MONOGRAPH OF THE GENUS SAPERDA II 



and eyes varies greatly in different species. The punctures of some 

 species are quite constant ; but in others, populnea, moesta, 

 t u 1 a r i , they vary so much that httle dependence can be placed on 

 them. The species range in size from calcarata, which is from 

 Vs to iVs inch long, to populnea Vs inch in length, but occasional 

 specimens may be much smaller than the normal. The color and 

 markings are quite constant, and only lateralis shows marked 

 variations. Calcarata has a variety, adspersa, which is 

 entirely brown. The legs of most species are black, covered with a 

 gray pubescence, yellow in v e s t i t a ; those of obliqua, cre- 

 t a t a and d i s c o i d e a are reddish brown with gray pubescence. 



Arrangement indicates the degree of specialization. The salient 

 characters of the various species having been given, it now remains 

 to use them in a natural grouping of the forms. It is very apparent 

 that the usual arrangement is arbitrary and based almost entirely on 

 color and markings. It is not to be supposed that the following 

 grouping means that the species are derived or descended from each 

 other. It represents simply our idea of the degree of removal or 

 specialization from an ancestral type and is based on a study of char- 

 acters of unequal value. It is very evident that our own species 

 have specialized along different lines and have probably originated 

 from several type forms. 



The least speciahzed of our native species is evidently c o n c o 1 o r, 

 since it is unicolorous, has no striking characters and presents fewer 

 differences from its nearest allies in other genera, than any of the 

 other species. It has no process on the claws of the male 

 and the rather few elytral punctures are merely shallow depressions 

 without definite edge and are punctate like the remainder of the 

 elytra. The species diverging most widely from it, and thei^efore 

 the most specialized, is obliqua, since it has characters not 

 possessed by any of the others. It has the elytra separately narrowed 

 and armed with a spine. The thorax is narrowed in front, and the 

 head is small, and deeply impressed between the eyes. The annulated 

 antennae have the first joint swollen and dark, and the elytra are 

 embossed to match the color pattern. The process is very highly 



