410 (October, 



species (especially o£ the genus Stenobothrus) are rather more diffi- 

 cult to distinguish than in the other Families. Coloration is not 

 to be depended on, but notice should be directed rather to the form 

 and structure of the vertex and f rons ; the configuration of the lateral 

 carinse of the pronotum ; the direction of the veins and the shape of 

 the areas of the elytra ; and the external genital organs. 



The head (fig. 3) is not covered by the anterior border of the pronotum as in 

 the Blattidce, and is in our genera short ; the antennae (a) are short, and never have 

 more than twenty-fivo joints. The top of the head is the vertex, the anterior 

 margin of which has a small oblong-shaped depression on either side the foveolse (f), 

 these are more or less strongly marked in different species, and their propinquity to 

 each other anteriorly should be noticed. Below the vertex is the frons bearing 

 the antennae in a deep furrow or sulcus on either side, and with a central furrow, 

 near the top of which is one of the ocelli (o), the other two being situated between 

 the base of the antennae and the eyes. The eyes (e) are more or less prominent in 

 different species. The pronotum (fig. 3, p p') is the dorsal plate of the first thoracic 

 segment, and consists of an upper part or disc (p) and two lateral flaps (p'). On 

 the disc are three ridges, a median (m c) and two lateral (I c), and the curvature of 

 the latter gives us several specific characters. Crossing the disc from side to side is 

 the cross furrow (not lettered in the fig.), which is prolonged down across the side 

 flaps, and turning forwards, unites with another furrow which is not of importance. 

 The situation of the cross furrow must be noticed, as its position with regard to the 

 anterior and posterior borders of the pronotum is of importance. The posterior 

 border of the pronotum is generally bluntly angled, but in Tettix extends backwards 

 into a long pointed process. The posterior femora are strong and thick, and are 

 used for jumping ; the tarsi are three-jointed, and (except in Tettix) have a small 

 pad or cushion between the claws. 



The first abdominal segment has on each side an opening (more or less closed), 

 the tympanum or external auditory orifice. The apex of the abdomen (fig. 4) and 

 the external genitals also give important characters. The sexes can be readily dis- 

 tinguished by the form of the external genital organs ; the ? always having an 

 ovipositor consisting of four plates or valves (v o) which protrude beyond the supra- 

 a?ial plate (sa p), and subgenital lamina (sg I) ; while in the $ the subgenital 

 lamina is always recurved and more or less pointed, and forms the apex of the 

 abdomen. 



Fig. 5 shows the elytron of St. bicolor, Charp., 3 ■ The venation of which may 

 be taken as typifying that of the Orthoptera generally. The veins from before back- 

 wards are the mediastinal (m) running usually about two-thirds the length of the 

 elytron. The anterior radial (a r) ; the middle radial (m r) with numerous branches 

 running to the apex ; the posterior radial (p r), forming the upper border of the 

 discoidal area : these three are separate veins, but towards the base are almost con- 

 fluent. The anterior ulnar (a u) forming the lower border of the discoidal area ; 

 the posterior ulnar (p w) running close alongside the dividing vein (d), which is the 

 " vena analis " of L. Fischer ; and lastly the " vena plicata " (pi), Brunner. These 

 veins divide the elytron into the following areas : — the mediastinal (med ar) between 

 the mediastinal vein and the costal margin, this area is sometimes dilated anteriorly 



