108 AMERICAN COLEOPTERA. 



macro; and the metasternum as short, or shorter than the first 

 ventral segment, with the accompanying rudimentary wings in a 

 few others, may be set down as exceptions to the characters there 

 given. 



In addition, it may be said that the beak varies greatly in length, 

 form and sculpture. It is usually about as long as the head and pro- 

 thorax, l)ut varies from scarcely as long as the thorax (emaclipes) to 

 more than half the length of the entire body in certain females of 

 variconie, coloradense and pennsylvanicum. The eyes are genei-ally 

 more or less broadly elliptical in shape with the longest diameter a 

 little oblique to the vertical, but are sometimes nearly circular, and 

 in one species (persimile) they are obviously narrowed inferiorly. 

 The granulation also varies somewhat in coarseness and convexity, 

 but has not been used at all for specific separation, and is but once 

 or twice alluded to in the descriptions. The width of the front be- 

 tween the eyes, whether greater than the width of the beak at tip, as 

 is usual, or less, as is occasionally the case, has been used with ad- 

 vantage. The place of insertion and relative lengths of the basal 

 joints of the antennae are quite variable, and have been largely used 

 in the scheme which follows. The point of insertion is never beyond 

 the middle, usually much nearer the base, and in a few species quite 

 close to the eyes — {permtiiutnm, propiiiquiconie, etc.). It has been 

 found more convenient to indicate this distance by stating which 

 joint of the antenme reaches the eye ; or more properly, which joint 

 would reach the eye if tlie antennee could be directed against it. 

 The first joint may be very little longer than the second, or it may 

 be equal to or even exceed the three following in length. The sec- 

 ond is always as long, usually a little longer than the third ; the suc- 

 ceeding joints are gradually shorter, but it is not often that the outer 

 joints become transverse. 



The prothorax is usually more or less transverse with sides rounded 

 between the generally evident apical and basal contractions. The 

 variations here, as well as in the form of the elytra, can best be 

 appi'eciated by referring to the accompanying plates. The abdomi- 

 nal punctuation is very variable, and with a little experience is quite 

 useful, especially in the first section of the genus. The third and 

 fourth ventrals are, as a rule, impunctate, or with but a few small 

 punctures toward the sides. Unless otherwise stated, by abdominal 

 punctuation, or simply "punctuation beneath," is meant that of the 

 first two segments. 



