595 70673 AS S. L LIBRARY. ray ie t f | soe : PX) a wi wi MEMOIRS : OF THE AMERICAN ENTOMOLOGICAL SOCIETY > NUMBER 8” THE EUMASTACINAE OF SOUTHERN MEXICO AND CENTRAL AMERICA BY JAMES A. G. REHN AND JOHN W. H. REHN vo vA 96462 —. Wa pf TION as. muser PUBLISHED BY THE AMERICAN ENTOMOLOGICAL SOCIETY AT THE ACADEMY OF NATURAL SCIENCES PHILADELPHIA 1934 THE AMERICAN ENTOMOLOGICAL SOCIETY PHILADELPHIA Founded 1859 Incorporated 1862 Organized as “The Entomological Society of Philadelphia,” the present title was adopted February 11, 1867. PRESIDENT : VicB-PRESIDENT Roswell C. Williams, Jr. Max Kisliuk, Jr. CoRRESPONDING SECRETARY RecorDING SECRETARY Ezra T. Cresson, Jr. Rudolph G. Schmieder TREASURER James A. G. Rehn Finance CoMMITTEE ‘ PusLIcATION COMMITTEE Philip P. Calvert ; James A. G. Rehn - Carl Fenninger Eprror Philip P. Calvert Frank M. Jones Ezra T. Cresson, Jr. Morgan Hebard Stated Meetings are held in January, February, March, April, May, September, October, November and December. The offices, meeting-room, library and collections of een are in the Entomological Department of The Academy of Natural Sciences of elphia. SERIAL PUBLICATIONS OF THE SOCIETY Proceedings of The Entomological Society of Philadelphia, volumes I-VI, 1861-1867. Out of print and cannot be supplied Transactions of The American Entomological Society, volumes I-IV, out of print and cannot be supplied; V—date, price on application. Published in annual volumes of quasieny numbers. Subscription price $5.00 per volume. : The Practical Entomologist, volumes I-II, 1865-1867. Price $4.00 for the two volumes. Memoirs of The American Entomological Society, No. 1, 1916, price $2.00; No. 2, 1917, price $4.50; No. 3, 1919, price $1.50; No. 4, 1920, price $2.50; No. 5, 1928, price $2.00; No. 6, 1929, price $2.00; No. 7, 1930, price $4.50. Entomological News, volumes I-LXI; many out of print. Subscription price $3.00 per annual volume. Various irregular, non-serial publications have been issued, which may be found in our price list under their respective authors. To establish the date of issue, each paper, as soon as completed, is placed on sale and a copy of it is mailed to each of the following institutions, with a request that it be placed in their library for reference, Entomological Society of Ontario Boston Society of Natural Hiatory Entomological Society of London American Museum of Natural History Société Entomologique de France Smithsonian Institution Deutsche Entomologische Gesellschaft Field Museum of Natural History Societa Entomologica Italiana California Academy of Sciences Separates of papers published in the Proceedings and Transactions, if not out of print, can be supplied at prices given in our price lists, which are sent. upon application, stating order or orders desired. The Society has also inaugurated a system of subscrip- tion to papers published by it on individual orders, which arrangement is of material benefit to the student who desires promptly the literature on any special group, but who does not desire to subscribe to entire volumes of the Transactions. A method of noti- fication of the appearance in its publications of papers relating to individual orders or subjects has been developed by the Society. Information concerning these arrangements supplied upon application. In sending subscriptions or in making inquiries relative to publications, address: THE AMERICAN ENTOMOLOGICAL SOCIETY, Academy of Natural Sciences, Logan Square, Philadelphia, Pa. a MEMOIRS OF THE AMERICAN ENTOMOLOGICAL SOCIETY NUMBER 8 THE EUMASTACINAE OF _ SOUTHERN MEXICO AND CENTRAL AMERICA BY JAMES A. G. REHN AND JOHN W. H. REHN PUBLISHED BY THE AMERICAN ENTOMOLOGICAL SOCIETY At THE ACADEMY OF NATURAL SCIENCES PHILADELPHIA 1934 Issued April 14, 1934. 545. TOC AS AS! § dnrareks MEMOIRS OF THE AMERICAN ENTOMOLOGICAL SOCIETY NUMBER 8 THE EUMASTACINAE (ORTHOPTERA; ACRIDIDAE) OF SOUTHERN MEXICO AND CENTRAL AMERICA By James A. G. REHN AND JOHN W. H. REHN There is no group of acridoid Orthoptera which on the whole is more interesting or weirdly specialized than the Eumastacinae, yet few working orthopterists have been privileged to know these fascinating locusts in life. As one of these fortunate the senior author developed a special interest in the group as early as 1909, when Morsea was encountered and Psychomastax discovered by him in California. This interest steadily increased as his ac- quaintance with the species of the subfamily broadened through field work in Central and South America, in the former of which regions particular attention was paid to these insects during three seasons of field exploration. The bush-loving North American eumastacids prefer different environments from those of most of the Central and South American species, but all of these agree-with many of the other members of the subfamily found elsewhere in the sprightliness of their actions and their characteristic posture. With legs akimbo and their short antennae erect and parallel, they sit, vigilance personified, on bush tops in chaparral, silhouetted against the sky, on undergrowth foliage in dark rain-forests, or on the ground or low ground cover in mist-soaked mountain forests. The amount of Central American material and correlated in- formation now available has made desirable the preparation of a comprehensive study of the subfamily as found in Central America and adjacent southern Mexico. This is particularly warranted MEM, AM. ENT. SOC., 8. 2 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) as the extensive series now before us, from the Philadelphia collections, embraces all but one of the species now known to occur in the area under consideration. Rehn and Hebard more than a decade ago presented in the “Transactions”’ of this Society! a study of the Eumastacinae found in the United States. Much detailed information supple- mentary to that contained in the same paper recently appeared from Mr. Hebard’s pen. Nothing is known regarding the Eu- mastacinae which certainly occur in northern and central Mexico, in suitable environments. The sole vague record from ‘‘ Mexico”’ in the literature of the past is discussed on a following page under the genus Eumastax. The genus Tezcophrys was described by Bruner? from the Cape San Lucas region of Lower California, on the basis of an imperfect female and two very immature specimens. No additional information on this genus is available and its exact relationship remains problematical. In order to make the present study comprehensive and con- structive in its scope and treatment, we have limited its area on the north to southern Mexico, or to be more exact that portion below the Isthmus of Tehuantepec, thus confining it to the geo- logical, if not political, unit of Central America. Whether the rank of the entity here discussed should be that of a family or of a subfamily we shall leave to future research. Burr in his classic ‘‘Essai sur les Eumastacides’’? considered the primary divisions of the eumastacids to be sub-tribes or groups, but in his treatment in the Genera Insectorum‘ he departed from this arrangement, gave them as a whole family rank and called his previously segregated sub-tribes sub-families. In 1914 Candido Bolivar, in one of his earlier papers on the group,® used the term “‘sections”’ for the major divisions of the Eumastacinae, which he there considered a subfamily. In the first part of his ‘ Mono- 1 Vol. XLIV, pp. 223-250, pls. xi-xvi, (1918). 2 Biol. Cent.-Amer., Orth., 11, p. 21, (1901). 3 Anales Soc. Espafi. Hist. Nat., XXVIII, pp. 75-112, 253-304, pls. vili—ix, (1899). 4 Genera Insectorum, fasc. 15, Orth., Eumastacidae, pp. 2-23, 1 plate, (1903). 5 Trab. Mus. Nac. Cienc. Nat., Madrid, Ser. Zool., no. 16, pp. 3-46. JAMES A. G. REHN AND JOHN W. H. REHN 3 grafia de los Eumastacidos,’’® issued in 1930, the same author considers the group as a family and the major divisions as sub- families. Tentatively we prefer to call the assemblage a subfamily and to refer to the subdivisions as “groups.’”’ It should be under- stood, however, that this course implies no settled conviction, or opposition to the general raising of the whole acridoid group to superfamily rank, and the major divisions of the same to families. It has instead been dictated by a desire for reasonable conserva- tism, until the values of the conventional subdivisions of the acridoids have been more clearly interpreted. The arbitrary elevation of many genera groups to subfamily rank, which logically follows, seems unwarranted, at least until we have a better con- ception of the relative importance of the features characterizing these assemblages. A proper sense of proportion will doubtless prevent many absurdities which otherwise would result from an arbitrary “‘boosting”’ of the rank of many genera groups. We wish to thank Mr. B. Uvarov, of the British Museum of Natural History, and Dr. J. Carl, of the Museum of Natural History at Geneva, for their generous assistance, which made possible the solution of several of the most troublesome problems involving species of earlier authors. Their examination of historic type material enabled us to place two of the five species described prior to 1923 from the region covered by this study. The remain- ing three older names have given less difficulty, and the types or paratypes of those species described since that date have been before us. Of the fifteen species recognized in the present paper we have seen material of all but one, and the types of ten and ‘paratypes of another have been examined at this time. Of the fifteen species the senior author has personally collected eight. The total number of specimens examined is 443, all from the collection of the Academy of Natural Sciences of Philadelphia and the Hebard Collection, except thirty-eight from the Museum of Comparative Zoology and a few belonging to Cornell University. The splendid 6 Trab. Mus. Nac. Cienc. Nat., Madrid, Ser. Zool., no. 46, pp. vi-xxxii, 1-380. MEM. AM. ENT. SOC., 8. 4 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) representation of the subfamily taken in 1930 by the Academy- Emlen-Worth Expedition of the Academy of Natural Sciences to Honduras is largely responsible for the present study. The ex- tensive series then secured helped elucidate problems virtually impossible of solution at this time without them. The lively interest of Mr. John T. Emlen, Jr., and Mr. C. Brooke Worth, who accompanied the senior author, and through whose support the work was made possible, aided materially in building up this series of eumastacids. In addition the series taken in 1923 and 1927 in Costa Rica by the senior author, when on Academy ex- peditions, permitted a proper understanding of the Costa Rican members of the subfamily. In all 349 specimens of those studied were taken on Academy expeditions. For a characterization of the Eumastacinae which sufficiently embraces the many highly specialized and even grotesque genera, we would refer the student to Burr’s treatment in the Genera Insectorum,’ while for a comprehensive treatment of the limited representation occurring north of Mexico the study by Rehn and Hebard,’ already mentioned, should be consulted. A linear arrangement of the genera and species treated in the present study is as follows: Group Episacti Group Eumastaces Gymnotetiix Bruner Eumastax Burr G. occidentalis Bruner . kressi new species G. lithocolletus new species surda Burr Episactus Burr . dentata Saussure E. brunneri Burr . veraguae Hebard E. tristani new species . sylvicola new species E. eremites new species . hondurensis new species Lethus new genus . cerciata Hebard L. maya new species L. maya amrami new subspecies L. oresterus new species bt b&b 7 Genera Insectorum, fasc. 15, Orth., Eumastacidae, pp. 2-23, 1 plate, (1903). 8 Trans. Amer. Entom. Soc., XLIV, pp. 223-250, pls. xi-xvi, (1918). JAMES A. G. REHN AND JOHN W. H. REHN 5 Key to Genera 1. Caudal metatarsi with dorsal margins spinulose. Species apterous. (Group TE} OF SEVGUTLS) Gas Sis orb ert ot GG ortslorchn o Skea Ee te Oe cere ERI EET ic crs eer aero eens 2 Caudal metatarsi with dorsal margins unarmed. Species fully alate. (Group ES UITMIAS LACES) Era torave nitun, ee SIONS SE ore ond DeLee Eumastax Burr 2. Surface subglabrous to micro-shagreenous, never rugulose. Fastigium as seen in lateral aspect rectangulate, not at all acute produced. Median carina at most but indistinctly indicated on fastigium or occiput. Antennae hardly broadened distad, articles five to seven distinctly longer than broad, sub- cylindrical. Ultimate tergite (supra-anal plate) of male longer than broad, never broader than long................ ithe area Gymnotettix Bruner Surface rugulose to a variable degree, never generally subglabrous, in female sex at least. Fastigium as seen in lateral aspect acute-angulate and produced cephalad of eyes. Median carina distinctly, but sometimes finely, indicated on fastigium and occiput. Antennae broadened distad, articles five to seven little longer than broad and never subcylindrical. Ultimate tergite (supra- anal plate) of male broader than long.............. 000 cee ee ec eeeeaes B 3. Frontal costa hardly constricted at the paired ocelli, above same lateral margins of costa are somewhat evenly expanding, but costa there never three times as -broad as between ocelli. Ultimate sternite (subgenital plate) of maie with distal margin trigonal produced mesad to varying degrees, never styloid digitiform, margin of production evenly uncinato-denticulate. Ovipositor of female with valves less compressed; ventral valves mesad on ventro- internal margin with a single tooth of more marked development than the other marginal teeth. Ultimate sternite (subgenital plate) of female distad elongate produced, with apex acute or finely tridenticulate or little produced and deeply bis-emarginate...............00c0eeecseeaeee Episactus Burr Frontal costa distinctly constricted at the paired ocelli, above same lateral margins of costa are markedly bullate expanded laterad, costa there at least three times as broad as between ocelli. Ultimate sternite (subgenital plate) of male produced mesad into a pronounced recurved digitiform process, bearing an apical and lateral paired elongate spines. Ovipositor of female with valves markedly compressed, elongate; ventral valves lacking any specially developed tooth on ventro-internal margin. Ultimate sternite (subgenital plate) of female moderately produced meso-distad, apex of same rounded, tridentate or subtruncate with median trigonal tooth............. RSH eae ones nee aay ieneicct peter tiienck seen aeuah a reaction sal teen Nsmen e galy Gliic: ee whey Lethus new genus MEM. AM. ENT. SOC., 8. 6 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) (feat Text-figure 1. Distribution of the Group Episacti in Mexico and Central America, and of Eumastax hondurensis. Localities for the respective forms indicated as fol- lows: Gymnotettix occidentalis by dots, G. lithocolletus by circles, Episactus brunneri by solid squares, E. tristani by hollow squares, E. eremites by hollow diamonds, Lethus maya maya by solid triangles, L. maya amram by hollow triangles, L. oresterus by solid diamonds, Eumastax hondurensis by crosses. a jan fa 4 | 5 Z ian] (e) =) QA Z < a jan Gal fo S < M (ea Ss sg —_ o------4--> & Text-figure 2.—Distribution of Costa Rican and Panamanian species of the genus Eumastax. Localities for the respective species indicated as follows: kresst by dots, surda by circles, veraguae by solid squares, dentata by hollow squares, silxicola by hollow triangles, cerciata by solid triangles. MEM. AM. ENT. SOC., 8. 8 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) SYSTEMATIC TREATMENT Group Episacts GYMNOTETTIX Bruner 1QOI, Gymnotettix Bruner, Biol. Cent.-Amer., Orth., 11, pp. 20, 21. GENOTYPE (by monotypy): G. occidentalis Bruner. The present genus is more generalized than the other Central American genera referred to the Group Episacti. While fully representative of the latter in the spination of the dorsal margins of thé caudal metatarsi and in the fastigial and frontal costal structure, as well as the general build of the body and limbs, Gymnotettix suggests genera which are members of the Group Eumastaces. For this reason we are discussing it first and treating the other two genera as progressive specializations of the Episacti. The two species here referred to Gymnotettix differ very de- cidedly in structural details, particularly of the abdominal append- ages, but are clearly congeneric. The genus was based on a single female of G. occidentalis, not then recognized as immature. The anomalous character origin- ally ascribed to it, of toothless margins to the ovipositor jaws, and which figures in the generic diagnosis, is due to immaturity, while the fastigial structure described is also due to the same stage of development. We have been able to match the structural features of the type of G. occidentalis perfectly in the extensive series of G. lithocolletus now before us. Suspecting the unique type of occidentalis to be immature, we asked the help of our colleague Mr. Uvarov, of the British Museum of Natural History, where this specimen is preserved. He confirmed our suspicions and was also kind enough to send a sketch of the ovipositor jaws. The drawing shows the faint indications of future marginal teeth, as in similar females now before us. In consequence the generic features given by Bruner have no real value, and the following generic analysis is the first of Gym- notettix based on adult material. Generic features—Apterous, body subcompressed. Surface sub- glabrous to micro-shagreenous. Head with fastigium arcuate to arcuato-truncate, in profile rectangulate, non-produced; dorsum JAMES A. G. REHN AND JOHN W. H. REHN 9 of fastigium and occiput with median carina obsolete or sub- obsolete; face in profile oblique, low arcuate between antennal bases; frontal costa sulcate, little and then gradually narrowed between paired ocelli, margins gently diverging dorsad. Antennae ten-segmented, distad faintly broadening to ultimate article, in- dividual segments (except second) longer than broad, cylindrical except distal subdepressed one. Pronotum medio-longitudinally carinate, no lateral carinae present: cephalic margin of disk sub- truncate, caudal margin of same broadly and shallowly V-emargin- ate mesad: disk evenly passing into lateral lobes, in profile pro- notum is subequal in length and greatest depth or sublongitudinal ; ventro-cephalic angle rounded obtuse, ventro-caudal angle rounded rectangulate. Mesonotum, metanotum and abdomen markedly and continuously medio-longitudinally carinate. Fourth sternite of abdomen of male with a distinct node-like protuberance. Male with tenth tergite transversely emarginate mesad; ultimate tergite (supra-anal plate) scutellate, subequal in length and breadth or longer than broad, apex subacute; male cerci tapering in proximal half, distad incurved or inbent and with apices variously developed; ultimate sternite (subgenital plate) subscaphiform, distal margin sublamellately angulate produced, with border of production uncinato-denticulate. Female with tenth tergite broadly V-emarginate mesad; ultimate tergite (supra-anal plate) acute lanceolate; female cerci acutely tapering, simple; ultimate sternite (subgenital plate) narrowly produced meso-distad, apex angulate; ovipositor valves with all margins serrato-dentate except distal section of ventro-internal, ventral valves ventrad with a median transversely disposed dentation. Limbs slender; cephalic and median pair multicarinate, tibiae spinulose on ventral margins; caudal femora inflated proximad, slender distad, dorsal margins serrulato-denticulate, genicular lobes and angles briefly spinose; caudal tibiae with internal spines longer than external, former biseriate and somewhat crowded distad; apical spurs with internal pair larger than external, extensor one on each side longer than flexor; caudal metatarsi subequal to half of total tarsal length, concavo-sulcate dorsad with both dorsal mar- gins spined; caudal tarsal claw of each limb slightly longer than cephalic. MEM. AM. ENT. SOC., 8. 10 ' CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Distribution.—From the Usumacinta Valley of the Department of Peten, Guatemala, and very probably the adjacent portion of the same valley in the states of Chiapas and Tabasco, Mexico, south at least to the Cuyamaca Valley of northern Honduras, the Comayagua district, and the semi-arid upper valley of the Rio Cho- luteca, south-central Honduras, eastward in the northern portion of its range to the Rio Sarstoon, which forms the southern boundary of British Honduras. Key to Species Size larger (o, average body length, 14.9 mm.; caudal femur, 12.5: 9, body length, 21.7; caudal femur, 15). Male with tenth abdominal tergite having medio-dorsal emargination strongly transverse, concavely arcuate; ultimate tergite (supra-anal plate) of male with dorsal surface bearing acutely converging carinate ridges; male cerci markedly enlarged distad and there with a decided dorsal digitiform tooth; ultimate sternite (subgenital plate) of male with distal margin developed mesad into an erect, sublanceolate, strongly acute production. Cephalic and median coxae not marked with scarlet. Lateral lobes of pronotum washed with pale scarlet, which also colors the apex of the abdomen. (Guate- mala, British Honduras (?) and northern Honduras.)....... occidentalis Bruner Size smaller (, body length, 13.7-15.8 mm.; caudal femur, 11-12.3: 9, body length, 16.9-20.9; caudal femur, 12.8-13). Male with tenth abdominal tergite having medio-dorsal emargination subtransverse, subcuneate, not concavely arcuate; ultimate tergite (supra-anal plate) without acutely converging carinate ridges; male cerci not enlarged distad and without a dorsal digitiform tooth; ultimate sternite (subgenital plate) with distal margin subacute-angulate, but not sublanceolate produced. Cephalic and median coxae and adjacent portions of pleura almost invariably vividly scarlet,9 which also colors the apex of the abdomen; lateral lobes of pronotum without scarlet. (South and central LOMA UEAS ses ets cdarasoucaculos Sieeneec Sars ieiseueIe Nae leh pe lithocolletus new species Gymnotettix occidentalis Bruner (Plate III, figs. 5—10.) 1901. Gymnotettix occidentalis Bruner, Biol. Cent.-Amer., Orth., 1, p. 21. [(Im- mature) 9 ; Rio Sarstoon, British Honduras.]!° Under the generic treatment we have already discussed the 9 This species is dichromatic, possessing a brown phase, which may be rare, judging from present material. In that phase no scarlet is present on any part of the body. 10 While the type was said to be from British Honduras, the Rio Sarstoon forms the southern boundary of British Honduras and its right bank as well as the entire upper course is in Guatemala. The genus is also unrepresented in considerable series of Orthoptera now in our hands from southern British Honduras. These points are mentioned merely to show that occurrence on the Rio Sarstoon does not necessarily mean presence in British Honduras. JAMES A. G. REHN AND JOHN W. H. REHN II immature condition of the unique type of this, the genotypic, species. No further comment is necessary here, other than that the exceedingly brief (three line) specific description of occidentalis gives no feature which would distinguish the type from the pair here discussed. The description does, however, emphasize the reddish color of the lateral lobes of the pronotum and of the apex of the abdomen, while it makes no specific comment on the color of the coxae, which are such striking features of the color pattern of lithocolletus, combined with the absence of scarlet from the latter’s pronotum. The following description of an adult male and female should assist in the recognition of this species, so imperfectly known pre- viously. o'; Piedras Negras, Usumacinta River, Department of Petén, northern Guatemala. Elevation, 600 to 800 feet. June 30, 1933. (David W. Amram, Jr.) [Acad. Nat. Sci. Phila.] Size medium; surface of body almost entirely micro-shagreenous, dully glistening. Head with occiput appreciably ascending, in dorsal aspect regularly narrowing to the fastigium, which in width equals slightly more than one-fifth the entire width of the head across the eyes (as 13 to 60), but very faintly surpassing the eyes cephalad and transversely truncate with latero-cephalic angles sharply rounded, slight lateral bordering carinulae indicated, median carina obsolete; fastigium in profile rounded rectangulate; facial line with inter-antennal arcuation occupying about half of length of face; frontal costa more deeply sulcate in the area of the inter-antennal arcuation than elsewhere, becoming shallow dorsad toward the fastigio-facial angle: eyes moderately prominent, greatest width across same slightly greater than width of head at clypeal base, ovoid in basal outline, sub- acute ventro-cephalad, in greatest depth equal to 1.65 times depth of infra-ocular portion of genae. Antennae subequal in length to face dorsad of clypeus, relatively slender, distal broadening very gradual from third article; distal article faintly sub- spatulate, in part concave dorsad. Pronotum subsellate, but dorsal line nearly straight in profile, emargination of caudal margin of disk slight; in lateral view greatest (caudal) depth is subequal to dorsal length, ventral margin oblique, very faintly concave, caudal margin nearly straight, very obscurely bisinuate; impressed sulcation on ventral two-thirds of lateral lobes median, subvertical, inclining slightly cephalad, distinct. Mesonotum and metanotum distinctly tectate, caudal margins transverse truncate. Tenth abdominal tergite with median emargination over twice as broad as deep, strongly concave, caudo-lateral angles limiting same developed into decurved, elongate, acute, sublinguiform lobes covered with rasp-like asperities; lateral portions of margin of tergite, encircling bases of cerci, shallowly concave, with the MEM. AM. ENT. SOC., 8. 12 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) ventro-caudal angle rounded rectangulate. Ultimate tergite (supra-anal plate) with greatest proximal width subequal to median length, lateral margins acute converging distad, subsigmoid, apex sharply acute, faintly decurved; dorsal surface with a pair of marked straight oblique, converging, rounded ridges, which join at the apex of the tergite. Cerci slightly compressed in proximal two-thirds, in lateral aspect slightly narrowing distad in the same area; distal third sharply inbent at but slightly less than a right angle, enlarged and thickened, vertically truncate at the broadened apex and at the disto-dorsal angle furnished with a sub- erect, incurved, uncinate tooth, vicinity of the disto-ventral angle supplied with a few shagreenous denticulations. Ultimate sternite (subgenital plate) with its major portion relatively short, transverse, subscaphiform; distal margin with the sub- parallel lateral sections short, straight, unspined, median section of margin devel- oped into an erect, lanceolate lamellate process, with its greatest proximal width subequal to its median length, the margins concavely notched laterad at the base of the process thence, distad slightly arcuate, acute convergent to the apex, sup- plied with numerous, but generally spaced, slightly recurved denticulations; in lateral view the process is seen to incline slightly caudad, with the tip curving more strongly in that direction; ventral (i. e. caudal) surface of production distad briefly subcarinate mesad. Fourth sternite with nodose protuberance of caudal section broadly rounded but strongly marked, non-compressed. Cephalic femora twice as long as pronotum. Median femora but faintly shorter than cephalic pair, slightly more robust. Caudal femora surpassing apex of abdo- men by about two and two-thirds times the pronotal length. 2; Same data as described male. Differing from the above description of the male in the following noteworthy features. Size above medium for Episacti. . Head with width of fastigium slightly less than a fourth of width of head across eyes (as I8 to 76), as seen from dorsum fastigium is as a whole arcuato-truncate, less flattened than in the male; facial line with inter-antennal arcuation less elevated than in male; frontal costa less deeply sulcate immediately dorsad of the median ocellus; greatest width across eyes and of head at clypeal base subequal; eyes in greatest depth equal to 1.17 times depth of infra-ocular portion of genae. An- tennae damaged. Pronotum with dorsal portion of lateral lobes bearing obscure traces of longitu- dinal low carinulae, these disconnected and evanescent cephalad and caudad. Tenth abdominal tergite broadly V-emarginate dorso-mesad, the tergite severed and the emargination continued as a shallow groove-like depression mesad across the ninth tergite; caudo-ventral angles produced ventrad of cerci and infra-cercal plates into acute lobes. Ultimate tergite (supra-anal plate) subcompressed laterad, with sculpture of dorsal disk showing in proximal three-fifths a longitudinally disposed broad-ovate area, shallowly impressed within the peripheral margin and this divided in two longitudinally by a further shallow impression, which arcuately JAMES A. G. REHN AND JOHN W. H. REHN 13 widens proximad and distad, distal portion transversely arcuate, apex as seen from dorsum slightly acute. Cerci falling slightly short of apex of ultimate tergite, regularly tapering, apex acute. Ovipositor valves with external margin of dorsal valves more strongly and serrately dentate than internal margin, distal third of dorsal surface of same valves concavo-excavate, lateral areas of dorsal valves sub- deplanate; ventral valves with median tooth of ventro-internal margin marked, transversely disposed but not entirely crossing valve, surface divided into two planes at this tooth, the proximal deplanate, the distal distinctly concavo-excavate. Ultimate sternite (subgenital plate) with medio-distal production rectangulate at apex. ere and median. limbs proportionately somewhat shorter than in male. Caudal femora surpassing apex of ovipositor by faintly less than pronotal length. Coloratton.—General tone of males dull orange-citrine to dark citrine, lightening on the limbs to aniline yellow and darkening on the venter of the abdomen and much of the preapical portion of the dorsum of the same to medal bronze. The females, apparently discolored in this respect by desiccation, are more uniformly medal brown on the body as a whole, the limbs showing evidence of having been more uniformly aniline yellow to old gold. Head in the males medal bronze with blotchings of orange-citrine; eyes largely fuscous, in females marked obliquely (drying?) with buckthorn brown; antennae orange-citrine. Pronotum with ven- tral half of side washed with scarlet-red, females show evidence of same through its general discoloration. Coxae of body color; meso- sternum of males distinctly and metanotum weakly washed with scarlet-red. Apex of abdomen, in the males involving tenth and ultimate tergite, cerci and ultimate sternite and portions of the ninth tergite and ninth sternite, solidly scarlet-red to carmine, doubtless very vivid in life; in the females before us the abdominal apex is largely discolored and the extent of the scarlet cannot be determined, although traces of it can be seen on the ovipositor and ultimate tergite. Caudal tibiae dull olivaceous, with fuscous cari- nae and blackish spines and spurs; caudal tarsi courge green, clouded with fuscous distad, spines blackish. Supplementing the pair described above we have received for study from the collection of the Museum of Comparative Zoology, two males and one female from the Cuyamapa Valley, a tributary branch of the Sula Valley of northwestern Honduras, taken September 1 by Stadelmann. These individuals are inseparable MEM. AM. ENT. SOC., 8. 14 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) in structural features from the Piedras Negras specimens, but are very much larger, as the measurements given above demon- strate. The coloration, as far as preserved, would indicate in life a vivid brilliancy, probably equal to that known in the other species of the genus. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur o', Piedras Negras, Guatemala 14.9 2.18 12.5 o', Cuyamapa Valley, Honduras 21.7 2.85 15.7 o’, Cuyamapa Valley, Honduras 17.5" 2.77 16 9, Piedras Negras, Guatemala Di 2.6 15 9, Cuyamapa Valley, Honduras 25.5 3.19 18.5 Distribution—From extreme northwestern Guatemala south and east to the Rio Sarstoon district of eastern Guatemala, and the eastern arms of the Sula Valley of. northwestern Honduras (Cuyamapa Valley). Apparently the species does not occur across the Continental Divide on the Pacific slope, and, in Hon- duras at least, it is there replaced by the following species. The latter, however, seems partial to an environment of different character from that found where occidentalis has been taken. Gymnotettix lithocolletus! new species (Plate I, fig. 1; pl. III, figs. 11-15.) This very striking and distinctive species can at once be dis- tinguished from occidentalis by the form of the tenth tergite, the cerci, the ultimate tergite (supra-anal plate) and of the ultimate sternite (subgenital plate) of the male, as well, in both sexes, as by the absence of scarlet from the pronotum and the almost invariable presence of striking scarlet areas involving the cephalic and median coxae. Type.— &@; Cantarranas, Rio Choluteca, Department of Teguci- galpa, Honduras. Elevation, 2200 feet. August 4, 1930. (Academy- Emlen-Worth Expedition; J. A. G. Rehn.) [Academy of Natural Sciences of Philadelphia, Type no. 5531.] Size slightly smaller than in G. occidentalis; surface subglabrous to micro-sha- greenous, the pronotum laterad particularly subglabrous, body as a whole more glistening than in G. occidentalis. 11 Apex of abdomen sharply recurved. 22 From \boxbAdnros, inlaid with precious stones, in allusion to its gem-like brilliancy in life. ——— JAMES A. G. REHN AND JOHN W. H. REHN 15 Head with truncation of fastigium, as seen from dorsum, slightly more rounded laterad, width and production of same as in occidentalis; profile of fastigium and obsolescence of median carina of same as in occidentalis; facial line with inter-anten- nal arcuation slightly less marked than in occidentalis; frontal costa similar to that of occidentalis but slightly wider ventrad of the paired ocelli; eyes in profile faintly narrower than in occidentalis, slightly shorter proportionately, the greatest depth equal to 1.48 times depth of infra-ocular portion of genae. Antennae appreciably longer than face dorsad of clypeus (as 86 to 76), more slender than in occidentalis, distal article similar to that of latter species but less robust. Pronotum in general as in occidentalis but ventro-cephalic angle less broadly rounded and more truly obtuse-angulate, while the ventro-caudal angle is sharper and more nearly rectangulate, the caudal portion of the ventral margins being more distinctly truncate and less broadly arcuate; caudal margin of lateral lobes virtually straight, not bisinuate; lateral lobes with several low cicatriform areas longitudinally disposed dorso-mesad, these not true carinae, broken by the vertical impressed sulcus; median vertical sulcus as in occidentalis, with in addition two parallel, closely intermarginal ones near the caudal margin, that nearer the margin weaker and less extensive. ; Tenth abdominal tergite with median emargination twice as broad as deep, truncate subcuneate, the bottom of same arcuate truncate, the lateral portions of the margin diverging caudad, straight oblique, caudo-lateral angles limiting emargi- nation slightly acute, somewhat decurved, but not elongate lobes as in occidentalis, surface asperities of angles distinct but smaller and more numerous than in occiden- talis; lateral portions of margin of tergite, encircling cercal bases, as in occidentalis, but caudo-ventral angle faintly acute produced. Ultimate tergite (supra-anal plate) with greatest (median) width contained slightly more than one and one-half times in length of tergite (as 22 to 35), the shape of the tergite subpyriform, evenly narrowing proximad from widest point, and filling the emargination of the tenth tergite, the margins sinuately converging distad to the sublinguiform, acute apex, which reaches to the cercal apices when the cerci are in their usual position; dorsal surface of ultimate tergite with most of the distal two-thirds shallowly concave within the lateral margins, no indications present of converging carinate ridges, such as occur in occidentalis. Cerci proximad subcompressed as in occidentalis, dorsally carinate in that area, as seen from the dorsum the proximal half is slightly incurved, the distal half is strongly incurved but not bent, the slender distal fourth directed inward at slightly more than a right angle to the axis of the proximal half of the cercus; in profile the depth of the cercus tapers evenly from a deep base to the slender, subcompressed, forcep-like distal fourth, apex narrowly blunt acute with faint traces of single dorsal and ventral minute denticulations. Ultimate sternite (subgenital plate) with its proximal portion as in occidentalis but median production of distal margin slightly shorter and broad lanceolate, its height not more than two-thirds its proximal width, the lateral sections of the margin passing into that of the process without distinct notches as in occidentalis, the converging sides of the production nearly straight, the apex broadly rounded, the border of the whole production evenly supplied with larger, more distinctly recurved denticu- MEM. AM. ENT. SOC., 8. 16 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) lations than in occidentalis; in lateral view the production is seen to follow the regular convexity of the more proximal portion of the sternite. Fourth sternite with nodose protuberance more compressed and distally subtruncate than in occidentalis. Cephalic femora one and seven-tenths times the pronotal length. Median femora virtually subequal to cephalic in length, more robust. Caudal femora with inflated proximal portion slightly broader than in occidentalis. Allotype.— 2 ; Same data as type except date is August 9, 1930. Differing from the above description of the male in the following noteworthy features. Size when compared with female of occidentalis even smaller proportionately than the male of the present species; surface as in male. Head with truncation of fastigium, as seen from dorsum, faintly more rounded laterad than in male; facial line with inter-antennal arcuation distinctly shorter, lower and less evident than in male; frontal costa shallower in sulcation than in male; eye in depth equal to 1.3 times infra-ocular portion of genae along supple- mentary carinae. Antennae distinctly shorter than in male, shorter than face, the ratio of length to that of face dorsad of clypeus being 68 to 8o. Apex of abdomen when compared with the same area of G. occidentalis with the ninth and tenth tergites medio-longitudinally deeply and narrowly sulcate, ex- panding caudad on tenth tergite to receive base of the much narrower, acute lanceolate ultimate tergite (supra-anal plate), the apex of which is sharply acute, while the dorsal surface is concavo-excavate in the proximal half and there with a very finely impressed medio-longitudinal sulcation, the distal half of same surface subdeplanate but not at all excavate, lateral areas of ultimate tergite vertical, subconcave, in proximal half separated from concave dorsum by sharply carinate lateral margins of latter. Cerci as in occidentalis. Ovipositor with dorsal valves much as in occidentalis; ventral valves with teeth of ventro-lateral margins larger and without intercalated denticulations as in occidentalis, median tooth of ventral surface as in latter. Ultimate sternite (sub-genital plate) with median production elongate, subcuneate, its lateral margins subparallel in proximal half, then concavo- acute convergent to the slightly upcurved apex. Cephalic and median limbs proportionately somewhat shorter than in the male. Caudal femora surpassing apex of abdomen by less than pronotal length. Coloration.—This species is dichromatic, but the far rarer brown phase has been seen in but two adult specimens, both females. The green phase is certainly the dominant condition at the type locality and probably represents the more usual condition of the species. The following color description was made from a freshly killed green phase male, and we give it from the original field notes before presenting a more detailed analysis from the dried material. JAMES A. G. REHN AND JOHN W. H. REHN 17 Body above shining emerald green, turning turquoise blue on the head, apex of abdomen solidly carmine, above several ab- dominal segments before apex becoming pale turquoise blue with transverse black patches proximad, a medio-longitudinal fine black line. Eyes black; antennae black with two proximal segments pearl; postocular line black. Lateral lobes of pronotum of dorsal color with slight golden tendency; pleura in part and coxae of cephalic and median limbs carmine; remainder of mesopleura and metapleura turquoise blue; caudal coxae whitish. Lateral aspects of abdomen turquoise blue ventrad of lateral series of black patches; venter of abdomen pearl; meso- and metasterna turquoise blue with greenish reflections; base color of all limbs greenish straw yellow, lined with black. The dry material is naturally far less brilliant than the gem-like effulgence of the freshly killed insect. It shows, however, the extent of variation seen in a long series, and also presents the color tones seen in the cabinet specimen. Taken with the above notes on the life colors, the following specific and detailed analyses of dried material should be of service. Green phase—General body color ranging from sulphine yellow to olive-yellow, quite dull on the head, washed to a variable depth and extent with dull fuscous black, as a whole the more elevated surfaces or sculpture of the body moderately polished and in consequence more evident. The general fuscous black in- fuscation ranges from a recessive extreme in which on the head bordering dark areas throw into relief the facial carinae and the fastigium, occiput and postocular areas are largely infuscate, on the pronotum the more deeply sculptured areas alone are infuscate, the meso- and metanota and pleura, and abdomen except apex are infuscate as on the pronotum, except that the sides of the abdomen in the region of the spiracles is more heavily infuscate, the sternum is medal bronze, the limbs as a whole with the carinae lined with fuscous and the caudal tibiae basically very weak glaucous; to an intensive extreme in which the infuscation is so general and pronounced that the head, pronotum, mesonotum, metanotum and abdominal terga except for the apex are almost wholly very dark fuscous citrine, but small areas, chiefly marginal, on the lateral lobes of the pronotum and a series of paired quadrate MEM. AM. ENT. SOC., 8. 18 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) blotches on the abdominal dorsum being all showing sulphine yellow to citrine, the pleura largely sulphine yellow, the sternum medal bronze to citrine, the limbs as in the recessive extreme except that the pale glaucous of the caudal tibiae is more marked, while the caudal femora are distinctly infuscate distad. Eyes generally dresden brown to mummy brown, rarely as light as buckthorn brown, often the two tones are mottled one with the other. Antennae fuscous black with two to three proximal articles cream. Apex of male abdomen, embracing everything distad of the eighth tergite and sternite, the prothoracic pleura and cephalic coxae, the cephalic surface of the meso-episternum and the apex of the more lateral surface of the same area, and the median coxae vivid scarlet to light carmine; in the female sex the involvement is similar except that of the abdominal apex includes the distal margin of the eighth tergite and the entire ultimate sternite (subgenital plate), while the ovipositor jaws are of the base color, except proximo-laterad where the scarlet suffusion is indicated. Brown phase.—General color buckthorn brown to pale dresden brown, with broad lateral dull fuscous black bars extending from the postocular areas to the sides of the eighth tergite, the bars complete except for a diagonal paler linear interruption laterad on the pronotum and occasionally (one specimen) in part obsolete ventrad on the three proximal abdominal tergites; face ranging from the greenish of the green phase to dull ochraceous-buff; antennae dull vertiver green, darker distad, paler proximad, but with the two proximal articles light ochraceous-buff, the second in part annulate with fuscous; eyes as in green phase; ventral sur- face as dorsal surface; limbs ranging from much as in green phase to a pale buckthorn brown, in the latter the carinal infuscation is broken at many points and producing an interrupted “ticking”’ of the usually firm pencilling. No scarlet present anywhere in the brown phase. Immature material shows the major elements of the adult coloration back to at least the second instar preceding material. The scarlet markings, however, are weak in the instar preceding maturity and almost absent in that next preceding. In life, how- ever, this coloration was more evident than the dry immature JAMES A. G. REHN AND JOHN W. H. REHN 19 material would indicate, but never as vivid as in the adults. At least one individual in the instar preceding maturity (August 4) represents the brown phase. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur o', Cantarranas, Honduras, type 13.4% 2.10 II.5 o', Cantarranas, average of eleven PONG PSH eRe eee 14.3 2.11 11.6 (13.7-15.8) (2.01-2.18) (1I-12.3) o', Minas de Oro, Honduras..... 13.9 2.26 12.5 9, Cantarranas, Honduras, allo- DAV ALells ai acteate ant ace ek tet EO eer PEO 17.5 2.26 12.8 9, Cantarranas, average of eleven DOR OLY PO Siees ax evaie eee easel eet sisters 18.7 2.31 132 (16.9-20.9) (2.18-2.43) (12.8-13.9) 9, Minas de Oro, Honduras..... 20 2.85 16.5 Paratypic Ser1es—In addition to the type and allotype we have before us a series of one hundred and forty paratypic adult individuals (fifty-six males and eighty-four females) taken at the type locality, on various dates between July 19 and August 9, 1930, by the Academy-Emlen-Worth Expedition of the Academy of Natural Sciences of Philadelphia, in the collection of which it is contained. Distribution.—Known from the upper valley of the Rio Cho- luteca and the Comayagua district in southern and central Hon- duras. The two localities from which the species is known are Cantarranas in the former valley, and Minas de Oro, approxi- mately thirty miles northeast of the city of Comayagua and near the Rio Sulaco. Morphological Notes.—The extensive Cantarranas series is very uniform in structure, but the single pair from Minas de Oro is slightly (o) to appreciably (¢) larger than the average, or in some respects at least in the female sex than the maximum, from Cantarranas. The female from Minas de Oro is also noteworthy in having the lateral margins of the distal production of the ultimate sternite (subgenital plate) less narrowly produced and 13 The apex of the abdomen of the type is more strongly recurved than usual, and in consequence the body length is relatively short. MEM. AM. ENT. SOC., 8. 20 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) more evenly conical in outline. The shape of the distal extremity of the same production, however, is as in the Cantarranas material. It is possible a series of females from Minas de Oro may show variation in the shape of the above mentioned lateral margins. Biological Notes——The semi-arid Pacific tropical element ex- tends up the courses of at least certain of the rivers of western Honduras, and at Cantarranas on the upper Rio Choluteca we find well represented a flora strongly suggestive of that of the slopes bordering the Gulf of Fonseca. This is rich bush vegeta- tion with clumps of trees, often of acacia-like types, some large and spreading, open potreros with low mimosas, occasionally cacti, and dense tangles of higher trees, climbing lianes and vines along the rather shallow river. Here in low cover, from near the ground to not over five feet above it, the present species was locally abundant. The preferred habitats included garden weeds in the neglected grounds of an old hacienda, in potreros, and similar weedy cover along jungly trails. Generally a pair would be found near one another, rarely in coitu, always reasonably active irrespective of sex. The brilliant living coloration made them exceptionally conspicuous. Our first visit to Cantarranas was made July I9 to 20, when but five adults were taken, the majority of the specimens seen, twelve of which were taken, being immature. At least the two instars immediately preceding maturity were secured at that time. The second visit was August 2 to 9, during which time a steadily increasing proportionate number of adults was seen. On the 4th it was noted that about half were still immature, but no immature specimens were taken or noted after the 5th. On the 4th two out of ten immature females taken were in the second instar preceding maturity, the others being in that immediately preceding maturity. All immatures taken on the 5th (four) were in the instar preceding maturity. The brown phase was specifically noted in the field, and one immature female taken August 4 is distinctly representative of this type. Both color phases were taken under the same condi- tions and at the same time. Specimens examined: 177; 57 o&, 85 Q, 12 immature o, 23 immature 9. Honburas: Cantarranas, Rio Choluteca, Department of Tegucigalpa; elevation JAMES A. G. REHN AND JOHN W. H. REHN 21 2200 feet; July 19-20 and August 2-9, 1930; (Academy-Emlen-Worth Expedition; J. A. G. Rehn, J. T. Emlen, Jr. and C. Brooke Worth); 56 & type and paratypes, 84 @ (allotype and paratypes), 12 immature o, 23 immature 9; [A. N. S. P.]. Minas de Oro, Department of Comayagua; (J. B. Edwards); 1 #, 1 9; [Mus. Comp. Zool.]. EPISACTUS Burr 1893. Epeisactus Brunner, Ann. Mus. Civ. Stor. Nat. Genova, XXXIII, p. I15. (Invalid, no type species described or properly indicated.) 1899. Episactus Burr, Anales Soc. Espafi. Hist. Nat., XXvItl, pp. 94, 254, pl. viii, figs. 3, 3a. 1903. Parepisactus Saussure, Revue Suisse de Zoologie, x1, p. 88. (Not of Giglio- Tos, 1898.) : GENOTYPE (by monotypy): £. brunnerz Burr. Brunner’s use of this name cannot be maintained as a valid nomenclatoral proposal, even though it is clear that he applied the generic name to the same species, and the same material, later described in acceptable form by Burr. In the absence of any accompanying definite specific name or names, Epersactus Brunner does ‘not qualify, and Burr’s name, accompanied by a specific name and description, must be used. How distinct from Episactus is Giglio-Tos’ genus Parepisactus,' based on his P. carinatus from Pun, ‘‘ Ecuador,’ remains to be determined. The features of difference given in the literature are not wholly convincing, and are made more uncertain by the rather loose and contradictory character of the diagnoses of Episactus given by both Brunner and Burr, with which Giglio-Tos compared his new genus. Although Parepisactus is not repre- sented in the extensive series of Neotropical Acrididae now in hand for study, we feel it is a valid generic entity, not present in Central America, with a more generalized abdominal structure in the male than that of Epzsactus, judging from Giglio-Tos’ de- 14 Bollett. Mus. Zool. Anat. Comp. Univ. Torino, xl, no. 311, p. 36, (1898). 8 This locality will not be found in even the best general atlases. It is in a district now generally regarded as part of Colombia, on the Rio Pun, one of the head streams of the Rio Céfanes, a tributary of either the Rio Napo or the Rio Putamayo (not Rio Caqueta as said by Festa), about twenty-five kilometers southeast, in an air-line, from Tulcan, in the Altos de Boliche. The position of Pun is approximately 77° 25’ W., 0° 37’ N. From photographs given by Festa it is seen to be in the subtropical mountain cloud forest. See E. Festa, ‘Nel Darien e nell’ Ecuador.” 1909. Turin. MEM. AM. ENT. SOC., 8. 22 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) scription. The other features given as differential by Giglio-Tos apparently are of doubtful or no value generically. Saussure’s use of Parepisactus was doubtless occasioned by the hazy and unconvincing diagnoses of Episactus presented by the previous authors. All the material Saussure had was of the female sex, while all previously recorded of either Episactus or Parepisactus was a male or so of each.!® Under the circumstances he was compelled to make a more or less arbitrary assignment of the three females before him from two different areas. That he failed to distinguish two distinct species is shown on a following page. The genera Episactus and Lethus constitute a well defined assemblage, presumably of considerable antiquity, breaking up into a number of localized and highly specialized species. When compared with Lethus the genus Episactus is found to be closely related, but separable by a number of features in addition to the more obvious ones mentioned in the generic key. The body in the female sex of Episactus is never as strongly compressed and as deep as in that sex of Lethus, neither is the surface as heavily rugulose. The ovipositor in Episactus is less specialized in the structure of the valves, and never as scissor-like as in Lethus. The species Episactus eremites indicates in a number of features the line of transition to Lethus, possessing the same type of thickened lateral sections of the distal margin of the ultimate sternite (sub- genital plate) of the male, pronounced though broad median pro- duction of the same margin, and the reduction of the larger median tooth on the ventro-internal margin of the ventral ovi- positor valves. Against these tendencies toward Lethus the same species shows a type of ultimate sternite (subgenital plate) in the male which is a logical development of that found in the other species of Episactus, and is not of the digitiform spinigerous type found in Lethus, while the ovipositor jaws are not as compressed or scissor-like as in the latter genus. The bodily form of eremites is as a whole that of Epzsactus, and the position of the species is clearly in that genus, although exhibiting a tendency toward Lethus. 16 Aside from the figured but unrecorded female given in the Biologia Centrali- Americana by Bruner. V2de infra. JAMES A. G. REHN AND JOHN W. H. REHN 23 Generic features —Apterous; body subcompressed, particularly in female. Surface glabrous (in eremites) or subglabrous to micro-shagreenous. Fastigium transversely arcuate to semi- circularly arcuate, in profile subrectangulate to moderately acute produced; dorsum of fastigium and occiput weakly to distinctly medio-carinate; face oblique in profile, obsoletely or appreciably low arcuate between antennal bases; frontal costa sulcate, evenly narrowed between antennae. Antennae with ten to eleven articles, these appreciably broadening distad except for ultimate article, subdepressed except for proximal two. Pronotum sub- sellate but with dorsal line straight in profile; median carina marked, lateral carinae of the transversely tectate disk distinct and continuous or obsolete in part and represented merely by rem- nants; cephalic margin of disk truncate, caudal margin of same shallowly and broadly obtuse-emarginate; lateral lobes of pro- notum slightly longer than deep; an oblique carination present and directed ventro-cephalad, variable in strength; ventro-cephalic angle of lobes rounded obtuse, ventro-caudal angle rectangulate, rounded to a variable degree. Mesonotum, metanotum and abdomen markedly and continuously carinate medio-longitu- dinally, appreciably to distinctly tectate dorsad. Fourth stern- ite of abdomen of male with or without a carinate node-like pro- tuberance. Male with tenth tergite deeply and broadly emargin- ate meso-caudad; ultimate tergite (supra-anal plate) scutellate, acute, apex distinctly acute; male cerci tapering in proximal half, there straight, distal half incurved and sometimes weakly de- planate, apices slightly hooked; ultimate sternite (subgenital plate) subscaphiform, distal margin produced to a variable degree and obtuse-angulate to rectangulate in caudal aspect, margin of angulate section of margin with series of uncinate denticulations. Female with tenth tergite V-emarginate mesad; ultimate tergite (supra-anal plate) elongate acute-lanceolate; female cerci simple, acutely tapering; ultimate sternite (subgenital plate) either pro- duced into an elongate, subrostrate distal portion, which is acute or trifid at the apex, or the little produced distal margin of the sternite is deeply elliptically bisemarginate with a trigonal pro- duction between; ovipositor valves elongate, with margins serrato- dentate except distal section of ventro-internal; ventral valves MEM. AM. ENT. SOC., 8. 24 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) ventrad with the proximal tooth on ventro-internal margin some- what enlarged or enlarged and thickened on its internal side so that an appreciable but incomplete transverse ridge-like tooth is developed partly across the surface. Limbs slender; cephalic and median pair multicarinate; caudal femora moderately in- flated proximad, slender distad, median carina finely serrulato- denticulate, genicular lobes and angles appreciably to bluntly spinose; caudal tibiae with internal spines longer than external; spurs as in Gymnotettix; tarsi as in latter genus. Distribution.—The genus is known only from the mountains of the state of Chiapas, Mexico, an unspecified point in Guatemala and the more elevated central section of Costa Rica. It doubtless will be found in other suitable areas of the intervening portion of Central America, as well as:in other parts of extreme southern Mexico. The only detailed information we have on the zonal dis- tribution of the genus is from Costa Rica, where it is basically, but not exclusively, subtropical, while the Chiapas species, as far as present information goes, is probably subtropical. Key to Species 1. Lateral carinae of pronotal disk obsolete or but brokenly present (female only). Ultimate sternite (subgenital plate) of male with dorsal angle of median section of distal margin obtuse. Ultimate sternite (subgenital plate) of female produced into an acute process, the immediate apex of which may be entire or finely: tridentate... 0455200 eee Ree eee eee 2 Lateral carinae of pronotal disk in both sexes distinct, continuous, carried caudad aswell marked indicationsupon the dorsum of the abdomen. Ultimate sternite (subgenital plate) of male with dorsal angle of median section of distal margin acute. Ultimate sternite (subgenital plate) of female brief, broad, not produced, distal portion deeply bisexcavato-emarginate with a median acute production. (Chiapas, Mexico.)......... eremites new species 2. Size larger (body length, #, 13.7 mm.; @, 18: length of caudal femur, <7, 13; @, 14-14.5). Caudal femora proportionately longer, in female equal to about three-fourths of body length. Apex of male abdomen more longitu- dinal, less transverse; ultimate sternite (subgenital plate) of male more pro- duced, distinctly surpassing!” apex of ultimate tergite (subgenital plate) in distalvextent. “((Guatemalas)/,. seas oe eo ene brunnert Burr 17 We are compelled to base this feature on Burr’s original figure 3a of the apex of the abdomen. The ultimate tergite in not shown in that figure, evidently being strongly deflexed, but from the position of the cerci it is evident the ultimate sternite is much more extended distad than in tristanz. JAMES A. G. REHN AND JOHN W. H. REHN 25 Size smaller (body length, 6, 9.8-11.2 mm.; 9, 15.1-17.4: length of caudal femur, oc’, 8.5-9; @, 9-10.5). Caudal femora proportionately shorter, in female equal to about three-fifths of body length. Apex of male abdomen shorter, more transverse; ultimate sternite (subgenital plate) of male less produced, but little surpassing apex of ultimate sternite (subgenital plate) in distal extent. (Elevated interior of Costa Rica.)........ tristant new species Episactus brunneri Burr (Plate III, figs. 16 and 17.) 1899. Episactus brunneri Burr, Anales Soc. Espai. Hist. Nat., Xxvull, p. 254, pl. viii, figs. 3, 3a. [c*; Guatemala.] 1903. Parepisactus saliator Saussure, Revue Siiese de Zoologie, x1, p. 88. (In part.) [@,; Guatemala.] It has been exceedingly difficult to determine the relationship of Burr’s brunneri, Saussure’s saltator, the Costa Rican species now described as tristani, the Chiapas eremites and the species here referred to the genus Lethus. This situation was largely due to the inadequacy of original descriptions and figures, the fact that the older species were based on opposite sexes, and the composite character of the original (female) material of saltator. The interpretation of the situation here presented is supported by all the information procurable on the historic material in- volved. The unique type of brunnert was contained in the Brunner Collection, now the property of the Vienna Museum. The original description of brunnerz indicates the species has in the male an apically obtuse ultimate sternite (subgenital plate) with the free margin denticulate. The figures in Burr’s paper are crude and unreliable for exact details, but show a low, not strongly produced subgenital plate, with a distinctly denticulate margin. The text states the male subgenital plate is “large, elongate, incurved, apex obtuse, posterior (superior) margin denticulate,’ while in the key to the genera, following Brunner, the shape of this plate is said to be “lanceolate,” The measurements indicate the caudal femora of the male are but faintly shorter than the body. Saussure’s Parepisactus saliator was based on three females, although but a single set of measurements was given. The entire geographical and similar data for these specimens are:: ““Costa-Rica; Guatemala (Mus. Genavense, Rodriguez, 3 @).” Dr. J. Carl, of the Museum d’Histoire Naturelle at Geneva, has. very kindly re-examined for us the original Saussure material, MEM. AM. ENT. SOC., 8. 26 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) and supplied important notes and measurements which enable us to appraise the species properly. He writes, ‘‘There are not three but only two @ of this species in our collection: a greater one from Guatemala (Rodriguez) and a smaller one from Costa Rica, without any details concerning localities.’ Following this Dr. Carl gives the measurements of these two specimens, showing their rather marked size disparity. Continuing he states: ‘‘ None of them, as you see, agree perfectly with Saussure’s measurements, which may have been taken on (from) the third, now wanting 9.” It is evident from all of these measurements as given below and under E. tristanit, that Saussure had three specimens, two from Guatemala and one from Costa Rica, and that the original mea- surements were taken from one of the former now missing, and clearly not from the single Costa Rican individual. In view of this it is fair to conclude that saltator was based chiefly on the two Guatemalan females, as in addition to the measurements the features, ‘‘Pedes gracillimi longiusculi. . . . Femora postica elongata’”’ were drawn from them, and not from the Costa Rican female. The Costa Rican insect in both sexes is smaller and with proportionately much shorter caudal limbs, as shown in the fore- going key and the following description of tristani. Therefore we are restricting the name saltator to the female from Guatemala now contained in the Geneva Collection, the measurements of which are given below, and here placing the name as a synonym of brunnert. We have seen no material of brunneri, but we are able to give sketch figures of the head of the female type of saltator as indicated above. We owe these drawings to the courtesy of Dr. Carl. The genital characters of the male of brunnerz, translated and paraphrased from Burr, are as follows: Tenth tergite!® with caudal margin in middle deeply rectangulate excised. Subgenital plate (ultimate sternite) large, elongate, incurved, apex obtuse, distal (superior) margin denticulate. Cerci conical, robust, incurved, apex hardly (“‘vix’’) decussate. The whole apex of the abdomen was said to be rufous. Saussure in describing the female genitalia of saltator says the ultimate tergite (supra-anal plate) is minute, 18 Burr calls this the supra-anal plate. The type probably has the ultimate tergite reflexed into the anal chamber, and so not easily seen. JAMES A. G. REHN AND JOHN W. H. REHN 27 elongate, trigonal; ultimate sternite (ultimate ventral segment) elongate, subcompressed, apically trigonal-acuminate and chest- nut colored. The few ovipositor features given by Saussure are not specifically diagnostic. The measurements (in millimeters) of the historic material of brunnerz (and saltator), here referred to, are as follows: Length of Length of Length of body pronotum caudal femur o', Guatemala, type (ex Burr)... 13.75 3 13 @, Guatemala, paratype of salt- ator (ex Saussure)............ 18 9.5 14 9, Guatemala, type of saltator (ex Garlaintlitt])peaeene ss ac cee 18 2.5 14.5 Nothing is known regarding the distribution of this species other than its occurrence in Guatemala. By analogy with E. tristant we would conclude it is a native of the highland district of the republic generally known as the “Altos.’’ If so it probably inhabits the Subtropical Life Zone. Ppisactas tristani’® new species (Plate I, fig. 2; pl. III, figs. 18-23; pl. IV, figs. 24 and 26.) 1901. Episactus brunneri Bruner, Biol. Cent.-Amer., Orth., 11, pl. ii, figs. 15, 15a, 16, 16a, 16b. (Figures of & and 9 only.) 1903. Parepisactus saltator Saussure, Revue Suisse de Zoologie, x1, p. 88. (In part.) [9,; Costa Rica.] 1906. Episactus brunneri Rehn, Proc. Acad. Nat. Sci. Phila., 1905, p. 802. [0, @ ; Slope of Tablazo, Costa Rica.] (Not E. brunneri Burr.) We have already discussed under E. brunneri the original material on which Saussure based Parepisactus saltator. Further comment here is not necessary, while the measurements of Saus- sure’s Costa Rica female, as furnished by Dr. Carl, are given below. The figures by Bruner are clearly from a pair from Costa Rica, formerly in his collection and now before us as part of the Hebard Collection. No mention of these specimens is given in Bruner’s text, which merely lists Burr’s original reference and locality. The specimens considered by us to be the originals of these figures agree perfectly with the dimensions of the illustra- 19 Dedicated to the memory of Prof. J. Fidel Tristan, late Director of the Museo Nacional de Costa Rica, investigator, teacher and friend, in affectionate remembrance of happy days and rare companionship in Costa Rica in 1923 and 1927. MEM. AM. ENT. SOC., 8. 28 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) tions, and the apex of the male abdomen is little different from the rather conventionalized illustration of the same area. — This species is distinctly smaller than E. brunneri, with pro- portionately shorter caudal limbs, and the apex of the male abdomen is short, stubby and transverse, with the ultimate sternite (subgenital plate) quite brief and distinctly transverse, in both dorsal and distal aspects. Physical comparison with brun- nert, not possible at this time, doubtless will show other features of difference. Type.— &; La Carpintera, Candelaria Mountains,?° Costa Rica. Elevation, 6100 feet. September 4, 1923. (C. H. Lankester and J. A. G. Rehn; on foliage in cloud-forest.) [Academy of Natural Sciences of Philadelphia, Type no. 5529.] Size small (for group); surface micro-shagreenous. Head gently arcuate ascen- dent to fastigium as seen in profile: fastigium in dorsal aspect transversely arcuate, the length cephalad of the cephalic border of eyes equal to half width of fastigium at same point; median carinula distinct, surface of occiput somewhat rugulose; in profile fastigio-facial angle is faintly more acute than a rectangle; facial line in profile subconcave immediately ventrad of fastigio-facial angle, then broadly and shallowly convex to ventrad of eyes, thence straight oblique to ventral border of face; lateral facial carinae moderately diverging in dorsal half, subparallel in ventral half; frontal costa distinctly sulcate throughout, more shallowly so at dorsal extremity, the bounding carinae faintly converging ventrad to paired ocelli, thence subparallel and closely placed to the median ocellus, faintly and subsinu- ously diverging ventrad of same. Eyes moderately prominent, in outline sub- ovoid, somewhat deplanate cephalad, greatest length equal to one and one-half times the infraocular depth of genae. Antennae*! subequal to length of face; second article but half length of first; the incrassation affects solely the four distal articles, those distad of the second evenly thickening until the more incrassate section is reached. Pronotum subcompressed, dorsum appreciably tectate with each side of the tectation subconcave; median carina decided, nearly straight in profile; lateral carinae of disk very faintly diverging caudad, less decided than median and more subinterrupted; dorsum of pronotum narrow, its width at cephalic margin faintly more than half of the median length of the disk (as 20 to 38): lateral lobes moder- 20 This locality is the nearest shoulder of the mountains immediately southwest of El Alto, where the railroad and highway between Cartago and San José cross the con- tinental divide. La Carpintera, while part of the Candelaria Mountains which rampart the Meseta Central on the south, is actually one of the most northern points of the great Cordillera de Talamanca massif. In 1923 the summit of La Carpintera was still covered with Subtropical Zone cloud-forest. 21 Lacking in type. These characters are taken from paratypic males. JAMES A. G. REHN AND JOHN W. H. REHN 29 ately longitudinal, greatest dorsal length of same to caudal depth as 40 to 35; surface of lateral lobes with a weak oblique substrumose carina directed ventro- cephalad in the section cephalad of the principal transverse sulcus, latter deep but failing to reach the vicinity of the ventral margin or to sever the lateral carinae of the disk, several nearly obsolete lunate ridges cephalad of principal sulcus and dorsad of the oblique carina, while caudad of the same sulcus and parallel to the lateral carinae of the disk is placed a short but marked accessory carina; sulcus paralleling caudal margin of lobes distinct and more extensive than principal one. Mesonotum, metanotum and more proximal abdominal tergites with low and pro- gressively evanescent analogs of the lateral carinae of the pronotal disk accompany- ing the sharply decided and tectate median carina, which is distinctly indicated distad to the ninth tergite. Prosternum with a transverse carinate ridge; meso- sternum with interspace strongly transverse, shallow, caudo-lateral bordering angles oblique and rounded; metasternum with interspace small, triangular, bifoveolate, caudal margin of metasternum otherwise transverse concavo-truncate. Tenth abdominal tergite of male mesocaudad transversely subcuneate emargin- ate, proximal border of emargination truncate, lateral sections of border markedly oblique divergent to the bounding lateral angles, which are briefly produced, de- curved and with a number of shagreenous points: ultimate tergite (supra-anal plate) of male scutellate, lateral margins sigmoidally convergent to the acute, subrostrate apex: cerci of male relatively heavy, of the type described for the genus, incurving of distal half sharp and decided, its axis (at apex) forming a right angle with that of proximal half; apex with a slight apical tooth and immediately ventrad of same another similar tooth: ultimate sternite (subgenital plate) of male rela- tively short, but with its distal margin appreciably elevated and produced into a structure nearly rectangulate in outline as seen in caudal aspect, its ventral surface distad weakly but distinctly carinulate medio-longitudinally, the free margin broadly and very evidently uncinato-denticulate, these spaced teeth filling the whole distal margin except for brief marginal concavities immediately laterad. Production of fourth abdominal sternite distinct but low, carinato-tectate, more decided distad. Cephalic and median limbs of medium length, with the carinations quite decided. Caudal femora with their apices surpassing that of the abdomen by about the combined length of the head and pronotum, in form these femora are slender, the depth of the proximal bullation contained nearly six times in the femoral length; all three dorsal carinae, the main ventral and the ventro-external carinae are serru- lato-denticulate, the teeth more spaced on the ventro-external and larger and more pronounced on the lateral dorsal ones. Allotype— 2; Las Céncavas, southeast of Cartago,?? Costa Rica. Elevation, 4550 feet. July 23, 1927. (C. H. Lankester 22 This is the name of a coffee finca or plantation four or five miles southeast of Cartago. It is close to the village of Dulce Nombre, and southwest of Paraiso. The radio towers at El] Radio, near the railroad, and beyond them the Volcano of Irazi, are almost due north. MEM. AM. ENT. SOC., 8. 30 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) and J. A. G. Rehn; on weeds along road through coffee.) [Academy of Natural Sciences of Philadelphia. | Differing from the above description of the male in the foilowing noteworthy respects. Eyes less prominent than in male, in profile more attenuate and distinctly more acute dorso-cephalad, greatest length but slightly greater than infra-ocular depth of genae. Antennae slightly shorter than in male. Pronotum with dorsum more simply tectate in section: median carina distinct but less pronounced than in male; lateral carinae of dorsum represented solely by disconnected vestiges of papillose character, disposed in the same general fashion as the continuous carinae of the male. Mesonotum, metanotum and more proxi- mal abdominal tergites virtually lacking any indication of lateral carinae. Ninth and tenth abdominal tergites bearing mesad a longitudinal incised sulcus, which on the tenth distad becomes a small, quite narrow, triangular emargination of the distal margin: ultimate tergite (supra-anal plate) elongate, narrowly lanceo- late, in length hardly surpassing the apices of the infra-cercal plates, the apex narrowly rounded, the dorsal surface excavate in two concavities, the proximal larger and deeper than the distal: cerci of the female simple, styliform, tapering, apices slender and acute: ovipositor valves subcompressed; dorsal valves with dorso-external margin with marked but in part slender teeth, dorso-internal margin with small, irregularly disposed teeth on distal half, proximal section without teeth; ventral valves with ventro-external margin having two or three of the more distal teeth relatively large and robust, ventro-internal margin of ventral valves with a single marked median tooth, which is transversely disposed and covers about half the width of the ventral surface which it divides into two planes, the distal moderately concave; ultimate sternite of female (subgenital plate) with its caudal margin produced mesad into a marked subtrigonal rostration, which has its lateral margins broadly concave, its apex but little broader than a single ventral ovipositor valve and abruptly trifid, the three small teeth of equal length. Caudal femora with their apices reaching but hardly surpassing the abdominal apex, their greatest depth contained five and one-fifth times in the greatest length of the femora; serration of the carinae of the caudal femora less decided than in the male. Coloration.—It is evident from the material before us that this species is dichromatic in addition to showing definite intensive and recessive extremes in at least one of the phases. The rarer color phase is apparently a markedly bicolored one, in which the whole dorsal surface from the fastigium to the apex of the abdomen is sharply contrasted with the sides of the insect. In this phase (which is represented by a single female from the Rio Reventado) the pale dorsal bar, limited on the pronotum to the disk and on the abdomen to a somewhat broader but sharply JAMES A. G. REHN AND JOHN W. H. REHN 31 defined area, is cinnamon-buff to light ochraceous-buff, on the thoracic nota and the proximal abdominal tergite somewhat paler along the lateral borders; the remainder of the body in this phase ranges from dull russet on the head to mummy brown on the sides of the thoracic and abdominal segments, the venter of the abdomen pale cinnamon, this distad approaching the pale dorsal area and thus progressively narrowing the dark side areas of the abdomen; eyes prout’s brown; limbs cinnamon-brown to mummy brown, the latter chiefly evident on the more inflated portion of the caudal femora. The coloration of the other phase ranges from a pale recessive extreme with a nearly uniform coloration of cinnamon to sayal brown, to an intensive one in which the base tone is mummy brown, on the sides of the body darkened to blackish fuscous, the face (except ventral section of frontal costa), prosternum, cephalic coxae and some blotching on the caudal femora mikado brown, the cephalic and median limbs and ovipositor valves, basically tawny-olive, blotched or dotted with mummy brown, the venter of the abdomen sayal brown, darkening on the ultimate sternite (subgenital plate). A superimposed pattern of paired pale narrow cinnamon bars is also found in certain individuals of the intensive type, these extending on the dorsum of the thoracic nota and the more proximal abdominal tergites as closely placed parallel but well separated lines, in the same position as the ex- ternal sections of the broad dorsal pale band described above for the single bicolored specimen examined. All the males seen, and all the females except the bicolored one and the very intensive extreme, have the ventral half of the lateral lobes of the pronotum sharply and uniformly pale cinnamon-buff. We have seen the bilineate condition only in the male sex, and in addition to the features given above that sex invariably has the abdominal apex (i. e. everything distad of the eighth segment) solidly vinaceous- rufous. Between the intensive and recessive extremes above described the limited series before us shows distinct immediate conditions, in which the pale base color is progressively infuscate by traces of dark lateral bars, either as washes or as scattered markings. MEM. AM. ENT. SOC., 8. 32 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur Gh WWKCWITHIGWESs cacccobcvagen008 12 1.68 9 ol". Lablazosutt queen cer II 1.76 8.5 o', La Carpintera, type......... II.2 1.68 9 9), 'Cachiy eee a eee eee eae 15.2 1.93 10 @. Tablazon sie oid eden nets 12.8% 1.76 9 9, Las Céncavas, allotype....... 17.4 1.84 10.5 9, Rio Reventado............. 16 1.68 9.2 O° TresvRioss ans menace metas 15.1 1.84 9.1 Ol Alajuelas Gece ea cient 15.8 2.01 10.5 Paratypic Series.—We consider all the specimens of this species seen as paratypic. Morphological Notes.—There is some variation in the number and strength of the uncinate denticulations on the distal margin of the ultimate sternite (subgenital plate) of the male. These are much fewer, more spaced and smaller in the Tucurrique male than in the others seen. Distribution.—This species, as far as known, is limited in its range to the more elevated, interior section of Costa Rica, ranging as high as 6100 feet (La Carpintera) and as low as 3000 feet (Tucurrique) on the Atlantic slope and 3100 (Alajuela) on the Pacific side. Nothing is known regarding the extent of the range in the more elevated central areas to the north and south of the limited section represented by available material. Biological Notes—At Las Céncavas and Aserri, tristani was taken on weeds and low cover along roads through coffee trees, while at La Carpintera it was on undergrowth foliage in mountain cloud-forest with many tree ferns and bromeliads. No habitat notes are available for any other individuals of the species. The material before us shows the species occurs adult as early in the year as April 22 (Alajuela) and as late as September 4 (La Carpintera). We have no information as to its presence during the dry season. Specimens examined: 12;5 &,7 @. Costa Rica: Tucurrique; elevation, 700 meters; V 15, 1928; (M. Valerio); 1 & 23 The apex of the abdomen is curved dorsad, and the body length is consequently shorter than normal. JAMES A. G. REHN AND JOHN W. H. REHN 33 (paratype); [A. N. S. P.]. Cachi; (H. Rogers); 1 9 (paratype); [Hebard Cln.].*4 Tablazo; elevation, 1350 meters; (P. Biolley);1 @,1 92 (paratypes); [A. N.S. P.].25 La Carpintera, Candelaria Mountains; elevation, 6100 feet; IX, 4, 1923; (Lan- kester and Rehn); 1 o&@ (type); [A. N.S. P.]. Las Céncavas, southeast of Cartago; elevation, 4550 feet; VII, 23, 1927; (Lankester and Rehn);1 @ (allotype); [A. N. S. P.]. Aserrf; elevation, 4800 feet; VIII, 2, 1927, (Rehn); 1 & (paratype); [A. N. S. P.]. Rio Reventado on Volcan de Irazti; elevation, 5000 feet; V, 24, 1909; (P. P. Calvert); 1 @ (paratype); [A. N. S. P.]. Tres Rios; V, 3, 1924; (J. C. Bradley); 2 2 (paratypes); [Cornell Univ.]. Alajuela; IV, 22, 1916; (A. Alfaro); 1 92 (para- type);[A.N.S.P.]. ‘Costa Rica’; (Underwood); 1 & (paratype); [Hebard Cln.].2° Episactus eremites”’ new species (Plate IV, figs. 25, 27-33.) As shown above this species is an aberrant member of the genus, with a decided tendency toward the genus Lethus. The very distinctive characters of the ultimate sternites (subgenital plates) of both the male and female alone will serve to indicate the species, although the presence of definite lateral carinae on the pronotal disk in both sexes, with marked continuations of the same carried over much of the dorsum of the abdomen, and glabrous or even polished areas of the lateral lobes of the pronotum and the sides of the abdomen in the male, will be found of almost equal diagnostic value. Type.— &; San Crist6bal, State of Chiapas, Mexico. Elevation, 2300 meters. July 7, 1926. (A. Dampf.) [Hebard Collection, Type no. 1248.] Size rather small (for group): surface subglabrous on the dark colored lateral areas of the pronotum, mesonotum, metanotum and abdomen, remaining surfaces all smoother than in related species. Head as seen from dorsum with fastigium projecting cephalad of eyes a distance equal to one-half the width of same between eyes (as 8 to 16), the even arcuate outline very faintly flattened mesad and uniformly cingulate, the margining carinulations continued caudad about the eyes, the subincrassate median carinula joining the marginal border; surface of fastigium and of occiput otherwise trans- versely rugulose: frontal costa narrow, sulcate and brief, faintly expanding dorsad of paired ocelli, there progressively less deeply sulcate than in interantennal 4 This specimen came from the Bruner Collection and may have served as one of the originals for Bruner’s figures of brunneri mentioned at the head of the specific treatment. 2 This is the material recorded as brunneri by Rehn in 1906, to which the reference is given above. 26 See footnote 24 above. 27 From épyutrns, a hermit, in allusion to its mountain habitat. MEM. AM. ENT. SOC., 8. 34 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) region: accessory facial carinae but weakly converging dorsad in dorsal half: eyes moderately prominent, acute subovoid in basal outline: antennae damaged. Pronotum with dorsal surface appreciably tectate in cross section, relatively narrow, the greatest (caudal) width of this area but slightly greater than half dorsal length of pronotum (as 28 to 50); median carina marked, continuous, more tectate than carinate; lateral carinae of pronotal disk distinct, low carinate, con- tinuous, virtually entire, weakly sinuate but faintly diverging caudad; cephalic margin of dorsum arcuato-truncate, caudal margin with median emargination very shallow and not strongly marked: lateral lobes somewhat longer than greatest caudal depth (as 50 to 35); cephalic margin oblique subarcuate, ventro-cephalic angle broadly obtuse, ventral margin suboblique, weakly sinuate, ventro-caudal angle narrowly rounded rectangulate, caudal margin straight; surface of lateral lobes crossed obliquely ventro-cephalad, from vicinity of caudal fourth of lateral carinae of disk to slightly dorsad of ventro-cephalic angles of lobes, by a distinct cicatriform ridge, thickening ventro-cephalad and cut solely by a single transverse sulcus, which dorso-ventrad crosses the middle of the lobe but is not indicated on the disk, nor does it cut the lateral carinae of the disk. Mesonotum and metano- tum in general conforming to the abdominal structure; caudal margin of former broadly obtuse mesad, of latter transversely truncate as with most of the ab- dominal segments. Abdomen with tectation of tergites pronounced, particularly on the six proximal tergites preceding the clavation of the abdominal apex, in the same section the compression of the abdomen and adjacent thoracic terga and pleura is marked and unusual, the continuations of the lateral carinae of the pronotal disk also definitely cutting the dorsum off from the vertical side areas, these continuations becoming progressively obsolete distad; ventral surface of abdomen without indication of usual protuberance on fourth sternite; tenth tergite strongly transverse dorsad, median emargination very broad and shallow, obtuse-angulate with the base of the angulation transversely truncate, the emargination two-thirds filled by a membrane, lateral angles bordering emargination strongly obtuse, in no way specialized or armed, ventro-caudal angles of tergite beneath cercal bases moder- ately acute produced; ultimate tergite (supra-anal plate) relatively short, trans- verse trigonal, acute produced meso-distad; cerci moderately tapering, somewhat deplanate on internal surface particularly distad, distal half of cerci strongly but regularly incurved, apex blunt acute, external surface of distal half subcarinulate, in distal aspect the cercus is seen to be gently decurving distad; ultimate sternite (subgenital plate) transverse, with an erect median recurved trigonal process, slightly shorter than its width proximad, its distal margin with the angle in general rectangulate, the apex without a distinct spine and the margins of process laterad with recurved low but distinct and regular serrulations, the teeth ending abruptly where the lateral margins arcuately pass into the dorsal margin of the main portion of the sternite, which margin is broadly flanged but unarmed, surface of median production of ultimate sternite with a median subtectate ridge becoming obsolete proximad. JAMES A. G. REHN AND JOHN W. H. REHN 35 Mesosternum with cephalic margin broadly arcuate, the interspace strongly transverse, meso-caudal portions of lobes broadly and obliquely arcuate excised. Metasternum with margin over foveolae rectangulate emarginate, remainder of margin nearly transverse. Cephalic femora one and one-fourth times as long as the pronotal dorsum, carinations little evident except dorsal pair; median femora faintly longer than cephalic, slightly more robust, carinae similar. Caudal femora about four-fifths as long as the body, apices surpassing the extremity of the abdomen by more than pronotal length, moderately slender, margins not at all appreciably serrulate, pattern of the external paginae shallowly impressed; caudal tibiae with short spines of external margin numbering twenty, biseriate spines of internal margin all longer, sixteen in number, the last four of equal length, slightly closer together than the others of the same margin; caudal metatarsi slightly longer than remainder of tarsi, with three to five spines on internal and five on external dorsal margin, those of internal reaching less proximad than the external series. Allotype.— 2; Same data as type. [Hebard Collection.] Differing from the above description of the male sex in the following noteworthy features. Size larger: surface less glabrous and duller than in male. Heads in profile with fastigio-facial production somewhat more emphasized than in male, subrostrate; accessory facial carinae slightly more distinctly convergent dorsad than in male: eyes with dorso-cephalic angle, as seen in lateral aspect, nearly rectangulate. Antennae entire: in length slightly shorter than face, some- what broadening progressively from the third to the sixth, thence to apex subequal in width except for the apical narrowing of the ultimate article, from third distad the articles are subdeplanate dorsad, the same articles individually narrowing proximad as seen from dorsum. Pronotum with dorsum slightly broader than in male, the caudal width of same equal to about four-sevenths of the length of the dorsum; median carina less elevated than in male, the lateral halves of the dorsum less concavo-tectate and more truly tectate in cross-section; caudal margin of disk slightly more deeply and sharply emarginate than in male: lateral lobes faintly more quadrate than in male, greatest (dorsal) length to caudal depth of lobe as 60 to 52; ventro-cephalic angle more broadly arcuate than in male; oblique carina of lobes present as in male but less sharply marked, and the surface in neighborhood of its dorso-caudal section and the adjacent portion of the lateral carinae is less inflated and less inclined to mask the lateral carinae of the dorsum. Abdomen with tergites distad to and including the ninth distinctly tectate, the last with the tectation almost sublamellate in its differentiation from the main surface of the tergite; tenth tergite dorso-mesad subrectangulately emarginate to receive the base of the ultimate tergite (supra-anal plate), the latter being elongate acute lanceolate in shape, the apex acute with straight convergent lateral margins, the dorsal surface in its proximal two-thirds quite deeply concave, scutel- late in shape with the parallel lateral and sigmoidally converging distal margin sharply defined and elevated, surface of distal third subdeplanate and extending MEM. AM. ENT. SOC., 8, 36 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) proximo-laterad some distance about the periphery of the rim-like margins of the more proximal area: cerci rather elongate, reaching distad as far as apex of the ultimate tergite, styliform, tapering, apex very acute and faintly decurved: ovi- positor valves much compressed, distinctly deeper than broad, dorsal surface of dorsal valves narrow, particularly proximad, the surface concavity of the distal . section pronounced, marginal teeth of dorsal margins as a whole rather small, internal margin with proximal unspined area less than half of the entire marginal length; ventral valves with ventro-external margins having four to five broad teeth separated from the apical hook by a diastema with three or so crenulato- denticulations, ventro-internal margins with low. teeth except for the proximal one, which is larger, cusp-like, slightly thickened on internal side but not trans- versely disposed or sharply dividing the ventral surface of the valve: ultimate sternite (subgenital plate) but briefly produced distad, broad, distal margin broadly rounding from the lateral margins and between lateral blunt acute lobations is deeply bisemarginate into a pair of deep half elongate-elliptical concavities, each one and one-half times as deep as wide at broadest point, the production separating the two being an acute conical process reaching distad nearly to the apices of the lateral bounding lobes. Metasternum with angle over foveolae more obtuse-angulate emarginate. Caudal femora reaching briefly caudad of apex of abdomen. Coloration.—Male. Base color tawny to russet, passing to ochraceous-tawny laterad on a broad, pale, subequal dorsal ab- dominal band, and paling to yellow ocher on the ventral surface of the body and to yellowish citrine on the ventral surface of the cephalic and median femora. Genae, most of lateral lobes and broad lateral bars on the mesonotum and metanotum and sides of the abdomen, becoming less solid and more nebulous near the apex, mummy brown to shining blackish fuscous. Head with face weakly flesh-color, occiput and fastigium mummy brown like the genae, eyes deep olive speckled with fuscous. Pronotum with narrow median area of dorsal tectation and its continuation over other nota and abdomen mummy brown, ventral third of lateral lobes of base color, diagonal carina strikingly reed yellow, particularly ventro-cephalad. Citrine of ventral surface reaching in a clouded condition to the ultimate sternite (subgenital plate). Caudal femora of general color, slightly clouded dorsad on ex- ternal pagina, genicular extremity of same darkened; caudal tibiae and tarsi of general color; distal extremity of all tarsi (i. e. arolium, claws and distal third of third article) solidly fuscous. Female. Base color as in male but infuscation of mummy brown to blackish fuscous very general and covering almost all the JAMES A. G..REHN AND JOHN W. H. REHN 37 insect except the ventral surface which is dull tawny. The head is almost solidly dark, antennae included, the eyes dark grayish olive. The pronotum shows no pale markings except fine pale pencillings of the lateral carinae of the dorsum and the oblique carina of the lateral lobes. The dorsal bar of the other nota and the abdomen is indicated by structure and pencilled continuations of the pale tone of the pronotal lateral carinae, while the ovipositor valves are tawny tipped with blackish. The cephalic and median femora are obscurely, the tibiae more distinctly cloud annulate with fuscous, the femora nearly solidly of this dorsad. Caudal limbs as in male but darker and all tarsi are similarly fuscous tipped. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur o, San Cristébal, type.......... “11.8 1.09 9.1 9, San Cristébal, allotype....... 20 2.52 II This species is known only from the type and allotype. It is particularly interesting in that while the structure of the external genitalia of the male approaches that of Lethus more closely than in other Episactus species, that of the female is very different from the type found in any other known species of either genus. The surface of the integument in eremites is in part at least more glabrous than in any other species of the same genera, in fact more like that of Gymnotettix. Distribution.—It is probable that the present species is limited in distribution to forest areas on the higher mountains of Chiapas, occupying there the same ecological niche as does Lethus oresterus in the mountains of south-central Honduras. LETH US” new genus GENOTYPE: Lethus oresterus new species. This genus is a member of the same complex as Episactus Burr and Parepisactus Giglio-Tos, and its line of divergence from the former is apparently indicated by Episactus eremites, as discussed elsewhere. The main features of difference from Episactus have been set 28 From Anos, a Pelasgian prince, ally of Troy. MEM. AM. ENT. SOC., 8. 38 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) forth in the key to the genera, but they may briefly be summarized as the flask-like expansion of the frontal costa dorsad of a very definite construction of the same between the paired ocelli, the development of the ultimate sternite (subgenital plate) of the male mesad into a marked recurved digitiform, apically spinigerous, process, and the strongly compressed and scissor-like character of the ovipositor valves of the female, the ventral ones of which lack any pronounced tooth mesad on the ventro-internal margin of the ventral pair. The species of Lethus are also heavier, stockier and with shorter, thicker limbs than those of Episactus. From Parepisactus Giglio-Tos,® which has already been dis- cussed under Episactus, Lethus can be distinguished by the form and development of the ultimate sternite (subgenital plate) of the male, which is short, subglobose, apically truncate and un- armed in Parepisactus, and the incurved, hooked cerci of the same sex, while those of Parepisactus are cylindrical. The female sex of the sole species of the latter genus (P. carinatus) being un- known, it is not possible to determine at this writing what differen- tial characters may be present in both sexes. We have seen no material of Giglio-Tos’ genus. Generic features——Apterous. Body compressed, medio-longi- tudinally carinate from fastigium to apex of abdomen. Surface largely rugulose to subrugulose, dull. Fastigium arcuate as seen from dorsum, subproduced, transversely carinulate marginally; in profile fastigio-facial angle is brief but distinctly acute produced cephalad of inter-ocellar portion of the retreating facial line. Frontal costa sulcate throughout, constricted at paired ocelli, dorsad of same sharply broadened into a flask-shaped area. Pro- notum with a distinct but small medio-caudal emargination; lateral carinae of disk not indicated other than as broken and obsolete remnants: lateral lobes of pronotum subquadrate, ventral margin suboblique, ventro-cephalic angle obtusely angulate to broadly rounded, ventro-caudal angle distinct, rectangulate. Apex of abdomen of male?® moderately recurved, subclavate; tenth tergite of male transversely emarginate mesad, ventro- lateral angles of same tergite acute produced; ultimate tergite 29 Boll. Mus. Zool. Anat. Comp. Torino, x11, no. 311, p. 36, (1898). 30 Female sex alone known in L. maya amramt. JAMES A. G. REHN AND JOHN W. H. REHN 39 (supra-anal plate) trigonal, apex acute produced; cerci of male tapering styliform, regularly incurved in distal half, apex acute; ultimate sternite (subgenital plate) of male mesad produced dorso-cephalad in a recurved digitiform process extending to and between the cercal apices, apex acute with a single marked spine, proximad of apex the process bears a pair of lateral strongly di- verging spines, and another similar pair near the base of the pro- cess or laterad of same on the concave portions of the distal margin of the main area of the sternite. Female with ventro- lateral angles of tenth tergite acute produced; ultimate tergite (supra-anal plate) acute produced: ovipositor valves elongate, compressed, scissor-like, evenly tapering in profile; dorsal pair with external margins regularly serrato-dentate, dorsal surface of dorsal valves subconcave or declivent ventro-mesad; ventral pair of ovipositor jaws with external margins serrato-dentate, internal margins similar and without decided specialization or disposition of any particular teeth, ventral surface not broken into two distinct planes: ultimate sternite (subgenital plate) produced disto-mesad, narrowed apex obtusely angulate, transverse truncate or subconcave, in each case with a median trigonal point. Ce- phalic and median femora carinate; caudal femora with dorsal carinae weakly serratulate; caudal tibiae with spines of internal margin biseriate in length, except immediately distad where they are crowded and uniform in length; caudal metatarsi with both dorsal margins spaced serrato-spinose. Distribution —The species of Lethus occur in apparently localized habitats in the state of Chiapas, extreme southern Mexico, northern Guatemala and northern and central Honduras. At least one of the species is strictly a montane form, apparently restricted to the Subtropical Life Zone, while the other one, with two subspecies, occurs under more truly tropical conditions, with one of its forms (L. maya maya) reaching as high as 3000 feet in north-central Honduras. Doubtless further work will show the genus present, in suitable environments, over much of the southern third of Mexico—probably that section below the Isthmus of Tehuantepec—as well as suitable areas of El Salvador and Nic- aragua. We question its reaching Costa Rica, although such is possible. The absence of the genus, as well as Gymnotettix and MEM. AM. ENT. SOC., 8. 40 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Episactus from the many collections made in southern Mexico north of the Isthmus of Tehuantepec would indicate their absence from that area. This probably can be explained by the geological history of the country involved. As Schuchert has pointed out*! the ‘‘Tehuantepec portal’’ was open probably during the Upper Miocene and certainly in the Early Pliocene, and in consequence the entire Mexican tableland area was then separated by sea from the old land mass of northern Central America. The Episacti in Central America is clearly an ancient group, while the Eumastaces we would consider a much more recent arrival from South America, where they have reached an extraordinary diversification. Key to Species 1. Form more decidedly compressed. Fastigio-facial production of female, as seen in profile, extending cephalad of dorso-cephalic angle of eyes a distance equal to slightly more than half greatest width of eye. Face of female ventrad distinctly flattened, accessory facial carinae prominent ventrad, more elevated than borders of frontal costa. (Petén Department, Guate- pages) Cd Vantaa te, ech eee 2h Geet Bie Mes As Sek ae BNET ENG maya amrami new subspecies Form less strongly compressed. Fastigio-facial production of female, as seen in profile, extending cephalad of dorso-cephalic angle of eye a distance equal to little, if at all, more than one-third greatest width of eye. Face of female ventrad not distinctly flattened, accessory facial carinae no more prominent ventrad than borders of frontal costa.............. 00 eee ete cee e nena 2 2. Ultimate sternite (subgenital plate) of male with median production cuneate in caudal aspect, evenly narrowing distad, apical spine distinct but not greatly prolonged; lateral margins of production with two pairs of spaced spines, one near apex, the other near base. Lateral angles of disto-median production of ultimate sternite (subgenital plate) of female acute, subspini- form, but slightly less evident than median point. Size smaller (average body length, #, 15.6 mm.; 9, 20.9). (Chiapas, Mexico and north-central Hon- CAL Gris) Meena ee Ree poe ee RAS UR ag blciod maya new species Ultimate sternite (subgenital plate) of male with median production narrower, sublanceolate, lateral margins of same concave to subparallel, but little narrower at distal third than at proximal third, apical spine greatly prolonged, aciculate; lateral margins of production with a single pair of elongate, acicu- late diverging spines at distal third, more proximal pair of spines not on margins of process but situated on the concave lateral portions of the true distal margin of the tergite.** Lateral angles of disto-median production of 31 Bull. Geol. Soc. Amer., XL, p. 357, figs. 8 and 9, (1929). % Rarely these are absent or subobsolete. JAMES A. G. REHN AND JOHN W. H. REHN 4I ultimate sternite (subgenital plate) of female rectangulate but non-spiniform. Size larger (average body length, o, 16.7; 9, 25.5). (South-central Hon- LUIS) REE ea ys een ond a cee he aces ee tA ae oresterus new species In a linear arrangement we place L. maya first, and nearer in position to the genus Episactus, while L. oresterus, which is clearly the most divergent form, would in consequence come last at the other end of the series. Lethus maya* new species (Plate IV, figs. 34-41.) This species needs comparison solely with L. oresterus. It averages somewhat smaller, but shows a basically similar type of specialization of the ultimate sternite (subgenital plate) of the male. The proportions and details of the production and the marginal spination of this sternite, however, are different, as shown in the key to the species and the accompanying figures. In the female sex the external ovipositor margins of typical maya are more stoutly toothed and the lateral angles of the median pro- duction of the ultimate sternite (subgenital plate) are marked and subspinose, instead of rectangulate and unspined. Type.—o; Tuxtla Gutierrez, State of Chiapas, Mexico. June 6, 1926. (A. Dampf.) [Hebard Collection, Type no. 1249.] Size medium; form moderately compressed; surface as a whole closely micro- shagreenous, subrugulose on occiput and pronotum. Head with occipital line ascending moderately to the fastigium as seen in profile; fastigium, seen from dorsum, broad, short, greatest proximal width equal to three times the length of the fastigium cephalad of the eyes, the outline of the fastigium broadly and evenly arcuate; medio-longitudinal carina of the fastigium and occiput distinct and continuous, peripheral border of fastigium carinulate, continued caudad about eyes; fastigio-facial angle blunt acute as seen in profile, but moder- ately produced; facial line but moderately oblique, subconcave briefly ventrad of fastigio-facial angle, thence very low broad arcuate convex, passing to the straight oblique ventral section of the face; frontal costa rather narrow, sulcate throughout but more deeply so between the paired ocelli, where the lateral margins are gently constricted and dorsad of which the margins are expanded in a small but definite flask-shaped area ventrad of the fastigium; accessory facial carinae distinct, subparallel on ventral half of face, dorsad moderately and sinuately converging: eyes subovoid in outline, sharply angulate dorso-cephalad, greatest depth equal to one and one-fourth times that of the infra-ocular section of genae (as 23 to 18). | 33 After the Maya people, whose structures in the Usumacinta Valley of Tabasco, Chiapas and adjacent Guatemala are giving to the world increasing information on their culture. MEM. AM. ENT. SOC., 8. 42 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Antennae abbreviate, somewhat shorter than face, composed of nine articles, of the type usual in the group, the distal five subdeplanate dorsad. Pronotum subsellate with dorsal line straight in profile, its length slightly greater than that of head: dorsum sharply tectate, with lateral halves strongly declivent from the sharp and carinate median ridge, passing into the sub-vertical lateral lobes without marked separation: cephalic margin of dorsum rotundato-truncate, caudal margin subtruncate with a small but distinct and sharp median rectangulate emargination; lateral lobes and adjacent portion of dorsum slightly deeper than long, cephalic and caudal margins subparallel, in general straight, the former rounded obtuse at the ventro-cephalic junction with the distinctly bisinuate ventral margin, which caudad is briefly straight to the rectangulate ventro-caudal angle; sole indications of lateral carinae are short detached rugae, the more prom- inent a brief, nearly longitudinal, arcuate one placed dorsad between the two distinct vertical sulci which cross the sides but not the dorsum of the pronotum, one mesad, the other near the caudal margin; oblique, low, subcarinate ridge extending diagonally ventro-cephalad to the ventro-cephalic angle as in related species. Mesonotum, metanotum and eight proximal abdominal tergites distinctly tectate and sharply carinate medio-longitudinally, as on the pronotum. Tenth abdominal tergite distad broadly but shallowly concave emarginate, mesad the same concavity is flattened, while laterad, where it joins the juxta-cercal sections of the distal margin, is situated on each side a small tooth-like node, ventro-distal angle of tergite markedly produced and apically blunt acute; ultimate tergite (supra-anal plate) not separated from the preceding tergite by a distinct suture, but sharply so by contour, in form broad scutellate, slightly broader than greatest median length, its distal margin broad obtuse-angulate convergent with a median acute linguiform angulation, surface of tergite without marked sculpture, but laterad somewhat depressed toward cercal bases, and as a whole ventrad of the level of the tenth tergite. Cerci with proximal half straight, in dorsal aspect the same section is subequal in width, in profile the same area evenly narrows, distal half rather sharply curved at a right angle to the proximal portion, apex spiniform. Ultimate sternite (subgenital plate) with distal median production erect, wedge- shaped, narrowing evenly distad, the apex relatively broad and arcuato-truncate with a distinct erect median spine, a pair of longer, more slender spines are placed briefly proximad of the apical margin on the flange-like lateral margins of the process and directed latero-cephalad, while somewhat ventrad of this pair another similar but shorter pair of spines are situated, these directed slightly more dorsad; in profile the production of the sternite is seen to be erect subsigmoid, proximo- laterad with impressed, subconcave, reniform areas, while in caudal aspect the production shows three low ridges, one median, the others marginal, the area between shallowly channeled. Prosternum transversely carinate; mesosternum with cephalic margin cingulate and broadly arcuate, interspace between lobes strongly transverse, the lobes in large part obliquely truncate distad, surface of mesonotum with a distinct, straight, transverse carination; metasternum rectangulate emarginate over foveolae, distal JAMES A. G. REHN AND JOHN W. H. REHN 43 margin subtruncate. Fourth sternite with a low medio-longitudinal thick sub- carination. Cephalic femora somewhat less than one and one-half times the dorsal length of the pronotum, the six carinae equally evident and all rather finely serrulate; median femora slightly longer than cephalic, carination of similar character. Caudal femora with their apices exceeding the tip of the abdomen by slightly more than the length of the pronotum, relatively robust in proximal inflation when seen in profile, subcompressed in dorsal aspect, greatest depth of femur contained four and four-fifth times in their length, carinae sharp and all finely serrulate, these often widely spaced; “‘herring-bone”’ pattern of the pagina sharply and regularly impressed: caudal tibiae with 21 to 23 spines on external margin, internal with 18 to 19 spines; caudal metatarsus equal to length of remainder of tarsus, each dorsal margin with five spines. Allotype— 2; Same data as type. [Hebard Collection.] The female sex differs from the above described males in the following noteworthy features. Size somewhat larger than male; surface more distinctly multirugulose, although this is always of subtle character. Head with fastigio-facial angle in profile slightly more produced and acute than in male, more truly subrostrate; facial line as in male but the concavity ventrad of fastigio-facial angle more emphasized and that section ventrad is but faintly arcuate and less oblique than in male; frontal costa no broader than in male, more sharply and strongly constricted between the paired ocelli; accessory facial carinae more distinctly converging dorsad; eyes in depth subequal to that of infra-ocular portion of genae. Antennae missing. Pronotum with its dorsal length slightly greater proportionately than in male, a third longer than dorsal length of head, dorso-median carination marked and slightly but appreciably arcuate in profile; in lateral view the pronotum is pro- portionately deeper than in male, greatest length of whole pronotum one and three- sevenths times greatest dorsal length of same. Ninth abdominal tergite with a distinct, gutter-like medio-longitudinal sulcus; tenth tergite medio-dorsad completely and broadly rectangulate-emarginate, the borders of the emargination passing without angulation into the distal margin of the more lateral sections of the tergite, the caudo-lateral angles of which are elongate acute produced as in male; ultimate tergite (supra-anal plate) acute, sublanceolate, its dorsal surface divided into three areas by a pair of distad con- verging carinae, these areas being a moderately excavate, elongate scutellate section embracing the proximal three-fifths, a smaller distal section which is weakly impressed, and paired lateral, subvertical flattened areas beneath the overhanging carinae: ovipositor valves in dorsal aspect slender, rather deep in profile, appreciably compressed; dorsal valves with the serrate teeth of the external margin moderately spaced, about twelve in number, occasionally bifid, rather even in height, but shorter and less definite distad, internal margin with fewer, shorter, less definite serrato-dentations, lacking in proximal two-fifths of margin and very weak distad, MEM. AM. ENT. SOC., 8. 44 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) dorsal surface of dorsal valves ruguloso-deplanate, subexcavate distad; ventral valves with ventro-external margin bearing closely placed, biseriately sized teeth, becoming obsolete distad, internal margin with five to eight relatively short but sharp teeth proximad, none transverse in disposition, the margin distad without distinct teeth, ventral surface of ventral valves concavo-deplanate, not divided into two sections: ultimate sternite (subgenital plate) with disto-lateral angles broadly rounded rectangulate, median portion of distal margin briefly produced distad in a transverse structure with converging subconcave margins, which distad end in moderately acute angles, between which the terminal margin is transverse with a short but stout conical, spiniform process. Limbs proportionately shorter and stockier than in the male, caudal femora reaching to but not surpassing the ovipositor jaws. Greatest depth of caudal femora contained four and one-half times in their length. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur o', Tuxtla Gutierrez, Mexico, ES) Tea eT) 3 8 Bea Meh a ak, 15.2 2.35 11.8. o', Tuxtla Gutierrez, Mexico, PULAU DER a ere In ee 16.1 2.26 II &, Subirana, Honduras......... 15.5 DAG 12.7 o', Mataderos Mountains, Hon- Guraseaewat eos e eee Bek ee 17.9 3.36 13.3 @, Tuxtla Gutierrez, Mexico, Glloty pestas 5 ova mth cee ee 20.5 2.91 II .3 @, Tuxtla Gutierrez, Mexico, PUTGIN Pes 5 ae eee 21.3 3.02 11.8 9, Subirana, Honduras......... 25 3.69 15 9, Mataderos Mountains, Hon- duras= 2 ee ee nee 23.2 3.44 13.2 9, Progreso, Honduras......... Z5Eare 3.52 14.5 Coloration.—General color of male pale buckthorn brown to weak ochraceous-orange, becoming pale tawny or pale orange rufous on occiput and genae, overlaid with a pattern of dull fuscous of varying intensity as follows: pronotum infuscate except for paired longitudinal pale bars in the usual position of the lateral carinae, a lining of pale on the oblique carinae of the lateral lobes and a weakening of the overlying shade elsewhere on the lobes; other nota and abdomen infuscate dorsad, with the paired pale bars continued distad to the sixth tergite, where they become obsolete; sterna, abdominal venter and caudal femora except apices pale, unmarked; abdominal apex infuscate except for pale JAMES A. G. REHN AND JOHN W. H. REHN 45 cercal tips; cephalic and median limbs appreciably but unevenly infuscate, apices of the caudal femora, caudal tibiae and tarsi strongly infuscate; antennae infuscate, except for pale proximal article; eyes mottled dresden brown and fuscous. General color of female dresden brown, heavily and in general almost solidly overlaid with mummy brown, the head showing much mottling of the two tones, as is true of all the limbs, although the apices of the caudal femora and most of the caudal femora are prevailingly dark; ventral surface uniformly dresden brown to tawny, except that the ultimate sternite is solidly TTP brown distad ; eyes as in male. Paratypic Series—In addition to the type and allotype, we have before us a paratypic pair taken at the type locality by Dr. Dampf, July 17 (*) and June 6 (2), 1926. We have also before us a series of three males and six females taken at Subirana, Yoro Department, north-central Honduras, February 11 and 13 and March 14, 1933, by Stadelmann; six males and thirteen females taken at 3000 feet elevation in the Mataderos Mountains, near Subirana, Yoro Province, Honduras, February 13, 1933, by the same collector; and three females from Progreso, in the Sula Valley of northwestern Honduras, taken in August, similarly by Stadelmann. All of these Honduranian specimens are from the collection of the Museum of Comparative Zoology. Distribution.—From the available material it is evident that true maya ranges over an extensive area reaching from western Chiapas, Mexico, to central Honduras, probably in its typical form limited to country of some elevation, passing at lower levels into the superficially quite different, but actually extremely close L. maya amrami. ‘The latter is the more divergent member of the stock and apparently represents a relatively recent intrusion into lower, more truly tropical, levels, from the higher, geologically older territory inhabited by typical maya. The type locality, Tuxtla Gutierrez, is in the valley of the upper Rio Grijalva, which joins the Rio Usumacinta near its mouth. The elevation of the type locality is approximately 2000 feet above the sea. It is probable that the marked penetration of the central area of Honduras by semi-arid tongues, presumably from the Pacific MEM. AM. ENT. SOC., 8. 46 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) side, which follow river valleys and spread over the Comayagua plain, has completely isolated the areas inhabited by the maya complex from that in which L. oresterus occurs. Morphological Notes ——The series from Subirana and the adja- cent Mataderos Mountains in Honduras is fully typical, while the females from the lower levels of the Sula Valley at Progreso show distinct tendencies toward maya amram1, the fastigium being more produced, the face slightly more retreating and subconcave, the disto-lateral angles of the ultimate sternite (subgenital plate) being less rectangulate and more rounded obtuse-angulate, while the median projection of the distal margin of the same sternite is less strongly tridentate. In these individuals the features as a whole are nearer those of true maya than of m. amrami, but the appreciable divergence exhibited by them indicates they are atypical maya maya and establishes the subspecific character of m. amram. The measurements given above demonstrate the considerable amount of individual variation found in the species. From present material the typical form is smaller in Chiapas than it is in Honduras, but the series from Subirana and the nearby Matade- ros Mountains show the wide individual size range encountered in the latter country alone. As a whole the Mataderos Mountains males average larger than those from Subirana, although the females from the two localities are little different in size. A number of the Honduranian males have the distal extremity of the process of the ultimate sternite (subgenital plate) injured, often lacking the terminal spine and with the extreme distal margin having a deep median indentation or even a shallow cleft. There is no uniformity to this malformation, and apparently it is due to injuries received in the instar preceding maturity or when in a teneral condition following the last ecdysis. Specimens examined.—35; 11 o, 24 Q: Mexico (Curapas): Tuxtla Gutierrez; June 6 and July 17, 1926; (A. Dampf); 2 & (type and paratype), 2 2 (allotype and paratype); [Hebard Cln.]. Honpwras: Subirana, Yoro; February 11 and 13, March 14, 1933; (Stadelmann); 3 3&, 6 9; [Mus. Comp. Zool.]. Mataderos Mountains, near Subirana, Yoro; elevation, 3000 feet; February 13, 1933; (Stadelmann); 6 o, 13 9; [Mus. Comp. Zool.]. Progreso, Sula Valley; August; (Stadelmann); 3 2; [Mus. Comp. Zool.]. JAMES A. G. REHN AND JOHN W. H. REHN 47 Lethus maya amrami* new subspecies (Plate V, figs. 50-54.) This subspecies represents an extreme development of the Lethus maya stock, with which it is apparently connected by intermediates occurring in suitable environments in the lower levels of eastern, more coastal Guatemala. Under the typical form we have noted that material from Progreso in the Sula Valley of northwestern Honduras, while referable to maya maya is atypical of that form, showing a very distinct tendency toward the present subspecies. From this we infer that virtual inter- mediates will be found in portions of eastern Guatemala. From typical maya the subspecies amram can be distinguished by the more marked rostration of the fastigium as seen in profile, and also less evidently in dorsal view, the more deplanate face, the prominence of the supplementary facial carinae, the more strongly arcuate pronotal dorsal profile in the female, the extreme com- pression of the ovipositor valves, the less strongly spinoso-dentate apex of the ultimate sternite (subgenital plate) of the female, and the more obtusely arcuate disto-lateral angles of the margin of the same as seen in profile. The male sex of m. amrami is, as yet, unknown. Type. 2; Piedras Negras, Department of Petén, Guatemala. Elevation, 600 to 800 feet. July 30, 1933. (David W. Amram, Jr.) [Academy of Natural Sciences of Philadelphia, Type no. 5532.1 The features given in the description which follows are chiefly comparative with those already mentioned for the same sex of maya maya, or under oresterus which follows. Size much as in oresterus; form more distinctly compressed than in maya maya. Head with occiput less convex, more obliquely ascendant to the more sharply produced, subrostrate fastigium, which in profile shows a quite sharply acute fastigio-facial angle; from the dorsum the fastigium is seen to be narrower and more produced than in maya maya, subtrigonally arcuate in outline, the greatest width at cephalic angle of eyes being faintly less than twice the length of the fastigium cephalad of the same point (as 17 to 9), the bordering and median carinae of the fastigium as in the other species; facial line with the infra-fastigial concavity relatively marked and the section thence ventrad nearly straight oblique; face 34 Named for its collector Mr. David Werner Amram, Jr., who secured the type and paratype of this form, as well as important material of Gymnotettix occidentalis reported on another page. MEM. AM. ENT. SOC., 8. 48 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) as a whole more flattened than in the other species, particularly ventrad and laterad toward the more decidedly elevated accessory facial carinae; frontal costa with its median half narrow, slightly more so than in maya maya, there deeply sulcate, the dorsal flask-shaped expansion of the lateral margins as in L. oresterus, while the ventral fourth of the costa has the lateral margins appreciably diverging ventrad; clypeus with a definite transverse median carinate angulation, the more proximal sections of the lateral margins of the clypeus sublamellate and joining the trans- verse carina. Eyes in depth subequal to the infra-ocular portion of the genae, in shape as in oresterus. Antennae missing. Pronotum much as in oresterus except that it is more compressed, the dorsal line in profile is seen to be slightly more arcuate and the oblique carination on the lateral lobes is sharper and more elevated, and having at its ventro-cephalic extremity a low node-like protuberance, which is also the ventro-cephalic angle of the lobe margin. Structure of the mesonotum, metanotum and most of the ab- dominal tergites as in oresterus. Ninth, tenth and ultimate abdominal tergites as in L. oresterus, except that the scutellate area proximad on the ultimate tergite (supra-anal plate) has its caudad converging margins straighter than in oresterus: ovipositor valves more slender in profile and more compressed in dorsal aspect than in oresterus, the ventral valves also straighter in lateral aspect than in typical maya, marginal armament much as in oresterus but teeth as a whole smaller and shorter. Ultimate abdominal sternite (subgenital plate) with its distal margin produced mesad into a short lappet-like area with an acute but short median spine, but without lateral angles or points as in the other forms,*® the lateral borders of the production rounding to the distal margin of the same which is crowned by the low but distinct median point. Cephalic and median femora slightly but distinctly more elongate than in maya maya or oresterus, somewhat more slender, particularly proximad. Caudal femora with their apices reaching to the tips of the ovipositor valves, in character as in oresterus; caudal tibiae with external spines numbering from twenty-two to twenty- four, internal spines twenty-one; caudal metatarsi with teeth on dorsal margins four to six in number. Coloration.—General tone mummy brown to blackish fuscous, areas of an apparently base shade of ochraceous-buff, present (paratype) or absent (type) on the head, pronotum and bases of the caudal femora, and of dull dresden brown on the other nota and thoracic sterna in both specimens. The type in color strongly resembles the dark phase of oresterus (described on a 35 We are convinced that the condition of the extremity of the distal production of the ultimate sternite (subgenital plate) in the type and paratype is not fully normal, and that while the usual three angles or spines are almost obsolete, they may be present to some degree in the average female individual of the subspecies. It is possible, however, that the usual median point and the lateral angles of the production are uniformly as little evident as here described and figured, but this remains for the future to demon- strate. JAMES A. G. REHN AND JOHN W. H. REHN 49 subsequent page), the paratype is similar except for the pale areas which suggest, but in a reversal of tone, one of the color types seen in the same species. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur Q, Piedras Negras, type........ 24.2 3.94 8.9 9, Piedras Negras, paratype..... 24.5 3.44 8.9 In addition to the type we have before us a paratypic female bearing the same data. Except for the color features and the slightly shorter pronotum already noted this specimen shows no important differences from the type. Lethus oresterus*® new species (Plate II, fig. 3; pl. V, figs. 42-49.) This inhabitant of Honduranian cloud-forest needs no further comparison with maya. In addition to the key to the species, the accompanying figures give the chief differential features of this most interesting species, concerning which we know more than of any other species of this genus or Eptsactus. Type— @; Pefia Blanca, above Rosario Mine, San Juancito Mountains, Honduras. Elevation, 5900 feet. July 22, 1930. (Academy-Emlen-Worth Expedition; J. A. G. Rehn.) [Academy of Natural Sciences of Philadelphia, Type no. 5530.] Form and surface character as in L. maya except that body is slightly more robust; size slightly larger. Head with general form as in maya but occiput slightly more transverse, the width at cephalic angle of eyes equal to two and one-half times the fastigial length cephalad of the same point, the curve of the fastigial outline slightly flattened mesad; fastigio-facial angle faintly more produced than in maya, facial line ap- preciably more retreating than in maya, with the infra-fastigial concavity deeper and more sharply indicated, while ventrad of the antennae the facial line is nearly straight oblique; frontal costa with dorsal flask-shaped area broader than in L. maya; accessory facial carinae as in maya; eyes proportionately longer than in maya. Antennae slightly shorter than in maya. Pronotum in general as in maya, differing almost entirely in the ventral margin of the lateral lobes being less bisinuate cephalad, instead nearer straight oblique in that area. Mesonotum, metanotum and more proximal abdominal tergites as described under L. maya. Tenth abdominal tergite broadly concavo-emarginate distad, the curvature of the same is regular and not flattened mesad as in maya, the single tooth-like node 3% From épéarepos, dwelling in the mountains. MEM. AM. ENT. SOC., 8. 50 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) situated on each side of the emargination quite small, deflexed, ventro-distal angle of tergite acute produced, but less prolonged than in maya; ultimate tergite (supra- anal plate) no more distinctly separated by a suture from the preceding tergite than in maya, but similarly by contour, the form also broad scutellate with a disto-median acute linguiform production, which is slightly decurved at the apex. Cerci in their entirety more regularly incurved than in maya, and lacking the hook- — like flexure of the latter, the general character otherwise as in maya; apices blunt acute. Ultimate sternite (subgenital plate) with median production of distal margin narrower than in maya, evenly tapering to an elongate spiniform apex, the marginal spines consisting of one pair of heavy, elongate upcurved spines placed at the middle of the lateral margins of the process, toward the internal face of the same, the other pair of much smaller and less conspicuous spines placed on the lateral, cingulate sections of the distal margin distinctly laterad of the median production, directed cephalad; in profile the median production is seen to be strongly reflexed and directed dorso-cephalad, with the lateral sections of the distal margin bent arcuate and strongly sublamellato-cingulate; sculpture of dorso-caudal surface of median production as in maya. Fourth sternite with a similar but more elevated carination than in maya, the same obliquely bevelled distad. Limbs as in L. maya except that greatest depth of caudal femora is contained five times in length of same; dorsal margins of caudal metatarsi each with five or six spines. Allotype.— 2 ; Same date as type but date is August 14, 1930. [Academy of Natural Sciences of Philadelphia.] The female sex of oresterus differs from that sex of maya and the male of the present species, above described, in the following respects. Size appreciably larger; surface similar. Head with fastigio-facial angle in profile more produced than in maya, as in male sex; the infra-fastigial concavity of the facial line as pronounced as in the latter sex, the facial line ventrad of concavity nearly straight, the angle of inclina- tion of same less oblique and the face more vertical than in the male; frontal costa with form as in male sex but interocellar constriction of same more marked; eyes in depth slightly greater than depth of infra-ocular portion of genae (as 24 to 21); antennae faintly longer than the face ventrad of same. Pronotum differing from that of male sex in the same respects as the female of maya does from the male of that species, greatest caudal depth equal to one and nine-twentieths times greatest dorsal length of same; surface rugosities of disk chiefly low tubercles, usual oblique elevation on lateral lobes subobsolete, reduced remnant of lateral carinae of disk sharply bent arcuate. Ninth and tenth abdominal tergites essentially as in L. maya, except, as with the male sex, the less prolonged acute production of the caudo-lateral angles of the tenth: ultimate tergite (supra-anal plate) essentially as in L. maya except JAMES A. G. REHN AND JOHN W. H. REHN 51 that the more proximal section has the lateral margins more straight convergent and the lateral subvertical areas less overhung by these carinae: ovipositor valves much as in maya, but in dorsal aspect with the dorsal pair slightly more arcuate and the armament of the dorso-external margin of the dorsal valves more numer- ous, more truly serrate and less dentate, passing into a mere cutting edge distad, internal margin of dorsal valves armed much as in maya; ventral valves essentially as in maya, teeth of internal margin becoming subobsolete distad: ultimate sternite (subgenital plate) as in maya except that the lateral angles of the produced portion are more rectangulate and the median production is more conical. Limbs differing from those of the male sex in the same degree those of the female of maya differ from those of the male of the same species; greatest depth of caudal femur contained five times in the length of the same. Coloration.—General base color of male ranging from light ochraceous-buff to nearly as dark as ochraceous-tawny, overlaid by a pattern of mummy brown as follows: a narrow medio- longitudinal line from the cephalic border of the pronotum to the apex of the abdomen, finely divided by a pale pencilling of the medio-longitudinal carina; broad subequal bands on the sides from the cephalic border of the lateral lobes of the pronotum to the abdominal apex, broken only by a pale lining of the oblique carina on the lateral lobes and the pale ventral section of the same. Head solidly pale except for the infuscation of the supra-antennal sections lateral of the frontal costa, which latter is pale through- out; eyes sepia mottled with mummy brown; antennae mummy brown except for the pale proximal article. Pleura pale, mar- ginally in part pencilled with mummy brown. Apex of abdomen largely mummy brown, paling on venter of apex to brownish olive. Caudal femora pale becoming fuscous distad, the caudal tibiae and tarsi light brownish olive, the extensor surface, most of proximal section and a varying amount of the remaining areas heavily infuscate, spines light brownish olive, fuscous tipped. Cephalic and median limbs strongly infuscate, the femora showing more clear light brownish olive ventrad than elsewhere; cephalic and median coxae and trochanters with a usually definite wash of pale carmine. General color of female as a whole uniform in the individual but variable in tone, ranging from cinnamon-buff, through buckthorn brown, russet, and even buffy olive to blackish fuscous. The pattern found in the male sex is intimated only faintly and in few individuals by broken remnants of medio- MEM. AM. ENT. SOC., 8. 52 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) longitudinal and lateral dark bars. There is frequently present a pale fuscous wash which tints all the depressions, leaving the high points of the general color, while the caudal femora are occasion- ally obscurely cross-barred, the tibiae and cephalic and median limbs always largely infuscate. In one female of very light base color the limbs are relatively heavily infuscate. One marked color type, probably genetic, has a distinct infuscate fastigial and occipital median bar, which also covers much of the same area on the pronotum, weakest at the transverse center, but the continua- tion upon the other nota and abdominal tergites as vestiges of a medio-longitudinal bar is sometimes but not always correlated. An infuscation of the venter of the fastigium, the vicinity of the antennal bases and the whole ventral half of the frontal costa, and sometimes of other parts of the face and the genae, is, however, correlated with the infuscation of the occiput. Eyes range from ochraceous-tawny to blackish fuscous. Ventral surface generally paler than dorsum and never darker than dull russet or saccardo’s umber. Measurements (in millimeters) Length of Length of Length of body pronotum caudal femur o&, Rosario, type............-.. 15.9 2.68 11.6 o', Rosario, average of six para- PN PeSie ee Aiics asters ts pees teen 16.7 2.53 11.5 (15.3-17.9) (2.35-2.68) (10.5-12.2) @, Rosario, allotype............ 27.6 3.44 12.9 9, Rosario, average of six para- : PV DeSirey cis ofetc era eee Ne esr enR Cus Eee 25.5 3.52 13.1 (20.5-28.2) (3.19-3.78) (12.3-13.8) Paratypic Series —In addition to the type and allotype we have before us eighteen males and twenty-eight females, taken at the type locality (Rosario) between July 11 and 26, 1930. All of these we are considering paratypes. | Morphological Notes—The measurements given above will make evident the very considerable amount of size variation to be found in both sexes of this species. The frontal costa shows in both sexes a marked amount of variation in the degree of expansion of the dorsal flask-shaped section. The degree of emphasis of the oblique carinations of the lateral lobes of the pronotum varies JAMES A. G. REHN AND JOHN W. H. REHN 53 quite appreciably in different individuals of the female sex par- ticularly. The median production of the ultimate sternite (sub- genital plate) of the male shows an appreciable amount of variation in width, particularly of the more proximal section, as well as the exact trend of the lateral margins of the same. These may be converging distad or even subparallel for a short distance mesad. Similarly the paired spines distad on the same process vary in their relative length and in the exact angle of their divergence, while the more proximal (marginal) pair of spines also vary in their emphasis and somewhat in their exact position. Biological Notes——This striking species is partial to the sub- tropical cloud-forest zone on the San Juancito Mountains. It prefers the drier sections near the borders of the forest belt and was absent from the more moist and the denser interior of this very distinctive area. It was in particular locally numerous along a trail near the Pefia Blanca mine level, at 5900 feet eleva- tion, and here it was collected July 14, 22, 23 and 26. Adults were taken but twice below 5900 feet elevation—two males found July 18 in a ravine below cloud forest at 4900 feet, where the cover was virtually continuous with the forest above, which once had reached down to that point; and two females taken July 25 at 4800-5000 feet along a trail through culled cloud-forest and second growth brush. The preferred immediate habitat of adults of oresterus was on the ground in or near dead leaves, but occasionally it occurred in areas of short grass and other low cover, but always on the ground. Rarely it was noticed on bare rock outcrops. Both sexes are good jumpers, but the female appeared more active and harder to capture, although distinctly more numerous than the males. Probably the markedly protective coloration of the females en- abled them to escape observation more readily than the conspi- cuously bicolored males. The first adults taken were secured on July 11, those captured on the tenth being immature individuals. The latter condition was also taken outside of the forest, while sweeping bush cover along a flume across land which a few generations past had carried cloud forest. The last immature individual in the series was taken July 23. None of the immature specimens preserved is MEM. AM. ENT. SOC., 8. 54 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) older than the second instar preceding maturity, while a number represent one and even two preceding the antepenultimate one. Specimens examined: 73; 19 &, 29 2, 25 immature individuals. Honpuras: Rosario (and adjacent Pefia Blanca) San Juancito Mountains; elevation, 4800-6000 feet; July 10-25, 1930; (Academy-Emlen-Worth Expedition; J. A. G. Rehn, C. Brooke Worth and J. T. Emlen, Jr.); 19 & (type and paratypes), 29 Q (allotype and paratypes), 25 immature individuals; [A. N. S. P.]. Group Eumastaces EUMASTAX Burr?’ 1834. Mastax Perty, in Spix and Martius, Delectus Animal. Artic. Brasil., p. 122. (Not of Fischer, 1825.) 1899. Humastax Burr, Anales Soc. Espafi. Hist. Nat., X XVIII, pp. 90, 94, 257. GENOTYPE (by monotypy): Mastax tenuis Perty. Generic features—(Based on and adopted from Burr, 1899.) Vertex rotundate, passing into frontal costa; latter very narrow between antennal bases. Antennae short, slender, bicolored (two proximal articles of body color, remainder infuscate). Eyes moderately prominent. Pronotum relatively small, rather nar- row, with a low median carinula; cephalic margin straight to concave; caudal margin rotundate. Tegmina abbreviate*® or fully developed, narrow, apex roundly ampliate, hyaline, veins pencilled, venation multifenestrate, not closely reticulate. Wings, when present, large, broad, rounded, hyaline. Abdomen slender, in male apex is subclavate. Limbs long, slender; cephalic tibiae ventrad in distal part spinulose on both margins; caudal tibiae 37 Burr in 1899 (An. Soc. Espafi. Hist. Nat., XXVIII, p. 271) recorded the Ecuadorian Paramastax magna Giglio-Tos from ““Mexico.’’ If the material so reported really is magna, it undoubtedly did not come from Mexico, and if it actually came from Mexico it probably represents an undescribed species of Eumastax. The senior author many years ago (Proc. Acad. Nat. Sci. Phila., 1904, pp. 675-676, (1904)) called attention to the fact that Pdramastax magna as described by Burr in 1899 differs in maculation from that species as originally described by Giglio-Tos, and sug- gested Burr’s material was not magna. A male from the Perené Valley, Peru, then studied, agreed with the original description of the species. We are well acquainted with Paramastax, having before us the genotypic and a number of other species, but have seen no material of the genus from north of Colombia. The senior author, on the basis of his Orthoptera field work in Central America, feels confident Paramastax does not occur there. 38 Never truly abbreviate in Central American species. See comments below in re Scirtomastax. JAMES A. G. REHN AND JOHN W. H. REHN 55 with spines of dorso-internal margin of alternate length; caudal metatarsi unarmed and often hirsute dorsad. Coloration.—The species of the genus Eumastax are often exceedingly beautiful in life, possessing a vividly lustrous golden green sheen, which very soon is lost in the dry material. There is, apparently, no way of preserving this exceptional brilliancy, which with their unusual form and incredible activity places them among the most interesting of the Neotropical Acrididae. In consequence the coloration described in the following pages is not that of the living insect, but instead of the dried cabinet specimen, which merely suggests, and but faintly, the gem-like beauty of life. Certain species of the genus have been described as having the eyes bicolored, and this has been used as a specific feature. Evi- dently, however, it is merely a condition produced by desiccation, without sexual or geographic correlation, as we find bicolored and unicolored eyes in series of a single species taken by the senior author. at the same place and the same time. Another color feature which shows some variation is the extent to which the reddish area of the caudal femora, particularly in the female sex, is overlaid or infuscate with cloud annuli of fuscous. In certain species like hondurensis and cerciata this condition is more evident than in others, but it is apparent in all the Central American species except those of the Surda Group, in which it is little indicated. The degree of infuscation of the head and the extent to which the dorsum of the pronotum is involved by similar in- fuscation is apparently, or at least to a considerable degree, de- pendent upon the strength of the intensification or recession of the general darker pattern. Distribution —In Central America Eumastax is limited to the lowland truly Tropical Zone, and is not known from the Sub- tropical or Temperate Life Zones, in at least the former of which members of the Episacti occur. Its most northern definite record is from the north coast district of Honduras (hondurensis), but it doubtless occurs in the lower Motagua Valley of Guatemala, in British Honduras and the rain-forest areas of the Tehuantepec region of Mexico. Southward the genus ranges to at least south- central Bolivia (E. boliviana Hebard, from Buena Vista, Chuqui- MEM. AM. ENT. SOC., 8. ee ek 56 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) saca, Bolivia), eastward to eastern Brazil. No member of the genus occurs in the West Indies proper, although Bruner has reported a nymph of undetermined species from Trinidad. Classification of Central American Species —The Central Ameri- can members of the genus fall naturally into two major sections, one comprising the very distinctive E. cerciata Hebard, the other containing the remaining six species. The latter assemblage, however, is composed of four distinct species groups, of which three are represented by a single species each, while the fourth contains three very closely related Panamanian and Costa Rican forms (surda, veraguae and dentata), as well as one from Colombia (E. carrikert Hebard). The linear arrangement of Central American species which appears most logical and natural is as follows: Kressi Species Group. £. kresst new species (Costa Rica and Panama.) Surda Species Group. £. surda Burr. (Costa Rica and Panama.) E. veraguae Hebard. (Panama.) E. dentata Saussure. (Costa Rica.) Silvicola Species Group. £. silvicola new species. (Costa Rica.) Hondurensis Species Group. EE. hondurensis new species. (Honduras.) Cerciata Species Group. FE. cerciata Hebard. (Panama.) As mentioned above E. carrikert Hebard, described from Anda- goya, Antioquia (Choc6), Colombia,3* belongs to the Surda Species Group. The type of this species is now before us. Whether the rather sharply cut Surda Species Group occurs south of the terri- tory of carrikeri is not known, but it apparently reaches its maxi- mum differentiation in Costa Rica and Panama. Hebard in 1923 stated*® that dentata is inseparable from surda, an assumption quite logical in view of the fact that both were based on the female sex, in which these species are almost in- distinguishable. In addition the exceedingly slight differential features of the female had not been pointed out. However, the two as we understand them are distinct and inhabit altitudinally distinct although adjacent areas. Hebard’s further statement in the same footnote that but a single species of Eumastax is rep- resented in Costa Rica is, and was then, incorrect. Both silvicola and surda were in the series then examined. 3 Trans. Amer. Entom. Soc., XLIX, p. 181, pl. xi, figs. 6, 7 and 8, (1923). 40 Trans. Amer. Entom. Soc., XLIx, p. 178 footnote, (1923). JAMES A. G. REHN AND JOHN W. H. REHN 57 The following key is a purely artificial one, based chiefly on the male sex, as differential characters for the females in most species are very slight and then not wholly reliable. The key to the males, however, will serve to distinguish the species by characters which can readily be observed. That given for the female sex is in- tended merely as an auxiliary, and the authors suggest that the appropriate figures here given be consulted in all cases. No attempt has been made to use coloration as a distinguishing feature, as the living coloration has not been preserved and what remains shows little which could be used in a diagnostic sense. Key to Central American Species of Eumastax Males 1. Cerci styliform, tapering, rarely weakly clavate at apex, not angularly bent in vertical plane (i. e. as seen in lateral aspect), varying in length............ 2 Cerci elongate, heavy proximad, mesad bent obtuse-angulate ventrad in vertical plane (i. e. as seen in lateral aspect) and with the distal portion straight acute produced, subcompressed dorsad, in dorsal aspect moderately Meunvedumcistallhalts. 1 (eanamas)eeee ees. Geese. cerciata Hebard 2, Ultimate sternite (subgenital plate) in profile with dorso-lateral margins straight or as a whole evenly and but moderately arcuate....................-4-- B Ultimate sternite (subgenital plate) in profile with dorso-lateral margins strongly elevated, sinuato-arcuate proximad, straight distad to apex. (Size large.) (Hasternt@ostamRicas)!! naeaeinc Gas See nee ee silvicola new species 3. Cerci short, stocky, apex slightly but appreciably thickened and subclavate. Cephalic and median limbs proportionately more slender and elongate. @Nonéhcoastaofs honduras) sneer eee hondurensis new species Cerci tapering, styliform, sometimes blunt but not subclavate at apex. Ce- phalic and median limbs proportionately less slender and elongate......... 4 4. Size larger (average body length of male, 14.9 mm.; average length of caudal femur of male, 11.6). Ultimate tergite (supra-anal plate) not sharply cut off from preceding tergite by a decided transverse surface flexure. Dorso- lateral margins of ultimate sternite (subgenital plate) straight in profile, apex of sternite distinctly subrostrate produced distad. (Southeastern Costa RucarandradjacenteLanamas) paar eae enna eee eer Rressi new species Size smaller (average body length of male 12.6 mm.; average length of caudal femur of male, 10). Ultimate tergite (supra-anal plate) distinctly cut off from preceding tergite by a transverse surface flexure, usually very evident in profile.*4 Dorso-lateral margins of ultimate sternite (subgenital plate) faintly to appreciably arcuate in profile, apex not at all or but weakly (surda) subrostrate producedidistadic 4.0) .% -c0e a- meine sr seems sore aces 5 41 This feature must be used with caution. Compression or other stress will exaggerate or nullify the normal condition, which is that here characterized. (See page 66 footnote 49.) MEM. AM. ENT. SOC., 8. 58 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) 5. Caudo-lateral angles of tenth tergite, ventrad of cercal bases, but faintly acute. Dorso-lateral margins of ultimate sternite (subgenital plate) appreciably arcuate in profile, apex of same sternite in profile blunt, arcuate, not acute, in disto-dorsal aspect the apex is seen to be distinctly but narrowly and briefly fissate. (Western Costa Rica.)....................2.000- dentata Saussure Caudo-lateral angles of tenth tergite, ventrad of cercal bases, distinctly pro- duced, markedly acute. Dorso-lateral margins of ultimate sternite (sub- genital plate) hardly or but weakly arcuate in profile, apex of same in profile briefly acute, in disto-dorsal aspect the apex is not at all fissate........... 6 6. Cephalic and median limbs more elongate and more slender. Cerci more elongate and slender distad, slightly longer than the penultimate sternite. Dorso-lateral margins of ultimate sternite (subgenital plate) subsinuate, not weakly arcuate as a whole. (Chiriqui, Panama and western Costa Rica.)... se big la caw detaltc oa cake tae saan ree ae evant as eR tsk ee an On surda Burr Cephalic and median limbs shorter and more robust. Cerci less elongate and heavier distad, no longer than the penultimate sternite. Dorso-lateral margins of ultimate sternite (subgenital plate) weakly arcuate as a whole. (Rio Chagres and Porto Bello, Panama.)................. veraguae Hebard Females 1. Ultimate sternite (subgenital plate) with distal margin as a whole transverse ARCUATE ei Are alae ca eh se ae SARC ae ae cee cerciata Hebard Ultimate sternite (subgenital plate) with distal margin produced rectangulate to acute-angulate, at least a median angulation being conspicuously devel- (0) 01216 Jere con rR mete eee ere en rc reel ete AMG R Un Raine trea reowarna oh. Soin aad.6 °a 6 0 2 2. Ultimate sternite with distal margin distinctly denticulate, the margin as a whole rectangulate with a faintly acute apex........ hondurensis new species Jitimate sternite with distal margin smooth to micro-crenulate or micro- denticulate, but not distinctly denticulate as in alternative, median produc- tion of the margin averaging more pronounced.........................- 3 3. Immediate angle of distal margin of ultimate sternite distinctly but not strongly lanceolate acute produced distad of general angulation of lateral portions SC (0) s00t Utd) eae Menon atn ae cerns et 5 Auer fia.cleo 6:c4.0.4:0-9 ¢ kressi new species Immediate angle of distal margin of ultimate sternite less produced distad of general angulation of lateral portions of margin......................... 4 4. Distal margin of ultimate sternite with lateral portions arcuate convergent, the immediate angle brief and blunt arcuate; ventral surface of sternite with two boss-like areas separated by a very evident medio-longitudinal impression... Reenter. Re RE eae eM ee poe a Oe cints sae calc silvicola new species Distal margin of ultimate sternite with lateral portions regularly convergent, the immediate angle very sharply acute, spicate; ventral surface of sternite without structure given in alternative.................. eee ee cece ee ee ees 5 5. Distal margin of ultimate sternite without evident crenulations or denticulations, lateral portions of margin regularly and straight convergent to apex........ veraguae Hebard JAMES A. G. REHN AND JOHN W. H. REHN 59 Distal margin of ultimate sternite with micro-crenulations, lateral portions of margin somewhat concave before immediate apex..............+-+++++05- 6 6. Micro-crenulations of distal margin of ultimate sternite coarser and less dentic- WIE WES onc: en int cetaceans oe ea. tt Coal Seether ee eee Ree et dentata Saussure Micro-crenulations of distal margin of ultimate sternite finer, sharper and MOE TAEN tI CUAL Rr yee eue aS cueee sae he a ke Seco cl eee eee ed surda Burr Eumastax kressi*® new species (Plate V, figs. 55-57; pl. VI, fig. 58.) The chief differential characters of kresst have been summarized in the key to the species of the genus. Diagnostic comparisons of the other species with kresst are given under the respective specific treatments. Type—o; Along Duroy River, north end of Suretka Trail, Estrella Valley, Costa Rica. September 9, 1927. (J. A. G. Rehn; on foliage of forest undergrowth.) [Academy of Natural Sciences of Philadelphia, Type no. 5526.] Size relatively large (for Central American species); form as usual in genus, fully alate. Head with the ascending occiput regularly and moderately convex; least fastigio- facial interspace between eyes narrow, hardly greater than that between internal sides of the bases of the proximal antennal articles; frontal costa narrow, the margins in contact at the paired ocelli, faintly widening ventrad of median ocellus, sulcation there well indicated: accessory facial carinae subparallel: eyes short- ovate in lateral view, depth of eye in profile equal to one and one-half times depth of gena along accessory carina: antennae equal in length to seventeen-twentieths of depth of head, composed of fourteen articles. Pronotum with general sellate form modified by the appreciable deplanation of the dorsum, greatest caudal width of disk equal to three-fifths of greatest pronotal length: cephalic margin of disk subtruncate; caudal margin of same obtusely arcuate; median carinula more distinctly indicated on the rugulose metazona, which is not more than half as long as the much smoother prozona of the disk, the prozona with its surface broken only by the cephalic transverse sulcus, which is impressed, and cephalad of which the surface ascends somewhat to the cephalic margin; lateral carinae of disk indicated caudad on prozona and on metazona, subarcuate on prozona, broken by principal sulcus and not pronounced in emphasis: lateral lobes of pronotum appreciably longer than greatest caudal depth, the latter but three-fourths of the dorsal length of the lobe; cephalic margin and ventro- cephalic angle broadly arcuate; ventral margin subsinuate moderately cephalad 4 Named for Mr. Samuel Kress, Agricultural Superintendent of the United Fruit Company in Costa Rica, as a slight recognition of his many courtesies and cordial hospitality. MEM. AM. ENT. SOC., 8. 60 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) of middle, subarcuate caudad; ventro-caudal angle narrowly rounded rectangulate; caudal margin nearly straight, subvertical; cephalic transverse sulcus disappearing on dorsal section of lobes, median sulcus reaching continuously to ventral margin of lobes, principal sulcus distinct but less extensive ventrad; surface of metazona of lateral lobes largely subrugulose, of prozona subglabrous. Tegmina and wings slightly surpassing apex of abdomen. Tenth abdominal tergite with ventro-caudal angles (ventrad of cercal bases) rectangulate, but moderately produced: ultimate tergite (supra-anal plate) in general form acute produced, apex subuncinate in profile, surface proximad with paired lateral intercercal impressions and a median transverse impression, which forms the base of the tergite’s surface yet does not definitely cut it off from that of the more proximal ring-like tenth tergite: cerci styliform, tapering, blunt at apex, non-clavate, reaching about as far caudad as the apex of the ultimate tergite, in dorsal view weakly incurved in distal half: ultimate sternite (subgenital plate) subfornicate, at apex subrostrate produced, ventro-distal surface with a brief carinulate median ridge reaching the apex, which in dorsal aspect, with the ad- jacent converging distal two-fifths of the dorso-lateral margins, is rectangulate; the latter margins in profile virtually straight. Limbs of medium length for genus; caudal femora surpassing apex of abdomen by less than twice length of pronotal disk. Allotype.— 2 ; Same data as type but taken September 8, 1927. [Academy of Natural Sciences of Philadelphia. ] Differing from the description of the male sex (type) in the following noteworthy sexual features. Head with least fastigio-facial interspace between eyes slightly wider than width between internal sides of the bases of the proximal antennal articles: eyes less exserted than in male, in lateral aspect with depth but slightly greater than depth of gena along accessory carina: antennae equal to about three-fifths depth of head. Pronotum with caudal margin of disk broadly arcuate, less obtuse-arcuate, disk slightly broader; cephalic transverse sulcus less markedly indicated. Tegmina and wings falling short of apices of ovipositor jaws, hardly surpassing bases of same.*8 Tenth abdominal tergite apparently coalesced with ultimate tergite (supra-anal plate), no definite limiting sulcus being evident, the ultimate tergite, dove-tailing proximad into the former, bears on the proximal half of its surface mesad a sharply outlined, deplanate,* scutellate, distally narrowing area, with a distinct medio- longitudinal sulcus, the bounding lateral and distal carinae decided; distal half of ultimate tergite acute lanceolate and supplied medio-longitudinally with a carinu- 48 Other specimens with retracted abdomens show tegmina reaching to ovipositor apices. 44 Often this area is distinctly concave, apparently due to the degree of contraction which has taken place in drying. JAMES A. G. REHN AND JOHN W. H. REHN 61 lation which forks proximad and is thus continuous with the lateral bounding carinae of the more proximal scutellate area; in profile the apex of the ultimate tergite is moderately decurved: infra-cercal plates elongate, lanceolate, subacute at apex, external surface of same canaliculate-excavate: cerci slender, styliform, markedly tapering, reaching nearly to apex of process of ultimate tergite, slightly arcuate dorsad as seen in profile: ovipositor jaws moderately elongate, somewhat compressed, normally armed margins will supplied with teeth, those distad nearly trigonal in outline: ultimate tergite (subgenital plate) with its distal margin as a whole acute, the very sharp apex slightly more lanceolate acute than the general marginal angle, the distal two-fifths of the angulate margin micro-denticulate, ventral surface of sternite with a brief and fine sulcation. Caudal femora surpassing apices of ovipositor jaws by approximately the length of the pronotal dorsum. Coloration.—Pronotum, pleura, proximal section of abdomen, sterna, cephalic and median limbs and much of proximal half of caudal femora of male dull aniline yellow to pyrite yellow, with a metallic sheen in life; in female the same areas are nearer old gold (Ridgway) in tone; clypeus, labrum and less decidedly the man- dibles javel green to peacock green and parrot green, occasionally the clypeus is not involved and the two proximal antennal articles are wholly or in part of the same shade; face naples yellow to pale dull green-yellow in the male, nearly as dull as old gold in the female, its sulcal and lateral carinulae occasionally washed with orange-chrome to flame scarlet; genae and occiput suffused to a variable degree with fuscous brown, always more intense on the occiput and more dilute on the genae, the occiput sometimes solidly colored but usually showing pale greenish areolae and a median line; antennae distad of two proximal articles fuscous black; eyes uniform chestnut-brown to mummy brown, or bi- colored, dorsad fuscous brown, ventrad tawny-olive to snuff brown; tegmina and wings washed with pale fuscous, discoidal and anal veins of tegmina weakly pencilled with whitish. Ab- domen passing distad to old green to orange-citrine in the female, to olivaceous fuscous in the male, in the latter sex occasionally with indications of longitudinal darker lateral bars briefly dorsad of the ventral margins of the tergites; cerci and much of ultimate tergite (supra-anal plate) fuscous black; ovipositor jaws lettuce green to spinach green, teeth and more rugose portions of dorsal and ventral surfaces fuscous; other abdominal tergites occasionally show darkening in the forms of transverse bands at their apices. MEM. AM. ENT. SOC., 8. 62 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Cephalic and median tibiae distad and tarsi becoming clear grass green to parrot green, the dorsal carinae of the tibiae pencilled with fuscous black, the ventral spines of the same color; caudal femora with the blackish pencilling of the carinae in the proximal half pronounced, genicular area olivaceous green, very largely overlaid with black, the area between apex and proximal half solidly scarlet to brazil red; caudal tibiae oil green immediately distad (with tarsi), remainder olivaceous-fuscous with a weak but distinct preproximal paler annulus, spines blackish tipped. Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o', North end of Suretka rail ty perce ce uae eaetees 15.5 2.1 10.8 II.5 o', Same locality, average of six, type and paratypes... 14.9 2.21 II 11.6 (14.1-15.6) (2.05-2.35) (10.7-11.4) (11.3-I1.9) o, Saturno Farm, paratype 14.5 2.1 10.5 II.I o', Changuinola District... 14 2.1 10.9 11.2 9, North end of Suretka Trail, allotype.......... 21.4 2.68 12.8 15.2 9, Same locality, average of four, allotype and para- LY DE ee Rat tsa ees Aiea: 21.6 2.52 1 7) 15-3 (21.4-21.8) (2.27-2.77) (12.2-13.1) (15.2-15.8) Paratypic Series—We have indicated as paratypes six males and three females bearing the same data as the type and allotype; three males from the Suretka Trail, Costa Rica, taken May 19, 1924 by Dr. J. Chester Bradley and in the collection of Cornell University; two males from Vesta Farm, Estrella Valley, Costa Rica, taken September 11 and 13, 1923 by J. A. G. Rehn; one male, two females from Saturno Farm, Estrella Valley, Costa Rica, taken September 12, 1923 by J. A. G. Rehn; and one male taken in the Estrella Valley, Costa Rica, April 22, 1916, by C. H. Lankester. Unless otherwise specified these paratypes are the property of the Academy of Natural Sciences of Philadelphia. Distribution The species kresst is seen from the available material to occupy the Estrella Valley region of south-eastern Costa Rica and the Changuinola River section of the adjacent JAMES A. G. REHN AND JOHN W. H. REHN 63 Bocas del Toro district of Panama. The Suretka Trail crosses the forest mountain ridge which separates the Estrella and Sixaola Valleys, and apparently the distribution of kressz is continuous in this entire area, where forest conditions have not been destroyed. We have no information as to how high the species ascends,“ or how far it ranges to the eastward across northern Panama. Ap- parently, however, it is a species of relatively limited distribution. Biological Notes ——The environment preferred by kressz is the foliage of ground cover in heavy lowland rain-forest, where, like many of its relatives, it prefers the patches of sunlight which filter through the heavy leaf canopy overhead and spangle the forest shade with pockets of brilliancy. These “sunlight holes’’ prove gathering points for many of the forest acridids, which elsewhere are less in evidence. The present species has all the nimbleness of its relations in eluding capture, and sweeping was the surest method of collecting them. As soon as the sunlight failed, or the frequent rainy season showers descended, it was not tobe seen. It was rarely taken by systematic beating, which is often so produc- tive, although less so in tropical rain-forest than elsewhere. The immature individuals from Vesta Farm, taken over a three day period, represent the two instars immediately preceding the imagal condition. The data now in hand show the species occurs adult in the same region from at least as early in the year as mid- April to as late as mid-September. Specimens examined: 42;15 o&, 6 9, 7 immature o, 14 immature 9. Costa Rica: Suretka Trail, between Estrella and Sixaola Valleys; May 19, 1924; (J. C. Bradley); 3 & (paratypes), 1 immature 9; [Cornell University]. Along Duroy River, north end of Suretka Trail; September 8 and 9, 1927; (J. A. G. Rehn; 45 We have before us, in addition to the specimens listed, a single typical male of kresst, labelled as taken at Ujarras de Térraba, Costa Rica, September 10, 1907, by M. A. Carriker, Jr., from the Hebard Collection. This locality is at an elevation of 7000-8000 feet in the Cordillera de Talamanca, at an altitude and in an environment where Eumastax does not occur in Central America. We are convinced some error has taken place in the labelling of this and other material so credited. Other species of Orthoptera in the same lot and said to be from Ujarras de Térraba (see Carriker, Am. Carneg. Mus., vi. p. 356-357, (1910), for notes on this locality), we are equally con- vinced never came from there, as all are lowland Talamancan rain forest species and by no means cloud-forest forms, as would be found at 7000-8000 feet. For that reason we do not doubt that material taken by Mr. Carriker during a year’s residence in the Sixaola Valley has been erroneously labelled as from Ujarras de Térraba. MEM. AM. ENT. SOC., 8. ee ee 64 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) in dense forest);7 «,4 @ (type, allotype and paratypes), 5 immature 9 ;[A.N.S. P.]. Estrella Valley; April 22, 1916; (C. H. Lankester); 1 & (paratype), 1 immature 9; [A. N.S. P.]. Saturno Farm, Estrella Valley, 100 feet elev.; September 12, 1923; (J. A. G. Rehn; foliage on margin of wet forest); 1 o,2 2 (paratypes);[A. N.S. P.]. Vesta Farm, Estrella Valley, 200 feet elevy.; September 11 and 13, 1923; (J. A. G. Rehn; in dense forest, adults very scarce, immatures numerous); 2 o (paratypes), 7 immature o’, 7 immature 9; [A. N.S. P.]. PaNnaMA: Changuinola District, Bocas del Toro; May 15, 1924; (J. C. Bradley); 1 o'; [Cornell University]. Eumastax surda Burr (Plate VI, figs. 59-62.) 1899. Eumastax surda Burr, Anales Soc. Espaii. Hist. Nat., XXVIII, pp. 258, 264. [ 2; Chiriqui, Panama.]*® 1901. Eumastax surda Bruner, Biol. Cent.-Amer., Orth., 1, p. 23, pl. ii, figs. 14, 14a. [9,; Chiriqui [Panama]; Bugaba [Chiriqui, Panama]; Peru (in error).] The present species, the two here following it (veraguae and dentata) and carrikert Hebard, from the Colombian Chocé,4’ con- stitute a well marked group of very closely related forms, inhabit- ing different areas, each apparently of limited extent. As far as known surda has the widest range of the four, being found at relatively low elevations in the Chiriqui district of western Pan- ama and over parts of southwest and western Costa Rica. In the latter country it probably extends little, if at all, north of the Gulf of Nicoya region. : The species of the Surda Group are rather small and agree in their general similarity of size and proportions, but differ in less obvious features of the external genitalia of the males. The features separating these species have already been stressed in the key (see page 58) and need not be repeated in their entirety. The present species and veraguae are more nearly related to one another than they are to E. dentata, which differs mainly in the less decided production of the caudo-lateral angle of the tenth abdominal tergite of the male, and in the briefly fissate apex of the ultimate sternite (subgenital plate) of the same. Our knowl- edge of the female sex of the four species of the Surda Group is by no means full enough to warrant comparative discussion of their 48 This is given as ‘Chiriqui, Perou,’’ an evident transcriptional or typographical error for the well-known district of Chiriqui, Panama. 47 Trans. Amer. Entom. Soc., XLix, p. 181, pl. xi. figs. 6, 7 and 8, (1923). [o, 2; Andagoya, Antioquia (Chocé), Colombia.] JAMES A. G. REHN AND JOHN W. H. REHN 65 differential features, which latter are at best but slight. The determination of females of the genus Eumastax without ac- companying males is exceedingly difficult, unsatisfactory and hazardous, and will remain so until sufficiently long series of perfectly preserved specimens are available tc weigh properly the constancy of almost infinitesimal differences, which are found in the few available females accompanied by males collected at the same time. The species surda was based on a single female, originally in the Brunner Collection and now the property of the Vienna Museum. The original description is not sufficiently exact to fix the name beyond possibility of question on any particular species, naturally lacking the distinctive features found in the male sex. In con- sequence the placing of surda is largely a geographic proposition. We are therefore using the name for the species which more nearly tallies with the description, and which we have from a region near to and environmentally more like the lower levels of Chiriqui Province, Panama, than is true of the other members of the group known to us.. This seems the only logical course to follow with a species of which the unique female type specimen can give little or no definite assistance in the recognition of the species. So the species may be recognized with little difficulty, the following description of its more salient features should be of assistance. &; Pozo Azul de Pirris, near junction of the Rio Grande de Pirris and the Rio Parrita,*8 western Costa Rica. Elevation 325 to 550 feet. August 21,1927. (C.H.Lankester and J. A. G. Rehn.) [Acad. Nat. Sci. of Phila.] Size rather small (for genus); form as typical in genus, fully alate. Head structure and proportions as in E. kresst except that the fastigio-facial interspace between the eyes is slightly broader, the lateral margins of the frontal costa ventrad of the median ocellus are less distinctly carinate, and the accessory facial carinae are less emphasized. 48 This locality is on the extreme northern border of the plain of the Pirris, im- mediately on the Rio Parrita but a very short distance above its junction with the Rio Grande de Pirrfs. It is an abandoned small cattle ranch building in fairly heavy forest country, with cane areas along the Rio Parrita. Immediately to the north the hill slope rises to the low, forest-covered mountain ridge which intervenes between the Rio Parrita and the Rio Colorado, a parallel tributary of the Pirris. The elevations col- lected on the south slope of the hills are covered by the extremes given above. MEM. AM. ENT. SOC., 8. amt“ ee 66 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Pronotum slightly narrower on the dorsum than in E. kressi, cephalic transverse sulcus on the dorsum less definitely marked. Tegmina and wings of same proportions as in EF. kressi, but marginal field of tegmina proportionately narrow, with mediastine vein occupying middle of field for a greater portion of its length. Tenth abdominal tergite with ventro-caudal angles (ventrad of cercal bases) acute, distinctly sharper than a rectangle; ultimate tergite (supra-anal plate) elongate lanceolate, distinctly acute produced, apex non-uncinate in profile; surface of tergite cut off from that of tenth tergite by a transverse arcuate im- pression,*? which is usually quite evident in profile: cerci styliform, tapering, elongate, reaching as far distad as apex of ultimate tergite (supra-anal plate), apex blunt acute, more attenuate than in E. kresst, in lateral aspect nearly straight, in dorsal aspect slightly inbowed at apex: ultimate sternite (subgenital plate) less produced than in F. kressi, apex not distinctly rostrate, weakly produced, in profile blunt acute, seen from dorsum with dorsal margins weakly convex, acute convergent distad, in lateral aspect dorsal margins are shallowly convex in proximal two-thirds, thence to apex straight; disto-ventral surface of ultimate sternite briefly and finely carinulate. Cephalic and median limbs slightly more slender than in E. kresst. Caudal femora with apices surpassing apex of abdomen by faintly more than twice the pronotal length. A female, bearing the same data as the male described above, except that it was taken August 19, 1927, shows the following noteworthy differences from the female of EF. kressz. Size somewhat smaller. Head with the fastigio-facial interspace between the eyes proportionately broader, as in the male; frontal and accessory facial carinae as in the male. Pronotum with dorsum slightly narrower, as in the male sex. Tegmina with marginal field narrower proportionately and the mediastine vein in relatively the same position as in the male sex. Ultimate tergite acute lanceolate, narrower than in the female of E. kressi, the apex more sharply acute, the dorsal surface briefly distad of middle subcompressed laterad, medio-longitudinal carina of distal half similar to but less definite than that of E. kressi, the proximal forking sharper and broader than in the latter: ovipositor jaws in ventral aspect faintly stockier and less elongate than in E. kresst, 49 The degree of emphasis of this varies according to the compression or other stress to which the apex of the abdomen of the dried specimen had been subjected. It is sometimes little evident, again strongly marked, and the two conditions taken by themselves might be considered to represent quite different species. Similarly com- pression of the tenth and ultimate sternites produces a marked longitudinal sulcation of rectangulate cross-section, giving an entirely different appearance to the whole area from that seen in less distorted specimens. Due to the relative softness of the integu- ment the characters of this area must be carefully appraised and not over-emphasized. JAMES A. G. REHN AND JOHN W. H. REHN 67 surface dentations less robust and strongly elevated: ultimate sternite (subgenital plate) with distal margin acute-angulate, immediate apex sharply acute produced, spicate, micro-crenulations of distal half of angulate margins evident. Coloration.—Almost identical with that of E. kressi with a few noteworthy exceptions. The discoidal and anal veins of the tegmina are not distinctly pencilled with whitish; caudal tibiae almost completely lacking the pale preproximal annulus found in E. kresst. Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o', Pozo Azul, described Specimenta.- oe ee 12.9 Dei g.2 10.1 o', Same locality, average of SIAM etn ae re nea tie 12.4 2.18 9 10 (11.7-13) (2.1-2.26) (8.9-9.9) (9.9-10.5) Cy SWUM, sobavaseucooc II.9 2 8.1 — 9, Chiriqui, type (ex Burr) 18 ah 10 13 9, Pozo Azul, described specimen............. 16 2.35 10.9 13.7 2, Pozo Azul, average of Clevenicne aa sonten sie: 17.8 2.39 II.2 13.2 (15.5-18.9) (2.27-2.43) (10.5-12.1) (12.5-13.8) 9, Surubres, average of two 17.6 2.39 10.2 12.5 (2.35-2.43) (10-10.3) (12-13) Distribution.—Apparently the species suvda occupies at least the lower levels of the Department of Chiriqui, Panama, probably only on the Pacific side to the southward of the Volcan de Chiriqui. Its distribution is probably continuous northwestward over the lower country of the Pacific side of Costa Rica wherever suitable conditions are present. It very probably is absent from the savanna type country of the lower Rio Diquis and the same is true of the semi-arid, typically Guanacaste condition found at the head of the Gulf of Nicoya and along the Rio Tempisque. The highest elevation from which we have seen it is two hundred and fifty meters on the Rio Surubres, which is a tributary of the Rio Jestis Maria, western Costa Rica. At higher levels, at least in that region, it seems to be replaced by E. dentata. Nothing is 50 Tt is evident that this was taken hastily, and that it is too large for a member of this genus of the body bulk shown by the other measurements. MEM. AM. ENT. SOC., 8. ——. =f =e So 68 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) known regarding the eastern limit of its distribution toward that of EF. veraguae. The senior author did not see it at Oricuajo on the lower Rio Jests Maria, in park-like Guanacaste environ- ment, although many species which had been secured at Surubres were there taken. Biological Notes——The species surda has habits similar to the other Central American species of the genus, occurring, however, in a relatively drier forest than that inhabited by E. kressz or sylvicola. That frequented at Pozo Azul was also more open with more light penetration than the sombre depths preferred by kresst. The actions of individuals were quite similar to those described for the latter species. The Pozo Azul immatures rep- resent the two instars preceding maturity. Specimens examined: 26;7 o, 13 2; 3 immature o’, 3 immature @. Costa Rica: Pozo Azul de Pirris; (M. A. Carriker, Jr.); 2 9; [Hebard Cln.]: May Io to 20; (M. A. Carriker, Jr.); 1 9; [Hebard Cln.]; 325 to 550 feet elevation; August 19 to 24, 1927 (C. H. Lankester and J. A. G. Rehn; on foliage of under- growth in forest and along clearing edge of same); 6 o’, 8 9, 2 immature a, 3 immature 9;[A. N.S. P.]. Surubres, near San Mateo, Rio Surubres, Pacific side, 250 meters elevation; January, 1906 and March, 1907; (P. Biolley); I #, 1 9, I immature o’; [A. N.S. P.]. Bonnefil Farm, Rio Surubres, 700 feet elevation; October 17, 1909, (P. P. Calvert); 1 9; [A. N.S. P.]. Eumastax veraguae Hebard 1923. Eumastax cerciata Hebard, Trans. Amer. Entom. Soc., XLIxX, p. 178. (In part only.) [1 9; Porto Bello, Panama.] 1924. Eumastax surdus Hebard, Trans. Amer. Entom. Soc., L, p. 92. (Not £. surda Burr.) [o; Guamina, Rio Chagres, Panama.] 1933. Humastax veraguae Hebard, Trans. Amer. Entom. Soc., LIx, p. 127, pl. vi, figs. 9 and 10. [Based on the above recorded Guamina specimen.] Our colleague Mr. Hebard has recently described this species, which some years ago he recorded as E. surdus (sic pro surda). Un- fortunately veraguae is known in the male sex only from the type, the genitalic features of which have been described and figured by Hebard, and an additional male which has the apex of the abdomen somewhat crushed. In addition to the genitalic features mentioned by Hebard,*! we would call attention to those here given in the key to the species of the genus. In view of our 51 Hebard used the term “ninth tergite” for that referred to in this paper as the tenth tergite. JAMES A. G. REHN AND JOHN W. H. REHN 69 present broader knowledge of the Central American species of Eumastax, the emphasis placed on the constriction of the ultimate tergite (supra-anal plate) of the male in the original description of veraguae must be somewhat discounted. But slight compres- sion or other pressure gives to this area an exaggerated contour, often completely different from that of other material taken in the same hour’s collecting. In the present study we have endeavored to be guided by material with abdominal appendages showing no evidence of pressure. Among specimens originally considered paratypes of E. cerciata Hebard from Porto Bello, Panama, we find one female which was included in that series inadvertently, as it has the ultimate sternite (subgenital plate) radically different in shape from that of cerciata, lacking the distal arcuate-truncate outline so character- istic of the female of cerczata, and having the distinctly produced type of the same margin found in the Surda and Kressi Groups. From the latter, however, this individual can be separated by its smaller size and the exact shape of the distal margin of the ultimate sternite. It is also separable from the females here referred to those Central American members of the Surda Group other than E. veraguae, with the type of which it agrees in all ambisexual features. In consequence we feel it represents the female sex of veraguae, and are so recording it, although it lacks the conclusive evidence of accompanying males. Allotype.— 2; Porto Bello, Panama. April 18, 1912. (August Busck.) [Hebard Collection.] When compared with the female sex of E. surda as understood by us, the present specimen differs in the following noteworthy respects. Tegmina and wings actually and proportionately longer, reaching caudad nearly to the base of the genicular arches of the caudal femora; tegminal marginal field proportionately broader, the mediastine vein placed close to the costal margin and the area between it and the humeral trunk wider, and with fewer and more regular cross-veins producing elongate rectangular fenestrae. Ultimate sternite (sub- genital plate) differing from swrda merely in the shape of the distal margin being more truly rectangulate, the less briefly spicate acute apex, and the absence of marginal denticulations. Coloration essentially that of surda. MEM. AM. ENT. SOC., 8. 70 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o', Guamina, type (ex He- band). ace atreeee ar ee 13 1.9 10.2 10 o', Barro Colorado Island.. 12.5 1.97 10 10.2 9, Porto Bello, allotype.... 20” 2.52 13.5 14 Distribution.—The species is definitely known only from the type and allotype, and a male from Barro Colorado Island, Canal Zone, and its distribution is probably limited to the rain-forest area of the north coast section of Panama. It occurs at Porto Bello with E. cerciata, but was not met by the senior author in eastern Costa Rica, where the Surda Group appears to be absent. Specimens examined: 3;2 &, 1 @. PANAMA: Guamina, Rio Chagres; March 5, 1922; (G. H. H. Tate); 1 &@ (type); [Hebard Cln.]. Porto Bello; April 18, 1912; (August Busch); 1 @ (qallotype); {[Hebard Cln.]. Barro Colorado Island, Canal Zone; July 20, 1924; (N. Banks); 1 o'; [Mus. Comp. Zool.]. Eumastax dentata Saussure (Plate VI, figs. 63-65.) 1903. Eumastax dentatus Saussure, Revue Suisse de Zoologie, xI, p. 91. [9; Palmares, Costa Rica.] The name dentata was based on a single female, and the descrip- tion consequently lacks mention of any sharply distinctive feature to separate the species from surda, the sole previously known near relative, which unfortunately was not mentioned or compared by Saussure. As the type is a female its physical examination would give little help in the proper interpretation of the species, and lacking topotypic males we are compelled to fall back upon hypothesis in placing the name. Palmares, Costa Rica, the type locality of dentata, is situated near the head of the broad upper valley of the Rio Grande de Tarcoles, not far from the larger settlement of San Ramon. It is at an elevation of about three thousand feet above the sea, distinctly higher than any locality from which surda is known. We have before us a single male taken by the senior author on the south slope of the western end of the forested Cerros de Busta- mente, between the Rio Colorado, at the south foot of the slope, 52 Allowance made for abnormally curved abdomen. JAMES A. G. REHN AND JOHN W. H. REHN 71 and Sabanillas de Pirris, at the trail crossing on the summit of the range. The specimen was picked up along the trail in con- tinuously heavy forest, while travelling with a pack train. The exact elevation was not noted, as the train was moving over a very bad trail, often in deep mud and heavy rain. The altitude, however, was somewhere between 1500 and 3940 feet, and prob- ably much nearer the latter than the former figure, as a badly exhausted pack animal made frequent halts necessary as Saba- nillas was approached. We are concluding, therefore, that the species then secured is one of higher levels than surda, which had been taken at Pozo Azul on the same trip, and that the present specimen is probably identical with the insect found at approxi- mately the same elevation at Palmares, even though the localities are separated by the relative deep valleys of the Rios Candelaria and Grande de Tarcoles, with the Candelaria mountains between. Until topotypic or virtually topotypic males show the Palmares insect to be different from that for which the name dentata is here used, the present course seems warranted and logical. The more evident features separating dentata, as here under- stood, from surda and veraguae, have been presented in the key to the species, and it is not necessary to repeat these as a diagnosis. The male specimen above mentioned shows the following additional differential features deserving mention, as well as details of the genitalic features summarized in the key. Size and form similar to E. surda. Head with interspace between eyes at vertex faintly broader; frontal costa ventrad of median ocellus faintly broader, margins subparallel. Tegmina and wings reaching to the apex of the abdomen. Cephalic and median limbs slightly stockier and more robust than in E. surda, but hardly as much so proportionately as in E. veraguae, to which greater approxi- mation is made than to F. surda. Tenth abdominal tergite with ventro-caudal angles (ventrad of cercal bases) but faintly acute, little sharper than a right angle: ultimate sternite (supra-anal plate) as in surda but with lateral margins distad slightly more acute convergent, sculpture and contour similar: cerci as in surda but faintly less robust proximad: ultimate sternite (subgenital plate) in profile with its distal extremity rotundato- subtruncate, not weakly rostrate or subrostrate as in E. surda and veraguae, not at all acute; dorso-lateral margins from dorsum nearly straight acute convergent, in profile not strongly but distinctly arcuate, in distal aspect the apex is seen to be MEM, AM. ENT. SOC., 8. 22 See coe 72 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) narrowly and briefly but distinctly fissate, with a medio-longitudinal carination extending ventro-proximad from the apex over virtually all of the sternite. Coloration.—There is no colorational feature of important difference from those found in E. surda, veraguae and also in E. kresst. The anal and discoidal veins of the tegmina are pale, as in kressi, no definite preproximal pale annulus is indicated on the caudal tibiae, and the preapical red section of the caudal femora is less extensive than in the average of surda, in this respect more like veraguae. Additional Mater1al—We have before us a single female taken at the Cangrejal de Aserri, western Costa Rica, which, for purely geographic reasons, we are tentatively referring to E. dentata. Its specific reference is purely provisional and it shows no noteworthy difference from the same sex of surda, except that the micro- crenulations of the angulate apex of the ultimate sternite (sub- genital plate) are finer, sharper and more denticulate than in the related species. Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o', Betw. Rio Colorado and Sabanillas.............. 12.8 Doi 9 10 9, Cangrejal de Aserri.... 19 2.6 II 14 Specimens examined: 2;1 &,1 Q. Costa Rica: Between the Rio Colorado and Sabanillas de Pirris, south slope of the Cerros de Bustamente, elevation 1500-3940 feet; August 25, 1927; (J. A. G. Rehn; on foliage in heavy forest); 1 @;[A. N.S. P.]. Cangrejal de Aserri, elevation 800 meters; April, 1906; (P. Biolley); 1 9, [A. N.S. P.]. Eumastax silvicola new species (Plate VI, figs. 66-69.) 1904. Eumastax dentatus Rehn, Proc. Acad. Nat. Sci. Phila., 1904, p. 675. (Not E. dentatus Saussure.) [o%, 9; Carrillo, Costa Rica; Costa Rica.] The distinctive character of the ultimate sternite (subgenital plate) of the male in this species will distinguish it from the other Central American species. This is well shown in the accom- panying figures. In size szlvicola equals kressi and hondurensis, and is distinctly larger than the members of the Surda Group, from which it had not been distinguished previously. JAMES A. G. REHN AND JOHN W. H. REHN 73 Type.— &; La Emilia, near Guapiles, Costa Rica. Elevation, 1000 feet. August 20, 1923. (J. A. G. Rehn; on foliage in heavy forest.) [Academy of Natural Sciences of Philadelphia, Type no. 5528.] The features given below are those of difference from the detailed description of E. kressi given on a preceding page (p. 59). Size as a whole slightly smaller than in E. kressi; form similar. Head as in kressi but with the eyes slightly less protuberant in cephalic aspect and in profile faintly less inflated; least fastigio-facial interspace between eyes slightly but appreciably greater than that between internal sides of the bases of the proximal antennal articles; frontal costa slightly narrower than in kressi; antennae slightly more slender than in kresst. Pronotum as in kresst but with caudal margin of disk more broadly arcuate, the median carinula distinct and continuous, and the cephalic transverse sulcus much less evident on disk; lateral carinae of disk nearly straight and virtually subparallel caudad on prozona and on metazona. Tegmina and wings in length briefly surpassing the apex of the abdomen; media- stine vein of tegmina placed as in FE. kresst. Tenth abdominal tergite with ventro-caudal angles (ventrad of cercal bases) obtuse-angulate, little produced, the ventral margin of same angle well arcuate; ultimate tergite (supra-anal plate) in shape much as in kressi, the distal extremity with the angle less sharply acute as seen from the dorsum but equally subuncinate in profile; surface of ultimate tergite sculptured essentially as in kressz: cerci slightly shorter than in kressz, more distinctly tapering, as seen from dorsum nearly straight and not inbowed, apex more slender: ultimate sternite (subgenital plate) short, strongly fornicate, in no way rostrate, dorsal margins meeting distad at a right angle as seen from the dorsum, the same subparallel in proximal thirds, thence gently arcuate to distal thirds, which are straight convergent to apex; seen in profile the dorsal margins are markedly convex in proximal half, thence straight and gently declivent to apex; in distal view the apex of the sternite is seen to be briefly carinulate. Limbs as in E. kressz. Allotype— 2 ; Same data as type but taken August 12, 1923. [Academy of Natural Sciences of Philadelphia.| Differing from the same sex of EF. kressz in the following note- worthy features. 53 The immediate environment in which the type of this species, as well as many other Orthoptera, was taken, is that portion of the extensive Santa Clara plains rain- forest about one and one-half miles south of the cattle farm of La Emilia, which is on the Northern Railroad about a mile east of Guapiles. The senior author worked in this very rich locality for three weeks in 1923 and 1927. MEM, AM. ENT. SOC., 8. 74. CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Size slightly smaller. Eyes in profile faintly less inflated; frontal costa slightly narrow. Pronotum showing the same relative features of difference noted in the male sex. Tegmina and wings slightly shorter proportionately, not surpassing base of Ovipositor jaws.™4 . Tenth abdominal tergite and ultimate tergite (supra-anal plate) essentially as in E. kressi; cerci slightly heavier at base, more finely tapering, apex more delicate, nearly straight in lateral view; ovipositor jaws in dorsal and ventral views straighter, slightly less divergent meso-proximad: ultimate sternite (subgenital plate) with its distal margin as a whole subrectangulate, with the immediate apex short and blunt acute produced, the distal portion of the lateral sections of this margin more briefly and more shallowly concave before apex, proximad of this the sides of the margin are subarcuate, apical section with margin subcrenulate; ventral surface of sternite with a distinct medio-longitudinal impression separating two low sub- strumose areas. Coloration.—As in E. kressit in general features and also in the details except as follows: the discoidal and anal veins of the tegmina may or may not be pencilled with whitish (this variation is not governed by sex or locality and is found in both the La Emilia and Juan Vifias series); red area on caudal femora in both sexes slightly less extensive and duller in color, nearer brazil red, with a more definitely indicated tendency toward general subfuscous cloud annuli overlying the red. Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o, La Emilia, type........ 14.7 2.01 10.2 II o, La Emilia, paratype... . 13.9 2.05 10.8 I1.9 oe Carrillomeas sae 13 1.97 9.5 II CuauaneVinashse sane a 13°5 1.97 9.8 10.9 Gi, Wain WAG. ccons05000 14.9 1.97 10.2 Il. 9, La Emilia, allotype..... 20.3 2.35 II.2 13.8 9, La Emilia, average of four (allotype and para- EV DES) ee ras aren sree 19.9 © DB 11.2 1305 (19.5-20.5) (2.26-2.48) (10.8-12) (12.5-14) ©), [PRATT 5 s 5000000008 19.1 2.52 12 14.5 2, 52 miles, near Peralta. 21 2.52 II 14.6 ©), fcein Witt 6ocancs0ne 07/2 2EAS II.5 13.9 Ol INVANTO’. cai cee dt ate 19.1 2.35 9.1 13.2 54 Tn a few specimens in the series studied the tegmina and wings do surpass the base of the ovipositor jaws. In all, however, the abdomen is abnormally retracted. 55 Abdomen exceptionally recurved. JAMES A. G. REHN AND JOHN W. H. REHN 75 Paratypic Series —We have indicated as paratypes those adults before us from the type locality other than the type and allotype, consisting of four males and twelve females, taken on August 12, 15, 16, 18, 20, 22 and 24, 1923 and September 15, 1927. Distribution.—The present. species is one of the rain-forest of the Santa Clara plains of northeastern Costa Rica and the adjacent valley of the Rio Reventazén. How extensive its area of distribu- tion is to the northward we do not know, and also whether its range meets or overlaps that of the Talamancan kressz is equally undetermined. We are able to say it reaches tidewater areas on the lower Rio Parismina, and as high as Carrillo on the upper reaches of the Rio Sticio on the lower northern slope of the La Palma Pass between the Volcanos of Irazti and Barba, and up the Reventazon Valley to Navarro, virtually at its head at an eleva- tion of approximately 3950 feet. The species is limited to areas characterized by rain-forest, and does not occur in’ the Subtropical Zone of higher elevations. At Navarro we find the extreme upper limit of distribution of a number of characteristic Orthoptera species of the Santa Clara and Reventazén tropical element. Biological Notes——In habits silvicola is essentially similar to E. kresst and surda, always frequenting the more open sunny spots or “sunlight holes” of its forest habitat, perched on the leaves of vines and other low undergrowth. Its actions are very rapid, in common with most eumastacids, as like the bolt from a cross- bow, to which its hind limbs held akimbo bear a great resemblance, it launches away from a possible disturber. The advent of rain sends all into hiding, and until the sun appears again they will not be seen. The available data show the species occurs adult from as early as March (day unspecified, Juan Vifias) to as late as November 24 (Chitaria). The series of immature individuals from La Emilia represents three instars over periods as short as three to four days in both the months of August and September (i. e. August 13, 15 and 16, and September 12 and 14). Immature material has not been seen taken later than September 14. Specimens examined: 50; 12 o', 20 2, 6immature o’, I2 immature 9. Costa Rica: La Emilia, near Guapiles, elevation 1000 feet; August 12-24, 1923; (J. A. G. Rehn; on foliage of undergrowth in open sunny spots of heavy forest) ; MEM. AM. ENT. SOC., 8. 76 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) 5 0, 12 & (type, allotype and paratypes),2 immature &@,9immature 9;[A. N.S. P.]; September 12-15, 1927; (J. A. G. Rehn; same conditions); 1 9 (paratype), 2 immature o’, Limmature 9;[A. N.S. P.]. Carrillo; (Underwood); 1 =; [Hebard Cln.]. Gudcimo, elevation 350 feet; June 7, 1909; (P. P. Calvert);1 9;[A. N.S. P.]. Parismina (lower course of river), elevation one-half meter; July 26, 1928; (M. Valerio); 1 9: [A. N. S; B.] PReralitta, August (9) 1909; (Rl P. Calvert) mor [A. N.S. P.]. Fifty-two mile post on railroad, near Peralta; August 4, 1927; (C. H. Lankester); 1 9;[A. N.S. P.]. Chitaria, Province of Cartago, elevation 600 meters; November 24, 1928; (M. Valerio); 1 &;[A. N.S. P.]. Pejivalle, elevation 1850-2100 feet; August 11 and 13, 1927; (J. A. G. Rehn; from foliage of forest undergrowth); I 9, I immature <7; [A. N. S. P.]. Juan Vifias; March, 1902; (Bruner); 5 o’, I 9, I immature Caudal tibiae with a pronounced preproximal pale annulus. Measurements (in millimeters) Length of Length of Length of Length of body pronotum tegmen caudal femur o, Lancetilla, type........ 15.1 2.18 9 11.8 o, Lancetilla, average of three (type and para- DROS) So teg igor e cineiblak 15.4 2.16 9 Tes (15-16.2) (2.10-2.18) (8.9-9) (11-118) 9, Lancetilla, allotype..... 20.5 2.52 12 15.8 @, Lancetilla, average of three paratypes...... 20.5 2.52 II 15.4 (20-21) (10-12) (14.9-15.8) Paratypic Series—We have indicated as paratypes two males and four females bearing the same data as the type and allotype except that three days, September 4, 6 and 8, are represented. 56 These annuli are more decided in hondurensis than in any other Central American Eumastax except E. cerciata and an occasional female of E. silvicola. In the first men- tioned species they are as definite in the male as in the female. JAMES A. G. REHN AND JOHN W. H. REHN 79 Distribution.—The present species is known only from the lower slopes of the Sierra Pija at Lancetilla, near Tela, on the north coast of Honduras. It was found in a very small opening at 700 feet elevation, along a steep trail in very dense rain-forest. This very limited “sunlight hole’? had a thick stand of low, glabrous ovate-leaved plants, on which hondurensis was found. It was scarce and all seen on the three different visits to the im- mediate locality were taken, two females on the 4th, three males and two females on the 6th, and one female on the 8th. The actions of hondurensts, as far as noted, were essentially the same as those of the other Central American species of the genus. Specimens examined: 8;3 3,5 @. Honpuras: Lancetilla, near Tela, Department of Atlantida, elevation 700 feet; September 4, 6 and 8, 1930; (Academy-Emlen-Worth Expedition; J. A. G. Rehn); 30,5 @ (type, allotype and paratypes); [A. N.S. P.]. Eumastax cerciata Hebard 1923. Eumastax cerciata Hebard, Trans. Amer. Entom. Soc., XLIx, p. 178, pl. xi, figs. 4 and 5. [o, 2; Porto Bello, Panama (in part).*’] This very distinctive species can at once be separated from the other Central American ones by the characteristic form of the male cerci and the shape of the distal margin of the ultimate sternite (subgenital plate) of the female. At least one of the originally included Porto Bello females we find represents that sex of veraguae, and is discussed under that species. Having no material additional to that before the original describer, we can add nothing to the detailed description of the type and allotype presented in 1923. The figures then published emphasize the principal differential features of both sexes of cerciata. The elimination of erroneously referred females and immature individuals restricts the area of distribution originally assumed for 57 At least one Porto Bello female, listed as a paratype of cerciata, we now know rep- resents that sex of E. veraguae. The immature female from Gatun, Canal Zone, Panama, originally listed as cerciata is not that species, but may represent veraguae. It is somewhat shrivelled and definite reference is hazardous. The female individuals from Boca Murind6, Chocd, Colombia and El Tambo, Chocé, Colombia, originally referred to cerciata, similarly are not that species, as shown by the form of the ultimate sternite. Exact reference of these specimens awaits a more complete knowledge of the Colombian species. MEM. AM. ENT. SOC., 8. a oe 80 CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) the species. Porto Bello, Panama remains the sole locality from which cerciata is known, although it doubtless will be found to have a more extensive range over the northern and eastern rain- forest area of Panama and probably Darien. Specimens examined: 5;4 o,1 @. PANAMA: Porto Bello; February 19 and March 1, 1911, April 15 and 19, 1912; (August Busck); 4 o, 1 @ (paratypes); [Hebard Cln.]. EXPLANATION OF PLATES Plate I Fig. 1.—Gymnotettix lithocolletus new species. Lateral view of male (type). Cantarranas, Honduras. (xX 6%.) ‘ Fig. 2.—Episactus tristani new species. Lateral view of female (allotype). Las Céncavas, Costa Rica. ( 5.) Plate II Fig. 3.—Lethus oresterus new genus and species. Lateral view of male (type). Pefia Blanca, near Rosario, Honduras. (xX 4%.) Fig. 4.—Eumastax hondurensis new species. Lateral view of male (type). Lance- tilla, Honduras. (xX 4%.) Plate III Fig. 5.—Gymnotettix occidentalis Bruner. Lateral outline of dorsal portion of head of male. Piedras Negras, Guatemala. (Greatly enlarged.) Fig. 6.—Gymnotettix occidentalis Bruner. Lateral view of apex of abdomen of male. Piedras Negras, Guatemala. (Greatly enlarged.) Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. JAMES A. G. REHN AND JOHN W. H. REHN 81 7.—Gymunotettix occidentalis Bruner. Caudal aspect of apex of abdomen of male. Piedras Negras, Guatemala. (Greatly enlarged.) 8.—Gymnotettix occidentalis Bruner. Dorsal view of apex of abdomen of male. Piedras Negras, Guatemala. (Greatly enlarged.) 9.—Gymnotettix occidentalis Bruner. Outline of ovipositor jaws of type (immature female). Rio Sarstoon, British Honduras. From speci- men in British Museum of Natural History, through courtesy of Dr. Uvarov. (Greatly enlarged.) 10.—Gymnotettix occidentalis Bruner. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female. Piedras Negras, Guatemala. (Greatly enlarged.) 11.—Gymnotettix lithocolletus new species. Lateral view of apex of abdomen of male (type). Cantarranas, Honduras. (Greatly enlarged.) 12.—Gymnotettix lithocolletus new species. Caudal aspect of apex of abdomen of male (type). Cantarranas, Honduras. (Greatly enlarged.) 13.—Gymnotettix lithocolletus new species. Dorsal view of apex of abdomen of male (type). Cantarranas, Honduras. (Greatly enlarged.) 14.—Gymnotettix lithocolletus new species. Cephalic outline of head of male (type). Cantarranas, Honduras. ( 5.) 15.—Gymnotetiix lithocolletus new species. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (allotype). Can- tarranas, Honduras. (Greatly enlarged.) 16.—Episactus brunnert Burr. Dorsal outline of head of female (type of Parepisactus saltator Saussure). Guatemala. From specimen in Geneva Museum, through courtesy of Dr. J. Carl. (Greatly enlarged.) 17.—Episactus brunneri Burr. Lateral outline of head of female (type of Parepisactus saltator Saussure). Guatemala. From specimen in Geneva Museum, through courtesy of Dr. J. Carl. (Greatly enlarged.) 18.—Episactus tristant new species. Lateral outline of head and pronotum of male (type). La Carpintera, Costa Rica. (~ 5.) 19.—E pisactus tristant new species. Cephalic outline of head of male (type). La Carpintera, Costa Rica. ( X 5.) 20.—Episactus tristani new species. Details of cephalic aspect of fastigium of male (type). La Carpintera, Costa Rica. (Greatly enlarged.) 21.—Episactus tristant new species. Lateral view of apex of abdomen of male (type). La Carpintera, Costa Rica. (Greatly enlarged.) 22.—Episactus tristant new species. Caudal aspect of apex of abdomen of male (type). La Carpintera, Costa Rica. (Greatly enlarged.) 23.—Episactus tristant new species. Dorsal view of apex of abdomen of male (type). La Carpintera, Costa Rica. (Greatly enlarged.) MEM. AM. ENT. SOC., 8. a 82 Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Plate IV 24.—Episactus tristant new species. Lateral outline of apex of abdomen of female (allotype). Las Céncavas, Costa Rica. (Greatly enlarged.) 25.—Episactus eremites new species. Lateral outline of apex of ultimate sternite and ventral ovipositor valves of female (allotype). San Crist6bal, Chiapas, Mexico. (Greatly enlarged.) 26.—Episactus tristani new species. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (allotype). Las Céncavas, Costa Rica. (Greatly enlarged.) 27.—Episactus eremites new species. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (allotype). San Cristébal, Chiapas, Mexico. (Greatly enlarged.) 28.—Episactus eremites new species. Lateral outline of head and pronotum of female (allotype). San Cristébal, Chiapas, Mexico. (x 5.) 29.—Episactus eremites new species. Lateral outline of head and pronotum of male (type). San Crist6ébal, Chiapas, Mexico. (x 5.) 30.—Episactus eremites new species. Dorsal outline of head and pronotum of male (type). San Crist6ébal, Chiapas, Mexico. (> 5.) 31.—Episactus eremites new species. Lateral view of apex of abdomen of male (type). San Cristébal, Chiapas, Mexico. (Greatly enlarged.) 32.—Episactus eremites new species. Caudal aspect of apex of abdomen of male (type). San Cristébal, Chiapas, Mexico. (Greatly enlarged.) 33.—Episactus eremites new species. Dorsal view of apex of abdomen of male (type). San Crist6ébal, Chiapas, Mexico. (Greatly enlarged.) 34.— Lethus maya new species. Lateral outline of head and pronotum of male (type). Tuxtla Gutierrez, Chiapas, Mexico. ( 5.) 35.— Lethus maya new species. Dorsal outline of head and pronotum of male (type). Tuxtla Gutierrez, Chiapas, Mexico. ( X 5.) 36.—Lethus maya new species. Lateral view of apex of abdomen of male (type). Tuxtla Gutierrez, Chiapas, Mexico. (Greatly enlarged.) 37.—Lethus maya new species. Caudal aspect of apex of abdomen of male (type). Tuxtla Gutierrez, Chiapas, Mexico. (Greatly enlarged.) 38.—Lethus maya new species. Dorsal view of apex of abdomen of male (type). Tuxtla Gutierrez, Chiapas, Mexico. (Greatly enlarged.) 39.—Lethus maya new species. -Lateral outline of head and pronotum of female (allotype). Tuxtla Gutierrez, Chiapas, Mexico. (x 5.) 40.—Lethus maya new species. Lateral view of apex of abdomen of female (allotype). Tuxtla Gutierrez, Chiapas, Mexico. (Greatly enlarged.) 41.—Lethus maya new species. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (allotype). Tuxtla Gutierrez, Chiapas, Mexico. (Greatly enlarged.) Fi _ g Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. JAMES A. G. REHN AND JOHN W. H. REHN 83 Plate V . 42,—Lethus oresterus new species. Cephalic view of head of male (type). Pena Blanca, near Rosario, Honduras. ( 5.) 43.—Lethus oresterus new species. Dorsal view of head and pronotum of male (type). Pefia Blanca, near Rosario, Honduras. ( X 5.) 44.—Lethus oresterus new species. Lateral view of apex of abdomen of male (type). Pefia Blanca, near Rosario, Honduras. (Greatly enlarged.) 45.—Lethus oresterus new species. Caudal aspect of apex of abdomen of male (type). Pema Blanca, near Rosario, Honduras. (Greatly enlarged.) 46.—Lethus oresterus new species. Dorsal view of apex of abdomen of male (type). Pefia Blanca, near Rosario, Honduras. (Greatly enlarged.) 47.—Lethus oresterus new species. Dorsal outline of head and pronotum of female (allotype). Pena Blanca, near Rosario, Honduras. (> 5.) 48.— Lethus oresterus new species. Lateral view of apex of abdomen of female (allotype). Pena Blanca, near Rosario, Honduras. (Greatly en- larged.) 49.—Lethus oresterus new species. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (allotype). Pefia Blanca, Honduras. (Greatly enlarged.) 50.— Lethus maya amram new subspecies. Lateral view of head and prono- tum of female (type). Piedras Negras, Guatemala. (xX 5.) 51.—Lethus maya amrami new subspecies. Dorsal view of head and pro- notum of female (type). Piedras Negras, Guatemala. (x 5.) 52.—Lethus maya amrami new subspecies. Cephalic aspect of head of female (type). Piedras Negras, Guatemala. ( 5.) 53.— Lethus maya amrami new subspecies. Lateral view of apex of abdomen of female (type). Piedras Negras, Guatemala. (Greatly enlarged.) 54.—Lethus maya amrami new subspecies. Ventral view of apex of ultimate sternite and ventral ovipositor valves of female (type). Piedras Negras, Guatemala. (Greatly enlarged.) 55.—Eumastax kressi new species. Lateral view of apex of abdomen of male (type). Suretka Trail, Estrella Valley, Costa Rica. (Greatly en- larged.) 56.—Eumastax kressi new species. Caudal aspect of ultimate sternite of male (type). Suretka Trail, Estrella Valley, Costa Rica. (Greatly en- larged.) 57.—Eumastax kressi new species. Dorsal view of apex of abdomen of male (type). Suretka Trail, Estrella Valley, Costa Rica. (Greatly en- larged.) MEM. AM. ENT. SOC., 8. ae ee a 84 Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. CENTRAL AMERICAN EUMASTACINAE (ORTHOPTERA) Plate VI 58.—Eumastax kresst new species. Ventral view of apex of ultimate sternite of female (allotype). Suretka Trail, Estrella Valley, Costa Rica. (Greatly enlarged.) 59.—Eumastax surda Burr. Lateral view of apex of abdomen of male. Pozo Azul de Pirris, Costa Rica. (Greatly enlarged.) 60.—Eumastax surda Burr. Caudal aspect of ultimate sternite of male. Pozo Azul de Pirris, Costa Rica. (Greatly enlarged.) 61.—Eumastax surda Burr. Dorsal view of apex of abdomen of male. Pozo Azul de Pirris, Costa Rica. (Greatly enlarged.) 62.—Eumastax surda Burr. Ventral view of apex of ultimate sternite of female. Pozo Azul de Pirris, Costa Rica. (Greatly enlarged.) 63.—Eumastax dentatus Saussure. Lateral view of apex of abdomen of male. Between Rio Colorado and Sabanillas de Pirris, Costa Rica. (Greatly enlarged.) 64.—Eumastax dentatus Saussure. Caudal aspect of ultimate sternite of male. Between Rio Colorado and Sabanillas de Pirris, Costa Rica. (Greatly enlarged.) 65.—Eumastax dentatus Saussure. Dorsal view of apex of abdomen of male. Between Rio Colorado and Sabanillas de Pirris, Costa Rica. (Greatly enlarged.) 66.—Eumastax sylvicola new species. Lateral view of apex of abdomen of male (type). La Emilia, near Guapiles, Costa Rica. (Greatly en- larged.) 67.—Eumastax sylvicola new species. Caudal aspect of ultimate sternite of male (type). La Emilia, near Guapiles, Costa Rica. (Greatly en- larged.) 68.—Eumastax sylvicola new species. Dorsal view of apex of abdomen of male (type). La Emilia, near Guapiles, Costa Rica. (Greatly en- larged.) 69.—Eumastax sylvicola new species. Ventral aspect of apex of ultimate sternite of female (paratype). La Emilia, near Guapiles, Costa Rica. (Greatly enlarged.) 70.—Eumastax hondurensis new species. Lateral view of apex of abdomen of male (type). Lancetilla, Honduras. (Greatly enlarged.) 71.—Eumastax hondurensis new species. Caudal aspect of ultimate sternite of male (type). Lancetilla, Honduras. (Greatly enlarged.) 72,—Eumastax hondurensis new species. Dorsal view of apex of abdomen of male (type). lLancetilla, Honduras. (Greatly enlarged.) 73.—Eumastax hondurensis new species. Ventral aspect of apex of ultimate sternite of female (allotype). Lancetilla, Honduras. (Greatly en- larged.) Mem. Am. Ent. Soc., No. 8. PeAmE le REHN AND REHN—EUMASTACINAE Mem. Am. ENT. Soc., No. 8. Pac Ama Ile REHN AND REHN—EUMASTACINAE Mem. Am. ENT. Soc., No. 8. PLATE III. pr 3 REHN AND REHN—EUMASTACINAE Mem. Am. Ent. Soc., No. 8. PLATE IV. REHN AND REHN—EUMASTACINAE Mem. Am. Ent. Soc., No. 8. \ Se REHN AND REHN—EUMASTACINAE PS a OG OE RIE EP TP I an Nt I Mem. Am. ENT. Soc., No. 8. Prema, WL REHN AND REHN—EUMASTACINAE ; INDEX amrami (Lethus).......... 6, 40, 47 brunneri (Episactus) .6, 21, 24, 25,27 | carinatus (Parepisactus)......... 21 cerciata (Eumastax) .7, 57, 58, 68, 79 dentata (Eumastax)... .7, 58, 59, 70 dentatus (Eumastax)........ 70, 72 IS MEISACEUG. are ihn dalek cake ea 21 IEyOVISEYEII anid cup 'o. 5 Oteeeenig otis cee menos 8 IS MISAGUUSH nahi als ne vicsse sek 5, 21 (see also brunneri, eremites and tristani) eremites (Episactus)....... 6, 24, 33 PGIMASEACES 5 5 2 cic ee ee eee 54 ED inmaS Cages sos ace ares y 5, 54 (see also cerciata, dentata, den- tatus, kressi, silvicola, surda, surdus, tenuis and veraguae) Gymmnotettixase. ic ccmcey as cee 5,8 (see also lithocolletus and occi- dentalis) hondurensis (Eumastax) 6, 57, 58, 76 kressi (Eumastax)...... 7, 57, 58, 59 MEM. AM. ENT. SOC., 8. EG GUI Sirs pace cacti tomer cae es By (see also amrami, maya and ores- terus) lithocolletus (Gymnotettix) .6, 10, 14 magna (Paramastax)............ 54 Mas taxcenet tants tatsckers stein mo ate eye 54 (see also tenuis) maya (Lethus)............ 6, 40, 41 IND Or Sea Rie a cals aee yey eke I occidentalis (Gymnotettix)..6, 8, 10 oresterus (Lethus)...... 6, 37, 41, 49 Paramastax (see magna) Parepisactus). - ).ccescues esa 21, 38 (see also carinatus and saltator) Psy chomeastaxie es ease. dee I saltator (Parepisactus).......... 25 silvicola (Eumastax)...7, 57, 58, 72 surda (Eumastax)..7, 58, 59, 64, 68 surdus (Eumastax)............. 68 Metcoplary St cons. ees cases ee lees 2 tem ((MIEISUEDS) op coocanagg0scae 54 tristani (Episactus)....... O, 25, 27 veraguae (Eumastax)..7, 58, 59, 68