﻿MELOLONTHIDvE OF THE UNITED STATES. 263 



ligula truncata; palpi maxillares articulo ultimo niodice ovali, iuipresso. Antennae 10-articulatre, articulis 

 3 — 5 connatis, 3 et 4 aaqualibus ; clava triarticulata, maris elongata, feminse parva. Elytra stria suturali 

 profunda. Abdomen articulis 1 — 5 connatis, suturis haud medio obliterans, 6to brevi transverse Coxse 

 posticse angulo externo producto. Tibia? anticee tridentate, posteriores uni-coronatse, denteque parum pro- 

 minulo superiore proecipue armatas, bicalcaratse, calcaribus posticis sexus utriusque niobilibus, exteriore lon- 

 giore: tarsi tibiis longiores, verticillatim setosi, postici articulo primo paulo breviore, nonnunquam tibiis baud 

 longiores ; unguiculi (maris prsecipue) subtus sulcati, biseriatim pectinati, vel compressi, medio dentati, 

 subtus plus minusve uniseriatim serrulati. 



By the discovery of new species I have been compelled to modify the description 

 of this genus, until at last nothing distinct remains to separate it from Lachnosterna. 

 In one species the serration of the ungues disappears almost entirely, only a slight 

 trace near the base being left. There is however a peculiar appearance which renders 

 the genus easy of recognition, and notwithstanding the remarkable specific and sexual 

 characters, would make any further subdivision of the species here placed under it 

 eminently unnatural. 



A. Tibia? posticse sub-bicoronata?. 



1. L. mucoreus, longior, convexus, piceo-rufus, capite tboraceque nitidis, illo piano fortiter marginato, 



confertim punctato, antice rotundato baud emarginato, tborace punctato, lateribus obtuse angulatis, 

 antice subserratis, angulis posticis obtusis baud rotundatis ; elytris parce punctatis et breviter pilosis, 

 glauco-pruinosis ; supra versus latera parce longe pilosus, pectore villoso, calcare postico externo latiore 

 et longiore, tarsis posticis tibiis multo longioribus. Long. -6 — -65. 



Maris antennarum clava funiculo vix breviore ; pygidio convexo, unguibus subtus biseriatim fortius pectinatis; 

 antico exteriore prope apicem fere dentato. 



Feminse unguibus subtus prope apicem acute dentatis, a basi ad dentem pectinatis, postico interiore pectinato 

 baud dentato ; pygidio piano. 



Fort Yuma, Colorado River, California; Eagle Pass, Texas, Mr. Schott. The 

 outer spur of the posterior tibia? is longer and broader than the inner one, both are 

 flattened and obtuse. The hairs towards the base of the elytra are very long. 



2. L. t e x a n u s , longiusculus, oblongus, convexus, piceo-rufus, capite tboraceque nitidis, illo piano fortiter 



marginato, confertim punctato, antice rotundato subemarginato, tborace minus dense punctato, lateribus 

 fortius angulatis subserratis, angulis posticis obtusis haud rotundatis, ad basin longe erecte fimbriato, 

 elytris parce punctatis et breviter pilosis, glauco-pruinosis ; supra versus latera parce longe pilosus, 

 pectore villoso ; calcare externo postico fere duplo latiore et longiore, tarsis posticis tibiis longioribus. 

 Long. -5. 

 Mas notis sexus sicut in prsecedente. 



One specimen found in Texas by Mr. Schott. CloseJy related to L. mucoreus, but 

 is a little less elongated, with the sides of the thorax more strongly angulated, and 

 subconcave in outline behind the angle, and with a basal fringe of long erect hairs, 

 the inner spur of the posterior tibia? is only two-thirds as long as the outer one, and 

 is more slender than in the preceding species. 



