﻿MELOLONTHID^I OF THE UNITED STATES. 273 



modice punctato, brevi, ante medium valde angustato, lateribus obliquis, ad medium fere angulatis, 

 angulis posticis obtusis, subimpressis, ad apicem marginato, angulis anticis magis acutis, elytris fortius 

 punctatis, tricostatis, tibiis anticis tridentatis, dente ultimo oblique truncato, unguiculis medio breviter 

 dentatis. Long. -45. 

 Yellowstone River, Nebraska, Dr. F. V. Hayden. The mandibles are very pro- 

 minent, and bent at the apex so as to cover the ligula. The sides of the thorax, 

 from a ventral view hardly converge towards the base. The punctures between the 

 smooth lines of the elytra are confused, and somewhat rugous. The pygidium is 

 coarsely punctured and sparsely hairy ; the propygidium is more densely punctured, 

 with the usual transverse impression. 



29. D. i n n o x i a, oblonga, convexa, rufo-ferruginea nitida, capite sat dense punctato, clypeo fere hemi- 

 hexagono marginato, sutura frontali profunda, fronte transversim obsolete elevata, tborace modice punc- 

 tato, brevi, ante medium valde angustato, lateribus ibi obliquis, dein sequaliter rotundatis, angulis posticis 

 obtusis subimpressis, ad apicem marginato, angulis anticis acutis, elytris fortius punctatis, tricostatis, 

 tibiis anticis obtuse tridentatis, dente ultimo subtruncato unguiculis breviter dentatis. Long. -4. J 

 One specimen, Kansas. Closely allied to the preceding, and precisely similar to it 

 in sculpture: the body is, however, not at all ovate, and the sides of the thorax are 

 more regularly and less suddenly rounded. These two species by the strong apical 

 marginal line of the thorax form a passage to the Rhizotrogi ; many of which they re- 

 semble in the form of the claws. 



Species not recognized. 

 Diplotaxis punctato-rugosa Blanch. Cat. Col. Mus. Paris, 171; Burm. Lamell. 2, 2nd, 263. 

 Diplotaxis g e o r g i ae Blanch, ibid. 

 Diplotaxis frondicolaj Blanch, ibid. 



Diplotaxis castanea Burm. Lamell. 2, 2nd, 262; an D. subcostata? 

 Diplotaxis corpulenta Burm. ibid. 263. 



Alobus Lec. 



Corpus elongato-oblongum, subeylindricum : caput majusculum, clypeo marginato, antice subrotundato, 

 sutura frontali bisinuata; labrum transversum late emarginatum; palpi maxillares articulo ultimo tenui 

 cylindrico, reliquis coniunctis aequali; mandibulae prominulse ad apicem obtusae : men turn quadratum haud 

 impressum ; antennae breves 10-articulatae, clava parva triphylla. Tibiae anticae tridentatae unicalcaratae, pos- 

 teriores tenues haud coronatae, nee ad apicem incrassataa, posticae intus paree pilosae ; tarsi tibiis vix longiores, 

 subtus parce pilosi vel setosi, haud spinulosae ; ungues omnes dente inferno maximo truncato, ungue ipso haud 

 breviore. Thorax membranula apicali nulla. 



A genus which approaches the Rhizotrogi in another direction, viz., by the 

 absence of the apical membrane of the thorax ; nevertheless by the abdomen and by 

 the labrum it must clearly be associated with Diplotaxis. 



A. ful vus, elongatus, subcylindricus, testaceo-rufus nitidus, capite fuscescente, confertim punctato, clypeo 

 vix hemihexagono, anguste marginato, sutura frontali impressa, thorace latitudine plus duplo breviore, 

 dense, medio parcius punctato, antrorsum haud angustato, lateribus late rotundatis, angulis posticis ob- 

 tusis ; elytris fortiter punctatis, subtricostatis, propygidio subtiliter, pygidio grosse punctato. Long. -36. 



One specimen, New York. The three teeth of the anterior tibiee are near together. 



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