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WEG" he De 4 ( oe GEG we | { wR it ip + Wy i we ve t «Al ee en ) ey e oe ws « Olay \AdG vretll yy “wy v vwery By wy het as RMR TN Hh - “ a i &@ ay melee 5 x iy re v — Ld Wri * “Bu Win b Very ale Vt aeeten oe ak | | e hs Pa 4 te HHS LL TCG. | MTT TT Heal eee ee eaeatlbnea cei tlag ily renner etaNlh WN oes ik ye : ne WUhyertoy ' ae a FOE Teen 1 vigeeyep 8 SHS pha Th se . F Be sd Te MOM Ve OTe aye : x" Vip=\« TY i blll aaa tate (etal it aout geevapt yr enenny | ) we i @w wwe = { E aid In etl, gyal "wily i. bao ner ed oe wt yu Ne de bd eave ¥ _. peel hewn Walk Teh pe = Oe, ieee v a tah iy 711i A | bh doh 1 bet ee 4 for aAwNN, ef , 4ane say , Sar Y= E gee 4 Np, CL NO PIO ONL? Je mew! y | aL A Dd PAG. ? 4 eS aia Ar. nll bettatet Tt Bek bold awe uw aeee ie "SAA, Se . ety 4 5 dd TT sees hoe p) apie shes Ay M4 Lia! H 4 a svis . a a ’ an yall TET Ee Wears Kok OL " v6 6 V.weewe> = Pw we fl Pb | ie ane Nayt ws | ‘ hunt eas iw cil _ DEVONIAN FISHES OF IOWA BY CHARLES R. EASTMAN From Iowa Geological Survey, Vol. XVIII i ANNUAL REPORT, 1967, pp. 29-386 DES MOINES PUBLISHED FOR IOWA GEOLOGICAL SURVEY 1908 pe OF IOWA (SEOLOGICAL SURVEY VOLUME XVIII ANNUAL REPORT, 1907 WITH ACCOMPANYING PAPERS SAMUEL CALVIN, Pu. D., STATE GEOLOGIST JAMES H. LEES, Assistant STATE GEOLOGIST DES MOINES PUBLISHED FOR IOWA GEOLOGICAL SURVEY 1908 Wea" c he es ~ 5 i a Cy ba | i; - - f f EMORY H. ENGLISI E. D. CHASSELL, State Binder : 1908 GEOLOGICAL BOARD ISUIS) DDG LONOhe, JA Be (ChoiG GUO ONS anomie Gingold eo ocld gaoos ecu Governor of Iowa TON PS MME AO NRROGI ins fied: Wielash ts crew, alalcelalteper betel ogg faisesiene eye! as Gia vers eas Auditor of State Ni) Fa GeO we Fe VIVA CS HIAMING co ctiepe velercsveuste lene ereielscevece President State University of Iowa DRAGER ES eS TORNSH shaban cis «aiaeis Sane a sla pte reuee President Iowa State College i ES AUNT Ta. CUAUEVILIN ies cicuseetsie ice Rigo carga sete President Iowa Academy of Sciences GEOLOGICAL CORPS SAMUEL, “CALVIN tickets is moa a she 8s aveyatel ous ss Siento ee a Eee State Geologist ! Aas Gots Sal ss fecal Bi Ot Ot See meeatr conor a wep acon SG.OD OClGec Andon boc Assistant State Geologist NUE SB INGRRWANASN ccorauekerace Sidon, ot aca lobe reu og stone ae ato Looe te eae Secretary @HARDES ROU DAST MAINS. cals? Sere nicqe eee pretence rata reistN ieee sie Renee Special Assistant Soe Wes BEYER prin at ceaecn bales eo Ce eee Pee near Special Assistant WEES NORTON ee eis anes seca) sel cel te ea et ove OPI OCReoneNerc eocpeneet rs Special Assistant TEES UMEACBRIDE 5 'onc 25 epene. 0 araigs Shenae tenet otehe ect teieiona neve a teloreter tone Special Assistant BA SHIMER) 35 sicins aed a eee OE eee Cee ORE ee Special Assistant Ma WA UARRY < : oct ee eee eae ee Special Assistant DAS WLTTAMS 55 os) ltievese chrey 0 ase eae os Sere ass rete ahe ehevs tele tere baretere Special Assistant Sh We (STOOREY: «5. cloi-d, Geos Aer ee OO IEEE eee ree Special Assistant LEN RY. SEDINDS es cere cicvcieye euejet nein Seno eiee ier eRe rere OCR ere tere Special Assistant CONTENTS NiSKEEDRSHOE (GHOLOGICAT: JBONED sms cic sc = cisco © elec eect nie = rlcie)= ole ele sols III SUCILOtieAn, OMIT Vos ous conc pouorobe CooGouoS Cobo ro OU GU OUSROUoUG doo doo oss IV SENET EMM OF OONIEEIN IL Sis sepecniel creat aistatel ates wae oe “eiciic/euetste ouojlerw epelajeda) nieva\ln (=) 103 GenupseDiplodusiesavscivcae couches were, keerslaus se nrele Setter terete enesers 104 Gre mul seen Gel O GUS ree pie veitersyelestrer sie bevessclictaje is esajisnsieinieetepeucestoceensrelele 105 HamulysCladodontidaekycasccaesccceroce cakes ecient 107 Genus @ lad od grey -pmeaieistee ive sieleiaielieleinve see aye hy sereisteelaranteteistnvers G 107 OrdertAicanthodiisee mos hana sevens rousieiatercoe nena eer ete atea siete 112 Genus! Machaeracanthuseaassce sec soacieeaeiceeeee eccelcl 113 GenusiGrymacambl us’ sees ape ch cyovescavs siete ovcel os aieuseiianuet sa orcies svorclemnie cael 114 Sulclass#rloloceplvallite tists ceteveisld cc esalshess eveiaseiaieioy saayssauee ene eereNate lel ave eis 117 Orderg@ him Aeroid exe rer hie ayersieys «ess ecsoess wave he wiaaraeeeelsenle aestoaneercine 118 HamulysRtyctod ombid aevacp tactical viene teteeiieay stevia sieiey aa 120 Genus e Rhy meho uses ihc speleve riers, cise) voleuelanet tevokerateislsveneiers sain aicisrere 123 Gemma see by CLOG US pss :aistsle) cr\u.c elenstaleaters alencle aver stewcra Nera peys ieee sie sols) aoa) re 133 Accompanying detached parts, presumably referable to Ptycto- ClOMUES) 5 Woictg b OO ERIE OR Ee Ce Mee ie Sar ce a6 Ob ORS CAC CTC e nee Se 138 Ore ale Bim = spun esas Athy seein 5 ascte/ syern seterevaleloeay eeacersteievatewe aioe eitiersie eyele ae 138 (CGenuspeleteracanthushe ns seeee ore eeeer eer eee eee rere 138 GenusvAtcantholepisncs series ses sereeie cine toes coaaiaa niece cue sere 140 Genuspehhyctacnacanthusnes--eee ie rceeeee sce areciee 143 32 DEVONIAN FISHES OF IOWA. Genus: Acanthaspise 4. sie. 3s)<2 6 a cris sels. ciel ee See ete 144 Vertebral Centra): ci cae oe thon) stag sie etn weal ae eee eee 147 Tuberculated Dermal Plates ............... Meer eerie Hons ccc 149 Ichthyodorullitesy . 2tch 6 aaty.). Sencde cee fran tele ate ie genet een eee 150 Genus Onchuss) isc .casn bee. cee. os Cees 150 Genuspdomacanthilss ssc eee eee oa able ake eee eee 151 Genus'Ctenacanthus). c.).2).5 2A ac cs oe ee eee eee 152 Subclass: Dipmewstt sso once ave catndx Niwess sle cate «ese eee ee 157 Order jArthrodind.. tes. Aa, eda eee eG eta ee 158 HanulyaViacroperalichthyacdaecmer sees ores ee iit 2 Gears 167 Hamilye Miylostomatidaenc ns 1-2 hace eer a fee eee 177 Genus Dinomylostoma....... Sid hale) Sco ae Vi7 Genus Miylostomayisi. 23. 6 fis ened Soe tak ies oe eee 179 Hamily Coccosteidae suse 228i 2asewaincdeudas's os noid che eee eee 184 Genus Cotcosteus! 2.52). ee colon ca keer ete ete ke eee ee 186 Genus Brachy@irus 22.5056 io ee ere o Seca ela ose cl ie ete eee ee 187 Genus) Dimichthys) 2 ose uses fee cee be hae bho, eee ee ees 188 Genus Protitanichthys\s.c see oon eee eee 201 Genus: Litamichthysi.5c 2.6 ste as lok oes oe bee a eee 203 Generajoldoubtiul tanaily postition ee] ee see eee eee 205 Order’ Ctenodipterini.2) ih. cetes meen eee ohare k dee ee eee 207 Eamily ‘Ctenodontidae. . 42522-02410 sess sees seed ee eee 210 Genus: Dipterus ie: c.tce some shoe ee eee oes. Selene eee 210 Genus: Conchodus) iii essen eanees bese Lok se eee eee eee 227 Genus Synthetodusi. 25 seco cece cate seen ce ere eee 231 Genus Scaumenaciay. ss ..iies das sate ved tins sae eel ee eee 235 Subclass: Leleostomi:. o.iQusiiw ee ac tees oe ose eet. oe meee Se eee 236 Order Crossopteryen s.ii4h specs soe eld Wh wlan Srelecalee cele ea eo eee 237 Hamnillyselolopty.chitdlae ener na aneectis eee ee ie eee 238 Hannily, Onychodontidacte sete nena eee eee eee 240 Suborder A.ctimistiaw i). i5/. cs ctcece wena sce ke sagen 241 Family; Coelacanthid dens cui. este cise sec einer See eee 242 Genus-Coelacanthus#.: 5.00 steko seri seein os Oe eee 246 Genus; Palecophichthyssnacemm scree eee eae ere eee 252 Order Actinopterygii. 2... ais a. fate Sts cae open aneyee ale wetenieker oe eeeetere 255 Suborder Chondrostelsi2 Sa staccncise ant ce oe ears le eee 255 Family Paleeoniscid ae: ..s.)2c as asistere + ysis one afareloataten syele cries Starnes 256 Genus) Rhadinichthysrecs sees creates ee ce eae ieee 257 Special description of the auditory organ and other soft parts on Audeant. by DrsiG. He Parkers. en seers 272 Genus BWlonirhthy sei 5k. Sie sss,cisteshte seuss eae ies soe cee 273 Hee BAUMAN Ste) nth 28 2b cankesase ava rsravets ebateletere reitietarg aterereiare = ott satan aaa 275 Species of fossil fishes occurring in the Lower Devonian of North IAI OTICATS Sieve, deavavencre siaes sys bietsenicis dhe sueucverwbiece: alsiziane ebenes ss erste cee ate eee 275 Species of fossil fishes occurring in the Middle Devonian of North ATT ODIC Baia: os citsalla define ce wcucar abe leytumeessparat sce ale es alitusesuceatenie cite ie aan ree 276 Species of fossil fishes occurring in the Upper Devonian of North AIMOTIC Ben a ial. islets lata Meteor abet stamlomeratig asic it clave) alae eee 280 6s, VAcknowledigmientisa: aec.eacc fore cise Weveedivgb Ceusists) syafenelecteystedsie ouster suey esenere eee epee nae 291 “Die Natur ist das einzige Buch, das auf allen Blattern gewissen Inhalt bietet.’’— Goethe. DEVONIAN FISHES OF IOWA I. Aim and general outlook of palaeontolosgical inquiry, and relations of palaeichthyology to biology “Tie Weisheit ist nur in der Wahrheit.’’— Goethe. SCIENCE is knowledge. It is knowledge coordinated, ar- ranged and systematized. To ascertain and communicate know]l- edge is the primary object of science. Its mission is the quest after Truth, the discovery of the facts of actuality, of the invari- able laws operating in the universe; and finally the dissemination of this knowledge among men. The work of a true man of science, in the words of a great astronomer of our day, is ‘‘a perpetual striving after a better and closer knowledge of the planet on which his lot is cast, and of the universe in the vastness of which that planet is lost.’’ Imperfect, painfully imperfect as may be our present knowledge, its gradual extension quickens our life into a higher consciousness. Progressive understanding has also these advantages: it draws us out of and above our instincts and purely personal interests; it enables the intellect to project itself in a certain measure beyond our humanity, and to consider it from the exterior; it stirs within us that spiritual discernment which led Francis Bacon to exclaim: ‘‘Truth, which only doth judge itself, teacheth that the enquiry of truth is the sovereign good of human nature.’’ And likewise Boileau: “‘ Rien n’est beau que le vrai, le vrai seul est avmable.’’ What is true of science in general is true of any one of its subordinate members in particular. Paleontology is sometimes considered as an independent branch of inquiry, but this is to misconceive its relations to kindred sciences. For that reason it may be profitable, before passing to our special subject of fossil 3 (33) 34 IOWA GEOLOGICAL SURVEY fishes, to survey the larger aspects of paleontology and to set forth something of its general aim and scope. And first it is to be noted that the study of extinct animal organisms, that is, paleozoology, is merely an extension of zoological science, just as the study of fossil plants is an extension of botanical science. The former of these is, in fact, merely the rehabilitated zoology of the past, as the latter is merely the rehabilitated botany. The true aim of paleontology is to restore to us visions of van- ished life-periods; to unfold to our view the ceaseless procession of animate forms that, slowly transforming, very gradually pro- gressing, sometimes retrograding, keeps up its steady file through the ages from twilight antiquity down to our own day. Figuratively speaking, this science realizes the dream of the ancient poets who described certain gifted mortals as having been privileged to descend into the interior of the earth, and, after their return to the upper air, amazing their fellows with tales of the wonders thus revealed. Only, in the present case, the wonders are not imaginary but real, and we are permitted to behold through the windows which paleontology opens up for us amid stratifications and ruins, not only a manifold of shifting phenomena, but anon the glint and shimmer of the wheels, as it were, of the controllimg mechanism. Science shows us these manifestations, philosphy teaches us to think of them in terms of cause and effect, and to sift out from them certain ultimate con- ceptions. If the mind of the astronomer wearies in the effort to con- template an infinity of space, so the paleontologist is over- whelmed by the sweep of the universe through endless time. In his domain a sense of the time-element is ever-present and all- pervading. He acquires the habit of contemplating all things sub specie aetermitatis. He is concerned with fixing the order and character of events throughout all past time in all places. By virtue of the time-element entering into it, paleontology becomes at bottom an historical science, and the underlying attitude of the inquirer is, therefore, on a parity with that of the historian of human events. It is well not to lose sight of this fact. oe DEVONIAN FISHES OF IOWA 35 Nor, on the other hand, must it be supposed that the province of paleontology is limited to the investigation merely of dead organisms, any more than historical inquiry terminates in a dead knowledge of what happens to have happened during the course of human experience. Every student realizes that the profit of studying history lies in wnderstanding what has hap- pened, in perceiving the principles and causes that have deter- mined the progress of society, in discerning the action of those forces, motives, vicissitudes and transformations that, in so far as they affect the fate of nations or individuals, we can eall by the name of Destiny. In human history as in all other phe- nomena of life and motion, it is not so much the events or mani- festations that interest us, as their interpretation. We are not satisfied short of knowing the why, the whence and wherefore. To register the actual fact, whether in history or in science, is the indispensable first step, but only the first; its necessary com- plement is to perceive the relations between one fact and other facts, to search for causal sequences, in a word to conceive of things in terms of cause and effect. Let us illustrate our meaning a little further. What is there in a dead shell that interests the naturalist primarily? Is it the relation between the mollusk and its covering, or is it not rather the relation of the animal plus shell to another animal together with its shell, and so on until each has been assigned its position in the series of shell-bearing animals? And what matters it whether the animal has but recently become inanimate, or has lain entombed in the rocks throughout geologic cycles? The paleontologist is concerned with life, life in past periods it is true, but it is a purely secondary consideration that he has to deal with defunct materials. He takes his materials as he finds them, and though they be merely dry bones or considerably worse residue of mortuary corruption, eloquent of death and decay,* they are to him merely as so many inscriptions he has *The old-school idea of these things is poetically expressed by Chateaubriand: “‘C’est dans le cceur de l’homme que sont les graces de la nature. Quant a celui qui étudie les animaux, qu’est-ce autre chose, s’il est incrédule que d’étudier des cadavres? A quoi ses recherches le ménent-elles? quel peut étre son but? Ah! c’est pour lui qu’on a formé ces cabinets, écoles ot la Mort, la faux a la main, est le demonstrateur; cimetiéres au milieu desquels on a placé les horloges pour comp- ter des minutes 4 des squelettes, pour marquer des heures a 1’éternité!”’ 36 IOWA GEOLOGICAL SURVEY to decipher, or as the blocks with which he has to construct his temple of truth. Industriously to seek out his building stones, assemble them, and fit them deftly together, that is his proper function. Just as in the physical sciences the chief work to be done is observation and experiment, since from these alone conclusions can be drawn; so also in the natural history of the past the first duty of the worker is careful investigation before he may offer a presentation of results. It is incumbent upon him equally with the historical student to ‘‘expend all diligence in discovering and investigating all possible material, and after this has been done, to examine it with rigorous critical acumen.’’ Hnormous and bewildering as may be the task of assembling the material, the collection of facts is but preliminary to research of really useful character; facts must be reduced to orderly sys- tem, results must be combined, many phenomena included under one law, and many subordinate laws under one more compre- hensive, before we can gain approximate understanding, or be- fore judgment can be passed on knowledge. The method of both physical and natural science, as has been said, is to draw conclusions from known and recorded phenomena; and the ulti- mate object of each is to widen knowledge and deepen our understanding. Especially is the mind of the naturalist alert to grasp general principles involved amid the multiplicity and ecom- plexity of phenomena; by training he acquires a vivid sense of relations; it is instinctive with him for the part to suggest the whole; his intellect leaps from the specific instance to an appre- hension of the general law; and finally his generalizations attain significance through the clarifying ageney of ‘‘reorganizing ideas’’. By reorganizing ideas we mean those great and illuminating conceptions that enter the world of thought at propitious mo- ments and are sometimes epoch-making for the progress of science. ‘‘Kmancipating conceptions’’ they are called by some, idées directrices is the corresponding French term. ‘‘That which usually forms a grand coneception,’’? says Montesquieu, in portraying their influence, ‘‘is a thought so expressed as to reveal a number of other thoughts, and suddenly disclosing what we could not anticipate without patient study.’’ If we may be DEVONIAN FISHES OF IOWA 37 pardoned the digression, let us reflect for a moment on the far- reaching consequences of the Copernican conception of the world, one of the profoundest of all reorganizing ideas. Place alongside of it Newton’s theory of gravitation, which gave for all time a definite and demonstrated system of the universe, and to these two add Darwin’s theory of descent—that is, of organic evolution—we shall then have the leading factors which have immeasurably extended the material world in modern times, and vastly enlarged our horizon. Through their medium our ideas of space, durations and existence have acquired new validity, present a surprisingly larger manifold, and disclose to cognition unfathomable riches. If it be true, as Pascal says, that ‘‘all our dignity consists in thought,’’ how greatly have the boundaries of cur mental vision been widened and illumined, thanks to these three revolutionary ideas. To illustrate: We all know, for instance, that the ancient conception of the world was strictly limited. For the ancient and medieval man our earth stood at the middle of the world, and the vault of heaven, supposed to be not distantly removed, formed the outermost limit of creation. The Homers and Dantes of their time have pictured to us what a comfort and support this limited world-conception yielded to human imagination. But so soon as Copernicus had shown that the simplest way to conceive the world was to think of the earth as an unsupported ball revolving about the sun, beth being lost in limitless space, our planet could no longer occupy the center of the universe, and the satisfying framework which had supported the old cosmography was shat- tered in pieces. Religion itself received a violent shock as the thought gained ground that the human race was by no means the goal and acme of the universe. The established faith revolted at the idea of ultimate extinction of man and all his works, and repudiated whatever reasoning gave countenance to the pre- diction. Before the era of modern science had begun, leaders of public opinion were satisfied on the basis of traditional or preconceived ideas to explain what man is, whence he came, whither he is bound, what he may become, and what he should be. Armed with new truths, and enriched by a vast supply of demonstrated 38 IOWA GEOLOGICAL SURVEY facts, how different is the picture which the human mind draws of nature under the influence of eighteenth-century philosophy! How greatly has the point of view shifted, and how shrunken and inadequate is the older world-conception! The change is strik- ingly shown towards the middle of the century, when we find a naturalist of great ability like Buffon proclaiming, in his Théorie de la Terre (1749), the vast antiquity of life, the slow formation of stratified deposits and exceedingly gradual transformation of the earth’s surface. We owe to this author a truly grand picture of cosmic history. His writings describe for us, as a later com- patriot has said, ‘‘in approximate features the entire history of our globe, from the moment it formed a mass of glowing lava down to the time when our species, after so many lost or sur- viving species, was able to inhabit it.’’ As opposed to the tradi- tional view that in man’s destiny lies the central and most sig- nificant fact of the universe, that this is in verity the ‘‘Mar-off, divine event, Towards which the whole creation moves,’’ we find a man of Buffon’s genius rebuking such self-conceit. To his way of thinking, ‘‘a mite that would consider itself as the center of all things would be grotesque, and therefore it is essen- tial that an insect almost infinitely small should not show conceit almost infinitely great.’’ The same thought is amplified in interesting fashion by the philosopher-historian Taine, whose attitude is identical with that of the paleontologist. He bids us consider the spectacle of na- ture as if we were removed in imagination to another planet. This is the outlook that presents itself: ‘¢ Amidst this vast and overwhelming space and in these bound- less solar archipelagoes, how small is our own sphere, and the earth, what a grain of sand! What multitudes of worlds beyond our own, and, if life exists in them, what combinations are pos- sible other than those of which we are the result! What is life, what is organic substance in this monstrous universe but an in- different mass, a passing accident, the corruption of a few epi- dermic particles? And if this be life, what is that humanity which is so small a fragment of it? Such is man in nature, an atom, an ephemeral particle; let this not be lost sight of in our theories concerning his origin, his importance, and his destiny. . . How slow has been the evolution of the globe itself! What a a a eS DEVONIAN FISHES OF IOWA 39 myriads of ages between the first cooling of its mass and the beginnings of life! Of what consequence is the turmoil of our ant-hill alongside the geological tragedy in which we have borne no part, the strife between fire and water, the thickening of the earth’s crust, the formation of the universal sea, the construc- tion and separation of continents! Previous to our historical record what a long history of animal and vegetable existence, what a succession of flora and fauna! What generations of marine organisms in forming sedimentary strata, what genera- tions of plants in forming coal deposits! And at length comes man, the latest of all, shooting up as the terminal bud at the top of a lofty antique tree, growing there a few seasons, but destined to perish, like the tree, after a few seasons, when the increasing and foretold congelation allowing the tree to live shall force the tree to die. He is not alone on the branch: beneath him, around him, on a level with him, other buds shoot forth, born of the same sap; but he must not forget if he would comprehend his own being, that, along with himself, other lives exist in his vicinity, graduated up to him and issuing from the same trunk. If he is unique he is not isolated, being an animal among other animals. Thus surrounded, brought forth and borne along by nature, is it to be supposed that in nature he is an empire within an empire? He is there as part of a whole, by virtue of being a physical body, a chemical composition, an animated organism, a sociable animal, among other bodies, other compositions, other social animals, all analogous to him; and by virtue of these classi- fications he is, like them, subject to laws. . . . Im all this man continues nature; hence, if he would comprehend himself, he must observe him in her, after her, and like her, with the same independence, the same precautions, and in the same Sori: 7” An immediate application of the view just stated is that it constantly brings before us the eternal in the midst of the pres- ent. Turning now to our own times, by far the most trenchant of reorganizing or emancipating ideas that has modified the world of thought is the theory of organic evolution, first fully set forth by Darwin in 1858, although foreshadowed, suggested, and even explicitly proposed by various clear-sighted thinkers before a new era was opened up in natural science by the Origin of Species. Noteworthy is the fact that practically the same theory of the descent of species, though without the causo- mechanical explanation of their origin by means of natural se- lection (the essential idea to which the term Darwinism is prop- 40 IOWA GEOLOGICAL SURVEY erly applied), had been proposed by Lamarck in France a score of years earlier, only to be ignominiously rejected. All edu- cated readers are familiar with the example of Darwin’s per- sistent, long-continued striving for the truth, how at first it was dimly perceived and at length fully revealed to him after making the most wonderful collection of illuminating and explaining facts which had ever been assembled in biology by any single investigator, and how with utmost intellectual candor he tested it, as we are told, ‘‘by applying to it successively fact after fact, group after group, and category after category of facts, until he convinced himself of the theory’s consonance with all this vast array of observed biological actuality.’”’* Thanks in part to his masterly presentation of the theory, it gained almost imme- diately a wide acceptance, and is now held to be as thoroughly demonstrated a part of natural science as is Newton’s law of gravitation in physics, or the heliocentric system in cosmography. Paleontology in particular received a profound stimulus under the influence of evolutionary ideas, and its whole aspect, method and outlook were revolutionized in consequence. It is now uni- versally admitted that ‘‘the facts revealed by the study of paleontology are explicable wholly satisfactorily by the theory of descent and in no single instance do they contradict it.’’ Con- sider for a moment what this means. Naturalists are acquainted nowadays with about 400,000 species of living animals and half as many species of existing plants. A computation based on the number of new species being found and described from year to year, and the extent of biclogically unexplored areas of the earth’s surface, shows that the total number of species constitut- ing the modern fauna must number at least several millions. For the insects alone, entomologists hold that a total of two million species is not an excessive estimate. And these all belong to but a single geological epoch, the present. But in the case of extinct species, ‘‘those hosts of strange denizens of our changing earth in the ages gone,’’ it is evident that the variety of forms preserved for us in the rocks is but an insignificant fraction of * See the interesting recent work by Professor V. L. Kellogg, ‘‘Darwinism To- day’’, and his joint production with President Jordan, ‘‘Eyolution and Animal Life’’, 1907. DEVONIAN FISHES OF IOWA 41 the grand total that has existed since life began.* How now shall science answer the question as to the origin of these my- riads of forms? Evolution answers it in this way: the language in which it is here stated is that of Professor Kellogg (ibid. 10s LOE ‘‘Now all these millions of kinds of animals and plants can have had an origin in some one of but three ways; they have come into existence spontaneously, they have been specially ereated by some supernatural power, or they have descended one from the other in many-branching series by gradual trans- formation. There is absolutely no scientific evidence for either of the first two ways; there is much scientific evidence for the last way. There is left for the scientific man, then, solely the last; that is, the method of descent. The theory of descent (with which phrase organic evolution may be practically held as a syn- -onym) is, then, simply the declaration that the various living as well as the now extinct species of organisms are descended from one another and from common ancestors. It is the explanation of the origin of species accepted in the science of biology.’’ It is needless to pursue the subject further. Sufficient has been said to convey some notion of the extraordinary impetus given to science and all forms of speculative thought through the medium of a few grand illuminating conceptions, pre-eminent among which is the theory of evolution. Bear in mind that rarely are great truths hit upon offhand, as the result of hazard, by a fortunate guess, or by intuition. Enlightenment, the reward *The marvelous properties of radium furnish unexpected aid to the palzon- tologist by way of granting him a much greater time-estimate than physicists have been willing to allow. Professor Lankester, in his presidential address before the British Association at the York meeting (1906), states the matter in this wise: “‘Hiven a small quantity of radium diffused through the earth will suffice to keep up its temperature against loss by radiation! Ifthe sun consists of a fraction of one be pent of radium, this will account for and make good the heat that is annually ost by it. “This is a tremendous fact, upsetting all the calculations of physicists as to the duration in past and future of the sun’s heat and the temperature of the earth’s surface. The geologists and biologists have long contended that some thousand million years must haye passed during which the earth’s surface has presented approximately the same conditions of temperature as at present, in order to allow time for the evolution of living things and the formation of the aqueous deposits of the earth’s crust. The physicists, notably Professor Tait and Lord Kelvin, refused to allow more than ten million years (which they subsequently increased to a hundred million)—basing this estimate on the rate of cooling of a sphere of the size and composition of the earth. They have assumed that its material is self- cooling. But, as Huxley pointed out, mathematics will not give a true result when applied to erroneous data. It has now, within these last five years, become evi- dent that the earth’s material is not self-cooling, but on the contrary self-heating. And away go the restrictions imposed by physicists on geological time. They are now willing to give us not merely a thousand million years, but as many more as we want.’’ 42 IOWA GEOLOGICAL SURVEY only of unremitting toil, may be won by those who have been willing to suffer, endure, and devote lifetimes to the discovery of a small number of new truths. Ars longa, vita brevis. It is characteristic of science to be content with slight advances that may be slow as the precession of the equinoxes, if only they be sure; and the utmost that even the most patient and ingenious worker can achieve is to contribute but one little stone or two towards the building of that stately edifice in which Truth may dwell. Yet that little is enough. For Truth, no less than Wis- dom, as saith the Preacher, ‘‘exalteth her sons, and taketh hold of them that seek her. He that loveth her loveth life; and they that seek her early shall be filled with gladness. . . . For at first she will walk with him in crooked ways, and will bring fear and dread upon him, and torment him with her discipline, until she may trust his soul, and try him by her judgments: then she will return the straight way unto him, and will gladden him, and will reveal to him her secrets. If he go astray she will forsake him, and give him over to his fall.’’ In paleontology, though our knowledge has indeed grown apace, it is still uncertain and confused in places, and in others there are distressing voids. The present state of this special branch of science may be likened, even as archeology has been likened, to a mosaic of colored tessere, which, though broken here and there, yet shows broad patterns and many curious de- tails. Seattered in the surrounding débris and sometimes buried by this are the little cubes waiting to be found and fitted into their proper places. For the parts of the mosaic now complete, we have to thank the explorers of the past, for the filling in of the lacune, the explorers of the future. And we may be assured that future laborers, with broader knowledge, better training and greater means of investigation must eclipse all that the ablest workers of our generation can accomplish. Content as every earnest naturalist is to serve so pure and unapproachable a mistress as Truth, let each join in the hope that those who come after us, more favored than ourselves, may be permitted to hold some converse with the Sphinx! Finally, before passing from these general reflections to our special province, two thoughts may be singled out from the rest because they bear closely upon the real concerns of humanity, DEVONIAN FISHES OF IOWA 43 and refuse to be cast down amid the realm of vague and transi- tory ideas. They possess real and immediate values, and pro- foundly affect the attitude of modern science, as will be seen from one or two typical illustrations. The first of these com- prises a sense of the immeasurable, and indeed inconceivable length of time that life-processes have been at work onour planet, the chain of forms persisting in unbroken succession and ever- varying transformation since its earliest manifestations down to the exuberance and complexity of the world of today. And the second bids us contemplate not only the vast antiquity of life, but, which is still more impressive, the almost infinitely slow, gradual, often imperceptible advance in the scale of development, yet nevertheless indicating a constant tendency toward perfec- tion. Here if anywhere stands revealed to us, not the operation of blind forces amid the eternal flux of things, but a supreme intelligence manifesting itself through forever unchanecing uni- versal laws. Many examples might be chosen to show how these thoughts are reflected by scientific workers of our day: we will, however, single out but the two following in closing. The first is from Poinearé, in his essay on The Value of Science; the second is from Suess, founder of the ‘‘new geology,’’ and is contained in the final passage of The Face of the Earth. Says the former: ‘‘ All that is not thought is pure nothingness; since we can think only thought and all the words we use to speak of things can express only thoughts, to say there is something other than thought, is therefore an affirmation which can have no meaning. And yet—strange contradiction for those who be- lieve in time—geologic history shows us that life is only a short episode between two eternities of death, and that, even in this episode, conscious thought has lasted and will last only a mo- ment. Thought is only a gleam in the midst of a long night. But it is this gleam which is everything.’’ * *The salient thought here recalls one of Pascal’s Pensées, to which we have already once referred: ‘‘All our dignity consists in thought. It is from thought that we should take our point of departure, and not from space or duration, which we cannot fill. Let us endeavour then to think well; this is the principle of morality.’’ The central idea contains also a perhaps unconscious reflection from pagan sources. Compare, for instance, the following rendering from a fragment of Aschylus: ‘‘Pauvre espéce humaine, qu’éphémére est ta sagesse, rien de solide, Vombre d’une fumée.”’ 44 IOWA GEOLOGICAL SURVEY In these words Suess concludes his treatise: ‘‘There is no means of comparison by which we can illustrate directly the great length of cosmic periods, and we do not even possess a unit with which such periods might be measured. We hold the organic remains of the past in our hand and consider their phys- ical structure, but we know not what interval of time separates, their epoch from our own; they are like those celestial bodies without parallax, which inform us of their physical constitu- tion by their spectrum, but furnish no clue to their distance. As Rama looks out upon the Ocean, its limits mingling and unit- ing with heaven on the horizon, and as he ponders whether a path might not be built into the Immensity, so we look over the Ocean of time, but nowhere do we see signs of a shore.”’ Remains one more word only and we have done. For those to whom the prospect seems cold and dreary that modern mate- rialistic science discloses to our view, and for those who are not content with the mere objective values of science, there may be brought before the mind this inspiring message of Darwin. Readers who are not over-familiar with his works may be sur- prised to be told that this passage forms the conclusion of the Origin of Species: ‘‘Tt is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds simging on the bushes, with various insects flitting about, and with worms craw]- ing through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting aroundus. . . . [The more important of these laws are then enumerated.|] Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.’’ [NotE—The reader who desires information on the more particular relations of palxichthyology to biology—since we have preferred to dwell in the above on the larger aspects of paleeontology—will do well to consult two addresses by Smith Woodward: the first printed in the Proceedings of the Geologists’ Association for 1906, entitled ‘‘The Study of Fossil Fishes;’’ and the second in the Reports of the International Congress of Arts and Sciences at St. Louis, vol. IV, 1906, under the title of ‘‘The Relations of Paleontology to Biology.’’ DEVONIAN FISHES OF IOWA 45 I. Stratigraphy of the Devonian fish-bearing beds of Iowa. The assemblage of sediments representing the Devonian sys- tem in Iowa forms a belt averaging fifty miles in width, streteh- ing along the Cedar river from the Minnesota line to Muscatine county, and extending thence eastward into Illinois. The larger part of these rocks consists of limestones and shales whose bed- ding, in general conformable, gives indication of continuous de- position, whose faunal content is on the whole fairly character- istic of the Middle Devonian, and yet none of whose parts can be definitely correlated with formational units referred to the same system in New York. The reason for this non-homogeneity in the faunal characteristics of the two areas, namely the eastern or ‘‘Ohian”’ as it has been termed (known also as the ‘‘Appal- achian’’), and the western interior or ‘‘Dakotan’’, lies in the fact that these were distinct geographical provinces throughout the Devonian. They remained, in fact, completely separated from each’ other until towards the close of the Middle Devonian, and thereafter communication was maintained between them by means of a comparatively narrow passageway extending through Illinois and Wisconsin. These conditions are well por- trayed in the paleogeographic maps given in Plates XIV-XVI, hitherto unpublished, and for whose use we are indebted to Professor Schuchert. A tripartite division of the lowan Middle Devonian rocks into the Wapsipinicon, Cedar Valley, and Lime Creek stages was first proposed by Professor Calvin in 1878. It was pointed out also by the same author that, owing to migration of species, the faunas of the summital (Lime Creek) and basal shales (Inde- pendence beds of the Wapsipinicon stage) are substantially iden- tical, and that the fauna of the Cedar Valley limestone corre- 46 : IOWA GEOLOGICAL SURVEY sponds more or less closely with that of the Hamilton in the more eastern (‘‘Ohian’’) region.* To the Upper Devonian were re- ferred two units—the Sweetland Creek shales, and the State Quarry limestone—which rest unconformably upon the Cedar Valley limestone, and occur as outliers in the east central part of the State. The former of these is developed chiefly in Mus- eatine county, and the latter in Johnson county northward of Iowa City. A scheme of classification adopted in earlier volumes of the Survey Reports is reproduced immediately hereinafter for the purpose of showing the succession of Middle Devonian sediments as they have been commonly interpreted until within the past year or two. Conformably, however, to Professor Cal- vin’s most recent interpretation of the Lime Creek shales, based upon a study of their faunal relations, they are now assigned a somewhat higher stratigraphic position. This change is indi- cated in the second synoptical table presented herewith, which is reproduced from Professor Calvin’s ‘‘Notes on the Geological Section of Iowa’’ (Journ. Geol., 1906, vol. 14, p. 572). In connec- tion with the latter it is necessary to bear in mind the following statement of the author by way of explaining the succession: “ x |—j;—] —] — if ae Semicosiatus (Stu Ji. and Wi). se. )- snes x /—);—/—/]— 8 of SOE SIRE aVes Gascsagosdodagoonoaseond- x |/—}]—]—]— ¢). Ee SMEG IOUS ISkis Vo BHAGI WWigoheoa cbc0c0canc x }/—}—}—}] — 10. oe TUCLOS Shin Va DIVE Wie sogodsoaccnosogccc x /—};—]—}]— iil a VENUSTUSBHAS her emer eiacs eerie eres x }—/—]|—] — 12; * (?) burlingtonensis St. J. and W......... —|xj/—|—/]— 113}. oe IGhAAOGOStOLUS Stn dey an G Viena —;x}]—}]—)}]— 14. He ACULUS PIAS tM aaa aster nen ieee eeierets —-!—|xf|—-)|=— 15. uy CYUNCTECHSENE Ds. e eee ener eee —|—|x|]—}— 16. st GAGIOLIS Stin do BuaV6l Whocaogo dhocencoscs: —)—|x/—}]— Nie uf [SANKONG igidla Pin Wekoadngoone ooagoo docs —/)|—}xj—]— 18. as SHOCK (USkin is BRAC! Wo)ecoecdoosboccosue — —};x}—/]— 118), a CORA EWAN BIC WY ooengadonaae connue —|—}—); x] — 20. ie COURS Sin Uo BING Mo anca conse onee sane —|/—/;—|x]— Alle a GTO (Shin Uo BNC! Wigs poco aboouc edoose —|}—}]—|]x}]— D227 it GUTLEYOSNEW Dideirueyaeie cies cen tis lala lel eis erate —|—|]—] x] - 23% ne HOMTASONG Stade ANG We aaa eee iene —) —|—|}xj\— 24. MU OT GUINEN SMe ba a ho ev neta ne BA OE EG hina Glade o —) —|—|x}]— 25. i (ANICOSUS Sits dls BNO bconcigodnd ¢ood so0e —/—/—}|}x}j— 26. i angulatus Newb snd) Wits. ie) seis ciel —— | se 27. mS canaliratus St. J. and W........ .....--. —|-|— --| x 28. e RO GISity Ua EGl Wii oodoke cons aondone sac =.) > eels x | DEVONIAN. FISHES OF IOWA 157 Subclass DIPNEUSTI. (Dipnoans or Lung-Fishes.)* Fishes with partially ossified skeleton, numerous membrane or dermal bones, and persistent notochord; skull autostylic; dentition confined to inner bones of the mouth; premaxillae and maxillae absent; gill-clefts feebly separated, opening into a cavity protected by two opercular plates; paired fins archiptery- gial or reduced; tail diphycercal or heterocercal, median fins often subdivided; exoskeleton consisting of true bony tissue; sensory canals well developed; nostrils inferior; claspers ab- sent; a cloaca present, air-bladder single or paired, functioning as a lung. The few existing Dipnoan species, comprised by the fresh- water genera Neoceratodus, Protopterus and Lepidosiren, form a well-nigh inappreciable remnant of a once flourishing and highly diversified race of Lung-fishes, whose acme of develop- ment, specialization and numerical superiority occurred during the Devonian. One remarkable order comprising huge armored fishes passed entirely out of existence at the dawn of the Car- boniferous, without leaving descendants. Such, at least, ap- pears to be the most satisfactory interpretation of the group now commonly known as Arthrodira. Another division, Cten- odipterini, was conspicuous throughout the Paleozoic, and at- tained a higher degree of specialization along certain lines than is evinced by later forms. The geological history of the Sirenoid order, to which Ceratodus and its modern descendants belong, is not traceable with certainty earlier than the Trias, although it is not unlikely that some Paleozoic remains, known chiefly by the dentition, should properly be included here. That primitive members of the Sirenoid order were in existence at least as early as the Lower Devonian follows as a necessary conse- quence of regarding it as ancestral to both Arthrodires and Ctenodipterines. This view of their relations, however, is novel, and the considerations which make for its acceptance, and com- * As pointed out by Haeckel, Boulenger and others, the term Dipnoi, first ap- plied by Johannes Muller in 1845 for the group of Lung-fishes, is improperly so used, having been previously chosen by Leuckart as a name for Amphibians. There is no objection, however, to retaining the name Dipnoan as a vernacular equivalent of Dipneusti, and it is here employed in that sense. 158 IOWA GEOLOGICAL SURVEY pel us to look upon Neoceratodus as an archaic survival of the primal Dipnoan stock, will be discussed under the caption of Arthrodires immediately following. Order ARTHRODIRA. Dipnoans having a reduced number of dermal bones forming the cranial roof, arranged after essentially the same pattern as in Ceratodonts, and the dentition also paralleling that of modern forms. Dermal armor of abdominal region consisting of large plates, either in simple apposition with the headshield, or more commonly articulated with its posterior border by a pair of movable ginglymoid joints placed dorso-laterally. Col- umn notochordal, but with distinct neural and haemal arches. Tail apparently diphycereal in the best known forms (Coccos- teus and Dinichthys); pectoral fins wanting, and only obscure traces of the pelvic pair observed; pelvic arch represented by a pair of sigmoidal or club-shaped plates, sometimes (Dinich- thys) with an anterior ventral projection. The remarkable group of armored Coccosteus-like fishes was originally united with Asterolepids by M’Coy, in 1848, in a single ‘‘family Placodermi’’, and for more than forty years this arrangement was adhered to by writers generally, save for slight changes in the rank assigned to the main divisions. To Professor EH. D. Cope belongs the credit of having been the first naturalist to recognize the heterogeneous nature of this assemblage, and to initiate its disruption. In 1889, he proposed the removal of Asterolepids from the class of Fishes altogether, and at the same time referred Coccosteans provisionally to the Crossopterygii, or ‘‘fringe-finned ganoids’’.* Shortly there- after, however, following Smith Woodward’s suggestion, the several families of Coccosteus-like fishes were grouped, under Woodward’s new name of Arthrodira, in a distinct order of Dipnoans.+ This arrangement obviously implied, though it had not at that time been demonstrated, that the Arthrodiran skull was truly autostylic, and that a maxillary arch was not devel- * Cope, E. D., Synopsis of the Families of Vertebrata. Amer. Nat. 1889, 23, 56. p. 8 + Ibid, 1891, 25, p. 647. Also Syllabus of Lectures on Geology and Palzontol- ogy, p. 14. Phila. 1891. DEVONIAN FISHES OF IOWA 159 oped. Another feature which influenced the novel association of Arthrodires with Dipnoans was the parallelism, previously noted by Dr. Theodore Gill, and by him ealled to the attention of Professor Newberry,* between the dentition of Dinichthys and that of the modern Protopterus. The absence of any indication of a hyomandibular bone, even in the most admirably preserved specimens, and of more than a single ossification in the lower jaw, were considered sufficient reasons for excluding Arthro- dires from Teleostomes. This provisional association of Arthrodires with Dipnoans met with an indifferent reception on the part of most palzeon- tologists, and was afterwards rejected by some of its early sup- porters, notably Drs. Traquair and Bashford Dean. It was even conceded by Smith Woodward himself, a few years later, that “the systematic position of this extinct order is indeed doubt- ful.’’+ Traquair’s defection dates from 1900, when he declared, in his Bradford address, in favor of considering Arthrodires as ‘‘Teleostomi belonging to the next higher order, Actinoptery- e1i.’’ The following year Dean expressed the radical view that they were not true fishes at all, but representatives of a distinct class, called by him Arthrognathi, and conceived by him to have possible kinship with the Ostracophori.§ It was even allowed that subsequent researches might demonstrate a union between Arthrognaths and Ostracophores, whereby the time-honored group of Placodermata would be restored. This last was a complete reversal of his former view that the ‘‘jaws, specialized dentition, fin-spmes and highly evolved pelvic fins completely ‘separate this group [Arthrodira] from the lowly Ostraco- derms.”’’|| By far the most comprehensive use of the term Placodermata is that adopted by Otto Jaekel, in 1902, whereby the Pteraspids, Tremataspids, Cephalaspids, Asterolepids and Coccosteans were _ * Newberry, J. S., Descriptions of Fossil Fishes. Rept. Geol. Surv. Ohio, 1875, 2, pt. 2, Paleont. p. 15. The suggestion is here advanced that Protopterus and Lepidosiren are lineal descendants of ‘‘Placoderms’’. + Woodward, A. S., Outlines of Vertebrate Paleontology. 1898. p. 64. { Traquair, R. H., Vice-Presidential Address. Rept. Brit. Assoc. Ady. Sci., Bradford meeting, 1900, p. 779. 2 Dean, B., Paleontological Notes. Mem. N. Y. Acad. Sci. 1901. 2, p. 113. || Dean, B., Fishes, Living and Fossil. New York, 1895. p. 130. 160 IOWA GEOLOGICAL SURVEY all embraced within a single group.* This assemblage was modified a twelvemonth later, however, in that the two last- named families were bracketed together under the head of ‘‘Temnauchenia’’, all of the others, together with Drepanaspids, Coelolepids and Birkeniidae being collectively designated as ‘‘Holauchenia.’’+ Placoderms in this broadened sense were all considered by Jaekel to belong to fishes proper,i and it was further maintained by him that Coccosteans were ancestral to Chimaeroids, an opinion in which he clearly stands alone. The only other author who has ventured to recognize any descend- ants from Arthrodires whatsoever is Newberry, who, as we have seen, imagined Protopterus to be a modern lineal descend- ant of Dinichthys. We may now pass rapidly in review the minor fluctuations of opinion that are apparent during the last few years. Dr. O. P. Hay, in his ‘‘Catalogue of Fossil Vertebrata of North Amer- ica,’? employs the term Placodermi for both Arthrodires and Asterolepids, placing them in the same subclass with Dipnoans. Arthrodires and Ostracophores are awarded each the rank of a separate subclass in the English edition of von Zittel’s ‘‘Text- book of Paleontology’’, the lamented author having disap- proved of uniting Coccosteans with Dipnoans. In a remark- able paper published by Mr. C. T. Regan in 1904, the Placo- dermi are re-established so as to include Coccosteidae, Aster- olepidae and Cephalaspidae, all being placed in a single order of Teleostomes.§ During the same year Professor T. W. Bridge expressed the view, in the volume on ‘‘Fishes’’ in the Cambridge Natural History, that Coccosteans are ‘‘a highly specialized race of primitive Teleostomi,’’ and compared their cranial roof- ing bones with those of typical bony fishes. The idea of a rela- tion between Coccosteans and Lung-fishes is dismissed in the fol- lowing passage, found at page 537 of the work cited: * Jaekel, O., Ueber Coccosteus und die Beurtheilung der Placodermen. Situngs- ber. Ges. naturforsch. Freunde, 1902, p. 103. tIdem. Ueber die Organisation und systematische Stellung der Asterolepiden. Zeitschr. deutsch. geol. Ges. Mai-Protokoll, 1903, 55, p. 58. {This view as to the truly piscine character of ‘‘Placoderms’’, together with the descent of Coccosteans from Cephalaspids is reaffirmed in his recent paper on Pholidosteus, published in 1907. ? Regan, C. T., The Phylogeny of the Teleostomi. Ann. Mag. Nat. Hist. 1904, ser. 7, 13, p. 346. DEVONIAN FISHES OF IOWA 161 The Arthrodira have been regarded as armoured Dipneusti, a view which is mainly based on their supposed autostylism and the nature of the dentition. But this autostylism has yet to be verified, and, if proved, the possibility that it may be a second- ary feature, associated with the evolution of a peculiar dentition, must not be forgotten. Much more may be said for their claim to be regarded as a highly specialized race of primitive Teleos- tomi. Besides a well developed lower jaw, bones comparable to the elements of a secondary upper jaw are known, and in a general way the disposition of the cranial roofing bones, and the arrangement of the endoskeletal elements of the pelvic fins, tend to conform to the normal Teleostome type. In fact, Dr. Tra- quair has expressed the opinion that the Arthrodira are Teleos- tomi and Actinopterygil.* In several recent papers published by Dr. L. Hussakof, of the American Museum, the group of extinct forms we are consid- ering is designated as ‘‘Placoderms”’ and excluded from asso- ciation with Pisces proper.t With regard to their position, Mr. EK. Ray Lankester is entirely non-committal in his interesting lectures on ‘‘Extinect Animals’’, recently published in book form.t Dr. Frederic A. Lucas’ popular treatise on ‘‘ Animals before Man in North America’’ places them in association with Lung-fishes in accordance with Smith Woodward’s idea. Still another useful handbook deserves mention, whose scope includes not only recent fishes and fish-like vertebrates but treats of their fossil allies as well and ranks as a standard modern authority. We refer to President D. S. Jordan’s ‘‘Guide to the Study of Fishes,’’ published in 1905. At the time of preparing this treat- ise the author considered Arthrodires to be of extremely prob- lematical position, but has since expressed himself in favor of the view that they are specialized Dipnoans. Finally, reference may be made to several papers published by the present writer§ during recent years, in which fresh argu- ments were advanced, based upon newly discovered evidence, to show that the dentition of Arthrodires belongs distinctly to *In his latest reference to this subject, however, Dr. Traquair admits that Arthrodires are of uncertain subclass. Compare, for instance, his description of Coccosteus angustus in Trans. Roy. Soc. Edinburgh, 1903, 40, p. 732. + Hussakof, L., Articles 4 and 25 of Bull. Amer. Mus. Nat. Past. 1905, 21, 27-36, and 409- 414: also memoirs of same institution, 1906, 9, pp. 105-154. t Lankester, E. R., Extinct Animals, p. 256. New York, 1905. 2 Article 9 in American Journ. Sci. 1906, 21, p. 131; also Nos. 1 and 7 in Bull. Mus. Comp. Zool. 1906-7, 50, pp. 1-29 and 211-228. 11 ey = LS ———_ SSeS aS SSS Sl ee ‘ 162 IOWA GEOLOGICAL SURVEY the Dipnoan type, and that veritable homologies exist between their cranial roofing plates and those of the living Neoceratodus. This position is maintained in the following discussion of the group, as it seems to be most nearly in accord with the prepon- derance of known facts. FIG. 238. Fig. 23. Mylostomavariabile Newb. Cleveland shale; Sheffield, Ohio. Complete tritoral dentition arranged in natural position, but the elements of both pairs of palato-pterygoid plates belonging to different individuals. The presence ofathird pair of vomerine elements in advance of the two here shown has not yet been established by positive evidence. x1-l. Concerning the systematic arrangement of Arthrodires, it need only be said that, owing to faulty preservation, we are still too imperfectly acquainted with the details of structural organization in different families to permit of more than a provisional scheme for illustrating successive stages of ad- vancement. Analogy with other, and especially higher, groups leads one to expect the dentition to furnish not only reliable clues as to relationship, but also a convenient and serviceable basis of minor classification. Experience proves that the ex- pectation is only partially justified. As between the two well- marked types of dental structure, which find close parallels in the existing Neoceratodus and Protopterus respectively, there need be little hesitation in recognizing the former, or triturating type, as the more primitive, it being one of the most constant, persistent and distinctive features of the Dipnoan stem. Nothing is more natural than to regard the trenchant or sectorial type - ; 4 7 DEVONIAN FISHES OF IOWA 163 of dental plates, whether we find it already in vogue during the Devonian, or developed independently from the main stock in the Permian,* or again in evidence at the present day, merely as a derivative of the more simple, earlier, or perhaps even orig- imal type—the crushing or triturating type—which apparently resulted from the coneresence and fusion of hardened shagreen granules. The Mylostomid type of dental plate is, therefore, as implied by its structure, of more primitive nature than the Coc- costean or Dinichthyid type, and more faithfully reproduces the ancestral condition of things. On the basis of the dentition alone members of the latter category signalize themselves as more highly modified than the former. But other parts of the organization and the very similar structure of the headshield and body armoring in both Mylostomids and Coccosteids prove that these families have become relatively further advanced in certain directions than contemporary or earlier families (those typified by Macropetalichthys and Homosteus, for instance) of whose dentition we know little or nothing. In a word, the evi- dence of dental characters is decisive and positive enough so far as it goes, but should be supplemented by our knowledge of associated skeletal details before determining the precise rank of different families and genera. Present information, however, regarding these concomitant characters is in many cases meagre or very deficient. Under these circumstances it is evident that data are want- ing for a detailed classification of Arthrodires, and even a genetic grouping can only be provisionally outlined. As already inti- mated, the general indications (apart from dental characters) are that Macropetalichthys and Homosteus represent earlier and less advanced stages of evolution than the grade of typical Coc- costeus-like forms. In case the former of these genera were eventually found to possess the triturating type of dentition, it would fulfil very satisfactorily the requirements of an exceed- ingly primitive phase of Arthrodires, approximating closely to the primal Dipnoan stem. It is even conceivable that body armoring is absent from this phase, in consonance with its primitive condition; and certain it is that the genus itself pre- *The reference is to Sagenodus pertenuis, from the Permian of Texas and Russia described in Amer. Nat. 1903, 37, p. 493. af.) 164 IOWA GEOLOGICAL SURVEY sents no indications of having had the abdominal region pro- tected by a system of dermal plates. We may assume, provis- ionally, that this Meso-Devonian genus does indeed represent the most primitive known stage of evolution among Arthrodires; and in this case we may fix upon Homosteus as occupying an inter- mediate position between it and typical Coccosteans. These lat- ter forms represent the terminal members of a divergent series that agree with Mylostomids as regards cranial pattern and ar- rangement of body armoring, but differ from them in respect to the dentition. A graphical representation of these stages is attempted in the following scheme, with what claims to verisim- . ilitude we leave others to judge. It will at least serve to empha- size the point that in any conjectural line of descent two diverg- ent series of Arthrodires must be recognized, agreeing more or less as regards cranial pattern, but differing with respect to the dentition. Dinichthys, Titan- Mylostoma ichthys, etc. Le Vie Dinomy- Coccosteus m4 we lostoma (Unknown primitive Homosteus _~ — stage) an e Macropetalichthys Ancestral Ceratodont stock (Generalized Dipnoans) DEVONIAN FISHES OF IOWA 165 In conclusion, a brief rejoinder may be offered at this point to certain objections that have been raised against the above inferential line of descent. Dr. Bashford Dean, for instance, contends in two recent articles in Science* that Arthrodires cannot have been derived from ancestral Ceratodonts for the following reasons: (1) Writers who dissent from Dollo’s theory of the phylogeny of Dipnoans—that is to say, the majority of modern students—are not justified in considering Neoceratodus to be of primitive or ancestral nature as compared with Cteno- dipterines, since the modern genus may be supposed with even greater plausibility to have been descended from Ctenodipterine stock; (2) in case an ancestral line of Ceratodont lung-fishes had been in existence from the Devonian onwards down to the pres- ent day, it is inconceivable that the paleontological record should be destitute of all traces of it prior to the Triassic; and (3), accepting the view that a close kinship exists between Ar- throdires and Ostracoderms (‘‘bothriolepids and cephalaspids”’ as Dean terms them), it is difficult to imagine that the latter are also descended from a Ceratodont ancestor. Whence it fol- lows that if these forms are not so descended, neither are their allies. | Dean’s pronunciamento in regard to Neoceratodus, namely, that ‘‘there is, indeed, no reason evident why it should not have descended from an ancestor resembling Uronemus or Phanero- pleuron,’’ seems to us to be negatived by the conclusive argu- ments brought forward by Bridge, Firbringer and other leading opponents of Dollo’s theory.t Once this theory is discarded, the ease of Neoceratodus becomes identical with that of Sphenodon and other late survivals of a generalized stock which must of necessity have had an earlier origin and longer geological his- tory than more specialized derivatives of the same stock, whether still existing or long since extinct. Sphenodon, for instance, is *Dr. Eastman’s recent papers on the Kinship of Arthrodires. Science, 1907, 26, pp. 46-50.—Studies on fossil fishes during the year 1907. Jbid., 1908, 27, pp. 202-204. + See especially: Bridge, T. W., On the morphology of the Skull in the Para- guayan Lepidosiren. Trans. Zool. Soc. London, 1898, 14, p. 372. Ftrbringer, K. Beitrage zur Morphologie des Skeletes der Dipnoer. Jena Denkschr. 1904, 4, p. 481. Agar, W. E., Development of the skull and visceral arches in Lepidosiren and Protopterus. Trans. Roy. Soc. Edinb., 1906, 45, pp. 49-64. Jbid., 1907, pp. 611-641. 166 IOWA GEOLOGICAL SURVEY known only in the modern fauna, yet the evidence of compara- tive anatomy forces us to conclude that it has come down to us practically unchanged from Permian times, and that its imme- diate ancestors gave rise to all reptiles with two cranial arches (Archosauria or Diapsida), and possibly to a Dinosaur-avian offshoot as well. Similarly, if modern Ceratodonts can be shown to possess a more primitive organization than Paleozoic Cteno- dipterines and Arthrodires, with which groups they are eyvi- dently related, it becomes a logical necessity for us to suppose the more primitive group to have antedated and perhaps even to have given rise to the more highly specialized. The truth of this hypothesis does not require confirmation by positive evi- dence such as might be furnished by the paleontological record, its validity being established upon well ascertained principles of comparative anatomy. Our concern is neither to impugn nor to exalt the adequacy of the paleontological record. We have merely to take it as we find it, and where its continuity is broken, characters obliterated, and the chain of organic forms imter- rupted, there is no recourse but to fill in the lacunae as best we may through exercise of the trained imagination. What weight should be assigned to Dean’s third objection depends upon whether or not we adopt the view that Arthrodires and Ostracophores are closely related, and that both are dis- tinct from Pisces proper. The problem may be still unsolved, yet it must be remarked that very few morphologists favor a separation of Arthrodires from ordinary fishes, and the idea that ‘‘bothriolepids and cephalaspids’’ share close affinities with Coccosteus-like forms may be likened to a goal that is unat- tainable except after having penetrated a Daedalian labyrinth of uncertainties and possibilities. It may be pertinent: to recall, furthermore, that Patten’s recent studies of Bothriolepis have convinced him that the lowly group to which it belongs should be separated further than ever from true fishes, and elevated to the rank of a new and independent class. This implies, of course, an effectual separation between the two groups which Dean and Hussakof unite in their understanding of the term Placodermata. We may close this phase of the discussion by quoting Professor Patten’s latest utterance in regard to the DEVONIAN FISHES OF IOWA 167 position of Bothriolepis, which is summed up as follows: ‘‘The structure of the gills, anus, anal fin and other organs indicate that the Ostracoderms must be separated from all other known subdivisions of the Chordata and raised to the dignity of a sep- arate class.’’ * Family MACROPETALICHTHYIDAE. Cranial shield much arched from side to side, completely en- closing the orbits, and extending over the nuchal region poster- iorly. External surface covered with fine stellate tubercles which conceal the underlying sutures between dermal plates. Median series of the latter but two in number, narrow and elongate; external occipitals large; centrals divided, the two pairs on either side not meeting their fellows in the median line. Pineal foramen inconspicuous, situated shghtly in advance of a line joining the anterior borders of the orbits. Sensory canals form- ing large tubular excavations in the bone, opening at the ex- ternal surface by a continuous narrow slit or by a double series of pores. Parachordal cartilage and notochordal sheath ealci- fied. Nature of dentition unknown, although there is apparently an articular cavity for the lower jaw. No indications of ab- dominal armoring. The typical genus of this family is Macropetalichthys, known by a single American, and two or three Kuropean species. In addition, an undescribed species is reported by Jaekel from the Middle Devonian of the Hifel District, in Rhenish Prussia, the type of which is in the Senckenburg Museum at Frankfort, and at the same time the form described by Kayser in 1880 as M. pruemensis is made by Jaekel the type of a distinct genus.+ All these forms evidently stand in close relation to Homosteus as regards number and general arrangement of cranial roofing plates, position of the orbits, and in having the headshield pro- longed posteriorly over the nuchal region. It is perhaps of some significance to note that the median series of cranial plates are reduced to the same number as in Neoceratodus, and are fewer than in Dipterus. * Science, 1905, 21, p. 297.—See also Yearbook Carnegie Inst. Wash. 1904, no. 3, p. 140, where the same conclusion is presented. tiJaekel, O., Ueber Coccosteus und die Beurtheilung der Placodermen. Sit- zungsber. Ges. Naturforsch. Freunde, 1902, p. 118.—Jbid., 1906, pp. 73-85. 168 IOWA GEOLOGICAL SURVEY Genus MAGROPETALIGHTHYS Norwood and Owen. This genus, certainly one of the most primitive of Arthrodires, is represented in this country by the typical species, which was first described under the name of M. rapheidolabis.* Subse- quently, two new specific titles, M. sullwvanti and M. mannt, were proposed by Newberry for cranial shields that presented no important differences from the type, and it was afterwards proved that no constant distinctive features exist. Hence only the name originally proposed for the type species is entitled to recognition. The same author also pointed out that the so- called Placothorax agassizu of Hermann von Meyer, published at the same time as Norwood and Owen’s description, and more fully illustrated the following year, was founded upon a de- nuded headshield of Macropetalichthys. The so-called ‘‘Phys- ichthys’’ of von Meyer was also shown by Smith Woodward to be a composite aggregation including fragments belonging to Macropetalichthys, Rhynchodus and Pterichthys rhenanus.t A review of the more recent literature of the genus has been given by the writer in another place, and need not be repeated here.t Macropetalichthys rapheidolabis Norwood and Owen. (Text-figure 24) 1846. Macropetalichthys rapheidolabis Norwood and Owen, Amer. Journ. Sci. ser. 2, 1, p. 371, text-figs. 1,2. Also separate folio. 1851. ‘‘Buckler of ganoid fish,’’ L. Agassiz, Proc. Amer. Assoc. Ady. Sci. 5D, p. 179. 1852. Macropetalichthys sp. J. S. Newberry, Annals of Sci. 1, p. 12. 1857. Agassichthys sullivanti J. S. Newberry, Bull..Nat. Inst. p. 124. 1857. Agassichthys manni J. S. Newberry, Bull. Nat. Inst. p. 122, woodcut. 1862. Macropetalichthys manni and M. rapheidolabis J. S. Newberry, Amer. Journ. Sci. ser. 2, 34, pp. 75, 76, woodcut. 1873. Macropetalichthys sullivanti J. S. Newberry, Rept. Ohio Geol. Sury., Paleont. 1, pt. 2, p. 294, pl. 24, 25, fig. 1. 1889. Macropetalichthys sullivanti J. S. Newberry, Monogr. U.S. Geol. Sury. 16, p. 44, pl. 38, figs. 1, 2. 1890. Macropetalichthys sullivanti E. D. Cope, Amer. Nat. 24, p. 846. * Amer. Journ. Sci. 1846, ser. 2, 1, pp. 367-72. Also a separate abstract in folio, published at Madison, Iowa, under date of February 16, 1846, a copy of which is preserved in the library of the Museum of Comparative Zoology at Cambridge (ex bibl. N. S. Shaler). + Woodward, A. S., Vertebrate Paleontology in some American and Canadian Museums. Geol. Mag. 1890, Dec. 3, 7, p. 459; also Cat. Foss. Fishes Brit. Mus. 1891, pt. 2, p. 303. tMem. N. Y. State Mus. 1907, 10, pp. 100-103. DEVONIAN FISHES OF IOWA 169 1891. Macropetalichthys sullivanti and M. rapheidolabis E. D. Cope, Proc. U. S. Nat. Mus. 14, pp. 449, 455, pl. 29, 30, fig. 5. 1897. Macropetatichthys sullivanti and M. rapheidolabis C. R. Eastman, Amer. Nat. 31, pp. 493, 499, pl. 12. 1901. Macropetalichthys sp. B. Dean, Mem. N. Y. Acad. Sci. 2, p. 119, text- fig. 12. 1903. Macropetalichthys sp. O. Jaekel, Neues Jahrb. fiir Mineral. 1, p. 342. 1907. Macropetalichthys rapheidolabis C. R. Eastman, Mem. N. Y. State Mus. 10, p. 103, pl. 9. fig. 5, pl. 11. 1907. Macropetalichthys sullivanti E. Hennig, Centralbl. fiir Mineral. p. 587, text-fig. Headshield suboval, regularly arched in a transverse direc- tion, attaining a maximum length of about 25 cm and width across the posterior border of about 17 cm, but often consid- erably flattened’ by pressure. Ornamentation consisting of fine, closely crowded tubercles with stellate bases, sometimes display- ing concentric arrangement. Of the two pairs of small centrals, which are separated from contact with each other by the inter- vention of the median occipital, the anterior takes part in form- ing the orbital border and is not traversed by sensory canals. Pineal plate pierced by an inconspicuous foramen, and appar- ently equivalent to the so-called anterior median element or ‘‘mesethmoid’’ of Neoceratodus, or to the corresponding undi- vided area in Dipterus. Parasphenoid (or the element inter- preted by Cope as such) much expanded in front, posteriorly produced, resembling in a general way the corresponding mem- brane bone of Ctenodipterines and Sirenoids, but considerably less ossified. Preorbital sensory canals lyrate, and confluent in the middle line with the sharply angulated exoccipito-central system. The postorbital canal extends from the inferior border of the orbits to the center of the marginal plates, where it turns abruptly inward and continues in a straight line to meet the ex- occipito-central canal at the point of its angulation. The latter canal disappears beneath the surface of the external occipital plate on either side close to the hinder margin of the headshield, passing obliquely downward and inward below the cranial roof, and in the living state presumably communicated with the inter- nal auditory sense organs. — Speaking entirely within bounds, it is not too much to say that the characters of this long misunderstood genus and species 170 IOWA GEOLOGICAL SURVEY fail of comprehension, or at least of satisfactory analysis, save as they are brought into relation with those of modern Dip- noans and interpreted through comparison with them. Many students have puzzled over the cranial structure of Macropet- alichthys and the allied genus Asterosteus, of which only the median series of plates are known; but accumulation of details has resulted only in greater perplexity. A serious obstacle to their understanding has been the absence of a standard of com- parison or trustworthy clue by means of which their characters acquire significance; they must needs remain unintelligible until brought into harmonious adjustment with other established facts. Newberry, with an abundance of well preserved material at his command, went widely astray in imagining these forms to be ancestral to modern sturgeons. Cope’s keen insight led him immediately to perceive the community of structural plan be- tween Macropetalichthys and Dinichthys; and in suggesting a comparison of the former with Neoceratodus, he actually hit upon a solution of the whole matter, though unfortunately he did not rigorously apply it. He correctly identified the paras- phenoid as suech—a membrane bone that appears to have been incompletely formed in Arthrodires generally—and noted that it displayed the usual Dipnoan outline; but he was less happy in explaining the nature of the so-called ‘‘cerebral chamber’’ of Newberry, and other internal structures termed by him ‘‘nuchal elements’’. Cope’s ‘‘nuchal plate’’, or so-called ‘‘dorsal plate’’ of Dean and Hastman, was further misinterpreted by the last-named authors in that it was held to represent collectively the dorsal body plates of other Arthrodires. Dean’s definition of ‘‘An- arthrodira’’ was, in fact, based upon this erroneous view.* Indeed, it must be frankly acknowledged that serious misap- prehension has prevailed among all students, including the pres- ent writer, concerning the septate structures within the interior of the. headshield of Macropetalichthys. As in the ease of the eranial buckler itself, the conformation of the inner parts be- * As pointed out by O. Jaekel in the Newes Jahrbuch for 1903 (1, p. 342), the definition embraces structural characters which in reality do not exist. DEVONIAN FISHES OF IOWA 171 comes intelligible only through comparison with surviving Dip- noans, and without such aid must remain an enigma svi gen- eris. The pertinency of this statement will appear from the fol- lowing description of the headshield. Cranial characters—The arrangement of dermal roofing plates in the headshield of Macropetalichthys is shown in the accompanying restoration (text-fig. 24), which may be profitably compared with the diagram given on page 197 (text-fig. 29) of the cranial roof of Neoceratodus. One perceives that there is a general correspondence between the two genera as regards cra- nial pattern, and especially noteworthy is the similar disposition of the median series of plates, the more posterior of which is elongated nearly to the same extent as in Homosteus. Other points of agreement between the form under discussion and Homosteus consist in the elongation of the external occipitals, and enclosure of the orbits within the headshield. In more spe- eialized forms, the preorbital and postorbital plates are merely notched externally, but in Macropetalichthys, Homosteus, and presumably also in Asterosteus, these two plates are in contact with each other externally so as to form the inferior border of the orbits. A conspicuous difference between Macropetalichthys and other Arthrodires, one which has proved a stumbling-block to a correct understanding of the cranial osteology, lies in the fact that the central elements are divided so as to form two small plates on either side of the headshield back of the orbits. These more or less rounded plates are placed one behind the other, the two pairs being separated from contact with each other in the median line by the elongated median occipital plate (MO, text-fig. 24), very much as is the single pair of corresponding plates in Neoceratodus (text-fig. 29). That the plates here called the cen- trals are correctly determined as such is evident from the follow- ing reasons: First, the two pairs together occupy the usual - position of the centrals with reference to the preorbital plate in front, and to the postorbital and marginal plates externally; and secondly, they are proved to be such by the disposition of the sen- sory canals. Imagining the suture line as obliterated between the two independently ossified plates on either side, we shall have \ 172 IOWA GEOLOGICAL SURVEY FIG. 24. Fig. 24. Macropetalichthys rapheidolabis Norw. & Owen. Middle Devonian; Indiana, Ohio and New York. Restoration of headshield showing arrangement of cranial plates and course of sensory canals. x 3. C1, C2, divided centrals; HO, external occipital; M, marginal; MO, median occipital; P, combined pineal and rostral, corresponding to the anterior median unpaired plate (‘‘mesethmoid’’) in Neoceratodus; PO, preorbital; PtO, postorbital plate. . a single pair of elements occupying the same relative position as in Homosteus. The posterior moiety of this plate is seen to be traversed by three distinct canal systems, identifiable with those called by Dean the preorbital, postorbital and occipital. Now, in the headshield of all Arthrodires so far as known, the central DEVONIAN FISHES OF IOWA 173 ‘is the only plate traversed by all three of these canals. The pre- and post-orbital systems are sometimes confluent in other forms, but the occipital (oremore properly, the occipito-central) does not unite with these other systems save only in Macropetal- ichthys. Evidence of the primitive nature of this genus, as compared with other Arthrodires, is furnished by the following characters, which are strongly indicative of embryonic or ancestral condi- tions: (1) continuity of the sensory canal systems; (2) discrete- ness of the central elements and their separation on either side of the middle line by the elongated median occipital; (3) re- duced number of median series of plates; (4) complete enclosure of the orbits within the headshield; and (5), absence of any evidence of articulation, overlap, or other connection between the headshield and a system of dorsal body plates. That the headshield was produced posteriorly over the nuchal region, similarly, and im fact to about the same extent as in Homosteus, is apparent from the configuration of the under surface and structures seen within the interior of the cranial buckler. An interesting feature first noted by Cope is that a passageway for the notochord is provided by an ossified tubular sheath of small diameter, which is supported by the narrow posterior extension of the parasphenoid, and perforates by means of a triangular orifice the thin, vaulted and backwardly sweeping partition or septum depending from the under side of the occipital plates, and interpreted by the present writer as the ossified posterior wall of the chondrocranium. That this septum actually closed the chondrocranium behind seems ex- tremely probable both from its form and position, which are highly suggestive of the conditions observed by Traquair * in Dipterus; and by its suspension from the cranial roof in a man- ner recalling that in Neoceratodus. The septum is, however, very thin-walled, and there is no evidence of separately ossi- fied exoccipital plates adjacent to the triangular foramen magnum. Another thin transverse septum depends vertically from the posterior border of the headshield, and like the first, is rigidly united with the narrow extension of the parasphenoid * Ann. Mag. Nat. Hist. 1878, ser. 5, 2, p. 5, pl. 3, fig. 1. 174 IOWA GEOLOGICAL SURVEY below. It is along the plane of this septum that the exoccipito- central canals penetrate obliquely downward from the outer surface by means of funnel-shaped openings, the interior of which is filled with cancellated bony tissue. The function of the hinder transverse septum seems to have been to impart rigid- ity to the arch of the headshield, and to serve as a partial sup- port for the parasphenoid. The space included between the two septa just described is that which Newberry designated as a ‘‘cerebral’’ and Cope as a ‘‘nuchal chamber,’’ both authors apparently regarding it as closed along the sides as well as at either end. It was, however, only partially enclosed, its middle portion alone being floored by the parasphenoid, or backward prolongation of that element. No known organ could have been lodged in this partially enclosed space, and in all probability it merely contained fatty matter. We have already had occasion to speak of the element called by Cope the parasphenoid, and in our opinion correctly identified by him as such. In form this very tenuous plate resembles in a general way the familiar lozenge-shaped bone in Dipterus, Ctenodus and modern Dipnoans, but it is remarkable for its great expansion in front, where it occupies nearly the entire width of the headshield. Becoming rapidly constricted in the occipital region, it extends backward over the space separating the two transverse septa already mentioned in the form of an arched laminar plate, not unlike that of Neoceratodus in form, and serves as a floor for the parachordal cartilages and noto- chordal sheath. This hinder portion of the parasphenoid was interpreted by Cope as consisting of a pair of distinct elements, called by him the ‘‘lateral alae of the axis’’, and in another place, ‘‘descending osseous laminae’’; but it is clear from well preserved specimens that only a single ossified element is concerned in flooring the ear- tilaginous cranium and projecting backward as far as the ex- treme posterior margin. A right understanding of this feature shows that in the form under discussion the parasphenoid is produced posteriorly to the same extent as in Neoceratodus and Lepidosiren; hence Cope’s statement requires rectification when it is said that the corresponding bone in modern forms is abnor- DEVONIAN FISHES OF IOWA 175 mally produced behind.* The extreme thinness of the bone in its anterior portion forms a decided contrast to the solidly ossi- fied plate of Ctenodipterines, and it is further noteworthy that no specimen has yet enlightened us as to its relations with the palato-pterygoid cartilages. Near the point of its greatest con- _ striction, in what corresponds to the position of the quadrate element in Dipterus, is 'a well-marked oval concavity, described by Cope as a ‘‘glenoid fossa’’; and this may not improbably be looked upon as having served for articulation with the man- dibular suspensorium. Nothing whatever is known of the quad- rate, mandibles, or nature of the dentition. These parts must necessarily have existed, and our ignorance of them is attrib- utable to failure of preservation. Formation and locality. Onondaga limestone; Le Roy, New York. Columbus and Delaware limestones; Ohio. ‘‘Cornifer- ous’’ limestone of Indiana, and said to have been obtained also from equivalent strata in Canada. Although listed among Ken- tueky Devonian fossils, its reported occurrence within the limits of that State probably rests upon erroneous identification. Macropetalichthys agassizi (von Meyer). 1845. Asterolepis hoeninghausii L. Agassiz (errore). Poiss. Foss. V. G. R. p. 130, 147, pl. 30a, fig. 10. 1846. Placothorax agassizi H. von Meyer, Neues Jahrb. p. 596. 1847. Placothorax agassizi H. yon Meyer, Paleontogr. 1, p. 102, pl. 12, fig. 1. 1855. Physichthys hoeninghausii H. von Meyer, Eolmontogt. 4, p. 80, pl. 15, figs. 1-5 (non figs. 6-11). 1857. Agassichthys agassizi J. S. Newberry, Bull. Nat. Inst. p. 119. 1873. Macropetalichthys agassizi J. S. Newberry, Rept. Ohio Geol. Surv., Paleont. 1, pt. 2, p. 291. 1895. Macropetalichthys agassizi A. von Koenen, Abhandl. Ges. Wis. Gdot- tingen, 40, p. 22, pl. 4, fig. 3. 1907. Macropetalichthys agassizi C. R. Eastman, Mem. N. Y. State Mus. 10, 1D, Is 1907. Macropetalichthys hoeninghausii and Placothorax agassizii E. Hennig, Centralbl. ftir Mineral. Geol. und Pal. no. 19, p. 587. Reference has already been made to the fact that the type of Hermann von Meyer’s Physichthys hoeninghausii is now the property of the Museum of Comparative Zoology at Cambridge, * Cope states that ‘‘the parasphenoid in both Lepidosiren and Ceratodus is pro- duced abnormally, and it is only necessary to imagine this part to be reduced to its normal length to have the conditions found in Macropetalichthys. ”—Proc. U.S. Nat. Mus. 1891, 14, p. 455. 176 IOWA GEOLOGICAL SURVEY Mass. Although incomplete, the part that is preserved shows several of the cranial elements very distinctly, and also the narrowed posterior portion of the parasphenoid which sup- ports the notochordal sheath. This is deeply channeled in the median line for the passage of the notochordal sheath, and is concentrically striated in the same manner as the vertical lamina which descends from the posterior margin. The sheath itself exhibits no trace of segmentation, and, like that in the type species, 1s of remarkably small diameter. Formation and locality. Middle Devonian; Eifel district, Rhenish Prussia. Macropetalichthys pelmensis Hennig. 1907. Macropetalichthys pelmensis E. Hennig, Centralbl. fiir Min. Geol. Pal. no. 19, p. 589, text-figs. 1-3. Under the above name has been recently described a new species of Macropetalichthys which agrees very closely in form, size and general appearance with the type of M. agassizi (von Meyer), and indeed is only distinguishable from it by means of its finer ornamentation and gently ridged condition of the headshield over the occipital region. The cross-section of the latter shows that the cranial roof rises into a low peak in the median line, and slopes away rather abruptly laterad of the occipital sensory canals. The latter are conterminous with the posterior margin of the headshield, at which point they are de- flected abruptly downward and also at a slight angle inward, be- ing encased in a funnel-shaped duct which is partially filled with eancellated tissue. Identical conditions have been observed in the type species of Macropetalichthys, and also in M. agassizi. The peculiar structures in question are in nowise homologous with the articular sockets for antero-dorso-lateral plates in other Arthrodires, as supposed by Hennig, but are clearly the continua- tion of the sensory canals from the cranial roof downward into the interior of the headshield, where they were probably in communication with the internal auditory organs. According to this interpretation the funnel-shaped orifice would corre- spond to the ductus endolymphaticus, which in modern Elas- mobranchs opens on the dorsal surface of the head by an DEVONIAN FISHES OF 1OWA 177 obliquely placed mouth, but in higher fishes is closed or ends blindly. Formation and locality. Upper division of the Middle De- vonian; Pelm, near Berlingen, Hifel District, Rhenish Prussia. Holotype preserved in Museum of Berlin University. Family MYLOSTOMATIDAE. Headshield and abdominal armoring constructed essentially as in typical Coceosteids, but with dentition adapted to ecrush- ing instead of cutting. Upper triturating dentition consisting of two pairs of Ceratodont-like palato-pterygoid dental ele- ments, with non-denticulate margins. Well-developed vomerine teeth present in the earlier, but not yet observed in later forms. Genus DINOMYLOSTOMA Eastman. A genus transitional between Mylostoma and Dinichthyids, as its name implies, and partaking of the characters of both. Man- dibles with slightly prehensile symphysial beak, and broad, flat- tened, regularly excavated functional margin, showing marks of contact with dental plates of the opposite jaw, the latter essentially as in Mylostoma. Vomerine teeth subtrihedral, slightly prehensile. Dinomylostoma beecherit Kastman. 1906. Dinomylostoma beechert C. R. Eastman, Amer. Jour. Sci. ser. 4, 21, p. 83, text-fig. 2. 1906. Dinomylostoma beechert C. R. Eastman, Bull. Mus. Comp. Zool. 50, p. 23, pl. 1, figs. 4, 5; pl. 2, figs. 18, 14, 16, 17; pl. 4, 5. 1906. Dinomylostoma beecheri L. Hussakof, Mem. Amer. Mus. Nat. Hist. 9, pp. 119, 123. 1907. Dinomylostoma beecheri C. R. Eastman, Bull. Mus. Comp. Zool. 50, p. 226. 1907. Dinomylostoma beechert C. R. Eastman, Mem. N. Y. State Mus. 10, p. 151, pl. 14, figs. 5, 6; pl. 15. 1908. Dinomylostoma [beecheri] B. Dean, Science, n. s., 26, p. 50. The specific characters of this primitive form are included in the foregoing generic diagnosis. It may be noted, however, that its particularly distinctive feature consists in the acute ter- mination of both mandibles and vomerine teeth in front, together with the deeply concave or excavated functional margin of the lower dental plates. The triturating surface of all the dental elements is narrower than in Mylostoma, thus making some ap- 12 178 IOWA GEOLOGICAL SURVEY proach to Dinichthys-like conditions, and a still further resem- blance to the latter is observed in the form of the vomerine teeth. The latter, if found in the detached state, might readily be mistaken for the commonly so-called ‘‘premaxillary’’ teeth of typical Dinichthyids. In addition, the dorsomedian and other plates of the abdominal armoring are indistinguishable from those of Dinichthys. The mandibles of this species, which are extremely well pre- served in the holotype, bear a superficial resemblance to the lower dental plates of Palzomylus, especially P. greenei, and they are constructed more nearly after the pattern of Dinichthys than of Mylostoma. ‘Their anterior extremities are elevated into a rather obtuse symphysial beak, which rises but little above the broad, flat, deeply excavated functional surface. The latter displays a single inconspicuous eminence or tubercle close to the external margin, situated about midway the length of the oral surface; and at some distance behind this elevation is a second, larger tubercle, rather elongate, and externally situated like the first. This posterior prominence fits snugly against the single large rounded boss of the opposing palato-ptyergoid dental plate, thus determining the orientation of the latter with utmost nicety, and affording a certain clue to the position of the cor- responding element in Mylostoma. The splenial is developed ias a long, slender shaft of bone, re- sembling that of Dinichthys, but relatively deeper. In the type specimen, preserved in the Yale Museum, both the right and left elements are preserved in natural association with the articular cartilage. This last has become more or less compressed through fossilization, but remains attached to the outer face of the bony shaft near its posterior extremity. There is no separate angu- lare, nor dentary bone, the mandible being reduced to its lowest terms \and consisting, as is usual among Arthrodires, of merely the splenial and dental plate.* The vomerine teeth are prehen- * Jaekel’s claim to have discovered a well differentiated angulare in the mandible of his so-called ‘‘Pholidosteus’’, in reality a synonym of Brachydirus, is discredited by Dean (Science, 1908, 27, p. 203), who suggests that the structure in question may be a displaced portion of the well known interlateral plate. Jaekel’s supposed articular element Dean likewise interprets as a detached portion of the antero- ventro-lateral plate. It is indeed noteworthy that the former of these alleged man- dibular components shows a strongly tuberculated surface, which is scarcely recon- cilable with its assignment by Jaekel to an internal position. DEVONIAN FISHES OF IOWA 179 sile to about the same degree as the symphysial beaks of the lower jaw, against which they closed. Their posterior face is smooth and slightly hollowed, thus indicating that they were in direct contact with the anterior pair of palato-pterygoid plates, which are missing in the original example. The posterior pair, however, is admirably preserved, and on being brought into ad- justment with the opposing lower dentition, it is a comparatively easy matter to restore the outlines of the pair immediately pre- ceding. The external margin of the anterior pair must have been parallel to that of the functional surface of the lower dental plate; and as the upper elements were probably in contact with each other in the median line, the inner margin was rectilinear, as in Mylostoma (cf. text-fig. 25, page 181). The dorsomedian plate, with well developed posterior process, agrees closely in form and proportions with that of Dinichthys intermedius. The antero-ventro-laterals have ‘also approxi- mately the same form, but are nearly one-fifth smaller than the corresponding plates in the tolerably complete example of Mylos- toma variabile figured by Dean.* In that author’s restoration of the ventral armor, however, these plates have been interchanged with the postero-ventro-laterals, as is evident from an inspection of their respective centers of ossification, and direction of vas- cular canals. Formation and locality. Cashaqua shale (Portage); Mt. Mor- ris, Livingston county, New York. There is also indistinct evi- dence either of this or some other Mylostomid in the black Naples shale (Portage) at Sturgeon Point, on the south shore of Lake Erie near Buffalo; and an undescribed species, appar- ently of this genus, is thought by Dr. L. Hussakof to be indicated by dental plates from the New Albany (or Genesee) Black shale near Louisville, Kentucky. Genus MYLOSTOMA Newberry. Distinguishable from Dinichthys only by characters of the dentition. Oral surface of lower dental plates broad, more or less flattened, and bearing a rounded boss or V-shaped prom- *Dean, B., Paleontological Notes: On the Characters of Mylostoma Newberry. Mem. N. Y. Acad. Sci. 1901, 2, p. 108, pl. 7. 180 IOWA GEOLOGICAL SURVEY inence close to the inner margin, which plays into a correspond- ing depression of the upper pair. No positive evidence of the occurrence of vomerine teeth has yet been detected. Our knowledge of Mylostoma is confined at present to three species, all from the Cleveland shale of Ohio. These are, M. variabile Newberry, which is typical of the genus; M. terrelli Newberry, founded upon a unique example of a lower dental plate; and M. newberryi Hastman, of which the complete lower dentition is known. Notwithstanding the comparatively late geological horizon of all these forms, they are not to be regarded as incipient in the Upper Devonian, but as survivals of a primitive type of Arthrodire in which the crushing type of Dip- noan dentition was a persistent feature. One of the interesting points established by Professor Dean’s study of the type species of Mylostoma is the close agreement between it and Dinichthys in all essential respects save for the dentition; and as regards this latter feature, the same differ- ence is to be noted as exists between Rhynchodus and Palzo- mylus among Ptyctodonts, or between Protopterus and Neocer- atodus among modern Dipnoans. Parallel modifications of this nature, occurring as they do in very diverse groups, are doubt- less to be correlated with similar food habits. Among Chimae- roids, for instance, certain genera are shown by their develop- ment of tritoral dental plates to have subsisted on hard-shelled- prey, such as mollusks, echinoderms and the like, thus meriting Dollo’s term of ‘‘conchifrage’’;* whereas others, as indicated by their sharp sectorial rims, were adapted for subsistence on soft tissues, and were probably predaceous creatures (‘‘macro- phage’’ Dollo). Mylostoma and Dinichthys furnish examples of corresponding adaptations among Arthrodires, and an exact parallel is found in modern Lung-fishes. ) The mandibles of Mylostoma would seem to have retained with great persistency typical Dipnoan conditions. The form of the dental plates strongly recalls the unmistakable Ceratodont con- figuration, and these elements are more sharply demarcated from the supporting splenial than in other Arthrodires. AI- *Dollo, L., Sur quelques points d’éthologie paléontologique. Bull. Soc. Belge Géol. 1906, 20, p. 1. —, eS a DEVONIAN FISHES OF IOWA 181 though marginal serrations have disappeared,* the divided ridge which is situated close to the mner margin is perhaps to be regarded as a relic of one of the most persistent features of Dipnoan dentition. As for the upper dental plates, had they invariably been found in the detached condition, and were we ignorant of their association with typical Arthrodiran man- dibles, they would be unhestitatingly identified with the Cteno- dipterine order of Dipnoans. That these plates were supported by cartilage forming the roof of the mouth is distinctly apparent from their rugose, slightly hollowed upper surface, and out- wardly bevelled edges; and the contour of the hinder pair ren- ders it extremely probable, at least, that the supporting palato- — FIG. 25 Fig. 25. Mylostoma variabile Newb. Cleveland shale; Cleveland, Ohio. Restoration show- ing two pairs of palato-pterygoid dental plates arranged in their inferred normal position, and outlines of mandibular plates functioning against them, all drawn froma single, nearly complete and probably young individual. *They are prominently retained in Diplognathus, however, a genus that belongs indubitably to the same family as Mylostoma, and are developed in the form of powerful denticles entirely around the margin of the dental plate proper. Judging ‘from the relative proportions of plates forming the ventral armor in the imperfectly known genera Glyptaspis and Holonema, they should properly be included among Mylostomids, and it is extremely likely that they were provided with a crushing type of dentition, or modification of that type. Diplognathus is really only an extreme modification of the Mylostomid type, and, as suggested by Newberry, there is considerable reason to suppose that the mandibles known under this name, and the detached abdominal plates assigned to the provisional genus Glyptaspis, belonged in reality to the same kind of fish. 182 IOWA GEOLOGICAL SURVEY pterygoid cartilage was of the usual pattern found in all Dip- noans. This cartilage, when ossified, is commonly known as the ‘‘upper dentigerous bone’’; the fact that it is unossified in Arthrodires agrees with other evidence pointing to their less highly specialized condition as compared with Ctenodipterines. The restoration of the upper dentition of M. variabile, shown in the above figure, is based upon the naturally associated parts of a single individual—the same which has already been ecare- fully described in Dean’s memoir of 1901—and is consistent with the evidence obtained by fitting together of detached specimens belonging to the same species. It may be instructively com- pared with text-figure 23 (see page 162), which is reproduced from a photograph of the actual dental plates. The retention throughout life of two pairs of palato-pterygoid dental plates in this family, corresponding to an evanescent stage in Neocer- atodus, is regarded as a primitive characteristic. Hence, in so far as the dentition is concerned, members of this family recall ancestral conditions more distinctly than either Dinichthys or Coccosteus. In working out the above arrangement of Mylostomid denti- tion, upper and lower, the writer has used all available material illustrating the palatal dental plates of the type species; and in the whole number of specimens examined, absolutely no char- acters can be detected which point to more than individual differences between them. So close is their agreement with one another in form and relative proportions that is it quite im- possible to suppose, or at least to prove, that more than a single species is represented. Their impact against the lower dentition has given rise to facets and worn surfaces which are seen to occupy a constant position in all the plates, and furthermore to coincide perfectly with similar indications of wear in the lower dental plates when the latter are applied against the pave- ment teeth in their inferred natural position. In this position alone is there harmonious adjustment between all mutually op- . posed parts, and in no other position can all of the salient points of contact and worn areas be brought together when the jaws are closed. An arrangement in which all of the parts fit thus perfectly together, and which is capable of explaining a DEVONIAN FISHES OF IOWA 183 number of constant characteristics of all the elements thus far brought to light must be admitted to be the true arrangement; that is, the parts must have interacted according to this particu- lar fashion in order to have produced the observed effects, for had they operated after a different fashion they would have produced different effects. To anyone who has had the handling of the actual specimens and has experimented with them in the manner indicated, es- cape from the foregoing conclusion seems impossible. The evi- dence for it is not, however, accepted by Dean,* who believes that the normal position of palatal dental plates is indicated by two specimens lying side by side in the slab containing the sin- gle tolerably complete individual described by him in his memoir of 1901. It is assumed by Dean that the juxtaposition of these two palatal plates is natural, not fortuitous owing to post- mortem displacements, as is the case with the dissociated half of the same pavement. The reconstruction proposed by Dean rests entirely upon this unproved assumption, and his arguments in support of it lead from theoretical premises to theoretical conclu- sions. Some of the latter involve if not incredible, at least start- lingly curious features, such as the assignment to Mylostomids of rotary and other complicated jaw movements, the like of which exists nowhere among chordates; and partly as a corollary to this inference it is suggested that the jaws themselves are not homologous with those of ordinary fishes. The inherent im- probability of the conclusions depending upon Dean’s recon- struction is sufficient reason for distrusting the validity of the premises upon which it is based.t . . ek uti, “I DEVONIAN FISHES OF 1IOWA 24 it was necessary to postulate the existence of their ancestors during the Devonian, although their remains had escaped notice both in Europe and North America. Frequently it happens in natural as well as in physical science that, through the exer- cise of trained imagination, predictions can be made with such confidence that our faith in them amounts almost to a certainty, even though there appear to be little chance of ultimate demon- stration of the truth;* but in all such eases it is gratifying when well-founded forecasts happen to become verified by fresh dis- coveries. Smith Woodward’s recognition of a Devonian Coel- acanth in the new form brought to light by von Koenen is a good instance in point. Another instance, even more striking than the first, is found in the fortunate discovery by Dr. Stuart Weller of a completely developed Coelacanth, immediately to be deseribed under the name of C. welleri, at the base of the Kinder- hook limestone near Burlington, Iowa. These discoveries com- pel us to project the origin of the family backward in point of time to an earlier period than was at first thought necessary. Coelacanthus welleri, Hastman. (Plate III, Fig. 7; Text-fig. 36) 1908. Coelacanthus wellert C. R. Eastman, Journ. Geol. 16, p. 358, text-fig. 1. Holotype a somewhat imperfect fish, the total length of which to the base of the caudal fin is about 19 cm, or a little more than three times the length of the head with opercular appar- * The necessity for postulates of this nature in paleontology is too obvious, and the practice of making them too common, for illustrations not to suggest them- selves readily to all well informed persons. We may, however, be allowed to cite an excellent recent example of this art of visualizing undiscovered prototypes of fossil forms, which is to be found in Dr. Bashford Dean’s recently published “‘Notes on Acanthodian Sharks’’ (Amer. Journ. Anat. 1907, 7, p. 220). Having reached the conclusion that Acanthodian sharks ‘‘have passed through a stage which is best represented by the Cladoselachian,’’ the author seeks to answer the inquiry why it is that the more specialized group of Acanthodians is known from an earlier horizon than the less specialized? The situation is met by framing the following hypothesis: “This is in truth a question which can be answered only by the time-worn appeal to the defectiveness of the paleontological record, noting especially in this regard that the soft structures of the Cladoselachians would be less apt to be pre- served than the hard structures of the Acanthodians. We may, however, safely predict that from the earliest Acanthodian horizon there will be discovered forms which will represent the ancestors of all the early groups of sharks. And we may predict with the same degree of security that these forms will be found to picture the Cladoselachian in essential characters. For the Acanthodians, as we at pres- ent know them, are obviously too specialized to have represented the ancestors of the line of Cladoselachians.’’ (cf. supra, pp. 61, 99.) 248 IOWA GEOLOGICAL SURVEY atus. Trunk robust, its maximum depth twice as great as that of the caudal pedicle. Anal and paired fins situated as in the typical species (C. granulatus Ag.), the greater part of the caudal and both dorsals not preserved. Opereulum and cheek- plates ornamented with numerous fine antero-posteriorly di- rected spiniform ridges, their position being indicated in the worn condition by faint tubercles. Scales ornamented with nu- merous fine raised lines of ganoine, more or less continuous and rectilinear, but when worn assuming the appearance of elon- gated tubercles. Scales along the lateral line with prominent raised tubules directed parallel with the body axis. The unique and in many respects remarkable specimen answer- ing to the above description, and shown in the accompanying half-tone figure (Fig. 36), was discovered a few years ago by Dr. Stuart Weller, of the University of Chicago, in the course of his investigation of the Kinderhook fauna of Iowa and ad- joining states. In recognition of his important work, and for the rest, as hommage d’esprit, we have pleasure in dedicating the specific title of the new form brought to light by him in his honor. The exact horizon whence the specimen was obtained is the blue shale bed at the base of the Kinderhook limestone near Burlington, Iowa. An analysis of the fauna occurring in this bed, designated as No. 1 in the local section, is given by Dr. Weller in volume X (1899) of the Iowa Geological Survey Reports, p. 69 seq. The peculiar relations of this assemblage are thus noticed by the author in the course of his general re- marks (p. 70): ‘‘The fauna of this bed is a most interesting one, it probably being the oldest of the Kinderhook faunas of the Mississippi Valley. The presence of typical forms of the genus Productus gives to the fauna a strong Carboniferous aspect, the undeter- mined species of Productella and Gomphoceras being the only members which are suggestive of the Devonian, unless the fish- remains should show some such allianee. The fauna is really more strongly Carboniferous in aspect than is that of bed No. 2, whose large number of pelecypods are for the most part allied to Devonian species in New York. For the satisfactory study of this fauna, however, larger collections than are now available must be secured, and as soon as the necessary material 249 : : “oSeoIYO JO AUISIOALUY 94} JO WNIsSN| JOY[VA Ul [VUIsII 9-G x ‘edAJO[OY Jo JOodse [e1oJeT ‘“BAOT ‘UOUI[LING Iv9U ‘9UOJSOUI] YOOUIOPUIY “UPUT\SeA 24a722aN STAN) qa ® “98 “SIA DEVONIAN FISHES OF IOWA 250 IOWA GEOLOGICAL SURVEY is at hand, this fauna will be made the basis of one number of ‘Kinderhook Faunal Studies’.’’* . Bearing in mind the remote geological antiquity of the new Coelacanth we have just described, it is suggestive to note that its totality of characters by no means indicates a primitive mem- ber of the group, but on the contrary bespeaks a typical species as completely developed as any subsequent form with which we are acquainted. In this respect it resembles the only well known British Coelacanth of an age anterior to the Coal Measures, this being C. huxleyi, from the Calciferous sandstones of southern Scotland. Paleontologists are well aware that the oldest known Coelacanths from the western hemisphere are of Coal Measure age, and are represented by poorly or indifferently preserved material. In all, but four species of Coelacanthust proper, and three of Cope’s genus Peplorhina, are recorded from a few localities in Ohio and Illinois. It is now in order to present a more detailed description of the new Kinderhook form. The characters of specific value which it displays may be enumerated as follows: (1) The deli- eate spiniform ornamentation of the operculum and cheek plates, together with the form and disposition of the latter; (2) the peculiar form of the mandibular ramus; and (3) details of seale ornament; and (4) prominence of the lateral line canal. Owing to the decidedly imperfect preservation of most of the fin struc- tures, it is impossible to say in what respect, if any, these differ from the normal type. The cranial structure, however, offers a number of interesting points of comparison with other forms, as will be immediately pointed out. The roofing-bones of the skull are missing in the type speci- men, and that portion of the head in advance of the orbits has been fractured in such manner as to strip off the maxillary and other external facial elements, exposing at the same time the anterior spatulate portion of the parasphenoid, together with * Barlier numbers of these Studies, the second one dealing with the fauna of the Chonopectus sandstone at Burlington (immediately overlying the fish-bearing bed No. 1), are published in vols. 9 and 10 of the Transactions of the St. Louis Academy of Science. + Certain of these types are now preserved in the American Museum of Natural History in New York. Cf. Hussakof’s ‘‘Catalogue of Fossil Fishes,’’ etc., pub- lished in vol. 25, of the Bull. Amer. Mus. Nat. Hist., June, 1908. DEVONIAN FISHES OF IOWA 251 the steeply inclined triangular palatine plates that abut against it on either side. The inferior border of the palatines, para- sphenoid and vomer appears to have suffered somewhat from chemical corrosion, in consequence of which no indications of teeth are anywhere visible. Possibly for the same reason no teeth are to be observed along the margin of the lower jaw, nor lying free in the matrix, in case any had been broken off. The mandibular ramus of the right side is well displayed, and the dentary is seen to be still in union with its fellow of the left side at the symphysis. The articulo-angular element is long, narrow in front, its superior border rising into a small median and a large posterior elevation, between which is a deep con- cavity ; and its inferior border is nearly rectilinear. The super- ficial ornament of this piece has become well-nigh obliterated by weathering or abrasion, and of the two gular plates immedi- ately underneath, nothing remains but an impression of their inner surfaces. A notable peculiarity of the type specimen, one that possibly bears witness to primitive traits, consists in the arrangement of cheek-plates immediately in advance of the operculum. In all other Coelacanths so far as known, two postorbital plates of subequal size are placed one above the other in the space be- tween the orbit and operculum, in such fashion that the small triangular plate called ‘‘postmaxillary’’ by Huxley is excluded from contact with the operculum. The new Kinderhook species, however, has all three of these cheek-plates situated in vertical series, one overlapping the other from above downward, and each overlapping the anterior border of the operculum. The lowermost cheek-plate, that corresponding to the so-called ‘‘post- maxillary’’ of Huxley, terminates below in line with the inferior border of the operculum, and covers the space immediately be- hind the inflected portion of the articulo-angular element of the lower jaw. Its antero-superior margin is apposed to the strongly arched, probably semicircular suborbital element, of which only a small segment is preserved in the type example. In this latter respect the plate in question is seen to occupy the same relation as the ‘‘postmaxillary’’ of other Coelacanths. Owing to the fact, however, that in later species this plate is 252 IOWA GEOLOGICAL SURVEY displaced far forwards, and has to accommodate itself to the contours of the suborbital and lower postorbital, it suffers con- siderable reduction in size, whereas in the form under discus- sion it is fully as large as either of the superjacent postorbitals, and is ornamented in similar manner. No indications are to be observed in the specimen before us of a sclerotic ring, although one may be inferred to have been present as in other known Coelacanths. Neither is there any ex- ternal indication of the presence of an ossified air-bladder, for which members of this family are remarkable. The caudal, anal and pelvic fins are too imperfectly preserved for description, and the pectoral pair is altogether wanting. The squamation is admirably shown, especially in the posterior part of the trunk, where the fine longitudinal ridges of ganoine and concentric growth-lines are pyritized. The lateral line is rendered con- spicuous by a single large raised tubule of ganoine extending for nearly the entire length of each scale in this row. An enlarged view of the superficial ornament of scales lying a little above the anal fin is given in Plate ITI, Fig. 7. Formation and locality. Basal member of Kinderhook lme- stone, near Burlington, Iowa, beneath a bed carrying an inver- tebrate assemblage of markedly Devonian aspect. Holotype preserved in the Walker Museum of the University of Chicago. Genus PALAEOPHIGHTHYS, novum. An aberrant Crossopterygian genus provisionally referred to the Coelacanthidae, and distinguished from all other members of the family by its elongate, anguilliform body, and continuous me- dian fins. Scales very delicate with exceedingly fine antero- posterior striations. Neural and haemal spines long and deli- eate, almost filiform. Although the scope of this Report is limited in a strict sense to forms of fish life of Devonian age, yet on account of the great rarity and peculiar organization of the older Coelacanths in this country, it has been deemed advisable to include a notice here of a remarkable specimen from the famous Mazon Creek locality of Illinois, which differs notably from all other genera and species thus far described. We propose to recognize it, therefore, under the following caption: — et DEVONIAN FISHES OF IOWA 253 Paleophichthys parvulus, sp. Dov. (Text-fig. 37) A very small species, attaining a total length of 4 or 5 em, with very slender, elongated, eel-shaped form of body. Length of head contained nearly six times in the total length. Arrange- ment of cranial plates indistinguishable, and extremity of tail deficient in the solitary known specimen. Paired fins not ob- served. Median fins continuous, the dorsal arising behind the occiput at a distance equal to about one and one-half times the length of the head itself, and the origin of the anal not far behind that of the dorsal. The original specimen serving for the holotype of the above defined genus and species is preserved in counterpart, as is usually the case when organic nuclei are exposed within iron- stone nodules at the Mazon Creek locality in Grundy county, [h- nois. It at one time formed part of the S. 8. Strong collection, and is now the property, along with the type of Coelacanthus exiguus from the same locality and horizon, of the Museum of Comparative Zoology at Cambridge, Massachusetts. Interest- ing as the specimen is on account of its relations and general features, it is to be regretted that it is defective as regards preservation of certain parts, the head region being encrusted with a whitish film of silicious matter, the extreme tip of the tail wanting, and no trace remaining of the paired fins. The most salient and at the same time truly surprising charac- teristics of the new form are two: first, the angmlliform propor- tions of body; and secondly, the continuity of the median fins. i! wi Hi ae gas a FIG. 37. Fig. 37.—Palzophichthys parvulus, sp. nov. Coal Measures; Mazon creek, Illinois. Lateral aspect of holotype showing elongate form of body, degenerate squamation, and continuous median fins, x 2-1. IOWA GEOLOGICAL SURVEY We are justified in expressing surprise at these features, for not only is their occurrence singular for the family of Coela- canths in general, but they have not hitherto been known to be combined in any Paleozoic fish. Eel-shaped forms occur in a few groups, mostly sharks, during the Paleozoic, as has already been noted in treating of Cladoselache and Acanthodians; and it will be remembered that this form of body has been interpreted as a symptom of decadence.* These forms do not, however, develop continuous median fins. Contrariwise, Phaneropleuron and Uronemus furnish examples among Paleozoic Dipnoans where the unpaired fins are confluent, but the form of body is massive and cylindrical, and hence can hardly be described as eel-shaped. Typical eels, as every one knows, do not occur until the Upper Cretaceous. In so far as the specimen before us is remarkable for exhibit- ing the combination of characters just described, precisely on that account is it difficult to affiliate it with other contemporary forms of fish life with which we are familiar. Its reference to Coelacanths is admittedly provisional. Yet at the same time we cannot deny that its affinities are more readily to be sought in the vicinity of this group than any other. Grounds for this belief are to be found in the delicately striated scales of the new form, the posterior prolongation of the body axis, and its ossified neural and haemal spines, features which offer suggestive points of comparison with typical Coelacanths. One will recall also, that at least one undoubted member of the family, C. exiguus,t is of about the same size, has degenerate squamation, and accom- panies the present form in the same fauna. On the whole, the most plausible interpretation of Paleophichthys seems to be to regard it as an aberrant and extremely degenerate offshoot of fringe-finned ganoids adapted to a mud-grovelling mode of existence. Formation and locality. Coal Measures; Mazon creek, Grundy county, Illimois. * Cf. ante, p. 61. + Described in Journal of Geology (1902), vol. 10, p. 538, text-fig. 3. DEVONIAN FISHES OF [OWA bo or wo Order ACTINOPTERYGII. Paired fins nonlobate, having an extremely abbreviated endo- skeletal portion, and the dermal rays prominent. Caudal fin abbreviate-diphycercal, heterocercal, or homocereal. P : ~ : j J Me . = ts is =a - 3 “4 4 y « i - \t) Plate VI. EXAMPLES OF PTYCTODONT DENTITION FROM THE IOWA UPPER DEVONIAN. All figures are of the natural size. A miscellaneous assortment of detached tritors, all more or less worn by use, and otherwise rolled and abraded, this being the usual condition in which remains of this sort are found in the Old State Quarry beds near North Liberty, in Johnson county, Iowa. The greater number of these tritors belong to Ptyctodus calceolus Newb. and Worthen, and are shown of the natural size. Originals in the Museum of Iowa State Univer- sity. (Pa@e) yen eee) ae ne re ee 133 316 IL. Plate V XVIII. Vol. Iowa Geological Survey, ‘i re | “ | i : | : | . = | | | . | é . 1 ee ae See a Plate VII. EXAMPLES OF CTENODIPTERINE DENTITION, MOST- LY FROM THE IOWA UPPER DEVONIAN. All figures are of the natural size. Figs. 1-4. Dipterus nelsoni Newberry. Chemung; Warren. Pennsylvania. In Fig. 1 is shown a right upper dental plate of the so-called ‘‘D. flabelliformis’’ type, and in Figs. 2-4 the corresponding mandibular dental plates of both sides of the mouth. The original of Fig. 2 is one of Newberry’s cotypes of this species, and is now preserved in the Peabody Museum at Yale University. The others are the property of the Museum of Comparative Zoology at Cambridge. The original of Fig. 3318 also shown Plate Mi hic. i tia. Page? =) eee 223 Figs. 5-9. Dipterus mordax Wastman. State Quarry beds (Upper Devonian); Johnson county, Iowa. Small sized ex- amples of the inferior dental plates, to be compared with those shown: in Plate 1], Kies4,°5. Page.2.. 35-40... 00eeee 220 Figs. 10-15. Dipterus pectinatus, sp. nov. State Quarry beds (Upper Devonian) ; Johnson county, Iowa. Lower dental plates represented in Figs. 10, 13, 14; upper m Figs. 11, 12, 15. The original of Fig. 13 is also shown in Plate II, Fig. 2. Page. .222 Figs. 16-25. Dipterus digitatus, sp. nov. State Quarry beds (Upper Devonian) ; Johnson county, Iowa. Lower dental plates represented in Figs. 16-19, 25; upper in Figs. 20-24. The orig- inal of Fig. 20 is also shown in Plate Il, Wig. 6. Page... ... 2221 320, Iowa Geological Survey, Vol. XVIII. Plate VII. r as * rn , wUe ‘ SA Se f % 7 a ; : ‘ 7 am an oe Fe . * - - * + . ‘ { N é Plate VIII. HXAMPLES OF STATE QUARRY CTENODIPTERINE DENTAL PLATES. All figures very nearly of the natural size. The greater number of specimens selected for illustration in this Plate (all except Figs. 16, 20, 29, 34) are determined as belonging to Conchodus variabilis, sp. nov., and form a repre- sentative series, showing the wide range of variation exhibited by the detached dental structures, and with evanescent traces of coronal plications (seen especially at the bottom of Figs. 13, 15, 28, 33, ete.). The four exceptional figures are probably worn or otherwise imperfect specimens of Synthetodus calvini, all from the State Quarry beds near North Liberty in Johnson county, Lowa. Originals preserved in the Museum of Iowa State University. Pages. os 245 ohad el Fie Be eh oS Oe 324 ———— Iowa Geological Survey, Vol. XVIII. Plate VIII. Plate IX. HXAMPLES OF STATE QUARRY SYNTHETODONT DEN- TAL PLATES. All figures reduced slightly less than the natural size. In this plate is shown a representative assortment of the compound dental plates of Synthetodus trisulcatus, with per- haps one or two mutilated examples (Figs. 19, 32) of S. calvini, all from the State Quarry beds near North Liberty, in John- son county, lowa. The two upper rows represent the normal expression for the type species. Originals preserved in the Museum of Iowa State University. PageSis 54 ssl! RL Nee bee Doe eee 231 and 233 328 Iowa Geological Survey, Vol. XVIII. Plate IX. Plate X. EXAMPLES OF STATE QUARRY SYNTHETODONT DEN- TAL PLATES. All figures reduced slightly less than natural size. The larger specimens in the middle row and at the bottom of the Plate are determinable as belonging to Synthetodus calvin, the remainder as imperfect examples of S. trisulcatus; all from the State Quarry beds near North Liberty, in Johnson county, Iowa. Originals preserved in the Museum of Iowa State University. Pages, jo ke Oe ots Ole te eee 231 and 233 332 ————————— a ee ee Plate X. ey, Vol. XVIII Towa Geological Surv ei A ‘x Plate XI. EXAMPLES OF STATE QUARRY SYNTHETODONT DEN- UAT EA BS: All figures reduced slightly less than the natural size. The smaller plates with more or less distinct sulci, such as the originals of Figs. 6, 8, 10, 15, 22, 23, 25, ete., are determinable as belonging to Synthetodus trisulcatus, the larger ones, which are apparently simple, as somewhat imperfect examples of S. calvini; all from the State Quarry beds near North Liberty, in Johnson county, Lowa. Originals preserved in the Museum of Iowa State University. Pages: ee ee a es oa 231 and 233 336 Iowa Geological Survey, Vol. XVIII. Plate XI. Plate XII. EXAMPLES OF STATE QUARRY SYNTHETODONT DEN- TAL PLATES. All figures reduced slightly less than the natural size. In this Plate is shown a representative assortment of dental plates belonging to Synthetodus calvim. The originals of Figs. 7, 9, 12-15, are interpreted as constituting the lower, and the remainder, with the exception of Fig. 16, as the upper pave- ment dentition of this species. In Fig. 16 is seen a unique eal- ecified vertebral body, also from the State Quarry ‘‘fish-beds,’’ whose relations are considered problematical. Originals preserved in the Museum of Comparative Zoology a @amilorid cess Nlaissan ikvelo CS pea ee 147 and 233 340 Plate XII. Iowa Geological Survey, Vol. XVIII. Plate XIII. CRANIA OF RHADINICHTHYS DEANI, SP. NOV. All figures are represented of the natural size. A series of phosphatic nodules from the base of the Waverly near Junction City, in Boyle county, Kentucky, which have been cleaved in such manner as to display their organic nuclei. In the case of each specimen here illustrated, this consists of the headshield, sometimes with other naturally associated parts of a new species of Rhadinichthys. The cranial roof may be exposed, with or without the superficial ornament, according to the position of the plane of fracture; and in a few fortunate instances, an example of which is furnished by Figs. 8, 9, the cranial roof has been lifted off so as to reveal the structure of the mineralized brain, auditory organs, and arterial blood- vessels. Most of these specimens, like the originals of Figs. 8 and 9, 14 and 15, are preserved in counterpart. The first of these pairs is also shown in text-figure 40, A-B. Originals preserved in the Museum of Comparative Zoology at Cambridge, Mass; Page.s 925. 40005) 20 ee ee 264 344 Iowa Geological Survey, Vol. XVIII. Plate XIII. 2 ' tS ts Pe ied oe ee 1S oe Plate XIV. Areal Map of North American Middle Devonian Professor Schuchert’s reconstruction of Middle Devonian paleogeography at the close of Onondaga time. Noteworthy is the large extent of the interior continental area, the western borders of which are only conjecturally indicated. 348 nf *S oe = By gat = iG pou. Gaeojo * “AIX 948Id ‘IIIAX ‘I0A ‘Aaarng [eorsojoan eMoy TESS aeusk RA Rt AS yous. a / 7 ; \ oO \\ Cc \\ ftom ecm, on \\ X \ & Sas ¢ @ Sean a | | | SOUTH ERICA MIDDLE DEVONIC PALEQGEOGRAPHY CLOSE OF ONONDAGA TIME Towa Geological Survey, Vol. XVIII. Plate XTV. zr — y i i >! Li . \ i i \ be ow i j L, fe ‘ae Sean sea MIDDLE DEVONIC PALEOGEOGRAPHY CLOSE OF ONONDAGA TIME CFO2E Ok OMOMOVEY LIWE WIDDE DEAQMIC KLVTEGeEORBYEHA Plate XV. Areal Map of North American Middle Devonian. Professor Schuchert’s reconstruction of Middle Devonian paleogeography at the close of Hamilton time. Partial sub- mergence is indicated for the interior continental area, the two principal land-masses (designated as ‘‘ Laurentia’’ and ‘‘Colum- bia’’) being separated by the encroachment of the ‘‘Dakotan sea.’’ The ‘‘Ohioan sea’’ is represented as being in less open communication with oceanic bodies on the east and south than during the period immediately preceding. 354 SRT aE a rr Rae I et. TOA9 GSOLOBIGE] yaLsGh” Aor RATE ST NSCS Orie: SOW aces a TN —_— : a ’ = Ws 5 ee S oO = ~ fs} HF mM 3 4 NG [o} , (r) \ ‘ a Oo re a Ee N —— ° = = = | ig tg Fr ™ 2) / wn i 7 . x =- . =, a vv. ul ll ; : AWS | j i | feet. ir ; ; ‘ 4 i an \ w | | \ ~¢ | | Pe i 2" \\ a . j _ NAH MIDDLE DEVONIC PALEOGEOQGRAPHY CLOSE OF HAMILTON TIME a a i - . ! ‘ ; ' ¢ } I) { j ¢ f { 4 j ‘ it 1 ie I wi hd : ¥ : vy, } hi \ ‘ vy oo B | ; oft x h > “54 1 . a 1 1) iene * oy = aes fy «! MIDDLE DEVONIC PALEOGEOGRAPHY CLOSE OF HAMILTON TIME Iowa Geological Survey, Vol. XVIII. bYFEOCEGREVbHA CPOeE Ok HVWIFLOU LIWE DEADMIC WIDDTE -, So SSR > tees, pets o> eens Hinabitee és ‘ * ue ew Plate XVI. Areal Map of North American Upper Devonian. Professor Schuchert’s reconstruction of Upper Devonic paleogeography. The Appalachian and Columbian land-masses are represented as more shrunken in area than during earlier periods of the Devonian, and a westward extension of the Miss- issippian sea receives the name of Oklahoman. In the Cordil- leran region it is probable that a larger land-mass was elevated above sea level than is here conjecturally represented. 360 a inter emp te f Of; q, yf j y i] Yip Zi WT) — TOMY GbopoRsesy aries” Kop RAIT’ \ A \\ \ \ N 7 WX, ae i : a \\\ ee, Senay \ ~ v \ \ “ 4 ¢ | 7 | \ 2) AREY, ‘we a 7 a ) —"" AI TNL Tit tida Xv. Titrigii er «Of . = 2 ———— /—=| © ——4 a —-~ ! le | do | | ! | a LU M BY A ay GULE OF M Pot! ij ( ‘ ; \ \\ ae : f \\ >» aie \) \) \ UPPER DEVONIC PALEOGEOGRAPHY A — == & >» z eer G re. Sw Q mate =) Lt fas ee 9) \ \ \\ ae UPPER DEVONIC PALEOGEOGRAPHY Iowa Geological Survey, Vol. XVIII. an a es = ee Se SEE RR eS EI hs he | | } | | i | | | | | | MbbEB DEAOUIC byT Naa OW Pedal ei ; me ¢ Rok athe lose steerer ee ht eA RDI SA RET ~: | | | | | i i 1] i 1 | INDEX Figures in Italics refer to pages a Acanthaspis, 142 characters of genus, 144 Acanthaspis armata, 145, 188, 277 decipiens, 188 minor, 145 pruemensis, 145 tuberculatus, 145 Acanthodes, 61 Acanthodes affinis, 280 brown, labyrinth of, 266 concinnus, 280 gracilis, 60 (?) pristis, 118, 281 semistriatus, 275 sulcatus, 60 Acanthodians, 99 advent of, 53 Silurian, character of, 59 Acanthodidae, range of, 112 Acanthodii, 68, 69 characters of order, 112 Acanthoossus ? pristis, 113 Acantholepis, 143, 144 characters of genus, 140 Acantholepis fragilis, 141, 142, 277 pustulosus, 142 Acanthopterysgii, 68 character of, 64 Acipensideridae, degeneration of, 256 Acknowledgments, 291 Actinistia, 69 ; characters of suborder, 241 Actinophorus clarki, 285 Actinopterygii, 69 character of order, 255 | list of, 280, 282, 285 Actinotrichia, 103 on which descriptions are given. Adams, F. D., cited, 264 Administrative reports, 1 Aetheospondyli, 69 Agar, W. E., cited, 165 Agassichthys agassizi, 175 manni, 168 sullivanti, 168 Agassiz, L., cited, 168, 175, 187, 243 mentioned, 147, 150, 242 Agnatha, advent of, 53 characters of, 53 classification of, 69 systematic account of, 70 Albert coal mine, New Brunswick, fish remains from, 257, 261, 262 Albert county, New Brunswick, fish remains from, 261, 262, 273 Alleghany county, New York, fish remains from, 225, 288 American Museum of Natural History, 124, 158, 250, 265, 271 Amia, 63 “Amphistyly”, 66, 96 “Anarthrodira”’, 170 Anaspida, 69, 72 occurrence of, 74 Antiarchi, 69, 72 characters of order, 74 classification of, 56 occurrence of, 75 Apateacanthus vetustus, 281 Apedodus priscus, 288 relations to Holoptychius, 238 Appalachian district, fish remains from, 215, 239, 261, 281 “Appalachian” sea, 45 Archipterygium, 100 Arctolepis, 145 Arctolepis decipiens, 145 (367) 368 INDEX Arey, M. F., work of, 4 Arisaig series, Nova Scotia, fish re- mains from, 276 _Arms, or brachia, of Pterichthys, 80 Aroostook county, Maine, fish remains in, 75, 838, 275 Arthrodira, 68, 69, 157 characters of order, 158 dermal armor of, 286 fragmentary remains of, 205 in Iowa Devonian, 48 list of, 276, 278, 281, 283, 286, 287, 289 relations of, to modern Dipnoans, 209 relationships of, 158 Arthrognathi, 159 Aspidichthys, in Lime Creek beds, 50 Aspidichthys, sp., 282 clavatus, 206, 285 (?) notabilis, 207, 279 Asterolepidae, 69 appendages of, 71 character of family, 75 classification of, 56 Asterolepids, 158 relations of, 159, 160 Asterolepis, 79 characters of genus, 82 Asterolepis clarkei, 75, 83, 275 hoeninghausti, 175 Asterospondyli, 69 Asterosteus stenocephalus, 278 Astraspis desiderata, 75 Ateleaspidae, 69 Ateleaspis tesselata, 56 Auditory organs of fishes, preservation of, 269 Australia, fish remains from, 104, 113 “Autostyly”, 65, 96 B Bacon, Francis, cited, 33 Balfour and Parker, mentioned, 208 Bedford, Ohio, fish remains from, 283 Beecher, Chas. E., mentioned, 155, 224 Belgium, fish remains in, 94, 200, 227 Beliveau, New Brunswick, fish remains from, 263 Belonorhynchidae, relations of, 256 Berea, Ohio, fish remains from 283-285 Berlin University, fish remains in mu- seum of, 177 Berndorf, Germany, fish remains from, 227 Berycoids, 64 Beyer, S. W., work of, on peat, 2 work of, on road materials, 3 Bicken, Nassau, fish remains from, 187 Bigelow, H. B., cited, 271 Bigsby, J. J., cited, 275 Bilstein, Belgium, fish remains from, 227 Birkeniidae, 69 relations of, 160 Blood vessels of Rhadinichthys deani, 272 Blossburg, Pennsylvania, fish remains from, 290 Bohemia, fish remains in, 104, 242 Boileau, cited, 33 Boston Society of Natural History, fish remains from, 257 Bothriolepis, 58, 75, 78, 79 characters of genus, 83 relations of, 165, 166 Bothriolepis canadensis, 83, 84, 280 coloradensis, 94, 285 leidyi, 92 minor, 93, 287, 289 nitida, 92, 289 Boulenger, mentioned, 157 Bowfin, 63 Boyle county, Kentucky, fish remains from, 132, 149, 265, 273 Brachia of Pterichthys, 80 Brachydirus, 178 characters of genus, 187 mandible of, 191 relations to Coccosteus, 187 Brachydirus bickensis, 187 bidorsatus, 188 Bradford county, Pennsylvania, fish re- mains from, 94, 155, 206, 212, 287- 289 Brain of Rhadinichthys deani, 267 INDEX 369 Branson, E. B., cited, 190, 284 Bremer county, lowa, fish remains in, 49, 134, 139, 196, 213, 225, 241, 279 Brick, production of, 19 Bridge, T. W., cited, 96, 160, 165, 208, 242, 255 Bristol Center, New York, fish remains from, 199, 281 Brongniart, mentioned, 101 Brontichthys clarki, 284 Brooklyn, Ohio, fish remains from, 285 Buckland, mentioned, 150 Buffalo, Iowa, fish remains from, 140, 2113, 219, 279 Buffalo, New York, fish remains from, 135, 148, 179, 257, 281 Buffon, cited, 38 Building block, hollow, production of, 19 Building stone, production of, 23, 24 Burlington, Iowa, fish remains from, 111, 149, 155, 248, 252 Burlington beds, Iowa, fish remains in, 156 Cc Calciferous sandstones, Scotland, fish remains from, 246, 250, 261 Callognathus serratus, 282, 285 Callorhynchus, 143 Calvin, Samuel, acknowledgments, 291 cited, 45, 46, 133, 196, 216, 229, 233 work of, 4 Calvin collection of fish teeth, 229 Cambrian, vertebrate life in, 53 Campbellton, New Brunswick, fish re- mains from, 114, 116, 152, 275, 276 Canada, fish remains from, 213, 235, 278 Canandaigua Lake, New York, fish re- mains from, 139, 199, 281 Canyon City, Colorado, fish remains from, 75, 119 Carboniferous system, fish remains in, 61, 97, 100, 104, 112, 117, 149, 152, 211, 231, 236, 246, 258 sturgeons in, 63 Cashaqua shale, New York, fish re- “mains in, 179 Catskill beds, fish remains in, 92, 94, 114, 117, 212, 226, 239, 287, 289 Cattaraugus county, New York, fish re- mains from, 287 Cayeux, L., cited, 266 Cayuga lake, New York, fish remains from, 281 Cedar Valley limestone, Iowa, fish re- mains in, 45, 49, 107, 126, 134, 137, 139; 140; 197, 2135 215, 219" 2205 225, 241, 277-279 Cephalaspidae, 69 Cephalaspis, 74 armor of, 58 classification of, 56 relations of, 159, 160, 165 Cephalaspis sp., 275 campbelltonensis, 275 dawsoni, 275 laticeps, 280 murchisoni, 58 Ceratodonts, development of, 164 Ceratodus, relations of, 157, 211 Ceratotrichia, 96 Cerro Gordo county, Iowa, fish re- mains in, 49, 134 Chapman, F., cited, 74 Chapman sandstone, Maine, fish re- mains in, 75, 83, 275 Chateaubriand, cited, 35 Chautauqua beds, fish remains in, 109, 187, 200, 226 Cheiracanthus costellatus, 275 Cheirodus, 227, 234 Cheirolepis, occurrence of, 255 relations of, 256 Cheirolepis canadensis, 280 occurrence of, 256 trailli, occurrence of, 256 Chemical action on Dipterine teeth, 216 Cheraung beds, fish remains in, 94, 109, 112, 114, 117, 132, 151, 152, 154, 155, 186, 200, 201, 213, 214, 224-226, 239, 241, 260, 279, 287, 288 Chester beds, fish remains in, 156 Chickasaw county, Iowa, gravel roads in, 3 Chimaera colliei, food-habits of, 217 370 INDEX Chimaeroidei, 68, 69, 118 autostyly in, 65 characters of order, 118 fin spines of, 139 in Iowa Devonian, 48 list of, 277 origin of, 119 “Chirodus”, 228 Chondrostei, 69 characters of suborder, 255 history of, 255 Paleozoic, characters of, 63 Chordata, characters of, 52 Cladistia, 69 Cladodontidae, characters of family, 107 Cladodus, characters of genus, 107 Cladodus sp., 287 alternatus, 111 carinatus, 109 claypolei, 282 | concinnus, 109, 110, 283 coniger, 109, 287 exiguus, 111 exilis, 111 formosus, 110, 286 monroei, 108, 276 pattersoni, 111 prototypus, 108, 276 rivi-pctrosi, 283 ; Springeri, 111 Striatus, 108 subulatus, 283 succinctus, 111 terrelli, 283 tumidus, 283 urbs-ludovici, 110, 281 wachsmuthi, 111 Cladoselache, characters of genus, 97 (?) dermal denticles of, 281 dermal tubercles of, 276 fins of, 99 musculature of, 266 spines of, 152 Cladoselache sp., 281 clarki, 283 fyleri, 61, 288 kepleri, 283 sinuatus, 283 Clark county, Kentucky, fish rer-ains from, 283 Clarke, J. M., acknowledgments, 291 cited, 83, 105, 118, 114, 116, 132, 191, 198, 257, 258, 260 Clay, production by counties, 14, 19 by years, 13 classified, 19 rank of Iowa in, 21 Clay, raw, production of, 22 Claypole, E. W., cited, 73, 146, 154, 193, 199, 200 Cleveland, Ohio, fish remains from, 61, 213, 285 Cleveland shale, Ohio, fish remains ia, 100, 106, 180, 201, 213, 282, 283 Clifton Springs, New York, fish re- mains from, 278 Climatius, 61 Climatius latispinosus, 276 scutiger, 60 Coal, production of, by counties, 14, 17 by years, 13 rank of Iowa in, 18 Coal, use of topographic maps in study of, 4 Coal Measures, fish remains in, 104, 234, 250, 254, 273 Coblenzian fauna of Germany, relations of, to Lower Devonian of Maine, 83 Coccosteans, development of, 163, 164 relations of, 159, 160 _Coccosteidae, characters of family, 184 Coccosteus, characters of genus, 186 relations to Brachydirus, 18% relations to Dinichthys, 185, 188 relations to Protitanichthys, 201 vertebral arches in, 185 Coccosteus sp., 278 americanus, 187 canadensis, 186, 280 cuyahogae, 283 decipiens, 186, 187 halmodeus, 191 macromus, 186, 287 occidentalis, 186, 187, 278 relations to Protitani-hthys. 202 spatulatus, 278 . | ; ; . } ES ee a ai Ee INDEX 371 Coelacanthidae, Agassiz on, 243, 244 characters of family, 242 Coelacanthus, characters of genus, 246 geological range of, 242 Coclacanthus exiguus, 253, 254 granulatus, 248 granulosus, 245 huxleyi, 250 kayseri, 246 welleri, 247 Coelolepidae, 69 classification of, 55 relations of, 160 Coelolepis, shagreen granules of, 276 Colfax, Iowa, mineral water from, 27 - Colorado, fish remains from, 75, 94, 110, 119, 239, 285-289 “Columbia”, 94 Columbus, Ohio, fish remains from, 108, 276, 278 Columbus limestone, Ohio, fish remains from, 107, 108, 114, 124, 143, 146, 175, 240, 276-279 Combes, Paul, and Meunier, S., cited, 266 “Conchifrage’ dentition, 180, 217 Conchodus, 234 characters of genus, 227 relations of, to Dipterus, 231 to Synthetodus, 229 Conchodus ostraeformis, 228 plicatus, 234 variabilis, 213, 228, 230, 286 Concrete, stone for, production of, 23, 24 Concrete, use of gravels in, 7, 26 Cope, BE. D., cited, 53, 71, 84, 92, 100, IBS, IBS, We, sre ales, TS Copulation among sharks, 97 Cornell College, Iowa, fish remains in museum of, 279 Corniferous beds, fish remains in, 100, 124, 141, 142, 149, 175, 199, 276 Cortland county, New York, fish re- mains from, 143 Cranium, structure of, in classification, 65 : Saad fish remains from, 64, 241, 24 Cross, Whitman, cited, 110 Crossopterygii, 68, 69 advent of, 62 ancestral to amphibians, 237 characters of order, 237 evolution of, 237 in Iowa Devonian, 48 list of, 276, 280, 285, 287, 288, 290 relations to Dipnoans, 237 remains of, 236 resemblances to Labyrinthodonts, 65 Crushed stone, production of, 23, 24 Ctenacanthus, characters of genus, 102 post-Devonian species, 155 Ctenacanthus acutus, 156 angulatus, 156 brevis, 155 (?) burlingtonensis, 156 canaliratus, 156 chemungensis, 154, 287 clarki, 155, 283 compressus, 283 costatus, 156 coxianus, 156 cylindricus, 156 decussatus, 156 deflerus, 155, 156 depressus, 156 excavatus, 156 gemmetus, 156 gradocostatus, 156 gurleyi, 156 harrisoni, 156 keokuk, 156 littoni, 156 longinodosus, 156 lucasi, 156 pellensis, 156 randalli, 154, 287 sculptus, 156 semicostatus, 156 similis, 156 solidus. 155, 156 speciosus, 154 spectabilis, 155, 156 varians, 155, 156 venustus, 156 vetustus, 155, 283 wrighti, 153, 276 xiphias, 156 372 INDEX Ctenodipterini, 69 characters of order, 207 list of, 212, 279, 282, 285 286, 288, 289 relations of, 165 relations to Lung-fishes, 208 een oe era, characters of family, Ctenodus, relations of, 211 Ctenodus fleischeri, 225 sherwoodi, 226 wagneri, 212, 213, 285 Cuba sandstone, New York, fish re- mains from, 288 “Cuboides zone” of Devonian, Mani- toba, fish remains from, 277, 279 Culm beds, Thuringia, phosphatic con- cretions from, 266 Cumberland, Maryland, fish remains from, 150 Curbing, production of, 23, 24 Cuyahoga county, Ohio, fish remains from, 283-285 Cyathaspis, 72, 73 Cyathaspis acadica, 72 Cyclostomes, 69 characters of, 70 occurrence of, 71 Cyrtacanthus, 119 Cyrtacanthus dentatus, 149, 278 D “Dakotan” sea, 45, 94, 215, 225, 235 Darwin, C., cited, 39, 44 Dasyatis say ?, 218 Davenport beds, 47 Davis, J. W., cited, 129, 151 Dawson, J. W., cited, 261, 262, 263, 266 De Koninck, L., cited, 111 De la Beche, mentioned, 150 Dean, B., acknowledgments, 291 cited, 61, 73, 98-100, 118, 118, 119, Pal, ale, arirS lA) alpy 18355. ali). 159, 165, 169, 177-180, 188, 189, 190, 194, 209, 217, 247, 265, 266 271 Delaware, Ohio, fish remains from, 278, 283, 285 Delaware county, New York, fish re- mains in, 92-94, 151, 212, 226, 241, 287-289 Delaware limestone, Ohio, fish remains in, 114, 124, 143, 146, 175, 203, 240, 277-279 Delhi, New York, fish remains from, 239, 240 Delphi, New York, fish remains from, 198 Dendrodus arisaigensis, 276 Derbyshire, England, fish remains from, 228 Dermal armor, Arthrodiran, 286 Dermal armor, Dinichthyid, 281 Dermal plates, tuberculated, 149 Des Moines, Iowa, topographic map- ping near, 4 Devon Point, Colorado, fish remains from, 94, 286, 287 Devonian age, fishes in, 61, 62 Lung-fishes of, 157 Ostracophores in, 171 Devonian Ctenodipterines, list of, 212 Devonian fishes, systematic account of, 70 Devonian fishes of Iowa, 33 Devonian land, 45, 94 Devonian system, fish remains in, 48, 72, 74, 83, 91, 92, 94, 97, 100, 104- 107, 110, 111, 114, 117, 119, 1382, 185, 143, 150, 152, 167, 175, 176, 186, 200, 20%) 212) 2205 225: (2270) ol eee 238-240, 242, 247, 255, 275 Devonian system of Iowa, stratigraphy of, 45 fish-remains in, 48 Dictyorhabdis priscus, 119 Dinichthyid, dermal armor of, 281 Dinichthys, 158 characters of genus, 188 comparison with Dinomylostoma, 178 dentition of, 189 development of, 164 homologies with modern Lung- fishes, 189 in Wapsipinicon beds, 48 mandible of, 191 relations to Coccosteus, 188 relations to Mylostoma, 179 relations to Titanichthys, 203 —v se Se Se ee ee ee Es es a eee eee _— Dinichthys sp., 282, 289 canadensis, 279 clarki, 284 curtus, 200, 284, 287 dolichocephalus, 281 gouldi, 284 gracilis, 284 halmodeus, 191, 201, 278 relations to Brachydirus, 187 herzeri, 193, 194, 198, 288 descended from Coccosteus, 195 specialization of, 188 INDEX 37: Oo Dipnoans, 62, 68, 157 advent of, 62 dentition of, 180 development of, 164 list of, 208 relations of, 208 Dipterines in Iowa Devonian, 48 Dipterus, absence of ossified centra in, 147 characters of genus, 210 in Iowa Devonian, 49 occurrence of, in Paleozoic, 231 ingens, 283 relations of, 211 ‘intermedius, 179, 193, 195, 199, 200, two types of, 214 284 Dipterus alleghaniensis, 233, 288 kepleri, 283 lincolni, 191, 193, 278 minor, 284 newberryi, 198, 281 precursor, 199, 278 prentis-clarki, 284 angustus, 289 calvin, 49; 213, 219; 220, 221, 279 contraversus, 212, 289 costatus, 218, 219, 220, 221, 286 digitatus, 213, 219, 221, 286 flabelliformis, 213, 221, 223, 224, 288 pustulosus, 49, 194, 198, 278, 281, 286 a type form, 214 ancestral to D. intermedius, etc., fleischeri, 212, 225, 289 195 ithacensis, 212, 213, 282 comparison of, with Neoceratodus, laevis, 223 . 196 levis, 213 ringuebergi, 281 terrelli, 198, 284 specialization of, 188 tuberculatus, 199, 279 (?) 286, 288 variety of D. nelsoni, 214 minutus, 213, 223, 288 variety of D. nelsoni, 214 mordax, 218, 219, 220, 222, 223, 225, Dinomylostoma, characters of genus, 286 177 development of, 164 Dinomylostoma beecheri, 177, 282 Diplacanthidae, advent of, 53 range of, 112 Diplacanthus horridus, 280 striatus, 280 Diplodus, characters of genus, 104 Diplodus, sp. ind., 286 priscus, 104, 286 striatus, 105, 286 Diplognathus, dentition of, 181 Diplognathus mirabilis, 285 Diplurus, geological range of, 242 Dipneusti, 62, 69 characters of subclass, 157 relations of, 215 murchison, 226 nelsoni, 213, 221, 228, 224, 288 a type form, 214 pectinatus, 213, 222, 286 quadratus, 213, 223 variety of D. nelsomi, 214 radiatus, 212 sherwoodi, 212, 226, 289 uddeni, 213, 215, 218, 222, 225, 279 valenciennesi, 210, 227, 234 Dog-fishes, 97 Doliodus, 100 Doliodus problematicus, 275 Dollo, L., acknowledgments, 291 cited, 96, 122, 124, 127, 129, 165, 180, 208, 237 374 INDEX Dorsal fin-spines, 138 Downtown beds, Great Britain, verte- brate life in, 53 Drain tile, production of, 19 Drepanaspids, relations of, 160 Drevermann, F., cited, 57 Dubuque, Iowa, lead and zine from, 26 Dubuque county, Iowa, crushed stone roads in, 3 Ductus endolymphaticus, 176 E Ears of Rhadinichthys deani, 269, 272 East Lothian, Scotland, fish remains from, 274 Hastman, C. R., cited, 73, 84, 92-94, 104-106, 108, 113, 128, 124, 127, 131, 133-185, 138, 139, 142, 143, 146, 150- 154, 161, 169, 175, 177, 184, 186, 191, 193, 194, 198-201, 218-223, 225, 226, 231, 233, 247, 258 work of, on Devonian fishes of Iowa, 4 Hezematolepis pustulosus, 142 Edinburgh, Scotland, fish remains from, 60 Hel-shaped fishes, decadent forms, 254 Eels, occurrence of, 254 Egerton, P. G., cited, 261 Hichwald, cited, 228 Hifel District, Prussia, fish remains from, 128, 167, 176, 177, 225-227, 240 Highteen Mile Creek, New York, fish remains from, 278, 281, 282 Elasmobranchii, 68, 69 characters of subclass, 95 dermal plates of, 149 hyostyly in, 66 list of, 275, 276, 280-282, 286, 287, 289 origin of, 71 Silurian, character of, 59 Elbert formation, fish remains in, 94, 110, 285, 286, 287 Elgin, Scotland, fish remains from, 228 Elmhurst, Illinois, fish remains from, 105, 135; 286 Elonichthys, characters of genus, 273 Elonichthys browni, 274 “eye” of, 266 elegantulus, 274 striatulus, 273 England, fish remains in, 104, 228 231, 242 Enniskillen, Lord, mentioned, 244 Enteropneusta, characters of, 52 Eocene, fishes in, 64, 255 Erian group, fish remains in, MT ae 154, 193 Hrie county, New York, fish remains from, 260 Erie county, Ohio, fish remains from, 285 Erie shale, Ohio, list of fossil fishes from, 282 Hrismacanthus barbatus, 149 Eskdale, Scotland, fish remains from, 261 . Etheridge, R., Jr., cited, 225, 227, 275 Euomphalus bed, Iowa, fish remains from, 219 Euphaneropidae, 69 Euphanerops longaevus, 74, 280 Europe, fish remains from, 207, 240 Hurylepis from Waverly beds, 260 Eusthenopteron, 236 Eusthenopteron foordi, 280 Evolution, effect of, on paleontology, 40 Evolutionary history of fishes, 51 F Fairport, Iowa, fish remains from, 213, 220, 279 Falls of the Ohio, fish remains from, 141 Faunal lists of fossil fishes, 275 Fayette breccia, 47 Fertile, Iowa, peat briquetting plant near, 28 Fin-spine, undetermined, 281 Fin-spines, dorsal, 138 origin of, 59 Fins, character of, in Pleuropterygii, 98, 99 evolution of, 67, 68 origin and development of, 59, 68, 65, 67 ~ eee — a ee INDEX Fire brick, production of, 19 Fischer, Moritz, cited, 265 Fish remains in Devonian of Iowa, dis- tribution of, 48 Fishes, advent of, 53 characters of, 95 classification of, 65, 67, 69 development of, 64, 67 Devonian, of Iowa, 33 systematic account of, 70 work of C. R. Eastman on, 4 evolutionary history of, 51 fossil, lists of, 275 origin of, from Enteropneusta, 52 Silurian, character of, 59 Flagging, production of, 28, 24 Foerste, A. F., cited, 265 Fossil fishes from Lower Devonian of North America, list of, 275 from Middle Devonian of North | America, list of, 276 from Upper Devonian of North America, list of, 280 Fourmaier, P., cited, 227 France, fish remains in, 104 Frankfort, Germany, fish remains at, | 167 Franklin, New York, fish remains | from, 131, 241, 287-289 Franklin county, Ohio, fish remains | from, 285 Frech, cited, 275 Friendship, New York, fish remains | from, 155 | Fritsch, mentioned, 101 Fuels of Iowa, investigation of, 1 Furbringer, K., cited, 165, 186, 208 G Gamphacanthus, 137, 138 Gamphacanthus politus, 138 “Ganoids’, 66 characters of, 236 Paleozoic, absence of ossified centra in, 147 Ganorhynchus beecheri, 213, 214, 225, 288, 289 suessmilchi, 235 | | similarity of, to Scaumencia, 227 Garman, S., cited, 137, 142 ; Garpike, 63 370 Gas, natural, in Iowa, 2 Gaskell, W. H., cited, 74 Gaspe, Quebec, fish remains from, 275, 276 Gaspe series, fish remains in, 114, 276, 278 Genesee Black shale, fish remains in, AeA Shel Oy L985 90s 20a 208, Pt, PUD, PM, AS Geneva, New York, fish remains from, 278 Genundewah, New York, fish remains from, 198 Germany, fish remains in, 104, 119, 167 Gerolstein, Prussia, fish remains from, 246 5 Gill, Theodore, mentioned, 159 Girty, G. H., cited, 110, 265 Glen Park, Missouri, fish remains from, 138, 149 Glen Park limestone, fish remains from, 137, 149 Glenville, New York, fish remains from, 260 Glyptaspis, dentition of, 181 relations to Mylostomids, 207 Glyptaspis abbreviata, 282 verrucosa, 285 Glyptolepis quebecensis, Holoptychius, 238 Glyptopomus sayrei, 290 Goethe, cited, 29, 32, 33, 70 Goniatite limestone, New York, list of fossil fishes from, 281 Gorgonichthys clarki, 284 Gravels, Iowa, ages of, 3 production of, 13, 26 quality of, for road materials, 3 uses of, on roads, 3 Greenland, fish remains from, 239 Grundy: county, Illinois, fish remains from, 254 Grundy county, Iowa, work in, 4 Gudger, E. W., cited, 218 Gurich, cited, 188 Gypsum, production of, by years, 13 classified, 27 Gyracanthides, 113 Gyracanthides murrayi, 114 relations to 376 INDEX Gyracanthus, 61 character of genus, 114 Gyracanthus incurvus, 114, 276 primaevus, 114 Sherwoodi, 114, 117, 287, 289 H Hackberry beds, 47 Haeckel, mentioned, 157 ‘Haemal arches in Coccosteus, 185 Hag-fishes, 70 Hall, James, cited, 239 Hamilton series, correspondence of, with Cedar Valley, 46 fish remains in, 107, 109, 114, 126, 134, 137, 139, 140, 142, 144, 154, 198, 204, 207, 240, 241, 276-279 Haplistia, 69 Harpacanthus, 119, 150 Harvard museum, see Museum of Comparative Zoology Hawkesbury formation, New South Wales, fish remains in, 104 Hay, O. P., cited, 104, 109, 110, 113, 160, 275 Helderberg beds, 83 Helderbergian series (?), Nova Scotia, fish remains from, 276 Heliodus lesleyi, 213, 288 Helodus comptus, 112 gibberulus, 112, 287 Hemlock Lake, New York, fish remains from, 260 Hennig, E., cited, 169, 175, 176 Herefordshire, England, fish remains from, 58 Heteracanthus, 137 characters of genus, 138 in Iowa Devonian, 49 Heteracanthus politus, 138, 277, 281 uddeni, 139, 277 Heterostraci, 69 divisions of, 55 occurrence of, 72 High Point sandstone, New York, list of fossil fishes from, 132, 287 Hinde, G. J., cited, 53 Hinds, Henry, work of, on coal, 1 Hoats, J. H., mentioned, 147 Holauchenia, 160 Holocephali, 68, 69 characters of subclass, 117 dermal plates of, 149 Holonema, dentition of, 181 relations to Mylostomids, 206 3 Holonema horridum, 206, 288 rugosum, 92, 206, 288, 289 Holoptychiidae, characters of family, 238 Holoptychius, 117, 236, 238 scales of, 279 Holoptychius americanus, 92, 239, 288, 290 filosus, 239, 288 flabellatus, 239 giganteus, 239, 287, 288, 290 granulatus, 239, 288 halli, 239, 290 latus, 239 pustulosus, 239, 288 quebecensis, 280 radiatus, 290 serrulatus, 239 tuberculatus, 239, 287, 289 Homacanthus, characters of genus, 151 Homacanthus acinaciformis, 151, 287 delicatulus, 152 gracilis, 152, 276 Homosteus, development of, 163, 164 relations of, 167, 171 Hoplonchus parvulus, 152, 283 Hunsruck slates, Prussia, Ostraco- phores from, 54 ’ Huron shales, Ohio, fish remains in, 109, 282, 288, 285 Hussakof, L., cited, 124, 131, 146, 161, 166; D7, 9) Akos Sie VO Sseenoae 198, 200, 225, 226, 239, 250, 275 Huxley, T. H., cited, 65, 66, 96, 208, 211, 237, 242, 243, 246, 251 Hydraulic limestone, Wisconsin, fish remains from, 198 “Hyostyly”’, 65, 96 Hyperoartia, 69 Hyperotreta, 69 : Ichthyodorulites, 150 “Tehthyopterygium” of fishes, 95 Ichthyotomi, 68, 69 characters of order, 1/01 j ee ee ee INDEX Illinois, fish remains from, 105, 135, 196, 250, 253, 277, 278, 285, 286 Independence beds, 45, 47 relation with Lime Creek beds, 49 Indiana, fish remains from, 175, 206, 278 Ionia, Iowa, gravel roads near, 3 Iowa, coals of, investigation of, 1 Devonian fish-bearing beds of, strat- igraphy of, 45 Devonian fishes of, 33 study of, 4 fish remains in, 107, 111, 134, 139, 140, 147, 152, 155, 196, 206, 213, 219, 220, 221, 2238, 231, 2338, 235, 241, 248, 252, 277-279, 285 geological maps of, 7 mineral production of, in 1907, 11 oil-rock of, 3 peat of, investigation of, 1 road materials of, 3 State University of, fish remains in museum of, 229 Iron, production of, 28 Isospondyli, 69 advent of, 64 Ithaca, New York, fish remains from, 155, 213, 282 Ithaca beds, New York, fish remains in, 143, 218, 282 J Jackson, C. T., cited, 257, 261 Jaekel, Otto, acknowledgments, 291 cited, 55, 74, 76, 81, 101, 102, 119, 121, 122, WAY, WA, eis aah), alta alka} 159 160) 167, 169; 170; 178, 184, 185, 186, 187, 191, 227 James Bay region, Canada, fish re- mains from, 278 Jefferson county, Missouri, fish re- mains from, 138, 149 Jeffersonville, Indiana, fish remains from, 206 Johnson, J. B., cited, 270 Johnson county, Iowa, fish remains in, 49, 50, 134, 135, 137, 139, 147, 196, 206, 213, 220, 221, 223, 231, 233, 235, 286, 287 Jordan, D. S., cited, 40, 52, 67, 70, 71, 161 377 Junction City, Kentucky, fish remains from, 265 Jurassic system, fish remains in, 211, 242 sturgeons in, 63 K Kashong creek, New York, fish re- mains from, 154 Kayser, E., mentioned, 167 Kellog, V. L., cited, 40, 41 Kentucky, fish remains in, 111, 135, Wd) as, i), we wey 260; 265, 273, 277, 279, 281, 283, 287 Kentucky State College museum, remains in, 260 Keokuk beds, Iowa, fish remains in, 156 Keuper beds, England, fish remains from, 104 Kinderhook beds, Iowa, fish remains in, 111, 138, 149, 152, 155, 156, 247, 248, 252 Knott, W. T., cited, 265 Koken, E., cited, 101 L 132, 206, 282, fish Lampreys, 70 Lanarkia, 57 “eye spots” of, 266 Lanarkia spinosa, 55 Lanarkshire, Ostracophores in, 58 Land vertebrates, descent of, from fishes, 62 Lankester, HE. R., cited, 41, 114, 161 “TLaurentia’’, 94 Lead and zinc, prices of, 27 production of, by years, 13 classified, 27 LeGrand, Iowa, fish remains from, 149, 152, 155 Lehder, Joh., cited, 266 Leidy, J., cited, 92, 98, 238 Lepidosiren, 157 relations of, 208 Lepidosteus, 63 Leptolepis, characters of, 64 Leriche, M., cited, 53, 73 LeRoy, New York, fish remains from, 133, 143, 146, 175, 240, 276-278, 281 Leroy, Pennsylvania, fish remains from, 212, 287-289 | 378 INDEX Lesley, J. P., cited, 258, 261 Leuckart, mentioned, 157 Lexington, Kentucky, fish remains in museum, 260 Liege, Belgium, fish remains from, 200 Lime, production of, 23, 24 Lime Creek shales, Iowa, 45 fish remains from, 49, 134, 286 Lime Rock, New York, fish remains from, 277 Limestone, production of, by counties, 24 classified, 23 Lindahl, J., cited, 139 Linn county, Iowa, fish remains in, 48 gravel roads in, 3 Liognathus spatulatus, 186, 278 relation to Protitanichthys, 202 Livingston county, New York, fish re- mains from, 179, 240, 260, 282 Livonia, New York, fish remains from, 278 Loess, work of B. Shimek on, 4 Logan, mentioned, 114 Logan Water, Scotland, fish remains from, 55 Longworth, W. N., mentioned, 111 Loraine county, Ohio, fish remains from, 106, 282-285 Louisville, Kentucky, fish remains from, 111, 1385, 179, 198, 206, 279, 281, 282 Lower Carboniferous series, fish re- mains from, 261, 262, 273 Lower Devonian series, list of fossil fishes from, 275 Sirenoids in, 157 Lucas, F. A., cited, 161 Ludlow beds, 73 vertebrate life in, 53 Lung-fishes, 95, 157 autostyly in, 65 Devonian, absence of ossified centra in, 147. homologies of Dinichthys with, 189 in Iowa Devonian, 48 © modern, relations of Ctenodipterines to, 208 Luther, D. D., cited, 258 M Machaeracanthus, 112, 113 Machaeracanthus longaevus, 114, 278 major, 278 peracutus, 277 sulcatus, 114, 276, 278 Macropetalichthyidae, characters of family, 167 Macropetalichthys, characters of ge- nus, 168 cranial structure, 170, 171 development of, 163, 164 distribution of, 167 Macropetalichthys agassizi, 175 hoeninghausti, 175 mannii, 168 pelmensis, 176 rapheidolabis, 168, 278 sullivanti, 168 “Macrophage” dentition, 180 Macropoma, geological position of, 242 Maine, fish remains in, 75, 83, 275 Mandible of Dinichthys, 190 Manitoba, fish remains from, 135, 207, 2, 209 Manlius, New York, fish remains from, 278 Mansfield, Pennsylvania, fish remains from, 289 Maps, geological, of Iowa, 7 topographic, necessity of, 4 Marcellus beds, New York, fish re- mains from, 117, 193, 194, 241, 276, 278 Marion county, Kentucky, fish re- mains from, 265 c Marsh, O. C., mentioned, 111 Marsipobranchs, characters of, 70 Martin, Karl, cited, 256 Maryland, fish remains from, 150 Mason City, Iowa, cement plant at, 28 Mazon creek, Illinois, fish remains from, 254 McCoy, mentioned, 158, 227, 228, 234 McGill University, fish remains in mu- seum, 264 Meadville, Pennsylvania, fish remains from, 109, 112, 287 Meadville Upper Shale, Pennsylvania, fish remains from, 109, 112 INDEX Mesacanthus, 61 Mesacanthus mitchelli, 60 Mesozoic period, fishes in, 255 Sturgeons in, 63 Meunier, S., and Combes, Paul, cited, 266 Middle Devonian series, list of fossil fishes from, 276, 279 ‘of Iowa, 45 fish remains in, 48 Miller, A. M., acknowledgments, 291 Miller, Hugh, mentioned, 207, 211 Miller, S. A., cited, 104, 188, 142, 207, 261 Milo, New York, fish remains from, 281 Milwaukee, Wisconsin, fish remains from, 109, 114, 126, 139, 140, 143, 144, 198, 204, 207, 240, 276-279 Mineral production of Iowa, by years, 13 classified, 14 Mineral water, production of, by years, 13 classified, 27 Mississippi valley, oil rock of, 3 Mississippian series, fish remains in, 104, 137 Missouri, fish remains in, 135, 149, 277 Missouri Iron Company, work of, 28 Mollier, S., cited, 100 Monocladodus elarki, 283 pinnatus, 283 Monroe, Charles E., mentioned, 108 Moscow, Russia, fish remains from, 112 Moscow shales, New York, fish remains in, 154, 276 Mount Morris, New York, fish remains from, 179, 282 Muller, Fritz, cited, 183 Muller, J., mentioned, 157 Munster, Count, mentioned, 245 Murrumbidgee, New South Wales, fish "remains from, 225 Muscatine county, Iowa, fish remains in, 49, 134, 213, 220, 238, 235, 286 379 Museum of Berlin University, fish re- mains in, 177 Museum of Comparative Zoology, 49, 106, 126, 141, 148, 149, 155, 175, 203, 205, 206, 220, 224, 227, 241, 253, 260, 261, 265 Mylostoma, characters of genus, 179 comparison with Dinomylostoma, 177 development of, 164 relations to Dinichthys, 179 Mylostoma newberryi, 180, 285 terrelli, 180, 285 variabile, 162, 172, 180, 285 Mylostomatidae, characters of family, Hie dental structure of, 163 relations to Glyptaspis, 207 to Holonema, 206 Myriacanthus, 121, 126, 149 Myxinoidea, 69, 70 N Naples, New York, fish remains from, 135, 281, 287 Naples shale, New York, fish remains in, 139, 179, 199, 257, 260, 281, 282 Nassau, fish remains from, 187 Needles Mountain, Colorado, fish re- mains from, 110, 286 Neoceratodus, 157 comparison of dentition of, with Dinichthys, 190° relations of, 165, 208 to Arthrodira, 162 to Macropetalichthys, 170 Neoceratodus forsteri, 197 Nerve endings of Rhadinichthys deani, 272 Neural arches in Coccosteus, 185 New Albany shale, Kentucky, fish re- mains in, 111, 135, 179, 198, 206, 279, 281, 282 New Brunswick, fish remains from, 72, 100, 114, -152, 257, 261, 262, 278, 275, 276 New South Wales, fish remains from, 104, 225 380 ; INDEX New York, fish remains from, 92, 94, 100, 113, 114, 117, 132, 1838, 135, 139, 143, 146, 151, 154, 155, 175, 179, 186, 198, 194, 198-200, 206, 212, 225, 226 239, 240, 241, 257, 260, 276, 277, 278, 279, 281, 282, 287, 288, 289, 290 New York State Museum, 117, 131, 139, 148, 225 Newberry, J. S., cited, 92, 93, 106, 109, 117, 128, 124 1383, 1388, 141, 144, 145, 151-154, 159, 160, 168, 170, 175, 181, 198-200, 207, 211, 223-226, 231, 239, 241 Newberry and Worthen, cited, 133 Niagara series, fish remains in, 72, 150 vertebrate life in, 53 Nictaux Falls, Nova Scotia, mains from, 275 Nile, New York, fish remains from, 155 North America, fish remains in, 104, 119, 150 list of fossil fishes from, 275 North Evans, New York, fish remains from, 282 North Liberty, Iowa, fish remains from, 50; 134, 1135, 137; 139) 206) PAB) PRL Apa 2ePAS Weil, P83, 2B 286, 287 Northwestern States Portland Cement Company, plarit of, 28 Norton, W. H., acknowledgments, 291 cited, 49, 134 work of, on artesian waters, 4 Norwood and Owen, cited, 168 Notidanus, 66 Nova Scotia, fish remains from, 234, fish re- 25, 276 Novgorod, Russia, fish remains from, 147 10) Oestophorus, 207, 279 “Ohian” sea, 45, 215 Ohio, fish remains from, 100, 106, 108, 1109, 114, 124, 133, 135, 143, 146) 149, 175, 180, 186, 200, 201, 2038, 204, 213) 231, 282-285 240, 250, 276-279, |. Ohio shale, Ohio, list of fossil fishes from, 282 Oil rock, use of, as fuel, 2 Old Chickasaw, Iowa, gravel roads near, 3 Old Red Sandstone, Scotland, 73 fish remains from, 210, 226, 234, 236, 238, 256 Olean conglomerate, Pennsylvania, fish remains in, 154, 287 Onchus, characters of genus, 150 Onchus sp., 276 rectus, 150, 289 Oneonta beds, New York, fish remains in, 198, 278, 281 Onondaga county, New York, fish re- mains from, 241 Onondaga limestone, fish remains from, 133, 143, 146, 175, 186, 202, 240, 277, 278, 279 Ontario, fish remains from, 277, 278 Ontario county, New York, fish re- mains from, 194 Onychodontidae, characters of family, 240 Onychodus, 236 characters of genus, 240 Onychodus sp., 279 hopkinsi, 241 ortoni, 285 sigmoides, 240, 279 Oracanthus abbreviatus, 142 fragilis, 142 granulatus, 142 Oran, New York, fish remains from, 241, 279 Ordovician system, fish remains in, 75, 119 vertebrate life in, 53 Oriskany beds, 83 Oriskany sandstone, Nova Scotia, fish remains from, 275 Orkney, Scotland, fish remains from, 234 Orodus, 153 Osteolepis sp., fragments of, 288 Osteostraci, 69, 72 classification of, 56 occurrence of, 74 ! ee ee ee a a : INDEX 381 Ostracoderms, advent of, 71 ‘characters of, 72 _ in Silurian, 53 list of, 275, 276, 280, 285, 287, 289 relations of, 165 skeleton of, 57 Ostracophores, 69, 157 advent of, 71 character of, 54, 72 classification of, 55, 72 habits of, 54 history of, 54 relations of, 160 skeleton of, 57 see Ostracoderms Otis limestone, Iowa, 47 Ouray limestone, Colorado, mains in, 110, 286 Owen, Norwood and, cited, 168 Owen beds, Iowa, 47 Oxford, New York, fish remains from, 198, 281 fish re- P Paleaspis, 72 Palaeaspis americana, 73 bitruncata, 73 sericea, 73 Paleomylus, 119, 120 fin spines accompanying, 142 Palaeomylus crassus, 128, 144, 277 frangens, 144, 277 greenei, 128, 144, 178, 277 Paleoniscidae, characters of family, 256 history of, 255 Paleozoic, absence of ossified centra in, 147 3 Palaeoniscus alberti, 261 antiquus, occurrence of, 257 cairnsti, 261 carinatus, 258 devonicus, 258 occurrence of, 257 modulus, 262 - ornatissimus, 258 reticulatus, occurrence of, 257 wardi, 258 Paleontology, character of, 33 Palexophichthys, characters of genus, 252 26 Palaeophichthys parvulus, 253 Palzospondylus, 70 Paleozoic system, Lung-fishes of, 157 Pander, C. H., cited, 79, 120, 147, 184, 208, 211, 226-228, 237 Parasphenoid of Dipnoans, 174 Parker, G. H., cited, 271 Special description of auditory or- gans and other soft parts of Rha- dinichthys deani, 272 Parker, Balfour and, mentioned, 208 Parrish limestone, New York, list of fossil fishes from, 281 Pascal, cited, 43 Passage beds of France, vertebrate life in, 53 Patten, Wm., cited, 55, 71, 74, 76, 84- S30 D5 WO, Aral Paving brick, production of, 19 Paving stone, production of, 23. 24 Peabody Museum of Natural History, 155, 178, 224, 234, 236 Peat, Iowa, investigation of, 1 production of, 28 Pelm, Germany, fish remains from, 177 Pennsylvania, fish remains from, 73, 92, 94, 109, 112, 114, 117, 152, 154, heel Ci amee OOne2 Ole s20 Gre 2dlaey2las 224-226, 239, 260, 279, 284, 287-290 Peplorhina, occurrence of, 250 Permian system, fish remains from, 61, 104, 1638, 211, 242 Sturgeons in, 63 Perry county, Pennsylvania, fish re mains in, 73 Phaneropleuron, 165 fins of, 210 form of, 254 °* Phlyctaenacanthus, 142 characters of genus, 143 Phlyctaenacanthus iclleri, 141, 143, 277 Phlyctaenaspis acadica, 188, 276 Phoebodus, characters of genus, 105 Phocbodus macisaacsii, 106 politus, 106, 282 Pholidophorus, characters of, 64 Pholidosteus, 178 Pholidosteus friedelii, 188 Phosphate nodules, Kentucky, fish re- mains in, 265 382 INDEX “Phragmoceras beds’, 48 Phyllolepis delicatula, 207, 288 Physichthys, 168 Physichthys hoeninghausii, 175 Physonemus, 140 Physonemus hamus-piscatorius, 149 pandatus, 149 Pisces, characters of class, 195 classification of, 68, 69 Placodermata, use of term, 159 “Placodermi”, 158 “Placoderms’’, 142, 158, 161 Placoid covering, 95 Placothoraxz agassizii, 168, 175 Plaster of Paris, production of, 27 Platteville, Wisconsin, oil rock of, 2 Platteville limestone, oil rock of, 3 Platysomidae, relations of, 255 Pleistocene gravels of Iowa, study of, 6 Pleuracanthidae, characters of family, 103 Pleuracanthus, 66, 101 characters of genus, 103 Pleuracanthus decheni, 102 Pleuropterygii, 68, 69 characters of order, 97 Poincare, cited, 43 Polyodontidae, degeneration of, 256 Polypterus bichir, 245 Portage beds, New York, fish remains from, 100, 113, 135, 139, 142, 179, 199, 206, 213, 241, 257, 260, 277, 278, 281, 282 Portland cement, production of, 28 Pottery, production of, 19, 22 Powell county, Kentucky, fish remains from, 279, 283 Poweshiek county, Iowa, work in, 4 Protitanichthys, characters of genus, 201 relations with Titanichthys, 202 Protitanichthys fossatus, 201, 278 Protochordata, characters of, 52 Protodus, 100 Protodus jexi, 275 Protopterus, 157, 159 relations of, 208 Protospondyli, 69 characters of, 63 Prussia, fish remains from, 119, 167, 176, 177, 225-227 Ostracophores from, 54 Psammites de Condroz, Belgium, fish remains from, 200 ? Psammodes antiquus, 276 Psammosteidae, 69 classification of, 55 Psammosteus, 142 Pteraspidae, 69 classification of, 55 relation of, 159 Pteraspis, 58 Pteraspis rostrata, 73 Pterichthys, 75 armor of, 58 characters of genus, 76 Pterichthys canadensis, 84 milleri, 77 rhenanus, 168 Ptycholepis, resemblance of, to Elon- ichthys, 274 Ptychopterygium, 100 Ptyctodonts, dermal plates of, 149 detached parts of, 138, 1438 enemies of Dipterines, 217 in Iowa Devonian, 48 vertebral centrum accompanying, 148 Ptyctodus, characters of genus, 133 fin-spines accompanying, 139 relations of, 120 Ptyctodus sp., 281 calceolus, 128, 133, 137, 277, 281, 286 in Lime Creek beds, 49 in Sweetland Creek beds, 50 in Wapsipinicon beds, 48 compressus, 135, 286 eastmani, 187, 149 ferox, 128, 185, 277, 286 punctatus, 1383, 277 O Quebec, fish remains in, 74, 83, 91, 213, 236, 256, 275, 276, 278, 280 R Railway ballast, production of, 23, 24 Ramphodus, 121 — => as INDEX 383 Randall, F. A., mentioned, 214, 260 Rays, characters of, 95 Redfield collection, Yale, 257, 261 Redpath Museum, McGill, fish remains in, 264 Regan, C. T., cited, 67, 160 “Reorganizing ideas’, 36 Retzius, cited, 270 Rhadinichthys, characters of 257 Rhadinichthys sp., 260 alberti, 261 antiquus, 282 cairnsi, 261 deani, 264 devonicus, 258, 282 elegantulus, 260 modulus, 262 reticulatus, 282 “Rhamphodus”, 121, 145, 146 Rhamphodus tetrodon, 126, 127 Rhineland, Germany, fish remains from, 227 Rhinestreet shale, New York, fish re- mains in, 113 Rhinochimaera, 143 Rhipidistia, 69 Rhynchodus, 119, 120, 136, 149 characters of genus, 123 dermal plates of, 144 fin-spines accompanying, 139, 142 in Iowa Devonian, 48 Rhynchodus sp., 132, 277, 281, 287 emigratus, 127 excavatus, 124, 127, 132, 145, 277 major, 127, 132, 146 occidentalis, 124 pertenuis, 131, 287 rostratus, 127 secans, 123, 128, 131, 145, 277 Riprap, production of, 23, 24 Roadmaking, stone for, production of, 23, 24 Roads, gravel, advantages of, 6 genus, Rock Island, Illinois, fish remains from, 49, 196 Rockwood, Colorado, fish remains from, 94, 285 Rocky river, Ohio, fish remains from, 282-284 Rohon, mentioned, 139 Rubble, production of, 23, 24 “Ruderorgan” of Coccosteus, 185 Russia, fish remains from, 112, 119, 147, 1638; 226, 228 S Sagenodus angustus, 212 pertenuis, 163 St. John, O. H., cited, 49, 126, 194 St. John and Werthen, cited, 106 St. Louis beds, Iowa, fish remains in, 156 Salina beds, fish remains in, 73 Sand and gravel, production of, by counties, 26 by years, 13 Sand-lime brick, production of, by years, 13 classified, 28 Sandstone, production of, 23 Sauripteris taylori, 290 Sauripterus, 236 Sauripterus taylori, relations to Rhiz- odonts, 238 Savage, T. E., mentioned, 49 Scat Craig, Scotland, fish from, 228 Scaumenac Bay, fish remains from, 74, 91, 213, 236, 256, 280 Scaumenacia, absence of ossified cen- tra in, 147 characters of genus, 235 relations to Arthrodires, 235 to Dipterus, 235 Scaumenacia curta, 213, 235, 280 Schuchert, Charles, acknowledgments, 291 mentioned, 45, 111, 196, 224, 257 Schwalbe, G., cited, 270 Scombroids, 64 Scotland, fish remains in, 55, 60, 104, 210, 226, 228, 231, 234, 236, 238, 246, 250, 256, 258, 261, 273 Ostracophores from, 54 Seott county, Iowa, fish 48-50, 213, 219 Selachii, 68, 69 Selenosteus kepleri, 285 Senckenburg Museum, Frankfort, Ger- many, 167 remains remains in, 384 INDEX Senecan group, New York, fish remains in, 198, 199, 281 : Sensory canals of Protitanichthys, 202 Sewer pipe, production of, 19 “Shagreen”, 66, 95 Sharks, characters of, 95 Paleozoic, spines of, 152 “Shear teeth” in Dinichthys, 190 Sheffield, Ohio, fish remains from, 283, 285 Sherborn, C. D., cited, 275 Shimek, B., work of, on loess, 4 Silurian system, fish remains in, 59, 72 Ostracophores in, 71 vertebrate life in, 53, 150 Sirenoidei, 68, 69 in Devonian, 157 Skeleton, structure of, in classification, 66 Solon, Iowa, vertebral centrum from, 147 Sonrel, plates by, 257 Sparta, New York, fish remains from, 118, 257, 260, 281, 282 Sphenodon, development of, 165 Sphenophorus sp., 279 lilleyi, 207, 288 Spine-finned fishes, development of, 64 Spitzbergen, fish remains from, 239 Spyrna zygaena, food habits of, 218 Stafford, New York, fish remains from, 117 State Quarry limestone, Iowa, 46 fish remains from, 50, 134, 135, 137, IBS), POS, VIB, ally, PAO Pel P78}, 226, 231, 233, 235, 277, 286, 287 notice of fish-fauna from, 5 Stegocephalia, descent of, from fishes, 62 : Stenacanthus nitidus, 92 Stenognathus corrugatus, 284 Stenosteus glaber, 285 Stethacaninus, 140, 141, 143 Stone, crushed, use of, as road ma- terial, 3 Stone, production of, by counties, 14, 24 by years, 13 classified, 23, 24 Stookey, S. W., work of, 4 Stratigraphy of Devonian fish-bearing beds of Iowa, 45 Strepsodus sp., tooth of, 288 Strong collection of fossils, 253 Sturgeon Point, New York, fish re- ‘mains from, 179, 281 Sturgeons, characters of, 63, 255 ‘Styliola beds, New York, fish remains from, 198 Suess, E., cited, 44 Susquehanna river, Pennsylvania, fish remains from, 290 Sweetland Creek shales, Iowa, 46 fish remains from, 50, 134, 233, 235,. 286 Synthetodonts, in Iowa Devonian, 48 Synthetodus, characters of genus, 231 Synthetodus calvini, 213, 233, 287 trisulcatus, 213, 231, 286 T Taine, cited, 38 Tamiobatis vetustus, 279 Taylor county, Iowa, work in, 4 Tectospondyli, 69- Teleostomi, 68, 69 characters of subclass, 236 relations of, 159, 160 scales of, 66 “Teleosts”, 66 characters of, 236 Teller, E. E., cited, 143 mentioned, 141 Temnauchenia, 160 Texas, fish remains from, 163 Thelodus, 57, .72 “eye spots” of, 266 scales of, 275 shagreen granules of, 276 Thelodus scoticus, 55 Thuringia, phosphatic concretions from, 266 Thyestes, 74 classification of, 56 INDEX Tioga county, Pennsylvania, fish re- mains from, 92, 212, 226, 289, 290- Titanichthys, characters of genus, 203 development of, 164 . relations to Dinichthys, 203 Titanichthys agassizti, 284 attenuatus, 284 brevis, 284 clarki, 285 rectus, 285 Tornquist, A., cited, 262 Trachosteus clarki, 285 Traquair, R. H., acknowledgments, 291 cited, 54-56, 60, 76, 77, 84, 85, 116, Hp abe 14 59) igs, 1845 188) 208, 210; 211, 227, 237, 256, 258, 266, 273, 274 Tremataspids, relations of, 159 Tremataspis, classification of, 56 Trenton limestone, fish remains in, 75 oil rock of, 3 Triassic system, fish remains from, 104, 211, 242 Protospondyli in, 63 Troy Mills, Iowa, gravel roads near, 3 Truxton Corners, New York, fish re- mains from, 143 Tully limestone, list of fossil fishes from, 281 U Udden, J. A., acknowledgments, 291 cited, 49, 218-220, 233 Ulsterian group, fish remains in, 107, 108, 133, 148, 203, 204 Undina, characters of, 245 geological position of, 242 United States, fish remains from, 273 United States Geological Survey, co- operative topographic work of, in Iowa, 4 tests of Iowa coals by, 1 United States National Museum, fish remains in, 259 385 Upper Devonian, fish remains in, 49, Ce Oe 4 1055 106) 135; 137%. 139) 147, 180, 200, 201, 204, 206, 213, 214, 220, 221, 223, 225, 231, 233, 235, 239, 241, 246, 256, 277, 279, 280, 288, 289 list of fossil fishes from, 280 of Iowa, 46 fish remains in, 48 Uronemus, 165 form of, 254 V Vanceburgh, Kentucky, fish remains from, 260 Vermillion .river, Ohio, fish remains from, 285 Vertebral centra of Devonian fish, 147 Vertebral column, development of, in fishes, 64, 98 Von Huene, F., cited, 127 Von Koenen, A., cited, 175, 187, 246 Von Meyer, H., cited, 175 Von Zittel, K., mentioned, 160, 187 WwW Waldeck, Germany, fish remains from, 128 Walker, Iowa, gravel roads near, 3 Walker Museum, University of Chi- cago, fish remains in, 252 Wapsipinicon stage, 45 fish remains from, 48 Warren, Peunsylvania, fish remains from, 152, 154, 200, 213, 260, 279, 284, 287-289 Warren county, Pennsylvania, fish re- mains from, 109, 155, 201, 213, 224, 225 Waterloo, Iowa, fish remains from, 49, 107, 12H, 137%, Bo) Waverly, lowa, fish remains from, 49, 120, iss), ae), Paley, PA By) Waverly beds, fish remains in, 100, 109, 112, 149, 260, 265, 273 Webster, C. L., mentioned, 50 386 Weller, S., acknowledgments, 291 cited, 104, 105, 111, 134, 137, 248 Wellsville, New York, fish remains from, 239 Wenlock beds, 73 Whiteaves, J. F., cited, 79, 84, 85, 117, 152, 207, 235, 238, 256 Wiedersheim, R., cited, 130 Wilder, F. A., work of, on coal, 1 work on peat under, 2 Wildungen, Germany, fish remains from, 128 Williams, H..S., cited, 84, 92, 206, 212, 2235 209 Williams, H. U., cited, 257 Wisconsin, fish remains from, 107, 109, 14 126; 135, 913%, 1395 140; 143° 144, 200, 204, 207, 240, 276-279 oil rock from, 2 Woodward, A. S., 291 cited, 44, 53, 54, 57, 58-60, 62, 65, 67, 18, US; 9, SEs 85, Oil, On, Qoaloll, INDEX BS aks Ghee alley ale alae). 126, 142, 145, 149-152, 158, 168, 186, 188, 234, 237-239, 241, 246, 247, 262, 275 Worth county, Iowa, peat briquetting plant in, 28 ; - Worthen, Newberry and, cited, 133 Worthen, St. John and, cited, 106 Worthington, Ohio, fish remains from, 283 Wright, A. A., cited, 200 xX Xenodus herzeri, 283 Y Yale Museum, see Peabody Museum Yates county, New York, fish remains © from, 154, 276, 281 ' Young, J., cited, 258 acknowledgments, | Z | Zinc, prices of, 26 production of, 26 ————— " ; 4 ap. el on ie ; 4 i | Me he Die. = a” yim 6 ipimr ens a - ee sat a & ’ > yy? ~\ 4 1aq@a a i ~ SN& > * mee ays ‘. a WL pone » Doren ren ahi 1] || tiled | heat af* eae, AXA aap sibdh , - SSA bole Pte ett a 4 a 7 . o> Na), AD, ante oun Seer Nanna - 9284509 ~. aa INN ew at & rt) at : tT 44). ep) x 15am oe panel erere gsAny | ar) Nasu? . a4 } i ‘a5. ee " a. bw - 2846 on ph e Wess: -~. 2° ,¥¥ Viae., Mg ms reel? aac aL te sat hw: * al a a ‘ ot TT a a” Ane er ne/ Tei OLE REAL yi tt ice a ee ag yt LA Aura S Dau je 7 f e° LL el ‘ 7) 9 rt ab * bing Sy pas ehy at Pen tangy - ia n oT yacr L ih Mone! 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