the Orthoptera in the British Museum. 143 



and prominent above the supra-anal plate, not acuminate apically. 

 Subgenital plate small, very obtuse. 



$. Subgenital plate with a feeble, but distinct, convex transverse 

 sulcus beyond the middle; the apex broadly triangular. Lower 

 valves of the ovipositor with broad rounded teeth and small, narrow 

 apical parts. 



Genotype : Caloptenus crassus Walk. 



It is a very well-defined genus, easily recognised by the 

 hooked male cerci, incrassate hind femora, curved hind 

 tibiae and the prosternal tubercle not truncate but either 

 triangular, or with the apex strongly rounded. The 

 following species, known to me by specimens, belong here : 

 crassus Walk., ceraseus, sp. n., and nigripes, sp. n. From 

 the species previously described by different authors under 

 Caloptenus and Euryphymus the following ones (unknown 

 to me save by descriptions) should be also included into 

 Rhachitopis : melanopus Burm., saphiripes Serv., curvipes 

 Stid, vylderi Stal ( ?), adspersus BoL, stolidus Bol. As 

 the majority of species are not known to me, I will not 

 attempt to draw a key to species, and proceed to describr 

 those in the British Museum collection. 



1. Rhachitopis crassus (Walk.). 



1870. Caloptenus crassus Walker, Cat. Derm. Salt. B. M,, 



iv, pp. 690, 694, no. 39 {partim !). 

 1910. E[ury2)hymus] crassus Kirby, Syn. Cat. Orth., iii, 



p. 547, no. 17 {syn. excl. !). 



C. illepidus Walk. (=; pinguis Walk.), which has been 

 regarded by Kirby as conspecific with crassus, is really 

 not even congeneric with it and belongs to the new genus 

 Platyphymus (see below). The specimens labelled by 

 Kirby as the types of C. crassus Walk, belong to two 

 distinct species, and I have selected one male as the holo- 

 type of crassus, while the second species is described below 

 as nigripes, sp. n. A supplementary description of crassus, 

 should be, I believe, useful ; it is as follows : — 



Head moderately, pronotum distinctly rugose. Median keel of 

 pronotum between sulci very low, not higher than the tubercles 

 on the disc between sulci ; lateral keels scarcely distinct in prozona, 

 none in metazona; metazona longitudinally rugulose. Lateral 

 lobes with a whitish callous spot in the middle and a shining black 



