ORTHOPTERA 23 



five genera characterized below are well marked, and their peculiarities seem to 

 warrant the establishment of a special group, Prognathogryllides. They are dis- 

 tinguished from the Podoscirtes group by the form of the head, which is strongly 

 porrect ; and by the armature of the apex of the posterior tibiae, there being only 

 two calcaria on either side of each. The number given by Herr Brunner is five, 

 three outer and two inner, but the examination of many more species and examples 

 than were submitted to him, has led to the conclusion that the upper of what he 

 considered to be the three outer calcaria should rather be counted as the apical spine 

 of its series. In the first place its position and appearance are rather those of a 

 spine than of a true calcar, and secondly in some of the species, in certain examples 

 it may be altogether absent, whilst in others of the same species it is present. If 

 this spine be admitted as a calcar, the apical spine of the inner series must in many 

 of the species be also considered as such, since the appearance of both, and their 

 position as regards the calcaria, are precisely similar. This apical spine of the inner 

 series is also sometimes wanting in some examples of a given species, in which case 

 there are no spines adjoining the calcaria, and these stand out distinctly as two on 

 each side. (Cf. Plate II. figs. \ob, xor, \od\ 15, 15^, \^b; etc.) \\i Prognathogryllns 

 as now restricted, the apical spine of the inner series is very distinct from the calcaria, 

 and this fact renders it probable that in the allied genera the true inner calcaria are 

 also two, that which might at first sight be considered a third being merely the apical 

 spine of the inner series. 



All the species are of elongate and slender form, except Prognathogryllus robustns, 

 which is comparatively short and robust. In Thaitmatogryllus and Leptogryllus the 

 tegmina are very small and scale-like, and sometimes only visible at the sides of 

 the body at the hind margin of the pronotum, and the wings are wanting. ApJiono- 

 gryllus has no free tegmina. In the ? of Prognathogryllus (the I being unknown) 

 they are about equal in length to the head and pronotum together, but in P. robustus 

 they extend nearly to the apex of the abdomen. The wings in this genus are ill- 

 developed, being about as long as the short tegmina in P. alatus, and much shorter 

 than the tegmina in P. robustus, but they are always present. 



In Nesogryllus $ (the ? being unknown), the tegmina are well developed for 

 stridulation, but they do not extend back as far as the apex of the long and slender 

 abdomen, and the wings are rudimentary. 



Prognathogryllus and Nesogryllus have a distinct tympanum on the inner face 

 of the front tibiae. The other genera have none. 



The males of those species of Leptogryllus, which have the metanotum exposed, 

 bear on this part two punctures, one on either side of the middle line, which are 

 represented by two smooth points in the females. When the scale-like tegmina are 

 larger, and conceal (at least for the most part) the metanotum, its basal part is 

 depressed, and the punctures or orifices, which lie within, this cavity, are furnished 



