i "i pi \\D OOL< 189 



thi> variation in tin- rli;illy in< li< ;i t -<| in 1'i'j. .'40, ;uirl that 



Ida in I-'i.u. .' 1 1 . 

 Individuals of ("n'nnlrlii vary in pattern in a few definite di; 



and tin- pattern- that characterize the \an< to be 



fixation- of individual variations, According to l)r. (. H. Hon. 

 The l\'f><' of marking i- the same in all our ipet U . well- 



marked -peeies, trdmjucbtir it'll ("cul^iris, I-'i^. 241, / Bl B <-ntral type. 

 the markings of other -perie- vary from that type, (0) by a pr< 

 spreading of the white, (6) by a gradual thinning or absorption of the 

 white, (c) by a fragmentation of the markings, (d) by linear -upplemen- 

 tary extension. (3) Many species are practially invariable Ci.e., the 

 individual variations are small in amount as compared with those in 

 other species). These fall into two series: (a) those of the normal type. 

 as tmmjucbiirica, hirticollis and tenuisignata; (b) those in which some 

 modification of the type has become permanent, probably through 

 isolation, as margin! pennis, togata and lemniscata. (4) Those species 

 which vary do so in one direction only. New types of pattern, of 

 specific value, appear to have arisen by the isolation and perpetuation 

 of individual variations. 



Professor Shelford, in his important monograph on the colors of 

 beetles, draws the following conclusions, among others: 



Longitudinal stripes in which pigment usually occurs lie in the area 

 of the chief tracheal trunks of the elytron; there are seven cross bands in 

 which pigment does not develop; the second and third and fifth and 

 -ixth of these are often joined to make one of each pair. 



Pigment usually occurs about the bases of hairs, which usually lie 

 in the lines of the tracheae. 



In ontogeny the elytra show a spotted condition corresponding to the 

 system of cross bands and longitudinal stripes. The longitudinal 

 stripes are usually more pronounced. 



The characteristic markings of the group are composed of spots or 

 elements joined in the longitudinal light stripe areas and areas of cross 

 bands, with the loss of various spots or elements which occur in onto- 

 ixeny ; joinings are sometimes oblique, and when so markings are some- 

 times parallel with the curved end of the elytron. 



rtain particular types of markings made up of a few elements joined 

 particular way characterize the majority of species of the group. 



These markings as derived from the cross and longitudinal bands are 

 angular; reduction of angles, straightening and turning into oblique 



