QE 729 B65 ,1921 pt.2 ENT THE CARBONIFEROUS INSECTS. PAGES 81—156; PLATES V— X. Tillp-pag'p aud Index. O Ipalaeontoorapbtcal Society A MONOORAPH OF THE FOSSIL INSECTS OP THE BRITISH COAL MEASURES. BY HERBERT BOLTOX, M.Sc., F.R.S.E., F.G.S., DIRECTOR OF THE BRISTOL MUSEUM. PART II. PAGES 81—15(5; PLATES V— X ; TITLE-PAGE AND INDEX. LONDON: FEINTED FOE THE PAL^ONTOaEAPHIC AL SOCIETY. JULY, 1922. PIUNTED ET ADLAKD AND KON ANU WEST NEWMAN, LTD., LONDON AND DORKING. THK PALjEONTOGRAPHlCAL SOCIETY. INSTITUTED MDCCCXLVH. VOLUME FOE 1920. LONDON: MDCCCCXXII. MONOGRAPH OF THE FOSSIL INSECTS OF THE BRITISH COAL MEASURES. ORDER OF BINDING AND DATES OF PUBLICATION. PARTS AND PAGES PLATES ISSUED IN VOL. FOR TEAK PUBLISHED General Title and Index 1920 July, 1922 1—80 I— IV 1H19 July, 1921 81—156 V— X 1920 July, 1922 A MONOdKAPH FOSSIL INSECTS BRITISH COAL MEASURES. BY HERBERT BOLTON, M.Sc., F.R.S.K., F.G.S., DIRECTOR OF THE BRISTOL MUSEUM. LONDON: PRINTED FOR THE P A L7EONTOGR AP HIC AL SOCIETY. 1921—1922. l'KINTK)> BY ADLAKJJ AND SON AN I' \V KST N K\VM AN, LTI>., LONDON AND DORK I N SYSTEMATIC INDEX. INTRODUCTION ......... HABITS AND MODE OF OCCUR- RENCE OF FOSSIL INSECTS ... CONDITIONS OF LARVAL INSECT LIFE FOOD OF COAL MEASURE INSECTS CLASSIFICATION ...... FAUNAL ASSOCIATION... SYSTEMATIC DESCRIPTIONS ...... Order PAL.EODICTYOPTERA ... Family DICTYONEURIDJE Dictyoneura higgiusii Family ORTHOCOSTID/E Orthocosta PAOK 1 Family PTERONIUIID^E Pterouidia ... plicatula Family HYPEKMBGETHID.* Hyperiuegethes riorthumbriae Family CRYPTOVENIID^E Cryptoveuia moyseyi Family MECYNOPTERIDJE Mecyuoptera tuberculata INCERT.E SEDIS Pakeoinantis macroptera Family LITHOMANTID.* Lithomantis carbonarius ... Lithosialis ... brongniarti Pruvostia ... spectabilis Family BREYERIID^E... Breyevia wood ward iaua . I Id 11 18 24 24 24 25 25 27 29 30 30 82 32 34 35 35 36 36 37 40 40 42 42 43 45 46 48 48 50 50 50 Order PALJEODICTYOPTERA (r»nf.) Family SPILAPTERID* ... Spilaptera ... sutcliffei Family LAMPROPTILITI.*, Boitoniella , .. tenuitegminata Family BKODIID/E priscotincta juvenis furcata ... ... " Pterouepionites " ... jolmsnni ainbigua lepus Family ^NIGMATODIDVE j?Enigmatodes ... (?) regularis Pseudofouquea ... ... cambrensis INCERT.K SEDIS... Archeoptilus iugens ... Order MIXOTERMITOIDEA ... Cleroneura ... ... (r) ovata ... Order PROTORTHOPTERA ... jEdceophasma ... ... anglica Family COSELIIDJE ... Coselia palmiformis Family (EDISCHIID.E ... Genentomum ... (?) subacutum Xeroptera ... ... ... ol'tusata Scaloeoptera recta ... Order PROTOBLATTOIDEA ... Ptenodera .PAGE 53 :,:; 54 56 56 56 57 58 59 63 6ii 67 6S 68 69 7() 71 71 74 74 74 76 76 77 78 78 78 81 81 81 84 84 84 85 85 • 88 88 90 90 VI SYSTEMATIC INDEX. Order PROTOBLATTOIDEA (con/.} Ptenodera dubius I.vcERTjE SEDIS... Plesioidischia sp. Order BLATTOIDEA ... Family ARCHIMYLACRID.+; Aphthoroblattina ... johnsoni eggintoni Archimylacris hastata woodwardi incisa (Schizoblatta) vata SP. sp. . Phyloblatta sulcat a trausversalis ... (Archimylacridffi) kirkbyi BLATTOIDS INCERT.-E SEDIS h'amily MYLACRID.K Hemimylacris i)l it usa convexa obo- PAGE 91 92 92 93 96 96 96 100 103 103 106 Kt7 109 112 113 113 113 L15 118 119 L20 121 122 123 Order BLATTOIDEA (cunt.) Family MYLACRID.K (font.) Phylomylai-ris mantidioides Snoniylacris deanensis stock! burri . . Ortlioniylacris lauceolata . . . LARVAI, BLATTOIDS (Blattoidea) peaclii Leptoblattina exilis Order PROTODONATA Family MEGANEUBID* .Mi'L;aneura ... Boltonites ... radstockensis . . . INCERTA: SEDIS.. Tilly ardia ... multiplicata ADDENDUM Archimylacris pringlei BIBLIOGRAPHY . INDEX I'AUK 124 125 128 128 130 lol | '.'>'.'> 133 184 134 136 139 139 140 140 140 144 144 145 146 146 146 148 1 54 LIST OF TEXT-FIGURES. FIG. 1. Orthoeosta i 2. Pteronidia ^ 3. Hypermegethes inn-lliiinibrise 4. Cryptovenia ///•///.<./// 5. Meeynoptera fuJi^ri-nlut,! 6. Ditto 7. Palseomantis niin'i-njitera 8. Ditto 9. Lithomantis carbonarius 10. Litliintitilia lii-tinytiiarti ... 11. Pruvostia spectabUis 12. Breyeria woodwardiana... 13. Ditto 14. Spilaptera smffliji'i-i 15. Br:>,lin jirixi-nfi'iii'tii 16. Ditto 17. Ditto, fin-mil jnr, nig 18. Ditto 19. Brodin I'lii-fn/ii ... 20. " Pteronepionites ' julinsoni 21. ^Enigmatodes (.') i-i'i/itlarin 22. Pseudofouquea i-nmlirensis 23. Archaeoptilus ii, PAGE 28 30 32 36 37 37 41 U 43 47 48 51 51 54 59 62 64 65 66 68 71 73 75 FIG 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. dEdceophosma anglica ... Cuiti'liii jnil niii-'uniiist ... X' l'nji/fl-,1 ,,litllst:lfil iliibiiist ... Plesioidischia sp. Aphthoroblattina johngorii ... Ditto Aphthoroblattina eggintoni An-liinylacris luiftntn ... Archimylacris woodwardi ... Archimylaeris (Schizoblatta) obovafa l'/i//l:,!i/,itf:i fi-iuigversalis Heiuiiiuiliii-ris obtusa ... Phylomylacris inmitidioides Soomylacris deanensig ... Soomylacris at nek! ... Soomylacris burri Orthomylacris laneeolata Bottonites radstockensis ... Tillyardia mxltipUcata ... PAGE 79 82 85 88 91 92 97 97 101 Iu4 106 110 114 116 122 125 129 131 132 134 141 145 PREFACE. This monograph owes its existence to the friendly encouragement of Dr. A. Smith Woodward, F.R.S., Keeper, and of Dr. F. A. Bather, F.R.S., Deputy- Keeper of the Geological Department of the British Museum (Natural History), and to these gentlemen I am indebted for the loan of the undescribed Coal Measure fossil insects in their charge, and for much helpful assistance in other ways. Others to whom my thanks are due are the Director of the National Museum, Washington, U.S.A.: Dr. F. L. Kitchin, of the Museum of the Geological Survey; Mr. G W. Lee, of the Scottish Geological Survey; Dr. J. A. Clubb, of the Derby and Mayer Museums, Liverpool; Dr. W. B. Hoyle, of the National Museum of Wales, Cardiff ; Prof. W. S. Boulton, of the Birmingham University ; Dr. W. M. Tattersall, of the Manchester Museum, Victoria University ; Mr. L. Gill, M.Sc., of the Hancock Museum, Newcastle; Mr. 11. Y. Simpson, of the Kilmarnock Museum ; and Messrs. Eltringham, S. Priest, W. Egginton, and D. Davies. To Mr. W. J. Tutcher I am deeply indebted for his ready assistance in photographing all the various specimens submitted for examination. His remark- able skill has been always at my service, and by means of it I have been able to determine many details of structure which otherwise would have remained obscure. I am indebted to the Royal Society for several grants towards the cost of the work. H. BOLTOX. COSELIA PALMIFORMIS. 81 Family CoSGLinu-:, nova. A group of large-winged insects in which the principal veins are openly spaced ; the radial sector joined by an outer branch of the median, and the median sending a strong inward commissure to the cubitus. The family shows relationships with the (Edischiida?, Omaliidse, and Cacurgidae. Genus COSELIA, novum. iri'in'rii- Characters. — Costa and subcosta feeble, intercostal area very wide ; radius straight; radial sector arising near middle of wing. Cubitns S-shaped, its branches occupying most of the inner margin of the wing. Interstitial neuration of transverse nervures uniting in some areas to form an open mesh work. Coselia pahniformis, sp. nov. Plate V, fig. '•} ; Text-figure '.!•">. '/'///»('. — Basal half of a left \ving in counterpart in an ironstone nodule ; British .Museum (Johnson Collection, no. T. 158'.*:1,). Horizon and fjuniliti/. — Middle Coal Measures (binds between the "Brooch" and "Thick" coals); Coseley, near Dudley, Staffs. frjiffijir Characters. — Subcosta united to radius basally, giving off numerous branches, united by irregular cross-nervures, to the outer margin. Radius strong, divergent from subcosta. Radial sector diverging from . the radius. Median steadily divergent from radius and radial sector, and giving off an inner branch in the first third of the wing to the main stem of the cubitus. Beyond the middle of the wing, the median sending off several outer branches, the first uniting with the radial sector. Cubitus with its divisions extending over the greater portion of the inner margin of the wing. First anal vein strongly curved, the next thrice forked. l>i'.-ii. — This species is represented by a little over the basal half of a left wing, 54 mm. long and '20 mm. wide, showing the under surface only. The outer or costal margin is convex and very thin. The costal area very wide at its base (6 mm.) and diminishing towards the wing-apex. The subcosta is a feeble vein, apparently united basally to the radius, and passing outwards in a straight line towards the distal end of the outer margin, or into the outer part of the wing-apex. It gives off numerous branches to the outer margin, the branches being disposed regularly, and inclining apically in their course. They are joined by a few irregular cross-nervures, most of which are at right-angles to the branches of the subcosta. The radius arises with an inward curve near the point at which the subcosta is given off, diverging from it and following a straight line to the wing-apex. 11 82 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. The r;i. — l.'usi'lin juilnii/in-iiii!.. <_;rii ot sp. imv . ; din i;Tain of 1>asal portion of left win ;•;. showing- tin- general i-liavaetfr of tin- venation, three-lialvos natural size. — MieMle Coal Measures: Coseley. Stall'or.lslmv. Johnson ( 'olleetion, Hrit. Mus. (no 1. l.'.MCt). of the cubital area Iving bevond the junction with the median is extremely wide. The cubitus gives off four inwardly directed branches at wide intervals, the first branch having a wide forking in the first third of its length. The branches of the median must have occupied the greater part of the inner margin of the wing. The cubitus gives off six inward branches, the first arising very low down, and the remaining five at regular intervals, the first being given off a little way bevond the junction with the commissural vein. The first and fourth of these branches fork into two widely separated twigs. The first anal vein is simple, and has a broad convex outward sweep down to the inner margin; the second anal vein gives off three branches on its inner side. Other anal veins mav have been present, but the wing-st met lire is missing at this point . \\ ith the except ion of the subcosta and radius, all the main veins are widely spaced, and no branches arc given off, except the tirst median, m the basal third of I he w ing. The interstitial neural ion is well marked, and of unusual character. That COSBLIA PALMIFORM1S. of the intercostal area has been already described; that between the subcosta and radius, between the radius and radial sector, and between the radial sector and the median, consists of a few irregular cross-nervnres, one or two of which unite. In the median-cubital area the cross-nervures are joined up by longitudinal branches following a zig-zag course. A similar neuration is seen between the inner branches of the cubit us, while the anal area is crossed by irregular cross-iKTVures occasionally uniting, as in the fore-part of the wing. Affinities. — The general characters agree most closely with those of the Caeurgida?, a family of insects which Handlirsch has described from ironstone nodules found in and around Mazon Creek, Illinois, U.S.A. It comprises insects which possess well-marked characters, but which, as a whole, Handlirsch is unable to assign with certainty to the Protorthoptera, or to the Protoblattoidea (Handlirsch, 'Amer. Journ. Sci.' [4], vol. xxxi. 1<>11, p. 323). The wing of Gacurgus x/>il<>i>t<'i'ii$, Handlirsch, has the same wide costal area; the radial sector arises far out, and the median gives off a commissural vein to the cubitns. The central portions of the median and cubital areas are also very wide, and the anal veins have the same strong inward curve. The interstitial neuration is much similar, but the formation of a meshwork lias not proceeded so far in the British specimen as in ( 'in-itniiix spilopteruz, where it is present between all the main veins, except the costal and subcostal. In the British specimen the meshwork is chiefly developed in the median and cubital arras. Areolas are present in the wings of both species. The differences between the wings of the two species are, however, important, In Gacurgus y/iiln^tri'nx. the first branch of the median does not unite with the radial sector, nor does it approach it very closely, whereas in the British wing, the first outer branch must have united with the radial sector. The median also branches again further out, the median in C. xpifopti'nix having one outer branch only. Lithosiali* liriiiii/nim-ti (Mantel!) shows less affinity to the wing, but possesses the wide costal area, the same irregular and ramified interstitial neuration, but a more complex median and simpler cubitns. The commissural vein is also wanting. One other form with which a comparison needs to be made is Oinisciiin>:i-:, Handlirsch. !9nr>. Handlirseh, Pn>r. U.S. National Museum. vol. xxix, p. "lie,. and Die Ko.-,silen Inseki.-n. ].. 14:2. 1919. Handlirsdi. Revision der Palao/..isrljen lusekten. p. 39. IJ;i(li;il sector coalescing with the main stem of the median, and branching as if a part of (lie latter vein. Haiidlirsch regards the family as closelv related to the Sthenaropodidse. Goims GENENTOMUM, Seudder. 1885. lii-in-iiliniiiiiii, Sriiddfi-, Mem. Host. Sue. Nat. Hist., vol. iii, p. 3-j;i. 1893. 'AV/sr'/M, liron-mart, Famie Kntom. Terr. Prim. , p. 559. Generic Characters. — Wings aliout three times as long a^ \\ide ; principal veins and their branches well spaced, and united by a series of straight and well- defined nervures. Apex of wing obtuse. Considerable doubt exists as to the true relationship of this genus. Scudder referring it to the Homothetidas, Hrauer considei-ing it to have affinity with the Sialidaj, while Brongniart placed it with the (Mdischiida'. Genentomum (?) subacutum, Bolton. Plate V, fig. 4. 1911. Genentomum snil>in:/itnn>, Boltou, Quart. Journ. C4eol. 8oe., vol. l\vii. p. 33-1, ]>l. \\vii, tiu-s. 18, 19. 'l'i/jii'. — Two small wing-fragments. '.I mm. in length, and <> mm. in bivadth; Bristol Museum (no. ('. (.>7l'). ll»ri::. T///II'. — A right fore-wing in counterpart in nodule; British Museum (Johnson Collection, no. I. 1558). l-'i... L'ii. Xeroptera "'nl.-liiiv Johnson Collection, Brit. Mus. (no. 1. l.v>si Lettering as in Text-figure 16, p. •'- Horizon and Loc'ality. — Middle Coal Measures (binds between the "Brooch" and "Thick " coals); Coseley, near Dudley, Staffs. Description,. — The wing is not complete, the whole of the outer margin being missing, or hidden by the matrix ; the apex is raggedly torn, and much of the sii FOSSIL IXSKCTS OK TIIK IJHITISII COAL MKASTRKS. inner margin is missing. So far as preserved it is 41 greatest breadth. The fore-wing lies on a hind-wing which is partly traceable, and both have been cruni|il(Ml together, some of the veins of the hind-wing showing through the fore-wing. This renders the unravelling of the venation difficult, while the fragmentary condition of the stems of the main veins in the basal part of the wing hinders the definite determination of their course, and their relation to one another. A small portion of the distallv outer or costal margin has been uncovered sufficient to show that it was slightly convex. Close to the margin is a trace of the subcostal vein, proving that it continued well towards the wing-apex, if it did not reach the latter. The outer part of the wing has been torn away along the area separating the subcosta and. radius, and the latter vein is seen to traverse the whole length of the wing, but whether it joined the outer margin distallv or came out on the wing- apex is not discernible. The basal half of the radius is confused with the basal portions of the median and cubitus veins, owing to the crumpling which the wing has undergone. The radial sector arises in the basal half of the wing and diverges from the radius, a wide area separating the two. Soon after its origin it receives a branch from the median, and immediately afterwards gives off the first of three inwardly directed branches, the middle one soon dividing into two e<|iial twigs, while the first branch forks on the margin. These divisions of the radius and the radial sector occupy the whole of the outer part of the wing-apex. The first branch of the radial sector probably represents the union of two twigs of the radius and median, and the small marginal fork mav also represent their separation. The median vein is incomplete basally. and appears to be large and much divided. Apparently it separates early into two main branches, the first dividing into two almost equal twigs, which again fork, the outer branch of each fork going forwards as an oblique commissure and joining the vein next in front. This is a somewhat unusual feature. The course of the outer twig after its juncture with the stem of (lie radial sector we have already traced. The outer twig of the second branch of the median, after fusing with the inner t\\iu' of the first branch. is probably continued by the inner of the two later divisions formed by that I wig. The third branch of the median passes obliquely inwards, giving off an outer twig which forks twice, ami, be\ond the middle of the wing, yives off outer and inner branches from one point, afterwards forking twice before it reaches the inner margin of the \\ing. The whole structure ends m fourteen divisions on the distal hall ol the inner margin, and occupies a considerable area ol ihe \\hole wing. ll is possible that this complex of branching veins ivpre.M'iits the median and cubitus combined, but I do not think it likely. If such be the case, the first branch given XBEOPTBRA OBTTJSATA. 87 off from the main stem is the median with four ultimate divisions, plus a branch to the radial sector, all the rest forming a much-divided cubitus with miter branches. It' this interpretation is correct, the next veins in the series are anal. I'nfor- tunatelv, these are far too broken and uncertain in character to supplv any evidence on the point. The first vein has a bold sweep from the base of the wing well outwards towards the middle of the inner margin, and seems to divide into a wide fork before reaching it. The second vein is simple, and may also fork, but low down, although it is impossible to say whether or no the forked appear- ance is due to a fold of the crumpled wing. If the two veins present are anal, then the anal area is very large, and the divisions of the cubitus are directed so as to lie almost wholly in tin- distal half of the wing. This appears nnlikely. The divisions of the cubitus are usually simple, or but once forked, and usually directed inwards, ending normally on the middle of the wing-margin. The vein is united to the undoubted median stem and has a similar mode of branching, while its position on the margin is in the distal half. I see no reason, therefore, to regard this vein as a cubitus. The next vein, with its bold semicircular sweep to the margin, has the character of a cubitus, and so T regard it. The second more incomplete vein may also be a cubital vein or the first anal. The interstitial nenration consists of a numerous series of straight cross-nervures. The wing is thin and membranous. Affinities. — The salient features of this wing include the union of the median with the radial sector and of one branch of the median with another, the con- siderable branching of the median and its extension on to the inner margin, the reduced cubitus, a small anal area and the long spathulate shape of the wing. These general characters belong in varying degrees to a group of families, among which may be instanced the (Edischiida?, Sthenaropodida?, Spanioclerida?, and (leraridaa. The genus ll<'<->N7S). llnrh.iDi mill Lfn'ulif//. — JMiddle Coal Measures (binds between the "Brooch" and "Thick " coals); Coseley, near Dudley, Staffs. Description. — The inner maryin of the wing is lost or concealed in the matrix. FiQ.27.—Scalseoptera recin, gen. et sp. nov. ; <) mm., and judging from its apparent relationships, may have been more. The surface of the wing is slightly plicated, two low ridges bearing the radius and principal branch of the cubit us, while the snlicosta and the median are deeply sunk. Its membranous portion is strongly coriaceous, with stout cross-nervmvs at wide intervals. The outer margin and the principal veins are feeblv spinnlose. as best seen on the radius and radial sector. The outer margin is feeblv convex, the fairly straighl course of the margin, and of ;dl the principal veins, pointing to the wln^- being much longer than wide; a view also borne out. as we shall see later, by its possible relationships. The silbcosta is widel\ removed from the margin, parallel with it, and yivinn' off a series of stout branches passing olilnpielv outwards to the margin. Of the^e divisions, one onlv is clearlv forked. Two portions of the radius are present, a short basal port ion, and a second pieer lurther out. The vein is separated from the snbco.Ma bv an interval less SCAL^EOPTERA RECTA. 89 llinn half that separating I lie sulicosta and the margin. It lies also on a ridge which increases in strength distally. The radins and subcosta are parallel. The actual point of origin of the radial sector is not shown, but can be determined within narrow limits. It arises almost in the basal fourth of the wing, and so far as its course can lie traced, diverges from the radius. The median diverges along its whole course from the radins, and gives off on its outer side two branches, which remain undivided to the broken edge of the nodule. The first branch arises in line with the origin of the radial sector, and at an acute angle which soon enlarges, so that the interval separating it from the radial sector is less than half that separating them at their origin. The cubitns divides into two nearly equal branches very low down in the base of the wing, the second branch sending off a short division against the broken edge of the nodule. The stem of the median, and the two branches of the cnbitus. have a parallel course, like the outer margin, subcosta and radius, the widening interval between the two groups of veins being occupied by the radial sector, and the two outer branches of the median. The direction of the subcosta, radius, radial sector, and first branch of the median, indicates that they traversed almost the whole length of the wing and ended on the wing-apex. The main stem of the median and the branches of the cubitns would reach the distal half of the inner margin. There are no traces of anal veins. Affinities. — The extreme width of the intercostal area, the marked divergence of the costa, subcosta and radius from the median and cubit us, are features not readily recognisable among other known fossil insects. The few widely-spaced cross-nervures are not wholly peculiar to the specimen. Similarly, the spinulose principal veins are paralleled by those of Broil in [irixi'nti mi,/ and Archaeoptilus iiif/t'ii*. \ have not seen so marked a coriaceous texture in any British fossil insect. The length of the wing-fragment before branching of the principal veins occurs, implies a long and relatively narrow wing. Such a wing-form is seen in the Palreodictyoptera and in the Protorthoptera, The wing differs from that of Jirodin prim.'ofixcta in its much greater size, in the presence of a well-developed series of cross-nervures, and in the coriaceous surface of the wing-membrane. The direction of the radial sector and the divisions of the median vein are unlike those in RrmJin, where these veins curve steadily from their points of origin inwards to the wing-margin. O O Two groups of insects described by Ilandlirsch ('Amer. Journ. Sci.' [4], vol. xxxi, 1'Jll), from the Pennsylvania!! Series of the Carboniferous of blazon Creek, 111., under the family names of Spanioderida' and , appeal' to resemble most nearly the wings we are considering. The wings in these families are long and narrow, and obtusely rounded at the apex, and the principal veins, especially in the Spanioderida', pass straight out for the whole, or the greater 12 90 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. part, of their length. Their costal area is also broader than the subcostal-radial area, and in both families the interstitial nenration consists of straight cross- nervnres, except in the costal area, where they are oblique, as in this specimen. These resemblances, however, are not sufficient to justify the inclusion of the new wing among the Geraridre, because they are accompanied by equally or more important differences, such as the spinulose character of the principal veins, the great development of the intercostal area, the marked divergence of the stems of the radius and the median, the coriaceous wing-membrane and the much fewer cross-nervures. The wing, too, possesses quite a leathery texture, while the cross-nervnres are broad and flat, forming conspicuous details of the surface. With our present knowledge, it is only possible to infer that the wing is related to the Geraridre and Spanioderid;e, that it is a Protorthopteroid, and that it still retains traces of its Palseodictyopteroid ancestry. Order PROTOBLATTOIDEA, Handlirsch. The Protoblattoids have a well-rounded head, a prothorax showing little or no expansion, and the wings intermediate in type between those of Palasodictyopteroids and Blattoids. The anal areas of the fore-wings or tegmina1 are well marked out, and crossed by arcuate or oblique veins reaching the inner margin, while those of the hind-wings are enlarged and marked off from the rest of the wing by an anal fold. The body is more slender than in the majority of Blattoids. The members of this order form a connecting link between the Palaeodictyoptera and the Blattseformes. In manv respects there is a close resemblance between the members of the order and those of the Protorthoptera, and the two may have arisen from nearly related stocks. Genus PTENODERA, novum. Generic Characters. — Subcosta reaching1 almost to the wing-apex. Radial sector twice furcate; median well divided, with its minor divisions crowded on the inner half of the wing-apex. I have formed this genus to include a win^-fra^ment of unusual character in which the principal veins are long, and directed towards the wing-apex with few divisions, and the interstitial neurat inn consists of straight cross-nervures. The specimen shows thai the brandling of the principal veins is much similar to that of Polyetes among the Protoblattoidea, and to that of S/nniimli'i'ii scltuclierti, Hand!.. ammiL!' the I'rnt nil hopt era. in this respect support iniy I'rnvost. \\lio has estab ished 1 The thickened ri^i.l foiv-win^s of Bkitloi.ls uiv usually termed " li-iniiina." PTENODERA DUBIUS. 91 a sub-order, Archiblattides, to receive many of the insects classed as Protorthoptera by Handlirsch. The wing- is apparently related also to Scalseoptera recto, Bolton, and as the latter shows no trace of the formation of an anal lobe, I class this genus with the Protorthoptera rather than with the Protoblattoidea. The Protoblattoidea probably arose from a Protorthopteroid stock. Ptenodera dubius, sp. nov. Plate VI, fig. "2; Text-figure 28. - — Distal half of a left wing, on the split surface of one half of an ironstone nodule; British Museum (Johnson Collection, no. T. 1559). Horizon . 346. Plesioidischia sp. Plate VI, rig. 3; Text-figure l^'.i. Ti/}>t'.—A fragment of a right wing, Id mm. long and Id mm. wide; Manchester Museum (no. L. 400.")). ll»ri::ini nut] Lnca/ifi/. — Middle Coal Measures (binds between "Brooch" and " Thick " coals) ; Tipton, Staffs. ' Km. L'IP. rii'fiiniliscluii sji; diii^i-iiiii "I' vc'iml ii'ii "f wiutf-fragment, tlirrc- lialvrs nalm'al ize, Mi. Mir ('...•il MI-.ISMIV.- ; Tipton, Staffordshire. Manchester MM emu (no, I. I'.NP.'O. Description. — The wing-fragment lies on the irregular surface of a small i roust i me nodule, the outer costal margin and costal area on one hall ol the nodule, and the middle portion of the wing on the oilier. The liase BLATTOIDKA. <»3 and apex of the wing are missing, or still concealed in the matrix. Few definite factors are presented for determination, and the following description is the best we can give. The outer margin of the wing is formed by the costa, and seems to be curved basally and straight distallv. The costal area is widest at the base, and gradually narrows by the approach of the subcosta, which doubtless reached the outer margin far out. The costal area is crossed by a few stout straight branches of the subcosta. The subcosta passes straight from the base to the distal portion of the wing-margin. The radius is close to and parallel with the subcosta. It gives off two inward diverging branches, the first uniting with the median, but giving off a secondary branch before it reaches the latter. The median gradually diverges from the radius. It gives off two well-marked inner branches, and then bends forwards to join the first branch of the radius. The point of union of the two branches gives origin to a backward twig parallel with the secondary branch of the radius, and with the two inner branches of the median. The cubitus is represented by a long oblique vein going down to the inner margin. It gives off near its base an outer branch, which curves inwards parallel with the main stem, and reaches the wing-margin much beyond it. The wing appears to have broken along the level of a succeeding vein, but whether this was also a cubital or an anal vein it is impossible to determine. The interstitial neuration consists of a series of stout strong cross-nervures. The texture of the wing seems to have been membranous. AtJiiiitii'x. — The chief features of the wing are the strong parallelism of|the veins, the numerous and strong cross-nervures, and the unusual mode of union of the radius and median. This assemblage of characters serves to place the specimen in the Protorthoptera, but it is not referable to any known genus, and is too incomplete to justify a new genus for its reception. The nearest approach appears to be Progenentomum c< trim nix, Handl., in which the subcosta reaches the middle of the wing, the radial sector unites with the median, and the interstitial neuration is of straight cross-nervures. Order BLATTOIDEA. The most numerous and varied insects found in the Coal Measures are the Blattoids, the recorded forms being classified in several families, embracing nearly 100 genera and -1-00 species. The early history of their study is dealt with by 8. H. Scndder ('.Mem. Bost, Soc, Nat, Hist,,' vol. iii, pt, 1, no. :>, 1S7(.>), and need not be repeated here. Notwithstanding the abundance of specimens and forms known, they are insufficient for a satisfactory classification of the group, and do not provide the 04 FOSSIL IXSKCTS OF THE BRITISH COAl. MKASTRKS. stages in the life-history of any species. Handlirsch lias recorded the occurrence of several egg-cases of Blattoids from the Carboniferous (' I 'roc. U.S. National Museum,' vol. xxix, p. 7I<>, I'.Hlii). Larval forms have been described li\ Scudder, Handlirsch, Woodward, and cspeciallv by Sellards ('Ainer. Journ. Sci.' [4], vol. xviii, p. llo, 11)04), but in all eases the remains are too incomplete for satisfactory study. The Coal Measure Blattoids show unmistakably that the race had a much earlier ancestry, as they depart widely from the L'aheodictyopteroid type, and have attained a high degree of specialisation. The eggs were enclosed in capsules (Ootheca) much as in modern cockroaches, and the development was by a progressive metamorphosis, in which the rudimentarv wings were formed at a relatively early stage, and increased in complexity of structure and six,*' at successive ecdyses. It would also appear that the rudimentary wings were attached to the thorax by broad bases, and that the formation of an articular joint was not developed until the adult stage was reached. The elements of the thorax were as well developed in Coal Measure times as they are to-day, both in structure and function, while the legs, as seen in examples from Commentry (Allier), France, were long, spiny, or covered with stiff hairs, and well adapted for walking or running. The wings display a remarkable diversity of neuration. The fore-wings are invariably modified by the formation of chitin into stout, horny structures, usually termed "tegmina," which served to protect the more delicate membranous hind- wings concealed beneath them. The costa is always marginal. The hind-wings are not well known. When found, they are thin, membranous, larger than the tegmina, and folded beneath them. The enlargement of the wing has taken place over the inner half, the costal ami radial areas being reduced, and the anal area not marked off from the rest of the wing by a furrow, as is seen in the fore-wings or tegmina. The wide variation in the neuration of the tegmina furnishes the only satisfactory data for classification. Assuming, as \ve must, that the Blattoids were derived from the I'aheodiclyoptera. the simplest form of Blattoid must be that in which the wing-neiiratioii most nearly approximates to the latter type. This principle is the basis of llandlirseli's classification. Modification of the wing-membrane for Might in the ease of the hind-wings has brought about, or been accompanied bv, a narrowing of I lie costal and radial areas, a reduction in the strength and extent of these veins, and an increased development of the median and cubital areas, coupled with an increased growili of the wing-membrane mwardlv. The hind-wing is, therefore, a much more asymmetrical structure than the fore-wing or legmen. The abdomen is broad, somewhat flattened and well-segmented, but no positive evidence is known of an imagination of the terminal segments to carry the BLATTOIDBA. 95 egg-capsule. Cerci are present, and Sellards has identified lung ovipositors, though this identification is not accepted by Handlirsch. The habits of Carboniferous Blattoids can only be inferred from those of living- forms. I have previously (p. 11) drawn attention to the occurrence of Blattoid wings among the leaves of CorJuiti** bearing numerous shells of the small annelid, Spirorbis iJttsilhis, and suggested that the Blattoids frequented decaying vegetation to feed on the N/»/'/v//7i/'x and similar organisms. The tegmina of 'r/ii//nun/lhiHip*ii in coal shales of the Durham Coalfield. Most of the other Blattoid remains from the Coal Measures of this country have been found in sedimentary deposits in which Ustracods also occur. Apart from these facts, the general faimal associations of fossil insects to which I drew attention on pp. 18 — 24 are, I think, of great importance, as furnishing definite clues to habits. The same Arthropod-association still persists, and the lagunal and marshy phases of the Coal Measures would furnish a fitting and desirable environment for the whole series. l''ltxx!jii_-. 710, and I>ie Fossileii Insekteu, p. IS:!. Generic < '//^/v/r/r/v--. — Tegiiiiua two-and-a-half times as long as wide, with convex outer margin. Costal area narrow and strap-shaped. Snbcosta extending over two-thirds the wing-length. Radius giving off radial sector near middle of wing, and sending a few simple Branches to the apex. Radial sector forking into four or six branches. Median small, with few branches directed inwardly. Cubitus giving off 7 — ^ branches alono- its whole length, and extending well out O O O ' ' ^ towards the wing-apex. Anal area small. Aphthoroblattina johnsoni (Woodward). I'late YLligs. t,5; Text-fignres 30, 31 . 1-t/tiltltillinti jiiliiixniii. \V 01 id ward, (Iml. Mai:. '•'' • vol. iv. p. ">:!. |>l. il, li^s. 1 c. 1 I'. HUH;. Aphthoroblaltina, Handlirsch, l>ir Kossilm lns.-lj<'ii, ].. is:!. I'. — The pronotum and tegmina in an inverted position with traces o| hind- wings on a small ironstone nodule, in counterpart: British Museum (Johnson Collection, no. I. K»i;7). APHTIIOROBLATTIXA .KWNSOM. '.•7 :!!// inn! //«(•/(/////.— -Middle Coal Measures (binds bet ween the "Brooch" and " Thick " coals) ; Coseley, Staffs. S/irrijii- I '/Kii'nrh'i'x. — Tegmina slightly convex ami expanded towards the apex, alxiut two-and-a-quarter times as long as wide. Apex broadly nmmled. Costal area occupying three-fourths of the outer margin of the wing. Subcostal vein weak. Radius almost straight and giving off the radial sector about the middle of its length. Radial sector doubly furcate. Median vein widely spaced across the middle of the wing. Cubital vein reaching the inner angle of the wing-apex, giving off outer and inner branches. Anal area large, and crossed by a few small anal veins. Hind-wings thin, larger than the tegmina, and with strong veins. Description. — The elucidation of the neuration of the wings of the type specimen is difficult, owing to the venation of the hind-wings being impressed Pio. 30. FIG. 31. FIG. 30. — Aphthoroblattina johnsoni ( Woodward) : diagram of venation of the two fore-wings ',f tin- type-specimen, twice natural size. — Middle Coal Measures (binds between " Hrooch " and " Thick" coals); Coseley, Staffordshire. Johnson Collection, Brit. Mus. (no. I. 1067). FIG. 31. — Aphthoroblattina johnsoni i Woodward) ; diagram of venation of the fore-wings of a normal example of the type-series, twice natural size. — Same horizon and locality as Fig. 30. W. Egginton's Collection, "no. 2." on that of the tegmina. The veins of the hind-wings are stronger than the distal portions of those veins of the tegmina which they overlie. It is probably owing to these factors that the original figures of the type are incorrect. In both tegmina, as indicated by Dr. Woodward, the median and cubitus are shown as united, whereas this union takes place in the left wing only. Neither of the figures gives an adequate indication of the presence of the hind-wings. In the larger figure the radius and cnbitns are represented by a single vein, which is also incorrect. Allusion has already been made to the wings lying on the smaller portion of the nodule in an inverted position. This is demonstrated by the pronotum, which dips under the mesonotum into the matrix, and by the deep impressions of the veins of the hind-wings crossing over, and not under, the veins of the tegmina. The veins of the tegmina are also in relief, instead of being sunken as they normally are on the dorsal surface. 13 98 FOSSIL TXSLTTS OF TTTK BRITISH COAL M K.\sr UES. The pronotnm li:is ;i diameter of I :'> iiini.. :MK| S nun. of its length is exposed. The sides curve evcnlv backwards, and show no si»-n of flattening, so that its . i* o •* general shape is semicircular. The hinder border is hidden, and disposed at an tingle to the surface-plane of the \vmgs. The presence of a sunken, central, pyrit'orm area on the inner surface of the proiiotum probably marks the position occupied by the head of the insect. The downward inclination of the front margin of the pronotum, and the elevation of the hinder border, is a t'reipieiit feature in the Coal Measure Blattoids. During life a small gap interposed between the pro- and mesonotinn, and this became tilled up by sediment on burial in sufficient (piantitv to cause the pronotum to be lifted from the body of the insect by that half of the nodule which carries the wing-impressions. This inclined position of the pronotnm is so common that it appears to have been normal. The mesonotal area is covered by the anal areas of the tegmina, and its character cannot be determined. The venation of the right tegmen differs considerably from that of the left. The under surface of the latter is the more nearly perfect, and the venation is more distinct. The costal margins of the tegmina form two broad arcs, sharply bent inwards at the base, and distally merging into the wing-apex. The left subcosta is widely separated from the margin, giving off three oblique branches which fork, the first twice, before reaching the margin. Beyond these branches, the left costa curves inwards and unites with the main stem of the radius tit the disttd third of the wing. The right costa is more normal, and does not unite with the radius. It gives off six outward branches, of which only the lirst is forked. The left radius, after a slight basal curve, passes straight out to the apex, giving off four forward branches, the first forked. This first forked branch appears to be the continuation of the subcosta. The radius of the right tegmen gives off two simple outer branches only. There is a wide difference between the radial sectors of the two tegmina. That of the left divides in the middle of its length into two equal branches, which in turn fork, the outermost twig forking again, so that the radial sector ends on the margin in five divisions. The right radial sector forks once onlv beyond the middle of its length, and ends on the margin in only two divisions. The median in each tegmen is a comparatively simple vein, that of the left being united with the cnbitus in the basal Fourth, and separating from it at tin acute tingle. Beyond the middle of the wing it gives oil' a, single forked branch on its outer side. These divisions of the median, with the first branch of the radial sector, occupy the inner hall ol the apex. The median of the right tegmen is well separated from the CubituS along its whole length, and passes in a bold curve to the inner hall of the apex, giving off four simple outer branches. Apart from its union with the stem of the median, the cubitus of the left APHTHOKOBLATTINA JOHNSON F. <»'.) teamen agrees fairly well with its fellow. Both veins curve inwards, and reach the junction of the inner margin with the apex, and both give off 6 — 7 branches inwardly, the first branch in each case forking. Which forward branches were given off on the outward side of the cubitus in the left teginen cannot be made out. but faint furrows on the right tegmen seem to indicate that three simple outer veins were present. The anal area is long and acutely ovate, extending over nearly a third of the inner margin. Six anal veins are present, the distal one with a strong fork. The interstitial neuration consists of stout, straight nervures, not always well shown. The inner margin is nearly straight. The veins of the hind-wings arc very fragmentary. They are much thinner than those of the tegniina, and have left a much slighter impress. They appear to consist of a straight costa, separated by a very narrow area from an equally straight subcosta, below which can be made out a portion of the radius, radial sector, and median. All the veins are widely spaced, and the breadth of the hind-wings must have been about double that of the tegmina. The dissimilarity between the neuration of the left and right tegmina in tin- type-specimen suggests a wide varietal range among Coal Measure Blattoids, a feature which needs to be taken into account in the definition of species. The presence of these abnormalities in the type-specimen somewhat militates against its value for reference, and I therefore add other details from a second example which I received from Mr. W. Egginton. The specific characters given above have been drawn up from this specimen, which lies in a small ironstone nodule, marked " No. 2." having a length of -to mm. and a breadth of 38 mm. The Blattoid has a total length of oo'5 mm., and a maximum breadth across the tegmina of 24111111. The inner margins of the tegmina overlap, evidently in their position of rest during life. The pronotum, apparently in natural position, lies a little out of the horizontal, the front margin dipping downwards, and the hinder margin upwards and a little forwards, so that a slight gap occurs between it and the wings. This feature we have already alluded to, and in this ease the pronotum has been carried away as usual, but the wings remain, so that the wing-impressions with the pronotum are on the upper surface of one half of the nodule, the other half carrying the pronotal impression and the wings. The pronotum is 12mm. wide and broadly rounded, only a little more than half being visible. It shows a central raised area, oval in outline, and defined from the margins by lateral grooves. The meso- and meta-notal segments show as a low. fiat, elongated, heart-shaped region overlain by the anal areas of the tegmina. Both tegmina are still attached high up on the sides of the body. So far as can be determined through the substance of the tegmina. the hind-wings are 100 FOSSIL IXSKCTS OF TIIK BRITISH COAL MKASTHMS. attached nearer the middle line, and alnio>t mi tlie upper surface. All four wings are present, tin- teamen of the right side being perfect, while that nn thiv lett has lost a portion of the inner part of the apex. The right legmen is ll") nun. long, and 12 mm. wide at its broadest part. The costal margin is broadly arcuate, and merges into a well-rounded apex. The siibeosta is feeble, and gives off 7 — 10 very oblique branches, each breaking up into numerous twigs before reaching the margin. The intercostal area is wide and strap-shaped, and occupies the greater part ol the outer margin. The radius is well separated from the subcosta at its base, and diverges a little from it along its course. It gives off the radial sector before the middle of the wing is reached, and then passes forward undivided until near the end of the sub- costa, where it gives off four or more short oblique branches forward. The radial sector diverges strongly from the radius, ami, like the latter, remains undivided for the greater part of its length. In the last third it gives off two, possibly three, outer twigs, which fork before reaching the margin. The inter- radial area at the point where the first branch arises is very wide. The median arises close to the radius, but soon bends stroiiglv towards the inner side of the apex. It gives off three outer parallel branches, the first of which forks. The cubitus is a powerful and lar^e vein, well apart from the median at its origin, and passing above the middle of the wing in its proximal third, beyond which it curves inwards to the end of the inner margin. It gives off six simple branches and ends in a feeble fork, while two strong branches arise on the outer side and pass to the apex. The anal area, is large, occupying one-third of the margin, and containing six anal veins, the first, second and third forking. The inner margin is almost straight. The interstitial ueuration consists of numerous raised cross-nervures, best seen in the anal and cubital areas. In the radial and median areas the cross-nervures unite laterally and occasionally fork. Portions of the hind-wings are present, but only the distal branching of the radial sector, median and cubitus is shown beyond the broken end of the lett legmen. The course of the radius and median is t raceable across t he surface of the legmen of each side. The wing-membrane is so tlnn as to be scarcely discernible. Aphthoroblattina eggintoui, sp. nov. Plate \'l. fig. 6; Text-tig i1. — Prmiotiim, teyimiia and portions ol hind-wings King on the surfaces of a split irons! one nodule ; " No. I " in the ( 'oiled ion ol Mr. \\ . Eggilll on. I li'i'i::nii ii ml TjOCCllitll. — Middle ('oal Measures (binds between the " Urooch and " Thick " coals) ; Coseley. near Dudley, Staffs. APHTHOROBLATTINA EGGINTONT. 101 Y C'/iaracft'i-fi. — Costal margin convex. Cubitus long, strap-shaped, and extending almost the whole length of the outer margin. Radial sector \vith few simple branches. Median vein forking three times, and ending in middle and inner side of the wing-apex. Cubitus extending the whole length of the inner margin, with no evident outer branches, and feeble forking. I >,<.-<• ri [it itn/. — The specimen is contained in a small greyish-brown nodule, 48 nun. long and 35 mm. wide, and lies with the dorsal surface of the wings and the impression of the pronotum on one half of the nodule, and the wing-impressions and pronotum on the other half. The remains are in good condition, and show a small portion of the head, the pronotum and mesonotum, almost the whole, of the left tegmen, and the basal two-thirds of the right tegmen, while a portion of the left hind-\ving is disclosed over that area from which the fragment of the FIG. 32. — AplttlwrnMiittin'1 r2 FOSSIL IXSF.CTS OF THK BRITISH TOAL MEASURES. back. The central area has a deep median furrow, and is marked oft from the lateral halves by two ridges (representing the furrows on the dorsal surface). These ridges converge anteriorly and almost meet. The inner surface is slightly concave, and indented by three faint furrows on each side, parallel with which are traces of tine st rial ions. The mesonotum is -I'o mm. long, and much wider anteriorly than posteriorly. It is convex, and the hinder border has a raised rounded edge. It is strongly chitinous, much more so than the metanotum, which is crushed down beneath the anal areas of the tegmina, only a little of the hinder portion of the left side showing at one point where the anal areas of the wings have been broken away. The right tegmen lies in the position of rest, its inner margin being in line with the axial line of the bodv. The left tegmen was rotated outwards to a slight degree before entombment — a feature which, combined with the breaking away of its distal third, has enabled the left hind-wing to be better shown. The right tegmen has a length of oo mm. and a breadth of I '.\ mm. The costal margin is moderately thickened, convex, and merges gradually into the wing-apex, the latter bluntly rounded. The subcostal vein is thin, and encloses a long strap-shaped area, crossed by 0 — ]<> oblique branches, most of them forking twice before reaching the margin. The radius is a strong vein, nearly parallel with the subcosta, and ending on the outer margin in four small branches, the second only forking. The radial sector arises just before the middle of the wing, diverging but slightly from the radius. It gives off three short outward branches to the apex. The main stem of the median passes along the middle line of the wing for some distance, and curves inwards to the distal end of the inner margin. The first outward branch arises a little beyond the middle of the wing, and forks into two equal-sized twigs; the remaining two branches remain undivided to the broken edge of the wing. The median and its subdivisions occupy the centre and inner half of the wing-apex. In the left tegmen the second branch of the median forks. The ciibitus is strongly convex in the proximal two-thirds, and bends forwards in the distal third and inwards again to the inner margin. It gives off six inward branches, the fourth and fifth forking before reaching the margin. The anal veins are eight in number, three being verv small and short. The first forks twice, and the second once. The inner margin is almost straight. The inters! it ial neuration is made up of straight nervures. The surface of the tegmina is chitinous. The hind-wings appear not only to have been covered by (he tegmina. when they \\ere in a position of rest on the bodv, but to have stretched a little beyond I hem like a frm <_!'e. The left hind-wing is thin and membranous, and marked by numerous veins, tin-' bases .-till hidden under the legmen. A little of the distal portion of the ARCHIMYLACRIS HASTATA. 103 costal margin is shown, passing into a very broad and expanded apex. The subcosta reaches nearly to the end of the costal margin, and gives off numerous oblique and forked branches Immediately behind the sulicosta is a stout vein with two outer branches, both forking. This vein seems to be the radius. Tts basal extension under the legmen can be traced by a raised line. Behind the radius are two stout veins, each of which forks into equal-sized twigs some distance from the margin. Their position justifies the inference that they unite proximally and join the radius, in which case they must belong to the radial sector. The median is a doubly forked vein. The remainder of the wing is either bent under, or folded upon itself, and further details cannot be made out. Affinities. — The species differs from Aphtlioroblattinajolinsom in several important details. The radial sector arises further out, and instead of forking twice, gives off three simple forward veins. The median forks three times, the proximal branch forking again before reaching the wing-apex. In J. julnixniii there are two branches, both of which fork. The cubit us vein differs considerably owing to the fact that the main stem divides at the outer third into two branches of equal strength, the outer immediately forking again into two equal twigs, while the inner gives off a small inner twig. No definite outer branches are distinguishable. A strong anal furrow is present, and the first anal vein on both sides divides into three twigs, the remaining 5 — G anal veins being undivided. Genus ARCHIMYLACRIS, Scudder. 1868. Arrli'ninjltK-r'm, Sciultler. in Duwson's Acadian Geology, ed. 2, p. 388. Generic Characters. — Tegmina twice as long as wide, with convex outer margin. Inner margin concave. Radial sector arising in basal half of wing. Anal veins O O O few, anal area large. Neuration of abundant stout straight cross-nervures. Archimylacris hastata, Bolton. Plate VII, fig. 1; Text-figure 08. 1911. Archimylacris (Etoblattina) Imatufa, Boltou, Quart. Journ. Geol. Soe., vol. Ixvii, p. lilo, pi. ix, figs. 1_3. '/'///"'• — '^ue greater part of a left tegmen and its counterpart, showing the upper surface; Museum of Practical Geology, Jermyn Street (nos. 24501 and 24502). llm-i-uii niul Locality.— Upper Coal Measures (Gellideg Level of the Mynyd- dislwyn Vein) ; near Maes-y-cwmmer, Monmouthshire. tfjierijir I 'h« rnrli'i-*. — Wing broadly elliptical. Costal margin convex; costal area broad at base and stretching beyond the middle of the wing. Subcosta with numerous branches, all oblique. Radius forking twice, and ending near 104 FOSSIL INSECTS OF THE BRITISH f'OAL A apex of wing. Median branching further out than the radius. Cubitns reaching margin in distal third of winy. Anal veins numerous. Inner margin aliiinst straight. [)excription. — A portion ot the base of the wing and a considerable part of the apical and inner margin are missing, lint the length preserved is :'>:'>•)• nnn. and its breadth is 1 nun. The wing is strongly outlined, especially along the outer margin, partlv owing to a broad concave depression which runs almost the whole length of the subcostal and radial areas, causing the anterior margin tc reflexed dorsallv. The inner margin is preserved only along a portion of the anal border, and the inner two- thirds of the wing-apex are also missing. Sufficient is left of the apex to show that it must have been bluntly rounded. ffl FIG. 3M. — ArcMmylacris hmstntn. I!<.lt<>n; diagram of venation of left fore-wing, tlirfe times natural size. --Upper Coal Measures (Grellideg Level of the M\iiy. 'Alcmoires pour servir a 1'Bxplication de la Carle (ieologique Detaillee de la I'Yance.' p. 1-M), but I cannot perceive this. The median vein [irises in actual contact with the stem of the radius, or is ARCHIMYLACRIS HASTATA. 105 united with it, rapidly diverging to the distal part of the inner margin. Four branches are given off on the outer side, the first forking before the broken edge of the wing is reached. The remaining three probably forked also on the missing part of the wing-apex. The subdivisions of the median occupy the inner half of the wing-apex, and the apex itself. The regularity of arrangement of the minor veins is a marked Feature of this wing, and lends colour to our supposition. The cubitus gradually diverges from the median along the whole of its course. Ten branches are given off on the inner side, the first only forking. The anal area is sharply marked off from the rest of the wing by a deep anal groove, the anal area being elevated and somewhat convex in outline. Ten to eleven anal veins can be distinguished, the marginal ones being very short and feeble. The interstitial neuration consists of close, strong, transverse nervures so numerous as to give the wing-surface a finely corrugated appearance. The tegmina were apparently of great strength, the unusual development of the transverse nervures adding to the rigidity, while the presence of an oblique ridge served to support and strengthen the radius, median and cubitus at their base, and a similar ridge gave support to the whole of the anal area. Affinities. — In 1911 (Inc. eif.) I gave reasons for regarding this species as an Archimylacrid, comparing it with .1. spectabilis, Goldfuss, and J. rnnixfn. More recently, Dr. Pruvost ('Ann. Soc. Greol. Nord,' vol. xli, p. 335, pi. ix, figs. 4 — 4 n, T.I12) has expressed the opinion that it is so nearly like A. lelf/ica, Handlirsch, and a specimen he has himself described from the roof of the Alfred Vein, Lievin, Northern France, as to be referable to that species. An examination of the figures published by Handlirsch and Pruvost does not support this view. Afi-liiiiu/lacrtx belyica was founded by Handlirsch ('Mem. Mus. Roy. Hist. Nat. Belg.,' vol. iii, p. lj!, pi. iv, figs. 17 — 18, 1'.MJli) on a wing in the Brussels Museum, from the West- phalian or Middle Upper Carboniferous of Jemappes, Belgium. It was afterwards transferred by him to a new genus, Pareltlioblattit ('Die Fossilen Insekten,' p. 184, pi. xviii, fig. 54, 1!»0(3). This new genus is not accepted by Pruvost, who considers that it is founded chiefly on the pectinate character of the first branch of the radius. He therefore replaces the species in the genus Archimylacris, and refers his own specimen to the same genus and species. With this conclusion I cannot agree. Handlirsch's species is characterised not only by the pectinate character of the first branch of the radius, hut (and much mure important) by the presence of a meshwork of interstitial neuration between the radius, median and cubitus. This latter feature clearly separates not only the French specimen from Handlirsch's genus Parelthoblatta, and therefore from P. behjica, but the British specimen also ; for in both the interstitial neuration consists wholly of a close series of straight cross-nervures, with not the slightest trace of the development of a network. 14 ] 0(5 FOSSIL TXSKCTS OK TIIK MIUTISH COAL MEASURES. A. liitxlittn is closely allied to the French species, but the divisions of the main veins are fewer and of a more simple nature. I see no reason to remove the British species from the genus Archimylqcris, and would refer the French example also to the same genus. This view is now accepted by I'nivost (In,-, elf., p. ].">8). Archimylacris woodward!, Bolton. Plate VII, fig-. 2; Text-figure :U. 1910. ArrJilmi/Iiicris (Etoblattlna) u-uwJ irt< nl i , Bolton, Geol. Mag. [5], vol. vii, pp. 147 — 1M, pi. xv, figs. 1 — 1 «. Tijpi'. — A left tegmen or fore-wing, IS mm. long and 10 mm. wide; collection of Mr. I). Davies, F.G.S. Horizon inn! Lurnliti/. — (V>al .Measures (a ten-foot shale overlying the Xo. - Rhondda Seam, base of the Pennant Scries] ; ( 'lydach Vale. South \Vales. /' ( 'Inii-iii'fi',:-!. — Wing short and broad. Apex well rounded and merging Fio. 34. — Archimylacris woodooardi, Bolton ; diagram of wing-venation of left fore-wiiif*. three times natural size.— Base of Pennant Series imof ,,f ton-t'<".t slink overlying the No. -' KliomLla Senin) ; <'lyilacli Vale, South Wales. 1'avi'l Davies Collection. into costal border. Anal area convex. Interstitial neuration of abundant stout cross-nervures, occasionally uniting laterally. Description. — -The tegmen, which is short, broad and strongly chitinous, lies with the convex dorsal surface uppermost. The well-rounded outer margin of the wing merges into the equally well-rounded apex. The inner margin is nearlv straight, a slight hollowing only of the' middle portion being shown. Notwith- standing its small si/e, the details of the wing art1 very clear, the veins and the interstitial neuration being well shown. The basal portions of the main veins are elevated above the surface, the rest of their length and also their divisions being sunk below I he general level. The subcostal vein is weak, and sunk along its whole course. It is widelv separated from the costal margin, following a parallel course to beyond the middle of the wiiiu1, where it bends outward and joins the margin. The subcosla gives off a numerous scries of forked and simple divisions to the costal margin. The radius arises close to the subcosla and median, diverging from the former in the middle of its length, ami approaching it again by the lirsi of the four outer ARCHIMYLACRIS INCISA. 107 branches which it gives off. The first two branches of the radius are forked, the rest undivided. The radius with its divisions occupies the distal third of the wing-margin. At the junction of the basal and middle thirds of the wing, the radius gives off a strong radial sector which diverges from it, giving off two outer branches, the first forking twice into four twigs. The radial sector occupies the outer half of the wing-apex. The median curves regularly inwards along its whole course, reaching the inner end of the wing-apex, and giving off three outer branches, of which the first is forked. With its subdivisions it occupies a much less area than any other main vein. The cubitus follows a course nearly parallel with the median, and gives off nine inward branches. With its subdivisions, it occupies almost the whole of the distal two-thirds of the inner margin. The anal area is strongly convex, and crossed by at least five anal veins, the third being forked. The interstitial neuration is well developed in the neighbourhood of the subcosta, and consists of a close-set series of straight cross-nervures. These are in relief, and in places seem to unite laterally, and to cross the main veins. .\tfrnities. — The wing is typically Archimylacrid. At the time of its discovery in 1910 I was unable to show that it possessed a close relation to any known species, but more recently Dr. Pruvost has recorded a very similar example, A. ntrc/iaticn, Pruv., from the Coal Measures of Bruay, Northern France. The presence of a well-defined radial sector is a Palaeodictyopteroid feature which most Blattoids have lost, and stamps the species as primitive. It is therefore interesting to find that Pruvost draws special attention to the fact that .1. iiti'i-lintlL-it, Pruv., is the oldest Archimylacrid of the Northern French Coal Measures, being found in the lower portion of the Formation of Bruay, over the vein Ernestine at Lens, in a shale containing seeds and drifted plant-remains. Archimylacris incisa, sp. nov. Plate VII, fig. ;'. Ti//n\ — Pronotum, mesouotum, and the basal portions of the tegmina in an ironstone nodule; British Museum (Johnson Collection, no. I. 15900). H»ri:.<:«-r!i>fi