C^Ljl #\n nr*+^

DEPARTMENT OF MARINE BIOLOGY

OF

CARNEGIE INSTITUTION OF WASHINGTON

ALFRED G. MAYER, Director

PAPERS FROM THE TORTUGAS LABORATORY

OF THE

CARNEGIE INSTITUTION OF WASHINGTON

VOLUME IV

WASHINGTON, D. C.
Published by the Carnegie Institution of Washington

1910

CARNEGIE INSTITUTION OF WASHINGTON
Publication No. 133

»iec of this. B

were first tssu#^

PRESS OF J. B. L1PPINCOTT COMPANY
PHILADELPHIA, PA.

MONOCOTYLE FLORIDANA, A NEW MONOGENETIC TREMATODE.

By HENRY S. PRATT.

HELMINTH FAUNA OF THE DRY TORTUGAS. II. TREMATODES.

By EDWIN LINTON.

A CONTRIBUTION TO THE GEOLOGIC HISTORY OF THE FLORIDIAN

PLATEAU. Bv THOMAS WAYLAND VAUGHAN.

CONTENTS.

PAGE

Monocotyle floridana, a new Monogenetic Trematode. By

Henry S. Pratt 1-9

With 11 text figures.

Helminth Fauna of the Dry Tortugas. II. Trematodes. By

Edwin Linton J I-98

With 28 plates.

A Contribution to the Geologic History of the Floridian

Plateau. By Thomas Wayland Vaughan 99-185

With 15 plates, 6 text figures.

43949

MONOCOTYLE FLORIDANA,
A NEW MONOGENETIC TREMATODE.

BY HENRY S. PRATT,
Haverford College.

n figures.

MONOCOTYLE FLOR1DANA, A NEW MONOGENETIC TREMATODE.

By Hexry S. Pratt.

The genus Monocotyle was established by Taschenberg, in 1878, for
a worm which he had found on the gills of the eagle-ray (Myliobatis
aquila) at Naples, and which he named Monocotyle myliobatis. The
only other known species is Monocotyle ijinice, which was discovered in
Japan in the mouth of Trygon pastinacea, and described by Goto in
1894. The worm herein described makes the third member of the genus
and was taken from the gills of the whip-ray (Myliobatis freminvillei) in
the Gulf of Mexico and studied at the Marine Biological Laboratory of
the Carnegie Institution of Washington at Tortugas, Florida. It differs
in certain features from the two other species of the genus, but in the
general shape and size of the body, the form and structure of the suck-
ers, down to the smallest details, and the general arrangement of the
genital organs it shows a close relationship to them, especially to M.
ijimoi. M. aquila is not well known anatomically. Its male genital organs
have not been seen at all and the descriptions of the female genital tract
are not complete.

The body of Monocotyle floridana is elongate and thin, being convex
dorsally and flattened ventrally. A large individual, selected for descrip-
tion, measures 1.3 mm. in length and 0.58 mm. in width in the widest
place, which is just back of the middle, and is about half as long as the
Japanese and a third as long as the Mediterranean species. From the
widest point the body tapers towards both ends. The anterior end is
usually more or less truncated, as in M. ijimce, and also possesses the
sticky glands which characterize that species. These glands (fig. 2) are
four in number and are dorsal in position, lying embedded in the muscle
of the oral sucker; but instead of being near the surface or at the for-
ward end of the body, they are situated at a considerable distance from
the forward end, as is also the case in the closely allied genus Calicotyle,
being dorsal to the brain, and are joined with the forward end of the
body by long sinuous ducts. Each gland is irregular in shape and about
0.03 mm. long, while its duct has a length of about 0.17 mm.

The mouth is a large funnel-shaped opening, subterminal in position ,
0.10 mm. in diameter and 0.12 mm. deep. It is surrounded by a lip-like
projection which forms a slight flange posteriorly and laterally and
which extends forward anteriorly and dorsally beyond the end of the body
(figs. 1,2, and 3, /.). This lip is non-muscular and apparently receives
the secretions of the four glands just mentioned. Surrounding the

3

4 Papers from the Marine Biological Laboratory at Tortugas.

mouth is a powerful sucker which entirely fills the anterior end of the
body, but is not separated from the parenchyma by a definite boundary.
Goto describes a similar structure in M. iiimce as a sucker-like organ
which, as he says, undoubtedly functions as a sucker. He refuses, how-
ever, to recognize it morphologically as a sucker because of the lack of
definite boundaries.

The posterior sucking-disk is not so large relatively as in the other
two species of the genus, having a diameter of 0.52 mm., which is some-
what less than that of the body (figs. 1 and 4). It is circular in outline
and shaped more or less like a saucer, having a curled rim, and is sub-
terminal in position, being attached to the body by a short, thick pe-
duncle. The ventral surface of the disk is divided by eight radial ridges
into as many segments, each of which contains a large oval sucker about
ci mm. in diameter. The sucker occupies about two-thirds of the space
in the segment, extending from the outer rim or margin of the disk to
the peduncle. The center of the disk, where the peduncle is attached,
is somewhat depressed (fig. 5, c.d.) and contains no muscular tissue. The
parenchyma, however, immediately beneath the cuticula in the center is
arranged in parallel lines perpendicular to the cuticula and has some-
what the appearance of a musculature. Extending from the outer
margin of the sucking-disk is a lip or flange of non -muscular tissue (figs.

5 and 6, /?.) similar to the lip at the anterior end of the body. It will be
seen that the sucking-disk is not a single sucker, as it is described as
being in the other two species of the genus, but a pedunculated plate
containing eight distinct suckers.

Two small hooks (fig. i,h., fig. 7) are embedded in two of the posterior
radii of the sucking-disk, but do not usually extend beyond the margin.
Each hook has two parts, a crescentic portion 0.027 mm. in diameter
and a straight portion extending from it, 0.034 mm. long.

On the dorsal or reverse side of the sucking disk, opposite to the two
posterior segments and between the two hooks, are two groups of short
finger-like projections (figs. 4 and 5, d.p.). Each group is V-shaped, with
the apex directed towards the center of the disk, and each projection
has the same structure as the suckers. No similar structures, so far as
I know, have been observed in any other trematode.

Goto has called attention to the unusual structure of the musculature
of the sucking-disk in M. ijimce, the radial muscle-fibers composirg the
main mass of the disk being striated. In M. floridana identical relations
exist. The musculature of the suckers of the disk is made up principally
of perpendicular striated fibers (fig. 6, 5. m.), most of which run inde-
pendently from the cuticula on one side of the sucker to that on the other.
Between the ends of these fibers are very delicate non-striated fibers
which run parallel to the cuticula. The muscle-fibers composing the
dorsal finger-like projections have a direction transverse to that of those
of the suckers (fig. 5, d.p.).

The body of the worm is smooth. The chitinous pieces on the radial
elevations of the sucking-disk which have been described by Goto in
M. ijimce are not present.

Monocotyle Floridana, a New Monogenetic Trematode. 5

The large mouth opens through a small passage into the pharynx,
receiving at the juncture a circular pocket which lies over the anterior
end of the pharynx (fig. 3, p.p.). The pharynx is of enormous size, being
0.19 mm. long, 0.18 mm. wide, and 0.17 mm. thick in the worm selected
for description, and is the most conspicuous organ in the body (figs. 1
and 3, ph.) ; but it varies considerably in relative size in different indi-
viduals, being relatively smallest in the youngest individuals. In the
smallest worms in my collection its length is one-twelfth that of the
body; in the largest this proportion is 1 to 6. The small lumen is three-
cornered in cross-section and the walls are very thick and composed of
closely compacted, deeply staining radial muscle -fibers. Sparsely dis-
tributed throughout these fibers are large oval cells, which are probably
nerve-ganglia. Surrounding the radial fibers is a thin layer of delicate
circular fibers.

The intestine branches just back of the pharynx, there being no esoph-
agus present (figs. 1 and 3). The two intestinal trunks pass directly to
the right and left sides of the body. They then pass first forward a
short distance, and then, turning abruptly, run posteriorly along the
medial surfaces of the voluminous yolk-glands and parallel to the lateral
margins of the body to the hinder part of it, where their posterior ends
meet and unite (figs. 1 and 4). In the two other species of this genus the
hinder ends of the intestinal trunks do not thus join, but remain apart.

The diameter of each trunk is about 0.04 mm. in a large individual.
Projecting posteriorly from the point of juncture of the two lateral
trunks in all the individuals examined by me (about twenty-five), is a
median trunk which extends to the extreme hinder end of the body (figs.
1 and 4 m. t.). This median trunk has exactly the same structure as
the lateral trunks and about the same diameter (figs. 9, 10, 11); but
in several individuals it was much thicker than they and took stains
much more deeply.

In two individuals examined the median trunk opens to the outside
by means of a median, dorsal, thick-lipped pore, situated at the extreme
posterior end of the body and just in front of the point of attachment
of the sucking-disk (fig. 4, t. p.). In all other individuals examined no
such pore could be seen and the median trunk ends blind, forming thus
a caecum.

The occurrence of a median, posterior intestinal caecum similar to
the one here described is exceedingly rare among trematodes, the only
other species with which I am acquainted in which it occurs being Vallisia
striata, which has been described by Perugia and Parona (1890). The
terminal pore is difficult to explain and may be simply an accidental
opening in the two individuals in which it was seen, although its well-
defined form and broad lips would seem to preclude this interpretation.

The excretory system has not been distinctly seen, but has undoubt-
edly the same arrangement as that described by Goto in M. ijimce and
in other monogenetic trematodes. The longitudinal trunks are small
and delicate tubes which open to the outside through a pair of lateral
pores situated at about the level of the hinder part of the pharynx, each

6 Papers from the Marine Biological Laboratory at Tortugas.

pore being in the dorsal surface a short distance from the lateral margin
of the body.

The nervous system is also of the usual type, the brain lying dorsal
to and just in front of the pharynx (fig. i, b.) and the anterior and pos-
terior paired nerves extending from its lateral ends to the extremities of
the body (fig. i, a. n., I. n.). The main posterior nerves run lateral to the
massive yolk-glands and along the margin of the body. No ocelli ai'e
present.

The genital organs are similar in arrangement to those of M. ijimce.
The single testis (figs, i and 8, t.) is a spherical structure 0.115 mm. in
diameter, which lies just back of the middle of the body at the left of the
median line. In M. ijimce three testes are present, while in M. myliobatis
no one has yet seen any of the male genital organs. The vas deferens (figs.
1 and 8, v. d.) is a narrow tube with rather thick, structureless, highly
refractive walls; it arises from the anterior surface of the testis and
passes forward at the left of the median line to the vaginal pore (figs. 1
and 8, v. p.), which is situated in the ventral surface on the left side of
the body near the hinder end of the pharynx. No penis, cirrus, or vesicula
seminalis is present, the vas deferens having exactly the same structure
and diameter from one end of it to the other. I have also been unable
to detect any trace of specialization in the parenchyma surrounding the
anterior end of the vas deferens, such as is present in M. ijimce and
forms the so-called connective-tissue penis in that species.

The ovary (figs. 1 and 8, o) is made up of two distinct portions, one
of which, the formative portion, is spherical in shape and about the same
size as the testis, and lies immediately in front and at the side of it at
the right of the median line. The other portion is cylindrical in shape
and extends from the spherical portion to the right side of the body,
where it forms a single loop around the right intestinal trunk, tapering
in size as it proceeds until it becomes so narrow that it contains but a
single row of elongated ova. It thus runs to the left side of the body,
where it passes, without further decrease in size, into the oviduct, which
is a very short tube (fig. 8, ov.), which joins the posterior surface of the
ootype. The ova filling the ovary are of large size, those in the cylindrical
portion being about 0.025 mm. long and 0.013 mm. thick.

The ootype (figs. 1 and 8, oot.) is a large spherical sac, about 0.09 mm.
in diameter and with thick walls, which is situated just in front of the
ovary on the left side and near the dorsal surface of the body. The walls
are composed of a high pavement-epithelium of deeply staining, glandu-
lar cells, which forms the interior surface of the organ, and a layer of
rather delicate muscle-fibers lying back of it. Grouped at the antero-
medial side of the ootype, where the uterus leaves it, are the large pear-
shaped cells which form the shell-gland. The ootype occasionally con-
tains a single large oval egg (fig. 8, e.), which about half fills it and has a
length of about 0.045 mm- and a thickness of 0.03 mm. Projecting
from the hinder end of the egg, as it lies in the ootype, is a short, straight
chitinous process about 0.02 mm. long. It seems certain that the chitin-

Monocotyle Floridana, a New Monogenetic Trematode. 7

ous chorion of the egg is formed from the secretion of the epithelial
lining of the ootype, as well as from that of the shell-gland.

Extending from the ootype to the birth-pore (figs, i and 8, b. p.) is
the uterus (figs, i and 8, u.). This vessel is a long tube of large size at
its point of origin at the ootype, which makes two complete turns, first
running forwards, then backwards, and finally forwards again, passing
ventral to the intestine and dorsal to the receptaculum seminis and
opening to the outside at the birth-pore. Its diameter decreases towards
its forward end, and throughout the greater part of its extent it is a very
narrow tube. It possesses, however, a chitinous lining which renders it
a conspicuous object under the microscope. The birth-pore is situated
in the ventral surface of the body in the median line near the hinder end
of the pharynx.

The vagina (fig. 8, v.) is very short and leads from the vaginal pore
(fig. 8, v. p.) on the left side of the body near the hinder end of the
pharynx across to the right side of the body and into the large cylindrical
receptaculum seminis (figs, i and 8, r. s.). This is a prominent thin-
walled organ, always filled with sperm, which lies just back of the pharynx
on the right side and near the ventral surface of the body. Its hinder
end is rounded and about 0.08 mm. in diameter, and is connected with
the uterus by means of a short canal.

The yolk-glands consist of small, closely compacted spherical follicles
and are very voluminous. They extend from the forward portion of the
pharynx to the hinder end of the body, occupying the areas lateral to the
intestinal trunks as far back as the hinder end of the ovary and testis.
Posterior to these organs they fill the entire body, completely immersing
the hinder portions of the digestive tract. The two transverse yolk-ducts
lie in very nearly the middle of the body. They meet near the hinder end
of the ootype and form a very short common duct, which enters the
oviduct almost at the point where it enters the ootype. No yolk reservoir
is present. No genito-intestinal canal is present.

The genital organs of this worm exhibit several interesting and
unusual features. As will have been noticed, there is here no common
genital pore. The vas deferens, instead of opening to the outside together
with the uterus, finds an outlet, as I have determined with perfect
certainty, through the vaginal pore, and the sperm undoubtedly passes
directly from the vas deferens through the vagina and into the recepta-
culum seminis of the same animal. The self-fertilization which is thus
brought about may be necessary because of the total lack of a penis
and a vesicula seminis.

The receptaculum seminis, as in other monogenetic trematodes, is
nothing more than a distended portion of the vagina and is invariably
filled with sperm in all the worms I have studied. The vagina is peculiar
in that it opens into the uterus near the forward end of the ootype instead
of into the oviduct or the yolk-duct near the hinder part of that organ.

The birth-pore is what is left of the common genital pore after the
migration of the terminal end of the vas deferens to the vaginal pore,

8 Papers from the Marine Biological Laboratory at Tortugas.

i. The whole worm viewed from ventral side: actual length 1.3 mm.

2. Dorsal surface of anterior portion of worm: X 25.

3. Sagittal section of anterior portion of worm: X 18.

4. Dorsal view of posterior portion of worm: X 20.

5. Longitudinal section of sucking-disk and peduncle: X 40.

6. Section of outer portion and flange of a sucker : X 200.

7. Hook in sucking-disk: X 150.

8. Diagram showing arrangement of reproductive organs.

Monocotyle Floridana, a New M onogenetic Trematode.

9

and serves as the outlet of the uterus alone. It will at once be noticed
that the birth-pore is a very small opening and the uterus is a very nar-
row tube and that the egg which must pass through them is several times
their width. It is evident, consequently, that they must be capable of
great distention while the egg is being extruded. In fact, although no
individuals have come under my observation in which an egg is present
in the uterus, I have seen several individuals in which the terminal
portion of the uterus is very much distended and several times its usual
width.

LITERATURE.

Taschenberg, E. O. Helminthologisches. Zeitsch. f. d. gesammten Naturwiss.

Bd. 51, p. 562, 1878.
Parona, C, e Perugia, A. Di alcuni trematodi ectoparassiti di pesci adriatici.

Annali del Museo civico di Storia Naturale di Genova. Ser. 11 a, vol. ix,

Goto, S. Studies on the Ectoparasitic Trematodes of Japan.
Imp. Univ. Tokyo, vol. vm, p. 229, 1894.

Jour. Col. of Sci.

l.m.

9 ^ 10

9. Transverse section of worm back of testis: X 25.

10. Transverse section of worm where the intestinal trunks meet: X 2

11. Transverse section of worm showinsr median trunk of intestine: X

-5-

Abbreviations used on Figures.

a. n anterior nerve.

b. p birth-pore.

b brain.

c. d centerof sucking-disk.

d. p dorsal projection of

sucker.

e egg.

e.t excretory trunk.

fl flange of disk.

gl glands.

h hooks.

* intestine.

I lip.

I. m longitudinal muscles.

I. n longitudinal nerve

(posterior).

m mouth.

m.t median trunk of in-
testine.

o ovary.

oot ootype.

o. s oral sucker.

ov oviduct.

ph pharynx.

p. p pharyngeal pocket.

r. s receptaculumseminis.

5 sucker.

s. d sucking disk.

s. )>: striated muscles.

/ testis.

t. p terminal pore.

if uterus.

v vagina.

v. p vaginal pore.

y. d yolk-duct.

y. g yolk-glands.

HELMINTH FAUNA OF THE DRY TORTUGAS.
II. TREMATODES.

BY EDWIN LINTON,
Professor of Biology, Washington and Jefferson College.

28 plates.

11

CONTENTS

PAGE

Introduction 15

List of Tortugas trcmatodes and their hosts '7

List of hosts and food notes 19

Key to the genera and species described in this paper 20

Descriptions of species, habitats, etc. :
I. Trematodes from loggerhead turtle:

Cricocephalus delitescens Looss 23

Distomum sp., related to Calycodes 24

Pachypsolus ovalis sp. nov 24

Cymatocarpus undulatus Looss 26

Orchidasma amphiorchis (Braun) Looss 28

II. Trematodes from fish:

Malacotylea 29

Fasciolidae 29

Table of Allocreadiinae 29

Helicometra torta sp. nov 29

Helicometra execta sp. nov 31

Helicometrina nimia gen. et sp. nov 33

Hamacreadium gen. nov 34

Hamacreadium mutabile gen. et sp. nov 34

Hamacreadium gulella gen. et sp. nov 35

Hamacreadium consuetum gen. et sp. nov 36

Hamacreadium oscitans gen. et sp. nov 37

Lebouria crassigula sp. nov 38

Megasolenaestrix gen. et sp. nov 38

Didymorchis latus gen. et sp. nov 39

Enenterum aureum gen. et sp. nov 40

Theledera (g. n.) pectinata (Linton) 40

Lepocreadium trulla (Linton) 41

Lepocreadium levenseni (Linton) 42

Distomum sp. (D. valdeinflatum Stossich) 43

Mesolecitha linearis gen. et sp. nov 43

Stephanochasmus casus sp. nov 44

Stephanochasmus sentus sp. nov 45

Lechradena edentula gen. et sp. nov 46

Mesorchis urna gen. et sp. nov 47

Diplangus paxillus gen. et sp. nov 48

Deretrema fusillus gen. et sp. nov 49

Distomum fenestratum Linton 51

Xystretrum gen. nov 51

Xystretrum solidum gen. et sp. nov 51

Xystretrum papillosum gen. et sp. nov 52

Hysterolecitha rosea gen. et sp. nov 52

Macradena perfecta gen. et sp. nov 53

Opisthadena dimidia gen. et sp. nov 54

Brachadena pyriformis gen. et sp. nov 55

Dichadena acuta gen. et sp. nov 56

Leurodera decora gen. et sp. nov 57

Dictysarca virens gen. et sp. nov 58

Theletrum fustiforme gen. et sp. nov 59

Hemiurus merus sp. nov 60

Sterrhurus monticellii (Linton) 61

Sterrhurus fusiformis (Liihe) 62

Ectenurus virgula sp. nov 63

Ectenurus (?) sp., immature 64

Dinurus rubeus sp. nov 64

Hapladena varia gen. et sp. nov 65

Deradena gen. nov 66

Deradena ovalis gen. et sp. nov 67

Deradena acuta gen. et sp. nov 68

Deradena obtusa gen. et sp. nov 69

13

14 Contents.

II. Trematodes from fish — Continued:

Monostomidae 69

Barisomum erubescens gen. et sp. nov 69

Himasomum candidulum gen. et sp. nov 71

Paramphistomidae -,2

Cleptodiscus reticulatus gen. et sp. nov 72

Siphoderidae fam. n 74

Siphodera (gen. nov.) vinaledwardsii (Linton) 74

Stegopa globosa gen. et sp. nov 7 ^

Metadena crassulata gen. et sp. nov 76

Prodistomum gracile gen. et sp. nov 76

Genolopa gen. nov 77

Genolopa ampullacea gen. et sp. nov 77

Genolopa truncata gen. et sp. nov 78

Gasterostomidas 70

Gasterostomum gracilescens Rudolphi (?) 79

Gasterostomum sp. (near G. baculum Linton) 79

Gasterostomum sp., from Mycteroperca venenosa 80

Gasterostomum sp., from Barracuda 80

Heteracotylea 81

Microcotyle incisa sp. nov 81

Udonella socialis sp. nov 82

Aspidocotylea 82

Aspidocotyle ringens Linton 82

Deontacotylea subord. n 85

Deontacylix ovalis gen. et sp. nov 83

Index 85

Explanation of plates 87

HELMINTH FAUNA OF THE DRY TORTUGAS.
II. TREMATODES.

By Edwin Linton.

INTRODUCTION.

The collection here described was made at the Marine Biological
Laboratory of the Carnegie Institution, Tortugas, Florida, in the sum-
mers of 1906, 1907, and 1908. In each season my stay at the Labora-
tory was about three weeks. Without exception the fishes examined
were from the shallow waters of the reef. Tables showing the distri-
bution of parasites together with food notes have already been pub-
lished in the Year Book of the Carnegie Institution of Washington for
the years above named.

While the exact method of collecting material varied with the size
and number of the hosts, in general I found it best to open the alimen-
tary canal, wash out the contents with sea-water, wash and decant
several times if necessary, and then collect the small distomes with a
pipette. The distomes were killed in various ways, hot corrosive sub-
limate, picro-sulphuric acid, etc. A very satisfactory way for whole
mounts is a method used by Fuhrmann, viz., kill in 70 per cent alcohol
and stain in very dilute hasmatein. Preliminary to this it is a good
plan to flatten the distome under a cover-glass and heat it a little before
placing in the killing fluid. My best sections are from material fixed
in picro-sulphuric acid, although material killed in hot corrosive sub-
limate and stained with carmine is usually very satisfactory. In spite
of precautions much material which one collects proves unsatisfactory
or difficult. In many of the smaller distomes the vitellaria conceal the
general anatomy. In other cases the uterus is so full of eggs that other
parts are obscured or displaced. Again, the spinose cuticle is often
evanescent, and one is frequently much puzzled over a specimen that
has a close resemblance to forms with spines, but which is itself entirely
destitute of spines or of any certain indications that it ever had spines.

All measurements are given in millimeters.

Where no other habitat is mentioned the intestine is to be under-
stood as the habitat.

I am disposed to think that modern helminthologists have unduly
narrowed the idea of genus among the distomes. At the same time I
recognize the futility of attempting any change at present in the con-
ception of what should constitute a generic character in this difficult
group. Therefore, since I find it quite impossible to secure an abiding-
place for a majority of the Tortugas distomes in any existing genera,
I have thought it best to make new genera rather than to extend the
limits of genera that have been established. It has been my aim to

15

16 Papers from the Marine Biological Laboratory at Tortugas.

describe such details of structure as I was able to make out from the
living material and supplement it with further details obtained from
stained and mounted specimens. In many cases I was able to get fairly
satisfactory series of sections, in which case such details as seemed to
me to be of service in identification, or which appeared to be new, were
added. Since this paper contains mention of all the trematodes which
I found while at the Tortugas laboratory, it is unavoidable that many
of the descriptions will be incomplete in some particulars. If the paper
were intended simply as a contribution to systematic zoology, only
those forms would have been included which were represented by abun-
dant material or by material in good condition for study. Since my
purpose is to make a contribution to the knowledge of the helminth
fauna of the Dry Tortugas, the paper should be regarded as bionomic
in intention while largely systematic in form.

On account of the many new forms which are described, a key to
the genera and species has been prepared, which, together with the
figures, it is believed will make it possible for future workers to recog-
nize most of the forms readily.

One trematode, Deontacylix ovalis, was found which I do not rec-
ognize as having any near resemblance to any family, and I have there-
fore made it the type of a new suborder Deontacotylea (figs. 231-235).
I have also added the family name Siphoderidce to accommodate cer-
tain trematodes with an anterior oral and a ventral genital sucker.
The Allocreadiince are well represented and some very interesting prob-
lems in morphology are suggested. Prof. H. S. Pratt proposes to take
up the morphological study of this and other groups. The field is cer-
tainly a rich one. Especially suggestive is the singular trematode fauna
of the black angel-fish (Pomacanthus arcuatus), some of the genera of
which bear a strong resemblance to genera which are characteristic of
turtles.

Attention is here called to an interpretation of certain cells, espe-
cially abundant in the neck of many distomes, but found elsewhere less
abundantly. These appear to be yolk-forming in their function. They
are mentioned in the descriptions of a number of the distomes described,
but the best example is that afforded by Deradena ovalis; see especially
fig. 169.

For a cheerful readiness to compare notes and to confer upon ques-
tions of classification, I should be remiss if I did not take this opportu-
nity of thanking Professor Pratt, who spent the season of 1909 at the
Tortugas laboratory, where he began studies on the morphology of the
trematodes.

I must especially express my obligations to Dr. Alfred G. Mayer,
whose invitation led me to investigate the rich and interesting helminth
fauna of the Dry Tortugas, and whose unfailing courtesy made my
sojourn there most enjoyable.

Helminth Fauna of the Dry Tortugas. 1 <

List of Tortugas Trematodes and Their Hosts.

PARASITE. HOST.

Aspidogaster ringens Linton Calamus calamus.

Barisomum erubescens gen. et sp. nov Angelichthys isabelita.

Pomacanthus arcuatus.
Scarus croicensis.

Brachadena pyriformis gen. et sp. nov Calamus calamus.

Haemulon macrostomum.
plumieri.
sciurus.

Calycodes(?), immature Caretta caretta.

Cleptodiscus reticulatus gen. et sp. nov Pomacanthus arcuatus.

Cricocephalus delitescens Looss Caretta caretta.

Cymatocarpus undulatus Looss . .Caretta caretta.

Deontacylix ovalis gen. et sp. nov Kyphosus sectatrix.

Deradena acuta gen. et sp. nov Tylosurus marinus.

Deradena obtusa gen. et sp. nov Teuthis caeruleus.

hepatus.

Deradena ovalis gen. et sp. nov Scarus caeruleus.

croicensis.
sp.

Deretrema fusillus gen. et sp. nov Abudefduf saxatilis.

Haemulon macrostomum.
< )cyurus chrysurus.

Dichadena acuta gen. et sp. nov Teuthis caeruleus.

Dictysarca virens gen. et sp. nov Lycodontis funebris.

moringa.

Didymorchis latus gen. et sp. nov Calamus calamus.

Dinurus rubeus sp. nov Lycodontis funebris.

moringa.

Diplangus paxillus gen. et sp. nov Calamus calamus.

Ha?mulon macrostomum.
plumieri.
sciurus.

Distomum fenestratum Linton Haemulon plumieri.

sciurus.

Distomum sp. (D. valdeinflatum Stossich) Calamus calamus.

Ectenurus( ?), immature Auxis thazard.

Ectenurus virgula sp. nov Clupanodon pseudohispanicus.

Enenterum aureum gen. et sp. nov Kyphosus sectatrix.

Gasterostomum gracilescens Rudolphi Lycodontis moringa.

Gasterostomum sp Mycteroperca bonaci.

Gasterostomum sp Mycteroperca venenosa.

Gasterostomum sp Sphyraena barracuda.

Genolopa ampullacea gen. et sp. nov Haemulon plumieri.

macrostomum.
sciurus.

Genolopa truncata gen. et sp. nov Haemulon plumieri.

sciurus.

Hamacreadium consuetum gen. et sp. nov Haemulon plumieri.

sciurus.

Hamacreadium gulella gen. et sp. nov Neomaenis griseus.

Hamacreadium mutabile gen. et sp. nov Anisotremus virginicus.

Xeomaenis apodus.
griseus.
Ocyurus chrysurus.
Pomacanthus arcuatus.

Hamacreadium oscitans gen. et sp. nov Anisotremus virginicus.

Haemulon plumieri.
sciurus.

Hapladena varia gen. et sp. nov Teuthis caeruleus.

hepatus.

IS Papers from the Marine Biological Laboratory at Tortugas.

Helicometra execta sp. nov Chlorichthys bifasciatus.

Haemulon plumien.

sciurus.
Iridio bivittatus.
Lachnolaimus maximus.

Helicometra torta sp. nov Epinephelus mono.

stnatus.

Helicometrina nimia gen. et sp. nov Calamus calamus.

Eupomacentrus leucostictus.
Neomsenis griseus.
Ocyurus chrysurus.

Hemiurus merus sp. nov Clupanodon pseudohispanicus.

Himasomum candidulum gen. et sp. nov Angehchthys isabehta.

Pomacanthus arcuatus.

Hysterolecitha rosea gen. et sp. nov Teuthis caeruleus.

hepatus.

Lebouria crassigula sp. nov Calamus calamus.

Lechradena edentula gen. et sp. nov Neomaenis griseus.

Lepocreadium levenseni (Linton) Epinephelus mono.

stnatus.
Mycteroperca venenosa.

Lepocreadium trulla (Linton) Calamus calamus.

Ocyurus chrysurus.

Leurodera decora gen. et sp. nov Anisotremus virginicus.

Haemulon macrostomum.
plumieri.
sciurus.
Neomaenis griseus.
Teuthis hepatus.

Macradena perfecta gen. et sp. nov Teuthis caeruleus.

Megasolena estrix gen. et sp. nov Kyphosus sectatnx.

Mesolecitha linearis gen. et sp. nov Teuthis caeruleus

Mesorchis urna gen. et sp. nov Angehchthys isabehta.

Pomacanthus arcuatus.

Metadena crassulata gen. et sp. nov Neomaenis analis.

Microcotyle incisa sp. nov Neomaenis griseus.

Opisthadena dimidia gen. et sp. nov Kyphosus sectatnx.

Orchidasma amphiorchis (Braun) Looss Caretta caretta.

Pachypsolus ovalis sp. nov Caretta caretta.

Prodistomum gracile gen. et sp. nov Clupanodon pseudohispanicus.

Siphodera (g. n.) vinaledwardsii (Linton) Ocyurus chrysurus.

Stegopa globosa gen. et sp. nov Neomaenis griseus.

Stephanochasmus casus sp. nov Epinephelus stnatus.

Neomaenis griseus.
Neomaenis analis.
Ocyurus chrysurus.

Stephanochasmus sentus sp. nov Calamus calamus.

Haemulon plumien.
sciurus.

Sterrhurus fusiformis (Luhe) Lycodontis funebris.

monnga.

Sterrhurus monticellii (Linton) Abudefduf saxatilis.

Chlorichthys bifasciatus.

Echeneis naucrates.

Neomaenis griseus.

Theledera (g. n.) pectinata (Linton) Auxis thazard.

Theletrum fustiforme gen. et sp. nov Pomacanthus arcuatus

Udonella socialis sp. nov Neomaenis griseus, on Argulus

sp.
Xystretrum papillosum gen. et sp. nov Lactophrys tnqueter.

Helminth Fauna of the Dry Tortugas.

19

The following food notes were made as to hosts from which trema-
todes mentioned in this paper were obtained:

Name.

Number of

hosts
examined.

Food notes.

Abudefduf saxatilis. . .
Angelichthys isabelita.

Anisotremus virginicus .

Auxis thazard

Calamus calamus

Chlorichthys bifasciatus

Clupanodon pseudohispanicus.

Echeneis naucrates

Epinephelus mono

striatus

Eupomacentrus leucostictus . . .

Hasmulon macrostomum

plumieri

sciurus . . .
Iridio bivittatus. . . .
Kyphosus sectatrix .

Lachnolaimus maximus.
Lactophrys triqueter. . . .

Lycodontis funebris ....

moringa

Mycteroperca bonaci . . .
venenosa .

Neomaenis analis

apodus

griseus

Ocyurus chrysurus

Pomacanthus arcuatus.

Scarus caeruleus . .
croicensis .

sp.

Sphyraena barracuda.

Teuthis caeruleus

hepatus

Tylosurus marinus . . .
Caretta caretta

6 Character of food not recognized.

3 Red sponge and associated material, worm-

tubes, coralline and other vegetable ma-
terial.

i Alimentary canal empty.

i Character of food not recognized.

ii j Annelids, broken shells, isopods, spines of
sea-urchin.

4 : Annelids, small arthropods.
33 Small annelids.

2 ! Fragments of fish.

7 Crabs, fish, octopus.
ii Fish, crabs.

3 Annelids, fragments of sea-weed.

5 ! Annelids, fragments of crabs, mollusks.

i6g i Annelids, Crustacea, fish, octopus, spines and
test of sea-urchin.
26 Annelids, Crustacea, octopus, ophiurans.

6 Character of food not recognized.

7 Sea- weeds, small gastropods, ostracodes, iso-

pods.
1 Broken mollusk shells and fragments of Crus-

tacea.

5 Annelids in specimen in which distome was

found; in others sponges and vegetable de-
bris.

4 i Fish and Crustacea.
4 Fish.

1 Fish and crabs.

6 Fish.

1 Crustacea.

8 Crustacea.

69 Fish, Crustacea, mollusks, spines of sea-urch-

ins, kitchen refuse.

20 Annelids, crabs, fish.

14 Food evidently such as is browsed off the

reef; mainly red sponge and associated ma-
terial; sea-weed, fragments of Crustacea,
ascidians, annelids.

7 Crushed mollusk-shells, crabs, spines and test

of sea-urchin, sand.
4 I Chalky material, vegetable material, and

sand.
1 , Chalky material.
10 Fish.

8 , Annelids, scales of fish, vegetable debris.
7 Crustacea, fish, sea-weed, sand.

1 ! Fish.

3 Fragments of sea-weed and Palinurus in one;

vegetable debris in one; alimentary canal

of the other empty.

20 Papers from the Marine Biological Laboratory at Tortugas.

Key to the genera and species described in this paper.

Heteracotylea :

i. Body without tentacles elongate, paired anterior suckers 2

2. Posterior sucking-disk unarmed and without radial ridges. . Udonella socialis
Posterior elongated disk provided with numerous small suckers

Microcotylc incisa

ASPIDOCOTYLEA :

Large elliptical ventral sucker with numerous depressions, no oral
sucker, intestine not bifurcate ; one testis ; marginal sense-organs

Aspidogaster r in gens
Deontacotylea :

No suckers, mouth minute, intestine biramous, the rami with branches;
genital apertures separate at posterior end; body covered with
minute spines, oval Deontacylix ovalis

Malacotylea:

1. One sucker (oral) present (Monostomid.*) 58

2. Two suckers present 3

3. (a) An anterior sucker (acetabulum) and a small ventral sucker (oral)

(Gasterostomid^e) 4

(b) An anterior sucker (oral) and a small ventral sucker (genital)

(SlPHODERID^S) 5

(c) An anterior sucker (oral) and the acetabulum at the posterior end

(Paramphistomid.^) 11

(d) An anterior sucker (oral) and the acetabulum on the mid-ventral

surface (Fasciolid^e) 13

4. Gasterostomid.^. The species of the genus Gasterostomum could not

be satisfactorily determined on account of the poor condition of
the material. See figures 217-225.

5. SlPHODERIDvE 6

6. Testes more than one 8

One testis 7

7. Esophagus short or none, body ovate Gcnolopa ampullacea

Esophagus as long or longer than pharynx, body linear-oblong

Gcnolopa truncata

8. Testes two 9

Testes more than two Siphodcra vinalcdwardsii

9. Testes opposite, vitellaria compact 10

Testes tandem, uterus in front of testes vitellaria diffuse

Prodistomum gracile

10. Ovary behind testes, body subglobular Stcgopa globosa

Ovary between testes, body short-oval Metadena crassulata

1 1 . Paramphistomid.* 12

12. Lateral pharyngeal pockets and cirrus-sac present; no ventral papilla?;

testes slightly lobed . . Cleptodiscus reticulatus

13. Fasciolid^e 14

14. Pharynx present 15

No pharynx (immature) Distomum fenestratum

15. Ovary behind testes 45

Ovary in front of testes (beside testes in Dichadena, No. 43) 16

16. Vitelline glands compact 42

Vitelline glands diffuse or dendritic 17

1 7 . Body smooth 22

Body more or less spinose l 18

18. Without oral spines 20

With oral spines 19

1 Spines, both those on the body and neck and those around the mouth, are often deciduous.
There may be cases therefore of really spined forms described as spineless. See for example fig. 87,
which is plainly near the genus Stephanochasmus ,

Helminth Fauna of the Dry Tortugas. 21

Ovary in front of testes, vitellaria diffuse, more or less spinose.

19. Neck not slender, esophagus very short Stephanochasmus casus

Neck slender, esophagus about as long as pharynx . . .Stephanochasmus sentus

20. Two testes 21

One testis Hapladena varia

2 1 . Body short oval, esophagus short or none, testes diagonal . Lcpocreadium trulla
Body linear oval, esophagus distinct, testes nearly tandem

Lcpocreadium levenseni

Ovary in front of testes, vitelline glands diffuse, body smooth (except in Pachy psoitis) .

22. Testes two 25

One testis 23

23. Ventral sucker larger than oral, ova large 24

Suckers about equal, ova moderate Deradena ovalis

24. Ventral sucker nearly twice diameter of oral Deradena acuta

Ventral sucker about 1.25 times oral Deradena obtusa

25. Folds of uterus extend back of one or both testes 39

Folds of uterus not back of testes, at least not behind both 26

26. Head without appendages 29

Head with appendages 27

27. Intestinal rami not united at posterior end 28

Intestinal rami united at posterior end Enenterum aurcum

28. Head with short nodular papillae and ventral flap

Immature distome related to Calycodes
Head and neck with tentacular lobes Theledera pectinata

29. Seminal vesicle near anterior border of acetabulum 30

Seminal vesicle behind acetabulum Lcchradena edentula

30. Ova not filamented 33

Ova filamented 31

31. Vitelline glands extend into neck 32

Vitelline glands behind acetabulum Helicometra torta

32. Testes irregular Helicometra execta

Testes usually 5 right and 4 left Helicometrina nimia

23- Vitellaria extend into neck 3 5

Vitellaria do not extend into neck 34

34. Ventral sucker larger than oral Hamacreadium oscitans

Ventral sucker smaller than oral Mcgasolena cstrix

3 5 . Esophagus short 37

Esophagus long 36

36. Genital aperture median Hamacreadium consuetum

Genital aperture not median Hamacreadium mutabile

37. Testes diagonal, or nearly so 38

Testes opposite, or nearly so, body broad Didymorchis latus

38. Genital aperture median Hamacreadium gulella

Genital aperture not median Lebouria crassigula

39. Folds of uterus extend back of both testes 40

Folds of uterus mainly between the separated testes, but not behind the

posterior testis Orchidasma amphiorchis

40. Intestinal rami without lateral projections 41

Intestinal rami with lateral projections Pachy psoitis ovalis

41. Intestinal rami long Mesolccitha linearis

Intestinal rami short Cymatocarpus undulatus

Ovary in front of testes, vitelline glands compact.

42. Testes tandem 4^

Testes opposite 44

43. Ovary in front of testes Diplangus paxillus

Ovary beside testis Dichadcna acuta

44. Genital aperture lateral Deretrema fusillus

Genital aperture median, body subcircular in outline, neck linear

Xystretrum papillosum

22 Papers from the Marine Biological Laboratory at Tortugas.

Ovary behind testes.

45. Appendiculate 53

Not appendiculate 46

46. Testes behind acetabulum 47

Testes in front of acetabulum, spinose Mesorchis urna

47. Seminal vesicle in front of or dorsal to acetabulum 4Q

Seminal vesicle behind acetabulum 48

48. Vitelline glands with numerous lobes Macradena perfecta

Vitelline glands not lobed Opisthadena dimidia

49. Ovary in front of vitelline glands ' 50

Ovary behind vitelline glands Dictysarca virens

50. Body without papilla? 51

Body with coarse papilla? in mid-ventral region Thclctrum fustifortne

51. Vitelline glands not deeply lobed 52

Vitelline glands with long clavate lobes Brachadena pyriformis

52. Vitelline glands slightly lobed, body oval Leurodera decora

Left vitelline gland deeply, right slightly lobed Hysterolecitha rosea

53. Vitellaria tubular 56

Vitellaria not tubular 54

54. Body smooth • 55

Body serrate Hemiurns merits

55. Vitellaria moderately lobed Sterrhurus monticellii

Vitellaria with about 7 long-clavate, slender lobes Sterrhurus fusiformis

56. Body serrate 57

Body wrinkled, not serrate, greatly elongated posteriorly.. .Dinurus rubeus

57. Two dorsal eminences on neck Ectenurus virgula

No eminence evident Immature distome near Ectenurus

58. Monostomid^; 59

59. Anterior end somewhat triangular, a prominent muscular ridge separat-

ing it from the rest of the body 60

Body boat-shape Barisomum erubescens

60. Linear oblong, posterior end truncate with 2 small, postero-lateral pits;

intestinal rami with side projections Cricocephalus delitescens

Linear, strap-shape ; intestinal rami simple Himasomum candidulum

Helminth Fauna of the Dry Tortugas. 23

I. TREMATODES FROM LOGGERHEAD TURTLE.
Cricocephalus delitescens Looss. (Figs. 1-3.)

Zool. Jahrb., xn, pp. 666-667, 759-762, Taf. 31, figs. 76-80. ■

A single specimen, actively contractile, 4 to 10 mm. in length, is
referred to this species, although there are some differences between
its anatomy and that of C. delitescens as given by Looss. Unfortunately
the specimen, when stained and mounted, revealed but little of the
anatomy, and it was damaged in attempting to section it later. The
sketch (fig. 1) was made from the stained and mounted specimen, but
a few details were added from the fragments of the damaged sections.
It will be noted that the intestines lie laterad of the testes, which would
point to Looss 's genus Pronocephalus. On the other hand the presence
of the peculiar structures at the lateral angles of the posterior end of
the body, which are the principal justification for the erection of the
genus Cricocephalus, are quite distinct in this specimen. The descrip-
tion which follows is necessarily incomplete.

Body long-oval; head blunt, triangular, marked off from the body
proper by a distinct muscular eminence; posterior end truncate, with
a small sucker at each lateral margin. Oral sucker a little broader than
long; mouth with notch on posterior border; esophagus slender with a
pharyngeal enlargement at its base and followed immediately bv the
bifurcation of the intestine. The intestinal rami extend to the posterior
end of the body; anteriorly they have numerous short branches, but
at their posterior ends, which pass laterad of the testes, the branching
is not so evident. The structures at the postero-lateral angles of the
body appear to be small suckers. Each sucker consists of a slight con-
ical elevation, which, upon magnification, is seen to be shaped like a
low frustum of a cone hollowed out into a shallow pit. They are sur-
rounded by dense muscular tissue. The genital aperture is ventral at
the left side of the neck and near the lateral margin. The cirrus-pouch
is long and consists of three portions: proximal, middle, and distal,
reckoning from the anterior end. The proximal division contains the
retracted cirrus which is surrounded by prostate cells; the middle part
is cylindrical and contains the convoluted seminal duct; the distal part
is long oval-elliptical in outline, and contains the seminal vesicle, which
also is surrounded by prostate cells. Behind the cirrus-pouch is the
vas deferens, a comparatively capacious duct lying along the middle line
and extending as far as the vitelline glands. The testes are 2, lateral,
opposite, and near the posterior end of the body. The ovary is near the
antero-median border of the right testis and is situated a little to the
right of the median line. It appears to be slightly lobed. The shell-
gland is on the posterior border of the ovary between the testes. The
vitellaria are lateral and extend for a short distance forward from the
anterior borders of the testes. Each gland consists of a cluster of irregu-
larly rounded, compact masses. The uterus begins at the shell-gland
and passes to the anterior end of the body by a series of transverse folds
packed closely together and filling all of the body between the vitelline
glands and the anterior third of the body. The metraterm is capacious,

24 Papers from the Marine Biological Laboratory at Tortugas.

muscular, and lies parallel with the cirrus-pouch on its left side. The
ova are long-elliptical in outline, the longer diameter being more than 2.5
times the shorter. Each ovum is provided with a single filament at one
pole. In a few cases there appeared to be a filament at the other pole,
but in these cases the second filament did not appear to be a prolongation
of the shell as in the ordinary cases. The body -wall is thickly beset with
small, granular clusters which give a mottled appearance to the surface
of the specimen in balsam. These may be clusters of yolk-forming cells.

Host, Caretta caretta: July 1, 1906, one specimen.

Dimensions in balsam: Length 4.60; breadth 1.33; oral sucker,
length 0.34, breadth 0.38; posterior pit 0.10; ova 0.029 by 0.011; length
of ovum and filament 0.12.

Distomum sp., immature, related to genus Calycodes. (Figs. 4-6.)

The following description is based on a single immature specimen:
Body linear, rather stout ; at the anterior end there is a deeply emarginate
flap which is muscular and a continuation of the wall of the oral sucker.
This flap projects ventrally and overhangs the mouth like an upper lip.
There appear to be 4 low, lateral papillae on the head, one of each pair
being the lateral angle of the upper lip; oral sucker nearly twice the
diameter of the ventral sucker; pharynx moderate, pyriform; esophagus
long; bifurcation of the intestine at the ventral sucker which is situated
a little back of the middle of the length of the body. The intestinal rami
are thick- walled and extend to the posterior end of the body. The speci-
men is too immature to permit of satisfactory identification of the rudi-
ments of the genitalia. The genital aperture is at the anterior border
of the ventral sucker. Two small bodies, median, and near the posterior
end are probably rudiments of the testes. In front of the anterior of these
there is another small body which presumably represents the ovary.
In front of the latter there is a spiral tube which reaches to the ventral
sucker and doubtless is the uterus.

Host, Caretta caretta : July 4, i9°7> l specimen, immature.

Dimensions, life: Length 1.50; breadth 0.45; oral sucker 0.30;
pharynx 0.08; ventral sucker 0.17 ; breadth of head 0.33.

Dimensions in balsam: Length 1.40; breadth 0.43; length of neck
0.66; oral sucker, length 0.24, breadth 0.28; pharynx, length 0.10,
breadth 0.08; ventral sucker, length 0.14, breadth 0.15.

Pachypsolus ovalis sp. nov. (Figs. 7-14. )
Under moderate magnification this species appears to be smooth,
but when more highly magnified it is seen to be covered by a peculiar
layer consisting of slender, rod-like structures embedded in a fine gran-
ular matrix. This layer is rather thick and has a tendency to separate
from the underlying layer, or to disintegrate. A sketch representing
the species as spinose would be misleading. In cases where this layer
has partly disintegrated the outline left often presents the appearance
of being beset with slender rod-like or cilia-like structures. Indeed the
layer when intact is not unlike in appearance to a ciliated surface. The
most obvious difference between this species and P. irroratus (R.) Looss is.

Helminth Fauna of the Dry Tortugas. 25

to be found in the nature of the cirrus-pouch. In P. oval is it is relatively
short, reaching barely to the posterior edge of the acetabulum, while in
P. irroratus it extends far back of the acetabulum between the testes.
Body compressed, thickish when at rest; outline long-oval or ellipti-
cal, in some cases oblong with extremities bluntly rounded; living speci-
mens very active, the shape constantly changing; translucent with con-
spicuous excretory vessels. Oral and ventral sucker- about equal, the
latter about the middle of the body. Pharynx relatively large, longer
than broad, joined with oral sucker by a very short prepharynx; esoph-
agus very short, only discernible in sections. In transverse sections
the lumen of the pharynx, at its anterior end, is surrounded by 4 blunt,
tooth-like lobes (fig. 11). The rami of the intestines are capacious,
sacculate, with thick mucous membrane composed of large, granular
cells. In some preparations these cells have striated borders. The
intestines extend to the posterior end of the body. Each ramus sends
2 or 3 short diverticula? forward. The first diverticulum on each side
lies beside the pharynx and extends cephalad as far as the anterior end
of the pharynx. The genital aperture is immediately in front of the
ventral sucker, close to its anterior border, and a little to the left of the
median line. The cirrus-pouch, in most cases, lies along the anterior
border and right side of the ventral sucker; the anterior portion contains
the cirrus surrounded by prostate cells, the posterior portion contains
the convoluted seminal vesicle. There are some variations in the posi-
tion of the cirrus-pouch and of the genital aperture, as well as in the
proportions of the prostate and seminal vesicle. In the majority of
the cases examined the prostate occupied a little more than half the
length of the cirrus-pouch, and the genital aperture was very close to
the anterior border of the ventral sucker. Testes 2, opposite, lobed,
close behind the ventral sucker. The ovary is subglobular, subtriangular
to oval-elliptical in sections, and lies very close to the posterior border
of the ventral sucker, a little to the right of the median line, in front of
the right testis and close to its antero-median border. The shell-gland
with the seminal receptacle on its lateral border is dorsal to the ovarv.
Where best seen the seminal receptacle is globular and dorsal to the
posterior edge of the ovary. Laurer's canal opens dorsally opposite the
posterior border of the ventral sucker and near the median line. The
position of the vitellaria, as seen in the larger specimens in balsam, is
lateral and dorsal from a point on a level with the anterior edge of the
ventral sucker, then lateral only as far back as the posterior edge of the
testes. In other cases they extend from the anterior edge of the ventral
sucker or slightly in advance of that point to a point about midway
between the testes and the posterior end. In sections they were seen
to extend laterally nearly to the posterior end. They are diffuse and
somewhat dendritic. The voluminous folds of the uterus fill the body
behind the testes extending forward between the testes and dorsal to
them to pass to the left of the cirrus-pouch, where, as the metraterm,
it lies parallel to the cirrus-pouch and opens along with the cirrus at the
genital pore. The excretory vessels, while presenting very many differ-
ences of detail, were in general as represented in the sketch (fig. 14).

26 Papers from the Marine Biological Laboratory at Tortugas.

They are irregularly branching and unite behind the ventral sucker.
In general there are 2 main lateral branches, but with transverse con-
necting vessels in front of the ventral sucker and in the vicinity of the
pharynx, and are confluent in the head region.

Host, Caretta caretta: June 29, 1907, 275 distomes, collected from
the intestine of one turtle.

Some of the distomes were opaque white, thickish, and quiet; others
were translucent and very active. The larger of each kind about the same
size, 4 mm. in length. The smallest were without ova. One of the smaller,
quiet specimens measured 1.61 in length and 0.67 in breadth. The two
kinds do not differ much after they have been in alcohol.

Dimensions of one of the larger, active specimens, flattened and
fixed over the flame: Length 3.8; breadth 1.6; oral sucker, length 0.56,
breadth 0.64; pharynx, length 0.33, breadth 0.28; ventral sucker 0.63;
ova 0.042 by 0.015.

Dimensions of another taken from sections: Length 2.76; breadth
0.84; length of neck 1; oral sucker 0.50; pharynx, length 0.28, breadth
0.21 ; ventral sucker 0.50; ova 0.047 by 0.020.

The ova in a small specimen, which was 1.54 in length, measured
0.030 by 0.015.

Cymatocarpus undulatus Looss. (Figs. 15-22.)

Zool. Jahrb., xn, pp. 593-594, Taf. 27, figs. 32, 33, 34.

Body moderately thick, broadest in front of ventral sucker, some-
what narrowed posterior to ventral sucker; when flattened often spatu-
late. Color translucent white except in uterine portion, which in adult
individuals is characteristically colored by the eggs, the folds on the right
side being dark-brown and those on the left side lemon-yellow. The
body is covered with very dense, fine spines. Suckers about equal;
ventral sucker a little in front of the middle of the body; pharynx small,
adjacent to oral sucker ; esophagus long and slender ; intestinal rami short,
divergent, clavate, not reaching the ventral sucker. Genital aperture
near anterior border of ventral sucker. Copulatory apparatus large
and complex. The large cirrus-pouch curves around the left side of the
ventral sucker. At the base of the cirrus there are a number of small
bursse (about 4 small and 2 large) lined with fine spines. The cirrus
is peculiar and difficult to understand. Besides the base, already men-
tioned, there is a cylindrical portion with fine, short spines and compact
walls, i.e., its component muscle fibers not unusually coarse. Following
the cylindrical portion is a shorter, slightly enlarged portion with very
coarse, circular muscle fibers. Following this and between it and the
seminal vesicle there is a short, cylindrical portion with moderately
strong fibers. In this portion the circular and longitudinal fibers are
about the same size, giving the effect of a sieve or grating. Beyond this
is an oval sac, the seminal vesicle, constricted at its distal end and with
a strong wall which is continuous with the cirrus wall. The cirrus and
seminal vesicle are both surrounded by the cells of the prostate and all
are inclosed in the strong walls of the cirrus-pouch (figs. 15 and 16).

Helminth Fauna of the Dry Tortugas. 27

The testes are 2, subglobular, oval in flattened specimens, situated
a short distance behind the ventral sucker and more or less diagonally
placed. The ovary is in front of the left testis and close to the cirrus-
pouch. On its posterior border and between it and the left testis is the
oval or pyriform seminal receptacle. The shell-gland lies mediad of
the ovary and seminal receptacle. Ducts from the vitellaria meet ducts
from the seminal receptacle and ovary near the distal end of the cirrus-
pouch. The vitellaria are somewhat racemose clustered bodies, lateral,
and extending from the anterior border of the testis on the right side
and from the anterior border of the ovary on the left forward to a point
about half-way between the two suckers. The broad neck is filled with
large nucleated, peripheral cells, and the inclosed parenchyma contains
much granular material which appears in rather ill-defined spaces. I
interpret these cells as yolk-forming cells, the granular material as yolk
stuff, and the vitellaria as accumulated yolk (fig. 22). Beginning with
the shell-gland the uterus passes between the testes, its voluminous
folds filling the left side of the body behind the testes and returning by
equally voluminous folds on the right side. Again passing between the
testes it turns to the right and passing along the right side of the ventral
sucker it expands into the capacious and muscular metraterm which is
surrounded by glandular cells and opens with the cirrus at the genital
pore. The main excretory vessel was seen in sections to begin dorsal
to the pharynx, where it occurred in 1 section. In the 9 succeeding sec-
tions the excretory vessel appeared as a vertical slit beside the esophagus.
It then passed to the ventral side of the esophagus whence it continued,
in 6 sections, to the bifurcation of the intestine (figs. 18 and 19). In the
next 3 sections it passed dorsally between the intestinal rami. Thence
it passed on the dorsal side of the cirrus-pouch, then descending a little
to lie directly on the ventral sucker. It then passed ventrad to the
posterior end of the cirrus-pouch and seminal vesicle, between the testes,
then dorsal to the folds of the uterus, where for a time it was indistinct
because its walls were pressed close together by the distended uterus
Toward the posterior end it became more distinct again and was traced
to the terminal excretory pore which is guarded by a number of triangu-
lar valve-like flaps (fig. 21) The same sequence was found in two other
sets of transverse sections. The nature of the excretorv system presents
the only important difference between my specimens and Looss's species.

Host, Caretta caretta:

1906, July 1, very numerous, approximately 3,000.

1907, June 29, 130; July 4, numerous.

The following note is extracted from notes made at the time of
collecting: On July 1 the stomach and intestine of a loggerhead turtle
were examined. There was no food, but the mucous membrane of the
intestine as far as the rectum was thickly peppered with small, black
spots which proved to be small distomes. There were about 50 to the
square inch in a surface 18 inches long by 3 inches broad. The dark
color is due to the eggs which are collected in a mass at the posterior
end of the distome. Specimens which had lain in sea-water overnight

28 Papers from the Marine Biological Laboratory at Tortugas.

and were somewhat flaccid were measured after they had been flattened
under the cover-glass. The longest were 5.5 mm. in length and 2 mm.
in breadth; the smallest 2 by 1 mm. More detailed dimensions of the
larger specimen are: Length 5.5, breadth 2; breadth, through anterior
sucker 1, between suckers 1.8, at ventral sucker 1.5, between ventral
sucker and posterior end 1.4, near posterior end 0.7; oral sucker, length
0.28, breadth 0.30; pharynx 0.11; ventral sucker 0.28; distance from
oral sucker to forks of intestine 1.9; length of rami of intestine 0.7;
greatest breadth of intestine 0.25; ova 0.024 by 0.012.

Orchidasma amphiorchis (Braun) Looss. (Figs. 23-28.)

Braun, Mitt. a. d. Zool. Mus. Berlin, Bd. 11, 1901, p. 20, Taf. 1, figs. 7, 11.
Looss, Centralbl. f. Bak., Par. u. Infek., Bd., xxx, 1901, p. 560; Zool. Jahrb.,
xvi, 1902, pp. 500, 502.

Body of various shapes, but prevailingly linear, sometimes vase-
shape, usually rounded in front and slightly contracted back of the head,
posterior end narrowing to a blunt point, anterior end densely covered
with short spines. Oral sucker about twice the diameter of the rather
weak ventral sucker ; pharynx a little less than half the diameter of the oral
sucker, its length about equaling its breadth. There is a short prepharynx
and an esophagus about equal in length to the pharynx. Intestinal rami
with rather thick walls and extending to the posterior end of the body.
Genital aperture on median line at anterior edge of ventral sucker.
Cirrus-pouch very long, the retracted cirrus lying in convoluted folds
behind the ventral sucker. It is thickly beset with relatively large spines.
Testes 2, small, subglobular, remote from each other, with folds of the
uterus between them. One testis is near the posterior end of the body,
the other a little behind the middle. Seminal vesicle inclosed in cirrus-
pouch at its distal end. Cirrus surrounded by prostatic cells. Ovary
small, lying close to antero-dorsal surface of anterior testis. In most
cases it can be seen only in dorsal view. Seminal receptacle dorsal to
anterior testis and protruding beyond its right anterior edge. Shell-
gland on medial side of seminal receptacle. Vitelline glands marginal,
extending from anterior testis, or a little in front of it, to the anterior edge
of the ventral sucker or not quite so far, made up of small, subglobular
bodies. The folds of the uterus lie between the testes and in front of the
anterior testis. The uterus ends in a capacious, muscular metraterm,
which, like the cirrus, is lined with relatively large spines. These spines
are larger at the distal end than they are near the genital aperture. The
spines in both cirrus and metraterm have basal supports. Ova small,
short-oval or circular in outline, with thick shells.

In some of the mounted specimens there were numerous, dark-
colored, slender, bristle-like structures in the lumen of both the cirrus
and metraterm.

Dimensions in balsam.

Length

Breadth

Oral sucker. . . .
Ventral sucker
Pharynx

2-31
0.63
°-33
o . 16

0.13

.46

2 .

•37

0 .

.28

0.

• 14

0 .

. 11

0 .

.66
.45
•32
.16

1.42
0.58
0.25
o. 16
o . 11

Helminth Fauna of the Dry Tortugas.

29

Dimensions of ova: 0.034 by 0.040; 0.037 by 0.030; 0.040 by 0.040.

Thickness of shell 0.0034.

Host, Caretta caretta : June 29, 1907, 12 specimens, in stomach.

II. TREMATODES FROM FISH.

MALACOTYLEA.

FASCIOLIDjE.

Comparative table of the Allocreadiince described in this paper.

Shape.

Length.

Breadth.

Oral
sucker.

Pha-
rynx.

Ratio

Ventral of neck Esoph-

sucker., to agus.

length.

Helicometra

torta
Helicometra

execta.
Helicometrina

nimia.
Hamacreadium

mutabile.

Hamacreadium

gulella.
Hamacreadium

consuetum.
Hamacreadium

oscitans.
Lebouria cras-

sigula.

Oval

1. 18 to 3.08 0.05 to 0.77 O.I

Linear, oval, 0.43102.450.27100.70 0.17

pyrif.,etc.
Oval, fusi- 1.04 to 2.46 0.58 to 0.91 0.15
form, etc.

Various 1.5 to 4:0.98 0.22

5.5 max.,
life.
Oval 1.85 0.67

Ovate 0.77 to r.61 0.46

Oval 1.37 0.48

1.54 'o.66

Oval-ellipti-
cal.

0.15
0.15
0.15
0.25

o . 11
o . 10
0.08
0.15

0.08
o .06
o .07

0.15

o .40
0.21
o . 29

= ph.+
= ph.+
= ph.+

0.33

I —

= ph.+

0 . 24

§ +

short.

O. 21

1
3

= ph.+

0.43

3 +

= ph.+

°-35

3 +

short.

Genital

Pros-

Yolk-
glands.

aper-
ture.

tatic
cells.

Ovary.

Testes.

Ova.

Helicometra

Median .

Many .

About 3-lobed

2 diagonal, faint-

To uterus. . .

0.06 by 0.03 fila-

torta.

ly lobed.

mented.

Helicometra

Median .

Many .

About 4- to 5-

Variable

About to

0.0s by 0.03 fila-

execta.

lobed.

pharvnx.

mented.

Helicometrina

Median .

Few . .

Much lobed. . .

Usuallv 5 right

To fork of

0.05 by 0.03 fila-

nimia.

and 4 left.

intest.

mented.

Hamacreadium

Left

Many .

Much lobed. . .

2 diagonal,

To fork of

0.078 by 0.031

mutabile.

slightly lobed.

intest.

Hamacreadium

Median .

Few . . .

About 4-lobed

2 oval, diagonal.

To fork of

0.078 by 0.044.

gulella.

intest.

Hamacreadium

Median .

Many .

Lobed vari-

2 oval, diagonal.

To pharynx.

0.052 by 0.039.

consuetum.

able.

Hamacreadium

Median .

Few. . .

About 4-lobed

2 oval, diagonal.

To ventral

0.044 by 0.031.

oscitans.

sucker.

Left ....

Few. . .

Oval

0.07 by 0.04.

sigula.

er.

Helicometra torta sp. nov. (Figs. 29-33.)

Body oval or long oval, often folded or crumpled and yellowish
green in life; neck rather short in preserved specimens; ventral sucker
2 to 2.5 times the diameter of the oral sucker, usually with its aperture
longitudinal; oral sucker usuallv nearly circular in outline, but ventral
sucker in most cases longer than broad. There is a short prepharvnx.
The pharynx is somewhat variable, in some cases about as broad as long,
in others cylindrical and much longer than broad. The esophagus is
slender and as long or longer than the pharynx. The intestinal rami
extend to the posterior end of the body. Reproductive aperture median,
near the posterior end of the pharynx. The cirrus-pouch passes dorsad

30

Papers from the Marine Biological Laboratory at Tortugas.

and caudad, its basal portion containing the seminal vesicle and lying
dorsal to the anterior border of the ventral sucker, or, in contracted
specimens, along the right border of the ventral sucker. The prostate
gland is represented by many cells inside the cirrus-pouch, around the
ejaculatory duct and folds of the seminal vesicle. The testes are 2, close
together, one behind the other, or very slightly diagonal, oval, or, under
pressure, more or less lobed. Ovary close to anterior border of anterior
testis, a little to the right side, lobed, especially on the posterior border,
where usually about 3 lobes can be distinguished. A yolk-reservoir, in
most cases pyriform in shape, lies dorsal and in front of the ovary, and
a seminal receptacle in front of the yolk-reservoir toward the left side.
The vitelline glands are diffuse masses along the margins from the pos-
terior end to the posterior folds of the uterus, and in two rows behind
the posterior testis, one on each side of the median line; uterus in close
wreath-like folds between the ovary and the ventral sucker. The ova
are arranged in orderly fashion, the filaments being joined in such a way
as to make it appear that the ova are so many beads pendent from a
supporting cord. The excretory vessel is not evident in the mounted
specimens, but was noted in life to be a conspicuous, dark-brown vessel
extending from the posterior end of the body to the ovary.

The following measurements are from 6 specimens mounted in
balsam:

Length.

Length of neck.

Diameter of

Diameter of

breadth.

oral sucker

pharynx.

ventral sucker.

308

0.77

0.77

0.18

0 . 11

0 .40

2.38

0.75

0.35

0.17

0.08

0-35

2 . 10

0.50

0.34

0.15

0 .06

o.35

1.76

0.56

0.43

0.14

0 .06

0.28

1 -54

0-53

0.43

0.12

0 .06

0.28

1. 18

0.50

0.3s

0. 14

0 .06

0.30

The diameters given are transverse.

The ova are about 0.06 by 0.03 mm. Filaments in living specimens
0.17 mm. in length.

Some details of the anatomy of this species will be found in the
figures. An interesting feature is shown in fig. 33, viz., the peculiar shape
of the germ cells when they are mature and ready to enter the ootype.

This species was found in the following hosts:

Host, Epinephelus striatus: 1906, July 7, 3 fish examined; 1 distome.

Dimensions, flattened: Length 3.15; breadth anterior 0.35, middle
0.98, posterior 0.63; diameter oral sucker 0.23, pharynx 0.18, ventral
sucker 0.51 ; ova 0.047 DY °-°23 J length of filament 0.17.

1906, July 8, 1 fish, 3 distomes; July 12, 2 fish, few distomes; July
13, 1 fish, 8 distomes.

1907, July 2, 1 fish, 8 distomes; July 8, 1 fish, 2 distomes.
Host Epinephelus morio:

1907, July 4, 1 fish, 4 distomes; July 8, 1 fish, 2 distomes.

1908, June 28, 1 fish, 2 distomes; June 30, 1 fish, 6 distomes; July 1,
2 fish, 3 distomes; July 3, 1 fish, 5 distomes.

Helminth Fauna of the Dry Tortugas.

:;i

Dimensions of one flattened: Length 2.17; breadth 1.08; diameter
of oral sucker 0.23; pharynx 0.11; ventral sucker 0.50; ova, exclusive
of filament, 0.054 by 0.027.

Helicometra execta sp. nov. (Figs. 34-39.)

Body variously shaped, linear, oval to pyriform; ventral sucker
from 1.25 to twice the diameter of the oral sucker; pharynx subglobular,
preceded by a very short prepharynx; esophagus relatively long; intes-
tinal rami extend to near the posterior end; genital aperture median,
at bifurcation of the intestines; cirrus-pouch cylindrical, median, or its
posterior end deflected to the right. In any case the principal length
of the cirrus-pouch is in front of the ventral sucker ; prostate represented
by many cells which surround the ejaculatory duct. Testes variable; in
some specimens they were not present; in others they were represented
only by loose aggregations of testicular cells, as if the organ was almost
spent. In those individuals in which testes were present there was little
uniformity. In some there was but one testis, which corresponded in
appearance and position with the left anterior testis of Helicometrina
nimia. In other cases (figs. 38a, 38J) there was a single median testis
immediately behind the ovary. In others no testis was present (fig. 38c).
This figure was drawn from the ovary of one of the largest mounted
specimens in my collection, 2.45 mm. in length. The specimen is stained
and mounted in balsam and shows the details of structure very well.
The testes have entirely disappeared. The ovary is lobed; usually 4 or 5
lobes can be made out. It lies transversely about half-way between the
ventral sucker and the posterior end. Anterior and dorsal to the ovary
is a transversely placed yolk-reservoir which receives ducts from each
side, and dorsal to this is the seminal receptacle. The shell-gland lies
on the anterior and dorsal border of the ovary. The vitelline glands are
diffuse, posterior, and marginal, and extend forward about to the pharynx.
Behind the ovary they tend to form 4 parallel, longitudinal rows, the
2 on one side of the median line being separated from each other by the
intestine, and the 2 median rows having the excretory vessel between
them. The wreath-like folds of the uterus lie between the ovary and
the ventral sucker. Each ovum is provided with a long filament and
their arrangement in the uterus is similar to that of Helicometra torta.
The excretory vessel is inconspicuous in the mounted specimens. It
appears to be essentially like that of the preceding species.

Following are measurements of specimens mounted in balsam:

I. From Hccmitloii phtmieri.

Length.

Breadth.

Length of
neck.

Diameter of
oral sucker.

Diameter of
pharynx.

Diameter of
ventral
sucker.

Dimensions of ova.

2.45
2.03
1. 6S
1.47
1 .40
1 .40
1 .04

0 . 70
0. 70
0.56
0.56
0.63
0.56
0.36

0
0
0

°
0
0
0

80
73
56
52

70
56
38

0 . 17
0.18
0.14
0. 14
0.13
0.14

O.IO

0 . 10
0 . 10
0.08
0 .07
0.07
0.07
0.08

0
0
0
0
0
0
0

21
28
27
24
24
21
22

0.051: 0.031
0 .051: 0.034

32 Papers from the Marine Biological Laboratory at Tortugas.

II. From Chlorichthys bifasciatus.

I .00
0 . 72
0 . 70
0.50
0.43

0 .46

0.31

o-3S
0.21
0.21

0.36
0.28
0 . 26

0 .22
0 .21

0.17
0.13
0.17
0.13
0.13

0 .054: 0.027

0 .050: 0 .024
0.051: 0.027
0.051: 0.027

0.08
0 . 1 1
0 .06
0 .06

0 .04
0 .06
0.03
0.03

It will be observed that the most striking difference between this
and the preceding species is in the character of the testes, the greater
anterior prolongation of the vitelline glands, and the range in size. In
this species adults with ova range from 1 mm. to 2.45 mm., while those
from Chlorichthys are all small, varying from 0.43 to 1 mm. in length.
The difference in size between the distomes from these two hosts is very-
marked. This leads to a decided difference in appearance. In the small
distomes the number of ova is very few, while the size of the ova remains
the same as in the larger distomes from Hcemulon. I do not feel justi-
fied at present in placing them in different species, but prefer rather to
regard the differences as due to the fact that they are living in hosts
which are not closely related.

Variability of Testes. — Five of these small distomes were examined,
with the following result: (1) 1 testis, median; (2) no testis seen, (3)
1 testis, median; (4) 2 testes, 1 left, 1 right; (5) 1 testis, transverse,
faintly bilobed. The cells of the testes were loosely clustered as if the
organs were disintegrating. Ovary variously lobed.

This species was found in the following hosts:

Host, Hcemulon plumieri:

1906, July 5, 6 fish, 7 distomes; July 15, 1 fish, 9 distomes; July 13,
2 fish, 1 distome.

1907, June 28, 2 fish, few distomes; July 3 and 4, 16 fish, many
distomes; July 10, 12 fish, few distomes; July 13, 6 fish, few
distomes.

1908, July 1, 7 fish, few distomes; July 14, 14 fish, few distomes.
Dimensions in life, flattened: Length 1.54, breadth 0.75; diameter

of oral sucker 0.14, pharynx 0.07, ventral sucker 0.25 ; ova 0.048 by 0.027
excluding filament.

Host, Hcemulon sciurus:

1907, June 28, 1 fish, few distomes; July 12, 3 fish, 1 distome.

Host, Chlorichthys bifasciatus:

1907, July 1, 1 fish, 4 distomes; July 8, 1 fish, 2 distomes.

Various shapes, linear to pyriform. Dimensions, life: Length 0.73,
breadth 0.23; diameter oral sucker 0.07, ventral sucker 0.14; ova 0.056
by 0.028. Another, length 1.15, breadth 0.45, pharynx 0.07, oral sucker
0.13, ventral sucker, 0.22; ova 0.054 by 0.027.

Host, Iridio bivittatus: June 28, 1907, 6 fish, few distomes.

These were small, pyriform with slender neck in some, oval when
compressed. Dimensions, life, flattened: Length 1.22, breadth 0.59,
oral sucker 0.11, pharynx 0.08, ventral sucker 0.28; ova 0.042 by 0.018;
length of filaments about 0.18.

Host, Lachnolaimus maximus: July 18, 1906, 1 fish, 1 distome.

Helminth Fauna of the Dry Tortugas.

33

Helicometrina nimia gen. et sp. nov. (Figs. 40-48.)
I have adopted a suggestion made to me by Professor Pratt that
this form be placed in a new genus, but at the same time giving it a name
that would remind one of the genus Helicometra.

Body oval, but assuming various contraction shapes, fusiform, pyri-
form, etc., slightly nodular on head and neck; ventral sucker about 1.5
times the diameter of the oral sucker; neck one-third or more the length
of the body. There is a short prepharynx and the pharynx is longer
than broad; esophagus relatively long; genital aperture median, just
behind the bifurcation of the intestine; cirrus-pouch clavatc, inclosing
the tubular and convoluted seminal vesicle in its basal portion. The
cirrus-pouch may be wholly median, its base slightly overlapping the
anterior edge of the ventral sucker, or the base may lie along the antero-
lateral margin of the ventral sucker either on the right or the left side.
The prostate is represented by a few cells in the anterior portion of the
cirrus-pouch. Testes normally 9, usually in two longitudinal rows, one
row on each side of the median line in the posterior part of the body,
5 testes on the right side and 4 on the left. A few variations from this
order are noted below. Ovary median, ventral, and much lobed, in part,
at least, between the two anterior testes. A yolk-reservoir lies dorsal and
a little in front of the ovary, and a seminal receptacle on its right anterior
border. The vitelline glands are diffuse and lateral from the posterior
end to the bifurcation of the intestine, or a little in front of that point.
The wreathed folds of the uterus lie between the ovary and the ventral
sucker. The ova are filamented. The excretory vessel is not distinct
in the mounted specimens, but was noted in the living specimens as a
conspicuous median vessel extending from the posterior end, where it
may be greatly inflated, along the median line as far as the ovary.

While the testes are usually arranged in two longitudinal rows, 5 on
the right side and 4 on the left, one was noted with 4 on the right side
and 5 on the left (44c). Another was seen with 4 on the right and 5 on
the left, the extra testis being at the level of the second where there were
2 transversely placed instead of 1 (446). A similar doubling was noted
in another, where the last two testes on the right side were transversely
placed (44(f) .

Dimensions of specimens mounted in balsam.

Length.

Breadth.

Neck.

Oral sucker.

Pharynx.

Ventral sucker.

2 .46

0 .91

0.90

0.1s

0 . 10: 0 .08

2.31

0

77

0

84

0.14

0 . 10: 0 .07

25

25
28

2 .06

0

72

0

80

0 . 14

0 . 10: 0 .07

0

77

0

63

0.17

0 . 1 1 ; 0.08

1 .96

0
0

77
61

0

0

7°
70

0.18
0-13

0 . 10: 0 .08
0 . 1 0 : 0.07

0

24

0

63

0

71

0 . 14

0.10: 0.07

.

1.78

0

71

0

63

0 . 14

0 .08: 0 .07

1 -5i

0

60

0

57

0.15

0 . 1 1 : 0 .06

1.43

0

38

0

65

0 . 10

0 .06: 0 .05

18

0 5H

0 .42

013

0 .07: 0.06

0

17

The cirrus-pouch was on the right side of the ventral sucker in 4, on
the left side in 1, median in 5, right central in 1, and right median in 1.
3

34 Papers from the Marine Biological Laboratory at Tortugas.

The testes were 5 right and 4 left in 8 out of the 1 1 , in the other 3
they were 4 right and 5 left. The length of the ova, exclusive of the
filament, is about 0.05 and the diameter 0.03 mm.

This species was found in the following hosts:

Host, Neomcenis griseus:

1906, July 5, 11 fish, few distomes; July 9, 14 fish, few distomes;
July 10, 4 fish, few distomes; July 16, 4 fish, few distomes.

1907, July 7, 4 fish, few distomes; July 9, 5 fish, 7 distomes; July 14,
4 fish, 2 distomes; July 15,5 fish, few distomes.

Host, Ocyurus chrysurus:

1907, July 10, 3 fish, 1 distome.

1908, June 30, 3 fish, 1 distome; July 4, 1 fish, 3 distomes.
Host, Calamus calamus: July 10, 1907, 2 fish, 1 distome.

Host, Eupomacentrus leucostictus: July 2, 1908, 1 fish, 2 distomes.

HAMACREADIUM gen. nov.

Etymology: «!ja, together with; tcpsddtov, a morsel of meat.

Generic characters: Ventral sucker larger than oral; vitelline
glands diffuse, posterior, and lateral; testes 2, diagonal; cirrus-pouch in
front of ventral sucker, its base overlapping the ventral sucker for a
short distance, or deflected on the right or left anterior border of the
ventral sucker; ovary in front of testes, or on right side of anterior
testis, lobed; seminal vesicle inclosed in cirrus-pouch; seminal receptacle
dorsal to ovary; uterus usually entirely in front of ovary.

Hamacreadium mutabile gen. et sp. nov. (Figs. 49-54-)

Body of great variety of shapes, long-oval under compression, broad-
est and often emarginate at posterior end, tapering to anterior end;
head and neck sparsely nodular; ventral sucker usually about 1.5 times
the diameter of oral sucker; pharynx separated from oral sucker by a
short prepharynx; esophagus long and slender; intestinal rami extend
to posterior end of body. Genital aperture a short distance in front of
the ventral sucker, on the left side of the median line; prostate cells
clustered around the ejaculatory duct, most abundant near the genital
aperture; cirrus-pouch cylindrical, inclosing the seminal vesicle and
lying on the anterior border of the ventral sucker, often extending along
the right border of the ventral sucker. Testes 2, in some slightly lobed,
in others the lobation was not evident, largely on account of the obscura-
tion caused by the vitelline glands. In some specimens which had been
killed under pressure the testes were distinctly lobed. The testes are
near together and diagonally placed, in some cases about half-way
between the ventral sucker and the posterior end, in other cases they
are nearer the posterior end. Ovary much lobed, in front of right testis,,
the seminal vesicle lying on its dorsal side. The vitelline glands are
diffuse, on margins and behind testes, and extend into the neck a little
in front of the bifurcation of the intestines. Uterus between the ovary
and ventral sucker; ova relatively large. The excretory vessels are not
distinct in the mounted specimens. In living specimens a large median

Helminth Fauna of the Dry Tortugas. 35

vessel was seen. It was dark in color, extended from the posterior end,
and terminated abruptly in front of the cirrus-pouch.

Dimensions of a specimen from Neomcenis griseus, life, flattened:
Length 4; breadth, anterior 0.37, middle 0.98, posterior 0.93 ; oral sucker,
length 0.22, breadth 0.26; pharynx, globular, 0.15; ventral sucker 0.33;
ova 0.078 by 0.051.

Dimensions of a specimen with tiiangular outline and emarginate
posterior end, balsam: Length 2.30; breadth 0.94; neck 1.12; oral
sucker 0.24; pharynx 0.11 ; ventral sucker 0.34; ova 0.075 by 0.034.

Another with similar outline but with the posterior end bluntly
rounded: Length 3.02; breadth 0.77; neck 1.50; oral sucker 0.22;
pharynx 0.08; ventral sucker 0.32; ova 0.075 by 0.034.

In life the active specimens are flat and leaf-like, and greenish-
yellow, especially by transmitted light. The active specimens are elon-
gated and taper anteriorly. Others, not active, are thick, squarish,
opaque, and white.

This species was found in the following hosts:

Host, Neomcenis griseus:

1906, July 5,11 fish, numerous distomes; July 7, 4 fish, 4 distomes,
length of one of largest 5.5 mm.; July 9, 14 fish, 27 distomes;
July 10, 4 fish, 4 distomes; July 16, 4 fish, 4 distomes.

1907, July 7, 4 fish, numerous distomes; July 9, 5 fish, numerous
distomes.

1908, July 1, 1 fish, 13 distomes; July 4, 1 fish, 50 distomes; July 12,
4 fish, few distomes; July 14, 4 fish, 9 distomes.

Host, Neomamis apodus:

1907, July 1, 2 fish, 1 distome, immature; July 3, 4 fish, 20 distomes,
mature and immature; July 9, 2 fish, 12 distomes, immature,
with conspicuous excretory vessel, dark-brown; July 11, 1 fish,
1 distome, immature.

Host, Anisotremus virginicus: July 6, 1907, 1 fish, 1 distome.

Host, Ocyurus chrysurus: July 10, 1907, 1 fish, 1 distome, immature.

Host, Pomacanthus arcuatus: July 3, 1907, 1 fish, 1 distome, imma-
ture.

Hamacreadium gulella gen. et sp. nov. (Fig. 55.)

Here are described two distomes which were found with a lot of the
preceding species from Neomcenis griseus {Hamacreadium mutabile)
probably collected on July 4, 1908. They were not noticed to be dif-
ferent from the other species at the time of collecting.

Body oval, the greatest diameter behind the ventral sucker and
tapering gradually to the anterior end; mouth subterminal; neck more
than one-third the entire length; ventral sucker more than 1.5 times the
diameter of the oral sucker ; pharynx separated from the oral sucker by a
short prepharynx; esophagus very short. The intestinal rami appear
to extend to the posterior end. Genital aperture in front of ventral
sucker, about half-way between it and the bifurcation of the intestines,
median (in one of the worms it is nearly as far forward as the bifurcation) .
The cirrus-pouch inclosed the scanty prostate cells and the seminal ves-

36 Papers from the Marine Biological Laboratory at Tortugas.

icle, its base overlapping the anterior edge of the ventral sucker. The
metraterm lies on the left side of the cirrus-pouch. Testes 2, oval, about
half-way between the ventral sucker and the posterior end, diagonally
placed and near together. Ovary about 4-lobed on right of median line
near right anterior border of anterior testis. Vitelline glands diffuse,
somewhat scattered, behind testes, and marginal to about the level of the
bifurcation of the intestines. Uterus between anterior testis and ven-
tral sucker; ova large. Excretory vessel a straight, median tube from
the posterior end to caudal edge of ovary where it divides, the 2 lateral
branches reaching the level of the pharynx. Numerous anastomosing
vessels surround the oral sucker (fig. 5 5 exv) .

Dimensions in balsam: Length 1.85; breadth 0.67; neck 0.71; oral
sucker 0.15; pharynx 0.08; ventral sucker 0.24; ova 0.078 by 0.044.

Hamacreadium consuetum gen. et sp. nov. (Figs. 56-59.)

Body ovate, flattened, oral sucker subterminal, pharynx adjacent to
oral sucker; esophagus usually as long as pharynx or longer; intestinal
rami extend to the posterior end of the body; ventral sucker 1.5 times
the diameter of the oral sucker, or more. Neck approximately one-
third the entire length. Reproductive aperture median, immediately
behind the bifurcation of the intestines. Cirrus-pouch overlaps anterior
edge of ventral sucker, or it may pass for a short distance to one side,
usually the right, but it was not seen to reach as far as the middle of the
ventral sucker. The seminal vesicle and prostate gland are both inclosed
in the cirrus-pouch. Testes 2, oval, one diagonally behind the other on
opposite sides of the median line, about midway between the ventral
sucker and the posterior end. Ovary lobed, somewhat variable, near
anterior border of posterior testis, with the oval seminal receptacle on its
dorsal surface, in some cases extending much beyond the anterior border
of the ovary. Vitelline glands diffuse, along margins as far forward as
the pharynx. Folds of the uterus between the testes and the ventral
sucker. The metraterm passes to the left of the cirrus-pouch to the
genital aperture; ova relatively large with a tubercle at one pole.

The principal variations noted in the distomes referred to this
species were in the position of the cirrus-pouch and in the outlines of
the ovary. The cirrus-pouch in worms which were well extended lay
in front of the ventral sucker with the posterior end but slightly over-
lapping. In those which were more or less contracted the cirrus-pouch
lay at one side of the anterior border of the ventral sucker, but did not
extend as far as the middle of that organ. The ovary is sometimes dif-
ficult to make out on account of the dense masses of yolk-gland which
often overlie it. In some it appeared to be bilobed, but usually deeper
focussing or viewing from the opposite side brought another lobe into
view. In one specimen there were as many as 5 lobes visible. The
seminal receptacle is dorsal to the ovary, as shown in the figure, and
extends much in advance of the ovary. This was the case in the 5 -lobed
ovary.

Some are much more broadly ovate than the one shown in fig. 56.
This was particularly true in specimens from Hamulon sciurus. In these,

Helminth Fauna of the Dry Tortugas. 37

moreover, the ovary, while lobed, had a tendency to be elongated and to
lie with its long axis inclined to the axis of the body. In some the testes
are relatively nearer the posterior end than they are in the one figured.

Mounted specimens, with ova, vary from 0.77 to 1.61 mm. in length.

Dimensions of specimen in balsam: Length 1.55; breadth 0.46; oral
sucker 0.15; pharynx 0.06; ventral sucker 0.27; ova 0.052 by 0.039;
length of neck 0.56.

This species was found in the following hosts:

Host, Hcemulon plumieri:

1906, July 5, 6 fish, few distomes; July 13,2 fish, 1 distome; July 15,
1 fish, 1 distome.

1907, July 3, 16 fish, few distomes; July 12, 12 fish, few distomes.

1908, July 9, 3 fish, 3 distomes.

Host, Hcemulon sciurus: 1908, July 5, 6 fish, few distomes.

Dimensions, life, flattened: Length 1.37; breadth 0.63; oral sucker
0.17; pharynx 0.06; ventral sucker 0.32; ova 0.051 by 0.034.

Dimensions, life, of a specimen from H. plumieri: Length 1.90;
breadth 0.70; oral sucker 0.22; pharynx 0.08; ventral sucker 0.36; ova
0.051 by 0.034.

Hamacreadium oscitans gen. et sp. nov. (Figs. 61-633.)

Body oval, usually broadest a short distance back of ventral sucker
and tapering scarcely at all at the posterior end; neck bluntly conical,
about equal to one-third the entire length. In some the greatest thick-
ness is at the ventral sucker. The ventral sucker is rather more than
1.5 times the diameter of the oral sucker; pharynx close to oral sucker;
esophagus about as long as the pharynx ; intestinal rami extend to the
posterior end. Genital aperture median at the bifurcation of the intes-
tine; cirrus short, the small prostate and seminal vesicle inclosed in the
cirrus-pouch which lies in front of the ventral sucker, its basal end over-
lapping the ventral sucker a very little. The testes are 2, close together,
diagonally placed, about half-way between the ventral sucker and the
posterior end, not lobed. The ovary is about 4-lobed and is on the right
side at the anterior border of the right testis. The seminal receptacle is
on the dorsal side of the ovary. The vitelline glands are diffuse, densely
packed behind the testes, marginal to the posterior edge of the ventral
sucker. The uterus is between the ventral sucker and the testes and
ovary; ova with small tubercle at one pole. The metraterm lies on the
left side of the cirrus-pouch. The excretory vessels were not seen.

This species was found in the following hosts:

Host, Hcemulon plumieri:

1907, July 4, 8 fish, 1 distome; July 5, 12 fish, 1 distome.

1908, July 6, 5 fish, 1 distome; July 10, 12 fish, few distomes.
Dimensions, balsam: Length 1.37; breadth 0.48; neck 0.43; oral

sucker 0.15; pharynx 0.07; ventral sucker 0.43; ova 0.044 by 0.031.

Host, Hcemulon sciurus:

1907, July 5, 6 fish, few distomes.

Dimensions, balsam: Length 1.40; breadth 0.70; neck 0.33; oral
sucker 0.16; pharynx 0.07; ventral sucker 0.31 ; ova 0.046 by 0.027.

38 Papers from the Marine Biological Laboratory at Tortugas.

Host, Anisotremus virginicus: July 6, 1907, 1 fish, 2 distomes.
Dimensions in balsam: Length 1.29; breadth 0.59; neck 0.48; oral
sucker 0.17 ; pharynx 0.07 ; ventral sucker 0.31 ; ova 0.041 by 0.027.

Lebouria crassigula sp. nov. (Fig. 60.)

This species resembles Lebouria idonea Nicol, but the habit is more
stocky than in that species, and the dense vitellaria meet in front of the
intestinal bifurcation.

Body short oval or oval-elliptical; diameter of ventral sucker 1.25
to 1.33 times that of the oral sucker; pharynx relatively large ; esophagus
apparently very short ; intestinal rami not distinctly seen but appear to
reach to the posterior end ; genital aperture a short distance in front of the
ventral sucker on left side of the median line ; cirrus-pouch nearly cylin-
drical, lying along the anterior and right antero-lateral border of the ven-
tral sucker, the seminal vesicle being included in its basal portion ; pros-
tate cells few, mainly anterior to the seminal vesicle; metraterm on left
side of the cirrus-pouch. Testes 2, near together on the median line,
little if any diagonal, and near the posterior end of the body, oval.
Ovary oval, on right side of the median line a short distance in front of
the testes; seminal receptacle dorsal to the ovary and projecting caudad
of its posterior border; vitelline glands very dense, obscuring the intes-
tines, posterior and lateral, extending forward to the posterior edge of the
oral sucker and meeting in front of the intestinal bifurcation ; uterus
between testes and ventral sucker; ova large.

Host, Calamus calamus:

1907, July 6, 1 fish, 1 distome, immature.

1908, June 28, 2 fish, 1 distome; July 8, 5 fish, 2 distomes.
Dimensions, life: Length 1.54; breadth 0.66; oral sucker 0.25; phar-
ynx 0.15 ; ventral sucker 0.35 ; ova 0.068 by 0.040.

Dimensions of another, in balsam: Length 1.33, breadth 0.52, neck
0.53; oral sucker 0.24; pharynx 0.15; ventral sucker 0.29; ova 0.07 by
0.04.

Megasolena estrix gen. et sp. nov. (Fig. 64.)

Etymology: fiiya?, large; <rwkrjv. pipe.

Body nearly linear in outline, tapering slightly at posterior end and
abruptly truncate anteriorly. Mouth nearly terminal, oral sucker and
pharynx about same size and each larger than the ventral sucker. The
musculature of the ventral sucker is weak, while that of the oral sucker
and pharynx is strong. Genital aperture in front of ventral sucker;
cirrus-pouch with relatively thick wall and inclosing the short cirrus and
seminal receptacle. It lies in front of the ventral sucker. The prostate
lies alongside the cirrus-pouch and extends posteriorly on the right side
of the ventral sucker. The cirrus-pouch is contiguous with the anterior
border and the prostate extends to about the middle of the ventral
sucker. There is a distinct prepharynx and an esophagus which is
longer than the pharynx. The bifurcation of the intestine is dorsal to the
ventral sucker and the rami extend to the posterior end. The prephar-
ynx, pharynx, esophagus, and intestines are all relatively large. The

Helminth Fauna of the Dry Tortugas. 39

ovary is small, subspherical, situated near the median line, a little to the
right and a short distance behind the ventral sucker. The shell-gland
lies on the antero-dorsal border of the ovary and the seminal receptacle
a little in front of the ovary and to the right of the shell-gland. The
testes were subglobular in life, ovate-elliptical in the mounted specimen.
They lie close together on the median line, one behind the other, a short
distance back of the ovary. The vitelline glands are diffuse and occupy
nearly the whole space marginal and posterior to the ovary and testes,
but do not extend quite as far forward as the posterior border of the
ventral sucker. The ova are few, relatively large, and lie between the
anterior testes and the ventral sucker. The metraterm passes dorsad
of the cirrus-pouch and opens at the common genital aperture. The
excretory vessel was not seen, but two patches of fine granular, black
pigment lying lateral to the prepharvnx are probablv in the lateral ex-
cretory vessels of the neck.

Host, Kyphosus sectatrix:, July 5, 1908, 1 distome.

Dimensions in life: Length 3; breadth 0.83; diameter of oral sucker
0.38, pharynx 0.38, ventral sucker 0.28; ova 0.06 by 0.03.

Didymorchis latus gen. et sp. nov. (Figs. 65, 65a.)
Etymology: dldu/ios, twin; <"'(>/'■•*, testicle.

Body broad-oval, nearly as broad as long, or breadth equal to about
three-fourths of length; the diameter of ventral sucker is about three
times that of the oral. There appears to be a short prepharynx but no
esophagus. The intestinal rami extend to the posterior end. Genital
aperture median at base of pharynx; cirrus-pouch short, lying at the
anterior border of the ventral sucker, and containing the meager prostate
and seminal vesicle which is, for the most part, a compactly folded tube.
Testes 2, opposite and adjacent, somewhat triangular in outline, and
lying near the posterior end. Ovary subglobular, lying between the
posterior margin of the ventral sucker and the anterior margin of the
right testis; seminal receptacle on right dorsal border of ovary. The
vitellaria are diffuse and lie along the posterior and lateral margins,
extending to the pharynx. Transverse yolk-ducts lie along the anterior
border of the left testis dorsally and on the dorsal side of the ovary;
shell-gland dorsal to posterior edge of ventral sucker and along anterior
edge of seminal receptacle. The uterus is mainly on the left side between
the left testis and the anterior border of the ventral sucker. The metra-
term passes on the left of the cirrus-pouch to the genital aperture.

Host, Calamus calamus:

1908, June 29, 2 fish, 1 distome; July 11,5 fish, 1 distome.

Length of first 2.03, breadth 1.54. The latter specimen was yellow-
ish in life. Its dimensions were: Length 2.24, breadth 2.38; oral sucker
0.35; pharynx 0.28; ventral sucker 1.36; ova 0.064 by 0.037.

The dimensions of this specimen in balsam are : Length 2.17; breadth
1.46; neck 0.84; oral sucker, length 0.46, breadth 0.49; pharynx, length
0.42, breadth 0.24; ventral sucker, length 0.70, breadth 0.90; ova 0.061
by 0.034.

40 Papers from the Marine Biological Laboratory at Tortugas.

Enenterum aureum gen. et sp. nov. (Figs. 66-70.)

Etymology: &, preposition in; svrepov, intestine.

Body smooth, nearly linear, tapering near the posterior end and
narrowing slightly at the anterior end, dorso-ventrally compressed.
Color in life yellow to orange, with transparent or colorless borders at the
extremities, particularly the anterior. Mouth surrounded by 10 short
rounded lobes arranged in pairs, 2 dorsal, 2 lateral, and 1 ventral, the
ventral pair being larger than the others. Oral sucker with its axial
diameter greater than the transverse; ventral sucker nearly circular,
slightly exceeding the oral sucker, situated at about the anterior fourth.
Prepharynx very short, pharynx globular, no esophagus; intestinal
rami uniting behind posterior testis near posterior end, the common
intestine extending nearly to the posterior end. Genital aperture in
front of ventral sucker, a little to left of median line; seminal vesicle,
prostate gland, and the short cirrus are included in the space bounded
by the anterior edge of the ventral sucker and the rami of the intestines.
The vas deferens passes back from the seminal vesicle dorsal to the
ventral sucker and a little to the right of the median line. Testes 2,
lobed, conspicuous, on middle line one behind the other and near to-
gether, the anterior one being about half-way between the ventral sucker
and the posterior end. Ovary subglobular, a short distance in front of
the anterior testis and a little to the right of the middle line. There is a
seminal receptacle which lies dorsal to and extends beyond the caudal
border of the ovary. In sections the antero-dorsal part of the ovary was
seen to contain large, loosely arranged germ-cells. The shell-gland was
dorsal and anterior to this part of the ovary. The vitelline glands are
diffuse and extend from a little behind the caudal edge of the ventral
sucker to the posterior end, densest along the margins, and scattering
over the median region. The folds of the uterus lie between the ovary
and the ventral sucker. Metraterm on left of middle line. The excretory
vessels are not distinctly shown in the mounted specimens. In the living
worms they were seen as lateral vessels behind the ventral sucker, as a
median vessel in the posterior third in dorsal view, and again at the
posterior end in ventral view.

Host, Kyphosus sectatrix:

1906, July 16, 5 fish, 16 distomes.

1908, July 5, 1 fish, 1 distome; July 8, 1 fish, 8 distomes.

Dimensions of living specimen: Length 5; breadth, anterior 0.50,
middle 1.12, posterior 1.00; oral sucker 0.42; pharynx 0.28; ventral
sucker 0.53; ova 0.058 by 0.032. Length of alcoholic specimens from 3
to 8 mm. The larger specimens, that is those containing ova, are rather
thick or cylindrical-compressed, younger specimens are flat.

Theledera (g. n.) pectinata (Linton).

Distomum pectinatum, Linton, Bull. U.S. Fish Commission, vol. xxiv, p. 389,
figs. 200-203.

Etymology: Oyty, nipple; Siprh neck.

Host, Auxis thazard: July 10, 1906, 1 fish, 1 distome.
The only note made at time of collecting was a brief remark referring
the single specimen to this species.

Helminth Fauna of the Dry Tortugas. 41

The specimen was stained and mounted and found to agree closely
with D. pectinatum. There is a slight difference in the proportions of
the suckers. In this specimen the ventral sucker is rather less than 1.5
times the diameter of the oral, while in the Beaufort forms the ventral
sucker is twice or more the diameter of the oral. Dimensions in balsam:
Length 1.86; breadth 0.30; neck 0.67; oral sucker 0.14; pharynx, length
0.14, breadth 0.07; ventral sucker 0.18; ova 0.024 by 0.017 and 0.020 by
0.014.

Lepocreadium trulla (Linton). (Figs. 71-74.)

Distomum trulla, Linton, Proc. U. S. Nat. Mus., vol. xxxm p 100 plate xi
fig- 79-

The distomes here considered agree closely with those found in
Ocyurus chrysurus in Bermuda.

Body pyriform, truncate at posterior end, triangular in outline when
compressed; covered with small, low, rounded spines; oral sucker equal
to or slightly exceeding the ventral. The pharynx is separated from
the oral sucker by a very short prepharynx, and the esophagus is so
short that it is indistinguishable in most of the mounted specimens. The
intestines extend to near the posterior end. From a point opposite the
caudal border of the ventral sucker to the posterior end the intestinal
rami are thick-walled, the columnar cells staining deeply. Testes 2,
near posterior end, diagonally placed and near together. Genital aper-
ture median, ventral to bifurcation of the intestine. Cirrus-pouch long-
clavate, inclosing the seminal vesicle at its posterior end, which is behind
the ventral sucker and close to the anterior edge of the anterior testis;
prostate conspicuous in cirrus-pouch from seminal vesicle to near the
genital aperture. Ovary 3-lobed, in front of testes, contiguous to anterior
edge of anterior testis and a little to the right of the median line. Semi-
nal receptacle in front of anterior testis, to the left of the ovary, and near
the caudal end of the cirrus-pouch. Vitelline glands diffuse, abundant,
filling the posterior and lateral regions of the body as far forward as the
pharynx. Uterus with rather numerous ova between the anterior testis
and the ventral sucker; the thick- walled and glandular metraterm lies
on the left side of the cirrus-pouch. The excretory vessel is not clearly
defined in the mounted specimens, but it was seen as a relatively large,
inflated vessel in living specimens, most conspicuous at the posterior
end where the opening was surrounded by radiating lines in a definite
area (fig. 73).

The spinose cuticle has a tendency to separate rather easily. Manv
of the mounted specimens show no signs of spines and others have but
few. Fresh specimens in good condition are conspicuously spinose.

In 8 out of 12 the oral sucker was larger than the ventral, in the
remaining 4 the suckers were equal ; even where the oral sucker is the
larger the difference is slight. In one the oral sucker measured 0.168
and the ventral 0.154; in another they were 0.158 and 0.144 respectively.

Host, Ocyurus chrysurus:

1907, July 10, 3 fish, few distomes; July 12, 3 fish, few distomes.

42 Papers from the Marine Biological Laboratory at Tortugas.

1908, June 30, 3 fish, 25 distomes; July 1, 1 fish, 12 distomes; July
4, 11 fish, 2 distomes; July 11, 1 fish, 4 distomes; July 14, 1 fish,
2 distomes; July 15,1 fish, 5 distomes.
Color in life translucent white tinged with yellowish-green.
Dimensions, life, slightly flattened: Length 0.92; breadth, anterior
0.21, near posterior 0.50; oral sucker 0.18; pharynx 0.07; ventral sucker
0.16; ova 0.048 by 0.031.

Host, Calamus calamus: July 6, 1907, 1 fish, 1 distome.

Lepocreadium levenseni (Linton). (Figs. 75-77.)

Distomum levenseni, Lixtox, Proc. U. S. Nat. Mus., xxxin, p. no, plate xit.
figs. 80-83.

Certain distomes from Tortugas groupers are here recorded.

One of them, from Epinephelus striatus, agrees with D. levenseni
in every essential particular. The cirrus-pouch is long and passes on
the left side of the ventral sucker. It includes the voluminous, tubular
seminal vesicle in its basal portion which lies along the median line
behind the ventral sucker. The muscular excretory bulb is conspicuous.

Dimensions, life: Length 1.58; breadth, anterior 0.16, middle 0.49,
posterior 0.28; oral sucker 0.11 ; pharynx 0.07; ventral sucker 0.12; ova
0.068 and 0.040. A larger specimen measured 2.75 mm. in length.

Dimensions of a specimen mounted in balsam: Length 1.96; breadth
0.46; neck 0.50; oral sucker, length 0.12, breadth 0.14; pharynx, length
0.07, breadth 0.05; ventral sucker 0.11 ; ova 0.06 by 0.034.

Three distomes, from Epinephelus morio and Mycteroperca venen-
osa, while quite incomplete in that neither cirrus-pouch nor genital aper-
ture could be made out and they may indeed represent different species,
are referred to this species provisionally. Thus it is probable that the
distome from Mycteroperca is specifically different from those found in
EpinepJielus, but on account of the meagerness in the amount of material,
and also in view of the fact that there seems to be a considerable range
of variation in this species as seen in the material collected from the
Bermuda groupers, it would be inadvisable to give to this lot definite
specific position at present. In the specimen from Epinephelus (fig. 75)
the oral sucker was invaginated. The relative size and position of the
suckers agree with D. levenseni. The pharynx is' relatively larger and
the vitellaria extend nearly to the bifurcation of the intestine. This
latter fact might justify placing them in a different species. There is a
distinct esophagus and the thick-walled intestines extend to the posterior
end. The relative positions of testes, ovary, seminal receptacle, and
uterus agree with the Bermuda specimens. There is a globular, muscular
bulb at the excretory pore, as in D. levenseni.

In the specimen from Mycteroperca (fig. 77) the same resemblances
and differences, when referred to D. levenseni, prevail as in the specimens
from Epinephelus . In addition the ventral sucker is situated relatively
farther from the anterior end, although in this specimen the oral sucker
is not invaginated, so that the neck is not shortened as it is in the speci-
mens from Epinephelus. In all the specimens the general outline of the
body and the investment of spines are as in D. levenseni.

Helm iii tli Fauna of the Dry Tortugas.

43

Comparative measurements, specimens in balsam:

[Nos. i and 2 from Epinephelus, No. 3 from Mycteroperca.]

No. 1. No. 2. No. 3.

Length

Breadth

Neck

Oral, sk

Pharynx

Ventral sk. . .
Ova

1 .68 2.10 2 .45
0.56 0.59 0.59
0.50 0.71 1.03
lg. 0.18, br. 0.17 lg. 0.14. br. 0.19 lg. 0.12, br. 0.14
lg. 0.14. br. 0.19 lg. 0.12, br. 0.19 lg. 0.14. br. 0.14
lg. 0.15, br. 0.17 lg. 0.14. br. 0.14 lg. 0.13. br. 0.15

Host, Epinephelus striatus: July 7, 1906, 3 fish, 2 distomes.

Host, Epinephelus morio: June 29, 1908, 1 fish, 2 distomes.

Host, Mycteroperca venenosa: July 16, 1907, 1 fish, 1 distome.

In this specimen small tube-like structures were noted in the walls
of the head and neck like those in Siphodera vinaledwardsii. Length
of this specimen in balsam is 2.28, length of neck, 1.02.

Distomum sp.

Immature, encysted in flesh.

These distomes were encysted in the flesh above the backbone, near
the dorsal spines, about midwav between the abdominal cavity and
base of caudal fin. Diameter of cyst 1.35 mm. There is a general resem-
blance to the form which I have recorded in reports on the Woods Hole
and Beaufort regions under the name Distomum valdeinflatum Stoss
The worms could be seen plainly through walls of the cysts. Dimensions,
flattened: Diameter of anterior sucker 0.20; ventral sucker 0.28; diam-
eter of body, in front of caudal enlargement 0.30, of caudal portion 1.75.

Host, Calamus calamus: June 29, 1890, 2 fish were examined and
2 cysts found in one of them.

Mesolecitha linearis gen. et sp. nov. (Figs. 170-172.)
Etymology: piaov, middle; liKtdos. yolk.

The body linear, bluntly rounded at both ends, smooth under low
magnification, but when highly magnified minutely or prickly spinose
on the margins, cylindrical; mouth subterminal; oral sucker larger than
ventral; pharynx adjacent to oral sucker; esophagus short; rami of
intestines thick-walled and reaching nearly to the posterior end of the
body: ventral sucker at about the anterior fourth. Genital apertuie at
the anterior border of the ventral sucker; cirrus short, stout, and armed
with short spines: prostate conspicuous, dorsal to the ventral sucker
and extending beyond its caudal border; seminal vesicle oval, strong-
walled, at base of prostate; testes 2, close together, one behind the other
and situated a little nearer the ventral sucker than the posterior end.
Ovary oval elliptical, a short distance behind the central sucker on
ventral side of body; shell-gland on right antero-dorsal side of ovary.
To the right of the ovary and shell-gland and extending caudad is a
convoluted tube, a portion of the titerus, which appears to represent the
seminal receptacle with ova lying in the midst of the spermatozoa which
fill the tube. Folds of the uterus lie between the testes and the ventral

44 Papers from the Marine Biological Laboratory at Tortugas.

sucker and also fill the body behind the testes to the caudal end. Excre-
tory vessel not made out clearly, but a spacious median vessel was noted
extending from the caudal end to the ventral sucker. The ova are char-
acteristically long and slender. The yolk-glands were not conspicuous,
the specimens evidently having been producing eggs for a long time..
They are diffuse, marginal, and peripheral between the ventral sucker
and the anterior testis. Conspicuous nucleated cells form the inner layer
of the body-wall from about the level of the middle of the ventral sucker
to the posterior end. They are probably yolk-forming cells.

Dimensions of specimen mounted in balsam: Length 4.55; breadth
0.86; oral sucker 0.53; pharynx 0.17; ventral sucker 0.38; ova 0.051 by
0.024 and 0.047 by 0.024 and 0.044 by 0.020.

Host, Tenthis cceruleus: July 10, 1908, 1 fish, 2 distomes.

General color orange-yellow. Dimensions of smaller specimen, life,,
flattened: Length 4.20; breadth 0.90; oral sucker 0.42; pharynx o.t6;
ventral sucker 0.23; ova 0.047 by 0.020.

Stephanochasmus casus sp. nov. (Figs. 78-83.)

Body linear to clavate, neck tapering; mouth surrounded by a
double row of spines, neck also spinose; all the spines are evanescent;:
ventral sucker 1.5 to 2 times the diameter of oral sucker; pharynx large,
usually pyriform, nearer ventral than oral sucker; prepharynx long,
esophagus very short ; rami of intestine extend to posterior end of body ;
genital aperture median at anterior border of ventral sucker; cirrus
spinose, cirrus-pouch long, slender, and cylindrical with the seminal
vesicle inclosed in its basal portion well behind the ventral sucker and
with the prostatic cells in its wall. Testes near posterior end close
together, one behind the other, on the median line; posterior testis, in
most cases oval and larger than the anterior, which is usually subglobu-
lar. Ovary subglobular, at anterior border of anterior testis. There is
a seminal receptacle in front of the ovary. The vitelline glands are diffuse
and fill the posterior and lateral regions of the body as far forward as
the ventral sucker. Out of 9 specimens the vitellaria of 6 extended a
little farther on the right than on the left side, reaching as far as the
middle of the length of the ventral sucker. The uterus lies between the
ovary and the base of the cirrus-pouch. The metraterm is beside and
dorsal to the elongated portion of the cirrus-pouch which it joins near
the genital aperture. The ova are large, and in the preserved specimens
are collapsed in a characteristic manner, with about 6 longitudinal fur-
rows, giving a ribbed appearance to them. In the specimens from
Neomcenis griseus and Ocyurus the ova in mounted material were from
0.061 to 0.065 in length. In those from Neomcenis analis they ranged
from 0.075 to 0.085 in length. In those from Epinephelus they meas-
ured 0.078 in length.

The specimens from Neomcenis analis were much larger than the
others, but they appear to agree with the smaller specimens from the
other hosts in all essential particulars. The spines around the mouth
and those of the neck were very poorly represented in all the distomes.
referred to this species.

Helminth Fauna of the Dry Tortugas.
Dimensions of distomes mounted in balsam.

45

Host.

From ante°ri^r
Oral sk. Pharynx. Vent. sk. ^J™1" Tnd'to' Length. Breadth.

Epinephelus striatus.
Neomaenis griseus

Do

Ocyurus chrysurus. . .

Do

Xeomaenis analis

Do

Do

fig.

\br.

o

II

0

20

0

2S

o

21

0

16

0

26

Jig.
tbr.

o

14

0

28

0

36

o

17

0

17

0

V)

Jig.
tbr.

o

15

0

24

0

28

0

17

0

17

0

'■,0

Jig.
tbr.

o

IS

0

25

0

28

o

18

0

IS

0

?6

Jig.
tbr.

o

17

0

31

0

•!M

o

17

0

21

0

4Q

Jig.
tbr.

0

28

0

33

0

So

0

28

0

22

0

45

Jig.
tbr.

o

25

0

31

0

4?

0

2 5

0

18

0

42

Jig-
tbr.

o

2 5

0

^

0

;o

o

25

0

25

0

45 J

0.44

0.52
0.32
0.45

o .60
1-37
1.47
I-I5

0.80

1 .06
o .60

0 . 70

1 . 20

2.38

2 .60

I .90

.24

0

SO

. 1 7

0

72

•35

0

60

• 52

0

64

■ 42

0

77

•47

0

77

.00

I

20

37

0

84

Host, Xeomcenis griseus:

1906, July 5, 11 fish, 3 distomes; July 7, 4 fish, 1 distome; July 9,

14 fish, 3 distomes; July 12,4 fish, few distomes.
1908, July 14, 4 fish, 1 distome.

Host, Xeomanis analis: July 1, 1908, 1 fish, 3 distomes.
Host, Epinephelus striatus: July 4, 1907, 1 fish, 1 distome.
Host, Ocyurus chrysurus:

1906, July 6, 3 fish, 1 distome.

1907, July 11,3 fish, 1 distome.

1908, July 3, 1 fish, 2 distomes; July 11, 1 fish, 1 distome; July 12,
3 fish, 1 distome; July 14, 1 fish, 1 distome.

One specimen from this host had most of the spines still attached
to the circumoral region. There appeared to be 36 in the two circles.

The length of the cirrus spines in a specimen from Epinephelus, in
life, was 0.01 mm.

Stephanochasmus sentus sp. nov. (Figs. 84-86.)

Body linear or slightly clavate, neck tapering, cylindrical, often
arched; mouth surrounded by a double row of spines, 18 in each row;
neck and anterior part of the body covered with spines which are evan-
escent. In some cases the neck was covered with globular tubercles,
in others the tubercles were flattened, in still others they were spines
of the usual low rounded type. All these conditions appear to be different
stages of shedding the spines, which seem to be evanescent, not only
those on the neck and body but also those around the mouth. The spines
do not, however, appear to be so readily lost as they are in Stephano-
chasmus casus. The oral sucker is variable ; the ventral sucker is usually
nearly circular in outline and 1.5 times the diameter of the oral sucker;
pharynx usually pyriform and much longer than broad, situated near the
ventral sucker and separated from the oral sucker by a long prepharynx.
There is an esophagus which may be as long as the pharynx, and' the
intestinal rami extend to the posterior end of the body. Genital aperture
median at anterior border of the ventral sucker; seminal vesicle behind

46 Papers from the Marine Biological Laboratory at Tortugas.

ventral sucker inclosed in the posterior end of the cirrus-pouch; prostate
gland not conspicuous, represented by cells in the walls of the cirrus-
pouch. Testes 2, close together, one following the other in the median
line near posterior end. Posterior testis usually long oval, with its long
axis corresponding to the long axis of the body; anterior testis smaller,
globular or subglobular, or oval; ovary at anterior border of anterior
testis, globular or oval. There is a seminal receptacle in front of the
ovary. The vitelline glands are diffuse, dense, filling the posterior part
of the body and often obscuring the other organs; they extend forward
to about the posterior end of the seminal vesicle, thus leaving a consider-
able area behind the ventral sucker where they do not occur. Folds of
the uterus between ovary and base of seminal vesicle; metraterm long,
parallel to the slender cirrus-pouch, and viniting with it near the genital
opening. The ova are relatively few and large; in preserved specimens
they are collapsed in the same manner as in Stephanochasmus casus,
that is, by the formation of about 6 longitudinal furrows, producing a
ribbed appearance. The length of the ova in balsam is about 0.075 mm.,
though measurements as great as 0.085 mm. were obtained.

Host.

Calamus calamus.
Do

Do

Do

Haemulon sciurus .
Do

Oral sk.

Jig.
\br.
jig.
\br.

He.

Haemulon plumieri lip-

fig. o . 1 1
br. o . to
lg. 0.08
br. o . 1 1
jig. 0.11
\br. 0.14
fig. 0.10
\br. 0.12

Pharynx. Vent.sk.

!5 0.30I

[4 0.30J

19 0.24I

"0.181

f

0.15I
.07 o . 19/

o . 20 \

/

.18 0.281

.09 0.22

0.22

.07 C2I

From
anterior
end to
pharynx. ™*'

From
anterior
end to
ventral

o . 52
0-35

0.50

o . 50
o . 40

0.56
0.56

.56

70
70
.67

Length. Breadth.

3 -64
1 .96
2.91
2.28
2.66
3.78

'■55
1.42
'.30
■ •38
'■30
'•47

Host, Calamus calamus:

1907, July 10, 2 fish, 9 distomes.

1908, July 7, 1 fish, 1 distome; July 8, 1 fish, 1 distome; July 14,

I fish, 1 distome.
Host, Hcemulon plumieri:

1906, July 8, 1 fish, 2 distomes.

1907, July 1, 4 fish, 1 distome; July 3, 16 fish, 1 distome; July 12,

II fish, 1 distome.

1908, July 3, 2 fish, 2 distomes; July 6, 5 fish, 1 distome.
Host, Hcemulon sciurus: July 2, 1907, 3 fish, 1 distome.

Lechradena edentula gen. et sp. nov. (Fig. 87.)
Etymology: ^/<>'.<:, crosswise; ad-rjv, gland.

A single distome evidently near the genus Stephanochasmus , but
without spines, is here described. It was found in a gray snapper
(Neomcenis griseus), July 5, 1906.

Helminth Fauna of the Dry Tortugas. 47

Outline of body very long ovate, broadest near posterior end and
tapering rather uniformly to the anterior end; smooth, but neck crossed
by fine wrinkles; oral sucker nearly terminal, much smaller than ventral
sucker; neck one-third the entire length; prepharynx long, pharynx
large. There seems to be a short esophagus, and the wide intestinal
branches extend to the posterior end of the body. Reproductive opening
on median line at anterior border of ventral sucker; cirrus smooth and
cylindrical; cirrus-pouch slender, prostate not seen; seminal vesicle
cylindrical, on median line, its anterior end at the caudal border of the
ventral sucker; testes 2, near together on median line, one behind the
other and contiguous ; posterior testis larger and longer than the anterior.
Ovary suboval, at anterior border of anterior testis; seminal receptacle
in front of ovary a little to right of median line. Vitelline glands diffuse,
dense, with a peculiar transverse arrangement of the lobes, from posterior
end to ventral sucker. Uterus median, the ova lying between the ovary
and the caudal end of the seminal vesicle.

Dimensions in balsam: Length 2.10; breadth 0.61 ; oral sucker 0.13 ;
pharynx, length 0.18, breadth 0.14; ventral sucker 0.29; ova 0.052 by
0.034.

Mesorchis urna gen. et sp. nov. (Figs. 88 93.)

Etymology: ;j.iao<st middle; 8p%t?, testicle.

Body variable in shape but usually fusiform, truncate anteriorly,
and tapering to a blunt point posteriorly, covered, at least anteriorly,
with minute, short spines; oral sucker terminal, vase-shape, broad in
front, narrowing at posterior end; ventral border of lip usually rather
deeply notched; pharynx close to oral sucker; esophagus long and slender;
intestinal rami short, with thick walls, as a rule diverging widely, in which
case they do not reach the ventral sucker. The ventral sucker is rather
weak and often hard to distinguish in living specimens, its anterior
border about the middle of the length of the body. Genital aperture
at anterior edge of ventral sucker; cirrus-pouch large, median, vertical;
seminal vesicle a large convoluted tube inclosed in the cirrus-pouch and
lying dorsal to the ventral sucker. The metraterm passes on dorsal side
of ventral sucker, ventral to seminal vesicle. Testes 2, lateral, their
anterior borders in front of level of anterior edge of ventral sucker. In
what is perhaps an average case a line joining the middle points of the
testes passes along the anterior edge of the ventral sucker. Ovary dorsal
to ventral sucker, extending a short distance caudad of ventral sucker.
At its posterior border is the shell-gland which, in turn, is followed by
the seminal receptacle. A short distance back of the seminal receptacle
on the dorsal side is the opening of Laurer's canal, which is exceptionally
conspicuous. The opening is thick-lipped and surrounded by strongly
staining nuclei. The vitelline glands are lateral, mostly in front of the
testes, and extending about half-way from the testes to the anterior end.
Each lateral gland is composed of a considerable number of compact,
rounded, and comparatively small masses. The folds of the uterus are
ventral and occupy the greater part of the space behind the testes. The
excretory vessel is capacious, with a short, thick stem at the posterior

48 Papers from the Marine Biological Laboratory at Tortugas.

end, soon dividing into two branches which lie ventrally and laterally
and extend as far forward as the testes. The shape of the excretory
vessel is thus like the letter Y. The ova are pyramidal or ovate, with
rather thick shells.

Dimensions in balsam: Length 1.50; breadth, anterior 0.18, middle
0.45, posterior 0.10; neck 0.70; oral sucker, length 0.21, breadth 0.18;
pharynx, length 0.08, breadth 0.06; ventral sucker 0.16; ova 0.031 by
0.019.

Host, Angelichthys isabelita:

1906, July 10, 1 fish, 1 distome.

1908, July 3, 1 fish, 3 distomes.

Host, Pomacanthus arcuatus:

1906, July 18, 1 fish, 5 distomes.

1907, July 3, 1 fish, 12 distomes; July 11, 1 fish, 238 distomes; July
15, 1 fish, 150 distomes.

1908, June 29, 1 fish, 93 distomes; July 1, 1 fish, 39 distomes; July
3, 2 fish, 68 distomes; July 4, 2 fish, 28 distomes; July 5, 2 fish,
2 distomes; July 7, 2 fish, 6 distomes.

The color of these distomes in life in some cases was red. The shape
varied from long oval to short oval. Measurements of ova showed a
variation in the same individual of 0.037 DY o-OI7 and 0.031 by 0.019.
The length in one of the smaller lots varied from 0.84 to 1.68.

Diplangus paxillus gen. et sp. nov. (Figs. 94-101.)
Etymology: 8mX6ost double; ayyos, vessel.

This distome is characterized by its cylindrical body, which is atten-
uate posterioi'ly, and by its prominent ventral sucker. Although found
on many occasions, my material does not allow details of structure to be
made out with entire satisfaction.

Body cylindrical, smooth, thickest at ventral sucker, neck abruptly
conical, body usually attenuate behind ventral sucker and tapering to
the posterior end. Oral sucker subterminal; pharynx adjacent to oral
sucker or separated from it by a very short prepharynx ; ventral sucker
larger than oral, prominent, almost pedicelled in some; esophagus short;
intestinal rami extending a little more than half-way to the posterior
end. Genital aperture median, ventral to pharynx; cirrus short, slender;
seminal vesicle in two parts, a posterior prostatic portion with large
cells in the wall and an anterior globular portion with thinner walls
(sv and pr in figs. 94-100). The testes are 2, globular, near together,
one behind the other, and placed about half-way between the ventral
sucker and the posterior end. Ovary dorsal, a short distance in front of
testes; seminal receptacle immediately in front of ovary. The vitelline
glands are clustered lateral masses behind the ventral sucker and ex-
tending to the ovary. The folds of the ovary fill the body both in front
of and behind the testes; ova oblong-elliptical, the long diameter twice
the shorter. Numerous glandular cells in the neck are interpreted to be
yolk-forming.

Host, Hasmulon macro sternum:

1907, June 28, 2 fish, 1 distome.

Helminth Fauna oj the Dry Tortugas. 49

Dimensions, life, flattened: Length 1.35; breadth 0.40; oral sucker
0.14; pharynx 0.11 ; ventral sucker 0.21 ; ova 0.036 by 0.017.

1907, July 12,1 distome, length 1.75.

Host, Hcemulon plumieri: July 13, 1906, 2 fish, 1 distome.

Dimensions, life: Length 1.75; breadth, anterior 0.16, base of neck
0.50, middle 0.40, posterior 0.21 ; oral sucker 0.14; pharynx 0.07 ; ventral
sucker 0.20: ova 0.037 by 0.020. Body filled with minute ovate bodies,
0.003 m length, not seen in the mounted specimen.

1906, July 8, 1 fish, 1 distome; July 15, 1 fish, 1 distome.

1907, June 27, 2 fish, 1 distome; July 6, 16 fish, 6 distomes; July 8,
2 distomes; July 10, few distomes; July 12, few distomes; July
13, 1 distome.

1908, July 3, 2 fish, 1 distome; Jul v 6, 5 fish, 1 distome; July 9, 1 fish,
2 distomes; July 10, 5 fish, 1 distome; July 11,2 fish, 1 distome;
July 12,1 fish, 1 distome; July 14, 14 fish, few distomes.

Host, Hamulon sciurus:

1907, June 28, 1 fish, 1 distome.

1908, July 2, 1 fish, 1 distome.

Dimensions, life: Length 1.20; breadth 0.25; oral sucker 0.08;
ventral sucker 0.15; ova 0.030 by 0.015.

Host, Calamus calamus:

1907, July 6, 1 fish, 1 distome; July 10. 2 fish, 1 distome.

Dimensions, life, flattened: Length 1.47; breadth 0.53; oral sucker
0.13; pharynx 0.08; ventral sucker 0.21 ; ova 0.041 by 0.017. Scattered
among the ova and also in other parts of the body were immense numbers
of small oval bodies, 0.007 by c.004. These are not evident in the
mounted specimen.

Deretrema fusillus gen. et sp. nov. (Figs. 102-1043.)
Etymology: dipy, neck; rpr^a, hole.

The description which follows is based on a distome from Ocyunis
ckrysurus (fig. 102). Other distomes from Hcemulon macrostomum and
Abudefduf saxatilis are referred to the same species with some hesitation.

Body smooth, in living specimen crossed by minute, transverse,
wavy lines, close together and occasionally reticulated. Color in life
translucent yellow, deeper amber near center when slightly flattened,
ventral sucker with reddish granular pigment, ovary pink by transmitted,
white by reflected, light. The shape is fusiform, the greatest thickness
being at the middle through the ventral sucker, tapering to a bluntly
rounded point at the anterior end and to a sharper point at the posterior
end. The oral and ventral suckers are each nearly circular in outline,
the ventral being more than 1.5 times the diameter of the oral. Pharynx
adjacent to oral sucker, broader than long; esophagus broad and thin-
walled; intestines almost entirely concealed by the uterus. Reproduc-
tive aperture on left side at about level of the bifurcation of the intestine ;
cirrus short; cirrus-pouch incloses the seminal vesicle, which is oval and
lies transverse to the axis of the body. No prostate was seen, but a few
cells around the cirrus probably represent that organ. Testes 2, lateral,
4

50 Papers from the Marine Biological Laboratory at Tortugas.

opposite, a short distance back of the ventral sucker. They are rather
small and long oval, and are near the lateral margins of the body. The
ovary is an oval body dorsal to the right caudal margin of the ventral
sucker. At its left side is a globular, rather strong- walled sac, in the
mounted specimen very slightly stained and empty, which seems to be the
seminal receptacle. The vitelline glands are compact, subglobular bodies,
about 6 or 8 visible on each margin without deep focussing. They lie
on each margin lateral to the ventral sucker, the cluster on the right
occupying a little less, and the cluster on the left a little more, than the
diameter of the ventral sucker. The uterus is very voluminous and
fills almost all of the postacetabular region, its folds being very numerous
and distinct in the living specimen. A considerable mass of ova lies in
front of the ventral sucker. The eggs are small and there seems to be
some variety in the size. The excretory vessels were conspicuous in the
living worm and are still more easily seen than usual in the mounted
specimen. Inflated vessels are to be seen on each side of the esophagus,
and a longitudinally ribbed posterior vessel, though less easily seen than
in the living worm. The length in life was 2.10 and the breadth 0.90,
and the ova 0.034 by 0.020.

Dimensions in balsam: Length 1.82; breadth 0.64; neck 0.66; oral
sucker 0.25; pharynx, length 0.07, breadth 0.08; ventral sucker 0.43; ova
largest 0.037 by 0.024, smallest 0.027 by 0.015.

Host, Ocyurus chrysurus: July 15, 1908, 1 fish, 1 distome.

Two distomes from Hoemulon macrostomum are referred to this
species with much hesitation, not only with regard to placing them in
this species, but as to whether they themselves should be placed in the
same species.

These distomes are figured (figs. 103, 104) and may be seen to be
quite different in shape. The differences, however, do not appear to
me to be sufficient to justify their separation at present. The esophagus
and intestine in fig. 104 were very indistinct, and the apparent shortness
of the esophagus may be due to the contracted condition of the neck.
The metraterm lay on the anterior border of the cirrus-pouch instead
of on its caudal border, as in the specimen figured in figs. 102 and 104.
Since all the specimens were more or less flattened and consequently
somewhat distorted, the difference may be due to forced displacement.

Dimensions of the specimen shown in fig. 103, mounted in balsam:
Length 1.68; breadth 0.58; neck 0.72; oral sucker 0.21; pharynx, length
0.06, breadth 0.08; ventral sucker, length 0.35, breadth 0.32 ; ova, largest
0.044 by 0.024, smallest 0.034 by 0.024, usual size about 0.040 by 0.020.

Host, Hcemulon macrostomum: July 10, 1906, 2 distomes.

A distome found in the cow pilot (Abudefduf saxatilis), July 15,
1906, appears to belong here.

The stained and mounted specimen is little more than a mass of ova.
The following features, however, can be recognized: The testes are 2,
nearly opposite each other at about the posterior third, each near the
lateral margin of its side. The ovary is near the middle line, a short
distance in front of the testes. The vitelline glands consist of a few granu-
lar masses along the margins extending from about the level of the ovary

Helminth Fauna of the Dry Tortugas. 51

for a short distance toward the anterior end. The anterior end is prob-
ably broken.

Dimensions: Length 1.40; breadth, anterior 0.42, middle 0.60;
maximum breadth about posterior fourth 0.72; ova 0.040 by 0.017.

Distomum fenestratum Linton. (Figs. 105, 106.)

These distomes were active, the neck, when fully extended, being
quite slender and as long as that part of the body which lay behind the
ventral sucker. When the neck was thus stretched out it was seen that
the convoluted tubule shown in sections (Proc. U. S. N. M., vol. xxxm,
plate xni, fig. 90) and in contorted specimen (Bull. U. S. Fish Commis-
sion, vol. xxxiv, plate xxx, figs. 213, 214) is really made up of the caudal
end of the esophagus and the beginnings of the intestinal rami.

These specimens agree closely with the forms which I have described
from Coryphcena at Beaufort and Lycodontis at Bermuda. Measure-
ments were not made at the time of collecting and the only specimen
which I have preserved is broken. The length, estimated, is 3.5 and the
breadth 0.40. Sections show the parenchyma to be reticulated. The
body-wall is lined with glands whose exact nature is not evident. They
strongly resemble the cells which I have interpreted as yolk-forming
cells in other distomes described in this paper. These cells begin on the
dorsal side in front of the ventral sucker. Behind the ventral sucker
they surround the body cavity to the posterior end. The diameter of
the oral sucker in the specimen sectioned is 0.08, of ventral sucker 0.19.

Host, Hcemulon plumieri:

1908, June 28, 2 fish, 1 distome; July 4, 12 fish, 1 distome.

Host, H. sciurus:

1907, July 1, 1 fish, 2 distomes.

Length of one in life 2.10, breadth 0.42. There was a rudiment of
a slender organ in front of the ventral sucker.

XYSTRETRUM gen. nov.
Etymology: goarpa, scraper, rasp; yrpov, belly.

Generic characters: Neck cylindrical; body suborbicular with a
thin border and thickened central portion, which is crossed on its ven-
tral surface by numerous, low, transverse ridges. Testes nearly opposite,
behind ventral sucker; ovary in front of testes; vitelline glands median be-
hind ventral sucker and in front of testes; folds of uterus mainly behind
testes; genital aperture median, behind oral sucker; pharynx none.

The posterior ends of the intestinal rami approximate, but whether
they actually unite could not be ascertained.

Xystretrum solidum gen. et sp. nov.
Distomum sp., Proc. U. S. Nat. Mus., vol. xxxvi, p. 119, plate xv, figs. 100-102.

The most obvious difference between this and the following species
is the more compact character of the vitelline glands and the tendency
of the border to roll under in the Bermuda species.

The longitudinal striae on the ventral disc are simply the longitudinal
muscle fibers of the body-wall. These striae are 0.02 mm. apart.

52 Papers from the Marine Biological Laboratory at Tortugas.

Xystretrum papillosum gen. et sp. nov. (Figs. 107-111.)

Neck distinct from body, cylindrical, arcuate; body suborbicular
with thin border and thickened, muscular ventral disc crossed by low,
transverse ridges. Papillar spines cover the neck and body and line the
cavities of the suckers. In life, color of neck pink, of body yellow with
white margin; mouth subterminal; ventral sucker larger than oral; no
pharynx, no esophagus; intestinal rami in the neck with irregular out-
line extending to posterior edge of disk. The intestines follow the lateral
borders of the disk but being obscured by the uterus it could not be deter-
mined whether they unite at the posterior end or not. Genital aperture
median, ventral, near the posterior border of the oral sucker; cirrus short
and smooth; cirrus-pouch between the intestinal rami in front of the
ventral sucker, inclosing the convoluted seminal vesicle; prostate not
distinct. Testes 2, nearly transverse, deeply lobed, situated a short
distance behind the ventral sucker. Ovary indistinctly lobed, close to
anterior border of right testis. Vitelline glands between the left testis
and ovary at caudal border of ventral sucker, made up of about 4 very
irregular and somewhat lobed tubular masses. The uterus is a very
slender tube lying in intricate folds and filling all the body behind and
lateral to the testes except the thin border which lies outside the ventral
disk. The metraterm lies on the right side of the seminal vesicle and ap-
pears to enter the cirrus to open with it by a common duct; ova small
and presenting some variety in size.

Dimensions in balsam: Neck, length 1.40, breadth at anterior end
0.50, at base 0.73; body, length 2.10, breadth 2.17; oral sucker, length
0.42, breadth 0.45; ventral sucker, length 0.62, breadth 0.63; diameter
of ventral disc 1.58; distance between ridges of disk 0.04; ova 0.030 by
0.015 and °-°4° by 0.020.

Host, Lactophrys triqueter: July 8, 1908, 1 fish, 1 distome.

Hysterolecitha rosea gen. et sp. nov. (Figs. 112-117.)
Etymology: u«rre/oos, last, posterior; liicidos, yolk.

Body smooth, cylindrical, red in life, greatest diameter at ventral
sucker, which is situated near the anterior third of the length, thence
tapering to each end; mouth subterminal, oral sucker and pharynx each
nearly globular and contiguous; ventral sucker nearly three times the
diameter of oral sucker; esophagus about as long as the pharynx. The
intestinal rami extend nearly to the posterior end. Reproductive aper-
ture on the midventral line at the junction of the intestinal rami. Cirrus
short; prostate represented apparently only by a small cluster of cells
near the reproductive aperture. The seminal vesicle is an elongated
tube, somewhat convoluted and lying beside the metraterm in the neck.
Testes 2, near together, one following the other a little diagonally, not
far back of the caudal border of the ventral sucker. The ovary is situated
towards the posterior end, at about the posterior fourth or fifth, sub-
globular; yolk-glands at caudal border of ovary, 2, the left deeply lobed,
the right less deeply lobed. There is a seminal receptacle which is tubular
and situated behind the yolk-glands. The shell-gland is dorsal to the

Helminth Fauna of the Dry Tortugas. 53

yolk-gland and there is a yolk-reservoir on the dorsal side of the ovary.
The folds of the uterus are most abundant between the ovary and testes,
although the uterus begins at the caudal border of the yolk-glands and
the folds extend to the ventral sucker, whence the metraterm traverses
the neck to the reproductive aperture. The excretory vessel is slightly
enlarged at the posterior end near the excretory pore. It is a single
ventral vessel thence to a point about on a level with the anterior testis,
where it divides, the two branches passing forwards laterally to unite
above the pharynx. Length 2 to 5.5 mm.
Host, Teuthis hepatus:

1907, July 1, 1 fish, 12 distomes.

Two of the distomes from this host, collected on this date, were
apparently macerated. The reproductive organs were mere vestiges.
The bodies were filled with ova associated with black pigment. Bodies
cylindrical, neck short. While the details of structure are too meager
to permit of identification the distomes are probably near this species.

Dimensions of larger, life: Length 5 ; oral sucker 0.22 ; pharynx 0.14;
ventral sucker 0.50; ova 0.027 by 0.015.

1908, July 11, 1 fish, 3 distomes; July 11,3 fish, 3 distomes; July 14,
3 fish, 7 distomes; July 15, 1 fish, 3 distomes.

Bright red by reflected, yellow by transmitted light; irregular
cylindrical, more or less contorted.

Dimensions, life, flattened: Length 4.5; breadth 0.73; oral sucker
0.23; pharynx 0.10; length of ventral sucker 0.70; ova 0.027 by 0.017.
The surface of some specimens was nodular, especially on the neck.

Host, Teuthis cceruleus:

1908, June 27, 1 fish, 2 distomes; July 5, 1 fish, 1 distome; Julv 10,
1 fish, 1 distome.

Pale red, intestines black.

Dimensions, life, flattened: Length 5.5; breadth, anterior 0.32, at
ventral sucker 0.92, behind ventral sucker 0.65, posterior 0.28; oral
sucker 0.28; pharynx 0.15; ventral sucker 0.77; ova 0.030 by 0.015.

Macradena perfecta gen. et sp. nov. (Figs. 118, 119.)

Etymology: ,'j.aK<»h\ long; atty'v, gland.

The following notes are based on a series of longitudinal horizontal
sections, and a few transverse sections, the greater part of the trans-
verse series having been lost by accident.

Body crossed by fine rugae, linear, tapering very slightly at the ex-
tremities ; neck between one-fifth and one-sixth the entire length ; mouth
ventral; esophagus very short; reproductive aperture about on a level
with caudal end of pharynx; cirrus-pouch long, cirrus short, prostatic
portion long and slender, extending 0.3 mm. caudad of the ventral
sucker. The seminal vesicle is at the caudal end of the prostate and
beside the anterior testis. The testes are ovate, their longer axes trans-
verse to the long axis of the body. They lie close together one behind
the other. The ovary, which in some of these sections appears to be
2-lobed, is near the caudal border of posterior testis. The outline of the

54 Papers from the Marine Biological Laboratory at Tortugas.

section of the ovary shows the organ to be long oval, with its longer axis
transverse. Behind the ovary and contiguous with it is the relatively
large seminal receptacle, and ventrally on the right side of the ovary are
the lobes of the yolk-gland. This organ is deeply lobed, the lobes being
long clavate and apparently radiating from the right side. The ova are
very numerous, the entire body back of the ventral sucker being in large
part filled with them. They lie in dense masses behind the seminal recep-
tacle and between the ventral sucker and the ovary. The excretory
vessels could not be made out satisfactorily in the sections.

Host, Teuthis cceruleus: June 27, 1908, 2 distomes.

These were associated with the species of Hysterolecitha rosea and
were not noted until after they had been sectioned.

Dimensions: Length 2.55; breadth 0.45; oral sucker, length 0.28,
breadth 0.22; pharynx, length 0.13, breadth 0.11 ; ventral sucker, length
0.32, breadth 0.28; ova 0.024 bv 0.014.

Opisthadena dimidia gen. et sp. nov. (Figs. 120-122.)
Etymology: d-xicdios, hinder; aSrjv, gland.

Body rather slender, linear, compressed; ventral sucker three or
more times the diameter of the oral ; neck very short and conical ; pharynx
subglobular adjacent to the oral sucker; esophagus very short, only
recognized in sections; intestinal rami extend to the posterior end.
Genital aperture between oral and ventral sucker on median line; cirrus
short and smooth; prostate large, elongated, along median line, dorsal,
behind ventral sucker, extending nearly to the middle of the length of the
body and followed closely by the seminal vesicle. Testes 2, one behind
the other and behind the middle of the body, oval, transverse. Ovary
situated a short distance behind the posterior testis, ovate, the longer
diameter transverse; yolk-glands 2, lying side by side immediately
behind the ovary ; seminal receptacle dorsal to the ovary ; shell-gland
behind the ovary and between the yolk-glands. The uterus begins be-
hind the yolk-glands where a few folds lie ; folds of the uterus in mature
specimens occupy the middle region of the body forward to the posterior
border of the ventral sucker, few between ovary and testis and between
the testes, but abundant in front of the testes. Anteriorly the metraterm
passes beside the prostate dorsal to the ventral sucker. It appears to
join the male genital duct a short distance from the genital aperture.
The ova are a little more than twice as long as broad. The excretory
vessel is single from the posterior end to a point a short distance behind
the ventral sucker. It there divides and the two lateral branches unite
above the oral sucker.

A characteristic of this species is the very coarse muscle fibers
which lie in the body -wall. Coarse, longitudinal fibers also occur in the
intestinal walls. These intestinal muscles make their appearance near
the caudal border of the ventral sucker and continue to the posterior
end. They are strongest in the middle regions and grow somewhat
weaker toward the posterior end.

Helminth Fauna of the Dry Tortngas. 55

The first specimen collected was young. The intestines in the middle
third of the body were inflated, and there were two distinct lateral pa-
pillae situated one on each side of the body opposite the antero-lateral
border of the ventral sucker (fig. 120). This character was noted in
subsequent finds, although it did not always present quite the same
appearance shown by the one sketched.

The living worms are characteristically colored, the testes and ovary
being ivory-white, the intestine and vitellaria golden -brown.

Length of alcoholic specimens 3.5 to 7 mm.

Dimensions of living specimen (fig. 120): Length 2.80; breadth at
ventral sucker 0.45, behind ventral sucker 0.42 ; oral sucker 0.14; pharynx
0.07; ventral sucker 0.40.

Ova, balsam: 0.038 by 0.014 and 0.042 by 0.017.

Host, Kyphosus sectatrix:

1907, July 16, 5 fish, 1 distome.

1908, July 5, 1 fish, 6 distomes; July 8, 1 fish, 9 distomes.

Brachadena pyriformis gen. et sp. nov. (Figs. 123-126.)
Etymology: foa^us, short; adijv, gland.

Body fusiform, greatest breadth at level of ventral sucker, in most
cases tapering to each end. In some the posterior end is bluntly rounded.
Oral sucker subterminal, about one-third the diameter of the ventral
sucker ; pharynx contiguous with the oral sucker ; no esophagus ; intestines
extend to the posterior end. Reproductive aperture ventral to pharynx;
cirrus and the relatively large prostate between the oral and ventral
suckers; seminal vesicle at caudal border of prostate, usually partly
dorsal to the ventral sucker. Testes 2, transversely placed, at caudo-
lateral margin of ventral sucker; ovary subglobular, behind testes on
median line; seminal receptacle dorsal and extending a little beyond
the right anterior border of the ovary. The yolk-glands are about 7
long-pyriform lobes radiating from the caudo-lateral border of the ovary ;
uterus filling the body generally behind the ventral sucker to the pos-
terior end and dorsal to and on right side of ventral sucker.

A few small distomes (fig. 124) are also referred to this species.
They may belong to another species, but my material does not justify
a more complete separation than is involved in this special mention.

Host, Hcemitlon macrostomum: 1906, July 13, 1 fish, 1 distome.

Dimensions, life: Length 1.12; breadth, anterior 0.19, middle 0.70,
posterior 0.42; pharynx 0.07; ventral sucker 0.50; ova 0.034 by 0.017
and 0.040 by 0.020.

Host, Hcemulon plumieri:

1906, July 8, 1 fish, 1 distome; July 10, 24 fish, 6 distomes.

1907, July 3, 16 fish, 1 distome; July 13, 6 fish, few distomes.
Dimensions, life: Length 1.26; breadth, anterior 0.14, middle 0.70,

posterior 0.28; oral sucker, length 0.08, breadth 0.16; pharynx, length
0.05, breadth 0.08; ventral sucker 0.53; ova 0.040 by 0.020. In this
specimen the oral sucker and pharynx were variable.

56 Papers from the Marine Biological Laboratory at Tortugas.

Host, Hcemulon sciurus:

1907, June 28, 1 fish, 1 distome; July 1, 1 fish, 1 distome.

Dimensions, balsam: Length 0.65; breadth 0.43; oral sucker 0.11;
pharynx 0.04; ventral sucker 0.33; ova 0.034 by 0.017. This specimen
is shown in fig. 124.

1907, July 5, 6 fish, 1 distome.

1908, July 7, 1 fish, 1 distome.

Dimensions, life: Length 1.82; breadth 0.98; oral sucker 0.15;
pharynx 0.07; ventral sucker 0.49; ova 0.037 by 0.020.

Host, Calamus calamus: July 10, 1907, 2 fish, 1 distome.

Dimensions: Length 0.84; breadth 0.42; oral sucker 0.12; pharynx
0.05; ventral sucker 0.28; ova 0.031 by 0.017.

Dichadena acuta gen. et sp. nov. (Fig. 127.)
Etymology: Si/a, in two; adrjv, gland.

Body smooth, fusiform but tapering more toward anterior than
posterior end, greatest breadth back of ventral sucker; neck conical, its
length but little exceeding the diameter of the ventral sucker; oral
sucker sub ventral, its diameter scarcely equal to one-third the ventral
sucker; pharynx short-pyriform adjacent to oral sucker; esophagus appar-
ently none; intestinal rami obscured by the enormous number of ova
but probably extending to, or nearly to, the posterior end. Genital
aperture on median line about half-way between the suckers; cirrus
short; cirrus-pouch oval and containing numerous cells. From this oval
pouch a long prostatic tube passes diagonally to the left margin, extend-
ing farther caudad than the posterior margin of the ventral sucker. The
prostatic tube is clavate, increasing in size gradually to the posterior
end, and the prostatic cells are confined to the posterior half of the tube.
At the caudal end of the prostate there is an oval seminal vesicle which
is sharply marked off from the prostate. A short vas deferens leads back
from the seminal vesicle to the testes, which are two in number, one fol-
lowing the other and contiguous to each other. They lie near the left
margin and about half-way between the ventral sucker and the posterior
end. The ovary lies on the median border of the posterior testis. It is
oval and its longer diameter is transverse. The shell-gland is on the
dorsal side of the ovary, in ventral view appearing on its left border
(fig. 127 sg). The seminal receptacle is relatively large, oval, and lies
on the caudal borders of the ovary and the posterior testis. The vitelline
gland is on the antero-lateral border of the ovary and consists of 6 or
more rounded lobes somewhat indistinctly divided into two main masses.
A cluster of nucleated cells lies in front of the vitelline glands between
them and the ventral sucker, and a large number of similar cells fill the
neck. These I take to be yolk-forming cells. The ova are abundant and
fill all the posterior parts of the body not occupied by the other organs
from the ventral sucker to the posterior end.

Host, Teuthis cceruleus: July 6, 1908, 1 fish, 2 distomes.

Dimensions, life: Length 1.89; breadth 0.53; oral sucker 0.08;.
pharynx 0.04; ventral sucker 0.32; ova 0.024 by 0.015.

Helminth Fauna of the Dry Tortugas. •"><

Dimensions in balsam: Length 1.55; breadth 0.58; neck 0.38; oral
sucker 0.08; pharynx 0.05; ventral sucker, length 0.28, breadth 0.31;
ova 0.024 by 0.014.

In the other specimen the ventral sucker measures 0.35 in length
and 0.29 in breadth.

Leurodera decora gen. et sp. nov. (Figs. 128, 129.)
Etymology: Xsvpos, smooth; Siprj, neck.

Body smooth, compressed, long ovate, greatest breadth back of ven-
tral sucker; middle of ventral sucker about middle of length of body, or a
little nearer posterior than anterior end; diameter of oral sucker about
half that of ventral ; oral sucker ventral ; pharynx a little longer than
broad, adjacent to the oral sucker; esophagus short or none; intestinal
rami, often inflated, extend to posterior end of body. Genital aperture
ventral, on median line just behind pharynx; cirrus short, prostatic cells
few, small ; cirrus-pouch about dorsal to bifurcation of intestine ; seminal
vesicle dorsal, median, extending from cirrus-pouch to ventral sucker;
metraterm ventral to seminal vesicle. Testes 2, lateral, opposite, be-
hind ventral sucker; ovary median, behind testes; seminal receptacle in
front of ovary at its anterior border; vitelline glands 2, slightly lobed,
situated to right of ovary and behind the right testis. The folds of the
uterus occupy a large part of the I ody in front of the ventral sucker and
behind it, between the testes and behind the ovary, in some cases largely
obscuring the other organs. The excretory vessel is single, median, and
dorsal to ovary, from posterior end to a point a short distance behind the
ventral sucker, where it divides into two branches. The two anterior
branches meet above the anterior end of the pharynx. The posterior
stem was seen in one case to be deflected to the left. Ova small, about
twice as long as broad.

Host, Hcemulon macro stomum:

1906, July 10, 1 fish, 2 distomes; July 13, number not noted, few.

1907, June 28, 2 fish, 2 distomes; July 13, 1 fish, 6 distomes.
Dimensions, life: Length 2.24; breadth 0.73 ; oral sucker 0.22 ; phar-
ynx 0.08; ventral sucker 0.39; ova 0.04 by 0.02.

Host, Hcemulon plumieri:

1907, July 15,1 fish, distomes few.

1908, July 6, 1 fish, 1 distome.

Dimensions, balsam: Length 1.96; breadth 0.68; oral sucker 0.22;
pharynx 0.11 ; ventral sucker 0.40; ova 0.039 by 0.017.

Host, Hcemulon sciurus:

1907, June 28, 1 fish, few distomes.

Dimensions in life: Length 1.50; breadth 0.68; oral sucker 0.22;
pharynx 0.13; ventral sucker 0.51 ; ova 0.038 by 0.018.

Host, Anisotremus virginicus: July 6, 1907, 1 fish, 1 distome.

Dimensions, life: Length 1.89; breadth 0.74; oral sucker 0.22 ; phar-
ynx 0.12; ventral sucker 0.45; ova 0.037 by 0.017.

Host, Neomoenis griseus:

One specimen found on a slide containing distomes from this host.
Length 0.91 ; breadth 0.47.

58 Papers from the Marine Biological Laboratory at Tortugas.

Host, Teuthis hepatus:
1908, July 11, 1 fish, 1 distome.

Dimensions, life: Length 0.86; breadth 0.44; oral sucker 0.22;
pharynx 0.09; ventral sucker 0.29; ova 0.031 by 0.017.

Dictysarca virens gen. et sp. nov. (Figs. 130-136.)

Etymology: Sbcruov, network; «■«/>!, flesh.

Body variable, pyriform, fusiform, or ovate when at rest, rather thick,
translucent greenish. So far as observed the body appears to be char-
acteristically reticulated, especially when viewed with transmitted light ;
ventral sucker 1.33 to 1.5 times the diameter of the oral; neck approxi-
matelv 0.25 the entire length ; pharynx adjacent to oral sucker ; esophagus
short or none; intestinal rami, inflated in some cases, extend to the pos-
terior end. Genital aperture median, ventral, a short distance behind
mouth; cirrus very short, prostatic portion vertical, cells small, tube
relatively large, continuing in a seminal vesicle dorsal to the ventral
sucker. Testes 2, lateral, opposite, a short distance back of the ventral
sucker, ovary towards the posterior end, dorsal; shell-gland and seminal
receptacle ventral to ovary; vitelline glands 2, lobed, in front of ovary.
Folds of the uterus voluminous, mainly dorsal, from near the posterior
border of the ventral sucker to near the posterior end; ova small. The
metraterm is ventral to the seminal vesicle, turns sharply ventrad just
behind the prostate, and runs parallel to the caudal border of the pros-
tate to open with it into the common genital duct.

The excretory vessels appear to unite above the oral sucker. They
approach each other a short distance back of the ventral sucker. At
first they are ventral to the intestines, behind the ventral sucker they
become median, later they are variable. Thus in the vicinity of the
yolk-glands the intestinal rami are close together and the excretory
vessels are lateral to them. Near the posterior end they unite into a
single larger vessel which opens at the posterior end. The excretory
pore is surrounded by numerous nucleated cells.

In sections the intestines are seen to be about midway in a dorso-
ventral direction. The yolk-glands are ventral and nearly symmetri-
cally placed on either side of the median line. The shell-gland is between
them and about on the same level. On the right margin, at about the
posterior third and for some distance back, the folds of the uterus contain
copious spermatozoa mingled with the ova. In all of my specimens the
parenchyma is characteristically areolar, as shown in figs. 133 and 134.
Among the specimens which I have studied there are individuals in which
only rudiments of the genital organs appear. In them as well as in the
larger specimens there is the same loose, areolar structure of the paren-
chyma. There is, however, a larger proportion of structureless material
in the loose framework of tissue in the smaller specimens than in the
larger. One of the small distomes when sectioned showed rudiments of
an ovary, but little more that could be distinguished with certainty.

Helminth Fauna of the Dry Tortugas.

:.«.»

Dimensions of 3 specimens in balsam,

each more or less compressed.

From L. moringa. From L.funebris.

Length

Breadth

Neck

3-64
1 05
0 .91
0 .22

O.II

033

3 90
1. 61
0.89
0.28

O.II

4.27

1 -54
1 .07
0 .42
0 . 22

o.54

Average dimensions of ova, alcoholic: 0.03 by 0.02.

Host, Lycodontis moringa: July 2, 1907, 1 fish, 4 distomes.

Dimensions: Length of largest 5 mm., breadth 2.5 mm. Intestine in
one filled with dark-brown or black granular material. Suckers filled
with blood-cells of host.

Host, Lycodontis funebris:

1906, July 4, 1 fish, 4 distomes from swim-bladder; June 28, 2 fish,
4 distomes from swim-bladder.

1908, July 7, 1 fish, 2 distomes from swim-bladder.

The following remarks are condensed from notes made at the time
of collecting the material from L. funebris.

In the first lot the genitalia were not well developed. One of the
specimens was 2.5 mm. in length, 1.75 in breadth, and 1.25 in thickness.
After it had been flattened and fixed over the flame it measured 5 mm.
in length and 2 in breadth. In the second lot two distomes were found
in the swim-bladder of each of the morays. The largest was 5 mm. in
length and 3 in breadth. Uterus voluminous, yellow; intestines dark
brown; other organs white or colorless. In the third lot the distomes
were variable, tense, body -wall thin. One of them burst open after
lying for a short time in sea-water. The other at times contracted into
a nearly spherical shape, and then changed to pyriform, short-clavate,
cylindrical, arcuate. The prevailing color white, uterus in voluminous
folds on dorsal side, golden-yellow, other genitalia ivory-white; intestine
dark brown; dark-brown, irregular lines showing through the body-wall
throughout the entire length appear to be excretory vessels. The unin-
jured specimen was killed in 70 per cent alcohol and straightened with
a brush. It then measured 10 mm. in length and 5 in breadth.

Theletrum fustiforme gen. et sp. nov. (Fig. 137.)

Etymology: Qyhj, nipple; ^~/">'-', the belly.

The following description is based on a single specimen mounted in
balsam and seen in lateral view.

Body cylindrical with rather thick walls, enlarging slightly to pos-
terior end; smooth, but somewhat corrugate with transverse striae and
with a cluster of low but distinct rounded papilla? on the ventral surface
behind the ventral sucker and occupying a little less than the middle third
of the length; neck equal to about one-fourth the length. Oral sucker
sub terminal, approximately half the diameter of the ventral sucker;
pharynx subglobular, contiguous with the oral sucker; esophagus two
or more times as long as the pharynx. The intestinal rami are slender,
slightly sinuate, and extend to the posterior end. Genital aperture

60 Papers from the Marine Biological Laboratory at Tortugas.

immediately behind pharynx, ventral, median; cirrus-pouch pyriform
with conspicuous prostate and muscular cirrus; seminal vesicle a con-
spicuous and convoluted tube lying to the left and behind the cirrus-
pouch; cirrus-pouch and seminal vesicle lying in neck. Testes 2, rather
small, somewhat pyriform, nearly opposite, and nearly at the middle
point of the length of the body. Ovary long-oval, near the posterior end
of the body, with the shell-gland at its caudal border; vitelline glands 2,
subglobular, behind the ovary and touching each other, the more anterior
one in contact with the ovary. A fold of the uterus lies behind the vitel-
line glands, and other folds fill the space not occupied by the other organs
between the ovary and the ventral sucker. A muscular seminal recep-
tacle, pyriform in shape and about the size of a testis, lies a short distance
behind the testes. The metraterm passes ventrad of the seminal vesicle
and cirrus-pouch and opens at the genital aperture. The ova are small
and very numerous.

Dimensions of the specimen mounted in balsam: Length 1.47;
breadth, near anterior end 0.18, at ventral sucker 0.22, near posterior
end 0.35; length of neck 0.36; oral sucker, length 0.08, breadth 0.04;
pharynx 0.03; ventral sucker 0.18; ova 0.024 by 0.013.

Host, Pomacanthus arcuatus: July 18, 1906, 1 fish examined, 1 dis-
tome.

This distome was not studied much at the time of collecting. The
following measurements were made on the living worm: Length 1.82;
breadth, anterior 0.21, middle 0.32, posterior 0.35; oral sucker 0.09; ven-
tral sucker 0.22; ova 0.025 by 0.014.

Hemiurus merus sp. nov. (Fig. 138.)

The distomes which are referred to this species agree so closely with
the species which I have recorded under the name Disiomum appendicu-
latum (Bull. U. S. Fish Commission for 1899, p. 289, plate 36, figs. 25, 26)
that I was at first disposed to refer them to that species. When they are
compared with specimens in my collection from the alewife they are seen
to be specifically different. Although the character of the seminal ves-
icle in this species is different from that required for the genus Hemiurus,
I place it in that genus, preferring to extend the limits of the genus rather
than to be a party to any further dismemberment of the genus.

The following description is based on specimens which were stained
and mounted in balsam.

Body cylindrical to fusiform and clavate, crossed by stria? which
make a sharply serrate outline, distinct on the margins as far back as the
ovary, dorsally not usually distinct so far back as the ventral sucker;
appendicular portion approximately equal to half the length of the body
proper; neck short, tapering, slightly arcuate. The rami of the intestine
enter the appendiculate portion when the latter is extended. In some
which have the appendix retracted the intestines appear to stop at the
anterior end of the appendix. Mouth ventral; ventral sucker about
twice the diameter of the oral sucker. Genital aperture at posterior
ventral border of oral sucker; cirrus smooth, cirrus-pouch rather slender,
reaching usually to about the middle of the dorsal side of the ventral

Helminth Fauna of the Dry Tortugas. 01

sucker; prostate large, extending from dorsal side of ventral sucker pos-
teriorly for a greater distance than the diameter of the ventral sucker.
The seminal vesicle is relatively large, oval, and is inclosed in a muscular
wall; it lies dorsal to the posterior end of the prostate and immediately
in front of the testes. The testes are 2, small, globular, close together,
ventral and slightly diagonally placed. The ovary lies some distance be-
hind the testes, its longer diameter transverse to the axis of the bo
At its posterior border lie the 2 yolk-glands, the right being globular or
oblong elliptical, the left more or less 3-lobed. The folds of the uterus
are for the most part between the seminal vesicle and the base of the ap-
pendix. The excretory vessels are not distinct in the mounted specimens.

This distome agrees closely with Hemiurus appcudiculatus as de-
scribed by Looss (Zool. Jahrb., 1907, p. 103, plate 7, figs. 1, 2, 3). The
most marked difference is in the character of the seminal vesicle, which
is not divided into two portions, but consists of a single, oval structure,
inclosed in a strong, muscular wall and with its longer axis coinciding
with the long axis of the body.

Host, Clupanodon pseudohispanicus: July 10, 1906, few.

Dimensions, life: Length 2.94; breadth 0.5; oral sucker 0.09; phar-
ynx 0.07 ; ventral sucker 0.21 ; ova 0.027 by 0.010.

Sterrhurus monticellii (Linton). (Figs. 139, 140.)

Distomiim monticellii, Proc. U. S. Xat. Mus., pp. 518-520, plate xliv, tigs. 2-8.
Bull. U. S. Fish Commission, 1899, pp. 451, 473, 482. Bull. Bureau of
Fisheries, vol. xxiv, p. 334, figs. 154, 155, 158.

The distomes upon which this description is based were collected
from a remora which had been taken on a tiger shark before I reached
the laboratory, and had been preserved in formalin. The stained and
mounted material shows but a part of the anatomy, but so far as can be
seen they agree with the species which I have recorded under the name
Distomum monticellii. This distome agrees closely with the genus Ster-
rhurus Looss.

Following are the characters that can be made out from these dis-
tomes: Body smooth, nearly cylindrical, largest near posterior at level
of ovary; ventral sucker 2.5 times the diameter of oral sucker; seminal
vesicle elongated, situated at cephalo-dorsal border of ventral sucker and
preceded by the prostate. Intestinal rami long. Testes small, close
together, one behind the other and close to the posterior edge of the
ventral sucker; ovary larger, separated from the testes by folds of the
uterus; yolk-glands 2, at posterior border of the ovary, each rather deeply
lobed; uterus filling a large part of the body.

Dimensions, balsam: Length 1.45; breadth 0.35; oral sucker 0.12;
pharynx 0.06; ventral sucker 0.35; ova 0.02 by 0.01.

Transverse and tangential sections were cut of these distomes; of
these the tangential were the most satisfactory. From them it was
seen that there is a seminal receptacle situated caudo-dorsad of the yolk-
glands. There is a deep cleft (fig. 139 n) on the ventral side of the neck,
immediately in front of the ventral sucker, which has a thick, muscular
wall at its inner end. The genital pore is close behind the oral sucker.

62 Papers from the Marine Biological Laboratory at Tortugas.

The folds of the uterus are closely compacted. The lateral excretory
vessels appear to meet above the oral sucker. There does not appear
to be an upper lip, as is shown in Looss's various closely allied genera.
Fig. 139 is a sketch of a tangential section through the head and neck.
It shows the cirrus, portions of the seminal vesicle, prostate gland,
metraterm, cleft in front of ventral sucker, with its thickened muscular
wall at the inner end, an ovum in the common genital duct, oral sucker,
pharynx, intestine and excretory vessel.

Host, Neomcenis griseus: July 4, 1908, 1 fish, 1 distome.

Dimensions, life: Length 1.20; breadth 0.35; oral sucker 0.11;
pharynx 0.04; ventral sucker 0.28; ova 0.012 by 0.006.

Host, Echeneis naucrates: June 24, 1907, 1 fish, 8 distomes.

Host, Abudefduf saxatilis: July 7, 1907, 1 fish, 1 distome.

Dimensions, life: Length 1.05; breadth 0.25; oral sucker 0.10;
pharynx 0.04; ventral sucker 0.16; ova 0.017 by 0.010.

Host, Ocyurus chrysurus: July 12, 1907, 3 fish, 2 distomes.

Dimensions, life: Length 1.26; breadth 0.40; oral sucker 0.10;
pharynx 0.06; ventral sucker 0.24; ova 0.016 by 0.011.

Host, Chlorichthys bifasciatus:

July 8, 1907, 1 fish, 1 distome, immature.

Dimensions, life: Length 0.46; breadth 0.19; oral sucker 0.07;
pharynx 0.03; ventral sucker 0.11.

The specific relations of this young distome are doubtful. There
is a distinct prepharynx represented in the sketch made at the time of
collecting. The specimen was lost.

Sterrhurus fusiformis (Liihe). (Figs. 141-147.)

The general appearance of this distome is much like that of the
species I have recorded under the name Distomum monticellii, but the
vitelline glands are more numerously and more deeply lobed than in
that species. It appears to agree closely with Lecithochiriwm fusiformis
Liihe (Zool. Anz. xxiv, p. 476, fig. 3). Looss refers this species to the
genus Sterrhurus Looss (Zool. Jahr., 1907, p. 143, figs. 52, 55, 56).

Body in general fusiform, but very variable; pale red or flesh-color,
body reddish, neck translucent yellowish (a specimen which had been
lying under the cover-glass for 2 hours or more was pale greenish-yellow
by transmitted light) ; neck short, frequently arched or abruptly folded
ventrally on itself; ventral sucker rather more than twice the diameter
of the oral sucker; esophagus very short; pharynx contiguous to oral
sucker. The rami of the intestines may reach to the cephalic end of the
large excretory organ in the appendix. Genital aperture ventral to the
caudal end of the pharvnx; cirrus-pouch muscular, surrounded by large
prostatic cells; seminal vesicle at its caudal end irregularly pyriform, in
front of and dorsal to the ventral sucker. Testes 2, small, nearly trans-
versely placed and near the caudal border of the ventral sucker. Ovary
subglobular or oval, not lobed, situated about the middle of the length
of the body; vitelline glands adjacent to and behind the ovary, made
up of 7 slender-clavate branches uniting in an attenuated middle part.
There appear to be 7 of these branches, 4 on the right and 3 on the left

Helminth Fauna of the Dry Tortugas. 63

side. The seminal receptacle is oval, behind the ovary and dorsal to and
touching the vitelline glands; uterus in many folds in the mid-region
of the body, extending from the caudal end of the body proper to the
ventral sucker. The metraterm enters the cirrus-pouch (figs. 146, 147).
Excretory vessel voluminous and thick-walled in the appendix, passing
as a single vessel to the caudal border of the ventral sucker, where it
divides into 2 lateral vessels. These lateral branches unite dorsal to the
oral sucker.

Host, Lycodontis moringa:

1906, July 4, 1 fish, 4 distomes, in stomach.

1907, July 2, 1 fish, 1 distome; July 11, 1 fish, 3 distomes.
Dimensions, life: Length 3.50; breadth 0.91; oral sucker 0.25;

pharvnx 0.07 ; ventral sucker 0.56; ova 0.018 by 0.009.
Host, Lycodontis funebris:

1906, July 4, 1 fish, 1 50 ± distomes, stomach.

1907, June 28, 2 fish, 82 distomes, stomach.

When placed in sea-water these distomes adhere strongly to each
other and to individuals of other species.

Dimensions, life: Length 3.5; breadth, anterior 0.28, middle 0.90,
posterior 0.28; oral sucker 0.22; pharynx 0.07; ventral sucker 0.50; ova
0.02 by 0.01.

Mature and immature occurred together in these lots.

Ectenurus virgula sp. nov. (Fig. 148.)

This species, according to Pratt's Synopsis, belongs to the genus
Lecithocladium. When one attempts to give it a place among the nu-
merous genera established by Looss (Beitrag zu Syst. d. Dist.) it must be
placed in or near the genus Ectenurus, on account of the 2 lateral emi-
nences (fig. 148 n) situated on the dorsal side of the neck above the
pharynx.

The following description is based on specimens mounted in balsam:
Body cylindrical to fusiform with transverse rings making a sharp
serrate outline which is most conspicuous on the ventral side, where
it continues caudad to about the base of the appendix, very faint on
the dorsal side; appendix approximately one-third of the entire length;
neck short, its diameter much less than that of the body, with 2 slight
eminences dorsal to pharynx; ventral sucker prominent, 2.5 times the
diameter of the oral sucker; pharynx subglobular, adjacent to oral
sucker; rami of intestine extend into the appendix. Genital aperture
ventral, median, at posterior margin of oral sucker; cirrus slender, about
as long as the diameter of the ventral sucker; cirrus-pouch dorsal to ven-
tral sucker, prostatic portion rather small and inconspicuous, somewhat
variable in position but always behind the ventral sucker, its long axis
coinciding nearly with the long axis of the body. Seminal vesicle divided
usually into 3 parts, which, in most cases, increase in size posteriorly, the
anterior division ellipsoidal, the others subspherical, the whole vesicle
surrounded by a definite muscular wall. There is considerable varia-
tion shown by the seminal vesicle. Testes 2, close together, one behind
the other, just back of the seminal vesicle and with but a short interval

64 Papers from the Marine Biological Laboratory at Tortugas.

between the posterior one and the ovary, somewhat variable in shape
but in the main subglobular; in some cases equal, in others the posterior
is the larger. Ovary near, in some cases, touching, the posterior testis;
in some cases larger, in others equal to, and in others smaller, than the
posterior testis, usually ellipsoidal with longer axis transverse to the long
axis of the body. Yolk-glands tubular, lying beside the ovary and ex-
tending a little way both in front and behind the ovary. In one case
there appeared to be only 2 of these tubular glands. In others there
were more, possibly as many as 4- The yolk-glands are much convo-
luted and consequently difficult to make out. The seminal vesicle,
testes, ovary, and yolk-glands are all ventrally situated. The folds of
the uterus for the most part lie dorsal to the other genitalia and behind
them, extending as far back as the base of the appendix. The metra-
term was not seen satisfactorily. It appears to lie dorsal to the base of
the cirrus-pouch, thence it was traced along the left side of the cirrus-
pouch to the base of the retracted cirrus. The excretory vessels do not
show distinctly in the mounted specimens, but it could be made out that
they end blindly lateral to the oral sucker.

" Dimensions, life, flattened: Length 3; diameter 0.5; oral sucker
0.15; pharynx 0.08; ventral sucker 0.38; ova 0.017 by 0.008.

Host, Clupanodon pseudohispanicus : July 10, 1906, numerous.

Ectenurus sp., immature. (Fig. 155.)

The specimens in this lot, which are small and immature, are near
Ectenurus (fig. 148). The following description is based on specimens
mounted in balsam:

Body nearly linear; neck cylindrical, arched; neck and body crossed
by fine, transverse lines making a serrate outline; ventral sucker about
1.5 times oral. There is a slight projection of the head beyond the oral
sucker. There seems to be a very short esophagus and the intestinal
rami extend to the extreme posterior end. In one specimen the intes-
tines are convoluted in the tail region (fig. 155); in another they are
straight. Genital aperture ventral to the subglobular pharynx; cirrus-
pouch long, inclosing the seminal vesicle, the latter lying behind the
ventral sucker. Testes 2, close together and just behind the seminal
vesicle.

Ovary a short distance behind the testes, oval; vitelline glands
tubular, beginning at the ovary and extending some distance back of it.
In two of the specimens the tail was inclosed in a sheath as shown in the
sketch (fig. 155). In the third specimen the tail was narrower than the
body and tapered uniformly to the posterior end.

Dimensions of specimen figured: Length 2; breadth 0.28; length of
neck 0.35; oral sucker 0.16; pharynx 0.07; ventral sucker 0.25.

Host, Auxis thazard: July 10, 1906, 1 fish, 3 distomes.

Dinurus rubeus sp. nov. (Figs. 149-154.)

This species resembles Dinurus longisinus Looss, but differs from
that species in having a preoral projection and in the character of the
seminal vesicle, which is without constrictions.

Helminth Fauna of the Dry Tortugas. 65

Body elongated, cylindrical; color somewhat variable, but in most
cases tinged with red in the middle portions; the intestines dark brown,
nearly linear in middle region but tapering gradually to the posterior
end; neck short; head with short, conical projection in front of oral
sucker; ventral sucker about twice oral; pharynx subglobular, contig-
uous with oral sucker, its lumen quadrangular; esophagus short; intes-
tinal rami ample, sacculate, extending to the posterior end, in my speci-
mens filled with black, granular material. Genital aperture median,
ventral to pharynx; cirrus short; prostate large, its tube much convo-
luted ; in my specimens the prostate begins at the anterior edge of the
ventral sucker and extends to the posterior edge ; seminal vesicle behind
ventral sucker. Testes 2, near posterior edge of ventral sucker, slightly
diagonally placed; ovary subglobular or oval, a short distance behind
testes; seminal receptacle behind ovary and close to it; vitelline glands
tubular, lateral, beginning a short distance in front of ovary and con-
tinuing for a short distance back of the seminal receptacle ; uterus volu-
minous, mainly dorsal and median, from level of testes back rather more
than half-way from the ventral sucker to the posterior end; ova very
numerous and minute. The metraterm joins the duct of the prostate
at base of the retracted cirrus in a specimen studied in sections (fig. 152).
Excretory vessel single, from posterior end to a point a short distance
behind seminal vesicle, where it divides into two lateral branches which
unite above oral sucker. The cells lining the excretory vessel near pos-
terior end appear to be ciliated. Length 5 to 25 mm. ; diameter 1 to 2 mm.

Host, Lycodontis moringa: 1907, June 30, 1 fish, 1 distome.

This distome was translucent greenish- white, intestines black. Neck
actively contractile, body less so. There were a few, low, fleshy papillae
scattered over the surface of the body.

Dimensions, life: Length 5.5; breadth 0.98; oral sucker 0.42; phar-
ynx 0.28; ventral sucker 0.84; neck, extended, length 1.40, breadth 0.35.
Ova, balsam, 0.018 by 0.010.

1907, July 2, 1 fish, 1 and fragment.

Suckers transparent greenish, from ventral sucker to posterior yel-
lowish, due to ova, posterior third very dark; length 25 mm.

Host, Lycodontis funebris:

1906, July 4, 1 fish, 3 distomes in stomach, 1 in intestine.

Middle of body tinged with red, anterior end translucent whitish or
greenish-yellow; intestines conspicuous, black; length of largest 22;
diameter 1.5 to 2; oral sucker 0.98; pharynx 0.42; ventral sucker 1.92.
Ova, balsam, 0.017 by 0.010.

1907, June 28, 2 fish, 2 distomes, in stomach, 8 and 16 mm. long.

1908, Julv 7, 1 fish, 3 distomes.

Length 15 and 18 mm. respectively. General ground-color reddish,
especially in the middle third, growing paler toward the posterior end
and becoming translucent anteriorly in the vicinity of the suckers ; intes-
tines black, conspicuous the entire length.

Hapladena varia gen. et sp. nov. (Figs. 156, 157.)
Etymology: &TtX6o^1 single; Myvt gland.

Body, especially anteriorly, covered with dense, short, flat spines;
shape variable, fusiform to linear; suckers nearly equal and not far apart;
5

66 Papers from the Marine Biological Laboratory at Tortugas.

pharynx usually about half the diameter of oral sucker. There is a dis-
tinct prepharynx and an esophagus. The proportions of the prepharynx
and esophagus are variable (figs. 156, 157). The forking of the intes-
tines is, in some cases, on a level with the ventral sucker, in others
behind it. The rami of the intestines reach nearly to the posterior end
of the body. Genital aperture in front of ventral sucker and near it.
There is a conspicuous cirrus and cirrus-pouch, the latter inclosing the
convoluted seminal vesicle and prostate, extending dorsal to the ventral
sucker and behind it. There is but one testis, which is relatively large,
especially in the younger adults, and is situated about the posterior
third. The ovary lies a short distance in front of the testis. It is an
oval or subspherical body, and, like the testis, lies on the median line.
It is preceded by the conspicuous shell-gland, on the right and ventral
side of which there is a seminal receptacle. The folds of the uterus lie
between the ovary and the ventral sucker. The vitelline glands are
diffuse and lie along the margins at the posterior end, and are scattered
through the median region of the body. They extend forward about to
the ventral sucker.

Host, Teuthis hepatus:

1907, July 1, 1 fish, 3 distomes.

1908, July 11, 1 fish, 14 distomes; July 13, 3 fish, 17 distomes; July
15, 1 fish, 9 distomes.

In some the spinose cuticle was separating from the body; intes-
tines frequently dark brown. In one lot there were thought at first to
be three distinct species: (1) Translucent, plump, cylindrical, old speci-
mens. Dimensions, lying free in water: Length 2.66; breadth 0.70;
oral sucker 0.21 ; pharynx 0.07; ventral sucker 0.21 ; ova 0.042 by 0.024.
(2) Opaque, white, thickish. Dimensions, compressed: Length 2.87;
breadth 0.97; oral sucker 0.21; pharynx 0.08; ventral sucker 0.26; ova
0.045 by 0.027. (3) Flat, thin, faint greenish-yellow, translucent, appar-
ently younger forms of the foregoing but with fewer ova. In these
there was a great variety of outline, especially of the anterior end, taper-
ing, bluntly rounded, and a few knobbed by a constriction just behind
the oral sucker. The opaque forms, before compression, were often trun-
cate and had a strong tendency to slough off the epidermis.

One slender, immature distome had the following dimensions: Length
1.50; breadth 0.40; oral sucker 0.12; pharynx 0.06; ventral sucker 0.10.

Host, Teuthis cceruleus:

1908, June 27, 1 fish, 1 distome; July 6, 1 fish, 5 distomes.

Dimensions, life, flattened: Length 3; breadth not recorded; oral
sucker 0.27; pharynx 0.14; ventral sucker 0.27; ova 0.04 by 0.02.

DERADENA gen. nov.

Etymology: dipy, neck; a^'v, gland.

Body smooth. Vitellaria diffuse, posterior, and lateral, in most
cases entirely behind ventral sucker and not reaching to the anterior
border of the ventral sucker in any of the species here described. Testis
one, oval, or somewhat triangular in outline, on median line towards
the posterior end of the body; ovary oval, not lobed, in front of testis;

Helminth Fauna of the Dry Tortugas. 67

genital aperture median, in front of the ventral sucker; ova large. The
character which suggests the name of the genus is the presence of con-
spicuous glands in the neck, which are interpreted to be yolk-forming

cells.

Deradena ovalis gen. et sp. nov. (Figs. 162-169.)

The following description is based on whole mounts and sections of
specimens from Scarus ccernleus:

Body smooth, oval, thickish, pale red, suckers about equal, neck
about 0.25 of entire length; pharynx longer than wide; esophagus rela-
tively long; bifurcation of intestine not far from posterior edge of ventral
sucker, the rami extending to the posterior end. Genital aperture at
anterior border of ventral sucker ; no penis ; genital pouch containing the
comparatively straight and strong-walled metraterm, which, near the
outlet, receives a small tube from the seminal vesicle (fig. 164 z) and is
dorsal to the ventral sucker; prostatic cells accompany both metraterm
and seminal vesicle. There was considerable difference in details in the
two series of sections as shown in figs. 164 and 165. One testis, large,
near posterior end of body. Ovary in front of testis and near it, nearly
median, its vertical diameter greater than the lateral ; shell-gland ventral
and median to the ovary, as seen in sections; in whole mounts it is on
the anterior and lateral border of the ovary. In one of the whole mounts
the shell-gland extends along the entire anterior border of the ovary and
about half-way back on each lateral border. In the other it is so much
obscured by the vitellaria that it is difficult to see it at all. The vas
deferens is voluminous and was traced in sections from the posterior
end of the cirrus-pouch to the shell-gland. There is a large seminal recep-
tacle which is situated for the most part ventral to the shell-gland. No
Laurer's canal was recognized in the sections. The vitellaria are very
abundant and are distributed peripherally throughout the bod v. Large
cells extend from the body -wall into the parenchyma (fig. 168 d). At
their inner ends they are yolk-bearing (fig. 169 d and d'). I interpret the
cell to which the index line d' points as having undergone nuclear division,
and the inner nucleus with thr mass of yolk surrounding it as about to
separate. The masses of yolk (fig. 169 vg) forming a concentric layer
within the layer of yolk-forming cells can be seen to be made up of cells
which resemble the inner ends of such cells as d' . These yolk-cells tend
to fuse together, their nuclei disappear, and the yolk is at first reduced
to a granular condition, as in the duct yd seen in longitudinal section in
fig. 169. Next it collects into coarse granular masses, as in the duct yd,
shown in cross-section in fig. 169. The folds of the uterus lie between
the ovary and the ventral sucker. There is a distinct excretory pore at
the posterior end of the body, and a straight excretory vessel appears
in the series of sections on the dorsal side as far forward as the anterior
border of the testis. My notes, made at the time of collecting, mention
in one of the specimens the occurrence of dark, lateral lines meeting be-
hind the ventral sucker whence the single tube extends to the posterior
end. Some very small vessels, which appear in the transverse sections
but which I have been unable to trace to the posterior single vessel, may

68 Papers from the Marine Biological Laboratory at Tortugas.

represent the excretory vessels in the anterior part of the body. The
body -wall is rather thick and the musculature is well developed.

Dimensions of mounted specimen: Length 3.50; breadth 1.12;
length of neck 0.88; oral sucker, length 0.48, breadth 0.46; pharynx,
length 0.21, breadth 0.14; ventral sucker, length 0.42, breadth 0.48; ova
0.054 by 0.027.

Host, Scarus cceruleus: July 13, 1908, 2 fish, 3 distomes.

Host, Scarus sp. (This was a parrot-fish having many points of
resemblance to Sparisoma abildgaardi .)

July 11, 1908, 1 fish, 2 distomes.

Pale red, thickish, with lateral dark lines meeting behind ventral
sucker. Dimensions, flattened: Length 5; breadth 2.5; oral sucker
0.56; pharynx, length 0.43, breadth 0.35; ventral sucker 0.86; ova 0.047
by 0.034.

July 8, 1908, 1 fish, 1 distome.

Not in good condition. Ova 0.09 by 0.06.

The distomes here recorded probably represent different species.

Host, Scarus croicensis (?): July 8, 1908, 2 fish, 1 distome.

Specimen in poor condition. Fusiform, no ova.

Dimensions: Length 1.12; breadth 0.67; oral sucker 0.22; pharynx
0.15; ventral sucker 0.35.

Host, Scarus croicensis: July 7 and 8, 1908, 3 fish, 1 distome.

Dimensions in glycerin, flattened: Length 2.10; breadth 0.77,
oral sucker 0.29; pharynx 0.07 ; ventral sucker 0.49.

Deradena acuta gen. et sp. nov. (Figs. 158, 159.)

Distoinum sp., from Tylosurus acus. Parasites of Bermuda Fishes, Proc. U. S.
Nat. Mus., xxxiii, p. 115, fig. 62.

This species bears a superficial resemblance to Haplosplanchnus
Looss, but the vitellaria are diffuse instead of dendritic.

Body fusiform, broadest in middle, whence it tapers to each end,
the posterior end being rather the more slender. Ventral sucker at about
anterior third, nearly twice the diameter of the oral, its aperture narrow
and nearly coinciding with the axis of the body. There is a short pre-
pharynx and an esophagus. The pharynx is slightly pyriform. The
genital aperture is close behind the pharynx and a little to the left of it.
The cirrus-pouch proper is adjacent to the genital aperture and is nearly
circular in outline. What seems to be the prostatic portion and the metra-
term lies on the right side of the ventral sucker. A characteristic striated
appearance of the cirrus-pouch, noted in the living specimen, is evident
in the mounted specimen, both in the globular portion and in the slender
prostatic portion. The rami of the intestine appear to extend nearly
to the posterior end. Two glandular bodies at the antero-lateral bor-
ders of the ventral sucker (fig. 159 d) are interpreted to be yolk-forming
glands. The vitellaria are dense and diffuse, filling the greater part of
the body behind the ventral sucker. They extend about as far forward
as the middle of the ventral sucker. In the stained specimen they are a
rich reddish-brown, and lie in dense masses between and to some extent
over the other organs. There is a single large testis which is somewhat

Helminth Fauna of the Dry Tortugas. 69

triangular, with the pointed end directed caudad. The ovary lies on the
anterior border of the testis. It is oval, its longer diameter transverse,
and it is much smaller than the testis. The seminal receptacle lies on the
left side, extending from the ovary along the margin to a point a little
behind the level of the posterior edge of the ventral sucker. The folds
of the uterus lie behind the ventral sucker and between that organ and
the ovary. The ova are large and not numerous.

Host, Tylosurus marinus: July 9, 1906, 1 fish, 2 distomes.

Dimensions of larger specimen, life, moderately compressed: Length
1.96; breadth, anterior 0.22, middle 0.66, posterior 0.11; oral sucker
0.21; pharynx, length 0.12, breadth 0.09; ventral sucker, length 0.40,
breadth 0.35; ova 0.071 by 0.054. Length of smaller specimen 1.50.

The body was smooth, but with a few small nodular papillae at the
anterior end.

Deradena obtusa gen. et sp. nov. (Figs. 160, 161.)

The specimens here figured and described may belong to different
species. They are in poor condition and but little of the anatomy could
be made out. Body smooth, fusiform, tapering to each end, but rather
more posteriorly than anteriorly. The rami of the intestine extend to the
posterior end. The pharynx is adjacent to the oral sucker; ventral
sucker larger than oral. Genital aperture between the suckers but nearer
oral than ventral. Ovary and seminal vesicle at caudal border of ventral
sucker. Testis one, conspicuous, occupying a large part of the space
behind the ventral sucker. The vitellaria are diffuse, posterior, and mar-
ginal, and extend forward in front of the ventral sucker. In front of the
ventral sucker there are lateral clusters of large, nucleated cells, which
are interpreted as yolk- forming glands, as in the preceding species. The
ova are few and large and lie dorsal to the ventral sucker. In the
specimen figured from T. cceruleus they lie for the most part behind the
ventral sucker.

Host, Teuthis hepatus:

1907, July 1, 1 fish, 3 distomes; July n, 1 fish, 1 distome.

Dimensions, life: Length 1.22; breadth 0.50; oral sucker 0.19;
pharynx 0.07; ventral sucker 0.24; ova 0.075 by 0.051.

Host, Teuthis cceruleus: July 6, 1908, 1 fish, 2 distomes.

Dimensions, life: Length 0.98; breadth 0.29; ventral sucker 0.16;
ova 0.075 by 0.051.

MONOSTOMIDiE.

Barisomum erubescens gen. et sp. nov. (Figs. 173-183.)
Etymology: /&*/>£?, a boat; ow/ia, body.

Body smooth, convex dorsally, both transversely and longitudinally,
and concave both transversely and longitudinally on the ventral surface.
Viewed from the ventral side the body is boat-shape. The ground-color
in life is pink; the excretory vessels usually, and the intestines often,
filled with black, granular material. Oral sucker circular in outline,
subterminal. A cross-section of the body behind the oral sucker is more
or less circular, as is also a section made near the posterior end. In all

70 Papers from the Marine Biological Laboratory at Tortugas.

intermediate portions of the body a transverse section is horseshoe-
shaped (fig. 175). The lateral margins, beginning in 2 thick muscular
folds a short distance behind the oral sucker, are bent downward and
inward until the gap between the edges may be no more than one-third
the whole breadth of the body thus folded. The edges are muscular,
being provided with strong, longitudinal muscle fibers. The body
throughout is supplied with numerous fascicles of strong muscle fibers
which connect the morphologically dorsal and ventral surfaces (figs.
175, 178-180). There is no pharynx, but there is a slender esophagus
(fig. 183) . The intestinal rami extend to the posterior end, with numerous
short branches throughout. In one set of sections they were observed
to anastomose (fig. 177). In other sets of sections the rami of the intes-
tines do not appear to anastomose, although their walls were seen in
juxtaposition in two sets of sections. In the most satisfactory set they
were entirely separated by parenchymatous tissue. The genital aperture
is on the left margin approximately at the anterior third. The cirrus-
pouch is relatively large, cylindrical, the basal half consisting of the
conspicuous prostate. The seminal vesicle, as a convoluted tube, lies
caudad of the basal portion of the cirrus-pouch and enters the distal end
of the prostatic portion. The testes are 2, somewhat lobed, and lie oppo-
site to each other at the extreme posterior end of the body. The ovary,
also more or less lobed, lies on the median line a little in front of the testes,
its posterior margin about on a level with the anterior edges of the testes.
The seminal receptacle lies anterior and dorsal to the ovary, and the shell-
gland is behind the ovary and between the testes. The vitelline glands
are massed laterally on the margins immediately in front of the testes,
extending from the anterior border of the testes for a short distance
along the margin. The folds of the uterus lie in close, transverse loops
running from margin to margin between the testes and the cirrus-pouch.
The ova have a slender filament at each pole. The excretory vessels are
conspicuous, being in most cases filled with black pigment, which remains
in the mounted specimens. The excretory vessels begin at the head in
a net-work of fine vessels. These soon unite into 2 main lateral branches
about half-way between the mouth and the bifurcation of the intestine.
They pursue a somewhat irregular, meandering course, but mainly lat-
eral, to the posterior end, where they unite just before entering the excre-
tory pore.

One of the most characteristic features of this singular worm is the
musculature, especially as seen in the numerous fascicles of transverse
fibers and in the strong marginal fibers (fig. 175 tm, Im).

Host, Angelichthys isabelita:

1906, July 10, 1 fish, 2 trematodes.
1908, July 3, 1 fish, 3 trematodes.

These trematodes were boat-shape, pinkish, anterior end lighter
colored; dark-brown intestines, branched; genitalia white. Length 2.5
to 3 mm.

Host, Pomacanthus arcuatus :

1907, July 3, 1 fish, 1 trematode; July 11, 1 fish, 8 trematodes; July
15, 1 fish, 1 trematode.

Helminth Fauna of the Dry Tort it gas. 71

Ground-color pink ; body characteristically canoe-shape ; intestine
with black pigment, rami with numerous short branches. Length from
2.5 to 3.5 mm. A small specimen, flattened, had the following dimen-
sions: Length 2.60; breadth, anterior 0.40, middle 0.80, posterior 0.70;
oral sucker 0.20; oral aperture 0.07; ova, exclusive of filaments, 0.037
by 0.017; length of filament 0.30.

Host, Scarus croicensis:

1908, July 13, 2 fish, 1 trematode.

Much smaller than specimens from Pomacanthus and in poor con-
dition; recorded here on account of its general appearance, character
of the intestines, uterus and ova.

Himasomum candidulum gen. et sp. nov. (Figs. 184- 197a.)

Etymology: lf*ds, strap; trtb/ia, body.

Body slender, nearly linear, thin, the edges usually folded under
ventrally, especially towards the posterior end; color white. Head vari-
able, a muscular collar or ridge separating it from the body; oral sucker
nearly terminal. The muscular collar on the neck is sometimes contracted
until it is simply a more or less prominent ridge ; at other times it may be
very prominent, with a thin, frill-like edge, which may be reflected (figs.
184a, 185-187). The musculature is less developed on the ventral sur-
face back of the mouth, so that there is often the appearance of a deep
notch, or even the entire absence of a collar. There is no pharynx; the
esophagus is relatively long and quite slender. The rami of the intestine
extend to the posterior end, where they pass mediad of the testes. Their
posterior ends do not unite. In some cases the intestines appear to be
slightly branched, especially near the anterior end, where the outlines
seem to show that there were very short digitations on the intestinal
walls. The walls may be quite irregular, but neither the mounted speci-
mens nor the sectioned material shows a condition which will justify
the statement that the intestinal rami are branched. Genital aperture
on the left margin at about the anterior fifth. Cirrus rather long and
smooth. The cirrus-pouch passes diagonally to the middle line, its dorsal
half lying along the middle line and inclosing the prostate gland. The
seminal vesicle is a slender, coiled duct posterior to the cirrus-pouch.
Testes 2, lobed, lateral, opposite, at posterior end of the body, their
anterior borders behind the level of the ovary. They are separated from
each other by the excretory vessel and by the intestines. The ovary is
lobed, nearly median, or a little to the right of the median line and a
short distance in front of the testes. The shell-gland is posterior to the
ovary, median and between the anterior portions of the testes. The
vitellaria consist of a number of solid masses of irregular shape, but in
general more or less rounded, beginning posteriorly at the anterior
border of the testes and extending along each lateral margin to a point
which is about as much in front of the ovary as that organ is in front of
the posterior end of the body. The folds of the uterus begin behind the
ovary at the shell-gland. Passing to the left of the ovary thev occupy
the median region of the body forward as far as the base of the cirrus-

72 Papers from the Marine Biological Laboratory at Tortugas.

pouch. The folds are so disposed as to incline from their marginal limits
postero-mediad to the median line. The muscular metraterm lies parallel
with the proximal portion of the cirrus-pouch and on its posterior side.
The ova are oblong elliptical with a long filament at each pole. The
characteristic musculature of the preceding species (Barisomum erubes-
cens) is seen in this species, though neither the fascicles nor the fibers
are so strongly developed as they are in that species. The excretory
vessels unite near the head above the esophagus. They pass laterad of
the intestines until a short distance in front of the ovary, where they
pass under the intestinal rami, then mediad to unite just behind the
shell-gland. The single excretory vessel now passes between the testes
and the posterior extremities of the intestines to the terminal excretory
pore. Further anatomical details are given in the figures.

Host, Angelichthys isabelita: July 3, 1908, 1 fish, 1 trematode.

Host, Pomacanihus arcuaius:

1906, July 18, 1 fish, 5 trematodes.

1907, July 3, 1 fish, 4 trematodes; July 11, 1 fish, 48 trematodes;
July 15, 1 fish, 7 trematodes.

1908, June 29, 1 fish, 7 trematodes; July 1, 1 fish, 4 trematodes;
July 3, 2 fish, 18 trematodes; July 4, 2 fish, 4 trematodes;
July 7, 2 fish, 4 trematodes.

Dimensions in glycerin: Length 2.46; breadth, anterior 0.08,
middle 0.33, posterior 0.28; breadth 0.12 from anterior end 0.26; geni-
tal aperture 0.7 from anterior end; diameter of oral sucker 0.08; ova,
exclusive of filaments, 0.034 by 0.017.

Length in most cases from 3 to 4.5 mm.

Dimensions of one of larger specimens, life, flattened and the pos-
terior end unrolled: Length 4.69; breadth, anterior 0.36, middle 0.36,
posterior 0.78; ova, exclusive of filaments, 0.033 by 0.017; length of
filaments 0.42 ±.

PARAMPHISTOMIDjE.
Cleptodiscus reticulatus gen. et sp. nov. (Figs. 198-204.)
Etymology: k.II-to>, to conceal; SitrKos, a quoit.

Outline of body somewhat variable but usually fusiform or long
oval, tapering moderately to the rounded anterior end and narrowing
very slightly towards the posterior end, which bears a round sucker
ventrally placed. Body smooth, crossed by fine transverse lines which
give to the surface a somewhat crinkly appearance; color white, some-
times tinged with red or pink, especially in the vicinity of the posterior
sucker. Mouth terminal, provided with a muscular, pharynx-like sucker,
which is glandular in its peripheral portion, at least supplied with numer-
ous, deeply staining nuclei (fig. 200 a'). There are 2 small, rudimentary
suckers at the postero-lateral border of the mouth-pharynx, which,
however, can be seen only by deep focussing (figs. 201 r and 202 r). The
esophagus is slender and surrounded by deeply staining nuclei (figs. 200
and 202 w), which are more abundant around its anterior portion. Rami
of the intestine simple, extending to the posterior end, often inflated,

Helminth Fauna of the Dry Tortugas. 73

especially at the distal ends. Genital aperture ventral, median, at
bifurcation of intestines, surrounded by a muscular disk with abundant,
deeply staining nuclei. The cirrus-pouch is oval and contains the pyri-
form cirrus and a few coils of the seminal vesicle. The prostate gland is
not conspicuous and is represented apparently only by the not numerous
cells in the cirrus-pouch. Testes 2, more or less lobed, situated about
the middle of the body, one following the other and close to it, slightly
diagonally placed. Vas deferens very long, in a coiled mass behind and
ventral to the cirrus-pouch. Ovary small, subglobular, usually median
and near the posterior end. Shell-gland at caudal border of ovary and
between it and the anterior border of the posterior sucker. In one speci-
men both ovary and shell-gland were to the left of the median line, and
those folds of the uterus which were immediately in front of the posterior
sucker contained spermatozoa. The vitelline glands are represented
by lateral clusters of irregularly rounded masses, somewhat variable in
extent, but usually extending from a little in front of the posterior sucker
to a point on a level with the middle of the posterior testis. The uterus
extends from the shell-gland at the posterior end of the body to the coiled
vas deferens, and the metraterm continues ventrad of the cirrus-pouch
to open beside it at the common genital opening. The ova are relativelv
large and oval. The lateral excretory vessels unite above the esophagus
just back of the mouth-pharynx, pass ventrad of the intestinal rami, and
unite at the anterior border of the posterior sucker. The single excretorv
vessel now passes to the dorsal side of the posterior sucker, but the excre-
tory pore was not seen. A light-gray non-staining mass above the mouth-
pharynx and another smaller one below were noted, faintly indicated in
fig. 202 dh, rh. They suggest nerve masses, but no cells were demonstrated
in them. With the exception of these fine, granular, non-staining masses
the parenchyma of the body consists of a loose network of fibers. The
body-wall is rather weak, the cuticle, circular and longitudinal muscle
layers each rather thin. Peripheral gland-cells few and scattering.

Dimensions in balsam : Length 3.78; breadth, anterior 0.14, middle
0.71, posterior 0.86; anterior sucker, length 0.14, breadth 0.11 ; posterior
sucker, length 0.51, breadth 0.65. Dimensions of a smaller specimen:
Length 1.60; breadth, anterior 0.14, middle 0.77, posterior 0.67; anterior
sucker, length 0.14, breadth 0.11 : posterior sucker, length 0.30, breadth
0.39. Ova in each 0.075 by 0.034.

Host, Pomocanthus arcuatus:

1906, July 18, 1 fish, numerous trematodes.

1907, July 3, 1 fish, 10 trematodes; July 11, 1 fish, 43 trematodes;
July 15, 1 fish, 1 trematode.

1908, June 29, 1 fish, 60 trematodes; July 1,1 fish, 18 trematodes;
July 3, 2 fish, 65 trematodes; July 4, 2 fish, 190 trematodes;
July 5, 2 fish, 13 trematodes; July 7, 2 fish, 52 trematodes in
larger and 1 in smaller fish.

Dimensions, life: Length 1.65; breadth, anterior 0.21, middle 0.32,
posterior 0.35; oral sucker, length 0.15, breadth 0.14; posterior sucker,
length 0.46, breadth 0.30; ova 0.078 by 0.040. The length in general
varied from 1.5 to 3.5.

74 Papers from the Marine Biological Laboratory at. Tortugas.

SIPHODERID^.

Siphodera (gen. nov.) vinaledwardsii (Linton). (Figs. 208, 209a.)

Monostomum vinaldwardsii, Linton, Bull. U. S. Fish Commission 1899, p.
470, figs. 373-376; Bull. Bureau of Fisheries, vol. xxiv, 1904, p. 370 and
410'; Proc. Nat. Mus., xxxn, p. 118, fig. 97.

Etymology: trtywv, a tube; 8 1 py, neck.

Two trematodes from Ocyurus chrysurus appear to belong to this
species. The most striking difference between them and specimens from
Opsanus tau and from Ocyurus chrysurus in Bermuda is in the character
of the testes. The right testes agree with the descriptions already pub-
lished, but on the left side instead of 4 or 5 testes there is but 1. Until
the limits of variability are better known it does not seem advisable to
place this form in a new species.

In order to compare this with specimens in my collection, and at the
same time taking advantage of the opportunity thus afforded to revise
the description of the species, I made sections of old material and there-
fore can make a few needed emendations and corrections in the original
description. I am still obliged to leave one point in the anatomy not
entirely cleared up, viz., the real nature of the tube-like structures in
the neck.

EMENDED DESCRIPTION OF THE SPECIES.

Body thickish, depressed, slightly convex above, flat below, outline
varying, but approximately ovate, covered with exceedingly minute
villous spines. Oral sucker circular, subterminal, the aperture nearly
circular. Pharynx varying in preserved specimens, subglobular in life,
near oral sucker but in favorable positions it is preceded by a short
prepharynx. Esophagus short; intestinal rami extending to posterior
end of body. The ventral sucker is a part of the genital apparatus
(cirrus) and is depressed in a circular pit of the body-wall. The border
of this pit is muscular and has strong, muscular fibers radiating from it.
Contiguous with the genital sucker, dorsal or a little in front of it, is
a muscular, subglobular portion lined with coarse, wedge-like masses
resembling the lining of the prostatic portion of the cirrus-pouch in many
of the distomes figured in this paper. Since this portion is surrounded
by a few cells which appear to be prostate cells, this is doubtless the real
nature of the structure. This portion is followed by a tubular seminal
vesicle with muscular walls. Towards its posterior end it is more or less
convoluted. On the right side of the undoubted seminal vesicle is a larger,
oval seminal vessel, which is probably the seminal receptacle, although
of this I am not quite certain. Posteriorly it lies dorsal to the ovary.
A structure which appears to be Laurer's canal was noted in one set of
sections. Testes variable, but usually 4 or 5 on each side. They begin
from about the middle of the length to the posterior third and extend
from the point of beginning approximately half-way to the posterior
end. The ovary is many-lobed and situated on the median line a short
distance behind the genital sucker, from which it is separated by the
seminal vesicle. The vitelline glands in the older specimens are confined
mainlv to the lateral regions of the middle third of the body ; in younger

Helminth Fauna of the Dry Tortugas. 75

specimens they are distributed generally in the posterior part of the body
behind the genital sucker. They are dendritic, or, in the older specimens,
represented by small, compact masses. The excretory vessels begin
anteriorly in 2 lateral vessels beside the oral sucker. These branches
unite dorsal to the ovary a little in front of the middle. Thence a single
median vessel extends to the posterior end, near which it enlarges into a
muscular excretory vessel. The living worm is characterized by having
numerous, conspicuous, small, tube-like structures in the neck. These
were wrongly called excretory vessels in the original description of the
species. I am not altogether sure of their real nature, but have reason
to think them to be similar to the cells which elsewhere in this paper are
called yolk-forming cells. In sections they are seen to be slender, long-
pyriform, and pyriform bodies, not staining in haematein but staining
strongly in orange G, with a fine granular structure. In transverse
sections these pyriform bodies are peripherally placed with their small
ends inserted in the body-wall. Nuclei were indistinctly seen in some of
them. In the central portion of the sections of the neck were somewhat
similar bodies but more coarsely grained and less elongated. In some
of the sections the more coarsely granular bodies strongly suggest an
intermediate stage between the fine granules of the peripherally placed
bodies and the vitelline glands, as in the case of Deradena ovalis (fig. 169).
If this is a correct interpretation we have here an example of yolk-
forming cells in the neck. In that case the tube-like structures which
appear to be penetrating the body-wall would turn out to be slender
cells with the small ends peripheral and the large ends central, the re-
semblance to tubes penetrating the body-wall being deceptive. The
folds of the uterus are very voluminous and fill up all the postero-median
part of the body. In life the beginning folds on the left side are opaque-
white, the next towards the posterior end on the right side are light
yellow, shading into amber and smoky brown, becoming much darker
toward the anterior. The metraterm was traced to the prostatic portion
of the cirrus-pouch, but it was not seen to enter it. It appears to enter
the genital pit in front of the genital sucker.

Dimensions of Tortugas specimen, life: Length 1.75; breadth 0.70;
oral sucker 0.14; genital sucker 0.10; ova 0.017 by 0.007.

Host, Ocyurus chrysurus: July 10, 1907, 3 fish, 2 trematodes. one
with ova and one without.

Stegopa globosa gen. et sp. nov. (Figs. 205-207.)
Etymology: ariym, to protect; 6irjt an opening.

The anatomy of these trematodes has been but imperfectly made
out, mainly on account of the immense number of ova which obscure
the various organs. The following incomplete description, it is to be
hoped, will make future recognition of these minute forms possible.

Body nearly spherical ; oral sucker three or more times the diameter
of the genital sucker: pharynx adjacent to oral sucker about equal to
genital sucker; intestine not seen; genital sucker median; cirrus, cirrus-
pouch, and seminal vesicle not made out; testes 2, transverse or nearly

76 Papers from the Marine Biological Laboratory at Tortugas.

so on opposite sides of the genital sucker; vitellaria mainly lateral and
dorsal in the anterior half of the body. The ovary is deeply lobed and
lies behind the testes. An oval body lying dorsally and in front of the
genital sucker may be a cirrus-pouch, but was too indistinctly seen to
be determined satisfactorily. The uterus fills the greater part of the
body and the very numerous ova conceal and obscure the other organs.

Dimensions in balsam: Length 0.55 ; breadth 0.42 ; diameter of oral-
sucker 0.24; pharynx 0.07; ventral (genital) sucker 0.07; ova 0.0 11 by
0.007.

Host, Neomcenis griseus: July 5, 1906, 11 fish, few trematodes.

Dimensions, life, flattened: Length 0.67; breadth 0.58; ova 0.020
by 0.013(F).

These trematodes bear a close superficial resemblance to' Distomum
monorchus Stoss. (Bull. Soc. Adr. Trieste, vol. xn, plate xv, fig. 62.)

Metadena crassulata gen. et sp. nov. (Fig. 210.)
Etymolgy: fj.erdt among; adijv, gland.

The specimens here described when first seen were oval and rather
thick. They were killed over a flame under pressure. The following
description is based on a single very much flattened specimen.

Body oval, covered with exceedingly minute, short, bristle-like
spines; oral sucker relatively large; pharynx adjacent to oral sucker;
esophagus short ; intestinal rami extend to near the posterior end. Geni-
tal aperture on median line, a little in front of the middle of the length,
a little broader than long ; cirrus-pouch lies caudad and the large seminal
vesicles cephalad of the genital sucker. Testes two, oval, lateral, oppo-
site, their anterior borders about at the middle of the length of the body.
The ovary is many-lobed and situated in the middle of the body behind
the cirrus-pouch and between the testes. The vitelline glands are lateral
and extend from the level of the anterior edges of the testes to a point
about on a level with the seminal vesicle, or a little in front of it and nearly
opposite the bifurcation of the intestine ; vitellaria also median between
the marginal lobes and the genital sucker and seminal vesicle. The
uterus is very voluminous and is filled with ova which obscure the other
organs. Excretory vessels not made out except to note that the excretory
pore is surrounded by radiating muscular fibers.

Dimensions in balsam: Length 1.83; breadth 1.25; oral sucker^
length 0.42, breadth 0.39; pharynx 0.15; genital sucker, length 0.12,
breadth 0.15; ova 0.017 by 0.009.

Host, Neomamis analis: July 1, 1908, 1 fish, 2 large and 1 small
trematode.

Prodistomum gracile gen. et sp. nov. (Figs. 211, 212.)

Etymology: izpo, in sense of for, instead of.

The specimens on which this description is based were in poor con-
dition and the anatomy could be only imperfectly made out.

Helminth Fauna of the Dry Tortugas. 77

Body oval, clothed throughout with dense, slender spines; genital
sucker about equal to oral and situated at about the anterior fourth of
the length. The pharynx is adjacent to the oral sucker: esophagus is
relatively long and slender. The bifurcation of the intestine is near the
anterior border of the genital sucker. The rami of the intestine could
be traced but a short distance on account of the dense vitellaria. The
cirrus-pouch is oval, on middle line, its long axis corresponding with the
long axis of the body, immediately behind the genital sucker, and fol-
lowed at its caudal end by the seminal vesicle. Testes 2, oval or suit-
globular, on the median line, one following the other and close to it, and
near the posterior end. Ovary oval-elliptical, on middle line in front of
the anterior testis. There is a yolk-reservoir between the ovary and the
anterior testis. The vitelline glands are diffuse and extend from the
posterior end to within a short distance behind the genital sucker. The
uterus lies between the ovary and the genital sucker; ova rather large.
The terminal excretory pore is conspicuous and surrounded by a charac-
teristic rosette-like arrangement of the muscles.

Host, Clupanodon pseudohispanicus : July 10, 1906, 2 trematodes.

Dimensions of smaller, life: Length 1.4; breadth, anterior 0.1 1,
middle 0.30, posterior 0.19; oral sucker 0.09; pharynx 0.05; genital
sucker 0.09; ova 0.061 by 0.047.

GENOLOPA gen. nov.
Etymology: y£vost sex; Aojrd?, a dish.

Body covered with minute spines. Vitelline glands compact, lateral,
near middle of length of body; 1 testis; ovary in front of testis, neither
testis nor ovary lobed; cirrus relatively large, spinose; seminal vesicle
inclosed in cirrus-pouch ; folds of uterus mainly in the posterior part of
the body behind testis; metraterm ample, muscular, joining cirrus at or
in front of ventral (genital) sucker.

Genolopa ampullacea gen. et sp. nov. (Fig. 213.)

Monostomum sp. from Hamilton ftavolineatus and Bathystoma striatum Ber-
muda. Proc. U. S. Nat. Mus., xxxin, pp. 118-119, plate xiv, figs. 92, 93.

Shape very variable, long oval, fusiform, vase-shape. The anterior
end of specimens which have been compressed is usually broad, making
the outline ovate, the broad end being anterior. In some uncompressed
individuals there is a decided narrowing of the anterior end into an
abruptly tapering neck. The body is covered with minute spines. The
transverse diameter of the oral sucker is approximately one-fourth
greater than that of the genital sucker, The latter is sometimes rather
faint, so that measurements made on the living specimens are often too
small. The pharynx is close to the oral sucker in specimens which have
been compressed; in others there is a short prepharynx. The pharynx
is longer than broad and there is a short esophagus. The rami of the
intestines were indistinct beyond the middle of the body, but they extend
to the posterior end. The genital sucker is not far from the anterior
third and on the median line. The spinose cirrus curves around the

78 Papers from the Marine Biological Laboratory at Tortugas.

anterior edge of the genital sucker, and the ample cirrus-pouch, inclosing
the large prostate, and, at its posterior end, the seminal vesicle, lies along
the right side of the genital sucker, and, extending back of it, curves to
the left, so that the posterior end of the pouch usually lies on the median
line behind the genital sucker. On the left side of the genital sucker is
the ample, muscular-walled metraterm which opens, along with the cirrus,
at the genital sucker. The single testis is relatively large and lies be-
hind the cirrus-pouch; in flattened specimens it is crowded to the right
side. Immediately at its anterior border is the ovary which is smaller
than the testis and subglobular in shape. The seminal receptacle is
situated near the base of the cirrus-pouch. The vitelline glands are
rather compact, lobular masses lying at the margins in the middle of the
length of the body. A yolk-duct runs from each to the vicinity of the
seminal receptacle. The folds of the uterus are very voluminous and
lie on left side of body between the metraterm and left vitelline gland.
From this region they extend caudad, filling posterior half of body. The
ova were of fairly uniform size in all the specimens measured from the
different hosts in which this worm was found.

Host, Hcemulon macrostomum: June 28, 1Q07, 2 fish, 1 trematode.

Dimensions, life, flattened: Length 1.15; breadth 0.63; oral sucker
0.14; pharynx 0.04; genital sucker 0.12; ova 0.017 by 0.010.

Host, Hcemulon plumieri: July 7, 1907, 14 fish, few trematodes,
from pyloric caeca.

Dimensions, life: Length 0.87; breadth 0.27; oral sticker 0.06;
pharynx 0.02: genital sucker 0.03 (?); ova 0.017 by 0.010.

Host, Hcemulon sciurus: 1907, July 7, 4 fish; July 12,3 fish, few
trematodes.

Dimensions, life, flattened: Length 0.84; breadth 0.39; oral sucker
0.08; pharynx 0.03; genital sucker 0.04 (?); ova 0.017 by 0.013.

Genolopa truncata gen. et sp. nov. (Figs. 214-216.)
Body spinose, linear or long oval, variable, the anterior end usually
truncate, posterior end blunt or blunt -pointe d ; oral sucker relatively
large; pharynx close to oral sucker, though there appears to be a short
prepharynx; esophagus as long, or a little longer than pharynx. Genital
sucker a little in front of middle ; cirrus spinose ; cirrus-pouch and extrem-
ity of metraterm capacious; seminal vesicle inclosed in cirrus-pouch.
There is 1 testis, oval or subspherical, median, behind cirrus-pouch;
ovary on right side of testis and a little in advance of it. The vitelline
glands are compact bodies near the margin on a level with the cirrus-
pouch. The folds of the uterus fill up all the available space behind the
cirrus-pouch; ova small, short-oval or elliptical.

This species resembles Monostomum sp. from Orthoprisiis chrysop-
terus (Parasites of Fishes of Beaufort, Bull. U. S. Fish Commission, xxiv,
p. 379, fig. 223), but the ova are very different. In the Beaufort species
the longer diameter of the ova is three times that of the shorter.
Host, Hcemulon plumieri:

1906, July 8, 1 fish, 1 trematode.

1907, July 5, 12 fish, 1 trematode; July 10, 12 fish, 1 trematode.

Helminth Fauna of the Dry Tortugas. 79

Dimensions, life, flattened: Length 0.96; breadth, anterior 0.22,
middle 0.36, posterior 0.08; oral sucker, length 0.15, breadth 0.14;
genital sucker 0.07; ova 0.017 by 0.010. Another: Length 1; breadth
0.23; oral sucker 0.27; pharynx 0.03; genital sucker 0.07; ova 0.014 by
0.010.

Host, Hamilton sciurus: July 4, 1907, 4 fish, 1 trematode.

Dimensions in balsam: Length 0.51; breadth 0.32; oral sucker,
length 0.17, breadth 0.11 ; genital sucker 0.09; ova 0.017 by 0.010.

GASTEROSTOMIDJE.
Gasterostomum sp. (Figs. 219-221.)

This species is probably G. gracilescens Rudolphi, or near it.

The one specimen here noted proved to be so far advanced in the
production of eggs that details of structure can not be made out. The
body is blunt at the anterior end, where it terminates in a sucker which
is but little narrower than the body. The anterior two-thirds is linear.
At the anterior end of the cirrus-pouch the body begins to grow narrower
and tapers thence to the posterior end. The vitellaria are lateral and
occupy about the middle third of the length. They are compact, but
are not in distinct, rounded masses of definite number, as is usually the
case in this genus. The body is filled with ova from the posterior end to
the anterior sucker.

Host, Lycodontis moringa: July 7, 1907, 1 fish, 1 trematode.

Dimensions, life: Length 1.61; breadth 0.57; anterior sucker 0.35;
ova 0.027 by 0.017.

In balsam the length is 0.7, breadth 0.4, diameter of anterior sucker
0.3, and diameter of ventral sucker 0.06.

Gasterostomum sp. (Figs. 222, 222 a.)

Body linear, anterior end truncate; anterior sucker about as broad
as the anterior end of the body. Ventral sucker about middle of length;
intestine oblong-elliptical. Testes equal, near median line, one in front
and the other behind the ventral sucker and very near it. Ovary be-
hind posterior testis, adjacent to it and a little to the right of the median
line. The vitellaria are irregularly rounded masses, lateral and extend-
ing, from about the anterior end of the intestine, half-way to the anterior
end of the body. Details of the structure of the cirrus-pouch could not
be made out. The folds of the uterus lie between the ventral sucker
and posterior end. The ova vary considerably in size and shape.

The species represented by this lot is nearer G. baculum than are
those from Mycteroperca venenosa.

Host, Mycteroperca bonaci: July 11, 1906, 1 fish, numerous trem-
atodes.

Dimensions, life: Length 2.52; breadth, anterior 0.21, middle 0.35,
posterior 0.17; anterior sucker 0.17; ventral sucker 0.056; ova 0.034
by 0.024.

Other ova, in balsam: 0.034 by 0.020, 0.027 by 0.024, 0.027 by
0.020.

80 Papers from the Marine Biological Laboratory at Tortugas.

Gasterostomum sp. (Figs. 217, 217a, 218.)

Body linear, truncate, or capitate anteriorly, bluntly rounded pos-
teriorly, covered with very minute spines; anterior sucker large, terminal,
with conical base ; genital sucker a little in front of the middle of body ;
esophagus short, intestine ovate. Testes 2, 1 behind genital sucker
and close to it, the other a little farther caudad, nearly as far back as
the anterior end of the cirrus-pouch; both nearly on the median line, the
anterior the larger. The cirrus-pouch lies along the left side, ample,
with small pyriform seminal vesicle inclosed in the anterior end (fig.
21857;) and the prostate throughout its length. Ovary small, situated
at the right of the genital sucker and a little caudad. Vitelline glands
lateral, from level of genital sucker, or a little in front of it, in an irregular
row, sixteen, more or less, globular bodies in each row. The folds of the
uterus extend from the anterior testis to the posterior end. The ova are
elliptical with rather thick shells. This description is based on the
specimen sketched (fig. 217). There is considerable variation in the rela-
tive position of the testes and ovary.

This species bears some resemblance to G. baculum Linton.

Host, Mycteroperca venenosa:

1907, July 14, 1 fish, few trematodes.

1908, June 27, 1 fish, 10 trematodes.

Dimensions, in life, flattened: Length 0.95; breadth 0.21; anterior
sucker 0.14; ventral sucker 0.04; ova 0.030 by 0.020. Dimensions of
another, in balsam: Length 1.20; breadth 0.24; anterior sucker 0.15;
ventral sucker 0.05; ova 0.03 by 0.02; distance from anterior end to
ventral sucker 0.56.

Gasterostomum sp. (Figs. 223-225.)

Brief mention is here made of finds of this genus in the barracuda.
Like all the representatives of this genus found by me at the Tortugas,
they are in poor condition and it is impossible to make out details of the
anatomy satisfactorily. It does not seem credible that such diverse
forms as those shown in figs. 223, 224, and 225, can belong to the same
species. Figure 225 was sketched from life, but neither it nor any speci-
men exactly like it appears among my stained and mounted material.
Aside from this there is still a perplexing variety in the material collected
from the barracuda.

In general these forms are characterized by having the anterior
end elongated in front of the vitelline glands, with a rather small, but
apparently anterior, sucker. Both fusiform and linear forms occur.
The body is covered with exceedingly minute spines. A striking differ-
ence is found, among forms otherwise in close agreement, in the character
of the ova. Indeed there seems to be greater diversity in the shape of
the ova in the same species and even in the same individual in this genus
than prevails among the distomes.

These specimens agree in having the vitellaria lateral to the genital
sucker and in having the testes behind the genital sucker. Also the
ovarv is in front of the testes and on the right side in all. The testes
do not agree either in relative size or in position. In fig. 223 they are

Helminth Fauna of the Dry Tortugas. 81

relatively small and opposite; in fig. 225 they are relatively large and
tandem. There is also variety in the position of the ovary, it being
beside the genital sucker in fig. 224 and behind it in the others.
Host, Sphyrcena barracuda:

1906, July 4, 4 fish, 6 trematodes; July 11,2 fish, 1 trematode, small;
July 15, 1 fish, 7 trematodes.

1907, July 10, 1 fish, 5 trematodes.

Dimensions, life, specimen shown in fig. 225: Length 1.48; length
of posterior portion behind constriction 0.64; anterior sucker, length
0.11, breadth 0.16; ventral sucker 0.12; breadth of body, anterior 0.16,
middle 0.33, posterior 0.12; ova 0.017 by 0.010.

Dimensions of a fusiform specimen, life: Length 1.33, breadth,
anterior 0.07, middle 0.32, posterior 0.11; anterior sucker 0.07; ventral
sucker 0.06; ova 0.020 by 0.014.

Dimensions of specimen belonging to the lot collected July 10, with
ova as in fig. 224a: Length 1.12; breadth 0.28; anterior sucker 0.06;
ventral sucker 0.04; ova 0.04 by 0.01.

HETERACOTYLEA.

Microcotyle incisa sp. nov. (Figs. 226-230.)

Bod\' proper nearly linear, greatest diameter at about its junction
with the sucker-bearing portion, narrowing from bifurcation of the intes-
tine to the bluntly rounded anterior end ; upper lip with a narrow emargi-
nation; anterior suckers oval-elliptical; posterior sucker-bearing portion
tapering uniformly to the posterior end. The vitellaria are marginal
from a point a short distance back of the intestinal bifurcation to the
posterior end of the body proper, where the two lateral glands unite
behind the testes and enter for a short distance into the sucker-bearing
portion. The region of the vitellaria is plentifully sprinkled with small,
black pigment spots which continue back of the testes dorsally in 4
parallel rows in the median third of the width for a little less than one-
third the length of the sucker-bearing portion ; about 8 larger pigment
spots in 2 rows dorso-lateral to the esophagus. There are about 45
suckers in each row on the sucker-bearing portion, which portion equals
a little more than one-third the entire length. There appear to be about
24 testicules which lie in an oval cluster at the base of the body proper.
They are irregularly hexagonal in outline in one case, but more or less
rounded in others. The ovary lies a short distance in front of the testes;
it is best seen in dorsal view, when, as in specimen sketched, it appeared
to be made up of a number of small lobes arranged in a wreath-like cluster.

Host, Neomcenis griseus: 1907, July 9, 5 fish, 4 trematodes.

1908, July 1, 1 fish, 2 trematodes.

Dimensions, life: Length 2.40; length of body proper 1.40; maxi-
mum diameter 0.42, tapering to 0.14 at each end.

Another: Length 4.35; length of body proper 2.32; breadth, ante-
rior 0.16, maximum, back of middle 0.56; anterior sucker, length o.n,
breadth 0.16; posterior suckers, length 0.12, breadth 0.08; ovum 0.18
by 0.07.
6

82 Papers from the Marine Biological Laboratory at Tortugas.

Udonella socialis sp. nov. (Figs. 238-241.)

This species is near Udonella caligorum Johnston, but is much
smaller.

Body generally linear in outline, cylindrical; in some cases with
transverse annulations, thus resembling a leech; anterior end somewhat
truncate in contracted specimens. The 2 small, anterior suckers are
ovate in outline ; pharynx longer than broad. Ovary about middle of
body, with large cells; testes, in the larger specimens, smaller than
ovary, immediately behind and contiguous with it. The vitelline glands
are lateral, subglobular bodies extending laterally throughout the greater
part of the length. Near the posterior end of the body, 2 oval structures
(fig. 238 q), agreeing in position with the posterior lobes of the vitelline
glands, were seen in the larger individuals, which may represent yolk-
reservoirs. They do not resemble the tubular organs represented in
figures of U . caligorum. Posterior sucker cup-shape, circular, unarmed.

Adults, young, and eggs were attached to the two copepods. There
were also numerous empty egg-capsules, from which the larvae had
escaped, a few with larvae already developed, and a few with the larvae
in the act of escaping from the eggs (fig. 241 e, j, k).

Host, Argulus sp., in mouth of Neomcenis griseus: 1908, July 4,
2 fish.

Two copepods in mouth of one of the fish; many trematodes and
eggs of same attached to the 2 copepods.

Twenty trematodes were counted on the edges and ventral surface
of one of the copepods, and there were others on the dorsal side. Each
egg is fastened to its host by means of a filament which is attached to the
smaller end. Dimensions, life: Length 0.71; breadth, anterior 0.14,
middle 0.27, posterior 0.15; posterior sucker 0.21; ova 0.15 by 0.09.
Dimensions of another, compressed: Length 1.82; breadth, anterior
0.27, middle 0.50, posterior 0.30; ova 0.21 by 0.11.

ASPIDOCOTYLEA.

Aspidogaster ringens Linton. (Figs. 236, 237, 237a.)

Bull. Bureau of Fisheries, xxiv, pp. 367, 397, figs. .243-249; Proc. U. S. Nat.
M., xxxiii, p. 104, figs. 98, 99.

Only one specimen was found. It agrees closely with this species.
There is the entire ventral lip with a median shallow notch, the lobed
dorsal lip, and the 42 loculi around the border, with the marginal sense-
organs between. The median ventral ridge is not evident in the mounted
specimen. The pharynx is pyriform, the larger end directed posteriorly.
The single testis is near the posterior end on the right side. The ovary
is contiguous with the anterior end of the testis. Both ovary and testis
are long-oval, the long axis of each corresponding to the long axis of
the body. The vitellaria extend from the posterior end of the disk in
two narrow lines on each side of the intestine, diverging slightly ante-
riorly and reaching to about the anterior third of the disk. Genital aper-
ture on the left side of the neck.

Helminth Fauna of the Dry Tortugas. 83

The absence of a median ventral ridge does not justify the erection
of a new species, since only one specimen was seen at the Dry Tortugas;
moreover, many of the Beaufort specimens had very faint median ridges.

Host, Calamus calamus: July n, 1908, 5 fish, 1 trematode.

Dimensions, life: Length 1.51; breadth, of head 0.42, of disk 0.86,
of neck 0.31; pharynx, length 0.14, breadth 0.10; ova, variable, 0.075
by 0.045.

DEONTACOTYLEA.

Deontacylix ovalis gen. et sp. nov. (Figs. 231-235.)

Etymology: Siovra, lacking; /outc, a cup.

A few small trematodes are here described which appear to represent
a new genus of certain affinities. It was nearly dark when I began to
examine them, so that but few notes were made of the living specimens.
They were afterwards stained, some in carmine and some in haematein,
and mounted whole in balsam.

Body long-oval, flattened, tapering gradually to the anterior end
and more abruptly to the posterior end. General color white, the
branches of the intestine yellow. The mouth is minute, on the ventral
side very close to the anterior end. The body is covered dorsally and
laterally with minute, short, slender, rod-like spines in transverse rows,
the rows about 0.009 mm. apart. There is no distinct oral sucker, no
pharynx, and no ventral or other sucker present. The moderately
narrow esophagus pursues a somewhat sinuous course to about the
anterior third of the body, where it divides into two branches. These
branches soon divide into two smaller branches, one extending forward
and the other back. These secondary branches are somewhat irregular
in outline, being short-sinuate or sacculate with one or more additional,
shorter branches. The posterior rami reach to about the middle of the
length of the body. Along the margin of the body there is a distinct
border, finely granular and more lightly staining than the interior, and
separated from the interior region by a light line having the appear-
ance of a nerve. That is, 2 lateral nerves can be traced from a short
distance behind the mouth, where they form a common band which
crosses the esophagus dorsally and sends branches forward to unite again
around the mouth, back to near the posterior end of the body.

The genital openings are close together and close to the posterior
end on the dorsal side. A short tube (fig. 231m) leads from its aperture,
a little to the left of the median line, to a closely folded, tubular organ
which appears to be the uterus. It is crowded with small, granular
masses which are probably ova, although they do not look like any
trematode ova that I have seen before. When isolated they are ovate,
oval-elliptical, and pyriform, and there appears to be a thin shell. When
highly magnified each ovum is seen to contain several coarse, granular
masses of yolk (fig. 234). The cirrus (or ejaculatorv duct) is short and
leads from its opening near the opening of the metraterm to a seminal
vesicle near the right border. In some specimens there was a tubular
vas deferens without any noticeable enlargement into a seminal vesicle.
The vas deferens could be traced forward between the uterus and ovary,

84 Papers from the Marine Biological Laboratory at Tortugas.

then along the right side of the uterus to the testis (fig. 231 vd). A short
distance in front of the seminal vesicle there is another seminal reservoir,
which I take to be a seminal receptacle (fig. 231 sr). Along its median
side a yolk-duct was seen, and a short distance in front and near the
right side a small, deeply-staining lobed organ which appears to be the
ovary. Concerning the limits of the other organs I am not quite certain.
The vitelline glands appear to fill the greater part of the anterior half
of the middle region of the body around the intestinal rami and with a
greater dorsal than ventral distribution and are also distributed periph-
erally over the testes. The testes, while not altogether satisfactorily
determined, appear to be diffuse organs lying ventrally in front of the
folds of the uterus, extending laterally to the lateral nerves and forward
between the posterior intestinal rami. The uterus is conspicuous and
fills up the greater part of the posterior third of the body.

Host, Kyphosus sectatrix: July 16, 1907, 1 fish, few trematodes.

The longest specimen measured 4 mm. Dimensions of a smaller
specimen, life: Length 2.24; breadth 0.77 ; diameter of mouth 0.06; ova,
somewhat variable, 0.022 by 0.013.

INDEX.

Abudefduf saxatilis 19, 49, 50, 62

Allocreadiinae 16,29

Angelichthys isabelita. . . . 19, 48, 70, 72
Anisotremus virginicus 19, 35, 38, 57, 90

Argulus sp 82, 98

Aspidocotylea 20, 82

Aspidogaster ringens 17, 20, 82, 98

Auxis thazard 19, 40, 64, 94

Barisomtim erubescens ... 17,22
Brachadena pyriformis. . . 17,22

Calamus calamus. . 19, 34, 38, 42,

49. 56. 83, 89. 9°

Calycodes 17, 21

Caretta caretta 24, 26

Chlorichthys bifasciatus. . 19, 32
Cleptodiscus reticulatus.... 17, 20
Clupanodon pseudohispanicus.. .

64, 77
Cricocephalus delitescens.. 17, 22
Cymatocarpus undulatus.. 17,21

69- 95

55. 92

43.
92
24
27
62
72
19,
93
23
26

46,
,98
,87
. 29
.93
,96
61,

97
87
88

Deontacotylea 16, 20, 83

Deontacylix ovalis. . . . 16, 17, 20, 83, 98

Deradena 66

Deradena acuta 17, 21, 68, 94

obtusa 17, 21, 69, 94

ovalis. . . 16, 17, 21, 67, 75, 94

Deretrema fusillus 17, 21, 49, 91

Dichadena acuta 17, 21, 56, 92

Dictysarca virens 17, 22, 58, 93

Didymorchis latus 17, 21, 39, 90

Dinurus rubeus 17, 22, 64, 94

longisinus 64

Diplangus paxillus 17,21, 48, 91

Distomum appendiculatum 60

fenestratum. . . 17,20,51,92

levenseni 42

monticellii 61

pectinatum 40

sp., immature 43

trulla 41

valdeinflatum 17, 43

Echeneis naucrates 19, 62, 93

Ectenurus sp 17, 22, 64, 94

virgula 17, 22, 63, 93

Enenterum aureum 17, 21, 40, 90

Epinephelus morio. . . . 19, 31, 42, 43, 90

striatus 19, 30, 43,

44,45,88
Eupomacentrus leucostictus.. 19, 34, 89

Fasciolidae 20, 29

Food notes 19

Gasterostomidae 20, 79

Gasterostomum baculum 79, 80

gracilescens 79, 97

sp 17,79,80,97

PAGE

Gcnolopa 77

Genolopa ampullacea 17, 20, 77,97

truncata 17, 20, 78, 97

Haemulon macrostomum. ... 17, 48, 49,

5°, 55, 57, 78.91. 97

Haemulon plumieri..i7, 31, 32, 37, 46, 49,

5i, 55,57, 78,88,89, 91,92,93,97

Haemulon sciurus.. 17, 32, 36, 37, 46, 49,

5i. 55. 57. 78, 79. 89, 9°. 91,92

Hamacreadium 34

Hamacreadium consuetum. . 17, 21, 29,

36,89
gulella..i7, 21, 29, 35, 89
mutabile. . . . 17,21,29,

34,35,89

oscitans 17,21,29,

37, 89, 90

Hapladena varia 17, 21, 65, 94

Helicometra execta. . . 18, 21, 29, 31, 88

torta 18, 21, 29, 88

Helicometrina nimia. . 18, 21, 29, ^^, 89

Hemiurus appendiculatus 61

merus 18, 22, 60, 93

Heteracotylea 20, 81

Himasomum candidulum.. . . 18, 22, 71,

95,96
Hysterolecitha rosea. . 18, 22, 52, 54, 92

Iridio bivittatus 19, 32

Kyphosus sectatrix.. . 19, 39, 40, 55, 84,

90, 92, 98

Lachnolaimus maximus 19, 32, 90

Lactophris triqueter 19, 52, 92

Lebouria crassigula. . . 18, 21, 29, 38, 89

idonea 38

Lechradena edentula 18, 21, 46, 91

Lecithochirium fusiformis 62

Lepocreadium levenseni .. 18, 21, 42, 90

trulla 18,21,41,90

Leurodera decora 18, 22, 57, 93

Loggerhead turtle 23, 87

Lycodontis funebris 19, 59, 63, 65,

93,94
mormga. . 19,59,63,65,79,

93,97

Macradena perfecta 18, 22, 53, 92

Malacotylea 20, 29

Megasolena estrix 18, 21, 38, 90

Mesolecitha linearis 18, 21, 43, 95

Mesorchis urna 18, 22, 47, 91

Metadena crassulata 18, 20, 76, 97

Microcotyle incisa 18, 20, 81,97

Monostomidae 20, 69

Monostomum vinaledwardsii 74

Mycteroperca bonaci 19, 79, 97

venenosa. . 19, 42, 43, 79,
80, 90, 97

85

86

Index.

Neomaenis analis 19, 44, 45, 76, 97

apodus 19, 35

griseus. 19,34,35.44,45,46,
57, 62, 76, 81, 82, 89, 90, 91, 96, 97, 98

Ocyurus chrysurus. . . 19, 34, 35, 4*. 44,

45,49,50,62, 74, 75,9°, ^n.a6

Opisthadena dimidia. .... 18, 22, 54, 92

Orchidasma amphiorchis.. 18, 21, 28, 88

Pachypsolus irroratus 25

ovalis 18, 21, 24, 87

Paramphistomidae 20, 72

Pomocanthus arcuatus ... 16,19,35,48,
6o, 70, 72, 73, 91, 93, 95, 96

Prodistomum gracile 18, 20, 76, 97

Pronocephalus 23

Scarus coeruleus 19, 67, 68, 94

croicensis 19, 68, 71

sp 19, 68, 94

Siphodera vinaledwardsii . 18, 20, 74, 96

Stegopa globosa

PAGE

16, 20, 43, 74

. .. 19,81,97

18, 20, 75, 96

Stephanochasmus casus. . .

sentus. .

Sterrhurus fusiformis

monticellii. . . .

Teuthis coeruleus.. 19, 44,

18, 21, 44,

46, 90

18, 21,45,9°

18, 22, 62, 93

18, 22, 61, 93

53, 54, 56,66,
69, 92, 94, 95
53, 58,66,69,
92> 94
... 18, 21, 40

Theletrum fustiforme

Tylosurus marinus

18, 22, 59,93
... 19, 69, 94

82

socialis

Zystretrum papillosum. . .

18, 20, 82,98

18, 21, 52, 92
Si

EXPLANATION OF PLATES.

The following reference letters have the same significance in the different
figures unless otherwise indicated.

a. oral sucker. o. ovary.

b. ventral sucker. oe. esophagus.

c. cirrus, or ductus ejaculatorius. p. prepharynx.
on. circular muscle. ph. pharynx.
cp. cirrus-pouch. pr, prostate.

d. subcuticular gland-cells; in many pr'. duct of prostate.

cases these are interpreted to be sg. shell-gland,

yolk-forming cells. sr. seminal receptacle.

dm. diagonal muscles. sv. seminal vesicle.

e. ova. t. testes.

exp. excretory pore. tin. transverse muscle.

exv. excretory vessel. u. uterus.

g. genital aperture. vd. vas deferens.

i. intestine. vg. vitelline gland.

Int. longitudinal muscle. yd. yolk-duct.

m. metraterm, i.e., the ejaculatory por- yr. yolk-reservoir,
tion of the uterus.

Figures i to 28 inclusive are from material collected from the loggerhead
turtle; the remaining figures illustrate trematodes from various Tortugas fishes.

Plate i.
Cricocephalus delitescens Looss.

Fig. 1. Ventral view, life; some details added from stained and mounted

specimen; intestine somewhat diagrammatic; length 4.6 mm.

/, postero-lateral pit ; k, muscular ridge.
Fig. 2. Enlarged view of one of the characteristic pits situated at lateral

angles of trtmcated posterior end; actual diameter of pit 0.010

mm. From specimen mounted in balsam.
Fig. 3. Ovum; length of egg 0.029 mm., length of filament 0.12 mm.

Immature dislomum. Related to Caly codes Looss.

Fig. 4. Ventral view, life; a few details added from mounted specimen;

length 1.5 mm.
Fig. 5. Ventral view of anterior end of same; diameter of head 0.34 mm.
Fig. 6. Dorsal view of same.

Pachypsolus ovalis sp. now

Fig. 7. Ventral view. The specimen was flattened and the positions of some

of the organs are somewhat changed from the normal; length 3.36

mm.
Fig. 8. Dorsal view of specimen reconstructed from sections.
Fig. 9. Transverse section of body at posterior edge of ventral sucker;

diameter 0.84 mm.
Fig. 10. Transverse section at level of testes. Excretory vessels unite in next

section posterior to this; diameter 0.88 mm.

Plate 2.
Pachypsolus ovalis, continued.

Fig. 11. Nearly transverse section of the pharynx; diameter 0.14 mm.
Fig. 12. Sagittal section, diagrammatic, of cirrus-pouch, etc.
Fig. 13. Ova; maximum length 0.048 mm.

Fig. 14. Dorsal view, life, showing branching and anastomosing excretory
vessels; length 4.4 mm.

87

88 Papers from the Marine Biological Laboratory at Tortugas.

Cymatocarpus undulatus Looss.

Fig. 15. Dorsal view of flattened specimen, life; length 3.57 mm. Ova in
folds of uterus on right side and in posterior folds of left side dark
brown, those in other folds of left side yellow. Metraterm sur-
rounded by gland-cells resembling prostate gland.

Fig. 16. Ventral view, life, showing details of the genitalia.

Fig. 17. Transverse section of cirrus-bulb, showing prostate cells, part of
seminal vesicle, and secretion in wall of prostatic duct; diameter
0.30 mm.

Fig. 18. Transverse section of neck showing esophagus and excretory vessel;
diameter 0.86 mm.

Fig. 19. Transverse section just behind the bifurcation of the intestine;
diameter 0.87 mm.

Plate 3.

Cymatocarpus undulatus, continued.

Fig. 20. Ova; length 0.024 mm.

Fig. 21. Excretory pore and surrounding glandular cells; diameter of pore
0.04 mm.

Fig. 22. Portion of transverse section of neck, showing yolk-forming cells
and accumulating yolk in central parenchyma. Thickness of
worm at this point 0.15 mm. y, accumulating yolk.

Orchidasma amphiorchis (Braun) Looss.

Fig. 23. Ventral view of specimen mounted in balsam; length 2.3 mm.

Fig. 24. Details of genitalia, dorsal view; breadth of body at level of antenor

testis 0.63 mm.
Fig. 25. Ova; diameter 0.039 mm.
Fig. 26. Spines from cirrus; length 0.05 mm.
Fig. 27. Spines from metraterm; length 0.040 mm.
Fig. 28. Spines from distal end of metraterm; length 0.05 mm.

Trematodes from Fish.
Helicometra torta sp. nov., from Epinephelus striatus.

Fig. 29. Ventral view, life, flattened; length 4 mm.

Plate 4.
Helicometra torta, continued.

Fig 30. Dorsal view of another specimen, not much flattened; length t. 5 7 mm.
Fig. 31. Surface view, life, ventral; length 2 mm.

Fig. 32. Details of ovary etc., of another specimen, life, ventral view, diam-
eter of posterior testis 0.27 mm. k, ootype.
Fig. 33. Portions of ovary, shell-gland and yolk-reservoir, with ootype, from
section; diameter of ootype 0.03 mm. e', germ cell entering ootype.

Helicometra execta sp. nov.

Fig. 34. Dorsal view, life, details added from mounted specimen; length
1.90 mm.
This and the following figures, with the exception of 38 J,
from Hamulon plumieri.

Fig. 35. Ventral view of another specimen; length 1.50 mm.
Fig. 36. Cirrus-pouch and metraterm from longitudinal section, n, cells
surrounding genital aperture.

Plate 5.
Helicometra execta, continued.

Fig. 37. Transverse section of cirrus-pouch and metraterm at anterior border

of ventral sucker.
Fig. 38. Ovary and testes from different specimens.
Fig. 38a. Ovary in contact with single testis, latter not lobed.

Explanation of Plates. 89

Fig. 386. Deeply lobed ovary separated from the 2 testes, one of the latter

lobed.
Fig. 38c. Ovary, no testis present.
Fig. 3&d. Ovary and single testis in contact; from H&mulon sciunts.

All dorsal views, and drawn to the same scale.
Fig. 39. Filamented ovum; length of ovum 0.051 mm., length of filament
3 mm.

Helicometrina nitnia gen. et sp. now All except fig. 48 from Neomcenis griseus.

Fig. 40. Ventral view of stained and mounted specimen; length 2.70 mm.
Excretory vessel added from another specimen. This is the usual
arrangement of testes, viz., 5 on right and 4 on left side.

Fig. 41. Ventral view of a smaller specimen; length 1 mm. In this case there
are 5 testes on left and 4 on right side.

Fig. 42. Dorsal view of neck of another; length of neck 0.50 mm.

Fig. 43. Ventral view of neck of another; length of neck 0.74 mm.

Fig. 44. Diagrams showing variations of testes, a, usual plan; b, c. d, varia-
tions noted. All ventral view.

Fig. 45. Sagittal section through cirrus-pouch and metraterm; thickness of
body at this point 0.30 mm. The ejaculatory duct is shown cut
through in several places.

Plate 6.
Helicometrina nimia, continued.

Fig. 46. Median portion of transverse section through cirrus-pouch and

metraterm. Thickness of body at this point 0.24 mm.
Fig. 47. Ovum; length 0.043 mm.

Fig. 48. Dorsal view of young specimen from Eupomacciilrus leucostictus;
length 1 mm.

Hamacreadium mutabite gen. et sp. now (Figs. 49 to 54 from Neomcenis griseus.}

Fig. 49. Dorsal view of flattened specimen, life, details added from stained

and mounted specimen; length 2.62 mm.
Fig. 50. Ventral view of another specimen not much flattened; length 2.28

mm. Specimens of this shape when flattened under a cover-glass

and killed over flame may assume shape shown in preceding fig.
Fig. 51. Young, ventral view, in balsam; length 1.37 mm.
Fig. 52. From memorandum sketch made at time of collecting.
Fig. 53. Sketch of 4 specimens showing variety of form.
Fig. 54. Horizontal section of cirrus-pouch. Im, longitudinal muscles of

cirrus-pouch.

Plate 7.
Hamacreadium gulella gen. et sp. now, from Neomcenis griseus.

Fig. 55. Ventral view, balsam; length 1.85 mm. exv', the anastomosing
vessels in the head appear to be excretory vessels, although their
connection with the more prominent Y-shaped excretory vessel was
not made out.

Hamacreadium consuetum gen. et sp. now, from Hcemulou plumieri.

Fig. 56. Ventral view, life, details added from mounted specimen; length

1.90 mm.
Fig. 56a. Ovum.
Fig. 57. Sagittal section of cirrus-pouch; length 0.30 mm. c. ejaculatory

duct; e, egg lying at junction of ejaculatory duct and metraterm.
Fig. 58. Dorsal view of cirrus-pouch; length 0.22 mm.
Fig. 59. Dorsal view of ovary and seminal receptacle and part of right testis ;

length of seminal receptacle 0.08 mm.

Lebouria crassigida sp. now, from Calamus calamus.
Fig. 60. Ventral view, balsam; length 1.33 mm.

Hamacreadium oscitans gen. et sp. now, from Hcemidon plumieri.
Fig. 61. Ventral view, life, details added; length 1.05 mm.

90 Papers from the Marine Biological Laboratory at Tortugas.

Plate 8.
Hamacreadium oscitans, continued.

Fig. 62. Ventral view, life, details added; length 1.50 mm; from Lachnolaimus
maximus.

Fig. 63. Ventral view, life, details added; length 1.12 mm. Ovary not dis-
tinctly seen. Cirrus-pouch turned to the left by the contraction
of the neck. From Anisotremus virginicus.

Fig. 63a. Ovum; length 0.043 mm.

Megasolena estrix gen. et sp. nov., from Kyphosus sectatrix.
Fig. 64. Ventral view, life; length 3 mm.

Didymorchis latus gen. et sp. nov., from Calamus calamus.

Fig. 65. Ventral view, life, details added; length 2.03 mm.
Fig. 650. Ventral sucker, balsam.

Enenterum aureum gen. et sp. nov. from Kyphosus sectatrix.

Fig. 66. Ventral view, life, details added; length 5 mm.

Fig. 67. Front-ventral view of head showing arrangement of lobes, life ;

diameter 0.5 mm.
Fig. 68. Horizontal section showing cirrus, prostate, seminal vesicle, and

metraterm.

Plate 9.
Enenterum aureum gen. et sp. nov.

Fig. 69. Horizontal section. One section of the series intervenes between this

and the previous figure.
Fig. 70. Cirrus-pouch and metraterm, balsam, ventral view; diameter of

ventral sucker 0.5 mm., compressed.

Lepocreadium trulla (Linton) from Ocyurus chrysurus.

Fig. 71. Dorsal view, balsam; length 1.12 mm. The spines are evanescent.
Fig. 72. Ventral view, life, somewhat distorted by pressure; length 1.22 mm.
Fig. 73. Excretory pore at posterior end of body.
Fig. 74. Spines, length 0.006 mm.

Lepocreadium levenseni (Linton).

Fig. 75. Ventral view, life, details added; length 1.68 mm. Oral sucker

invaginated. From Epinephelus morio.
Fig. 76. Muscular bulb of excretory vessel at posterior end of body; diameter

of bulb 0.04 mm.
Fig. 77. Ventral view of specimen from Mycteroperca venenosa, life; length

2.75 mm.

Plate 10.
Stephanochasmus casus sp. nov.

Fig. 78. Ventral view, life, details added; length 3.3 mm. Spines evanes-
cent. From Neomcenis griseus.

Fig. 79. Horizontal section; length 2.1 mm.

Fig. 80. Ovum, life; length 0.068 mm.

Fig. 81. Transverse section of ovum, showing characteristic contraction
character; diameter 0.031 mm.

Fig. 82. Nearly horizontal section of cirrus-pouch showing seminal vesicle
and cells of prostate.

Fig. 83. Nearly horizontal section of young specimen from Ocyurus chrysurus;
diameter of section at ventral sucker 0.41 mm.

Stephanochasmus sentus sp. nov.

Fig. 84. Dorso-lateral view, life, details added; length 3.15 mm. Spines
evanescent. Peculiar papillate character of neck due to degener-
ation changes following falling off of spines. From Hcemulon

Fig.

88.

Fig.

89.

Fig.

90.

Fig.

91.

Fig.

92.

Explanation of Plates. 91

Fig. 85. Ovum showing characteristic ribbed appearance of collapsed ova;

length 0.075 mm.
Fig. 86. Ventral view of head of specimen from H. plumieri. Diameter of

head 0.15 mm.

Lechradena edcntula gen. et sp. nov., from Neomcenis griseus.

Fig. 87. Ventral view, life, details added; length 2.10 mm.

Plate ii.
Mesorchis urna gen. et sp. nov.

Ventral view, life, details added, uterus diagrammatic; length 2.5
mm. From Pomacanthus arcuatus.

Dorsal view, balsam, excretory vessel diagrammatic and added from
another specimen; length 1.5 mm. I, opening of Laurer's canal.

Tangential section showing excretory pore, Laurer's canal (I), cirrus,
seminal vesicle, ovary, shell-gland, etc.; thickness of body at this
point 0.26 mm. Sketch made from 3 adjacent sections.

From horizontal section, showing ventral sucker, metraterm, and
cirrus-pouch; diameter of ventral sucker 0.14 mm.

Transverse section, showing ventral sucker, metraterm, branches of
excretory vessels, posterior end of one testis, uterus, and yolk-
duct; breadth 0.4 mm.
Fig. 93. Transverse section near posterior end, showing single excretory
vessel, h, wall of branch of excretory vessel which is cut through
in next section anterior to this; breadth 0.4 mm.

Diplangus paxillus gen. et sp. nov., from Hcemulon macrostonium .

Fig. 94. Lateral view, life, details added; length 1.35 mm.
Fig. 95. Dorsal view, life, details added; length 1.47 mm.
Fig. 95a. Ovum; length 0.041 mm.

Plate i 2 .
Diplangus paxillus, continued.

Fig. 96. Lateral view, life, details added, somewhat diagrammatic; length
1.38 mm. From H. plumieri. The prostatic portion of the cirrus-
pouch also contains a part of the seminal vesicle.

Fig. 96a. Ova; length 0.041 mm.

Fig. 966. Outline, showing a common form, lateral view; length 1 mm.

Fig. 97. Ventral view, life, details added; length 1.75 mm.

Fig. 98. Transverse section through pharynx and cirrus-pouch. From H.
sciurus.

Fig. 99. Nearly transverse section through neck, showing subcuticular
glands which seem to be yolk-forming glands. Thickness of
body at this point 0.08 mm. From H. plumieri.

Fig. 100. Nearly transverse section through seminal vesicle, a few cells of
subcuticular glands showing. Thickness of body here 0.01 mm.
sv', prostatic part of seminal vesicle.

Fig. i 01. Nearly transverse section through prostate gland and seminal
vesicle and ventral sucker. From H. sciurus.

Deretrema fusillus gen. et sp. nov.

Fig. 102. Ventral view, life, details added ; length 2.10 mm. Uterus some-
what diagrammatic. Contents of esophagus deeply stained.
From Ocyurus chrysurus.

Fig. 102a. Ova, life; length 0.034 mm. Left ramus of intestine appeared to
pass ventrad of cirrus-pouch as indicated in sketch.

Plate 13.
Deretrema fusillus, continued, from Hcemulon macrostonium.

Fig. 103. Ventral view, life, details added; length 1.68 mm.
Fig. 104. Dorsal view, balsam; length 1 mm.
Fig. 104a. Ova, one collapsed; length 0.04 mm.

92 Papers from the Marine Biological Laboratory at Tortugas.

Distomum fenestratum Linton, from Hamilton plumieri.

Fig. 105. Ventral view, life; length 3.5 mm.

Fig. 106. Transverse section near posterior end, somewhat diagrammatic;
breadth 0.25 mm.

Xystretrum papillosum gen. et sp. nov., from Lactophrys triqueter.

Fig. 107. Ventral view, balsam; length 3.5 mm. Folds of the uterus dia-
grammatic. The ova are really much more numerous than
represented, c, cirrus extruded; n, ventral corrugated disk.

Fig. 107a. Spines from posterior border enlarged.

Fig. 108. Papillary spines lining mouth cavity; diameter of mouth 0.16 mm.

Fig. 109. Papillary spines on ventral sucker; diameter of ventral sucker
0.21 mm.

Fig. 1 10. Transverse ridges of ventral disk.

Fig. hi. Outline of vitelline glands.

Hysterolecitha rosea gen. et sp. nov., from Teuthis hepatus.

Fig. 112. Ventro-lateral view, life, details added; length 3.36 mm.
Fig. 113. Ovary and vitelline glands seen from right side; longer diameter
of ovary 0.11 mm.

Plate 14.

Hysterolecitha rosea, continued, from Teuthis hepatus.

Fig. 114. Ejaculatory duct, seminal vesicle, and metraterm, life; highly

magnified, pr, cell's surrounding genital aperture.
Figs. 115, 116, 117. Sketches of ovary, vitelline gland, and seminal receptacle

from different specimens.

Macradena perfecta gen. et sp. nov., from Teuthis cceruleus.

Fig. 118. Sketch made up from about 3 adjacent, horizontal sections, some-
what diagrammatic; length 2.55 mm.

Fig. 119. Part of transverse section through seminal receptacle, yolk-gland
and shell-gland; diameter 0.45 mm.

Opisthadena dimidia gen. et sp. nov., from Kyphosus sectatrix.

Fig. 120. Ventral view, life, details added; length 2.80 mm.
Fig. 120a. Ova; length 0.038 mm.

Fig. 121. Dorsal view, made up from horizontal sections, diagrammatic;
length 5 mm.

Plate 15.

Opisthadena dimidia, continued.

Fig. 122. Transverse section showing extraordinary development of longi-
tudinal muscles of body-wall and of walls of intestine; diameter
0.45 mm.

Brachadena pyriformis gen. et sp. nov.

Fig. 123. Ventral view, life, details added; length 1.61 mm. From H&mulon

plumieri.
Fig. 123a. Ovum; length 0.037 mm.
Fig. 124. Ventral view of small specimen, balsam; length 0.65 mm. From

H. sciurus.
Fig. 125. Sagittal section of neck; diameter of oral sucker 0.010 mm. From

Calamus calamus.
Fig. 126. Ventral view of cirrus-pouch, balsam. From H. plumieri.

Dichadena acuta gen. et sp. nov.

Fig. 127. Ventro-lateral view, balsam; length 1.55 mm. From Teuthis
cceruleus.

Explanation of Plates. 93

Plate 16.
Leurodcra decora gen. et sp. nov.

Fig. 128. Ventral view, balsam; excretory vessel added from another speci-
men; length 1.86 mm. From Hamilton plumieri.

Fig. 129. Free-hand sketch from life showing an inclosed nematode («) near
posterior end; length 1.75 mm.

Dictysarca virens gen. et sp. nov.

Fig. 130. Ventral view, diagrammatic and some details added from sections;

length 4.5 mm. From Lycodontis funebris. exp, excretory pore

surrounded by gland-cells; u, probably uterus, though no ova

were present.
Fig. 131. Ventral view of anterior end of specimen with short esophagus,

life; diameter of oral sucker 0.5 mm.
Fig. 132. Superficial view of alcoholic specimen; length 4.5 mm., breadth

2.5 mm., thickness 2 mm.
Fig. 133. Transverse section through cirrus-pouch, the next section behind

this contains vertical part of metraterm; breadth 1.56 mm.

Index line, pr', points to duct of prostate.
Fig. 134 Memorandum sketch, life, ventral view showing the intestine and

characteristic reticulated or areolated structure; length 5 mm.

From L. moringa.
Fig. 135. Sagittal section, diagrammatic, of anterior end.
Fig. 136. Transverse section of body through ventral sucker; breadth 1 .05 mm.

Theletrum fustiforme gen. et sp. nov.

Fig. 137. Lateral view, life, details added; length 1.83 mm. From Poma-
canthus arcuatus. w, ventral papilla?.

Plate 17.
Hemiurus merits sp. nov., from Clupanodon pseudohispanicus.
Fig. 138. Ventro-lateral view, balsam; length 1.66 mm.

Sterrhurus monticellii (Linton).

Fig. 139. Sagittal section of neck; diameter of oral sucker 0.12 mm. h, cleft
in front of ventral sucker. From Echeneis naucrates.

Fig. 140. Immature specimen from Chlorichthys bifasciatus, life; length 0.46
mm.

Sterrhurus fusiformis (Ltihe ) .

Fig. 141. Ventral view, balsam; length 2.52 mm. From Lycodontis funebris.
Fig. 142. Ovary and vitelline glands, dorsal view.

Fig. 143. Posterior end showing retracted condition; diameter 0.45 mm.
Fig. 144. Dorsal view, life, details added; length 1.96 mm. The oral sucker
is invaginated. From L. moringa.

Plate 18.
Sterrhurus fusiformis (Ltihe), continued.

Fig. 145. Ventro-lateral view of body, dorsal of head, showing course of
excretory vessels, life, details added; length 2.70 mm. The head
is bent sharply ventrad. From L. funebris.

Fig. 146. Nearly sagittal section through cirrus-pouch, prostate, and metra-
term; diameter of intestine 0.07 mm. pr', duct of prostate; cp',
muscles of cirrus-pouch.

Fig. 147. Transverse section of cirrus-pouch; diameter of cirrus 0.05 mm.
cp' , muscles of cirrus-pouch.

Ectenurus virgula sp. nov., from Clupanodon pseudohispanicus.

Fig. 148. Lateral view, life, details added; length 2.35 mm. n, lateral emi-
nence on neck.

94 Papers from the Marine Biological Laboratory at Tortugas.

Dinurus rubeus sp. now, from Lycodontis funebris.

Fig. 149. Superficial ventral view of specimen in alcohol; length 7.5 mm.

Fig. 150. Transverse section intestines with granular contents, single excre-
tory vessels, uterus, ovary, shell-gland, seminal receptacle, and
vitelline glands; diameter 1.18 mm.

Plate 19.

Din itrus rubeus, continued, from Lycodontis funebris.

Fig. 151. Dorsal view, balsam; length 15 mm.

Fig. 152. Lateral view of cirrus, prostate, seminal vesicle, and metraterm ;

reconstructed from sections.
Fig. 153. Transverse section showing ventral sucker, prostate, metraterm,

and excretory vessel; breadth 1.05 mm.
Fig. 154. Transverse section near posterior end, showing intestines and

dorsal excretory vessel; diameter 0.72 mm.

Ectenurus (?) sp., immature, from Auxis thazard.

Fig. 155. Ventral view of immature specimen in balsam; length 2 mm.

Hapladena varia gen. et sp. nov.

Fig. 156. Ventral view, life, details added; length 3 mm. /.ootype. From

Teuthis cceruleus.
Fig. 157. Ventral view of another specimen, life, details added; length 1.96

mm. /, ootype.

Deradcna acuta gen. et sp. nov., from Tylosurus marinus.
Fig. 158. Ova, life, details added; length 0.071 mm.

Plate 20.
Deradena acuta, continued.

Fig. 159. Ventral view, life, details added; length 1.166 mm.

Deradena obtnsa genr et sp. nov.

Fig. 160. Ventral view of specimen from Teuthis hepatus, life, details added;
length 1.33 mm.

Fig. 161. Ventro-lateral view of specimen from T. cceruleus, life, memorandum
sketch. The specimen when stained and mounted showed no
more details than are given in the sketch. Length 0.98 mm.

Deradena ovalis gen. et sp. nov.

Fig. 162. Ventral view of specimen from Scarus sp. The anatomy was very

poorly shown on account of the diffuse vitelline glands which

obscured details of structure. Length 1.75 mm.
Fig. 163. Ventral view, balsam; length 3.5 mm. The vitelline glands were

much denser than represented in sketch. Figs. 163-169 from

Scarus cceruleus.
Fig. 164. Diagram of sagittal section of prostate, etc. sv' , communicating

duct between seminal vesicle and common genital duct (c) ; z,

point where seminal vesicle joins metraterm.
Fig. 165. Same view taken from another specimen, z, point where seminal

vesicle joins metraterm; c, common genital duct.
Fig. 166. Transverse section through prostate made at x in fig. 165.
Fig. 167. Nearly transverse section made through x of fig. 164; e, ovum in

common genital duct. Other reference letters as in fig. 164.
Fig. 168. Transverse section of body near posterior end; diameter 0.81 mm.
Fig. 169. From transverse section, showing active yolk-forming cells, d' ',

and different stages of the accumulation of yolk. See text for

description.

Explanation of Plates. 95

Plate 21.
Mesolecitha linearis gen. et sp. nov., from Teuthis cceruleus.

?!.' 17°" Ventro-lateral View' life> detaiIs added: length 4.cc mm

Fig. i7i. Nearly g horizontal view of ovary, shell-gfand,4 filiform seminal

Fig t*9 SacrfttJ? ? ' ,' made Up from ^ or 4 horizontal sections.
J?lO. 172. Sagittal section of cirrus, seminal vesicle, and metraterm made up
irom 3 or 4 sections. l

Barisomum erubescens gen. et sp. nov., from Pomacanthus arcuatus.

Figs. 173-173C Sketches from life showing different specimens in various
positions. Intestines dark brown or black, reproductive organs
generally white, ground-color pink. organs

p!r' II3' YGn^al ViGW' lateral edges rolled under! ^ngth 2.5 mm
Jig. 173a. Another, same view; length 3.25 mm -3 mm.

Jig. 1736. Lateral view; length 3.25 mm.

Fig. 173c. Dorsal view; length 3.50 mm

Fig. i74. Posterior end [.ventral view; diameter i.5 mm. The end has been

cut, the lateral edges unrolled and spread apart. At * the intes-

Fig. 175. Transverse section, showing prostate, seminal vesicle, etc : diame-

ter 1.26 mm. '

p!r' lit' Cirrus-pouch, prostate, etc., ventral view, edge turned under
Fig. 177. Transverse section near posterior end, showing anlstomosTs of
intestinal rami (this seems to be exceptional), ventral excretory
pore and excretory vessel. Diameter 0.63 mm. ' eXCretory

Plate 22.
Barisomum erubescens, continued.

Fig. 178. Transverse section showing intestinal diverticula, strong transverse

muscles, duct of prostate (no prostatic cells shown in this sec!

tion), metraterm, and cirrus. Thickness of body at this point
Pro * t °-22 mm- m ' Cells surrounding metraterm. P

*IG. i J 9. Transverse section showing duct of prostate, vas deferens, uterus

transverse muscles, etc. Thickness of body here 0.25 mm u>'

uterus with ova cut transversely
*ig. 180. Transverse section showing fascicles of strong transverse muscles ;

tnicKness 0.19 mm.

Fir' ill' nfnSVer!t SiiCti°n °f cirrus-P°uch; diameter 0.14 mm.
Jig. 182. Ovum with filaments

Fig. 182a. Ovum without filaments, more highly magnified; length of ovum

Fm T« n°-°37 mm; length of filament 0.30 mm

Fig. 183. Dorsal view, life. The intestines, from the bifurcation to the level
of the point marked x were pink with clear granules; beyond
this point they were filled with dark-brown or black Wanular
contents. Length 2.6 mm. granuiai

Himasomum candidulum gen. et sp. nov., from Pomacanthus arcuatus.

Fig. 184. Ventral view, life details added folds of uterus diagrammatic;
r* lengtn 5 mm. k, muscular ridge.

*ig. 184a. Ventral view of head; diameter 0.32 mm.

Plate 23.
Himasomum candidulum, continued.

Fig. 185. Ventral view of head of a different specimen from that sketched in
nS- 104a; diameter 0.50 mm.

f!.' ll n*! VieW °f,head with definite muscular ridge ; diameter o « mm
F... ,„. Do-ja. ™w of headof another sPeeimen wit! faint .S^;

96 Papers from the Marine Biological Laboratory at Tortugas.

Fig. i 88. Dorsal view of esophagus, intestines, and excretory vessel. The dots,
tm, represent fascicles of transverse muscles seen in section.

Fig. 189. Cirrus-pouch and metraterm, ventral view; diameter 0.90 mm.
k, filaments of ova protruding from genital aperture. The ova
are drawn on a slightly larger scale than remainder of sketch.

Fig. 190. Ventral view of posterior end, uterus diagrammatic; diameter
0.52 mm. The edges were turned under, but this was disregarded
in the sketch to avoid confusion.

Fig. 191. Horizontal section of the head showing arrangement of muscles;
diameter 0.20 mm.

Fig. 192. Plan of musculature of body-wall. There is an outer transverse
(circular) layer, under this a longitudinal layer, and under this
again 2 diagonal layers. The diagonal layers are of coarser fibers
than the 2 outer layers.

Fig. 193. Section of cirrus and metraterm, from horizontal section of body,
but nearly tangential of the marginal region at this point. Diam-
eter of cirrus-pouch 0.05 mm.

Fig. 194. Tangential section of cirrus and prostate, tube of latter with pros-
tatic secretion in elongated masses on walls. Diameter 0.11 mm.

Fig. 195. Transverse section of body in front of reproductive aperture,
showing intestines, excretory vessels, and fascicles of transverse
muscle fibers. Breadth 0.30 mm.

Fig. 196. Ova, apparently without filaments, from posterior end of body.
Length 0.037 mm.

Plate 24.

Himasomum candidulum, continued.

Fig. 197. Ovum with filaments, from folds of uterus in front of ovary.
Fig. 197a. Ovum greatly enlarged; length of ovum 0.037, of filament 0.42 mm.

Cleptodiscus reticulatus gen. et sp. nov.; from Pomacanthits arciiatus.

Fig. 198. Dorsal view, balsam, showing characteristic areolar structure;
length 1.75 mm. s, posterior sucker showing from under side

Fig. 199. Section of esophagus, nearly transverse; diameter 0.04 mm. n,
cells surrounding esophagus.

Fig. 200. Sagittal section through oral sucker and esophagus; diameter of
head at base of oral sucker 0.20 mm. dh, dorsal, and vh ventral
granular masses; a', cells in oral sucker; n, cells surrounding
esophagus.

Fig. 201. Ventral view, life, details added; length 4 mm. r,r, rudimentary
suckers; 5, posterior sucker.

Fig. 202. Horizontal view of head showing rudimentary suckers r; n, cells
surrounding esophagus. Diameter at level of rudimentary suck-
ers 0.30 mm.

Fig. 203. Sagittal section through genital aperture showing cirrus-pouch,
metraterm, vas deferens, intestine, portion of anterior testis, and
characteristic areolar parenchyma, i, intestine with granular
contents; n, cells surrounding genital aperture. Thickness of
body at genital aperture 0.40 mm.

Fig. 204. Transverse section showing cirrus-pouch, metraterm, cells surround-
ing genital aperture, intestine, and excretory vessels. Diameter
0.45 mm.

Stegopa globosa gen. et sp. nov., from Neomczms griseus.

Fig. 205. Ventral view, life, details added; length 0.56 mm.

Fig. 206. Dorsal view of same.

Fig. 207. Ventral view of anterior end, life. Diameter of oral sucker 0.1 1 mm.

Explanation of Plates. 97

Plate 25.

Siphodera (gen. nov.) vinaledwardsii (Linton), from Ocyurus chrysurus.

Fig. 208. Ventral view, balsam. Posterior end of excretory vessel supplied
from a sketch from life. The crenulations did not appear and
the longitudinal ribs were faint in mounted specimen. Uterus
diagrammatic. Folds on right side are ventral and filled with
dark-brown ova, those on left side are dorsal and filled with
yellow ova. Tube-like gland-cells («) in neck are more numer-
ous than represented in sketch, and in sections are seen to be
elongated cells similar to those represented in fig. 169. They
are interpreted to be yolk-forming cells. Length 1.82 mm.

Fig. 209. Ventral view of genital sucker, prostatic portion of cirrus-pouch,
and metraterm. rm, radial-muscle fibers; diameter of genital
sucker 0.09 mm.

Fig. 209a. Diagram made up from sagittal sections of specimens from this
host collected in Bermuda.

Metadena crassulata gen. et sp. nov., from Neomcenis analis.

Fig. 210. Dorsal view, life, details added; length 1.83 mm.

Prodistomum gracile gen. et sp. nov., from Clupanodon pseudohispanicus .

Fig. 211. Ventral view, balsam; length 1.33 mm.

Fig. 212. Enlarged sketch of posterior excretory pore; diameter of muscular
disc 0.04 mm.

Genolopa ampullacea gen. et sp. nov., from Hcemulon macrostomum.

Fig. 213. Ventral view, life, specimen much flattened; length 1.42 mm.

Genolopa truncata gen. et sp. nov., from Hcemulon plumieri.

Fig. 214. Ventral view, life, details added; length 0.96 mm.
Fig. 215. Ova; 0.017 by 0.010 mm.

Plate 26.
Genolopa truncata, continued.

Fig. 216. Ventral view of another specimen, life; length 0.78 mm.

Gasterostomum sp., from Mycteroperca venenosa.

Fig. 217. Ventral view, life, details added; length 1.20 mm.
Fig. 217a. Ova, 0.027 by 0.020 mm.

Fig. 218. Posterior end, ventral view, balsam. Length of cirrus-bulb 0.7 mm.
n, opening into cirrus seen through body-wall.

Gasterostomum gracile sec ns{'t), from Lycodontis moringa.

Fig. 219. Anterior sucker, life; diameter 0.35 mm.

Fig. 220. Ventral view, balsam.

Fig. 221. Ova, life; 0.027 by 0017 mm.

Gasterostomum sp., from Mycteroperca bonaci.

Fig. 222. Ventral view, life; length 1.90 mm.

Fig. 222a. Ova, balsam; 0.027 by 0.024 mm., 0.034 by 0.020 mm.

Gasterostomum sp., probably more than one species, from Sphyrcena barracuda.

Fig. 223. Ventral view, life, a few details added; length 0.91 mm. a, ova,

maximum length 0.024 mm.
Fig. 224. Ventral view; length 0.94 mm.
Fig. 224a. Ova, 0.03 by 0.01 mm.

Fig. 225. Ventral view, life. No others seen like this. The specimen was
not found among the mounted material. Length 1.48 mm.

98 Papers from the Marine Biological Laboratory at Tort it gas.

Plate 27.
Microcotyle incisa sp. nov., from Neomcenis griseus.

Fig. 226. Dorsal view, balsam; length 2.30 mm.

Fig. 227. Ventral view of head, balsam; diameter 0.09 mm.

Fig! 228. Dorsal view of head, balsam; diameter 0.09 mm. n, coarse pig-
ment granules beside esophagus.

Fig. 229. Lateral view, life, caudal region distorted by pressure; length 2.4
mm.

Fig. 230. Two pairs of caudal suckers. Diameters of single sucker 0.06 and
0.03 mm.

Deontacylix oval-is gen. et sp. nov., from Kyphosus sectatrix.

Fig. 231. Ventral view, balsam; length 1.86 mm. a, mouth; c, ejaculatory

duct; n, n, lateral bands uniting anteriorly above the esophagus

and resembling nerves.
Fig. 232. Posterior end, dorsal view, of another specimen, balsam; diameter

at level of ovary 0.6 mm.
Fig. 233. Ventral view of anterior end showing the minute mouth; greatly

enlarged.
Fig. 234. Ova, highly magnified; 0.027 by 0.014 mm.
Fig. 235. Spines of body greatly enlarged; distance between rows of spines

0.009 mm.

Plate 28.

Aspidogaster ringens Linton, from Calamus calamus.

Fig. 236. Ventral view, somewhat diagrammatic, life, details added; length

1. 5 1 mm. There did not appear to be any longitudinal, median

ventral ridge. /, marginal sense-organs; h, transverse ridges;

k, marginal loculi.
Fig. 237. Ventral view of left margin. Coarse stippling represents nuclei of

cells. Reference letters as in 236.
Fig. 237a. Right margin near anterior end, ventral view. Reference letters

as in 236.

Udonella socialis sp. nov. on Argulus sp. in mouth of Neomainis griseus.

Fig. 238. Dorsal view of adult, balsam; length 1.20 mm. e, ovum in uterus;

q, q, volk-reservoirs (?).
Fig. 239. Ventral view of head, life; diameter of head 0.27 mm. w, mouth.
Fig. 240. Lateral view of head of small specimen, balsam.
Fig 241. Posterior end of Argulus with trematodes, young and adult, and

ova attached. Sketch made from specimen mounted in balsam.

ad, adult; j, egg from which a young trematode is in act of

escaping; k, egg-capsule from which the young has escaped;

/, part of egg-chain of copepod; y, young.

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A CONTRIBUTION TO THE GEOLOGIC HISTORY
OF THE FLORIDIAN PLATEAU.

BY THOMAS WAYLAND VAUGHAN,

Geologist in Charge of Coastal Plain Investigation, U. S. Geological Survey,
Custodian of Madreporaria, U. S. National Museum.

15 plates, 6 text figures.

99

CONTENTS.

PAGE

Introduction io5

Topography of the Floridian Plateau i°7

Relation of the ioo-fathom curve to the present land surface and to

greater depths io7

The io-fathom curve Io8

The reefs io9

The Hawk Channel 1 10

The keys I IO

Bays and sounds behind the keys 1 1 1

Relief of the mainland 112

Marine bottom deposits forming in the bays and sounds behind the keys 114

Biscayne Bay 1 * °

Between Old Rhodes Bank and Carysfort Light 117

Card Sound "7

Barnes Sound II7

Blackwater Sound II7

Hoodoo Sound ll7

Florida Bay T l 7

Gun and Cat Keys, Bahamas 119

Summary of data on the material of the deposits 119

Report on examination of material from the sea-bottom between Miami

and Key West, by George Charlton Matson 120

Sources of material I2°

Silica 126

Geologic distribution of siliceous sand in Florida 127

Calcium carbonate . 129

Calcium carbonate of inorganic origin 13°

Pleistocene limestone of southern Florida 130

Topography of southern Florida 13 x

Vegetation of southern Florida 13 l

Drainage and rainfall of southern Florida 132

Chemical denudation 133

Precipitation of chemically dissolved calcium carbonate.. . . 135

White-water periods 136

Effect of sea-spray 13°

Calcium carbonate derived through surface erosion 136

Calcium carbonate of organic origin 137

Resume of sources of calcareous sediments 137

Geologic distribution of limestone in Florida 138

Tertiary coral reefs of the Southern United States 138

Transporting agents of the Florida coast and their effects 14°

Constant currents I4°

Tidal currents *4 1

Winds Mi

Effect of Florida count ercurrent on shore topography of Florida. ... 142

Banks behind keys 145

Deltas at outer ends of passages between keys 145

Areal distribution of the geologic formations 146

Oligocene 146

Vicksburg Group 146

Apalachicola Group 146

Miocene 147

Pliocene 147

Pleistocene 14 7

General relations of geologic boundaries in Florida 148

Drainage lines 148

Geologic history of the Floridian Plateau 15°

Events of Vicksburgian time 15°

The Vicksburgian stibmergence 15°

Depth and temperature of the waters 15°

Summary of Vicksburgian events 152

101

102 Contents.

PAGE

The Vicksburgian-Apalachicolan interval 152

Events of Apalachicolan time 153

Earlier stage 153

Shore-line 153

Material of the sediments 153

Fatmal characters 154

Summary of events of earlier stage 155

Later stage 155

Shore-line 155

Suwanee Strait and Orange Island 156

Deformation 156

Temperature 156

Absence of Apalachicola sediments west of the Vicksburg

nucleus 157

Apalachicolan-Miocene interval 157

Events of Miocene time 157

Distribution of Miocene sediments 157

Lithology 1 59

Miocene corals 159

Shore-line 159

Depth of water 160

Temperature 161

Currents 161

Uplift at the close of the Miocene 162

Events of Pliocene time 162

Stratigraphic relations of Pliocene to Miocene sediments 162

Areal distribution of Marine Pliocene in Florida 162

Lithology and thickness 164

Shore-line 164

Depth and temperature of the Pliocene Sea 164

Conformity of the Pliocene to other geologic boundaries 165

Events above sea-level 166

Uplift at the close of the Pliocene 166

Pliocene-Pleistocene interval 166

Events of Pleistocene time 168

Pleistocene submergence 168

Differences in Pleistocene sediments 168

Coquina 169

Shell marl 170

Southward extension of buried sands 172

The Florida oolites 173

Lostman's River limestone 178

Key Largo limestone 178

Surface sands overlying the marine Pleistocene 178

Upland gray sands 178

River terraces and other Pleistocene formations 179

Summary of Pleistocene history 179

Recent 181

Resume of the geologic history of the Floridian Plateau 181

Deformation 184

Currents 185

ILLUSTRATIONS.

PLATES. PLATES TO FACE

Plate i. Topographic map of the Floridian Plateau, showing the submarine

and subaerial topography • • Io8

2. Map of Florida keys, on which are shown the station numbers of

the bottom samples * 1 4

3. Map showing Caesars Creek and Old Rhodes banks 144

4. Geologic map of Florida .•,"'• I46

5. Topographic map of Peninsular Florida with the principal drainage

lines emphasized ■ ■ 1 4 °

6. (a) Cape Florida, Key Biscayne, showing surface of siliceous sand

and cocoanut palms • J °5

(b) Cape Florida, Key Biscayne, showing surface of siliceous sand

and sea-grape • • ; • x °5

(c) The Marquesas, south side, beach ridge of calcareous sand in

the foreground, mangroves in the distance • 185

7. (a) Loggerhead Key, showing bay cedars and loose calcareous sand 185

(b) Loggerhead Key, western beach, northeast of light-house, show-

ing passage of beach curve from indurated material along
water's edge into that of the loose material lying above it.. 185

(c) Edge of the Everglades, near Miami, showing saw-grass 185

(d) Edge of the Everglades, near Miami, showing a lily pad 185

8. (a) Miami oolite, pine lands, outskirts of Miami 185

(b) Erosion by sea-spray, Picquet Rocks, Bahamas, western shore,

distance 1 5 feet J °5

(c) Erosion by sea-spray, Gun Key, Bahamas, western shore 185

9. Young mangroves, showing stages of development from the pod.

The four small figures represent pods plucked from the tree 185

10. Young mangroves: (a) and (6) shoal about two miles north of

Pigeon Key, water about one foot deep; (c) and (d) shoal
upper end of Long Island, water about one foot deep 185

1 1 . Mangroves, Miami River I°5

12. (a) Mangrove roots, Pigeon Key l85

(b) " Black mangroves," Pigeon Key 185

13. (a) Cross-bedded calcareous sandstone, probably aeolian, eastern

side of Gun Key, Bahamas 185

(b) Miami oolite exposure, Miami, showing cross-bedding 185

14. (a) Cross-bedding by water in an Eocene exposure, Central of

Georgia Railway, two miles northeast of Andersonville, Georgia 185

(b) Mud cracks, surface of Key West oolite, Big Pine Key. 185

(c) Surface of Key West oolite, Summerland Key 185

15. (a) Surface of Key West oolite, Boca Grande Key 185

(b) Key Largo limestone, southern end of Old Rhodes Key 185

(c) Coral head in Key Largo limestone, Key Vaca 185

TEXT FIGURES.

PAGE

Fig. 1. Tortugas, East Key, west side looking north. Note vegetation on

the summit of the key ll°

2. Middle Key, looking north along the axis. This key was washed

away during a storm on June 28, 1909, but was restored between

August, 1909, and May, 1910 no

3 . Current chart of Florida waters * 4°

4. Map of the Florida Coast from the mouth of St. Mary's River to the

mouth of St. John's River 143

5. Map of the Florida keys in the vicinity of St. Augustine 143

6. Map of Cape Canaveral '44

103

A CONTRIBUTION TO THE GEOLOGIC HISTORY OF THE
FLORIDIAN PLATEAU.

By Thomas Wayland Vaughan.

INTRODUCTION.

This paper is the outgrowth of my association with two organiza-
tions, the United States Geological Survey and the Carnegie Institution
of Washington. As Geologist in charge of Coastal Plain Investiga-
tions of the former organization, I have had unusual opportunities
to familiarize myself with the geology of Florida, supplementing my
previous field work in the State by several additional trips. I super-
vised and participated in the preparation of a report on the stratigraphic
geology and a geologic map of the State, done in cooperation between
the United States Geological Survey and the Florida State Survey, by
Messrs. George Charlton Matson, Frederick G. Clapp, and Samuel San-
ford. I have therefore had at my disposal not only the results of my
personal work for the Geological Survey, but also those of Messrs. Matson,
Clapp, and Sanford. The information derived from my association with
the United States Geological Survey is here utilized with the permission
of the Director of that Bureau, and my hearty thanks are extended to
him for the privilege.

Through facilities afforded by Dr. Alfred G. Mayer, Director of the
Department of Marine Biology of the Carnegie Institution of Washington,
I have been able to visit all the principal keys belonging to the main
line, to collect and study bottom samples between Miami and Key West,
particularly the deposits accumulating behind the keys, to examine
several important living coral reefs, and to make detailed investigations
of the reefs around the Tortugas. I was also able to visit Cat and Gun
keys and the Picquet rocks of the Bahamas.

It was at first contemplated to give an account only of the sedi-
mentation now taking place in the bays and sounds behind the keys.
Naturallv, the questions arose, whence come these sediments, by what
processes are they brought to the sea, how great is their quantity, and
how are they distributed over the ocean floor? An extension of these
questions led to a general consideration of sedimentation on the Floridian
platform and the growth of the platform itself.

The scope of the paper was therefore enlarged, and an attempt is
made to trace the geologic history of the Floridian Plateau from Oligo-
cene to Recent time. The work of previous investigators has been exten-
sively drawn upon, and the debt owed them is gratefully acknowledged.
The principal of these are Louis Agassiz, Alexander Agassiz, Eugene A.
Smith, Angelo Heilprin, William H. Dall, N. S. Shaler, Leon S. Griswold,
George C. Matson, Frederick G. Clapp, Samuel Sanford, and E. H.

105

106 Papers from the Marine Biological Laboratory at Tortugas.

Sellards. Each of these men has made a distinct contribution to our
knowledge of the geology and geologic history of the region.

In the preparation of this paper I have received assistance or advice
from several of my scientific colleagues, and express my thanks for their
kindness. Professor Charles E. Munroe advised me regarding some of the
chemical problems; Mr. J. C. Hoyt supplied information on the surface
run-off of streams on the Atlantic slope of the United States; Rear-
Admiral Pillsbury, U. S. N., retired, discussed the oceanic currents with
me; and Dr. Wm. H. Dall, Mr. George C. Matson, Mr. Samuel Sanford,
Dr. L. W. Stephenson, and Dr. Paul Bartsch each read my manuscript.
Mr. Matson made physical examinations of the bottom samples col-
lected and has contributed the report published on pp. 120-125 of this
paper, and Dr. Dall has furnished a note on the Suwanee Strait region
during Miocene time.

Geologic research in Florida, and in Southern Florida particularly,
is not now the difficult and hazardous task it was even 10 or 15 years
ago. The Florida East Coast Railway has extended its line from the
mainland along the keys, and canals have been cut into the Everglades,
the excavations for both the railway and the canals revealing excellent
exposures hitherto obscured by soil and dense vegetation. Numerous
wells, of which we have records, have been put down on both the main-
land and the keys, and the shallow-draft naphtha launch renders easy
and speedy the examination of banks and keys hitherto accessible only
with difficulty. The recently increased facilities for investigation have
not been neglected, and results have been obtained sometimes at variance
with former opinions, as might have been anticipated.

This is to be regarded as only a sketch of the geologic development
of the Floridian Plateau, as many problems need solution and many
phases of its history need further investigation. Perhaps its principal
value may be in directing attention to some of the unsolved problems.
It is necessary to know more accurately the amount of water discharged
by the streams and the quantities of solids borne by them to the sea.
The chemical processes of precipitation have not been sufficiently studied.
Dall's researches on the paleontology of Florida have been epoch-making
in their importance, but still our knowledge of the fossils of most of the
geologic formations and horizons is far from complete. Additional
paleontologic research is needed for every geologic formation known in
the State, from the formations of the Vicksburg group to those of the
Pleistocene. The paleontologic studies should be an accompaniment
of more detailed stratigraphic work. Topographic maps and detailed
geologic mapping are essential before the details of the successive defor-
mations to which the area has been subjected can be ascertained. There
is also great need for more extensive studies of the marine bottom
deposits within the 100-fathom curve.

The deep wells recently put down on Key Vaca, Big Pine Key, and
Key West have given valuable data, but deep wells are also needed on
Key Biscayne or Virginia Key, the Marquesas, and the Tortugas, in
order to discover what underlies the surface formations. It is important
to ascertain whether the Miami oolite is older than or contemporaneous

,4 Contribution to the Geologic History of the Floridian Plateau. 107

with the Key Largo limestone. A well on Old Rhodes or Elliott Key
might give the desired information.

Probablv a number of years will elapse before these deficiencies
in the information on the geology of Florida will be supplied, as tedious
and protracted research is necessary. It is hoped this paper may serve
as a convenient summary of the present knowledge of the geologic
history of this interesting region, perhaps present an interpretation
somewhat different from those preceding, and be a stimulus to further
investigation.

TOPOGRAPHY OF THE FLORIDIAN PLATEAU.

That the land surface of Florida represents only about half of the
area of the Floridian Plateau has been known for a number of years.
A. Agassiz has called attention to it in his " Three Cruises of the Blake " ' :
Shaler, in his "Topography of Florida"2; Dall, in his "Neocene" Corre-
lation Paper 3 ; and Sanford in his " Topography and Geology of Southern
Florida."4

RELATION OF THE 100-FATHOM CURVE TO THE PRESENT LAXD
SURFACE AND TO GREATER DEPTHS.

The ioo-fathom curve, which is considered the delimitation of the
continental shelf, lies between 85 and 90 miles offshore, east of Fernan-
dina; south of this locality it curves gently and gradually approaches
the shore, until opposite Fort Lauderdale it is less than 5 miles distant.
It follows closely the seaward face of the main line of the reefs, curves
to the westward, passing between 10 and 15 miles south of Key West,
about the same distance south of the Marquesas, and 20 miles south of
the Tortugas, beyond which it bends to the north of west. The width
of the Plateau along the 250 of latitude, which passes through Florida
Bay, is between 240 and 250 miles. Just south of its intersection of the
25° parallel it takes a slightly curving course to the north of west and
lies about 45 miles south of Pensacola. (See plate 1.)

The width of the Plateau along different parallels is given in the
following table:

Width of the Floridian Plateau along Parallels of Latitude.

r> 11 1 Total West of T „ , „„„ East of

Parallel. width_ land area. Land area. land area.

Ten miles south of St. Augustine.

29°

280

27°

260

25°

miles.

405
335
310
297
266
242

miles.
205
180
130
130
160

225

miles.
135
US

140
145
100

-> 1

miles.
65

1 Distance across Key Largo.

1 Vol. I. p. 152. 1888.

2 Mus. Comp. Zool., Bull., vol. 16, p. 139, 1890.
3U. S. Geol. Surv., Bull. 84. p. 86. 1891.

4 Florida Geol. Surv., 2d Ann. Report, p. 180, 1910.

108 Papers from the Marine Biological Laboratory at Tortugas.

The preceding measurements are made along parallels of latitude
and are not precisely transverse to the long axis of the Peninsula, which
is from N. 200 W. to S. 200 E., but they clearly indicate the approach
southward of the 100-fathom curve to the shore, and the persistent width
of the submarine portion of the Plateau on the west. In no instance is
the width of the subaerial portion of the Plateau so great as that of the
subaqueous portion. They are most nearly equal along parallel 270.

In the Gulf of Mexico the descent from the 100-fathom curve is
abrupt until a depth of 1,500 or 2,000 fathoms is reached. The steepest
portion of this declivity is about 60 miles slightly north of west (N. 68°
W.) of the Tortugas, where within 22 miles there is a drop from 100 to
1,500 fathoms, and within about 12 miles further an additional descent
from 1 ,500 to 2 ,000 fathoms. The usual depth to the south in the Florida
Straits is over 500 and less than 1,000 fathoms. Off Havana is a tongue
of deep water, which the 1 ,000-fathom curve marks. The Florida Straits
are from 500 to 1,500 fathoms shallower than the nearby bottom of the
Gulf of Mexico.

The water between the southern portion of the east coast and the
Bahamas is still shallower, being less than 300 fathoms in depth. The
500-fathom curve passes around the eastern side of the Bahamas. Off
the eastern coast the descent from the 100-fathom curve is not nearly
so precipitous or so great in amount as in the Gulf. In the Atlantic the
1 ,000-fathom curve is slightly sinuous, but follows a southerly course
from near Hatteras to the eastern side of the Bahamas and forms the
eastern boundary of the "Blake Plateau."1

THE 10-FATHOM CURVE.

The 10-fathom curve does not in all places lie close to the shore,
indicating extensive areas of shoal water. It is about 25 miles offshore
east of Fernandina and slightly less opposite Jacksonville, south of which
it irregularly approaches the shore, coming very near it opposite Jupiter
Inlet and from there to Key Biscayne. It closely follows the outer edge
of the growing coral reefs, extends westward beyond the Marquesas
and more than halfway from them to the Tortugas. It also incloses
the Tortugas, but does not connect them with the Marquesas. North of
the latter keys it bends eastward, lying between 40 and 45 miles west of the
mouth of White Water Bay. Thence it runs northward to beyond the
Thousand Islands, and from there roughly parallels the west coast. It
is about 1 5 miles west of the mouth of Charlotte Harbor, about the same
distance west of the mouth of Tampa Bay, 30 miles west of Cedar Keysr
10 miles south of Cape San Bias ; westward of the last-mentioned locality
it is from 5 to 10 miles offshore. (See plate 1.)

If Florida were elevated only 60 feet, all of the area surrounded by
the 10-fathom curve would be added to the land surface. The whole of the
key region, excepting the Rebecca Channel, would be above water-level,
leaving the bottom of Florida Bay dry, as would also be a strip of land
25 miles wide opposite Fernandina, but narrowing southward on the
east coast, and a strip from 10 to 30 miles wide on the west coast east

1 A. Agassiz, Three Cruises of the Blake, p. 96.

fe^ssacsw

",." ' * v '■ O '»■ Sg

*

.1 r /. ,1 a' t i C

4

J-.M . ■- " i: - S .. I ■ ■ E "-"-

HI^VXm " -«^.»-

......<■ L . * <*.c..-..

1 ' -

,:VogrsphicOli

t

■■'

TOPOGRAPHIC MAP OF THE FLORIDIAN PLATEAU

A Contribution to the Geologic History of the Florid i an Plateau. 109

of the mouth of the Apalachieola River. Such a slight elevation would
increase the land surface approximately one-third.

THE REEFS.

No attempt will be made to give a detailed account of the reefs, as
the classic descriptions of Louis Agassiz 1 and Alexander Agassiz 2 are
so well known. The reefs occur as a disconnected series just landward
of the io-fathom curve, between it and the main line of keys, extend
from Fowey Rocks as far westward as the Marquesas, and disappear in
the Tortugas. The northernmost living reef known is that at Fowey
Rocks. L. Agassiz says3 "in the immediate vicinity of Cape Biscayne
there is a mud shoal, laid partly bare at low water, over which grow
branching Millepora, with small tufts of Oculina and Caryophyllia 4
rising between them, and here and there a few Porites furcata."

On the surface of the tongue of land east of the northern end of
Biscayne Bay and Virginia Key, I collected wave-tossed, dead speci-
mens of the following corals: Cyphastrea hyades, Orbicella annularis,
Orbicella cavernosa, Mussa (Isophyllia) sp., Favia fragum, Mceandra
areolata. The original source of these specimens was not determined.

I found living specimens of Siderastrea radians and Porites forma
furcata off the northeastern end of Key Biscayne in water from 2.5 to 4
feet deep. The living corals do not form a reef, but grow on a sandy flat.

Professor Shaler's report 5 of the extension of the Florida reef as
far north as Hillsboro River is not convincing. An occasional coral does
not mean a coral reef; besides " Manicina" areolata is, according to my
experience with Florida corals, not a reef coral, strictly speaking. Its
habitat is on protected flats. The species cited, when found alone, rather
indicates the absence of a reef.

The water over the reefs is always shoal. The following table, com-
piled from United States Coast Survey charts, gives the names of the
principal reefs from Fowey Rocks southward, and the depths of water
over them. It shows that the reefs occur between water-level at low
tide and depths of 18 to 20 feet. The reefs, as already stated, are discon-
nected, with passages a few fathoms — usually 9 to 12 feet, always less
than 10 fathoms — between them.

Name.

Depth
in feet.

Name.

Depth
in feet.

1 to 9
3 15
5 12
3 11

2 18

* 16

Pickles Reef

1 4

2 8

6 8

Conch and Little Conch reefs. .

3 8

1 Report on the Florida Reefs, Mus. Comp. Zool., Memoirs, vol. vn, 1880.

2 Three Cruises of the Blake, vol. 1, Chapter m, 1888.

3 Op. til., p. 16.

4 Probably Cladocora.

5 Mus. Comp. Zool., Bull., vol. 16, p. 148.

110 Papers from the Marine Biological Laboratory at Tortugas.

THE HAWK CHANNEL.

Behind the keys is an open-water channel, known as Hawk Channel,
having shoals from place to place in it and extending from the upper
end of the series of reefs to the Marquesas. Its maximum depth is from
5.5 to 6 fathoms, and its width varies from 3 to 7 miles. The landward
boundary is formed by the main line of keys.

THE KEYS.

The Florida Keys are a series of islands rising slightly, a maximum
of 10 to 12 feet above tide-level, forming a curve paralleling the reefs,
bounded by the landward side of the Hawk Channel as far as the Marque-

Sfi&~:Z

Yig. 1. — Tortugas, East Key, west side looking north. Note vegetation
on the summit of the key.

Fig. 2.— Middle Key looking north along the axis. This key was washed
away during a storm on June 28, 1909, but was restored between
August, 1909, and May, 1910.

sas, and extending from the seaward face of Biscay ne Bay to the Tortu-
gas. In form these keys may be divided into three groups:

(1) The first group consists of long, narrow islands, stretching
along a gentle curve to the southwest from Biscayne Bay to Bahia

.4 Contribution to the Geologic History of the Floridian Plateau. 1 1 1

Honda Key. Key Largo, the largest, has a maximum width of about
3.5 miles and is about 27 miles in length.

(2) Beginning with Little Pine and No Name keys, the axis of elon-
gation is from northwest to southeast, or practically at right angles to
the first group. This group includes the keys between Bahia Honda and
Boca Grande, although one key, Key West, has its longer axis east and
west, and not north and south. The largest of these keys, Big Pine, has
the following dimensions: length 8 miles, width of southern end 2.375
miles, average width about 1.25 miles.

(3) The third group comprises the rather typical atoll of the Mar-
quesas and the less perfect one of the Tortugas.

In composition the keys represent four types:

(1) The most northern group, comprising Virginia Key and Key
Biscayne, has its surface composed of sands, largely arenaceous (plate 6,
figs, a and b).

(2) Those from Soldier Key to Bahia Honda inclusive and the
southern end of Big Pine are elevated coral reef rocks (plate 15, figs.
b and c).

(3) The group from Little Pine and No Name to Boca Grande are
formed of oolite, the Key West oolite (plate 14, fig. c; 15, fig. a).

(4) The Marquesas and the Tortugas show on their surfaces the
more or less comminuted remains of the calcareous skeletons of organ-
isms, mollusks, corals, nullipores, etc. (plate 6, fig. c; 7, figs, a and b,
and text figs. 1 and 2).

THE BAYS AND SOUNDS BEHIND THE KEYS.

The landward face of the keys is bounded by a series of bays and
sounds, beginning at the north with Key Biscayne, followed, going south-
ward, by Card, Barnes, Blackwater, and Hoodoo sounds, and terminated
westward by the Bay of Florida.

Biscayne Bay has a more pointed northern end, bounded on the
eastward by a sandy spit of land, Virginia Key, and Key Biscayne,
between which are passages. Its southern portion is wider, bounded
on the east by Sands, Elliott, and Old Rhodes keys, and has an obtuse
termination before communicating with Card Sound, to the south.
The length of this bay is 35 miles, maximum width 10 miles, maxi-
mum depth 17 feet. Featherbed Bank extends across its median portion
and makes two divisions.

Card Sound has its northern end almost opposite the northern end
of Key Largo, toward which point is a projection from the mainland; its
southern end is formed by a spur projecting from Key Largo toward
the mainland. The length of this sound is 6 miles, width 3 to 3.5 miles,
maximum depth 12.5 feet.

Barnes Sound has as its northern boundary the spur from Key
Largo, forming the lower end of Card Sound; its southern boundary is
formed by projections from Key Largo and the mainland. Its length
is 6.5 miles, width 5.5 miles, maximum depth 11 feet.

Blackwater Sound is south of Barnes Sound, and has its northern
boundarv determined by the features forming the southern boundary

112 Papers from the Marine Biological Laboratory at Tortugas.

of the latter. Its lower boundary is formed by spurs from the mainland
and Key Largo. This sound is quadrangular in outline; length 4 miles,
width 3.5 miles, maximum depth 9 feet.

Hoodoo Sound is a small body of water lying within the western
part of the spur of Key Largo, which forms the southern boundary of
Blackwater Sound. It has a length of 1.5 miles, width 0.5 mile, depth
8.5 feet.

Florida Bay is of cornucopia shape, with its narrower end at the
western outlets of Blackwater and Hoodoo sounds. The width of the
upper end is about 10 miles; it opens toward the west and is 27 miles
wide south of Cape Sable. The water also deepens toward the west
from 4 to 7 feet, at its upper end, to 10 to 12 feet between Cape Sable
and Key Vaca; farther westward it deepens to 12 to 14 feet, and then
gradually slopes to the 10-fathom line in the Gulf.

Keys, Mud Flats, and Shoals in the Bays and Sounds. — Here it need
only be mentioned that behind the main keys and betweeen them and
the mainland are keys mostly overgrown with mangroves, mud flats
exposed at low tide, and shoals built almost to water-level. The axes
of these keys and banks trend from north to south, at right angles to
the main keys, which are elongated from northeast to southwest. Their
origin will be especially discussed in succeeding pages.

To summarize the features occurring between the 10-fathom curve
and the shore of the mainland, there are:

(1) The reefs lying just inside the 10-fathom curve.

(2) The Hawk Channel, separating the reefs from the main line of

keys, varying in width from 3 to 7 miles and having a maximum
depth of 5 or 6 fathoms.

(3) The main keys.

(4) The bays and sounds separating the keys from the mainland.

RELIEF OF THE MAINLAND.

In the following remarks the physiography of the mainland will
not be treated in detail, the purpose being to consider the land surface
as only a subaerial portion of the more extensive Floridian Plateau.
Matson and Clapp have compiled a topographic map of the State, with
50-foot contour intervals. This map, although it does not claim to be
without minor inaccuracies, gives the best available information on the
relief of the land surfaces. (Plate 1, the subaerial topography.)

Florida is a land of low relief, perhaps two-thirds of it lying below
the 50-foot contour. This line extends far up St. Mary's River on the
northern boundary of the State, whence, proceeding southward.it passes
about 9 miles west of Jacksonville and through Palatka on the west side
of St. John's River. On the east side of the latter river, from just below
Palatka to the latitude of Lake Monroe, it circumscribes a ridge. It
continues down the west side of St. John's River, extending up its tribu-
taries and passes well to the north of Lake Okeechobee, at least 15 or 20
miles. On the western side of the Peninsula it lies above the level of
Arcadia on Peace River; it passes around the head of Tampa Bay, thence

A Contribution to the Geologic History of the Floridian Plateau. 113

northward to Dunnellon at a distance of from 5 to 12 miles from the
coast; thence it bends to the northwest and west, keeping from 10 to 25
miles from the shore in the interstream areas, while it digitates up the
various rivers and other streams.

If Florida were depressed 50 feet the greater portion of the Penin-
sula would be submerged — or most of Florida is less than 10 fathoms
above sea-level.

The 100-foot contour is not a continuous line around the whole
Peninsula, but circumscribes disconnected areas. One of these areas
lies west of Kissimmee River, extends from Summit in Marion County
southward to near Zolfo Springs in De Soto County, and has its western
boundary determined by Hillsboro and Withlacoochee rivers.

There is another ridge, rising above 100 feet, between Dunnellon
and Dade City on the west coast. Between Dunnellon and Hawthorne
are other but isolated areas above the 100-foot level. From Gainesville
northward, lying between the valleys of St. John's and Suwanee rivers,
is another area above this level. West of the Suwanee River the 100-
foot contour is present on all interstream lobes.

If Florida were depressed 100 feet there would remain of the present
land surface of the Peninsula four large and a number of smaller islands.

The 1 50-foot level is attained in each of the four areas surrounded
by the 100-foot contour. Haines City is situated on a ridge extending
southward from near the northern boundary to near the southern boun-
dary of Polk County. West of Dade City is another ridge over 150 feet
in elevation. Between Dunnellon and Hawthorne are isolated peaks
above this level. Between St. John's and Suwanee rivers on the north
considerable areas are circumscribed by this contour.

The areas circumscribed by the 200-foot contour are much smaller.
Haines City, De Soto County, is located on one of them, and south of
that town the map indicates five others on the north and south ridge
through Polk County. Four hills over 200 feet in altitude are in northern
Pasco County, west of the longitude of Dade City. The only other 200-
foot elevation on the Peninsula is the Trail Ridge, along the north and
south boundaries of Baker-Duval and Bradford-Clay counties.

The only 250-foot elevation indicated on the Peninsula by the map
is south of Haines City in central Polk County.

If the Floridian Plateau were depressed 250 feet (about 42 fathoms)
only one small island, about 5 miles long and 2.5 miles wide, situated
in central Polk County, would remain of the present land surface of the
Peninsula. If the 100-fathom curve is taken as the submarine limit of
the Floridian Plateau, it immediately becomes evident that in vertical
measure the submarine exceeds the subaerial portion by 58 fathoms;
or iff is below water, while yyV is above water.

In the preceding account, the remarks have been confined to the
relief of the Peninsula of Florida, as the westward extension belongs
more properly to the continental mass forming the northern boundary
of the Gulf of Mexico. In this portion of the State there are higher ele-
vations than on the Peninsula; at Mount Pleasant is a small area over
300 feet in elevation, and considerable areas are above 250 feet. Mossy -
8

114 Papers from the Marine Biological Laboratory at Tortugas.

head is 264 feet above tide, and near the Alabama line some localities
may be somewhat higher, small areas perhaps exceeding 300 feet.1

Before leaving the subject of the relief of the subaerial portion of
the Plateau, two features should be mentioned. All areas delimited by
contours above the 50-foot lie to the west of St. John's and Kissimmee
rivers and north of the latitude of Sarasota. Most of the lakes of the
State occur in the more elevated region, or along its western or southern
periphery. This distribution of more elevated areas, particularly with
reference to drainage lines, will be discussed subsequently.

MARINE BOTTOM DEPOSITS FORMING IN THE BAYS AND
SOUNDS BEHIND THE KEYS.

During the latter part of April, 1908, I went from Miami to Key
West on the yacht Physaha; and also made a short excursion from Miami
to Cat and Gun keys of the Bahamas. The route followed from Miami
to Bahia Honda Key was that known as the "inside passage," but
several short side-excursions were made outside the main line of the
keys in a smaller launch. One object of making the trip within the main
line of the keys was to procure bottom samples, particularly for ascer-
taining the nature of the deposits now being laid down behind the keys.

The specimens were procured by attaching a cup to the bottom
of the sounding lead; they were then put into glass bottles with screw
tops and brought to the laboratory for more detailed investigation.
The material after arriving in the Geological Survey office was placed in
the hands of Mr. G. C. Matson for examination. His report is given on
subsequent pages.

For convenience of discussion the material will be described from
(1) Biscayne Bay, (2) Card Sound, (3) Barnes Sound, (4) Blackwater
Sound, (5) Hoodoo Sound, (6) Florida Bay, (7) Material from Cat and
Gun keys, Bahamas.

A few beach specimens will be discussed in connection with the
bottom deposits of the neighboring waters, and in a similar connection
a few bottom specimens obtained from the outside of the keys will be
considered.

1 G. C. Matson, Preliminary Report on the Geology of Florida, Fla. Geol.
Surv., 2d Ann. Report, p. 30.

PLATE 2

MAP OF FLORIDA KEYS, ON WHICH ARE SHOWN THE STATION NUMBERS
OF THE BOTTOM SAMPLES

A Contribution to the Geologic History of the Floridian Plateau. 115

List of Localities from which Bottom Samples were Obtained.
(See plate 2, localities platted on the map.)

Spec-
imen
No.

25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45

46

47

Locality.

Junction of the two canals off mouth of Miami River

Oolite from dredged canal to main ship channel in Biscayne Bay

Midway between main ship channel and West Point, Key Biscayne, between buoys

Depth.

Feet.

7 and 4.
Northern end of Key Biscayne, Bear Cut, Biscayne Bay

Opposite West Point, Key Biscayne, Biscayne Bay 13

Off eastern shore of Cat Key, south of passage between it and Gun Key (Bahamas) . 9

Off eastern shore of Gun Key, north of passage between it and Cat Key (Bahamas) . About 12

Calcareous sand from shore, above tide, eastern face of Gun Key (Bahamas)

Calcareous beach sand, western face of Cat Key (Bahamas)

Mainland north side of New Cut, Biscayne Bay

North side of Norris Cut between Biscayne Bay and ocean

Northeastern corner of Key Biscayne 2.5

South of eastern end of Featherbed Bank About 8

Lower Biscayne Bay, deepest portion, southwest of Sands Cut 12

West of Rubicon Key, off mouth of Caesar Creek, lower end of Biscayne Bay 11

0 .5 mile west of inner end of Caesar Creek, lower end of Biscayne Bay 9

Off eastern end, western side of Elliott Key, 50 feet offshore 2 to 4

Hawk Channel, off mouth of Broad Creek, 2 miles offshore 18

o . s mile east of mouth of Angelfish Creek 12

Northern end of Card Sound, inner end of Broad Creek About 9

Card Sound, west of Pumpkin Key, about 200 feet offshore 12

Card Sound, southwestern end, 0.5 mile west of Key Largo, and 0.5 mile north of

spur at lower end of the Sound About 10

Steamboat Creek, between Card and Barnes sounds 12

Barnes Sound, near mouth of Steamboat Creek About 12

Barnes Sound, center of the Sound 1 1

Blackwater Sound, upper end, off mouth of Jewfish Creek 12

Blackwater Sound, 0.5 mile northeast of Bush Point 9

Lower end of Hoodoo Sound About 6

Bay of Florida, entrance from Hoodoo Sound 9

Bay of Florida, shoal, 2 miles northeast of Pigeon Key 1

The material composing Pigeon Key

Off inner end of Ta vernier Creek 7

Shoal southwest of Tavernier Creek about a mile off Long Island 1

On Line between McGinty and Torrey keys 6

1 mile northwest of Shell Key 9

Southwestern end of cut across the bank south of Bowlegs Key

2.25 miles northwest of upper end of Long Key 6

1 mile west of north of western end of Long Key 6

1. 25 miles north and east of end of Grassy Key 12

1 mile N. N. E. of Bamboo Key 9

0.75 mile north of eastern end of Stirrup Keys 9

1 mile northeast of the western end of Key Vaca ! 6

0.5 mile S. E. of Porpoise Key 4

0.25 mile W. N. W. of northern end of No Name Key 9

Middle of channel between No Name and Big Pine keys opposite middle of No

Name Key j 9

Eastern shore of No Name Key, opposite middle of island, 100 to 200 feet offshore. . 2.5
0.75 mile north of Bahia Honda Key I 12

BISCAYNE BAY.

From the vicinity and bottom of this bay thirteen samples, including
a few beach specimens and one off the northeast corner of Key Biscayne,
were obtained. These specimens are Nos. i to 5 and 10 to 17 of the list.

Specimen No. 2 and some dredged material obtained in digging the
canal from Miami to New Cut, which crosses the southern end of the cape
east of Miami, show that the Miami oolite extends beneath the northern
end of Biscayne Bay and at least partially forms its floor.

Specimens collected on the north side of New Cut (No. 10) and on
the north side of Norris Cut (No. 11) are composed of calcareous and
siliceous constituents. There is at both localities a considerable amount
of fine quartz sand.

Specimen No. 4, which comes from the northern end of Key Bis-
cayne, Bear Cut, contains an abundance of quartz mixed with shell

116 Papers from the Marine Biological Laboratory at Tortugas.

fragments and amorphous carbonate of lime. The special point in call-
ing attention to the specimens from the southern end of the cape on the
east side of Biscayne Bay and from the two succeeding keys to the
south, Virginia Key and Key Biscayne, is to emphasize the presence on
them of a large proportion of quartz sand. Cape Florida, which is the
southern extremity of Key Biscayne, has its surface covered by siliceous
sand with an admixture of comminuted shells.

Soldier Key, the next key to the south of Cape Florida, has on its
summit and western side a coating of siliceous sand underlain by elevated
coral reef rock. Proceeding southward along the main line of keys the
siliceous constituents progressively diminish.

Attempts were made to obtain bottom samples at two places on the
east side of Key Biscayne, but in both instances the bottom was hard and
no specimens were procured.

Three bottom samples were obtained from the northern end of
Biscayne Bav, Nos. i, 3, and 5. Specimen No. i, which was collected
a short distance off the mouth of the Miami River, showed shell frag-
ments, amorphous carbonate of lime, much quartz sand, sponge spicules,
and diatoms. The presence of quartz sand is to be expected, as it forms
the surface coating over the Miami oolite of the surrounding country.
Specimen No. 3, which was taken between the mouth of the Miami River
and the western point of Key Biscayne in about 12 feet of water, was
composed mostly of shell fragments and amorphous carbonate of lime,
with very little quartz. Specimen No. 5, which was taken in about 13
feet of water off West Point, Key Biscayne, was also composed of shell
fragments, amorphous carbonate of lime, and considerable quartz, with
some sponge spicules and diatoms.

One specimen, No. 12, collected from the northeast corner of Key
Biscayne, depth 2.5 feet, contained shell fragments, calcite, amorphous
carbonate of lime, and considerable fine quartz, the quartz passing
through the 40 and 80 to the inch mesh sieves, showing some silica on
the sea floor east of this key. The bottom off the southwest corner of
Key Biscayne consists of calcareous ooze and comminuted shells.

Five specimens, Nos. 13 to 17, were obtained from the southern end
of Biscayne Bay, from the latitude of Sands Key southward. An inspec-
tion of Mr. Matson's table will show that most of the material is fine;
by far the larger portion passed through the 40-mesh sieve but was
retained by the 80. Quartz is abundant in No. 13, and there is some in
Nos. 14, 15, and 16. In No. 16, however, the siliceous component is
comparatively small in amount, while in No. 17 fine quartz, all of which
passes through No. 80 sieve, is rare.

These observations on the bottom deposits of Biscayne Bay indicate
that considerable quartz is being washed into the northern end of the
bay, and that as one proceeds southward the calcareous constituents
become predominant, while the siliceous constituents become insignifi-
cant. The material, when collected, consisted mostly of oozes and no
intimation of the formation of oolite was observed.

.4 Contribution to the Geologic History of the Floridian Plateau. 117

BETWEEN OLD RHODES BANK AND CARYSFORT REEF LIGHT.

Two specimens, Nos. 18 and 19, were collected between Old Rhodes
Bank and Carysfort Reef Light. Both of these specimens consisted
mostly of shell fragments, amorphous carbonate of lime, sponge spicules,
diatoms, and a very little quartz. In this region quartz is rare outside
the main line of keys.

CARD SOUND.

Three specimens were collected from this sound, Nos. 20, 21, and
22, and one, No. 23, was taken from Steamboat Creek between Card and
Barnes sounds. Nos. 20 and 21 both contained considerable quantities
of quartz as well as shells, shell fragments, amorphous carbonate of lime,
sponge spicules, and diatoms. In No. 22, however, quartz was rare.
Specimen No. 23 from Steamboat Creek consisted mostly of organic
matter with some amorphous carbonate of lime, sponge spicules, diatoms,
and a very little quartz.

BARNES SOUND.

Only two specimens were taken from Barnes Sound, the first, No. 24,
near the mouth of Steamboat Creek, at a depth of about 12 feet; the
other, No. 25, near the center of the sound, depth about 11 feet. Speci-
men No. 24 in Mr. Matson's table is queried and perhaps should be
omitted from the discussion. No. 25 consists mostly of shells, shell
fragments, amorphous carbonate of lime, sponge spicules, and diatoms,
with very little quartz, indicating a progressive diminution of quartz
toward the southwest.

BLACKWATER SOUND.

Two samples, Nos. 26 and 27, were obtained from this sound. No.
27, it appears, was lost. No. 26, which was taken from the upper end of
the sound off the mouth of Jewfish Creek, depth 12 feet, consisted
of organic matter, shells, shell fragments, calcite and aragonite, sponge
spicules, and a little quartz was retained by sieves Nos. 40 and 80.
Material thrown out of a canal dredged between Blackwater and Hoodoo
sounds was similar to that forming the bottom of the neighboring sounds,
except molluscan remains are so abundant as to constitute a shell marl.

HOODOO SOUND.

This is a small sound between the lower end of Blackwater Sound
and Florida Bay. One specimen, No. 28, was obtained from it at a
depth of about 6 feet. The material was similar to that from Black-
water Sound with somewhat less quartz.

FLORIDA BAY.

Specimens Nos. 29 to 47 were taken from Florida Bay. Nos. 39 to
42, and No. 47, were procured on the north side of the k'evs elongated
in a northeast-southwest direction. Nos. 43 to 46 were collected along
the group of keys lying slightly to the west of Bahia Honda and
elongated in a northwest-southeast direction.

North Side of Key Largo. — Nos. 29, 30, and 32 were obtained north
of Key Largo in depths ranging from 1 foot to 7 feet; No. 31 is from

118 Papers from the Marine Biological Laboratory at Tortugas.

the surface of Pigeon Key. The material in general was similar in com-
position, except the quantity of shells and shell fragments varied. Only
one sample, No. 31, which is the surface material of Pigeon Key,1 con-
tained any quartz. No. 32 was taken off the inner end of Tavernier
Creek, which forms the lower limit of Key Largo.

North of Long Island. — One sample, No. 33, was collected on the
shoals northwest of Tavernier Creek, about a mile off Long Island.
The material consisted of shells, amorphous carbonate of lime, sponge
spicules, and diatoms; no quartz was noticed.

North of Upper Matecumbe. — Between McGinty and Torrey keys one
specimen, No. 34, was obtained. It consisted of shell fragments, amor-
phous carbonate of lime, sponge spicules, diatoms, and some calcite,
and in the material retained by sieves Nos. 80 and 100 considerable
quartz was observed in the 22.9 per cent of the total weight of the sample
examined. This sample shows that quartz has worked its way as far to
the southwest as a point nearly opposite the lower end of Upper Mate-
cumbe Key. The bottom of the channel southwest of Shell Key is swept
clean by the currents passing between Upper and Lower Matecumbe keys.

North of Lower Matecumbe. — Two samples, Nos. 35 and 36, were
obtained on the north side of this key: No. 35, a mile northwest of Shell
Key; No. 36, the southwestern end of the cut across the banks south of
Bowlegs Key. Both specimens consisted mostly of shell fragments,
amorphous carbonate of lime, sponge spicules, and diatoms, with very
little quartz.

North of Long Key. — A specimen, No. 37, obtained from 2.25 miles
northwest of the upper end of Long Key, consisted mostly of calcareous
material with sponge spicules and diatoms. There was very little quartz
and a few calcareous oval grains. There is some doubt about the identi-
fication of the specimens from localities 38 and 39 and they are omitted
from the discussion. However, the bottom a mile west of north of the
western end of Long Key is hard, being swept almost clean by currents
passing between Long and Grassy keys. The bottom material north of
Grassy Key is a calcareous ooze with a little quartz (field examination).

North of Key Vaca. — Specimens Nos. 40, 41, and 42 were collected
along the north side of this key. The material .consisted of shell frag-
ments, amorphous carbonate of lime, sponge spicules, and diatoms.
There were a few oval grains in specimen No. 40 and a very little quartz
in each of the three. The bottom between Key Vaca and Bahia Honda,
midway between Molasses and Duck keys, depth 9 feet, is hard and
covered by a thin coating of shells and shell fragments.

North of Bahia Honda. — Specimen No. 47 was obtained 0.75 mile
north of this key in a depth of 12 feet It consisted of shell fragments,
amorphous carbonate of lime, sponge spicules, diatoms, and a very little
quartz. Bahia Honda is the westernmost of the main line of keys with
a northeast-southwest trend.

No Name and Big Pine Keys. — Four specimens, Nos. 43, 44, 45, and
46, obtained in this vicinity, consist mostly of calcareous material with
some sponge spicules and diatoms. Oval grains were in three specimens,

1 This is important in indicating the southward extent of surficial quartz.

A Contribution to the Geologic History of the Floridian Plateau. 119

Nos. 43, 45, and 46, and these specimens also contained a small propor-
tion of quartz.

The bottom samples show that quartz is disseminated over the
entire area of the bottom of Florida Bay; however, in comparison with
the calcareous constituents the proportion of quartz in the southwestern
corner of the bay is extremely small.

GUN AND CAT KEYS, BAHAMAS.

Four specimens, Nos. 6 to 9, were obtained from the sea-bottom
and the beaches of these two keys for purposes of comparison with
the material from the Florida keys. Specimens Nos. 6 and 7 were,
respectively, from the eastern shore of Cat Key, south of the passage
between it and Gun Key, and off the eastern shore of Gun Key, north of
the passage between it and Cat Key. The material consisted of shell
fragments, amorphous carbonate of lime, sponge spicules, and diatoms,
also a little aragonite and calcite. Specimen No. 6 contained a little
quartz which did not pass through mesh No. 80. This material is veri-
similar to that from the region of Key Vaca and Bahia Honda, with
perhaps a smaller quantity of quartz. Specimen No. 8 was from the
eastern shore of Gun Key, above tide, and No. 9 is beach sand from the
western face of Cat Key. This material was similar in composition to
that taken from the bottom except no quartz whatever was observed.
It should be noted that specimens Nos. 6, 8, and 9 all contained oval
grains of amorphous carbonate of lime. The nature of these grains will
be alluded to in the comparison of the lithologic specimens from the
Bahamas with those from the vicinity of the Miami and Key West oolites.

SUMMARY OF DATA ON THE MATERIAL OF THE DEPOSITS.

The material at present being laid down inside of the keys consists
mostly of silica and carbonate of lime. Silica is abundant in the form
of sand in the northern portion of Biscayne Bay, it becomes rarer toward
the southwest, and is present in small quantities as far as Big Pine Key.
Toward the southwest, as the siliceous material becomes rarer, calcium
carbonate becomes progressively more abundant, occurring as a flocculent
sediment or ooze over practically the entire region from the lower por-
tion of Biscayne Bay to the gulf end of Florida Bay.

120 Papers from the Marine Biological Laboratory at Tortugas.

REPORT ON EXAMINATION OF MATERIAL FROM THE SEA-BOTTOM
BETWEEN MIAMI AND KEY WEST.

By George Charlton Matson.

" The accompanying table gives the results of physical and micro-
scopic examination of the sea-bottom materials obtained among the
Florida keys. The physical examination was made by passing the ma-
terial through standard sieves having respectively 20, 40, 80, 100, and
200 meshes to the inch. The percentage of each sample remaining upon
the different sieves and the percentage which passed through the 200-
mesh sieve were determined by weight. Before sifting, the material
was carefully ground in a mortar to separate the grains which were aggre-
gated, care being exercised to avoid crushing the individual grains. In
this work considerable difficulty was experienced with the finer-grained
specimens because the grains adhered to each other with such tenacity
that it was hard to separate without pulverizing them.

"After grinding, a sample was taken for sifting. In order to have
the results of the examination of the different specimens comparable,
samples of as nearly uniform size as possible were used ; the weight of the
samples being fixed at 13 grams. In dealing with samples so small, it was
necessary to use an accurate balance, because an error of one-tenth of a
gram would amount to nearly 1 per cent. For this reason a chemical
balance was used, and the weights were determined to thousandths of a
gram. The percentage of the material of different sizes was computed
from the weights.

"The microscopic study included an examination of each sample
after sifting. This examination was made by mounting the material in
water and studying it with a petrographic microscope. It was found that
the coarse material consisted largely of shells and shell fragments and
that amorphous lime carbonate formed a large percentage of most of the
samples which passed through the 40-mesh sieve. A few specimens
were composed of almost pure quartz sand and this material was found
in smaller quantities in specimens from nearly all of the localities.

" Calcite and aragonite in the form of small fragments were present
in many specimens and in two cases spherules of chalcedony were ob-
served. Some of the specimens contained oval grains of carbonate of
lime which may possibly have an oolitic structure, though such slides
as we now have show nothing but aggregated calcite in a finely divided
state.

" Sponge spicules and diatoms were noted in many cases and they
are probably to be found in all cases where there is amorphous carbonate
of lime, but they were seldom detected without first dissolving the lime
in acid. After treatment with acid there was a gelatinous residue which
blackened on exposure to the air. It is doubtless organic matter of some
sort." (For a list of the localities by numbers see p. 115 ; see map, plate
2, on which the localities are platted.)

.4 Contribution to the Geologic History of the Floridian Plateau.

121

^

*

^

^

48

Per cent and

description of ma-
terial passing 200-
mesh sieve.

1.1 p. ct. About 0.3
quart z, remainder amor-
phous carbonate of
lime, sponge spicules
and diatoms.

0

0

_
d

13. S p.Ct. Chiefly quartz
some amorphous car-
bonate of lime, sponge
spicules and diatoms.

22.0 p. el . Amorphous
carbonate of lime,
quartz rare, sponge
spicules and diatoms.

15.9 p. ct. Amorphous
carbonate of lime,
sponge spicules and dia-
toms.

oc •-

w 0

0 —
M c

3 -

u

.'5

*> 0

0 u

a

■ u
Z- -

*> E •-'
0 r -
«co 0

O
O

s -

-
0

- =

r.x:

si

Per cent and
description of mate-
rial retained on
200-mesh sieve.

8.8 p. Ct. Chiefly quartz
sand, some amorphous
carbonate of lime sand,
sponge spicules and

diatoms.

,

0
0

0

0

d

n .

tf £■

a °"

°>

>■ ~
tC O .
Oj3 "

x ^E
-: =

si's

u
c. ■<->
Z'~~

<?E c
- 0 0

• 1. < p. ct . Amorphous
carbonate of lime sand.
Quartz o.in of whole.
Sponge spicules and

diatoms.

19..1 p. ct. Amorphous
carbonate of lime, ara-

gonite, diatoms and
sponge spicules.

0

CO

u

3
0

W5

0

0
CO

d
0'

d

—

CD

6

Per cent and
description of mate-
rial retained on
1 00- mesh sieve.

19.2 p. ct. Chiefly quartz
sand, some amorphous
carbonate of lime sand.

10.5 p. ct. Amorphous
carbonate of lime sand.
Quartz rare. Sponge
spicules and diatoms.

See 80. Amorphous car-
bonate of lime and
quartz about equal pro-
portions.

M — :

0 5 •

x ■* -^
dc 8

"-r -
0 ^ =

H -

9.9 p. ct. Amorphous
carbonate of lime. Some
crystalline, diatoms and
sponge spicules.

j i .7 p. ct. Like 80.

24.2 p. ct. Like 80, with
much calcite, diatoms
and sponge spicules,

6

3

d
d

Per cent and
description of mate-
rial retained on
80-mesh sieve.

47.3 p. ct. Amorphous
carbonate of lime sand
0.75, quartz sand 0.25.

0 s

x s
q a

? °

1J

. : E

- - -

c — -

"- d -,

- J _•

° 5

h«C

m

<**

u i) ™.

°te °

d = 5

2 •-

— -

>-• b 3

O

CO

ca

(U

E

ca
CO

0
d
q

35.9 p. ct. Amorphous
carbonate of lime —
smooth oval grains.
Quartz rare.

si.6 p. ct. Amorphous
carbonate of lime sand,

e spicules and dia-
toms.

44.2 p. ct . Some shells,
most ly oval grains. Am-
orphous carbonate of
lime,

0

3

0
&

0

Per cent and
description of mate-
rial retained on
40-mesh sieve.

1 1.6 p. ct. Amor-
phous carbonate of
lime sand and shell
fragments. Quartz
sand common.

6
a

0

E

0

w

p

a

E

60

ca

w

0

at

l-r

ca

E

0

CO

1 1.6 p. ct. Shell frag-
ments and amor-
phous carbonate of
lime sand. Quartz
rare,

fcc c

<tS.o

„ ca

"3 si

x .S

co jj

• 3

0 ^

dm ■

;:"
. ; oj S

- -.
- = —

12.8 p. ct. Amor-
phous carbonate of
lime sand. Quartz
common.

0

CD
3

d

0 ^

".5

o'ca

cd

>

*$

.si .

a w

i*ss

S §c

r-o S

36.1 p. Ct. Amorphous
carbonate of lime,
mostly oval.

Per cent and
description of mate-
rial retained on
20-mesh sieve.

1 2 p. ct. Shells, amor-
phous carbonate of
lime.

p
ca

-S c

CO 0

E

_' DC

00 "3

60
od

Ih

"2

X
CO

0

-1

OCD

^E

-a

p

CS

2 -

X d

co £

=

- ~

" 1-

P.-H

"Si

•0
G

ca

*3 m

x e

CO <u

E

« M

°g

r-"3

1 CO

X -

ca 0

.'"X .

^i

•" c -
0 ca 2

0.™ 2

° " ca

, v.
tc 3

ca 0
.*- x •

"a!
s u p

a c —

- EZ

CO r-

** cti
0 ca *

« c

- „ c

tut

dEg

to
ca
u

*5

X
CO

0

■ 09

P

dE

Weight
of

sample
(grams).

00
0

00

0
0
0

00

0

00

0

0
0

O

0
0
0

0
0
0

Spec-
imen
No.

»

"

^

•<t

«

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-

00

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122

Papers from the Marine Biological Laboratory at Tortugas.

Per cent and
description of ma-
terial passing 200-
mesh sieve.

6 03

8^

•a

|S

. CD

0. M , A

r, 0 E

4&5

0

a

On
—

7.7 p. ct. Amorphous
carbonate of lime,
organic matter, sponge
spicules and diatoms.

S.i p. ct. Amorphous
carbonate of lime,
quartz rare, sponge
spicules and diatoms.

8.2 p. ct. Amorphous
carbonate of lime, with
sponge spicules and dia-
toms.

15.8 p. ct. Amorphous
carbonate of lime.
Quartz rare, sponge
spicules and diatoms.

d
0

CD

+^
0

d
-0

ON

4-> N

0 3

■<* a"

CD -
^^

3-S

0

■ be

«2

a

CD .

co 0 as

Per cent and
description of mate-
rial retained on
200-mesh sieve.

3.2 p. ct. Amorphous
carbonate of lime sand.
Quartz common.

0

0

CD

M

rJ

O

d
6

1 ID

i3E
E-

u

0 «

•■S nl

no a t,

d

0

8.3 p. ct. Amorphous
carbonate of lime,
organic matter, sponge
spicules and diatoms.
Quartz 0.25.

7 p. ct. Amorphous car-
bonate of lime 0.8,
quartz 0.2, sponge spic-
ules and diatoms.

1°
a cd
SE

. CD ".
. C N

•a b

"^ 3
00 0 O1

is?

-G O

a CD

0 3

gs

O ^

4J CD ".

0t«o

Q. 3 N

o+j
0 « E

MOO*

14.3 p. ct. Amorphous
carbonate of lime, most-
ly oval grains. Diatoms
and sponge spicules.

O
■u' cd'

us

. l-c

Tea

cy> 3

- 0*

Per cent and
description of mate-
rial retained on
100-mesh sieve.

.2 c —

u 0 5
S-13 e

+>' 0 O

aiH -

0 CD

^SE

inca;3

3^

0. M <A

0 g ".

S^°

°o

• CD.O
0 rt d

s N

dot

£> o3

«JS

r- a!
°g

N j5

tjjd

CO 03 O

4J

u

d

5|

a

u

0

1°

O ta .
3 N

dot

■2 S

3 "?

.2°

a cd

s§

E"
<S _

4J- CD ">

dS.2

wo.O. b
mod1

3 '?

Z°

SE

E"
<•£ ^

+j CD ^
°rt O

do£

0 as 3

M CJ C

3^>*
2°

a cd

oS

E —

<-s _

+o' CD "*

■»cl3

M CJ O"

d

00

CD

0

d

3
0

3 N

d cd

Ih

mo

00 E

Per cent and
description of mate-
rial retained on
80-mesh sieve.

3 "2

■§§»

a M 0

Hi

*j DM
O "^ «

a! O

dg_S
wx> b

M rt E
>o 0 o"

1«

a<D g
0 E o"

^1

0 ta

dgi

cO cd 3
«^ 0 C

u ~

0 .

E^ °

< s

0

° 03 d

dg-2

t^J3 o3

•Art d
■=* oO

4->

CJ

d

ON
NO

CD CD
O 03
Sg

o-S

CM CIS

O

CD

. O

*>X (J

oaS
• 1- p

QOs
^r£c«
■on) 0

4_> U

u as
oS 0
3 m

>.o
°.E-

+^ c3 0
O

. a> 0
CWH +*

00 0

^r 03^1

S c c

_g "3 S
P-'ut

E-&

^ 0 a

jj CD "^

aS o*

O o3 03
tOO)

a
t-<
0

r°.

CD
^' « rt

• (3 N

O u

CN CJ<w»

38.1 p. c. Amorphous
carbonate of lime sand,
some oval grains.
Quartz rare.

0

■*

CD

d

NO_

On

Per cent and

description of mate-
rial retained on
40-mesh sieve.

22.9 p. ct. Amorphous
carbonate of lime
and quartz 0.2 of
whole.

15 p. ct. Amorphous
carbonate of lime
sand. Quartz about
0.1.

bo

03

Is

."aS
*J O
O .

HE

0

d

ON
CO

0

CD
O

d

ON
O

in -
d h

2°

&1
O.b

e^:

. CD c^

Srt°
• C N

a of
^ * E

MUtf

d on

o.S
c— '

< O .

. 0) M

•Cm
ao-e

■^1
H s S

MOD'

•O CD

05 3
33 O
CD .£

■b b

0 0 CO

iM

00 Em-i

M ai 0

d

CD

-t->
O

d

iio^
ca b

u- ca

'" 3
33 D*
CD .
J3 CD

tO.-S

0

4-i 03
O CJ

«£« _

o>C u

«E2

Per cent and
description of mate-
rial retained on
20-mesh sieve.

2.3 p. ct. Shell frag-
ments and amorphous
carbonate of lime.
Quartz rare.

i u

7> 0 'rt
.c-P 3

wis01

0 10 §

d°c

™J3 E

« as

so

03

u

TQJ

O
. w

a-^
a

NO CD

45

d
CO

6

0.9 p. ct. Chiefly
quartz, some organic
matter containing di-
atoms, &c.

M >A

go

^3 d
ai o1

4^ •
O O

d-^
c

1- CD

SO
as
u

0

« 3

Si

bo
as
u

"a!

J3
mE

BO
ai
u

"3

t72
O

d^

3

>0 CD

no'E

73 -a

3 3
03 0)

^ C
MS

E
u ca

^3J2

'tjs'ca

CM W O

Weight

of
sample
(grams).

0
0
0

CO

0
0
0

0
0

0

CO

0
0
0

0
0
0

CO

0
0
0

CO

0
0
0

CO

0
0
0

CO

0

00

00

CO

NO

8|d

0

»

s

CO

■c*

»o

CO

r~

00

On

A Contribution to the Geologic History of the Floridian Plateau. 123

o

s

£

^

^

•*» x:

Per cent and
description of ma-
terial passing 200-
mesh sieve.

0

0

4>

O
d

on p. ct. Amorphous
carbonate of lime,
quartz rare, diatoms
and sponge spicules.

d

0 u

« 1)

41 -jj

0

.'p

-^ a!
O M

d°

XI

o~

^ cti -

.§£
trag
. "-S

: = e
-II

0"
0

4)

'3

. 0

« HI

0 OS

u

. nl

~a

» E

-d 3

15. 2 p. ct . Amorphous

carbonate of lime.
Sponge spicules and di
atoms.

0
0

41

d
6

48 p. ct. Like 200.

Per cent and
description of mate-
rial retained on
200-mesh sieve.

t.2 p. ct. Amorphous
carbonate of lime, ara-
gonite. Quartz abun-
dant, sponge spicules
and diatoms.

0.6 p. ct. Amorphous
carbonate of lime.
Quartz common.
Sponge spicules and di-
atoms.

6

4>
4) £
^ 0!

3E

4)

0 M

. u

ao

11

£3

0

0

.a

4)

a
0

10.8 p. ct. Amorphous
carbonate of lime.
Sponge spicules and di-
atoms.

3
0
x;

a .

t- 4)

11

<•_

O

J :.
°-=

Q 3

- 2
nX

• t_

- u

- *^

s —

o'c
00 0

-.

8 -
TZ (-

_; B)

w 0

5.2 p. ct . Like So with
irtz.

Per cent and
description of mate-
rial retained on
100-mesh sieve.

1.1 p. ct. Amorphous
carbonate of lime with
considerable quartz.
Sponge spicules and di-
atoms.

.8 a

CV.-S

E°§

< 4)-g

^ 3
■ d 0

0 u as

•°,N
°"££

M. at 3

notf

7-7 P- ct. Chiefly amor-
phous carbonate of lime.
Much organic matter.
Sponge spicules and di-
atoms.

1 7- 1 P- ct. Amorphous
carbonate of lime and
organic matter, sponge
spicules and diatoms.

0

CO

4>

si

3 i

a

C
1°.

41

0 n V_

P N

d = r

o7So

0

*

0
a:

J

4)

d

,(.i p. ct. Like 80 with
aragonite.

Per cent and
description of mate-
rial retained on
80-mesh sieve.

15.8 p. ct. Amorphous
carbonate of lime 0.75,
quartz 0.25.

o'j°

d^-g

oVE>«
fo nj 0

ti 41°

0 p

t»o

sc 4<

x: c
°.S
tJ§
d«

. 0

MX

« a

25.7 p. ct. Like 40 but
nearly 0.5 amorphous
carbonate of lime.
Quartz very rare.

3 -'

i =

o«« c

E o_os

< <D c

+i «X!

oca
a ° .2

'fl.U
CT, a! 3

N OO

W 4/'

og

a~

u

0

1°.

4)
-J 4J .-;
'- - -

"*"£ rt

d n =

rs 3 1,
C 3^

S.S b

^ a 2

t- m 3

O <aO

60

'JaE

N4J*0

lo.i; p. ct. Amorphous
carbonate of lime.
Quartz rare. Sponge
spicules and diatoms.

Per cent and
description of mate-
rial retained on
40-mesh sieve.

27.2 p. ct. Amorphous
carbonate of lime and
quartz equal propor-
tions.

>>3,

.4} X

xi M

4)

E

• .p

as«

4>£ M

t cri!

22.2 p. ct. Shell, amor-
phous carbonate of
lime sand, quartz rare,
organic matter.

4.1 p. ct. Chiefly or-
ganic matter, some
amorphous carbonate
of lime.

•3 4)

5«

« c

w O

~X
<u ,_

XI OS

c/2 0

w

°.§ •

^e;z

« aS 0

5|
0.

t-
Ov-,

P s

< jj

do^

MX oS

d

4)

u as

djj

N OS

17.2 p. Ct. Shell frag-
ments and amorphous
carbonate of lime.

Per cent and
description of mate-
rial retained on
20-mesh sieve.

•a

c

a!

tfi

"3 <2

-P"B

€'!

• u

a>«

"~v
ro xj
1/1 w

M .

„ «

1-

W 4)

.E
->-> 0

0 tn
d w

— 4)

?E

ic
a!
t-

""cd
XI

O

a m
« c

41

c
0

T3
C
ai

"3 »>

• 6

"of

• u

a1—

Oxl

t7.3 p. Ct. Shells and
shell fragments.

•a

c

rs

W £
•E

2-?

_o

t/i

as
&
C

4)

_E
S -

4>

a
13

58.8 p. ct. Shells and
shell fragments.

Weight

of
sample
(grams).

r~

-0

ON

0
0

0

•s

0
0
0

m

0
0
0

"5

0

Spec-
imen
No.

O

3

a

7;

t

s?

S

t^

«

124 Papers from the Marine Biological Laboratory at Tortugas.

Per cent and
description of ma-
terial passing 200-
mesh sieve.

14. 1 p. ct. Amorphous
carbonate of lime, cal-
cite, aragonite. dia-
toms, sponge spicules.

d
00 B

D O
-*P

JE
. 0

0 ca

5$

. 0

in 60

« 03

Ih

<

6
0

0 4)

.0

00 00
m 03

d;i

00X

X
ca c
.* S

3g

"3

*» 2

0 §■
da, „•

to in

°°. o|

MM CS

6

00
0

0

d

'?

O
O

01

dS

f O

6
0

a

0
d

5.4 p. ct. Amorphous
carbonate of lime, cal-
cite. aragonite, diatoms
and sponge spicules.

6

0

ID

d

Per cent and
description of mate-
rial retained on
200-mesh sieve.

0

00

V

3£

cd
u

. >

c*3 D1

0

00

a

d

CO

0'

0

a)

A!

d

00

0

CO

u

d

00'

O

00

0

5.9 p. ct. Amorphous
carbonate of lime. Or-
ganic matter, sponge
spicules, and diatoms.

8.7 p. ct. Amorphous
carbonate of lime, cal-
cite, diatoms and
sponge spicules.

3

x>
0

CO

<u

d§

(fl 0

H C

0
0

<D

M

-p>
0

d
0

Per cent and
description of mate-
rial retained on
100-mesh sieve.

6

00

<D

M

0

d

0"

00
Qi

J

0

d
NO

to

8x1

X

3

0 a

»««

N c E

I05

"CO 03

0

00
a
M

0
d

On
0'

0

CO
<D

u

0.
H

3.8 p. ct. Amorphous
carbonate of lime.
Quartz abundant.
Sponge spicules and di-
atoms.

6.6 p. ct. Amorphous
carbonate of lime.
Some oval grains.
Quartz very rare.
Sponge spicules and di-
atoms.

0

CO

<l>

d

J3.i

.*3x

O P

00 ca

(D 0)
^J (D

0 m

dS°j
„pE

■go

" mta

Per cent and
description of mate-
rial retained on
80-mesh sieve.

13.2 p. ct. Amorphous
carbonate of lime, ara-
gonite, sponge spicules,
and diatoms.

£x

. X

_§ c
■2 *

3
• 0
o'o,

abow

„ C E

"CO a!

1"* •

_g ° >>

- - C

0 HX

<lS"2

-p-<D°

"-SX

• c P
e.§oj

""•■Si

« 0 0

22.8 p. ct. Amorphous
carbonate of lime, or-
ganic matter, diatoms,
and sponge spicules.

W <D

d'^-2
a; »3

-2 03

■p al w

0 to u

. oX

M.2

0 =0 i.
in o3 in

19. 1 p. ct. Amorphous
carbonate of lime 0.25,
quartz 0.75, sponge
spicules, and diatoms.

og

u

0

r°

aot-
ifl^Q ca

M oO

17.3 p. ct. Chiefly cal-
cite. Quartz rare. Dia-
toms and sponge spic-
ules.

0

T
<D

• ca

« ca

Ih

d «

u

>o ca
iAP

Per cent and
description of mate-
rial retained on
40-mesh sieve.

1 W

M3
$3 0

s&E

M ca 0
.X ca
0 rt g

d ™ 2
p^

M u c3

NO S O

U5 ■

§E

J- .3.

c~

Ih

On,

Eo

<

. V

0 "S .
• C 1>

e>£> o
' *-X
M oU

6

0

d

4

8 co

4> m

Hh3 .

JOO

•c e

d * »J

„.£ oi

■ 0 s

t- J; 0

o£ ■

JT.3X

c K

< 00

. <u 00
0 ta rt
• P >>

d

0

. 0

4-) u

O 03

Ih

d n

". (8

O 3

^•CT

a

Ih
2«H

E 0 .

•< J;
0 CO

•£ d

6-sX
■* oO

"SlH

P n)

lis

co-= E
0 g 0

■So

D. 03 jj
"J
M.X C
oCO
^f 03jO

24.9 p. ct. Shell frag-
ments. Amorphous
carbonate of lime and
a few oval grains.

Per cent and
description of mate-
rial retained on
20-mesh sieve.

M

0!

Ih

"3
.c

CO

0

d «
00 c

„: <u

«E

■a

p

c3
*ca j2

55 §

• E

*> 60

a.**-1

■ <U

5|

a

u

0*4-1

E° .

< t

•■8 2

d8^

-T b 3

o'gO

r- ^

05 c

01 O

3, .a

CD tn

x: nS

w °

in

. 3
-w 0

"is

vncj O

■95

d p
05 0

35J3
0) u

-C ca
co"

en

. 3

■u O

*CB^
<o 03 0

27.1 p. ct. Shell frag-
ments, amorphous
carbonate of lime (ag-
gregated).

03 £
«t! as

"3 N

CO o3
3

«o

0

Q. W

-P

co C

3S

2 0

•G P

MI'S

_; 4>
« tJ

^isg

r-302

?BS

14.9 p. ct. Shells and
shell fragments. Am-
orphous carbonate of
lime.

Weight

of
sample
(grams).

13 .000

O
0
O

0
0
0

O

?

0
0

0

0
0
0

t*3

0
0
0

0
0
0

CO

Spec-
imen
No.

29

O

to

l»!

tfi

«3

e«3

-4 Contribution to the Geologic History of the Floridian Plateau. 125

i
ki

s

^

£

^

^

Per cent and
description of ma-
terial passing 200-
mesh sieve.

3
0

J3

a .

£ <"

E°!
<Z
. 0

•4-> H

0 cd
. c

*l

0'
0

0
0

a

■4

d
0

0

d
to

0'
O

V

0
Q
00

O

&

o>

td
t-

td

0"
0

to
M

z ■:

Z-.ZZ

•:§
- -_

O'

00

to

§"=3

" —

— -

3

*-' z~
0 to
to .

Q IK) v.

-P P

h.&!

f.tZ) cd

ci
0

•-.

O

d

00

to
d

CO

m

Per cent and
description of mate-
rial retained on
200-mesh sieve.

o"

00

0

. t-
-M cd
0 1-

..S

" 3

od a

3 60

ogS

: -r
■ T =

O o

\o' O'n.
"Cm

4->

.Q
0
0

u cd

*3

" 0

T c

00^3

■a

0 c
^ td

3

0

•""5.

. <u .

C S£ w

1 vow cd

0"
0

to

O CO

d'B

0
oso

h cd

0'
0

to

O'

00

1/

i.E
a

- -/
= ._ 3
§ o'3
< •-

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• u 5

H - -

m coC/2

5E=-
x— 3 —
0, h p

B*S s

•< "cd 3

• to 0 a
«*> to

- 3

d 0 <o 3 2

^333
-0 *- 5 S 0

• 3 - — —

"i otZJCZ! cd

"id

0

0'
0

CO

J

-t-i
0

d
"'3

Per cent and
description of mate-
rial retained on
100-mesh sieve.

d

00

to

d

X
X

0'

00

0

0
G
co

b.2 n"2

>_ ~ - 3
cd g £ cd
*" O (3 „,

5 s " s x

^•00 &

u — -

G O «j 0)

dgE.li"

■J?1" cd D.
to<< O 0 w

0

O
0'

s.

0

6. .

00* *y

0'

00

--

°g
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C^

^" 1-.

cd

0>3

JO

0'

X

to

0
d

00

to

0'

00

to

0

d

0

d

00
0

d

33'^

= 3~

0 g

J': 3

d

*i CO m
&E 60 .

-.-gga

I 'or cent and
description of mate-
rial retained on
80-mesh sieve.

3 g cd

t- 0
O p

< id

°ttj3

to ■

2 <3

--

3i
B E

<C
0

t.2 0
• w -r

to cd CO
« O O

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.13 td

--1

-'5

M OO

6

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, !-.

7 cd
■*3

M O*

0* to a

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~

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r^ cd

1-5 t M

S3
0 p,

Cfl

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« CM td

>>

c
-

6.5

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S£

-
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&
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00 ■£ rt

N CjCJt

Per cent and
description of mate-
rial retained on
40-mesh sieve.

M cd
o°
J* M

"1 3 •

>-) 0 <u

— 3
ft.s

.E°
a - •-

^~ c
**>'£ S

n £,0

w

s
0

■as

< °
. 0

u cd

■ C
O. 0

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w 0

so "3
cd >

•is =

% s

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1 E 60

3 U

oE

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<

. V

0 td
-• = 0
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z - -.

w O O

£3

td 0

■ts-g ^-

i 3

,~ 0

T ; ;3

UJniO

-;;

u. <a g

-I 0

-4- <u b

~ 3 "

0'

Ji
0

d

DC

P
3

!g

- cd
. t-

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to to

0"

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— '3

. S

0*3

>
d°

to

^E

« 0

to X

O'

to
z<

d

Per cent and
description of mate-
rial retained on
20-mesh sieve.

•0
p

cd

•c R
.5

+J SC
O cd
. u
ft""

~"2

to yi

64

3
u

"3

X

cL w
>/-. c

»E

i 3

2 °

— *- c

x< :

•™o

- E.C

■' H U

60
td
u

vO C

• ^

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n
td

~ r-

W E

. E

og

c —
■ cu

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■a

c
cd
j^

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. p
83

• u
."«

2 0 .

■gol

— p

*> to

0 Id

"be

■a

c

cd
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7 ?
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8g

. u

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c 3:
0\j3

73

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td

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— -
to ~

■ E

s 9

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60

cd t«
."- 3 •
""Og

33J3 g
CO G-P

Mo-

*>' td «
0 3
ti r

- 3^
3 3-

- 3 O

Weight

of
sample
(grams).

7 . 720

0
0
0

0
0

0

0

0
0

(*3

0
0
0

to

0

0
0
0

O
O
O

O
O
0

0
O
O

to p .

a> 0 0

g F2

oc
to

01

to

O

-r

,^-

T

■»

10

r^.

126 Papers from the Marine Biological Laboratory at Tortugas.

SOURCES OF MATERIAL.

Table of Geologic Formations in Florida.

O

Period.

Recent

Pleistocene

Group.

Formation.

Pliocene

Miocene

Oligocene

Apalachicoia
Group

Vicksburg
Group

Lithologic description
of the formation.

Human remains. Vermetusrock.
Beach sands. Coquina. Aeo-
lian deposits. Lacustrine de-
posits. Chemical deposits. Al-
luvial deposits.

Palm Beach Limestone. .

Miami oolite

Key Largo limestone. . . .
Key West oolite

Lostman River limestone

Unconformity-
Lafayette ....

Bone Valley gravel .
Alachua clay

Nashua marl

Caloosahatchee marl..

Unconformity (?)

Jacksonville formation"
(East Coast)

Choctawhatchee marl
(West Florida and St.
John'?. Valley)

Unconformity

Yellow sand.

"Vermetus rock."

Coquina.

" Planorbis rock."

Gray sand.

Fossiliferous marls.
. Light-colored limestone with
sandy beds and loose sand.

Light-gray to white oolitic
limestone, sandy in places.

Coral limestone; reef rock.

Light-gray to white oolitic lime-
stone.

Dark to light, hard to friable,
limestone, sandy or marly in
places.

Clay and sand with some pebbles ,
color usually red or yellow.

Light-colored gravel and marl,
containing phosphatic pebbles.

Greenish sandy clay, weathering
yellow or red.

Light-colored sandy shell marl.

Light-colored sandy shell marl.

Light-gray to white limestone
weathering light yellow. Light
gray to yellow clay and gray
sand. Some chert beds.

Greenish to light-gray sandy
shell marl or greenish gray
clay.

Alum Bluff formation .

Chattahoochee forma-
tion (West Florida)

Hawthorne formation
(Central Florida)

Tampa formation
(South Florida)

Unconformity —
Ocala limestone.

Gray to green sands, clays and
fuller's earth. Limestone oc-
curs in some localities but it is
usually impure.

Light-yellow to gray earthy
and siliceous limestones, some-
times cherty. Sand and clay
rare.

Yellow limestones, often phos-
phatic. Greenish or reddish
sands. Green clays.

Yellow limestone and greenish
.clays. Some chert nodules
and layers.

Peninsula limestone (Central
Florida)

Marianna limestone (Western
Florida)

Soft, porous, light-gray to white
limestone with beds of marl
and layers of chert.

Soft, porous, light-gray to white
limestone containing marl
beds and layers of chert.

Soft, porous, light-gray to white
limestones containing some
marl and more rarely clay
beds. Layers of chert common.

Silica.
The presence of siliceous sand in the northern portion of Biscayne
Bay is accounted for by similar material overlying the Miami oolite in
the adjacent regions, and by the streams emptying into the bay median-

A Contribution to the Geologic History of the Floridian Plateau. 127

ically removing to it a portion of the deposit. The sand of southern
Florida has attracted the attention of a number of geologists, among
them Professor Shaler and Mr. A. Agassiz. The material must have been
derived from the continental masses to the north, but the various factors
by which it was brought so far south have not been thoroughly understood.

GEOLOGIC DISTRIBUTION OF SILICEOUS SAND IN FLORIDA.

Until recently the amount of sand in the geological formations under-
lving the surficial Pleistocene deposits was not known. Therefore it may
be interesting in this connection to outline the geologic history of arena-
ceous deposits in Florida. The table of geologic formations on the
preceding page is taken, with some verbal changes, from "A Prelim-
inary Report on the Geology of Florida, with special reference to the
stratigraphy, by George Charlton Matson and Frederick G. Clapp, includ-
ing a chapter on the Topography and Geology of Southern Florida by
Samuel Sanford." x

In northern Florida the following geologic formations older than
the Pleistocene contain sand beds:

Pliocene: Lafayette formation, Alachua clay, Nashua marl, Caloosahatchee

marl.
Miocene: Jacksonville formation, Choctawhatchee marl.
Oligocene: Alum Bluff formation, Hawthorne formation.

In the northern portion of the State formations of every period from
the Oligocene to the Recent contain deposits of sand. It should be
stated, however, that no predominantly sand beds have been reported
from the Vicksburgian Oligocene, although the formations of that group
contain some sand and silica of organic origin.

In southern Florida sand of Pleistocene and post-Pleistocene age
is generally known to be present, at least as far south as Miami. The
three following well records extracted from Mr. Sanford 's chapter in the
report on the stratigraphic geology of Florida will indicate its distribu-
tion in preceding geologic periods:

Partial record of well of C. I. Craigin, Palm Beach.

Description. Feet.

Sands with thin layers of semi-vitrified sand at so and 60 feet o to 400

Very fine-grained soft greenish-gray quartz sand, containing occasional foraminif-

era and water- worn shell fragments 400 800

White sand with abundant foraminifera of four or five species 850 860

Gray sand, containing shark's teeth, small water-worn shells and bone fragments,

sea-urchin spines, and lithified sand fragments 904 915

Samples at frequent intervals, Vicksburg limestone containing Orbitoides in
abundance throughout, together with occasional indeterminable fragments of
molluscan casts, corals, and echinoderms. It is a creamy white, hard, homoge-
neous limestone throughout 1 ,000 1,212

1 Prepared in cooperation between the United States Geological Survey and
the Florida State Geological Survey, under the direction of Thomas Wayland
Vaughan, Florida Geol. Surv., 2d Ann. Report, 1910.

128 Papers from the Marine Biological Laboratory at Tortugas.

Darton was unable to determine definitely the age of the series overlying the
limestones, but the organic remains from 800 to 915 feet suggested Miocene age,
while foraminifera between 400 and 800 feet indicated that the beds whence they
came are also probably of Miocene age.

This record shows that the top of the Vicksburg group (Lower Oligocene)
lies between 915 and 1,000 feet below the surface at Palm Beach. The great thick-
ness of quartz sands is the most noteworthy feature of the record.

Key Vaca. — Two wells were sunk at Marathon, Key Vaca, one reaching a
depth of 435 feet, the other 700 feet. The combined records of the two wells gives
the following section:

Record of wells of Florida East Coast Railway, Marathon.

Description. Feet.

Reef rock o to 105

Hard to soft white limestone, with much white marl 105 148

Soft white limestone with shell casts 148 1 s°

Medium hard white limestone, shell casts and shell fragments 150 155

Soft white limestone with quartz grains, proportion of quartz increasing with depth,

shell fragments and casts *55 x76

Medium fine white quartz sand containing numerous irregular nodules, with yellow-
ish marly sand at 210 to 215 feet 176 230

Quartz sand in a varying proportion of limy mud, sand grains colorless, mud yellow-
ish to dark green; streaks and beds of friable sandstone containing shell casts; bed

of oyster shells at 240 feet 23° 3°°

Quartz sands or beds of soft , friable sandstone containing shell casts ; streaks of dark
green limy clay, 306 to 310 ft.; beds of shells, few determinable fossils, probably

Miocene, 378 to 390 ■ 3°° 400

Quartz sands as below 230 feet; beds of soft friable sandstone with shell casts; gravel
bed with much worn pebbles up to 40 mm. long; tough green limy clay, at 407 to

410 feet 400 43 5

Quartz sands with little sandstone, tough dark clay in occasional streaks 43 S 700

While the many samples of drillings from this well show the lithology of the
formations penetrated, they give much less satisfactory evidence as to geologic
age. The sands below 176 feet yielded but a small variety of determinable fossils.
An occasional claw or carapace of a small crab or a few barnacle plates were the
only organic remains noted in going through many feet of sand. The friable sand-
stones contained many casts, internal and external, of pelecypod shells, the external
casts being of sandstone, the internal of more clayey material. These casts, while
numerous, were not sharp enough to be of diagnostic value.

The shell beds yielded a small variety of species. T. Wayland Vaughan
identified five species, including pectens and an oyster, which were probably
Miocene, from collections between 375 and 420 feet.

Thus the Key Vaca section, while it shows limestone, Pleistocene, and sands
probably Pliocene, gives no data for separating Pliocene from Miocene. The
coarseness of the sands, their barrenness and the character of the few determinable
fossils between 176 and 400 feet indicate shoal water and strong currents. No break
in deposition is determinable.

Fossils from Marathon Well, Key Vaca, were identified by T. W.
Vaughan, as follows:

Depth 375 to 400 feet: Turritella variabilis Conrad; Ostrea, appar-
ently a new species; Pecten sp. fragment, probably P. madisonius Say;
Pecten sp. fragment, very near P. humphreysi Conrad; Pecten sp. young,
apparently P. eboreus Conrad.

Geologic Horizon: Although the number of species is small, and
positive specific identification can be made in only one instance, the
fauna has a distinctly Miocene facies. The series of Pectens represented
by madisonius , humphreysi, and eboreus occur in association only in the
Miocene.

A Contribution to the Geologic History of the Floridian Plateau. 129

The matrix of these fossils is light olive-green quartz sand with
some calcareous material. A few oolitic granules are present. Similar
material continues to 640 feet, becoming coarser at the lower levels.
Between 620 and 640 feet there are quartz pebbles 0.375 inch long.

Depth 640 to 660 feet: Orbitolites complanata d'Orb.; Stylophora sp.;
Pontes sp.

Geologic Horizon: Apalachicolan Oligocene. The matrix is a whitish
limestone in which are small cavities.

Depth 680 to 700 feet: Pecten fragments, probably P. per planus
Morton.

Geologic Horizon: Not definitely determinable, but Vicksburgian
Oligocene is suggested.

A record of the Buck Key well (of W. H. Knowles) given from
memory by the driller, James Sykes, supplemented by samples saved
at odd depths, furnishes the following section:

Description.

Feet.

Sand and shells

Brown crystalline limestone with cherty streaks and sand grains

White quartz sand, with marl and" shell fragments

Brownish sandy limestone with shell fragments

Dark greenish marl

White quartz sand, with shell bed at 150 feet

Medium dark greenish marly sand, with shell beds, and streaks of lighter marl

White to brownish, and soft to hard, limestone, with a few shell casts; hard brownish
limestone contains many siliceous grains

0

to 50

SO

60

60

6s

63

6.1

65

145

142

27S

275

490

490 605

The correlation of the geologic formations penetrated in these wells
is a difficult matter, but we know sand is abundant below 155 feet in
depth on Key Vaca and we may be confident that Pliocene and Miocene
sands extend as far southward as that key. The quantity of siliceous
material contributed to southern Florida appears to have reached its
maximum in the Miocene period and since then to have diminished inter-
ruptedly. The Pleistocene limestones of the mainland rest on an
arenaceous foundation.

The presence of Miocene sands as far south as Key Vaca possesses
a geologic interest in 'that they indicate that the great Floridian plat-
form existed in Miocene times, and that sand which must have come
from the north, as no southern source is known, was being carried to
that region during that period.

Silica derived from sponge spicules and diatoms is universally
present in the near-shore marine deposits, but not in sufficient quantity
to form of itself important deposits.

Calcium Carbonate.

The origin of the material of the calcareous deposits presents a
more complicated problem than that of the siliceous. Its source is both
inorganic and organic.

9

130 Papers from the Marine Biological Laboratory at Tortugas.

CALCIUM CARBONATE OF INORGANIC ORIGIN.

The calcium carbonate is derived through two inorganic agencies:
chemical denudation and erosion. In order to understand both the
sources and the means by which the material is transported to the ocean, it
will be necessary briefly to consider the geologic formations, topography,
vegetation, drainage, rainfall, and surface run-off of the land areas.

PLEISTOCENE LIMESTONES OF SOUTHERN FLORIDA.

The whole of the surface of southeastern Florida is either formed
or underlain at no great depth by a series of limestones, all of which are
of Pleistocene age. The more important of these formations will be
described in the succeeding paragraphs.

The Miami oolite, named from the city of Miami, is a soft, white
or cream-colored, oolitic limestone breaking with an irregular fracture
and containing streaks of thin, irregular layers of calcite (plate 13, fig. b).
The rock is quarried as a building stone in the vicinity of Miami, and as
it hardens on exposure it serves its purpose well. Spheroidal oolite grains
are its most important constituent. The diameter of the granules ranges
from less than 0.5 mm. to a little over 1 mm. Mr. Sanford, who has
studied the granules microscopically, says:

Examination with the microscope shows that the ovules have a well-marked
concentric structure; the nucleus of some ovules is a rounded aggregate of minute
calcite crystals, of others a rounded aggregate less evidently crystalline; sometimes
the nucleus is a shell fragment and frequently it is a grain of quartz. The concen-
tric layers vary in number from 1 to 4 or 5, and in appearance from clear and
rather coarsely crystalline to opaque. The layers are darker or lighter from vary-
ing amounts of organic matter and amorphous material.

The oolites are embedded in a cement of amorphous or crystalline
calcium carbonate, and there is some sand. The latter material is more
abundant at the north and decreases southward; there is also a slightly
greater proportion of sand along the eastern outcrop than toward the
west. This formation has a maximum thickness of perhaps 50 feet. Its
areal extent is southward from the vicinity of Del Ray to 10 or 12 miles
beyond Homestead, and westward it forms the floor of the eastern por-
tion of the Everglades.

The Lostman River limestone, named by Mr. Sanford from its typical
occurrence along Lostman River, is a non-oolitic Pleistocene limestone
of varying physical characters; in some places it is hard, largely made up
of crystalline calcite; in others, soft and friable. At the head of Hender-
son Creek it contains considerable sand. Its thickness is said by Mr.
Sanford to be 30 feet at Everglade and over 40 feet at the mouth of
Shark River. It underlies the shore of the mainland from Jewfish Creek
westward and northwestward to near Marco, extends some miles to the
north of the last-mentioned place, and to the northeast passes beneath
the great swamps of the interior.

The Key Largo limestone is the elevated coral-reef rock forming
the main line of keys from Soldiers Key to the southern end of Big Pine
Key. Its name was taken from Key Largo because of the excellent ex-
posures recently made there by the excavations along the line of the
Florida East Coast Railway extension. The most conspicuous compo-

.4 Contribution to the Geologic History of the Floridian Plateau. 131

nent of this formation is coral, usually in the form of large heads of
Mceandra and Orbicella (plate 15, figs, b and c). The interspaces are
filled with various kinds of calcareous debris derived from marine organ-
isms. Over the surface there is frequently a hard crust composed of
colored, laminated, amorphous calcareous material. The lime of the
coral heads is frequently crystalline.

These three limestones are the principal geologic formations sur-
rounding the bays and sounds of southeastern Florida. Toward the
interior of the State, however, both the Miami oolite and the Lostman
River limestone are overlain by the great interior swamp deposits, the
most extensive and famous of which are the Everglades.

There is in this region another important limestone formation, the
Key West oolite, which closely resembles the Miami oolite in appearance
(plate 14, figs, b and c; plate 15, fig. a). It is a soft, white or cream-
colored limestone, mostly composed of oolitic granules embedded in a
loose matrix of amorphous, or occasionally crystalline, calcium carbonate.
The structure of the granules of the two is the same, except silica is rarer
in the Key West oolite. The thickness of this formation is unknown,
but is tentatively placed by Sanford at 50 feet. It is the rock composing
all the keys from No Name and Little Pine to Boca Grande, except the
purely mangrove keys.

Although the Key West and Miami oolites are so similar and may
be geologically contemporaneous, they are not known to be in contact
anywhere, as both the Key Largo and Lostman River limestones inter-
vene between their respective outcrops.

TOPOGRAPHY OF SOUTHERN FLORIDA.

The whole of the area under consideration is one of low relief, the
greatest elevation known being perhaps 30 feet. The Miami oolite forms
a limestone ridge extending southward from the vicinity of Del Rav to
beyond Homestead. The elevations along this ridge are about 8 feet at
New River, Fort Lauderdale; perhaps 30 feet south of Miami, and about
8 feet on Long Key in the Everglades. In the vicinity of Miami there
is a steeper sea-face with a westward slope, the rock passing beneath and
forming the floor of the Everglades. The width of this ridge west of
Miami is about 3 miles.

The Everglades are a vast interior swamp, the surface of which is
mostly an enormous saw-grass marsh with mottes of timber here and
there breaking the monotonous expanse. The altitude is almost the
same as that generally prevalent over this section of the State. Some
determinations along the eastern margin are: "west of Lantana, 18
feet; west of Hillsboro Inlet, 14 feet; west of Fort Lauderdale, 17 feet;
at the pool at the head of Miami River, 6.2 feet. South of the Biscayne
pineland and Long Key the height of the Everglades is less than 6 feet "
(Sanford) . The maximum elevation of the keys east of Key West perhaps
does not exceed 5 or 6 feet.

VEGETATION OF SOUTHERN FLORIDA.

The vegetation of the area presents three different types. The
oolite ridge is mostly covered by pines, the soil is thin and the surface
of the ground rocky (plate 8, fig. a); in the Everglades (plate 7, figs.

132 Papers from the Marine Biological Laboratory at Tortugas.

c and d) there is a growth of saw-grass and an accumulation of vegetable
muck of varying depth — in some places thin, merely a surface veneer;
in others 4 or 5 feet, or perhaps even more, in depth. The interior of
the keys is usually a jungle, while often, but not invariably, mangroves
fringe the water front (plates 9, 10, 11, and 12, fig. a).

DRAINAGE AND RAINFALL OF SOUTHERN FLORIDA.

Southeastern Florida is a very poorly drained country. There are
comparatively few streams leading from the interior swamp to the sea.
A small river at Miami, known as Miami River, leads from the Ever-
glades to Biscayne Bay. Another, Taylor River, empties into Florida
Bay in southern Dade County. However, a large proportion of the
waters of the interior works its way to the ocean, as there is a general
southward movement of the waters of the Everglades. There is in the
vicinity of Miami and also along the keys direct surface run-off from
the landmass into the ocean.

The rainfall for this section of Florida, according to Gannett,1 is
between 60 and 70 inches per annum.

No accurate records have been kept of the surface run-off of the
streams and from the swamps of southern Florida. Therefore any figure
given must be derived by applying the results obtained in other areas
and making allowance for peculiar conditions prevailing in this region.
Mr. J. C. Hoyt, in his "Comparison between Rainfall and Run-off in the
Northeastern United States," makes the statement:

The run-off is very consistent in the various groups, and decreases toward
the south, although the rainfall increases. It is about 60 per cent of the precipita-
tion in the northern areas, 55 per cent in the intermediate areas, and 40 per cent in
the southern areas. This decrease in run-off is due to the increase in evaporation
and the loss by vegetation, and shows that the climate and vegetation are probably
the principal regulating factors in the relation between rainfall and run-off.
*******

The climatic conditions are responsible for this change in the percentage of
run-off between northern and southern areas, rather than geologic conditions or
topography, as is shown in the " percentage " column for the summer months, where
the percentage of run-off s varies between 20 and 32, having a mean of 27 per cent
for all principal basins. This column shows no regular variations for the basins.
It also shows that the evaporation and loss through evaporation is very nearly
the same over the various areas considered, being about 9.5 inches. (American
Society of Civil Engineers, Transactions, vol. 49, p. 436.)

As the temperature of southeastern Florida is never lowered to the
freezing-point and as there is a luxuriant vegetation, it is probable that
the lowest estimate of run-off given by Mr. Hoyt, 27 per cent, is slightly
too high. Therefore 25 per cent2 is taken as a more probable figure;
and the annual run-off for this area is estimated as 25 per cent of 60
inches, or 15 inches.

1 U. S. Geol. Surv., Water Supply Paper 234. _

?Mr. J. O. Wright, Drainage Engineer, U. S. Department of Agriculture, by
a somewhat different process, arrived at the same estimate for the percentage of
surface run-off in southern Florida. (Report of the Special Joint Committee of the
Legislature of Florida on the Drainage of the Everglades of Florida, pp. 25-29,
Tallahassee, 1909.)

A Contribution to the Geologic History of the Floridian Plateau. 133

The area of Dade County, from which the surface run-off is into the
bavs and sounds behind the keys, is approximately 1,840 square miles.
The surface run-off from this territory would be approximately 0.52
cubic mile per annum. This amount, however, ought to be increased
as the waters from Lake Okeechobee and the Everglades move south-
ward, and a portion of them apparently must flow to the southeast. As
is well known, a considerable portion of the territory to the north of
Lake Okeechobee is drained into that basin and the water is discharged
through the rivers leading to the west, east, southeast, and south of the
Lake or the Everglades. Therefore the discharge into the bays and
sounds is probably between 1.0 and 0.5 cubic mile.

CHEMICAL DENUDATION.

Having given in the preceding remarks the physical surroundings
of the bays and sounds, and given an estimate of the surface run-off of
the waters, the chemical denudation of the region may be discussed.
That chemical denudation is active in southeastern Florida is attested
by numerous phenomena. The surface of the Miami oolite is extremely
irregular; some irregularities are due to rocks torn from the general
oolitic mass by uprooted pine trees, while others are produced by the
solvent effect of water, as is especially well shown by small sink-holes,
pot-holes, and such phenomena as the Arch Creek natural bridge.
According to Mr. Sanford:

The holes, which communicate with underground solution channels, are of
all sizes, varying from those not over an inch across to those 20 feet or more in
diameter. Their depths range from 3 to over 10 feet. Besides the sharply out-
lined holes, there are throughout the pineland countless shallow hollows 1 to 3 feet
deep and 10 to 100 feet across. A few of these hollows may owe their origin to
original conditions of deposition, some may be due to the overturning of trees and
consequent upheaval of the rocks loosened by roots, while others have been caused
by the falling in of the roofs of subterranean water-courses. Few of the holes and
hollows are large enough to be termed sinks. The large vertically walled holes
running down to permanent water-level form natural wells, the shallow hollows
are best denominated pot-holes. The writer has heard of only one rock-rimmed
opening in southern Florida that resembles the great sinks in the country to the
north.

"While there is danger of exaggerating the activity of underground and sur-
face water in eating away the soft limestone of the east coast, yet there is plentiful
evidence of solution. The pot-holes and the hollow-sounding areas of rock, per-
haps 2 5 feet across, with as many as 6 or 7 holes a foot or so in diameter showing
the water beneath, that are found along the edges of the southern Everglades, the
springs below tide-level at Cocoanut Grove, and other points on the shore of Bis-
cayne Bay, the Punch Bowl, a spring basin, the deep holes in New River, and the
shallow gorge of Arch Creek with its low rock bridge, all bear witness to the work
being done.

The conditions favorable for vigorous chemical denudation of lime-
stone are: (1) a supply of water charged with C02; (2) the water re-
maining in contact with limestone a sufficient time to permit solution;
(3) having dissolved lime to be able to move onward.

Conditions favorable for such denudation are largely realized in
southern Florida: there is limestone; the waters become charged with

134 Papers from the Marine Biological Laboratory at Tortugas.

carbonic-acid gas from passing over large areas of decaying vegetable
matter; and, as the flow toward the sea is gentle, there is opportunity
for the dissolving acid to act on the limestone. Over a considerable
area in the Everglades, although limestone underlies the surface material,
the water is prevented from coming in contact with it. Therefore, most
of the solution must be accomplished on the higher region of the Miami
oolite and the coastal fringe of the Lostman River limestone. There is
also chemical denudation on the Key Largo limestone and Key West
oolite of the keys. The following quotation from Dr. Sellards is appro-
priate in this connection:

Among these agencies of erosion, underground water has acted in Florida
under exceptionally favorable conditions. In areas of considerable slope, and
with relatively impervious formations, the surface run-off is large. Under these
conditions those features of topography determined by the rapid downward cut-
ting of the surface streams and their tributaries predominate. In Florida the sur-
face slope is slight. The open nature of the soil and rock permits the greater part
of the water to enter the earth, establishing subterranean rather than surface
drainage. The rocks are prevailingly calcareous and soluble. Under these con-
ditions the work of the underground water predominates over surface erosion. In
central Florida the topography, soil, and general surface features are determined
to a large extent by the work of underground water.

Solution is the most apparent, and geologically the most important result
of underground water circulation. Rainwater, while passing through the air,
takes into solution a small amount of C02 gas. To this is added organic and mineral
acids taken up while passing through the soil. Increased pressure, as the water
descends into the earth, enables the water to hold in solution greater quantities
of gases, acids, and salts, all of which greatly increase the dissolving power of the
water.

That underground water is efficient as a solvent is evident from the analyses
of well and spring waters. Rainwater entering the earth with almost no solids in
solution returns to the surface through springs and wells with a load of mineral
solids in solution determined by the length of time it has been in the ground, the
distance traveled, and the character of the rocks and minerals with which it comes
in contact.

The mineral matter thus taken into solution is carried along with water, and
while some of it is redeposited, a large amount is removed annually. An estimate
of the total mineral solids thus removed is difficult. A conception of the largeness
of the amount removed is obtained from a consideration of some of the individual
springs.

The water of Silver Springs contains, as shown by analysis, 274 parts solids
per 1,000,000 parts water. Otherwise expressed, each 1,000,000 pounds of water
is carrying with it 274 pounds of solids in solution. Silver Spring is estimated to
flow a' little more than 3,000,000 pounds of water per minute (368,913 gallons).
The interior of Florida is thus being carried into the ocean through Silver Springs
at the rate of more than 340 pounds per minute or about 600 tons per day.

The total solids removed in solution through 6 other springs of central Florida,
expressed in tabular form, gives the following results:

Name of spring.

County.

Total solids
parts per
1,000,000.'

Blue Marion

Blue Levy

Ichatucknee Columbia .

Newland Suwanee . .

Weekiwachee Hernando .

White Sulphur Hamilton .

Suwanee Suwanee . .

112
196
311
233
227
166
332

Estimated
flow (gal-
lons per
minute).

Solids
removed
(pounds).

349,166
25,000

180,000
75,000

100,000
32,400
52,000

469,698
59.040
457.056
210,150
273.360
64.744
207,605

1 Organic matter is deducted from the total solids as given for Suwanee Sulphur and White Sulphur
Springs. The organic matter occurring in the other springs is of small amounts and was not separately
determined.

.4 Contribution to the Geologic History of the Floridian Plateau. 135

As the basis of an estimate of the total solids removed annually from the
interior, let it be assumed : (i) that the average total solids in spring water amounts
to as much as 219 parts per 1,000,000, this average being obtained from 8 of the
typical large springs of central Florida; (2) that the annual escape of the under-
ground water approximates the annual intake, amounting, as previously estimated
(p. 16), to 460,536,689 gallons per square mile. Upon these estimates the mineral
solids removed amount to a little more than 400 tons annually per square mile.

Of the minerals thus removed, calcium carbonate or limestone greatly pre-
dominates, exceeding the combined weight of all other minerals. From the analy-
ses it appears that magnesium carbonate, magnesium and calcium sulphates are
present in variable, although usually limited quantities. Chlorides are normally
present in small amount, although occasionally, as in the case of Perrian Spring,
they are exceptionally high. Silica is present in amounts varying from 5 to 25.5
parts per 1,000,000. Traces of phosphoric acid and of iron and alumina are usually
present.

The several undetermined factors which enter into the above estimates of
mineral solids removed make it difficult to formulate a concrete statement of the
rate of lowering of the general surface level. Nevertheless, such statements are
desired and have a comparative value. Assuming for the rock removed, most of
which is limestone, an average specific gravity of 2.5, a layer a foot thick over a
square mile should weigh about 2,166,666 tons. The calculated rate of removal
of this rock is about 400 tons per square mile per year. From these estimates it
would appear that the surface level of the central peninsular section of Florida is
being lowered by solution at the rate of a foot in 5,000 or 6,000 years. (Prelim-
inary Report on the Underground Water Supply of Central Florida, Florida Geol.
Surv., Bull. No. 1.)

When an attempt is made to estimate the amount of calcium car-
bonate borne into the sea by the waters of southeastern Florida, the diffi-
culty is immediately encountered of no analytical records having been
kept of the waters ; therefore any estimate must be based upon a com-
parison with other regions, and the result obtained in those regions is of
doubtful applicability to the one under discussion. Sir John Murray '
averaged the analyses of 19 rivers and obtained the result that 326.710
tons of CaC03 per cubic mile of water were discharged into the ocean.
The quantity per cubic mile in southeastern Florida may be somewhat
greater. Therefore it is suggested that the amount of this material
poured annually into the bays and sounds of this region may be between
400,000 and 500,000 tons, or about Y0V0 of a cubic mile of limestone.
This amount of material spread over the floor of the. bays and sounds
after a considerable proportion has drifted seaward would give only a
thin coating for each year.

PRECIPITATION OF CHEMICALLY DISSOLVED CALCIUM CARBONATE.

The problem of the precipitation of the CaC03 in solution after it
has been carried into the sea presents itself. The only definitely known
process by which this may be accomplished is by the expulsion of the
CO,. This may be brought about by several methods: it may be driven
off by the heat of the sun, it may be lost by the agitation of the waters,
or extracted by marine plants. As it is not likely that the surface of the
sea is heated to a higher temperature than that of the land, mechanical
agitation and the action of marine plants are considered the most prob-
able causes of precipitation in Florida waters.

1 Scottish Geograph. Mag., vol. in, pp. 76, 77, 1887.

136 Papers from the Marine Biological Laboratory at Tortugas.

In the shallow waters near the shore the opportunity for re-solution
as the material settles to the bottom is not afforded and the accumula-
tion on the sea-bottom of large quantities of amorphous calcium car-
bonate, apparently not of detrital origin, is undeniable. The series of
samples collected between Miami and Big Pine Key is evidence of this,
and additional evidence was obtained by the examination of the surfaces
of numerous banks.

One bank about 2 miles northeast of Pigeon Key and another, the
shoal west of the upper end of Long Island, have been built nearly to
the surface of the water, and are composed of loose calcareous ooze into
which I sank while attempting to walk on them to my knees or slightly
deeper. An oar could be pushed an undetermined number of feet into
the material. Mr. Sanford informs me that a rod can be forced down
10 feet or more. In fact, the depth of this soft material has not been
determined.

WHITE-WATER PERIODS.

The white-water periods in the Floridian region are famous. One
of the early descriptions of them was given by Captain Hunt.

The tidal currents set strongly across the reef and through the channels be-
tween the kevs, the flood running to the north and the ebb to the south side of
the key crescent. When storms occur, the agitation of the waves extends to the
bottom, over the shallower portions of the grand Bank, and stirs up the sand
violently. This causes the water to take up and maintain in mechanical suspen-
sion such finely comminuted particles as have too little sinking force rapidly to
reach the bottom again. The finer the particles the longer will they remain sus-
pended, and the very coarse grains will hardly be lifted from the bottom. Between
the coarsest and finest are grains of all intermediate sizes, and whether they will
be suspended or not depends on the violence of the storm, and their interval of
suspension varies with their size and the violence of the waves. It results that,
in all storms of much violence, the water over the Florida Bank becomes white
with the bottom deposits. In long, severe northers or gales, the water becomes
almost milk-white across the whole Bank. This ' ' white water " is a familiar appear-
ance, and is one of the sure signs of proximity to the reef. As storms subside, the
white sand and mud are gradually thrown down, and the water clears, after a day
or two, to its peculiarly delicate transparency. (Am. Jour. Sci., 2d Ser., vol. 35, p.
200, 1863.)

EFFECT OF SEA-SPRAY.

So far the only kind of chemical denudation considered is that
resulting from the surface run-off of rainwater, but there is another kind
operative around a considerable portion of the south Florida shores.
This is corrosion by waves and sea-spray beating on limestone ledges.
Very good instances of this kind of corrosion are seen on the western
face of Gun Key, Bahamas, and illustrations from photographs are
shown on plate 8, figs, b and c. There are at present no means of
estimating the amount of CaC03 derived in this way, but it is probably
considerable.

CALCIUM CARBONATE DERIVED THROUGH SURFACE EROSION.

A considerable portion of the Miami oolite is soft and more or less
pulverulent. The detachment of masses from the surface by uprooting
due to falling trees, etc., furnishes an opportunity for running water to
wash away considerable quantities of limy matter. A portion of this,

A Contribution to the Geologic History of the Floridian Plateau. 137

of course, is washed into the sea in suspension, where it is precipitated
on the bottom, increasing the quantity of the calcareous sediments.

Another possible source of material is the region north of the west
coast of Florida Bay. Various streams, namely Caloosahatchee River,
a number of smaller streams emptying into the Gulf in the vicinity of
Thousand Islands, and others further south, cross areas underlain by
strata containing more or less lime. A portion of these waters may work
their way southward into Florida Bay and contribute to the supply of
sediment for that region.

CALCIUM CARBONATE OF ORGANIC ORIGIN.

A large proportion of the calcium carbonate of this region is of
organic origin. This is shown by the number of tests of various animals
found in almost any dredge haul, and those washed ashore, particularly
after storms. The principal constituent of this material is furnished by
marine mollusks. Foraminifera are important, as along the shores of
the keys one of the commonest organisms is Orbiculina adunca. Corals
have contributed to the calcareous material, but they are not very
abundant within the main line of the reefs and behind the keys. The
region between the keys and the main Florida shore is decidedly different
from that further to the west represented by the Marquesas and the
Tortugas. The limestone composing these two groups is very likely
almost entirely of organic origin. On the Tortugas, although corals con-
tribute a large proportion of the calcium carbonate, it appears that they
are probably secondary in importance to the mollusks. The breccia on
Loggerhead Key is largely formed of wave-tossed molluscan shells.

Two additional sources may furnish calcareous sediment to the
bays and sounds. The first is one to which attention was first called by
Captain Hunt,1 whose view was advocated by Mr. Agassiz in his "Three
Cruises of the Blake" (p. 57).

As the prevailing direction of the winds and waves, both of trade
and hurricane origin, upon the Florida reef is from northeast to south-
east, they tend to pick up and carry behind the keys the loose sediment
previously prepared by the pounding of breakers; and sediment once
having lodged behind there is not likely all to be transported back to
the sea by the ebbing of the tides, although, as will be shown later, the
outward flowing tidal currents in some instances build deltas at the
seaward end of passages between keys.

The general character of coral reefs and the effect of the waves in
comminuting pieces of coral or the shells of other organisms have been so
frequently and fully described that it is superfluous to furnish a descrip-
tion here.

RESUME OF SOURCES OF CALCAREOUS SEDIMENTS.

Reviewing the sources of the calcareous sediment poured into the
bays and sounds we find:

(1) That from the mainland and keys surrounding them. This
material is derived both by chemical denudation and mechani-
cal erosion.

1 Am. Jour, of Sci., 2d Series, vol. 35, p. 202, 1863.

138 Papers from the Marine Biological Laboratory at Tortugas.

(2) The calcareous remains of organisms living in the waters.

(3) Detrital material washed behind the keys from the reefs and

flats lying outside of them.

(4) Some material may be brought southward along the west

coast of Florida.
At present data are not available for determining the proportion due
to each one of these sources.

GEOLOGIC DISTRIBUTION OF LIMESTONE IN FLORIDA.

It may be appropriate here to give a statement of the geologic
history of limestone in Florida similar to that made for the siliceous
deposits. The following is a list of the calcareous formations of the State,
presented in stratigraphic sequence:

Pleistocene: Palm Beach limestone, Miami oolite, Key Largo limestone,

Key West oolite, Lostmans River limestone.
Pliocene: Marls are abundant but limestone is not known.
Miocene: Jacksonville formation : Contains some limestone beds.
Oligocene :

Apalachicola group: Alum Bluff formation, some impure limestone;

Chattahoochee formation, mostly impure limestone; Hawthorne

formation, some limestone; Tampa formation, some limestone.

Vicksburg group: This group is composed mostly of more or less pure

limestone. There are some marl and sandy beds and layers of chert.

In reviewing the geologic formation of Florida it is immediately
evident that the Vicksburg group comprises the great limestone forma-
tions of the State. Although there are calcareous constituents in the
Upper Oligocene, Miocene, and Pliocene, very rarely is there pure lime-
stone ; more frequently the material is composed of clays or sands with
a large proportion of calcareous matter. In other words, Florida is very
largely made up of continental waste, but the older geologic formations
contain sufficient lime to furnish calcareous material to the streams flow-
ing across their surface.

TERTIARY CORAL REEFS OF THE SOUTHERN UNITED STATES.

The role coral reefs have played in building up the Peninsula of
Florida can easily be understood by outlining the geologic history of the
reefs of that and adjacent regions as we now know them.

Oligocene, Vicksburg Group. — There was no extensive development
of coral reefs during Vicksburgian time. In fact, the only reef known
which may be referable to it is the one at Salt Mountain, near Jackson,
Alabama. It is of comparatively few acres in extent, and regarded as a
constructive geologic factor is of almost negligible importance.

Oligocene, Apalachicola Group. — Coral reefs belonging to this group
are known at several localities. Probably the most extensive develop-
ment is in the vicinity of Bainbridge, Georgia, where exposures may be
seen along Flint River from a point 3 or 4 miles below that town through
a distance of 4 or 5 miles. Reef corals of the same geologic age are also
known from the Mclntyre plantation, 11 miles south of Thomasville, and
at other places in Thomas County, Georgia; and from southern Lowndes
County. In Georgia, however, although there were Upper Oligocene
coral reefs they were not of great importance as constructional agents.

.4 Contribution to the Geologic History of the Floridian Plateau. 139

In Florida, Upper Oligocene reef corals are known from several
localities. The most northern is in Wakulla County, near Wakulla
Station, between Tallahassee and St. Marks; fossil corals are also found
at White Springs, on the Suwanee River; large heads of Siderastrea are
abundant in the vicinity of Alachua, Alachua County, and the chalce-
donic replacements of corals from the vicinity of Tampa are widely
known. Compared to the total extent of the Upper Oligocene formations
in Georgia and Florida, corals play an insignificant role; they possess
more importance as furnishing means of correlating geologic formations
than as constructional agents.

Miocene. — No coral reefs of Miocene age are known in the Atlantic
and Gulf Coastal Plain. A few fossil species are known and for strati-
graphic purposes they are of value.

Pliocene. — No Pliocene coral reefs are known. Professor Heilprin,
in his discussion of the exposures along the Caloosahatchee River, called
attention to the comparative scarcity of corals and the great abundance
of shells in the Caloosahatchee marl. On Shell Creek corals are rela-
tively more abundant, but they are not strictly reef-building species,
belonging rather to species that grow on flats, and especially the inner
flats behind keys.

Pleistocene. — The second extensive development of coral reefs in
Florida took place in Pleistocene time.

Attention may be called to Captain Hunt's estimate of the time
necessary for the formation of southern Florida. He bases his estimate
on two assumptions: first, the rate of growth of corals as observed by
him in the neighborhood of Key West ; second, that the whole of south-
ern Florida has been built up by the activity of these organisms, whose
calcareous remains after having been pounded into sand by the sea go
to form great limestone flats. Captain Hunt's estimate of the rate of
growth of corals is open to doubt, and his second assumption is funda-
mentally wrong.

140 Papers from the Marine Biological Laboratory at Tortugas.

TRANSPORTING AGENTS OF THE FLORIDA COAST AND
THEIR EFFECTS.

In the preceding pages an attempt has been made to give an account
of the character of the sediments accumulating along the shores of south-
ern Florida, to determine the sources of their constituents, to indicate
the processes by which they were brought to the sea, and to trace in
outline the stratigraphic distribution of similar material in the State.
It is now proposed to consider the destiny of the sediment delivered to
the ocean. This subject will be introduced by an account of the forces
operating in the ocean to distribute the sediments or accumulate them
in certain areas.

Currents are the agency by which distribution is effected, and are
represented by three types, viz: (i) more or less constant oceanic cur-
rents; (2) tidal currents; (3) currents due to winds.

Fig. 3. — Current Chart of Florida Water (from Pilot Chart, Hydrographic

Office, U. S.N.).

CONSTANT CURRENTS.

The most important constant current is the Gulf Stream, which
flows along the 100-fathom curve, passing between the Florida Keys
and Cuba on the south, and the eastern coast of Florida and the Bahamas
on the east. This current can not directly have much influence on the

.4 Contribution to the Geologic History of the Floridian Plateau. 141

sedimentation on the Floridian Plateau, although it is indirectly of great
importance. The current of greatest direct importance is the counter-
current which follows the eastern coast of the United States from Cape
Hatteras southward. In the Floridian region it is called the Florida
countercurrent and has long been known to be an important factor in
building up the Floridian Plateau, as is attested by the writings of
Captain Hunt and Mr. Alexander Agassiz ; and Dr. Gulliver has recognized
its importance in determining the configuration of the shore-line. This
current passes through the Straits of Florida and continues as far west
as the Tortugas. The direction of its movement is southward until the
southern extremity of the Peninsula is reached, where it turns westward.
According to the Pilot Chart of North Atlantic Ocean, March, 1909:

In the Straits of Florida the countercurrent is very uncertain. Under favor-
able conditions of weather it extends as much as 11 miles offshore, but it generally
makes a westerly course to Sand Key within the line of the reefs, though with
certain winds it runs north or south between the keys and northeast around the
Tortugas.

TIDAL CURRENTS.

The flow of the tides is transverse to the keys, and rather strong
tidal currents pass in and out between the keys. These are strong enough
to sweep the bottoms of the passages clean.

WINDS.

The following data on the winds of southern Florida are taken from
the Pilot Char-ts of the North Atlantic Ocean for the year 1907, published
by the Hydrographic Office of the Navy Department. No attempt will
be made to present the data in detail, and only the prevailing directions
of the winds for each month will be given:

Jan.: Northeast, east, northwest, north, June: Southeast, east, south.

southeast. (The component di- July: Southeast, east, south.

rection is from the northeast.) Aug.: Southeast, east, south.

Feb. : Southeast, northwest, east, and Sept.: Northeast, southeast, east.

northeast. Oct. : Northeast, east, north.

Mar.: Southeast, northwest, northeast. Nov.: Northeast, north, northwest.

Apr. : Southeast, east, northeast. Dec. : Southeast, northeast, east, north-
May : Southeast, east, northeast. west.

The preceding data show the prevailing direction of the winds to
be from the southeast from February to August inclusive, varying from
northeast to southeast from February to May, and from southeast to
south from June to August; from the northeast from September to
January, but with considerable variation. The general direction of the
winds is either along or transverse to the line of the keys.

The tides and winds, as Captain Hunt suggested, tend to carry
material from the reefs and flats to the area behind the keys; while the
countercurrent moves material southward and westward. The winds
and tides by agitating the sea-bottom bring material within the influence
of the countercurrent and thus aid in its work of southward transporta-
tion. Without this assistance probably the countercurrent would not
produce great effects.

142 Papers from the Marine Biological Laboratory at Tortugas.

EFFECT OF THE FLORIDA COUNTERCURRENT ON THE SHORE TOPOGRAPHY OF

FLORIDA.

When a map of the east coast is examined, its long sweep and gentle
curves are immediately observed; there are no prominent salients or
deep indentations, no small irregularities, and for miles the shore-line
may be almost straight. Several other features are to be correlated with
the alongshore current.

(i) Elongated sottnds called rivers paralleling and lying near the
coast: north of St. Augustine are Tolomato or North River and Guano
River, both of which empty to the southward, and south of that city is
the Matanzas River which empties to the northward, the three finding an
exit to the ocean through St. Augustine Inlet (fig. 5). The Matanzas River
has a smaller inlet from the sea at its southern end. Following the coast
southward, Halifax and Hillsboro rivers are in communication with the
ocean through Mosquito Inlet. The latter "river" connects at its south-
ern end with Mosquito Lagoon, which is just north of Cape Canaveral.
Back of this cape and of the beach to the south of it is Banana River,
which is barely separated from the northern portion of Indian River.
In fact, Mosquito Lagoon, Banana River, and Indian River are all more
or less in communication through Banana Creek, which forms an irregu-
lar, sinuous northern boundary of Merritt Island. Indian River is suc-
ceeded to the southward by Hobe and Jupiter sounds and Lake Worth.
Between Hillsboro Inlet and the northern end of Biscayne Bay are
several small lagoons and salt-water creeks.

(2) The beaches and islands along shore have their southern ends
elongated, often pointed, while their northern ends are wider and fre-
quently more or less truncated. Amelia Island, on which Fernandina is
situated (fig. 4) , is an instance of such an island with a truncated northern
end. Anastasia Island, on the "south side of St. Augustine Inlet, is
another instance, but its northern end is not so obtuse as that of Amelia
Island (fig. 5).

(3) Southward Deflection of Stream-mouths. — Two good instances
of this phenomenon are seen in the vicinity of Fernandina (fig. 4). To
the north of Anastasia Island is Cumberland Sound, through which St.
Mary's River empties into the ocean; to the south is Nassau Sound,
through which Nassau River flows. Both of these sounds are directed
from the northwest to the southeast. New and Middle rivers, the streams
next north of the upper end of Biscayne Bay, have their mouths deflected
southward. The phenomenon is general along the Florida east coast.

(4) Overlaps and Offsets.1 — Instances of both these phenomena are
present and can be seen in the vicinity of St. Augustine (fig. 5) . The point
of land north of St. Augustine Inlet overlaps the northern end of Anas-
tasia Island; overlap and offset are necessary accompaniments of the
kind of stream deflection exhibited along this coast.

(5) Current Cuspate Forelands. — Gulliver has cited Cape Canaveral
as an almost typical example of this shore form (fig. 6).2

1 Gulliver, Shore-line Topography, Proc. Amer. Acad., vol. xxxiv, 1899, p. 178.

2 Proc. Amer. Acad., vol. xxxiv, p. 180, fig. 10.

A Contribution to the Geologic History of the Floridian Plateau. 143

Fig. 4. — Map of the Florida Coast, from the Fig. 5. — Map of Florida Coast in vi-

mouth of St. Mary's River to the mouth cinity of St. Augustine. (From

of St. John's River. (From U. S. Coast U. S. Coast Surv. Chart, No.

Surv. Chart, No. 158.) J59-)

144

Papers from the Marine Biological Laboratory at Tortugas.

6.- -Map of Cape Canaveral. (From U. S. Coast
Surv. Chart, No. 161.)

PLATE 3

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30 15

MAP SHOWING CAESARS CREEK AND OLD RHODES BANKS

(From U. S. Coast and Geodetic Survey Chart No. 1 66 »

A Contribution to the Geologic History of the Floridian Plateau. 145

The west coast of Florida strongly contrasts with the eastern; the
absence of prevalent alongshore currents is especially striking. Cape
Sable seems current-shaped by alongshore currents. From Cape Sable
to Cape Romano the coast line is minutely laciniate ; from Cape Romano
to Anclote Keys there is evidence of shore currents, keys with sounds
behind them paralleling the coast ; from Anclote Keys to the mouth of
Ocklockonee River, just east of St. George Island, the coast is minutely
irregular. From the eastern end of St. George Island the coast is swept
by the countercurrent on the north side of the Gulf.

The preceding account of the shore-line topography of Florida from
the standpoint of currents has an immediate bearing on contemporaneous
sedimentation and the building of such sand-spits as occur on the eastern
side of Biscayne Bay, and such keys as Virginia Key and Key Biscayne.
Arenaceous material is swept southward by the ocean currents on the
outside of this spit and the two mentioned keys ; while behind them Snake
Creek and Miami River are bringing their burdens of sand from the main-
land. The tendency of the process is to fill up Biscayne Bay and not onlv
to connect the spit and arenaceous keys to the mainland, but to join
them to the coral reef keys farther south.

RANKS BEHIND KEYS.

Sediment, mostly calcareous, is accumulating in the bays and sounds
behind the keys and is gradually filling them, although some is carried
to the outside. As has been stated, the tides run across the line of keys,
and the tidal currents have usually swept clean the channels between
them; but behind them are regions of slack water, and shoals are
built. The ridges and shoals behind Key Largo, Long Island, and the
Metacumbes are very instructive. No hard material at all was found
at any locality examined.

Mangroves are an important factor in this work of construction.
When a shoal attains to about a foot of the surface of the water, the
floating pods of these plants catch on the soft bottom, take root, grow,
and develop root tangles below and tangles of branches above. They
catch and retain floating debris and convert the shoal into an island.
(See plates 9, 10, 11, and 12, fig. a.)

DELTAS AT OUTER EXDS OF PASSAGES BETWEEN" KEYS.

Attention should also be called to the deltas forming at the seaward
end of some of the passages between keys. Professor Shaler was the first
to remark on this phenomenon,1 stating, "The volume of the material
can best be judged by the conditions exhibited by the deposits of limy
matter at the eastward end of the channel passing from Biscayne Bav
to the sea, known as Caesars Creek." This is not the only locality at which
such a delta is forming. The U. S. Coast Survey chart, No. 166, indicates
one at the eastern end of Bear Cut, off Cape Florida, and at the mouth
of Broad Creek, the last-mentioned bank being known as Old Rhodes
Bank (plate 3). There are probably other instances of this phenomenon.

1 Topography of Florida, Mus. Comp. Zool., Bull., vol. xvi, p. 147, 1890.
10

146 Papers from the Marine Biological Laboratory at Tortugas.

AREAL DISTRIBUTION OF THE GEOLOGIC FORMATIONS.

This subject may be introduced by reference to the Table of Geologic
Formations given on page 126 of this paper and to plate 4. For strati-
graphic descriptions the " Preliminary Report on the Geology of Florida"
by Messrs. Matson, Clapp, and Sanford l may be consulted.

OLIGOCENE.
VICKSBURG GROUP.

The rocks belonging to this group, the oldest geologic formation
known on the Peninsula, form the surface of the area from Sutherland
in the northwest corner of Hillsboro County northward to the vicinity
of Newberry and Gainesville. The western boundary is almost on the
water front at Sutherland and lies only 5 or 6 miles from the shore of
the Gulf from that place to Crystal River, beyond which it curves to the
northwest, roughly paralleling the shore at a distance of 6 to 12 miles
from it, to 6 miles south of the latitude of Cross City. This boundary
is slightly concave toward the west and is separated from the shore of
the Gulf by a narrow fringe of Quaternary deposits, ranging from 1 to 12
miles in width. The northern boundary of the area is a slightly sinuous
line running in an easterly direction from opposite. Pine Point through
Old Town, Newberry, just south of Gainesville, to Lockloosa. From
the last -mentioned town, the boundary bends southward and passes
through Sumterville, whence it extends southwestward to Sutherland.
The eastern boundary is strongly convex to the east. North of this
main area there are outlying small areas almost as far north as the
latitude of Lake City. If the boundaries of the main area were
extended so as to include the outliers, they would still retain a con-
cavity on the west and a convexity on the east.

APALACHICOLA GROUP.

As is implied in the preceding paragraph rocks of the Apalachicola
Group are not present between the western boundary of those of the
Vicksburg and the Gulf. The rocks of the main Vicksburg area pass
beneath the Apalachicola rocks on all sides except on the west, and all
outlying areas of the former are surrounded by rocks of the latter group.
The Apalachicola rocks continue northward into Georgia where outcrops
of the Vicksburg limit their northern extension. They extend to the
westward, separated from the coast by a margin of Pleistocene deposits,
to the vicinity of the mouth of St. Marks River, where they reach the
coast through a stretch of several miles. Thence they extend westward
to the Ocklockonee River near Sopchoppy, from which place the bound-
ary bends northward, passing west of Tallahassee; there it is sharply
flexed to the west and crosses the Apalachicola River at Alum Bluff.
Westward of a point 9 to 10 miles west of Tallahassee an area of Miocene
(the Choctawhatchee formation) intervenes between the Apalachicola
and the coastal fringe of Pleistocene deposits.

1 Florida Geol. Surv., 2d Ann. Report.

■■ " ■ ■ . ■ i ■

Adapiw Fran

.4 Contribution to the Geologic History of the Floridian Plateau. 147

Toward the east the Apalachicola Group is overlain near the eastern
boundaries of Baker and Bradford counties by Miocene sediments (Jack-
sonville formation). The Miocene projects southward, as a tongue, over
the Apalachicola as far as Waldo. Northwest from Palatka to the south
fork of Black Creek the Apalachicola boundary is formed by the Pleisto-
cene of St. John's River valley. Along the west side of St. John's River
valley, from Palatka southward to Enterprise Junction, the boundary
is formed by the overlapping of the Pliocene Nashua marl. The boundary
curves to the southwest of the latter town, passes through Orlando, Lake-
land, and reaches the Gulf at Tampa. Along this stretch from Enter-
prise Junction to Tampa, the boundary is between the Apalachicola and
the Pleistocene. South of Tampa two small outlying areas of Apalachi-
cola sediments are known, one at Ellenton near the mouth of Manatee
River; the other at White Beach,1 between Osprey and Sarasota.

MIOCENE.
Two Miocene areas are known in the State, a western and an eastern.
The former extends westward from near Tallahassee, and is bounded
on the north by deposits of the Apalachicola Group, and on the south by
those of Pleistocene age. The eastern area has its western boundary
formed by the Apalachicola Group. Except below the south loop of
St. Mary's River, where the Apalachicola outcrops, the northern boundary
is formed by Pleistocene deposits to St. John's River, about 6 miles north
of Jacksonville. From Jacksonville to St. Augustine on the east the
Miocene passes below Pleistocene and also from St. Augustine westward
to the South Fork of Black Creek. This area of Miocene is bounded on
the west by rocks of the Apalachicola Group; on the north, east, and
south by Pleistocene.

PLIOCENE.

There are two principal areas of Marine Pliocene. The more eastern
and northern of them (the Nashua marl) flanks the Apalachicola Group
from Palatka to Enterprise Junction along the west side of St. John's
River, and is overlain on the east by Pleistocene formations. On the
northeast the boundary runs southeast from Palatka toward Daytona,
thence it turns south to Osteen, then westward to Enterprise Junction.

The other area of Pliocene (the Caloosahatchee marl) is mostly
overlain by Pleistocene deposits, and outcrops of it are seen only along
streams, the Miakki River, Chiloccohatchee River, Peace, Prairie, and
Alligator creeks, all of which flow into Charlotte Harbor and Caloosa-
hatchee River.

PLEISTOCENE.

Southeast of the surface exposures of the Nashua marl and coast-
ward of the southeastern and southern margin of the Apalachicola Group
lying west of those exposures the entire surface to the sea front is
formed by Pleistocene formations, except a few outliers of the Apalach-
icola Group, the marine Pliocene Caloosahatchee marls along some
streams, and the non-marine Pliocene Bone Valley gravel near Bartow,
from Homeland to Mulberry, and at Bone Valley.

1 It seems that this locality was not included by Messrs. Matson and Clapp
in their report.

148 Papers from the Marine Biological Laboratory at Tortugas.

GENERAL RELATIONS OF GEOLOGIC BOUNDARIES IN FLORIDA.

The preceding account of the areal distribution of the geologic
formation according to successive ages has been given to show how the
rocks of Vicksburgian age form an eccentric nucleus, on whose northern,
eastern, and southern slopes younger geologic formations have been laid
down. The next younger group extended northward into Georgia, in
which State the Vicksburg again comes to the surface; but toward the
east, southeast, and south in Florida it is overlain by later sediments.
The boundaries between older and younger sediments are roughly con-
centric to the Vicksburg nucleus on the east and south, tending to widen
their areas to the south. This statement may appear doubtful, but when
it is recalled that Apalachicola sediments extend from the northern end
of Tampa Bay to below Sarasota Bay, a glance at the map will show
the greater width along a north-and-south line in this area than along an
east-and-west line through Palatka. A curved line would have to be
drawn from Daytona to Lake Flirt on the Caloosahatchee to show the
widening of the Marine Pliocene toward the south. South of St. Augus-
tine the Miocene has been buried by Pliocene and later sediments.

The present coast line preserves this relation to the Vicksburg
nucleus, but with the southward extension there has been a flattening
opposite the eastern convexity of the old nucleus.

DRAINAGE LINES.

An examination of the map of Florida with reference to the drainage
lines immediately shows that the State may be divided into two areas.
In the extension westward from Aucilla River, a region actually a part
of the main continental mass lying north of the Gulf of Mexico, the
stream courses are normal to the Gulf Coast. The other area is the Pen-
insula portion of the State. In the latter there is a general conformity of
the stream courses in the vicinity of the Vicksburg nucleus to its outline,
while away from it they more or less parallel the east and west coasts.

The streams of the Peninsula are those of special importance for
this discussion. Santa Fe River runs westAvard near the northern
boundary of the Vicksburg, to its confluence with the Suwanee River,
whence the latter stream trends southward across the northwestern
corner of the Vicksburg area. Between the headwaters of the Santa Fe
River and the Ocklawaha is a comparatively low divide with an elevation
of very little over ioo feet. Ocklawaha River follows near the eastern
boundary of the Vicksburg-Apalachicola from Lake Griffin northward
to the latitude of Nashua; then it bends abruptly eastward and flows
into St. John's River. Between the headwaters of the Ocklawaha and
those of the Withlacoochee and Hillsboro rivers is a region of low relief,
in which, excepting a few hills, no place attains an elevation of ioo
feet above the sea. Hillsboro River approximately parallels the south-
eastern boundary of the Vicksburg-Apalcahicola groups. These data
show that there is from the confluence of the Santa Fe with the Suwanee

1 1

A Contribution to the Geologic History of the FloriJian Plateau. 149

a valley approximately paralleling the northern, eastern, and south-
eastern boundary of the Vicksburg and the Apalachicola. (See plate 5.)

The only stream which does not conform to this arrangement is the
Withlacoochee. A study of the map leads to the suggestion that it has
been formed bv a stream working backward from the coast across the
Vicksburg area, and capturing a part of the headwaters of both Hillsboro
and Ocklawaha rivers, so that the non-conformity of the Withlacoochee
to the arrangement of the other streams is a later development.

The striking manner in which the northward flowing St. John's
River parallels the coast has frequently been emphasized, but the trends
of the southward flowing Kissimmee and Peace rivers are not less striking.
South of the elevated region in the vicinity of Haines City, the two main
drainage lines not only trend southward, but at their southern extremi-
ties are deflected toward the west. The deflection of Peace Creek is
through Charlotte Harbor, and the Kissimmee flows through Lake
Okeechobee, which is connected with the Gulf by the Caloosahatchee.

The trend of the drainage lines of Florida is therefore at first roughly
concentric to the Vicksburg nucleus and proceeding away from this
nucleus toward the east and the south the trends conform to the general
scheme of arrangement of the geologic formations and to the coast line.
The eastern coast of Florida follows a long sweep toward the southeast,
then bends south and turns by a curve toward the west.

The analogies of the eastern and southeastern outlines of the Vicks-
burg nucleus, the arrangement of the main drainage lines, and the outline
of the eastern and southern coasts of Florida are so striking that one is
forced to the conclusion that some common cause lies beneath all of these
phenomena.

150 Papers from the Marine Biological Laboratory at Tortugas.

GEOLOGIC HISTORY OF THE FLORIDIAN PLATEAU.

EVENTS OF VICKSBURGIAN TIME.
THE VICKSBURGIAN SUBMERGENCE.

During Vicksburgian time remarkable uniformity of marine condi-
tions prevailed throughout an extensive area of what are now the south-
ern United States, from central Louisiana, across Mississippi, Alabama,
and Georgia, and similar sedimentation was also taking place on the
Floridian Plateau, practically to its southern extremity, should the
material from the deep well at Key West, studied by Hovey, be trust-
worthy. A well record from Palm Beach, given on page 127, shows
that Vicksburg rocks were there encountered between 915 to 1,000 feet
below the surface. At Key West, according to Hovey,1 Orbitoides first
appears in abundance at a depth of 900 feet.

DEPTH AND TEMPERATURE OF THE WATERS.

It is important to determine the approximate depth of the Vicks-
burgian Sea; as it is the oldest geologic formation known on the Floridian
Plateau, light will be thrown on the age of the Plateau. The formation
of an opinion on this subject may be made possible by data from two
sources: (1) the material composing the sediments; (2) the character
of the fauna.

In Florida, the Vicksburg Group has been tentatively divided into
three formations, as follows: in west Florida, the Marianna limestone;
on the Peninsula, "Peninsular" and Ocala limestones. Recent investi-
gations in Georgia render it probable that only one formation should be
recognized, for in that State the Ocala can be definitely identified, and
no demarcation of the Marianna or "Peninsular" at present seems pos-
sible. In this discussion, which is an account of physical events, the
" Peninsular" and Ocala limestones are spoken of collectively by the
group-name Vicksburg. The Vicksburg limestones are predominatingly
calcareous, as the terminology suggests, but they are not pure, consider-
able proportions of both clay and silica being present. Matson makes
the following statement:

These beds are uniformly fine-grained and show little variation in chemical
composition. There is a predominance of limestone, though sand and clay occur
in small quantities, and the percentage of these impurities in the limestone increases
in the upper beds of this age. There is also an increased percentage of terrigenous
material toward the northern end of the State, where the proximity of older land
afforded opportunity for the entrance of considerable sand and mud into the Vicks-
burg sea. Toward the close of this period of deposition there appears to have been
a shoaling of the seas which permitted the entrance of the fresh-water shells and
the land-derived sediments noticeable in the Ocala limestone of the Vicksburg
Group. The excellent state of preservation of many of these shells shows that the

1 Mus. Comp. Zool., Bull., vol. xxvm, p. 67, 1896.

A Contribution to the Geologic History of the Floridian Plateau. 151

water must have been comparatively quiet during the deposition of the limestone.
The inclusion of a small percentage of land-derived sediments and in some places
of fresh-water shells shows that a portion of the limestones of Vicksburg age were
probably deposited at no great distance from land. Locally the calcareous sedi-
ments appear to have contained large quantities of silica, probably in the form of
tests of microscopic plants (diatoms) and spicules of sponges. (Florida Geol. Surv.,
2d Ann. Report, p. 162, 1910.)

The most persistently conspicuous fossils of this group of rocks are
foraminifera. Specimens and species of the genus Orbitoides are the
most abundant. This genus occurs not only from bottom to top, but
extends upward from the Jackson 1 below, and into the higher Chatta-
hoochee.2

In the Jackson at Montgomery, Louisiana, Orbitoides is associated
with shallow-water corals, as Astrangia; in the Vicksburg at Rosefield,
Louisiana, and in Mississippi and Alabama it is associated with shallow-
water mol'lusks, as Ostrea. The Vicksburg corals of Mississippi indicate
a depth of water not over 50 fathoms, and it may have been much shal-
lower. As the same species found in Louisiana, Alabama, and Mississippi
occur in Georgia, a similar moderate depth is inferred for that region.
The fauna of the area extending from Louisiana to the Savannah River
distinctly indicates shallow-water conditions, probably a maximum depth
of 50 fathoms, as the faunal associations of Orbitoides are those of
shallow water, or less than 100 fathoms. Doctor Dall has given a list
of species from the Ocala limestone in his Tertiary Fauna of Florida.3

The recent collections made by the Bureau of Fisheries steamer
Albatross in the Philippine Islands throw additional light on this problem.
At Station D 5179, off the northeast shore of Tablas Island (depth 37
fathoms, bottom temperature 76. 2° F., bottom hard, sandy), hosts of
foraminifera were obtained, two of which were identified by Dr. J. A.
Cushman as Operculina complanata var. granulosa and Amphistegina
lessoni. The material is remarkably similar to that of which the Vicks-
burg limestones are composed ; and the two are f aunally so similar that
it seems a sound opinion to consider the conditions of depth and tempera-
ture for the two deposits as similar.4 Operculina complanata var. granu-
losa is a common fossil in the Vicksburgian rocks in southern Georgia.

Mr. A. H. Clark informs me that he found large numbers of an
Orbitolites-\ike form in shell sand brought up on the flukes of an anchor
on the Grenadine bank near Union Island in a depth of between 4 and
7 fathoms.

The data presented in the foregoing remarks and the conclusion as
to the depth of the Vicksburg Sea mean that the Floridian Plateau
existed in Vicksburg time, and that its southern extent was about as
great as it is at present. The date of the origin of the Plateau is therefore
pre-Oligocene.

1 Orbitoides dispansa (Sow.) and O. papyracea (Boubee) are found in the
Jackson at Montgomery, Louisiana.

2 Orbitoides occurs in the basal Chattahoochee in the vicinity of Bainbridge,
Georgia. O. dispansa (Sowerby) is the usual species.

:t Wagner Free Institute, Transactions, vol. in, part vi, 1903.

4 I am indebted to Dr. Paul Bartsch for the opportunity of using this note.

152 Papers from the Marine Biological Laboratory at Tortugas.

SUMMARY OF VICKSBURGIAX EVENTS.

The following statement of the early history of this Plateau seems
substantiated:

(i) The Plateau was in time of pre-Oligocene origin.

(2) In Vicksburgian time there was an extensive submarine plateau

reaching from Central Louisiana to the Atlantic Ocean, with
a salient projecting from its southeastern corner as far south
as the southern limits of the present land surface of Florida.

(3) The depth of water on this Plateau probably in no place was so

great as 100 fathoms, more likely not over 50 fathoms.

(4) The temperature of the bottom was tropical or subtropical,

between 700 and 8o° F.

(5) Over the Plateau currents from the equatorial regions gently

swept, with the general direction of the ocean drift probably
from west to east. As no Vicksburgian strata have been
found in Texas and as there is a great thickness of Eocene
sediments in that State, it seems probable that there were
extensive landmasses west of the Vicksburg Sea as well as
north of it, and that these landmasses deflected the currents
from the south toward the east. However, the data are
not at hand for positively determining whether the main
drift toward the east passed over the submarine plateau,
or whether there was a countercurrent of warm water mov-
ing westward.

(6) Deposits of both terrigenous and organic origin accumulated

on this Plateau to a depth ranging from 100 to 200 feet
near shore to over 1,000 feet near the southern margin. As
the maximum depth at which any of the deposits were
formed was probably less than 100 fathoms, the deposition
took place on a sinking sea-bottom. The depression, how-
ever, kept pace with the deposition of organic and detrital
debris, thus permitting a considerable thickness of similar
material to accumulate on the sea-floor.

(7) During the latter part of Vicksburgian time the sea-bottom

was gradually elevated and a large area was uplifted into
dry land.

THE VICKSBURGIAN-APALACHICOLAN INTERVAL.

A large area of the Vicksburgian sea-bottom was elevated above the
sea-level before the initiation of the Apalachicola deposition; and this
elevation extended as far south as Tampa, and perhaps further. The
Apalachicola Group is divided into four geological formations, three of
which, the Hawthorne, Chattahoochee, and Tampa, were in part at least
contemporaneous; the fourth, the Alum Bluff, is geologically younger
than the three others. The Chattahoochee formation lies in Florida to the
northwest and north of the Vicksburg nucleus, and covers an extensive
area in southern Georgia; the Hawthorne formation occurs in Central
Florida to the north, northeast, and east of the Vicksburg; and the

A Contribution to the Geologic History of the Floridian Plateau. 153

Tampa lies to the south. The stratigraphic relations of each of these three
formations to the Vieksburg have been studied by a number of geologists,
and thev have been found to rest in the eroded surface of the Vieksburg.
Matson and Clapp have described these relations in detail in their Pre-
liminary Report on the Geology of Florida.1

The uplift of the Plateau produced differential movement, and it is
desirable to ascertain the relative amounts of movement in different
directions, but at present sufficient data bearing on the problem are not
available.

EVENTS OF APALACHICOLAN TIME.

The events of Apalachicolan time need separation into an earlier
stage, represented by the deposition of the Chattahoochee, Hawthorne,
and Tampa formations; and a later, represented by the Alum Bluff
formation.

Earlier Stage.

SHORE-LIXE.

The elevation which is described in the preceding section was
followed by subsidence, and large areas that had been dry land were
lowered beneath sea-level. The interior margin of the Apalachicolan
Sea lav considerably to the north of the Florida-Georgia line in Georgia,
and extended from the southwest corner of Decatur County northeast-
ward to the boundaries of Burke and Screven counties on Savannah
River. This sea was a shoreward portion of the Atlantic Ocean, but it
seems probable that a small area in Florida, in northeastern Marion
Count v, mav not have been entirely submerged, and that in other areas
over the Vieksburg nucleus these sediments were very thin. In Apalach-
icolan time a dome of Vieksburg rocks already existed. This land area
in the Apalachicolan Sea, however, could not have been extensive, as
rocks of Apalachicolan age occur as patches overlying the Vieksburg in
Hernando Count v, the town of Brooksville being on one of them, and
on the highland 6 miles west of Dade City, Pasco County, the Apalachi-
cola forms the ridge from the altitude of 150 feet to the hill summit,
200 feet or somewhat higher. The Apalachicola therefore, it appears,
entirelv covered the summits of Hernando County and has been removed
bv erosion. Another outlying area of this group is at Levyville, Levy
Count v. If the outlying patches are connected according to altitude with
themselves and the main Apalachicola area, the only area remaining
which was probably an island is the one near Orange Lake, on its south-
west side, in Marion County.

MATERIAL OF THE SEDIMENTS.

The nature of the deposition in the Apalachicolan Sea varied greatly.
Although calcareous constituents were common, argillaceous and are-
naceous material frequently predominated. Matson and Clapp state.
Florida Geological Survey, Second Annual Report:

1 Florida Geol. Surv., 2d Ann. Report, pp. 69, 75, 86.

154 Papers from the Marine Biological Laboratory at Tortugas.

The changes from sediments of one character to those of another were fre-
quently rapid, and during the entire time there was more or less intermingling of
different kinds of sediments, giving rise to the marls, impure limestones, shales,
and sands of this epoch.

In the east and south central portions of the Peninsula the clay and sand
predominated during the earlier part of this epoch, while farther north and west
(also east on the Savannah River) similar deposits characterized the later stages.
The calcareous materials which are found now in the form of marls and limestones
were especially important in the area drained by the Apalachicola River, but they
were also deposited in smaller quantities farther south and east. Throughout the
period represented by the Apalachicola Group the conditions governing deposition
appear to have differed considerably in neighboring localities, but there was no
such abrupt variation as ma}- be found along the present coast.

The facts recited in the preceding remarks indicate very shallow-
water conditions.

FAUNAL CHARACTERS.

Some of the faunal characters of the older formations of this group
are important. Coral reefs and massive corals which probably did not
form reefs were present. They have already been alluded to in the sec-
tion of this paper giving the stratigraphic distribution of reef corals,
but may be repeated.

In Georgia fossil reef or massive corals have been reported from the
following localities:

Decatur County: Flint River at Cherry Shoot, 3 miles below Bain-
bridge ; Blue or Russell Spring, 4 miles below Bainbridge ; Little
Horse Shoe Bend, about 0.75 mile below the preceding locality;
and Hales Landing, 7 miles below Bainbridge.

Grady County: 4 miles northeast of Forest Falls; 9 miles a little
west of north of Whigham.

Thomas County : 3 miles west of Metcalf ; 1 1 miles south of Thomas-
ville; 3 miles west of Boston; 4.5 miles south of Boston.

Brooks County: 1.5 miles east of Quitman.

Lowndes County: Withlacoochee River, about 3 miles below the
Valdosta Southern R. R. bridge; 2 miles northeast of Clyatts-
ville.

Screven County: Old Jacksonboro near Bascom P. 0.

In Florida the following localities are known:

Gadsden County: The vicinity of River Junction.

Wakulla County: The vicinity of Wakulla.

Suwanee County: White Springs on the Suwanee River.

Columbia County: 2 miles south of Lake City.

Alachua County: Numerous localities from 2 miles to 6 miles north

of the town of Alachua.
Hillsboro County: Ballast Point.

These corals occur in each of the three local formations forming the
lower portion of the Apalachicola group, viz: the Chattahoochee, the
Hawthorne, and the Tampa.

.4 Contribution to the Geologic History of the Floridian Plateau. 155

SUMMARY OF EVENTS OF EARLIER STAGE.

From the nature of the sedimentation and the faunal characters
the physical condition of the Floridian Plateau during this deposition
period may be reconstructed with considerable accuracy.

(i) The Plateau had approximately the same outline as at present,
reaching from the northern boundary of the Chattahoochee,
which, as previously stated, extends from southwestern
Decatur County to the boundary of Burke and Screven
counties on the Savannah River, positively south of the
latitude of Tampa, and probably to the northern edge of
the Florida Strait. In the area now known as Marion County
there may have been a small island of Vicksburg rocks.

(2) The depth of the water was probably at no place north of

Tampa so great as 100 feet.

(3) The temperature was tropical, the lowest for the year at least

as high as 700 F.

(4) As the temperature was tropical, the movement of the waters

must have been from the tropics, by a direct or by a return
or countercurrent.

(5) Terrigenous material was deposited over practically the whole

submerged plateau surface.

Later Stage.
SHORE-LIXE.

Conditions in the later stage of the Apalachicolan deposition had
changed considerably from those of the earlier. The physiography
of the region was different, and the approximate distribution of land
and sea should be determined at the beginning of this section of the
discussion. The sediments belonging to the Apalachicola Group subse-
quent in age to the Chattahoochee, Hawthorne, and Tampa formations
are referred to the Alum Bluff formation. The northern boundarv of
the Alum Bluff extends from the higher summits in Decatur County
northeastward to the Savannah River in southern Screven County.
South of this line the sea extended beyond the base of the Florida Penin-
sula to an island with a north-and-south axis from Gainesville to Tampa ,
and an east-and-west axis from Ocala to the west coast. This island,
here named Orange Island, may have extended farther westward and
comprised territory now beneath the waters of the Gulf. A submarine
platform extended southward of this island of Vicksburg and early
Apalachicola sediments. The evidence of the deposition of later Apalach-
icola sediments southward of Orange Island rests upon the discoverv
by Matson and Clapp of fossils of the Alum Bluff horizon in the vicinity
of Ellenton, on the Manatee River, south of Tampa l; and upon Dall's
previous record of fossils at White Beach, Little Sarasota Bay, of an
Oligocene horizon later than that of the Tampa localities.2

1 Florida Geol. Surv., 2d Ann. Report, p. 101, 1910.

2 Wagner Free Inst. Sci., Trans., vol. m. pt. vi, pp. 1 568-1 570.

156 Papers from the Marine Biological Laboratory at Tortugas.

SUWANEE STRAIT AND ORANGE ISLAND.

Orange Island was separated from the mainland to the north by a
broad strait, the Suwanee Strait of Dall.1 That marine conditions pre-
vailed across this area is proven by the occurrence of Alum Bluff species
of fossils at White Springs on the Suwanee River, where Matson and
Clapp obtained specimens of Ostrea rugifera Dall, Pododesma scopehts
Dall, and Pecten madisonius var. say anus Dall.2

For the details of the Alum Bluff formation across northern Florida
the report of Matson and Clapp in the Second Annual Report of the
Florida Geological Survey may be consulted.

DEFORMATION.

It is evident from the preceding remarks that during Apalachicolan
time there was differential earth-movement in the Floridian region. As
all of the sediments were laid down in shallow water, the sea-bottom
must have been subsiding to receive the considerable thickness known to
be present in west Florida and through the Suwanee Strait; while the
area represented by Orange Island was a region of uplift. These changes
in physiography were accompanied by changes in sedimentation, in
climate, and in the fauna.

TEMPERATURE.

The basal bed of the Alum Bluff formation on the Apalachicola and
the Chipola rivers is a yellow clay marl, the Chipola marl member, replete
with excellently preserved fossils, indicating a tropical temperature. The
vellow color is noteworthy, as it is predominant in the older stage of the
Apalachicolan time. The climatic conditions have been the subject of
detailed consideration by Dall.3 During the latter part of Apalachicolan
time the waters gradually cooled, ultimately becoming temperate. These
changes are most appropriately described by Dall, whose account is here
quoted:

As indicated by the changes in the fauna, the physical changes attending
the close of the Oligocene were at first slow, allowing a certain element of transition
to appear in the Oak Grove or uppermost Oligocene fauna. At the last they appear
to have been sudden, at least the change in the fauna on the Gulf coast was abso-
lute and complete. The change was not only in the species and prevalent genera
of the fauna, but a change from a subtropical to a cool temperate association of
animals. Previously, since the beginning of the Eocene, on the Gulf coast the
assemblage of genera in the successive faunas uniformly indicates a warm or sub-
tropical temperature of water, and the sediments uniformly show, from the Jack-
sonian upward, a yellowish tinge due to oxidation. In the Oak Grove sands come
the first indications of a change towards the gray of the Miocene marls. With the
incursion of the colder water the change becomes complete. Not only do northern
animals compose the fauna, but the southern ones are driven out, some of them
surviving in the Antilles to return later. Some change along the northern coast
permitted an inshore cold current to penetrate the Gulf, depositing on the floor of
the shoal Suwanee Strait, separating the island of Florida from the continental
shore, a thin series of Miocene sediments, which were also carried as far south as
Lake Worth on the east coast of Florida and Tampa on the west coast, as shown
by artesian borings. {Op. cit., pp. 1549, 1550.)

1 U. S. Geol. Surv., Bull. 84, p. in, 1892.

2 Florida Geol. Surv., 2d Ann. Report, p. 100.

3 Wagner Free Inst. Sci., Trans., vol. in, pt. ir, pp. 1574-1575, 1903.

.4 Contribution to the Geologic History of the Floridian Plateau. 157

The series of Apalachicolan events was terminated by a general
•elevation of the Plateau.

ABSENCE OF APALACHICOLA SEDIMENTS WEST OF THE VICKSBURG NUCLEUS.

Before taking up the discussion of the subsequent stages in the
history of the Plateau, the very striking peculiarity of the present sur-
face distribution of the geologic formations will again be noticed. The
Apalachicola Group is not now exposed above sea-level on the seaward
side of the Vicksburg exposures in Lafayette, Levy, Citrus, and Her-
nando counties; nor does any later geologic formation except a coastal
fringe of Pleistocene occur above sea-level in that area. As it does
not seem at all probable that no Apalachicola sediments were laid down
in this area, the explanation may be found in erosion during the Apalach-
icolan-Miocene uplift, or in a subsequent depression which submerged
the Vicksburg- Apalachicola boundary. The growth of the Peninsular
land-surface toward the east, southeast, and south, while there has been
no addition of importance on the west since Oligocene time, will be con-
sidered on later pages.

APALACHICOLAN-MIOCENE INTERVAL.

The uplift closing Apalachicolan deposition carried areas of the
former sea-bottom above the sea-level, and was followed by the sub-
aerial erosion of the Apalachicola sediments. The evidence of the ero-
sion of the Apalachicola previous to the deposition of the Miocene is
seen at Alum Bluff on the Apalachicola River and at Jackson Bluff on
the Ocklockonee River. At both localities the upper surface of the Alum
Bluff formation shows distinct erosion furrows and channels, with the
Miocene (Choctawhatchee formation) filling and overlying the irregu-
larities.1 It is difficult to find a gage of the amount of this elevation,
but it is evident that extensive areas of the Apalachicola sediments
became dry land and the subsequent Miocene depression did not again
carry all of them below the ocean level.

On the east coast, in the vicinity of Jacksonville and St. Augustine,
it appears from well-borings that sediments of Apalachicolan age are
either verv thin or even absent,2 the Miocene apparently resting on the
eroded surface of the Vicksburg. It is probable that the rocks of the
Apalachicola Group were entirely or almost entirely eroded away over
this area during the erosion interval immediately previous to the
Miocene depression.

EVENTS OF MIOCENE TIME.
DISTRIBUTION OF MIOCENE SEDIMENTS.

The Miocene was another period of subsidence and the sea was again
admitted over a considerable area of the Apalachicola sediments which
had been subjected to subaerial denudation, but not all of the previous
land area of those sediments returned to marine conditions. The present

1 Vaughan, in Matson and Clapp's report, Florida Geol. Surv., 2d Ann. Report,

pp. 114, Hi.

• Matson and Clapp, Florida Geol. Surv., 2d Ann. Report, p. 108, iyio.

158 Papers from the Marine Biological Laboratory at Tortugas.

surface distribution of Miocene deposits is from a locality about 9 miles
southwest of Tallahassee westward along the western extension of the
State. This is a narrow strip, 6 to 12 miles wide, bounded on the north
by the Apalachicola Group, on the south by Pleistocene deposits, except
at the eastern end of the area where the Miocene has been eroded and
the Apalachicola is exposed southwest of Wakulla River. No Miocene
outcrops are known on the base of the Peninsula between Tallahassee
and Trail Ridge, which forms the divide between the headwaters of
Santa Fe River and the St. John's River drainage. Miocene sediments
compose Trail Ridge whence they extend eastward to Jacksonville and
St. Augustine. The Miocene Sea extended northward, Miocene fossil-
iferous deposits being known at Brunswick, Doctortown, on the Altamaha
River, and at Porter's landing in Effingham County, on the Savannah
River, in Georgia. South of the latitude of St. Augustine the Miocene
is usually overlain by more recent deposits, and few exposures have
been reported. The reported localities are given in the following notes:

Dall 1 reports Pecten jeffersonius and Carditamera arata from Pres-
ton sink, 3 miles north of Waldo, Alachua County, a locality at the south-
ern end of Trail Ridge; and Venus rileyi, V. permagna, and Arcalimula
at a depth of 208 feet in a well at St. Augustine. The presence of Pecten
madisonius in a collection of Pliocene fossils from the banks of St. John's
River, a quarter of a mile below Nashua, Putnam County, indicates
Miocene at that locality.2 Pecten of the type of madisonius , and a Chi one
of the type of cancellata were obtained from a well at De Land, the former
suggesting Miocene as the age of the bed.2

E. A. Smith obtained from Rock Springs near Zellwood, Orange
County, Pecten madisonius, Venus alveata, V enericardia granulata, Car-
ditamera arata, and Mytiloconcha incurva identified by Heilprin.3 Heil-
prin reports from Rocky Bluff on the Manatee River, 5 or 6 miles above
Braidentown, Area incongrua, Perna maxillata, Pecten jeffersonius, P.
madisonius, and Venus alveata.* Dall states that "it is probably from
more westerly submarine strata belonging to this series of beds that was
derived the Ecphora collected by Doctor Stearns in 1868-69 on the
beach of Long Key."5 Miocene fossils, Pecten jeffersonius and Pecten
madisonius, were also obtained by Professor Heilprin on Phillips Creek,
which flows into Little Sarasota Bay.G

No Miocene outcrops occur between the Vicksburg and Apalachi-
cola areas of the Peninsula and the west coast.

Well-borings show that Miocene is present beneath later formations
even as far south as the keys. The records of the Palm Beach well given
on page 1 27 of this paper show Miocene between 800 and 915 feet and per-
haps at 400 feet beneath the surface. The deep well at Marathon on
Key Vaca (see page 128) revealed probably Miocene fossils between 375

1 U. S. Geol. Surv., Bull. 84, pp. 124, 125, 1892.

2 Matson and Clapp, Florida Geol. Surv., 2d Ann. Report, p. 122, 19 10.

3 Am. Jour. Sci., 3d ser., vol. xxi, p. 302, 1881.

4 Wagner Free Inst. Science, Trans., vol. 1, p. 13, 1887.
5U. S. Geol. Surv., Bull. 84, p. 125, 1892.

6 Dall, op. cit., p. 126.

.4 Contribution to the Geologic History of the Floridian Plateau. 159

and 420 feet below the surface. The arenaceous composition of the
Miocene near the southern edge of the Plateau has already been stated,
but may be repeated.

LITHOLOGY.

Lithologically the Miocene of the western area (the Choctawhat-
chee formation) and that of the eastern (the Jacksonville formation)
are decidedly different. The former is predominantly arenaceous, the
sands are of a greenish color, weathering yellow or reddish, with an
abundance of well-preserved fossil shells, overlain at Alum Bluff by a bed
of plastic clay ; the latter contains light-colored, impure, arenaceous lime-
stone beds, particularly near the top, with a large amount of argillaceous
material, varying in color from light gray to pale yellow.1 There are
sands and clays below the limestone beds of the Jacksonville formation.
The thickness of the Choctawhatchee formation varies from 25 to 50
feet, while that of the Jacksonville may be from 400 to 500 feet.

MIOCENE CORALS.

Attention has not been called to the changes in the coral fauna of
the Miocene from that of the preceding Apalachicola Group. The change
in it is more striking, if not more important, than that in the mollusks.
Reef corals abounded in the older beds of the Apalachicola Group.
Corals of that type become rarer in the younger deposits of that group,
and are entirely absent in the Miocene formations. The change is dra-
matic in its intensity.

SHORE-LINE.

In reconstructing the marine conditions of Miocene time the approxi-
mate shore-line must be determined, and the focal point of interest is
the Suwanee Strait. As has been stated, no Miocene deposits are defi-
nitely known between Tallahassee and Trail Ridge. The altitude of the
exposures near Tallahassee is about 100 feet ; near Trail Ridge they attain
a height, according to the map, of 200 feet. Intervening altitudes are
above 150 feet, as at Lake City and Houston. Dall says:

West of Jacksonville, at Live Oak, Suwanee County, and Lake City, Colum-
bia County, specimens of fossils were obtained which may prove to belong rather
to this (Jacksonville formation) than to the Chattahoochee group of beds. (U. S.
Geol. Surv., Bull. 84, p. 125, 1892.)

This is a surmise and not an opinion, and later work has not verified
the surmise, but it seems probable that Miocene deposits may have
extended across this intermediate area. Matson and Clapp say:

At the close of the Oligocene the State of Florida appears to have had the
same general form that it now has, though its area was doubtless less than it is at
the present time. With the inauguration of the Miocene there came a submergence
which appears to have reduced the land area to a narrow strip along the northern
end of the State, and a peninsula which was shorter and narrower than it is at pres-
ent. During part of this period the central portion of the peninsula may have
been separated from the mainland by a shallow strait. The exact extent of the
encroachment of the sea during Miocene times is difficult to determine because

1 Matson and Clapp, op. cit., p. 108.

160 Papers from the Marine Biological Laboratory at Tortugas.

the deposits have been partially removed by subsequent erosion and their present
extent is often obscured by considerable thickness of younger beds. (Florida
Geol. Surv., 2d Ann. Report, pp. 165, 166, 1910.)

The question as to whether or no the Miocene sea extended through
the Suwanee Strait must for the present remain without a definite answer.
The available evidence now permits only the statement that the Strait
may have again had ocean currents flowing through it. Except in the
Suwanee Strait region, the Miocene shore may be outlined with consider-
able definiteness. In west Florida it reached from a short distance north
of the present Apalachicola-Miocene boundary, probably not extending
to the southern limits of Georgia, into Alabama in the vicinity of
Mobile. The problematic condition of the Suwanee Strait has been fully
discussed; it is not positively known whether the Strait was open, or
whether there was a short peninsula bounded on the east by a shore-line
just west of Trail Ridge and projecting as far south as Tampa. Doctor
Dall has at my request contributed the following remarks to this
discussion :

In the absence of evidence which would conclusively prove the post-Oligo-
cene existence of the Suwanee Strait, one consideration had much weight with me
in assuming it as highly probable. This is connected with the presence of the phos-
phate beds in the central peninsular region of Florida. There is practically no
doubt as to the origin of these beds from the presence in Miocene and perhaps later
times of immense rookeries of birds, and perhaps other animals, whose guano was
absorbed by the porous limestone underlying their chosen habitat. Now experi-
ence shows that such rookeries are invariably separated from possible incursions
of carnivorous continental enemies by impassable bodies of water. Otherwise the
birds could not maintain themselves, and the occupation of their rookeries for a
period, such as was necessary for the formation of the phosphatic deposits, would
have been impossible. The erosion of shallow beds of Miocene age under condi-
tions which have existed in Florida, over part of the area of the supposed strait,
is not an exceptional or remarkable phenomenon; and it is quite possible that
more exhaustive exploration than has yet been possible may reveal traces of the
missing Miocene sediments.

In Georgia the shore of the Miocene sea lay somewhat west of a line
passing through Doctortown, on the Altamaha River, and Porter's Land-
ing, on the Savannah River, but it did not entirely overlap the Apalachi-
cola sediments. All of Florida excepting the land areas indicated was
submerged.

DEPTH OF WATER.

The depth of the sea is shown by both the kind of sediments and the
fauna. The sediments are near-shore, shallow-water deposits, and are
predominantly terrigenous, although there is some lime in the Jackson-
ville formation, probably chemically precipitated, and lime of organic
origin, the calcareous remains of fossils. The fossils, comprising such
genera as Ostrea, etc., indicate shallow-water conditions. The Floridian
Plateau extended to the southern margin of the keys, as shown by
the deep well at Marathon, Key Vaca. Probably at no place over the
platform did the depth exceed a few fathoms, 25 or 30 seems a safe
maximum. The maximum thickness of the Choctawhatchee formation,
50 feet, demands no continuous depression of the rea-bottom along the

A Contribution to the Geologic History of the Floridian Plateau. 161

western extension ; but the thickness of the Jacksonville formation, 400
to 500 feet, indicates progressive subsidence during a portion of Miocene
time.

TEMPERATURE.

Dall has given an excellent statement of the temperature of the
Miocene waters of the region (see quotation on page 156). He also says:

As I have on various occasions insisted, the faunal gap between the upper-
most Oligocene (Oak Grove) l and the Chesapeake or Miocene is the most sudden,
emphatic, and distinct in the whole post-Cretaceous history of our southeastern
Tertiary, and indicates physical changes in the surrounding region, if not in Florida
itself, sufficient to alter the course of ocean currents and wholly change the tem-
perature of the waters of our southern coast. (Wagner Free Inst. Sci., Trans., vol.
in. pt. vi, p. 1594, i9°3-)

Temperature conditions had within a relatively short time passed
from tropical to those of the latitude of Chesapeake Bay, or even the
southern coast of Cape Cod and Long Island.

In an attempt to deduce the temperature of the Miocene waters of
Florida, the data presented in Sir John Murray's "On the Temperature
of the Floor of the Ocean and of the Surface Waters of the Ocean" 2
have been used. As the Miocene fauna was one of shallow water, the
bottom temperature was probably not greatly different from that of the
surface. It may also be said that the minimum temperature of the winter
months is much more influential in determining the distribution of organ-
isms than the maximum temperature of the summer months. For in-
stance, according to Map 3 of the paper cited, a summer temperature
of 8o° to 900 F. extends from the Caribbean Sea and Gulf of Mexico
northward to New York Harbor, or during the summer a tropical tem-
perature extends far northward.

In the winter conditions are very different. The minimum tempera-
ture for the west coast of Florida is between 6o° and 700 F.; for south
Florida and the east coast, between 700 and 8o° F. ; on the south side of
Cape Hatteras, 400 to 500 F.; north of Hatteras to Delaware Bay, 300 to
400 F.; north of the last-named locality the temperature may be below
300 F. Therefore during the Miocene the minimum winter temperature
of the waters was at least as low as between 400 and 500 F. and it may
have been as low as between 300 and 400 F.; or between 200 and 300 F.
cooler than the present winter temperature of the west coast, and between
300 and 400 or even 500 cooler than the present winter temperature of
the east coast.

CURRENTS.

There was indisputably, as Dall has so often emphasized, a cold
current admitted along the shores of the land of embryonic Florida,
assuredly as far west as Pensacola Bay. This current could not have
been from the Equator, but must have been a southward flowing return
or countercurrent from the north ; and in my opinion this countercurrent

1 The Shoal River marl, member of the Alum Bluff formation, has been sub-
sequently differentiated. (Vaughan, in Matson and Clapp, Preliminary Report
on the Geology of Florida, Florida Geol. Surv., 2d Ann. Report, pp. 104-106, 1910.)
3 The Geograph. Jour., July, 1899.

11

162 Papers from the Marine Biological Laboratory at Tortugas.

initiated that series of countercurrents so important in the subsequent
accumulation of sediments on the Floridian Plateau, and the formation
of much of the present land surface of Florida. It brought sand and
other terrigenous material from the north to be dropped on the Plateau,
causing its surface gradually to approach sea-level. The transportation
of sediment from the north by a current flowing down the western side
of the Peninsula or island of Vicksburg and Apalachicola formations
partly explains why the land surface has grown on the east and south
and why there has been so little growth on the west. It partly explains
the arrangement of the surface outcrop of the later geologic formations
with reference to the older eccentric nucleus, and the arrangement of
the main drainage lines, described on preceding pages. It also partly
explains why there are 400 to 500 feet of Miocene sediments on the east
coast and only 25 to 50 feet on the westward extension. The burden
of sediment brought to the ocean by streams in Georgia and the Caro-
linas was by the agency of this current moved southward to the Florida
bank. Henceforth, the development of Florida was largely dominated
by the southward moving shore currents.

UPLIFT AT THE CLOSE OF THE MIOCENE.

Toward the close of Miocene time the Plateau was again subjected
to an upward earth-movement, whereby the Suwanee Strait, which,
should it have been open during a portion of the period, was definitely
closed, and it is probable the Trail Ridge was uplifted. There was more
upward movement on the east and south than on the west, for no Mio-
cene was brought above the sea-level along the shore from Levy to Pasco
counties, while submerged Miocene is apparently present off the mouth
of Tampa Bay.

EVENTS OF PLIOCENE TIME.

STRATIGRAPHIC RELATIONS OF PLIOCENE TO MIOCENE SEDIMENTS.

There is a lack of defmiteness of information regarding the strati-
graphic relations of the Pliocene to the Miocene sediments. It is not
positive whether there was a subsidence at the beginning of the Pliocene
or whether Pliocene sedimentation took place on areas of the Miocene
that remained submerged. Matson and Clapp say concerning the strati-
graphic position of the Pliocene Nashua marl of St. John's River valley:

The Nashua marl is thought to rest uneonformably upon the Miocene at De
Land, but this opinion lacks confirmation, as the collections from that locality
have not been studied in sufficient detail to determine the exact age of the beds.
(Florida Geol. Surv., 2d Ann. Report, p. 128, 1910.)

The same authors say concerning the Caloosahatchee marl:

The contact of the Caloosahatchee marl with the underlying Miocene has not
been observed, but there is considerable change in fauna between it and the Miocene,
which is probably due to physiographic changes which may have permitted the
erosion of the Miocene beds before the beginning of the Pliocene deposition.

AREAL DISTRIBUTION OF MARINE PLIOCENE IN FLORIDA.

There are two important areas of marine Pliocene in Florida. The
more northerly, the Nashua marl, occurs along the St. John's River
valley from the vicinity of the town of Nashua southward to Enterprise

.4 Contribution to the Geologic History of the Floridian Plateau. 163

junction, and extends eastward until overlain by Pleistocene deposits.
There are certain peculiarities of this formation that should be noticed.
The following five species, collected at Nashua, Eupleura miocenica var.
intermedia Dall, Ilyanassa porcina Say, /. isogramma Dall, /. granifera
Conrad, and Nassa scalaspira Dall, occur in the Waccamaw Pliocene
of the Carolinas, but not in the Caloosahatchee marl of Florida. The
presence of Pecten madisonius suggests Miocene in the same bluff, and
that both Miocene and Pliocene are represented, but the beds have not
been differentiated.

Exposures of Pliocene marl occur at the following additional locali-
ties southward along the St. John's River: 0.5 mile above the Atlantic
Coast Line bridge over St. John's River. Putnam County; 0.5 mile south
of De Leon Springs Station, Volusia County, 5 miles below Sanford
railroad bridge, east side of St. John's River, and perhaps 7 miles below
Sanford railroad bridge.

Proceeding southward the species belonging to the Waccamaw
fauna disappear; they are found only at Nashua; and the southern
exposures seem geologically younger. In the exposure 7 miles below the
Sanford railroad bridge, every species might be Pleistocene, and the
exposure was tentatively referred to the Pleistocene because of its simi-
larity to the one 5 miles below the bridge.

In the northern drainage ditch 6.5 miles west of Fort Lauderdale,
Mr. Matson obtained 17 species of fossils that were specifically identified;
16 of these are also Recent, and one, Strombus leidyi, was not previously
known from beds younger than the Caloosahatchee. This exposure
was tentatively referred to the Pleistocene because of its relation to other
exposures definitely Pleistocene. These facts lead to the inference that
southward from Nashua younger Pliocene beds are encountered, and that
the Pliocene fauna is very gradually supplanted by that of the Pleistocene.1

A considerable collection of Pliocene fossils was obtained from a
well on the property of Mary Boss, on an island in Lake Tohopekaliga,
about 3 miles from Kissimmee, at a depth of 150 feet. The Pliocene is
here overlain by at least 100 feet of Pleistocene beds.

The eastern Pliocene area overlaps the Miocene, and flanks the east-
ern side of the Apalachicola Group, extending southward along St. John's
River valley from Nashua to Sanford ; it is overlain on the east and south
by Pleistocene deposits, but is shown by well-borings to be present at a
depth of 150 feet in Lake Tohopekaliga. No surface exposures of marine
Pliocene are known between Sanford and Zolfo Springs on Peace Creek.

The Caloosahatchee marl constitutes the second, the more southerly,
of the marine Pliocene formations. The type locality is along the Caloosa-
hatchee River from Fort Thompson, near Labelle, to Olga. This river
stretch has been studied and described by Heilprin,2 Dall,3 Matson and

1 A collection made by me on North Creek, near Osprey, Manatee County,
furnishes additional evidence in favor of this opinion. Besides usual Pleistocene
species I also obtained at this locality specimens of Pyrazisinus scalatus Heilprin,
a species previously known only from Pliocene beds.

- Wagner Free Inst. Sci., Trans., vol. 1, pp. 22-33, 1887.

3 U. S. Geol. Surv.. Bull. 84, pp. 142-146. 1892, and Wagner Free Inst. Sci.,
vol. in, pt. vi. pp. 1603-1614, 1903.

164 Papers from the Marine Biological Laboratory at Tortugas.

Clapp,1 and I went over it with the two last-named geologists. Thanks
to the splendid researches of Dall, no Tertiary horizon is paleontologi-
cally better known.

Besides the exposures along Caloosahatchee River, others are known
along streams or the tributaries of streams flowing into Charlotte Harbor,
viz: Miakki River, Chiloccohatchee River, Peace Creek, as far north
as Zolfo Springs, Prairie Creek, Alligator Creek, and the famous Shell
Creek; and along streams that do not flow into Charlotte Harbor, " Rocky
Creek, which flows into Lemon Bay, near Stump Pass." 2 Considerably
east of Peace Creek beds of marl containing "large clams" have been
reported to Mr. Willcox as occurring on the banks of Arbuckle Creek.2

The last-mentioned exposure deserves careful investigation, as it is
directly in line between the Caloosahatchee exposures and the buried
Pliocene of Lake Tohopekaliga.

It has not so far been possible to differentiate Pliocene from Pleisto-
cene and Miocene in the well-borings south of the latitude of the southern
end of the Lake Okeechobee, but it is not to be doubted that Pliocene is
represented in the wells. The borings, however, do not indicate any
great changes of deposition conditions.

LITHOLOGY AND THICKNESS.

Both the Nashua and Caloosahatchee marls bear close lithologic
resemblance, both consisting of shell marls interstratified with beds of
sand. The maximum thickness of the former is about 32 feet at De
Land3; that of the latter probably about 25 feet.4

SHORE-LINE.

The Pliocene submergence was not so extensive as that of the Mio-
cene. The shore-line lay west of St. John's River from Palatka south-
ward to opposite Sanford, whence it continued southward keeping on
the west side of Lake Tohopekaliga ; it probably passed around the south-
ern end of the ridge on which Haines City is situated, and then turned
southwest to the vicinity of Sarasota Bay. Probably the territory east
of St. John's River extending from Palatka northward to beyond
Jacksonville, was also submerged. There is no evidence of any sub-
mergence of the west coast north of Tampa.

DEPTH AND TEMPERATURE OF THE PLIOCENE SEA.

Dall has attempted to reconstruct the conditions of depth and tem-
perature prevalent during the deposition of the Caloosahatchee marl.
He says:

The assemblage of species on the whole, in the principal stratum, is such as
one might expect to find in water from 20 to 25 feet in depth, judging by what we
know of living mollusks. Mixed with these are a certain number of shallow-water
forms which may be supposed to have flourished as the water became shoal by

1 Florida Geol. Surv., 2d Ann. Report, pp 123-128, 1910.

2 Dall, U. S. Geol. Surv., Bull. 84, p. 148.

3 Matson and Clapp, Florida Geol. Surv., 2d Ann. Rept., p. 129.

4 Matson and Clapp, op. cit., p. 124.

.4 Contribution to the Geologic History of the Floridian Plateau. 165

elevation of the sea-bottom. There were lagoons of fresh water and probably
streams emptying into the sea and in time of flood sweeping their fresh-water
population out onto the shoals, where it perished. Part of the bottom became
elevated nearly to the surface, oyster banks were formed on it, and the compacter
parts became water-worn. The absence of shells like Litorina and Nerita seems
to indicate that the dry beaches were muddy or sandy rather than rocky. In the
course of time elevation so shoaled the water that only species like Venus cancellata
and others able to live between tide marks could remain. This portion of the for-
mation constitutes the so-called Venus cancellata bed, though neither of its compo-
nent species is peculiar to it. Finally the area became cut off almost entirely from
the sea and occupied more or less by fresh-water ponds in which the pond snails
multiplied in myriads. (U. S. Geol. Surv., Bull. 84, pp. 145. J46.)

Concerning Venus {Chione) cancellata, Dall says in a preceding
paragraph:

In this connection it may be stated that Chione cancellata is known from the
Chipola Old Miocene [Apalachicola Group] marls, in no respect differing from
recent specimens, and that it has continued as a conspicuous member of the Florida
fauna (except during the epoch when the Ecphora beds [Miocene] were being de-
posited) up to the present day. It is a warm-water shell and extended in abundance
farther north during Chipola times and the newer Pliocene than during the period
when the beds of the Chesapeake Group were being deposited or at present. The
last-mentioned periods were and are entirely relatively cooler, and the two former
relatively warmer, judging by the fauna. The species has never been entirely absent
and at the present day reaches as far north as Hatteras, in the warm-water area.
It is also a shallow-water shell, living chiefly between tides when the climate
is mild enough.

Corals are found fossil in the Caloosahatchee marl, although no
reefs are known. The genera comprise Dichocamia, Meandrina (" Pec-
tin ia"), Cyphastrea, Mceandra (M. areolata is abundant), Siderastrea,
etc. These genera indicate shallow water, a maximum of not over 25 or
30 feet, more probably not more than 10 or 15 feet, and a tropical tem-
perature, 700 F. as a minimum. The assemblage is that of an extensive
flat . The corals and mollusks both indicate the same physical conditions
prevalent over the areas in which the Caloosahatchee marl was deposited.

In the area of the Nashua marl conditions nearly the same, but
with a slightly lower temperature, must have prevailed, for Chione can-
cellata was included in the collections of fossils from every locality except
one, and that was a small collection from the east side of St. John's
River, 7 miles below Sanford. The opinion may therefore be confidently
expressed that seaward, east and south of the Pliocene shore, the Florid-
ian Plateau continued as a shallow submarine bank, having practically
the same outline as the present Plateau. The cold water of Miocene
time had been diverted offshore, or had at least been replaced by warm
waters from the tropical regions, and on this bank arenaceous sediments
brought from the north entombed the calcareous remains of organisms
that lived on it.

CONFORMITY OF THE PLIOCENE TO OTHER GEOLOGIC BOUNDARIES.

The conformity of the western boundary of the Miocene sediments
to the outline established by the Oligocene, Vicksburg and Apalachicola,
formations, and to the present outline of the east and south coasts of
the State, is observed by the Pliocene deposits, leading to the inference

166 Papers from the Marine Biological Laboratory at Tortugas.

that the material was largely brought from the north by alongshore
currents, moving toward the south and southwest. This was not a
cold but a warm return or countercurrent similar to the one now moving
southward along the Florida east coast.

EVENTS ABOVE SEA-LEVEL.

Important events were taking place on the land on which fluvial
and lacustrine deposits were accumulating, while the marine history
outlined in the foregoing remarks was being enacted. As this paper is
especially devoted to the marine history of the State, the episodes con-
fined to the land surface will not be recounted. They may be found in
Dall's chapter on Florida in the Correlation Paper, "Neocene,"1 by him
and Harris, and Matson and Clapp's Preliminary Report on the Geology
of Florida.2

UPLIFT AT THE CLOSE OF THE PLIOCENE.

Toward the close of the Pliocene deposition the Plateau mass again
began an upward movement, as was evidenced by the shoaling in the
Caloosahatchee area and the formation of fresh-water ponds. This
upward movement continued until extensive areas of the Pliocene sea-
bottom were lifted above sea-level.

PLIOCENE-PLEISTOCENE INTERVAL.

The history of this interval unfortunately is not so clear as is desir-
able. The shoaling of the Pliocene sea and the rise of former sea-bottom
was made evident in the preceding paragraph. Data are deficient for
a definite estimate of the amount of the emergence.

Professor Shaler, because the Vicksburg limestone has lost its salt
water to a depth of a thousand feet, postulated an elevation of at least
that amount.3 Matson in criticism of this conclusion says:

The deep wells all penetrate the limestones of Vicksburg age, and hence it is
the beds of that age which have been drained of salt water. As a portion of these
beds have been above sea-level since Oligocene time, the salt water may have been
removed before the Pleistocene. The magnitude of the emergence is not necessarily
so great as 1,000 feet, because, given the necessary chance for escape, the salt
water would probably be displaced by fresh water, provided the surface was high
enough to afford a small hydrostatic pressure. The absence of impervious beds
of clay above the submarine portion of the Oligocene limestones would permit the
escape of the water, and hence considerable thicknesses of the older rocks may
have been filled with fresh water without being raised much above their present
altitude. (Florida Geol. Surv., 2d Ann. Report, p. 169, 1910.)

Two other probable criteria are left. The first is the existence of
underground channels from which submarine fresh-water springs issue
near the coast. The best known of these springs is one near St. Augus-
tine. Matson and Clapp furnish the following account of it:

According to Captain E. C. Allen of that city [St. Augustine], the orifice of
the spring is about 60 feet across and the depth is about 200 feet. The depth of
the sea at the point of emergence is said to be about 50 feet and the water emerges

1 U. S. Geol. Surv., Bull. 84, pp. 127-131, 1892.

2 Florida Geol. Surv., 2d Ann. Report, pp. 133-145, 167, 1910.

3 Bost. Soc. Nat. Hist., Proc, vol. xxiv, p. 584, 1890.

A Contribution to the Geologic History of the Floridian Plateau. 167

with force enough to cause a distinct convexity of the surface during calm weather.
According to some authorities, it is difficult to row a small boat across the surface
above the spring on account of the outward movement of the water from above
t he i >rifice.

These springs can scarcely be older than the age here assigned them,
otherwise they would have been filled by sediments. During this uplifl ,
it appears the main drainage lines north of Lake Okeechobee were deter-
mined. It is known that the St. John's River channel has a depth of 65
feet below mean tide opposite Jacksonville.1

The precise date of the cutting of the submerged channel at the
mouth of St. John's River has not been determined and is here only
tentatively referred to the interval between the deposition of the Pliocene
and Pleistocene.

That there was uplift in this interval is indisputable. The available
evidence does not suggest that it was over 200 feet.

Accompanying this oscillation, either with the uplift or the subse-
quent depression, there was deformation. Pliocene fossils occur at a
depth of 150 feet in Lake Tohopekaliga and it is overlain by at least 100
feet of Pleistocene deposits— perhaps 150 feet. As the elevation of the
land surface at Kissimmee at the northern end of this lake is 60 feet, the
Pliocene is 90 feet below sea-level. The Pliocene at De Leon Springs
on the north is between 20 and 40 feet above sea-level ; along the Caloosa-
hatchee River 6 to 12 feet. The Pleistocene in the vicinity of Kissim-
mee fills a depression in the surface of the Pliocene to a depth of at least
100 feet, while it is thin along the Caloosahatchee and also at De Leon
Springs. The thickening of the deposits near Kissimmee seems to indi-
cate that a Pliocene syncline existed at the time of this deposition, and
that there was a very gentle anticlinal ridge, or swell, parallel to the
east coast, and a second similar gentle swell extending north from the
Caloosahatchee west of Kissimmee River, between it and Peace Creek.
Haines City occupied the northern end of this ridge. Between these
two gentle anticlines is the shallow syncline occupied by the Kissimmee
Valley. The eastern anticline was one of the agencies determining the
location of St. John's River. It seems probable that there was a third
gentle fold between Peace River and the west coast.

These structural features have their axes parallel to the axis of the
Peninsula. Heilprin, Dall, and Matson and Clapp have all described the
folding of the Pliocene strata along the Caloosahatchee. Dall says con-
cerning these folds:

As the river [Caloosahatchee] is ascended, a close scrutiny shows that it cuts
through a succession of gentle waves, gradually increasing in height, inland, whose
crests would show a general parallelism with the direction of the Peninsula of
Florida, or transverse to the average course of the river. Near the headwaters of
the river these waves of elevation rise above the level of the river at low water to
a height of perhaps 12 feet at most, and their individual length from one trough
to another may average about a quarter of a mile. Though insignificant as flexures,
thev are interesting as showing that a lateral as well as a vertical thrust has attended
the movements of the rocks in this part of the State, a fact which has been ques-
tioned. (U. S. Geol. Surv., Bull. 84, p. 143, 1892.)

1 Matson and Clapp, op. cit., p. 172.

168 Papers from the Marine Biological Laboratory at Tortugas.

In February, 1908, I went over the exposures along the Caloosa-
hatchee described by Dall in the preceding quotation, and observed the
phenomena. The Pleistocene deposits did not seem to participate in all
of the deformation of the Pliocene, pointing to the conclusion that defor-
mation intervened between the two deposition periods. This period of
elevation was succeeded by one of depression.

EVENTS OF PLEISTOCENE TIME.

The elevation described in the preceding section is supposed to initi-
ate the Pleistocene, but it is given an individual caption, following the
plan of separating intervals of uplift from those of depression. ^ In a
region such as the Floridian, which lies outside the area of glaciation,
it is not possible sharply to differentiate between the end of the Pleisto-
cene, marked by the final retreat of the glaciers, and Recent, which
succeeded their disappearance.

PLEISTOCENE SUBMERGENCE.

The Pleistocene submergence was extensive. Along the western
extension and the west coast as far south as Tampa, a narrow border
was below sea-level. Proceeding eastward from Tampa Bay, marine
Pleistocene fossils are found at the following localities: Six Mile Creek,
at Orient Station, Hillsboro County; in a ditch alongside the railroad,
0.125 of a mile south of Manatee Station, Manatee County; North Creek
near Osprey; Caloosahatchee River; Kissimmee, in wells at depths of
90 to 100 feet; West Palm Beach, depth 74 feet; 2 miles southeast of
Eau Gallie; 4 miles west of Eau Gallie; 0.25 mile and 1 mile north of
Mims; Ormond, depth 50 to 56 feet; St. Augustine, at least 30 feet
thick, and on St. Mary's River near its mouth.

The localities mentioned indicate that the Pleistocene shore-line lay
slightly north of the head of Hillsboro Bay, whence it probably passed
south of the southern end of the divide west of Peace Creek, keeping
between the 50- and 100-foot contours of the present land area; thence
it extended around the southern end of the divide between Peace Creek
and Kissimmee River, it followed the west side of the valley of the latter
stream, by Orlando, a few miles west of Sanford, and very likely the
area east of St. John's River was submerged; certainly the valley of this
stream and a coastal fringe from Daytona northward into Georgia were
under water. Over half of the present land surface of Florida was below
sea-level.

The Pleistocene formations extend down the east coast and thence
across the southern end of the Peninsula, exhibiting relations to the old
Oligocene nucleus and the present coast line similar to those exhibited
by the Miocene and Pliocene, except there is a coastal fringe of Pleisto-
cene on the west coast north of Tampa Bay.

DIFFERENCES IN PLEISTOCENE SEDIMENTS.

The material of the marine Pleistocene varies greatly in different
areas. There are shell marls, coquina beds, the Palm Beach limestone,
the Miami oolite, the Key Largo and Lostman River limestones, and

.4 Contribution to the Geologic History of the Floridian Plateau. 169

the Key West oolite, besides deposits of non-fossiliferous sands. There
are estuarine deposits along the lower courses of some streams and stream
terraces. The respective areas of the various marine deposits will be
briefly outlined in order to determine the physical conditions prevailing
over those areas during the deposition of each kind of material.

COQUINA.

Coquina is composed of more or less water-worn molluscan shells
embedded in a matrix of calcium carbonate and sand. The degree of
cementation varies from that sufficient for use as building stone, as in the
neighborhood of St. Augustine, to very loose aggregation. The loose
aggregations of course grade into shell marls. Coquina occurs along
the Florida east coast southward from St. Augustine to beyond Palm
Beach, as far as Boca Ratone, forming in its more southern exposures
a portion of Sanford's Palm Beach limestone; in fact the Palm Beach
limestone extends northward and some of the east coast Pleistocene
coquina may be referable to it. Localities at which this kind of rock
has been observed are St. Augustine, Ormond, Mims, and Canaveral,1
north of Palm Beach; and south of the last-mentioned place at Linton,1
Hillsboro Inlet, and Boca Ratone. Griswold says, concerning the southern
localities examined by him:

About 30 miles north of New River, at Linton, another examination was
made. A cross-bedded fragmented rock was abundant, but contained considerable
quartz. Coquina was also abundant, and the two rocks were found interbedded.

At Palm Beach and vicinity the Coquina and fine fragmental rock also occur
closely associated; the Coquina perhaps predominates. This is about 20 miles
north of Linton. * * *

A trip to Cape Canaveral disclosed there a rock which may well represent
the fine fragmental rock of Palm Beach and Linton. The quantity of quartz is
greater, the quartz grains are larger, and the rock less coherent than to the south.

The following record of a well drilled at Delray by Edwin T. King,
for O. Eleasen, shows that the coquina is interbedded with sand.

Record of well at Delray.

Depth.

Feet.

Surface sand o to 40

Coquina 40 43

Quicksand 43 108

Coquina 108 119

Thickness.

Feet.

A list of a collection of fossils obtained here by Mr. King from a
depth of 118 feet is given below.

Oculina sp.

Siderastrea radians (Pallas).
Porites divaricata Le Sueur.
Cidaris tribuloides Lamk.
Tornatina bullata Kiener.
Terebra dislocata Say.

dislocata var. indenta Conrad.

protexta Conrad.

Terebra concava Conrad, var.

new. x
Conus floridanus Gabb.
Drillia digitalis Reeve.
Oliva reticularis Lam. var.
Olivella mutica Say.
Marginella opalina Stearns.
Latirus brevicaudata Lam. ?

may be

1 Griswold, Mus. Comp. Zool., Bull., vol., xxvni, p. 59, 1896.

170 Papers from the Marine Biological Laboratory at Tortugas.

Murex rufus Lam. Erato maugeriae Gray.

Sistrum sp. , recent on Florida east coast . Trivia quadripunctata Gray.

Engina turbinella Kiener ? x Omphalitis fasciatus Born.

Columbella pulchella Kiener. Fissurella alternata Say.

mercatoria Lam. Area gradata Broderip.

Colubraria lanceolata Menke. Lucina radiata Conrad.

Strombus, young, probably pugilis Linn. Chione cancellata Linn.

All of the identifiable forms perhaps excepting three (those indicated by an
" x ") are recent. On a percentage basis 90 per cent are surely recent. The horizon is
therefore probably old Pleistocene, probably somewhat older than the Miami oolite.

This list will be referred to subsequently.

The prevalence of coquina on the east coast indicates shallow-water
beach conditions, with alternations of accumulations of sands and wave-
ground shells.

Dall says concerning the west coast:

There is general opinion among the inhabitants, which was frequently ex-
pressed to me in conversation, to the effect that between Tampa and the keys
Coquina-rock is only to be found at one place, the mouth of Little Sarasota Bay.
But this idea is certainly erroneous, as at every projecting point of the keys along
the Gulf shore which we visited, I found traces of this rock, though often not visible
above water, and frequently composed more of sand grains than of shell, so that
it looks much like wet loaf sugar. (Amer. Jour. Sci., 3d ser., vol. xxxiv, pp. 162,
163, 1887.)

SHELL MARL.

This material is composed mostly of the tests of mollusks, embedded
in a matrix of quartz sand with a varying proportion of amorphous and
fragmental calcium carbonate. It occupies a very large area extending
south and southwest from Daytona from the northern margin of the
Pleistocene sea at least as far as the northern margin of Lake Okeechobee,
on both its east and west sides. It probably extends as far as the south-
ern end of the Lake on its east side; and certainly does on the west,
where there are excellent exposures on Caloosahatchee River.

The fossils listed from the well at Delray represent a shell marl,
and give evidence of the southward extension of this class of material
along the east coast.

West of Fort Lauderdale, along the southern drainage ditch, there
is evidence of intergradation of shell marls and the Miami oolite. First
Shaler 1 and later Griswold 2 have called attention to the contemporaneity
of coquina and the oolite. The same may be said of the shell marls.

The collections of fossils from the shell marls, made by Dall and
Willcox, later by Matson, Clapp, and myself, have given a fair knowledge
of the paleontology of these Pleistocene deposits. Dall has published
a list of the species obtained from North Creek, near Osprey. Manatee
County,3 and Matson and Clapp have published lists, based on my identi-
fications, of the species from a number of localities. They, however,
omitted two important lists, and I insert them in this paper:

1 Mus. Comp. Zool., Bull., vol. xvi, p. 143, 1890.

2 Mus. Comp. Zool., Bull., vol. xxviii, pp. 55, 56, 1896.

3 Wagner Free Inst. Sci., Trans., vol. in, pt. vi, pp. 1616, 1617, 1903.

A Contribution to the Geologic History of the Floridian Plateau. 171

List of Fossils from Oscar Michael's Marl Pit, One Mile Southwest of Daytona
(George C. Matson, collector).

Tomatina canaliculata Say.

Drillia sp.

Olivella mutica Say.

Marginella sp.

Nassa acuta Say.

Anachis sp.

Turbonilla sp.

Cerithium sp.

Bittium sp.

varians Pfr.
Crepidula fornicata Say.

plana Say.
Xtieula proxima Say.
Area pexata Say.

transversa Say.

ponderosa Say.
Anomia simplex d'Orb.

Ostrea virginica Gmel.
Plicatula spondyloidea Meusch.
Venericardia radians Conrad.
Cardium isocardia Linn.
Venus campechiensis Gmel.

mercenaria Linn.
Chione caneellata Linn.
Timoclea grus Tuomey and Holmes.
Anomalocardia caloosana Dall.
Gemma magna Dall.
Parastarte trigona Dall.

triquetra Conrad.
Tellina (Angulus) tampaensis Conrad.
Tagelus divisus Spgl.
Semele sp.

Donax variabilis Say.
Mulinia lateralis Say.

List of Pleistocene Fossils front Labellc, CaloosahatcJiee River
(T. Wayland Vaughan, collector).

Natica canrena Linn.
Barbatia adamsi Smith.
Area transversa Say.
Plicatula spondyloidea Meusch.
Crassinella lunulata Conrad.
Carditamera arata Conrad.
Venericardia tridentata Say.
Codakia speciosa Rogers.
Phacoides sp. indet.

nassulus Conrad.

pennsylvanicus Linn.

multilineatus T. & H.

radians Conrad.

aff. waccamensis Dall.

anodonta Say.
Montacuta floridana Dall.
Cardium robustum Sol.
isocardia Linn.
Laevicardium mortoni Conrad.
Dosinia elegans Conrad.
Callocardia sayana Conrad.
Macrocallista nimbosa Sol.
Transennella caloosana Dall.
Chione caneellata Linn.
Anomalocardia caloosana Dall.
Venus campechiensis Gmel.
Parastarte triquetra Conrad.
Tellina sp. indet.
sayi Desh.
Tellidora cristata Recluz.
Macoma sp.

Semele purpurascens Gmel.
Mulinia lateralis Say.

sapotilla Dall.
Corbula cuneata Say.

aff. caloosse Dall.

Ameria scalaris Jay.
Bulla striata Brug.
Actaeon sp.

Tomatina canaliculata Say.
Terebra protexta Conrad.

dislocata Say.
Conus floridanus Gabb.

proteus Hwass.
Drillia aff. ulocyma Dall.
Olivella mutica Say.
Marginella avena Val.

apicina Menke.
Fasciolaria distans Lam.
Fulgur perversum Linn,
pyrum Dillwyn.
Melongena corona Linn.
Urosalpinx floridanus Conrad.
Nassa vibex Say.
Columbella rusticoides Heilprinv
Astyris lunata Say.
Eupleura caudata Say.
Strombus pugilis Linn.
Eulima subcarinata Orb.
Turbonilla sp.
Pyramidella sp.
Cerithium muscarum Say.

floridanum Morch.
2 sp. indet.
Bittium sp.

Modulus floridanus Conrad.
Turritella perattenuata Heilprin (prob-
ably not in place) .
Calyptrea trochiformis Lam.
Crepidula aculeata Lam.

convexa Say.
Cryptonatica pusilla Say.
Neverita duplicata Say.

As there is intergradation between the fossiliferous marls and the
Miami oolite in the vicinity of Fort Lauderdale, as exposed in the drain-
age ditches to the west of the village, lists of the fossils from there are
inserted here.

172 Papers from the Marine Biological Laboratory at Tortugas.

List of Fossils from near Fort Lauderdale (George C. Matson, collector).
Locality: South drainage ditch, 8 miles from Fort Lauderdale.
Pecten irradians Lam. Chione cancellata Linn.

Lagvicardium serratum Linn.

Locality: 7 miles from Fort Lauderdale, south ditch.

Cerithium thomasiae Sowerby. Transennella caloosana Dall.

Phacoides pennsylvanicus Linn. Anomalocardia caloosana Dall.

trisulcatus Conrad. Chione cancellata Linn.

Divaricella densata Wood. Mcerella sp.

Locality: 6.5 miles from Fort Lauderdale, Florida, northern drainage ditch.

Bulla striata Brug.
Conus proteus Hwass.
Marginella apicina Menke.
Melongena corona Linn.
Cerithidea turrita Stearns.
Pyramidella dolabrata Lamarck.
Strombus leidyi Heilprin. (Hitherto
known only from the Pliocene.)
Cerithium muscarum Say.

thomasiae Sowerby.
Cerithium prob. littoratum Born, junior.
Modulus floridanus Conrad.
Area auriculata Lam.
Pecten irradians Lam.

Avicula atlantica Lam.
Cardium isocardia Linn.
Laevicardium serratum Linn.
Phacoides pennsylvanicus Linn.
Semele sp.

Phacoides trisculatus Say.
amiantus Dall.
Divaricella densata Wood.
Chione cancellata Linn.
Dosinia elegans Conrad.
Anomalocardia caloosana Dall.
Macoma brevifrons Say.
Ervilia (4 lots).
Mcerella sp.

Two warm-water non-reef -building corals, Siderastrea radians and
Porites divaricata, were obtained from the well at Delray, depth 118 feet.
This place is slightly north of Hillsboro Inlet, but slightly south of the
latitude of the Caloosahatchee exposures and considerably south of those
around Charlotte Harbor. It appears that in Recent time the waters
may have been cooled somewhat more.

SOUTHWARD EXTENSION OF BURIED SANDS.

The intergradation between both the coquina and the Miami oolite
with arenaceous shell marls has already been described, also the inter-
bedding of siliceous sands with the predominantly calcareous material
has been mentioned. On the east coast south of Delray, the surface,
•except a surficial coating of sand, is formed by the Miami oolite and the
Key Largo limestone; on the west coast by the Lostman River limestone ;
and that of the keys west of Bahia Honda by the Key West oolite.
Beneath these limestones, however, are sands probably in part Pleisto-
cene and in part Pliocene in age.

The following well records will show the southward extension of
these buried sands:

Depth.

Thickness.

Well at Fort Lauderdale; P. N. Bryan, owner; record furnished by
Edwin T. King:

Sand

Oolitic limestone (Miami oolite)

Sand

Limestone

Sand and gravel

Hard white limestone

Sand and gravel

Limestone, in alternating harder and softer layers

Feet.
to

14
30
30. S
68.5
69-5
100.5

14
3°
30.5
68.5
69. S
100.5
108.5

Well at Dania; property of town; record furnished by Edwin T. King:

Surface sands °

Oolitic limestone (Miami oolite) 6

Blue mud with some gravel 1 46

Hard limestone 80

Feet.

38

34
8

.4 Contribution to the Geologic History of the Floridian Plateau. 173

At Miami, "samples from the wells of the water company show that
the oolite loses its typical appearance a few feet below sea-level and rests
on an irregularly cemented aggregate of shell fragments and quartz
sand." l

The record of the well at Marathon, Key Vaca, revealed quartz sand
below 155 feet (see page 128). Some of these sands may be Pleistocene.

Sands underlie the Lostman River limestone at a depth of 30 feet
at Everglade postoffice.2

Sanford reports a thickness of probably less than 50 feet for the
Kev West oolite 3 and mentions over 200 feet of quartz sand beneath it 4
on Big Pine Key.

These records show sand beds underlying the Pleistocene limestones
as far south as Big Pine Key; some of the sands, the more northerly, are
surely Pleistocene, the more southerly may be partly Pleistocene and
partly Pliocene.

THE FLORIDA OOLITES.

The presence of two oolitic formations in Florida, the Miami and
Key West oolites, has been stated on preceding pages (pp. 130, 131) and
certain of their characters have already been given, viz.: their geologic
age, their general appearance, the structure of the granules, and their
areal distribution. As the object of the following remarks is to throw
such light as is possible on the origin of these deposits, a brief state-
ment will be made of the views of the principal previous students.

Louis Agassiz 5 in his report for 1851 to Professor A. D. Bache,
Superintendent of the Coast Survey, says:

The main islands of this group (west of Bahia Honda) are very flat, and
consist of thin layers of a regularly stratified and somewhat oolitical limestone,
evidently formed by deposits of limestone mud.

E. B. Hunt 6 seemed to be of the opinion that the Key West oolite
might be partly due to the direct transformation of calcareous mud, or
to the transformation of calcareous sand lying above sea-level.

Shaler considered the oolite a coral-reef rock and named that in the
vicinity of Miami the Miami Reef.7 The oolite is distinctly not a coral-
reef rock, and Shaler's opinion is to be attributed to the fashion at that
time of considering practically all limestone in that area as having been
formed through the agency of corals. The differentiation 8 of varieties
of limestone had not then progressed so far as at present.

The next important contribution to the subject came from Mr.
Alexander Agassiz in his "The Elevated Reef of Florida,9 with notes on

1 Florida Geol. Surv., 2d Ann. Report, p. 212, 1910.

2 Sanford, op. at., p. 223.

3 Op. cit., p. 220.

4 Op. cit., p. 206.

5 Mus. Comp. Zool., Mem., vol. vn, p. 19, 1880.

6 Amer. Jour. Sci., 2d Ser., vol. xxxv, p. 203, 1863.

7 Topography of Florida, Mus. Comp. Zool., Bull., vol. xvi, p. 143, 1890.

8 Compare Mr. Agassiz's remarks in his "A Reconnaissance of the Bahamas
and of the Elevated Reefs of Cuba in the Steam Yacht Wild Duck, January to
April, 1893." (Mus. Comp. Zool., Bull., vol. xxvi, p. 179, 1894.)

9 Mus. Comp. Zool., Bull., vol. xxvn, pp. 29-62, 26 plates, 1896.

174 Papers from the Marine Biological Laboratory at Tortugas.

the Geology of Southern Florida by Leon S. Griswold." Mr. Agassiz
has presented the salient features of his conclusions as follows:

I was quite surprised on examining a bluff about 10 feet in height, extending
eastward from Cocoanut Point toward the mouth of the Miami River, to find that
it consisted of csolian rocks which have covered the elevated reef in many places.
On the low shores these geolian rocks are honeycombed and pitted and might be
readily mistaken for decomposed reef rocks; but they contain no corals. This
looks as if the lower southern extremity of Florida, the Everglade tracts, was a
huge shallow sink, or a series of more or less connected sinks, into which sand had
been blown, forming low dunes which have little by little been eroded, and which
former observers had mistaken in some localities for reef rock. The material for
these dunes coming from the now elevated reef or the beach rock at a time when
it was either a fringing or a barrier reef along the former coast line of Florida, all
of which, back of the reef, has little by little been eroded by the mechanical and
solvent action of the sea, leaving on the mainland only an occasional outcrop of
the elevated reef as observed by Professor L. Agassiz and Shaler. The outer line
of reef has also been elevated.

There are in this view several points that need to be emphasized:
(i) The Miami oolite is not a coral reef rock. (2) It is of aeolian origin.
(3) In southern Florida a huge sink existed, into which the material of
the oolite was blown. (4) The source of wind-blown sand was either
the now elevated reef or the beach rock at a time when it was either a
fringing or a barrier reef along the former coast -line of Florida. (5) The
bays and sounds are due to the mechanical and solvent action of the
sea. What is of particular concern here is the supposed aeolian origin
of the oolite and the source of the material. The discussion of the " huge
shallow sink" and the formation of the bays and sounds may be laid
aside for the present.

A careful reading of the text of Mr. Agassiz's remarks does not
reveal the criteria by which he determined the oolite to be aeolian; he
has merely given his opinion. In his foot-notes to Mr. Griswold's " Notes
on the Geology of Southern Florida," although dissent from Griswold
is expressed, still no criteria are given for distinguishing between water-
laid and aeolian cross-bedded calcareous deposits. At the bottom of
page 52 is the statement: "This bluff is a most distinctly marked aeolian
rock exposure, with characteristic knife-edge stratification." A com-
parison of plate xv of Mr. Agassiz's report on the Bahamas with plate
xix of Griswold's "Notes" will show considerable similarity in structure
of the Bahaman and Floridian materials.

Griswold in his "Notes on the Geology of Southern Florida," already
cited, says concerning the origin of the oolite:

The low undulations of the land surface in the pine belt can scarcely be
accepted as evidence of former dunes. They would well accord, however, with the
inequalities of a sea floor like the present one between the keys and the mainland.
The cross-bedding and oolitic structure favor neither water nor wind as the primary
agent in the construction of the rock. Therefore, since the land appears to be very
young, being almost without soil and surface drainage ways, the topography favors
an origin for the limestone in water.

Sellards has published the opinion that the Miami oolite is a marine

formation.1

1 Florida Geol. Surv., 1st Ann. Report, p. 22, 1908.

A Contribution to the Geologic History of the Floridian Plateau. 1 75

Vaughan published the next opinion on the origin of the oolite.1
According to him it was formed as a water-laid deposit, probably behind
a seaward barrier. He states:

The reasons for this opinion are that numerous marine fossils are found in
the oolitic material, the two valves of bivalve mollusks arc frequently in place,
showing no damage by attrition, and fossil corals which exhibit no indication of
having been rolled or waterworn were found. The marine fossils found in the oolite
had evidently lived in the water during the formation of the oolite. On the
surface of Big Pine Key original mud cracks formed by desiccation were observed
and photographed.

The last published opinion is that of Sanford, who says:

The characteristics of the calcareous sands and marls accumulating about
the keys and in the Bay of Florida, and the distribution, topographic relief, bed-
ding, contained fossils, and structure of the Key West and Miami oolites indicate
that the latter were limy muds, with a varying proportion of lime sand and a little
quartz sand, which accumulated on the bottom of shallow bays or lagoons, where
in places the water was relatively still, in places agitated by waves and currents
strong enough to build up and level off banks and bars. (Florida Geol. Surv.. 2d
Ann. Report, p. 222, 1910.)

Two theories have been proposed for the origin of the Florida oolites,
viz: (1) that of Alexander Agassiz, who considered that the deposits
were of aeolian origin and were made in a "huge shallow sink"; and (2)
that of Louis Agassiz, which considered them of aqueous origin.

In the following account an attempt will be made to assemble the
data bearing on these two theories.

The macroscopic and microscopic structure of the oolite granules
shows them to be composed of concentric shells of calcareous substance
accumulated around a nucleus in some instances calcareous, in others
siliceous. This structure is characteristic of concretions, but the problem
of the origins of concretions is raised, and a definite answer is not obtained
as to whether the material is of subaqueous or subaerial origin. However,
it may be mentioned that the specimens I collected on Cat and Gun keys,'
Bahamas, distinctly showed their detrital nature, while the typical
Miami and Key West oolites are distinctly not detrital. But as I did not
visit a great number of the Bahaman Islands and have seen none of the
Bermudas, I have not the necessary information for a general comparison.

The topography of the surface of the Floridian oolites is not of
criterional value, as gentle undulations may be produced under the water
or the air, or by slight folding. Here again, however, the flat upper
surface of the Key West oolite is more suggestive of water-laid than wind-
blown deposits.

The strong cross-bedding of the Miami oolite has been mentioned
in the quotation from Griswold. This has been interpreted by Mr.
Agassiz as evidence of aeolian action, and it is stated by Griswold that
as evidence it is not decisive.

In order to illustrate bedding presumably due to wave and aeolian
action, separate or combined, a series of photographic illustrations are
introduced. Plate 13, fig. a, illustrates an exposure on Gun Key, Ba-

1 Carnegie Institution of Washington, Year Book No. 7, p. 133, 1909.

176 Papers from the Marine Biological Laboratory at Tortugas.

hamas, eastern side, below the lighthouse. This is probably an seolian
sandstone, and exhibits cross-bedding very well. Plate 7, fig. b, repre-
sents the western beach of Loggerhead Key, Tortugas, looking northeast.
It shows indurated calcareous sandstone along the water's edge and
loose calcareous sands higher on the beach slope. Note the continuity
of the slope of the lower indurated with that of the higher unconsolidated
material.

The material represented in all of the illustrations mentioned is of
detrital origin, and illustrates bedding by shore waves and the wind.
Plate 14, fig. a, illustrates cross-bedding in a water-laid deposit.

Plate 13, fig. b, represents exposures of the Miami oolite. The sharp
cross-bedding is brought out, but the rock occurs in distinct ledges.
This massive bedding with the cross-bedding of the smaller divisions is
suggestive, and it should be emphasized that the oolite granules are
not similar to the detrital sands composing the Bahaman and Tortugas
exposures.

The data so far presented indicate an individuality of the Floridian
oolite areas different from that of the other areas discussed, although as
yet definite criteria for determining the conditions under which the oolite
was formed have not been advanced. Cross-bedding may be due to
current, wave, or wind action, and the three processes may be more or
less cooperative.

Illustrations of the surfaces of two oolitic keys bear on the solution
of the problem, viz: Plate 14, fig. c, which represents Summerland Key;
and plate 15, fig. a, a view of Boca Grande Key, show remarkably flat
surfaces, not in the least suggestive of dunes. On Big Pine Key the
surface of the oolite shows mud cracks from drying (plate 14, fig. b).
Fortunately the oolites are rather rich in fossils.

Fossils from the Miami Oolite.1

Locality: Golf Ground, Miami.

Cyphastrea hyades (Dana) . Glycymeris pectinata Gmelin.

Conus floridanus Gabb. Avicula atlantica Lam. . _

Columbella mercatoria Lam. Lasvicardium serratum Linn.

Cerithium muscarum Say. Codakia orbicularis Lam.

littoratum Born. Phacoides pennsylvanicus Lmn.

Area gradata Broderip. Chione cancellata Linn.

Locality: Kronkheit- Offer Quarry, Miami.1

Siderastrea radians (Pallas). Livona pica Linn.

Strombus gigas Linn.

Correlation. — The species are all Recent, and the age of the oolite
is therefore Pleistocene.

Locality: Buena Vista.1
Mellita sexforis Lamarck.

Fossils from the Key West Oolite.
Locality: Big Pine Key (collected by Samuel Sanford).
Mussa (Isophyllia) sp. Cardium isocardia Linn.
Encope michelini Agassiz. Lsevicardium serratum Lmn.
Terebra dislocata Say. Phacoides pennsylvanicus Lmn.
Strombus pugilis Linn. Divaricella densata Wood. ^

lThe fossils from these .localities were presented by Dr. J. N. McGonigle, of Miami.

A Contribution to the Geologic History of the Floridian Plateau. 177

Dolium galea Linn. Tellina radiata Linn.

Natica canrena Lam. Metis intastnata bay.

Neverita duplicata Say. Macrocalhsta maculata Linn.

Pecten irradians Lam. Chione cancellata Linn.

Locality: Torch Key, eastern side, along railroad embankment (A. G. Mayer and

T. Wayland Vaughan, collectors).
Siderastrea radians (Pallas). Cardium isocardia Linn.

Fulgur perversum Linn. Phacoides pennsylvanicus Linn.

Dolium galea Linn. Divaricella quadrisculata Orb.

Cerithium thomasiae Sowerby. Dosmia elegans Conrad.

Cerithium littoratum Born. Chione cancellata Linn.

Modulus modulus Linn. Tagelus divisus Spengler.

Pecten gibbus Linn. Semele cancellata Orb.

iThe two valves are still adherent.

All of the species are Recent, and the geologic age is Pleistocene.

The fossils show no attrition, and the two valves of some of the
pelecvpods are still in their natural position. These fossils must have
remained embedded in the material in which they were more or less
embedded when alive. In other words, the surrounding oolite must have
originated as a water-laid deposit.

' Mr. Agassiz, in his theory of sands blowing into sounds behind the
keys and still preserving the character of wind-blown deposits, could
scarcely have had it in mind that the sounds or hollows were filled with
water. 'as it could not be expected that sand blown into water, and
deposited through it, would preserve the same structure as if subaenally

deposited. .

To summarize the conclusions pointed by the data presented in the

foregoing remarks: .

i . The fossils show that the oolite is a water-laid deposit formed in
shallow water, a few fathoms, or more probably only a few feet,
in depth.

2. The cross-bedding shows it was formed in areas of moderate

and variable currents.

3. The topography shows it was formed on flats.

4. The Miami oolite has been elevated above the water-level a

sufficient time for it to have suffered considerable denudation;

while the Key West oolite preserves its original flat surface

with intact mud cracks.
One object in view in collecting bottom samples within the keys
was to obtain light on the problem of the origin of the oolites, and the
effort had a negative result. A study of the oolites themselves seems to
have answered the question. While on Boca Grande Key, on the beach
of which oolite occurs, I obtained a suggestion that was perhaps of value.
It seems to me that the shells of an oolite grain accumulate around some
nucleus by the gentle rolling of that nucleus on a bottom on which
calcium carbonate is being precipitated. There is no evidence that
oolite is being formed behind the keys east of Bahia Honda, but I think
it very likely that it is forming around some of the more westerly keys.
Two geological formations of marine origin remain to be discussed:
the Lostmans River and Key Largo limestones. The former was de-
scribed on page 130; the latter on pp. 130, 131.
12

178 Papers from the Marine Biological Laboratory at Tortugas.

LOSTMANS RIVER LIMESTONE.

Sanford says concerning the origin of the Lostman River limestone:

Origin: — Willis has suggested that the rock at Lostmans River was perhaps
formed by the deposition of crystallizing calcium carbonate from the presumably
limy waters of the Everglades. While there can be no doubt that deposits of marl
are now accumulating along the coast, the present hardening of marl to crystalline
limestone or the direct deposition of such limestone is not established. As the
writer has stated, the bed rock of the western coast, wherever soundings have been
made, whether in the Everglades, on swamp islands, along the coast, or in the
numerous creek channels, seems to have a gentle slope toward the Gulf. The rock
is no farther below water-level in the swamp than in adjacent channels; moreover,
the rock surface in channels where the current runs strongly is full of crevices, is
extremely rough, and is evidently being eroded. Loose fragments that have been
detached' by solution are found, not only near the mouths of rivers, but at their
heads, on the bare rock, under marl, and under vegetable muck. Another fact
that impairs the deposition and crystallization theory is the character of the Ever-
glades water. Most of the marl in the Ten Thousand Islands has come from the
ever-dirty shallows of the Gulf. The dark limestones below water in the creeks are
the same as those that outcrop above water a short distance away, and a recent
crystallization from solution of those is hard to understand.

The limestone on Lostmans River, though containing calcite crystals an inch
long, is not greatly different from other limestones of southern Florida; removal,
deposition, and crystallization of carbonate of lime are characteristic of the region.1

The limestone, from its petrographic and paleontologic characteristics, is a
shoal-water deposit of marl and limy sand, containing shells of living species of
mollusks, that has been solidly cemented and subjected to conditions favoring
crystalline growth. This growth may be in progress. (Florida Geol. Surv., 2d
Ann. Report, pp. 224, 225.)

KEY LARGO LIMESTONE.

The Key Largo limestone is so closely similar to that being formed
by the present reefs, that it is safe to postulate the same physical condi-
tions for the fossil as for the living reefs. They were formed in water
having a maximum depth of 18 to 20 feet, a minimum temperature of
700 F., and lay just landward of the current of the Florida Straits.
They were separated from the inner bank by a deeper channel, compar-
able to the present Hawk Channel, and now represented by the bays
and sounds between the keys and the mainland.

SURFACE SANDS OVERLYING THE MARINE PLEISTOCENE.

The surface of the Pleistocene fossiliferous deposits is usually
overlain by a coating of surface gray or white sand, of variable thick-
ness, from a few inches to several feet. Most probably this sand was
originally a marine deposit, laid down as the sea shoaled. Wind has
been active in distributing some of it over the land surface, as is
attested by the dunes of the east coast as far south as Pine Island in
the Everglades, back of Fort Lauderdale,2 and on the west coast as far
south as Caximbas Pass.

UPLAND GRAY SANDS.

The suggestion may be ventured that a portion of the upland gray
sand, which covers all pre-Pleistocene formations and has puzzled so
many geologists, may be sand of beaches formed as the successive seas

JFor references to calcite crystals in other Pleistocene limestones of Florida,
see pp. 130, 131.

2Florida Geol. Surv., 2d Ann. Report, pp. 224, 225.

A Contribution to the Geologic History of the Floridian Plateau. 179

shoaled and then blown inland by winds. According to this theory the
surface sands would belong to no one geological period, but would
represent all the periods since the Vicksburg. Some of these surface
sands are undoubtedly residual deposits.

RIVER TERRACES AND OTHER PLEISTOCENE FORMATIONS.

River terraces are present in Florida, as in the valley of St. John's
River, where a well defined one rises 20 to 30 feet above tide,1 and there
is evidence of their occurrence along other streams, but in the absence
of detailed topographic maps they can not be satisfactorily discriminated.

Other Pleistocene formations are aggregates of the shells of the
fresh-water mollusk Planorbis 2 and masses of the tubes of the marine
mollusk Vermetus negricans.3

SUMMARY OF PLEISTOCENE HISTORY.

In the preceding discussion of the marine Pleistocene formations of
the Peninsula of Florida, their salient characteristics, their distribution,
and the conditions under which they were formed have been given.
These data permit a general statement of the conditions prevalent over
the submarine portion of the Plateau, with some deficiency in precision
due to a lack of accurate knowledge of succession and synchrony between
all cf the deposits. There are undoubtedly several horizons in the
Pleistocene. The material from west of Fort Lauderdale seems, from
the fossils, to be older than the Miami and Key West oolites. The
material in the Delray well, depth 118 feet, may be older than that
west of Fort Lauderdale. Additional detailed stratigraphic and paleon-
tologic work on the Pleistocene deposits is needed.

The Pleistocene shore-line has already been outlined. Seaward of
this margin the entire Peninsula was submerged, but to no great depth ;
very likely, unless in channels or entrants, in no place did the depth of
the water exceed 50 feet. During a portion of the period of submergence
the sea-bottom was gradually lowered and deposition kept pace with the
sinking.

Shell marls were deposited over practically the entire surface of the
submerged platform north of the present southern margin of Lake Okee-
chobee. The fauna indicates for this region a warm temperature; how-
ever, it was a few degrees cooler than that of the present east coast south
of Key Biscayne. Arenaceous sand was brought from the north and carried
practically to the southern margin of the Plateau, but in the later Pleis-
tocene in much diminished quantities south of Miami. This sand came
partly from the mainland to the north and partly by southward-moving
shore currents, which must have been warm return-currents, as the fauna
was characteristic of warm water. Shell-banks formed by wave-wash
accumulated on the east coast from St. Augustine to at least 20 miles
below Palm Beach, and are now coquina. These deposits may have been
formed along the margin of the bank as it was elevated. Similar
coquina beds appear to have been formed on the west coast.

1 Matson and Clapp, Florida Geol. Surv., 2d Ann. Report, p. 39, 19 10.
- Matson and Clapp, op. cit., p. 153.
3 Matson and Clapp, op. cit., p. 154.

180 Papers from the Marine Biological Laboratory at Tortugas.

South of the latitude of the present southern end of Lake Okee-
chobee, limestones were the prevalent geologic formations, and in this
region the four limestone formations of south Florida were formed, all
in shallow water. On the southwest it was the Lostman River limestone ;
along the southeastern and southern margin coral reefs grew and formed
the Key Largo limestone. Behind the line of reefs was a channel com-
parable to the Hawk Channel of present time. East of the Lostman
River limestone, in shoal water, agitated by strong currents, the Miami
oolite accumulated. Whether this oolite was formed previous to the
formation of the Key Largo limestone, or whether the two are contem-
poraneous, is an unsolved problem. Westward of the Key Largo lime-
stone, oolite was forming on a shallow bank, later to form the group of
keys from the Pine Keys to Boca Grande.

The temperature of this portion of the ocean and the direction of
the currents were practically as to-day.

Pleistocene time was closed by an uplift of the Plateau — the uplift
evidently being accompanied by deformation, as the elevations of the
surface of the marine Pleistocene are by -no means the same. Those in
the central portion of the Peninsula are greater than toward the south,
and the east coast is higher than the west. There is evidence of a slight
ridge on each side of Lake Okeechobee, the eastern ridge being the
higher.

J..O. Wright, Supervising Drainage Engineer of the Department of
Agriculture, in a report embodied in the Report of the Special Joint
Committee of the Legislature of Florida on the Everglades of Florida,1
gives the mean water-level in the Okeechobee Lake as 20.5 feet above
tide, level at low stage about 19 feet; the greatest depth at low water
is 22 feet, or the bottom is 3 feet below sea-level; the average depth is 12
feet, or the bottom is 7 feet above sea-level. Heilprin says concerning
the depth of the Lake:

We took numerous soundings all along our course, probably fifty or more,
which gave an average depth ranging from about 7 to 10 feet. The deepest sound-
ing made on the diagonal connecting Taylor Creek and the mouth of the canal,
about 4 miles southwest of Eagle Bay, gave 15 feet, but this is the only instance
when we obtained this depth. (Wagner Free Inst, of Sci., Trans., vol. 1, p. 41,1887.)

Accurate geologic information on the bottom of the Lake is scanty,
but as it is surrounded by marine Pleistocene, the surface deposit on the
bottom may be safely inferred to be Pleistocene. As Pleistocene occurs
at higher elevations on both the east and west sides, the conclusion is
pointed that the Lake lies between gentle anticlines, one toward the
east, the other westward, and there may have been somewhat greater
elevation between its southern end and the southern shore than in the
area of the Lake itself, producing a shallow synclinal hollow.

In the vicinity of Kissimmee the amount of elevation was 60 to 70,
or perhaps 100 feet; of Miami, 40 to 50 feet; along the coral reef keys,
10 to 15 feet; along the Caloosahatchee, near Fort Thompson, perhaps
30 to 40 feet; near Osprey, less than 30 to 40 feet; along the keys west

Tallahassee, Florida, 1909.

.4 Contribution to the Geologic History of the Floridian Plateau. 181

of Bahia Honda, perhaps 10 to 20 feet. Along the west coast in places
there may have been very slight elevation.

The details of these differential earth-movements have not been
worked out, and until accurate topographic maps are available and
more thorough studies of the stratigraphy and structure have been made,
it will not be possible to decipher them.

This uplift may have been intermittent, or there may have been
oscillation. The presence of terraces along some stream indicates one or
the other. The amount of the elevation closing the main Pleistocene
deposition was probably greater than that now shown by the land
surface, it being followed by a slight depression, as is evidenced by the
drowned valleys of recent times; that of St. John's River is an instance.1

RECENT.

The events closing Pleistocene time gave the Plateau its present
configuration, and although no attempt will be made to recount in detail
Recent phenomena, the development of both the present coral reefs and
the interior swamps of the Everglades may be mentioned. The reefs
developed next the pure ocean waters just inside the 10-fathom curve,
and the Everglades were formed on the flat, imperfectly drained area
south of Lake Okeechobee.

The geologic history of the Marquesas and Tortugas is reserved for
future consideration. The present surface above sea-level of these two
groups of islets seems to be geologically Recent. They are mostly or
entirely composed of organic detritus and calcareous material drifted
westward along the southern margin of the Floridian bank, as both
Hunt and A. Agassiz have contended. However, important geologic
details remain to be worked out for each group.

RESUME OF THE GEOLOGIC HISTORY OF THE FLORIDIAN PLATEAU.

The agencies which originally shaped, and subsequently dominated,
the development of the Plateau, were of two kinds: (1) those that cause
warpings of the earth crust; (2) those resulting in the deposition of
material on the sea-floor, viz: corrosion and erosion of the land surface
above sea-level, transportation to the sea, transportation and deposition
of land-derived material in the sea, and organisms which added their
skeletal remains to the material of inorganic origin.

The Plateau existed in Vicksburgian , Lower Oligocene, time, pro-
jecting as a submarine platform from the southeastern corner of the
continental shelf and extending at least to its present southern limit.
The forces by which this older Oligocene platform was formed at present
can only be the subject of speculation. It was due to some fold of the
ocean-bottom, perhaps in some way connected with the angle of the
Piedmont area in central Georgia.

The water over this Plateau was shallow, probably in no place 100
fathoms deep; the bottom temperature was between 700 and 8o° F.;
tropical currents passed over its surface; deposits of both terrigenous

1 Matson and Clapp, op. cit., p. 172.

182 Papers from the Marine Biological Laboratory at Tortugas.

and organic origin accumulated on it ranging in thickness from ioo to
200 feet near shore to the north to over 1,000 feet near its southern
margin. As the water was shallow, the sea-bottom must have been
gradually depressed while the material accumulating on its surface was
being deposited.

At the close of Vicksburgian time the Plateau was elevated and
areas of its surface were subjected to subaerial denudation, as is attested
by the erosion uncomformity along the contact of the basal Apalachicola
with the underlying Vicksburg sediments.

Apalachicolan time needs separation into two stages, an earlier,
represented by the Chattahoochee, Hawthorne, and Tampa formations,
and a later, represented by the Alum Bluff formation. The areal extent
of the deposits of the earlier stage was not so great as that of the Vicks-
burg deposits, indicating the later was not so extensive as the previous
submergence. The northern shore-line was'seaward of that of the Vicks-
burg Group ; it seems probable that a small island existed in the sea in
what is now the northeastern corner of Marion County, and in other
areas the sedimentation over the Vicksburg deposits was thin. Along
the western coast of Florida the Vicksburg formations were being gently
folded, and a dome-like structure was developing southward.

The Plateau, in early Apalachicolan time, had practically the same
outline as at present ; the depth of water north of Tampa was probably
in no place over 100 feet. Coral reefs were present in southern Georgia,
across the base of the present Peninsula, and around Tampa; the tem-
perature was tropical, the minimum for the year being at least as high
as 700 F. ; the main movement of the ocean water was from the tropics;
the sediments consisted to a lesser degree of organic debris, and were
predominantly of terrigenous constituents.

In the later stage of Apalachicolan sedimentation, the island of
Oligocene lying west of the present longitudinal axis of the Peninsula,
here named Orange Island, had by further uplift increased in size and
was separated from the mainland to the north by the Suwanee Strait.
There was differential earth-movement, the sea-bottom being depressed
around Orange Island and between it and the shore of the mainland to the
north, permitting additions to the thickness of Apalachicola sediments.
During this later stage of the Apalachicola the oceanic waters of the
region gradually cooled and coral reefs disappeared. The sediments were
mostly of terrigenous origin and were laid down in shallow water.

This period of deposition was succeeded by one of uplift and sub-
aerial erosion, the Apalachicolan-Miocene Interval, after which was
another, the Miocene, subsidence. This subsidence was not so extensive
as that of the preceding deposition period, and although it seems prob-
able it is not positively proven that the Suwanee Strait was again open
water, the Miocene deposits did not extend so far inland as the margin
of the Apalachicolan Sea, and there were extensive land areas west of
the present longitudinal axis of the Peninsula. The Plateau had approxi-
mately its present outline, and thick deposits of arenaceous sands were
formed practically to its southern limit, certainly as far south as the
locality of Key Vaca; the sea was shallow, perhaps 25 fathoms is a safe

.4 Contribution to the Geologic History of the Floridian Plateau. 183

maximum; there was depression coincident with deposition on the east
coast; the waters were cold, a cold inshore countercurrent lowered the
temperature to that of the region between Cape Hatteras and Long
Island. This southward-moving countercurrent, aided by winds and
waves, is largely responsible for the greater thickness of sediments on
the east than on the west coast, and it is the forerunner of the series of
countercurrent s so important in the later history of the region. Toward
the close of the Miocene period uplift was again initiated, and the Suwanee
Strait, should it not have been previously closed, was then assuredly
above' sea-level, and the north and south Trail Ridge was formed. The
uplift seems to have been greater on the east than on the west, for no
Miocene is above sea-level from Levy to Pasco counties on the west coast,
while submerged Miocene is apparently present off the mouth of Tampa

Bay.

The Pliocene submergence was extensive, over half of the present
land surface of the Peninsula lying below sea-level. The submergence
of the present land surface along the east coast extended down the west
side of St. John's River valley, and entirely across the median portion
of the Peninsula northwest of Lake Istokpoga. No known marine Plio-
cene occurs on the west coast north of the Charlotte Harbor localities.
The general outline of the Plateau remained as it was in Miocene time ;
the water was shallow, usually between 20 and 30 feet in depth; the tem-
perature was tropical in the southern, the Caloosahatchee area; and
warm, but slightly cooler in the northeastern area, in the vicinity of
Nashua. The oceanic current over the Pliocene bank must have been a
warm countercurrent — a countercurrent because it brought sands from
the north and deposited them on the Pliocene submarine bank.

While the Pliocene marine deposition was taking place important
lacustrine and fluvial deposits were accumulating on the land surface
above the sea.

Pliocene deposition was closed by another uplift of the Plateau.
Data for a precise estimate of the height of the land during this emergence
are not available, but the evidence obtainable indicates that it was not
over 200 or 250 feet as a maximum, and as the previous movements of
the Plateau were differential it is most probable that only portions were
subjected to oscillations so great. Accompanying this oscillation a
shallow syncline was developed along the axis now occupied by the
Kissimmee River, with low anticlines on each side. Probably a third
anticline was developed west of Peace Creek. The axes of these folds are
parallel to the longitudinal axis of the Peninsula, and have been impor-
tant in influencing the drainage courses of middle Florida.

The Pleistocene submergence was as extensive as that of the Plio-
cene, all Pliocene areas, perhaps, but not probably, excepting one be-
tween St. John's River and the east coast, being resubmerged, and there
is a border of Pleistocene on the west coast and the western extension
where Pliocene is not now known. The Plateau throughout Pleistocene
time preserved its general outline. Shallow-water conditions pre-
vailed over its entire submerged portion. In no place were the known
deposits laid down in water much deeper than 50 feet, and usually from

184 Papers from the Marine Biological Laboratory at Tortugas.

barely below sea-level to 25 or 30 feet. The temperature north of the
latitude of the southern end of Lake Okeechobee was slightly cooler than
in Pliocene time, but it was still warm. In this shallow, warm sea
sediments of diverse kinds were deposited. Sands and shell marls are
probably the most extensive, forming widespread deposits over almost
the entire submarine bank. The sands extend beneath the limestone
formations as far south as Miami, and perhaps to the southern keys.
Along the more northerly portions of the bank coquina accumulated.
Along a curve, first southward and then bending westward, from Biscayne
Bay, a coral reef flourished, separated by a channel of deeper water from
the main bank, on which the Miami oolite was forming or had formed in
shoal water strongly agitated by currents. Along the southwestern por-
tion of this bank, also in shoal water, the Lostmans River limestone
accumulated. West of the coral reef, on an extensive flat in the shoal
water over them, the Key West oolite was formed. Toward the close
of the Pleistocene the previously formed sands, marls, and limestones
southward beyond Miami received a thin coating of siliceous sand.
Contemporaneous with this purely marine work, the terracing of rivers to
the north was taking place.

Pleistocene time was closed by an uplift, which may have been
intermittent or may have been accompanied by oscillations. There is
some evidence of slight depression since the principal uplift. After this
uplift the living coral reefs developed, the Everglades were formed, and
the Florida of to-day was the result.

This summary will be closed by an account of the roles played by
deformation and ocean currents in the history of the Plateau.

DEFORMATION.

The Floridian Plateau owes its origin to a fold of the sea-floor in
pre-Oligocene, probably Eocene time, producing a platform on which
sediments during the later geologic periods were laid down. The whole
earthmass, since the origin of the platform, has been subjected to a
succession of deformations due to compression between forces acting
from the east and west, resulting in the axes of the gentle folds being
coincident in direction with the longitudinal axis of the Plateau, and to
downward and upward tilting around a landward fulcrum. The initial
uplift with deformation took place, as nearly as can be determined,
toward the close of the Vicksburgian deposition period. The Vicks-
burg nucleus lay nearer the eastern than the western margin of the
Plateau surface, and was roughly dome-like in form, but with a longer
north-and-south than east-and-west axis. The subsequent growth of
the Peninsula was by filling the channel between the island of older
Oligocene (Vicksburg) rocks and the mainland, and by growth east-
ward and southward from it. There was little or no westward growth.
There was additional deformation in later Oligocene (Apalachicolan)
time, between the Apalachicolan and Miocene deposition periods, between
the Miocene and Pliocene, between Pliocene and Pleistocene, and suc-
ceeding the Pleistocene deposition. The result of each of the series of
deformations was to add, beginning with the Miocene-Pliocene member

A Contribution to the Geologic History oj the Floridian Plateau. 185

of the series, one or more anticlinal swells with intermediate synclinal
depressions to those that preceded, the additions above sea-level always
taking place toward the east, and at each elevation the uplifting was
propagated southward. The continued effect of all the uplifts was to
elevate the eastern portion of the Plateau above the western, or there
has been elevation on the eastern side of the Plateau coincident with
stability or even slight depression on the western side.

CURRENTS.

The importance of currents in shaping the land area of Florida has
been emphasized in several sections of the preceding discussion. Before
the history of the currents of the region can be thoroughly understood
it is necessarv to know the history of the Hatteras axis of North Carolina.
The present Florida count ercurrent seems due partly to the impingement
of the Gulf Stream against the Hatteras projection, resulting in a portion
of the waters being deflected southward along the coast instead of con-
tinuing their northward journey. The Hatteras axis has existed as a
dividing line between depositional areas apparently since middle Cre-
taceous time, and it has been either a region of shoal water, or occasion-
ally a land area, since later Eocene time. The Yicksburgian and Apa-
lachicolan seas were both warm, tropical or subtropical in temperature.
It is not definitely determinable at present whether the warmth of these
waters was due to currents directly from the Tropics or to warm return
currents produced by the northward flowing Gulf Stream having a por-
tion of its waters diverted southward by impinging against a salient
from the more northerly land area.

In Miocene time it is definitely known that a cold inshore current
found its way southward to Florida and westward to Pensacola. This
current may be due to the Miocene submergence of the Hatteras area
sufficiently lowering the sea-bottom off Hatteras to permit the Gulf
Stream to continue its course unobstructedly northward. Should this
hypothesis be correct a re-examination of the faunas of the Miocene
deposits of northern North Carolina and Virginia, and those of southern
North Carolina (the Duplin marl), South Carolina, Georgia, and Florida,
with reference to synchrony may be necessitated. The Miocene south-
ward current transported quantities of terrigenous material and deposited
it on the eastern border of the Floridian Plateau.

Since Miocene time there have been constantly return currents of
warm water (however, not so warm as the Gulf Stream), and they, aided
by winds and tides, have deposited terrigenous material on the east-
ward side of the existing land areas, sweeping a portion of it to the
southern end of the Plateau. These currents were active during Pliocene
and Pleistocene times, and are still active to-day .

The shape of the upper surface of the Floridian Plateau, the land
area of its eastern side, the arrangement of the geologic formations of
successive ages, the directions of the stream courses, and the contour of
the present coast line, owe their peculiarities and characteristics to the
concomitant operation of the forces producing deformation and to
oceanic currents.

VAUGHAN

5 -&J* --•:. av

A, Cape Florida, showing surface of siliceous sand and cocoanut palms.

B, Cape Florida, showing surface of siliceous sand and sea-grape.

C, The Marquesas, south side, beach ridge of calcareous sand in the fore-
ground, mangroves in the distance.

.^^-^-^

*' ; ^P

J^wfkMH««ffr'

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. -f •£j£^;V^!i--

* •'

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**' JJayaajfc

* -^ •

D.

A, Loggerhead Key, showing bay cedars and loose calcareous sand.

B, Loggerhead Key, western beach, northeast of lighthouse, show-
ing passage of beach curve from indurated material along water's
edge into that of loose material above it.

C, Edge of the Everglades, near Miami, showing saw-grass.

D, Edge of the Everglades, near Miami, showing a lily pad.

I ■

*§&£§£

^A?

c.

A, Miami oolite, pine lands, outskirts of Miami.

B, Erosion by sea-spray, Picquet Rocks, Bahamas, western shore, distance 15 feet.

C, Erosion by sea-spray, Gun Key, Bahamas, western shore.

VAUGHAN

p

be

o

bfl
PI
<S

E

be
a

o

i T ;;^ ff^ffj1? ' vTJ

Young mangroves. A and B, shoal about 2 miles north of Pigeon Key, water about
a foot deep. C and D, shoal upper end of Long Island, water about a foot deep.

-%

Mangroves, Miami River.

VAUGHAN

PLATE 12

A.

A. Mangrove roots, Pigeon Key.

B. " Black Mangroves," Pigeon Key.

VAUGHAN

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i

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>-^

f tfr* t ' " ' - • * "**" ■'■ t ■*-;-. - '

- - *? ' * fL. . ■ , ■ : ■— , ■' ...-.-*■■

A.

A

■ftfbr '<""%£

:**

; - --< j#&ajfe&

B.

A. Cross-1>e<l(le<l calcareous sandstone, probably ;colian,

western side of Gun Kcv, Bahamas.

B. Miami oolite exposure, Miami, showing cross-bedding.

VAUGHAN

h * j

n uk

.xm'.y^'iB

*
1 1

•

• v^

V

"j*"^* '

B.

I

tiMify' '_

/-ft * .*

c.

A. Cross-bedding by water in an Eocene exposure,

Central of Georgia Railway, two miles northeast
of Andersonville, Georgia.

B. Mud cracks, surface of Key West oolite, Big Pine Key.

C. Surface of Key West oolite, Summerland Key.

V A U G H A N

PLATE 15

-

B.

c.

A. Surface of Key West oolite, Boca Grande Key.

R. Key Largo limestone, southern cud of Old Rhodes Key.

C. Coral head in Kev Largo limestone, Ke-\ Vaca.

WH IfijD mn