EXTERNAL ANATOMY OF INSECTS. 569 



Anoplognathus it is horizontal, straight, and figures an 

 isosceles triangle ; in Cetonia suturalis, vitticollis, &c. 

 it is very long, passing between the arms and nearly 

 reaching the head ; in C. marmorea, Lanius, &c. it is a 

 lofty, robust, conical prominence ; and in many Jtute- 

 lidce, especially those with striated elytra, it is pyramidal 

 or four-sided ; it varies also in its termination, particu- 

 larly in the Cetonia dee ,- and even where there is little or 

 no elevation of it, as in the Scarabaidce MacLeay, it is 

 often terminated anteriorly by lines that vary in their 

 angle or curvature. The genus Copris, as restricted by 

 Mr. W. S. MacLeay, may from an inspection of this 

 circumstance be divided into several families. Thus in 

 C. Molossus and affinities its termination represents the 

 letter ^ reversed, or a triangle surmounted by a mucro ; 

 in C. orientalis, &c, it ends in an acute-angled trian- 

 gle ; in C. lunaris, &c. in an obtuse-angled one ; and in 

 C. lacchus, &c, in the segment of a circle. 



The part we are considering is not so important in 

 the other Orders. In the Orthoptera, however, it is occa- 

 sionally remarkable. In Acrida viridissima (Locusta F.) 

 attached to the anterior margin of the peristethium are 

 two long triangular pieces which appear to represent this 

 part ; in the kindred subgenus, Conocephalus a , it is a 

 single piece bifid at the apex ; in Gryllotalpa it is a very 

 elevated hairy ridge ; and in Locusta Leach, it is a flat 

 anterior process of the mesostethium. In the Heteropte- 

 rous Hemiptera this part is often merely a portion of 

 the channel in which the promuscis reposes ; but some- 

 times, as in Edessa F., it is an elevated piece varying 



* I would restrict this name to the conical-headed Locusta; F, 



