HARVARD UNIVERSITY. LIBRARY OF THE MUSEUM OF COMPARATIVE ZOOLOGY. | A MONOGRAPH « AND CRYPTONYMUS. $38 s- 3 By A: W: VOGDES; U.-5. A, CORRESPONDENT OF PHILADELPHIA AND CHICAGO ACADEMIES OF NATURAL SCIENCES, CHARLESTON, S. C. ‘1878. GHN HRA Zethus,' Cybele, Enerinurus, JUL A MONOGRAPH ON THE GHN HRA Zethus, Cybele, Knerinurus, CRYPTONYMUS. — ——_+es—-——__ — By A. W. VOGDES,U. 8S. A. CORRESPONDENT OF PHILADELPHIA AND CHICAGO ACADEMIES OF NATURAL SCIENCES. CSAS Rear Soi. 1S GS. 1878. The Genus Cryptonymus, Kichwald, 1840. HISTORICAL NOTICE. In the year 1711, Herrmann published, in his Mas- lographia, the following description: “ Pectunculites marmoreus trilobus imbricatus in medio dorsi punctatus, et striis exiguis per transversum notatus,’ and figures (plates 9 and 11, fig. 50) the pygidium of Cryptonymus punctatus. He represents a specimen with 6 tubercles _ on the axis, and 9 pleure. These figures are the first that we possess of this trilobite. In 1759, Linneus figures (table 1, fig. 2) the pygi- dium of C punctatus under the common designation for all the genera, “Hntomolithus paradoxus.” These figures appear in his pamphlet, Petrificatet Entomol., ete., copied in the Act. Reg. Acad. Scient. Holmiens, pages 22-24, pl. 1, fig. 2. In 1763, Lehmann, in the Noy. Comm. Acad. Scient. Imper., vol. x., (table 12, fig. 10) represents a pygidium of the C. punctatus. In 1768, C. F. Wilckens, in Stralsundishes Maga- zin, vol. iv, p. 267 (table 3, fig. 12) figures a pygidium. Joh. Beckman, in De Reductione Rerum Fossilium, ete., published in the Nov. Comment, Soc. Reg. Scient. Getting, vol. 3, 1773, p. 102, describes a pygidium. In 1781, M. T. Brunnich, in Nye. Samling af det Kong. Danske ' Vidensk: Skrifter. Kiobenk,, vol. i, p. 2 394, publishes a description of the then known trilo- bites. He uses ¢rilobus, Walch’s designation, in an abbreviated form, and classes the whole family under this name. He was the first author giving specific names to the different species, and calls our present species, C! punctatus, from its series of perforated tu- bercles, Tribolus punctatus In 1820, Schlotheim (Paleontology in its Present State, Gotha, 8vo., p. 34, No. 3) published a descrip- tion of five different species, two of which, however, belong to doubtful forms. His No. 3 is designated Tri- lobites variolatus. Parkinson, in his “Organic Remains of a Former World,” on p. 266, vol. iii, gives the following . descrip- tion of the species quoted by Brongniart, for the type of his Calymene variolaris: “The representation of a mutilated fragment of which is given plate 17, fig. 16, is a very extraordinary fossil. In this animal, the lobu- lar divisions seem to have very nearly corresponded with those of the Dudley species (Calymene Blumen- bachii). But the structure of the head part of the animal differs exceedingly from every other species. In this fossil, instead of the appearance of the distinct parts of a face, there are three large round protuber- ances, the middle being the largest ; and all the other protuberances are closely beset with small tubercular ris- ings, * * * the eyes being placed in the centre of each lateral rising.” In 1821, Wahlenburg published, in the Nova Acta Reg. Scient., vol. viii, his Petrificata Telluris Suecane. He describes 14 species under the general generic name oO oO of Entomostracites,and gives the following description of E. punctatus, p. 32, plate 2, fig. 1, (the pygidium only, the head represented and described belongs to Aci- | Calymene Blumenbachii, Brong. ‘ Cauda verrucarum punc- tatarum serie triplici,” and on p. 33, “The shell of the pygidium is longer than it is broad. The axis (back yoke) is furnished along its middle in a longitu- dinal line with a series of elevated tubercles, perforated at their apex. The lateral folds (pleurz) also have on each side a very similar series of perforated warts; from this, Brunnich derived the distinctive name of the species.” In 1822, the celebrated Alex. Brongniart published his excellent book upon the Fossil Crustacea. This treatise is the first work which points to the generic differences of the trilobites, exhibiting five genera. On p- 14, he describes Calymene variolaris, and refers Par- kinson’s figure (pl. xvii, fig. 16, vol. iii) to this species. He figures Calymene variolaris, on pl. i, fig. 3a, (Oryp. punctatus) and fig. 3b (C. variolaris). The locality for the fossil represented on pl. i, fig. 3b, is unknown, but he quotes the specimen figured on pl. i, fig. 3a, from Dudley. In his description of the species he says: “We count 12 to 13 rings in the thorax.” His fig. 3a, however, shows 12 articulations in the thorax. If this is his 15 ringed specimen, the author has included the occipital ring in his numeration. The Orypt. variolaris has 11 thorax segments, and the posterior angles of the cephalic shield are not produced into spines. This, in connection with his fig. 3b, and reference to Parkinson, we think clearly indicates his species, Calymene variolaris. The follow- a ing description is evidently of Crypt. punctatus : “The glabella seems divided into three hemispherical masses, the middle one being the largest. * * * The sides of the head exhibit at their angles an appendage which is prolonged on the sides of the thorax to the 6th seg- ment (5th). These parts are covered with'small grains or tubercles, very numerous and more salient than in the preceding species (C. Tristanz). They are provided at their summit with a small puncture, like the tubercles of the Echinoderms of the genus Cidaris.” Eichwald, in his Obser. Geognostico-Zoologice per Ingriam Marisque Baltici, 1825, describes 8 specimens of trilobites, under his generic denomination, Crypto- nymus. Three of these fossils are now referred as synonyms to Asaphus expansus ; and the others to the genus J//enus, established by Dalman, in 1826. Eich- wald has claimed the priority of the genus Cryptony- mus over Dalman’s genus, but abandons his claim in 1840, and substitutes his generic name, Cryplonymus, with the Calymene punctata, Dal., as its type for a new genus. In the year 1826, Dalman published his essay upon the Paleaden, which appeared-in the Kongliga Svenska vet. Akademien, 1826, p. 226-293, and the German edition, 1828. On p. 40, No. 6, the Calymene punctata is described, and represented on plate 2, fig. 2, as a py- gidium, with 10 thorax segments; and fig, 2 b. repre- sents the same part, with 6 tubercles on the axis, and 7 pleure. In 1830, Eichwald, in his Zoologia Specialis, pars. 2, p- 115, advocates his claim of priority for the genus Cryptonymus over Dalman’s genus, Lllenus. 5 In 1830, Pander published his Beitrege zur Geogno- sie des Russlands. In his review of the heterogeneous species, which then existed under the genus Calymene of Brongniart, he saw the confusion caused by its ill de- fined limits, and properly sub-divided the genus in proposing the genera Amphion and Zethus; but not having in his possession the type of the genus, (Caly- mene Blumenbachii) he has added to the confusion in the nomenclature. He thus describes his genus Zethus: “Middle body (thorax) as in the genus Calymene, (Pha- cops and Amphion) side segments of the body and tail provided with strong folds, the latter appearing to be free at their extremities. We count 16 segments of the body and tail together, for we are unable to properly sepa- rate them from each other. Cheeks without furrows ; no eye tubercles.” Pander refers two species to this genus, the type Z. wniplicatus (pl. v, fig. 7,) and Z. verrucosus (pl. v, fig. 6, also pl. iv, fig. 4). Portlock says: “The two species which Pander cites as examples of this genus, do not agree with each other in what must be considered an essential character.” The author of the genus Zéhus remarks, with regard to Zethus verrucosus: “We are only in possession of a part, and it may be possible that the fossil belongs to the Ento- mostracites punctatus, Wahl., the Calymene punctata, Dalman ; but we see from the fragment, more or less disarranged and broken, that the segments‘and also the head shield were covered with close Jayers of tubercles, while those of C. punctatus appear to be smooth. The furrows of the glabella can be seen, as in Amphion fron- tals ; eyes wanting. Not having in our possession the 6 pygidium, we can not say with certainty that this form belongs to Zethus.” Burmeister refers the Z. verrucosus to C. Tristani ; Buch, to C! Blumenbachii, and Doctor Volborth, in the Trans. Royal Minerval So., St. Petersb., 1847, quotes the Z. wniplicatus, Pander, under the genus Cheirurus and Z. verrucosus, Pander, under Loven’s ge- us Cybele. Corda takes the same species for the type of his genus Atractopyge. Nieszkowski assigns the Zethus uniplicatus to the genus Spherexochus. Portlock (page 289) refers the genus Zethus to Amphion. It is sufficient- ly evident that the generic description is very imperfect and ill defined; and also that iis type belongs to the genus “eraurus, Green, or to its sub-genus, Spherexoch- us ; and that all attempts made by authors to class as its type the second species, Zethus verrucosus, with Pander’s uncertain description, has only propagated an error that leads to great confusion. In the Petrifactions of the Duchy of Brandenburg, published in 1834, Klceden, p. 106, gives a short descrip- tion of Calymene punctata, without figures. Buckland, in the Bridgewater Treatises, 1836, on pl. xlvi, fig. 6, represents the Crypt. punctatus as Asaphus tuberculatus. The specimen was cited from Dudley and from Mr. Johnson’s collection. It is evidently the same that Brongniart figured on pl. i, fig. 3a. In 1839, Murchison in The Silurian System, on plate Xxiil, fig. 8, represents the C. punctata, and on pl. xiv, fig. 1, the C. variolaris, The last figure has 13 segments in the thorax. Fletcher remarks, in his article on the Dudley Trilobites : “A recent inspection of the specimen. figured by Sir R. I. Murchison (pl. xiv, fig. 1) from, We may be justified in rejecting Zethus of Pander, a name lately revived by Dr. Volborth, for the genus as constituted by Pander, consisting of the fol- lowing species: Zethus uniplicatus and Z. verrucosus ; to either of which the meagre and incorrect description will apply. The first of these being, by Dr. Volborth’s own admission, a species of Cheirurus, the second a Oybele. He | ri the cabinet of Mrs. Downing of the Priory near Dudley, enables me to say that it has 11 thorax segments.” Emmrich, in the De Trilobitis Dissertatio, ete., 1839, on p. 20, describes, under Phacops variolaris, Park., the Crypt. punctatus, as follows: “ Head tuberculated; the posterior angles are produced into short horns; glabella convex: the thorax posteriorly diminishes; pygidium pointed.” | In 1840, Eichwald, in his Silurian System of Esthland, on p. 71, gave to his former generic name, Cryptonymus another signification, and proposed this genus for such typical forms as Calymene punctata and C. variolaris, in part, with Cryp. Werthii and C. parallelus. In thus abandoning his claims of priority for his genus, Crypto- nymus, of 1825, over Dalman’s genus, Li/enus, of 1826, the author substituted for his genus a generic name, which had been used for an entirely different set of fossils, and only pointed out his generic type, without giving a defined description of the genus. To us it ap- pears that he has clearly indicated the group, and given a definite exposition of its essential characters in assign- ing Calymene punctata, Dal., for the type. Eichwald says, in his Die Urwelt Russlands, p. 22: “I found also in Odinsholm fragments of other species, viz: Calymene variolaris, Brong., which belongs to the genus Crypto- nymus. * * * J discovered near Reval an interest~ ing small species of Cryptonymus, which has a pygidium similar to Calymene punctata, Dalman.” Munster, in his Beit. zur Petrefactenkunde, vol. iii, p. 34, pl. v, fig. 1, describes and figures Crypt. variolaris, In 1843, Burmeister, in his work on the Organization would restrict the name to the latter; but custom and the opinion of natural- Mists in general would point in dontful cases like this to the first as the typical species, and we should then have to apply Zethus to all we now call Cheiru- rus; more especially as it was only the entire body of Cheirwrus that Pander knew. (Fide Salter. Decade vii, part ii, p. 9.) 8 of Trilobites, pointed out the discrepancy between the two figures referred by Bronginart (plate i, fig. 3a-b,) to Calymene variolaris, and cited the erroneous 13 seg- mented C. variolaris, Murch., under the genus Calymene, and Brongniart’s 11 segmented figure under the genus Phacops. He also correctly refers the Calymene vario- laris of Brongniart’s pl. i, fig. 38a, under C. punctatus. In 1843, Prof. Hall, in a pamphlet on the Trilobites of the Inferior Strata of New York, describes Oeraurus (Oryptonymus) vigilans. Emumrich, in Zur Naturgesch. der Trilobiten, 1844, in reclassifying the genus Calymene, clearly indicated, though not well described, the divisions of this family in creating the genus Hncrinurus, with the following generic formula: “Hnerinurus noy. gen. (der schwanz und Encrinites)—Eyes smooth, the glabella inflated, and club-shaped, the pygidium with a many ringed axis and few pleure. Hntomostracites punctatus, Wahl., is so different from all other trilobites, that it is entitled to form a separate genus; it unites the clavate glabella of the Asaphus, and has the facial line and eyes like Oalymene. The facial line is an intermediate between the genera Calymene and Phacops. On account of its peculiar shaped pygidium, I have given it the above name. In addition to the above named, two of Port- lock’s species belong to this genus, viz: Amphion mul- tisegmentatus and Ogygia rugosa.” In 1845, Loven, in the Trans. Swedish Royal Acad. of Science, p. 110, proposed the genus Cybele for such types as Oalymene bellatula, Dalm., and referred to this genus Caly. verrucosa and Caly. velata. Judging from 9 the marked character of Caly. bellatula, we are of the opinion that Loven’s genus should be retained as a sub- genus for the Cryptonymide. In 1846, McCoy, in the Synopsis of Silurian Fossils of Ireland, (pl. iv, fig, 15) represents the Encrinurus Stokesii. This species is a synonym of C. punctatus. In 1847, Dr. Volborth, in the Verhandl. des Mineral. Gesellsch., zu St. Petersb., (p. 10, pl. i, fig. 1-4) de- scribes and figures Zethus bellatula. This species is referred by Eichwald to Crypt. Werthii. Corda, in Prodrom einer Monographie d.Bohmischen Trilobiten, 1847, on p. 206, pl. v, fig. 52, takes for the type of his genus, Atractopyge, the C. verrucosa, Dalm. This genus, owing to Pander’s imperfect description of Zethus, will probably form a sub-genus for the Cryptonymide. During the same year the Paleontology of New York, vol. i, appeared with a description of Oeraurus vigilans. This fossil is figured on pl, Ixv, fig. 2a—g. In 1848, Salter described the following species in the Memoirs of the Geol. Sur., Great Britain, vol. ii, part 2, viz: Cybele sexcostata. (PI. viii, fig. 10—not fig. 9.) Kutorga advocates the rightful claim of priority for the genus Cryptonymus over Enecrinurus, and recom- mends the adoption of Eichwald’s genus instead of Enerinurus. (Trans. Royal Mineral Soc., of St. Peters- burg, 1848.) In 1849, Dr. Volborth, in the Bull. de la Soe. des Nat., de Moscow, published an article on the genera Zethus and Cryptonymus. In the Quarterly Geological Journ., vol. vi, pl. xxxii, 10 Fletcher published an essay on the Dudley Trilobites, in which he points out the obvious discrepancies which heretofore existed in regard to the identification of the species Oybele punctatus and C. variolaris. In 1851, McCoy, in the Paleozoic Fossils of the Woodward Museum, on p. 156-8, mentions the following species: Hnerinurus Stokes, Zethus sexcostatus.and Z. variolaris. Angelin’s Palseontol. Scandinavica appeared in 1852, with the generic formula of Cryptonymus. This author also describes the following species: Crypt. punctatus, syn. Encrinurus variolaris, et Stokesii ; and in addition, the Crypt. bellatulus, C. obtusus, C. levis, C. caudatus, and Crypt. verrucosus. In the Memoirs of the Geol. Sur., United Kingdom, Decade vii, on plate iv, fig. 1-16, Salter describes and figures Encrinurus sexcostatus, E. punctatus and E. var- iolaris, and remarks: “If the strict rule of priority were observed, irrespective of clear definition, we should be compelled to adopt the name Oryptonymus for this ge- nus, as that of Zethus for Cybele. Doctor Kutorga, indeed, in the Tran. of the Royal Mineralogical Society, St. Petersburg, 1848, advocates this course, and has re- stored the name Oryptonymus, under which Eichwald at first described several varieties of the common Asaphi of the Russian Silurian rocks. Subsequently, (1840) aware of his error, he restricted Cryptonymus to such trilobites as the Calymene variolaris, Brong., including the Calymene punctata, and some forms of Cybele. But, though thus marking out the group he intended, he gave no description of the amended genus; besides which, 11 he is now applying the name to a totally different set of fossils to those for which it was originally intended. Under such circumstances, it is impossible to retain his name in opposition to the genus clearly indicated, though not sufficiently described, in Kmmrich’s scien- tific arrangement of 1845.” Eichwald’s essay on the genera Cryptonymus and Zethus, published in 1855, says: “Soon after my jour- ney from Wilna to St. Petersburg, I had the opportunity to renew my observations in the neighborhood of Zar- skoje-Selo and Pawlowsk, and shortly afterwards, on several different occasions, in Esthland. My collection of trilobites consisted not only of the species which I _ had described, but also of many new forms. I referred the species, which had hitherto been classed under my genus Oryptonymus, to Illenus, for this genus had meet with universal acceptance, to the detriment of my Cryptonymus. In the year 1840, I gave to Cryptony- mus a new signification, and referred the Calymene punctata, Dalm., and C. variolaris, Brong., in part, and added two new species, Crypt. Werthii and C. parallelus, to it. In taking the well known Calymene punctata, Dalm., as the typical form for the genus, we gave a short description, reserving the exact diagnosis for the Paleon- tology of Russia. It is evident to every person who will decide impartially and generously with regard to the new limitation of the genus Cryptonymus, to easily perceive its characters from the given type. The learn- ed Angelin, in his Monograph of Swedish Trilobites, not only recognized my genus, but also gave the generic formula. 12 “The following are the reasons which I previously held and still advocate: First—to mantain Cryptony- mus as a genus for seyeral Russian and Swedish trilo- bites, according to Angelin’s diagnosis, which was de- rived from my short, but distinct, description given in my work on the Silurian System of Esthland. “Second—To acknowledge the Zethus, Pander, only as a genus for the Z. wniplicatus. This is the typical species given by its author: we have no authority to take this species, which differs from all other trilobites, and class it under Zethus verrucosus, which was doubtfully re- ferred to this genus by Pander, and by this combination establish an independent genus. “Third—The Zethus verrucosus, Pand.,is probably the Crypt. verrucosus of Angelin; not Crypt. parallelus, Eichw., or Oybele bellatula, Loven. ‘The Z. bellatulus, Volb., isa synonym of Crypt. Werthu, and not of Cal. punctata, Dalm., or variolaris, Brongniart.” Doctor Volborth advocates the priority of the genus Zethus over that of Cryptonymus, in an article published in the Bull. de Acad. des Scien., de St. Petersburg, vol. xili, No. 19, 1855. Dr. Shumard describes, in the Geological Survey of Missouri, 1855, p. 198, pl. b, fig. 10, Hnerinurus deltoideus. In 1857, Nieszkowski, in his Monograph of the Tri- lobites found in the Silurian System of the Baltic Prov- inces, on p. 72-103, describes the genera Hnerimurus and Zethus. This author correctly figures and describes the facial angle of Enerin. punctatus, and the follow- ing species: EH. punctatus, pl. iil, fig. 6-7 ; HH. multiseg- 13 mentatus; HE. sexcostatus; Zethus bellatulus, with the following synonyms: Crypt. punctatus, variolaris, and Werthii, Eich., also Z. bellatulus, Volb. He describes Zethus rex, pl. i, fig. 3; Z. atractepyge, McCoy, and Z. brevicauda, Ang. In 1858, Schmidt, in an article on the Silurian Sys- tem of Esthlands, describes Hnerinurus punctatus. Doctor Volborth, in the Memoirs de l’Acad. imp. d. Sciences, de St. Petersburg, vol. vi, No. 2, p. 20, 1863, remarks: ‘“Eichwald abandoned his original genus, Cryptonymus, about twenty years ago, and transferred the generic name to other trilobites. He cannot forget this fact, that the genus Cryptonymus of 1825 has pri- ority over J//enus, which was established in 1826 ; and he refers on every occasion to it,even in his Lethea Rossica, on p. 1476. In his pamphlet on the genera Zethus and Cryptonymus, he endeavors to prove his opinion by taking the absolute majority, remarking : ‘That of the eight published species of Cryptonymus, five, the majority, belong to the genus J//wnus, and only three to Asaphus’; the author therefore claims the priority for his genus over Jd/enus, which was published two years afterwards. The majority cannot decide this question, but only the total number. The author would have the right to claim his generic priority, if each of the 8 spe- cies of Cryptonymus had the ten segments of the genus Iilenus. Suppose it could be possible to give to two different forms the same characteristics, (which is an im- possibility) and we take Eichwald’s given numbers, we must give three species to the genus Asaphus, and five to that of Jdlenus. Now, Gryptonymus, which represents 4 14 both, would be equal to 3 plus 5, which is 8. Now, if we take away the Asaphus, or the number 3, the J/len- us, or 5 remains. This number cannot alone establish the genus Oryptonymus. -* »*: *_* *.:*) Foes The new genus Cryptonymus, established from the for- mer name, meets with the same objection that the older genus had ; for it was established upon two altogether different genera, viz: Zethus and Encrinurus. The former calculation reappears with the same consequence; the younger genus J//enus having replaced that of Cryptonymus of 1825, so also will the Enerinurus of 1844 be substituted for the Cryptonymus of 1840.” In 1865, Billings, in his work on the Paleozoic Fos- sils of Canada, vol. i, describes Encrinurus mirus, on p- 292, fig. 282. In the Catalogue of Silurian Fossils of Antic., Anti- costi, which was published in 1866, the Encrinurus ele- gantulus, Billings, is described. In 1867, Prof. Hall described Enerinurus nereus, in the 20th Regents’ Report, N. Y. State Cabinet, p. 375. In 1874, Steinhart described and represented Encrin. punctatus, in the Beit. zur Natur., Preussens, on p. 57, Tab. iv, fig. 15. In 1875, Hall and Whitfield (Geol. of Ohio, vol. ii, part 2,) deseribe Encrinurus ornatus. In 1877, Walcott described the following species: Encrinurus raricostatus and E. Trentonensis, in a pam- phlet published in advance of the 29th Regents’ Report of the New York State Cabinet. Miller, in his Catalogue of American Paleozoic Fos- sils, part Crustacea, gives a list of the North American Trilobites. CRY PTON YMUS—EICHWALD, 1840. Srmtveian System or Estuianps, P. 71. “Corpus obovatum, convexum, longitudinaliter trilo- bum, crusta levissima vel granulata. Caput semilunare, cornigerum 1. muticum ; margine incrassato, sulcoque intramarginali;segmentum oculi- ferum distinctum: sutura facialis postice ab oculo extror- sum ad marginem lateralem decurrens, antice prominen- tiam frontalem arcte circumscribens. Oculi parvi, subglobosi, minute reticulati pedicellisque immobilibus suffulti. Frons antrorsum dilatata, limbum attingens. Thorax segmentis circiter 11 angustis, sulco longitu- dinali destitutis, apicem versus retroflexis. Abdomen capite multo augustius, immarginatum : latera utrinque costis distinctis, marginem superantibus : rachis conica, crebre transversim striata.”* Sub-genus I. Cryptonymus, Fichwald, 1840. The cephalic shield is semi-circular, or parabolic, with the posterior angles extended into spines, (Cryptonymus punctatus) or obtusely rounded (Cryptony. variclaris). Glabella inflated and clavate, with three indistinct later- al lobes, and a large forehead lobe ; eyes pendunculate, finely facetted. The facial sutures commence a little above the posterior angles of the head, and run directly to the eyes; bending at this point, they curve to the front, and running anterior to the glabella, they turn suddenly * Angelin’s Palzontol. Ca i i 16 at an angle of nearly 90° downwards, and then par- allel with each other, ina vertical direction they cut the marginal edge; the lines at this point converge and com- bine into a rostral suture. ( Nieszk.) The cheeks are separated in front by the vertical suture. Thorax with 11 equal segments, without pleural grooves, notch- ed at the ends, but not produced into spines. Pygidium with the ends of the pleurz free ; axis with many rings. The axisis perfectly ringed in Cryptonymus multiseg- mentatus ; notched on both sides in Orypt. variolaris. The type for this sub-genus is Crypt. punctatus. Dal. Sub-genus II. Cyperer, Loven, 1845, ‘ Cephalic shield semiluna, with broad and rounded posterior angles; glabella with three furrows, the ante- rior lobe clavate. The posterior branches of the facial line commence some distance above the posterior angles of the head, and run obliquely to the cone shaped eyes, which are well advanced on the cheeks, nearly opposite the third glabella furrow. Anterior branches of tle facial line run from the eyes, and then con- verging to the front of the glabella, to the outer margin, they are then combined into a short rostral suture. Cheeks convex, deflected before the eyes and covered with large tubercles. The thorax consists of 12 segments, 6th to 12th run parallel with the five anterior segments to the fulcrum point; at this place they bend posteriorly at an angle of 90°, and terminate in long pointed spines, particularly the 6th segment, according to Angelin’s figures represented on pl. iv, fig. 1. The five anterior thorax segments are altogether of a different character the pleurz being facetted at their extremities. 17 Loven, on pl. ii, fig. 3a-c, represents three copies of C. bellatulus ; fig. 3a has the first three thorax segments facetted, and fig. 3c, the first to fourth. From these figures we would judge that the first 5 thorax segments had distinct fulcral points, which consisted of an attach- ed articulated extremity. The pygidium is triangular and has a conical axis, which consists of 16 to 18 notches; only the first 4 or 5 axis joints have pleura. The type for this sub-genus is Oybele bellatulus, Dalm. Sub-genus III. Atractorye®, Corda, 1847. Cephalic shield semiluna, with the posterior angles al- most produced into short spines. Glabella clavate, with a wide anterior lobe; the eyes are situated in the centre of the cheeks; if an imaginary cirele be drawn, with its central point in the middle of the occipital ring, and if 4 its diameter be equal to the length of the glabella, on the median line, it will cut the eyes at their base. The posterior branches of the facial sutures commence on the outer margin, near the lateral posterior angles of the cheeks. The thorax has 11 segments; the pleure are posteriorly bent,.and have pointed extremities, with a central row of tubercles. The pygidium has a double row of tubercles on each side of the axis and four pleu- re ; the first, second and third are twice the width of the axis joints ; fourth is three times the width. The type for this sub-genus is Calymene verrucosa, Dalm. Loven’s copy of this species, figured on pl. i, fig. 5f, does not represent the dorsal furrows, which divide the axis from the segments; therefore, Corda, who copies this figure for the type of his genus, remarks: “the py- 5 18 gidium consists of only the axis.” (Vide p. 206, plate v, fig. 52, Prod. einer Monographie- der Bohmischen Trilobiten.) Crypronymus punctatus, Wahl. 1821. Puate I, Fie. 1-6 and 17. Puate III. Fie. 15-16. General form ovate ; length nearly twice the width ; cephalic shield and pygidium about equal, excluding the terminal mucro. Thorax nearly half the entire length. Cephalic shield semi-circular, gibbous in front; its posterior angles are produced into extended spines ; its length equals about half its width; the surface is coarsely granulated with large tubercles, each with a mi- nute perforation or puncture. (PI. i, fig. 9b.) The cephalic shield is bounded by a wide, thick edge margin, which is narrow at the glabella, and covered with two rows of tubercles—(Nieszk.) Glabella clavate and gibbous, overhanging the slight anterior margin, nearly spherical in front, where it has a distinct border of large tubercles, (pl. i, fig. 1,) and narrowing anteri- orly to half its front width, its base being less than one- third of the entire width of the head; two or three tu- bercles are arranged on each side of the lower half of the glabella, occupying the situation of the lateral lobes, the furrows between which are not visible; the dorsal furrows are deep, the cervical furrow curving outwards to the front; the cheeks are separated with deep sulca- tions from the margin of the head. The posterior branches of the facial sutures com- mence on the exterior edge of the cephalic shield, just above the posterior angles, and run in an oblique direc- 19 tion to the large pedunculated eyes, over their base, which are nearly in the middle of the cheeks; the anteri- or branches of the facial sutures converge from the base of the eyes to the front of the glabella ; they then turn suddenly at an angle of 90° downwards, and running parallel in a vertical direction to the marginal edge, which they cut, and then converging, combine into a rostral suture. (PI. i, fig. 17.) A flattened space, bordered by a row of tubercles, sur- rounds the base of the eyes; the distance of the eyes from each other exceeds the extreme width of the gla- bella, and are finely facetted, according to Kutorga. The cheeks are triangular; and separated in front by a vertical suture, convex and tumid. The occipital fur- row is continuous; and the occipital ring broadest in the centre, which is smooth, but has a tubercle at each extremity. Hypostoma ovate, rhomboidal, subtri- lobed tubercular and surrounded by a sinuated margin ; its convex extremity very broad, and its cucullated tip buts against a large tubercle, placed upon the anterior margin of the head; (pl. i, fig. la,) the wings or apophy- sis of the hypostoma are short and triangularly pointed. The thorax has 11 segments; the slightly convex axis is distinctly bounded by dorsal furrows. The axis joints are somewhat narrower than the pleurse, and wider on the median line than at their lateral extremities ; 7th and 9th axis joints (7th and 10th, according to Salter and Barrande) have on their median line a small spine. ~ The pleuree are without grooves, notched at their ends, and usually covered with small tubercles, the pleurse are horizontal half way down, then strongly curved 20 downward, and at their fuleral points they are slightly bent backwards. The pygidium is long and acutely tri- angular, terminating in an extended mucro; its axis ta- pering posteriorly to its acute termination, which has from 28 to 80 distinct side notches, the centre is smooth and has 7 prominent tubercles, 4 articulations interven- ing between two tubercles ; 8 pleurz on each side of the axis, gradually decrease in size as they approach the termination of the pygidium ; the anterior pleure eurve backward, and they are separated by deep fur- rows, anda distinct tubercle is placed upon the upper and inner part of each pleure, near the dorsal furrows. According to Nieszkowski, between the 1st, 2nd and - 3rd tubercles of the axis of the pygidium, 2 notches appear ; between the 3rd and 4th, 4 notches ; between the 4th and 5th, 4 to 5 notches appear, and between the 5th and 6th, 5 to 6 notches. Wablenburg represents on pl. ii, fig. 1,a pygidium with 7 tubercles and 28 notches on the axis, and 8 seg- ments; Angelin’s copy of the same, figured on pl. iv. fig. 4, has 8 tubercles and 26 notches on the axis, with 8 pleure. Both these specimens are from Gothland. Dal- man’s representations of the pygidium on pl, ii, fig. 2a and 2b, have 5 and 6 tuburcles on the axis, and 7 pleure ; Corda, on pl.v, fig. 55, represents a copy with 6 tubercles and 22 notches on the axis, and 7 pleure : Nieszkowski figures a specimen from Oesel, with 6 to 7 tubercles and 25 to 28 notches on the axis, with 8 pleure. Geological localities—U pper Silurian : Dudley, Gott- land, ete. Lower Silurian: Bala Rocks, Pwllheli, Carnarvon- shire. 21 CRYPTONYMUS VARIOLARIS. Brong., 1822. Puate I, Fie. 6-10. Pxuare III, Fie. 13-14. The general form is obtusely ovate. Cephalic shield obtuse, and not produced into spines ; the posterior angles are ornamented with a cluster of tubercles, which occasionally terminate intoa single tubercle. The gla- bella is inflated and covered with large tubercles, equally disposed. The thorax consists of 11 segments. The pygidium is convex and triangular, its length and breadth about equal; and its axis has 9 to 10 rings, much natrower than its lateral portions, and gradu- ally diminishing into a blunt apex; the 7 pleure are broad and abruptly bent downwards and backwards. The posterior pleurz are rounded off at their extrem- ities and extended below the blunted axis. Each pleure has a tubercle near the axis. ‘The upper ring of the axis has usually a single large tubercle upon its centre, the 2nd has a central puncture or slight depression be- tween 2 large tubercles; the remaining rings have al- ternately a tubercle and a puncture between 2 tubercles, except the 3 posterior rings, which have each a single tubercle only. Variations: the front of the glabella is more gibbous in some specimens than in others, and the marking of the pygidium is not constant. Localities: Wenlock Limestone, Dudley, ete. CRYPTONYMUS DELTOIDEUS. Shumard, 1855. GEOLOGICAL SuRvEY oF Missouri, P. 198, Pui. B, Fie. 10, Pygidium subtriangular, width greater than the length, moderately convex, arched before, posterior ex- tremity rounded and bent slightly upwards. The axis 6 22 tapers to a point at some distance within the blunt apex ; it is convex at its broadest end, and becomes flattened and slightly elevated above the pleurz ; the dorsal fur- rows are well defined. Axis with about 24 narrow rings, only the first 4 or 5 are entire, the others are notched at the sides, leaving the centre free, which has several very small granules. The 7 pleure are narrow at their base, and become wider at their extremities; they curve downwards and backwards, the last 2 or 3 pleure being almost parallel with a line drawn through the length of the axis. The surface is minutely granular. The length of the largest specimen is 9 lines, with a width of 102 lines. Locality : Cape Girardeau Limestone, 2 miles above Cape Girardeau, Missouri. The only difference between this species and Salter’s Encrinurus sexcostatus is the addition of one pleure, giving Shumard’s species a more pointed form. CryPTonyMus L&vis. Angelin, 1852. PALZONTOLOGIA ScANDINAVICA, Pu. tv, Fie. 10. PuatTE II, Fie. 10. “Cryptonymus fronte subintegra, abdomine levissimo, triangulari, acuminato, costis utrinque 8. Regionis E, Gottlandie, ex gr. ad Hugklint prop Wisby.” CrYPTONYMUS oBTUSUS. Angelin, 1852. PALZONTOLOGIA ScANDINAVICA, Pu. Iv, Fic. 9. “Crypt. abdomine obtuso : rachi obsoletius granulata : lateribus leevissimis, costis utrinque 10. Regionis E, Gottlandie, ad Katthammarsvik.”” 23 Cryptonymus ornatus. HA. and W., 1875. Syn. CyBeELE PuNncTATA, Haut, Pau. N. Y., Vou. II, P: 297. ENCRINURUS ORNATUS. HAtt, GEou. Onto, Vor. II, P. 154. The cephalic shield is semilunar or subcrescentiform, with the posterior angles extended into long spines. Gabella clavate, not lobed ; surface of the glabella and cheeks tuberculated. Thorax composed of 11 segments. Pygidium triangular; as wide, or a little wider than long. Theaxis forms less than 3 of the entire width, is strongly marked and somewhat flattened on the top, ex- cept at the anterior portion ; it has about 20 or more segments ; the centre is marked with a row of five prom- inent tubercles, the anterior one of which is situated on the 2nd ring, the next on the 5th; the others have 3 rings between each tubercle. Seven well defined pleure exist in the Ohio specimen, and they are all directed backwards, gradually decreasing in size; each pleure appears to have been marked near the dorsal furrows with a node, and also with two or more other nodes further out on the pleure. A specimen of a pygidium represented on pl. Ixvi, fig. 1g, Pal. N. Y., vol. ii, shows a row of four tubercles on the centre of each pleure. Steinhart figures in his work on the Trilobites of Prussia, pl. iv, fig. 15, a triangular pygidium of “rypt. punctatus with 20 axal notches and 5 nodes. This speci- men has 7 pleure, and also latteral tubercles; each pleurse being marked at its base with a prominent tu- bercle. We know of no species belonging to this section which has a central row of tubercles along the pleure 24 of the pygidium. In the Atractopygide the pleure of the pygidium of A. verrucosus, have from 4 to 6 nodes running down the centre of each pleure, but the axis is marked with 4 lateral rows of tubercles. Niagara Group: Eaton and Yellow Springs, Ohio; Medina, Orleans County, and Reynale’s Basin, Niagara, New York. Cryptonymus Nereus. Hall, 1867. Encrinurus Nereus. Haut, 20TH. Rec. Rep. N. Y. Cas. P. 375. “Pygidium triangular; length and breadth about equal. Axis sharply elevated and marked by about 18 rings, (well defined and extending across the axis) with a further extension upon which no markings are dis- tinguishable. The latteral lobes are marked with 8 or 9 pleurz, which in the cast are not tuberculated.” Formation and locality: Niagara Group; Racine, Wis. The Encrinurus Trentonensis, Wal., may be a syno- nym of this species, although Walcott’s species has an axis, in which the first anterior ring is marked with a node on its centre, then in order the 3, 4, 10, 18 and 22 rings; which gives these forms certain affinities with the Encrinurus multisegmentatus, of which Nieszkowski says: “The axis has not the smooth central space com- mon in all other species of Encrinurus and generally covered with tubercles; very small nodes can be seen, with a lens, on perfect specimens along the centre of the axis of the pygidium. The number of pleure is generally nine, seldom ten.” 25 CrYPTONYMUS CauDaATUs. Ang., 1852. PALZXONTOLOGIA SCANDINAVIA, P. 88, Pu. tv, Fie. 2. “Pygidium triangular with a mucronated tail, smooth, with 5 or 6 pleurz on each side. ‘ Locality : Regions D. and E., Norway, Brevig.” CrypronyMus strietus. Tail of a triangular form, wider by one third than the length, with an obtuse rounded apex, and flattened above, the sides and the tip deflected, so that the tail is moderately convex ; the axis at the upper part is about one fourth the width of the tail, and tapers to a point at some little distance within the blunt apex ; it is con- yex at its broadest end, and there the rings are contin- uous across, but from about the upper third it becomes flatter, and the rings are effaced along the middle; its 27 apex is quite flat. There are about 20 rings in all, and no tubercles down the smooth central portion. The sides of the tail have 6 strong ribs, which are broad and some- what flattened, divided from each other by narrow deep furrows, and have the tips squarish and obtuse. The ends of the four upper ones are free (or rather much overhanging the margin) ; the remaining two are dis- tinct nearly as far as tothe margin, but they become fused with those from the opposite side, and extend ina very blunt point beyond the tip of theaxis. The upper- most ribs arch strongly outward, the next less so, and the last pair lie parallel to the axis. Externally the whole surface of the tail is covered with a close sca- brosity (figure 10). Variations—In the east from Sholes Hook (fig. 12) the rings on the axis of the tail are effaced down the middle for a broader space, and there are but few of the upper rings continuous across. Our figure in this case does not show the uppermost rings. There are some- times (fig. 11) seven rings on each side of the tail.” Localities and Geological Range: Llandeilo Flags: Rhiwlas and Llwyn-y-ci, north west of Bala Lake, etc.* CRYPTONYMUS RARICOSTATUS. Walcott, 1877. PUBLISHED IN A PAMPHLET IssuED IN ADVANCE OF THE 29TH RE- GENTS’ Report, N. Y. CasBinet, P. 16. “Pygidium subtriangular, convex ; length and breadth about equal; anterior lateral angles truncated, so that the lateral margins commence opposite the centre of the pygidium. Axial lobe not very prominent ; crossed by * Copied from The Mem. Geol. Survey of the United Kingdom, Decade vii. 28 about 16 smooth rings—the anchylosing of the posterior rings renders it difficult to determine the exact number. The lateral lobes are marked by 6 broad, pleure—the posterior pair unite back of the posterior termination of the axial lobe. Formation and Locality. Trenton Eheente Min- eral Point, Beloit and north of Janesville, Wisconsin.” Compare Crypt. sexcostatus and Crypt. deltoideus. Crypronymus TRENTONENSIS. Walcott, 1877. Description oF New SpeEciEs oF FossiLs, FROM THE CHAZY AND TRENTON Limestone, P. 16, “Pygidium triangular, convex ; length and breadth about equal; axial lobe rounding, tapering toward and terminating within the posterior margin ; marked by 23 rings, beyond which there are several, too indistinct to be counted ; the first anterior ring has a node at its cen- tre; then, in order, the 3, 6, 10, 14, 18 and 22 have a similar node at the centre. Lateral lobes slope rapidly to the margin; each has 9 elevated coste running ob- liquely backward to the margin. Formation and Locality. Clifton, Grant county, Wis., and two miles above Dunlith, Ill., north of State Line monument.” This species has certain affinities with Cryptonymus Nereus, Hall, and it may be identical ; although the axis represented in the copy of the cast figured in the 20th Regents’ Report, N. Y. State Cabinet, does not show the tubercles along its centre. 29 CRYPTONYMUS VIGILANS. Hail, 1847. PuaTe 1, Fie, 1 4-H. The cephalic shield is more than semiluna in form, with its posterior angles produced into long sharp spines, which, when perfect, extend to the pygidium; their extremities curve upwards. The glabella is not lobed ; the front margin (limbus) is thickened, and marked by two lines of nodes; the eyes are facetted, sub-con- ical and remarkably prominent. The surface of the head is marked by large tubercles; each node has a minute perforation or puncture at its apex. The small hypostoma is ovate and attached to the glabella. The thorax consists of 11 segments; the pleurz are extended and three times the width of the axis joints; the axis of the thorax has on every second joint a node or short spine. The pygidium is triangular and consists of 9 pleure, every alternate one being ornamented with a node: the axis has about 18 rings, every third one being mark- ed by a tubercle. Locality : Trenton Limestone; Middleville, N. Y. CRYPTONYMUS MULTISEGMENTATUS. Fortlock, 1843. Cephalic shield, with prolonged posterior angles ; gla- bella convex, clavate, being in front twice as wide as at the base; the surface is covered with large convex and pointed nodes; the cheeks are separated from the glabella by deep dorsal furrows, and are also covered with nodes. The pygidium is triangular, with a conical axis, consist- ing of many rings, about 32 or 33; but they are not 8 30 clearly defined. Small tubercles can be seen on the axis of the pygidium, along its centre. The number of pleure is generally nine, very seldom ten. (Nieszk.) The original description of this species is as follows: “Axial segments very narrow and numerous, 28 being enumerated as far as the last side segments, and still continuing, though very minute, to the very apex. A small lozenge shaped caudal plate. Side segments 12 on each side, exclusive of the false segment. ‘They are rounded, and slighty bent or raised at their extremities ; no punctures or marks of any kind.” Salter’s descrip- tion of the pygidium gives 30 axis rings and 12 pleure. We would suggest that the species described by Niesz- kowski, be cited as a variety under the name of Crypt. Meszkowskir. Lower Silurian : Tyrone, Montgomeryshire, Ireland ; Neuenhof, near Hapsal, Russia, ete. ; Cryptonymus (CYBELE) REX. Mieszkowski, 1857. The cephalic shield is semilunar. The glabella is clavate in form, prominently convex in the middle, and has on each of its slopes three deep oval notches; its surface is marked by four pair of smooth tubercles, placed in two lines and converging posteriorly towards each other. The marginal border (limbus) has in front of the glabella five short equi-distant spines, giving to the glabella a crown; this border is wide and thick, and its surface is covered proportionally with large round tubercles, placed in irregular lines. The course of the facial suture is the same as it is in the other spe- cies of this group, and has a row of small nodes on each 31 side of the line. The cheeks are as much arched as the glabella, and they appear from impressions left by casts to be deeply striated. On the anterior portion of _ the cheeks, at their greatest convexity, the elevated pe- dunculated eyes are located; they are small, and club shaped. The cervical and occipital furrows are deep and wide. The occipital ring is marked by four tubercles. Locality : Wesenberg, Wannamois, Odinsholm, Rus. Cryptonymus (CYBELE) BELLATULUS. Dalman, 1828. PLATE wu, Fia. 1, The general form of the cephalic shield is semilunar, its width is twice its length; the marginal border (lim- bus) is wide and thick, the posterior angles being short and obtuse. The moderately convex glabella is marked with three furrows, which do not extend across it; from the base of the glabella to the first furrow its form is nearly cylindrical, and from this furrow towards the front it is clavate. The prominently arched cheeks are separated from the glabella by deep and wide dorsal furrows; the eyes are small and pedunculated, inclin- ing to the front. The surface of the head is covered with large tubercles. The facial sutures commence on the outer margin, some little distance above the posterior angles, and run obliquely to the eyes; they then converge towards the front of the glabella, and afterwards to the outer mar- gin. The occipital ring is greatly convex. The thorax consists of 12 segments, and has marked 32 characters ; the first to six pleure are nearly cylindri- eal, smooth, and terminating with rounded extremities, which incline towards the front.* The sixth pleuree is about twice the thickness of the others; it gently slopes posteriorly until it reaches the fulcrum point, where it is suddenly bent at an angle of 90° to the rear, and runs parallel with the axis, termi- nating in a long pointed spine; the other segments conform with this one, and gradually diminish in size as they approach the posterior extremity of the animal. The pygidium consists of four pleure: the axis is pointed, and marked with 16 notches, which do not ex- tend across it; the first four notches only have pleure. The pleure as they approach their ends run almost parallel with a line drawn through the centre of the axis; the last pair are united at their extremities, Length one and one-half inch. Locality: Wesenburg, Wannamois, Russia. CryPTonyMUS (CYBELE) ATRACTOPYGE. McCoy, 1851. The pygidium is obtusely triangular ; the axis, which becomes narrower, consists of about 16 rings, only the first four extending across it, and have pleure; the others are notched on the sides: its surface is marked with two lateral rows of convex tubercles (7 on each side) ; the last pair are in the middle of the axis. *Note—Angelin figures a copy with an attached process to the second seg- ment; and future observation may develop the fact that the five anterior pleure have distinct fulreum points at theirrounded extremities, with a sep- _ arate articulated attachment. Should this be so, all the pleurm would con- form to the sixth. 33 Cryptonymus (CYBELE) BREVICAUDA. Ang., 1854. Pau. Scanp., PLATE xut, Fia. 14. The axis of the pygidium consists of 13 articulations ; the first four have perfect rings with pleurse, the others are notched at the sides without pleure ; along its lateral portions the axis is marked by 2 parallel rows of nodes. The pleurz are directed backward, being almost parallel with a line drawn through the centre of the axis ; their surface is smooth. Locality: Regions D. and E., Dalecarlize, Sweden ; Neuenof, near Hapsal, Russia. CryptonyMus (CYBELE) DENTATA. Esmark, 1832. TRILOBITES DENTATA. EsmARK, MAG. FoR NATURVIDENSE., VOL. I, P. 269. Pu. vit, Fie. 10. TRIL. DENTATUs, AND T, pLicATus. L. C. Pages 189 anp 140. Pygidium smooth ?—axis transversely striated, with about 17 segments: they are obliterated in the middle of the axis. Locality : Regions D. and E., Christiana, Norway. Cryptonymus (CYBELE) Wertuu. Hichwald, 1840. Syn. ZetHus BELLATULUS. -VoLBoRTH, 1847. VERHANDL. DES MINERAL. GESELLSCH. zU St PETERSBURG, P. 10, PL. 1, Fieurss 1-4 CrypronymMuS Wa@xrTuil. EichwAub, LETHmA Rossica, P. 14-16, Pu. tiv, Fie. alive 1860. Cephalic shield convex. The eyes are placed nearer to the posterior margin than to the anterior margin. The C. bellatulus has directly opposite characters, The eye pedicles of this species are placed more to the 9 34 front, on both sides of the front lobe of the glabella ; the facial line, therefore, runs obliquely to the front, from the posterior angles of the head; this line in C. Werthii terminates nearly parallel with the pos- terior margin of the cephalic shield; the eye pedicles on the high arched chéeks are placed alongside of the middle furrow, and not, as is in C. bellatulus, on the side of the large anterior front lobe of the glabella. The three glabella furrows are indistinctly marked. Thorax has 12 segments. The sixth segment of the thorax in (. bellatulus extends itself, as Angelin shows it in his plate, and terminates in a very long sharp point. This character is not noted in C. Werthi. The four segments of the pygidium are wider than long. Length generally about one inch. Locality: Pawlowsk, (Fide Eichwald, Zethus and Oryptonymus, pages 13, 19 and 20.) Crypronymus (ATRACTOPYG#) minus. Billings, 1865. Cephalic shield semi-elliptical ; width more than twice the length. Glabella clavate, moderately convex; the anterior dorsal furrows are irregularly rounded, with a notch in the middle. Occipital margin half the width of the limbus; cervical furrow extending across. The three glabella furrows on each side extend one- third across; the lobes gradually diminishing in size © posteriorly. Fixed cheeks broad, gently convex. Eyes distinct ; located about the width of the glabella from the dorsal furrows, opposite the second lobe, and placed about opposite the last glabella furrow. They appear to be small, and are connected with the front furrow by an ocular ridge. Movable cheeks unknown. 30 Pygidium with an elongated conical, convex axis, with from 12 to 14 distinctly defined articulations, with four narrow pleure, gradually diminishing in size and bent backwards ; the last pair commencing at about the mid-length of the axis, and extending posteriorly par- allel and close to the axis. The next also nearly par- allel, and the anterior, two pair, with the posterior half of their length parallel or converging. Between each two principal ribs there is a smaller one, slightly ele- vated, and seems to become obsolete before reaching the fulcrum. The pleure are at this point bent to the rear at an angle of 90°, and terminating in short spines. Surface of the glabella with a few small tubercles ; cheeks coarsely punctate; pygidium with three or four tubercles on the principal pleure. Locality and formation: North of Table Bay, Pisto- let Bay, Portland Creek, Newfoundland ; Quebec group. If an imaginary circle, with half its diameter equal to the length of the gabella, be drawn with its centre in the middle of the occipital ring, it will intercept the eyes at their base. A measurement which agrees with An- gelin’s figures of Cryptonymus verrucosus. PLATE IL. : BACT 113 hewn ee EXPLANATION OF PLATE I. PHOTOGRAPHED FROM THE QUART. JOUR. OF THE GEOLOGICAL SOC. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig, Fig. Fig. OF LONDON. vob. VI, 1850. PLATE XXXII. 1. CRYPYONYMUS PUNCTATUS, an adult specimen. la. The same specimen, under side of the cephalic shield showing the hypostoma, and the node against which it buts. 1b. The eye magnified, upper side. Ge: oe s lower side. 1d. The tenth thorax segment with spine on the axis ring. 2. The same species, adult specimen. By e fe the pygidium. Amen ss a the under side of the thorax and pygi- dium, to show the bifid or notched terminations of the pleure and the manner in which they are facetted. 5. Ditto, the hypostoma; the hooded tip is slightly recurved. 6. CRYPTONYMUS VARIOLARIS, a young specimen. 7. A rolled specimen. 8. Ditto, nearly full-grown. 8a. Ditto, a side view of the same specimen. 9. Ditto, a fine specimen; the thorax is slightly bent back- ward; it shows the sharpened front edges and notched pleure. 9a. Ditto, the under side of the cephalic shield of the same specimen ; the hypostoma is not recurved at the tip, but regu- larly convex. 9b. Ditto, a few of the nodes with a punctum on each. 10. Ditto, an under view, showing a similar structure to that represented at figure 4. 17. CrypronyMus puNcrATUS. This fine specimen shows an anterior view of the course of the facial sutures. The figure is copied from Nieszkowski’s Monograph of the Trilobites of the Silurian Formation in the Baltic Provinces. ae 5 BATAC ae Par ACS : : \ rit tb Pie d are 5 A a dia j Ph k ne : 7 ERO ok Sal Pa iv age avd GS an " ws Ke tappic re ae ol ay airs a fy suit ‘ ® f a ‘ if tel | ur sit Aged: ah Rae ed 1 ~#s tmfdhys etek ie “ ad al ee A eth, * : : : Vt Lor WPA ni * t i ‘ hay cm - "1 4 . ‘ . P | ie re ae h ’ ibe a 4 _ Z i 4a nt f Bike PLATH IL aM dice hes edi VA cS if EXPLANATION OF PLATE II. PHOTOGRAPHED FROM ANGELIN'S PALMONTOLOGIA SCANDINAVICA, Fig. Fig. Fig. Fig. Fig. PLATE IV. 1. Oryprt. (CYBELE) BELLATULUS, Dalm. 2. Side view of the same, showing the attachment to the second pleure. 3. The pygidium. 9. CRYPTONYMUS OBTUSUS, a fragment showing part of the thorax with the pygidium. 10. CryYPTONYMUS LAVIS. PHOTOGRAPHED FROM HALL’S PALHONTOLOGY OF N. Y. VOL. Hs Fig. Fig. Fig. Fig. Fig. Fig. Fig. PLATE LXV. 2a, CRYPTONYMUS VIGILANS, an entire specimen, presery- ing the posterior spines of the cephalic shield. 2b. Front view of the same, showing the elevation of the eyes. 2c. A small specimen. 2e. A pygidium of a larger individual. . 2f. An enlarged portion of the cephalic shield of fig. 2 a, showing the nodes with the puncture at their apex. The eyes under an ordinary magnifying glass, present an irregular facetted appearance. 2g. The pygidium and part of the thorax enlarged, showing the nodes upon the alternate axis rings, and also those on every third axis ring of the pygidium. 2h. - Profile view of the same. ee PLATE IIL. EXPLANATION OF PLATH III. PHOTOGRAPHED FROM THE MEMOIRS, GEOL. SUR., UNITED KINGDOM. Fig. DECADE VII, PLATE IV. ig: 1. CRryproNyMuUs sExcosTaTus, a coiled specimen ; see, bi wlaseeees. Seema! eee. — eee i on Re is. 2. Ditto, back view, to show chet 11 thorax segments. ig..3. Ditto, showing the raised fascia a. .4. Ditto, side view. ig. 5. Imperfect cephalic shield ; the dotted lines are added from other specimens ; the cheeks show the pitted surface. . 6. Magnified portion of cephalic shield. . 7. ea Ty