236 



ANATOMY. 



two horny arches spring, which pass over the cavities of the coxae, and 

 attach themselves to the sides of the pronotum. These arches serve for 

 the insertion of the muscles of the coxse. Two other spinous processes 

 originate from the upper half of the ring yet more laterally, and bend 

 down to the beforementioned arch, proceeding gradually further from 

 the exterior case. In the very large mesothorax, anteriorly there is no 

 prophragma, whereas posteriorly, beneath the scutellum, a very large 

 mesophragma, which is longitudinally divided, the lower points of 

 which unite with the arch, which, as in the prothorax, span themselves 

 over the cavity of the intermediate coxae. Other lateral ridges cor- 

 respond with exterior furrows. The metathorax is again very narrow; 

 it has no metaphragma, and no arch spanning the cavities of the coxae, 

 the muscles of which are attached to the mesophragma. This descrip- 

 tion is sketched from Cicada fraxini, Latr. In the bugs, which pos- 

 sess a much smaller, at least flatter, thorax, I found (namely, in Penta- 

 toma hcemorrhoidalis,') traces of the horny arch, and a distinct meta- 

 phragma, which likewise, like the mesophragma of the Cicada, is 

 divided, but at its centre diverges much more considerably, and is in 

 intimate connection with the pleura?. 



The skeleton is much more perfect in the Orlhoptera. Among them 

 the grasshoppers occupy the lowest place. In the prothorax, the 

 saddle-shaped pronotum of which encloses the entire part, we observe 

 two bent, flat, but high processes, which originate from the exterior 

 margin of the prosternum and rise to the pronotum. Two other pro- 

 cesses spring from the middle between the cavities of the coxae, and 

 form in removing from each other two arches, which span those cavities. 

 On the interior of each bow there is also frequently a smaller process, 

 which bends to its opponent, and thus covers the nervous cord (PI. XL 

 No. 2. f. 2. a, a). Both processes serve for the attachment of muscles, 

 and the larger bow for those of the coxae ; from the smaller ones two 

 narrow muscles spring, which ascend to the back and affix themselves 

 to the margin of the dorsal piece. The same processes are found also 

 in the second and third thoracic segments, which likewise form small 

 arches, beneath which the nervous cord runs. Instead of the first 

 named exterior ones from each pleura a strong hook-shaped carina runs, 

 which separates the muscles of the legs and wings (the same, 6. \>, 6). 

 The superior partitions, the meso- and metaphragma are small, and do 

 not lie vertically but obliquely, whence the cavity of the thorax acquires 

 much compass and wide avenues. The most perfect skeleton amongst 



