BEETLES OF THE GENUS MYOCHROUS — BLAKE 5 



not coming much below the elytral humeri and with thickened outer 

 joints, anterior tibiae usually with an inner tooth, and posterior femora 

 often bluntly toothed. 



Head broad and rounded over the occiput, ordinarily roughly 

 sculptured, with the punctures often in lines or wrinkles down the 

 occiput, on each side nearly always a more pronounced ridge extending 

 down above the eyes; frequently a depressed median line down the 

 front ; no transverse line between the eyes, the scales coming down to 

 the antennal sockets and hiding the punctation beneath. Lower front 

 short, the surface less scaly, with a few finer hairs, transversely placed, 

 and the surface luster shining through; jaws large and powerful. 

 Eyes widely separated, nearly entire, only lightly sinuate on inner side. 

 Antennae not extending much below the humeri, very much the same 

 throughout the genus, usually yellowish or reddish; the first and 

 second joints swollen, second short, third a little longer than fourth, 

 3 to 6 more slender, 7 to 11 thicker, a little longer aaid hairy. Pro- 

 thorax usually not so wide as the elytra, varying greatly in propor- 

 tions, but most frequently wider than long and with three teeth along 

 each side and a smaller tooth at apical and basal angles ; lateral teeth 

 varying greatly in prominence, sometimes heavy and wide, sometimes 

 tiny, in some few cases, as often in M. exylanatus Baly, simply an 

 undulation of the margin; in one group {squamosus) these lateral 

 teeth or angularities not pronounced and usually represented only by 

 a rounded angle slightly behind the apical angle and sometimes another 

 below the middle ; in some groups the anterior m.argin produced over 

 the head and thickened, and in one species {M. cv/rculionoides Lefevre) 

 this thickening taking the form of two gibbosities. Upper surface 

 of prothorax usually densely and often rugosely punctate, frequently 

 with longitudinal ridgings, or the punctures at times dense, deep, and 

 distinct, sometimes round, at other times elongate. Convexity and 

 shape of the prothorax varying in different species, in some narrowly 

 convex {curculionoides group), in others only moderately rounded, 

 and in still another {explanatus Baly), with the margins dilated and 

 flat; frequently a depression along the basal margin, most marked 

 over the scutellum. Scutellum small, lightly scaly. Elytra oblong, 

 with parallel sides and small humeri, the margin about the humeri 

 often quite serrate, this serration in the curculionoides group extend- 

 ing all along the margin ; a short intrahumeral sulcus and usually a 

 little depression behind the basal callosity that is often on either side 

 of the scutellum; surface densely, coarsely, and sometimes rugosely 

 striate-punctate, with ridges or wrinkles often across the basal half; 

 usually densely covered with scales, these scales varying greatly in 

 size and shape, from short, broad, and closely appressed to long, 

 curved, coarse, hairlike scales, usually at least two different kinds on 



