF LOBES
Besides the two main trends in the formation of suture line,
by subdivision of saddles, there are still several other modes of
minor importance. It is not our intention to describe all the
different processes forming median saddles, the so-called " statur-
al'' lobes, which could be translated as seam-lobes, or the strange
anomalies to be observed in the insertion of umbilical lobes in a
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
233
u
f
Fig. 20. Development of suture line of Marathonites dieneri Smith from
the Lower Permian. (Adapted from Schindewolf 1939b.)
234 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
certain group of Jurassic ammonoids. But one more process should
be mentioned and that is the partition of lobes. It is much rarer
than the subdivision of saddles and is subordinate to it insofar
as it occurs on the platform of the one or the other of the main
types in the elaboration of suture line. Nevertheless, it is very-
characteristic for several distinct groups of ammonoids, as for
instance the Agathiceratidae and Popanoceratidae among the
Paleozoic forms, the genera Metaplacenticeras and Coilopoceras
in ammonites.
In these forms one or several lobes are affected by the sub-
division. From the base of these lobes two saddles rise and split
up the original lobe into three components, which with growing
saddles appear as independent lobes. But of course they are not
autonomous lobes in the sense of the independent lobes newlj
inserted by subdivision of saddles. They are only parts of pre-
existing lobes and are to be marked as such.
This kind of development has been studied in detail by myself
in the genus Marathonites (Schindewolf 1931, 1939b). Since it
and the popanoceratids are on the whole derivatives of the main
goniatite group with the A-type of suture line, I assume now
that Marathonites also will follow this type. The earliest ob-
served stage of development (the primary suture unfortunately
is not accessible) then is to be interpreted as noted in Figure
20a. Concerning the number and position of lobes it corresponds
to the suture lines of Imitoceras (Fig. 10), Reticuloceras (Fig.
7), Anthracoceras (Fig. 9), and other Carboniferous genera. All
the lobes are still undivided ; only the median saddle in the ex-
ternal lobe makes its first appearance.
In the stage of Figure 20b the adventitious lobe A has become
trifurcated and shows a development as in the permanent suture
of Proshumardites. In the following ontogenetic steps (Fig.
20c-/) the saddles in the lobe are growing higher and the dorsal
element is divided once more into two parts by a saddle rising
from its base. So in the suture of Figure 20g, the adventitious
lobe is represented by a large complex consisting of four ap-
parently independent lobes. In a similar manner the umbilical
lobe and a little later also the lateral lobe is split up into a series
of components. In the umbilical lobe it is, however, the ventral
of the three elements that is bifurcated once more in the same
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 235
way as the dorsal one of the adventitious and the lateral lobes.
The adult suture of Marathonites and of the other popanocera-
tids thus contains only five lobes, though it is composed of a
large number of elements. It is self-evident that in terminology
of lobes this type of development must be distinguished from
the mode of subdividing the saddles.
THE SUTURE LINE OP SPIROCERAS
In conclusion, I wish to demonstrate a unique, strange case
which I recently analyzed and which furthermore may prove
the necessity of carefully studying the development of suture
line. It concerns the criocone genus Spiroceras of the Middle
Jurassic. The mature suture line (Fig. 14a") is strongly reduced.
It seems to contain only three lobes. Besides the ventral and
the dorsal lobes there is only one definite lobe which, without
knowledge of its development, would be identified with the lateral
lobe. Each of the two saddles between these lobes bears in its
apex a somewhat deeper indentation. They have been interpreted
either as mere crinkles or as reduced lobes, as an adventitious or
an umbilical lobe, respectively.
The development of suture line, however, proves that each of
these interpretations is absolutely erroneous. The primary suture
of Spiroceras (Fig. 14a) agrees completely with that of the
other Jurassic and Cretaceous ammonites (Fig. 13a). It is com-
posed of the elements I, Ui, U2, L, and E. They show the same
position and relative size as usual. In the course of development,
however, the porportions are profoundly changed. The initially
very shallow lobe U2 quickly becomes deeper and larger, whereas
the neighbouring lobes are gradually reduced in size. The large
lobe of the adult suture, supposed to be the lateral, is thus in
reality the accelerated lobe U2, while the two insignificant
crinkles are to be homologized with the lateral and the first
umbilical lobe !
This is a very surprising result, which by no means could have
been deduced from the adult suture line. It corroborates our
thesis that a scrupulous study of ontogeny is necessary for a
consistent interpretation of suture line. Only in this way can the
true homologies of lobes be recognized and distinguished from
mere analogies. If such investigations could be done in all crucial
236 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
cases, the suture line would prove still more valuable for reveal-
ing the natural relationship of ammonoids than is the case today.
REFERENCES
BOHMERS, J. C. A.
1936. Bau und Struktur von Schale und Sipho bei permischen Am-
monoidea. Diss. Univ. Amsterdam, 125 pp., 2 pis.
Erbbn, H. K.
1953. Goniatitacea (Ceph.) aus dem Unterdevon und dem unteren
Mitteldevon. Neues Jahrb. Geol. Palaontol., Abh., vol. 98, pp.
175-225, pis. 17-19.
Hyatt, A.
1883- Genera of fossil cephalopoda. Proc. Boston Soc. Natur. Hist.,
1884. vol. 22, pp. 253-338.
Karpinsky, A.
1896. Sur 1 'existence du genre Prolecanit.es en Asie et sur son de-
veloppement. Bull. Acad. imp. Sci. St.-Petersbourg, ser. 5, vol.
4, pp. 179-194.
NOETLING, F.
1905. Untersuchungen iiber den Bau der Lobenlinie von Pseudosage-
ceras multilobatum NOETLING. Palseontographica, vol. 51, pp.
155-260, pis. 19-27.
1906. Die Entwickelung von Indoceras baluchistanfinse NOETLING.
Ein Beitrag zur Ontogenie der Ammoniten. Geol. u. palaeontol.
Abh., n.ser., vol. 8, pp. 1-96, pis. 1-7.
Peena, E.
1914. Die Ammoneen des oberen Neodevon vom Ostabhang des Siid-
urals. Mem. Com. geol. St.-Petersbourg, n. ser., vol. 99, 114 pp.,
4 pis.
SCHINDKWOLF, O. H.
1928. Zur Terminologie der Lobenlinie. Palaeontol. Zeitschr., vol. 9,
pp. 181-186.
1929. Vergleichende Studien zur Phylogenie, Morphogenie und Termi-
nologie der Ammoneenlobenlinie. Abh. preuss. geol. Landesanst.,
n.ser., vol. 115, 102 pp., 1 pi.
1931. Uber den Ammoniten-Sipho. Sitz.-Ber. preuss. geol. Landesanst.,
vol. 6, pp. 197-209, pi. 5.
1932. Zur Stammesgesehichte der Ammoneen. Palaeontol. Zeitschr.,
vol. 14, pp. 164-181.
1933. Vergleichende Morphologie und Phylogenie der Anfangskam-
mern tetrabranchiater Cephalopoden. Eine Studie iiber Herkunft,
Stammesentwicklung und System der niederen Ammoneen. Abh.
preuss. geol. Landesanst. n.ser., vol. 148, 115 pp., 4 pis.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 237
1934. Tiber eine oberdevonische Ammoneen -Fauna aus den Rocky
Mountains. Neues Jahrb. Mineral., etc., Beil.-Bd., ser. B, vol. 72,
pp. 331-350.
1935. Zur Stammesgesehiehte der Cephalopoden. Jahrb. preuss. geol.
Landesanst, vol. 55 (1934), pp. 258-283, pis. 19-22.
1939a. Tiber den Bau karbonischer Goniatiten. Palaeontol. Zeitschr.,
vol. 21, pp. 42-67, pi. 4.
1939b. Zur Kenntnis von Pericleites RENZ und verwandter palaozoia-
cher Ammoneen. Jahrb. preuss. geol. Landesanst., vol. 59 (1938),
pp. 423-455.
1942. Evolution im Lichte der Palaontologie. Bilder aus der Stam-
mesentwicklung der Cephalopoden. Jenaische Zeitschr. Med. u.
Naturw., vol. 75, pp. 324-386.
1951. Zur Morphogenie und Terminologie der Ammoneen Lobenlinie.
Palaontol. Zeitschr., vol. 25, pp. 11-34, pi. 1.
1953. Tiber Strenoqeras und andere Dogger-Ammoniten. Neues Jahrb.
Geol. Palaontol., Monatsh., 1953, pp. 119-130.
1954. Tiber die Lobenlinie der Ammonoideen. Neues Jahrb. Geol.
Palaontol., Monatsh., 1954 (in press).
Spath, L. F.
1933. The evolution of the Cephalopoda. Biol. Reviews, vol. 8, pp.
418-462.
1936. The phylogeny of the Cephalopoda. Palaeontol. Zeitschr., vol.
18, pp. 156-181, pi. 9.
Whdhktktd, R.
1913a. Beitrage zur Kenntnis des Oberdevon am Nordrande des Rhein-
ischen Gebirges. 2. Zur Kenntnis der Prolobitiden. Neues Jahrbl
Mineral., etc., 1913, vol. 1, pp. 78-95, pi. 8.
1913 b. Die Goniatitenkalke des unteren Oberdevon von Martenberg bed
Adorf. Sitz-Ber. Ges. naturf. Freunde Berlin, 1913, pp. 23-77,
pis. 4-7.
1916. Tiber Lobus, Suturallobus und Inzision. Centralbl. Mineral., etc.,
1916, pp. 185-195.
1918. Die Genera der Palaeoammonoidea (Goniatiten). Palaeonto-
graphica, vol. 62, pp. 85-184, pis. 14-22.
Bulletin of the Museum oi Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
IX. M acroevolution and the Problem of Missing Links
By Alexander Petrunkevitch
Yale University, New Haven, Conn.
The problem of missing links had its inception in Darwin's
theory of evolution. As soon as his Origin of Species by Means
of Natural Selection was published, it was generally assumed
that if this theory is correct then there must be an unbroken
chain of connecting links between living animals and their fossil
ancestors. Because of the direct bearing of the theory on the
question of the origin of man, the search for missing links was
taken up by anthropologists, paleontologists and zoologists. It
has continued unabated for almost a century and presumably
will continue to occupy our attention for many years to come.
However, with the universal acquiescence in the idea that all
species of plants and animals, man included, are the product
of evolution and not of creation, the problem of missing links
assumed an aspect different from its original one which concerned
the proof of evolution as against special creation. At present
evolution is an accepted fact. What remains in dispute is only
the method of evolution. On the answer to this question there
is considerable disagreement. Opinions differ not only about the
ancestry of various categories of animals, but also about the
probability of the eventual discovery of now missing connecting
links, as well as about the possibility or impossibility of explain-
ing the origin of larger categories by a process of speciation as
attempted by Darwin. The reason for such disagreement lies not
in insufficiency of evidence, but in the undeniable fact that, with
the exception of observations made in breeding experiments, all
evidence relating to ancestry is of an indirect nature. As such,
it is subject to doubt, error and different interpretation.
The truth of this statement becomes immediately apparent
when one considers the question of the relationship between the
coelenterates and the flat-worms. Basing their opinion on an
analysis of extensive data gradually accumulated during more
240 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
than a century of careful research, the majority of zoologists
derive the flat-worms from the coelenterates, especially from
the ctenophores or comb- jellyfish which they resemble in many
respects. The greater complexity of organization of flat-worms
is generally explained by progressive evolution and by the
formation of new characters better adapted to crawling. On
the other hand, the Yugoslavian zoologist Hadzi (1953), using
the same data, derives the coelenterates from the flat-worms. He
explains the origin and the greater simplicity of structure of the
former as a result of regressive evolution. According to his
theory, rhabdocoele Turbellaria gave up their mode of life as
crawling animals, became sessile and gradually lost all structures
which were now useless to them. At the same time they acquired
a new plan of structure, becoming radially symmetrical out of
originally bilateral animals. Developing his theory to its logical
end, Hadzi reverses the current idea of the evolution of coelen-
terates also within that group itself. He considers the Anthozoa
to be the oldest group which developed first and then produced
the Scyphozoa and finally the Hydrozoa. According to his in-
terpretation, the latter represent the acme of regressive evolution.
The ctenophores Hadzi derives from another class of flatworms,
namely the Polyclada.
Hadzi 's ideas cannot be dismissed lightly. The fact that they
are diametrically opposed to the ideas promulgated by other
zoologists is not caused by insufficiency of knowledge or by faulty
logic. In the absence of direct evidence which could be furnished
only by breeding, both his and his opponents' ideas are based
entirely on similarities of structure. Such similarities can be
arranged in a series of either increasing or diminishing complex-
ity of organization. The controversy could be settled, but even
then only partially, by paleontological evidence. If it were pos-
sible to show that one of these groups of animals appeared at
an earlier geological period, then the later group could not pos-
sibly be the ancestral one. But this would be insufficient as proof
of the correctness of the opposite contention, namely that the
older group produced the younger one. There is another possi-
bility, besides that of direct descent, that can account for the
existence of similar structures in groups otherwise differing in
many ways. It is the simple assumption that both groups are
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 241
descendants of the same ancestral stock, but that their relation-
ship to each other is that of "cousins" and not of parents and
children. "We are all familiar with such cases when animals origi-
nally considered to be direct ancestors were later demoted to
the status of more or less distant relatives representing branches
of a common ancestral stem. This applies not only to larger and
smaller categories of animals, but also to closely related genera
as exemplified by the history of the derivation of man from
anthropoid apes.
Leaving out of consideration the direction of evolution, i.e.,
the question as to whether in a given case we have to do with
progressive or regressive changes, the strength of an argument in
favor of direct ancestral relationship grows with the increase
of similarities in number and in degree. If speciation is assumed
to be the only method of evolution, operating since the appear-
ance of animal life on earth, then it should not be difficult to
find connecting links between species possessing the greatest
number of similar structures and the greatest degree of simi-
larity. The theory demands that new species be produced by
old species and in that way produce new genera ; or better, that
new species become eventually so different from their parental
ancestors that the erection of a new genus for their reception
becomes necessary; that some of the new genera produced by
speciation require the erection of new families and so on until
through the same process of continued speciation new orders,
classes and phyla are produced. Let us assume for the sake of
simplicity that a new species can be produced through the trans-
formation of a population owing to the gradual spread of a
single new mutation — the extinction of the parent species and
the survival of the new species being the result of natural selec-
tion. With the exception of special cases, the number of deaths
corresponds to the size of a population regardless of its com-
position, decreasing or increasing with the population. On the
other hand, the number of fossils is always much smaller than the
number of individuals which die, because the majority of the
bodies disintegrate before they can become fossilized. Conse-
quently fossils represent only a random sample of a living
population. If that population consists of a much greater num-
ber of individuals of the parental type with the characters of
242 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the original species than of individuals with modified characters,
as one would expect to be the case at the beginning of speciation,
then all fossils of that generation may be entirely of the original,
parental type, because the ratio between living and fossilized
individuals is so great that the chance of mutants becoming
fossilized is greatly reduced and approximates zero. But when in
the course of time and owing to the survival of the fittest, the
mutants have reached the point at which their number in the
living populaion is equal to that of the parental type, i.e., when
the population consists of 50 per cent of the old type and 50
per cent of the mutant type, then each random sample of the
population will also contain the same proportion of both types.
Environmental conditions and chances of fertilization being the
same for both types, both should be represented by an equal num-
ber of fossils. From now on, with an increase of mutants over
old types, fossils should also show an increasing number of
mutants. The number of fossils of the old type will now grow
smaller and smaller until their complete disappearance at an
earlier date than the actual extinction of the living species. Thus
for the total span of time required for the production of a new
species the number of fossils of the parental type should be the
same as that of the mutant type. In other words, connecting
links between any two species standing in a direct relationship
of ancestor and descendant should be as common as the two
species themselves. If, as Darwin's theory assumes, all higher
categories of classification have been produced by speciation of
the kind with which we are now familiar (owing to the extensive
work of geneticists), then the ratio of connecting links between
all higher categories should also be the same as between species all
the way back to the first appearance of fossils in the strata of
the earth, forming an unbroken chain between them. There
should be no missing links at all except in cases of animals whose
fossilization is either impossible on account of the softness of
their body, causing its rapid decay, or is indeed so rare for the
same reason, that if such fossils were ever found it would be
impossible to decide whether they represent the typical or the
mutant type.
The above analysis is correct only on the assumption that
speciation is a continuous process. That mutation is a constant
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 243
process is generally accepted today. Thus Dobzhansky (1951)
says on page 73, "The mutation process constantly and unremit-
tingly generates new hereditary variants — gene mutations and
chromosomal changes." But if it could be shown that in each
line of evolution there are long periods of rest between periods
of speciation, intervals during which newly produced species con-
tinue their existence as such and no new mutations or heritable
changes of any kind are produced, then, of course, the ratio
between typical and mutant fossils would be considerably greater.
It would depend on and reflect the duration of each pause. But
the greater ratio would apply only to the total number of
fossils during the combined periods of pause and speciation.
The ratio for the latter alone would still remain the same, only
the horizon containing the fossils of both types would be re-
duced to a thinner layer corresponding to the time between the
beginning of speciation and the extinction of the parental species.
In cases of common species there should be no difficulty in finding
connecting links.
The existence of such pauses was assumed by de Vries, the
creator of the mutation theory (1901). In his address before
the society of German naturalists and physicians he considered
the average duration of each interval between the periods of mu-
tation to be no less than 4000 years. Accepting the then current
idea that the age of life on earth amounted to 24,000,000 years,
de Vries arrived at the conclusion that 6000 mutations sufficed
to complete the evolution of now living phanerogams from their
unicellular ancestors to the present state of their organization,
(de Vries, 1901, p. 63). Although the total time allotted to the
existence of life on earth has been greatly increased since de
Vries 's time, owing to new methods of measurement devised by
students of radioactivity, its span seems still to be much too small
to account for the evolution of all animals by the slow process of
speciation. Species are not produced suddenly, by a single muta-
tion. Even with the selection intensity equal to 0.5, it requires
30 generations to bring a mutation frequency to 100 per cent
(Lerner, 1950). The time required for the production of a new
species varies considerably. But with the exception of special
cases, speciation is much slower. Haldane, in his controversy with
Lunn (1935, p. 164), admits that "selection is the only agency
244 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
which can lead to important changes within times measured in
millions of generations." Simpson (1944, p. 69), in discussing
the classical case of the evolution of the horse, writes : ' ' In larger
populations dominated by selection, a million years may not
suffice to introduce a new species and relatively seldom suffices
for evolution of generic rank. Note the previous estimate that
the actively and progressively evolving tertiary horses took on an
average 8,000,000 years for evolution from one genus to the
next." If we put the average time for the production of a
vertebrate species at only 500,000 years, and regard the process
of evolution as being continuous, it would have to be completed
from fish to man within only about 625 steps from one species to
another. If we accept intervals between speciation equal to the
time required for speciation, we would have to accept that only
312 species-transformations separate man from fish.
But the slow tempo of speciation is not the only reason for
my belief that the evolution of the higher categories of animals
could not have been accomplished by speciation. If it depended
entirely on speciation, then formation of new species either by
production of new characters or by modification or loss of old
species characters would be insufficient for achieving the evolu-
tion of higher categories. To do this, every animal of whatever
phylum, class, order or family would have to be first completely
dedifferentiated to the state of organization of the ancestor of the
corresponding category. Production of new characters required
for the establishment of a new phylum by speciation is a step
toward complication of organization, not toward its simplifica-
tion. Nobody could maintain that our ancestors were more
complexly built than we are. To be sure, we are familiar with
numerous cases of regressive evolution leading to secondary
simplification of structure, due to various causes, such as para-
sitism, loss of locomotion with adaptation to sessile existence,
etc., but such dedifferentiation is not identical with that which
is prerequisite for the evolution of a new phylum or class. A
creature like the parasitic cirripede Sacculina or the parasitic
copepod Lernaea (the adult females of which have no resemblance
whatsoever to other, free living species of Crustacea because in
the course of development their organization becomes reduced to
nothing but reproductive glands and nutritive tubes), would still
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 245
have to return to the state not of their own nauplius which can-
not reproduce, but to that of their ancestor which still could
not only reproduce and develop into an adult of its own species,
but which was so primitive that it still possessed the potential
ability of developing into a new order of Entomostraca. If that
ancestor of Entomostraca were to engage in the evolution of a
phylum other than that of Arthropoda, to which it belongs, then
it would have to dedifferentiate further yet to the state of the
ancestor which still possessed the potential ability to start the
evolution of any other phylum, including even the vertebrates.
The necessity of dedifferentiation of this kind before a species
can resume creative speciation in a new line may be called the
law of precession. It involves the formation of a chain of regres-
sive links in addition to that of progressive links. Of course,
nobody imagines that a Recent primate, carnivore or monotreme
could ever start evolving a new phylum, because all Recent mam-
mals are so complex that one could not expect fundamental
changes in their anatomical structure, but attempts are still
made to derive vertebrates from various groups of invertebrates,
arthropods from annelids, and practically all classes of arth-
ropods from trilobites. If phylogeny through speciation were
possible, then the law of precession would have to be taken into
account, the time required for the evolution of the animal king-
dom would have to be extended to include the time required for
dedifferentiation. There should be a chain of transitional links
similar to that of progressive evolution, but reversed in the order
of sequence and representing the steps of regressive evolution,
preceding and prerequisite for each start on a new line of pro-
gressive evolution.
It is well known that not only species, but genera and even
families present transitional characters, while orders, classes and
phyla are sharply delimited. There are no transitions between
scorpions and spiders, between beetles and butterflies, between
fairy-shrimps and daphnids; there is none between Crustacea,
Arachnida and Hexapoda ; between Arthropoda and Echinoder-
mata and so on. Some striking resemblances exist, but they are
only external resemblances. Some cockroaches look like beetles,
but are in every other way typical cockroaches. A Carboniferous
arachnid of the order Ricinulei resembles some beetles to such
246 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
an extent that its discoverer Buckland actually mistook it for a
beetle and gave it the generic name Curculioides, Curculio being
a well known genus of beetles. But Curculioides was soon proven
to have all the characteristic structures of an arachnid, which
could not possibly be confused with the characteristic structures
of beetles. Nor can resemblances between so-called homologous
structures be regarded as evidence of close relationship and used
as examples of connecting links. This lamentable overestimation
of their value is still broadly in vogue. Invertebrate zoologists
and paleontologists cling tenaciously to the old concept of homol-
ogy as defined by Owen. In the case of arthropods they regard
as sufficient evidence of homology the presence of even widely
dissimilar appendages on the same segment of the body, counted
in an early embryonic stage from its anterior end backward.
Vertebrate anatomists, beginning with Owen himself, did not
use this method because of the fluctuation in the number of
cervical vertebrae in birds, but never doubted the homology of
such structures as the foreleg on a mammal and the wing of a
bird. The segmentation of the arthropod head is still a subject
of controversy. While we may safely homologize the segmenta-
tion of an insect leg with that of an arachnid leg, although they
may not belong to the same body segment, we may not do this
so easily when comparing the arachnid chelicerae with the crusta-
cean second antennae even though they are regarded as belonging
to the same cephalic segment. The fact is that under the influence
of experimental zoology the concepts of homology and analogy
have undergone considerable change and the very distinction
between them is now not simple to define. This is further compli-
cated by the phenomena of so-called homomorphism (Novikoff,
1953), the existence of similar organs in unrelated classes of ani-
mals, and by cases of accidental and experimental development
of eyes and of appendages on segments of the body to which they
do not normally belong. All this and similar facts make the
use of "homologous" organs as an argument in favor of direct
ancestry or even of close relationship, not nearly as convincing
as it was thought to be some time ago. They are suggestive of
some relationship, but by no means a proof of it. We have to
admit and to face the fact that such connecting links representing
gradual transition from one phylum to another, from one class
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 247
to another and from one order to another do not exist in in-
vertebrates. Vertebrate anatomists seek to prove that such tran-
sitions exist between the classes of vertebrates. They derive the
higher classes of vertebrates from fishes on the basis of struc-
tural evidence. But even if such transitions among vertebrates
can be demonstrated, there may be some other explanation for
their existence than that offered by evolution through speciation
— an explanation which would bring them in line with the in-
vertebrates.
It seems clear that if we are to solve the problem of evolution
within the available geological time, we must either admit the
possibility of a much greater speed of speciation or restrict the
scope of speciation and accept the existence of another mode of
evolution in the case of the higher categories. The speed of selec-
tion is undoubtedly correlated with the speed of reproduction.
Other factors are known which also have a bearing on the speed
of speciation. But the paleontological evidence is rather in favor
of slow speciation, while the evolution of higher categories often
showrs a remarkably higher speed. Moreover, evolution by specia-
tion offers no other answer for the lack of connecting links be-
tween higher categories, except the lame one of the extreme rarity
of such fossils. On the other hand, an answer involving the as-
sumption of another mode of evolution was given several times,
although its bearing on the problem of missing links seems to have
been overlooked. Goldschmidt (1933, 1940) called this mode
macroevolution ; Lunn (1935) spoke of it as major evolution;
Simpson (1944) referred to it as megaevolution. In view of the
objections raised by geneticists, zoologists and paleontologists to
the existence of another mode of evolution differing from that of
speciation, we must first consider wherein phylogeny differs from
ontogeny besides the already mentioned lack of connecting links,
and then show why macroevolution gives an answer to the above
questions.
When one considers the development of any animal, one is
forced to regard the regularity of the process as something much
more striking than its casual and slight irregularities, as if the
development followed a predetermined design. The sequence of
the stages of development is fixed, some following one upon the
other, some beginning at the same time and either running
248 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
synchronously to completion or if asynchronously, yet at a pre-
determined rate and time required for completion. If ever a
deviation of the development from its prescribed course takes
place, it is either corrected by the intervention of regulatory
forces or else leads to the formation of monstrosities or even
causes the death of the embryo. In closely related species out-
ward differences in development appear only toward maturity,
even though microscopic study and breeding reveal differences
in the egg. The less two animals are related to each other, the
earlier some differences in their embryonic development appear.
In species belonging to different families, differences may appear
shortly after the appearance of the first rudiments of organs ; in
different orders — even shortly after gastrulation. It is now
known that all such changes are the result of corresponding,
invisible changes in the genes either through mutation, recom-
bination or loss. This knowledge is relatively recent and did not
exist in the past century. When Ernst Haeckel (1866) proposed
his Biogenetic Law according to which ontogeny is an abbreviated
recapitulation of phylogeny, he conceived it on the evidence of
the regularity of development and of striking similarities between
early embryos of distantly related species, as had been pointed
out even earlier by von Baer. Haeckel (1877) further elaborated
his theory by postulating the existence of a hypothetical ancestor
of all metazoa. He imagined that it was a free-living, marine
animal having the simple structure of a gastrula and proposed
for it the name Gastraea. Haeckel 's theory attracted a number
of enthusiastic supporters, but was later attacked from all sides
and almost discarded as a fanciful speculation. Some of Haeckel's
examples were indeed fanciful and the objections to them are
valid and remain in force. Other objections require careful re-
examination. It was pointed out, for example, that the de-
velopment of Recent animals takes place along narrow lines
which are similar in only closely related groups, but differ widely
in the case of different phyla; that free-living animals morpho-
logically similar to the later embryonic stages do not exist; that
the gastrula stage can be easily explained as a result of special
mechanical and physiological requirements of growth and nour-
ishment ; that free-living larvae with the structure of a gastrula,
such as the pluteus, bipinnaria, auricularia, tornaria, trocho-
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 249
shaera, veliger, etc., are as highly specialized as the corresponding
adults and therefore cannot be used as evidence of relationship
or, as Yves Delage (1898, p. 331) puts it in discussing the origin
of Prochordata, that they represent at best a very distant rela-
tionship of the Prochordata to the Echinodermata, as if the
latter were separated from the ancestors of the former consider-
ably before these acquired their distinctive characteristics.
After serious examination of the value of these objections on
the basis of evidence adduced by others and that assembled by
myself in the course of long study of arthropods and especially
of arachnids, I have come to the conclusion that most of the
objections are wrong because of a literal interpretation of
Haeckel's Biogenetic Law which, when properly interpreted in
the light of modern knowledge, is perfectly sound and universal
in its application. The objection that no living or fossil animal
has the structure of the hypothetical gastraea endowed with the
ability of self-perpetuation is quite correct as far as it goes,
but it is also true that if it ever existed in the past, a fossilized
gastraea, on account of its small size and perishable constitution
would be not only much rarer than even a fossilized medusa,
but also would be much more difficult to find, unless preserved
in something like the Old Red Sandstone of Rhynie Chert and
handled in a similar way, i.e., in thin sections through the rock,
and studied with the aid of a microscope under high power.
It is quite true that free-living larvae having the structure of
a gastrula are all specifically distinct and that the invagination
of the blastoderm, leading to the formation of a gastrula can
be explained as a response to physico-chemical stimuli, but such
an explanation does not take into account the genetic composi-
tion of the hereditary apparatus of the nuclei. The fact that
pressure on the elastic wall of a thin rubber balloon may produce
an invagination similar to that produced by gastrulation does
not prove that pressure is the only requirement in both cases.
All attempts to explain even such a simple phenomenon as loco-
motion on the basis of simple physical laws have broken down
completely unless the voluntary element is taken into account.
The free-living larvae of Echinodermata, Annelida, Mollusca,
etc., are indeed specifically distinct, showing modifications of
both the adaptive and the passive type, but their possession of
250 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
specific characters does not change the fact that they all have
the same basic structure of a gastrula. The objection that there
never have been any free-living animals comparable to the later
embryonic stages is not only true in this respect, but far from
being a refutation is, on the contrary, a direct confirmation of
the Biogenetic Law, because it is quite true that beyond the
gastrula stage the development of any animal species repeats
the development of its ancestors and is thus a recapitulation of
its own line of descent. A species of Drosophila does not repeat
in its ontogenetic development the evolution of a starfish or an
octopus. It repeats only its own evolution. It follows the de-
velopment of an arthropod through the stage of a gastrula to
the point at which that arthropod ancestor became an insect,
then the development of that insect ancestor to the point when
it became a fly and finally the development of the fly ancestor
through the stage of the Drosophila ancestor to the stage of the
particular species under observation. Anything else is impos-
sible and unthinkable, because it would contradict every principle
of genetics. A deviation from this rule is possible only when
some change in the genetic composition has taken place or some
subsequent injury has interfered with normal development.
The objection of geneticists to a mode of evolution different
from that of speciation (based on the assumption that changes
of the magnitude of macroevolutionary ones would be so rare
and so disadvantageous that they would be eliminated by selec-
tion or would be lethal from the start), is as unsupported by
evidence as the assertion that if they were viable we would meet
with such changes either in nature or in the laboratory. Both
objections are based on observations of living animals, apply
only to speciation, and are gratuitous when applied to macro-
evolution which took place in past geological eras. Highly dis-
advantageous non-heritable monstrosities of various kinds do
not necessarily cause premature death, nor prevent monsters
from giving birth to normal children. The celebrated Siamese
twins, Cheng and Eng, married two sisters in America, had 22
children by them and died in 1874 at the ripe age of 62 years,
one a few hours after the other, because they could not be sepa-
rated from each other surgically. Human monsters with two
heads, two chests and four arms, but a single pelvis and a single
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 251
pair of legs have been observed several times. One of the most
celebrated cases of this type came to the notice of King James
IV of Scotland, who took the twin monsters under his protection
and gave them an education. They lived 22 years (Martin,
1880). Monsters among invertebrates are not uncommon. One
finds them in medusae, in worms, in starfishes, in molluscs, in
arthropods. Many of them become sexually mature and repro-
duce. Under my own observation a female Cynthia moth with
rudimentary wings copulated with a normal male and laid a
normal batch of fertilized eggs. I have caught, in Saxony, a
male beetle Prionus coriarius copulating with a normal female.
The male had deformed elytra and lacked one leg. In Panama
I watched a male spider Nephila clavipes copulating with a
normal female. He lacked three of his legs and was of small size,
while in the same web were several normal males of larger size.
If one wished to list all monsters which lived to mature age one
could write a whole book about them. But "hopeful monsters"
of macroevolution, a humorous term proposed by Goldschmidt
to emphasize their ability to survive, are not even real monsters.
They differ from non-heritable monsters in that the changes
which produce them involve only fundamental structural charac-
ters, which are not necessarily a handicap and may have been
even of advantage. These changes also differ from those produced
in speciation by their magnitude and suddenness. Moreover they
are restrictive in eliminating other changes of a similar nature
in their own line of evolution and are therefore directive as
pointed out by various writers. And in addition, evidence of
their existence and of their independence from speciation is
abundant, as may be seen in arachnids, at least in so far as the
formation of suborders and families is concerned. I have dis-
cussed the evolution of Arachnida in former contributions to
our knowledge of their geological past, and of the principles
which should govern the natural classification of that class. Here
I want only to point out by the example of scorpions the
difference between macroevolutionary and microevolutionary
changes, and the fact that both are plainly preserved in fossil
material. The macroevolutionary change on which I based the
classification of Carboniferous scorpions involves the loss of
thoracic sternites and the shifting into the place vacated by
252 BULLETIN : MUSEUM OF COMPAEATTVE ZOOLOGY
1 2 3
rl «""
<* j
k-
0
('
0
1(-
*)/
OPISTHACANTHUS
(RECENT)
i sobuth us
(carboniferous)
PALAEOBUTHUS
(PENNSYLVAN IAN)
Fig. 1. The ventral surface of Opisthacanthus elatus (Gervais), a Recent
scorpion of the family Scorpionidae. The arrangement of its coxae is the
same as in the fossil family Eoscorpionidae.
Fig. 2. The ventral surface of Palaeoluthus distinctus Petrunkevitch, a
Pennsylvanian scorpion of the family Isobuthidae. The arrangement of its
coxa? is the same as in Isobuthus, but the posterior edge of its abdominal
sternites is straight as in Opisthacanthus.
Fig. 3. The ventral surface of Isobuthus Tcralupensis (Th. and L.), a
Carboniferous scorpion of the family Isobuthidae.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 253
EOSCORPIUS 5 ISOBUTHUS
(PEN N SYLVAN I an)
(CARBON I FE ROUS)
HORMURUS 7 MICROLABIS
(RECENT) (carboniferous)
Fig. 4. The sterno-coxal region of Eoscorpius typicus Petrunkevitch, a
Pennsylvanian scorpion of the family Eoscorpionidae. Notice that the
arrangement of its coxae is the same as in the Recent Hormurus, while the
structure of the combs resembles that of Isobutlius.
Fig. 5. Isobutlius rakovnicensis Fritsch, a Carboniferous scorpion of the
family Isobuthiclae. Notice that its disposition of coxae is the same as that
of Hicrolabis, but its combs resemble those of Eoscorpius.
Fig. 6. The sterno coxal region of Hormurus australasiae Fabricius, a
Recent scorpion of the family Scorpionidae. Notice that the disposition of
its coxae is the same as in Eoscorpius, while its combs resemble those of
Micro labis.
Fig. 7. Microlabis sternbergii (Corda), a Carboniferous scorpion of the
family Isobuthidae. Notice that the disposition of its coxae is the same as
that of Isobutlius, while its combs resemble those of Hormurus. Abbrevia-
tions: C\, C2, Cz, d, coxa of leg 1, 2, 3 and 4; GO, genital opercula; -ST,
sternum.
254 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
them of the second and third abdominal embryonic sternites
represented in the adult by the genital opercula and the median
piece of the combs. This change (Figs. 1-7) is possible in several
different combinations, all of which are represented in the fossil
material, but only two of which are shown in the figures and
only one of which survived and produced all Kecent scorpions
(Figs. 1, 4, 6). This is not the extreme modification. Yet all
extinct modifications, even that of the original type in which
only the first sternite was lost, survived long enough to produce
other changes by speciation, namely the change in the shape
of the posterior edge of the abdominal sternites (Figs. 1-3), and
the change in the size and shape of the combs and in the number
of their teeth (Figs. 4-7). The straight posterior edge of ab-
dominal sternites is the original type found in all Recent scor-
pions without exception and in almost all fossil scorpions. It is
also found in the genus Palaeobuthus of the Family Isobuthidae
to which the other two genera, Isobuthus and Microldbis, also
belong. Isobuthus has bilobed sternites. In Microlabis the first
and second sternites have a small median indentation, while the
third sternite is clearly, though not deeply, bilobed. It seems to
be an "ornamental" change rather than anything else. The
combs are sense organs of unknown function, but being sense
organs, they probably represent "adaptive" speciation. Eoscor-
pius is a genus of the fossil family Eoscorpionidae from which
all Recent families may be derived. Hormurus is a genus of the
Recent family Scorpionidae. Figures 4 to 7 show similar, parallel
changes in two different families, changes consisting in a reduc-
tion of the number of teeth, and therefore independent of the
macroevolutionary changes which gave rise to different families.
In this connection I would like to point out that the chief
difference between macroevolutionary and microevolutionary
changes is not the magnitude of the change, but the nature of
the trend which produced it and the fact that no dedifferentia-
tion is required in the case of macroevolutionary changes. The
magnitude in itself is a very relative concept. All evolutionary
changes are of the saltatory, discontinuous type, even those
which appear to be gradual. Moreover, a change in the genetic
composition of chromosomes may produce an outwardly invisible
change of considerable importance, such as color blindness for
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 255
example, but it is a saltatory change, nevertheless. When a
series of small changes confronts us, we speak of them as gradual
or transitional. When a change is considerable enough to make
the difference glaring, we look for the missing connecting links,
not realizing that the change in itself is the connecting link be-
tween the parents with the original structure of their body and
the offspring with the modified structure. This connection can
be discovered only through a study of fundamental trends.
Macroevolution leaves no evidence of its operation other than
accomplished changes, nor any regressive links, for it is not
subject to the law of precession. But it offers an indirect evi-
dence of its existence by leaving unaffected all specific characters
in the branches of the same line, characters subject to independ-
ent speciation.
Oparin (1953) has shown how self -perpetuating, living sub-
stance of the nature of colloidal protein may have originated on
earth. He has also explained how the original substance may
have broken up into individual "droplets" and how these drop-
lets may have formed clusters by coacervation. He also pointed
out how such clusters may have become cellularized and thus
given rise to primitive animals. Being a biochemist, Oparin
left the problem of further evolution to zoologists and botanists.
Whether or not his outline of the origin of life is correct in every
detail, his approach to its solution is sound and we may accept
his hypothesis as far as the formation of clusters. Finding fur-
ther support in Haeckel's Biogenetic Law and in the principle
of macroevolution, we may now attempt to get some insight into
the phylogenetic evolution of animals. To begin with, instead
of deriving the Metazoa from this or that class of Protozoa, as
is usually done in phylogenetic trees, we may assume that in-
dividual "droplets" developed a somewhat different genetic
apparatus, remained single and produced the kingdom of Pro-
tista, while clusters cellularized and some of them became the
ancestors of the kingdom of plants, others changed into free-living
moreae with a structure resembling that of a morula and became
the ancestors of the kingdom of Metazoa. The next change must
have resulted in the transformation of the morea first into a
blastea and then into a gastraea, retaining the ability of asexual
self-perpetuation, presumably by transverse division comparable
256 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
to stabilization in the scyphostoma larva of the medusae. Such
a gastraea must have had the shape of an ellipsoid, a ciliated
ectoderm, a nutritive endoderm and a mouth at one end of its
longitudinal axis. As it still possessed the potentiality of eventu-
ally developing into any of the future phyla, this stage may be
properly called protogastraea. Its plan of symmetry must have
been radial and its asexual reproduction made it still "immortal"
in Weismann 's sense of this word as he applied it to the Protozoa.
Now some molecular change in the genetic apparatus must have
brought about a differentiation of the cells into reproductive
ones and somatic ones, restricting the "immortality", or as I
prefer to call it "the ability of self-perpetuation" to the repro-
ductive cells, while the soma became the protective carrier of
the reproductive cells, and the perishable residual of the organ-
ism. Before this change, competition between individual proto-
gastraeae was strictly intra-specific because there did not exist
as yet any other species of Metazoa. But now, owing to the
separation of the soma from the reproductive cells, a new type
of competition arose. Under the influence of this competition
the protogastraeae were changed into Metagastraeae with poten-
tialities now restricted to the production of individual phyla.
This macroevolutionary change which produced as many species
of metagastraea as the number of future phyla, did not need to
be synchronous in all cases. It may have occurred repeatedly as
long as protogastraeae survived. But the complexity of the
structure of animals found in the Cambrian makes it certain that
the separation into phyla had been completed before that era.
The difference between the various species of metagastraea at
that time may have been only intracellular, in the structure of
the genetic apparatus ; the outwardly visible specific differences
were probably developed by speciation at a later period. It would
be futile to speculate further as to how the present modes of
reproduction involving complicated life cycles were evolved,
because we have not enough evidence to do so. Such evidence
could be assembled only by extensive study of comparative em-
bryology and anatomy. For the present we may abide by the
assumption of an independent origin of all phyla from specifically
different metagastraeae, but all produced by the same type of
protogastraeae. But even resigning myself to this limitation, I
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 257
believe that the thoughts which I have presented here in brief
outline give us a much simpler picture of evolution, and are in
closer agreement with the fossil evidence and with the available
span of time that has passed since the first appearance of animal
life than does the theory of evolution by speciation.
REFERENCES
Beer, G. R. db
1951. Embryos and ancestors. Revised edition. Oxford University
Press.
Delage, Y., and E. Herouard
1898. Traite de zoologie concrete. Vol. VIII, Les Procordes. Paris.
DOBZHANSKY, T.
1951. Genetics and the origin of species. Columbia University Press.
New York. Third edition.
Garstang, W.
1922. The theory of recapitulation. Jour. Linn. Soc. London, Zoology,
vol. 35.
GOLDSCHMIDT, R. B.
1940. The material basis of evolution. Yale University Press.
1952. Evolution, as viewed by one geneticist. American Scientist,
vol. 40.
Haeckel, E.
1866. Generelle Morphologie der Organismen. Berlin.
1877. Biologische Studien: II Heft: Studien zur Gastrsea-Theorie.
Jena.
Hadzi, J.
1953. An attempt to reconstruct the system of animal classification.
Systematic Zoology, vol. 2, no. 4.
Lerner, M. M.
1950. Population genetics and animal improvement. Cambridge Univer-
sity Press.
Lunn, A., and J. B. S. Haldane
1935. Science and the supernatural. New York.
Martin, E.
1880. Histoire des Monstres depuis l'antiquite' jusqu'a nos jours.
Paris.
258 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
MAYR, E.
1942. Systematica and the origin of species. Columbia University
Press.
Mayr, E., E. G. Linslby and E. L. Usinger
1953. Methods and principles of systematic zoology. New York.
Novtkoff, M. M.
1953. Regularity of form in organisms. Systematic zoology, vol. 2,
no. 2.
Oparin, A. I.
1953. Origin of life. Translated by S. Morgulis. New York.
Petrunkevitch, A.
1952. Macroevolution and the fossil record of Arachnida. American
Scientist, vol. 40.
ScHINDEWOLF, O. H.
1950. Grundf ragen der Palaontologie. Stuttgart.
Simpson, G. G.
1944. Tempo and mode in evolution. Columbia University Press.
Stern, C.
1953. The geneticist 's analysis of material and the means of evolution.
Scientific Monthly, vol. LXXVII.
Vries, H. de
1901. Die Mutationen und die Mutationsperioden bei der Entstehung
der Arten. Leipzig.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1954
Status of Invertebrate Paleontology, 1953
X. Evolution of Late Paleozoic Invertebrates in Response to
Major Oscillations of Shallow Seas.
By Raymond C. Moore
University of Kansas, Lawrence, Kansas
INTRODUCTION
The Problem
Among the many factors which influence evolution of inverte-
brate organisms, particularly those of benthonic habitat in a
marine environment, are composite effects of broad oscillatory
movements of shallow seas.
When such seas transgress widely over portions of the conti-
nental shelf, areas available for occupancy by marine organisms
may be expanded vastly. During the enlargement of shallow
seas and for a time after maximum expansion has been attained,
competition for food and for a place of attachment is made
easier. Concurrently, the opening of new territory for habitation
by bottom-dwelling organisms may foster and then tend to stabi-
lize adaptive changes. This should operate in roughly the same
manner as alteration of human societies which has marked the
spread of white men throughout the North American continent.
Regression of a shallow sea introduces conditions opposite to
those of transgression. Inevitably it shrinks space (Lebensraum)
available to the shallow-water marine organisms. It causes
crowding, and increases competition to survive. If retreat of
the shallow sea is measured in terms of many hundreds or thou-
sands of square miles, not only must populations be drastically
reduced but the effects on those that continue to live may be
profound. Weaker, less well adapted marine invertebrates are
sure to be weeded out and only animals which can hold their
own, perhaps expanding at the expense of those which disappear,
belong to the remnant shallow-water fauna. It seems reasonable
to construe times of marine regression as more significant in
terms of accelerated evolution than times of marine transgression.
260 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Inadequacy of Evidence from Living Faunas
For the most part a zoologist working on living marine organ-
isms can only theorize about effects on life of the enlargement
or reduction in area occupied by a given shallow sea. He cannot
make surveys of bottom-dwelling populations in some chosen
area in a manner serving to demonstrate change introduced by
expansion or contraction of the selected seaway. Quantitatively
significant advance or retreat of seas is much too slow to permit
observation of its effects on bottom dwellers in any one region.
Collection of reliable data would require millennia. Accordingly,
the neo-zoologist can only compare assemblages of organisms in
broad continental-shelf areas with those occurring in narrow
shallow-sea belts, trying to interpret the origin of such differences
as he finds. Although some of the differences may reflect evolu-
tion at work, he cannot safely identify them, let alone evaluate
them.
Paleontological Investigation
A paleontologist is able to study the record of life in three
dimensions, for he can both observe areal distribution of organic
assemblages represented by remains preserved in rock strata,
and he can study the nature of closely adjacent different as-
semblages higher or lower in the geologic column. The nature of
this advantage is very well known.
In most sections of conformable marine strata, fossils collected
from two or more contiguous layers are properly inferred to
represent samples of successive populations in an area continu-
ously occupied by the sea. Whether the collections are derived
from a former biocoenose or give evidence of a thanatocoenose,
for present purposes makes little difference. The small fraction
of the paleontological record reveals at most the nature of slowly
changing conditions that reflect lapse of geologic time (excluding
effects of possible physical changes in environment). Study of
fossil collections from such conformable strata does not supply
information on effects of advancing or retreating seas.
If the faunal assemblage in one layer is known to represent
part of an extremely wide-spread shallow-sea deposit, whereas
a not-far-distant higher or lower assemblage represents a similar
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 261
fraction of organisms living in a much restricted seaway, this
would begin to meet the conditions of the problem proposed for
investigation. Unfortunately, it is almost impossible to find geo-
logical conditions which can be so interpreted reliably.
Evidence from Cyclic Deposits
Another approach is the comparison of successive widely dis-
tributed marine faunas, each of which is independent, repre-
senting a shallow-sea transgression wholly distinct from others.
Such independence may be demonstrated by the presence of a
disconformity, indicating nondeposition and possibly erosion of
previously formed deposits, which intervenes between the com-
pared fossiliferous marine strata. It may be proved also by
widespread occurrence of nonmarine deposits belonging to a
time of considerable marine regression, where these subaerially
formed beds are found between two sets of shallow-sea deposits.
Late Paleozoic sedimentary rocks of the northern midcontinent
region in the United States offer ideal examples of such cyclic
sedimentation. They include many units consisting of very
widely distributed marine strata that record extensive inundation
of the continental platform, and they include equally widespread
nonmarine deposits that occur between the marine units. The
beds which were laid down on land incontrovertibly prove ab-
sence of the sea at the time and place where they were formed.
If fossil invertebrates found in one of these independent wide-
spread marine deposits are lineal descendants of similar organ-
isms found in a next-lower broadly distributed marine band,
then the differences between them, if any, should measure the
effects of sea retreat and re-advance between the times of exten-
sive marine sedimentation.
The examination of successive assemblages of marine fossils
belonging to cyclic deposits in Kansas is comparable to study of
a series of individual pictures ("frames") in a motion picture
film. Each such picture furnishes a single glimpse of an ever-
moving subject separated from the slightly different next picture,
by blank film. The blanks (nonmarine record) of the strati-
graphic succession are much longer than those of ordinary film,
however.
The cyclic aspects of Pennsylvanian strata and to a lesser
261!
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Phases
SCALE
IN FEET
300
25d—
200 —
150—
100—
50—
jFloranee Is.
BLUE SPRINGS
SH.
KINNEY. LS.
WYMORE SH
SPEISER SH
EASLYCR.SH
STEARNS SH
Morrill Is —
Floreno sh,
•^Vr'Wcottonwooa: Is.
ESKRIDGE SH.
1 | ' - Nevo !».
Fig. 1. Composite geologic section of part of the Lower Permian succession
in Kansas with accompanying graph showing nonmarine units and inferred
depth of inundation in marine units (after ML K. Elias).
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
263
Fig. 2. Paleogeographic sketch maps showing inferred approximate loca-
tion of seaways during (A) one of the several times of relative continental
emergence (when Eskridge deposits were made in Kansas) and (B) the
immediately following rather considerable shallow-sea transgression (when
fusulinid-bearing Beattie strata were laid down in Kansas).
264 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
extent of Lower Permian deposits in the northern midcontinent
region have been described in some detail (Condra and Upp,
1931; Jewett, 1933; Moore, 1936-1953; Moore and Thompson,
1949; Moore et al., 1951). Also the nature of faunal associations
belonging to different subdivisions of the marine part of cyclic
deposits has been delineated and interpreted (Elias, 1937 ; Moore,
1936, 1949, 1950, 1953). Therefore, discussion here is superfluous,
but a part of the Lower Permian succession may be shown graphi-
cally (Fig. 1). This is chosen because fusulinids derived from
these rocks are employed in a later part of this paper as material
for investigation of evolutionary changes.
A method of illustrating the geographic magnitude of shallow-
sea oscillations in Pennsylvanian and Permian time in the central
United States is by means of paleogeographic maps. Figure 2
presents such maps for two adjoining segments of the Lower
Permian succession in the midcontinent region. Taken together,
they represent only a very small fraction of Permian time, for
Figure 2A represents geographic conditions perhaps only 100,000
years before those depicted in Figure 2B. In early Permian time,
the areas successively flooded and laid bare in the central United
States were much smaller than in the preceding Pennsylvanian
period. Although outlines of the seas shown in Figure 2 are
conjectural, they emphasize the point that the marine oscillations
affected many thousands of square miles. They should have had
an influence on evolution of invertebrate animals living in the
shallow seas.
EVIDENCE FURNISHED BY SELECTED
INVERTEBRATE GROUPS
General Statement
For the purpose of studying effects of broad shallow-sea oscilla-
tions on the evolution of bottom-dwelling invertebrates, any
group of them found preserved in a number of successive distinct
cycles is appropriate for investigation. Some assemblages are
likely to be better than others, however. The chief guides in
choosing materials for study are : (1) availability of a reasonably
large number of specimens belonging to the group in each of
the compared marine deposits, (2) adequacy of fossil collections
from precisely known stratigraphic positions, (3) thoroughness
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 265
of investigations leading to discrimination of significant morpho-
logical and taxonomic interrelations, and (4) distinctness of
differences that may be judged ascribable to evolutionary change.
A fairly large sample of an invertebrate group in a specified
shallow-sea deposit is required in order to appraise characters
that possess value in defining evolutionary trends. Such a sample
may be composite, coming from many localities, but it must be
representative. Also, each of the two or more compared inde-
pendent marine units needs to supply materials of this sort, for
otherwise comparison leads to dubious conclusions or it is impos-
sible. Genera, subgenera, and possibly species that exhibit at
least moderately extended stratigraphic range are the only taxo-
nomic units which can be considered suitable for this study.
Adequacy of fossil collections is a self-evident requirement.
Evidence that exists in the field is not usable until it is brought
to the laboratory and subjected to careful analysis. In early
geological studies, knowledge of detailed stratigraphic relations
was lacking generally and its value was unappreciated. There-
fore, most fossil collections from late Paleozoic strata in the
northern midcontinent region which were made before 1920
have greatly impaired usefulness unless locality records permit
accurate identification of the exact source of the fossils.
Comprehensive research of so-called monographic sort is
needed before almost any roup of Pennsylvanian or Permian in-
vertebrates can be studied usefully with the object of recognizing
evolutionary distinctions and trends. Seemingly, all kinds of
benthonic organisms living in shallow seas of the North American
continental platform had attained remarkable stability in late
Paleozoic time and although faunas are varied and some of them
large, their components mostly persist. As result, a Lower Per-
mian fauna may resemble a Lower Pennsylvanian one so closely
in a majority of its elements as to be distinguishable only by
specialists. Few invertebrate groups have yet been examined
thoroughly.
It is recognized universally that invertebrate groups vary
enormously, both within themselves and between time-defined
segments within almost any single group, in the clearness and
rapidity of evolutionary change which is discernible in their
geologic history. Linguloid brachiopods furnish examples of un-
266
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Form Ratio
1.2
I.I
0.9
M. copha (Atokan)
M. lepta
(Desmoinesian)
M. wyomingensis—~-
(Missourian)
M. miopetina — -
10 (M.Virgilian)
M. pliopetina
(L. Permian)
M. copei — »—
(L. Permian)
M.arbala (Missourian) —
M glossoidea (Virgilian)
M petina (U. Virgilian)
I i i_
2.4
2.0 1.6 1.2
Ratio Lfi:L<*
0.8
0.4
Fig. 3. Evolutionary trends of myalinid shells represented by species
from Pennsylvanian and Lower Permian strata of the midcontinent region.
The form ratio (shell length to shell height) of species is plotted against
the ratio of angle beta to angle alpha (inserted diagram A). Taking
account of stratigraphic occurrence, two main trends seem to be derived
from Myalina lepta of Desmoinesian age (data from Newell 1942).
STATUS OF INVERTEBRATE PALEONTOLOGY. 195:$
267
L$-
. copha --, Atokan
130"
115
100°
/"V
Desmoinesian '.* —jLepta^J f.% ;-•., \
\/ \ / wyo'mLn'g'ensis -Desm.-Virg.~
/ \y \
'. yglossbidea- L.Virgilian
V. \
/ N\
M. Virgilian « • J> .,
\ mtopetlna
arbala-M\ssb\ir'\Qn
Fig. 4. Eange in values (shown by quadrilaterals) and mean values
(black dots) of the alpha and beta angles of species of Myalina from Penn-
sylvanian and Lower Permian rocks of the midcontinent region (data from
Newell, 1942).
268
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
detectable alteration in the course of what must be ten-million-
year intervals, whereas the complexly organized crinoids display
profound and generally rapid evolutionary change. A satisfac-
tory rating of late Paleozoic invertebrate groups according to
Fig. 5. Inferred phylogenetic relations of some Pennsylvanian and Lower
Permian myalinid species from the midcontinent region, based largely on
data illustrated in Figures 3 and 4.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 269
distinctness of numerous evolutionary modifications is not now
possible, although ammonoids, fusulinids, and crinoids surely
would rank high. The fusulinids are a supremely useful group
because of their almost incredible abundance, wide geographic
distribution, occurrence in nearly every cycle of Pennsylvanian
and Permian deposits, and considerable range of morphological
differentiation.
In the study here reported, attention was directed to chonetid
brachiopods, fistuliporoid bryozoans, myalinid and pectinoid
clams, and Lower Permian fusulinids. This choice was based
on the availability of monographic studies completed or in prog-
ress. Only the myalinids and fusulinids, however, are discussed
in this paper.
Myalinid Pelecypods
Pelecypods of the group called myalinids are widely distrib-
uted in late Paleozoic near-shore marine deposits of the northern
midcontinent region. They are more or less common in nearly
every cycle. A comprehensive study of these shells, based on
large collections from precisely controlled stratigraphic positions
and from very numerous localities, has been made by Newell
(1942). His work has led to recognition of ten generic or sub-
generic groups in the family Myalinidae and to differentiation
of some 30 species of Myalina.
Among characters found by Newell to be most useful for classi-
fication and recognition of evolutionary trends are shape of
the shell, including especially the angle between the umbonal
ridge and the hinge line (termed alpha angle) and the similar
angle between hinge line and growth lines at the posterior mar-
gin (termed beta angle). In addition to a tendency of shells to
become larger and thicker in the course of evolution, unidirec-
tional trends in the nature of these angles is observed. Figures
3 to 5 furnish graphic indication of characters of some species
belonging to the subgenus Myalina {Myalina). Evolutionary
modifications can be detected and reasonable inferences as to
genetic relationships among species can be drawn. The assigned
stratigraphic range of most species, however, is too great to
allow recognition of differences between specimens found in
marine parts of the successive Pennsylvanian and Permian cyclic
deposits.
270
BULEETIN : MUSEUM OF COMPARATTVB ZOOLOGY
Fig. 6. Generalized section of Lower Permian deposits in Kansas showing
longitudinal sections of representative fusulinids from various shallow
marine strata (modified from Thompson, 1954).
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
271
Fig. 7. Generalized section of Lower Permian rocks of north-central
Texas showing longitudinal sections of representative fusulinids from shallow
marine strata. Heavy vertical bars represent nonmarine red deposits (modi-
fied from Thompson, 1954).
272 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Fusulinids
Study of Lower Permian fusulinids as markers of evolution in
response to extensive marine oscillations was undertaken be-
cause of the completion recently of comprehensive research by
M. L. Thompson (1954) on these fossils. Primarily based on col-
lections from Kansas (40 localities) and Texas (47 localities)
representing every discovered fusulinid-bearing zone in the Wolf-
campian part of the rock column, Thompson's investigation also
included very numerous specimens from Oklahoma, New Mexico,
Nevada, Utah, Arizona, and California. One new fusulinid hori-
zon (Wreford limestone) has been discovered in Kansas since
the time of Thompson's work (D. E. Hattin, personal communi-
cation). The monograph by Thompson describes and illustrates
56 species (42 new) which are distributed among 11 genera. The
stratigraphic occurrence of all forms is recorded precisely, and
accordingly a good source of information is offered for investiga-
tion of the sort here discussed.
Cyclic deposits containing fossiliferous marine strata separated
by generally unfossiliferous nonmarine beds characterize the
Lower Permian succession in Kansas and Nebraska, parts of
Oklahoma, and north-central Texas. They may occur in other
states also but my attention in the present study has been re-
stricted to the part of Thompson's paper concerned with Kansas-
to-Texas fusulinids. These include species which are identified
both in the north and south and those recorded as yet only from
the Kansas region or from north-central Texas. Figures 6 and 7
show the Lower Permian succession and stratigraphic position
of fusulinid-bearing rocks in Kansas and Texas, respectively.
In order to obtain a common denominator for the Kansas and
Texas sections, identifying as exactly as possible the equivalent
marine rock units in each, two paleontological main tie points
are employed. The lower one consists of fusulinids near the base
of the northern and southern successions; they include Triticites
confertus Thompson and Dunbar inella eoextenta Thompson,
found in both, associated with slightly different but closely related
fusulinids {T. pointensis Thompson, in Kansas, and D. en tenia
Thompson, in Texas) and other species (Meekopora prosseri Ul-
rich, M. mollis Moore and Dudley, and distinctive abundant
crinoid ossicles including the so-far-as-known very short-ranged
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
273
Triceracrinus Bramlette). The higher tie point is located at the
horizon of the Goldbusk limestone in Texas and Florence lime-
stone in Kansas, each of which contains an assemblage of fusu-
EXPLANATION 9"! Coleman
EH opecies common to Kansas $
and Texas I
I I 5pecies only known in Kansas or Texas
^M Marine deposits
Ejj Nonmarine deposits
100 ft.
Oft.
£
Florence s- -*■
*tSW- corrtptexa,
I Goldbusk
%
% S3-^er^lUei D8-wetkererusls
I <5'2b- ernxLcixt-ta.
D7c-koscnntcLrun, p ft
Neva
I?
G/enrock -P.-
Foraker e|e
Americus -=-
.i.
Five Point -=-
v— v/c - tcowrw
n (5 U»D7b- obesa
*■ -D7cl - tumida>
\52-turtcL
[ 1'T6-roc/csns6s
67- casnpa.
- = Stbckwether
T7- creekensis =
\
Sl-bngissi/noulea
| Camp Creek
| Saddle Creek
-{Waldnp3
-g Waldrip 2
-I Waldrip I
D3-ex.ten.ta
KT3- direct us
D€-glenertsis I
\nr l l T ¥ T5- ventrlcosus
KDS-!uqhesensis\ T ^-nxeeki
D4-a/7t£riccma \ D2- eoextenta.
—. . , • T2-con,fertus
77- potfiterbSLs
XD/- fi.ven.sis
Fig. 8. Stratigraphic distribution of selected fusulinid species in the
Kansas and Texas Lower Permian sections. The Florence and Goldbusk
fusulinid-bearing strata are judged to be closely contemporaneous for, in
addition to Schwagerina complexa, they contain Pseudoschwagerina texana
and Pseudofusulina? moranensis, all three species being found in no other
rocks of north central Texas or the Kansas region. Other species found
near the base of the Permian deposits in Kansas and Texas indicate age
equivalence of these rocks. Thus, an integrated scale in terms of fusulinids
can be constructed. (T1-T7, species of Triticites; D1-D8 species of Dunbar-
inella; S1-S4 and S'l-S'4, species of two inferred lineages of Schwagerina).
274 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
linids found nowhere else, although one of the species occurs also
in Lower Permian rocks of western Texas and New Mexico.
The Goldbusk and Florence species are distinctive forms named
Pseudoschwagerina texana Dunbar and Skinner (also in Wolf-
camp rocks of the Glass Mountains and Hueco limestone of the
Sierra Diablo and Hueco Mountains), Schwagerina complexa
Thompson and Pseudofusulina? moranensis Thompson. The
strata containing this fusulinid assemblage must be very nearly
equivalent in age, if not precisely so. A comparison of the Kansas
and Texas sections showing placement of fusulinid species studied
in preparing this paper is given in Figure 8 and a tabulation of
marine units which tentatively are considered to have the same
age follows.
Correlation of Marine Lower Permian Stratigraphic
Units in Kansas and North-central Texas
(Units containing identical species of fusulinids marked by **;
other fusulinid-bearing units marked by *)
Kansas Texas
Nolans limestone "Coleman Junction limestone
Winfield limestone Sedwick limestone
**Florence limestone **Goldbusk limestone
*Wreford limestone *Camp Colorado limestone
•Beattie limestone *Stockwether limestone
**Neva limestone **Camp Creek shale (and lime-
stone)
**Glenrock limestone ** Saddle Creek limestone
**Foraker limestone (Hughes **Waldrip shale (No. 3 limestone)
Creek)
**Foraker limestone (Americus) **Waldrip shale (No. 2 limestone)
**Fivepoint limestone **Waldrip shale (No. 1 limestone)
Comparison of fusulinid species belonging to any given generic
assemblage with the object of distinguishing evolutionary trends
naturally must take account first of relative age of the chosen
fossils. Older forms may have given rise to younger ones but
not the reverse. Morphological features must be examined in
order to discover resemblances and differences. Average size of
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 275
individuals is not likely to be significant, although this may be
a specific character along with others. Nearly all descriptions
of fusulinid species are accompanied by more or less extensive
tables of measurements which furnish record of observations
concerning not only the whole shell but the proloculus and each
successive volution. These data constitute a statistical delimita-
tion of various morphological elements but it is difficult indeed
to use them directly in making comparisons and in learning what
may be most significant. Graphic analysis of such information
rarely is given by authors and therefore a good deal of time
was spent by me in trying to plot useful graphs. Some showed
average measurements or computations and others showed values
reported for individual specimens, thus indicating range of varia-
tions. Ratios of two selected characters recorded by measure-
ments can be plotted against a third set of measurements or
against other ratios. Some work along this line seemed to be
worth while but most of it was discarded.
Triticites
A somewhat arbitrarily chosen but seemingly useful starting
point for the comparative study of fusulinid species consists in
plotting average measurements for the diameter and wall thick-
ness of the proloculus. Among Lower Permian species from
Kansas and Texas described by Thompson, the proloculus diam-
eter is found to range from less than 100 to nearly 250 microns
and the wall thickness from 9 to 25 microns (Fig. 9).
If the stratigraphically lowest species is postulated to be
ancestral (or alternatively, closely similar to ancestral) to
younger species found higher in the section of Kansas, Texas,
or both, a line or lines drawn from the plotted point for the
oldest species to points representing other species indicates the
nature of evolutionary trends. The premise that evolutionary
trends are consistent, rather than erratically reversible, underlies
the conclusion that not all observed species belong to a single
chain between the presumed progenitor and its youngest known
descendant. Rather, the directions of evolutionary alteration
may diverge from a parent stock so that graphic representation
of inferred relationships has a branched pattern, as in Figure 9.
It is obvious that an inherent assumption in the procedure
276
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
just described is that all of the forms considered are actually
interrelated, all being derived from a source consisting of the
oldest species of the group. The validity of this assumption is
open to challenge, since one or more of the studied species may
be immigrants to the Kansas or Texas areas, being derivatives
of stock that resided in some "foreign" part of the Permian
shallow seas such as New Mexico, Arizona, or Utah. Also, if
Triticites rockensis Thompson from the Glenrock limestone of
Kansas) is a lineal descendant of T. point ensis Thompson or
T. confertus Thompson, found in stratigraphically lower marine
TS T7
verttricosLLS creetcertsLs
I
coriferbus rockensis
77
poirttertsis
100
Triticites
Proloculus
150
Diameter in yx.
200
250
Fig. 9. Proloculus of species of Triticites plotted according to diameter
and wall thickness. Taking account of stratigraphic occurrence, three dif-
ferent lineages are suggested. The letters T1-T7 inclusive correspond to
those shown in Figure 8.
deposits of Kansas, and if the line of descent to T. rockensis does
not include T. ventricosus (Meek and Hayden) or T. meeki (Mol-
ler), which occur in Kansas rocks older than the Glenrock lime-
stone, a question is raised concerning the identity and place of
occurrence of immediate forerunners of T. rockensis.
Figure 10 illustrates morphological characters (form ratio,
height of chambers, thickness of spirotheea, cumulative number
of septa, and tunnel angle) of the Lower Permian species of
Triticites from Kansas and Texas as measured at the fifth volu-
tion, lines being drawn between plotted points for the individual
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
277
Fig. 10. Morphological features of the fifth whorl of Lower Permian
species of Triticites arranged according to lineages suggested by Figure
9 (A, form ratio; B, height of chambers; C, thickness of spirotheca; D,
number of septa, cumulative to end of fifth whorl; E, tunnel angle:
278
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
species in a manner corresponding; to that in Figure 9. Graphs
which were constructed similarly for all volutions do not differ
enough from the one presented here to warrant publication of
them.
Average values for form ratio (Fig. 10A) are almost the same
in Triticites pointensis and T. rockensis but show ups and downs
along the lines leading- to other species. This suggests that form
140
Diameter in jj.
Fig. 11. Proloculus of Lower Permian species of Dunbarinella showing
diameter and wall thickness. Taking account of stratigraphie occurrence,
three lineages of these species are suggested. The letters D1-D8 inclusive
correspond to those in Figure 8.
ratio is not a very reliable indicator of evolutionary change
because it moves in reverse directions or else the compared species
are not actually a genetically related series. The same inference
is appropriate in trying to interpret the graph of tunnel angles
(Fig. 10E). On the other hand, comparison of values for cham-
ber height, thickness of spirotheca, and number of septa (Fig.
10B-D) plausibly conform to a pattern of evolution having
consistent trends.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
279
Dunbarinella
Studies of the Kansas and Texas species of Dunbarinella de-
scribed by Thompson (1954) were made in the same way as for
Triticites. Graphic representation of proloculus characters (Fig.
11) suggests existence of four lines of development, but attention
needs to be called to the record of D. eoextenta Thompson asso-
Fig. 12. Form ratios of Lower Permian species of Dunbarinella showing
variation during growth.
ciated with D. fivensis Thompson in the Pivepoint limestone of
Kansas and the presence of both D. eoextenta and D. extenta
Thompson in rocks of the same or nearly identical age in north-
central Texas. Thus, these three species which have notable dif-
ferences in character of the proloculus are contemporaneous at
least in part ; because they have other features that indicate close
280 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
relationship, it is probable that they are slightly divergent de-
rivatives of a late Pennsylvanian ancestor. In wall thickness
and diameter of the proloculus, D. extenta rivals the stratigraphi-
cally higher D. glenensis Thompson and D. obesa (Beede).
In order to illustrate ontogenetic changes, as well as the range
of variation among the studied species of Dunbarinella, the values
of computed form ratios for each volution have been plotted (Fig.
12). They show that conclusions based on comparison of a single
growth stage may not be reliable. Since similar graphs of other
characters mostly demonstrate acceleration or retardation in the
rate of change from volution to volution, they offer little indica-
tion that successive growth stages furnish record of the course
of phylogeny. Diagrams prepared in the manner of Figure 12
seem to be useful for summarizing taxonomic aspects of morpho-
logical features but they fail to indicate directly the nature of
evolutionary trends which otherwise may be discernible in the
group of species.
Comparison of morphological characters of species of Dun-
barinella, based on measurements of the sixth volution, which
is nearest to the adult stage as far as data for all species are
available, is shown in Figure 13. The line connecting D. fivensis
with D. americana Thompson and D. hughesensis Thompson and
that joining D. fivensis with D. extenta and D. glenensis are both
consistent with evolution in fairly uniform though divergent di-
rections. On the other hand, indicated trends from D. fivensis
through D. eoextenta to D. tumida (Skinner) and 0. wether -ensis
Thompson, and less clearly to D. obesa (according to the pattern
suggested by Figure 11) seem to be anomalous. D. tumida and
D. obesa, which occur with D. koschmanni (Skinner) (Figs. 8,
12, 13) in the Neva limestone of Kansas and northern Oklahoma,
are conceivably derivatives of the older D. eoextenta but not from
the also older D. americana and D. hughesensis group or the D.
extenta and D. glenensis group. That some of these species are
interlopers of unknown origin, rather than descendants of in-
digenous midcontinent species, is very possible. The wide range
in values of measurements representing most morphological ele-
ments is a noteworthy feature of these fusulinids, leading one
to think that recognition of definite evolutionary trends should
be relatively easy. Such is not true.
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953
281
t3
si
SSI i?| *■«
Q..3 Q^ Q|
1
Fig. 13. Morphological features of Lower Permian species of Dun-
barinella with differentiation of inferred lineages as shown in Figure 11.
A, indicates diameter of the proloculus (in microns). B to F represent
characters of the sixth whorl (B, form ratio; C, height of chambers, in
microns; D, thickness of spirotheca, in microns; E, number of septa to
end of sixth whorl; F, tunnel angle, in degrees). (Data from Thompson,
1954.)
282
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Schwagerina
Another Lower Permian genus which is represented by nu-
merous species (10 in the midcontinent area and 9 others from
trans-Pecos Texas and country farther west) is Schwagerina.
Characters of the proloculus (Pig. 14) suggest division of the
midcontinent forms into two sharply distinguished groups. These
respectively comprise 8. campa Thompson, 8. jewetti Thompson,
S. vervillei Thompson, S. emaciata (Beede), and S. complexa
Thompson in one assemblage and S. longissimoidea (Beede), S.
Wall Thickness
30
Coleman Is. (Tex)
34 cotemanl
Gold busk Is. (Tex.)
Florence Is. (Kan.)
S'4 compLexa
Morrill Js. (Kan.) ^
vervUlec. ~j£uu*ata. Cottonwood Is. (Kan.)
S'2b
Red Erie's. **&***£
(Kan.) I Cottonwood Is. (Kan.)
.100.
I
.120-
S3
campensis
Camp Creek sh. (Tex)
62 turki Foraker fm. (OklaJ
<S/ '• longLssunolcLea.
Foraker- Grenola Fms. (Kan.)
Waldrip No. 3 Is. (Tex.)
Sch. wager Inez
Proloculus
.160.
180^.
Diamerer
Fig. 14. Proloculus of Lower Permian species of Schwagerina showing
diameter in relation to wall thickness. Taking account of stratigraphic
occurrence, two groups of divergent lineages are suggested. These are
marked by letters S1-S4 and S'l-S'4, respectively, corresponding to nota-
tions on Figure 8.
turki (Skinner), 8. campensis Thompson, and S. colemani
Thompson in the other. As shown by Figure 14 and also by
plotted measurements of various morphological features (Fig.
15), it is reasonable to suggest that the group containing S.
campa is based on this species as origin, whereas the group con-
taining 8. longissimoidea was derived from this species. Studies
which I have made are insufficient to warrant postulates con-
cerning the common origin of the two assemblages or that of the
genus, but the oldest known representative (8. longissimoidea) in
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953
283
Form
5
•3
3.
3
Ratio t^a » 5 »N5 :«5 ;I o
4.0
Chamber Height
300/x.
250
200 —
Spirotheca Thickness
80 jjl
Septa
100
Tunnel Z
60*
1 II
==«
Fig. 15. Morphological features of Lower Permian species of Schwagerina,
all representing growth stages at end of the fifth volution. Septal counts
are cumulative, including volutions 1-5 (Data from Thompson, 1954).
284 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the midcontinent is rather surely not the form sought. The 8.
campa group of species exhibits structural characters and trends
that are unrelated to those of the 8. longissimoidea assemblage.
CONCLUSIONS
Comparative study of marine invertebrates preserved as fossils
in successive cyclic deposits of late Paleozoic age in the central
United States is a very promising type of research for evaluation
of the effects on evolution of broad oscillations of shallow seas
which in relatively short spans of geologic time alternately inun-
date and then uncover large parts of continental platforms. In-
vestigations of this nature may be undertaken profitably on
deposits of Chesteran (late Mississippian) age as well as in Penn-
sylvanian and Permian parts of the rock column.
Fossils adapted for this study are somewhat narrowly defined
taxonomic groups which are Well represented in each of several
succeeding cycles and which are suited by the nature of their
morphological characters to receive a clear impress of evolu-
tionary changes. Generally speaking, the best groups are those
having rather complex structural organization and those which
are not too specialized by reason of adaptation to a narrow eco-
logic niche. Large collections of fossils from precisely known
stratigraphic positions must be obtained and thorough taxonomic
investigation of the selected groups is needed. Statistical analy-
sis, preferably accompanied by graphic treatment of measure-
ments and computations, may aid in the possibly arduous task
of finding most significant directions of evolution. Interpretation
of the accumulated observations is likely to be less difficult.
A chief question encountered in work on this problem relates
to recognition of true lines of descent, for the occurrence of
more or less similar species in the marine parts of successive
cycles does not prove that the younger is derived from the older.
Effects of migration must be taken into account and, depending
on circumstances that may be almost wholly conjectural, these
effects can be judged -to obscure or obliterate evidence otherwise
interpreted to signify evolution of indigenous stocks.
Observations on the distribution and nature of species belong-
ing to the pelecypod subgenus Myalina (Myalina) serve to define
evolutionary trends but evidence is insufficient to establish per-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 285
ceptible changes in species from one Pennsylvanian or Permian
cycle to the next.
The fusulinid genera Triticites, Dunbarinella, and Schwage-
rina, represented by numerous species in Lower Permian cyclic
deposits of Kansas, Oklahoma, and north-central Texas, seem to
reflect influences of shallow-sea oscillations in the midcontinent
region, as shown by analysis of shell characters of forms found
in successive cycles. In each genus, divergent trends are seen
but interpretation of some species is uncertain because they may
be immigrants from distant parts of the Permian sea rather than
lineal descendants of forms found lower in the rock section of
Kansas or Texas.
EEFERENCES
Condra, G. E. and J. E. Upp
1931. Correlation of the Big Blue series (Permian) in Nebraska.
Bull. Nebraska Geol. Survey, ser. 2, vol. 6, pp. 1-74, figs. 1-15.
Elias, M. K.
1937. Depth of deposition of the Big Blue (Late Paleozoic) sediments
in Kansas. Bull. Geol. Soc. America, vol. 48, pp. 403-432, pi. 1,
figs. 1-4.
Jewett, J. M.
1933. Evidence of cyclic sedimentation in Kansas during the Permian
period. Trans. Kansas Acad. Sei., vol. 36, pp. 137-140, figs. 1, 2.
Moore, R. C.
1936. Stratigraphie classification of the Pennsylvanian rocks of Kan-
sas. Bull. Kansas Geol. Survey, vol. 22, pp. 1-256, figs. 1-12.
1949. Divisions of the Pennsylvanian system in Kansas. Bull. Kansas
Geol. Survey, vol. 83, pp. 1-203, figs. 1-37.
1950. Late Paleozoic cyclic sedimentation in central United States.
Internat. Geol. Congress, Rept. 18th Sess., Gt. Brit., 1948, pt. 4,
pp. 5-16, figs. 1-6.
1953. Les cycles sedimentaires du paleozoique superieur. Mem. Inst.
Geol. Univ. Louvain (Belg.), vol. 18, pp. 31-57, figs. 1-13.
Moore, R. C. and M. L. Thompson
1949. Main divisions of Pennsylvanian period and system. Bull. Am.
Assoc. Petroleum Geologists, vol. 33, pp. 275-302, figs. 1, 2.
286 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Moore, R. C, et al.
1951. The Kansas rock column. Bull. Kansas Geol. Survey, vol. 89,
pp. 1-132, figs. 1-52.
Newell, N. D.
1942. Late Paleozoic pelecypods, Mytilacea. Kansas Geol. Survey,
vol. 10, pt. 2, pp. 1-115, pis. 1-15, figs. 1-22.
Thompson, M. L.
1954. American Wolfcampian fusulinids. Univ. Kansas Paleont. Con-
trib., Protozoa, Art. 5, pp. 1-226, pis. 1-52, figs. 1-14.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 3 October, 1951
Status of Invertebrate Paleontology, 1953
XI. Systematic, Paleoecologic and Evolutionary
Aspects of Skeletal Building Materials1
By H. A. Lowenstam
California Institute of Technology
Skeletal remains of organisms constitute the common records
of bodily preserved components in the sedimentary sequences of
the earth's crust. Paleontology, as of to date, has been predomi-
nantly occupied with the study of skeletal types of records. The
initial task has been, and for this matter still is, to canvass these
biologic records and to place them into the broader framework
of the recognized levels of increasing complexity and to relate
them to others within these, in order to chart the course of phylo-
genetic changes through geologic time. With the increase in
knowledge of the principal types of organic representatives with
preservable skeletons through the time succession, interpretive
aspects of the meaning of evolution (based on a better under-
standing of the mechanisms of dynamic changes, largely through
genetic concepts) have progressively become the focal point in the
synthesis of the paleontologic records. With recognition of the
screening effects of the environmental framework (apart from
the controls exerted by the interrelations of the biota as a whole,
i.e. the channeling mechanism of evolutionary processes), ecologic
factors have become of increasing concern in the paleontologic
inquiry. The approaches here were directed toward discerning
skeletal expressions in adaptive, functional morphologic terms
and to integrate these with environmental expressions of the en-
closing sedimentary rocks, wherever living and burial grounds
were assuredly coincidental or closely related. The expressions of
concern were largely physical in nature, as observed in the macro-
and micro-architecture of the skeletal records or physical expres-
sions of chemically induced morphologic changes. This is best
shown by the factors of concern in the paleoecologic investiga-
tions of marine fossil assemblages, e.g., turbulence, turbidity,
depth of water, bottom consistency, salinity, and temperature, all
i Publications of the Division of the Geological Sciences, California Institute
of Technology, Pasadena, California, Contribution No. 700.
288 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
of course in relative terms. For instance, regarding the detec-
tion of physical expressions of a chemical environmental effect,
such as that of salinity, criteria of marginal (either hypersaline
or brackish water) conditions were deduced by analogy with pres-
ent day representation in the changes effecting shell morphology
of pelecypods in the form of dimensional distortion, thickness and
size reductions.
In recent years, there has been a rapid improvement of earlier
established techniques and the development of new ones in the
field of X-ray mineralogy, and in trace element and isotope chem-
istry which in their applications have been concerned incidentally
or specifically with recent and fossil skeletal building materials.
These have demonstrated that skeletal mineralogy constitutes, po-
tentially, a supplementary source vector of anatomic-physiologic
and ecologic information ; this knowledge, through integration
with that of physical aspects of morphology and sediment-derived
information, promises not only to strengthen interpretational
aspects, but also to aid in quantifying previously qualitatively-
evaluated parameters. There are further indications that such
applications will widen the scope of the paleontologic inquiry,
beyond the range of morphologically-derived information amen-
able to analyses in the morphologic area, to physiologic aspects
and hence will reveal phases of biochemical evolution. Progress
and scope of the inquiry in this area will depend equally if not
to a greater extent upon information derived from biochemical
studies of organic remains and their degradation products in the
fossil records, already under scrutiny (Abelson, 1954).
The investigation of biologic properties by biogeochemical
means must be evaluated, and procedure is initially determined
by a number of considerations. The basic concerns are the prin-
ciples governing the inorganic processes of precipitation and the
isotope chemistry of inorganic precipitation of the crystal types
that constitute skeletal hard parts (or, where organic matrices
are initially elaborated, their strengthening agents), and also the
trace element uptake levels by the respective host minerals. As
organisms constitute the synthesizing agents of skeletal crystal-
line matter, the framework of reference of the crystal chemical
precipitation and activity levels over the range is controlled by
such determining factors as those related to biologic tolerances
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 289
(which vary as a function of a given species and with reference
to their ecologic valence), the response characteristics, and the
degree of environmental dependence of the species upon the
activation of the skeletal secretionary processes. Next, from the
paleobiologic point of view, one should consider, after thorough
diagnosis of the enclosing sediments, the stability relations of the
original skeletal mineralogic compounds, their isotopic ratios
and trace element concentrations over the range of differing
physical-chemical environments through which the skeletal min-
eral components have passed (from the moment of burial under
similar conditions to quite different ones).
The primary level of background information on the funda-
mental physico-chemical and isotope chemistry concepts in their
development concerns us as paleontologists only insofar as it may
be applied to obtaining information on biologic aspects. The
second level of background knowledge, the investigation of the
principles of the channeling effects of the biochemical catalysts in
their expressions in the secretionary products of the skeletal
crystal aggregates, lies basically in the domain of neobiologic
inquiry. Contrary to the consideration of morphologic aspects,
where replacement of e.g., calcific skeletons by calcium phosphate
or silica compounds such as low temperature crystobalite or
quartz, is of no concern as long as it does not affect macro-
or micro-architecture (whichever may be critical), the biogeo-
chemical investigation is at present confined to entirely, or
in part, unaltered skeletal remains. The task at the third level
which is assigned to paleontology would then seem to pertain
initially to applying the principles evolved by neobiology to the
investigation of the stability ranges of the skeletal crystal chemi-
cals and their trace element and isotopic properties with refer-
ence to each individual character and by crystal characteristics
within each of the skeletal-bearing groups. The aspect of concern
here is primarily to' find criteria to recognize where post mortem
changes have taken place, and to avoid erroneous interpretations
of the history of origin as it reflects the environmental frame-
work. Properly screened by distinguishing differences of ecologic
from evolutionary changes, it should then be possible to chart the
course of phylogenetic changes in skeletal secretionary processes
and their contribution to the modes in evolution. The disadvan-
290 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
tageous position of paleobiology with reference to neobiology is
to be confronted with fragmentary remains of organisms ; one
must then place emphasis on searching always for criteria of
correlation of biologic and ecologic properties which lie in the
range of what may be potentially preserved in the fossil remains.
This may restrict the consideration of paleobiology not infre-
quently to second or third order expressions of phenomena in
organic components which seem preservable but of little concern
and, hence, not correlated by the neobiologist as long as they are
obscure, by comparison with obvious though not preservable
expressions. It is thus not a coincidence that in the investigation
of physical properties that, for instance, denote ecologic expres-
sions, the ranges of criteria which are amenable to paleontologic
research have commonly been and are still being extended by
paleoecologists rather than by neoecologists from observations of
skeletal characteristics of present-day biota. In the area of skele-
tal biogeochemistry the situation is even more acute in that
information fundamental to the definition of principles is highly
unsatisfactory. Hence, to utilize basic knowledge accumulated
on the first level and apply it to the third level, that is, to paleo-
biology, the principles on the second level must first be developed.
It is for this reason that consideration of skeletal mineralogy and
trace element chemistry is at present preoccupied almost entirely
with aspects of present-day organisms.
It is the purpose of the following to elaborate the results of bio-
geochemical studies on calcium carbonate skeletons. The writer
has participated in such studies as oxygen isotope method of tem-
perature determinations with reference to ecologic factors and
evolutionary aspects and has investigated aragonite-calcite rela-
tions to environmental factors and certain aspects of trace ele-
ment chemistry in relation to temperature. Temperature effects
can be detected in some carbonate skeletal types by 018/016 ratio,
the calcite-aragonite ratio and trace element concentrations. The
best documentation of the trace element relation with reference to
temperature has been worked out by Chave (1954) for the mag-
nesium content of carbonate skeletons and hence consideration is
given to his work. The potential application of three independent
sets of criteria for temperature determinations is, from the
methodological point of view, encouraging, as it will tend to re-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 291
duce erroneous temperature determination. The oxygen isotope
method and the magnesium concentration scales allow quantita-
tive temperature determinations. As such they constitute refine-
ments of means of investigations beyond our previous qualitative
evaluation of this property. Integration with independently
arrived source data of the sort to be pointed out in connection
with the paleo-temperature method, reveals the contribution
which can be made through biogeochemical studies, and stresses
the fact that only if integrated with all sources of basic data will
they then become meaningful.
OXYGEN ISOTOPE TEMPERATURE DETERMINATION
The isotope method of temperature determination derives its
information from carbonate skeletons of marine organisms (Urey,
1948). It is basically then a biologic tool dependent initially upon
groups of organisms which lay down their skeletal carbonate in
isotopic equilibrium with that of their surrounding waters (Low-
enstam, 1948). These groups must be determined from exam-
ination of the spectral range of present-day carbonate-secreting
forms. The relations of the range of skeletal secretion to that of
the yearly amplitude in temperatures of the inhabited waters
must next be clarified. Specifically, it is then an ecologic tool
designed to define the skeletal secretionary range for a given
species and compare it with biotope associated elements — a
parameter to date little investigated. From this it follows that
the initial test is to lay a foundation of comparative data on the
skeletal secretionary-temperature relations in present day biota
where the climatic amplitudes are known. With this as a back-
ground it should then be possible to investigate skeletal paleo-
temperatures of fossils, in which the original isotopic abundances
have remained unaltered. This raises the question as to the types
and numbers of burial-associated biotic elements which can be
employed for paleotemperature determinations and also how far
back in geologic time these may be found. In turn, this knowledge
can be employed to evaluate the climatic conditions under which
the organisms lived.
The present state of information obtained for each of the phases
indicated as vital prerequisites to the paleotemperature investiga-
tion is as follows. Regarding the question of the group-distribu-
292 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
tional spread of present-day organisms which lay down skeletal
carbonate in isotopic equilibrium with that of the inhabitant
waters, these groups have been shown to be species examined from
among the foraminifera, hydrozoans, bryozoans, amphineurans,
gastropods, pelecypods, and cephalopods (Urey et al., 1951,
Emiliani and Epstein, 1953, Epstein and Lowenstam, 1953,
Emiliani, 1954, Lowenstam and Epstein, 1954). Thirty-eight
Recent species of the inshore water biota from Bermuda, includ-
ing in group distributional terms some representatives of
foraminifera, hydrozoans, and bryozoans, but centered on the
molluscans, served as models to investigate the relations of skele-
tal secretionary behavior with reference to environmental tem-
peratures (Epstein and Lowenstam, 1953). The yearly amplitude
in water temperatures at Bermuda extending from 16 °C to 30° C
was found admirably suited for comparative study of this partic-
ular aspect. Average skeletal growth temperatures determined
from representatives of each of the thirty-eight species were found
to extend from 18.1°C to 29.1°C, with the density clustering in
the range from 23° to 24° C. The average skeletal growth tem-
perature of from 2 to 6 individuals of the same species but from
different micro-environments was found to vary within 2°C or
less. Comparison of the average shell-growth temperature of the
numerically-more-thoroughly-investigated pelecypod and gastro-
pod species, by integral temperature intervals, indicates class-
characteristic-frequency groupings for the pelecypods between
23° and 24°C, and for the gastropods between 20° and 22°C. The
data are as yet too limited to justify the generalization that class
distinct shell-secreting behavior is involved. However, the aspect
which did forcibly emerge from limited range in temperature
variations per species as contrasted with the overall range in
average temperatures by species when all are examined in toto, is
that skeletal-secreting processes are species-controlled . The mean-
ing of species-determined differentiation in temperature record-
ing was investigated further by means of cross-sectional studies
of shells of the pelecypod Chama macerophylla with an average
shell growth temperature of 23.6 °C and of the gastropod Strom-
bus gigas with a shell growth temperature of 21.7°C. The results
for Chama macerophylla showed shell depositional temperatures
lying above 21 °C throughout. Considering, on the basis of the
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 293
irregular temperature fluctuations, the possibility of recurrent
partial dissolution and redeposition with the latter process domi-
nant during the warm part of the year, this does not alter the
fact that the depositional balance is confined to the elevated
temperatures of the yearly range. By contrast, Strombus gigas
showed rhythmic fluctuations of shell growth temperatures ex-
tending over all but the opposite extremes of the yearly tempera-
ture range, hence depicting fairly accurate seasonal temperature
variations of the inhabiting waters. Considered in terms of the
implications of the cross-sectional seasonal temperature studies
of these two forms, the comparison of average skeletal tempera-
tures of the scatter range near that of Strombus gigas-inlerred
species with skeletal temperature recordings essentially through-
out the year, while those near that of Chama macerophylla
are confined in their recording range to the warmer temperatures
of the yearly amplitude. The highest determined mean average
temperatures such as, e.g., the ones of the sessile reef-dwelling
Homotrcma rubrum (27.2-29.1°), imply even more rigorous
temperature-time range restriction in deposition as compared
with Ch. macerophylla, those determining the lower end of the
temperature range probably corresponding to the restriction
or preferential deposition during the cold part of the year.
The latter aspect of temperature-determined-volume-secretionary
rates, and also the age of the individual with reference to the
yearly climatic range, must enter into consideration and is prob-
ably contributory to the distributional scatter of the average-
growth temperature observed. Evidence had accumulated for
some time, mostly from study of recent pelecypods, that shell
secretion becomes discontinuous or at least greatly retarded dur-
ing the reproductive period, during unfavorable weather condi-
tions such as storm periods, and in the temperate and arctic
waters during hibernation in winter, e.g. through species and
ecologically determined factors. Compared with the qualitative
nature of these data the Bermuda study has demonstrated the
value of the isotope temperature methods as a quantitative tool
to investigate skeletal depositional relations. Most critically, it
has established that there is sharp differentiation by species of the
threshold limits of the secretionary range of skeletal carbonate.
Illustrated by the example of the tropical species ynacerophylla,
294 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
which occupies reproductively a marginal ecologic niche in the
shore waters of Bermuda, the skeletal secretionary range as
apparently determined by environmental temperatures is re-
stricted as compared with the climatic and climatic-reproductive
tolerance range of the species. This then constitutes a refinement
in extending the range of ecologic parameters for a given species
to the skeletal secretionary processes, which in Recent forms
can, of course, be determined also by systematic observational
means. From the paleoecologic point of view, the primary signifi-
cance lies in the fact that this has been the first method developed
which makes it potentially feasible (and it has been demon-
strated) to obtain information on this particular parameter in
the fossil record. In consequence, the method potentially opens
the way to charting evolutionary changes in skeletal secretionary
behavior with reference to environmental temperatures in line-
ages. The information may further aid in such cases where
habitat-restricted-ranges become evident with time, from zoogeo-
graphic studies, to determine whether the skeletal-secretionary-
range relations with environmental temperatures indicate pre-
adaptations with reference to the restrictive drift or shifts, which
in turn may contribute towards the evaluation of the genetic
relationships of lineages where such are open to question.
The degree of differentiation in skeletal-secretionary behavior
and the common incidence of this phenomenon in the Recent Ber-
muda biotic elements examined center the orientation of the
method of approach in the paleobiologic inquiry where the cli-
matic amplitudes (against which the recording ranges of skeletal
carbonate are measured) are unknown. The nearly complete cli-
matic range obtained (from the sum total of average growth
temperature of a large number of species from different classes)
indicates that this approach should then lead in paleotemperature
studies, to defining climatic amplitudes more likely averaged over
the length of time involved in the fossil samples examined, hence
to climatic information. In turn it should lead to the evaluation
of the temperature niche position of the individual species. Thus,
where the variety of fossil species of isotopically unaltered car-
bonate can be obtained in assemblage form, and provided that
these do not constitute a condensation product of skeletal accumu-
lations across a significant climatic gradient or period of fluctua-
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 295
tion, reliable information with reference to the various aspects
of application considered potentially feasible, heretofore, should
be obtainable.
The question whether fossil skeletal carbonates with original
isotopic abundances extend back in the sedimentary records in
time has been answered in the affirmative for individual cases
as far back as the early Jurassic (Urey ct al., 1951). Criteria to
recognize original 018/016 ratios in fossil carbonate skeletals
have been based on the following considerations :
(1) The isotopic ratio-inferred-temperatures lie within a rea-
sonable range of present-day temperatures, e.g. from 0 to 30 °C.
(2) Where cross-sectional temperature determinations could
be carried out, variations (if they occurred) would follow the
familiar pattern of seasonal variations established in present-day
carbonate skeletons and lie within a reasonable range.
(3) The inferences from the burial assemblages and their
faunal compositional makeup and regional paleogeographic con-
siderations indicate the probability that we are dealing with
essentially normal salinity ranges ; hence, that the isotopic abund-
ances had not been affected critically by lighter fractions from
fresh water dilution or by heavier fractions due to excess insola-
tion, i.e. hypersaline enrichment.
Within the framework of the orientation required from the
study of present day biota as to the mode of reliable information,
investigations and the criteria employed to evaluate isotopic
abundances as to their state of retention of the original composi-
tion, Pleistocene (Bmiliani and Epstein, 1953; Epstein and Low-
enstam, 1953), Tertiary (Emiliani, 1954), and Cretaceous fossils
(Lowenstam and Epstein, 1954) have been examined in numbers
as far back as the post-Aptian. The most extensive exploratory
studies to date (concerned with the potential applicability of
the method to the fossil record) were those of mid-to-late Cre-
taceous assemblages (Urey et al., 1951; Lowenstam and Epstein,
1954). As these are also the oldest assemblages investigated in
space and time, the results from the latter study serve best to
illustrate the status of information obtained with reference to
the various questions raised earlier in this still exploratory phase
of the investigation.
The preservation of entirely aragonitic skeletons and aragonitic
296 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
micro-architectural units in other skeletons in the Coon Creek
fauna at the type locality in Tennessee widened the range of
investigation to all burial associated elements. Hence, it has been
possible here to integrate average skeletal growth-temperatures of
extinct species, to define the approximate amplitude of local tem-
perature variations, and to study the growth ranges of each
species within the range as indicated by their average skeletal
temperature records. The mean temperature of seventeen species
including polychaete annelids, pelecypods, gastropods, and scaph-
opods extends from 20-28 °C, a range of 8°C, which roughly
corresponds to that of the Bermuda niche temperatures of today.
The average temperatures are reasonable throughout, compared
with the present day range and, further, show differences between
the gastropods and pelecypods as noted in the Recent Bermuda
assemblages. Extended in time to other burial associated species,
and supplemented by individual seasonal variation studies, it
should be possible to gain in this (as well as similar preservational
cases) insight into the climatic framework and the skeletal tem-
perature niches of the biota.
The incidence in preservation of aragonitic skeletal materials
has been shown to decrease the further back we go in time in the
sedimentary record. Cast and mold preservation, recrystalliza-
tion or replacement by calcite are numerically vastly more com-
mon in Upper Cretaceous deposits than aragonitic preservation.
The selective screening processes of aragonitic skeletal material
in the common facies range found in the Upper Cretaceous, such
as the characteristic chalks, reduces the range of the analysis to
the calcific fraction of the burial records, e.g. to the calcific skele-
ton or the calcific portions where both polymorphs were involved.
Ostreidae constitute one of the common calcitic elements encoun-
tered in many facies. Loosely meshed layers characterize the shell
of many Ostreidae. Infiltration by diagenetically introduced
calcite of habitat-foreign isotopic abundances is commonly found
in these cases. Hence, calcitic preservation does not a priori assure
reliable temperature information. This, in turn, further reduces
the number of potentially available fossil elements in the arago-
nite screened facies. Because these facies types form the average
situation available for temperature investigations, the analysis
became centered on the question as to the extent to which environ-
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 297
mental temperature ranges can be determined in these cases,
which in turn determines whether species-characteristic tempera-
ture threshold limits of their skeletal deposition can be defined.
The common calcitic fossils in this facies range, from sandy
marls through pure chalks to coarse bioclastic debris sands, con-
sist of belemnite guards, the prismatic layers of Inoceramus
species, Ostreidae and brachiopods. Of these, the belemnite rostra
had been found early in the investigation (Urey et al., 1951) from
several seasonal variation studies and average temperature deter-
minations, to preserve, commonly, original isotopic abundances.
Confirmed by subsequent investigations of large numbers (Low-
enstam and Epstein, 1954), belemnites were selected as points of
reference for evaluation of the isotopic abundances of representa-
tives of other common burial associates. Comparison of such
assemblages in limited stratigraphic sequences in individual
quarry sections, between quarry sections and also over wide areas,
as e.g. from southwest Sweden to the Paris basin, and in time
from the Albian through the Maestrichtian, showed the mean
temperatures of the few brachiopods examined were consistently
higher than those of the associated belemnites, the average differ-
ence of 7 brachiopods amounting to about 5°C. In the case of the
Inoceramidae there were indications that the average tempera-
tures roughly correspond to those of the belemnites, while those
of the Ostreidae appeared to be again elevated (Lowenstam and
Epstein, 1954). Poor correlation between belemnites and burial
associated Inoceramidae, and randomness with reference to the
Ostreidae, and the occasional find of shells with inferred tempera-
tures in excess of 30° C in both groups indicated that secondary
calcite introduction has induced shifts in many cases to varying
extent, requiring a higher degree of critical examination as com-
pared to the brachiopods. Of the less common burial-associated
elements with reliably appearing temperature records, including
some aragonitic forms, there are some indications that Dentalium
representatives have a lower average temperature range; Pec-
tinidae seem to correspond in average temperature to those of the
belemnites ; and echinoids seem to show a higher temperature
roughly corresponding to those of the brachiopods. Numerically,
the data in these belemnite associates are few and their skeletal-
depositional-threshhold ranges can only be considered as approxi-
298 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
mately defined. They seem to corroborate, however, by means of
the relations indicated by the brachiopods and the reliable
appearing Ostreidae data, that the average temperature of the
belemnite lies somewhere in the lower range of the yearly ampli-
tude. Following roughly the time-temperature trend of such
benthonic elements as the brachiopods seems to strengthen the
view that the nektonic belemnites of the post-Aptian Cretaceous
were entirely (or during most of their skeletal growth periods)
shelf dwellers. This view is in harmony with the results obtained
from functional morphologic studies and their restricted facies
distribution.
The results from the average facies faunae though meager as
compared to that of the Coon Creek type of assemblage-preserva-
tions, nevertheless lead to a number of critical biologic and
climatic deductions from the belemnite data. The inference that
the belemnites occupied a shelf -water niche rather than migrated
seasonally to deeper cooler waters implies that the oscillating
curve exhibited by the average temperature data from the post-
Aptian through the Maestrichtian depicts the climatic history of
this time interval between Scandinavia and the Paris basin.
Climatic deterioration from the Albian into the Cenomanian
followed by a recurrent rise in temperature to a climatic optimum
in the Coniacian-Santonian followed by a decline towards the
Danian is thus depicted. The distributional pattern of the warm
water Globotruncana species follows the same trend in western
and central Europe (Wicher, 1953). A slight equatorially north-
ward displaced tropical belt, flanked by relatively cooler boreal
zones, though poorly defined, is indicated for the Albian by the
belemnite data from widely scattered parts of the world. From
southwestern Scandinavia to England and the northern rim of
the Paris Basin, essentially uniform climatic conditions are
indicated for the Campanian. If a poleward climatic gradient
existed it must have been located north of the traverse. Further
climatic deterioration in the succeeding Maestrichtian period is
evidenced by climatic differentiation along a belemnite tempera-
ture traverse from the Gulf coast in the U.S. through Holland
northeastward and toward Scandinavia. The indications of simi-
lar to perhaps still cooler temperatures for the Danian, as indi-
cated by the few echinoid and brachiopod temperature data in
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 299
agreement with the type of Coccolithophoridae found in Danian
deposits of Denmark (Henning, 1899), and foraminiferal evi-
dence, accentuates rather than contributes toward solving the
problem of mass extinction among marine and terrestrial groups
at this time.
Another aspect, to which the paleotemperature determinations
do seem to contribute, is an ecologic facet of the belemnites, the
evolution of temperature niche occupation. The cosmopolitan
distribution pattern of the early Cretaceous belemnites, particu-
larly notable for the Albian species, underwent a sudden restric-
tion in that their descendents become confined to the boreal zones.
At first eurythermal, as indicated by the mean temperatures of
the Albian species, the belemnites became subsequently steno-
thermal with temperature tolerance limits ranging from temper-
ate to marginal subtropical. This view is supported by the
northward migration of their spacially-defined distribution-zone
(from Turonian to early Campanian) in the northern hemisphere
reaching into the arctic and shifting subsequently back towards
the south thus corresponding to the gross climatic fluctuations
indicated. Parallel migratory shifts of the Belemnitella-Belem-
nella species during the Maestrichtian, as shown by Jeletzky
(1951), suggest further partition in temperature range on the
generic level.
The fairly smooth curve of Upper Cretaceous belemnite data
seems to speak against major evolutionary changes in tempera-
ture threshhold ranges of the belemnites. The only detailed sec-
tion at Balswick, Sweden, where temperature data on two genera
( Actinocamax and Belemnitella) in close stratigraphic succession
were determined, lacks corresponding evidence of a shift in genus
determined threshold limits.
Though still in the exploratory phase of the investigation, the
manifold potential contributions by the oxygen isotope method
are already in evidence. They pertain basically toward gaining
a clearer concept of the threshold limits of skeletal deposition
with reference to environmental temperatures in the Recent as
well as fossil forms, and toward quantification of the climatic
history. It is also evident that evaluation of, and full advantage
of the resulting information from, the fossil record is dependent
upon the integrated analysis of functional, morphologic, zoogeo-
300 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
graphic and paleo-geographic information derived by already
established conventional methods.
SKELETAL MINERALOGY
The crystalline calcium carbonate skeletal hard parts of recent
marine organisms consist in most cases examined of the two poly-
morphs calcite and aragonite. Consideration in the following is
confined to their distribution relations in marine organisms.
Determinations initially directed towards surveying skeletal
polymorph composition in different species were concerned prin-
cipally with the elucidation of their distributional pattern across
the spectral range of carbonate synthesis. Data were accumulated
gradually on numerous species in the different phyla. These indi-
cated that single polymorph composition, that is, either calcite
or aragonite, was dominant. When viewed in the order of suc-
cessive levels of increasing complexity in organization, the impres-
sion of a random distribution pattern in synthesis products
seemed indicated. Polymorph compositions were found largely
to be constant on the order level and in the Echinodermata even
on the phylum level. By contrast, considerable complexity in
polymorphic differentiation on the genus or even in a few cases
on the species level was found to exist in the pelecypods and gas-
tropods. In these (comparatively) most thoroughly investigated
groups (Boggild, 1930), coexistence of calcite and aragonite was
shown to occur. The determinations of skeletal polymorphs were
generally presented without accompanying information on the
number of individuals per species examined, their location of
derivation or their ecology. The investigations once made were
treated as diagnostic for the species and where the composition
was found to coincide in several unrelated species, the diagnosis
was extended to be inclusive for higher taxonomic categories. The
basic assumption underlying such treatment seems to have been
that polymorph composition is invariably genetically fixed within
a given species or complex of species.
In paleobiologic terms the polymorph composition furnished
independent criteria for defining species or higher taxonomic
categories. In turn, it extended the potential basis of phylogenetic
studies of carbonate skeletons from pure morphologic to crystal
compositional aspects. In this, it opened a distinct avenue of
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 301
approach to the charting of certain physiologically determined
surface expressions of biochemical evolution.
Data accumulating on the polymorph composition and their
micro-architectural characteristic in calcareous fossil skeletons
soon pointed to the existence of such shifts and occasional compo-
sitional changes within a number of phyletic lines. Critical data
and the pertinent literature will be found in Boggild's 1930
study on the micro-architecture and polymorph composition of
the Mollusca; it contains notes also on representatives of most
major carbonate-secreting groups. Polymorph compositional
changes were shown to occur in a number of mollusk lineages and
a shift from calcite in the Paleozoic corals to aragonite (with some
exceptions) in the post-Paleozoic ones was inferred on grounds of
micro-architectural retention in many of the ' calcite preserved
Paleozoic forms. While these examples furnished evidence of
factual changes of polymorph composition in certain lineages,
and provided indirect evidence for others, the implication that
these constitute physiologically determined evolutionary changes
was dependent upon the correctness of the basic premise that the
polymorph composition in species is generally fixed genetically.
Recent studies have shown, however, that species defined con-
stancy in skeletal polymorphs, while common and perhaps even
prevalent among marine carbonate-secreting species is by no
means the general rule. Instead, examples have been detected
among the Bryozoa, polychaete annelids, pelecypods and gastro-
pods in which the skeletal polymorph compositions vary in species
defined terms in individuals as a function of relative age and in
response to environmental factors (Lowenstam, 1954 a, b). The
range of total variability observed extends from 100 per cent
calcite through intermediate mixtures of calcite and aragonite
all the way to 100 per cent aragonite. Where examined specifi-
cally, the co-existing polymorphs always form micro-architectur-
ally distinct skeletal elements. Also, as far as determined to date,
the variability ranges extend for individual species only over
parts of the total range of from 100 per cent calcite to 100 per
cent aragonite. The general tendency of an increase of aragonite
over calcite with increasing environmental temperatures indi-
cates that temperature effect is primarily involved. Two distinct
types of relations between polymorph composition and tempera-
302 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
ture have been noted: (1) The crystal chemical composition in a
given species varies between individuals in response to environ-
mental temperatures over the entire species-defined climatic
range. The average polymorph composition of an individual is
then dependent further upon an array of factors such as the secre-
tionary range as defined by species characteristic threshold limits,
which may or may not coincide with the yearly amplitude of
environmental temperatures. It further depends upon the volume
secretion of the two polymorphs at a given temperature, again as
«0%
abcdefgh i j k Imnopqr
Fig. 1. Variations of aragonite with consecutive growth increments of a
recent polychaete worm tube of Ewpomatus gracilis from Bermuda.
characteristic for a given species, the relative age of the individ-
ual, and individual growth rates. (2) The polymorph composi-
tion varies only at locations at the fringe of climatic tolerance,
but is constant for the species within its climatic range. The
temperature-skeletal-polymorph-relations exhibited in the latter
type are transitional between species with skeletal-polymorph-
deposition independent of the environmental framework and those
of the first type dependent throughout. The relation most clearly
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 303
defined in the latter type hence will be considered first. The most
convincing evidence that a temperature effect is involved should
be provided by skeletons in which deposition is confined to periph-
eral growth expansion. Consecutive growth increment should
then consist of polymorph compositions differing as a function of
the temperature at which they were laid down. Such skeletons
grown in an environment with a large yearly amplitude in tem-
peratures should then exhibit corresponding seasonal variations
in polymorph composition. Corroborating evidence is provided
by the polymorph compositional changes of successive increments
determined for a polychaete serpulid worm tube from the Ber-
muda inshore waters (Fig. 1). The oscillating curve of the
aragonite-calcite ratios is based on the averages of successive cuts
of three mm. in length each separated by a gap amounting to
1 mm. The curve defines partially two maxima and one aragonite
ratio minimum. The aragonite ratios defining the last growth
stages decrease progressively to a minimum. The value of the
very last growth portion is slightly lower than the one defining
the maximum aragonite ratio peak of an earlier growth stage.
The specimen was collected alive on July 2, 1953, at a temperature
of 27 °C, which is 3°C lower than the summer maximum of
30 °C at this location. Hence, the oscillating curve can be inter-
preted as a seasonal variation curve of temperature-related
aragonite ratios. In mollusk shells such as pelecypods, skeleton
secretion has been shown to take place not only at the shell mar-
gins, but also intermittently on the inside. This obviously negates
seasonal variation studies similar to those feasible for serpulid
worm tubes. A measure of the existence of a temperature effect
on the shell polymorphs can be obtained, however, even here by
determining the aragonite ratios of graded shell size series repre-
sentatives of the size range of habitat-associated conspecific popu-
lations. This has been demonstrated, e.g., in a growth series of
Mytilus calif or nianus (Lowenstam, 1954 b) (Fig. 2) where the
oscillating curves thus obtained showed correspondence to a 2
year period, with the largest shell corresponding to a 2 year old
individual as determined by the growth studies of Coe and Fox
(1942). Obviously the aragonite ratios of the individual shells
represent averages of the growth period. Hence, the aragonite-
calcite minima and maxima ratios defined by the oscillation
304 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
curves thus obtained in pelecypods and gastropods do not corre-
spond to the values of secretion at the opposite ends of the yearly
temperature range as in the growth increments in the Serpulidae
tube.
The secretionary behavior pattern of skeletal polymorphs of
the second type is illustrated by the subtropical to tropical gastro-
pod species Littorina ziczac. Individuals analyzed from Bermuda
and the Keys of Florida showed shell compositions of 100 per
cent aragonite throughout, while those taken from the marginal
MYTILUS CALIFORNIANUS, LA JOLLA, CALIFORNIA
1 1 ■
ii i
.. . _
»«
III
Z
O
o
<60%
<
50%
40%
30%
'■ A.
/. "S
■ i i
-
01 0.5 1.0 5.0 100 50.0 100.0
WEIGHT, GRAMS
Fig. 2. A plot of shell weight of Mytilus calif omianus versus aragonite
in the shells taken from a single growth series from La Jolla, California.
temperature range at Galveston, Texas, where temperatures ex-
tend down to 14.3 °C exhibit traces of calcite as indicated by the
range from 97 per cent aragonite to 100 per cent aragonite. A
skeletally defined temperature effect in the polymorph composi-
tion here as in other species reported (Lowenstam, 1954) is thus
clearly confined here, to the marginal climatic range.
The relations to temperature indicated by the skeletal-poly-
STATUS OP INVERTEBRATE PALEONTOLOGY, 1953 305
morph composition in species of the two types are consistent in
that they conform to a common pattern of increase in aragonite
over calcite with elevation and temperature. The relations differ
in that the polymorph ratios in species group 1 may increase only
to very high aragonite values without total suppression of the
calcite fraction, while in species in group 2, threshhold conditions
for 100 per cent aragonite synthesis are attained commonly in
the range from warm temperate to marginal subtropical tempera-
tures. There is secretion of aragonite only from there on up
through the subtropical to tropical temperatures, which define
most of the entire range of species in this group. This raises the
question whether constant polymorph composition as found in
many species can be considered a priori as a sound criterion of
species-determined-modification-synthesis, independent of eco-
logic controls such as temperature. There are numerous species
with constant aragonite-composed skeletons which are distribu-
tionally confined to warm water temperature range. For instance,
in the genus Choromytilus, the tropical species palliopunctatus
has, where examined, a shell composed of 100 per cent aragonite.
If the species were capable of occupying colder-water niches,
threshold conditions for calcite secretion would likely be attained
with the result of shifting aragonite-calcite-ratio of secretion
similarly to that actually found in the cooler-water niche occu-
pants (the species meridionalis and chorus of this genus). Cor-
roboration of the interpretation that a temperature effect is the
determining factor in the constant aragonite composition of the
tropical species seems here to be provided by examining jointly
the modification synthesis pattern of congeneric species occupy-
ing successively higher temperature niches as similarly observed,
e.g. in the Littorinidae and Spirorbinae (Lowenstam, 1954 a, b).
Based on these observations the interpretation of temperature-
determined-modification-synthesis has been extended to embrace
species with constant aragonitic skeletons over their distributional
range in which all species in a given genus, order or even class
are either confined to the warm water range or only there synthe-
size aragonite or skeletal carbonate as such. This is the case in
the green, brown, and red aragonite secreting algae, the aragonite
secreting alcyonarians and numerous pelecypod and gastropod
species such as the Tridacnidae and Cypraeidae. The abrupt
306 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
reduction in number of species of scleractinian corals, aragonitic
in skeletal composition throughout at the lower subtropical tem-
perature limit from the wealth of reef building forms above to a
few deep water type species below, then seems to be the least
conspicuous expression of the grading spectrum of temperature
related polymorph compositional patterns so far noted.
At this early phase of the inquiry, temperature affected modi-
fication synthesis has been widely recognized to extend over the
phyla spectrum of increasing complexity discontinuously from
the Anthozoa to the Mollusca and to the calcareous algae. Species
with temperature-sensitive aragonite-calcite ratios are found
among the Bryozoa, polychaete worms, gastropods and pelecy-
pods, while those with constant aragonite composition throughout
are confined to the warm water range among the Anthozoa, gas-
tropods, pelecypods, and polychaete worms.
In relating temperature as a determinant on the calcite or
aragonite secretions or both in varying ratios, it is not known at
present whether temperature acts directly upon the biochemistry
of the secretionary processes (i.e., determines certain enzyme
activation between certain threshold temperatures and the activ-
ity levels over their denning ranges) or, whether temperature
affects intermediate steps in the reaction, such as an effect by
temperature of external environmental properties such as the pH
of the surrounding aqueous mediums which in turn effects the
biochemistry of the secretionary processes. Differences in the
aragonite ratios and the range in value as found among species
occupying the same habitat, and hence subject to the same yearly
amplitude in environment, demonstrate, however, that species-
determined differences in biochemical reactions (of whatever
nature they may be), are involved. Some of the differences in
range of variations in aragonite ratios may be attributed to
species determined differences in threshold limits of carbonate
secretion. This aspect has been brought into focus and further-
more demonstrated in an example among pelecypods in the dis-
cussion concerning oxygen-isotope-determined-shell-growth-tem-
peratures. Other species-determined-modifying-effects possibly
concerned, suggested by Epstein and Lowenstam (1953), may
involve differences in volume secretion of the aragonite calcite
ratios at a given temperature and in some cases intermittent
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 307
partial skeletal resorption.
Other environmental factors may also affect, though to a lesser
extent, the aragonite calcite secretion (Lowenstam, 1954 a, b).
At present the possibility of a salinity effect seems indicated.
The aragonite-calcite ratios in species occupying brackish waters
appear to be considerably higher in eonspecific populations than
would be expected for the species within the temperature range
which they occupy.
In the Littorinidae some species with entirely aragonitic shells
may be found in temperate climates side by side with species with
temperature affected shifting aragonite calcite ratios. Ecologi-
cally, it can be shown that the former species is more advanced
in its adaptation to subaerial respiration and is interpreted as
physiologically more independent of temperatures because of its
higher degree of adaptation to land life, as compared with the
latter.
The implications discernible at this stage of the investigation
of recent forms concern primarily the definition of species with
temperature affected polymorph composition other than those
where the polymorph composition is constant throughout. In
terms of the two parameters : temperatures and aragonite-calcite
ratios and their range involved, Littorina ziczac can be defined
as 97-100 per cent aragonite/14°-30.5°C. As shown by numerous
investigators most admirably by Boggild (1930) in the Mollusca,
the two polymorphs, where they are found coexistent in the shell
of a given species, form micro-architecturally separate elements.
These are found in layered succession or sometimes alternation
and differ microstructurally not only between polymorph-defined
layers but may be differentiated further in the layered succession
in monomorphic units. One of the obvious questions since raised
by the discovery of a temperature effect on skeletal polymorph
composition concerns the micro-architectural changes involved
in the change from aragonite and calcite bearing shells to entirely
aragonitic ones. In the Mytilidae, in the species californianus
from La Jolla, the outer calcitic portion is composed of a prismatic
layer of, in part, regularly vertically arranged, and in part
slightly inclined, crystals similar to that found in the species
edulis. The aragonitic portion of the shell consists of the common
nacreous type distinguished by Boggild, which forms thin-leaved
308 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
lamellae essentially parallel to the shell curvature in edulis. In
the species perna shells from Manila, Philippines, and the South
China Sea with entirely aragonite exoskeleton show two nacreous
units in succession. The outer aragonitic unit consists of lamellae
which are steeply outwardly inclined, then curve downward to
become parallel to the shell axis and thus acquire here the struc-
tural attitude of the lower aragonitic unit steeply outwardly in-
clined but curved downward. The outer lamellar aragonitic layer
corresponds to the prismatic calcitic layer in the species calif orni-
anus and edulis. Hence, in an extreme shift such as the one
discussed from a shell composition of coexistent aragonite-calcite
to 100 per cent aragonite, the ecologic, that is the temperature,
effect involves further a radical change in micro-architecture,
perhaps basically determined by crystal chemical growth char-
acteristics.
The development of trace amounts of calcite only in the mar-
ginal temperature range of otherwise aragonite-secreting species
may find application in paleoecologic research. The lower limits
of the climatic range, hence the evaluation of the geographic
range, may be thus detectable in similar fossil occurrences.
The most critical implication, however, concerns the realization
that polymorph compositional and related micro-architectural
changes in species traced back in lineages through geologic times
are not necessarily to be attributed to evolutionary changes but
may be purely ecologic expressions. The supposed mytilid Cune-
olis tippana from the Maestrichtian Coon Creek deposits of west-
ern Tennessee composed entirely of aragonite is a case in point.
Polymorph shell composition at variance with that of Mytilus
edidis (Boggild, 1930; Stephenson, 1941) which was until re-
cently thought to be representative of the Mytilidae lineage, had
been considered of evolutionary significance. As noted in the
discussion of the paleotemperature determinations of parts of the
Coon Creek burial assemblages, the environmental water tem-
peratures were shown to be subtropical. The average shell-deter-
mined temperature of Cuneolis tippana, one of the species
analyzed by the oxygen isotope method, assures further its deriva-
tion from this climatic niche. Lying within the temperature range
where present, Mytilidae secrete entirely aragonitic shells; the
same shell composition in Cuneolis tippana can be attributed to
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 309
its ecologic temperature niche rather than an evolutionary change.
Aside from Cuneolis tippana, Boggild (1930) called attention
to differences in crystal polymorph composition between present-
day and fossil representatives mostly in other families of the
pelecypods, gastropods, cephalopods and the Anthozoa but with-
out interpreting their biologic significance. The differences are
in part factual, that is they are based on observed differentiations
in crystal polymorph compositions. In part they are inferred,
based on the evaluation of calcite-preserved fossils as to whether
their skeletal calcites are primarily secretionary in origin or con-
version or replacement products of original aragonite. Crystal
arrangement and orientation in their relations to micro-architec-
tural preservation constitute Boggild 's criteria for differentiat-
ing the two. Differences in crystal polymorph composition
between fossil and present-day representatives, based on the
latter criteria, are therefore interpretive in nature and their
reality is dependent upon the validity of the criteria employed.
In the pre-Cretaceous deposits aragonite preservation in skeletal
carbonates is, as earlier pointed out, rare ; hence tracing of the
polymorph compositional characteristics here becomes largely in-
terpretive. Therefore, when considered in conjunction with the
as yet inadequate information on crystal polymorph distribution
in present day biota, which initially constitutes our plane of ref-
erence for comparison, the inquiry into aspects of skeletal evolu-
tion is best confined at this stage toward interpretation of the
published data in phyletic lines and largely as a matter of orienta-
tion. Crystal polymorph compositional determinations of fossils
exist only for a few time-distant representations of the various
lineages in which compositional changes were reported by Bog-
gild. The patterns derived from these, if they indicated trends
in polymorph compositional changes in consequence must be
treated with utmost caution as to their evolutionary implications
and can at best be regarded as probable rather than certain.
From the methodical point of view, examples with the least com-
plex relations are the most desirable for the initial analyses.
Therefore, consideration of those groups in which present-day
species indicate either throughout or at most a partial tempera-
ture effect on their skeletal-crystal-polymorph compositions,
seems best postponed at least until the relations for all present-
310
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
day species have been precisely defined. This eliminates most
pelecypod and gastropod lineages in which polymorph composi-
tion changes were indicated by Boggild. This view is fully justi-
fied in the light of the earlier noted example of Cuneolis tippana
which in consequence of the relatively more representative data
COELENTERATES
I 2 3 4 5 6 7 8
M
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
CEPHALOPODS
12 3 4 5 6
X
25
?
EzzaCalcite
mm Araqonite
77m Calcite S
Aragonite
Fig. 3. A schematic presentation of some inferred phylogenetic changes
in crystal polymorph compositions. (Fossil data from Ikrggild.) Coelenter-
ates: 1. Hydrocorallina, 2. Stromotoporoidea, 3-4. Alcyonaria, 5. Tabulata,
6. Eugosa, 7-8. Scleractinia. Cephalopods: 1-2. Nautiloidea, 1. shell, 2. beak
tippings; 3-4. Ammonoidea, 3. shell, 4. aptichi; 5. Belemnoidea; 6. Sepi-
oidea; 7. Octopoda.
for the present day Mytilidae could be evaluated to the effect
that the aragonitic shell can be related to environmental control
and not to an evolutionary change.
Groups which comprise species with single crystal polymorph
composition which are today either environment independent
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 311
throughout, or where the type of polymorph secretion seems to
be temperature determined but remains unchanged over the niche
range of the species, would seem best suited for the analyses of
few time-distant representatives with crystal polymorph deter-
minations in phyletic lines.
Changes in crystal polymorph composition in the course of
evolution of groups of this type have been reported by Boggild
for the Coelenterata and Cephalopoda. Their crystal-polymorph-
compositional-distribution relations as derived from Boggild 's
data are schematically shown in Figure 3. The principal features
of the relations indicated are: 1) the skeletal-polymorph compo-
sition of the fossil representatives indicated at variance with
those of the present-day species, appear so far as determined,
prevalently monomorphic in most cases for all members of a given
family, order, or even subclass, which is analogous to the present
day representatives. 2) Once a compositional change became
initiated, the composition appears to have remained constant from
the start of differentiation of the group, as far as determined,
until the present day or until extinction. 3) The changes in
polymorph composition in the cephalopods coincided and were
apparently related to effects which involved profound changes in
morphology and body function of the skeletal hard parts in con-
junction with anatomical reorganization that determined their
relocation in the body. 4) "Organo-typic" that is, anatomically
localized calcium carbonate secretion, occurred in the course of
evolutionary phases in the cephalopods. These are the calcitic
aptychi in the Mesozoic ammonites and beak calcitic calcification
in the nautiloids. In all cases these differed in their calcitic com-
positions from that of aragonitic shells. 5) Calcite appears to
have formed the secretionary product more prevalently in the
early phases either alone as in many Paleozoic coelenterate
groups, or was coexistent with aragonite in the early nautiloids.
Aragonite seems to have become more prevalent in the later
phases in evolution in these cases either through group replace-
ment with aragonitic skeletal bearing types, as indicated by the
change from calcite in the Paleozoic tetracorals to the aragonitic
scleractinians, or, as in the alcyonarians, it occurred through late
introduction of aragonite secreting groups. Thus if any reliance
can be placed on the crystal polymorphs assigned to the earlier
312 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
representatives on grounds pointed out previously a slight net
gain in spread of aragonite over calcite seems to be indicated.
More reliable data based on added criteria of evaluation of cal-
citic skeletons in the lower half of the stratigraphic column are
obviously required to ascertain whether the indicated relations
are correct.
TRACE ELEMENT CONCENTRATIONS
The trace element content of skeletal carbonates has long been
the subject of investigation. For most elements the widely scat-
tered literature1 shows that the studies have been limited in scope
and confined to small biotic groups or to scattered individual
analyses. Two major trace elements, strontium and magnesium,
are notable exceptions. In recent years broad surveys of the dis-
tributional abundances of these elements have been made with
improved techniques over the range of the phyla spectrum of
carbonate synthesis. The biogeochemistry of strontium has been
investigated by Odum. To date only the general conclusions and
certain phases of the study have been published (1950-51).
Magnesium has been studied, principally in the calcite-secreting
biotic representatives, by Chave (1954). The toleration of stron-
tium is greater in aragonite than in calcite while magnesium is
more acceptable in calcite than in aragonite.
The two studies clearly establish the significance of skeleton
trace element chemistry as an added source of information on
physiologic, and therefore phyletic aspects. There are certain
common features that determine the distribution levels of both
elements. Within the limits imposed by the toleration of the
crystal chemical composition the physiology of the species as
determined by its phyletic position controls the uptake ranges of
these groups. The strontium uptake is apparently ecologically
dependent only on the concentration in the aqueous medium. In
the case of magnesium, temperature plays a major role.
The initial discovery of a temperature effect on the magnesium
!The widely scattered information on the biochemistry of marine organ-
isms has been brought together and interpreted by Vinogradov. Thanks
to G. E. Hutchinson this work has been translated into English, brought up
to date and the bibliographic presentation revised to allow easy consultation
of references cited in the text.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 313
level in certain biotie groups was made by Clarke and Wheeler
(1922). The work of Chave (1954) has shown that a temperature
effect is generally involved in calcite-bearing species throughout
the entire phyla spectrum. He shows that the effect may further
extend to the low magnesium types of aragonitic skeletons. At-
tempts to quantitatively evaluate the temperature effect can now
be made. Certain deviations from the trends in the temperature-
magnesium concentration relations are interpreted to denote
discontinuous skeletal growth. This is consistent with relations
shown to exist by the oxygen isotope method (Urey et al., 1951;
Epstein and Lowenstam, 1953).
The concentration relations of magnesium exhibited by the cal-
cific skeletal types may provide another independent index of
the temperature. They are subject, however, to modification by
physiological influences reflecting the phyletic position these
occupy.
The isolation of environmental effects such as temperature on
the magnesium levels is dependent upon selection of appropriate
specimens where environmental data pertinent to the evaluation
are available. The same approach has brought out the existence
of the earlier noted temperature effects on the polymorph compo-
sition as expressed in aragonite ratios. Although temperature has
no apparent influence on the strontium levels in either calcite or
aragonite, the temperature influence on the crystal polymorph
ratios should be reflected in the total strontium content of the
calcium carbonate skeleton. In consequence of the increase in
aragonite content with elevation in temperature, it would follow
that the strontium concentrations for the skeletons as a whole
should increase with the elevation in temperature. This has been
demonstrated in the case of the serpulid worm tubes where there
is a trend of increasing strontium concentration between the
calcific cold water and nearly all the aragonitic warm water end
members of a series examined (Lowenstam, 1954a).1 The same
relations have since been noted in two small population samples
of Littorina littorea from the Mt. Desert area in Maine with the
magnesium, barium and manganese levels paralleling the trend,
though differing in particulars. These examples indicate then
1 These, as well as all subsequent trace element data discussed were deter-
mined spectrographieally by O. Joensuu of the University of Chicago.
314 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY
that temperature may indirectly, through its effect on the arago-
nite ratios in certain species, also control the total strontium con-
centrations of carbonate skeletons. It should be noted, however,
that the data for the Mytilidae are as yet inconclusive and those
for the Littorinidae as a whole seem to be so far negative. Other
local ecologic factors appear to be involved in the latter case.
Therefore, not until the same relations observed in the Serpulidae
and local Littorina populations have been established in other
biotic groups with temperature-sensitive-skeletal polymorph-
compositions would it seem legitimate to assume that we are
dealing with a widespread phenomenon. Despite this distribu-
tional uncertainty, the fact that temperature may indirectly
affect, via the shifting aragonite-calcite ratios, total strontium
levels in skeletal carbonates at all, adds basically another ecologic
factor to the one pointed out by Odum (1950). With regard to
the influence of the aqueous medium on the strontium concentra-
tion, it is worth noting that biotic mass fixation of high strontium
bearing aragonites, by green, red, and brown algae, scleractinian
corals, and serpulid worms on the warm water reef sites may in
turn affect the concentration levels locally in the waters. Stron-
tium fixation is here faster than the rate of mixing (Lowenstam,
1954b). This is at least indicated by a comparison of the stron-
tium-calcium ratio of four water samples from over two reefs,
which on the average are lower by about 15 per cent as compared
with that of six samples from cold to temperate waters. Spirally
directed water circulation as shown for Bikini and Bermuda
(Boden, 1952), restricted by the biochemically active reef front,
would seem a plausible mechanism to explain the biologic effect
on the strontium-calcium ratios of the waters here. Verification
by additional data is clearly needed before its implications can be
projected into paleobiologic consideration.
Regarding the paleobiologic aspects, Odum (1951) and Kulp
et al. (1952), have examined the distributional aspects of stron-
tium in fossil carbonates. Where original carbonate compositions
are preserved, as is commonly the case through the Tertiary but
rarely through the Paleozoic, the results are encouraging. In
general, however, conversion, or replacement following solution-
removal of aragonite, is accompanied by reduction in strontium
levels. Older samples tend to have the biologic abundance levels
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 315
modified. Chave's study on magnesium distribution in fossils is
still to be published.
The present task in the trace element studies is the elaboration
of the principles governing- the relations under investigation as
found in present-day biota. It is further dependent upon the
understanding of the post-mortem geochemical processes imposed
upon the skeletal remains of the fossil records.
The foregoing discussion of the present status of investigations
of the various biogeochemical aspects of skeletal building mate-
rials, viewed in this case for that of calcium carbonate, shows that
at this early phase of the inquiry primary concern rests with
the elucidation of relations in present day biota and the formula-
tion of the principles involved. The application to the paleobio-
logy inquiry pertains as far as discernible at present to: (1)
added criteria of taxonomic groups in physiologically determined
crystal chemical and trace element concentration expressions ;
(2) qualitative and quantitative evaluation of ecologic factors
such as temperature through the 018/01G ratios through skeletal
carbonate secretion in polymorph compositional terms and their
trace element concentration levels; (3) the charting of phylogen-
etic changes in the area of biochemical evolution as reflected in
skeletally preserved expressions and in ecologic, e.g. temperature-
defined, niche tolerances.
In the area of actual application, only the paleotemperature
method which utilizes the 018/016 ratios has been extended to
fossil investigations systematically, as shown by its successful
application as far back as the Liassic, and in regional terms to the
post-Aptian Cretaceous, where the results are most encouraging.
These pertain to a better evaluation of the biology of the belem-
nites and their temperature niche adaptational evolution from
mid- to late Cretaceous time, and to the semi-quantitative evalua-
tion of the climatic history of this time interval. The results
corroborate the qualitative temperature evaluation obtained
earlier from zoogeographic studies for this time interval. These
underline the thesis that the value and the rate of progress in the
area of concern by any of the biogeochemical studies is dependent
upon an integration of the various approaches rather than sepa-
rate operation in a vacuum.
Because of the preoccupation with defining the basic relations
316 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
as observable in present day biota, the applications of the poly-
morph compositional relations and trace element abundances are
as yet few or, in the case of evolutionary trends, suggestive rather
than proven. In principle these approaches have basically con-
tributed in orienting the inquiry into paleoecology and skeletal
evolution, and in their various degrees of proven application have
extended the foundations of inquiry into these aspects.
LITERATURE CITED
Abelson, P. H.
1954. Amino acids in fossils. (Abstract). Science, n.s., vol. 119,
p. 576.
BODEN, B. P.
1952. Natural conservation of insular plankton. Nature, vol. 169,
p. 697.
B0GGILD, 0. B.
1930. The shell structure of the rnollusks. K. Danske Vidensk. Selsk.
Skr. Naturvidensk. og Math., Afd. 9, vol. 2, no. 2, pp. 232-326.
Chave, K. E.
1954. Aspects of the biogeochemistry of magnesium. 1. Calcareous
marine organisms. Jour. Geol., vol. 62, pp. 266-283.
Clarke, F. W., and W. C. Wheeler
1922. The inorganic constituents of marine invertebrates. U. S. Geol.
Survey, Prof. Paper 124, pp. 1-62.
Coe, W. R., and D. L. Fox
1942. Biology of the California sea-mussel (Hytilus calif omianns)
I. Jour. Exper. Zoology, vol. 90, pp. 1-30.
Emiliani, C.
1954. Depth habitats of some species of pelagic foraminifera as indi-
cated by the oxygen isotope ratios. Amer. Jour. Sci., vol. 252,
pp. 149-158.
Emiliani, C, and S. Epstein
1953. Temperature variations in the Lower Pleistocene of Southern
California. Jour. Geol., vol. 61, pp. 171-181.
Epstein, S., and H. A. Lowenstam
1953. Temperature-shell-growth relations of recent and interglacial
Pleistocene shoal-water biota from Bermuda. Jour. Geol., vol. 61,
pp. 424-428.
Henning, A.
1899. in Schwarzbach, M. 1950, Das Klima der Vorzeit, p. 135. Stutt-
gart. Ferdinand Enke Verlag.
STATUS OF INVERTEBRATE PALEONTOLOGY, 1953 317
Jelbtzky, J. A.
1951. Die Stratigraphie und Belemnitenfauna des Obercampans und
Maastricht Westfalens, Nordwestdeutsehlands und Danemarks
sowie einige allgemeine Gliederungsprobleme der jiingeren
borealen Oberkreide Eurasiens. Beiheft Geol. Jahrbuch, Heft 1,
pp. 1-142.
Kulp, T. L., K. Turekian, and D. W. Boyd
1952. Strontium content of limestones and fossils. Bull. Geol. Soc.
Amer., vol. 63, pp. 701-716.
LOWENSTAM, H. A.
1948. Paleobiologic implications of the measurement of paleotempera-
tures (abs.). Bull Geol. Soc. Amer., vol. 59, p. 1337.
1954a. Environmental relations of modification compositions of certain
carbonate secreting marine invertebrates. Proc. Nat. Acad. Sci.,
vol. 40, pp. 39-48.
1954b. Factors affecting the aragonite: calcite ratios in carbonate-
secreting marine organisms. Jour. Geol., vol. 62, pp. 284-322.
Lowenstam, H. A., and S. Epstein
1954. Paleotemperatures of the post-Aptian Cretaceous as determined
by the oxygen isotope method. Jour. Geol., vol. 62, pp. 207-248.
Odum, H. T.
1950. Strontium biogeochemistry, ecosystems and paleoecological tools.
Natl. Res. Council, Rept. Comm. on Treatise of Marine Ecology
and Paleoecology, 1949, 1950, no. 10, pp. 55-58.
1951. Notes on the strontium content of sea water, celestite radiolaria
and strontianite snail shells. Science, n.s., vol. 114, pp. 211-212.
Stephenson, L. W.
1941. The large invertebrate fossils of the Navarro group in Texas.
Texas Univ. Publ., vol. 4101, pp. 156-158.
Urey, H. C.
1948. Oxygen isotopes in nature and in the laboratory. Science, n.s.,
vol. 108, pp. 489-496.
Urey, H. C, H. A. Lowenstam, S. Epstein, and C. R. McKinney
1951. Measurement of paleotemperatures and temperatures of the
Upper Cretaceous of England, Denmark, and the southeastern
United States. Bull. Geol. Soc. Amer., vol. 62, pp. 399-416.
Vinogradov, A. P.
1953. The elementary chemical composition of marine organisms.
Sears Foundation for Marine Research, New Haven. Mem. 2.
647 pp.
Wicher, C. A.
1953. Mi'kropalaontologische Beobachtungen in der hoheren borealen
Oberkreide besonders im Maastricht. Geol. Jahrbuch, vol. 68,
pp. 1-26.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 4
REVISION OF THE CHRYSOMELID SUBFAMILY
AULACOSCELINAE
By F. Monros
Fimdacion Miguel Lillo, Tucuman, Argentina
CAMBRIDGE, MASS., U.S.A.
PRINTED FOR THE MUSEUM
November, 1954
Publications Issued by or in Connection
with THE
MUSEUM OF COMPARATIVE ZOOLOGY
AT HARVARD COLLEGE
Bulletin (octavo) 1803 The current volume is Vol. 112.
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Memoirs (quarto) 1864-1938 -- Publication was terminated with Vol. 55.
Johnsonia (quarto) 1941 - A publication of the Department of Mollusks.
Vol. 3, no. 33 is current.
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Vol. 1, no. 17 is current.
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1948 -- Published in connection with the Museum. Publication terminated
with Vol. 24.
These publications issued at irregular intervals in numbers which may
be purchased separately. Prices and lists may be obtained on application
to the Director of the Museum of Comparative Zoology, Cambridge 38,
Massachusetts.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 4
REVISION OF THE CHRYSOMELID SUBFAMILY
AULACOSCELINAE
By F. Monros
Fundacion Miguel Lillo, Tucuman, Argentina
CAMBRIDGE, MASS., U.S.A.
PRINTED FOR THE MUSEUM
November, 1954
No. 4 — Revision of the Chrysomelid Subfamily Avlacascelinae
By F. Monros
INTRODUCTION
Since Crowson's revision of Aulacoscelis in 1946, several
changes have been introduced in the group, so that it seems time
to study it again.
I have undertaken the present revision because I have been
able to examine all the described species (76% of them on the
basis of type specimens) and also because it seems worth while
to make a more detailed study of a group of Chrysomelidae which,
from a theoretical point of view, figures among the most interest-
ing of the whole family.
MATERIAL STUDIED AND ACKNOWLEDGEMENTS
An alphabetical list of the collections examined follows, with
the abbreviations used in the text and the names of the ento-
mologists who made the examination possible, to all of whom
I want to express my best thanks.
California Academy of Sciences, San Francisco (CAS) —
Mr. H. B. Leech.
Carnegie Museum, Pittsburgh (CM) — Dr. G. Wallace.
Chicago Museum of Natural History (CMNH) — Mr. R. L.
Wenzel.
Cornell University, Ithaca (CU) — Dr. H. Dietrich.
Museum of Comparative Zoology, Cambridge (MCZ) — Dr.
P. J. Darlington.
Philadelphia Academy of Sciences (PAS) — Dr. A. G. Rehn.
United States National Museum, Washington (USNM) — Dr.
E. Chapin.
Wilcox collection, Albany, N. Y. (W) —Dr. J. C. Wilcox.
I also want to thank the John Simon Guggenheim Memorial
Foundation for making it possible to study the chrysomelid col-
lections in the United States, and also to collect in the southwest-
ern states, and to make some observations on living Aulacoscelis.
Finally, I want to express my gratitude to the following per-
sons, who contributed in different ways to make the present
revision possible :
Dr. W. H. Anderson, U. S. Dept. of Agriculture, Washington,
for some specimens of Aulacoscelinae intercepted at the
Mexican border.
322 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Dr. E. B. Britton, British Museum of Natural History, Lon-
don, for sending paratypes of Aulacoscelis melyroides Crow-
son, at my request.
Dr. P. J. Darlington, Cambridge, for kindly reading the manu-
script and correcting the language, as well as for the facilities
given at all times.
As for the collections in the Museum of Comparative Zoology,
the following remark seems necessary : Most of the Aulacoscelinae
studied are in the Bowditch collection, which is based mostly on
Jacoby's material. Some of the specimens which have been used
by Jacoby in the Biologia Centrali Americana and are now in the
Bowditch collection have a "type" label, while specimens of
the same species in the British Museum also studied by Jacoby
have been regarded as "types" by Crowson. As it seems difficult
and almost useless to establish which of these specimens must
be considered as the holotypes, I regard all the specimens used
in the Biologia Centrali Americana which fit Jacoby 's original
descriptions and localities as cotypes, regardless of the collection
in which they are now deposited.
HISTORY
1842. Duponchel and Chevrolat briefly described the genus Aulacoscelis
and the species melanocera which they considered close to Phyllocara
(Chrysomelinae). The genus and species were credited to Chevrolat
in Dejean's catalogue, 1837, but the reference cannot be taken into
account, as in that catalogue both terms are nomina nuda.
1865. Without referring to the previous description by Duponchel and
Chevrolat, Stal described Aulacoscelis melanocera which he placed
among the Chrysomelinae, without analyzing its relationship.
1874. Chapuis created the tribe Aulacoscelini (Aulacoscelites in Chapuis),
and transferred the genus Aulacoscelis from the Chrysomelinae to
the Sagrinae; he described a second species from Guatemala.
1874. Gemminger and Harold listed the known species of Aulacoscelis as
Sagrinae.
1877, 1880 and 1888. Jacoby described and illustrated several species and
listed the Aulacoscelis known to occur in Central America. He placed
the genus in the Sagrinae, without further analysis.
1892. Horn described Aulacoscelis purpurea, from southwestern United
States.
MONROS : REVISION OF THE AULACOSCELINAE 323
1903. In the revision of the genera of Sagrinae for Wytsman's Genera In-
sectorum, Jacoby excluded Aulacoscelis which he referred to the
Chrysomelinae.
1913. Clavareau listed the known species of Aulacoscelis, numbering 12. He
placed the genus in the tribe Aulacoscelini at the end of the Sagrinae.
In the more recent catalogues (Leng, 1920 and supplements; Black-
welder, 1946), Aulacoscelis has also been included in the Sagrinae.
1933. Schaeffer described Aulacoscelis ventralis, from Arizona.
1941. Maulik briefly stated that Aulacoscelis cannot be considered as be-
longing to the Sagrinae.
1946. Crowson published a careful revision of the genus which he placed
in a special tribe in the Sagrinae. It is to be noted that in this
paper the Sagrinae had a broad sense, including Orsodacna and re-
lated genera, now split into as many as three different subfamilies
(Orsodacninae, Zeugophorinae and Synetinae), and the tribe Horni-
biini, which is now considered to be a tribe of primitive Eumolpinae.
In the key to species, Crowson omitted A. melanocephala and
wrongly credited A. melanocera to Jacoby.
1949. Monros excluded Aulacoscelini from the Sagrinae and suggested a
position among the primitive Eumolpinae.
1950. Bechyne described A. costaricensi-s, from Costa Rica.
1953. Monros described the new genus Janbechynea from Bolivia and de-
fined the new subfamily Aulacoscelinae, which he considered close
to Chrysomelinae.
PUBLISHED ILLUSTRATIONS AND MORPHOLOGICAL
DATA ON AULACOSCELINAE
General habitus illustrations of the following species have
been published in color :
Aulaoosofilis candezei (Chapuis, 1874, pi. Ill, f. 6; Jacoby, 1888, pi.
35, f. 7).
A. confusa (Jacoby, 1888, pi. 35, f. 6).
A. sanguinea (Jacoby, 1888, pi. 35, f. 10).
A. melanocephala (Jacoby, 1880, pi. 1, f. 1).
A. variabilis (Jacoby, 1888, pi. 35, f. 8, 9).
A. tibialis (Jacoby, 1888, pi. 35, f. 2).
A. grandis (Jacoby, 1888, pi. 35, f. 1).
Janbechynea fulvipes (Jacoby, 1888, pi. 35, f. 3, 4).
J. elongata (Jacoby, 1888, pi. 35, f. 5).
The following species have also been illustrated :
Aulacoscelis melanocera (Monros, 1949, f. 22).
Janbechynea paradoxa (Monros, 1953, f. 1, 2).
324 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Also the following parts have been described and figured :
Labium and maxilla of Aulacoscelis candezei (Chapuis, 1874, pi. Ill, f.
6a, 6b) ; labium of A. melanocera (Monros, 1949, f. 6) and buccal pieces
of Janbecliynea paradoxa (Monros, 19.13, f. 3-6).
Ventral thoracic morphology of Aulacoscelis hogei (Crowson, 1946, f. 26)
and lateral prothoracie of A. melanocera (Monros, 1949, f. 9).
Wing venation of Aulacoscelis hogei (Crowson, 1946, f. 13), A. melanocera
(Monros, 1949, f. 14), and Janbechynea paradoxa (Monros, 1953, f. 8).
Tarsi of Janbechynea paradoxa (Monros, 1953, f. 7).
Metendosternite of Aulacoscelis Mgei (Crowson, 1946, f. 23).
Male genitalia of AuJacoscelis melanocera (Monros, 1949, f. 21).
As can be seen, 70 per cent of all the known forms of the group
have been illustrated, which is much more than the average in the
Chrysomelidae. The morphology of the Aulacoscelinae is also one
of the best known of the entire Chrysomelidae. In spite of these
facts, however, their systematic position has been much confused.
CHARACTERS OF SUBFAMILY AULACOSCELINAE
Of elongate and more or less parallel shape; ventrally pube-
scent. Head not concealed under thorax, pro- or orthognathous.
Clypeus separated from interocular space by a distinct transverse
depression. Eyes rounded, entire, moderately projecting, not
touching anterior margin of prothorax. Antennae inserted on
sides of head, between eyes and base of mandibles, separated by
entire width of frons and not able to be concealed under ventral
surface, subfiliform to slightly serrate, nearly as long as or little
longer than one half the body length. Palpi not truncate at apex.
Ligula semimembranous and distinctly bilobed. Dorsal surface of
head without deep interantennal crossed sulci.
Prothorax narrower than base of elytra, with distinct and
entire lateral margins and evident angles, all without sensorial
setae. Prosternum narrow but visible between procoxae, the
latter projecting and transverse; procoxal cavities closed behind.
Mesosternum advanced between mesocoxae which are moder-
ately separated. Metendosternite as shown in Figure 53.
Elytra longer than abdomen, rather soft and often with carinae
or tubercles, slightly to moderately dehiscent at apex and with-
out regular rows of punctures.
Wing venation of the Chrysomelinae-type, without cells be-
tween M3 and Cull.
MONROS : REVISION OF THE AULACOSCELINAE 325
Femora not dilated and without teeth. Tibiae with two small
but distinct apical spurs on inner edge. Tarsi without empodium,
third segment slightly bilobed ; claws simple, equal and divergent.
Abdomen with five visible sternites, the last with sexual differ-
ences.
Male genitalia with tegmen forming a ring prolonged ventrally
in a long median process and entire dorsally, and with lateral
lobes articulate ; median lobe with two long basal median struts
under which the internal sac is protected.
SYSTEMATIC POSITION
The combination of characters just described easily dis-
tinguishes the Aulacoscelinae from the remaining Chrysomelidae.
It is not easy, however, to establish its relationship, as the group
presents a misleading mixture of characters which conceal its
real affinities.
The bilobed ligula appears only in the primitive Chrysomelidae
as a character which they retain in common with the Ceramby-
cidae. The Aulacoscelinae need thus to be differentiated only
from the other Chrysomelidae with bilobed ligula, from all of
which they are easily distinguished by the pronotum with entire
and distinct lateral margins. From the Bruchidae, also with bi-
lobed ligula and undoubtedly related to the Chrysomelidae, the
Aulacoscelinae differ by the non-pedunculate mentum and their
entirely different shape, as well as probably a different biology.
From the Cerambycidae too, they may be easily distinguished
by the cephalic and ocular morphology and antennal insertion,
as well as probably by different larval biology.
From the other Chrysomelidae with bilobed ligula, the Aula-
coscelinae may be distinguished not only by the prothoracic struc-
ture but also in different cases as follows : From the Sagrinae by
absence of cephalic sulci, simple hind femora, and tibiae with
apical spurs. From the Orsodacninae (including the subfamilies
Zeugophorinae and Synetinae, of dubious significance), by the
simple claws. From Megalopinae, by the antennal shape, non-
constricted sternites, tarsi without empodium.
The only significant character which the Chrysomelidae with
bilobed ligula seem to have in common is the bilobed ligula itself,
and each of the subfamilies which possesses it seems to represent
326 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
a different phylogenetic line, so that they can hardly be grouped
together in one section, as is customarily done, under the name
of Eupoda. The section Eupoda seems to cut across the true rela-
tionships of the chrysomelids, and so appears to be of no use. The
term may be retained to designate the group formed by Sagrinae,
Donaciinae and Criocerinae, which represent one evolutionary
line.
Except for the Hispinae and Cassidinae, of which the connec-
tions with the rest of the Chrysomelidae are not yet known and
which should perhaps be considered as forming a separate family,
comparable in distinctness to the Bruchidae or the Cerambycidae,
all the more specialized groups of Chrysomelidae seem to have
retained some primitive members represented by the forms with
bilobed ligula. Thus, the Sagrinae may be placed at the base of
the line leading to the Criocerinae and the Donaciinae ; the Mega-
lopinae, at the beginning of the line of Camptosoma, in spite of
the different larval habits and several other minor differences
which make the relationship not very close ; Orsodacna and
allied genera (whether or not they are considered to form dif-
ferent subfamilies and excluding the Zeugophorinae which seem
to be no more than a tribe of the Megalopinae) at the beginning
of the line of Eumolpinae, and the Aulacoscelinae, at the begin-
ning of the line of the Chrysomelinae and Alticinae-Galerucinae.
This does not mean that the Aulacoscelinae can be considered
as direct ancestors of the Chrysomelinae, nor that the center of
origin of this section can be placed in Central America, but
simply that the tendency which culminates in the more specialized
Chrysomelinae or the still more specialized Alticinae-Galerucinae
is already present in the Aulacoscelinae. The latter must be
considered as a relict and one which may illustrate the probable
general appearance of primitive Chrysomelidae.
In connection with that point of view, the genera of the Chryso-
melinae need to be rearranged and Timarcha, with a male genital
structure closely resembling that of the Aulacoscelinae, must
be placed at the beginning of the Chrysomelinae ; the order of
the remaining genera must be reversed so that the more special-
ized Doryphorini are considered at the end, and not at the begin-
ning of the Chrysomelinae
Each one of the lines analyzed represents a natural unit and
MONROS : REVISION OF THE AULACOSCELINAE 327
may be identified by a name. The term Cyclica may be applied
to the phylogenetic line represented by Aulacoscelinae-Chrysome-
linae and Alticinae-Galerucinae, and there seems to be no good
reason to subdivide it into Cyclica s. str. and Trichostoma as is
frequently done.
GEOGRAPHIC DISTRIBUTION
(Figures 2, 3)
The Aulacoscelinae are restricted to the Western Hemisphere.
The Central American mainland has most species, and two species
of Janbechynea are found as far south as Peru and Bolivia; the
same genus (subgenus Bothroscelis) has extended north to the
southwestern United States, where also the genus Aulacoscelis is
known to occur. The North American specimens of Aulacosce-
linae are the extreme northern representatives of species which
have their center farther south. As for Aulacoscelis hogei, re-
ported by Jacoby from Vancouver Island in western Canada,
it is probably an error of labeling.
The subfamily is absent in the Caribbean Islands and in
Florida, in spite of the fact that it is found at equivalent latitudes
on the Central American mainland.
BIOLOGY AND ECOLOGY
According to the labels which accompany some of the specimens
studied, the host plants of adult Aulacoscelinae are the following :
Aulacoscelis candesei, flowers of Compositae in New Mexico (Monros).
A. melanocera, Cycas revoluta in Mexico and El Salvador; "Palm" in
Honduras (this could also refer to Cycadaceae, commonly known as
"sago palms") (Specimens in USNM).
A. costaricensis, leaves of Cycas revoluta in Costa Rica (Specimens col-
lected by Nevermann in USNM).
Janbeoliynea elongata, cycads in Mexico, with the remark "infestation
heavy." (Specimens intercepted at Laredo, now in USNM.)
In the United States National Museum collection there are some
unidentified specimens of Aulacoscelis from the Rio Grande area
in southern Texas collected by G. Vogt on flowers of Hechtea
texensis (Bromeliaceae) ; their specific identity has not been
established.
328 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Nothing is known of the host plants of the remaining species,
and no larva has yet been collected.
It is worthy of note that the Aulacoscelinae are absent from
Florida and the West Indies, even though Zamia and other
cycads are known from these areas. In the case of the South
American species of Janbechynea the host plant association is
not established, but the coincidence of their ranges with those
of Cycadaceae in South America is perhaps suggestive.
Aulacoscelis seem to prefer semi-arid regions and in spite of
some exceptions, for instance A. costaricensis and A. melanocera
found in tropical rain-forest, most of the species occur where
semi-arid conditions prevail. Although little is known of the
ecological limitations of the subfamily, the species seem to have
rather wide ranges and to occur under several and sometimes
quite opposite environmental conditions. This is true not only
of the different species but also in some cases of single species as,
for instance, A. melanocera, collected on the high plateaus of
central Mexico as well as in the limestone country of north Yuca-
tan and in the tropical rain-forest of the Canal Zone.
As to their habitats, some species seem to be not uncommon, and
A. melanocera or A. candezei are not rare in the collections ; the
majority of the species, however, are known only from the type
specimens or typical series, and too little is known of their
biology to allow general conclusions to be reached.
The fact that A. melanocera and A. costaricensis are reported
feeding on the introduced Cycas revoluta seems to point out some
degree of plasticity in the feeding habits.
I have collected one specimen of A. candezei in Isleta (Pueblo
Indian Reservation in New Mexico, not far from Albuquerque).
The area is a dry one, highly modified by irrigation and cultiva-
tion. The only specimen collected was found on the flowers of an
unidentified Compositae and its behavior was similar to that of
an adult Orsodacna. It was collected at about 11 A.M. on June
14, 1953. This specimen was not very active but tried to fly away
and to bite with its mandibles in an attempt to escape. Several
mutilated specimens of Janbechynea elongata in a vial, inter-
cepted at Laredo, also show signs of using their mandibles when
excited.
Aulacoscelis candezei does not stridulate nor jump and the
MONROS : REVISION OF THE AULACOSCELINAE 329
color of the living specimen is almost the same as that of the
specimens in the collections.
I have studied some specimens of Aulacoscelis hogei in Cornell
University collections with the label "at light."
VARIABILITY
Although the samples studied are too small to show the infra-
specific variability of the Aulacoscelinae, in the cases in which
I have seen enough material, some color variability has been
observed, culminating in Aulacoscelis candezei, in which there
are both totally brick-red specimens and totally dark brown ones.
Size seems to vary less than color, but one of the specimens of
A. tibialis studied is nearly one third smaller than the other
one. The pilosity and miscrosculpture of the dorsal surface ap-
pear quite constant within each species. If A. costaricensis and
A. melanocera are two different species and not two races with
different sexual dimorphism, A. melanocera is a very constant
species in spite of being the most widely distributed one. All
the studied specimens of it are almost alike. In the case of
A. candezei, although it has not been possible to distinguish
allopatric subspecies, a weak tendency has been observed towards
predominance of dark specimens in the northern part of the
range of the species from where no unicolorous red specimens
have been seen. In A. variabilis, with similar type of chromatic
variation, no such tendency has been detected.
CLASSIFICATION
(Figure 1)
Two divergent lines, represented by two different genera, may
be recognized :
1. Aulacoscelis, restricted to the Central American area and
adjacent parts of the southwestern United States and in-
cluding the less specialized species.
2. Janbechynea, which includes more differentiated species
and extends as far south as Peru, Brazil and Bolivia.
Aulacoscelis grandis may prove to represent an independent
subgenus or even a genus ; its inclusion in Aulacoscelis is doubt-
ful and due to the fact that I have not seen a male of the species.
The remaining species of Aulacoscelis seem to be rather closely
330 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
related and the differentiation between them is not always easy.
The genus Janbechynea may be divided into two well defined
subgenera, which represent two different levels of differentiation :
1. Bothroscelis, with the species melyroides and fulvipes,
considered as connecting Aulacoscelis and Janbechynea but
more closely related to the second, and
2. Janbechynea s. str. including the most atypical species of
the subfamily and representing the most peculiar Aulaco-
scelinae. Although the three included species bear a close
resemblance, they may be grouped as follows :
2a. J. (J.) elongata from Mexico, in which the subgeneric
characters are not fully expressed and in which sexual
dimorphism consists in longitudinal costae on elytra
in 9 .
2b. J. (J.) inverosimilis and J. (J.) paradoxa, from Peru,
Bolivia and Brazil, with a very peculiar type of 9
(no S $ are known of those species) and a tendency
to modification of the metacoxae which, although al-
ready present in J. (J.) elongata, reaches its maximum
in J. (J.) paradoxa.
The differentiation between the species of Aidacoscelis and
those of Janbechynea seems to be closely correlated with the
geographic distribution, and the isolation of the South American
species has probably contributed to their greater distinctness.
The pronotal fold, peculiar to Aulacoscelis, is lost in Janbechy-
nea s. lat. and the basal groove which remains in that genus as
the only evidence of the fold tends to disappear; in J. (J.) para-
doxa it is less conspicuous than in J. (Bothroscelis) melyroides,
for instance.
NOTES ON PHYLOGENY
It is not probable that feeding on Cycadophyta is a derivative
habit in Aulacoscelinae. The origin of the group probably pre-
cedes the appearance of the angiosperms. If so, the Aulacosce-
linae are among the most ancient of living Chrysomelidae.
From the fact that the sagrid genus Carpophagus in Australia
has also been reported on Cycadaceae and that it represents
another and quite different line of evolution, it may be concluded
MONROS : REVISION OF THE AULACOSCELINAE 331
that the Chrysomelidae differentiated in early times (before the
Jurassic period, for the gymnosperm-feeders) and that each one
of the archaic living types is the relict of a different evolutionary
line. Correlated with morphological and ethological characters,
this may provide a clue to breaking up the immense number of
chrysomelid species — of which more than 30,000 are already
described — into smaller families of common but ancient an-
cestry. The uniformity of appearance of chrysomelids is undoubt-
edly due to their fairly uniform mode of life and requirements,
but it must not be allowed to hide the fact of their very early
divergence.
As for the center of origin of the Aulacoscelinae, the existing
forms seem to have a relict distribution, and the data are insuf-
ficient for speculation. The isolation in South America of Jan-
bechynea inverosimilis and J. paradoxa, which differ very much
from the Central American Aulaeoscelis, suggests a rather ancient
and probably much wider distribution.
Key to the Genera
Prothorax with a short longitudinal fold on each side, extending from basal
margin to beginning of disc. Scutellum triangular .... Aulaeoscelis
Prothorax without such folds but with two basal grooves, contiguous to
basal margin. Scutellum transverse and more or less triangular
Janiechynea
I. Genus AlJLACOSCELIS Duponchel and Chevrolat
Duponchel and Chevrolat, 1843, p. 338; Stal, 1863, p. 341; Chapuis, 1874,
p. 54; Jacoby, 1880, p. 1; Crowson, 1946, p. 83; Monros, 1949, p. 547.
Etymology : From the Greek aulacos and scelis (fold and leg).
Type of genus: Aulaeoscelis melanocera Dup. & Chevr., mono-
basic.
To define this genus, the general description of the subfamily
may be supplemented as follows : Form more or less flattened,
size from about 6.5 to about 12.5 mm. Integuments without
metallic colors and rather soft. Head similar in both sexes.
Prothorax with a short longitudinal basal fold on each side,
extending from the basal margin to the posterior half of the disc
and limiting a groove between this fold and the dilated basal
margin of pronotum (fig. 15). Elytra irregularly punctured or
332 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
almost smooth, rarely with dense pubescence; sometimes with
longitudinal costae which are always more visible in 9 . Scutel-
lum triangular. Trochantin visible in antero-lateral angle of
anterior coxae.
Key to the Species of Aulacoscelis
1. Elytra with douse and fine, rather long, pubescence throughout
(fig. 13). Sides of pronotum subparallel, narrowed in front, and
separated from disc by a broad and rather deep longitudinal
depression. Pronotal surface uneven and with longitudinal tracts
of decumbent pilosity. Black; elytra yellowish to reddish (fig.
37) ........... grandis
Elytra glabrous or almost so (figs. 4-12). Pronotum of different
shape and sculpture ......... 2
2. Pronotum rather densely and deeply punctured and not shining
(figs. 11 and 47) . variabilis
Pronotum smooth and shining, almost impunctate .... 3
3. Elytra elongate and subparallel on basal 2/3; about as wide at
base as in the middle ......... 4
Elytra more or less oblong elongate, broader towards middle than
at base ............ 6
4. Antennae slender; segments 8-10 distinctly longer than wide at
apex (fig. 18) . 5
Antennae broader; segments 8-10 almost as wide at apex as long
(fig. 17). Humeral elytral depression with long erect bristles.
hogei
5. Elytra with 3 more or less raised longitudinal carinae, of which
the central one is shorter than the others and oblique ; elytral
disc brown or dark to a variable extent (fig. 16) . . . candezei
Elytra without carinae or only with a sublateral, rather feeble one
in the 9 ; dorsal surface reddish unicolorous . . . confusa
6. Black; elytra yellowish (fig. 35) . . . . . melanocephala
Coloration different .......... 7
7. Sides of prothorax rather broadly expanded, its disc depressed.
Yellow with apex of femora, tibiae and tarsi black (figs. 54-55) tibialis
Sides of prothorax less expanded ; its disc moderately convex.
Eeddish ............ 8
8. Pronotum distinctly transverse, its sides very slightly curved.
Form comparatively short and broad. Elytra not shining (fig.
36) ........... sanguinea
Pronotum subquadrate, distinctly narrowed at base. Form more
elongate and slender ......... 9
MONROS : REVISION OF THE AULACOSCELINAE 333
9. Legs completely black. Elytra finely shagreened and with humeral
longitudinal costa in $ ; shining and without costa in $
(figs. 21, 22) . . oostarioensis
Basal 2/3 of femora orange-red like rest of body. Elytra as in $
of A. costaricensis and without sexual dimorphism. . melanocera
1. AULACOSCELIS CANDEZEI Chapuis
(Figures 4, 16)
Chapuis, 1874, p. 55, atlas, pi. Ill, f. 6; Jacoby, 1880, p. 1; 1888, p. 2,
pi. 35, f . 7 ; Crowson, 1946, p. 90.
A. purpurea Horn, 1892, p. 46; Crowson, 1946, p. 90 (new synonym).
United States. New Mexico (Horn) : Las Vegas (1 $ Barber & Schwarz
in USNM) ; Albuquerque (1 <J Wickham in USNM) ; Isleta (1,5 June
14, 1953 in col. Monros, on flowers of Compositae). Arizona (3 col. Horn
in PAS; 1$ Ulke in CM): Walnut (1$, 1$ Wickham in USNM);
Pinal Mts. (2<5 col. Van Dyke in CAS); Flagstaff (1, W). California:
Needles (1 5 Wickham in USNM).
Mexico. Tepic (1 $ June 24, 1940 L. W. Saylor in CAS); Durango:
Ventanas (3<5 Hoge in col. Jacoby, col. Bowditch MCZ) ; Cerro de
Plumas, San Miguel del Bio (Jacoby).
Guatemala (Chapuis).
Sexual dimorphism involves the basal segments of tarsi I and
II and the last sternite.
Measurements. $ 6.8 x 2.1 to 8.7 x 2.8 mm. ; 9 7.5 (Crowson)
to 8.8 x 3.2 mm.
Form. Subcylindrical, moderately shining, sometimes with
feeble violaceous metallic lustre. Color variable, from ochraceous
yellowish with elytral disc more or less brownish, to obscure
brown unicolorous with appendages black. Some intermediate
specimens with head reddish brown, prothorax dark brown,
elytral disc dirty brown with violaceous lustre on yellow ground ;
others with head dark brown, prothorax orange, elytra dirty
brown, etc.
Punctuation. Head with some sparse, rather deep punctures,
some with single short bristles. Prothoracic punctures smaller
but more dense. Elytral punctures shallow, rather large and
dense, most with one or two very short decumbent hairs.
Microsculpture. Minute granulation which somewhat dimin-
ishes the smoothness of the surface and is more visible in dark
specimens or on dark areas.
334 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Pilosity. Labrum with some long bristles on anterior margin.
Sides of clypeus, antennae and sides of prothorax with whitish,
decumbent, medium sized, moderately dense hairs; some sparse
hairs of same type on postero-lateral pronotal margin. Elytra
with some very short, decumbent setae, more abundant on basal
third and placed one or two in most of the punctures. Ventral
surface and legs with rather long but not dense pilosity, except
on head and prosternum, which are glabrous and shining.
Head. With the buccal parts, somewhat elongate in shape.
Antennae slightly longer than half the body ; basal segment sub-
globose ; apical one elongate rhombif orm ; intermediate ones
obtusely triangular or subcorneal, slightly compressed, each one
( except 2 ) distinctly longer than wide ; segments 4-7 as much
compressed as segments 8-10.
Pronotum. Feebly transverse. Sides slightly sinuate at basal
third. Greatest width at anterior third. Disc slightly convex
and without impressions.
Elytra. Elongate, subparallel in basal two-thirds, acute towards
the apex, with apical margin subtruncate and somewhat de-
hiscent. Suture with a narrow raised border. Each elytron with
a sublateral, longitudinal, distinct carina, which limits the lateral
declivity, another one discal, parallel to the suture, and more or
less fused to the preceding one at apex ; and between them a
third one, oblique, which begins at shoulder and ends near discal
costa about mid-length of elytron. Carinae distinct in both sexes,
but more so in the 2 .
Ventral surface and legs. Normal. Basal segments of tarsi I
and II distinctly broadened in $ . Last sternite subtruncate in $ .
Male genitalia. Normal.
Host plant. One S specimen of this species has been collected
on flowers of Compositae in New Mexico (Monros).
Remarks. Although the original description of this species is
rather vague and although I have not been able to find out
where the type specimens are, the figure given by Chapuis of
A. candezei makes its identification rather sure. The identity of
A. candezei and A. purpurea (of which I have seen holotype and
2 paratypes in PAS) is complete, and the latter name represents
only a minor color variation without any significance.
It is the only known species of the genus with the described
type of elytral coloration combined with the elytra! costae.
M0NR6S : REVISION OF THE AULACOSCELINAE 335
2. Aulacoscelis hogei Jaeoby
(Figures 5, 17, 19, 20)
Jaeoby, 1888, p. 3; Crowson, 1946, p. 90 (pars).
Mexico. Guerrero: Chilpancingo (1$ cotype #8448 Hoge in col. Jaeoby,
col. Bowditch MCZ; 5 9 col. Bowditch MCZ) ; Mexcala (1 S allotype,
2$ June 29, 1951, H. E. Evans in CU; 1$, 2$ col. Monros ex CU,
collected at light).
Sexual dimorphism as in A. candezei.
Measurements. $ 8.1 x 2.9 mm. ; 9 9.2 x 3.2 mm.
Form. Similar to A. candezei. Color yellowish orange to brick
red, with antennae, palpi, apices of femora, tibiae, and tarsi black.
Punctuation. Punctures on head and prothorax as in A. can-
dezei; on elytra smaller and feebler.
Microsculpture. Of same type as A. candezei, but less con-
spicuous.
Pilosity. Head and pronotum like A. candezei. Elytra with
some sparse, erect, short, golden bristles.
Head. Of same type as A. candezei. Antennae slightly shorter
than half the body, of same general type as A. candezei, but seg-
ments shorter and more triangularly compressed, especially 8-10
which are almost as wide at apex as long. The whole antenna
is distinctly more robust than in A. candezei.
Pronotum. About as wide as long, with greatest width at
middle ; otherwise similar to that of A. candezei.
Elytra. Elongate, subparallel in basal two thirds, acute to-
wards the apex, with apical margin almost entire. Suture with a
narrow raised border. Carinae as in A. candezei, but less distinct
and almost invisible in $ and sometimes only the lateral one is
visible in 9 .
Ventral surface and legs. Normal. Basal segments of tarsi I
and II broadened in $ , but less so than in A. candezei. Last
sternite subtruncate in S .
Male genitalia. Normal (figs. 19, 20).
Remarks. This species is very similar to the following one
(confusa, q.v.). From A. candezei, to which it is also closely
related, A. hogei may be distinguished by the somewhat shorter
and distinctly broader antennae with more compressed segments,
as well as by the less raised elytral costae and the short, erect
elytral bristles, absent in A. candezei.
336 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
3. AULACOSCELIS CONFUSA Il.Sp.
(Figures 6, 18)
A. hogei Jacoby, 1888, p. 3, pi. 35, f. 6; Crowson, 1946, p. 90 (pars.).
"Canada: Van Couver Island" (1 allotype $ col. Jacoby, col. Bow-
ditch MCZ, in bad shape; 1 paratype 9 same data, with label "type
8448 of A. hogei.")
Mexico. Tehuantepec (1 holotype 9 #29238 in col. Bowditch MCZ; 1 para-
type 9 same data; 1 paratype 9 T. F. Sumichrast in col. Monros, ex
Bowditch MCZ).
This species is so closely related to A. hogei, with which it has
been confused, that only the differences need to be pointed out.
Measurements. $ (allotype) 7.8 x 2.8 mm.; paratype 9 8.8
x 3.5 mm.
Color. Like A. hogei, but dark parts dark brown (not black).
Pilosity. Elytra with some sparse, erect, rather long bristles
in humeral depression, more conspicuous when observed from
the side.
Head. Antennae as in A. candezei, i.e. more slender, somewhat
longer, and less compressed than in A. hogei (fig. 18).
Elytra. Completely without costae in $ and with only 1 feeble
one in 9 , corresponding to the discal-lateral one in A. hogei and
A. candezei.
Legs. Basal segments of tarsi I and II somewhat broadened
in $ , but less so than in A. hogei and much less than in A.
candezei.
Male genitalia. Not examined.
Remarks. This species has been confused with the preceding
one by Jacoby and probably also by Crowson, so that it is not
possible to accept the localities they give without checking each
one of them.
In spite of being very closely related, A. confusa may be dis-
tinguished from A. hogei by its longer and more slender antennae,
and also by the presence of erect bristles on the humeral depres-
sion of the elytra, these bristles being entirely absent in A. hogei.
The whitish bloom described by Jacoby on A. hogei actually oc-
curs on the present species and not on the real A. hogei. From
A. candezei, to which it is also more or less similar, the present
species may be distinguished by color as well as by near absence
of elytral costae and presence of erect bristles on the humeral
MONROS : REVISION OF THE AULACOSCELINAE 337
depression. From A. melanocera and related forms of similar
coloration, it differs in being more elongate and slender.
The specimens recorded by Jacoby as A. hogei from Vancouver
Island belong to the present species as does the one illustrated
in the Biologia Centrali Americana under the name A. hogei.
I have examined the specimens labeled "Van Couver Island"
and they completely agree with the typical specimens from
Tehuantepec. It is almost certain that the "Vancouver Island"
specimens are wrongly labeled.
4. Aulacoscelis melanocera Duponchel and Chevrolat
(Figures 7, 15, 31 to 34)
Duponchel and Chevrolat, 1843, p. 338; Stal, 1863, p. 342; Jacoby, 1880,
p. 2; Crowson, 1946, p. 90; Monros, 1949, figs. 6, 9, 14, 21, 23.
Mexico (Duponchel and Chevrolat, Stal) ; Oaxaca, N. Yucatan (Jacoby) ;
5. Mexico (Crowson); Oaxaca: Almoloya (1 S , 2 2 F. Knab in USNM,
det. A. hogei); Vera Cruz (1 USNM, W. Anderson det.) ; Nogales (1?
June 16, 1905 F. Knab in USNM) ; Tampico (1 $ , 1$ June 1910 Palmer
in USNM) ; N. Yucatan (19 USNM, Jacoby det.) ; Mexico (1 Bowditch
leg. USNM; 3 col. Bow-ditch MCZ ; 3 col. Jacoby in col. Bowditch MCZ) ;
Paristlahuaca (1 Salle leg. in col. Jacoby, col. Bowditch MCZ) ; Tama-
zunchale (5 col. USNM, intercepted at Laredo) ; Cerro de Plumas (3
Hoge leg. in col. Jacoby, col. Bowditch MCZ) ; Huauchinango (1 col.
Bowditch MCZ); Oaxaca (2 Hoge in Bowditch MCZ); N. Yucatan (1
Gaumer leg. in col. Jacoby, col. Bowditch MCZ) ; Jalapa (Flohr leg. in
col. Jacoby, col. Bowditch MCZ) ; Vera Cruz: Atoyac (1 col. Jacoby, col.
Bowditch MCZ).
Guatemala. Chacoj, Panzos (Jacoby); Vera Paz: Chacoj (4 Champion in
col. Jacoby, col. Bowditch MCZ).
Honduras. Siguatepeque (3 Eittenhouse in USNM).
Nicaragua. Managua: La Calera (3 5, 4$ May 14, 1952 B. B. Swain in
USNM).
Panama (Crowson). Volcan de Chiriqui (Jacoby); Panama city (3 col.
Bowditch MCZ).
Canal Zone. Summit (1 $ , 2$ June 12, 1928 Zeteck in USNM).
El Salvador (85 S. Calderon in USNM).
Published localities in Costa Rica are not listed as it seems
probable that they really concern A. costaricensis.
Sexual dimorphism as in A. candezei.
Measurements. $ 7.7 x 2.8 mm. ; 5 8.2 x 3.1 mm. (somewhat
variable, plus and minus)
338 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Form. Oblong, rather short, moderately convex and shining,
broader and more depressed than preceding species. Red, with
antennae (except basal segments), tarsi, tibiae and apices of
femora black. The red color varies from pale orange to blood
red. In one of the specimens examined the legs are completely
black.
Punctuation. Head and prothorax almost impunctate. Elytral
punctures small and moderately dense, smaller towards apex.
Micro sculpture. Surface smooth and shining, micro-reticula-
tion not visible.
Pilosity. Head and prothorax as in preceding species. Elytra
with some very sparse, erect, short bristles, especially on basal
half. Ventral pilosity whitish.
Head. As in preceding species. Antennae little longer than
half the body, of the general type of A. candezei but somewhat
less slender (and in that respect more similar to A. hogei).
Pronotum. Very slightly transverse, of same shape as in pre-
ceding species.
Elytra. Elongate, suboblong, separately rounded at apex and
without apical sutural denticle. Suture with a narrow raised
border. Sides moderately expanded. Surface moderately shining,
moderately convex, with a distinct post-scutellar depression and
a humeral sulcus. In the 9 , the elytra show a feeble and some-
times almost obsolete humeral carina which is totally absent in
the S .
Ventral surface and legs. Normal. Basal segments of tarsi I
and II broadened in $ . Last sternite notched in <5 .
Male genitalia. Normal (figs. 33, 34).
Host plants. Cycas revolula (specimens from El Salvador in
USNM) ; cycad plant (specimens from Tamazunchal in USNM) ;
palm (specimen from Honduras in USNM).
Remarks. This is the type species of the genus and also one
of the most typical Aulacoscelis. It is the most common species
in collections and the most widely distributed one. The re-
semblance between the present species and A. hogei or A. confusa
is only superficial ; the body shape as well as the elytral punctures
are quite different.
M0NR0S : REVISION OF THE AULACOSCELINAE 339
5. Aulacoscelis costaricensis Bechyne
(Figures 8, 21 to 30)
Bechyne, 1950, p. 237.
Costa Rica. San Carlos (9$, 2 9 Schild & Burgdorf in USNM, topotypes;
1$ with label "A. melanocera") ; Naranjo (1? Bowditch leg. USNM) ;
Aleluya (2$, 4 9 E. Morales M. in USNM); Concavas (7$, 9 9 May
17, 1938, Lankester leg. col. Nevermann in USNM); San Jose (2 3
Underwood in col. Bowditch MCZ).
Sexual dimorphism involves the basal segments of tarsi I and
II, the elytra, and the last sternite
Measurements. $ 8.2 x 2.9 mm. ; 9 8.4 x 2.8 mm.
Form. As in A. melanocera. Color identical, except legs en-
tirely black, and red color always somewhat darker.
Punctuation and pilosity. As in A. melanocera.
Microsculpture. Male smooth and shining, without visible
microsculpture ; 9 with a fine shagreen on elytra which makes
them less shining.
Head and pronotum. As in A. melanocera.
Elytra. Male as in A. melanocera. Female somewhat broader,
subtruncate at apex, and with a distinct longitudinal sublateral
carina beginning at shoulder and ending at anterior third.
Ventral surface and legs. As in A. melanocera.
Male genitalia. Normal (figs. 27 to 29).
Host plant. Nevermann 's specimens in USNM with label
"Frisst an Blatt von Cycas revolata."
Remarks. The main difference between the present species and
A. melanocera is the different type of sexual dimorphism; the
difference in coloration of the legs seems not important since
specimens of A. melanocera occur with legs completely black.
Whether these two forms are specifically different or whether they
are merely subspecies of one species, must be decided by study
of more and more significant material.
6. Aulacoscelis sanguinea Jacoby
(Figures 9, 36, 39)
Jacoby, 1888, p. 5, pi. 35, f. 10; Crowson, 1946, p. 89.
Mexico. Guerrero: Chilpancingo (IS col. Jacoby in Bowditch MCZ, co-
type) .
340 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Sexual dimorphism (according to Crowson) involves the
elytral apex.
Measurements. $ 8 x 2.8 mm
Form. As in A. melanocera. Antennae entirely black.
Punctuation and pilosity. As in preceding species.
Microsculpture. Elytra with distinct microgranulation, less
shining than in A. melanocera.
Head. Antennae somewhat longer and more slender than in
A. melanocera.
Pronotum. Slightly transverse; sides very slightly arcuate;
greater Avidth at middle ; anterior and basal margins of almost
equal width ; sides not constricted at base.
Elytra. Rather broad and short, widest behind middle, with
lateral margins expanded. Humeral impression almost obsolete.
According to Crowson, the 9 has an apical denticle on elytra!
suture, which distinguishes it from the £ .
Ventral surface and legs. Normal.
Male genitalia. Normal (fig. 39).
Remarks. I have examined only one $ to which the preceding
description refers.
This species, although appearing similar to A. melanocera and
A. costaricensis, may be easily distinguished by the different
shape of pronotum and less shining elytra, which are also shorter
and broader.
7. AULACOSCELIS MELANOCEPHALA Jacoby
(Figures 10, 35, 38)
Jacoby, 1877, p. 510; 1880, p. 2, pi. 1. f. 1.
Guatemala. (1$ holotype in col. Jacoby, col. Bowditch MCZ).
Measurements. $ 9.0 x 3.3 mm.
Form. As in A. sanguined. Color black, with a feeble reddish
tint dorsally and the elytra ochraceous yellow.
All the characters almost identical with A. sanguinea, from
which it is distinguished by different 6 genitalia (fig. 38).
8. Aulacoscelis variabilis Jacoby
(Figures 11, 40 to 53)
Jacoby, 1888, p. 4, pi. 35, f . 8, 9 ; Crowson, 1946, p. 90.
Mexico. Hidalgo: Pachuea (4 5, 7$ Hoge leg. in col. Jacoby col. Bowditch
MONROS : REVISION OF THE AULACOSCELINAE 341
MOZ, cotypes ; 3 Hoge leg. USNM, Jaeoby det., cotypes) ; Sierra de
Durango (3, col. Bowditeh MCZ) ; Real del Monte (1, Flohr leg. col.
Jaeoby, col. Bowditeh MCZ, cotype).
Sexual dimorphism involves only the last sternite. Basal seg-
ments of tarsi almost equal in both sexes. No sexual dichromism.
Measurements. 8.4 x 2.9 mm. to 8.7 x 3 mm.
Form. Oblong-elongate, rather depressed, not shining. Color
variable: dirty brown either unicolorous (about half the speci-
mens examined) or with prothorax and elytral epipleurae
orange-red to a variable extent.
Punctuation. Cephalic punctures rather dense and deep, es-
pecially towards base, most of them with a short, white, oblique
bristle. Pronotal punctures sparser, especially on disc, but denser
and deeper than in preceding species. Elytral punctures closer
than those of prothorax, most with a very short, white bristle
directed obliquely backwards.
Microsculpture. Dorsal surface of body with a minute reticula-
tion which makes it dull.
Pilosity. Of the same type as in preceding species ; elytra with
some longer hairs on shoulders, and entirely covered with the
very short ones already described.
Head. Antennae about half the length of body, slightly com-
pressed, of the type of A. candezei; antennal pilosity shown in
Figures 49 to 51.
Pronotum. About as wide as long. Sides slightly sinuate at
basal third. Disc rather depressed and sometimes with two shal-
low, irregularly rounded depressions.
M et end o sternite. Shown in Figure 53, similar to that of A.
candezei figured by Crowson.
Elytra. Elongate, subparallel in basal two thirds and acute
at apex, where very slightly dehiscent; without sutural denticle.
Suture narrowly bordered ; sides moderately expanded, more so
in basal half. Surface rather flat, each elytron with a slight post-
scutellar depression and another, elongate one, on the shoulder.
Ventral surface and legs. Normal, similar in both sexes. Last
sternite of S deeply notched.
Male genitalia. As shown in Figures 44 to 46.
Remarks. This is a very easy species to recognize because of
the dull pronotum, the rather depressed body, and the dense
dorsal punctures.
342 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
9. Aulacoscelis tibialis Jacoby
(Figures 12, 54 and 55)
Jacoby, 1888, p. 3, pi. 35, f. 2; Crowson, 1946, p. 88.
Guatemala. Vera Paz: San Juan (Jacoby); Senahu (1$ cotype Champion
leg, in col. Jacoby, col. Bowditch MCZ).
British Honduras: M-tee Dist. (1 $ , 19 August 10, 1906 col. Bowditch
MCZ).
Sexual dimorphism involves the tarsi, abdomen and elytra.
Measurements. $ from Honduras 10.6 x 3.7 mm. ; 9 cotype
12.6 x 5 mm ; 9 from Honduras 7.4 x 3 mm.
Form. Oblong-elongate, rather flat, moderately shining. Pale
yellow to orange-yellow ; antennae (except basal segments), palpi,
tarsi, tibiae, and tips of femora black
Punctuation. Cephalic punctures sparse and superficial, very
few of them with short, decumbent bristles. Prothorax almost
impunctate. Elytral punctures sparse and superficial, with
some sparse decumbent hairs in them at base and sides.
Microsculpture. Dorsal surface minutely shagreened, but this
does not affect the lustre and is visible only under strong magnifi-
cation.
Pilosity. Dorsal surface practically glabrous.
Head. As shown in Figure 55. Antennae half the body length,
with segments 3-7 somewhat compressed, increasing in length
from second to apical one.
Pronotum. Rather depressed, shape as shown in Figures 54 and
55.
Elytra. With sexual dimorphism. Male, oblong-oval, elongate,
with maximal width behind middle, the surface practically with-
out irregularities, except for the humeral callus and the sub-
lateral depression; 9 with 3 longitudinal costae of which the
external one is long and well developed, the internal one short
and very feeble, and the intermediate one visible especially on
the shoulder; between the last carina and the lateral declivity
there is a rather inconspicuous fold.
Ventral surface and legs. Normal. Basal segments of tarsi
I and II broadened in $ . Last sternite as in preceding species.
MONROS : REVISION OF THE AULACOSCELINAE 343
10. Aulacoscelis grandis Jacoby
(Figures 13, 37)
Jacoby, 1888, p. 6, pi. 35, f . 1 $ ; Crowson, 1946, p. 88.
Mexico. Durango : Ventanas (Jacoby); Mexico (1? Flohr leg. col. Jacoby
col. Bowditch MCZ).
Measurements ( 9 ). 10.9 x 3.2 mm.
Form ( 9 ) . Elongate oval, depressed ; widest behind middle.
Black, elytra orange-brownish.
Punctuation. Head with some small punctures, each with a
long hair. Prothorax with punctures only at base of hairs.
Elytral punctures moderately dense and deep.
Micro sculpt ure. Head, prothorax, and scutellum smooth and
shining ; elytra inconspicuously finely shagreened.
Pilosity. Labrum with long, white setae directed forward.
Interocular depression with long, crossed hairs ; postocular region
with similar hairs, directed forward. Prothorax with two longi-
tudinal irregular rows of hairs on each side of disc, and a dense
pilosity on all margins. Scutellum with some sparse hairs. Elytra
with a fringe of bristles along the margin, longer towards apex ;
and surface with rather dense, rigid bristles, directed backwards.
Pilosity of ventral surface, antennae, and legs fine and moderately
dense.
Head. Elongate, depressed ; eyes small and rather prominent ;
postocular region slightly constricted and with a transverse im-
pression on each side ; interocular and interantennal space de-
pressed, limited on each side by a thick carina ; clypeus on a
lower level than rest of head. Antennae half body length, with
segments 3-8 moderately, triangularly expanded (the fourth is
the most expanded, and from it the antenna diminishes in width
toward apex and base).
Pronotum. About as long as wide, with sides somewhat con-
vergent anteriorly. Anterior margin feebly bilobed. Sides with
narrow, elevated margins, separated from disc by broad and
shallow depressions. Base subtruncate, narrowly bordered. Disc
scarcely convex, with feeble impressions arranged as shown in
Figure 37, and with a short but distinct longitudinal carina on
each side at base.
Elytra. Elongate, depressed, gradually broadened in basal
two thirds, then conjointly and broadly rounded. Suture nar-
344 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
rowly bordered. Lateral margins horizontally expanded and
separated from the disc by very distinct longitudinal impressions,
which disappear towards apex.
Ventral surface and legs. Normal.
Remarks. The specific name of this species may lead to con-
fusion, as A. tibialis is larger than the present one. A. grandis
is very peculiar looking, and its prothorax as well as the antennal
shape easily distinguish it from the other Aulacoscelis.
II. Genus JANBECHYNEA Monros
Monros, 1953, p. 21.
Etymology : Named for Jan Bechyne, a specialist on Chrysome-
lidae.
Type of genus: Janbechynea paradoxa Monros, monobasic and
orthotype.
The addition of some other species to the present genus makes
the following modification of the generic description necessary:
Form elongate and somewhat acute. Head distinctly broader
in $ . Antennae at least as long as half length of body in both
sexes ; segments elongate-triangular, not much expanded in-
ternally. Pronotum with a basal elevated margin, and in front
of it, on each side, a deep circular impression (fig. 14) ; pronotal
disc without longitudinal fold at base. Scutellum transverse-
rectangular. Elytra densely covered with fine pilosity. Legs
rather long and slender. Male genitalia with median lobe pro-
longed into a long median projection.
This genus, thus redescribed, may be distinguished from
Aulacoscelis by the lack of pronotal folds, the different shape of
the scutellum, the different type of $ genitalia, and the sexual
dimorphism of the head. In Aulacoscelis (except A. grandis,
which is doubtfully included in that genus) the elytra are glab-
rous or almost so. In all the species of Janbechynea they are
covered by dense pilosity.
The present genus is divided into two subgenera, distinguished
in the following key.
Elytral apices rounded in both sexes, moderately dehiscent.
Elytra not sexually dimorphic. Size smaller (up to 10 mm.).
Abdomen of normal length in both sexes . . . Bothroscelis
Elytral apices in the 9 prolonged into divergent points and
MONROS : REVISION OF THE AULACOSCELINAE 345
strongly dehiscent. Elytra with sexual dimorphism. Size larger
(over 13 mm.). Abdomen shortened, especially in the 9. .
Janbedhynea s. str.
A. subgenus BOTHROSCELIS nov.
Etymology: From the Greek bothros (groove) and scelis
(leg)-
Type of subgenus: Aulacoscelis fulvipes Jacoby.
The differences between the present subgenus and Janbechynea
s. str. are given in the preceding key.
Bothroscelis contains species which are less differentiated from
Aulacoscelis, while Janbechynea s. str. includes the most special-
ized species and those which differ most from the rest of the
Cyclica.
The subgenus Bothroscelis includes two known species.
Elytral pubescence decumbent and dense. Prothorax densely and
deeply punctured, with distinct pubescence along the borders
(figs. 64, 65) fulvipes
Elytral pubescence recumbent and sparser. Prothorax with only
some punctures on marginal areas and some scattered bristles
on lateral borders (fig. 57) melyroides
1. Janbechynea (Bothroscelis) melyroides (Crowson)
(Figures 57, 63)
Aulacoscelis melyroides Crowson, 1946, p. 89.
Mexico. Guerrero: Chilpancingo, 4600 ft. H. H. Smith (Type locality; 1$,
19 paratypes in coll. Monros, ex British Museum).
Sexual dimorphism involves the head and elytral pilosity.
Measurements. $ 6-7 mm ; 9 5-7 mm. (according to Crowson).
Form. Elongate-oblong, subdepressed, elytra subparallel. Shin-
ing, rather densely pubescent on elytra. Color variable (sexual
dichromism ?) : $ dark brown, almost black on head and elytra,
paler and reddish on legs and antennae, mouth parts yellowish,
pronotum yellow with a discal, ill-defined, large brown patch and
elytral epipleurae pale yellow; 9 with elytra and basal half of
head deep black, rather shining, pronotum unicolorous yellow,
anterior half of head yellow ; otherwise, including elytral epi-
pleurae, as in $ .
Punctuation. Cephalic punctures sparse, rather deep, most
346 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
with fine, oblique bristles. Pronotal punctures of same type, very
distinct but not dense on disc. Elytral punctures shallower but
closer than those of head and prothorax, with hairs.
Microsculpture. Head and pronotum smooth and shining;
elytra with a fine but distinct microgranulation.
Pilosity. Head wTith some long setae on clypeus and labrum and
shorter ones rather sparse on front and interocular area. Anten-
nal pilosity of same type as in Aulacoscelis. Prothorax almost
glabrous except for fringes of bristles on anterior and basal
margins and some sparse bristles near basal angles at sides.
Scutellum with some long, decumbent setae. Elytra dimorphic:
male with rather long, moderately dense hairs, directed obliquely
backwards and almost uniformly distributed, lateral margins
with fringes of short, dense bristles ; $ with pilosity longer, finer,
and more erect, especially on basal half; lateral fringes longer
and finer.
Head. Male almost as broad as long and of the normal Aulaco-
sceline-type. Antennae somewhat longer than half the body, its
segments elongate and rather slender, 5-11 more than twice as
long as broad at apex. Female narrower and more elongate
than $ . Antennae shorter than half body length and somewhat
more robust than in $ but of same general form.
Pronotum. In $ of normal Aulacosceline-type, as (for in-
stance) in A. melanocera; in $ more subparallel, with less con-
spicuous lateral-basal constriction. Basal fold and discal impres-
sions absent ; basal grooves distinct and deep.
Elytra. Elongate, subparallel in basal two thirds, moderately
acute towards apex, where they are somewhat dehiscent. Sutural
angles without denticles. Suture with a narrow raised border.
Sides slightly horizontally expanded. Surface rather flat in both
sexes, with an inconspicuous, longitudinal, short humeral carina
in the 9 but completely absent in the $ .
Ventral surface and legs. Normal. Abdomen somewhat short-
ened in 2 .
Remarks. The erect elytral pilosity, together with the smooth
pronotum and the small size, easily distinguish the present species
from J. fidvipes, with which it has been confused.
M0NR0S : REVISION OF THE AULACOSCELINAE 347
2. Janbechynea (Bothroscelis) fulvtpes (Jacoby)
(Figures 56, 64 to 71)
Aulaooscelis fulvipes Jacoby, 1888, p. 4; Crowson, 1946, p. 90.
Aulaooscelis femorata Jacoby, 1888, p. 5, pi. 35, f. 3$ , 4? ; Sehaeffer, 1905,
p. 168; Crowson, 1946, p. 88 (new synonym).
Aulacoscelis ventrali-s Sehaeffer, 1933, p. 297.
United States. Arizona: Huachuca Mts. (4 $, 3 9 July, 1905 C. W. Leng
in Hopping col. CAS; 3 9 col. Sehaeffer in USNM) : Carr Canyon (1 $
J. O. Martin in CAS; 19 August 6, 1924 E. P. Van Duzee in CAS);
Cochise Co.: Palmerlee (IS, 19 col. Sehaeffer in USNM).
Mexico. Chilpancingo (Jacoby), Capulalpam (Jacoby); Durango: Ventanas
(15, 7 9 cotypes col. Jacoby in col. Bowditch MCZ) ; Chihuahua (8$,
5 9 Wickham leg. in col. Bowditch MCZ); Guanajuato (1 Salle leg.
col. Jacoby in col. Bowditch MCZ).
Sexual dimorphism involves the last sternite, head, antennae,
and somewhat shortened abdomen in 9 . Basal segments of tarsi
almost equal in both sexes.
Measurements. 8 x 2.8 mm. to 8.7 x 3 mm.
Form. Subcylindrical, acute towards apex. Color variable,
from testaceous with apices of femora and bases of tibiae brown,
to reddish-brown with legs and apex of abdomen yellowish brown,
with a wide variety of intermediate colorations (head dark
brown, prothorax orange, elytra reddish brown ; head and pro-
thorax orange, elytra grayish brown, etc.)
Punctures. Head densely and rather deeply punctured, es-
pecially near base ; most of the punctures with short decumbent
bristles. Elytral punctures rather close, each with a long, decum-
bent hair. Prothoracic punctures variable, from rather sparse
and shallow to dense and deep, especially on anterior angles.
Micro sculpture. Microgranulation present without dulling the
surface, but hidden by the pilosity on prothorax and elytra.
Pilosity. Head with some decumbent, sparse, short hairs.
Scutellum and elytra covered with moderately long, rather dense,
decumbent, slightly depressed hairs. Pronotal pilosity variable ;
specimens with dense punctuation have also dense pilosity, espec-
ially on sides; in others the pilosity is sparser but basically
similar.
Head. Transverse, interantennal depression U-shaped, open
behind, rather deep. Clypeus at level of antennal border. Anten-
348 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
nae of same type as in Aulacoscelis variabilis, longer than half
the body, moderately expanded.
Prothorax. Somewhat transverse, with anterior margin slightly
broader than basal one. Sides slightly constricted in basal third
in both sexes, but more so in 9 . Disc with two transverse depres-
sions near anterior angles, more impressed on specimens with
abundant pilosity.
Elytra. Elongate, acuminate in apical third, with the border
obliquely truncate at apex on suture, without sutural denticle.
Suture narrowly bordered. Sides not expanded, narrowly bor-
dered. Dorsal surface moderately convex, with a shallow, longi-
tudinal humeral depression, without carinae in both sexes.
Ventral surface and legs. Normal.
Male genitalia. As shown in Figures 70 and 71 ; median lobe
prolonged into an acute point.
Remarks. Specimens in the Schaeffer collection in USNM are
the types (holotype $ , allotype 9 and 3 paratypes) of Aula-
coscelis ventralis. One specimen in MCZ with label "Type 8449"
of Aulacoscelis femorata. One specimen in MCZ with label ' ' Type
8447" of Aulacoscelis fulvipes.
The identity of A. femorata with A. fulvipes has been estab-
lished by comparing the types of both and by study of a series
of intergrading specimens. A. femorata is based on a pale colored
$ with sparse pronotal punctures and pilosity ; A. fulvipes on a
brown 9 with dense pronotal punctures and pilosity, but no real
structural differences have been discovered between the specimens
with these two types of sculpture, and they intergrade in series
from the same localities. As for A. ventralis, its identity with A.
femorata has been pointed out by Crowson, and the study of
the types confirms it.
B. subgenus JANBECHYNEA s. str.
Key for the separation of the species (based on 99 )
1. Elytra with three longitudinal diseal costae. Orange; elytra brown-
ish. Metaeoxae normally shaped ...... elongata
Elytra with two transverse diseal tubercles. Brick-reddish, elytra
more or less metallic bluish ........ 2
2. Metacoxa prolonged into a triangular plate which reaches end of
MONROS : REVISION OF THE AULACOSCELINAE 349
third abdominal sternite paradoxa
Metaeoxa shorter, prolonged into an oblong, stout projection not
longer than first abdominal sternite .... inverosirnilis
3. Janbechynea (s. str.) elongata (Jacoby)
(Figures 58, 72, 75 to 78)
Aulacoscelis elongata, Jacoby, 1888, p. 5, pi. 35, f . 5 ; Crowson, 1946, p. 88.
Mexico. Playa Vicente (Jacoby); San Luis de Potosi: Tamazunchale
(2$, 1$ allotype May 20, 1952 intercepted at Laredo, Texas, feeding
on Cycads, in USNM collection).
Sexual dimorphism strong
Measurements. $ 16 x 4.3 mm. ; 9 (allotype) 16.2 x 4.4 mm.
Form. Distinct in both sexes. Color pale orange ; elytra pale
brown, yellowish at suture and lateral margin; antennae (except
basal segments), tibiae, tarsi and apices of femora black; elytral
pilosity pale.
Punctuation. Cephalic punctuation moderately dense and
deep ; pronotum almost without punctures ; scutellum and elytra
with punctures hidden under pilosity.
Microsculpture. Elytra minutely shagreened in both sexes.
Pilosity. Head and pronotum glabrous and shining, except for
some bristles on basal margin of pronotum. Scutellum and elytra
with long, dense, decumbent pilosity, sparser on disc in 9 .
Male. Head as described for subfamily, nearly as broad as pro-
notum. Antennae two thirds as long as the body, with inter-
mediate segments rather elongate. Pronotum as long as wide,
with maximum width at middle. Sides distinctly sinuate in basal
half. Basal margin with a rather deep, small groove on each side.
Elytra narrowed in apical third, somewhat dehiscent at apex,
which is rounded, practically without irregularities, except for
the somewhat expanded sutural and lateral margins. Abdomen
less than one quarter shorter than elytra, its last segment with
a rather deep but narrow, angular incision. Mesotibiae somewhat
curved. Basal segments of tarsi I and II broadened. Median
lobe of genitalia very long and slender, prolonged into a median
elongate hook curved dorsally, in which no median suture is
visible.
Female (allotype). Head distinctly narrower than pronotum.
Antennae about one half length of body. Pronotum widest before
350 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
middle. Basal grooves not as deep as in $ . Elytra longer than
in $ , very acute towards apex, and with a long, dehiscent, acute
external angle. Disc with three distinct, longitudinal, subparallel
costae, the outer one limiting the lateral declivity, the inner one
shortest, Abdomen shortened ; about one third shorter than
elytra ; its last segment with a short, obtuse, apical, angular pro-
jection. Mesotibiae almost straight. Tarsi not broadened.
Remarks. Although Jacoby mentions the existence of a longi-
tudinal pronotal groove, none of the specimens studied has it.
4. Janbechynea (s. str.) inverosimilis n. sp.
(Figures 59, 61, 62, 73, 79)
Peru. Chanchamayo (1 holotype 5 #29237 in col. Bowditch MCZ).
Measurements. 9 holotype 16 x 5.8 mm.
Form. Elongate and acuminate at apex. Color brick-red;
elytra blue-greenish, with moderate metallic shine. Antennae
(except basal segments), hind legs, tibiae, tarsi, and apices of
femora of other legs black. Scutellum paler than pronotum.
Elytral pilosity black.
Punctuation. As in J. elongata.
Microsculpture. Elytra minutely shagreened.
Pilosity. As in J. elongata but elytral hairs finer and shorter.
Head. Similar to that of J. elongata 9 but more elongate and
with mandibles more projecting.
Pronotum. About as long as wide, widest slightly before mid-
dle. Sides moderately rounded, not sinuate at base. Basal grooves
not so deep as in J. elongata.
Scutellum. Very distinctly transverse, broader and more
rectangular than in J. elongata.
Elytra. Of same general form as in 9 of preceding species,
but more elongate. Disc with 2 transverse tubercles, the anterior
one larger and higher.
Legs. As in 9 of J. elongata. Metacoxae swollen, their pos-
terior margins extended in irregular curves.
Abdomen. Very short; first segment with a longitudinal, ex-
cavated, pubescent tract.
Remarks. A very large, strange-looking species, easy to recog-
nize.
MONROS : REVISION OF THE AULACOSCELINAE 351
5. Janbechynea (s. str.) paradoxa Monros
(Figures 60, 74)
Monros, 1953, p. 21, figs. 1-8.
Bolivia. Santa Cruz (19 holotype, 2$ paratypes in Museum Frey, Miin-
chen; 2$ paratypes in col. Monros, ex Frey).
Brazil. Chapada (19 CM; 1$ col. Monros ex CM).
This species so closely resembles J. invcrosimilis, that only the
differences need to be pointed out.
Size somewhat smaller (13 to 14 mm. x 5 mm.) ; coloration
same but somewhat paler and elytra duller and more violaceous,
with extreme base orange reddish in the specimens from Chapada.
All femora with basal halves orange-reddish. Pronotal grooves
shallower than in J. inverosimilis. Elytral pilosity finer ; elytral
tubercles less raised. Metacoxae extended as triangular plates of
which the lateral margins reach the posterior edge of the third
ventral segment. Those plates are flat and finely pubescent
ventrally.
Remarks. This species could be confused with the preceding
one, but is easily distinguished by the very peculiar shape of the
metacoxal plates.
SUMMARY
1. The history, characters, systematic position and geographic
distribution of the Subfamily Aulacoscelinae are described
and the relationships with the other Chrysomelidae are dis-
cussed.
2. Host plants for some species, and some observations on the
habits of Aulacoscelis candezei Chap., are reported for the
first time.
3. Some remarks on the probable phylogeny, variability and
significance of the group are added.
5. Keys for the genera, subgenera and species are given, and
all the species redescribed.
6. Aulacoscelis melanocera is credited to Duponchel and Chev-
rolat, 1842, and not to Stal, 1865 as is usually done.
7. The male genitalia of several species are described and il-
lustrated for the first time, and so is the pilosity and sculp-
ture of the dorsal surface. The habitus of most of the species
is figured from typical material.
352 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
8. The genus Janbechynea Monros is redescribed and its limits
broadened.
9. Bothroscelis (type Aulacoscelis femorata Jac.) is described
as a new subgenus of Janbechynea.
10. New distributions: Aulacoscelis melanocera Dup. & Chevr.
for British Honduras and Nicaragua; A. tibialis Jac. for
British Honduras; Janbechynea paradoxa Monros, for
Brazil.
11. New combinations: Aulacoscelis melyroides Crowson anchA.
fulvipes Jac. are transferred to Janbechynea (Bothroscelis) ;
and Aidacoscelis elongata Jac, to Janbechynea s. str.
12. New species: Aulacoscelis confusa and Janbechynea (s. str.)
inverosimilis.
13. New synonyms: Aulacoscelis candezei Chap. {—A. purpurea
Horn) ; Janbechynea (Bothroscelis) fulvipes (Jac.) (= Aula-
coscelis femorata Jac).
The identity of Janbechynea fulvipes (Jac.) and Aida-
coscelis centralis Schaeffer is confirmed by type examination.
14. Allotypes described : $ of Aulacoscelis tibialis Jac, $ of
Janbechynea elongata (Jac).
15. A bibliographical list intended to cover the whole subfamily
is appended.
BIBLIOGRAPHY
Beohyne, J.
1950. Notes sur les Chrysomeloidea de l'Amerique du Sud et du
Centre. Ent. Arb. Mus. G. Trey, I.
BliACKWELBER, E.
1939. Fourth Supplement to the Leng Catalogue.
1946. Checklist of the Coleopterous Insects of Mexico, Central America,
the West Indies, and South America. U. S. Nat, Mus. Bull., 185.
Chapuis, F.
1874. In Laeordaire, Genera des Coleopteres, X.
Cl/AVAREAU, H.
1913. In Junk & Schenkling, Coleopterorum Catalogus, 51.
Crowson, E.
1946. A revision of the genera of the Chrysomelid group Sagrinae.
Trans. Eoy. Ent. Soc. Lond., 97, 4.
DUPONCHEL AND CHEVROLAT
1842. In d'Orbigny, Diet. Univ. Hist. Nat., X.
MONROS : REVISION OF THE AULACOSCELINAE 353
Gemminger and Harold
1874. Catalogus Coleopterorum, XI.
Horn, G. H.
1892. Random studies in North American Coleoptera. Trans. Amer.
Ent. Soc, XIX.
Jacoby, M.
1877. Descriptions of new species of phytophagous Coleoptera. Proc.
Zool. Soc. Lond.
1880. Biologia Centrali Americana, Ins. Col., VI, 1.
1888. Loc. Cit. supplement.
Lbng, Ch. W.
1920. Catalogue of the Coleoptera of America, north of Mexico.
Monros, F.
1949. Sobre la posicion sistematica de algunos Eupoda dudosos. Acta
Zool. Lilloana, VII.
1953. Aulacoscelinae, eine neue Chrysomeliden-Unterfamilie, mit Be-
schreiburg einer neuen bolivianischen Gattung. Ent. Arb. Mus.
G. Frey, IV.
ScHAEFFER, Ch.
1905. Some additional new genera and species of Coleoptera found
within the limits of the United States. Brookl. Inst. Mus. Sci.
Bull., I, 7.
1933. Short studies of Chrysomelidae. Journ. N. York Ent. Soc, 41.
Stal, C.
1865. Monographic des Chrysomelides de l'Amerique III. Acta Soc.
Roy. Sci. Upsala, (3) 5.
354 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
13 * #
Fig. 1. Phylogenetic relationship of Aulacoscelinae : 1. Aulacoscelis
candezei Chap.; 2. A. hogei Jac. ; 3. A. confusa n. sp. ; 4. A. w^elanocera Dup.
& Chevr. ; 5. A. costaricensis Bech. ; 6. A. sanguinea Jac; 7. A. melanooeph-
ala Jac; 8. A. variabilis Jac; 9. A. tibialis Jac; 10. A. grandis Jac; 11.
Janbeohynea (Bothroscelis) melyroides (Crowson) ; 12. J. (B.) fulvipes
(Jac) ; 13. J. (s. str.) elongata (Jac) ; 14. J. (s. str.) inverosimilis n. sp.;
15. J. (s. str.) paradoxa Monros.
Fig. 2. General distribution of Aulacoscelinae.
Fig. 3. Distribution of the Central American species of Aulacoscelinae;
numbers as in Figure 1.
MONROS : REVISION OF THE AULACOSCELINAE
355
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^Mo/jtos
O.tJmm
Figs. 4-13. Dorsal punctures and pilosity in Aulacoscelis. In each case
the left square is taken from the head, the central square from the prothorax,
and the right square from the elytra; the places indicated by the squares
are represented in Figure 36. The microsculpture is not indicated in the
figures. 4. A. candezei Chap.; 5. A. hogei Jac. 6. A. confusa n. sp. ; 7.
A. melanoeera Dup. & Chevr. ; 8. A. costaricensis Bech. ; 9. A. sanguinea Jac;
10. A. melanocephala Jac; 11. A. variabilis Jac; 12. A. tibialis Jac; 13.
A. grandis Jac
litim
17W18i
23 Ik
F.Monr6*
Figs 14-30. 14. Base of prothorax, seutellum and base of elytra in Jan-
bechynea (Bothroscelis) fulvipes (Jac). The pilosity indicated on the left
side, only the structure on the right side. 15. Same in Aulacoscelis melanocera
Dup. & Chevr. 16. Aulacoscelis candezei Chap. The specimen illustrated is
a paratype of A. purpurea Horn in PAS; structure indicated on left side,
color on right side. 17. Antenna of A, lwgei Jac. cotype $ (pilosity not
indicated). 18. Same of A. confusa n. sp. holotype $ . 19. Male genitalia
of A. hogei Jac; apex of median lobe from the side. 20. Same from below.
21. Aulacoscelis costaricensis Bech. $ topotype in USNM. 22. Same, $ .
23. Same, anterior tarsi of $ . 24. Same, of 5 . 25. Same, apex of elytron
of $ . 26. Same, of $ . 27. Same, $ genitalia, from the side. 28. Same,
from above. 29. Same, median dorsal process of tegmen from above. 30.
Same, posterior prothoracic angle showing basal fold and groove.
tMonrJi
Figs. 31-46. 31. A. melanocera Dup. & Chevr. ; apex of elytron of $. 32.
Same, $ . 33. Same, $ genitalia from the side. 34. Same, from above. 35.
A. melanocephala Jae. holotype S in MCZ; pilosity and structure on left
side, colors on right. 36. A. sanguinea Jac. cotype $ in MCZ; the squares
represent the approximate places from which the samples of punctures and
pilosity are taken. 37. A. grandis Jac. cotype $ in MCZ (as fig. 35). 38.
A. melanocephala Jac. $ genitalia. 39. A. sanguinea Jac. $ genitalia.
40. Last sternite of A. variabilis Jac, inner side. 41. A. variabilis Jac,
first invaginated abdominal sclerite. 42-43. Sclerites appended to genitalia
$ in A. variabilis Jac. 44. A. variabilis Jac, $ genitalia from the side with
tegmen and internal sac in place. 45. A. variabilis Jac, median lobe of $
genitalia from below. 46. A. variabilis Jac, annular tegmen from above.
358
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
5 *
<
, V
\
: k
- »
|
4
: £
: ?
.- tc
y^
. i'
: t
* >S
:■:■:' -f.
: t
• t
'. i"^
'•:': V
Figs. 47-55. 47. .4. variabilis Jac. $ cotype in USNM (as fig. 35). 48.
Same, antenna without pilosity. 49-51. Same, type of antennal pilosity.
52. Same, head of $ . 53. Same, metendosternite. 54. A. tibialis Jac. cotype
$ in MCZ. 55. Same from front with indication of colors.
MONROS : REVISION OF THE AULACOSCELINAE
359
Figs. 56-71. 56-60. Dorsal punctures and pilosity in Janbechynea. As
figs. 4-13. 56. J. (Bothroscelis) fulvipes ( Jac.) ; 57. J. (B.) melyroides
(Crowson) ; 58. J. (J.) elongata (Jac.) ; 59. J. (J.) inverosimilis n. sp.
60. J. (J.) paradoxa Monros. 61. J. inverosimilis n. sp. apices of elytra. 62.
Same, from the side. 63. J. (B.) melyroides (Crowson) paratype 9 in col.
Monros; as fig. 35. 64. J. (B.) fulvipes (Jac), pronotal punctures and
pilosity in cotype $ . 65. Same as shown in cotype $ of Aulacoscelis
femorata in MCZ. 66. J. (B.) fulvipes (Jac). The specimen illustrated is a
paratype $ of Aulacoscelis ventralis Schaeffer in USNM. 67. Same, from
the side. 68. Same, last sternite in $ . 69. Same in $ . 70. Same, $ genitalia
from the side. 71. Same, apex of median lobe from below.
360
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
/fMaaros
Figs. 72-79. 72-74. Metacoxae $ from the inner side in Janbechynea s.
str.; position of femur indicated by dotted lines. 72. J. (J.) elongata (Jac).
73. J. (J.) inverosimilis n. sp. 74. J. (J.) paradoxa Monros. 75. Janbechynea
(s. str.) elongata (Jac.) ; the arrow indicates length of abdomen. 76.
Same, allotype 2 in USNM. 77. Same, genitalia $ from the side. 78.
Same from above. 79. J. (J.) inverosimilis n. sp. holotype $ in MCZ
(colors and pilosity Jiot indicated).
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 5
THE COMPARATIVE BIOLOGY OF REPRODUCTION
IN THE WOOD-BORING ISOPOD CRUSTACEAN
LIMNORIA
By Robert J. Menzies
CAMBRIDGE, MASS., U. S. A.
PRINTED FOR THE MUSEUM
December, 1!>54
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MUSEUM OF COMPARATIVE ZOOLOGY
AT HARVARD COLLEGE
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These publications issued at irregular intervals in numbers which may
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Massachusetts.
Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 5
THE COMPARATIVE BIOLOGY OF REPRODUCTION
IN THE WOOD-BORING ISOPOD CRUSTACEAN
LIMNORIA
By Robert J. Menzies
CAMBRIDGE, MASS., U. S. A.
PRINTED FOR THE MUSEUM
December, 1954
No. 5 — The Comparative Biology of Reproduction
in the Wood-Boring Isopod Crustacean Limnoria1
by Robert J. Menzies
CONTENTS
PAGE
Introduction 364
Materials and Methods 364
Comparative morphology of the reproductive organs . . . 365
Internal anatomy 366
Female 366
Male 367
External anatomy 370
Sex determination 371
Sex ratio 371
Ambisexual individuals 372
Reproductive behavior 373
Brood-pouch formation 373
Incubation 374
Pairing, fertilization, and burrow construction .... 375
Size of brood 379
Discussion 384
Summary 385
Literature cited 387
1 Contribution from the Scripps Institution of Oceanography, new series, 740.
These studies were aided by a contract between the Office of Naval Research,
Department of the Navy, and the University of California, S.I.O., NR 163-084.
364 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
INTRODUCTION
A study of the biology of an organism necessarily involves
the accumulation of data concerning many aspects of its anatomy
and behavior. Knowledge about the way in which an animal re-
produces, maintaining itself in its environment, is highly sig-
nificant to an understanding of its biology. Here the external
and internal anatomy of the marine pest Limnoria is described.
Comparisons are made with other isopods in order that an idea
may be had of the basic similarities and differences which
Limnoria shows with the members of the crustacean order to
which it belongs. Where possible, correlations are drawn between
the structure of the reproductive system and the reproductive
behavior of the animal.
This paper represents the results of part of a general study
on the biology of Limnoria which was done under contract with
the Office of Naval Research at the Scripps Institution of Ocea-
nography in the Division of Marine Invertebrates in collaboration
with Dr. Martin W. Johnson.
The first study of the internal anatomy of Limnoria was
made by P. P. C. Hoek (1893, 97 pp., 7 pis.). Although written
in Dutch and thus largely unavailable to American scientists, his
work represents a most comprehensive study which has often
been quoted and which forms the basis for a similar report by
Kofoid and Miller (1927, pp. 306-332). Both investigations
dealt with the entire organism, with only brief reference to the
reproductive system. Various aspects of the reproductive be-
havior of Limnoria are also mentioned briefly by Coker (1923,
pp. 95-100), Henderson (1924, p. 320), Johnson (1935, p. 428),
Somme (1940, p. 155) and Shiino (1950, p. 348), all of whom
were mainly interested in the ecology of the animal.
MATERIALS AND METHODS
The species investigated was Limnoria tripunctata Menzies
(Menzies, 1951, pp. 86-88) collected from San Diego harbor, Cali-
fornia. Its reproductive system has been compared with those
of L. quadri punctata Holthuis and L. lignorum (Rathke). No
structural deviations of major importance were found, and it is
therefore believed that the findings reported here are applicable
to the majority of the species.
MENZIES: REPRODUCTION IN LIMNORIA
365
Living specimens, whole and decapitated, were fixed prior to
sectioning, in formalin (10 per cent), Carnoy's fluid acid alcohol,
formalin-alcohol-acetic acid (F.A.A.), and 70 per cent alcohol.
Cytological details were best preserved in decapitated specimens
fixed in F.A.A. Sections were made of paraffine-embedded
samples at 7 \i and 10 pt.. Three staining techniques were em-
ployed: Heidenhain's iron hematoxylin (counterstain eosin),
Mallory's triple stain, and Harris' hematoxylin. The first gave
the most generally useful results for this study.
COMPARATIVE MORPHOLOGY OF THE
REPRODUCTIVE ORGANS
In common with all known isopods the body of Limnoria can
be divided into three major regions (Fig. 1) : the cephalon or
head bearing the eyes, antennae, and mouth parts ; the peraeon
peraeon
pleon
cephalon
(head)
pleotelson
( telson)
antennae brood pouch with eggs 5th peroeopod pleopods
(leg)
Fig. 1. Gravid female Limnoria (from G. O. Sars, 1897). Major regions
of the body mentioned in text are noted. (The assistance of Mr. Robert
Winsett, Scientific Illustrator, Publications Division, S.I.O., in the final
preparation of Figures 1, 2, 5, 6 is particularly appreciated.)
or thorax bearing usually seven pairs of walking legs; and the
pleon or abdomen bearing usually five pairs of swimming and
respiratory appendages, the pleopods. The male and female
gonads are contained within the peraeon. Their relationship to
other major organs is shown in Figure 2. In Limnoria the sexes
are separate but this is not true for several other isopods (p. 372) .
The body of an adult Limnoria tripunctata is roughly 2.50 mm.
long and 0.60 mm. wide at the pleotelson.
366
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Internal Anatomy
Female. The ovaries are paired organs located below and on
either side of the tnbular heart and above the intestine and di-
gestive glands. Each ovary when mature extends from the second
to the seventh (last) peraeonal somite. Both their size and extent
are governed by the size and number of the developing ova. The
thoracic ganglion-
dorsal branch of _
digestive caeco
7th somite of peraeon
genital opophysis
pleopods
-vos deferens
genital opophysis
rectum -
A D
Fig. 2. Internal and external reproductive organs of Limnoria. A.
Female, ventral view, body wall cut away. B. Male, pleon and seventh
somite of peraeon, ventral view. C. Testes. D. Second pleopods of male.
Figures B and D after G. 0. Sars, 1897; A and C original.
immature ova (Fig. 3C) are about 0.045 mm. along the long axis
and have a characteristic uniform cytoplasm when preserved, and
a discrete nucleus. Yolk globules are not differentiated. In con-
trast, the mature ova (Fig. 4) are large oblong yolk-filled cells
with a length of 0.30 mm. and a cross-sectional diameter of 0.12
MENZIES: REPRODUCTION IN LIMNORIA 367
to 0.18 mm. The space occupied by the eggs at the middle of the
body is equal to about 30-40 per cent of that of the expanded
body cavity itself. The increased volume of the maturing eggs
compresses the other internal organs to the extent that females
in the stage prior to egg deposition frequently do not have food
in the gut.
The oviduct, attached laterally to each ovary at about its
middle, extends ventro-laterally to open at the base of the fifth
pair of legs. Each oviduct is band-shaped with a length of 0.08
mm., a thickness of 0.01 mm., and a height (distance between
ovary and orifice of oviduct) of 0.12 mm.
Much of the tissue surrounding each ovum consists of follicle
cells (flc, Fig. 3C). The oogonia are distributed along the lateral
margin of each maturing ovum and at the ends of the ovary
(oag, Fig. 3C).
Posterior to each ovary are located two elongate glands which
have a narrow lumen (called accessory glands by Kofoid and
Miller). The function of these is not known. Dorsally they are
in contact with the pericardium. Their cells (Fig. 3B) are unlike
those of the ovary or any other organ in Limnoria. The location
of the accessory glands near the heart and their presence only
in the female suggest that they might have an endocrine func-
tion.
Male. The testes of the male are similarly paired (Figs. 2C,
3A). Each testis consists of a single lobe of approximately 0.08
mm. in diameter and 0.1 mm. in length, located between the fourth
and fifth peraeonal somites, below and on either side of the heart
and not in the last (7th) peraeonal somite as maintained by Ko-
foid and Miller (1927, op cit.).1 A vas deferens proceeds from the
testis to the seventh peraeonal somite. Here, as is usual for
isopods, it turns medially and extends along the ventral body wall
to one of the paired genital apophyses. The genital apophyses
(=penis) consists of a pair of movable skin folds on either side
of the midline of the seventh peraeonal somite.
The structure of the testis is unusual in having only a single
lobe. Cytologically, spermatogenesis and spermiogenesis (Fig.
3A) are easily traced. Spermatogonia consist of rectangular
shaped cells of uniform consistency and with an evident nucleo-
1 Kofoid and Miller's error might be due to the mistranslation of Hoek's
(op. cit., p. 33) statement that the testes were located in the last body segments :
"De testes nenien in de laatste borstsegnienten . . ."
308
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
MENZIES : REPRODUCTION IN LIMNORIA 369
lus. Primary spermatocytes have a greatly swollen nucleus and
at the metaphase show tightly compacted tetrads and evident
centrosomes. The nuclei of secondary spermatocytes are about
one-half the size of those of primaries and have peripheral chro-
matin granules and an evident nucleolus. Spermatids show a
variety of structure during their maturation to sperms. The
nuclei of early spermatids have a granular nucleoplasm and ap-
parently two nucleoli. Those in a later stage are much smaller
with a clear nucleoplasm and two marked nucleoli. Mature sperm
have a cap (head?), an elongate midpiece, and a tail piece which
is at least twice the length of the midpiece. The precise length
of the sperm tail was not determined. Various parts of the
testis appeared to be in different phases of development. Mor-
phologically mature sperm, however, were found in the lumen
throughout the length of the testis. A hyaline membrane covered
the testis and formed the wall of the vasa deferentia. It was
associated with minute nuclei of the connective tissue outside
the testis and appeared to have been secreted by those cells.
Some small nuclei found inside the testis are considered to belong
to interstitial cells.
It is common among isopods for sperm to mature together in
compact batches (spermatophores). This bunching of sperm
was not observed, however, to occur in Limnoria, and no sperma-
tophore seems to be produced. Except for this deviation, the
Fig. 3. Sections of reproductive organs 0/ Limnoria A-C, E-F. A. Cross
section through testis. B. Longitudinal section through part of an ovarian
accessory organ. C. Longitudinal section through immature ovary. E. Part
of a cross section through testis showing large primary spermatocytes and
smaller secondary spermatocytes. F. Section through oviduct of fertilized
female; note sperm in oviduct. Abbreviations: blc, bloodcell; bis, blood
sinus; ct, connective tissue; inc, interstitial cell; flo, follicle cell; Iff, lumen
of accessory gland; Iv, lumen of vas deferens; n, nucleus; oog, oogonium;
ov, ovum; ovd, oviduct; spg, spermatogonia; spt, spermatid; sps, sperma-
tozoa; ylk, yolk.
D. Outlines of second pair oostegites of L. quadripunctata, all drawn to
same scale. Widths of pleotelsons of specimens in millimeters are: a, 0.59, b,
0.65, c, 0.70, d, 0.77, e, 0.77, /, 0.88.
Sections all drawn to about the same scale as indicated in figure A; all
drawings were done with the aid of a camera lucida.
370 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
testis cytologically appeared much like those described for other
isopods.
A sperm storage organ or seminal receptacle has been dis-
covered in many of the female isopods whose internal anatomy
has been studied. This includes Trichoniscus, Aselhis, and Jaera
(Fig. 5). In Jaera and Asellus the seminal receptacle consists
only of a swollen part of the oviduct, but in Trichoniscus a
separate pouch is present. The genus Jaera shows an apparently
unusual modification in also having a dorsally-opening vagina.
Female Limnoria appear to lack any sperm storage organs and in
this regard are apparently similar to Sphaeroma.
External Anatomy
The secondary sex characteristics of the female consist of leaf-
like plates (oostegites) originating at the medial base of the
coxal plate of legs two, three, four, and five ; and of the paired
openings of the oviducts medial to the base of each fifth leg.
With the absence of a vagina in the genus, each of these openings
might be considered a vulva. The vulvae were not found in im-
mature females. Similarly the oviducts seemed to remain closed
(without a lumen) until a short time prior to copulation.
The male secondary sex characteristics consist of the genital
apophyses (Figs. 2C, 6) which were already mentioned and a
stylus-like appendage (appendix masculinum) attached on the
medial side of the endopod of each second pleopod (Fig. 2D).
The secondary sex characteristics of isopods show some remark-
able variation. For example, oostegites do not appear in the sub-
order Gnathiidea (Monod, 1926, pp. 202-210), Fig. 5E, although
the area of the ventral part of the body surrounding the genital
atrium might be considered homologous. Oostegites, as indicated
for Limnoria, are present in most members of the suborders, e.g.
Anthuroidea, Flabellifera, Bopyroidea, Valvifera, Asellota and
Oniscoidea. The movable plates which form the genital apophyses
of Limnoria develop from simple swellings of the integument.
Such swellings constitute the adult condition in Cymothoa (Fig.
6G). A fusion of these lobes into a single piece (ductus ejactula-
torius) seems to have occurred in at least two suborders inde-
pendently. Thus Idothea (Valvifera) has two plates, whereas
Synidotea has one (Valvifera) . Ligidium has two, while Philoscia
MENZIES: REPRODUCTION IN LIMNORIA 371
(Fig. 6C) has one (Oniscoidea). An appendix masculinum is
present on the endopod of the second pleopods of males belonging
to the suborder Flabellifera. Here its function is not known but
it has been presumed to act as an intromittent organ in passing
the sperm from the genital apophyses to the vulva (or equivalent
opening) of the female. In the suborder Asellota (the genus
Asellus perhaps being exceptional), the first two male pleopods
combine as a functional penis. This is the case also in the sub-
order Oniscoidea (Vandel, 1925) ; however, the pleopods are of a
structure quite different from those of the Asellota (Fig. 6D).
Within the suborder Flabellifera, each appendix masculinum
consists only of a flattened part of the endopod of the second
pleopod which originates by splitting off the endopod. In most
genera it is within the realm of possibility that the appendix is
long enough to reach the oviducal opening of the female ; how-
ever, on the appendix masculinum of Limnoria the lack of any
grooves, specialized bristles, or rugosities, in which sperm might
be transferred or held prior to or during copulation, suggests
that the appendix masculinum might not have such a function.
On the other hand, the genital apophyses are generally so short
and located so near the midline of the male that it is difficult to
imagine that these might reach the vulvae of the female which
in contrast are located at the base of the legs of the female, far
from the midline. Copulation among the Flabellifera has not
been observed in detail and, therefore, no solution to the above
puzzle is offered.
SEX DETERMINATION
Sex Ratio
The sexes of Limnoria are found in about a 50/50 ratio when
taken from piling populations (Station A,1 mean ratio of males
to mature females, 0.95, and Station B,2 mean ratio of males to
mature females, 1.06; see Table 1). It is probable that males and
females are produced in that ratio ; however, this needs further
confirmation. The presence of sex chromosomes might be sug-
gested for Limnoria and other marine isopods in view of the
finding by Staiger and Bocquet (1954) of female heterogamety
in the marine isopod Jaera marina.
1 Located at the U.S. Navy Target Repair Base, Point Loma.
2 Located near the San Diego landing of the Coronado Ferry.
372 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
TABLE 1
Batio of males to females (those with oostegites) on piling.
Specimens were taken from heavily infested wood, each sample
averaging about 1 square inch in area.
Station
Station
Month
A
B
September 1952
0.95
0.83
October 1952
1.05
1.19
November 1952
1.26
0.93
December 1952
1.26
—
January 1953
1.12
1.31
February 1953
0.65
1.00
March 1953
1.20
1.00
April 1953
0.44
1.19
May 1953
0.95
—
June 1953
1.00
—
July 1953
1.92
—
August 1953
0.65
—
Mean
0.95
1.06
Mean Sta. A and B
0.99
Ambisexual Individuals
Ambisexual animals, those having the primary and secondary
characteristics of both sexes, were encountered rarely. Out of the
1423 sexually mature animals examined from thirteen migrant
populations, they were found only twice ; once in a sample having
39 specimens, and once in a sample having 137 specimens. Three
were found out of a total of 657 specimens from piling; one
sample of 91 animals had two while another of 30 animals had
one. These individuals had the genital apophyses of the male
as well as the immature or postgravid oostegites of the female.
Sections of one ambisexual individual (Fig. 3G) showed the
presence of ovaries with immature ova as well as testes with
mature sperm. No oviducts were found. Protandry is a charac-
teristic feature of one family of the Flabellifera, the Cymo-
thoidae, in which the young are functional males (with rudi-
ments of ovarian tissue) and progressively become functional
females. In the Sphaeromidae, rudimentary testes are attached
to the ovaries of the female.
MENZIES: REPRODUCTION IN LIMNORIA
REPRODUCTIVE BEHAVIOR
Brood-Pouch Formation
373
The development of the oostegites prior to copulation and
brood deposition is a gradual process with their size increasing
as the animal grows (Pig. 3D). Copulation, fertilization, the
production of the large oostegites of the fully formed brood
pouch, and egg deposition into the pouch of Limnoria all appear
to take place within a brief period of time (probably no more
than two or three days) . The release of the young from the brood
pouch is followed by a molt of the female (several laboratory
observations) and a reduction in size of the oostegites to their
pregravid size (Fig. 3D). This was suspected earlier to be the
case when females with small oostegites were found to have ap-
parently recently released young in their burrows. It follows
then that females with pregravid oostegites can be either virgin
O O R S A L
VENTRAL
Fig. 4. Cross section through pre-gravid female Limnoria at oviduct. The
animal had molted and the chitin was not heavily sclerotized at this stage.
Note huge size of eggs and absence of food in intestine. Abbreviations, same
as for Figure 3 with the following added: dg, digestive gland; gang,
ganglion ; intest, intestine ; oost, oostegite ; per csi, pericardial sinus.
374
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
females or females which have already produced one or more
broods.
Incubation
Limnoria incubates its young within its external brood pouch
(Fig. 5B). This mode of incubation is common to the majority
of isopods, including the suborders Asellota, Oniscoidea, Valvi-
fera, Anthuridea, Bopyroidea, Phreatoicidea, and most of the
sp#rmotophore
brood pouch
C F
Fig. 5. Schematic diagrams of the female reproductive systems of the
Isopoda. A. Epipenaeon, note external fertilization and absence of sperm
storage organs. B. Limnoria, note absence of sperm storage organs. C.
Oniscoid isopods, note presence of seminal receptacle and/or spermatophores.
D. Sphaeroma, note presence of uterus and functionless "brood pouch."
E. Adult Paragnathia, note absence of brood pouch and modifications under-
gone by female in development. F. Jaera, note presence of dorsal vagina.
Figure A based on data from Hiraiwa (1936) ; B, original; C, from Vandel
(1925); D, from Leichmann (1891-93); E, from Monod (1926), young
based on figures given by Monod, adult from description by Monod ; F, from
Forsman (1944).
MENZIES: REPRODUCTION IN LIMNORIA
375
Flabellifera. The Gnathiidea and the Sphaeromidae (suborder
Flabellifera) incubate their young "internally." In the Sphae-
romidae the eggs are deposited into the brood pouch but then are
taken into uteri which consist of paired invaginations of the
ventral body wall. In the Gnathiidea no brood pouch is formed ;
instead the eggs are deposited into a genital atrium and then
taken into the uteri which are reminiscent of those of the
Sphaeromidae.
Pairing, Fertilization, and Burrow Construction
The occupation of a burrow usually by only a sexually mature
male and female (plus any young produced by the pair) has been
penis
exopod
endopod
sympod
exopod
endopod
Fig. 6. Male reproductive organs. A. Penis of Trichnoiscus dentiger
(after Vandel, 1925), B. Genital apophyses of Ligidium hypnorum (after
Vandel, 1925), C. First pleopods and penis of Plriloscia muscorum (after
Vandel, 1925), D. First two pleopods of Ianiropsis sp. (after Menzies, 1952),
EG. Genital apophyses, E. Adult Cirolana, F. Young Limnoria, G. Adult
Cymotlwa, all original. Scales of magnification variable. Abbreviations
same as for other figures, vd, vas deferens.
376
BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY
TABLE 2
A comparison of the length of burrows occupied by single or by
paired animals on test blocks of one- and two-month exposure at
the U.S. Naval Target Eepair Base, San Diego harbor, California
(1953).
Burrow No. Burrows with No. Burrows with
Length Single Animals Paired Animals
in mm. One-Month Two- Month One-Month Two-Month
1.5
3
3
0
0
3.5
42
13
2
0
5.6
11
10
16
2
7.5
1*
6
12
8
9.5
1*
24
16
11.5
2*
14
13.5
10
15.5
9
17.5
2
19.5
1
21.5
1
23.5
1*
Total
57
33
56
64
Mean
Burrow
3.8±0.97
4.8±1.95
7.6±1.9
11.8±3.4
* Length of longest burrow.
frequently observed (Henderson [1924], Johnson [1935], Shiino
[1950], etc.). Examination of burrows in test blocks revealed
that a burrow generally had two animals only when long enough
to fully enclose two specimens (around 5.5 mm. and longer).
The proportion of paired animals was found to increase markedly
as the length of burrows and the length of exposure to migrant
populations increased. Test blocks of one-month exposure had
about as many burrows occupied by one as occupied by two
animals, while those of two-month exposure had twice as many
paired organisms as single ones (Table 2). Organisms kept in
the laboratory have been observed to pair with each other for
periods exceeding ten months (one case) and four months (four
cases) ; presumably a similar relationship between paired sexes
can be expected to occur in nature. Accordingly, it appears
MENZIES: REPRODUCTION IN LIMNORIA 377
that the pairing of sexually mature animals within a burrow is
an essential and consistent feature of their biology.
Copulation apparently occurs in the burrow. The sperm pro-
duced by the male are relatively few in number and these, as
has been seen, are not combined into a spermatophore. Sperm
have been found in the oviduct of the female and probably ferti-
lize the eggs as they pass down the oviducts. The absence in the
female of any seminal receptacle suggests that a copulation must
precede the deposition of each brood. This is more strongly in-
dicated by the observation that sperm were not found in the
oviducts of females bearing embryos or in virgin or post-oviger-
ous females but only in those with ripe ovaries which were
molting, prior to egg deposition (Fig. 3F). In the terrestrial
isopods which have been extensively studied in this regard and
which bear a seminal receptacle, a single copulation has been
found sufficient for the production of two broods (Armadillidium,
Howard, 1940, p. 84). Heeley (1941, pp. 136-137) reports viable
sperm to have been stored by isolated females of Porcellio
dilatatus, P. scdber and Oniscus asellus for at least two succes-
sive year's brood. The sexes of Porcellio and Armadillidium
show no tendency to pair and in the case of the latter, natural
populations often have twice as many of one sex as the other
(Howard, op. cit.). Oniscoid isopods (Porcellio, Trichoniscus,
Armadillidium, etc.) usually have a seminal receptacle and the
males produce many sperm which are united into a spermato-
phore (Schobl, 1880; Vandel, 1925). In contrast, it is interesting
to note that the diverse genera in which a long-term sexual pair-
ing is a pronounced characteristic of the animals, no seminal
receptacle is known to exist. These include the bopyrid, Epi-
penaeon, in which fertilization is apparently external (Hiraiwa,
1936, p. 108), the commensal and parasitic cymothoid, Anilocra
physoides (Montalenti, 1941, pi. XIX), and Sphaeroma (Leich-
mann, 1891). It appears that pairing, a long-term association
of members of the opposite sex, is correlated generally with an
absence of sperm storage organs in the species which have been
studied. In Limnoria, in view of its pairing habit, the production
of sperm storage organs would teleologically seem superfluous.
There exists the remote possibility that parthenogenesis (which
is known for several species of terrestrial isopods) might occur
378
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
in Limnoria. Five females kept for one year without a male
failed to produce any brood, whereas seven paired animals
produced one to two broods during that time. Hence partheno-
genesis by Limnoria is considered unlikely.
TABLE 3
Size of broods (egg number) produced by various isopods
Classification Species Reference Brood Size
ONISCOIDEA
Ligiidae
Ligia oceanica
Vandel, 1925
25
Ligidium hypnorum
( t it
3-17
Trichonisidae
Trichoniseus provisorius
it ii
3-19 (7-11 av.)
Trichoniseus flavis
t < it
6-18 (12 av.)
Oniseidae
Tracheoniscus rathhei
t i it
63
Porcellio monticola
a 1 1
73
Porcellio scaber
it it
88
Oniscus asellus
i i it
74
Armadillidiidae
Armadillidium vulgar e
it t i
up to 200
FLABELLIFERA
Cymothoidae
Anilocra physodes
Legrand, 1952
100-350
Livoneoa conv.exa
Original
67-130
Limnoriidae
Limnoria spp. (4)
This paper, p. 380
1-32 (6-21 av.)
Sphaeromidae
Sphaeroma rugicauda
Leiemnann,
GNATHILDEA
1891-93
63
Paragnathia formica
Monod, 1926
1004- (in ovary)
ASELLOTA
Janiridae
Jaera albifrons
Forsman, 1944
5-60
Desmosoma spp. (3)
Hult, 1941
8, 12, 16 (av.)
Ilyaraclxna sp.
it it
64
Munnopsidae
Munnopsis typica
1 1 tt
32 (greatest
ANTHURIDEA
No data available
number)
BOPYROIDEA
20004- ("several
Bopyridae
Epipenaeon
Hiraiwa, 1936
thousand")
VALVIFEEA
Idotheidae
Idothea (P.) resecata
Original
46 (29-65)
MENZIES: REPRODUCTION IN LIMNORIA 379
Size of Brood
The size of the broods produced by Limnoria is comparatively
small and variable both with regards to species and differing
populations of the same species.
Isopods with pelagic young (bopyrid parasites) characteristic-
ally produce thousands of eggs per brood (Table 3). Other
marine isopods belong to a category of marine organisms which
produce fewer than a thousand young per brood (Thorson, 1950,
p. 4). No free-living form is known to brood an excess of three
hundred eggs.
The members of the genus Limnoria produce an average maxi-
mum of only 30 eggs per brood. Since few marine animals, even
isopods, produce a smaller number of eggs, Limnoria may be
classified with those marine animals which produce only a few
eggs at one time. Except for the correlation between pelagic
development of young and a high egg number, which is the rule
among marine invertebrates, egg number among the isopods
shows no pronounced phylogenetic correlation or pronounced
correlation with size. Thus, within the suborder Oniscoidea, egg
number per brood varies between 3 and 200, and in the suborder
Flabellifera between 32 and 350. The size of the species is not a
significant factor governing egg number because Ligidium hyp-
norum, a species much larger than Limnoria, does occasionally
produce even fewer eggs than Limnoria. Similarly cymothoids
which are generally much larger than many bopyrids produce
several times fewer eggs. The number of eggs produced by an
isopod seems more intimately related to the ecology and behavior
of the species, and those factors influencing survival rate, than
to other factors. One might suspect, in the burrow-producing
Limnoria, that the survival rate of the young is very high in view
of the animal's small brood size.
To judge from the available data on brood size (Table 4), it
appears that the different species of Limnoria have differing
brood sizes. Thus L. lignorum has been observed with a maximum
of 35 eggs (mean 22), L. qitadripunctata with 17 eggs at a
maximum (9.5 mean), L. tripunctata with a maximum of 22
eggs (ca. 4-10 on an average), and finally L. andrewsi with a
maximum of only 6 eggs. Here it is interesting to note that
L. lignorum, a boreal species, has the greatest number; whereas,
380
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
L. andrewsi, a tropical species, has the least.
The evidence thus far assembled does not conclusively suggest,
as has been the observed case for many organisms, that younger
specimens (smaller) produce fewer eggs than larger specimens.
In the species Limnoria lignorum (Rathke), Somme (1940) re-
ported that broods produced during the summer were on an
average larger by 10-12 eggs than autumn broods. Coker (1923)
TABLE 4
Number of eggs per brood in several species of Limnoria
Species
Kind of
Distribution
Keference
Locality
Egg Number
Mean Range
L. lignorum Arctic-Boreal Henderson (1924) St. Andrews,
(Rathke) Bay of Fundy
21.7
14-32
Johnson (1935)
Friday Harbor,
Washington
10-23
Semme (1940)
a. summer broods
FLefdvigen,
20-30
20-35
b. autumn broods
Nor.
10-20
L. quadri-
punctata
Temperate
Kofoid and Miller
San Francisco
9.5
1-17
Holthuis
(1927)
Bay, Calif.
L. tri-
Temperate
Coker (1923)
Beaufort, N.C.
punctata
piling populations
Menzies
a. early spring
broods
4.2-6.6
1-12
and
b. summer broods
and fall
1.5-4.0
1-9
c. winter broods
none
none
Tropical
Shiino (1950)
ORIGINAL
Misaki, Japan
—
1-8
a. piling
San Diego,
•
populations
Calif.
4.6±2.74
1-14
b. Test-block
San Diego,
population A
Calif.
10. 6 ±3. 94
1-18
c. Test-block
San Diego,
population B
Calif.
9.6±4.24
1-22
L. andrewsi
Tropical
Shiino (1950)
Kominato,
oa. 4-5
2-6
Caiman
Japan
MENZIES: REPRODUCTION IN LIMNORIA 381
conversely found spring broods larger than summer and fall
broods by several eggs (Table 4). He found no gravid females
during the winter months. During the spring (April to May)
the mean water temperature was near 17 °C ; during the summer
and fall (June to September) it was near 26 °C and never below
22°C. In contrast the 5-day averages of the winter water tem-
peratures (December 13 to early March) varied between 11.3 °C
and 5.2° C. His data strongly suggest a close correlation between
temperature and the production of eggs and a less strong correla-
tion between temperature and brood size. Coker probably was
working with tripunctata (not L. lignorum) which is the only
species known to occur in North Carolina. As far as is now
known L. lignorum does not occur south of Massachusetts on
the Atlantic Coast.1
Somme (op. cit.) found gravid females of L. lignorum through-
out the year with maximal numbers occurring at temperatures
averaging only 9°C and lesser numbers occurring when the
temperatures averaged 3.9 °C. During periods having similar
water temperatures Coker [op. cit.) found no gravid females of
L. tripunctata. Somme 's evidence (op. cit.) indicated that little
or no egg deposition occurred during the winter months but
that the eggs deposited earlier were carried throughout the
winter by the female.
These data indicate that an optimal range of temperature for
the production of maximal-sized broods might occur in both
species.
The presence of gravid females of L. tripunctata from piling
in San Diego harbor and their absence from test blocks of one-
month exposure during the winter months, when the temperature
of the water was below 17°C, suggests a similar phenomenon ;
however, their presence on test blocks of two-months' exposure
strongly indicates that egg deposition does not cease entirely as
Coker found at Beaufort, but is only retarded under these less
extreme conditions (Table 5).
In the case of L. tripunctata from San Diego harbor where
temperatures near to Beaufort's spring temperatures (17°C)
prevailed, it seems that factors besides temperature govern brood
size. It has been found that migrant females (those from test
1 Unpublished data.
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MEXZIES : REPRODUCTION IN LIMNORIA 383
blocks) produce an average of 5 more eggs per pouch than non-
migrants (those from piling populations). The variable factor
which correlates best here is differences in population density.
The mean number of animals per square inch on test blocks of
one-month exposure (Station A) from the top and bottom sur-
faces of the blocks for one year was 3.9.1 The maximum density
encountered (August 13, 1953) on those surfaces was 60 per sq.
in. In contrast the density of piling populations (also sampled
monthly at Station A) varied between 142 (lowest figure) and
620 (highest figure) animals per square inch (Table 6). A simi-
lar relationship between population density and fecundity has
been indicated by Park (1939) for the flower beetle Tribolium
confusion. It is equally difficult in the case of Limnoria to prove
the modus operandi of a population density factor in lowering
the fecundity of a population.
The fact that different species have differing brood sizes is of
considerable interest indicating that perhaps the ecological fac-
tors associated with the reproductive capabilities of the various
species are also different. Differences may be found in the fre-
quency with which the broods are produced but this is an item
about which no data are available at present.
TABLE 6
Egg number per brood of females from a piling population
(presumably nonmigrant) and a test-block population (migrant)
compared. Data collected at monthly intervals (1952-53) for
twelve-thirteen months in San Diego harbor at two widely sep-
arated stations.
Number of
Mean
a
Location
Gravid Females
Examined
Number
Eggs
of
±
Eange
Piling, Sta. A.
307
4.66
2.70
1-14
Test-block, Sta.
A.
105
10.06
3.94
1-18
Test-block, Sta.
B.
113
9.63
4.27
1-22
1 An empirically determined ratio of 1.5 animals times the number of burrows
has been used here to estimate the total population of each test-block.
384 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
DISCUSSION
From this study it is apparent that the reproductive system
of Limnoria, except for the fact that fertilization is internal, is a
simple one with none of the specializations such as a vagina,
spermatophore, seminal receptacle, or "internal" uterus which
are known for many other isopods. Correlated with this simplic-
ity of structure is the tendency of an adult of each sex to occupy
a single burrow for long periods of time. This latter phenomenon
suggests that Limnoria shows an elementary social life, with the
paired animals working together in the construction and main-
tenance of a burrow and the production of the young.
The observation that the size of the brood of the various species
is different, with the more tropical species having a fewer num-
ber of eggs than the species living in colder water, suggests that
the rate at which broods are produced might be different with
the different species. The fact that the rate of production of
broods is dependent upon the environment inhabited by a speeies
(as indicated by the data given here and earlier by Coker [1923]
and Somme [1940]) strongly suggests that the rate of brood
production is not constant. These observations lead to a method
for the evaluation of one hypothesis as to the cause of migration
by Limnoria, namely overcrowding of the burrows. Once produc-
tion rates for species in various localities and during various
seasons are determined, these may be compared with the migra-
tory picture, and a relationship based on more direct evidence
can be established. The data indicate another important item
relative to brood production, namely that both high and low
temperatures encountered by a species can be associated with a
lowering of the brood size. A rising environmental temperature
then cannot be presumed always to be accompanied by a cor-
responding rise in the size of broods or in the rate of brood
production.
Perhaps the most significant observation, one which should
play a profound role in an estimation of the productivity of
natural populations, is that the brood size of specimens from
dense piling populations was found to be significantly lower than
that of specimens from less dense migrant populations. Investi-
gation of the factors associated with this observation should lead
MENZIES: REPRODUCTION IN LIMNORIA 385
to a better understanding of the population dynamics of this
species as such investigations have done with other organisms
for which this phenomenon has been reported.
SUMMARY
1. The internal and external anatomy and general histology
of the reproductive organs of Limnoria tripunctata Menzies are
described and compared with those of other isopods.
2. The male was found to have one-lobed testes in contrast to
most isopods and was found not to produce spermatophores.
3. The female was found to have no sperm storage organs.
Sperm were observed in the oviducts and it is believed that ferti-
lization of the eggs occurs as they are passed down the oviducts
into the brood pouch.
4. The absence of spermatophore production by the male, the
absence of sperm storage organs in the female, and the finding
of sperm in the female oviduct only prior to egg deposition sug-
gest that a copulation must precede each brood.
5. The method of copulation was not observed. The simple
unmodified structure of the appendix masculinum suggests that
it is possibly not involved in sperm transfer.
6. A sex ratio of one male to one female is suggested from
piling population analysis.
7. Ambisexual individuals were rarely encountered. These
individuals had the genital apophyses of the male as well as the
oostegites of the female externally and both testes and ovaries
internally.
8. It was found that oostegites gradually increase in size
until, within one molt, they suddenly increase greatly to form
the brood plates of the brood pouch of the gravid female. A
release of the young was observed to be accompanied by a molt
of the female and a return of the oostegite to a pregravid size.
Accordingly, it is indicated that females with pregravid oostegites
can be either virgin females or females which have produced one
or more broods.
9. The long-term pairing of a sexually mature male and a
female in a burrow apparently is an essential and consistent
feature of the biology of Limnoria. Specimens have been ob-
served to remain paired as long as ten months.
386 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
10. The pairing behavior of Limnoria and that of several
other isopods appears generally to be associated with an absence
of any sperm storage mechanism.
11. The reproductive system of both sexes of Limnoria is
simple in its organization as compared with that of other isopods.
12. Parthenogenesis does not appear to occur in Limnoria.
13. Limnoria belongs to a category of isopods which produce
only a few eggs (average maximum of 30) per brood. A high
survival rate of the young and/or a rapid rate of production is
indicated.
14. Brood size was found to vary both with regards to the
species and differing populations of one species.
15. The boreal species L. lignorum (Rathke) produces as
many as 35 eggs per brood, whereas the tropical L. andrewsi
Caiman produces only 6 at a maximum. The temperate and
temperate-tropical species L. quadripunctata Holthuis and L.
tri punctata Menzies were found to produce broods between those
extremes in size.
16. Under conditions of moderately low temperature (near
10°C) at Beaufort, N. C, L. tripunctata produced no broods.
The brood production of the same species at San Diego during
the winter months (temperature near 15°C) was retarded but
did not cease entirely.
17. The data suggest that both high and low temperatures
are associated with a lowering of brood size in L. tripunctata at
Beaufort, N. C.
18. At San Diego harbor where seasonal temperature varia-
tions are moderate as compared with Beaufort, N. C, variation in
brood size was found to correlate with population density, with
animals from piling populations (high density) having fewer
eggs per brood than animals from test-block populations (low
population density).
19. A method of testing the hypothesis that overcrowding is
the cause of migration in this species is proposed.
20. The following factors are indicated as important in esti-
mations of the production rate of Limnoria: a) species involved,
b) temperature and its effect on brood size and rate of brood
production within a single species, c) population density and
its associated factors as they affect brood size.
MENZIES: REPRODUCTION IN LIMNORIA 387
LITEEATURE CITED
Cokbr, R. E.
1923. Breeding habits of Limnoria at Beaufort, N. C. Jour. Elisha
Mitchell Sci. Soc, 39: 95-100.
FORSMAN, BROR
1944. Beobachtungen iiber Jaera albifrons Leach an der Schwedischen
Westkiiste. Ark. f. Zool., 35a(ll) : 1-33.
Hbblby, William
1941. Observations on the life-histories of some terrestrial isopods.
Proc. Zool. Soc. London, 111(7): 79-149.
Henderson, Jean T.
1924. The gribble: A study of the distribution factors and life-history
of Limnoria lignorum at St. Andrews, N. B. Contrib. Canadian
Biol., n. s. 2(1) : 309-325, 2 pis.
HlRAIWA, YOSHI KUNI
1936. Studies on a bopyrid, Epipenaeon japonica Thieleman. III.
Development and life-cycles, with special reference to the sex
differentiation in the bopyrid. Jour. Sci. Hiroshima University.
Ser. B, Div. 1, 4(8) : 101-141.
Hoek, P. P. C.
1893. Betreffende de Levenswijze en de werking van Limnoria lig-
norum. In Rapport der Commissie uit de Koninklijke Akademie
van Wetenschappen. Verhandel. K. Akad. Wetensch. te Amster-
dam (Tweede Sectie), 1(6): 1-97.
Howard, H. W.
1940. The genetics of Armadillidium vulgare Latr. Jour. Genetics,
40(1): 83-108.
HULT, J.
1941. On the soft-bottom isopods of the Skager Rak. Zool. Bidrag f.
Upsala, 21: 3-223.
Johnson, Martin W.
1935. Seasonal migrations of the wood-borer Limnoria lignorum
(Rathke) at Friday Harbor, Washington. Biol. Bull., 69(3):
427-438.
Kopoid, Charles A. and Robert C. Miller
1927. Biological Section, in Hill, C. L. and C. A. Kofoid, Marine
borers and their relation to marine construction on the Pacific
Coast. San Francisco: 357 pp.
Leichmann, Georg
1891. Beitrage zur Naturgeschichte der Isopoden. Bibliotheca Zool.,
3(10): 1-44.
388 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Legrand, J. J.
1952. Contribution a 1 'etude experimental et statistique de la biologie
d'Anilocra physodes L. Arch. Zool. Exper. et Generale, 89(1):
1-55.
Mentzies, Eobert J.
1951. A new species of Limnoria (Crustacea: Isopoda) from Southern
California. Bull. Southern California Acad. Sei., 50(2): 86-88.
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Bulletin of the Museum of Comparative Zoology
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Vol. 112, No. 6
THE GENUS EUSTALA (ARANEAE, ARGIOPIDAE) IN
CENTRAL AMERICA
By Arthur M. Chickering
Albion College, Albion, Michigan
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Bulletin of the Museum of Comparative Zoology
AT HARVARD COLLEGE
Vol. 112, No. 6
THE GENUS EUSTALA (ARANEAE, ARGIOPIDAE) IN
CENTRAL AMERICA
By Arthur M. Chickering
Albion College, Albion, Michigan
CAMBRIDGE, MASS., U. S. A.
PRINTED FOR THE MUSEUM
March, 1955
No. 6 — The Genus Eustala (Araneae, Argiopidae) in Central
America
By Arthur M. Chickering
In connection with previous publications (1943, 1948, 1950)
I have pointed out some interesting instances of the process of
speciation among certain genera of spiders in Panama. The
present study of the genus Eustala has been somewhat broadened
to include the known species of the whole of Central America
although the genus remains best known in Panama where the
most careful collecting has been done. In several respects this
study has proven to be the most difficult of any thus far under-
taken on Central American genera. Differences between species
are often obscure and very puzzling. Color patterns have been
shown to be of little value as a means of distinguishing species.
The male palps and the epigyna are the most reliable specific
structures upon which one can rely in separating species. Doubt-
less there will be araneologists who will differ with me in respect
to the degree of reliability shown by these structures. The dif-
ficulties I have mentioned have in the past caused much confusion
and many errors in identification. It seems evident from a study
of specimens of nearly all of the species recognized by the Cam-
bridges (1889-1905) that even they dealt, to some extent, with
mixed material. Among females I have found that close attention
must be paid to such details of the epigynum as : shape of base,
shape of scape, shape of the clear central area of the base bor-
dered by tubules, relative proportions of base and scape, positions
of the apertures to the spermathecae, positions of the spermathe-
cae, etc. F. P. Cambridge (1904) recognized and definitely
named several parts of the male palpal tarsus considered im-
portant in distinguishing species. I have thought it best to
retain the Cambridge terminology for these parts with little
modification and few additions. These palpal parts may be
named as follows: basal apophysis (basal tarsal hook), uncus,
embolus, conductor, clavis, vesicle, terminal laminae, maxillary
tooth, femoral tubercle. The named parts of the male palpal
tarsus are shown in Figures A and B, based upon E. fusco-
vittata (Keyserling).
392
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Acknowledgments are due and gratefully extended to the fol-
lowing persons and organizations for their interest and aid : Dr.
A. S. Romer, Director, and Dr. P. J. Darlington, Jr., Curator of
Insects, respectively, in the Museum of Comparative Zoology
at Harvard College where much of the work of preparing this
paper was carried on ; Dr. W. J. Gertsch, American Museum of
Natural History, for the loan of much valuable material from
Central America; Dr. G. Owen Evans, Department of Zoology,
British Museum (Natural History), for the loan of almost in-
dispensable material studied by the Cambridges; the donors of
the Penrose Fund of the American Philosophical Society and
The Society of Sigma Xi for their financial aid which made it
possible for me to spend the summer of 1950 engaged in field
studies and collecting in Panama.
The types of Eustala abdita sp. nov., E. banksi sp. nov., E.
mexicana sp. nov., E. mimica sp. nov., E. panamana sp. nov. will
be deposited in the American Museum of Natural History, New
External Anatomy of Eustala
Figures A and B
Fig. A. Diagram of male palpal tarsus; lateral view; showing important
features.
Fig. B. The same; view from in front.
1 — vesicle ; 2 — embolus ; 3 — uncus ; 4 — conductor ; 5 — clavis ; 6 — ■
tarsal hook (basal apophysis) ; 7 — -terminal laminae.
(Both diagrams based upon E. fusco-vittata)
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 393
York City. All other types will be deposited in the Museum of
Comparative Zoology at Harvard College.
Genus EUSTALA Simon 1895
The Cambridges (1889-1904) reported the following eleven
species of Eustala from Central America: E. anastera (Walcke-
naer) ; E. bifida F. P. Cambridge; E. clavispina (0. P. Cam-
bridge) ; E. fragilis (0. P. Cambridge) ; E. fusco-vittata (Keyser-
ling) ; E. guttata F. P. Cambridge ; E. illicita (0. P. Cambridge) ;
E. latebricola (0. P. Cambridge) ; E. scutigera (0. P. Cam-
bridge) ; E. semifoliata (0. P. Cambridge) ; E. vegeta (Keyser-
ling). E. conformant Chamberlin completes the list of twelve
species known from Central America prior to the present work
on this genus. According to my present view of speciation in
this genus we must now add the following twenty-six new
species to the known list from this part of the world : E. abdita
sp. nov. ; E. banksi sp. nov. ; E. bucolica sp. nov. ; E. delecta sp.
nov. ; E. exigua sp. nov. ; E. gertschi sp. nov. ; E. inconstans sp.
nov. ; E. ingenua sp. nov. ; E. innoxia sp. nov. ; E. lata sp. nov. ;
E. longembola sp. nov.; E. maxima sp. nov.; E. mexicana sp.
nov. ; E. mimica sp. nov. ; E. minima sp. nov. ; E. montana sp.
nov. ; E. montivaga sp. nov. ; E. oblonga sp. nov. ; E. panamana
sp. nov. ; E. redundans sp. nov. ; E. rustica sp. nov. ; E. scitula
sp. nov.; E. sedula sp. nov.; E. tantula sp. nov.; E. tumida sp.
nov. ; E. venusta sp. nov. Thirty-two of the thirty-eight species
now known in Central America are found in Panama. Those
which thus far appear not to occur in Panama are the following
E. abdita sp. nov.; E. anastera (Walck.) ; E. banksi sp. nov.
E. bifida F. P. Cambridge; E. clavispina (0. P. Cambridge)
and E. mexicana sp. nov. The total number listed here will
probably be somewhat reduced when it becomes possible to match
up males and females more successfully than I have been able
to do. There are few reliable guides in this genus, particularly
among those with the round-triangular form, which can be used
to match males and females. Among the species from Central
America, I have found the color pattern so highly variable
within the species and between males and females that I am
compelled to avoid its use in any important way. My experience
394 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
is, therefore, very different from that of Mello-Leitao (1947).
Where there is reasonable doubt I have chosen to describe the
males and females as separate species rather than run the danger
of missmating, with the resulting complications in later litera-
ture.
Key to the Species of Eustala in Central America
Males
*
1. Abdomen elongate, slender (fusco-vittata, illicita, oblonga) 2
1. Abdomen not elongate; rounded-triangular 4
2. Clavis with a distinct robust lateral process at base ; conductor simple,
without distinct processes (Fig. 3) E. fusco-vittata, p. 398
2. Clavis without distinct lateral process; conductor with two or three
distinct processes 3
3. Clavis deeply excavated at base; conductor with three slender processes
(seen in lateral view, Fig. 15) E. oblonga, p. 404
3. Clavis without basal excavation; conductor with two robust processes
(seen in lateral view, Fig. 8) E. illicita, p. 401
4. Uncus with a broad basal enlargement more or less concealing the tip
( bifida, mimica, Figs. 37 and 92) 5
4. Uncus with only a shoulder at base or without any basal en-
largement 6
5. Conductor robust; uncus without a distinct shank E. bifida, p. 421
5. Conductor smaller; uncus with a distinct shank proximal to basal
enlargement E. mimica, p. 467
6. Uncus long slender, with no basal shoulder or enlargement (exigua,
gertschi, tantula) 7
6. Uncus robust, with or without a basal shoulder 9
7. Uncus somewhat concealed; vesicle extremely large, spirally twisted
E. tantula, p. 505
7. Uncus not concealed; vesicle of more normal relative size, not spirally
twisted ; 8
8. Conductor with two slender extensions, seen in lateral view (Fig. 57) . .
E. exigua, p. 435
8. Conductor without slender projections (Fig. 61) ...E. gertschi, p. 440
9. Conductor with a definite lobe {delecta, scutigera) 10
9. Conductor without any definite lobe 11
10. Conductor with a conspicuous lobe somewhat overlapping the uncus ;
embolus relatively long and slender E. scutigera, p. 496
10. Conductor with an inconspicuous lobe not overlapping the uncus ;
embolus relatively broad and flat E. delecta, p. 431
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 395
11. With an extremely long slender embolus (Fig. 83) E. longembola, p. 458
11. Without an extremely long slender embolus 12
12. Uncus distinctly sickle-shape, with a marked shoulder at its base
E. montana, p. 474
12. Uncus not distinctly sickle-shape, with no shoulder at its base or with
a moderately developed shoulder 13
13. Uncus short, small and somewhat concealed ; vesicle concealed
E. abdita, p. 410
13. Uncus a more or less robust hook; vesicle usually exposed (concealed
in inconstans) 14
14. Massive conductor continued posteriorly as a slender, setose extension . .
E. anastera, p. 414
14. Conductor of moderate size and not continued posteriorly as a slender,
setose extension 15
15. Embolus relatively long and slender ; vesicle relatively large and bulbous
(guttata, scitula) 16
15. Embolus not so long and not so slender; vesicle of moderate size or
concealed 17
16. Uncus of moderate size, with a definite shoulder at its base
E. guttata, p. 442
16. Uncus more robust, without a definite shoulder at its base
E. scitula, p. 492
17. Embolus very short, very broad at base; vesicle withdrawn or greatly
reduced in size E. inconstans, p. 446
17. Embolus moderately long and slender; vesicle of moderate size and
clearly exposed 18
18. Fourth femur with ventral spines confined to distal third of segment
( bucolica, rustica) 19
18. Fourth femur with ventral spines extending throughout much more than
distal third of segment (banlcsi, vegeta) 20
19. Embolus with free part relatively short and slender . .E. bucolica, p. 425
19. Embolus terminally broad and grooved E. rustica, p. 486
20. Uncus with a long robust base or shank; conductor deeply grooved on
distal surface E. banlcsi, p. 417
20. Uncus without a long robust basal shank; conductor without a deep
groove on distal surface E. vegeta, p. 511
Females
(E. fragilis (O. P. Cambridge) is not included in the key because of
the lack of clear and definite knowledge about the species.)
1. Abdomen elongate, slender (fusco-vittata, illicita, oblonga) 2
1. Abdomen not elongate; rounded-triangular 4
396 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
2. Scape of epigynum not clearly separated from base ; gradually narrowed
from base to tip E. fusco-vittata, p. 398
2. Scape of epigynum clearly separated from base; not gradually narrowed
from base to tip 3
3. Scape arises from near middle of base and extends as a slender median
structure E. oblonga, p. 404
3. Scape arising from near anterior margin of base and widened in
middle E. illicita, p. 401
4. Pars cephalica extended into a distinct eye-bearing cone (Fig. 131) . . .
E. tumida, p. 508
4. Pars cephalica normal, not extended into an eye-bearing cone 5
5. Base of epigynum expanded into a pair of shoulders surrounding the
apertures; scape relatively very slender (guttata, redundans) 6
5. Base of epigynum not expanded into a pair of shoulders surrounding
the apertures 7
6. Base of epigynum with a posterior projection from the central area . .
E. redundans, p. 484
6. Base of epigynum without any posterior projection from the central
area E. guttata, p. 442
7. Scape of epigynuni sharply narrowed where it joins the base, viewed
from below (ingenua, latebricola, mexicana, minima, vegeta, ve-
nusta ) 8
7. Scape of epigynum gradually narrowed from base to tip, viewed from
below (anastera, maxima, innoxia, montivaga, panamana, rustica,
scutigera, s.edula, semifoliata) 13
8. Scape of epigynum short, expanded at tip, originates from base behind
the anterior margin E. minima, p. 471
8. Scape longer, not expanded at tip or, if expanded at tip, originates at
anterior border of base 9
9. Apertures nearly in contact in middle; scape of epigynum only slightly
rugulose E. ingenua, p. 449
9. Apertures of epigynum much farther apart; scape at least moderately
rugulose 10
10. Scape of epigynum with a semicircular ridge just anterior to apertures;
the latter barely two diameters of one of them apart
E. latebricola, p. 457
10. Scape of epigynum without a semicircular ridge in front of the aper-
tures; the latter more than two diameters of one of them apart . . .11
11. Central area of base of epigynum drawn out laterally into narrow
extensions; base in general quite oval in outline . .E. mexicana, p. 465
11. Central area of base of epigynum not drawn out laterally into narrow
extensions ; base in general not oval in outline 12
12. Apertures of epigynum fully five times the diameter of one of them
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 397
apart ; spermathecae several diameters of one of them apart
E. vegeta, p. 511
12. Apertures of epigynum not so far apart; spermathecae in contact in
middle of central area E. venusta, p. 515
13. Venter with a pair of white spots transversely placed
E. s.emifoliata, p. 502
13. Venter without a definite pair of white spots transversely placed ... .14
14. Abdominal hairs abruptly dilate basally E. clavispina, p. 428
14. Abdominal hairs not dilate basally 15
15. Apertures of epigynum hidden; epigynum in general simple, with few
external features E. innoxia, p. 452
15. Apertures of epigynum clearly exposed but sometimes small; epigynum
more complicated, with several external features 16
16. Central part of base of epigynum relatively small; only about one
fourth as broad as base; base nearly as broad as long; chitinized
areas lateral to base E. conformans, p. 430
16. Central part of base of epigynum relatively larger and considerably
broader; without conspicuous chitinized areas lateral to base 17
17. Scape of epigynum nearly or quite as long as base is broad 18
17. Scape of epigynum not nearly as long as base is broad 19
18. Apertures of epigynum nearly in contact; central area of base triangu-
lar in outline E. sedula, p. 500
18. Apertures of epigynum well separated; central area of base more oval
in outline E. lata, p. 454
19. Apertures of epigynum nearly or quite at lateral margins of base
( bifida, maxima ) 20
19. Apertures of epigynum far removed from margins of base 21
20. The inner of the paired tubules bounding the central area of *base
shorter and broader ; central area of base raised into two marked
prominences E. bifida, p. 421
20. The inner of the two tubules bounding the central area of base narrower
and much longer; the central area of base not raised into prominences
E. maxima, p. 461
21. Central area of base of epigynum bounded by only one definite pair of
curved tubules; scape much narrower at its base than width of the
latter E. rustica, p. 486
21. Central area of base of epigynum bounded by two pairs of more or less
distinct tubules; scape nearly as wide at its base as the width of
the whole base 22
22. The central area of the base of the epigynum considerably longer than
broad E. anastera, p. 414
22. The central area of the base of the epigynum as wide as long or wider
than long 23
398 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
23. Scape of the epigynum not much narrowed until a considerable distance
in front of the apertures E. scutigera, p. 496
23. Scape of the epigynum gradually narrowed from opposite the apertures
(montivaga, panamana) 24
24. Central area of base of the epigynum definitely wider than long
E. panamana, p. 480
24. Central area of base of the epigynum about as wide as long
E. montivaga, p. 478
Eustala fusco-vittata (Keyserling) , 1863
(Figures 1-5)
Epeira fusco-vittata Keyserling, 1863
E. fusco-vittata Keyserling, 1892
Cyclosa thorelli McCook, 1893
Eustala fusco-vittata Simon, 1897
E. caudata Banks, 1898
E. fusco-vittata F. P. Cambridge, 1904
E. fusco-vittata Petrunkevitch, 1911
E. fusco-vittata Petrunkevitch, 1925
E. fusco-vittata Banks, 1929
E. fusco-vittata Petrunkevitch, 1930
E. fusco-vittata Bryant, 1940
This is the best-known species in the genus, in Central America.
It has been collected over a wide area throughout Central Amer-
ica, several of the West Indies, and much of South America. In
this species, as in others previously known, figures and the most
important facts concerning basic structural features are given
herewith as an aid to identification and study of the group.
Male hypotype. Total length 8.58 mm. Central ocular quad-
rangle wider in front than behind in ratio of 4 : 3 ; almost
exactly as wide in front as long. Ratio of eyes AME : ALE :
PME : PLE = 13 : 9 : 11 : 8.5. AME separated from one
another by about four-thirds of their diameter, from ALE by
nearly five-halves of their diameter. PME separated from one
another by a little more than two-thirds of their diameter, from
PLE by nearly four times their diameter. Laterals separated
from one another by the radius of ALE. Promargin of fang
groove with four teeth, the second and fourth smaller, the others
robust; retromargin with three teeth. Secondary sexual char-
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
399
acters on maxillae and adjacent segments appear as usual and
are well developed. Sternum longer than. wide in ratio of 23 : 13.
Legs. 1423. Width of first patella at "knee" .433 mm.,
tibial index of first leg 9. Width of fourth patella at "knee"
.390 mm., tibial index of fourth leg 9.
External Anatomy of Eustala
Figures 1-5, E. fusco-vittata
Fig. 1. Left second tibia; ventral view.
Pig. 2. Right second femur ; ventral view.
Fig. 3. Left male palpal tarsus; lateral view.
Fig. 4. Left male palpal tarsus ; from in front.
Fig. 5. Epigynum; from below.
3.900
1.267
14.267
2.860
1.235
10.530
1.625
.845
7.150
3.250
1.170
12.870
1.235
2.522
400 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.030 1.560 3.510
2. 3.250 1.235 1.950
3. 2.405 .845 1.430
4. 4.030 1.430 2.990
Palp. .715 .352 .220
Second tibia with ventral and related spines as shown in
Figure 1. The ventral femoral spines on the second leg are
particularly prominent ; in the hypotype there are twelve on
the right (Fig. 2) and seven on the left. The fourth femur ap-
pears regularly to be devoid of ventral spines.
Palp. Complicated and characteristic; features of femur,
patella and tibia are about as usual in the genus. Tarsus: the
basal tarsal apophysis has a distorted arrow-shape ; the clavis is
deeply excavated at its base and has a robust anterolateral
process, and is also seen to be geniculate when viewed laterally ;
the uncus is long, rather slender, and has a central medial curved
ridge ; the conductor is relatively simple and when viewed ven-
trolateral^ it appears more or less quadrilateral but is deeply
grooved distally; the vesicle is small, strongly chitinized; the
embolus is thin, grooved, and gently curved at its distal end ; the
terminal laminae include a series of strongly chitinized denta-
tions (Figs. 3-4).
Color in alcohol. The carapace has a rather narrow central
brownish stripe and is yellowish elsewhere. The sternum is yel-
lowish flecked with grayish. Abdomen : there is a fairly well
marked dorsal folium divided into three stripes of which the
laterals are lighter and contain reddish dots ; the venter has a
broad central brownish stripe on each side of which there is a
yellowish granular stripe. Much variation in color pattern has
been noted among the many individuals studied.
Female hypotype. Total length 8.255 mm.
Legs. 1423. Width of first patella at "knee" .433 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .401
mm., tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.625 3.055 3.445
1.495 2.925 3.120
.780 1.235 1.430
1.365 2.730 3.120
1.
3.380
2.
2.795
3.
2.015
4.
3.500
1.170
12.675
1.105
11.440
.780
6.240
.975
11.690
OHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 401
Epigynum. The apertures are nearly in contact in the middle ;
the posterior surface has a characteristic central convexity ; the
scape, broad at the base, gradually tapers to the tip (Fig. 5).
Type locality. Male hypotype from Barro Colorado Island,
C. Z., August, 1950; female hypotype from the same locality,
July, 1939. Several hundred specimens of both sexes have been
examined from many localities in Mexico, Guatemala, Honduras,
Costa Rica, Nicaragua, and Panama.
Eustala illicita (0. P. Cambridge), 1889
(Figures 6-11)
Epeira illicita O. P. Cambridge, 1889
E. cambridgei Keyserling, 1893
Eustala illicita F. P. Cambridge, 1904
E. illicita Petrunkevitch, 1911
I have had only females from the British Museum for compari-
son but there can hardly be any doubt of the correct identification
of the males, however.
Male hypotype. Total length 6.50 mm. With an elongated
form like that of E. fusco-vittata but more slender than in that
species. Central ocular quadrangle wider in front than behind
in ratio of 6 : 5 ; slightly wider in front than long. Ratio of eyes
AME : ALE : PME : PLE = 11 : 8 : 10.5 : 7.5. AME separated
from one another by nearly five-thirds of their diameter, from
ALE by nearly five-halves of their diameter. PME separated
from one another by nearly their diameter, from PLE by about
seven-halves of their diameter. Laterals separated from one an-
other by the radius of ALE. Three long slender spines form a
triangular area between AME. Height of clypeus equal to nearly
three-halves of the diameter of AME. Promargin of fang groove
with five teeth, the fourth the largest; retromargin with two
on the right side and three on the left. The secondary sexual
characters appear about as usual on the first coxa and second
femur.
Legs. 1423. Width of first patella at "knee" .379 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .357 mm.,
tibial index of fourth leg 9.
402
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Femora Patellae Tibiae Metatarsi
(All measurements in millimeters)
1. 3.835 1.365 3.315 3.347
2. 3.185 1.170 2.405 2.605
3. 2.145 .715 1.170 1.237
4. 3,575 1.235 2.470 3.120
Palp .466 .314 .271
Tarsi
Totals
.975
12.837
.910
10.275
.715
5.982
.845
11.245
.980
2.031
Fig.
6.
Fig.
7.
Fig.
8.
Fig.
9.
Fig.
10.
Fig. 11.
External Anatomy of Eustala
Figures 6-11, E. illicita
Left second tibia, ventral view.
Left second femur, ventral view.
Left male palpal tarsus, lateral view.
Left male palpal tarsus, from in front.
Epigynum, from below.
Epigynum, lateral view.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 403
Second tibia with ventral and related spines as shown in
Figure (J. The first femur has a double series of ventral spines
as follows : promargin with one or two near distal end and
hardly more than bristles ; the retromargin has three all in the
distal two fifths of the segment. The second femur has a single
series of ventral spines with four on the left side and five on
the right (Fig. 7) ; all are fairly robust. The third femur has
a series of two or three ventral spines. The fourth femur appears
to be regularly devoid of ventral spines.
Palp. Features of the femur, patella, and tibia appear to be
typical of the genus. Tarsus : basal tarsal apophysis well de-
veloped but unnoteworthy ; clavis moderately robust, with its
surface somewhat irregular, and with base strongly chitinized
but unexcavated; the uncus is a well developed, evenly curved,
sickle-shaped hook; the conductor is massive, deeply excavated
along its lateral surface and with two processes as seen in lateral
view ; dista'ly the conductor and terminal laminae combine to
make two conspicuous grooves; the vesicle is small but clearly
evident; the embolus is relatively short, flattened, and curved
(Figs. 8-9).
Color in alcohol. Carapace and legs almost unicolorous am-
ber-yellow. Sternum yellowish, flecked with brownish gray.
Abdomen : dorsal folium very poorly defined ; in a male from
Mexico the abdominal markings are very similar to those recorded
for E. fusco-vittata; the venter has a broad dark stripe from
genital groove to base of spinnerets together with a narrow
whitish granular margin.
Female hypotype. Total length 12.22 mm.; with the elongated
form characteristic of E. fusco-vittata (Keys.) and E. oolonga
sp. nov.
Legs. Width of first patella at "knee" .542 mm., tibial index
of first leg 9. Width of fourth patella at "knee" .520 mm.,
tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.950 4.225 4.160
1.820 3.640 3.900
1.105 1.495 1.885
1.820 3.445 4.030
1.
4.875
2.
4.290
3.
2.600
4.
4.875
1.170
16.380
1.170
14.820
.910
7.995
1.170
15.340
404 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOr Y
Ventral femoral spines are rare in the females and, apparently,
quite irregular.
Epigynum. The base appears to have a more or less distinctive
pattern of tubules, apertures, and striations. The scape is very-
distinctive ; it begins narrow, almost immediately broadens, and
then narrows again to terminate in a blunt point (Figs. 10-11).
Color in alcohol. There is a narrow dark middorsal stripe
on the abdomen with the dorsal folium also poorly defined. The
venter has a moderately broad dark median stripe and a yellow-
ish area on each side.
Type locality. The Cambridges had this species from Mexico
and Guatemala. The hypotype male is from Madden Dam
Forest, C. Z., July, 1950; the female hypotype is from San
Luis Potosi, Mexico, July, 1941 (L. I. Davis). Specimens from
Mexico, Guatemala, Costa Rica, El Valle, R. P., November, 1946 ;
Canal Zone, July, 1950 (but not yet from Barro Colorado Island)
have been studied.
EUSTALA OBLONGA Sp. nOV.
(Figures 12-18)
Male holotype. Total length 6.825 mm. Carapace 3.25 mm.
long, 2.47 mm. wide opposite interval between second and third
coxae where it is widest; .975 mm. tall and, therefore, nearly .4
as tall as wide ; gently raised from PME to opposite third coxae
from where descent arches sharply to posterior border ; well
rounded from opposite posterior border of fourth coxae to op-
posite anterior border of second coxae from where it is narrowed
to a blunt point between AME ; longitudinal thoracic groove
long and well marked ; with a moderately well developed covering
of light yellowish hair; with several slender spines in ocular
area.
Eyes. Eight in two rows, all dark; ocular tubercle bearing
ALE quite prominent; viewed from above, both rows strongly
recurved; viewed from in front, anterior row moderately pro-
curved; central ocular quadrangle wider in front than behind
in ratio of 20 : 17, slightly wider in front than long ; ALE extend
somewhat beyond margins of carapace at their level. Ratio of
eyes AME : ALE : PME : PLE = 14 : 9 : 11 : 10. AME sep-
CHICKERING : GENUS EUSTALA IN CENTRAL AJ ER i
405
External Anatomy of Eustala
Figures 12-18, E. oblonga sp. nov.
Fig. 12. Male maxilla, palpal femur and trochanter
Fig. 13. Left second tibia from below.
Fig. 14. Left second femur from below.
Fig. 15. Left palpal tarsus, lateral view.
Fig. 16. Left palpal tarsus from in front.
Fig. 17. Epigynum from below.
Fig. 18. Epigynum, lateral view.
406 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
arated from one another by nine-sevenths of their diameter, from
ALE by about 1.6 times their diameter. PME separated from
one another by their diameter, from PLE by about three times
their diameter. Laterals separated by three-tenths of the diam-
eter of PLE. Height of clypeus equal to about six-sevenths of
the diameter of AME. Clypeus strongly receding and with a
recess between it and base of chelicerae ; apparently with a single
long slender spine between each AME and other smaller and
weaker spinules and bristles.
Chelicerae. Somewhat receding but essentially vertical and
parallel; with basal boss moderately well developed; basal seg-
ment .758 mm. long; each with several very slender spines or
bristles in front; with well marked fang groove studded with
minute denticles; retromargin of fang groove with three teeth
of moderate size, all in basal half with middle one somewhat
the smallest; promargin with four teeth, the third from base
being the largest; fang of moderate length, evenly curved and
finely dentate along inner margin.
Maxillae. Essentially parallel; about two-thirds as broad
as long; with a robust, strongly chitinized lateral tubercle
opposed to a corresponding tubercle at base of palpal femur ; with
marginal serrula well developed at lateral distal corner; with
well developed scopula along distal lateral medial corner and
adjacent distal border (Fig. 12, from a dissected paratype).
Lip. Broader than long in ratio of about 4:3; with cross
striations in basal third. Sternal suture indefinite, gently pro-
curved.
Sternum. Narrowly scutiform; mildly convex; moderately
scalloped opposite coxae ; longer than wide in ratio of about 3:2;
slightly the widest at interval between second and third coxae;
posterior end continued as a very slender sclerite between fourth
coxae which are separated only by a little more than one fifth
of their width.
Legs. 1423. Width of first patella at "knee" .433 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .379 mm.,
tibial index of fourth leg 9.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 407
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.095 1.430 3.640 3.900 1.365 14.430
2. 3.380 1.235 2.795 3.250 1.150 11.810
3. 2.285 .845 1.267 1.495 .845 6.737
4. 3.965 1.267 2.795 2.990 1.040 12.057
Palp .585 .330 .220 ■ ■ 1.105 2.240
Spines. First leg: femur dorsal and prolateral 0-0-1-1-1,
retrolateral 0-0-0-0-1-1, ventral with six or seven along retro-
margin and two or three along promargin, all in distal half;
patella dorsal 0-1, prolateral and retrolateral 1-1; tibia dorsal
0-1-0-1-1-0, prolateral 1-1-1-1-1-0 on right but with six on left,
retrolateral 0-1-0-1-0, ventral 2-2-lr-lp-2-lp-2 ; metatarsus dorsal
0-1-0-1-0-0, prolateral 0-0-1-0-1-0, retrolateral 0-1-0-1-0, ventral
2-2-2 with considerable irregularity. Second leg: femur dorsal
as in first, prolateral only one near distal end, retrolateral
0-0-0-1-1-1, ventral a row of nine short but robust spines extend-
ing to retromargin distally (Fig. 14) ; patella as in first; tibia
dorsal 1-0-1-1-0, prolateral 1-1-1-1-1, retrolateral 0-1-1-1, ventral
2-lp-2-2-lp-2 (prolateral and ventral spines appear to be modified
for a common use, Fig. 13) ; metatarsus dorsal 0-1-0, prolateral
0-1-0-0-0, retrolateral 0-1-0-1-0, ventral 0-2-2-0. Third leg : femur
dorsal 0-1-0-1-1, prolateral and retrolateral only one near distal
end, ventral 0-0-2 (missing on left leg) -2; patella dorsal 1-1,
prolateral and retrolateral only one near distal end ; tibia dorsal
1-0-1, prolateral 1-1-1, retrolateral 0-1-1, ventral lp-lp-2 ; metatar-
sus dorsal 0-1-0-0, prolateral 0-1-1, retrolateral 0-1-0, ventral
0-1-1-1 (all median). Fourth leg: femur dorsal 0-1-0-1-1, pro-
lateral 0-0-1-1-1 (left) and 0-0-0-1-1 (right), retrolateral 0-0-1-1-1,
ventral only two near distal end ; patella as in third ; tibia dorsal
0-1-0-1-1-0, prolateral 1-1-0-1-1 (left) and 1-1-1-1-1 (right), retro-
lateral 1-0-1-0, ventral 2-2-2-2 (right) and 2-lp-lr-lp-2(left) ; meta-
tarsus dorsal 0-1-0-1-0-0, prolateral 0-1-0-1, retrolateral 0-1-0-
1-1-0, ventral 2-lp-lp-2. Palpal patella with a weak proximal
dorsal spine and a single distal dorsal long slender spine. Palpal
tibia with many long bristles and a single distal dorsal long
slender spine. There are apparently six trichobothria of varying
length also on the dorsal side of the tibia.
Palp. Very complicated; the trochanter has a strongly chitin-
408 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
ized tubercle which appears to act with those on the maxilla and
femur as already recorded (Fig. 12) ; patella very short, simple,
strongly chitinized ; tibia very short and trilobed, with the ventral
lobe provided with a strongly chitinized ventral rim. Tarsus
very characteristic ; basal apophysis a distorted arrow-shape ; the
clavis is robust, very broad and deeply excavated at its anterior
end; the uncus is a sharply pointed tooth; the conductor has a
broad central portion with three very characteristic extensions ;
the vesicle is small, strongly chitinized, and provided with a
lobule; the embolus is flat, rather short and curved; the terminal
laminae are raised into three prominences (Figs. 15-16).
Abdomen. Elongate as in E. fusco-vittata (Keys.) ; longer
than wide in a ratio of a little more than 2:1; widest about one-
third of length from base ; overlaps abdomen only slightly ; ex-
tends behind posterior margin of spinnerets about one-ninth of
its length; anal tubercle a short robust prominence strongly
chitinized at base ; six spinnerets as usual in the genus ; colulus
a small tubercle with several short erect dark bristles; tracheal
spiracle slightly in front of colulus and with a moderately chit-
inized ventral lip ; with a small rounded brown sclerite between
colulus and tracheal spiracle.
Color in alcohol. Carapace yellowish with darker flecks and
with considerable reddish brown around the eyes ; sternum gray-
ish ; legs and mouth parts generally yellowish but first and second
pairs of legs and fourth tibiae have broad brown bands in-
definitely delimited. Abdomen: there is a broad dark dorsal
folium extending throughout and divisible into three narrower
components; lateral to the folium is a light stripe on each side
beneath which occurs a dark stripe ; the venter has a median broad
dark stripe with a narrow light yellowish stripe on each side.
In some paratypes the dorsolateral light stripes have reddish
areas but the color appears to be less variable in this species
than in many others within the genus.
Female allotype. Total length 9.88 mm. Carapace 3.445 mm.
long; 2.60 mm. wide opposite second coxae where it is widest;
.975 mm. tall and, therefore, about .38 as tall as wide; broader
in front than in male. Otherwise essentially as in male.
Lyes. Seen from above, both rows less strongly recurved than
in male; ocular tubercles less prominent than in male; central
ocular quadrangle almost exactly as long as wide in front. Ratio
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
of eyes AME : ALE : PME : PLE = 6 : 5 : 6 : 5. AME sep-
arated from one another by nearly 1.5 times their diampte'-.
from ALE by slightly less than 3.5 times their diameter. PME
separated from one another by nearly their diameter, from
PLE by slightly more than four times their diameter. Laterals
separated by about two-fifths of their diameter. Height of
clypeus slightly less than diameter of AME. Clypeus with numer-
ous long stiff bristles.
Chelicerae. Basal segment 1.105 mm. long; teeth along fang
groove more robust than in male. Otherwise essentially as in
male.
Maxillae and Lip. Essentially as in male except for maxillary
tooth in the latter.
Sternum. Longer than wide in ratio of 24 : 17 ; with rather
marked convexities opposite third coxae, less prominent con-
vexities opposite first coxae and hardly any opposite second coxae.
Otherwise essentially as in male.
Legs. 1243. Width of first patella at "knee" .466 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .466 mm.,
tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Tola's
(All measurements in millimeters)
1.852 4.030 3.900
1.690 3.575 3.705
.910 1.495 1.690
1.560 3.185 3.575
Spines. First leg: femur dorsal 0-1-1 (both small), prolateral
0-0-1-1-1, retrolateral only one near distal end; patella dorsal
1-1, prolateral 0-1-1-0, retrolateral 0-1 on right and 1-1 on left ;
tibia dorsal 0-1-0-1-0, prolateral and retrolateral 0-1-0-1-0, ventral
2-lp-lp-lr-2 ; metatarsus dorsal 0-1-0-0-0, prolateral 0-1-0-1-0,
retrolateral 0-0-0-1-0, ventral 2-2-0-0 with some troublesome ir-
regularities. Second leg: essentially as in first with some varia-
tions. Third leg: femur dorsal, prolateral, and retrolateral with
a single spine near distal end; patella appears to have only
dorsal 1-1; tibia dorsal 0-1-0-0, ventral lp-lp-2 (hardly more than
stiff bristles) ; metatarsus dorsal 0-1-0, prolateral 0-1-1-0, ventral
2-lp-lp-lp-lp(and many spine-like bristles). Fourth leg: femur
as in third; patella dorsal 1-1 (both weak), prolateral and retro-
1.
4.420
2.
4.030
3.
2.470
4.
4.225
1.250
15.4-2
1.170
14.170
.910
i .475
1.170
13., 1
410 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY
lateral 0-1-0 ; tibia dorsal 0-1-0-0-1-0, prolateral 0-1-1-1, retro-
lateral 0-1-1 ; metatarsus dorsal 0-1, prolateral 0-0-1-0-1-1, retro-
lateral 0-1-1-0, ventral 2 (irregular) -lp-lp-lr. Palpal claw pec-
tinate in a single row of slender teeth diminishing in length
toward base. Palpal spines : femur with a single dorsal distal
spine ; patella dorsal 1-1 ; tibia dorsal 0-0-1-0, prolateral 1-1,
retrolateral only one distal ; tarsus with numerous spines and
spine-like bristles irregularly arranged.
Abdomen. Bluntly pointed at both ends; a little more than
twice as long as wide. Otherwise essentially as in male.
Epigynum. Very distinctive ; base nearly circular in outline
as seen in ventral view ; scape long, slender, arising from near the
center of base (Figs. 17-18).
Color in alcohol. Closely resembles that of male but the dorsal
folium is more broken and less distinct than in that sex.
Type locality. Male holotype from Barro Colorado Island
C. Z., July, 1950. Female allotype from the same locality, July
1936. Paratypes of both sexes from the following localities
Barro Colorado Island, July, 1924 (Banks) ; June- July, 1936
July-August, 1939; August, 1946 (L. H. Krauss) ; July, 1950
Canal Zone Forest Reserve, C. Z., July, 1939 and August, 1950
France Field, C. Z., August, 1939.
EUSTALA ABDITA Sp. nOV.
(Figures 19-23)
Male holotype. Total length 3.445 mm. Carapace 1.69 mm.
long ; 1.43 mm. wide between sectfnd coxae where it is widest ;
.704 mm. tall and, therefore, nearly .50 as tall as wide ; with well
developed longitudinal thoracic groove ; spines confined to ocular
region.
Eyes. Eight in two rows, all dark. Viewed from above, both
rows strongly recurved; viewed from in front, anterior row
moderately procurved, measured by centers ; central ocular quad-
rangle wider in front than behind in ratio of 16 : 13, wider in
front than long in ratio of 16 : 13. Ratio of eyes AME : ALE :
PME : PLE = 9:6:8: 5.5. AME separated from one another
by one and one-third times their diameter, from ALE by one
and one-half times their diameter. PME separated from one
CH1CKERING : GENUS EUSTALA IN CENTRAL AMERICA
411
another by one and one-fourth times their diameter, from PLE
by slightly more than three times their diameter. LE separated
from one another by two-thirds the diameter of ALE. Height of
clypeus equal to one and one-third times the diameter of AME.
A pair of long slender spines occurs dorsal to LE ; also a row
of spine-like bristles between ME.
Chelicerae. Basal segment .433 mm. long. Fang groove well
marked. Promargin of fang groove with three teeth, the middle
one small; retromargin with four teeth, the second and fourth
small, the other more robust (teeth observed on dissected para-
type to avoid injury to holotype). Fang evenly curved, finely
dentated along inner margin.
Maxillae. Parallel; full and convex on retrolateral surface;
scopula well developed along medial surface and inner distal
External Anatomy of Eustala
Figures 19-23, E. abdita sp. nov.
Fig. 19. Eight second tibia from below.
Fig. 20. Left fourth femur from below.
Fig. 21. Left palpal tarsus, lateral view.
Fig. 22. Left palpal tarsus from in front.
Fig. 23. Basal tarsal apophysis.
412 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
angle. Serrula moderately well developed along outer distal
angle. With well developed basal tubercle to oppose the chitinous
ridge on palpal femur ; also with a chitinous ridge extending
Nasally from the tubercle.
Lip. Wider than long in ratio of about 22 : 15 ; distal third
.long border full and well rounded; reaches only slightly beyond
middle of maxillae. Sternal suture gently procurved.
Sternum. Generally scutiform ; longer than wide in ratio of
35 : 2G ; a sclerite continues from posterior end between fourth
coxae which are barely separated ; covered by numerous long
curved bristles.
Legs. 1243. Width of first patella at "knee" .238 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .206 mm.,
tibial index of fourth leg 11.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
2.8::^
.812
2.2,5
1.787
.785
8.551
2.
2.047
.715
1.430
1.462
.715
6.369
:>,.
1.200
.455
.650
.61,
.520
3.442
4.
1.950
.650
1.200
1.200
.585
5.585
Palp
.314
.184
.141
.790
1.429
First coxa with well developed ventral distal hook on retro-
margin; prolateral groove and ridge at base of second femur
extends a little less than one-fifth of the length of the segment;
the dorsal tubercle on first coxa moderately well developed.
Spines. First leg: femur dorsal 0-0-1-0-1-1, prolateral 0-0-1-1-1,
retrolateral 0-0-0-1-1-1, ventral 0-0 lp-lp-2 ; patella dorsal, three
bristles in a median row-1, prolateral and retrolateral 0-1-1 ; tibia
(.orsal 0-1-0-1-1-0, prolateral and retrolateral 0-1-0-1-0, ventral
2-2-2-lp-2; metatarsus dorsal 0-1-1-0-0, prolateral 0, retrolateral
0-0-1-0, ventral lr-2-lp-0. Second leg: femur dorsal and retro-
lateral as in first, prolateral 0-0-0-1-1, ventral 0-0-lp-lp-lp ; patella
essentially as in first; tibia ventral 2-lp-2-lp-2 (Fig. 19), else-
where as in first; metatarsus dorsal 0-1-0, prolateral 0, retro-
lateral 0-1-1, ventral 0-lp-lr-lp-0. Third leg : femur dorsal
0-0-1-1-1, prolateral and retrolateral only one near distal end,
ventral 0-lp-lp-2-0 ; patella dorsal 1-1, prolateral and retrolateral
0-1-0 ; tibia dorsal 0-1-0-1-0, prolateral 0-0-1-0, retrolateral 0-0-1,
ventral lp-lp-2 ; metatarsus dorsal 0-1-1-0, prolateral 0-1-0, retro-
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 413
lateral 0, ventral 0-1-1-0 (both weak). Fourth leg: femur ventral
0-2-lr-lr-2 on right and 0-2-lr-2-2 on left (Fig. 20), elsewhere as
in first ; patella essentially as in third ; tibia dorsal as in third,
prolateral 1-1-1-1, retrolateral 0-1-1, ventral lp-lp-lp-2 ; metatar-
sus dorsal 1-1-0, prolateral 0-1-1-1, retrolateral 0-0-1-0, ventral
0-lp-lp.
Palp. Complicated ; the basal ventral femoral tubercle or ridge
opposing the maxillary tooth is moderately well developed ; the
patella is short and has a single long dorsal distal spine and
a weak proximal one ; the tibia is short, trilobed as usual with the
articular lobe provided with the usual strongly chitinized thin
lamina opposed to the strongly chitinized base of the tarsus.
Tarsus : the basal tarsal apophysis is more nearly arrow-shaped
than in some species; the clavis is moderately robust, unexcavated
at its base but it has a basal modified articular surface ; the uncus
is a short hook, more or less hidden against the conductor ; the
conductor itself is simpler than in some species but its distal end
has two clearly distinguishable surfaces ; the vesicle is largely
hidden within; the embolus is either modified into a broad thin
plate or hidden ; the terminal laminae are expanded into a
bulbous structure containing a prominent tubule and a median
tubercle; cuspules on conductor and laminae are almost lackin
(Figs. 21-23).
Abdomen. Total length 1.95 mm. ; rounded at both ends with
triangular form obscured ; longer than wide in ratio of 15 : 13 ;
widest about one third from base ; well covered dorsally by
moderately long slender spines. Otherwise essentially as usual
in the genus.
Color in alcohol. Carapace yellowish with brownish spots in
vicinity of thoracic groove ; with a pair of dots near the posterior
end of the groove. All eyes except AME ringed with black pig-
ment. Sternum with an irregular grayish border; elsewhere yel-
lowish flecked with gray. Mouth parts yellowish. Legs yellowish
with few brownish bars which are most prominent on femora.
Abdomen : dorsal folium poorly indicated ; dorsum variegated
yellowish elsewhere; venter yellowish, granulated with yellowish -
white subchitinous deposits. Two of the paratype males are more
deeply colored with the pattern somewhat different from that o
the holotype.
414 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Type locality. Male holotype from Huajuapan, Oaxaca, Mex-
ico, Sept., 1946 (H. Wagner). Five male paratypes from the
following localities in Mexico: Huajuapan, Oaxaca, Sept., 1946
(H. Wagner) ; Vera Cruz (Crawford) ; Teomixla, Morelos,
August, 1942 (H. Wagner) ; Santiago, Colima, January, 1943
(F. Bonet).
Note: Until recently this species has been regarded as the
male of E. mexicana sp. nov. At the present time this seems less
likely.
EUSTALA ANASTERA (Walck.), 1837
(Figures 24-29)
Epeira anastera Walckenaer, 1837
E. cepina Walckenaer, 1837
E. bombicinaria Hentz, 1847
E. prompta Hentz, 1847
E. parvula Keyserling, 1863
E. parvula Emerton, 1885
E. bombicinaria Keyserling, 1892
E. anastera McCook, 1893
E. anastera Simon, 1894
E. parvula Emerton, 1902
Eustala anastera F. P. Cambridge, 1904
Epeira anastei-a Banks, 1909
Eustala anastera Petrunkevitch, 1911
E. leuca Chamberlin, 1924
E. buliafera Chamberlin, 1924
E. anastera Petrunkevitch, 1930
Male hypotype. Total length 4.03 mm. The hypotype has the
more rounded abdomen which seems to be the usual form in the
males of this species. Central ocular quadrangle wider in front
than behind in ratio of 29 : 25, wider in front than long in about
the same ratio. Ratio of eyes AME : ALE : PME : PLE =
9:6:8: 6.5. AME separated from one another by one and
one-third times their diameter, from ALE by nearly two diam-
eters. PME separated from one another by about one and one-
fourth times their diameter, from PLE by slightly more than
three diameters. Laterals separated from one another by slightly
less than the diameter of ALE. Height of clypeus equal to eight-
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
415
ninths of the diameter of AME. Promargin of fang groove with
four teeth, second and fourth small, others of moderate size;
retromargin with three teeth of moderate size. Secondary sexual
characters on first coxa, maxillae, and adjacent palpal segments
together with the prolateral ridge and groove on the second femur
appear as usual in the genus. Sternum longer than wide in ratio
of 35 : 31.
Legs. 1243. "Width of first patella at "knee"
index of first leg 9. Width of fourth patella at
tibial index of fourth leg 13.
271 mm., tibial
"knee" .249 mm.,
29
Fig. 24.
Fig. 25.
Fig.
Fig.
Fig. 28.
Fig. 29.
26.
27.
External Anatomy of Eustala
Figures 24-29, E. anastera
Left second tibia from below.
Left fourth femur from below.
Male palpal tarsus, lateral view.
Male palpal tarsus from in front.
Epigynum from below.
Epigynum, lateral view.
416 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
2.600
.942
2.080
1.657
.715
7.994
2.
2.080
.845
1.430
1.462
.650
6.467
3.
1.365
.575
.682
.660
.487
3.769
4.
1.9:0
.770
1.170
1.170
.520
5.580
Palp
.303
.217
.141
.845
1.506
The second femur has only one weak spine near distal end on
the retromargin ; ventral spines on fourth femur as shown in
Figure 25. The ventral and related spines on the second tibia
are as shown in Figure 24.
Palp. Complicated and characteristic ; features of the femur,
patella and tibia appear to be typical of the genus. Tarsus : the
basal tarsal apophysis is quite unlike the typical arrow head shape ;
the clavis is robust, unexcavated at its base; the uncus is stout
and twisted; the conductor is massive, extensively setose, and
drawn out distally into a characteristically narrow extension
unlike that of any other species in Central America ; the vesicle
is of moderate size ; the embolus is of moderate length and size,
and is lance-like apically; the terminal laminae are also massive
and setose (Figs. 26-27).
Color in alcohol. The carapace is light brown with darker
flecks. The sternum is mottled brown. The legs are light brown
with faint darker spots. The abdomen has a poorly defined
folium. The venter has a faintly defined dark quadrilateral area
between the genital groove and the base of the spinnerets; the
dark area contains a poorly defined light spot. Other specimens
show much variation in the color pattern with the ventral light
spot usually much clearer.
Female hypotype. Total length 7.15 mm. (probably above
the average for females in this species).
Legs. 1243. Width of first patella at "knee" .455 mm., tibial
index of first leg 11. Width of fourth patella at "knee" .379
mm., tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.495 2.665 2.600
1.365 2.340 2.275
.845 1.040 1.170
1.300 1.950 2.015
1.
3.380
2.
2.990
3.
1.950
4.
2.860
.975
11.115
.910
9.880
.715
5.720
.780
8.905
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 417
There are two long and fairly robust spines on the first femur
near the middle, one prolateral and one ventral. Not all females
appear to have these spines.
Epigynum. Easily confused with that of E. bifida and, per-
haps, others in the genus; this is especially true of some of the
deviates in the species concerned. The apertures are about one
third of the width of the scape at their level from the lateral
margin (Figs. 28-29).
Abdomen. With the usual general form except that there are
three dorsoventrally arranged posterior tubercles thus giving a
marked trifid appearance to this part of the body. This em-
phasizes the widespread variation of details of form of the
abdomen in this species.
Color in alcohol. The carapace is dark brown along the middle,
lighter on the lateral sides. Sternum is grayish. Legs with many
dark brown bands. Abdomen : the dorsal folium is fairly well
defined; the remainder of the dorsum and lateral sides are dark
variegated with many lighter spots; there is a vaguely defined
ventral whitish spot in the middle of a median darker area.
Type locality. Male hypotype from Amatitlan, Guatemala,
August, 1947 (C. & P. Vaurie) ; female hypotype from San Juan
del Rio, Durango, Mexico, August, 1947 (W. J. Gertsch). Males
and females from many localities in Mexico and Guatemala have
been examined. The Cambridges reported the species from Costa
Rica but, so far as I know, it has not been taken in Panama.
Note : The male paratypes of E. anastera buliafera Chamberlin
in the Museum of Comparative Zoology are clearly E. anastera
(Walck.) but there is a question regarding the females. It seems
likely that the females belong to more than one species.
EUSTALA BANKSI Sp. nOV.
(Figures 30-34)
This species has previously been considered by Mr. Banks and
perhaps others as well as myself to belong to E. bifida F. P.
Cambridge. A closer study reveals so many differences from
that species, however, that according to my present views con-
cerning species it must be regarded as new to science. A holotype
has, therefore, been selected and is described in accord with my
418
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
usual formula. This specimen is not in the best of condition
but is the best available.
Male holotype. Total length 5.98 mm. Carapace 3.055 mm.
long, 2.535 mm. wide opposite intervals between second and third
coxae where it is widest ; .975 mm. tall and, therefore, about .38
as tall as wide ; only slightly raised from PME to beginning of
posterior declivity; with a well developed median longitudinal
groove; apparently with few spines, restricted to ocular region.
Eyes. Eight in two rows, all dark; LE on moderately prom-
30
34
External Anatomy of Eustala
Figures 30-34, E. banTcsi sp. nov.
Fig. 30. Left second tibia from below.
Fig. 31. Right fourth femur from below.
Fig. 32. Left male palpal tarsus, lateral view.
Fig. 33. Uncus, somewhat enlarged from Figure 32.
Fig. 34. Left male palpal tarsus from in front.
\
(
i
31
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 419
inent tubercles ; a low conical prominence in middle of median
ocular quadrangle from which two long slender spines protrude ;
viewed from above, both rows strongly recurved; viewed from
in front, anterior row moderately procurved, measured by cen-
ters; central ocular quadrangle wider in front than behind in
ratio of about 9 : 7, wider in front than long in ratio of 9 : 8.
Ratio of eyes AME : ALE : PME : PLE = 13 : 10 : 11.5 : 7.
AME separated from one another by slightly more than 1.5
times their diameter, from ALE by nearly two and one-fourth
times their diameter. PME separated from one another by about
four-thirds of their diameter, from PLE by four times their
diameter. Laterals separated from one another by the diameter
of PLE. Height of clypeus equal to about five-thirds of the
diameter of AME.
Chelicerae. Essentially parallel, but distal half somewhat
excurved ; with moderately well developed basal boss ; basal seg-
ment .65 mm. long. Fang groove well defined; promargin with
four teeth, the fourth small ; retromargin with three fairly robust
teeth.
Maxillae. In general, typical of the genus including the lateral
tooth opposing the modifications on the palpal femur and tro-
chanter.
Lip. Wider than long in ratio of about 4:3; bluntly pointed
distally ; extends only a little beyond middle of maxillae ; basal
half somewhat grooved. Sternal suture very slightly procurved.
Sternum. Elongate-scutiform ; longer than wide in ratio of
29 : 20 ; a sclerite continues from posterior end between fourth
coxae which are separated by one-eighth of their width ; with
numerous long slender bristles.
Legs. 1243. Width of first patella at "knee" .433 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .379 mm.,
tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.560 3.575 3.705
1.235 2.600 2.470
.910 1.300 1.495
1.365 2.210 2.632
.282 .217
i Lacking in holotype ; length estimated.
1.
4.095
2.
3.510
3.
2.535
4.
3.175
Palp
.444
1.235
14.170
U.OOO
10.815
.780
7.020
1.170
10.357
1.105
2.048
420 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
First coxa with a well developed ventral distal hook ; prolateral
proximal groove and ridge on second femur well developed and
extending slightly more than one-fifth of total length of seg-
ment ; the dorsal tubercle on first coxa moderately well de-
veloped.
Spines. First leg: femur dorsal 0-0-1-1-1-1, prolateral 0-0-1-1-1,
retrolateral 0-0-0-0-1-1, ventral in distal half three on promargin
and five on retromargin ; patella dorsal 1-1-1, prolateral and
retrolateral 0-1-1-0 ; tibia dorsal 0-1-1-1-1-0, prolateral and retro-
lateral 0-1-1-0, ventral 0-2-lp-lp-lp-2 ; metatarsus dorsal 0-1-1-1-0,
prolateral 0-0-1-0, retrolateral 0-1-1-0, ventral 2-2-lr-2. Second
leg : femur essentially as in first except ventral only one near
distal end on promargin ; patella as in first except dorsal 1-1
(bristle) -1 ; tibia essentially as in first except that prolateral and
ventral promarginal spines are especially robust (Fig. 30) ;
metatarsus dorsal 0-1-1-0, prolateral 0, retrolateral 0-0-1-0, ven-
tral 2-2-2. Third leg : femur dorsal 0-1-0-1-1, prolateral 0-0-1-1-1,
retrolateral 0-0-0-1-1, ventral with a double series, four on pro-
margin and six on retromargin; patella dorsal 1-1, prolateral
0-1-0, retrolateral 0-1 ; tibia dorsal 1-0-1, prolateral 1-1-0, retro-
lateral 0-1-1, ventral 2-2 (irregularly placed) -2 ; metatarsus dorsal
1-0-0, prolateral 0-1-1, retrolateral 0-1-0, ventral 2-lp-lp-2. Fourth
leg : femur dorsal as in third, prolateral only one near distal end,
retrolateral 0-0-0-1-1, ventral essentially as in third; patella as
in third; tibia dorsal 1-1-1, prolateral 1-1-0-1-1, retrolateral 0-1-0,
ventral 2-2-lp-2 ; metatarsus dorsal 1-1-0, prolateral 0-1-1-0, retro-
lateral the same, ventral 2-lp-lp-lp.
Palp. Complicated ; basal femoral ridge opposing the maxil-
lary tooth moderately well developed ; patella short, with a weak
basal dorsal spine and a long slender distal dorsal spine ; the tibia
is as usual, trilobed, with a well developed chitinous collar on
the ventral side of the articular lobe. Tarsus : the basal apophy-
sis is a rounded structure without much resemblance to the
typical arrow-head ; the clavis is a fairly robust structure ; the
uncus is a robust hook with a long shank and a prominent hump
at the base of the terminal hook; the conductor is a massive
structure, extensively setose, and distally provided with a deep
dorsoventral groove and other distinctive surfaces; the vesicle
is moderately large ; the embolus is short, slender, and lance-
CHECKERING : GENUS EUSTALA IN CENTRAL AMERICA 421
like terminally; the terminal laminae are massive on the medial
side but thin on the lateral half (Figs. 32-34).
Abdomen. Total length 2.787 mm.; with rounded triangular
form; with what appears to be a suppressed posterior conical
extension ; longer than wide in ratio of about 4:3; with numer-
ous long slender dorsal and dorsolateral spines; with other
features essentially typical of the genus.
Color in alcohol. Carapace yellowish with faint brownish spots
and streaks radiating from the median thoracic groove. The
most conspicuous of these markings consist of the following: a
minute dot on each side just in front of the median groove and
a transverse row of four dots a little behind the middle of the
furrow; from the second and third of these a narrow stripe
extends posteriorly. Sternum light yellowish, flecked with gray.
Legs yellowish with both broad and narrow brownish bands
and rings. Abdomen : the dorsal folium obscurely outlined in
dark brown with many white guanin granules ; venter with a
lighter area between the genital groove and base of spinnerets
surrounded by a narrow brownish border.
Type locality. Male holotype from Ocosingo, Chiapas, Mexico,
June, 1950 (Goodnight and Stannard). One male paratype from
Turrialba, Costa Rica (Tristan).
Eustala bifida F. P. Cambridge, 1904
(Figures 35-40)
Epeira bifida Banks, 1909
Eustala bifida Petrunkevitch, 1911
As indicated in the treatment of E. maxima sp. nov., the fe-
males reported by Banks (1929) from Barro Colorado Island are
now regarded as belonging to a species new to science. The
specimens in the Museum of Comparative Zoology from La
Verbena, Costa Rica, agree well with the specimens from the
British Museum and with F. P. Cambridge's figures. All of the
specimens from La Verbena are somewhat shrunken and dis-
torted but are, nevertheless, easily identified.
Male hypotype. Total length 6.175 mm. The hypotype has
the bifid condition at the posterior end of the abdomen but in a
reduced degree. Central ocular quadrangle wider in front than
422
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
behind in ratio of 7 : 6 only slightly wider in front than long.
Ratio of eyes AME : ALE : PME : PLE — 13 : 8 : 12 : 7.5. AME
separated from one another by 1.5 times their diameter, from
ALE by about 2.5 times their diameter. PME separated from
External Anatomy of Eustala
Figures 35-40, E. bifida
Fig. 35. Left second tibia from below.
Fig. 36. Right fourth femur from below.
Fig. 37. Left male palpal tarsus, lateral view.
Fig. 38. Left male palpal tarsus from in front.
Fig. 39. Epigynum from below.
Fig. 40. Epigynum ; a more posterior view.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 423
one another by 1.25 times their diameter, from PLE by about
four times their diameter. Laterals separated from one another
by about the diameter of ALE. Height of clypeus equal to
slightly more than 1.5 times the diameter of AME. Promargin of
fang groove with four teeth, second and fourth smaller than first
and third ; retromargin with three rather small teeth. Secondary
sexual characters appear about as usual except that the ridge
and groove on the promargin of the second femur is much shorter
than usual.
Legs. 1243. Width of first patella at "knee" .455 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .444 mm.,
tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
4.225
1.690
3.477
3.600
!1.300
14.292
2.
3.445
1.430
2.665
3.250
!1.225
12.015
3.
2.535
.975
1.365
1.570
.845
7.290
4.
3.185
1.495
2.405
2.730
1.105
9.920
Palp
.498
.249
.238
1.029
2.014
The special ventral and prolateral spines on the second tibia
are shown in Figure 35. The first femur has a double series
of ventral spines apparently with three on the promargin and
three or four on the retromargin, all in distal half. The second
femur is essentially like the first in this respect. The third femur
has one or two ventral spines on the promargin and three on the
retromargin. The fourth femur has the most fully developed
set of ventral spines with four on each margin (Fig. 36).
Palp. In very close agreement with the specimen from the
British Museum. The features of the femur, patella, and tibia
appear to be typical of the genus. Tarsus : basal tarsal apophysis
is typical; the clavis is robust, unexcavated at base but with a
short ridge as noted by F. P. Cambridge; the uncus has a
transversely inflated base from which the point of the hook
extends but there is no long shank ; the conductor is massive, ex-
tensively setose, with a ventral depression for the reception of
the point of the uncus, and with two characteristic surfaces at
the distal end, one of which has a shallow groove ; the vesicle is
of moderate size but is well defined ; the embolus is long, slender,
i Lacking in hypotype ; length estimated.
424 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
and terminally lance-like ; the terminal laminae are massive in the
medial half and bear two poorly denned grooves in the reduced
retrolateral half (Figs. 37-38).
Color in alcohol. Discolored by long preservation and, prob-
ably also, by drying out at some time. The dorsal folium was
probably well defined. In all available specimens the venter has
a somewhat elongated light spot in the center of what was prob-
ably a dark area behind the genital groove.
Female hypoiype. Total length about 7.475 mm. (distorted
and difficult to measure accurately). The bifid condition of the
posterior end of the abdomen is fairly conspicuous in spite of
the distortion.
Legs. 1243. Width of first patella at "knee" .601 mm., tibial
index of first leg 11. Width of fourth patella at "knee" .585
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
4.225
1.950
3.575
3.380
1.365
14.495
2.
3.705
1.885
3.055
3.250
1.235
13.130
3.
2.600
1.105
1.495
1.690
.975
7.865
4.
3.640
1.820
2.697
2.925
1.105
12.187
There is a double series. of weak ventral spines on the first
femur, three on promargin and two on retromargin, all in distal
half ; there are also three prolateral femoral spines the first two
of which are long and robust, all in distal half. The ventral
femoral spines appear to be lacking on the second leg but the
prolateral spines are three in number and all weak. The third
and fourth femora appear to lack the ventral spines.
Epigynum. Similar to that of E. maxima sp. nov. There are
quite definite though somewhat obscure differences in the pattern
of tubules and their boldness together with the prominences in
the expanded region from which the scape arises. These are best
shown in Figures 39-40.
Type locality. F. P. Cambridge had this species only from
Costa Rica. The only specimens available to me for study are
also restricted to Costa Rica. The hypotypes and two other
female specimens are from La Verbena, collected in January by
Tristan and now a part of the Nathan Banks collection in the
Museum of Comparative Zoology.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 425
EUSTALA BUCOLICA Sp. nOV.
(Figures 41-44)
Male holotype. Total length 3.835 mm. Carapace 1.982 mm.
long ; 1.755 mm. wide opposite third coxae where it is widest ; .845
mm. tall and, therefore, about .48 as tall as wide ; rises gradually
from PME to beginning of steep posterior declivity opposite
third coxae; with well developed median longitudinal thoracic
groove ; with no more than a weak covering of hair and with few
spines or spinules and these confined to ocular area.
Eyes. As usual, eight in two rows, all dark ; LE on moderately
prominent tubercles; viewed from above, posterior row strongly
recurved; viewed from in front, anterior row gently procurved,
measured by centers; central ocular quadrangle wider in front
than behind in ratio of about 8 : 7, wider in front than long in
ratio of about 16 : 15. Ratio of eyes AME : ALE : PME :
PLE = 10 : 7 : 9 : 7. AME separated from one another by 1.5
times their diameter, from ALE by the same distance. PME
separated from one another by 1.25 times their diameter, from
PLE by three times their diameter. Laterals separated from
one another by about two-thirds of their diameter. Height of
clypeus equal to the diameter of AME.
Chelicerae. Basal segment .758 mm. long. Fang groove well
defined and finely dentated; promargin with four teeth, the
second and fourth smaller; retromargin with three teeth (ob-
served on paratype to avoid injury to holotype). Otherwise as
usual in the genus.
Maxillae. As usual in the genus in all observed features in-
cluding the maxillary tooth which appears to be used in opposi-
tion to the basal palpal femoral ridge.
Lip. Wider than long in ratio of about 25 : 16 ; transversely
grooved in proximal half ; reaches to about the middle of maxil-
lae. Sternal suture gently procurved.
Sternum. Scutiform; longer than wide in ratio of 7 : 6; a
narrow sclerite continues between fourth coxae which are sep-
arated by about one-third of their width ; with the usual supply
of long slender spinules.
Legs. 1243. Width of first patella at "knee" .282 mm.,
tibial index of first leg 8. Width of fourth patella at "knee" .217
mm., tibial index of fourth leg 10.
426 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
2.990
1.012
2.405
2.156
.902
9.465
2.
2.200
.836
1.650
1.738
.792
7.216
3.
1.430
.550
.748
.770
.484
3.932
4.
1.980
.792
1.298
1.320
.616
6.006
Palp
.352
.220
.176
.704
1.452
The hook and tubercle on the first coxa and the ridge and
groove on the second femur appear to be typical of the genus.
Spines. First leg: femur dorsal 0-1-1-1, prolateral left 0-1-1-1-1,
right 0-0-1-1-1, retrolateral 0-0-1-1-1, ventral promargin 0-1-0-0-0
and retromargin 0-0-1-1; patella dorsal l(weak)-l, prolateral
0-1-0, retrolateral 0-0-1 ; tibia dorsal 0-1-0-0-1-1-0, prolateral
0-1-0-1-0, retrolateral 0-1-1-0, ventral 2-lr-lp-lr-lp-lp-2 ; meta-
tarsus dorsal 0-1-1-0, prolateral 0, retrolateral 0-1-0-1-0, ventral
0-2-lp-0. Second leg : femur dorsal and prolateral 0-1-1-1, retro-
lateral the same with slight variations, ventral only one on each
margin near distal end; patella dorsal as in first, prolateral 1-1,
retrolateral as in first; tibia dorsal 1-0-1-1-0, prolateral and
retrolateral 0-1-0-1-0, ventral 2-lp-2-lp-2 (Fig. 41) ; metatarsus
dorsal 0-1-0, prolateral 0, retrolateral 0-1-1-0, ventral 0-2-lp-0.
Third leg: femur dorsal 0-1-1-1, prolateral 0-0-1-1, retrolateral
only one near distal end, ventral only two on promargin and one
near distal end on retromargin; patella dorsal l(weak)-l, pro-
lateral and retrolateral 0-1-0 ; tibia dorsal 1-0-1, prolateral 1-1-0,
retrolateral 0-1-0, ventral lp-lp-2 ; metatarsus dorsal and pro-
lateral 0-1-0-0, retrolateral 0-1-0, ventral lp-lp-lp-lp(weak).
Fourth leg : femur dorsal 0-1-1-1, prolateral and retrolateral only
one near distal end, ventral promargin only one near distal end
and three along retromargin, all in distal half (Fig. 42) ; patella
as in third; tibia dorsal 1-1-1-0, prolateral 1-1-1-1, retrolateral
0-1-1, ventral 2-lp-lp-2 ; metatarsus dorsal 1-1-0, prolateral 1-1-1-1,
retrolateral 0, ventral O-lp-lp-lp(weak).
Palp. Complicated; basal femoral ventral ridge, patella, and
tibia typical of the genus. Tarsus : basal tarsal apophysis a
typical distorted arrow-head shape ; the clavis is moderately
robust, somewhat concave ventrally at its base and provided with
a marked carina along its basal lateral border; the uncus is a
stout hook with a pronounced shoulder at its base ; the conductor
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
427
is relatively small, less differentiated on its anterior surface
than usual and only sparsely and very finely setose ; the vesicle
is in its typical position and of moderate size; the free part of
the embolus is short and slender but its base extends nearly to
External Anatomy of Eustala
Figures 41-44, E. Tjucolica sp. nov.
Figures 45-48, E. clavispina
Fig. 41. Left second tibia from below.
Fig. 42. Right fourth femur from below.
Fig. 43. Left male palpal tarsus, lateral view.
Fig. 44. Left male palpal tarsus from in front.
Figs. 45-46. Two views of clavif orm abdominal spines.
Fig. 47. Epigynum from below.
Fig. 48; Epigynum, lateral view.
428 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the border of the bulb ; the terminal laminae are only moderately
wrinkled but there is a very prominent tubercle present together
with a large raised portion contiguous to the base of the con-
ductor (Figs. 43-44).
Abdomen. Total length 2.275 mm.; 1.625 mm. wide; with the
typical round-triangular form; with the usual long slender
dorsal and dorsolateral spinules; other observed features typical
of the genus.
Color in alcohol. Carapace yellowish with grayish flecks over
the anterior half; a transverse row of four small brownish dots
across near the posterior end of the thoracic groove and another
transverse row of two dots near the anterior end of the groove.
Sternum yellowish with a grayish margin. Legs as usual, yellow-
ish with brownish spots, bars, and rings. Abdomen : with a well
developed dorsal folium subject to many variations among
paratypes ; the holotype has a conspicuous round, central, deeply
colored, brown spot just in front of the middle of the folium but
this is not persistent among the paratypes ; the venter has a dark
quadrilateral area between the genital groove and the base of
the spinnerets and this has a very narrow dark lateral border
enclosing a curved light colored mark on each side ending in a
small posterior whitish spot but these are all subject to much
variation among the paratypes.
Type locality. The holotype male is from Boquete, R. P.,
August, 1939. Several male paratypes from the same locality,
August, 1939, 1950; one male paratype from El Volcan, R. P.,
February, 1936 (W. J. Gertsch).
Eustala clavispina (0. P. Cambridge), 1889
(Figures 45-48)
Epeira clavispina O. P. Cambridge, 1889
E. clavispina Keyserling, 1892
Amamra nigromaculata O. P. Cambridge, 1895
Eustala clavispina F. P. Cambridge, 1904
E. clavispina Petrunkevitch, 1911
This species has not yet appeared in my collection nor has
it been found in any of the material loaned me from the Ameri-
can Museum or available for study in the Museum of Compara-
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 429
tive Zoology. The only specimens I have seen are those loaned
from the British Museum. These have enabled me, however,
to form a clear conception of the female of the species. One
of these females has been made the source of the following data
and thus becomes the hypotype.
Female hypotype. Total length 6.467 mm. The abdomen
shows a slight tendency to be bilobed at its base and is quite
distinctly bifid at its posterior end as in E. bifida. There is also
a distinct low cone in the area enclosed by the central ocular
quadrangle ; above and medial to ALE there is also a distinct
convexity. The central ocular quadrangle is almost as wide
behind as in front; slightly wider in front than long. Ratio
of eyes AME : ALE : PME : PLE — 10 : 7.5 : 11 : 8.5. AME
separated from one another by 1.5 times their diameter, from
ALE by about three times their diameter. PME separated from
one another a little more than their diameter, from PLE by a
little more than four times their diameter. Laterals separated
from one another by the diameter of PLE. Height of clypeus
equal to a little less than twice the diameter of AME. Promargin
of fang groove with four teeth, the second and fourth the small-
est; retromargin with three teeth. Perhaps the most distinctive
feature of this species is the curious type of spinule common on
the dorsal and dorsolateral parts of the abdomen and on at least
certain segments of the legs (Figs. 45-46). A pair of these
unusual spinules also occurs on the tip of the low ocular cone
in central ocular quadrangle.
Legs. 1243. Width of first patella at "knee" .401 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .368
mm., tibial index of fourth leg 12.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
3.185
1.462
2.730
2.600
1.040
11.017
2.
2.795
1.300
2.275
2.340
.975
9.685
3.
1.852
.715
1.007
1.170
.715
5.459
4.
2.600
1.365
1.755
2.015
.780
8.515
Ventral femoral spines are few or lacking ; the first femur has
a pair of slender spinules in the position 0-lr-lr-0; the second
femur has a similar series of four as follows : lr-lr-lr-lr-0.
Epigynum. Base with the usual general pattern of tubules,
430 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
apertures, and striations ; the base is relatively broad and massive
(Figs. 47-48).
Color in alcohol. The dorsum of the abdomen is clay-yellow
with a poorly defined folium; laterally there is a series of narrow
brownish bands rising from the venter and ending dorsolaterally
in brownish lines ; these latter alternate with whitish bands from
the dorsum which point ventrally ; the venter is sprinkled with
whitish granules concentrated toward the center between the
genital groove and base of the spinnerets.
Type locality. The hypotype is from Teapa, Tabasco, Mexico
(H. H. Smith), included among three specimens from the British
Museum from the Godman and Salvin collection, April, 1905.
F. P. Cambridge had specimens from Mexico and Guatemala.
Eustala confoemans Chamberlin, 1925
(Figures 49-50)
E. conformans Banks, 1929
Banks (1929) had doubts about the validity of this species but,
after a careful study of the holotype female, I am forced to
accept it as a true species. All of my specimens referred to this
species are considerably larger than the holotype but the epigyna
agree remarkably well. I have, therefore, little doubt of the
accuracy of the identification.
Female hypotype. Total length 6.175 mm. The general
structure appears to be quite typical of the genus; there is a
slight convexity between AME and PME from which a pair of
slender spines extend; the carapace is covered by a well de-
veloped coat of whitish hair, raised into a tuft behind the LE ;
there is barely a suggestion of shoulder humps; the leg spines
appear to be developed as usual in the genus. The central ocular
quadrangle is only slightly wider in front than behind and
only slightly wider in front than long. Ratio of eyes AME :
ALE : PME : PLE = 11.5 : 9 : 11 : 8. AME separated from
one another by about 1.2 times their diameter, from ALE by
twice their diameter. PME separated from one another 1.3
times their diameter, from PLE by a little less than four times
their diameter. Laterals separated from one another by two-
thirds of the diameter of ALE. Height of clypeus equal to 1.3
CHICKERING : GENUS EUSTALA. IN CENTRAL, AMERICA 431
times the diameter of AME. Promargin of fang groove with the
usual four teeth and the retromargin with three teeth.
Legs. 1243. Width of first patella at "knee" .390 mm.,
tibial index of first leg 11. Width of fourth patella at "knee"
.379 mm., tibial index of fourth leg 14.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
2.665
1.300
2.210
2.080
.910
9.165
2.
2.567
1.170
1.885
1.917
.877
8.416
3.
1.690
.585
.845
1.100
.660
4.880
4.
2.600
1.170
1.630
1.852
.845
8.097
Ventral spines appear to be completely lacking from the
femora.
Epigynum. Somewhat resembles that of E. semifoliata but it
is relatively broader and shorter ; the apertures are much closer
together than in E. semifoliata; there is a large dark area on each
side of the base, not noted in any other species (Figs. 49-50).
Color in alcohol. Carapace yellowish with no dots or spots
such as so frequently occur. Sternum yellowish with a grayish
margin. The legs are yellowish with a few brown bars and spots.
Abdomen: the dorsal folium is almost completely lacking with
the dorsal and dorsolateral regions yellowish white from numer-
ous subchitinous granules; the venter has a large area between
the genital groove and base of spinnerets outlined irregularly
with a white margin and containing a somewhat aviform black
figure; this ventral pattern appears quite constant in all speci-
mens recently collected but there is great variation among these
in respect to other color features.
Type locality. The hypotype is from the Barro Colorado
Island, C. Z., May, 1946 (Schnierla). Four other specimens from
the same locality are in the collection: February, 1936 (Gertsch) ;
May, 1946 (Schnierla) ; July, 1950.
EUSTALA DELECTA Sp. nOV.
(Figures 51-54)
Male holotype. Total length 5.330 mm. Carapace 2.535 mm.
long; 2.210 mm. wide opposite interval between second and third
coxae; .845 mm. tall and, therefore, about .38 as tall as wide;
432
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
rises gently from PME to beginning of steep posterior declivity ;
with well developed median thoracic groove ; with spines appar-
ently confined to the ocular area.
Eyes. As usual, eight in two rows, all dark ; LE on moderately
prominent tubercles, viewed from above, posterior row moder-
ately recurved; viewed from in front, anterior row gently pro-
curved, measured by centers; central ocular quadrangle wider
53
External Anatomy of Eustala
Figures 49-50, E. conformans
Figures 51-54, E. delecta sp. nov.
Fig. 49. Epigynum from below.
Fig. 50. Epigynum, lateral view.
Fig. 51. Left second tibia from below.
Fig. 52. Left fourth femur from below.
Fig. 53. Left male palpal tarsus, lateral view.
Fig. 54. Left male palpal tarsus from in front.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 433
in front than behind in ratio of 44 : 39, wider in front than long
in the same ratio. Ratio of eyes AME : ALE : PME : PLE =
13 : 8 : 11 : 9. AME separated from one another by about 1.66
times their diameter, from ALE by a little less than twice their
diameter. PME separated from one another by about 1.7 times
their diameter, from PLE by a little less than four times their
diameter. Laterals separated from one another by nearly three-
fourths of the diameter of ALE. Height of clypeus equal to
1.15 times the diameter of AME.
Chelicerae. Basal segment .747 mm. long. Fang groove well
defined; apparently with four teeth on promargin and three on
retromargin as usual. Otherwise essentially typical of the genus.
Maxillae. In general quite typical of the genus including the
maxillary tubercle used in opposition to the palpal femoral ridge.
Lip. Wider than long in ratio of about 4:3; hence somewhat
narrower than usual in the genus; reaches to about the middle
of the maxillae. Sternal suture difficult to see but apparently
somewhat procurved.
Sternum. Scutif orm ; longer than wide in ratio of about 9:7;
a narrow sclerite continues between the fourth coxae which are
barely separated ; with the usual covering of stiff bristles.
Legs. 1243. Width of first patella at "knee" .368 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .325 mm.,
tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3,575
-1.170
3.055
2.892
1.137
11.829
2.
2.762
1.170
2.210
2.600
1.040
9.782
3.
2.015
.812
1.040
1.235
.715
5.817
4.
2.600
1.137
1.722
2.210
.788
8.454
Palp
.596
.260
.238
.823
1.917
First coxa with the usual well developed ventral distal retro-
lateral hook and the dorsal tubercle; the prolateral groove and
ridge on the second femur well developed.
Spines. First leg: femur dorsal 0-0-1-1-1, prolateral 0-0-2-1-1,
retrolateral 0-0-0-1-1, ventral a single series of five on retro-
margin 0-0-1-1-1-1-0-1; patella dorsal l(weak)-l, prolateral and
retrolateral 0-1-1 ; tibia dorsal 0-1-1-1-0, prolateral 0-1-0-1-0,
retrolateral 0-1-0-1-1, ventral 2-lp-lp-lp-2 ; metatarsus dorsal
0-1-1-0, prolateral 0, retrolateral 0-1-1-0, ventral 2-2 (irregular)-
434 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
lp-0. Second leg: femur dorsal as in first, prolateral and retro-
lateral 0-0-0-1-1, ventral with a double series, five along retro-
margin and two on promargin in distal quarter ; patella as in
first; tibia dorsal 0-1-1-1-0, prolateral 0-1-0-1-1, retrolateral
0-0-1-1-1, ventral lp-lp-lp-lp-2 (Fig. 51) ; metatarsus dorsal
0-1-1-0, prolateral 0, retrolateral 0-1-1-0, ventral 0-2-lp-0. Third
leg : femur dorsal as in first, prolateral and retrolateral only one
near distal end, ventral only two on retromargin in distal third ;
patella dorsal 1-1, prolateral and retrolateral 0-1-0; tibia dorsal
0-1-0-1-0, prolateral 1-1-1, retrolateral 0-0-1-1, ventral lp-lp-2 ;
metatarsus dorsal 0-1-0-0, prolateral and retrolateral 0-1-0, ven-
tral 1-1-1-1. Fourth leg: femur dorsal as in first, prolateral and
retrolateral apparently only one near distal end, ventral four
on retromargin in distal two thirds and three on promargin in
distal half (Fig. 52) ; patella as in third; tibia dorsal 0-1-1-1-0,
prolateral 1-1-1-1, retrolateral 1-1-1, ventral 2-lp-lp-2 ; metatarsus
dorsal 0-1-1-0, prolateral 0-1-1-0, retrolateral 0-0-1-1-0, ventral
0-1-1-1.
Palp. Complicated ; basal femoral tubercle or ridge opposing
maxillary tooth moderately well developed ; patella short with a
weak proximal dorsal spine and a long slender distal dorsal spine
as usual ; tibia also short, trilobed, and with the usual chitinized
rim or collar on the articular lobe together with a less conspicuous
dorsal rim. Tarsus : the basal apophysis is a distorted arrowhead
shape; the clavis is robust and projects ventrally more than
usual in the genus ; the uncus is a somewhat twisted spine lying
in a depression in the conductor largely made by a small marginal
lobe of the latter ; the conductor is relatively large, with a small
marginal lobe somewhat like that of E. scutigera and two charac-
teristic anterior surfaces both of which are finely setose and
with the smaller surface somewhat concave ; the vesicle is moder-
ately large ; the embolus is of moderate length, relatively broad
and flat ; the terminal laminae are only moderately wrinkled and
striated but are concave and massive contiguous to the conductor
(Figs. 53-54).
Abdomen. 3.12 mm. long ; 2.275 mm. wide about one-third from
base where it is widest; with the usual supply of long slender
spinules; other observed features appear to be typical of the
genus.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 435
Color in alcohol. Carapace shows no dots but the paratypes
show that these may be present in certain individuals; when
present they appear as a transverse row of four at level of
middle of thoracic groove; the holotype shows a large pale
brownish spot on each side at anterior end of thoracic groove and
this appears to be more or less constant among the paratypes;
the area behind LE is necked with gray. Sternum yellowish with
gray flecks around the margin. Legs are yellowish with broad
brownish rings together with pale and darker spots. Abdomen:
the dorsal folium is well developed; the venter has the usual
darker area between genital groove and base of spinnerets con-
taining a central granular oval white spot but the white mark is
variable among the paratypes.
Type locality. The holotype is from Barro Colorado Island,
C. Z., August, 1936. Six paratype males have been found in
my collections from the following localities: Barro Colorado
Island, August, 1936; July- August, 1939; July, 1950; Summit,
C. Z., July, 1950; Boquete, R. P., August, 1950.
EUSTALA EXIGUA Sp. nOV.
(Figures 55-58)
Male holotype. Total length 3.315 mm. Carapace 1.69 mm.
long; 1.386 mm. wide opposite interval between second and third
coxae where it is widest ; with shape typical of the genus ; with a
moderately well developed coat of light and dark hair; with
numerous long slender spines in ocular area and two pairs of
spinules just in front of the well developed median longitudinal
thoracic groove ; .638 mm. tall opposite third coxae and, therefore,
about .46 as tall as wide.
Eyes. Eight in two rows, all dark. Viewed from above, pos-
terior row gently recurved; viewed from in front, anterior row
straight. Anterior row nearly as wide as posterior row. Ratio of
eyes AME : ALE : PME : PLE = 12: 8.5 : 9 : 7.5. AME
separated from one another by their diameter, from ALE by
three-fourths of their diameter. PME separated from one an-
other by five-sixths of their diameter, from PLE by about five-
halves of their diameter. Laterals separated from one another by
one-third of the diameter of PLE. Central ocular quadrangle
436 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
wider in front than behind in ratio of 4 : 3, only slightly wider
in front than long. Height of clypeus equal to a little less
than three-fourths of the diameter of AME.
Chelicerae. Moderately robust ; essentially parallel ; basal seg-
ment .55 mm. long ; with a moderately well developed basal boss.
Promargin of fang groove with four teeth; retromargin with
four small teeth, one of which is minute (teeth determined from
a paratype to avoid injury to the holotype) . With well developed
scopulae.
Maxillae. Slightly convergent ; normal to the genus ; with the
tubercle well developed in opposition to the palpal femoral ridge.
Lip. "Wider than long in ratio of 13 : 8; maxillae extend
beyond lip to a distance equal to three-fourths of its length.
Sternal suture moderately procurved.
Sternum. Scutif orm ; moderately convex; widest between
second coxae; longer than wide in ratio of 31 : 29; sternum
proper not extended between fourth coxae but a narrow sclerite
continues posteriorly between fourth coxae which are separated
by about one-third of their width.
Legs. 1243. Width of first patella at ''knee" .249 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .206 mm.r
tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 2.530 .836 2.222 1.936 .792 8.316
2. 1.760 .660 1.430 1.606 .660 6.116
3. 1.166 .396 .638 .726 .440 3.366
4. 1.716 .616 1.188 1.364 .550 5.434
Palp .352 .132 .154 .594 1.232
Spines. First leg : femur dorsal 0-1-1-0-1-1, prolateral 0-1-1-1-1,
retrolateral 0-0-0-0-1-1, ventral a double series with two on pro-
margin and four on retromargin and all near middle; patella
dorsal l(weak)-l, prolateral and retrolateral 1-1; tibia dorsal
0-1-0-1-0 on right and 0-1-0-1-1-0 on left, prolateral 0-1-0-1-1,
retrolateral 0-1-1-0, ventral 2-2-2 with irregularities between
right and left; metatarsus dorsal 1-1-0-0, prolateral 0, retro-
lateral 0-1-1-0, ventral 0-2-0-0. Second leg: femur dorsal essen-
tially as in first, prolateral only one near distal end, retrolateral
0-0-0-1-1, ventral with no true spines on promargin but with an
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 437
irregular series of five on retromargin and stiff bristles which
suggest additional reduced spines ; patella dorsal as in first, pro-
lateral 1-0, retrolateral 1-1; tibia dorsal 1-1-1-0, prolateral
1-1-1-0-1, retrolateral 0-1-1-0, ventral 0-0-1-2 (Fig. 55) ; meta-
tarsus dorsal 1-1-1-0-0, prolateral 0, retrolateral 0-1-1-0, ventral
0-2-0-0. Third leg: femur dorsal 0-1-1-1, prolateral and retro-
lateral only one near distal end, ventral with four robust spines
on left and five on right and more or less medial in position;
patella only dorsal 1-1 ; tibia dorsa 0-1-0-1-0, prolateral 0, retro-
lateral 0-1-1, ventral 0-lp-2 ; metatarsus dorsal 1-0-0, prolateral
and retrolateral 0-1-0, ventral 0-lp-2. Fourth leg: femur dorsal
0-1-1-1, prolateral and retrolateral only one near distal end,
ventral a double series of eleven on left and seven on right,
irregularly placed (Fig. 56) ; patella dorsal 1-1, prolateral and
retrolateral 0-1-0; tibia dorsal 1-1-1-0, prolateral 0-1-1-1, retro-
lateral 0-1-1, ventral 0-0-lp-2 ; metatarsus dorsal 1-1-0, prolateral
0-1-1-1, retrolateral 0, ventral 0-0-2. Numerous variations of
spination have been noted among the paratypes and even from
side to side in the holotype. Palp : patella dorsal 1 ( weak )-l( long,
slender) ; tibia with numerous bristles some of which might be
considered slender spines; tarsus with numerous stiff bristles.
First coxa with the usual hook at the distal retrolateral corner.
Second femur with the usual chitinized ridge and groove on the
prolateral side.
Palp. Trochanter with a low, relatively large, chitinous tuber-
cle ; femur with a basal curved chitinous ridge ; patella with a
single long dorsal distal spine. The tibia is trilobate as follows :
dorsal lobe triangular with a ruffled chitinized anterior margin;
the body has a ventral chitinized rim and a strongly chitinized
prolateral tubercle; the retrolateral lobe is rounded and less
chitinized. Tarsus: the basal apophysis is a strongly chitinized,
modified arrow-shaped structure; the clavis is somewhat ex-
cavated at its base and is moderately robust; the uncus is a
relatively long slender spine which appears distally bifid; the
conductor is relatively large, with an excavated distal border, and
has two slender apophyses extending from its median rim; the
vesicle is large for so small an organ and has an unusual terminal
position ; the embolus is broad at its base and tapers to a point
after passing around the vesicle in an unusual manner; the
438 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
terminal laminae show a pair of low grooves distally placed
(Figs. 57-58).
Abdomen. Total length 1.885 mm.; with the usual rounded
triangular form ; longer than wide in ratio of about 5:2; with
the usual supply of long slender spines; with other features
essentially typical of the genus.
Color in alcohol. As usual the color pattern in this species is
highly variable and, as commonly used, of little value in de-
termination of the species. The holotype has a well defined
dorsal folium with a hexagonal dark spot at its anterior end but
the folium itself is highly variable in the different available
specimens and sometimes almost lacking. The median anterior
dark spot seems to be the most persistent part of the folium.
There is a transverse row of four small dots across the carapace
near the posterior end of the thoracic groove and a dark spot of
irregular shape on each side of the pars cephalica with a white
spot between. The holotype has a ventral triangular dark
spot with its apex at the base of the spinnerets without the usual
central white spot but the latter appears in some paratypes.
The sternum is yellowish with dark marginal flecks.
Type locality. Male holotype from Barro Colorado Island, C.
Z., July, 1939. Numerous male paratypes from the following
localities : Barro Colorado Island, July-August, 1936 ; July-
August, 1939 ; June-July, 1950 ; Ft. Sherman, C. Z., August,
1939 ; Canal Zone Forest Reserve, C. Z., August, 1936 and July-
August, 1939; El Valle, R. P., July, 1936; Arraijan, R. P.,
July, 1950.
Eustala fragilis (O. P. Cambridge), 1889
Epeira fragilis O. P. Cambridge, 1889
E. fragilis Keyserling, 1892
Eustala fragilis F. P. Cambridge, 1904
E. fragilis Petrunkevitch, 1911
E. fragilis Petrunkevitch, 1925
The Cambridges had this species from Guatemala and Panama
but the British Museum (Natural History) was unable to loan
me any representative. Until recently I have regarded the
species treated in this paper as E. minima sp. nov. as E. fragilis
(0. P. Cambridge) but at the present time I am unable to do
this. I am also unable to work out any clear understanding of
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
439
the species from published statements concerning it. I am, there-
fore, compelled to omit the species from the keys and to leave its
External Anatomy of Eustala
Figures 55-58, E. exigua sp. nov.
Figures 59-62, E. gertschi sp. nov.
Fig. 55. Left second tibia from below.
Fig. 56. Left fourth femur from below.
Fig. 57. Left male palpal tarsus, lateral view.
Fig. 58. Left male palpal tarsus from in front.
Fig. 59. Eight second tibia from below.
Fig. 60. Left fourth femur from below.
Fig. 61. Left male palpal tarsus, lateral view.
Fig. 62. Left male palpal tarsus from in front.
440 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
proper treatment until a more thorough understanding of it is
obtained.
EUSTALA GEBTSCHI Sp. nOV.
(Figures 59-62)
Male holotype. Total length 4.452 mm. Carapace 2.405 mm.
long; 1.950 mm. wide opposite interval between second and
third coxae where it is widest; .845 mm. tall and, therefore,
about .43 as tall as wide ; gently inclined from PME to beginning
of steep posterior declivity ; median longitudinal thoracic groove
well developed ; with a distinct but low convexity between AME
and PME from which two long slender spines extend ; with a well
developed coat of whitish procumbent hair extended into a dis-
tinct tuft dorsal and posterior to LE.
Eyes. As usual, eight in two rows, all dark ; LE on moderately
prominent tubercles ; viewed from above, posterior row distinctly
recurved; viewed from in front and measured by centers, an-
terior row gently procurved; central ocular quadrangle only
slightly wider in front than behind and only slightly longer than
wide in front. Ratio of eyes AME : ALE : PME : PLE —
12 : 8 : 10 : 8. AME separated from one another by nine-
eighths of their diameter, from ALE by five-thirds of their
diameter. PME separated from one another by seven-fifths of
their diameter, from PLE by seven-halves of their diameter. Lat-
erals separated from one another by one-half of their diameter.
Height of clypeus equal to three-halves of the diameter of AME.
Chelicerae. Basal segment .596 mm. long. Fang groove well
defined; promargin with the usual four teeth and retromargin
with three but these seem smaller and less clearly defined than
usual (observed on a paratype to avoid injury to the holotype).
Otherwise typical in all observed features.
Maxillae. As usual in the genus in all observed features in-
cluding the maxillary tooth used in opposition to the palpal
femoral ridge.
Lip. Wider than long in ratio of 35 : 22 ; moderately grooved
and striated in basal third. Sternal suture definitely procurved.
Sternum. Scutiform ; longer than wide in ratio of about 9:7;
a narrow sclerite continues between fourth coxae which are
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 441
separated by about one-seventh of their width ; moderately con-
vex; markedly scalloped opposite all coxae except the fourth
and with narrow sclerites continuing between all coxae.
Legs. 1243. Width of first patella at "knee" .347 mm., tibial
index of first leg 12. Width of fourth patella at "knee" .314
mm., tibial index of fourth leg 13.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
2.535
1.040
1.885
1.852
.942
8.254
2.
2.015
.910
1.657
1.787
.845
7.214
3.
1.495
.528
.770
.924
.594
4.311
4.
2.080
.910
1.560
1.848
.814
7.212
Palp
.425
.220
.180
.946
1.771
First coxa with the usual ventral hook and dorsal tubercle,
both well developed ; ridge and groove on second femur also
well developed as usual.
Spines. First leg: femur dorsal 0-0-1-1-1, prolateral 0-0-1-1
(both robust) -1 on right and 0-0-1-1-1-1 on left, retrolateral
0-0-0-1-1, ventral 0; patella dorsal l(weak)-l, prolateral 0-1-0,
retrolateral 0-1-1 ; tibia dorsal 0-1-1-1-0, prolateral and retro-
lateral 0-1-0-1-0, ventral lp-lp-lp-lp-2 ; metatarsus dorsal 1-0-1-0,
prolateral 0, retrolateral 0-1-0-0, ventral 0-2-2-lr-0. Second leg :
femur dorsal as in first, prolateral and retrolateral 0-0-0-1-1,
ventral 0 ; patella as in first except prolateral 0-1-1 ; tibia dorsal
0-1-1-1-0, prolateral 1-1-0-1-1, retrolateral 0-1-1-1, ventral lp-lp-
lp-lp-2 (Fig. 59) ; metatarsus dorsal 0-1-0, prolateral 0, retro-
lateral 0-1-1-0, ventral 0-2-2-lp. Third leg: femur dorsal 0-1-0-1,
prolateral and retrolateral only one near distal end, ventral
three on retromargin; patella dorsal 1-1, prolateral and retro-
lateral 0-1-0; tibia dorsal 0-1-0-1-0, prolateral 1-1-1, retrolateral
0-1-1, ventral lp-lp-2 ; metatarsus dorsal 0-1-0-0, prolateral 0-1-0-1,
retrolateral 0-1-0, ventral 0-1-0-1. Fourth leg: femur dorsal
0-1-0-1-1, prolateral and retrolateral only one near distal end,
ventral two on promargin in distal fourth and five on retro-
margin in distal two-thirds of segment (Fig. 60) ; patella as in
third; tibia dorsal 0-1-1-1-0, prolateral 1-1-0-1-0, retrolateral
0-1-1, ventral lp-2-lp-2; metatarsus dorsal 1-1-0-1-0, prolateral
0-1-0-1-1, retrolateral 0, ventral lp-lp-0-lp-lp.
Palp. Complicated; femur, patella and tibia all apparently
442 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
typical of the genus. Tarsus : basal apophysis well developed as
usual but its distal end is simply bent and knobbed, not a dis-
torted arrow-head as is typically the case ; the clavis is moderately
robust and somewhat excavated at its base and also has a char-
acteristic ridge and groove on the anterior surface of the proximal
part of the free portion ; the uncus is very long, slender, curved,
and apparently finely divided at its distal end; the conductor
is large and quadrilateral in outline as usually viewed; there is
also a fold and a depression on the ventral surface of the con-
ductor contiguous to the tip of the uncus which gives the appear-
ance of a distinct lobe in one of the paratypes ; the anterior end
of the conductor is differentiated into an extensive setose surface
and a small smooth portion ; in one paratype the anterior surface
of the conductor shows a shallow depression ; the vesicle is rather
smaller than average but definite and in its usual position ; the
embolus is long and somewhat sinuous, robust and somewhat
flattened ; the terminal laminae show a prominent elevation con-
tiguous to the conductor and a large blunt tubercle (Figs. 61-62).
Abdomen. Rather oval in outline; 2.470 mm. long; 2.242 mm.
wide ; somewhat flattened dorsoventrally ; with the usual supply
of dorsal and dorsolateral long slender spinules. With other
observed features typical of the genus.
Color in alcohol. Carapace : ocular area yellowish ; remainder
of pars cephalica brownish ; lateral sides of pars thoracica brown
with dorsal parts lighter and mottled. Sternum grayish with
white subchitinous granular spots. Legs : all femora dark brown
dorsally, lighter beneath; other segments yellowish with brown-
ish spots. Abdomen : with a moderately well developed narrow
dorsal folium; white or grayish from subchitinous granules else-
where dorsally, dorsolaterally and laterally; venter with the
usual dark central area containing a small central white spot.
The paratype collected by Dr. Gertsch is without a folium and
is much lighter throughout.
Type locality. Male holotype from Barro Colorado Island,
C. Z., June, 1950. Two male paratypes from the same locality;
February, 1936 (Gertsch) and June, 1948 (Schneirla).
Eustala guttata F. P. Cambridge, 1904
(Figures 63-68)
E. guttata Petrunkevitch, 1911
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 443
E. guttata Petrunkevitch, 1925
E. guttata Banks, 1929 (female but not male)
I have found it difficult to identify the males of this species.
The two male specimens on loan from the British Museum
(Natural History) differ considerably from one another. I have
chosen as my standard the one which agrees most fully with F. P.
Cambridge 's description and figures. I have also included in the
species as now recognized a few males which appear to be deviates
from the typical. The females appear to be endowed with
characters sufficiently distinctive to make their identification
relatively simple.
Male kypotype. Total length 4.225 mm. "With the usual round
triangular form of the body. Central ocular quadrangle wider
in front than behind in ratio of about 4:3, wider in front than
long in ratio of about 6 : 5. Ratio of eyes AME : ALE : PME :
PLE = 13 : 8 : 10 : 8. AME separated from one another by
about three-halves of their diameter, from ALE by nearly five-
thirds of their diameter. PME separated from one another by
slightly more than their diameter, from PLE by nearly four
diameters. Laterals separated from one another by five-eighths
of their diameter. Two long slender spines just posterior to LE
and a row of four similar spines between ME. Height of clypeus
equal to slightly more than the diameter of AME. Secondary
sexual characters on maxillae, first coxae, and second femur as
usual.
Legs. 1243. Width of first patella at "knee" .303 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .271 mm.,
tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3.445
.910
2.730
2.340
.975
10.400
2.
2.470
.780
1.787
1.885
.910
7.832
3.
1.625
.585
.910
.942
.747
4.809
4.
2.405
.780
1.560
1.755
.780
7.280
Palp
.379
.271
.195
.780
1.625
Spines are largely removed from the hypotype through hand-
ling and long preservation. However, the following records are
probably fairly accurate : the first femur appears to have two
ventral spines on the promargin and one on the retromargin
444
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
70
External Anatomy of Eustala
Figures 63-68, E. guttata
Figures 69-72, E. inconstans sp. nov.
Fig. 63. Left second tibia of male from below.
Fig. 64. Right fourth femur of male from below.
Fig. 65. Left male palpal tarsus, lateral view.
Fig. 66. Uncus of the same, somewhat enlarged.
Fig. 67. Left male palpal tarsus from in front.
Fig. 68. Epigynum from below.
Fig. 69. Left tibia from below.
Fig. 70. Right fourth femur from below.
Fig. 71. Left male palpal tarsus, lateral view.
Fig. 72. Left male palpal tarsus from in front.
69
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 445
near the distal end ; the second femur appears to have only one
ventral spine on the promargin near distal end; ventral and
related spines on the second tibia are shown in Figure 63 ; the
third femur has a definite double series of ventral spines with
three or four on each margin ; the ventral spines of the fourth
femur are shown in Figure 64.
Palp. Features of femur, patella, and tibia appear to be
typical of the genus. Tarsus : the basal apophysis essentially as
usual; clavis, somewhat damaged, but appears to be moderately
robust with small articular surfaces at its base; the uncus is a
pointed hook with a distinct shoulder at its base ; the conductor
is smaller proportionately than in many species and has a
moderately setose shallow excavation on its distal surface to-
gether with two other more or less distinctive surfaces; the
terminal laminae show a series of strongly chitinized ridges; the
embolus is moderately long and slender (Figs. 65-67).
Female hypotype. Total length 5.525 mm. Body form like
that of male.
Legs. 1243. Width of first patella at "knee" .379 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .357
mm., tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3.575
1.202
2.795
2.260
.975
10.607
2.
2.990
1.170
2.307
1.950
.942
9.359
3.
1.755
.715
1.040
1.040
.682
5.232
4.
2.860
1.105
1.820
1.820
.780
8.385
First femur with a pair of ventral spines near distal end ; the
remaining femora apparently lacking the ventral spines.
Epigynum. Pattern of spermathecae, tubules, and apertures
much as in E. scutigera and some other species ; the most distinc-
tive features appear to be the expanded auricular regions at
base of scape on each side (Fig. 68).
Color in alcohol. The hypotype male is discolored from long
preservation. The more recently collected males and females
show a highly variable color pattern the more persistent features
of which appear to be the following: a well developed dorsal
folium which is itself highly variable in color ; a transverse row
of four small brownish dots across the carapace at about the
446 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
middle of the thoracic groove and a transverse row of two
similar spots at the base of pars cephalica ; with a ventral elon-
gated whitish spot in the center of a dark area between the
genital groove and spinnerets.
Type locality. Male hypotype from San Jose, Costa Rica
(Tristan) ; probably collected a few years before 1909. Female
hypotype from Barro Colorado Island, C. Z., July, 1950. In the
various collections which I have had the opportunity of studying,
I have seen what I consider to be this species from many localities
in Mexico, Guatemala, Honduras, and Panama.
EUSTALA INCONSTANS Sp. nOV.
(Figures 69-72)
Male holotype. Total length 4.485 mm. Carapace 2.210 mm.
long; 1.852 mm. wide opposite interval between second and third
coxae where it is widest; .910 mm. tall and, therefore, about
.49 as tall as wide ; gently inclined from PME to beginning of
steep posterior declivity opposite interval between second and
third coxae; with well developed median longitudinal thoracic
groove; with spines confined to ocular area; apparently with a
rather sparse covering of procumbent, light colored hair ; with-
out definite tufts of hair behind PLE but with a group of eight
to ten bristles or spinules in this position.
Eyes. As usual, eight in two rows, all dark ; LE on moderately
prominent tubercles. Viewed from above, posterior row strongly
recurved; viewed from in front, anterior row gently procurved,
measured by centers. Central ocular quadrangle wider in front
than behind in ratio of about 5:4; wider in front than long in
ratio of nearly 9 : 8. Ratio of eyes AME : ALE : PME : PLE =
11 : 8 : 9.5 : 7.5. AME separated from one another by three-
halves of their diameter, from ALE by nearly fiv -thirds of
their diameter. PME separated from one another by slightly
more than their diameter, from PLE by about sev^n halves of
their diameter. Laterals separated from one anot'v r by three-
fifths of the diameter of PLE. Height of clypeus eqra to slightly
more than the diameter of AME.
Chelicerae. Basal segment .55 mm. long; transvers ely r-gulose
on anterior surface. Fang groove well defined; prrmnrorin and
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 447
retromargin appear to have the usual complement of teeth but
inspection is impossible without serious injury to holotype. Other-
wise typical of the genus in all observed features.
Maxillae. Apparently as usual in all observed features in-
cluding the maxillary tooth used in opposition to the femoral
palpal ridge.
Lip. Wider than long in ratio of about 3:2; cross striated
in basal half. Sternal suture definitely procurved.
Sternum. Scutiform ; longer than wide in ratio of 11 : 8 ; not
definitely continued between fourth coxae which are separated
by about one-fifth of their width; with the usual supply of long
stiff bristles or spinules.
Legs. 1243. Width of first patella at "knee" .314 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .271 mm.,
tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
2.925
1.072
2.340
2.210
.942
9.489
2.
2.405
.942
1.755
1.885
.780
7.767
3.
1.495
.520
.747
.780
.552
4.094
4.
1.900
.877
1.300
1.667
.760
6.504
Palp
.347
.227
.162
.942
1.678
Ventral hook on first coxa typical of the genus ; dorsal tubercle
on first coxa poorly indicated ; prolateral basal ridge and groove
on second femur well developed.
Spines. First leg: femur dorsal 0-0-1-1-1, prolateral the same
with the first two long and robust, retrolateral 0-0-0-0-1-1, ventral
promargin 0-0-1-0-1, retromargin 0-0-0-1-1; patella dorsal
l(weak)-l, prolateral and retrolateral 0-1-1; tibia dorsal 0-1-
0-1-1-0, prolateral and retrolateral 0-1-0-1-1, ventral 2-lp-2 (ir-
regular)-0-2; metatarsus dorsal 0-1-0-1-0, prolateral 0, retro-
lateral 0-1-0-1-0, ventral 2-2 (irregular) -lp-0. Second leg: femur
dorsal and retrolateral as in first, prolateral 0-0-0-1-1, ventral
promargin only one near distal end and retromargin 0-0-1-0-0;
patella as in first; tibia dorsal 0-1-0-1-1-0, prolateral 0-1-1-1,
retrolateral 0-1-1-0, ventral 2-lp-lp-lp-2 (Fig. 69) ; metatarsus
dorsal 0-1-0-0-0, prolateral 0-1-0, retrolateral 0-1-0-0, ventral
448 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
lr-lp-lr-lp-lr-O. Third leg : femur dorsal 0-1-1-1, prolateral and
retrolateral only one near distal end, ventral 0 ; patella 1 (weak) -1,
prolateral and retrolateral 0-1-0; tibia dorsal 1-0-1-0, prolateral
and retrolateral 0-1-1, ventral lp-lp-2 ; metatarsus dorsal 0-1-0-0,
prolateral and retrolateral 0-1-0, ventral lp-lp-lp. Fourth leg :
femur as in third except ventral as shown in Figure 70 ; patella
as in third; tibia dorsal 0-1-1-1-0, prolateral 1-1-1-1, retrolateral
0-1-1, ventral 2-lp-lp-2 ; metatarsus dorsal 0-1-1-0, prolateral
0-1-0-1-1, retrolateral 0-1-0-1-0, ventral O-lp-0-1.
Palp. Complicated; basal femoral ridge, patella, and tibia
essentially typical of the genus. Tarsus : basal apophysis a dis-
torted arrow-head shape distally as usual ; the clavis is moderately
robust and somewhat excavated at its base; the uncus is of
moderate length and a robust and twisted hook; the conductor
is relatively small, moderately concave on its anterior surface
where it is finely setose ; the vesicle is apparently withdrawn
to the interior and is nearly invisible externally; the embolus is
short and appears sharply pointed when viewed in the ordinary
way, and is very distinctive in appearance ; the terminal laminae
are massive, with a large tubercle close to the base of the clavis
(Figs. 71-72).
Abdomen. Total length 2.470 mm.; 1.852 mm. wide about
one-fourth from base ; with the usual round-triangular form ;
with the usual supply of long, slender, dorsal, and dorsolateral
spinules. Other observed features typical of the genus.
Color in alcohol. Carapace unicolorous yellowish except for
faint dots as they occur in so many species of the genus ; probably
here in two rows of two and four as described in E. guttata. The
sternum is a pale yellow throughout. The legs are yellowish with
faint indications of the usual brown bars, rings, and spots which
would show more or less clearly in many other members of the
species. Abdomen : the dorsal folium barely indicated ; general
color of dorsum and lateral sides whitish from the presence
of many subchitinous white granules; the venter is yellowish
white without distinctive markings.
Type locality. The holotype is from Barro Colorado Island,
C. Z., June, 1950. There are no paratypes.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 449
EUSTALA INGENUA sp. I10V.
(Figure 73)
Female holotype. Total length 4.745 mm. Carapace 2.080 mm.
long; 1.885 mm. wide opposite second coxae where it is widest;
.780 mm. tall and, therefore, about .41 as tall as wide; median
thoracic groove well defined ; with what appears to be only a
sparse coat of light colored procumbent hair.
Eyes. Eight in two rows, all dark ; viewed from above,
posterior row strongly recurved ; viewed from in front, anterior
row gently procurved, measured by centers ; central ocular
quadrangle wider in front than behind in ratio of 28 : 25, slightly
wider in front than long. Ratio of eyes AME : ALE : PME :
PLE = 8 : 6.5 : 8 : 6.5. AME separated from one another by
seven-fourths of their diameter, from ALE by nearly three
times their diameter. PME separated from one another by nearly
1.5 times their diameter, from PT E by four times their diameter.
Laterals separated from one another by ten-thirteenths of their
diameter. Height of clypeus equal to about three-fourths of the
diameter of AME.
Chelicerae. Basal segment .675 mm. long ; general features
typical of the genus. Fang groove with four promarginal and
three retromarginal teeth as usual.
Maxillae. Appear to be completely typical of the genus in
all observed features.
Lip. Wider than long in ratio of about 4:3; reaches slightly
beyond the middle of the maxillae. Sternal suture distinctly
procurved and with anterolateral angles of sternum produced
into distinct tubercles.
Sternum. Scutiform ; longer than wide in ratio of 8 : 7 ;
bluntly pointed at posterior end which is not continued between
fourth coxae which are separated by about one-sixth of their
width ; with low convexities opposite all coxae ; with the usual
stiff bristles (spinules).
Legs. 1243. Width of first patella at "knee" .3141 mm., tibial
index of first leg 11. Width of fourth patella at "knee" .2708
mm., tibial index of fourth leg 13.
450 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
2.470
1.040
1.936
1.760
.758
7.964
2.
2.275
.990
1.755
1.625
.747
7.392
3.
1.365
.575
.704
.747
.520
3.911
4.
2.080
.836
1.325
1.495
.585
6.321
Spines. First leg: femur dorsal 0-0-1-0-1, prolateral 0-0-1-1-1
(first two long and robust), retrolateral 0-0-0-0-1-1, ventral only-
one near distal end on both promargin and retromargin ; patella
dorsal l(weak)-l, prolateral and retrolateral 0-1-1; tibia dorsal
1-1-1-0, prolateral and retrolateral 0-1-1-1, ventral 2-lp-2-0-2;
metatarsus dorsal 0-1-1-0-0, prolateral 0; retrolateral 0-1-1-0,
ventral lr-2-lp-0 on left and 2-2-lp-0 on right. Second leg : femur
as in first except that the two corresponding to the two large pro-
laterals are small ; patella as in first ; tibia essentially as in first ;
metatarsus as in first except ventral lr-lp-lr-lp-0-0. Third leg:
femur dorsal 0-1-1-0-1, prolateral and retrolateral only one near
distal end, ventral 0 but several spinules suggest normal spines ;
patella probably only dorsal 1-1 ; tibia dorsal 1-0, prolateral 0, re-
trolateral 0-1, ventral lp-lp-2 ; metatarsus dorsal 0-1-1-0-0, prolat-
eral 0-1-0-0, retrolateral 0, ventral lp-lp-1-1. Fourth leg : femur as
in first except ventral one on retromargin near distal end ; patella
dorsal 1-1, prolateral 0-1-0, retrolateral 0-1 ; tibia dorsal 1-1-1-0,
prolateral 1-1-1-1, retrolateral 0-1-0-1, ventral lp-lp-lp-2; meta-
tarsus dorsal 0-1-1-0-0, prolateral 0-1-1-1, retrolateral 0-1-1-0,
ventral O-lp-lp-0-1.
Abdomen. 3.25 mm. long; 2.73 mm. wide about one-fourth
from base where it is widest ; with numerous long slender spines ;
other features essentially typical of the genus.
Epigynum. Quite distinctive ; with a relatively long and slen-
der scape which arises abruptly from the base which is con-
siderably wider than long; the apertures are separated by less
than the diameter of one of them (Fig. 73). The base is not
extended ; hence it seems unnecessary to include a figure drawn
from the lateral aspect.
Color in alcohol. Both of the available specimens of this species
agree well in coloration. Carapace yellowish with poorly defined
light reddish brown streaks passing from anterior end of the
thoracic groove to the ocular region. Sternum yellowish. Legs:
C1IICKERING : GENUS EUSTALA IN CENTRAL AMERICA 451
75
External Anatomy of Eustala
Figure 73, E. ingenua sp. nov.
Figures 74-76, E. innoxia sp. nov.
Figure 77, E. lata sp. nov.
Figures 78-80, E. latebricola
Fig. 73. Epigynum from below.
Fig. 74. Epigynum from below.
Fig. 75. Epigynum, a more posterior view.
Fig. 76. Epigynum, lateral view.
Fig. 77. Epigynum from below.
Fig. 78. Epigynum from below.
Fig. 79. Epigynum, a more posterior view.
Fig. 80. Epigynum, a lateral view.
452 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
different shades of amber yellow. Abdomen : dorsal and dorso-
lateral regions yellowish white from many subchitinous gran-
ules; venter yellowish and also with many subchitinous whitish
granules; just posterior to the genital groove there is a poorly
defined elongated whitish spot.
Type locality. Holotype and one paratype female are from
Summit, C. Z., July, 1950.
EUSTALA INNOXIA Sp. nOV.
(Figures 74-76)
Female holotype. Total length 5.135 mm. Carapace 2.015 mm,
long; 1.592 mm. wide opposite interval between second and third
coxae where it is widest ; .780 mm. tall and, therefore, about .49
as tall as wide ; median longitudinal thoracic groove well defined
but apparently not as pronounced as in the more typical mem-
bers of the genus; with a moderately well developed coat of
yellowish hair raised into a rather poorly developed tuft accom-
panied by bristles just posterior to PLE ; with two long slender
spinules centrally placed behind PME and further behind these
a short distance anterior to the thoracic groove are probably six
similar spines in two rows of three each.
Eyes. Eight in two rows, all dark as usual ; viewed from above,
posterior row moderately recurved ; viewed from in front, an-
terior row gently procurved, measured by centers ; central ocular
quadrangle wider in front than behind in ratio of about 11 : 10,
as long as wide in front. Ratio of eyes AME : ALE : PME :
PLE = 11 : 9 : 10 : 7.5. AME separated from one another by
their diameter, from ALE by about four-thirds of their diameter.
PME separated from one another by nine-tenths of their diam-
eter, from PLE by slightly less than three times their diameter.
Laterals separated from one another by two-thirds of the di-
ameter of PLE. Height of clypeus equal to seven-elevenths of
the diameter of AME.
Chelicerae. Basal segment .780 mm. long; fang groove well
developed and with four retromarginal and three promarginal
teeth as usual. Other observed features typical of the genus.
Maxillae. Appear to be completely typical of the genus in all
observed features.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 453
Lip. Wider than long in ratio of nearly 4:3; gently grooved
and cross striated in basal third. Sternal suture distinctly pro-
curved; with no marked anterolateral sternal tubercles at ends
of the suture.
Sternum. Scutiform; only slightly longer than wide; not
continued between fourth coxae which are separated by about
one-fifth of their width; with only slight convexities opposite
each coxa; probably in life with the usual supply of long stiff
bristles (spinules).
Legs. 1243. Width of first patella at "knee" .2816 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .2599 mm.,
tibial index of fourth leg 12.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
3.315
1.007
2.665
2.405
1.040
10.432
2.
2.600
.900
1.950
1.950
.910
8.310
3.
1.540
.572
.836
.996
.650
4.594
4.
2.535
.836
1.386
1.694
.770
7.221
Spines. First leg: femur dorsal 0-1-1-0-0-1, prolateral 0-0-1-
1-1-1, retrolateral only one near distal end, ventral probably
none but some might regard spinules present as weak spines and
worth recording; patella dorsal l(weak)-l, prolateral 0-1-0,
retrolateral 1-1; tibia dorsal 0-1-0-1-1-0, prolateral 0-1-0-1-1,
retrolateral 0-1-1-0, ventral lp-0-lr-lp-0-lr ; metatarsus dorsal
0-1-1-0-0, prolateral 0, retrolajterajl 0-1-1-0, ventral O-lr-0-0.
Second leg : femur dorsal as in first, prolateral and retrolateral
only one near distal end, ventral 0; patella dorsal as in first,
prolateral 0, retrolateral as in first on right but on left 0-1;
tibia dorsal and retrolateral as in first, prolateral 0-1-0-1-0, ven-
tral (only bristle) -2-lr; metatarsus dorsal 0-1-1-0, prolateral
0-1-0-0, retrolateral 0-1-1-0, ventral only bristles. Third leg:
femur dorsal 0-1-0-0-1, prolateral and retrolateral only one near
distal end, ventral only bristles or spinules; patella only dorsal
1-1; tibia dorsal 1-0-1-0, prolateral 0, retrolateral 0, ventral
lp-lp-2; metatarsus dorsal 0-1-1-0-0, prolateral and retrolateral
0, ventral 0-lp-lp. Fourth leg: femur dorsal 0-1-0-1-1 (last one
duplicated on left), prolateral and retrolateral only one near
distal end, ventral two on retromargin near distal end; patella
dorsal and prolateral as in third, retrolateral 0-1; tibia dorsal
454 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
0-1-0-1, prolateral 0-1-1-1, retrolateral 0-0-1-1-1-1, ventral lr-0-lr ;
metatarsus dorsal 0-1-0-0, prolateral and retrolateral 0-1-0,
ventral 0.
Abdomen. 3.120 mm. long; 3.445 mm. wide near middle; tall
as well as broad and, therefore, not of the usual Eustala form;
with numerous slender spines of moderate length ; other features
appear to be fairly typical of the genus.
Epigynum. Simple as compared to the typical organ in the
genus ; the scape is short and broadly attached to the base which
is relatively massive; apertures hidden (Figs. 74-76).
Color in alcohol. Carapace : yellowish with a black dot on
each side at base of pars cephalica and on a line with the LE ;
also with a few faint irregular grayish spots on the pars cephal-
ica. Sternum : yellowish with faint grayish spots opposite the
coxae. Legs : yellowish with a few grayish spots. Abdomen : the
dorsal folium moderately well outlined in posterior half ; most of
the dorsal and dorsolateral areas are white from many sub-
chitinous granules ; there is also a narrow dark transverse wavy
line just in front of the middle ; the venter is generally yellow-
ish with scattered white subchitinous granules; a few dark sub-
chitinous spots occur irregularly in the anterior third of the
venter; there is an incomplete dark ring around the spinnerets
and an accumulation of white granules in the center behind the
genital groove make a poorly outlined central white spot.
Type locality. The holotype and one female paratype are from
the Canal Zone Forest Reserve, C. Z., August, 1939.
EUSTALA LATA Sp. nOV.
(Figure 77)
This specimen had recently moulted when taken and is some-
what fragile but is in fair condition.
Female holotype. Total length 8.255 mm. Carapace 3.640 mm.
long; 3.380 mm. wide opposite interval between second and
third coxae where it is widest; 1.170 mm. tall and, therefore,
about .35 as tall as wide ; median longitudinal thoracic groove
well defined as usual; with a well developed coat of yellowish
procumbent hair and numerous brownish spinules over much of
the surface and with tufts of the hair behind PLE.
CHECKERING : GENUS EUSTALA IN CENTRAL AMERICA 455
Eyes. Eight in two rows, all dark as usual; viewed from
above, posterior row rather strongly recurved ; viewed from in
front, anterior row definitely procurved; central ocular quad-
rangle wider in front than behind in ratio of 46 : 41, wider in
front than long in about the same ratio. Ratio of eyes AME :
ALE : PME : PLE — 11 : 9 : 10 : 10. AME separated from
one another by nearly three diameters of one of them, from ALE
by about four diameters of one of them. PME separated from
one another by 2.5 times their diameter, from PLE by a little
more than seven times their diameter. Laterals separated from
one another by eleven-ninths of the diameter of ALE. Height
of clypeus equal to a little less than twice the diameter of AME.
Chelicerae. Basal segment 1.365 mm. long; fang groove well
developed; promargin with four teeth and only the last one is
noticeably smaller; retromargin with four fairly robust teeth
(one of the rare instances in the genus) ; other observed features
appear to be typical of the genus.
Maxillae. Appear to be typical of the genus in all observed
features.
Lip. Wider than long in ratio of 5 : 4; gently grooved and
cross striated in basal third. Sternal suture distinctly procurved.
Sternum. Scutiform ; longer than wide in ratio of about 3:2;
anterolateral corners produced into distinct tubercles at ends
of sternal suture ; posterior end bifurcated and not continued
between fourth coxae which are separated by about one-fifth of
their width; with the usual supply of longer and shorter stiff
spinules.
Legs. 1243. Width of first patella at "knee" .5848 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .5957
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.420 1.950 3.850 3.705 1.495 15.320
2. 4.030 1.950 3.250 3.510 1.495 14.235
3. 2.600 1.235 1.452 1.755 1.040 8.082
4. 3.850 1.885 2.860 3.120 1.250 12.965
Spines. First leg : femur dorsal 0-0-1-0-1, prolateral 0-0-1-1-0-1
on right and 0-0-1-1-1-0-1 on left, retrolateral 0-0-0-0-1-1, ventral
three along promargin all in distal half and only one on retro-
456 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
margin near distal end but a row of spinules along retromargin
suggests suppressed spines; patella dorsal 1-1, prolateral and
retrolateral 1-1-0 ; tibia dorsal 0-1-1-1-0, prolateral 0-1-0-0-1, retro-
lateral 0-1-0-1-1, ventral 2-lp-2-0-2; metatarsus dorsal 0-1-1-0,
prolateral 0-0-1-1, retrolateral 0-1-1-0, ventral 2-2-0-lr-0. Second
leg: femur dorsal as in first, prolateral 0-0-1-1-1, retrolateral
0-0-0-1-1, ventral only one definite spine on retromargin near
distal end but there is a row of eight or nine spinules before this :
patella as in first; tibia dorsal as in first, prolateral and retro-
lateral 0-1-1-1, ventral 2-lp-2-lr-2 ; metatarsus dorsal 0-1-1-0, pro-
lateral and retrolateral essentially like dorsal, ventral 2-lp-lr-lp-
lr-lp. Third leg: femur dorsal 0-1-0-1-1, prolateral 0-0-0-1-1,
retrolateral only one near distal end, ventral apparently 0;
patella dorsal as in first, prolateral 0-1-0, retrolateral 0-0-1;
tibia dorsal 1-0-1-0, prolateral 0-0-1-1, retrolateral 0-0-1, ventral
apparently lp-lp-2; metatarsus dorsal 0-1-1-0, prolateral 0-1-1,
retrolateral 0, ventral lp-lp-2-lp. Fourth leg: femur dorsal es-
sentially as in third, prolateral and retrolateral only one near
distal end, ventral only one on retromargin near distal end;
patella as in third; tibia dorsal 1-1-1-0, prolateral 0-1-0-1-1,
retrolateral 0-1-1, ventral 2?-0-lp-lp-2; metatarsus dorsal 0-1-1-0,
prolateral 0-1-1-1, retrolateral 0-1-1-0, ventral lp-lp-lp-lp. Tarsal
claws as usual in the genus. Palpal claw pectinate in a single row
of eight teeth ; the distal two robust, others very slender.
Abdomen. 5.01 mm. long; 4.420 mm. wide about one-third
from base; with the usual round-triangular form; with many
slender spines of moderate length ; without the long spines which
often occur in Eustala; other features appear to be typical of
the genus, except that two small posterior tubercles suggest a
potential bifid condition.
Epigynum. Nearly twice as long as wide at base of scape;
scape gradually narrowed to tip; tubules form an oval area at
base ; apertures small and nearly two diameters apart ; unex-
tended so as to be only partly visible in profile (Fig. 77).
Color in alcohol. Holotype recently moulted and normal color
probably not well established. Cephalothorax, legs, and mouth
parts light yellowish ; four small dark spots faintly outlining a
square in middle of dorsal area; legs with indications of large
dark spots on many segments. Abdomen : dorsum whitish with
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 457
small reddish dots and a mixture of grayish and greenish streaks ;
with a fairly well defined folium; venter with a large black
median spot enclosing a white spot of irregular shape.
Type locality. Holotype from Barro Colorado Island, C. Z.,
August, 1950. No paratypes have appeared in my collection.
Eustala latebricola (0. P. Cambridge), 1889
(Figures 78-80)
Epeira latebricola O. P. Cambridge, 1889
E. latebricola Keyserling, 1892
Eustala latebricola F. P. Cambridge, 1904
E. bifida Banks, 1909 (in part)
E. latebricola Petrunkevitch, 1911
E. latebricola Petrunkevitch, 1925
Female hypotype. Total length 4.875 mm. "With the body
form ordinarily described as round-triangular; with what ap-
pears to be nearly suppressed shoulder humps. The central
ocular quadrangle as wide behind as in front; wider than long
in ratio of 10 : 9. Ratio of eyes AME : ALE : PME : PLE =
9:8:9:7. AME separated from one another by five-thirds of
their diameter, from ALE by eight-thirds of their diameter.
PME separated from one another by about 1.5 of their diameter,
from PLE by about four times their diameter. Laterals sep-
arated by three-fourths of the diameter of ALE. Height of
clypeus slightly greater than the diameter of AME. Promargin
of fang groove with four teeth, the second and fourth smaller;
retromargin with three teeth.
Legs. 1243. Width of first patella at "knee" .3249 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .325 mm.,
tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.105 2.405 1.950
1.040 1.950 1.755
.617 .758 .812
.975 1.430 1.462
The hypotype seems to lack ventral femoral spines but some
specimens have a pair of ventral spines on the first and last
1.
2.990
2.
2.470
3.
1.527
4.
2.405
.975
9.425
.845
8.060
.585
4.299
.715
6.987
458 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
femora near the distal end.
Epigynum. Quite distinctive; the scape is bluntly rounded
at the distal end and somewhat constricted in the middle ; there
is a groove and a ridge, semicircular in shape, at the base of the
scape ; the base itself is very prominent in the middle as seen in
posterior view (Figs. 78-80).
Color in alcohol. The general color pattern is, as usual, exceed-
ingly variable ; the folium is often well developed but it may be
almost completely lacking; the transverse row of four small dots
across the carapace at the level of the posterior third of the
thoracic groove and the transverse row of two dots at the base of
the pars cephalica are present in the hypotype but are sometimes
reduced in number or lacking altogether; the elongated white
spot in the center of a dark area on the venter is usually present.
Type locality. The Cambridges had this species from Guate-
mala and Panama. The hypotype is from Boquete, R. P., August,
1950. In addition to the single female sent from the British
Museum I have several females from Boquete, R. P., July, 1939
and August, 1950. Numerous specimens labelled E. bifida Cb.
and, presumably, reported by Banks (1909) as E. bifida are in
reality E. latebricola (0. P. Cambridge).
EUSTALA LONGEMBOLA Sp. nOV.
(Figures 81-85)
Male holotype. Total length 4.29 mm. Carapace 2.210 mm.
long, 1.885 mm. wide between intervals separating second and
third coxae where it is widest; .845 mm. tall and, therefore,
about .45 as tall as wide ; rises gradually from PME to opposite
interval between second and third coxae from where it descends
to posterior margin ; with a well developed longitudinal thoracic
groove ; with a few weak spines and a sparse coating of procum-
bent brown hair.
Eyes. Eight in two rows, all dark; LE on moderately prom-
inent tubercles; viewed from above both rows of eyes strongly
recurved; viewed from in front, anterior row somewhat pro-
curved, measured by centers; central ocular quadrangle wider
in front than behind in ratio of 35 : 28 ; wider in front than long
in ratio of 35 : 32. Ratio of eyes AME : ALE : PME : PLE =
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 459
11 : 7 : 9 : 7. AME separated from one another by abont
fourteen-elevenths of their diameter, from ALE by eighteen-
elevenths of their diameter. PME separated from one another
by four-thirds of their diameter, from PLE by nearly five times
their diameter. Laterals separated from one another by four-
sevenths of their diameter. Clypeus very receding. Height of
clypeus equal to slightly more than the diameter of AME.
Chelicerae. Essentially parallel, but distal half is somewhat
excurved; with moderately well developed basal boss; basal
segment .617 mm. long, and somewhat cross striated in front.
Fang groove well defined; promargin with four teeth, fourth
somewhat isolated from others ; retromargin with three teeth
of moderate size. Fang evenly curved as usual.
Maxillae. In general as in male of E. mexicana in all observed
features.
Lip. Wider than long in ratio of about 7:5; extends only a
little beyond middle of maxillae ; basal half somewhat cross
striated. Sternal suture moderately procurved.
Sternum. Scutiform; longer than wide in ratio of 19 : 16; a
sclerite continues from posterior end between fourth coxae which
are almost in contact; covered with long curved bristles.
Legs. 1243. Width of first patella at "knee" .3249 mm.,
tibial index of first leg 8. Width of fourth patella at "knee"
.2708 mm., tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totala
(All measurements in millimeters)
1.
3.445
1.137
2.730
2.210
.910
10.432
2.
2.600
.942
1.820
1.885
.910
8.157
3.
1.495
.585
.845
.845
.585
4.355
4.
2.210
.910
1.560
1.625
.715
7.020
Palp
.412
.217
.162
.780
1.571
First coxa with a well developed ventral distal retromarginal
hook; prolateral groove at base of second femur also well de-
veloped ; dorsal tubercle on first coxa moderately well developed.
Spines. First leg: femur dorsal 0-0-1-1-1, prolateral and
retrolateral the same, ventral apparently 0-lp-0-0-2 (considerable
variation has been noted among paratypes) ; patella dorsal 1-1,
prolateral 0-1-0, retrolateral 0-0-1-0 ; tibia dorsal 0-1-0-1-1-0, pro-
lateral and retrolateral 0-1-0-1-0, ventral 2-2-2-lp-2 with some
460 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
irregularities between right and left; metatarsus dorsal 0-1-1-0,
prolateral 0-1-0-1-0, retrolateral 0-1-1-0, ventral lr-lr-0-0. Second
leg : femur as in first except ventral spines apparently consist of
only a pair near distal end; patella dorsal l(weak)-l, prolateral
and retrolateral 0-1-1-0; tibia dorsal 0-1-1-1-0; prolateral and
retrolateral 0-1-1-0, ventral 2-lp-2-lp-2 (Fig. 81) ; metatarsus
dorsal 0-1-0, prolateral 0, retrolateral 0-1-1-0, ventral lr-lp-lr-lp-0.
Third leg: femur dorsal 0-1-1-1, prolateral and retrolateral 0-0-1,
ventral 0-lp-lp-0 ; patella dorsal 1-1, prolateral 0-1-0, retrolateral
0-0-1-0 ; tibia dorsal 0-1-0-1-0, prolateral 0-1-0, retrolateral 0-1-1,
ventral 0-lr-lr-lr; metatarsus dorsal 0-1-0-0, prolateral 0-1-1,
retrolateral 0-1-0, ventral lr-lr-lr. Fourth leg : femur essentially
as in third except ventral with nine on right as in Figure 82
or six on left ; patella essentially as in third ; tibia dorsal 0-1-1-1-0,
prolateral 1-1-1-1, retrolateral 0-1-1, ventral 2-lp-lp-2 ; metatarsus
dorsal 0-1-0-1-0, prolateral 0-1-1-0, retrolateral 0-0-1-1-0, ventral
0-lp-0-lp.
Palp. Complicated; basal femoral tubercle or ridge opposing
the maxillary tooth well developed; the patella is short, with a
weak basal dorsal spine and a long slender distal dorsal spine;
the patella also has a well developed distal retrolateral tubercle
which is assumed to act in opposition to one of the other nearby
chitinized structures; the tibia has the characteristic tri-lobed
structure with each lobe well developed. Tarsus : the basal tarsal
apophysis only slightly distorted from an arrow-shape ; the clavis
is rather slender, not excavated basally; the uncus is sharply
pointed with a well developed shoulder at its base ; the conductor
is relatively simple, with an excavation on its distal face; the
vesicle is large, nearly as extensive as the embolus ; the embolus
is long, slender, and curves along the whole distal border; the
terminal laminae are only moderately grooved but they are
provided with a series of thin strongly chitinized raised surfaces
(Figs. 83-85).
Abdomen. Total length 2.405 mm.; rounded at both ends,
with obscure triangular form; longer than wide in ratio of
37 : 27; with the usual long slender dorsolateral and dorsal
spines; with other features as usual in the genus.
Color in alcohol. Carapace yellowish with a brownish dot on
each side near posterior end of the thoracic groove and another
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 461
similar dot on each side near the anterior end of the groove;
there are indications also of more or less extensive irregular
brownish spots including much of the anterior half ; these latter
markings are conspicuous in some paratypes but lacking in
others; the dots appear to be quite consistent in the paratypes.
Sternum : yellowish with only faint blotches of gray around the
margin. Mouth parts mostly yellowish but brownish flecks may
occur. Legs : with many brownish rings, bars, and spots. Abdo-
men : dorsal folium narrow in front, with a narrow brown margin
around posterior two-thirds; venter with a somewhat irregular
quadrilateral spot between genital groove and base of spinnerets
bearing a small central white spot. These ventral markings show
variations among paratypes but seem to be fundamentally quite
persistent.
Type locality. Holotype male from Barro Colorado Island,
C. Z., August, 1939. Male paratypes from the following locali-
ties: Barro Colorado Island, C. Z., June-July, 1934; June-
August, 1936 ; July- August, 1939 ; June-August, 1950 ; Arraijan,
R. P., August, 1950 ; C. Z. Forest Reserve, C. Z., August, 1936
and July- August, 1939 ; Ft. Sherman, C. Z., August, 1939 ; El
Valle, R. P., July, 1936; Madden Dam Forest, C. Z., August,
1939 and July, 1950; C. Z. Experiment Station, Summit, C. Z.,
July- August, 1950; near Chiva, C. Z., August, 1950; Chilibre,
C. Z., July, 1950; Variedades, Guatemala, August, 1947 (C. and
P. Vaurie).
EUSTALA MAXIMA sp. nOV.
(Figures 86-87)
This is the species which has been repeatedly identified as
E. bifida F. P. Cambridge. I am now convinced that it is dis-
tinct from the latter and inclined to believe that it is the female
of M. oanksi sp. nov. but there can be no certainty at present.
Female holotype. With the usual round-triangular form ; total
length 10.34 mm. Carapace 3.64 mm. long ; 3.12 mm. wide oppo-
site interval between second and third coxae where it is widest ;
1.30 mm. tall and, therefore, about .42 as tall as wide; with
median longitudinal thoracic groove well developed; with few
if any spines except in ocular region ; with a well developed coat
462
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
of almost white procumbent hair.
Eyes. Eight in two rows as usual, all dark ; viewed from above,
both rows strongly recurved ; viewed from in front, anterior
row moderately procurved, measured by centers; central ocular
External Anatomy of Eustala
Figures 81-85, E. longembola
Figures 86-87, E. maxima
Fig. 81. Left second tibia from below.
Fig. 82. Eight fourth femur from below.
Fig. 83. Tarsus of male palp, lateral view.
Fig. 84. Uncus of the same somewhat enlarged.
Fig. 85. Tarsus of male palp, from distal end.
Fig. 86. Epigynum, from below.
Fig. 87. Epigynum, lateral view.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 463
quadrangle exactly as wide in front as behind, slightly longer
than wide. Ratio of eyes AME : ALE : PME : PLE = 12 : 9 :
13 : 10. AME separated from one another by slightly less
than twice their diameter, from ALE by slightly more than four
times their diameter. PME separated from one another by
about 1.5 times their diameter, from PLE by nearly 5.5 times
their diameter. Laterals separated from one another by a little
more than two-thirds of the diameter of ALE. Height of the
clypeus equal to the diameter of AME. A transverse row of four
spinules extends between the rows of ME midway. Ventral
border of clypeus with the usual row of stiff bristles.
Chelicerae. Moderately robust; essentially parallel; front sur-
face with many slender spines. Basal segment 1.43 mm. long;
with moderately well developed basal boss. Promargin of fang
groove with four teeth, the fourth the smallest; retromargin
with four teeth, all close together, the second the smallest; the
fang is fairly robust, evenly curved, finely dentate along inner
margin ; the fang groove is well defined and finely dentate.
Maxillae. With all usual features well developed. There ap-
pears to be a somewhat suppressed maxillary tooth correspond-
ing to the strongly chitinized tooth on all males.
Lip. Wider than long in ratio of about 31 : 24 ; transversely
striated in basal two-fifths ; bluntly pointed distally ; reaches only
slightly beyond middle of maxillae. Sternal suture distinctly
procurved with distal lateral corners of the sternum extended
forward.
Sternum. Scutiform; longer than wide in ratio of 3 : 2;
continued between fourth coxae by a slender sclerite ; with fourth
coxae separated from one another by a little more than one-
fourth of their width; with slight convexities opposite first, sec-
ond, and third coxae.
Legs. 1243. Width of first patella at "knee" .5957 mm., tibial
index of first leg 11. Width of fourth patella at "knee" .6065
mm., tibial index of fourth leg 14.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.950 3.380 3.380
1.820 2.990 3.120
1.105 1.300 1.625
1.690 2.535 2.860
1.
3.640
2.
3.445
3.
2.340
4.
3.380
1.397
13.747
1.300
12.675
.975
7.345
1.170
11.635
464 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Spines. First leg : femur dorsal 0-1-0-1-1, prolateral and retro-
lateral the same, ventral spines weak but probably with three
or four on each margin and all in distal half; patella dorsal
1-1, prolateral and retrolateral 0-1-1-0; tibia dorsal 0-1-1-1-0,
prolateral and retrolateral 0-1-0-1-1 (weak), ventral 2-lp-lr-lp-
0-2; metatarsus dorsal 0-1-0-1-0, prolateral 0-1-1-0, retrolateral
0-0-1-0-1-0, ventral 2-2-2-0 with some irregularity. Second leg:
essentially the same as the first with few exceptions. Third leg :
femur essentially as in first and second; patella dorsal 0-1-0-1,
prolateral 0-1-0, retrolateral 0; tibia dorsal 1-0-1-0, prolateral
1-1-1 (first and last weak), retrolateral 0, ventral lp-lp-2; met-
atarsus dorsal 1-0-1-0, prolateral 1-0-1-0 (both weak), retrolateral
0, ventral lp-lp-lp-2. Fourth leg : with few exceptions like third
but differences seem unimportant. Palpal spines: femur dorsal
0-1-0-1 ; patella dorsal 1-1 ; tibia with several spines and numer-
ous spinules; tarsus also with numerous spines and spinules.
Palpal claw: pectinate in a single row of six or seven slender
teeth. Tarsal claws three ; proclaw with five or six teeth, retro-
claw with eight slender teeth.
Abdomen. 6.50 mm. long ; as wide as long ; low convexities sug-
gest suppressed shoulder humps; the posterior end is quite dis-
tinctly bifid dorsoventrally much like that of E. bifida. Other-
wise essentially typical of the genus.
Epigynum. Bears a close resemblance to that of E. bifida
F. P. Cambridge but there are clearly defined differences best
shown in figures (Figs. 86-87).
Color in alcohol. Carapace yellowish, flecked with brown;
with signs of dots and stripes as described for the male of E.
banksi sp. nov. Legs yellowish with brown spots and broad
irregular rings. Sternum yellowish with many subchitinous gran-
ules and a brownish margin. Abdomen: with a poorly defined
dorsal folium ; dorsum nearly white from the presence of many
subchitinous yellowish-white granules ; the venter has a somewhat
quadrilateral dark area between the genital groove and the base
of the spinnerets ; a central elongated white granular spot extends
through anterior half of the dark area.
Type locality. Holotype female from Summit, C. Z., July,
1950. Female paratypes from Barro Colorado Island, C. Z.,
July (Dodge) ; also from the Rau collection with no date.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 465
EUSTALA MEXICANA Sp. nOV.
(Figures 88-89)
Female holotype. With the conventional round-triangular
form; total length 5.20 mm. Carapace 2.08 mm. long, 1.80 mm.
wide opposite interval between second and third coxae where it
is widest ; .65 mm. tall and, therefore, about .36 as tall as wide ;
with a well developed longitudinal thoracic groove ; with a pair
of slender spines at anterior end of thoracic groove and several
other similar spines on cephalic part; also with a moderately
well developed coat of light yellowish procumbent hair.
Eyes. Eight in two rows as usual, all dark; none particularly
prominent ; viewed from above both rows strongly recurved ;
viewed from in front, anterior row moderately procurved, meas-
ured by centers; central ocular quadrangle wider in front than
behind in ratio of 15 : 13, wider in front than long in ratio of
about 15 : 13. Ratio of eyes AME : ALE : PME : PLE =
9:7: 8.75 : 6.5. AME separated from one another by a little
less than two diameters, from ALE by a little less than three
diameters of AME. PME separated from one another by nearly
one and one-third of their diameter, from PLE by four diameters
of PME. Laterals separated by slightly more than one-half the
diameter of ALE. Height of clypeus equal to about two-thirds
of the diameter of AME. Ventral border of clypeus with a row
of stiff bristles.
Chelicerae. Moderately robust, parallel ; medially the anterior
surface with numerous converging spine-like bristles. Basal seg-
ment .78 mm. long; with well developed basal boss. Promargin
of fang groove with four teeth, second and fourth small, others
moderately robust; retromargin with three moderately robust
teeth, all in basal half. Fang moderately robust and evenly
curved.
Maxillae. Essentially parallel; robust; with well developed
scopula along medial border and inner distal corner; with well
developed serrula along outer distal corner and adjacent distal
and lateral surfaces.
Lip. Wider than long in ratio of about 4:3; broad distal
border very full and well rounded; transversely excavated in
basal two-thirds ; reaches only slightly beyond middle of maxillae.
Sternal suture distinctly procurved.
466 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY
Sternum. Scutiform; only slightly longer than wide; slightly
the widest between second coxae ; not extended between fourth
coxae which are separated by about one-fourth of their width;
with moderately developed prominences opposite coxae.
Legs. 1243. Width of first patella at "knee" .3249 mm., tibial
index of first leg 10. Width of second patella at "knee" .3141
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 3.055 1.040 2.340 1.690 .715 8.840
2. 2.405 .970 1.755 1.495 .747 7.372
3. 1.365 .650 .780 .715 .552 4.062
4. 2.275 .970 1.462 1.300 .650 6.657
Spines. First leg : femur dorsal 0-1-0-1-1, prolateral 0-1-1-1-0,
retrolateral 0-0-0-1-1, ventral 0-0-1-0-1 on prolateral margin and
one near distal end on retromargin; patella dorsal l(weak)-l,
prolateral and retrolateral 0-1-1 ; tibia dorsal 0-1-1-1-0, prolateral
and retrolateral 0-1-0-1-1 (weak), ventral 2-lp-2-lp ; metatarsus
dorsal 0-1-0-1-0-0, prolateral apparently 0, retrolateral 0-1-0-1-0,
ventral lr-2-lp-0. Second leg : femur dorsal and retrolateral as
in first, prolateral 0-0-0-1-1-1 (weak), ventral apparently only one
weak spine near distal end on retromargin ; patella as in first ;
tibia as in first except ventral lr-2-lp-lr-0 ; otherwise essentially
as in first. Third leg : femur dorsal 0-1-0-1, prolateral and retro-
lateral apparently only one definite spine on each at distal end,
ventral 0; patella only dorsal 1-1, and prolateral 0-1-0; tibia
dorsal lr-lp, prolateral 0, retrolateral only one weak distal spine,
ventral lp-lp-2 ; metatarsus dorsal lp-lr, prolateral 0-1-0, retro-
lateral apparently 0, ventral lp-lp-lp-lp (all weak and little more
than bristles). Fourth leg: femur dorsal 0-1-0-1-1, ventral only
one distal on retrolateral margin ; patella retrolateral 0-0-1-0,
elsewhere as in third; tibia dorsal 1-1-1, prolateral 1-1-0-1-1,
retrolateral 0-1-1, ventral lp-lp-lp-lp ; metatarsus dorsal 1-1-0,
prolateral 1-1-1, retrolateral 0-0-1 (weak), ventral 0-1-1-1. Palpal
spines : femur dorsal 0-1 ; patella dorsal 1-1, prolateral 0-1 ; tibia
dorsal 0-1-0, prolateral 1-1, retrolateral 0-1 (weak), ventral 0;
tarsus with numerous spines irregularly placed. Palpal claws:
pectinate in a single row of about six or seven light colored teeth
and difficult to distinguish clearly. Three tarsal claws as usual
in the genus.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 467
Abdomen. Round-triangular, viewed dorsally ; shoulder humps
barely distinguishable; with a slightly developed tubercle at
posterior end; longer than wide between suppressed shoulder
humps in ratio of about 7:6; with numerous moderately long
slender spines. Otherwise as usual in the genus.
Epigynum. With a broad base and slender scape; difficult to
describe but quite distinctive ; apertures about two diameters
apart (Figs. 88-89).
Color in alcohol. Carapace : light yellowish with poorly defined
brownish radiations from the thoracic groove ; dark pigment sur-
rounds the eyes. Sternum : with a fairly broad brownish margin ;
yellowish elsewhere. Mouth parts yellowish, streaked with gray.
Legs and palps yellowish with brownish bands. Abdomen : dorsal
folium well marked, highly variegated; dorsolaterally are four
yellowish spots on each side ; the venter has a large median
quadrilateral brownish spot between the genital groove and base
of spinnerets ; the brownish spot is nearly divided by a narrow
white stripe and is bounded laterally on each side by a narrow,
somewhat incurved stripe.
Type locality. Holotype female from Lo Bajo, Guerrera, Mex-
ico, June, 1941 (L. I. Davis). Female paratypes from the fol-
lowing localities in Mexico : Boca de Pasquales, Colima, January,
1943 (F. Bonet) ; Chiapas, Rio de los Flores, near Cintalpa,
September, 1947 ; Conjumatlan, Michoacan, June, 1941 (A. M.
Davis) ; Hidalgo, Ixmiquilpan, August, 1947 (H. Wagner) ;
Huajuapan, Oaxaca, Sept.-Oct., 1946 (H. Wagner) ; Nayerit, San
Bias, August, 1947 (C. and M. Goodnight) ; Oaxaca, Tehuante-
pec, January, 1948 (T. MacDougal) ; Nayerit, Tepic, Sept., 1947
(B. Malkin) ; Teotitlan, Oaxaca, Sept., 1944 (H. Wagner) ;
Tamaulipas, Santa Gracia, July, 1940 (Rau) ; Vera Cruz, Vera
Crux, July, 1946 (H. Wagner).
EUSTALA MIMICA Sp. nOV.
(Figures 90-93)
All three specimens available to me for this study are in
rather poor condition. The one chosen for the holotype has an
injured and detached abdomen but is otherwise in good condi-
tion.
468
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Male holotype. Total length about 7.48 mm. Carapace 4.225
mm. long; 3.185 mm. wide opposite interval between second
and third coxae where it is widest; 1.365 mm. tall and, therefore,
90
89
External Anatomy of Eustala
Figures 88-89, JS. mexicana
Figures 90-93, E. mimica
Fig. 88. Epigynum from below.
Fig. 89. Epigyniun, lateral view.
Fig. 90. Left second tibia from below.
Fig. 91. Left fourth femur from below.
Fig. 92. Tarsus of male palp, lateral view.
Fig. 93. Tarsus of male palp from distal end.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 469
about .43 as tall as wide ; rises gradually from PME to highest
point opposite interval between second and third coxae from
where it slopes rather abruptly to posterior border ; well rounded
along margin from posterior border to opposite anterior border
of third coxae and then with little change to opposite anterior
border of second coxae from where it narrows to a blunt point
in region of AME ; longitudinal thoracic groove well marked
with considerable convexity on each side ; with two long slender
spinules midway between AME and PME and two similar
spinules on each side above LE.
Eyes. Eight in two rows, all dark ; ocular tubercle bearing LE
moderately prominent; viewed from above, both rows strongly
recurved; viewed from in front, anterior row moderately pro-
curved; central ocular quadrangle wider in front than behind
in ratio of 8 : 7, nearly as wide in front as long. Katio of eyes
AME : ALE : PME : PLE = 9:5:7:5. AME separated from
one another by nearly their diameter, from ALE by about
five-thirds of their diameter. PME separated from one another
by nine-sevenths of their diameter, from PLE by about three
and one-half times their diameter. Laterals separated from one
another by three-fifths of their diameter. Height of clypeus equal
to eleven-ninths of the diameter of AME.
Chelicerae. With basal boss moderately well developed ; basal
segment 1.11 mm. long; each with numerous long slender spinules
in front medially directed and overlapping ; fang groove well
marked, with four promarginal teeth the most distal of which
is merely a dentule and with three retromarginal teeth of moder-
ate size.
Maxillae. Essentially parallel ; with the usual robust lateral
tubercle opposed to the basal femoral palpal tubercle ; other
features as usual in the genus.
Lip. Wider than long in ratio of about 5 : 4. Sternal suture
obscure but apparently gently procurved.
.Sternum. Narrowly scutiform; mildly convex; moderately
scalloped opposite coxae ; longer than wide in ratio of 14 : 11 ;
slightly widest at interval between second and third coxae but
nearly as wide at interval between first and second coxae ; pos-
terior end continued as a very slender sclerite between fourth
coxae which are separated by about one-fifth of their width.
470 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
Legs. 1243. Width of first patella at "knee" .585 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .520 mm.,
tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
4.550
2.015
4.355
4.160
1.625
16.705
2.
4.030
1.625
3.120
3.965
1.527
14.269
3.
3.250
1.105
1.625
1.755
1.000
8.735
4.
3.575
1.900
3.120
3.575
1.350
13.520
Palp
.550
.440
.308
1.298
2.596
Spines. First leg : femur dorsal 0-0-1-1-1, prolateral the same
with slight irregularities, retrolateral 0-0-0-0-1-1, ventral ap-
parently 0-0-0-0-lp-2 ; patella dorsal l(weak)-l, prolateral and
retrolateral 0-1-1-0 ; tibia dorsal 0-1-1-1-0, prolateral and retro-
lateral 1-1-0-1-1 with some irregularities, ventral 2-lr-lp-2-lp-lp-2 ;
metatarsus dorsal 0-1-0-0, prolateral 0-1-1-0-1, retrolateral 0-1-1-0,
ventral 2-2-2-lp with some irregularity. Second leg : femur as in
first except only a single ventral pair near distal end ; patella as
in "first; tibia dorsal 0-1-1-1-0, prolateral 0-1-1-0-1-1 (long and
robust), retrolateral 0-1-1-1-1, ventral 2-lp-lp-lp-lp-2 (Fig. 90);
metatarsus dorsal 0-1-0^0-0, prolateral 0-0-1-0-1, retrolateral
0-1-1-0, ventral 2-2-24p. Third leg: femur dorsal 0-1-0-1-1, pro-
lateral and retrolateral 0-0-0-1-1, ventral 0-l-2-lr-2-2 (with some
irregularity); patella dorsal l(weak)-l, prolateral 1-0, retro-
lateral 0-1 ; tibia dorsal 1-0-1-0, prolateral 1-1-1, retrolateral
0-1-1, ventral lp-2-2-2 ; metatarsus dorsal 0-1-0-0, prolateral 0-1-1,
retrolateral 0-1-0, ventral 2-2-2-lp. Fourth leg: femur dorsal
0-1-0-1-1, prolateral and retrolateral only one near distal end,
ventral 0-2-2-lr-2-lr-2 (with some irregularity and differences on
right and left) (Fig 91) ; patella dorsal and retrolateral 0-1,
prolateral 0-1-0 ; tibia dorsal 0-1-0-1-1-0, prolateral 1-1-1-1, retro-
lateral 1-1-1, ventral 2-2-2-2 (with some differences between
right and left) ; metatarsus dorsal 0-1-1-0-0, prolateral 0-1-1-1,
retrolateral 0-0-1-1-1, ventral 2-2-2-2. Tarsal claws apparently as
usual in the genus. Trichobothria numerous and apparently
widely distributed at least on tibiae and metatarsi.
Palp. Very complicated as usual in the genus. Maxillary
tubercle, basal femoral tubercle, and probably trochanteral tuber-
cle as usual in the genus. There is a single slender distal dorsal
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 471
spinule on the femur and a single long dorsal distal patellar
spine. The patella is short, simple, strongly chitinized along its
distal prolateral boarder; the tibia is very short but relatively
broad with less well marked trilobate form than in many species
and with the usual strongly chitinized ventral collar. Tarsus:
basal apophysis a somewhat distorted arrow-shape ; the clavis is
robust, without basal excavation ; the uncus is robust, with a
relatively long robust shank and a marked shoulder at base of
terminal hook; the conductor is comparatively simple on the
ventral surface but is provided with several characteristic distal
surfaces with no slender extensions ; the vesicle is small, otherwise
normal ; the embolus is a slender, strongly chitinized tube termin-
ating in a lance-like tip ; the terminal laminae are simple with no
strongly developed characteristic folds (Figs. 92-93).
Abdomen. Badly shrunken and so distorted as to make it un-
desirable to describe it. Apparently with the usual round-
triangular form (shown clearly in paratypes) ; with many stiff
spinules of the common kind.
Color in alcohol. Cephalothorax, legs, and mouth parts with
various shades of yellowish without conspicuous! markings.
Holotype abdomen unsuitable for description. Paratype abdo-
mens show a median dark stripe along cardiac region, a fairly
well defined dorsal folium, many subchitinous whitish granules,
a large ventral black area enclosing a white spot broadened in
the middle.
Type locality. Male holotype from Summit, C. Z., December,
1946 (N. L. H. Krauss). Two male paratypes from the Phil Rau
collection in the Museum of Comparative Zoology with no ac-
companying collection data but I think these were taken during
the winter months on Barro Colorado Island, C. Z.
EUSTALA MINIMA sp. nOV.
(Figures 94-96)
This species has hitherto been regarded as E. fragilis (0. P.
Cambridge) but is now regarded as a species new to science.
Unfortunately, E. fragilis was not included among the specimens
loaned from the British Museum and, hence, it has been difficult
to reach a decision in respect to the status of the species. How-
472 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
ever, a drawing kindly sent by Dr. G. Owen Evans has aided
me in the final decision.
Female holotijpe. Of conventional, non-elongated, round-tri-
angular form; total length 5.33 mm. Carapace 2.02 mm. long;
1.69 mm. wide opposite interval between second and third coxae
where it is widest; .78 mm. tall anjd, therefore, about .46 as tall
as wide ; posterior declivity more precipitous than usual in the
genus; median thoracic groove moderately well developed but
relatively shorter than usual in the genus ; with a group of several
weak spines at anterior end of thoracic groove ; with a transverse
row of four slender spinules between MB ; also with a moderately
well developed coat of light colored procumbent hair.
Eyes. Eight in two rows, all dark ; viewed from above, both
rows moderately recurved; viewed from in front, anterior row
slightly procurved, measured by centers ; central ocular quad-
rangle wider in front than behind in ratio of 28 : 25 ; longer
than wide in front in ratio of 15 : 14. Ratio of eyes AME :
ALE : PME : PLE = 11 : 8 : 8 : 8. AME separated from one
another by slightly more than their diameter, from ALE by 15/11
of their diameter. PME separated from one another by their
diameter, from PLE by 27/8 of their diameter. Laterals sep-
arated from one another by their radius. Height of clypeus equal
to the diameter of AME.
Chelicerae. Basal segment .7 mm. long; general features as
usual in the genus. Fang groove well defined and finely dentate ;
promargin with four teeth, second and fourth small, others of
moderate size ; retromargin with three teeth, the third the largest.
Maxillae and Lip. Typical of the genus in all observed fea-
tures. Sternal suture procurved.
Sternum. Scutif orm ; almost exactly as wide as long ; with only
slight convexities at posterior end and opposite first, second, and
third coxae ; not continued between fourth coxae which are
separated by a little less than one fifth of their width.
Legs. 1243. Width of first patella at "knee" .2924 mm., tibial
index of first leg 9. AVidth of fourth patella at "knee" .2708 mm.,
tibial index of fourth leg 12.
1.
2.795
2.
2.370
3.
1.495
4.
2.340
.910
9.199
.700
7.620
.541
4.314
.650
6.987
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 473
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
.977 2.307 2.210
.845 1.885 1.820
.600 .812 .866
.910 1.430 1.657
Spines. First leg: femur dorsal irregular, 0-1-1-0-0-1 on right,
0-1-1-1-1-0-0-0-1 on left, prolateral 0-0-1-1-1-1-0, retrolateral ap-
parently only one near distal end, ventral apparently only one
weak spine on retromargin near distal end; patella dorsal 1-1,
prolateral 1-0, retrolateral 1-1-1 on right, 1-1 on left ; tibia dorsal
0-1-1-1-0, prolateral and retrolateral 0-1-1-1-1, ventral 0-lr-2-lp;
metatarsus dorsal 0-1-0-0-0, prolateral 0-1-0, retrolateral 0-1-1-1-0,
ventral 0-2-lr-0-0. Second leg: femur dorsal 0-1-1-0-0-1, pro-
lateral and retrolateral apparently only one near distal end,
ventral 0; patella dorsal 1 (weak)-l, prolateral 0-1 (weak)-O, ret-
rolateral 0-1; tibia dorsal 0-1-1-1-0, prolateral and retrolateral
0-1-1-1, ventral 0-lr-2 ; metatarsus dorsal 0-1-1-0-0, prolateral ap-
parently 0 but with several spinules, retrolateral 0-1-1-0, ventral
0-2-0-0. Third leg: femur dorsal 1-1 (weak) -1, retrolateral ap-
parently only one near distal end ; patella apparently only dorsal
1-1, tibia dorsal 1-1-0, ventral 1-1-2, elsewhere apparently 0;
metatarsus dorsal 1-0-0, prolateral only one distal, retrolateral
1-0-0, ventral 0-lp-0-2. Fourth leg : essentially like the third with
few exceptions which seem to be unimportant.
Abdomen. 3.25 mm. long; wider than long in ratio of 11 : 10.
Other observed features are typical of the genus.
Epigynum. Viewed from a true ventral position, wider than
long; with a short scape terminating in a bead-like expansion
(Figs. 94-96).
Color in alcohol. Carapace yellowish with brownish dots and
reddish flecks on cephalic part ; the dots are arranged as a trans-
verse row of four at about the beginning of the posterior declivity
and another pair of dots also forming a transverse row in front
of the thoracic groove. Sternum light yellow with a few brown
flecks. The legs are yellowish with brownish spots and irregular
reddish spots on the fourth tibiae and more distal segments.
Abdomen : only the anterior end of a dorsal folium persists ; most
of the dorsum is covered with white subchitinous granules ; there
474 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
is a paired series of small brown spots in the posterior half of
the dorsum which I also regard as remains of the folium; the
venter is light colored with white subchitinous granules. In
common with other species, the paratypes show a high degree of
color variations. In some the folium is well developed, and the
legs have many brown spots, rings, and bars. The dots on the
carapace appear to be fairly consistent in appearance. In some
specimens the venter is dark colored. These facts are added
evidence that no great importance can be attached to color pat-
terns in this genus.
Type locality. The holotype female is from Barro Colorado
Island, C. Z., June, 1950. Paratype females from the following
localities have been studied : Mante, Mexico, August, 1943 ; Barro
Colorado Island, C. Z., June-July, 1934; June-August, 1936;
July -August, 1939; June, 1950; Ft. Randolph, C. Z., August,
1936; France Field, C. Z., August, 1939; Ft. Sherman, C. Z.,
August, 1939; C. Z. Forest Reserve, C. Z., July- August, 1939;
Madden Dam, C. Z., August, 1939 ; Chilibre, C. Z., July, 1939 ;
Boquete, R. P., July, 1939, August, 1950 ; El Valle, R. P., July,
1936 ; Arraijan, R. P., August, 1936 ; Porto Bello, R. P., August,
1936.
EUSTALA MONTANA Sp. nOV.
(Figures 97-100)
Male holotype. Total length 5.395 mm. Carapace 2.665 mm.
long ; 2.275 mm. wide between second and third coxae where it is
widest ; .845 mm. tall opposite interval between second and third
coxae and, therefore, about .37 as tall as wide; gently inclined
from PME to beginning of steep posterior declivity; with well
defined median longitudinal thoracic groove; with spines con-
fined to ocular area ; covered with a well developed coat of brown
and light colored procumbent hair and with a tuft of long white
hairs just posterior to PLE.
Eyes. Eight in two rows as usual, all dark ; LE on moderately
prominent tubercles; viewed from above, posterior row strongly
recurved; viewed from in front, anterior row gently procurved,
measured by centers; central ocular quadrangle wider in front
than behind in ratio of 19 : 16, wider in front than long in
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
475
98
External Anatomy of Eustala
Figures 94-96, E. minima
Figures 97-100, E. montana
Fig. 94. Epigynum from below.
Fig. 95. Epigynum, a more posterior view.
Fig. 96. Epigynum, lateral view.
Fig. 97. Left second tibia from below.
Fig. 98. Right fourth femur from below.
Fig. 99. Tarsus of male palp, lateral view.
Fig. 100. Tarsus of male palp from distal end.
476 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
ratio of 19 : 17. Ratio of eyes AME : ALE : PME : PLE =
11 : 8.5 : 10 : 7.5. AME separated from one another by
slightly more than twice their diameter, from ALE by nearly
two and one-fourth times their diameter. PME separated from
one another by 1.3 times their diameter, from PLE by 3.7 times
their diameter. Laterals separated from one another by two-
thirds the diameter of PLE. Height of clypeus equal to about
13/11 of the diameter of AME.
Chelicerae. Basal segment .814 mm. long. Fang groove well
defined; promargin as usual with four teeth, second and fourth
smaller; retromargin with three teeth. Otherwise typical of the
genus as far as observed; teeth observed on paratype to avoid
injury to holotype.
Maxillae. As usual in the genus in all observed features includ-
ing the maxillary tooth in opposition to the palpal femoral
ridge.
Lip. Wider than long in ratio of about 8:5; grooved trans-
versely in basal third ; reaches to about the middle of the maxil-
lae. Sternal suture definitely procurved.
Sternum. Scutiform; longer than wide in ratio of 47 : 37 ;
a narrow sclerite continues between fourth coxae which are
separated by about one-sixth of their width; with the usual
supply of long stiff bristles or spinules.
Legs. 1243. Width of first patella at "knee" .4115 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .3357 mm.,
tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.095 1.300 3.445 2.990 1.170 13.000
2. 3.120 1.235 2.405 2.502 1.105 10.367
3. 1.950 .845 1.105 1.040 .650 5.590
4. 2.925 1.202 1.885 2.015 .780 8.807
Palp .401 .282 .217 .909 1.809
Ventral distal retrolateral hook and dorsal tubercle on first
coxa together with proximal prolateral ridge and groove on
second femur apparently normal for males of the genus.
Spines. First leg : femur dorsal 0-1-0-1-1, prolateral essentially
the same, retrolateral 0-0-0-1-1, ventral apparently only one on
promargin near distal end and 0-0-0-1-1 on retromargin ; patella
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 477
dorsal l(weak)-l, prolateral 0-1-1, retrolateral 0-0-1; tibia dorsal
0-1-0-1-1-0, prolateral and retrolateral 0-1-0-1-0, ventral 2-2-lp-
lp-2 ; metatarsus dorsal 0-1-0-0-0, prolateral 0-1-1-0, retrolateral
0-1-0-1-0, ventral lr-lp-lr-lp-0. Second leg: femur as in first ex-
cept ventral apparently only one on promargin near distal end
and four on retromargin, all in distal two-thirds of segment;
patella as in first; tibia dorsal 0-1-0-1-1-0, prolateral 1-1-1-0,
retrolateral 0-1-1-1, ventral 2-lp-lr-lp-lp-2 (Fig. 97) ; metatarsus
dorsal 0-0-1-0, prolateral 0, retrolateral 0-0-0-1-0, ventral lr-lp-
lr-lp-0. Third leg: femur dorsal and prolateral 0-0-1-1-1, retro-
lateral only one near distal end, ventral three on each margin and
all six in distal two-thirds of segment; patella dorsal 0-1-0-1,
prolateral and retrolateral 0-1; tibia dorsal 1-0-1-0, prolateral
1-0-1, retrolateral 0-1-1, ventral lp-lp-2 ; metatarsus dorsal 0-1-0-0,
prolateral 0-1-1, retrolateral 0-1-0, ventral 1-1-1-1. Fourth leg:
femur dorsal as in third, prolateral 0-0-1-1, retrolateral only one
near distal end, ventral as shown in Figure 98 ; patella as in
third ; tibia dorsal 0-1-1-1-0, prolateral 1-1-1-1, retrolateral 0-1-0,
ventral 2-lp-lp-2 ; metatarsus dorsal 0-1-0-1-0, prolateral 0-1-0-1-1,
retrolateral 0-0-1-1-0, ventral O-lp-0-0.
Palp. Complicated; basal femoral ridge, patella, and tibia
essentially as in E. scitula sp. nov. Tarsus: basal tarsal apophy-
sis a typical, somewhat distorted arrow-head in shape ; the clavis
is moderately robust, only slightly excavated at its base; the
uncus has a very pronounced shoulder at its base and curves
around in contact with the conductor as a robust hook; the
conductor is large, has a shallow depression to receive the uncus,
is finely setose along its anterior surface which is differentiated
into a concave and a rounded portion against which the distal
end of the embolus is applied; the vesicle is of moderate size
and is in the typical position; the embolus appears to have dis-
tinctive form best shown in drawings; the terminal laminae
have a series of conspicuous sharp carinae, a marked low tubercle,
together with a strongly raised portion contiguous to the con-
ductor (Figs. 99-100).
Abdomen. Total length 2.99 mm.; 2.47 mm. wide; with the
usual round-triangular form; with the usual supply of long
slender dorsal and dorsolateral spinules ; other observed features
typical of the genus.
478 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
Color in alcohol. Carapace yellowish with considerable brown-
ish color in the form of irregular spots and radiations from the
thoracic groove; there is a suggestion of a series of dots in a
transverse row such as occurs in so many species of the genus;
these come out quite clearly in a paratype as a row across at the
posterior third of the groove. The sternum is yellowish with a
broad grayish margin. The legs are much spotted and banded
with brown. Abdomen: there is a well marked brownish dorsal
folium ; there are three black spots along the dorsolateral regions
on each side ; the venter has a darker quadrilateral area between
the genital groove and the base of the spinnerets but the common
central white spot is only barely indicated.
Type locality. The male holotype and a single mature male
paratype are both from El Volcan, R. P., August, 1950.
EUSTALA MONTrVAGA Sp. nOV.
(Figures 101-102)
Female holotype. Total length of 7.80 mm. Carapace 3.185 mm.
long ; 2.5 mm. wide opposite second coxae where it is widest ; .975
mm. tall and, therefore, .39 as tall as wide ; median longitudinal
thoracic groove moderately well marked but less conspicuous
than in some other species of Eustala; with a moderately well
developed coat of light yellowish hair and numerous short spin-
ules especially on the cephalic region.
Eyes. Eight in two rows, all dark; viewed from above, both
rows strongly recurved; viewed from in front, anterior row
practically straight, measured by centers; central ocular quad-
rangle wider in front than behind in ratio of 10 : 9 ; wider in
front than long in ratio of 10 : 9. Ratio of eyes AME : ALE :
PME : PLE =7 : 5 : 6 : 4.5. AME separated from one an-
other by ten-sevenths of their diameter, from ALE by 2.5 times
their diameter. PME separated from one another by four-thirds
of their diameter, from PLE by about three times their diameter.
Laterals separated from one another by slightly less than the
diameter of PLE. Height of clypeus equal to four-sevenths of
the diameter of AME.
Chelicerae. With basal boss moderately well developed ; basal
segment 1.17 mm. long; each with long slender bristles in front,
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 479
medially directed and overlapping; fang groove well marked
and with small dentules; fang groove with four promarginal
teeth, the most distal of which is small, and with three retro-
marginal teeth all fairly robust (on the right side a dentule
occurs just external to the most distal normal tooth).
Maxillae. Appear to be entirely typical of the genus.
Lip. Wider than long in ratio of 14 : 9. Sternal suture pro-
curved.
Sternum. Scutiform ; moderately convex, especially opposite
coxae ; scalloped opposite coxae ; longer than wide in ratio of
57 : 55 ; widest between intervals separating second and third
coxae but nearly as wide between intervals separating first and
second coxae; not continued between fourth coxae which are
separated by about one-fourth of their width.
Legs. 1243. Width of first patella at "knee" .484 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .44 mm.,
tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 3.770 1.625 3.445 2.860 1.105 12.805
2. 3.380 1.430 2.860 2.470 1.040 11.180
3. 1.982 .845 1.105 1.105 .780 5.817
4. 3.120 1.310 2.080 2.145 .910 9.565
Spines. In general this species is apparently less spiny than
usual in the genus. First leg: femur dorsal 0-1-0-1, prolateral
0-0-1-0-1-1, retrolateral 0-0-0-1-1, ventral 0; patella dorsal 0-1,
prolateral 0-1-0, retrolateral 0-0-1 ; tibia dorsal 0-1-0-1-1-0, pro-
lateral 0-1-0-1-0, retrolateral 0-0-1-0-1-0, ventral lp-2-2-0-2(two
pairs near middle quite irregular) ; metatarsus dorsal 0-0-1-0,
prolateral 0, retrolateral 0-1-1, ventral 2-lp-lr-lp-0. Second leg:
femur essentially as in first ; patella as in first with spines weak ;
tibia as in first except ventral 2-2 ( irregular ) -lp-0-2 ; metatarsus
dorsal 0-1-0-0, prolateral 0, retrolateral 0-0-1-0, ventral 2-2 (irreg-
ular) -lp-0. Third leg: femur dorsal 0-1-1-1, prolateral 0, retro-
lateral only one near distal end; patella only dorsal 1-1 (both
weak) ; tibia dorsal 0-1-0-1-0 (both weak), prolateral 0-1-0, retro-
lateral 0, ventral 1-1-0 (both nearly median) ; metatarsus dorsal
0-1-0, prolateral 0-1-0-1, retrolateral 0, ventral 1-1-1-1 (all medi-
an). Fourth leg: femur dorsal 0-1-0-1, prolateral apparently 0,
480 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
retrolateral only one weak spine near distal end, ventral only
two on retromargin near distal end ; patella dorsal 1-1, prolateral
0-1-0, retrolateral 0-1; tibia dorsal 0-1-1-1-0, prolateral 0-1-1,
retrolateral 0-1-1-0, ventral lp-lp-2 ; metatarsus dorsal 1-1-0, pro-
lateral 0-1-1-1, retrolateral 0-1-0, ventral 0-1-1-1.
Abdomen. With the common round-triangular form and slight
suggestions of shoulder humps; 5.53 mm. long; 4.94 mm. wide;
with numerous recurved short spinules but apparently no long
ones such as occur in other species. Other features essentially
typical of the genus.
Epigynum. Similar to that of E. semifoliata (O. P. Cam-
bridge) but with certain clear differences (Figs. 101-102). Rela-
tively short and broad ; the scape gradually broadens to the base ;
apertures small and about four diameters of one of them apart;
spermathecae a little less than a diameter apart.
Color in Alcohol. Legs and palps yellowish with large dark
brown patches and rings together with smaller spots. Carapace
yellowish with four dark dots in two transverse rows in middle of
dorsal area (one paratype has these dots arranged in three
rows with two in the first, three in the second and four in the
third). Sternum dusty yellow with a broad grayish margin.
Abdomen : with a moderately distinct brownish dorsal folium ;
outside of the folium the dorsal and dorsolateral areas are
whitish from many subchitinous granules; the venter has a
median darker spot with irregular boundaries and whitish
patches but without the two conspicuous white spots possessed
by E. semifoliata; a narrow black ring surrounds the bases of the
spinnerets.
Type locality. Female holotype and two smaller but mature
female paratypes from El Volcan, R. P., August, 1950.
EUSTALA PANAMANA Sp. nOV.
(Figures 103-105)
Female holotype. Total length 5.265 mm. Carapace 2.275 mm.
long; 1.82 mm. wide opposite interval between second and
third coxae where it is widest ; .66 mm. tall opposite second coxae
where it is tallest and, therefore, about .36 as tall as wide ; rises
gradually from PME to highest point and then descends grad-
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
481
104
External Anatomy of Eustala
Figures 101-102, E. montivaga
Figures 103-105, E. panamana
Figures 106-107, E. redundans
Fig. 101. Epigynum from below.
Fig. 102. Epigynum, lateral view.
Fig. 103. Epigynum from below.
Fig. 104. Epigynum, a more posterior view.
Fig. 105. Epigynum, lateral view.
Fig. 106. Epigynum from below.
Fig. 107. Epigynum, lateral view.
482 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
ually to posterior margin ; with well marked median longitudinal
thoracic groove and only moderately convex lateral to the groove.
Eyes. Eight in two rows, all dark; viewed from above both
rows strongly recurved; viewed from in front, anterior row
slightly procurved, measured by centers; central ocular quad-
rangle wider in front than behind in ratio of 33 : 30, slightly
wider in front than long. Ratio of eyes AME : ALE : PME :
PLE = 5.5 : 4 : 5 : 4. AME separated from one another by
18/11 of their diameter, from ALE by twice their diameter.
PME separated from one another by seven-fifths of their diam-
eter, from PLE by a little more than three times their diameter.
Laterals separated from one another by slightly more than their
radius. Height of clypeus nearly equal to the diameter of AME.
Chelicerae. Basal segment .77 mm. long; general features
typical of the genus; fang groove well marked and with four
promarginal teeth and three retromarginal teeth.
Maxillae. Appear to be completely typical of the genus in all
observed features.
Lip. Wider than long in ratio of about 2:1; well rounded
along distal margin so that the organ is nearly semicircular in
outline. Sternal suture procurved.
Sternum. Scutiform; longer than wide in ratio of 6 : 5;
moderately convex but with additional convexities opposite all
coxae; not continued between fourth coxae which are separated
by nearly one third of their width.
Legs. 1243. Width of first patella at ''knee" .352 mm.,
tibial index of first leg 11. Width of fourth patella at "knee"
.330 mm., tibial index of fourth leg 15.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
2.795
.975
2.275
1.690
.845
8.580
2.
2.275
.900
1.755
1.625
.845
7.400
3.
1.495
.583
.780
.780
.640
4.278
4.
2.437
.910
1.397
1.462
.747
6.953
Spines. First leg : femur dorsal 0-1-0-1-1, prolateral 0-0-1-1-1-0,
retrolateral 0-0-0-0-1-1, ventral apparently only one on each
margin near distal end and both weak; patella dorsal 1-1, pro-
lateral 0-1-0-0, retrolateral 0-0-1-0; tibia dorsal 0-1-1-1-0, pro-
lateral nearly the same, retrolateral 0-1-1-0, ventral lp-0-lp-0;
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 483
metatarsus dorsal 0-1-1-1, prolateral only bristles, retrolateral
0, ventral 2-2-0. Second leg: femur dorsal 0-1-0-1, prolateral
and retrolateral only one near distal end, ventral apparently
only one weak spine on retromargin near distal end ; patella as in
first ; tibia dorsal as in first ; prolateral and retrolateral 0-1-0-1-0,
ventral 2-lp-lr ; metatarsus dorsal 0-1-0-1-0-0, prolateral 0-1-0-1-0,
retrolateral 0-1-0-0, ventral O-lr-0-0. Third leg: femur dorsal
0-1-0-1, prolateral and ventral 0, retrolateral 0-0-1, patella as in
first except prolateral 0; tibia dorsal 0-1-0-0, prolateral and
retrolateral 0, ventral lp-lp-2 ; metatarsus dorsal 0-1-1-1, pro-
lateral 0-1-0-0, retrolateral 0-0-1 (weak) -0, ventral 1-1-1-1 (all
median). Fourth leg: femur dorsal 0-1-1-1, prolateral and retro-
lateral only one near distal end, ventral apparently one on each
margin near distal end and both weak; patella essentially as in
first; tibia dorsal 0-1-0-1-0, prolateral 0-1-1-0, retrolateral 0-1-0,
ventral lp-lp-2; metatarsus dorsal 0-1-0-1-0-0, prolateral 0-1-1-0,
retrolateral 0-1-0-0, ventral 0-0-1 (median) . Tarsal claws as usual
in the genus. Palpal claw long, slender, gently curved ; pectinate
in a single row of about nine teeth increasing in length distally.
Abdomen. With the usual round-triangular form but more
rounded than usual; 3.282 mm. long; 3.25 mm. wide at greatest
width about one fourth from base ; high as well as relatively
broad ; with a moderate supply of long spinules ; other features
appear to be typical of the genus.
Epigynum. Kelatively broad ; with scape gradually narrowed
from base to tip which is not rugulose like the broader part ; the
apertures are three to four diameters apart; the spermathecae
are close together and when \iewed from a posterior position
seem to be in contact; the oval part of the base is prominent
(Figs. 103-105).
Color in alcohol. Legs and mouth parts generally yellowish
with dark spots of various sizes. Carapace : yellowish with con-
siderable dusty gray over the cephalic area ; this extends back as
a median stripe through most of the length of the median thoracic
groove ; the cephalic area has a more or less V-shaped, white spot
caused by an accumulation of subchitinous granules; there is a
black dot on each side just in front of the median groove and
a transverse row of four black dots at about the middle of the
groove. The lip is white in the middle at the base but gray else-
484 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
where. The sternum is light grayish with irregular white sub-
chitinous spots and opposite each coxa there is a much darker
rounded spot. Abdomen: nearly white from a large number of
angular subchitinous granules; with a faintly outlined dorsal
folium ; there is an elongated white spot just behind the genital
groove and this is bordered by a short narrow, nearly black stripe
on each side.
Type locality. The holotype is from Cerro Punta, Chiriquir
R. P., March, 1936 (W. J. Gertsch). There are two mature
female paratypes and what I assume to be an immature male
from the same locality and probably collected at the same time.
EUSTALA REDUNDANS Sp. nOV.
(Figures 106-107)
Female holotype. With the conventional round-triangular
form. Total length 6.175 mm. Carapace 2.41 mm. long; 2.08 mm.
wide opposite interval between second and third coxae where it
is widest ; .968 mm. tall and, therefore, about .47 as tall as wide ;
median longitudinal thoracic groove well defined ; with numerous
short brown spinules especially on the cephalic part together
with a moderately well developed coat of light colored procum-
bent hair.
Eyes. Eight in two rows, all dark as usual; viewed from
above, posterior row strongly recurved ; viewed from in front,
anterior row definitely procurved ; central ocular quadrangle
wider in front than behind in ratio of 11 : 9, wider in front
than long in ratio of 33 : 29. Ratio of eyes AME : ALE : PME :
PLE = 9 : 7.5 : 9.5 : 8. AME separated from one another by
twice their diameter, from ALE by slightly more than three
times their diameter. PME separated from one another by about
6/5 of their diameter, from PLE by a little more than four times
their diameter. Laterals separated from one another by 2/3 of
the diameter of ALE. Height of clypeus equal to a little more
than the diameter of AME.
Chelicerae. Basal segment .877 mm. long; general features
agree well with the typical species of the genus. The fang groove
is well defined and provided with the usual sets of teeth, four
on promargin and three on retromargin.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 485
Maxillae. Appear to be typical of the genus in all observed
features.
Lip. Wider than long in ratio of about 5:4; reaches to some-
what beyond the middle of the maxillae. Sternal suture distinctly
procurved.
Sternum. Scutif orm ; longer than wide in ratio of about
9:8; not continued between fourth coxae which are separated by
a little less than one-fifth of their width ; with low convexities
opposite each coxa; with the usual supply of long stiff bristles.
Legs. 1243. Width of first patella at "knee" .4007 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .3899
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3.380
1.170
2.925
2.740
.975
11.190
2.
2.925
1.170
2.340
2.275
.747
9.457
3.
1.885
.750
1.040
1.007
.682
5.364
4.
2.860
1.170
1.787
1.820
.785
8.422
Spines. First leg : femur dorsal 0-1-0-1-1, prolateral 0-0-1-1-1-0,
retrolateral 0-0-0-1-1-0, ventral apparently only one on retro-
margin near distal end; patella dorsal l(weak)-l, prolateral
0-1-0, retrolateral 0-1-1 ; tibia dorsal 0-1-1-1-0, prolateral 0-1-
0-1-1, retrolateral 0-1-1-1, ventral 2-2-2-0-0 with considerable
irregularity ; metatarsus dorsal 0-1-1-0, prolateral 0, retrolateral
0-1-1-0, ventral 2-2-lp-0-0. Second leg : femur essentially as in
first except ventral 0 ; patella as in first except right prolateral
0-1-1; tibia as in first except ventral lr-2-lr-lp-lr-lr(last two
weak) ; metatarsus dorsal 0, prolateral 0-1-1-1-0, retrolateral es-
sentially the same, ventral O-lp-lr-0-0. Third leg : femur dorsal
as in first, prolateral and retrolateral only one near distal end,
ventral 0 but spinules in rows suggest reduced spines ; patella
dorsal 1-1, prolateral 0-1-0, retrolateral 0 ; tibia dorsal 1-0-0, pro-
lateral 0-1-0, retrolateral 0, ventral lp-lp-2(weak) ; metatarsus
dorsal 0-1-1-0, prolateral and retrolateral 0-1-0, ventral lp-lp-lp-2
(weak). Fourth leg: femur as in third except ventral one on
retromargin near distal end ; patella dorsal and prolateral as in
third, retrolateral 0-0-1 ; tibia dorsal as in third, prolateral
1-1-1-1, retrolateral 0-1-1, ventral lp-lp-lp-2 ; metatarsus dorsal
0-1-1-0-0, prolateral 0-1-0-1-1, retrolateral 0, ventral lp-0-0-1.
486 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Abdomen. 3.77 mm. long; 3.77 mm. wide at its widest place
about one-fifth from base ; with the usual round-triangular form.
Other observed features appear to be typical of the genus.
Epigynum. Quite distinctive ; apertures nearly three diameters
apart ; scape of moderate length and arises abruptly from base
and appears bifid at its tip ; the central part of base with a
strongly developed postero-ventral projection different from that
in any other known species (Figs. 106-107).
Color in alcohol. Carapace: pars thoracica mostly yellowish;
the two rows of dots which so frequently appear in these species
are present and in addition there is a brownish bar extending
forward and laterally parallel to the cephalic groove ; the latter
is speckled with brown. The sternum is yellowish with grayish
marginal spots covering the convexities. The legs are yellowish
with many brown dots, larger spots, bars, and rings. Abdomen :
the dorsal folium is moderately well outlined and extends for-
ward as a narrow extension ; near the middle of the dorsum there
is an oval purplish spot, probably an individual mark; the re-
mainder of the dorsum and dorsolateral regions is darkly colored
from a combination of brown pigment, subchitinous yellowish-
white granules in the form of dots, streaks, and larger irregular
spots ; the venter has a large quadrilateral area between the
genital groove and base of the spinnerets containing an elongate
oval white spot.
Type locality. The holotype is from Madden Dam Forest,
C. Z., July, 1950. There are no paratypes.
EUSTALA RUSTIC A sp. 110 V.
(Figures 108-113)
Male holotype. Total length 4.03 mm. Carapace 2.068 mm.
long ; 1.716 mm. wide opposite interval between second and third
coxae where it is widest ; .78 mm. tall and, therefore, about .45
as tall as wide ; gently inclined from PME to beginning of steep
posterior declivity; with well defined median longitudinal tho-
racic groove ; with spines confined to ocular area ; with a moder-
ately well developed coat of light colored procumbent hair.
Eyes. As usual, eight in two rows, all dark ; LE on moderately
prominent tubercles; viewed from above, posterior row strongly
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
487
recurved; viewed from in front, anterior row gently procurved,
measured by centers; central ocular quadrangle wider in front
than behind in ratio of 19 : 16, wider in front than long in ratio
of 19 : 16. Ratio of eyes AME : ALE : PME : PLE = 12 : 9 :
11 : 8. AME separated from one another and from ALE by their
diameter. PME separated from one another by slightly more
than their diameter, from PLE by a little less than three diam-
eters. Laterals separated from one another by one-third of
108
External Anatomy of Eustala
Figures 108-113, E. rustica
Fig. 108. Left second tibia of male from below.
Fig. 109. Distal half of right fourth femur from below.
Fig. 110. Tarsus of male palp, lateral view.
Fig. 111. Tarsus of male palp from distal end.
Fig. 112. Epigynum from below.
Fig. 113. Epigynum, lateral view.
488 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
the diameter of ALE. Height of clypeus equal to about the
diameter of AME.
Chelicerae. Basal segment .594 mm. long. Fang groove well
defined ; promargin with four teeth, second and fourth smaller ;
retromargin with three teeth. Otherwise as usual and typical of
the genos in all observed features.
Maxillae. As usual in the genus in all observed features in-
cluding the maxillary tooth used in opposition to the palpal
femoral ridge.
Lip. Only slightly wider than long; moderately grooved and
transversely striated in basal half; reaches to about the middle
of the maxillae. Sternal suture gently procurved.
Sternum. Scutiform ; longer than wide in ratio of about 5:4;
a narrow sclerite continues between fourth coxae which are
barely separated ; with the usual supply of long slender spinules.
Legs. 1243. Width of first patella at "knee" .2924 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .2491 mm.,
tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3.315
1.108
2.665
2.275
.990
10.350
2.
2.600
.812
1.885
1.950
.910
8.157
3.
1.540
.528
.814
.902
.550
4.334
4.
2.405
.858
1.254
1.755
.780
7.052
Palp
.418
.253
.132
.792
1.595
Ventral distal retrolateral hook on first coxa, dorsal tubercle
on first coxa, and prolateral proximal ridge and groove on second
femur all well developed.
Spines. First leg: femur dorsal and prolateral 0-0-1-1-1, retro-
lateral 0-0-0-1-1, ventral 0-0-1-0-1 on promargin and only one
on retromargin near distal end; patella dorsal l(weak)-l, pro-
lateral 0-1-0, retrolateral 0-1-1 ; tibia dorsal 0-1-0-1-1-0, prolateral
0-1-0-1-0, retrolateral essentially the same, ventral 2-2-2-lp-2 with
some irregularity ; metatarsus dorsal 0-1-0-1-0-0, prolateral 0-1-0,
retrolateral 0-1-1-0, ventral lr-2-0-0. Second leg: femur dorsal
as in first, prolateral and retrolateral 0-0-0-1-1, ventral appar-
ently only one near middle on retromargin but lacking on right ;
patella dorsal as in first, prolateral and retrolateral 0-1-1 ; tibia
dorsal 0-1-1-1-0, prolateral 0-1-1-0, retrolateral 0-1-1-1, ventral
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 489
2-lp-lp-lp-2 (Fig. 108) ; metatarsus dorsal 0-1-0-1-0-0, prolateral
0, retrolateral 0-1-0-1-0, ventral 0-2-lp-0. Third leg : femur dorsal
as in first, prolateral and retrolateral only one near distal end,
ventral three on promargin all in distal half and one on retro-
margin near distal end; patella dorsal and prolateral as in first,
retrolateral 0-1-0 ; tihia dorsal 0-1-0-0, prolateral and retrolateral
0-1-1, ventral 0-lp-0-2 ; metatarsus dorsal 0-1-1-0, prolateral 0-1-1,
retrolateral 0, ventral 2?-lp-lp-lp. Fourth leg: femur dorsal as
in first, prolateral 0-0-0-1-1, retrolateral only one near distal end,
ventral two on promargin and three on retromargin (four on
retromargin of left femur), all in distal third of segment (Fig.
109) ; patella as in third; tibia dorsal 1-1-1-0, prolateral 0-1-1-1,
retrolateral 0-1-1, ventral 2-lp-lp-2; metatarsus dorsal 0-1-0-0,
prolateral 0-1-1-1, retrolateral 0-1-1-0, ventral O-lp-0-0. Ventral
distal retrolateral hook and dorsal tubercle on first coxa well
developed ; proximal prolateral groove and ridge on second femur
well defined.
Palp. Complicated ; basal femoral ventral ridge, patella, and
tibia all typical of the genus. Tarsus : basal tarsal apophysis as
usual a somewhat distorted arrow-head in shape ; the clavis is
moderately robust, not notably excavated at its base but with a
groove and sharp ridge ; the uncus is a rather slender long
pointed hook with a rounded shoulder at its base ; the conductor
is of moderate size, with a ventral depression for the reception
of the uncus and a moderately deep depression on its anterior
surface where it is finely setose ; the vesicle is of moderate size
and in its typical position ; the embolus is robust, grooved into a
trough, its free part is short and accompanied by a membrane ;
the terminal laminae are not strikingly differentiated but there
is a thin chitinous extension at the base of the clavis (Figs. 110-
111).
Color in alcohol. Both known male specimens of this species
are light colored. The carapace is bright yellowish with a few
pale brownish dots ; one pair of these occurs at the middle of
the thoracic groove ; another pair of larger dots lies at the base
of the pars cephalica and a third pair about halfway between
PME and the anterior end of the thoracic groove. The sternum
is yellowish with gray flecks around the margin. The legs are
yellowish with pale brownish bars, rings, and spots. Abdomen :
490 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
a well developed dorsal folium exists but elsewhere dorsally and
dorsolaterally this part of the body is white from the accumula-
tion of many subchitinous granules ; there is a small central white
spot with a dark irregular spot on each side of this in the area
between the genital groove and the base of the spinnerets. The
paratype agrees well with the holotype except that there is more
color on the carapace.
Although certainty is lacking, I think the evidence is suf-
ficient to allow the pairing of the females described below with
males already described as E. rustica sp. nov. The specimen
selected as the allotype is somewhat distorted by preservation
but is in good condition otherwise.
Female allotype. Total length 5.72 mm. Carapace 2.275 mm.
long; 1.82 mm. wide opposite interval between second and third
coxae where it is widest; .975 mm. tall and, therefore, about .54
as tall as wide ; steep posterior declivity somewhat more pro-
nounced than in male.
Eyes. Central ocular quadrangle only slightly wider in front
than behind; only slightly wider in front than long. Ratio of
eyes AME : ALE : PME : PLE = 11 : 8 : 11 : 7.5. AME sep-
arated from one another by about one and one-quarter times
their diameter, from ALE by nearly twice their diameter. PME
separated from one another by slightly more than their diameter,
from PLE by three times their diameter. Laterals separated
from one another by slightly more than the radius of ALE.
Height of clypeus equal to slightly less than the diameter of
AME.
Chelicerae. Basal segment .758 mm. long. Otherwise essen-
tially as in male.
Maxillae. Apparently as in male in all essential features.
Lip. Wider than long in ratio of 4 : 3. Otherwise essentially
as in male.
Sternum. Longer than wide in ratio of 40 : 37. The spinules
show more clearly than in male ; these consist of many short
spinules and longer and more robust ones situated as follows : at
the posterior end there is a group of four; opposite each of the
coxae except the fourth there is a pair ; in addition to these four
others make a nearly transverse row between the first coxae.
Similar spinules were probably present in the male before
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 491
handling and agitation in the vials. Otherwise essentially as
in the male.
Legs. 1243. "Width of first patella at "knee" .3682 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .3249
mm., tibial index of fourth leg 13.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
3.120
1.170
2.535
2.080
.942
9.847
2.
2.567
1.040
2.080
1.787
.845
8.319
3.
1.495
.660
.858
.942
.617
4.572
4.
2.372
.845
1.690
1.657
.780
7.344
Spines. First leg: femur dorsal 0-1-0-1, prolateral 0-0-1-1-1,
retrolateral 0-0-0-1-1, ventral 0; patella dorsal l(weak)-l, pro-
lateral 0-1-0, retrolateral 0-1-1 ; tibia dorsal 0-1-0-1-1-0, prolateral
and retrolateral 0-1-0-1-0, ventral 2-lp-lp-0-lr ; metatarsus dor-
sal 0-1-0-1-0-0, prolateral 0, retrolateral 0-1-0-1-0, ventral 0-2-lp-0.
Second leg: femur as in first except prolateral 0-0-0-1-1; patella
as in first ; tibia as in first except ventral 2-lp-0-2 ; metatarsus
as in first except ventral lr-2-lp-0-0. Third leg : femur dorsal as in
first, prolateral and retrolateral only one near distal end, ventral
spinules probably not to be regarded as spines; patella appar-
ently only dorsal 1-0, tibia dorsal 1-0-0, prolateral 0, retrolateral
0-0-1, ventral lr-lr-2; metatarsus dorsal 0-1-1-0, prolateral and
retrolateral 0-1-0, ventral lp-lp-lp-lp. Fourth leg: femur as in
third except ventral one on promargin near distal end; patella
dorsal 1-0, prolateral 0-1 ; tibia dorsal and prolateral 0-1-0-1-0,
retrolateral 0-1-0, ventral lp-0-2 ; metatarsus dorsal and pro-
lateral 0-1-0-1-0, retrolateral 0, ventral 0-0-1. Palp : with fewer
spines and spinules than is usual in the genus.
Abdomen. 3.77 mm. long; 3.445 mm. wide about one-fourth
from base. Apparently with slightly indicated shoulder humps.
Otherwise essentially as in male.
Epigynum. Base broad; scape of moderate length and gradu-
ally narrowed to tip. Apertures small and about two diameters
apart. The central conspicuous part of the base relatively nar-
row and longer than usual. Tip of scape turned dorsally (Figs.
112-113). Figure 113 is from the paratype because the base is
more completely expanded and shows in profile to much better
advantage.
492 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Color in alcohol. The female allotype is much more deeply
colored than the male holotype or the single female paratype.
The carapace lacks the dots but nearly the whole pars cephalica
is brown; there is also a pair of brownish bands each reaching
out from the thoracic groove a little posterior to the pars
cephalica. Abdomen : the dorsal folium is well developed ; there
is a pair of small white dorsal dots near the base ; the numerous
white granules so conspicuous in the males are nearly all obscured
in the female allotype ; the venter is like that of the male except
that there is more of the dark brown color.
Type locality. The holotype male and the allotype female are
from El Valle, R. P., July, 1936. Paratypes of both sexes are
in the collection from the same locality and collected at the same
time.
EUSTALA SCITULA Sp. 110V.
(Figures 114-117)
Male holotype. Total length 5.525 mm. Carapace 3.055 mm.
long ; 2.535 mm. wide opposite interval between second and third
coxae where it is widest; 1 mm. tall opposite third coxae and,
therefore, about .4 as tall as wide ; rises considerably but gradu-
ally to beginning of steep posterior declivity ; with well developed
median longitudinal thoracic groove; spines confined to ocular
area.
Eyes. As usual, eight in two rows, all dark; LE tubercles
less prominent than in many species of the genus; viewed from
above, posterior row strongly recurved; viewed from in front,
anterior row gently procurved, measured by centers ; central
ocular quadrangle wider in front than behind in ratio of 42 : 33 ;
wider in front than long in ratio of 21 : 19. Ratio of eyes
AME : ALE : PME : PLE = 13 : 8.5 : 11 : 8.5. AME separated
from one another by about five-thirds of their diameter, from
ALE by a little more than twice their diameter. PME separated
from one another by a little more than their diameter, from
PLE by a little less than four times their diameter. Laterals
separated from one another by a little more than their radius.
Height of the clypeus equal to a little more than the diameter
of AME.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 493
Chelicerae. Basal segment .780 mm. long. Fang groove well
defined; promargin with four teeth, second and fourth smaller
as usual ; retromargin with three teeth but two and four have
been found among the paratypes which were examined to avoid
injury to the holotype ; Aveaker than usual in males of the genus.
Maxillae. In general, as usually found in the genus, including
the lateral tubercle or tooth used in opposition to the palpal
femoral ridge.
Lip. Only slightly wider than long ; reaches to about the middle
of the maxillae. Basal half moderately grooved. Sternal suture
definitely procurved.
Sternum. Scutif orm ; longer than wide in ratio of about 5:4;
a narrow sclerite continues between fourth coxae which are
barely separated; rather deeply scalloped opposite all coxae;
probably with few bristles or spinules in life.
Legs. 1243. Width of first patella at "knee" .444 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .4115
mm., tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.680 1.365 3.900 3.250 1.300 14.49*5
2. 3.445 1.235 2.535 2.730 1.170 11.115
3. 2.080 .780 1.105 1.105 .650 5.720
4. 3.315 1.300 2.210 2.470 1.050 10.345
Palp .466 .325 .184 .940 1.915
First coxae with the usual well developed ventral distal retro-
lateral hook and the dorsal tubercle ; prolateral groove and ridge
on second femur also well developed.
Spines. First leg : femur dorsal 0-0-1-1-1, prolateral left
0-0-1-1-1-1-1, right 0-0-1-2-0-1, retrolateral 0-0-1-1-1, ventral with
several irregularities not recorded ; patella dorsal 0-1, prolateral
and retrolateral 0-1-1; tibia dorsal 0-1-0-1-1-0, prolateral 0-1-0-
1-1, retrolateral 0-0-1-1-0, ventral 2-2-2-2-2; metatarsus dorsal
0-1-0-1-0-0, prolateral 0, retrolateral 0-0-1-1-0, ventral 2-lp-lr-lp-0.
Second leg : femur dorsal 0-1-1-1, prolateral 0-0-1-1-1, retrolateral
0-0-0-1-1, ventral four on retromargin and apparently only one
on promargin near distal end; patella as in first; tibia dorsal
essentially as in first, prolateral 1-1-1-0, retrolateral 0-1-1-1,
ventral 2-lp-lp-lp-2 (Fig. 114) ; metatarsus dorsal 0-1-0, pro-
494
BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY
lateral 0-1-1-0, retrolateral the same except for minor differences
in position, ventral lr-lr-0-0. Third leg: femur dorsal 0-0-1-1-1,
prolateral and retrolateral 0-0-0-1-1, ventral three on promargin
and two on retromargin; patella dorsal l(weak)-l, prolateral
and retrolateral 0-1-0 ; tibia dorsal 1-0-1-0, prolateral and retro-
lateral 0-1-1, ventral lp-lp-lp-2 (second lacking on right) ; meta-
tarsus dorsal 0-1-0, prolateral 0-1-1, retrolateral 0-1-0, ventral
1-1-1-1. Fourth leg: femur dorsal and prolateral as in third,
retrolateral only one near distal end, ventral four on promargin
and five on retromargin (Fig. 115), all in distal three-fourths of
116
115
Fig. 114.
Fig. 115.
Fig. 116.
Fig. 117.
External Anatomy of Eustala
Figures 114-117, E. scitula
Eight second tibia from below.
Left fourth femur from below.
Tarsus of male palp, lateral view.
Tarsus of male palp from distal end.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 495
segment; patella as in third; tibia dorsal 1-1-1-0, prolateral
1-1-1-1, retrolateral 0-1-1, ventral 2-lp-lp-2 ; metatarsus dorsal
1-0-1-0, prolateral and retrolateral 0-1-1-0, ventral 0-lp-lp-l
(weak).
Palp. Complicated; basal femoral tubercle or ridge opposing
the maxillary tooth well developed; patella short, with the
usual weak dorsal proximal spine or spinule and the long slender
distal dorsal spine ; the tibia is also short and distinctly trilobed,
the chitinous ventral rim of the articular lobe well developed ; the
femur has a well developed dorsal distal spine. Tarsus : the basal
tarsal apophysis has the typical distorted arrowhead shape ; the
clavis is fairly robust and has a small shallow concave surface
at its base ; the uncus is a robust spine fitting into a very narrow
depression in the conductor ; the conductor is a massive structure
with a narrow longitudinal groove on its ventral surface and a
fairly deep depression and related surfaces on its distal end
which is extensively setose ; the vesicle is large and occupies the
typical position; the embolus is fairly long and moderately
slender; the terminal laminae are much wrinkled and strongly
chitinized (Figs. 116-117).
Abdomen. Total length 3.25 mm.; 2.405 mm. wide; with the
usual round-triangular form ; with the usual supply of long
slender dorsal and dorsolateral spinules ; other observed features
typical of the genus.
Color in alcohol. The general color of the carapace is yellow-
ish ; behind PME there is a pair of pale brownish spots somewhat
elongated; the remainder of the dorsal part of the carapace is
covered with an irregular brownish spot; the dots, so commonly
present, do not show in the holotype and very seldom among
the paratypes. The sternum is yellowish irregularly margined
in gray. Legs : generally yellowish but with anterior femora
brown in the distal three-fourths ; the second and fourth femora
are essentially like the first; all segments distal to the patellae
are banded with brown. Abdomen: the dorsal folium is well
developed but differs greatly among the paratypes; the most
persistent features appear to be an oval white spot set into the
middle of the usual dark ventral area between the genital groove
and base of the spinnerets, but this may be almost circular in
shape in certain paratypes.
496 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY
Type locality. The holotype is from Barro Colorado Island,
C. Z., July, 1950. Male paratypes have been collected from the
following localities : Barro Colorado Island, C. Z., June-August,
1936; March, 1936 (Gertsch) ; August, 1939; July, 1950; Canal
Zone Forest Reserve, C. Z., August, 1936 and July, 1939 ; Sum-
mit, C. Z., July-August, 1950. One specimen from near Hidalgo,
Mexico, July, 1936 (Davis) and another from Cuyutlan, Colima,
Mexico, January, 1943 (F. Bonet) are somewhat hesitantly as-
signed to the species.
Eustala scutigera (0. P. Cambridge)
(Figures 118-123)
Epeira scutigera O. P. Cambridge, 1898
E. nava O. P. Cambridge, 1899
Eustala scutigera F. P. Cambridge, 1904
Epeira scutigera Banks, 1909
Eustala scutigera Petrunkevitch, 1911
E. s. Petrunkevitch, 1925
Considerable doubt has hitherto existed as to the identification
of this species. The figures published by the Cambridges are not
as revealing and definite as desired. The male from the British
Museum has a clearly lobed conductor as suggested by F. P.
Cambridge's figure. The chief difficulty now arises from the
fact that another male from the British Museum labelled E.
guttata also has an identically lobed conductor and other features
like this species. The conclusion that the Cambridges were, at
least in this instance, using mixed material seems inescapable.
It is also difficult to separate females from those of E. vegeta
(Keyserling). About the only way to separate them is by using
the features of the epigynum; in E. vegeta the apertures are
further apart than in E. scutigera and there are differences in
the way in which the scape arises from the base.
Male hypotype. Total length 3.965 mm. With the abdomen
round-triangular as usual. Central ocular quadrangle wider in
front than behind in ratio of 34 : 29, slightly wider in front
than long. Ratio of eyes AME : ALE : PME : PLE — 12 :
8.5 : 9.5 : 8.5. AME separated from one another by seven-sixths
of their diameter, from ALE by four-thirds of their diameter.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
497
PME separated from one another by slightly more than their
diameter, from PLE by about three times their diameter. Later-
als separated from one another by about one-third of their
diameter. A pair of long slender spines arises between AME
and PME ; and another similar spine arises just behind PLE.
Height of clypeus equal to the diameter of AME. Promargin of
External Anatomy of Eustala
Figures 118-123, E. scutigera
Fig. 118. Left second tibia from below.
Fig. 119. Left fourth femur from below.
Fig. 120. Male palpal tarsus, lateral view.
Fig. 121. Male palpal tarsus from distal end.
Fig. 122. Epigynum from below.
Fig. 123. Epigynum, a more posterior view.
1.
3.380
1.072
2.
2.730
.950
3.
1.430
.520
4.
2.275
.910
Palp
.433
.173
2.145
.877
10.009
1.852
.845
8.327
.812
.520
4.192
1.560
.715
7.020
.770
1.538
498 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
fang groove with four teeth ; retromargin with three. The sec-
ondary sexual characters on the maxillae, first coxae, and second
femora appear as usual.
Legs. 1243. Width of first patella at "knee" .2924 mm., tibial
index of first leg 8. Width of fourth patella at "knee" .2383 mm.,
tibial index of fourth leg 9.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
2.535
1.950
.910
1.560
.162
The important spination of the second tibia is shown in Figure
118. The first femur appears to have no ventral spines; the sec-
ond femur has a short robust spine on the retromargin a little
distal to the middle and a pair of weak spines near the distal
end; the third femur has three fairly robust ventral spines on
the promargin; the fourth femur has a double series of ventral
spines with four robust spines on each margin (Fig. 119). Con-
siderable variation in spination has been noted among my speci-
mens.
Palp. It seems reasonably certain from F. P. Cambridge's
figure and the specimens from the British Museum that this is
the species named Epeira scutigera by the elder Cambridge.
Features of femora, patellae, and tibiae apparently typical of the
genus. Tarsus: basal tarsal apophysis a twisted arrow-shape;
clavis moderately robust, with a long basal articular surface
contiguous to the conductor but not excavated; the uncus is a
robust hook, broad at its base and with its tip somewhat recurved ;
the conductor is hollowed out for the reception of the uncus and
provided with a distinct setose lobe; the vesicle is moderately
large; the embolus is relatively long and nearly straight along
its distal border from the basal elbow to the tip ; the terminal
laminae show a very conspicuous elevation and together with the
conductor show several distinctive surfaces (Figs. 120-121).
Degrees of chitinization and folding of the parts in the resting
condition alter to some extent the appearance of some of these
parts and make it difficult to place certain individuals in the
collection.
1.
2.990
2.
2.405
3.
1.365
4.
2.145
.747
8.774
.747
7.701
.585
4.002
.650
6.435
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 499
Female hypotype. Total length 4.68 mm. With the same
general form as in the male.
Legs. 1243. Width of first patella at "knee" .3249 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .2816
mm., tibial index of fourth leg 12.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.105 2.080 1.852
1.007 1.690 1.852
.590 .715 .747
.975 1.365 1.300
Ventral femoral spines appear to be rather uniformly lacking
in females but may occasionally occur.
Epigynum (Figs. 122-123). The base is massive with the
scape abruptly narrowed in its terminal third; apertures more
than their width from the lateral side of the epigynum and about
three diameters apart ; spermathecae one diameter apart ; closely
resembles that of E. vegeta.
Color in alcohol. As usual the color pattern is extremely vari-
able. In both sexes there are two transverse rows of small brown-
ish dots across the carapace ; the folium is clear in both hypotypes
but may be lacking in some specimens ; in both hypotypes the
venter has a somewhat elongated central white spot in the mid-
dle of a dark area which is margined by incurved white marks;
the central white spot appears to be more persistent than the
other marks; the sternum is usually yellowish with marginal
brown spots opposite the coxae.
Type locality. Male hypotype from Barro Colorado Island,
C. Z., July, 1936 ; the female hypotype is from the same locality,
August, 1939. Males and females from Mexico: Cerro Azul, Vera
Cruz, March, 1945 (E. K. Waering) ; Mapastepec, Chiapas, June-
July, 1940 (H. Wagner) ; Teotitlan, Oaxaca, Sept., 1944 (H.
Wagner) ; Papanto, Vera Cruz, October, 1947 (H. Wagner).
Guatemala : Patulul, January, 1912 (W. M. Wheeler) ; Antigua,
August, 1947 (C. & P. Vaurie). Nicaragua: Granada (C. F.
Baker), Honduras: Subirana, Yoro, (Stadelman). Panama:
Barro Colorado Island, C. Z., June-August, 1936 ; July-August,
1939; June-July, 1950; El Valle, July, 1936; Porto Bello, Au-
gust, 1936 ; Ft. Sherman, C. Z., August, 1939 ; Boquete, July,
1939 and August, 1950.
500 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
EUSTALA SEDULA Sp. IIOV.
(Figures 124-126)
Female holotype. Total length 6.89 mm. Carapace 2.925 mm.
long; 2.6 mm. wide opposite interval between second and third
coxae where it is widest; .975 mm. tall and, therefore, about
.38 as tall as wide; median longitudinal thoracic groove well
defined and typical of the genus; with well developed coat of
yellowish white procumbent hair and numerous spinules es-
pecially on the pars cephalica.
Eyes. Eight in two rows, all dark as usual ; viewed from above,
posterior row definitely recurved ; viewed from in front, anterior
row definitely procurved; central ocular quadrangle as wide
behind as in front, wider than long in ratio of 11 : 10. Ratio of
eyes AME : ALE : PME : PLE == 12 : 9 : 13.5 : 10.5. AME
separated from one another by seven-fourths of their diameter,
from ALE by slightly more than two and one-half times their
diameter. PME separated from one another by a little less than
one and one-half times their diameter, from PLE by a little less
than three and three-fourths times their diameter. Laterals
separated from one another by two-thirds of the diameter of
PLE. Height of clypeus equal to the diameter of AME.
Chelicerae. Basal segment 1.105 mm. long; fang groove well
defined and with the usual complement of teeth on both margins ;
other observed features typical of the genus.
Maxillae. Appear to be completely typical of the genus in
all observed features.
Lip. Wider than long in ratio of about 23 : 19 ; gently grooved
and cross striated in proximal third. Sternal suture definitely
procurved ; with marked anterolateral sternal tubercles at lateral
ends of suture.
Sternum. Scutiform ; longer than wide in ratio of 29 : 25 ;
with a bluntly bifurcated posterior end which is not continued
between fourth coxae which are separated by about one-quarter
of their width ; only moderately convex opposite the coxae ; with
a moderately well developed supply of long and short bristles and
with a row of six spinules between first coxae.
Legs. 1243. Width of first patella at "knee" .4657 mm., tibial
index of first leg 10. Width of fourth patella at "knee" .4332
mm., tibial index of fourth leg 13.
1.
3.510
2.
3.315
3.
2.275
4.
2.990
1.170
11.862
1.040
11.017
.780
6.450
.910
9.490
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 501
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.495 3.022 2.665
1.495 2.567 2.600
.&25 1.17H 1.300
L.365 2.01 _. 2.210
Spines. First leg : femur dorsal 0-0-1-0-1, on right and 0-0-0-0-1
on left, prolateral 0-0-1-1-1 on right and 0-1-1-1-1 on left, retro-
lateral 0-0-0-1-1, ventral only one on promargin and retromargin
near distal end; patella dorsal l(weak)-l, prolateral and retro-
lateral 0-1-1 ; tibia dorsal 0-1-1-1-0, prolateral 0-1-1-0-0-1-1-1 on
left and 0-1-0-1-1 on right, ventral 2-lp-lp-0-2 ; metatarsus dorsal
0-1-1-0-0, prolateral 0, retrolateral 0-1-0-0, ventral 2-2-2-0. Sec-
ond leg : femur dorsal 0-0-1-1-1 on right and 0-0-1-0-1 on left,
prolateral 0-0-1-1-1, retrolateral 0-0-0-1-1 on right and only one
near distal end on left, ventral 0 ; patella essentially as in first ;
tibia dorsal as in first, prolateral and retrolateral 0-1-0-1-1, ventral
2-lp-lp-lr; metatarsus dorsal 0-1-1-0, prolateral 0-1-1-0, retro-
lateral 0-1-0-1-0, ventral 2-2-lp-0. Third leg : femur dorsal 0-1-1-1,
prolateral and retrolateral only one near distal end, ventral 0 ;
patella dorsal 1-1, prolateral 0-1-0, retrolateral 0; tibia dorsal
1-0-1-0, prolateral 0-1-0, retrolateral 0-0-1, ventral lp-lp-2 ; meta-
tarsus dorsal 0-1-0, prolateral 0-1-1, retrolateral 0, ventral lp-0-
1-1. Fourth leg: femur essentially as in third except ventral one
on retromargin near distal end ; patella as in third except retro-
lateral 0-0-1 ; tibia dorsal 0-1-1-1-0, prolateral 1-1-1-1, retrolateral
0-1-0, ventral lp-lp-2; metatarsus dorsal 1-1-0, prolateral 0-1-0-
1-1, retrolateral 0-1-1-0, ventral 0-lp-lp-lp.
Abdomen. 4.03 mm. long; 3.51 mm. wide between possible sup-
pressed shoulder humps nearly one-third of length from base ;
with the usual round-triangular form; also with just the sugges-
tion of a dorso ventral bifid condition similar to that found in E.
bifiida; other observed features appear to be normal to the
genus.
Epigynum. The scape is very long as compared to the width
of the base; the central part of the base is very prominent; the
apertures are very close together ; the internal tubules appear
to present a rather characteristic pattern (Figs. 124-126).
Color in alcohol. The carapace is generally yellowish ; the
502 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
pars eephaliea has a central darker patch behind the PME and a
pair of similar dorsal patches at the base of this region ; there
is also an irregular whitish spot halfway between PME and the
thoracic groove made by an accumulation of white subchitinous
granules. The legs are, as usual, yellowish with brown rings and
spots. Abdomen : isolated parts of the dorsal folium remain in
the holotype but the dorsum and lateral sides are largely yellow-
ish-white from an accumulation of subchitinous granules ; the
venter has a large brownish, somewhat quadrilateral area, be-
tween the genital groove and the base of the spinnerets containing
a rounded central white spot. In some paratypes the carapace
has a large irregular brownish spot on the pars eephaliea, a well
developed dorsal folium on the abdomen and an elongated white
spot in the center of the dark area on the venter.
Type locality. The holotype is from Barro Colorado Island,
C. Z., July, 1939. Several paratype females have been taken
in the same locality as follows: June, 1924 (Banks) ; June, 1934;
June-July, 1936; July-August, 1939; March, 1946 (Schneirla) ;
July-August, 1950.
Eustala semifoliata (0. P. Cambridge)
(Figure 127)
Epeira semifoliata 0. P. Cambridge, 1899
Eustala semifoliata F. P. Cambridge, 1904
Eustala semifoliata Petrunkevitch, 1911
Female hypotype. Total length 11.7 mm. There are several
distinctive features not sufficiently emphasized in the original
or later descriptions. The cephalic part of the carapace is prom-
inently raised ; the ME are raised up on a strongly developed
ocular cone ; the carapace has a heavy coat of white hairs ; there
is a pair of well developed abdominal shoulder humps ; the leg
spines are more robust than ordinarily found in females. The
ME of the hypotype are defective and, hence, the data on eyes
are taken from another specimen. The central ocular quadrangle is
wider in front than behind in ratio of 8 : 7, only slightly wider
in front than long. Ratio of eyes AME : ALE : PME : PLE =
9 : 6.5 : 8 : 6.5. AME separated from one another by about one
and one-half times their diameter, from ALE by four times their
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA
503
External Anatomy of Eustala
Figures 124-126, E. sedula
Figure 127, E. semifoliata
Figures 128-130, E. tantula
Fig. 124. Epigynum from below.
Fig. 125. Epigynum, lateral view.
Fig. 126. Epigynum, a posterior view.
Fig. 127. Epigynum from below.
Fig. 128. Left second tibia from below.
Fig. 129. Male palpal tarsus, lateral view.
Fig. 130. Male palpal tarsus from distal end.
504 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
diameter. PME separated from one another by about one and
one-half times their diameter, from PLE by about five and one-
half times their diameter. Laterals separated from one another
by slightly more than their radius. Height of the clypeus equal
to two and two-thirds of the diameter of AME. Promargin of
the fang groove with four teeth, the fourth the smallest; retro-
margin with three teeth, all nearly equal in size and fairly
robust.
Legs. 1243. Width of first patella at "knee" .7906 mm., tibial
index of first leg 12. Width of fourth patella at "knee" .8123
mm.,
tibial mdei
: oi iourth
leg 13.
Femora
Patellae
Tibiae
Metatarsi
Tarsi
Totals
(All measurements in
millimeters)
1.
5.525
2.470
4.160
4.420
1.625
18.200
2.
5.460
2.340
4.062
4.420
1.625
17.907
3.
3.o75
1.430
2.080
2.275
1.235
10.595
4.
5.785
2.405
3.705
4.030
1.430
17.355
Ventral spines on femora as follows : first femur with three on
promargin and apparently only one on retromargin near distal
end ; second femur only one on promargin near distal end ; third
femur apparently none ; fourth femur with one on each margin
near distal end.
Epigynum (Fig. 127). With a more or less distinctive pattern
of tubules, apertures, and striations ; best shown in a figure. The
base has not been seen inflated but it probably exists as in E.
bifida.
Color in alcohol. The general coloring of the two specimens
available for study together with the single specimen from
the British Museum is quite variable as usual in the genus.
Certain features, however, appear to be quite reliable as aids
to identification. These are : a pair of dark dots in front of
the median thoracic groove; six dark dots in a somewhat pro-
curved transverse row across the anterior end of the thoracic
groove ; a partial ring of white spots more or less surrounding
the bases of the spinnerets; a pair of white spots transversely
placed in a black area between the genital groove and base of
spinnerets; the whitish sternum is bordered with brown.
Type locality. The female hypotype and another female speci-
men are from Barro Colorado Island, C. Z., August, 1939 and
June, 1936, respectively.
CHICKERING : GENUS ETJSTALA IN CENTRAL AMERICA 505
EUSTALA TANTULA Sp. nOV.
(Figures 128-130)
Male holotype. Total length 3.315 mm. Carapace 1.755 mm.
long; 1.43 mm. wide opposite intervals between second and third
coxae where it is widest ; .615 mm. tall and, therefore, about
.43 as tall as wide; only gently raised from PME to beginning
of steep posterior declivity which passes abruptly to the posterior
margin; with a fairly well defined median longitudinal thoracic
groove; with two pairs of spinules at anterior end of thoracic
groove ; with numerous slender spines and spinules in ocular
area.
Eyes. Eight in two rows, all dark; LE on moderately prom-
inent tubercles; viewed from above, posterior row moderately
recurved ; viewed from in front, anterior row straight or slightly
procurved, measured by centers ; central ocular quadrangle wider
in front than behind in ratio of 18 : 13, wider in front than
long in ratio of 12 : 11. Ratio of eyes AME : ALE : PME :
PLE = 12 : 8.5 : 9 : 8. AME separated from one another by
slightly more than their diameter, from ALE by about two-
thirds of their diameter. PME separated from one another by
seven-ninths of their diameter, from PLE by about two and one-
half times their diameter. Laterals separated from one another
by slightly less than the radius of ALE. Height of clypeus equal
to the diameter of AME.
Chelicerae. Essentially parallel; with moderately well de-
veloped basal boss; basal segment .574 mm. long. Fang groove
well defined ; promargin with four teeth, retromargin with three
small teeth (recorded from a paratype to avoid injury to holo-
type).
Maxillae. Parallel; convex along retrolateral surface; with a
strongly developed serrula; maxillary tooth as usual to oppose
ridge on palpal femur.
Lip. Wider than long in ratio of 13 : 9 ; moderately pointed
at distal end; reaches only about two-fifths of the length of the
maxillae. Sternal suture gently procurved.
Sternum. Scutif orm ; as wide as long ; a sclerite continues be-
tween fourth coxae which are separated by a little more than
two-fifths of their width; with numerous long slender spinules
506 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
of which the largest eight make a transverse row across the
anterior fourth.
Legs. 1243. Width of first patella at "knee" .2383 mm., tibial
index of first leg 7. Width of fourth patella at "knee" .2058 mm.,
tibial index of fourth leg 11.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1 2.860 .780 2.535 2.156 .836 9.167
2, 1.950 .572 1.625 1.694 .660 6.501
3'. 1.202 .462 .704 .792 .440 3.600
4' 2.015 .585 1.267 1.592 .650 6.109
Palp .396 .184 .130 .594 1.304
First coxa with the usual distal retrolateral ventral hook;
dorsal tubercle on first coxa poorly developed. The prolateral
groove and ridge on second femur well developed.
Spines. First leg: femur dorsal and prolateral 0-1-1-0-1-1,
retrolateral 0-0-0-1-1 ; ventral 0-2-2-0-2 ; patella dorsal l(weak)-l,
prolateral 0-1-0, retrolateral 0-0-1 ; tibia dorsal 0-1-0-1-0-1-0, pro-
lateral 0-1-0-1-0, retrolateral 0-0-1-0-1-0, ventral 2-0-2 ( irregular )-
0-lr; metatarsus dorsal 0-1-0-1-0-0 prolateral 0, retrolateral
0-1-0-1-0, ventral 0-2-0-0. Second leg: femur dorsal 0-1-1-1-0-1,
prolateral apparently 0, retrolateral only one near distal end,
ventral three or four along retromargin ; patella as in first ; tibia
dorsal and prolateral as in first, retrolateral 0-1-0-1-1-1, ventral
0-0-lr (Fig. 128) ; metatarsus appears to be nearly as in first.
Third leg: femur dorsal 1-0-1, prolateral and retrolateral only
one near distal end, ventral 1-1-0-0-0; patella only dorsal 0-1;
tibia dorsal 1-0-1-0, prolateral 0, retrolateral 0-0-1, ventral 0-lp-2;
metatarsus dorsal 0-1-0-0, prolateral and retrolateral 0-1-0-0,
ventral 0-1-1. Fourth leg: femur dorsal 0-1-0-1, prolateral and
retrolateral only one near distal end, ventral 0; patella as in
first; tibia dorsal 0-1-0-0-1-0, prolateral 0-1-0-1-0, retrolateral
0-1-1-1-1, ventral 2-0-lp-2 ; metatarsus dorsal 0-1-0-0, prolateral
0-1-1-0, retrolateral 0-1-0-1, ventral 0. Considerable variation of
spination has been noted among paratypes and even from left
to right in the holotype.
Palp. Complicated ; basal femoral tubercle or ridge moderately
well developed; patella and tibia short and essentially typical
of the genus ; the patella has a weak proximal and a long slender
CHICKERING: GENUS BUSTALA IN CENTRAL AMERICA 507
distal spine on the dorsal side as usual. Tarsus : basal tarsal
apophysis geniculate near its distal end where the arrow-head
is slender ; the clavis is moderately robust, deeply excavate at its
base where it is broad and strongly geniculate; the uncus is a
long slender and somewhat flattened spine ; the conductor,
largely hidden in ventral view, has a thin transverse process
more or less parallel to the uncus and a broad, relatively massive
base which is sparsely setose only along a part of its medial
border; the massive base of the conductor is only seen well in
distal view ; the vesicle is very prominent and spirally twisted
in a very striking manner ; the embolus is apparently hidden by
the over-developed vesicle ; the terminal laminae have a dis-
tinctive pattern the most prominent feature of which is the
relatively large quadrilateral body contiguous to the conductor
(Figs. 129-130).
Abdomen. Total length 1.852 mm. ; longer than wide in ratio
of 4 : 3 ; with numerous long slender dorsal and dorsolateral
spinules; other features as usual in the genus.
Color in alcohol. Carapace yellowish with faintly outlined
dark dots along base of pars cephalica and a single large dark
spot on each side of lateral part of pars cephalica and passing
dorsally behind PME. The legs are yellowish with numerous
dark spots and rings. The sternum is yellowish with dusky
flecks concentrated into dark spots opposite all coxae except
the fourth. Abdomen : there is a poorly outlined grayish dorsal
folium ; on the venter between the genital groove and base of
spinnerets there is a light spot containing a dark colored cross
the central part of which extends to a narrow dark bar which
is a part of a broken ring around the spinnerets and anal
tubercle. As usual, no great reliance can be placed upon the
color pattern as an aid to identification of the species. The para-
types show many variations in color.
Type locality. The holotype is from Barro Colorado Island,
C. Z., August, 1939. Sixteen paratype males have been found
from the following localities: Barro Colorado Island, C. Z., July,
1936 ; Ft. Davis, C. Z., July, 1936 ; Canal Zone Forest Reserve,
C. Z., July and August, 1939 ; Ft. Sherman, C. Z., August, 1939 ;
Madden Dam Forest, C. Z., August, 1939; near Chiva, C. Z.,
August, 1950; El Valle, R. P., July, 1936; Boquete, R. P., July,
1939.
508 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
EUSTALA TUMTDA Sp. 110V.
(Figures 131-132)
Female holotype. Total length 6.045 mm. Carapace 2.73 mm.
long, 2.145 mm. wide opposite second coxae where it is widest;
1.04 mm. tall in cephalic region where it is tallest and, therefore,
about .48 as tall as wide; with median longitudinal thoracic
groove well defined and with a pair of short black spines at its
anterior end and another pair of short, light colored spines a
little further forward; with a moderately well developed coat
of whitish procumbent hair; pars cephalica drawn out into a
conspicuous cone upon which both pairs of median eyes are
placed in a very distinctive position (Fig. 131).
Eyes. Eight, probably to be considered as being placed in two
rows in spite of their unusual position on the cephalic cone,
all dark. Viewed from above, posterior row rather strongly
recurved ; viewed from in front, anterior row strongly procurved.
Central ocular quadrangle wider behind than in front in ratio
of 39 : 37, wider behind than long in ratio of 39 : 36. Ratio of
eyes AME : ALE : PME : PLE = 10 : 8 : 11.5 : 7. AME
separated from one another by nearly two diameters, from ALE
by 3.7 of their diameter. PME separated from one another by
about 1.5 times their diameter, from PLE by about 5.5 times
their diameter. Laterals separated from one another by three-
fourths of the diameter of ALE. Height of clypeus equal to a
little less than four times the diameter of AME.
Chelicerae. Basal segment .88 mm. long. Fang groove as usual
with four teeth along promargin and three along retromargin.
Other observed features typical of the genus.
Maxillae. Appear to be typical of the genus in all observed
features.
Lip. Wider than long in ratio of about 5:3; reaches somewhat
beyond middle of the maxillae. Sternal suture gently procurved.
Sternum. Scutiform; longer than wide in ratio of about
5:4; continued from posterior end by a narrow dark line be-
tween fourth coxae which are separated by nearly one-fourth of
their width ; with low convexities at posterior end and opposite
first to third coxae and with a small tuft of bristles and spinules
at each convexity; also with a transverse row of long slender
spinules between first coxae.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 509
Legs. 1243. Width of first patella at "knee" .3791 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .3791
mm., tibial index of fourth leg 12.
Femora
Patellae
(All measu
Tibiae
rements in
Metatarsi
millimeters)
Tarsi
Totals
1.
3.185 ,
1.300
2.957
2.665
1.105
11.212
2.
2.925
1.202
2.502
2.502
.975
10.106
3.
1.787
.682
1.0-40
.975
.650
5.134
4.
2.665
1.250
1.885
2.177
.877
8.854
Spines. First leg: femur dorsal 0-1-0-1 (weak), prolateral
0-1-1-0-1, retrolateral apparently only one near distal end,
ventral 0 ; patella dorsal 1-1, prolateral 0-1-0, retrolateral 0-0-1 ;
tibia dorsal 0-1-1-1-0, prolateral 0-1 (weak) -1-1-0, retrolateral the
same, ventral 2(irreg.)-lp-0-2; metatarsus dorsal 0-1-1-0-0, pro-
lateral 0-1-0-0, retrolateral 0-1-1-0, ventral 2-2-2-0. Second leg:
femur dorsal as in first, prolateral and retrolateral 0-0-0-1-1,
ventral 0; patella dorsal and retrolateral as in first, prolateral
0-1-1; tibia dorsal as in first, prolateral 1-1-0-0-1, retrolateral
0-1-1-0, ventral lp-lr-0-lr; metatarsus dorsal and retrolateral as
in first, prolateral 0-1-1-0, ventral lr-lr-0-0. Third leg: femur
dorsal, prolateral, and retrolateral apparently with only one
near distal end in each instance, ventral 0 ; patella dorsal 1-1,
prolateral 0-1-0, retrolateral 0-0-1 ; tibia dorsal 1-0-0, prolateral
and retrolateral 0, ventral 1-1-0-lr; metatarsus dorsal 0-1-0-0-0,
prolateral 0, retrolateral 0-1-0, ventral 1-0-1 and many spinules.
Fourth leg: femur apparently only one dorsal and one ventral
on retromargin both at distal end but a row of retromarginal
spinules suggest spines; patella essentially as in third; tibia
dorsal 0-1 (weak) -0-0-1-0, prolateral 1-1-0-1-1?, retrolateral 1-1-1
(weak), ventral lp-0-2; metatarsus dorsal 0-1-0, prolateral 0-1-
1-0, retrolateral 0-1-1-0, ventral 0.
Abdomen. 3.445 mm. long; 2.405 mm. wide about one-fourth
from base where is is widest; with a series of five pairs of low
dorsolateral tubercles; there is also a low median tubercle about
one-fourth from posterior end and another beneath this one and
just dorsal to the anal tubercle ; the abdomen extends posterior
to the spinnerets about one-fourth of its total length ; apparently
without the long dorsal and dorsolateral abdominal spines so
common in the genus but a type of short spines occurs in the
510
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
same regions ; other observed features appear to be typical of the
genus.
Epigynum. This organ illustrates well the difficulties involved
in recording the specific epigynal features in the numerous
species of Eustala and in making these distinctions clear to other
workers. Here the apertures are about two diameters apart; the
central part of the base exhibits a characteristic shape best shown
by a figure ; the scape is of moderate length and springs quite
abruptly from the base (Fig. 132). The base in the holotype
is not sufficiently extended to make practicable a drawing from
a lateral aspect.
Color in alcohol. Carapace : yellowish with small irregular
reddish brown spots over the dorsal part; in the region of the
clypeus there are irregular small gray spots; at the base of the
pars cephalica there is a white triangular subchitinous spot with
133
J
134
132
External Anatomy of Eustala
Figures 131-132, E. tumida
Figures 133-134, E. vegeta
Fig. 131. Cephalic cone, lateral view.
Fig. 132. Epigynum from below.
Pig. 133. Left second tibia from below.
Fig. 134. Eight fourth femur from below.
CHICKERING: GENUS EUSTALA IN CENTRAL AMERICA 5] 1
its apex directed posteriorly. The sternum is nearly white with
irregular chalk-white subchitinous marginal spots. The legs are
yellowish with grayish spots, rings, and bars. Abdomen : the
dorsal folium is poorly outlined by remnants only; the whole
dorsal and dorsolateral areas are largely white from a multitude
of white subchitinous granules but there are numerous reddish
dots and streaks as well as many black dots and streaks ; on the
venter there is an irregular white spot, composed of many sub-
chitinous granules, just in front of the spinnerets and another
similar spot between that and the genital groove and on each side
of the latter there is a large irregular elongated dark gray spot.
Type locality. The holotype is from Summit, C. Z., August,
1950.
Eustala vegeta (Keyserling)
(Figures 133-138)
Epeira vegeta Keyserling, 1865
E. vegeta Keyserling, 1892
Acacesia vegeta Simon, 1895
Eustala vegeta F. P. Cambridge, 1904
E. vegeta Petrunkeviteh, 1911
In defining the species, F. P. Cambridge emphasized the fol-
lowing features of the male palp : the uncus is without the
strong transverse enlargement at the base characteristic of E.
bifida; it does not have the enlarged shoulder on the inner
margin of the uncus as in E. guttata; the embolus is shorter
than in E. scutigera; the conductor is not sharply angled as in
E. scutigera. F. P. Cambridge also stressed the following features
in the epigynum : the scape is ' ' abruptly narrowed at its apex ' '
but it is broad and transversely wrinkled at the base ; the aper-
tures, "marked by circular black spots" are two to three diam-
eters apart. In view of the large number of species and the
difficulty of separating those which are closely related these
vague and very general definitions leave us with much un-
certainty. The study of specimens on loan from the British
Museum has greatly helped in clarifying the distinctions between
this and related species so that I feel fairly confident of the
facts as stated below.
512 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
Male hypatype. Total length 4.452 mm. With the typical form
of the body. Central ocular quadrangle wider in front than
behind in ratio of 35 : 26, wider in front than long in ratio of
35 : 32. Katio of eyes AME : ALE : PME : PLE = 11 : 8 : 9 : 8.
AME separated from one another by nearly 1.5 times their
diameter, from ALE by the same distance. PME separated from
one another by about five-fourths of their diameter, from PLE
by slightly more than three times their diameter. Lateral eyes
separated from one another by their radius. Height of clypeus
equal to the diameter of AME. Secondary sexual characters on
first coxae, maxillae, and second femora typical of the genus.
Legs. 1243. Width of first patella at ''knee" .3249 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .2708 mm.,
tibial index of fourth leg 10.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.
3.120
1.072
2.567
2.372
1.040
10.171
2.
2.470
.965
1.755
2.015
.942
8.147
3.
1.495
.585
.910
.900
.565
4.455
4.
2.210
.910
1.690
1.852
.812
7.474
Palp
.430
.264
J 54
.880
1.728
The first femur appears to have only two ventral spines, one
on each margin near distal end; the second femur has three
ventral spines along the retromargin and one near distal end on
the promargin ; the third femur appears to have three ventral
spines along the promargin and none on the retromargin; the
right fourth femur has five along the promargin and four along
the retromargin (Fig. 134), while the left femur has fewer.
The second tibia has special spines as shown in Figure 133.
Palp. Maxillary tooth, femoral ridge, and patellae typical
of the genus; the dorsal lobe of the tibia is somewhat longer
than in most species. Tarsus: the basal tarsal apophysis is a
typical arrow head with only slight distortion except the usual
bend in the shank; the clavis is moderately robust and has a
shallow basal ventral concavity which is very setose; the uncus
is a distinct hook with its curvature toward the tip of the
embolus as shown in F. P. Cambridge's Figure 16; the conductor
is fairly large, has no lobe such as that found in the palp of E.
scutigera but has a depression within which the uncus lies and
1.
3.120
2.
2.730
3.
1.690
4.
2.632
CHICKERING : GENUS BUSTALA IN CENTRAL AMERICA 513
it also has a deep dorsolateral concavity; the embolus is of
moderate length, slender, gently curved; the terminal laminae
are raised into a high prominence contiguous to the conductor
and have a prominent tubercle dorsal to the prominence (Figs.
135-136).
Female hypotype. Total length 7.02 mm. Body form like that
of male.
Legs. 1243. Width of first patella at "knee" .4007 mm., tibial
index of first leg 11. Width of fourth patella at "knee" .3574
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1.170 2.535 2.210 1.105 10.140
1.170 2.112 1.950 1.040 9.002
.747 .910 1.007 .715 5.069
1.040 1.625 1.885 .910 8.092
First femur with a single ventral spine on both margins but
apparently none of the other femora has ventral spines.
Epigynum (Figs. 137-138). Much like that of E. scutigera;
the scape is relatively longer and it arises more abruptly than
in that species ; both apertures and spermathecae are much
farther apart than in E. scutigera.
Color in alcohol. The color is much the same as in E. scutigera.
The two rows of dots on the carapace show well in the male
but are faint in the female; this color feature appears to be
less consistent than in several other species. In both hypotypes
the sternum is yellowish with a fairly broad brownish margin.
The legs have the common yellowish color with many brownish
dots, bars, and rings; in the male hypotype the femora are
nearly all brown except the yellowish proximal third. The dorsal
folium is clear and definite on the abdomen of the male and less
well outlined in the female. In both the venter has a dark and
more or less quadrilateral area between the genital groove and
the base of the spinnerets containing the usual white spot, small
and rounded in the male but larger and elongated in the female.
Collection records. The male hypotype is from Tlacotalpan,
Veracruz, Mexico, July, 1946 (H. Wagner) ; the female hypo-
type is from Vera Cruz, La Planta Moctezuma, near Fortin,
Mexico, July, 1947 (C. and M. Goodnight). Other females are
514
BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
139
External Anatomy of Eustala
Figures 135-138, E. vegeta
Figures 139-140, E. venusta
Fig. 135. Male palpal tarsus, lateral view.
Fig. 136. Male palpal tarsus, distal view.
Fig. 137. Epigynum from below.
Fig. 138. Epigynum, lateral view.
Fig. 139. Epigynum from below.
Fig. 140. Epigynum, lateral view.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 515
from the same localities as those from which the hypotypes were
taken, and other parts of Mexico as follows: Cordova, Jalapa,
Veragua, 1946 (J. C. and D. L. Pallister) ; Tlapocayan, Veragua,
July, 1946 (H. Wagner) ; Mantla, Veragua, July, 1946 (H. Wag-
ner). Males are in my collection from: Costa Rica, Santa Maria
(Tristan), no date; Porto Bello, R. P., August, 1936.
EUSTADA VENUSTA sp. nOV.
(Figures 139-140)
Female holotype. With the conventional round-triangular
form. Total length 7.67 mm. Carapace 3.25 mm. long; 2.697 mm.
wide opposite interval between second and third coxae where it
is widest ; 1.365 mm. tall and, therefore, about .5 at tall as wide ;
median thoracic groove deep and well denned; with numerous
short spinules and a fairly well developed coat of whitish
procumbent hair over most of the surface.
Eyes. Eight in two rows, all dark ; viewed from above, posterior
row strongly recurved ; viewed from in front, anterior row gently
procurved, measured by centers ; central ocular quadrangle wider
in front than behind in ratio of 37 : 34, only slightly wider in
front than long. Ratio of eyes AME : ALE : PME : PLE —
10 : 8.5 : 11 : 9. AME separated from one another by slightly
more than twice their diameter, from ALE by four times their
diameter. PME separated from one another by nearly one and
one-fourth times their diameter, from PLE by nearly 4.6 times
their diameter. Laterals separated from one another by two-
thirds the diameter of PLE. Height of clypeus equal to 6/5 of
the diameter of AME.
Chelicerae. Basal segment 1.3 mm. long; general features as
usual in the genus. Fang groove finely dentate ; promargin with
four teeth, as usual with second and fourth smaller ; retromargin
with three teeth.
Maxillae. Appear to be completely typical of the genus in
all observed features.
Lip. Wider than long in ratio of 4 : 3 ; reaches to about the
middle of the maxillae. Sternal suture distinctly procurved with
anterolateral corners of the sternum distinctly tuberculous.
Sternum. Scutiform; longer than wide in ratio of 62 : 55;
1.235
14.917
1.170
12.837
.758
6.463
.975
11.325
prolateral 0-0-1-1-
516 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY
truncated at posterior end which is not continued between fourth
coxae which are separated from one another by about one-sixth of
their width ; deeply scallopped marginally opposite all coxae
except the first ; only moderately convex opposite first to third
coxae ; well supplied with stiff spinules.
Legs. 1243. Width of first patella at "knee" .5307 mm., tibial
index of first leg 9. Width of fourth patella at "knee" .5198
mm., tibial index of fourth leg 13.
Femora Patellae Tibiae Metatarsi Tarsi Totals
(All measurements in millimeters)
1. 4.875 1.722 3.900 3.185
2. 4.160 1.560 3.120 2.827
3. 2.405 .858 1.210 1.232
4. 3.835 1.560 2.405 2.550
Spines. First leg : femur dorsal 0-0-1-0-1-1,
1-1, retrolateral 0-0-0-1-1-1, ventral 0; patella dorsal l(weak)-l,
prolateral and retrolateral 0-1-1-0; tibia dorsal 0-1-1-1-0, pro-
lateral and retrolateral 0-1-0-1-0, ventral 2-lr-lp-lr-lp-lp-2 ;
metatarsus dorsal and prolateral 0-1-0-1-0-0, retrolateral 0-1-0-1-0,
ventral 2-2-0-lp. Second leg: femur dorsal, retrolateral, and
ventral as in first, prolateral 0-0-1-1-1 ; patella as in first ; tibia
dorsal as in first, prolateral and retrolateral 0-1-0-1-1, ventral
2-2-2-2 ; metatarsus dorsal 0-1-0-1-0-0, prolateral and retrolateral
0-1-0-1-0, ventral 2-lr-0-lp. Third leg: femur dorsal 0-1-1-1,
prolateral and retrolateral 0-0-0-1-1, ventral 0; patella dorsal
1-1, prolateral and retrolateral 0-1-0 ; tibia dorsal 1-0-1, prolateral
0-1-0-1, retrolateral 0-0-1, ventral lp-lp-2; metatarsus dorsal
0-1-0-0, prolateral 0-1-1, retrolateral 0-1-0, ventral lp-lp-1-1.
Fourth leg: femur dorsal 0-1-0-1-1, prolateral 0-0-0-1-1, retro-
lateral only one near distal end, ventral 0; patella as in third;
tibia dorsal 1-0-1-1-0, prolateral 1-1-1-1, retrolateral 0-1-1, ventral
lp-lp-lp-2 ; metatarsus dorsal 0-1-0-1-0-0, prolateral 0-1-1-1, retro-
lateral 0, ventral lp-lp-lp-lp. Palp : femur with dorsal spines
0-1-1 ; patella with dorsal spines 1-1, prolateral 1-0 ; tibia with
dorsal spines 0-1-0, prolateral 1-1, retrolateral 0-1 ; tarsus with
many spines and spinules irregularly distributed. Palpal claw
pectinate in a single row of nine or ten slender teeth.
Abdomen. 5.135 mm. long; widest about one-fifth from base
where convexities suggest suppressed shoulder humps. Other
observed features are typical of the genus.
CHICKERING : GENUS EUSTALA IN CENTRAL AMERICA 517
Epigynum. Base with nearly the usual conventional forms of
tubules, striations, apertures ; spermathecae large and clearly
defined ; scape relatively long and arises from base abruptly, and
slender throughout as shown by lateral views (Figs. 139-140).
Color in alcohol. Carapace yellowish with faint darker stria-
tions contiguous to cephalic groove ; there is a brownish dot on
each side of median thoracic groove opposite its middle and an-
other faint dot on each side in front of the groove. Sternum
yellowish with a broad broken brownish margin. Legs : yellow-
ish with many brown bands. Abdomen : the dorsal folium is
fairly well outlined in the holotype but is highly variable in the
paratypes; the venter has a large brown quadrilateral area be-
tween the genital groove and the base of the spinnerets containing
an elongated white spot which seems to be quite persistent among
the paratypes.
Type locality. The female holotype is from Barro Colorado
Island, C. Z., July, 1950. About 25 female paratypes from the
following localities have been studied : Barro Colorado Island,
C. Z., June-July, 1934; July- August, 1936; July-August, 1939;
June-August, 1950. Canal Zone Forest Reserve, C. Z., August,
1939. Near Chiva, C. Z., July, 1950. Summit, C. Z., July-August,
1950.
BIBLIOGEAPHY
Banks, Nathan
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