NORTH AMERICAN COLEOPTERA. 105 



M,yiio|>««i«« oTtlio ITiiitod States spcciofii oT :\<>TO\'|!S and 

 MK< YKOTAKSUS. 



By Georoe H. Horn. M. D. 



\OTOXUS Gooll'. 



Since the })ublieation of the Synopsis of tlie Antliicides by Dr. LeConte 

 (Proc. Acad. 1852), material has accumuhited, and from want of proper 

 study, was ,su arranged in our cabinets as to indicate a great number of 

 uiidescril)cd species, the variations in color affording a basis for an iiideti- 

 nitc (livisi<in. 



As a general rule variations of color and markings are the loa,st reliable 

 means for the separation of species, and should be made use of only when 

 sup])orted by other characters. Structural characters are much more 

 detinite and positive in their nature. It is true that these are not always 

 easy to discover, but patient study will often make plain what has been 

 passed over as inextricable. Modifications of structure of a sexual nature 

 are very constant, practically invariable within specific limits, and aff'ord 

 the means of at least grouping species in series, and very often of sepa- 

 rating species otherwise very closely allied. 'J he use of sexual characters 

 has been objected to on the ground that in a cabinet the particular sex 

 used may not be |)resciit, and specimens of the opposite sex may be almost 

 indeterminable. The objection is certainly valid as far as the naming of 

 specinu ns is concerned, but it must not be forgotten that the aim of a 

 paper like the present when dealing with a more or less intricate subject 

 is to indicate the characters, by means of which species are distinguished, 

 and the possessor of a few specimens must await the acquisition of the 

 re(|uired sex or have the specimens determined by comparison. 



In the arrangement of the species known to him Laferte divided 

 Notoxus into four groups based on the style of elytral ornamentation. 

 One of his groups is entirely without value as many species of his other 

 groups may have unspotted elytra. In glancing over large series of our 

 species three types of elytral markings appear : Jirsf, elytra totally black, 

 opa(pie, finely punctured ; second, elytra piceous, with two transverse 

 3'ellow bands; third, elytra more or less testaceous, with a piceous band 

 and various spots or stripes. In the first and .second there is but one 

 .species to each, — /licoJor and /li/asciafKS. In the third group ancJuna 



U2) 



