He was of the same opinion in 1900, namely that the teeth belong to fish and not to any invertebrate. In 1886, Rohon and Zittel decided that "conodonts have nothing in common structurally with the dentine of Selachia and other fishes, the horned teeth of Cyclostomi, the lingual teeth of MoUusca, the booklets of Cephalopods, or the broken segments of spines of Crustacea; on the other hand, both in form and structure, they are remarkably match the masticatory apparatus of Annelida and Gephyrea." They came to the conclusion that all these microscopic teeth, those which Hinde recognized as ringed and those which he called conodonts, were the oral oroesophageal teeth of worms, because this agreement exists. If, as I shall attempt to prove below, certain leaf-like forms are the teeth of the pavement, then the conclusion seems almost inevitable that the conodonts must be regarded as the teeth of some primitive species of fish.
In the recent paper on conodonts by Ulrich and Bassler, they are regarded as teeth and plates of primitive fish. Bryan-. todus^ Ulrich and Bassler; Ewprioniodina^ Ulrich and Bassler; Hib-. l)ardella, Ulrich and Bassler; Lonchodus Pander, 1856; Valentina Smith, 1907;. Polygnathus (Hinde) Bryant, 1921; Ancyrodella Ulrich and Bassler; Palniatole'pis Ulrich and Bassler; Panderodella Ulrich and Bassler;.
ACT.5 BIBLIOGRAPHY OF CONODONTS HOLMES 5. Clabk, Thomas H., Bulletin American Paleontology, vol. 10, no. Describes seven supposed species of conodonts,) 1925. v., Bibliography of conodonts and Paleozoic ring jaws. Upper Devonian, Rhinestreet Shale of the Portage Shaleton Group, Erie County, N. Upper Devonian, Rhinestreet Shale of the Portage Group, Shaleton, Erie County, N. Upper Devonian, Rhinesti'eet Shale of the Portage Group, Shaleton, Erie County, N. Ordovician, Arenig- Llandeilo, South Highlands of Scotland.
ABT..5 BIBLIOGRAPHY OF THE CONODONTS HOLMES 11
Possibly a species of Lonchodina, but Hinde's restoration does not match any of the species noted so far. Upper Devonian, Genundewa Limestone at the base of the Genesee, North Evans, Eighteen Mile Creek, New York. Devonian, Genundewa limestone, foothills of Genesee, North Evans, Eighteen Mile Creek, New York; Ulrich and Bassler, 1926 (p.
Upper Devonian, Genundewa Limestone at base of Genesee, North Evans, Eighteen MileCreek, N. Mississippian, Hardin Sandstone at base of Chattanooga Shale, Mount Pleasant, Tennessee, Upper Devonian, Genundewa Limestone at base of Genesee, North Evans, Eighteen MileCreek , N. Upper Devonian, Rhine Street Shale of Portage Group, Shaleton, Erie County, N. 3), Upper Devonian, Rhine Street Shale of Portage Group, Shaleton, Erie County, N.
ART, 5 BIBLIOGRAPHY OF THE CONODONTS HOLMES 17
2, 3, 13), Upper Devonian, Genundewa limestone at base of Genesee, North Evans, Eighteen Mile Creek, N, Y. 24, 25), Mississippian, Hardin sandstone at base of Chattanooga shale.
ABT,5 BIBLIOGRAPHY OF THE CONODOITTS HOLMES 19
Upper Devonian, Genundewa Limestone at the base of Genesee, North Evans, Eighteen Mile Creek, N. Upper Devonian, Genundewa Limestone at the base of Genesee, North Evans, Eighteen Mile Creek, N. Upper Devonian, Rhine Strait Shale of the Portage Group, Shaieton, Erie County, N. Ordovician, Dicellograptus Zone ), Southern Norway, Prioniodus angulatus Hinde.
AET.5 BIBLIOGRAPHY OF THE CONODONTS HOLMES 21
ART. 5 BIBLIOGRAPHY OF THE OONODONTS HOLMES 23
DESCRIPTION OF EARLY MISSISSIPPIAN SPECIES
ART. 5 BIBLIOGRAPHY OF THE CONODONTS HOLMES 25
The rest of the bar is occupied by narrow, more delicate serrations that decrease in size towards the extremities. The two prongs on one side of the bar are short and strong; on the other side there are three which are thin. The teeth are all similar, being delicate and needle-like, but the extensions are grouped at the front of the bar and the short ones at the back.
This species is characterized by a distinct curvature of the rod, the absence of a main tip, and two sets of sensitive teeth.
ART, 5 BIBLIOGRAPHY OF THE CON'ODONTS HOLMES 27 Genus PRIONIODINA Ulrich and Bassler, 1926
The wide, almost fiat band is traversed along its entire length by a median line. The top and bottom of the bar are thus in two. There is a wide space on each side of the cusp, which is round, very thick, and slightly extended below the bar. On the short side of the bar, the teeth are thinner than the others, but they have a fairly substantial appearance.
The short, narrow, blunt point rises from the center of a strongly curved rod, both sides of which are about equal in length. The median ridge, which runs the entire length of the rod, divides the rod into two parts lying in different planes. The denticles, which appear on both sides of the cusp area, appear to rise from the middle ridge rather than from the edge of the bar.
The denticles themselves vary in size; the closer the ends of the rod are, the smaller and thinner they become. There are five short, thick denticles with blunt tips on each side of a narrow but very robust rod. Here the denticles gradually decrease in length, from the very long one next to the cusp to that at the end of the rod, which is so small as to be scarcely distinguishable from the rod itself.
It is about twice the length of the other teeth, which are similar in shape. All the teeth are set at right angles to the bar, which is very long on the steeper side of the arch. Our figure shows the convex side of the plate or tooth, the rod of which is very flat and wide.
ABT,5 BIBLIOGEAPHY OF THE CONODONTS HOLMES 31 PANDERODELLA SUBRECTA, new species
The rounded lateral lobes gradually disappear into the sides of the sharply pointed anterior lobe through a shallow, curved notch. The plate is slightly depressed towards the posterior end, but elevated in the anterior lobe. The median border, which is low but sharp at the posterior end, extends the entire length of the plate and becomes broad in the anterior lobe and opens onto the plate.
In the anterior lobe, where they cross the midback, they are so close together that they appear as solid lines. Compared to Polygnathus trilohahiSy, this species differs in the more finely marked basal part and in the extension of the median margin to the anterior end. The median margin, which extends the length of the plate, is extended beyond the plate by a short, narrow carina, which bears several denticles varying in shape and size.
At the anterior end of the plate, the ridge is interspersed with tubercles, which are concentrically arranged but terminate abruptly at an ill-defined base of the ridge. Parallel rows of denticles extend from the anterior lobe to the origin of the carina, where they turn at an acute angle and terminate at the edge of the lateral lobes. The tubercles on both sides of the plate occur in short parallel lines extending from the edge to a depression at the base of the ridge.
The largest part of the ridge, which is produced beyond the plate by a short, blunt carina, is broad and stout. This is a long, narrow, small plate with the finely denticulated central spine extending its entire length. The back is very low at the front end, but rises towards the rear end, where it becomes high and broad.
The relative lightness of the surface serves to distinguish this species from the related Palmatolefis verlohata Ulrich and Bassler. The ridge runs the entire length of the plate and is produced just beyond a short, thick carina. This on the back half of the slab are at right angles to the central ridge.
EXPLANATION OF PLATES
ART. 5 BIBLIOGEAPHY OF THE GONODOUTS — HOLMES 35
AKT.5 BIBLIOGRAPHY OF THE COXODONTS HOLMES 37
All specimens illustrated here and on plates 9 and 10 are from the Chattanooga black shale of the Lower Mississippianage at a locality 13 miles east of north Huntsville, Ala.. Fig. 1, 2. Prioniodus alaJyamensis, new species.
