AMTTSUS.— AMPHIACUSTES. 245 



AMUSUS, Sauss. 



Amnsus, Saussure, Melang. Ortbopt. 6 e fasc. pp. 537, 558 (1878). 



This genus is characterized in both sexes by its short corneous elytra, which are quite 

 polished and without veins in the dorsal field. In the males there is only a trace of a 

 stridulating vein. The anterior tibiae present one or two drums. The inner superior 

 spur of the hind tibiae is much the longest. 



l. Amnsus mexicanus, sp. n. (Tab. xil. figg. 11, 12, 13.) 



2 • Fusco-nigra, polita. Caput et pronotum nigra ; vertex anterius ad ocellum primo articulo antennarum 

 aequilatus. Ocelli minuti. Antennae fuscse, apice pallidiores, in medio annulis albis 3 (intermedio 

 longiore) ; parte basali longiuscule (articulis 20) aurantia, articulis l°-2° nigris. Palpi picei, articulo 

 quarto supra linea lutea. Pronotum nigrum, margine postico supra punctisque 2 ad marginem anticum 

 aurantiis ; lobis lateralibus immaculatis, margine infero subhorizontali, arcuato. Elytra brevia, supra 

 subquadrata, polita, venis nullis, primum abdominis segmentum partim tegentia, sese intus leviter tegentia, 

 margine postico leviter obliquo ; campo marginali fusco, venis longitudinalibus 4. Alas nullse. Pedes 

 fusco-nigri, pilosi. Tibise antiese in latere interno foramine elliptico, in latere externo foramine nullo. 

 Femora postica brevia. Tibise illis paulo breviores, fusco-rufse ; spinis 4 : 4 runs ; inter spinas intus 

 spinulis 3, 3, 1 ; extus 5, 4, 3 (variabiles) ; calcare supero-interno longissimo, metatarso tamen paulo 

 breviore. Metatarsus gracilis, 9 : 7-dentatus. Abdomen rufo-castaneum vel flavescens, plus minus fusco- 

 maculosum. Lamina supra-analis trigonalis, apice rotundata, marginibus lateralibus sinuatis, sub- 

 reflexis ; basi puncto impresso. Cerci run, mediocres, ovipositore sequilongi. Lamina infragenitalis 

 leviter incisa. Ovipositor quam femur brevius, rectus, flavescens, valvis apicalibus basi haud dilatatis, 

 anguste lanceolatis, acutis, baud serrulatis. 



2 ■ Long. 13-5 ; pronot. 3'5 ; latit. 4; elytr. 4*2; fern. post. 11-5 ; ovipos. 10. 



Figtjkes. — Figs. 11, 12, the insect, 5 . — Fig. 13, the terminal joints of the maxillary palpus. 



Hab. Mexico, Teapa in Tabasco (E. II. Smith). 



Somewhat smaller than A. Mrsckianus, Sss. (from Venezuela), with a different 

 coloration, and very distinct from it by the fact that the anterior tibiae have no drum 

 on the outer side, while in A. Mrschianus the tibiae are perforated on both sides. 



AMPHIACUSTES, Sauss. 



Amphiacusta, Saussure, Miss. Scient. Mex., Orthopt. p. 444 (1870). 

 Amphiacustes, Saussure, Melang. Orthopt. 6 e fasc. p. 569. 



Acrobatic insects, furnished with long legs. The females apterous ; with a straight 

 ovipositor, terminated by acute entire valvae, i. e. not serrulated. The males with 

 abbreviated rounded elytra and without wings ; the elytra presenting 4-6 oblique veins ; 

 the speculum generally divided by two veins ; the venae postanales variable. 



Synopsis specierum. 



I. 



a. Pedes longi. Tibiae interraedise calcaribus 3. 



b. Tibiae posticae supra spinis 5 : 5 armatae. Foveolae juxta-ocellares nullae. Verticis 

 rostrum cum piano arcuato verticis continuum, apice primo articulo antennarum 



