THE GENUS DENDROCTONXJS. 69 



PLAN OF SYNOPTIC TREATMENT. 



The plan here applied for the classification and synoptic treatment 

 of the species of the genus is one which appears to be most available 

 and practicable for the clear definition of the progressive modification 

 of taxonomic characters and for indicating the relative systematic 

 positions and limits of the major and minor divisions and the species. 

 It is not radically different from some of the more generally adopted 

 dichotomous systems, and it conforms to the primary objects of a 

 synopsis in that it provides (a) for a direct comparison of opposing 

 characters, (&) for a direct line of references leading down to the 

 specific characters, or vice versa. 



With this method of indicating the supposed natural relation of 

 the species, the described characters of the major and minor divisions 

 and sections, together with those of specific distinction, serve as a 

 description of the species. Thus, division I, subdivision A, section a2, 

 subsection b2, series c2, defines the characters common to species 

 6, 7, and 8, which are separated by their respective specific char- 

 acters. Some additional advantages of this method are the con- 

 secutive arrangement of letters and figures which throughout a given 



ible are not duplicated. The Roman numerals indicate at once the 

 tary divisions, the capital letters the subdivisions, and the com- 



ined small letter and Arabic numeral the sections, subsections, 

 series, etc., to any desired limit. The reference from right margin 

 to center, instead of to left margin, is also an advantage in defining 

 the limits of a major and minor division. It also provides for full 



niragraphs, thus economizing space and cost of printing. 



SYNOPSES OF MORPHOLOGICAL AND PHYSIOLOGICAL 

 CHARACTERS. 



SYNOPSIS OF ADULT CHARACTERS. 



bum somewhat elongate and as broad as elytra; not di jtiiic tly narrowed ante- 

 riorly except in subdivision B; anterior dorsal half of elytra without long hairs. 



Division I, pages 69, 81. 



lotum stout; usually narrower than elytra, and distinctly narrowed and constricted 

 anteriorly; anterior dorsal half of elytra normally with long hairs, except in tere- 

 brans Division II, pages 71, 116. 



DIVISION- I. 



Body somewhat slender, pronotum but slightly narrowed anteriorly; elytral declivity 

 with second stria straight, second interspace not distinctly broader or narrowed 

 toward apex; head with frontal groove and tubercles except in convexifrons. 



Subdivision A, pages 69, 81. 



Body stout; pronotum distinctly narrowed and constricted anteriorly; elytral decliv- 

 ity with second stria curved, second interspace broad and distinctly narrowed 

 toward apex; head without frontal tubercles or groove. 



Subdivision B, pages 71, 105. 



SUBDIVISION A. 



Elytral declivity without long hairs Section al, page 70. 



Elytral declivity with long hairs Section a2, page 70. 



