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GALE] Matai tne ciilig ayy alt Whit AAT] Sea ad Bill Pw Mas, 1] Novesa 4 Be 4 * UL ies AL OW Oa ae att) thi Puen Wives rer Wrey We SS Mae amy Seca ia a ERLE LLY ae, Swe i\q ts °* Piny SSSR eee ee SECURE bb )) 4 i ‘Hy r Tidy {| ATH Wniiiee vir heb ky a Wee “vy: "rr, ‘ale n Na Uegaylll Ut re Pee AML TRL hi 1 Et a OR i a TY Dott ate ww WY i a > v Ya! , ae swe o: ee 4 iA } ae Sa 2 A PL sa a VAs oy - ‘eat 4 nia” oer, | M. oo Sy. AN “ee "i | é | Wapemyoc? } ere al gue ees ~~ Pee ree Hoge 8 Ye e °° i LS ad iy Si), ‘ v > f v= : % bw Tit ° ives see. 7” 7 90 - “) =%0 dagen" Aon apte | 1 tt ' meet mney | coagegveenenee’” Sway eeu re | | jeer te | Cyryetal : Dio aera) | ia i oe ea ne , afP Ate ihn ef * (ay "4 Pat hte a cre RK D G : MA YER, DIRECT aR ¥, : « VOLUME IY WASH INGTO ‘<.@y me 9 f Va Js gas EPARTMENT OF MARINE BIOLOGY i. ee 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 IQIO CARNEGIE INSTITUTION OF WASHINGTON " PUBLICATION NO. 133 ‘ 7 Copies of this Book . were first issued . DEC 16 1910 r * PRESS OF J. B. LIPPINCOTT 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. By THOMAS WAYLAND VAUGHAN. CONTENTS. rans a PAGE Monocotyle floridana, a new Monogenetic Trematode. By lenin y oy Ec bias cha sare t tepth oe oa ates See ee, Souci Dm Seale) deaesetat I-9 With 11 text figures. Helminth Fauna of the Dry Tortugas. IJ. Trematodes. By DBs gt WELT OTN ots 85) ace gaat aparece eotaye anes oy biniGhors 6 s/he we ONS 11-98 With 28 plates. A Contribution to the Geologic History of the Floridian Plateau, By, Phomas Wayland Vaughan....0...2....... 99-185 With 15 plates, 6 text figures. MONOCOTYLE FLORIDANA, A NEW MONOGENETIC TREMATODE. BY HENRY 'S. PRADE, ~ Haverford College. 11 figures. MONOCOTYLE FLORIDANA, A NEW MONOGENETIC TREMATODE. By Henry 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 (Myliobatts aquila) at Naples, and which he named Monocotyle myliobatis. The only other known species is Monocotyle ijime@, 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 freminvillet) 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. aime. 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. 1j1m@, 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. zjime@ 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 c.I 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, fl.) 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. 1, 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. zjime, 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, s. 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. time 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, ft. p.). In all other individuals examined no such pore could be seen and the median trunk ends blind, forming thus a cecum. 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. 7jime@ 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. 1, b.) and the anterior and pos- terior paired nerves extending from its lateral ends to the extremities of the body (fig. 1, a. ”.,/..). The main posterior nerves run lateral to the massive yolk-glands and along the margin of the body. No ocelli are present. The genital organs are similar in arrangement to those of M. ijime. The single testis (figs. 1 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. zjime@ three testes are present, while in M. myliobatis no one has yet seen any of the male genital organs. The vas deferens (figs. r 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. zjime and forms the so-called connective-tissue penis in that species. The ovary (figs. 1 and 8, 0) 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 o.og 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. 1 and 8, b. p.) is the uterus (figs. 1 and 8, w.). 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. tr 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. A eee Cece ceureree> nae -s decency Seecencr ces Palaces i eo es 1a we oe ees move nner e U, a hee wes srqsene= TS, le paw cia sie /—'rs/s Chie Srrnosodlee tases tid0\- eve een ftw d - f- ae oe The whole worm viewed from ventral side: actual length 1.3 mm. Dorsal surface of anterior portion of worm: X 25. Sagittal section of anterior portion of worm: X 18. Dorsal view of posterior portion of worm: X 20. Longitudinal section of sucking-disk and peduncle: 4o. Section of outer portion and flange of a sucker : X 200. Hook in sucking-disk: XX I50. Diagram showing arrangement of reproductive organs. Ow An fW NH Monocotyle Floridana, a New Monogenetic 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. MHelminthologisches. Zeitsch. f. d. gesammten Naturwiss. Ba. 52; px 562, 2878- Parona, C., e Perucia, A. Di alcuni trematodi ectoparassiti di pesci adriatici. Annali del Museo civico di Storia Naturale di Genova. Ser. 11 a, vol. 1x, 1890. Goto, S. Studies on the Ectoparasitic Trematodes of Japan. Jour. Col. of Sci. Imp. Univ. Tokyo, vol. vii, p. 229, 1894. g. Transverse section of worm back of testis: X 25. 10. Transverse section of worm where the intestinal trunks meet: x 25. 11. Transverse section of worm showing median trunk of intestine: 25. Abbreviations used on Figures. Ge Bscccsies anterior nerve. Pease lip. Di Dive Gavavers pharyngeal pocket. EP Piarocie ies birth-pore. ee longitudinal muscles. Be Su creas. receptaculum seminis, ON eel eects brain. Lt ON eee longitudinal NERVEY PS jsteussye are sucker, Ct: Eee centerofsucking-disk, (posterior). SiG cecisscane sucking disk. Ds Drviercssiatere dorsal projection of m........ mouth. Sh MM Scieis ate striated muscles. sucker. Wiese median) trunk Of om=" 224.2 selene testis. Giiatere wicuevass egg. testine. dae 1 ees mea terminal pore. Gaibiayerevereiate excretory trunk. OLEN a tcheretae Ovary. BOs erateveis uterus. We ctoniea sais flange of disk. Ye, ARSE ORE ootype. Goya oer vagina. | ene glands. Os Se cceetas ora] sucker. UND) Aclcayote vaginal pore. sare efaxctaiate hooks. OU sare Tale. oviduct. a re Aa A yolk-duct. 2S a ae Te intestine. [| OSI A pharynx. I> Bitatcajanie yolk-glands. HEEMINTH -FAUNASOF, THE. DRY TORTUGAS. IT. . TREMATODES. BY EDWIN LINTON, Professor of Biology, Washington and Jefferson College. 28 plates. iy an Ae neTduates ' ey ieee To (i: pide wi gad 20" aime CONTENTS PAGE mir QGur Ch1O mM yes Ie eR Pane EERE tet SEG coaches Sua atcllebier a snalbsiie se = que 15 HASt oivhorgucas trematodes and) CueurMOSstsis a qt. sitet ciae laos) teisie/s «2 - 210! 17 ISOM MOStSsamN GC ReOOC em OLS 6 .ceetie a Ree SIA Rese ore he SO aie 6.6 19 ikey to the cenera and species described an ithis paper... 2... se oe es 20 Descriptions of species, habitats, etc.: I. Trematodes from loggerhead turtle: CricocephalucidelstescensmMemMasser, se ae petercna oer tever BR Platnocseadiai, Sei New oan se, PLE, e's ates oie Walane oe Stns ya ao lers 34 Hamacreadiniia mutable cen. 2G Sp MOVes an. «> + - vie 6s ols = ee 34 Hamacreadiam sulella cen..6b Sp. TOW. aq 4.15 siw.- sterale aie afielmre etal 7 35 Hamaecreadiunr Consuetim: gen. Eb Sp. NOV. 5. .-55. 050000 ee sens 36 Hamacreadiim Oscitans Sen. Gb/SPs NOW. cies ss eles o's wiclele @ alan els 37 Mebouna cracsieilatsps gO). tyeiaertenala cia sigsis «)ots Wincale tensa vessel 38 Mesnsolenaeshrie Sen, Eb SP- OV acne cites cues aia cine =e tis sce aera « 38 Dadyierehis lotus seniret Sp. MOVs). sane ae osm Dee else Yaron = 66 Meradena Ovalissen et Sp. HOW: 5... oe ae es Sen asece = oe opera ass 67 Peradens acuia Sen webispue nome )ss \sle-= pie a eieietan's 69 14 Contents. II. Trematodes from fish—Continued: Momostomiid et 6-5 5) cucica wi os Races woe sists Sielene weleeae te een eee eee 69 Barisomum erubescens gen. €t Sp. MOV. ios. sae cee een 69 Himasomum candidulim gen. €b'Sp. NOV «. ee. ik versie opps a cee ps Paramphistomidee «.. .-.:..; . anekontsirwas oe ee tees We ar os eee 72 Cleptodiscus reticulatus*gsen-7et;spi-00V... . as. 2t4se- Gets se eee 72 Siphoderitiae fata. 25. ch See iest esc eencts Sian e oe eee ee ee ee 74 Sitphodera (gen. nov.) vinaledwardsii (Linton)......:...sseeedees 74 stegopa globosa gen. et SpamOvs\sacs. hie aoe ee Ces ae 75 Metadena crassulata gen..etisp. NOV.........itclden see eee 76 Prodistomum gracile cen.vetispinov.ne > soon, cae sce eee ee 76 Genolopa gen. “NOV 22... 6. Bienmnacd ten eee eee Seen ee eae 77 Genolopa ampullacea genet. sp: nov-.2) i Gee eee oe eee 77 Genolopa truncata.gen. etisp nov.citesee ob ee eerie ee 78 Gasterostomidze.).,.<. 5 <<... AREER oe Cae ee Ee eee 79 Gasterostomum gracilescens Rudolphi (?):..%. f.tue< ek ee «ese 79 Gasterostomum sp. (near 'G. baculum Linton)ies.)..4:.22-..- 4.5 79 Gasterostomum sp., from Mycteroperca venenosa.............-. 80 Gasterostomum sp;, from: Barracuda, ..... sehen ae eee 80 Heteracotylea ccs cspin.ds scgaea iiwoean eso oleae eee ee 81 Microcotyle incisa,'Spy,MOwier 5 2 stecas a sun 2.0 eee 81 Udoniella socials’ sp. OV. src nc « «sss: 1 cS eee ee 82 Aspidocotylea . 22. jews aida 2-« ee busnaya sae ie ete Oe ee eee 82 Aspidocotyle ringens Linton’. ..224:)5, eae ee eee 82 Deontacotylea, subord. n.. o8h.e hes Se ene. eee 83 Deontacylix ovalis'gen-et Sp. NOV:...19-5 use ae ee ee ee eee 83 Eng OX sd vie vie lod o's Late a Grae wie S Mee AR IO Oe 85 HELMINTH FAUNA OF THE DRY TORTUGAS. I]. TREMATODES. By Epwin 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 hematein. 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 zodlogy, 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 Szphoderide to accommodate cer- tain trematodes with an anterior oral and a ventral genital sucker. The Allocreadiine 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. 17 List of Tortugas Trematodes and Their Hosts, PARASITE. HOST. Aspidogaster rmeens!Lintomi jo... 6.5 See se ess Calamus calamus. Barisomum erubescens gen. et sp. nov Brachadena pyriformis gen. et sp. nov Calycodes(@e immature. <= 25. .s.sc.0.52% Cleptodiscus reticulatus gen. et sp. nov Cricocephalus delitescens Looss Cymatocarpus undulatus Looss.......... Deontacylix ovalis gen. et sp. nov Deradena acuta gen. et sp. nov Deradena obtusa gen. et sp. nov Deradena ovalis gen. et sp. nov Deretrema fusillus gen. et sp. nov Dichadena acuta gen. et sp. nov......... Dictysarca virens gen. et Sp. nOV......... Didymorchis latus gen. et sp. nov Dinurus rubeus sp. nov sie {silo em. Rey e) a) miiey's) (eifel sa > i6 Diplangus paxillus gen. et sp. nov Distomum fenestratum Linton........... Distomum sp. (D. valdeinflatum Stossich) Botenurus(!). usmdttres. 25 acc ace td's 3 Betenurus virgula sp. nov’. ...6..0.658.% Enenterum aureum gen. et sp. nov....... Gasterostomum gracilescens Rudolphi Gasterostomum sp Gasterostomum sp Gast erestonmimtnpy> SNS. aca kaw Genolopa ampullacea gen. et sp. nov Genolopa truncata gen. et sp. nov Hamacreadium consuetum gen. et sp. nov Hamacreadium gulella gen. et sp. nov.... Hamacreadium mutabile gen. et sp. nov Hamacreadium oscitans gen. et sp. nov Hapladena varia gen. et sp. nov..... tye) Sie 0) le oh e Oe Oe Our @ (ee) 0/0) eum) 6 Angelichthys isabelita. Pomacanthus arcuatus. Scarus croicensis. Calamus calamus. Hemulon macrostomum. plumieri. sciurus. Caretta caretta. Pomacanthus arcuatus. Caretta caretta. Caretta caretta. Kyphosus sectatrix. Tylosurus marinus. Teuthis ceruleus. hepatus. Scarus ceruleus. croicensis. sp. Abudefduf saxatilis. Hemulon macrostomum. Ocyurus chrysurus. Teuthis czruleus. Lycodontis funebris. moringa. Calamus calamus. Lycodontis funebris. moringa. Calamus calamus. Hemulon macrostomum. plumieri. sciurus. Hemulon plumieri. sciurus. Calamus calamus. Auxis thazard. Clupanodon pseudohispanicus, Kyphosus sectatrix. Lycodontis moringa. Mycteroperca bonaci. Mycteroperca venenosa. Sphyrena barracuda. Hemulon plumieri. macrostomum. sciurus. Hemulon plumieri. sciurus. Hemulon plumieri. sciurus. Neomenis griseus. Anisotremus virginicus. Neomenis apodus. griseus. Ocyurus chrysurus. Pomacanthus arcuatus. Anisotremus virginicus. Hemulon plumieri. sciurus. Teuthis ceruleus. hepatus. 18 Papers from the Marine Biological Laboratory at Tortugas. Helicometra execta Sp. NOV. ....... ce seen eee eee Chlorichthys bifasciatus. Hemulon plumieri. sciurus. Iridio bivittatus. Lachnolaimus maximus. Helicometra torta sp. NOV..........5---.--+«-.-+- Epinephelus morio. striatus. Helicometrina nimia gen. et sp. NOV.............. Calamus calamus. Eupomacentrus leucostictus. Neomeenis griseus. Ocyurus chrysurus. Memiurus merus Spi TOW. scien. « ucpatener eter airs Clupanodon pseudohispanicus. Himasomum candidulum gen. et sp. NOV.......... Angelichthys isabelita. Pomacanthus arcuatus. Hysterolecitha rosea gen. et Sp. NOV............-. Teuthis ceruleus. hepatus. Mebouriacrassigulays py m1 Ovary. sented releney tele r Calamus calamus. Lechradena edentula gen. et sp. NOV.............. Neomenis griseus. Lepocreadium levenseni (Linton)..............-. Epinephelus morio. striatus. Mycteroperca venenosa. Lepocreadium trulla (Linton)........ .......---. Calamus calamus. Ocyurus chrysurus. Leurodera decora genet SP. DOV. jae eo led Anisotremus virginicus. Hemulon macrostomum. plumieri. sciurus. Neomeenis griseus. Teuthis hepatus. Macradena perfecta gen..et sp. NoV....:......-.+: Teuthis ceruleus. Megasolena estnx gen. et:Sp) NOV. = .)- 926-2667 =.= Kyphosus sectatrix. Mesolecitha linearis gen. et sp. NOV............... Teuthis ceruleus. Mesorchisiuimna gen. etspy MOVE ae meetin aie Angelichthys isabelita. Pomacanthus arcuatus. Metadena crassulata gen. et sp. NOV.............. Neomeenis analis. Microcotylesineisay Spe mlOjerrcttte tren tater ere Neomenis griseus. Opisthadena dimidia gen. et sp. MOV.............. Kyphosus sectatrix. Orchidasma amphiorchis (Braun) Looss........... Caretta caretta. Pachy psolus ovalis|Sp. MOWjenge plate eer ier pts eters Caretta caretta. Prodistomum gracile gen. et sp. NOV.............. Clupanodon pseudohispanicus. Siphodera (g.n.) vinaledwardsii (Linton)......... Ocyurus chrysurus. Stegopa. globosa gen: eb SP. NOV. si. «a. sae oe er Neomeenis griseus. Stephanochasmus casuS Sp. NOV................-- Epinephelus striatus. Neomeenis griseus. Neomeenis analis. Ocyurus chrysurus. Stephanochasmus Sentus Sp. MOV... 000 50-2--+5-6 6 Calamus calamus. Hemulon plumieri. sciurus. Stermiunus) fusttonmis: (lulhe)/s. 2) eyene cue sunetennana Lycodontis funebris. moringa. Sterchtinus monticellin (eimbom) peers isch iieereie ree Abudefduf saxatilis. Chlorichthys bifasciatus. Echeneis naucrates. Neomenis griseus. Theledera (g.n.) pectinata (Linton).............. Auxis thazard. Theletrum fustiforme gen. et sp. NOV...........-. Pomacanthus arcuatus. Udonelila Socialis Sp imOv.... sinnie sro ers sere el te tes te Neomenis griseus, on Argulus sp. Xystretrum papillosum gen. et sp. NOV............ Lactophrys triqueter. 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: Number of Name. hosts Food notes. examined. Abtudefdut saxatilss® .cjcie secs: dsterewte« 6 Character of food not recognized. Angelichthys isabelita.............- 3 | Red sponge and associated material, worm- tubes, coralline and other vegetable ma- terial. Anisotremus Virginicus............. I Alimentary canal empty. UNTO StS VCP Az:. ole aoe res a an ae I Character of food not recognized. Calamus calamiis es vjccm «cles /steteressteys II Annelids, broken shells, isopods, spines of sea-urchin. Chlorichthys bifasciatus............ 4 Annelids, small arthropods. Clupanodon pseudohispanicus....... 33 Small annelids. Meheneis maucrates cd: tens ccce sense 2 Fragments of fish. Epinepheltisimorios ico. scs cts one 7 Crabs, fish, octopus. Simatusin,. cietetehers oie, eke 11 Fish, crabs. Eupomacentrus leucostictus......... 3 Annelids, fragments of sea-weed. Hemulon macrostomum............ 5 Annelids, fragments of crabs, mollusks. OLUMIEH See avcke's, cttetol nese 169 Annelids, crustacea, fish, octopus, spines and test of sea-urchin. SCUAPUS S heveic, se eraabc.aieek aneres 26 Annelids, crustacea, octopus, ophiurans. Eiridinybivittatsn we scyyate cere tiers cere « 6 Character of food not recognized. Key phosus) Sectatricees ces ete era wetae < Ff See weds small gastropods, ostracodes, iso- pods. Lachnolaimus maximus............- I | Broken mollusk shells and fragments of crus- tacea. Laetophrys triqueters.. sic. ac sce oss 5 Annelids in specimen in which distome was focad, in others sponges and vegetable dé- ris. Lycodontis: fumebrisatis os ose 0s, « «ar 4 Fish and crustacea. WIOTINGA 5 :rsis wakes o1s,.0i8! 0) 5 4 Fish. Mycteroperca bonaci............... a Fish and crabs. MENETIOSA: 14 Food evidently such as is browsed off the reef; mainly red sponge and associated ma- terial; sea-weed, fragments of crustacea, ascidians, annelids. CATS CAONCLCUSs « <:< 610107 sis sce cie ose s' % 7 Crushed mollusk-shells, crabs, spines and test of sea-urchin, sand. CLHOICENSIS ioreeeS< wi sareye eevee tele 4 Challey material, vegetable material, and sand. Whgosoucssowesomocdoedocnas I Chalky material. SDPhiyrcena, ParhacuGar ce crcciecaesreieier Io Fish. Meuthisicerwleusiy. sarees ore ce eerees 8 Annelids, scales of fish, vegetable débris. IE DATE Ae als.0) Sis. oo wtenaun sie 7 Crustacea, fish, sea-weed, sand. SEAMS AG hilt ATUIAUTS sis, eucleiiey eieist cnet ene. o I Fish. Garebia Carehta tae vidios ce cxottelets. « 3 | Fragments of sea-weed and Palinurus in one; vegetable débris 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: 1. Body without tentacles elongate, paired anterior suckers............. 2 2. Posterior sucking-disk unarmed and without radial ridges. . Udonella soctalis Posterior elongated disk provided with numerous small suckers Microcotyle incisa ASPIDOCOTYLEA: Large elliptical ventral sucker with numerous depressions, no oral sucker, intestine not bifurcate; one testis; marginal sense-organs Aspidogaster ringens DEONTACOTYLEA: No suckers, mouth minute, intestine biramous, the rami with branches; genital apertures separate at posterior end; body covered with minute. SpinieShs Owaliscetel\Gie.« Hike =c2 cel eA Deontacylix ovalis MALACOTYLEA: rt. One sucker (oral) present (MoNOSTOMID 2) 32.7. 3-2 oe 58 2. Dwo stekers: poresemtsen: 4c qiartere ots= ncele fo. © pices nacuk een he eee 3 3. (a) An anterior sucker (acetabulum) and a small ventral sucker (oral) (GASTEROSTOMIDAS) spain: = «leven ers seo 2 OR teat gece eso re ee oer ame 4 (b) An anterior sucker (oral) and a small ventral sucker (genital) (SIPHODERTDZ)\o....chogete ncn =) soe eos oho on eIcleae eae ET CR eR ee se eee 5 (c) An anterior sucker (oral) and the acetabulum at the posterior end (CAUMTPEMEAO NOHO), f So gao sa asassoanocebooassoteusacoy oe II (d) An anterior sucker (oral) and the acetabulum on the mid-ventral Surface (CP ASGIOLID Ar) Pagid ca tare ensleitegee ere ue ran a ree ee 1} 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. &.. SIPHODERIDAS . Seeice. Glue iis chavs 6 oleae cs AG leu = naeeele ges ter ee era eee 6 6.. Testes more thanvones Me: iitia-). . 8h 2 = phen arc eal eeieree een ee 8 OmeHEStIS. so cee, Secetbe acces Catcedene, “OLA ore Sh tals Seen Eee et eS ohon mene 7 7. Esophagus short’ or nene, body ovate. ....-.22.-- Genolopa ampullacea Esophagus as long or longer than pharynx, body linear-oblong Genolopa truncata 9. Testes-opposite, vitellaria compact. <2... . s.r es 1-2 ee ee ee 10 Testes tandem, uterus in front of testes vitellaria diffuse Prodistomum gracile 10. Ovary behind testes, body subglobular.................. Stegopa globosa Ovary between testes, body short-oval.............. Metadena crassulata ite EI NM UUUHsTshISHNOMORDYD, Oo mco, codee OnAebnoe acon oeneoUdebe our cee tc 12 12. Lateral pharyngeal pockets and cirrus-sac present; no ventral papille; testes slightly lobed).5..4 sntsicc = =e ere tee Cleptodiscus reticulatus £3; HASCIOLID 2 a5 ge ee.crse «ie cue tclervenatice sonia er kore een ee 14 4, Pharynxspresemt. . 2. si ceiiecienne sects cena e eke CI cael erence eer 15 No: pharynx, (amature) s.\-qe omer kareena Distomum fenestratum 15. Ovary behind testes...... Ae NE mirineiorcn Goon Asa oC 45 Ovary in front of testes (beside testes in Dichadena, No. 43).......... 16 nO, Vatelline lands compacta errr entries tele eer ate en eter 42 Vitelline clands ‘difftise or dendritic... .co5- 4-0 ace ace ie er ee 7 7. Body smooth... 0. scm -seshieicpate dy bee hele ey eee nae areata toa ie ee 2 Body more or less *Spinose™. 1,4 ceria - a tktt ocr baer seone me casinos ee ieee 18 18.. Withott’ oralySpinies: << . GcTe Ret eects aisle mics oe a oie ee ee 20 With oralSpines. 5 i... ./c.cue cyan area ees ea eet eme ete ing eh = el eer eee 19 1Spines, 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. . Neck not slender, esophagus very short.......... Stephanochasmus casus Neck slender, esophagus about as long as pharynx. ..Stephanochasmus sentus Bee WC tne eee DIN a sats ee oe sic ee ue ale PA seg ecada Wns, oleae weeks. 5 21 QiTeIESES a 5 ESSN Ge a ote SPORES Bol ghee tic eet ol aE en ane ene et ame Hapladena varia . Body short oval, esophagus short or none, testes diagonal. Lepocreadium trulla Body linear oval, esophagus distinct, testes nearly tandem Lepocreadium levensent Ovary in frout oj testes, vitelline glands diffuse, body smooth (except in Pachypsolus). 22), Bia 24. 25. 26. 27. 28. 29. 2@: Rie BOE Sei 34- 35- 36. 37: 38. 39- 43- 44. GRESEES* GO newt ue eas teticanks oki cee ati peasp snare pau et yetetsy ctsatas st Sesh a) asta wr: 25 OMERCES EIS ears cous cpu node cReeeoR cheros VERS ae est age eis moh asa ce oye susgers ei wactane 23 Ventralisucker larger than oralinova lancet. +. acct «ac + crete s eck tise teh coe 24 puckers about equal ovajmoderate: 17 oi ajo ne o's Deradena ovalis Ventral sucker nearly twice diameter of oral............. Deradena acuta Ventral sucker about a2 5) times Onan. we se © ss eee en oe Deradena obtusa Folds of iterusiextend hack ofvoneor DOtM testes... f. coe oe ee nog: = 39 Folds of uterus not back of testes, at least not behind both........... 26 PICAG WA MOUtr ap POMGA Beet! Bian cra el tals gtr sak tick i rasa, te ce gm cgaiaus 20 Hleadewatarappemadares tects ws: arco tune srieta serene = ok cherie os Se) een rere 27 Intestinalframr not unirbediat postemormend...-.%5...--..+--++++ 02. 28 Intestinal rami united at posterior end. .......:..... Enenterum aureum Head with short nodular papillae and ventral flap Immature distome related to Calycodes HeadVand? neck with) tentacular\lobesy-4:..--2--2-.- - Theledera pectinata Seminal vesicle near anterior border of acetabulum.................. 30 Seminal vesicle behind acetabulum......:::...:..... Lechradena edentula AG MICE UL CM Ont 21) Sie tle isiece tne wee ik s esaas cla © fieje dis wise tse 6 os ain Be Owvariilatmente Gey aare Biot cas Setter ore cielae enepe es eke ect pach es seac va oars tigatiey/s an Niveiite Stats CX hema iiabe Meee no ae Mea ak sie Sono A oe oe i se one ous, 3 32 Vitelline glands behind acetabulum. ..5.......:.-:--.- Helicometra torta MLESEES SITE SUM AT A Nona. Na aie chs ides, Giteevale val sec seats is he. secaye ste Helicometra execta Westes usualy G.richt aid: 4 lett... oc miele als satan vee wot Helicometrina nimia etre Mea tea sence Meta MOON, ner peop hecel spate sen Pentre alias ler Aru valet soc ach at 35 Vatellania do mot extendumitte neck Arie ok vce aie a see Fok ase are os 34 Nentralksucker largernithan: oralley costa es ates Hamacreadium oscitans Ventralisnekerssmalienitihan oral: 2 ir.:,--s1. dhe chow cuckt Megasolena estrix ESO PM APTI SHS MON bee coe coer wrap ticus osasvsdlsngectetenah ese gole Gqere tiene) “inwirepe Gepceees tee ete. a7 Bisse piiap tesulon est aks. aye coed) ck, mL Steet Cama a ame eos 36 Genitalvaperture median. ijcmn py ae eee ose Hamacreadium consuetum Genta aper tare Ob MMeGIa I. ie oi oes, uta s cba aha ways Hamacreadium mutabile Aestes dinretial, “Or Hemi SO.a coo. Soins Sole oe eta aes ae awn ae a ee 38 Léestes opposite, orimearly so; body broads ss 5.. 0.08 Didymorchis latus Genital aperture mediate jc: Ne) acm “hain see fe ee ys Hamacreadium gulella Gemtal apercuce Mot COCOA fo tls ee wigs cud i ace 5 ep alelia eee Lebourta crassigula Holdslofeuterusiextendsback-of both testes: 7... sesso. 265s cts fein 40 Folds of uterus mainly between the separated testes, but not behind the POSLERION WESUISs esters ye anager = eee ae ai es Orchidasma amphiorchis Pabncestinalrdin without lateral projectiOms, 007 0+ es esc nes ee 6 eee) acl Intestinal rami ‘with lateral projections: 7... ....7.%5: Pachypsolus ovalis plntestinalararmi Mormoee aera caters byes eens tia rena Oe Mesolecitha linearis iimtestinal sramat SHOU. so.) sere s.a + ca choprteee s hem see os Cymatocarpus undulatus Ovary in front of testes, vitelline glands compact. wf LEST HS Syria (5 0 eRe RR aR aia I agp SPA ne ea ana fe e AR e 43 PRESECSHO MD POSILE MCA Mr ra RIE ee Te eM cTe ehs, tenets eaten ata eaeNse ye ah oce sho ke ost te 44 Ovaryoin. front Of Gestesn: aite.. Past. as siete 8 eye eta = Diplangus paxillus Ric cui EG GLE = Pe StS ae ao ets Ma an Bnet aa lee oan AS Dichadena acuta Genital apertite dcetd lo ths apogee a5 a) <95 1) Seeger teua one Deretrema fusillus Genital aperture median, body subcircular in outline, neck linear Xystretrum papillosum 22 45. 46. 47- 48. 49. 50. Ru 52. 53> 54- 55: 56. 57: 58. 59: 60. Papers from the Marine Biological Laboratory at Tortugas. Ovary behind testes. Agppendiculate is, « ..< xs 0's 4s: nies sueeyiye pier ko eel tele ER ieee ee 53 Not appetidiculate. «.. -.) 3255... -.-- eee a eee 52 Vitelline glands with long clavate lobes............ Brachadena pyriformis Vitelline glands slightly lobed, body oval......... eae Leurodera decora Left vitelline gland deeply, right slightly lobed........ Hysterolecitha rosea Vitellana tubular. 000 cee gbie en esas icy see A eee te ae ee 56 Vitellanis nottabular..,:..k es sacrces ie Gteios os qaho eek Ecler eee 54 Body Smoothness ive.) cacet.ascm bore cits 2 ens BRON E ae ee eee 55 BOG yiSErratern Zee ie we Sinus sexe ke oiol «ele esse Reels Re aE eC Hemiurus merus Vitellarianmoderately lobedii2 5 0 aus sve.) sue hlee iee: Sterrhurus monticellia Vitellaria with about 7 long-clavate, slender lobes...... Sterrhurus fusiformis Body Sereates 2.0250). Gvies, dvase Bsc aan be a6 «kis dole cree eae ee eee 57 Body wrinkled, not serrate, greatly elongated posteriorly...Dinurus rubeus Two dorsalvemimences On) Mee a. bcia cis seep e Ectenurus virgula No eminence sevident,. 2 2. a01.2h0« 068 wiser Immature distome near Ectenurus NEO NO STO MRI AE Fea tos isiriciats op otins tu aay cucn a are) 5am oe oe Se 59 Anterior end somewhat triangular, a prominent muscular ridge separat- ing it from the restsofthe body... 0%: 62 oss ope eee 60 Body boat-shape'!—. Jah. cerer. Secu as, opera eee Barisomum erubescens Linear oblong, posterior end truncate with 2 small, postero-lateral pits; intestinal rami with side projections........ Cricocephalus delitescens Linear, strap-shape; intestinal ramisimple........ Himasomum candidulum Helminth Fauna of the Dry Tortugas. 23 I. TREMATODES FROM LOGGERHEAD TURTLE. Cricocephalus delitescens Looss. (Figs. 1-3.) Zool. Jahrb., x11, 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 by 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 o.o11; length of ovum and filament o.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 papillze 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 ram1 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, 1907, 1 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 o.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. zrroratus (R.) Looss is. Helminth Fauna of the Dry Tortugas. 25 to be found in the nature of the cirrus-pouch. In P. ovalts 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 suckers 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 diverticule 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-giand with the seminal receptacle on its lateral border is dorsal to the ovary. 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,4mm.inlength. The smallest were without ova. One ofthe 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., xm, pp. 503-594, lak 27, gs 32) sang4. 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 bursz (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, 7.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, subglcbular, 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). Inthe 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 excretory 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 o.7; oral sucker, length 0.28, breadth 0.30; pharynx o.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. 1, ro0z, p: 20, Taf. 1, figs. 7, rz. 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; pharynxa 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. 2.46 2.66 I.42 Breadtitae. se cone een 0.63 0.37 0.45 0.58 le AOrallsuciker: tno ene ien 0.33 0.28 0.32 0.25 i Wentral stickers. senncee lees | 0.16 o.14 o.16 o.16 | Pinatas xd yeh jen tseel fecevat=le \eugOiues O.11 o.12 O.1I1 Helminth Fauna of the Dry Tortugas. Dimensions of ova: Thickness of shell 0.0034. Host, Caretta caretta: June 29, 1907, 12 specimens, in stomach. ik 29 0.034 by 0.040; 0.037 by 0.030; 0.040 by 0.040. MALACOTYLEA. FASCIOLIDZ. TREMATODES FROM FISH. Comparative table of the Allocreadiine described in this paper. Helicometra torta sp. nov. (Figs. 29-33.) | | Ratio | Oral | Pha- |Ventral| ofneck| Esoph- Shape. Length. | Breadth. sucker.| rynx. | sucker.| to agus. | | length.) } | | Helicometra Oval) w nb H 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 Hemulon. 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 mght: (5)w2stestis; transvesses 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, Hemulon plumiert: 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, Hemulon 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 clavate, 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 (44b). A similar doubling was noted in another, where the last two testes on the right side were transversely placed (44d). Dimensions of specimens mounted in balsam. Length. Breadth. Neck. Oral sucker. | Pharynx. Ventral sucker. 2.46 0.91 ©.90 0.15 0.10: 0.08 0.29 2. 3x | 0.77 0.84 oO.14 0.10: 0.07 0.25 2.07 | 0.72 °.80 o.14 0.10: 0.07 0.25 2.06 O77 0.63 0.17 0.11: 0.08 °.28 2.00 0.77 0.70 0.18 0.10: 0.08 0.24 1.96 o.61 ©.70 0.13 0.10: 0.07 0.21 I.go 0.63 0.71 o.14 O.tO..0).07) 0.25 1.78 o.71 0.63 ©.14 0.08: 0.07 0.21 TeSix 0.60 0.57 0.15 0.11: 0.06 | 0.22 I.43 0.38 0.65 o.10 0.06: 0.05 °.18 1.04 0.58 0.42 0.13 0.07: 0.06 | Only 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 11, 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, Neoments 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 to, 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: “va, together with; xezddov, 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 Neomenis 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 triangular 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 sounded: “Leneth. 3.02: breadth> o277;rneck 2-505/\oral, sucker!o.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, Neomenis 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 to, 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 r2, 4 fish, few distomes; July 14, 4 fish, 9 distomes. Host, Neomenis 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, r fish, 1 distome, immature. Host, Antsotremus 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 Neomenis 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.s5 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 posteriorend. 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. 55 exv). Dimensions in balsam: Length 1.85; breadth 0.67; neck o.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 Hemulon 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, Hemulon 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, Hemulon 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. 61-632.) 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, Hemulon plumert: 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, Hemulon 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 Lebourta tdonea 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: péyas, large; owdyy, pipe. Body nearly linear in outline, tapering slightlwat 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 prepharynx are probably 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: ddvpos, twin; ¢pzs, 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; ¢/tepov, 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 1o 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 to8mm. 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: 7, nipple; 7, neck. Host, Auxis thazard: July 10, 1906, x 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. 4l 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.) ee trulla, Linton, Proc. U. S. Nat. Mus., vol. xxx111, p. 109, plate x1, 8- 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 (ite 73). The spinose cuticle has a tendency to separate rather easily. Many 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; Julv 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 ©.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, LINTON, Proc. U. S. Nat. Mus., xxx1tI, p. 110, plate x11, figs. 80-83. Certain distomes from Tortugas groupers are here recorded. One of them, from Epinephelus striatus, agrees with D. levensent 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 o.o4o. 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 Epinephelus, 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. levensenit. 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. levensent. 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. Helminth Fauna of the Dry Tortugas. 43 Comparative measurements, specimens in balsam: [Nos. 1 and 2 from Epinephelus, No. 3 from Mycteroterca.] | No. 1 No. 2 No. 3 | | | | Length...... | 1.68 2.10 2.45 | Breadth..... | 0.56 | 0.59 ©.59 le eINEGk .o.2hs2.. 24 0.50 o.71 I.03 OralSsk-...-- ict Outs) Pil. O-L7 Ig. 0.14, br. 0.19 lp. Ons, "Dr. OL 14 Pharynx ....| lg. 0.14, br. 0.19 lg. 0.42, br: o./19 let o'.14, bY) 0.14 Vefitral sk...) lg. 0.15, br. 0.17 ig, Ord, br. Ore leHowrs, Dr oOLrs Owain eee 0.061 by 0.037 | 0.060 by 0.034 0.058 by 0.031 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 Szphodera vinaledwards, 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 midway 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: péoov, middle; AgkHos, 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 aperture 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 ventral 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 uterus, 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 jrom 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, Teuthis ceruleus: July 10, 1908, 1 fish, 2 distomes. General color orange-yellow. Drmensions of smaller specimen, life, flattened: Length 4.20; breadth 0.90; oral sucker 0.42; pharynx 0.16; 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 Neoments griseus and Ocyurus the ova in mounted material were from 0.061 to 0.065 in length. In those from Neomenis 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 Neomenis 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. 45 Dimensions of distomes mounted in balsam. | | | | | | | ofan | ioe. | | | Host. Oralsk. Pharynx.) Vent.sk. “.1qio | endto | Length. | Breadth. | | lees sersine ventral PharyNX.! sucker. 3 : ( | Epinephelus striatus... 1 pete eran 35 Cte AIP COtRS | 2.24 otee Neomenis griseus...... te are ee hee onse 2 “T206 2.17 0.72 Do.......-.-. fe ae a ie Bee ©.32 °.60 2.35 0.60 Ocyurus chrysurus..... lg. oats S ae pie | see Sone Re | Buen ! | | | Do.........-- | Ig. a ie ah ied | ©.60 | x.20 4.42 ©.77 N i lists nie le of : : | | | | ae cleo nt tied aee. hast, (al IDO Serre eh cietee| {ie. 0.25 0.31 0.43 | = 5 | \br. 0.25 0.18 | 0.42) | SA 2.60 eke BIAS Ob arciuerercrrsns ts flg. 0.25 ONSGuEa LOL SO \br. 0.25 0.25 0.45 aes) I.go 6.37 0.84 | Host, Neoments 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, Neoments 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 jrom 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 uniting 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. | | | From a ane Host. .| Oralsk. {|Pharynx.| Vent.sk. ee end to | Length. | Breadth. | sty Yentral Calamus calamus..... a ey | ne ie 0.52 0.84 3-64 | 0.55 Don aera iene he is as ee | aes 0.35 0.56 1.96 0.42 Hemulon plumieri..... iE epee | poe eae 0.50 | 0.70 a9) | TOW Dosen. le ae Ores | 2:39} 0.50 0.70 2.28 0.38 Do. aes. te 208 Al See al ee 22) leas ton im iia sGri| aman Hemulon sciurus...... | 1g = a aes o.2e ! 0.56 0.84 3.78 0.47 Dos. 3. | ee ei ee el oe alto sea Reece cee Host, Calamus calamus: 1907, July 10, 2 fish, g distomes. 1908, July 7, 1 fish, 1 distome; July 8, 1 fish, 1 distome; July 14, 1 fish, 1 distome. Host, Hemulon plumiert: 1906, July 8, 1 fish, 2 distomes. 1907, July 1, 4 fish, 1 distome; July 3, 16 fish, 1 distome; July 12, 11 fish, 1 distome. 1908, July 3, 2 fish, 2 distomes; July 6, 5 fish, 1 distome. Host, Hemulon sciurus: July 2, 1907, 3 fish, 1 distome. Lechradena edentula gen. et sp. nov. (Fig. 87.) Etymology: A¢zpts, crosswise; 407», gland. A single distome evidently near the genus Stephanochasmus, but without spines, is here described. It was found in a gray snapper (Neoments 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: pvéoos, middle; ¢py:s, 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 tsabelita: 1906, July to, x 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, x fish, yo 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 by 0.017 and 0.031 by 0.079. 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: dexdéos, double; ayes, vessel. This distome is characterized by its cylindrical body, which is atten- uate posteriorly, 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 (su 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, Hemulon macrostomum: 1907, June 28, 2 fish, 1 distome. Helminth Fauna of 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 r2, r distome, length 1.75. Host, Hemulon plumiert: 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 in length, not seen in the mounted specimen. 1906, uly 8, x 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; July 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, Hemulon 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 ro, 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 o.004. These are not evident in the mounted specimen. Deretrema fusillus gen. et sp. nov. (Figs. 102-1042.) Etymology: ey, neck; tezpya, hole. The description which follows is based on a distome from Ocyurus chrysurus (fig. 102). Other distomes from Hemulon 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 Hemulon 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. 1o2 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, Hemulon 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. xxx111, plate x1u1, 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 Coryphena 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, Hemulon plumiert: 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: f#otpa, scraper, rasp; 7tpoy, 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 striz on the ventral disc are simply the longitudinal muscle fibers of the body-wall. These striz 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 0.040 by 0.020. Host, Lactophrys triqueter: July 8, 1908, 1 fish, 1 distome. Hysterolecitha rosea gen. et sp. nov. (Figs. 112-117.) Etymology: Sezepus, last, posterior; A¢K:Bos, 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 volk-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, r2 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 o.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 ceruleus: 1908, June 27, 1 fish, 2 distomes; July 5, 1 fish, 1 distome; July to, 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: vexpés, long; 47, 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 ruge, 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 ceruleus: 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 by 0.014. Opisthadena dimidia gen. et sp. nov. (Figs. 120-122.) Etymology: ézicIos, hinder; 407», 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 Tortugas. 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- pill 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: fpazos, short; a4», 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, Hemulon 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, Hemulon plumiert: 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, Hemulon sciurus: 1907, June 28, 1 fish, 1 distome; July 1, 1 fish, r 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, r 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: ova, in two; 47, 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 subventral, 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 1s. 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 ceruleus: 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. 57 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 o.29 in breadth. Leurodera decora gen. et sp. nov. (Figs. 128, 129.) Etymology: Aeveds, smooth; oy, neck. Body’smooth, compressed, long ovate, greatest breadth back of ven- tral sucker; middle of ventral sucker about middle of length of body, ora 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 body 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, Hemulon macrostomum: 1906, July ro, 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, Hemulon plumiert: 1907, July 15, 1 fish, distomes few. 1908, July 6, x 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, Hemulon 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, Neoments 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: dkcvev, network; odpé, 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- mately 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. 59 Dimensions of 3 specimens in balsam, each more or less compressed. From L. moringa. From Pe eae Sav Z a ——— ———| | TO in seyevaday evn ley oroneuee 3.64 3-90 4.27 Breadth, :hicwhae sees 25 Hae « 1.05 1.61 1.54 INGe) SS Ser teres ome eel ©.9g1 0.89 1.07 Oralisttekere acho shoe eave | 0.22 0.28 0.42 Pharyaniee canoe cuclens 2 cieeesi | o.IL O.IL 0.22 Ventrallsucker. 2... ss cus 0.33 ©.39 0.54 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 2.5mm. Intestine in one filled with dark-brown or black granular material. Suckers filled with blood-cells of host. Host, Lycodontis junebris: 1906, July 4, 1 fish, 4 distomes from swim-bladder; June 28, 2 fish, 4 distomes from swim-bladder. 1908, July 7,4 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 2in 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 1o mm. in length and 5 in breadth. Theletrum fustiforme gen. et sp. nov. (Fig. 137.) Etymology: 9474, nipple; 7zpev, 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 striz and with a cluster of low but distinct rounded papille 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 subterminal, 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 o.or4. 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 Distomum 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 striz 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. 61 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 body. 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 appendiculatus 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 o.oTfo. Sterrhurus monticellii (Linton). (Figs. 139, 140.) Distomum monticellii, Proc. U. S. Nat. Mus., pp. 518-520, plate xLiv, figs. 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 isa deep cleft (fig. 139 2) 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 bean 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, Neoments 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, Abudefduj saxatilis: July 7, 1907, 1 fish, 1 distome. Dimensions, life: Length 1.05; breadth 0.25; oral sucker o.10; pharynx 0.04; ventral sucker 0.16; ova 0.017 by o.o1o0. 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 o.ort. 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 (Lihe). (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 Lecithochirium fusiformis Lithe (Zool. Anz. xxtv, 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 pharynx; 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; pharynx 0.07; ventral sucker 0.56; ova 0.018 by 0.009. Host, Lycodontis funebris: 1906, July 4, 1 fish, 150+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 o.go, posterior 0.28; oral sucker 0.22; pharynx 0.07; ventral sucker 0.50; ova 0.02 by o.o1. 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 ”) 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 le 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 2mm. Host, Lycodontis moringa: 1907, June 30, 1 fish, r distome. This distome was translucent greenish-white, intestines black. Neck actively contractile, body less so. There were a few, low, fleshy papille 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 o.otfo. 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 o.oTIo. 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: dzdos, single; ay, 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 ceruleus: 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: 0¢p7, neck; ayy, 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 ceruleus: 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 2) 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 body. 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 ad’). I interpret the cell to which the index line d’ points as having undergone nuclear division, and the inner nucleus with the 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 ceruleus: July 13, 1908, 2 fish, 3 distomes. Host, Scarus sp. (This was a parrot-fish having many points of resemblance to Sparisoma abildgaard1.) 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 o.og 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.) Distomum sp., from Tylosurus acus. Parasites of Bermuda Fishes, Proc. U.S. Nat. Mus., xxxIll, 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 o.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 papille 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. ce@ruleus they lie for the most part behind the ventral sucker. Host, Teuthis hepatus: 1907, July 1, 1 fish, 3 distomes; July 11, 1 fish, 1 distome. Dimensions, life: Length 1.22; breadth o.50; oral sucker 0.19; pharynx 0.07; ventral sucker 0.24; ova 0.075 by 0.051. Host, Teuthis ceruleus: 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. MONOSTOMIDA. Barisomum erubescens gen. et sp. nov. (Figs. 173-183.) Etymology: apts, a boat; saya, 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. eeeey PLATE 15 PLATE 16 e: TE pd: ghd ES a ef a PLATE 18 ck i i an TP iaeeeG iP fk a ean Laity) Ae ASAE eo 3 Boe ae | habcaaaail a WW = Ss a = oe 6 he PLATE 20 ae x 7® LAS) Pa PLATE 21 West guetens oes : 22-24 a BY fu » ‘ ". ; Pe, Fite" x > 7 Rie: @ LINTON PLATE 22 PLATE 23 \ xy greener ¢ Oy tees x \y \ gt \ SNA Ros : Dr) fh KY r fy te ss Ss 0A) PC) —_— = —-? ah my pT, PLATE 24 PLATE 25 E a CLA AL eta , MLOUP ACPA HA gpg pel te i co ae - 2 vies PPR La eee a ren aoa eee a PLATE 26 PLATE 27 PLATE 28 nm CONTRIBUTION. 10> 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 ORME <3) ! r el oe CONTENTS. Se PAGE MERE OCUICEION tes ea tebetetetore araecveredtare stoke Slcme te cis, eieneraye 0 sitet ocebalie leiie'e: 8 sie) @ fo! elie el sha) = 105 mopecraphy of the Plordian: Plateawe s,s idee ee ce eee eee 107 Relation of the 100-fathom curve to the present land surface and to SECA LER S PENS Aa tan a Were Secale en wletne Baar ehale aleve sw elena ietem 6 nla me 107 'Theiro-fatnommeanwes 7. ata. 2s ioiatase Were vole letala sls eiste st + + oie bisreiene ses 108 SRG: FCGME ee Net oe eh Metals! rot ctatetcldlaiad elute leis -eia’er eels, ene tens, « aiiei%, ab es eX 109 digsiowl Ba enhanc Sadie ei) ee ees Alea a ieee re eee IIo PROMS YSN NS Seacte ee eter cate Shane al atvtetetahataha Sieie sefalele wae ale eae e ie os 6% si'ire IIo Bays and sounds behind the keys... .....5... ccc eset teers se eee III Relief of the madaniamdss trial nice le Pega ee ee er ete sis aes s vis aes Tne Marine bottom deposits forming in the bays and sounds behind the keys..... 114 Biscayne: Daye ye lars cteeare taht ciate ata otal Potabeeatales sides 8 00a pare ar wcae as 116 Between Old Rhodes Bank and Carysfort Light ...............-.. 117 (Ciirgs Mesto, buaVOle yh Gc tog, Ae ee OTL Gr nee ch tae arch ee reenchiin GiO.0 ep eee EE CLO 117 Barnes Swit Secs Meet ek A) AM ro anata t's Osho. ol enater ohare TeP aca vi? JEU E Canter SObaKl s Qn were, Bic d 6 Giacie opined Bo web OG SO Cin co tkole CiooInIG 6 aie 117 LE KOTO VaIOxe) wLOWEDS lo orients hoa o.d de Keo CAGEHO eek es a DS CeOLUERO DROIUIS C Heo OTOL 117 PAL ORLA AB any er cte ch sete tone eer terete earn see creel ores otteete ale) wiles efiayeiiev ened ore erates irae) GinrandsGatikeyss Bahamast<£622 lx ox ce. a uc ote ected disse shale eee ms ole II9Q Summary of data on the material of the deposits.................. 119 Report on examination of material from the sea-bottom between Miami and ey Wiest; ‘by Georve:Charlitom Matsoni ar. to ece fecal cree we o's 120 SOUMUCESNOM tid UbeLIa tay pie Pee ee eect evel eee anc Poteet cede eseerolten eh ayrstal/otelesh-c/e'e!:s Jo) <\'ows 126 Silit@at: seems pee ree ear aah one eee pat ohata el oRetapaaelts, Seametnals sera seas) = 126 Geologic distribution of siliceous sand in Florida.............. 127 Calerumkcan bo meit esate ro ite acuta eres ote seen ote et tenayeicee sel elsiheiloy/=ye 129 Calcium carbonate of increanic origin =) iy ails. ee eee Ct 130 Pleistocene limestone of southern Florida................ 130 Roposraphy of southem: Plorida. 20%... oo: we. 2 ee eee 131 Verctaiton ol southerm florida vag. .6s ee fee. dale Sawn 131 Drainage and rainfall of southern Florida............... 132 Chenttcaldenudation. 354.018 fies ote ele wie eae eee = af 133 Precipitation of chemically dissolved calcium carbonate.... 135 Miiltibeswater periods. tia. c ae ces soc ate (cg cmiaie is A lal ele © wile mini 136 ilectroissedespra yrtciacasertsccae tenets eestonaral cer ean = heh oFol's ie 136 Calcium carbonate derived through surface erosion........ 136 Caleninr ecarhonate otrorganie @ricin hoy. Oe ene alerts sw iete we ayes 137 Résumé of sources of calcareous sediments...........--0+-045 137 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.................. 140 Constantreumrentish ersietace toe trae te ecto titi tate tetsli eh tetegenoliatotcysre rare alts I40 ‘Pidall eurremus ters ov. ait sieiens < cco rigs eee ond Steno tReet stella at S eee ee 141 AVVO SE Set ay Mee AR came sien A Ft Tes eA BeBe Pere cent men ets, aticteng ey'ey ose I41 Effect of Florida countercurrent on shore topography of Florida.... 142 Brartalles rebate Rese ayes a aaa cats eta crete cdot a aielai lat ee, Seo el etal ahskw aa stieoske Biato 145 Deltas at outer.ends of passages between keys......i2..02s00s0e0n% 145 ATeal Gist Uubion Ob Une CeOlOmIeMOrManONS = ..46)5 -aeieeie eke iets eyo r= = Ne enens 146 DUS OCERE een Eta Sore coe a is ee ae MOIS on Sitch ave Meverearete 8 eT aint gs 146 Vicksh ira Groupr ch actin coe eae seona tame hoag we ale etoeeuaetatatans ¥ als) ahs 146 ApalachicolatS Taupin. .o8. 0.0 26 6 oe, «icles ee eee Bevel rls se oer 146 IMI GCELC ALE Saree ore ists ne ents Peer nena eouneet uo eras Sav sielere 147 PO Cee Ras Heyy eects Jee cele: Sasha cuss iat strona ce ust seers yoncate, seshelrepenthn, i iiss 147 PE ACASLOCEIE hc ie eis seen ata aie eect ie Se ye le nial Saale elo ore Siem Fils S's inc 147 General relations of geologic boundaries in Florida.................4-. 148 Drain ace LiMEsh eee wae MTN ee a eee oh Ie. Sings fe Pol Rr Sadus beetotter «Sie ele sohse a) ate ers 148 Geologicinstory of thesMlondiam Plateatber satanic sea deities eeetenelotslc aie acta le « 150 Benes Ol /Vicksi urine inier mals 28/2). ay ace hie ace gia ie) she. bs Shae d=) 55 wists 150 ie: Vicks burst Submercenees os. i sisva cn neal @ aie = 2 os 150 Depthvandsteniperatuneror theawabers.. rin al s 6 = cicv-s see 162 Events of Phocenestime: a. $22.0 carci tetera esc eae Eo eee 162 Stratigraphic relations of Pliocene to Miocene sediments....... 162 Areal distribution of Marine Pliocene in Florida............... 162 Lithology and thickness): ts: cecthiteeneieas «ieee ee 164 SHOE HNC oho acs nk hehe: ahs ty rev Sears See ERIE ee RIS eee 164 Depth and. temperature of the Pliocene’ Sea... .. 2... ee eee 164 Conformity of the Pliocene to other geologic boundaries........ 165 Events above sea-levelc s2.cc av F sa - 185 (b) Erosion by sea-spray, Picquet Rocks, Bahamas, western shore, israneemnguicebut oaths. rents carats os ay Rei, eerie. cn aacd one 185 (c) Erosion by sea-spray, Gun Key, Bahamas, western shore...... 185 g. Young mangroves, showing stages of development from the pod. The four small figures represent pods plucked from the tree 185 to. Young mangroves: (a) and (b) 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 EL Mane ROVeS, iMag RT Ver 55). taluk see ei eee bios, ater aleues oh th 185 nes (a) MantrOve roots, biseom Key A. .1t5, Wan ncaa ulcak seilewiieias wo 185 tb) Bidele Maneraves.: igeOm ey sa. ack cei we aurea tae eee «oles 185 13. (a) Cross-bedded calcareous sandstone, probably eolian, eastern SidesomGtin Aseyn Ba komas.. Sots sast Sais bch bee aed as wih 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 . Tortugas, East Key, west side looking north. Note vegetation on the summaitaatitherke ye: i Siete: tnt ee agatha baal ortet Sin cye Bane IIo . Middle Key, looking north along the axis. This key was washed away during a storm on June 28, 1909, but was restored between AUsuUSt/g909.and. Mays Tono ssc. sceled on ch dclerne Selec aesloes Ilo » Current) chartoibloridaswabersess i facet as ase ea ane ae ereinoee ers 140 . Mapof the Florida Coast from the mouth of St. Mary’s River to the AMIOULMTOL Sica OMMESRTVETY aoe ee et oe ta ee ee eee eo. 143 . Map of the Florida keys in the vicinity of St. Augustine............. 143 go IR toi CC a ere Ne aca cage red Be es Bava < Prt anche) and vi ate Rais oh aie hanes Sicigedeclarrede kes acealbvatece 144 A CONTRIBUTION TO THE GEOLOGIC HISTORY OF THE FLORIDIAN PLATEAU. By Tuomas 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 codperation 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. Naturally, 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 detclanenera 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 1oo-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 —————— A 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. Probably 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’”’’; Dall, in his ‘ Neocene”’ Corre- lation Paper *; and Sanford in his “‘ Topography and Geology of Southern Plorida,’’ * RELATION OF THE 100-FATHOM CURVE TO THE PRESENT LAND SURFACE AND TO GREATER DEPTHS. The too-fathom curve, which is considered the delimitation of the continental shelf, lies between 85 and go 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 1o 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 25° 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. | Total | West of East of | Parallel. width. | land area. Land pon a land area. | miles. | miles. miles. Ten miles south of St. Augustine..... 405 205 135 BQO ele bce vise ee oO ee Damen taleiatars ess 180 IIs Be ran cite Mays Shays tobenaiaiayond-ct Amora arated, oliver. 310 130 140 Pe RDay OL aye tne ws ao™ ater ay cant aavaloraretiete ererers is eieiens 297 130 145 Ae Sa iee Geec oO. aco shea soe ce Beso | 266 160 100 DO Sra Mrs, Seay disray Mala icialelevee © eysieis. 6166 | 242 225 21 1 Distance across Key Largo. 1 Vol. 1, p. 152, 1888. *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, rgto. 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. 20° W. to S. 20° E., but they clearly indicate the approach southward of the roo-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 27°. 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 1oo-fathom curve is not nearly sO precipitous or so great in amount asin 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.’’! THE 10-FATHOM CURVE. The 1o-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 15 miles west of the mouth of Charlotte Harbor, about the same distance west of the mouth of Tampa Bay, 30 miles west of Cedar Keys, to miles south of Cape San Blas; 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. PLATE 1 a o em ptugss : Marquesas a | | 2 | = Mies =. ai | -\ zy Wood = sal 82° 78° THE FLORIDIA | ae ale 2000000 40 6O 80 ———— = ee = = 40 60. <= | go. 100K a —— ee SS mtour interval 50 feet a * 7 io) 7 iA | Fae = . 2% iradentown, (7 encase Pparasota | sy i KE CHOBRE af Py Hf \ Z 4 aaa ' \ (aleasenit ie: West aun WasonfePalm. Benen Settlement Pi = RI | Ceccens IPAS ys - ‘ » Ny BME | (fer Maver S PACM BEACH esac cel: a She yy | eS j ; |=} : Pe ‘ + \\] Captiva |, t } 4 \ A I . ay (a ] | gy Delray, | 4 ay 1 | Sania pore TY) } | 5. N eo Sethacte | Shey | Ah rey s|2- b= —2—- == -— | rhea ‘ | | \ e a lee vdeindalngi | ee et | = Eigen Ya of a. ' a Le 4 - | A) 00 St Sa Le ~ I | : — = _# or aS | af | : | | ee, | f oh | vi | SS \ 1 ail ie North Bemini | | ex ape, (ean A De PE paresis South Bamini | | . \ | FS lie xy \ unkey ia | | | i i P Nocth Cat Key | sas Th f (eo - - = : | | Vonaeas ga gine Vor Ss) \ \ Ss | 1 a \ \ (a) - |e |e ¢ . Bhatts \ | XK “\ A \ f dey en ea ® _/-~<018 Rharles Hey s Jou OMieantir | \y \ % hy as! te / y | sat ies Soabe lage PR, Soa? if = 8 | i Bela,” «+ oe i) t — ———____ . 3 ! | a eed / oa ae = SoS a a - 3-28 ; =| ee pin = fey 7? AOE \ Lay fe — ] © \ : | pA a Long Inland A | a \ - | OoFLOR 7 XN ! ‘ » 7 Te oe | ; =—“Long Ki < ™ t Code K Big Fine Key vat Say Kor ” is a , ; . ude Koy Knights Kexen * Witama' lL > oe { ay Saddle Bunch Koyw os po y ZH , og Me) far eco 0 ee) | = = 7 i. | . | - ie | | i oof Wood Ker \ ~ | 7 A I | : | : —F R ; ade) y | | | — b | 5 T | = | = ae a “5 | : ot a ; = Fe Base from tho map of Florida prepared by the US Geological Survey, 100 — = = ——— —— se eee os = Ka ua : Subaénal Contours by GC. Matson and F.G, Cla; ’ ‘ TOPOGR ’ = ——— —_——__— 1e. -G.Clapp APHIC MAP OF THE FLO TE Submarine Contours from Coast and Geodetic Survey and Hydrographic Office charts RIDIAN PLA TEA U Scale sooton0 7 = er eae : —A_ ee) ap___goKilometers Subaérial ooytour interval 50 feet DEDEDE '’ISSSS eR OE ee ee 7 - on etl Pits , } he wy i, gem A A MUSA NE ANABAENA SS “1 pane a A Contribution to the Geologic History of the Floridian Plateau. 109 of the rnouth of the Apalachicola 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! and Alexander Agassiz?” are so well known. The reefs occur as a disconnected series just landward of the 10o-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 says * ‘‘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* 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 annularts, Orbicella cavernosa, Mussa (Isophyllia) sp., Favia fragum, Meandra areolata. The original source of these specimens was not determined. I found living specimens of Siderastrea radians and Porites forma jurcata 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 ® 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 “ Mantcina’’ 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. Depth Depth Name. in feet. | Name. in feet. —|| ant Howey ROCKS. ase 5. onnneees 1to 9 | Tennessee Reef.............-. 2 hane Aspe Ne Sees SE bea 5o deen 3 15 Wotin See AatChes raisin w etetsinltss 5 DAUR TREEL cheis) leis Sepia sae) sl e-navere 5 12 | East Washerwoman........... 3 12 Pact: Reek. ites, «csc eae 2 3 II Sombrero FREY: .)6.cic.cis ds sjoisvo o's 4 5 Carysfort Reef. dsicc.s 2s Seaee 3 19 |' =Aanerican' Shoalsssocci sce se es Zi 16 rene Reef. .6 os)acue oye! os oleae I li Pelieas Shoals. aires ao tartan aver= 3 4 Molasses) Reef si.i55 8. boas 58 200 I Ale lle woamabot. asthe sis. web. dpc sient rene I Pickles Reet s)5.c0s so ace eo I PTAA | WES Ve Lin Sars Re eS aye 6 8 Conch and Little Conch reefs. . 2 8 ie PICS AS 21215, c)alcanlete alate alates) = 3 8 Groctker REEL ss. sisiceiers —AG3~ /o 2 i Marquesas Keys) w ECKERT LITHO, CO.. WASH.,D.C. JERS CAPE ROMANO }} Key T / Y $+. Charles assay ie / Marquesas Keys t w2) "Marathon, aor Knights Key” oi AT no? . Boot Key an SE Loggarhbad — KEY WEST ¢ a ae —F 5 Ea ; Boca Chica eee = Sica = eed ——— ee — ECKERT LITHO. CO.. WASH.,D.C. 4 Scale ifoo0 000 10 o 10 20 30 AO 50 60 70 80 90 100 Miles Sore ———— = ————— > = ——— SSS 10 ° 10 20 30 40 50 Kilometers 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 Locality. Depth. 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SOURCES OF MATERIAL. Table of Geologic Formations in Florida. - | . Lithologic description Period. | Group. Formation. of the temnation= | be =I Human remains. Vermetus rock. Beach sands. Coquina. Aeo- Recent lian deposits. lacustrine de- posits. Chemical deposits. Al- luvial deposits. Yellow sand. a “Vermetus rock.” x | Coquina. E “Planorbis rock.”’ re) | Gray sand. 3 / Fossiliferous marls. ; oO Palm Beach Limestone...... Tighe sored limestone with | : | | sandy beds and loose sand. itn e Miainilodlite i Reet | Light-gray to white oolitic | limestone, sandy in places. Key Largo limestone........ Coral limestone; reef rock. Key West oolite.<...-25 s-ien Light-gray to white oolitic lime- | stone. Lostman River limestone....| Dark to light, hard to friable, | limestone, sandy or marly in | k places. == |__| Unconformity 5 Latayette’..0. 3220s s sche ¢&| Clayandsand with some pebbles, Ee color usually red or yellow. Bone Valley gravel..... £¢)| Light-colored gravel and marl, Pliocene §2| _ containing phosphatic pebbles. Ailachiias Claas velcro =e apes sandy clay, weathering oz yellow or red. Was hitay mam oi ose = eters HS Light-colored sandy shell marl. Nae ee Sal ..J 4¢| Light-colored sandy shell marl. ——| Unconformity (? OO Jacksonville formation) ;,| Light-gray to white limestone (East Coast) a3 weathering light yellow. Light a 93 gray bo velloy Cee gray 1ocene ao sand. ome chert beds. Choctawhatchee marl S| Greenish to light-gray sandy west ee and St. 83 sell marl or greenish gray ohn’s Valley 0 clay. = —} Unconformity— —— Apalachicoia | Alum Bluff formation....... Gray to green sands, clays and = Group fuller’s earth. Limestone oc- & curs in some localities but it is os usually impure. 5 Chattahoochee forma-) Light-yellow to gray earthy a tion (West Florida) ca and siliceous limestones, some- a8 times cherty. Sand and clay Bes rare. Hawthorne formation|#%| Yellow limestones, ofteft phos- (Central Florida) aay phatic. Greenish or reddish Tamp for ti Be ae a eee greenish p a a mation 2 i Oligocene (South Florida) pe clays. Some chert nodules 4 and layers. ——————| Unconformity : : Vicksburg Ocala jimestones. seis a Soft, porous, light-gray to white Group limestone wie beds of marl and layers of chert. | Peninsula limestone (Central) Soft, porous, light-gray to white Florida) rnigpececr containiny marl beds and layers of chert. Marianna limestone (Western) Soft, porous, light-gray to white Florida) 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 mechan- 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- lying 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.” 4 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 50 and 60 feet................. | oto 400 Very fine-grained soft greenish-gray quartz sand, containing occasional foraminif- | ere) atid water-worn shell trapimentster rts sneer. 2 eee nee 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 FLASMETIES ea joete sie octet atea te etets e seteetess | go4 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 ste onete ren stake reteta bine nstavers peyetereie can eicsetexeehcueisiareleie ores ovate | I,000 1,212 1 Prepared in codperation between the United States Geological Survey and the Florida State Geological Survey, under the direction ot 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 g15 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. jaic.-1.ct «snide seated aw thee om 2 toe SE i a ee Lee o to 105 Hard to soft white limestone, with much white marl................----e++ece: | Sos 148 Softiwhite limestone witht shellicasts)so).2heme aoe oe een Een eee | 148 150 Medium hard white limestone, shell casts and shell fragments..................- | 50 155 Soft white limestone with quartz grains, proportion of quartz increasing with depth, | shell’ fragments amd) casts;. <2. caida oa ncieusanes ign cee eee er ee I55 176 Medium fine white quartz sand containing numerous irregular nodules, with yellow- ishwmanly; ‘sand attemoubovens teeters sacral cant tae cee eas 176 230 of oyster shellsiatia'do feetinc cc scccelecs ohare a ee ee 230 300 IMA OGENE: 137860: ZOO 2 ae.0 accu acc are Miata tere rots eee Ee ee 300 400 ATOVEC SEE iss 9h Srey'o arc ig Thtayo, Sn br MELT aE oti Sisson ee 400 435 Quartz sands with little sandstone, tough dark clay in occasional streaks......... 435 700 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, humphreyst, 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.; Porttes 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. perplanus 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. Sarl Saat SNS OS ois eters GEREN Heo CRER EPS GSS 28 MINES Pe SPS OS Rem ere Ge e o to 50 Brown crystalline limestone with cherty streaks and sand grains.............e08- 50 60 Wit esquartzpsasid «with manrliand ‘shell fragments... s02e. acs cic re aperwteosave oles 101s io voye “alle 60 63 Brownish sandy limestone with shell fragments..........cccccccccscccsccccvecs 63 65 Bere everee canny Tideneied Eaten) eine Nie 5 roan eee ee es a eS ee ee a eee ie G5) sas? | WMubiESwananez Sand ovith shell bedvat. sso Peek... 6 6 bs ic wie was are deve pedalere wave Oi cares 142 275 Medium dark greenish marly sand, with shell beds, and streaks of lighter marl..... 275 490 White to brownish, and soft to hard, limestone, with a few shell casts; hard brownish limMEeSEONeE COntATNS Many SINCCOUS) PTALNS). ose isis avaisre|m nv aye ecelaiele, eJols ais wie eave eleva 499 605 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. CaLciumM 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. 0). 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 o.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 4o 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- A Contribution to the Geologic History of the Floridian Plateau. 131 nent of this formation is coral, usually in the form of large heads of Meandra and Orbicella (plate 15, figs. b and c). The interspaces are filled with various kinds of calcareous débris 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 thé 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 Ray 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,! 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 4o 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. * * * * * X * 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-offs 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 cent” 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. 1U.S. Geol. Surv., Water Supply Paper 234. 2Mr. 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 bays 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 ro feet. Besides the sharply out- lined holes, there are throughout the pineland countless shallow hollows 1 to 3 feet deep and ro to too 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 25 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 CO,; (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 CO, 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: | | Total solids | Estimated | Solids Name of spring. County. | parts per 1 removed | | 1,000,000.1 CNS IIs (pounds) | r i ; mjnute). > | Blite's ae asic otter ie ae oe halartomiye setter II2.1 349,166 469,698 Less Cees ES & BION OOO AGE 4 te BSA ereteetsts Ors oh 196.8 25,000 59,040 Lehatickneelcretrcnenitere eiemics One | Coltmmibiamaecereetll caw egS) 180,000 457,056 Me wiland tai ccc conc eee eae | Suwanee........ 233-5 75,000 210,150 Weeki wachee:.iids ovaraee eee sear | Hernando....... 227.8 I00,000 273,360 Wihite: Sulphuraseeeennsncoewee soe ) daleyooblionlG o on cone 166.6 32,400 64,744 SUWANEE sas c oa raneneys ouckoenoahe qieumiearaoee | Suwanee........ 332-7 52,000 207,605 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. a ee A 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: (1) 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 CaCO, 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 3555 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 CaCO, 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. 111, 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 keys, 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 CaCO, 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,’ 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 réle 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 McIntyre 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. A 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 Szderastrea 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 importafice 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 kevs. 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 THEI EFREC Es. 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: (1) more or less constant oceanic cur- rents; (2) tidal currents; (3) currents due to winds. ; 85° Sushiee PESOS Ep] ees Ww fea °F 7 ~ y s <5 ‘ 1 Jupi oA Fic. 3.—Current Chart of Florida Water (from Pilot Chart, Hydrographic Ofiice; Ui. SoN.: CONSTANT CURRENTS, The most important constant current is the Gulf Stream, which flows along the 1oo-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 A 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 Charts 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. (Thecomponentdi- 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. (1) Elongated sounds 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 isiands 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..—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).? 1 Gulliver, Shore-line Topography, Proc. Amer. Acad., vol. xxx1v, 1899, p. 178. 2 Proc. Amer. Acad., vol. xxxIv, p. 180, fig. ro. A Contribution to the Geologic History of the Floridian Plateau. 143 Fic. 4.—Map of the Florida Coast, from the mouth of St. Mary’s River to the mouth of St. John’s River. (From U. S. Coast Surv. Chart, No. 158.) St. Augustine Tret S Matanzas Iniet, 4 MILES Fic. 5.—Map of Florida Coast in vi- cinity of St. Augustine. (From U. S. Coast Surv. Chart, No. 159.) 144 Papers from the Marine Biological Laboratory at Tortugas. Clifton: ’ q 5 saouray \ Cape Canaveral ‘, ‘, 10 MILES Fic. 6.—Map of Cape Canaveral. (From U. S. Coast Surv. Chart, No. 161.) ECKERT LITHO, CO., WASH,,D.C. MAP SHOWING CAES (From U.S. ECKERT LITHO, CO, WASH,,0.C 1 e 1 ——. = > = MAP SHOWING CAESARS CREEK AND OLD RHODES BANKS (From U.S. Coast and Geodetic Survey Chart No. 166) 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 only to connect the spit and arenaceous keys to the mainland, but to join them to the coral reef keys farther south. BANKS 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 débris and convert the shoal into an island. (See plates 9, 10, 11, and 12, fig. a.) DELTAS AT OUTER ENDS 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,! 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 Bay to the sea, known as Cesars 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 ! 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 Citv. 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 milesin 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. Eee ee ——————— ee a —_—_ = EE — 82° OF FLORIDA 80 100M ers! terval 50 feet ee : 190 Kilometers LEGEND QUATERNARY ie Apalachicola Group (Light gray to yellow siliceous and cherty limestones, sands, sandy clays and fuller’s earth) Vicksburg Group (Soft porous light gray to white limestone, cantaining marl beds and layers of chert) | 24° ~ 7B° Za. | nan by al Survey Report 1909 ae et Ley & Lostmans River Limostoue Key West Oolite (White oolitic: Himestone) (Ltght ety Aroce sand ™* TERTIARY Pliocene wo AS ine <— = ee | Bono Valley Gravel ’ \ (Light colored gravel and mart ’ i A “<. ’ / confatning phoaphatte pebbles) \ Ay Sans r \ Settlement Pri Alachua Clay (Greentah sondy olay | teeuthering red oF yellow) | | | Lafayette Formation A | (Clay or rand with some if ‘ pebbles; colore waually rel , — % | | or yellow) ; — 4 at Miocene | | = oe | ieee | | Choctawhatchee Marl and Jacksonville Formation | South Beinn | | | (Oreantah to Iight gray candy shell mori. ray clay, aM: = a Perera hoe it Mad . un Key \ North Cat Key | Oligocene Apalach{cola Group (Light gray fo yellow silfeeous and oherty limestones, wands, sandy claye cand fuller’a earth) f Himestome, cantotwing mari beds . and layers of chert) » | was if ae ine Key = Growsy Key \ } Cudjee K, Sights her i “ } ie SBN 7 ot Kart sy : ‘ Saddle Bunch Korg So | 0 | Dry Tortugas wens Keys Nee oy Se < | Bi) Newer) owen te, cin | — } | | ) | aoe » yt ers | Vicksburg Group oFLOR J } | (Soft porous light gray fo white Ain z | 4, | Witham | > | 7 al ’ (Bi a | ny 2 |-«@ i -~| | = | 5 | on | \f | Wood Key")! = A : | | = a | ; | erence \\\_| ss }. : = a ~ ie ove "i a ee a ee A ee. | Base from the map of Flonde prepared by the U.S.Geoloaical Survey, 1909 G EOLOGIC M AP OF FLORIDA . Subserial Contours by G.C. Matson and F.G Clapp Geology prepared under the direction of T.Wayland Vauehan by Submarine Contours from Coast and Geodetic Survey and Hydrographic Office charts anford in codperatior 10 Florida Geological Survey n Fiorida Geological Survey, Second Annual Reoort 1902. Seale soggy oo ie wee Ne yf bie ‘ i A 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,! 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 Caloosahatthee marls along some streams, and the non-marine Pliocene Bone Valley gravel near Bartow, from Homeland to Mulberry, and at Bone Valley. * It seems that this locality was not included by Messrs. Matson and Clapp in their report. 148 Papers jrom 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. Inthe 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 westward 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 100 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 100 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 VAUGHAN be. 8 | | ee 82° Si i ame RATE a io s ; ; : ag AY Se ee Bae Ey a | G E (eo) R S ! A a | exe 8 | , a | j eae sa seMarys Entrance Peal AS ONT) (av te ee nee WON ASS OE Ni Shale ae (23 (A eSS\S eat > —- — | vane | | F i Sf j ( or i \ MLA 4, | / C ie os --— . { 5 f | ! Mon: oe & 8 at soa \ Sar Rb aaloe' 5 ‘ Se vg Peis Sa / / Ne# BOAR. elena NEE Seal we g | ~ eae: Nassau Sourd ~, | / | eS) ane WA sae bo gale | ‘€ x | _— : : t iq =F <3 rv) } A i i IPT? lv || | rE ger | ya Live Oak Pt. Piney Pt, Pine PR re) a wed Big Pine Le ¢ ae r% 7 Laud! —— Pen ie 5 ; iI | we pen a PLATE 5 VAUGHAN ~ y e p \ —— Q i 6 DY BIN Augustin Stidugustine Iptet | | eo aTharessa) | ¥ 7 1s oc foo” NEN. f s iS 3} . yf | Gainesville ) ll [o) Mosgte Inlet | @De Land)! plow Smyrig | 20) Orange City June. \ = | enterprise Zunc.| ‘2 \y J i \ i ( , pric \ | ™% GE in a a False Cape ‘Orlando xe , \> EN i) ) > 9 merits teland Cape Canaveral \t | | ——F > <) a =e \ ~ a AR ° - sg ES \ | | ~P st} be: ap. Fe | 7 Ellenton | 13r p UCIE \ pirtianR Inher | nna Maria Key > @lradentowii i ‘| ‘i! ‘ = ) f ; bom | Ft. ue, Long Key’ MANATEES | te he H ont \ | \ 9 Jeol A ; Sos ecosrile Appksio 5 Luke }| | ol | \ ~ + ‘ a Ts toh ple | As I have on various occasions insisted, the faunal gap between the upper- most Oligocene (Oak Grove)! 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. III, pt. VI, p. 1594, 1903.) 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’’’ 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 80° to go° 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 60° and 70° F.; for south Florida and the east coast, between 70° and 80° F.; on the south side of Cape Hatteras, 40° to 50° F.; north of Hatteras to Delaware Bay, 30° to 40° F.; north of the last-named locality the temperature may be below 30° F. Therefore during the Miocene the minimum winter temperature of the waters was at least as low as between 40° and 50° F.. and it may have been as low as between 30° and 4o° F.; or between 20° and 30° F. cooler than the present winter temperature of the west coast, and between 30° and 40° or even 50° 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, gto.) > 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 definiteness 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 unconformably 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 A 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, I. isogramma Dall, I. 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 Recten 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 leidy1, 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.! 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,? Dall,? Matson and ‘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. 3U.S. Geol. Surv., Bull. 84, pp. 142-146, 1892, and Wagner Free Inst. Sci., vol. 111, pt. VI, pp. 1603-1614, 1903. 164 Papers from the Marine Biological Laboratory at Tortugas. Clapp,! 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.’’? 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.’ 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 Land?; that of the latter probably about 25 feet.‘ 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. A 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 ablesto 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, 146.) 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 isa 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 bythe 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 Dichocenia, Meandrina (‘“‘ Pec- tinia’’), Cyphastrea, Meandra (M. areolata is abundant), Szderastrea, etc. These genera indicate shallow water, a maximum of not over 25 or 30 feet, more probably not more than to or 15 feet, and a tropical tem- perature, 70° 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,’”’! by him and Harris, and Matson and Clapp’s Preliminary Report on the Geology of Florida.? 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.* 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, rgto.) 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 1U.S. Geol. Surv., Bull. 84, pp. 127-131, 1892. 7 Florida Geol. Surv., 2d Ann. Report, pp. 133-145, 167, 1910. § 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 the orifice. These springs can scarcely be older than the age here assigned them, otherwise they would have been filled by sediments. During this uplift, 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." 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 4o 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 too 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, they 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 go to roo 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 A 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,} north of Palm Beach; and south of the last-mentioned place at Linton,} 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 weve found interbedded. At Palm Beach and vicinity the Coquina and fine fragmental rock also occur closely associated; the oe perhaps predominates. This is about 20 miles north of Linton. * * A trip to Cape itech 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. z ] | | Record of well at Delray. Depth. Thickness. | = a x _| = | | Feet. Feet. | WULCACe Sanne aa eta cterate arate sevales Gere vio oto 4o 40 | (QGYeh Ih at borkens 5.6 OR] CEM OD EO a tit Cero 40 43 3 | || WETCISEIG = Se6 ss oecuuucdoesrescsaccd] 43 108 65 Ie (CORMEIAAS 0% Siecyaya Silas ales a Shes eet 108 119 Ir A list of a collection of fossils obtained here by Mr. King from a depth of 118 feet is given below. Oculina sp. Terebra concava Conrad, var., may be Siderastrea radians (Pallas). new. X Porites divaricata Le Sueur. Conus floridanus Gabb. Cidaris tribuloides Lamk. Drillia digitalis Reeve. Tornatina bullata Kiener. Oliva reticularis Lam. var. Terebra dislocata Say. Olivella mutica Say. dislocata var. indenta Conrad. Marginella opalina Stearns. protexta Conrad. Latirus brevicaudata Lam. ? x 1Griswold, Mus. Comp. Zool., Bull., vol., xxvitr, p. 59, 1896. 170 Papers from the Marine Biological Laboratory at Tortugas. Murex rufus Lam. Erato maugeriz Gray. Sistrum sp., recent on Floridaeast coast. Trivia quadripunctata Gray. Engina turbinella Kiener ? x Omphalius fasciatus Born. Columbella pulchella Kiener. Fissurella alternata Say. mercatoria Lam. Arca 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”’) arerecent. Ona percentage basis go 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 ! and later Griswold ? 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,? 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. ? Mus. Comp. Zool., Bull., vol. xxviil, pp. 55, 56, 1896. 3 Wagner Free Inst. Sci., Trans., vol. 111, pt. v1, 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). Tornatina 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. Nucula proxima Say. Arca 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 cancellata 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 from Labelle, Caloosahatchee River (T. Wayland Vaughan, collector). Ameria scalaris Jay. Bulla striata Brug. Actzon sp. Tornatina 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 Heilprin, 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. Natica canrena Linn. Barbatia adamsi Smith. Arca 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. Levicardium mortoni Conrad. Dosinia elegans Conrad. Callocardia sayana Conrad. Macrocallista nimbosa Sol. Transennella caloosana Dall. Chione cancellata 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. caloose Dall. 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. F 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. Levicardium serratum Linn. 4 Locality: 7 miles from Fort Lauderdale, south ditch. Cerithium thomasize Sowerby. Transennella caloosana Dall. Phacoides pennsylvanicus Linn. Anomalocardia caloosana Dall. trisulcatus Conrad. Chione cancellata Linn. Divaricella densata Wood. Meerella sp. Locality: 6.5 miles from Fort Lauderdale, Florida, northern drainage ditch. Bulla striata Brug. Avicula atlantica Lam. Conus proteus Hwass. Cardium isocardia Linn. Marginella apicina Menke. Levicardium serratum Linn. Melongena corona Linn. Phacoides pennsylvanicus Linn. Cerithidea turrita Stearns. Semele sp. Pyramidella dolabrata Lamarck. Phacoides trisculatus Say. Strombus leidyi Heilprin. (Hitherto amiantus Dall. known only from the Pliocene.) Divaricella densata Wood. Cerithium muscarum Say. Chione cancellata Linn. thomasiz Sowerby. Dosinia elegans Conrad. Cerithium prob. littoratum Born, junior. Anomalocardia caloosana Dall. Modulus floridanus Conrad. Macoma brevifrons Say. Arca auriculata Lam. Ervilia (4 lots). Pecten irradians Lam. Meerella sp. Two warm-water non-reef-building corals, Szderastrea 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: Feet. Feet. ST ols ee AOE NS CO Tins nod so mibiG is CCG REE AO SOS OB ACG nS OG: tO V2 2 Oolitic limestone a(MiamivOOliGe) ine sierielelete.sisse.s,oie leis spss! suetcioheaeeters 2 14 12 Saad ahs c Soe eS A Ee ae Grete SHON S TEIN Sve vs ava CauavareuanaVeunr's (oleh coe cle moroencosieee teteme 14 30 16 DG SSHO TIC ss has cus crake tuei nS eae Gie Ww ORXS OTe SAe fo laile eT aise CO arene eee ie | 30 30.5 0.5 Sand!and) gravels te ti tic onetne toilcis cena tiene ate exh ene RR Toes I 30.5 68.5 38 Fiardiwhite damestone acto vor Wicleiereva orate oo crn GES OLE aie tee ee ee Oey 69.5 I ~ Sand and! Sravel eee care wteete ole cele eles ie ware ef se sheliefoln cot oneret vist Po imcfe l= 69.5 100.5 31 Limestone, in alternating harder and softer layers................ 100.5 108.5 8 Well at Dania; property of town; record furnished by Edwin T. King: Surfaceisands:..c: Siac sears victelGoe, cnecekepteieiuhes seis uel eae sl eiegetctteiye ce te dete serena o to 6 6 Oolitic limestone: (Miami Oolite))y.19-- cieie = sietieysteineertrene rele eer ie eine 6 Ao | 40 Bliwe amid with someyeraveliersjercisiercucteracitaus eneteteuereletekeeet sie tiaaiecieia rane | 46 80 | 34 lard? limestone ia o.0.< ccorayelenaio uve shatevokors ielishe ss eis, eyaeneieasl ere a cisieisrenerenenits 80 88 8 ———s 7 A 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.” } 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.’ Sanford reports a thickness of probably less than 50 feet for the Key West oolite * and mentions over 200 feet of quartz sand beneath it ‘ 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 °® 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 ° 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.’ 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 * 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,® with notes on 1 Florida Geol. Surv., 2d Ann. Report, p. 212, 1gto. * Sanford, op. cit., p. 223. § Op. cit., p. 220. SOP..¢z., p. 200, > Mus. Comp. Zool., Mem., vol. v1, p. 19, 1880. ® 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. xxv1, p. 179, 1894.) ®Mus. Comp. Zool., Bull., vol. xxv, 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 ro feet in height, extending eastward from Cocoanut Point toward the mouth of the Miami River, to find that it consisted of @olian rocks which have covered the elevated reef in many places. On the low shores these zolian rocks are honeycombed and pitted and might be readily mistaken for decomposed reef rocks; but they contain uo 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: (1) The Miami oolite is not a coral reef rock. (2) It is of eolian 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 zolian 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 xolian; 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 zolian cross-bedded calcareous deposits. At the bottom of page 52isthe statement: “This bluffis a most distinctly marked zolian rock exposure, with characteristic knife-edge stratification.’’ A com- parison of plate xv of Mr. Agassiz’s report on the Bahamas with plate x1x 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 Florida Geol. Surv., rst Ann. Report, p. 22, 1908. A Contribution to the Geologic History of the Floridian Plateau, 175 Vaughan published the next opinion on the origin of the oolite.! 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 are frequently in place, showing no damage by attrition, and fossil corals which exhibit no indication of having been golled 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 zolian 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 xolian action, and it is stated by Griswold that. as evidence it is not decisive. In order to illustrate bedding presumably due to wave and eolian action, separate or combined, a series of photographic illustrations are introduced. Plate 13, fig. a, illustrates an exposure on Gun Key, Ba- * 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 eolian 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 codperative. 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. 0). Fortunately the oolites are rather rich in fossils. Fossils from the Miami Oolite. Locality: Golf Ground, Miami. Cyphastrea hyades (Dana). Glycymeris pectinata Gmelin. Conus floridanus Gabb. Avicula atlantica Lam. Columbella mercatoria Lam. Levicardium serratum Linn. Cerithium muscarum Say. Codakia orbicularis Lam. littoratum Born. Phacoides pennsylvanicus Linn. Arca gradata Broderip. Chione cancellata Linn. Locality: Kronkheit-Offer Quarry, Miami.! 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.! 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. Levicardium serratum Linn. Terebra dislocata Say. Phacoides pennsylvanicus Linn. Strombus pugilis Linn. Divaricella densata Wood. 1 The 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 intastriata Say. Neverita duplicata Say. Macrocallista 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 thomasize Sowerby. Dosinia elegans Conrad.* Cerithium littoratum Born. Chione cancellata Linn. Modulus modulus Linn. Tagelus divisus Spengler. Pecten gibbus Linn. Semele cancellata Orb. 1The 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 pelecypods 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 subaérially deposited. To summarize the conclusions pointed by the data presented in the foregoing remarks: t. 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." 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 70° 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,” 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 1 For references to calcite crystals in other Pleistocene limestones of Florida, Soon Ney wee ?Florida Geol. Surv., 2d Ann. Report, pp. 224, 225. 4 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,’ 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? and masses of the tubes of the marine mollusk Vermetus negricans.? 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 of 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, 19To. * 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,! 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 ro 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, to to 15 feet; along the Caloosahatchee, near Fort Thompson, perhaps 30 to 4o feet; near Osprey, less than 30 to 4o feet; along the keys west ' Tallahassee, Florida, 1909. A 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.' 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 ro-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 corsideration. 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 roo fathoms deep; the bottom temperature was between 70° and 80° 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 roo to 200 feet near shore to the north to over 1,o00 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 too 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 70° F.; the main movement of the ocean water was from the tropics; the sediments consisted to a lesser degree of organic débris, 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- aérial 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 shaliow, perhaps 25 fathoms is a safe 4q A 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 countercurrents 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 Buiological 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 réles 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 necessary to know the history of the Hatteras axis of North Carolina. The present Florida countercurrent 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 Vicksburgian 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. i daa bade: rethal Rane | hd. tose imbrer eta, Titi y cam Valiant, arete de prac ale ae ae eobaiy: ary’ veri Fade ae rw wiiyt ae Deer b 8s. Web eek VAUGHAN PLATE 6 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. VAUGHAN PLATE 7 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. VAUGHAN PLATE 8 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. ne i Fal PLATE 9 VAUGHAN *991} 94} Wo1y poyontd spod juasardar Ssoimsy {je us Inoj oy], “pod ay} uro1y yuoudojaasp jo se8vjs SUIMOYs ‘soaorsuem Sun0x VAUGHAN PLATE 10 Hap Young mangroves. A and B, shoal about 2 miles north of Pigeon Key, water about a foot deep. Cand D, shoal upper end of Long Island, water about a foot deep. VAUGHAN PLATE 11 Mangroves, Miami River. ase ali PLATE 12 A. Mangrove roots, Pigeon Key. B. ‘‘ Black Mangroves,’’ Pigeon Key. ‘ teat My ; 1) hb are diene pein apne la etl est =U ea Seip tims tl cha eset ° laa Soha tea, ewe LGA n r lS) 4 + ae \ we , A as Ms 4 : M Wed see na eam ameter tbls Satelit Sin angel pepsi enh inna tspmtarmnl leet a VAUGHAN PLATE 13 —-7. Meee” hy A. Cross-bedded calcareous sandstone, probably ceolian, western side of Gun Key, Bahaias. B. Miami oolite exposure, Miami, showing cross-bedding. * a mes oe ieee Te oe VAUGHAN A. Cross-bedding by water in an HKocene 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. VAUGHAN PLATE 16 C. A. Surface of Key West oolite, Boca Grande Key. B. Key Largo limestone, southern end of Old Rhodes Key O Coral head in Key Largo limestone, Key Vaca Wit, Dak Wer ‘ 4 Df ‘ Wil Mr UN SS Ty SUR a « oi in q if 'y vel uy Na ah i A ne ole LT al al ia FY Pay Mae AAA yyn® Vy ~ il aii < ya Re hie | Pe 3 By alte | | ae “aauseys 1|8:+fh a} Oe ih PRATT SAL inna yy aa AN o ie seeeice geet 4 4 ¢ Ws ; eel | : ‘ sal a) Se eet ts ny Wyre” paegiron aupeeeAbr? A ea ngnte Pinan) Tey | a ify Oe “48 wasn rN nlbye 4 om Saaere sogtstee a AF tha, Tree TT Rana, arta, aio os imesh - és Sehe al Seen 1 o 4 2% a ; A, ! wy aablacncal ww rEPYY I | laa = am) sa if sl AT: | All a ve iy, avai o é TT . | a | er : RS Ce ae sae D3 Se Sn Deak eae). . 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