120 ■ THE entomologist's KECOHl). 



subgeiiital plate rounded, with two lony' styles; in the $ thesuiira- 

 anal plate is triangular, the hinder border sometimes sinuate ; the 

 subgenital plate has a valve inserted with an articulation. 



Tablk ov Geneua. 

 1. Elytra <? truncate at apex; female, rudimentary .. Blaita, Linn. 

 1.1. Elytra perfectly developed in both sexes, rounded at 



the apex.. .. .. .. .. .. .. Periplankta, Burm. 



Genus 1 : I>latta, Linn. 

 Blatta germanica. 



The only European species is familiar ; it is deep claret-coloured ; 

 the 9 s are apterous, with minute flaps for elytra ; the ^ s have the 

 elytra and wings developed, but truncate at the apex. Length of body, 

 20mm. to 23mm. 3 , 19mm. to 23nnn. ? ; of elytra, 12mm. to 

 13-5mm. ^ , 4-5mm. to 5mm. $ . 



A familiar pest in houses throughout Europe ; not known in the 

 wild state. 



Geims 2 : Pemplaneta. liurmeister. 



Larger reddish insects, with the elytra and wings well-developed in 

 both sexes, rounded at the apex. 



Tahlk ok Species. 

 1.1. Pionotum reddish, with the centre clouded ; elytra 



uniform red .. .. .. .. .. ..1. Americans, Linn. 



1.1. Pionotum witk disc black, bordered with yellow; 



elytra blackish -red, with a yellow stripe on the 



costal margin .. .. .. .. .. 2. AiTSTi;ALASiA;,Fal)iicius. 



1. Pekiplaneta amekkax'a, Linn. 



Known by its large size, red colour, with clouded disc of pronoium. 

 Length of body, 28mm. -32mm. S ^ 28mm. -31mm. 9 ; of elytra, 

 2Bmm.-32mrii. S , 26mm. -28mm. 9 . 



A cosmopolitan species, established in many toA\ ns ni Europe ; in 

 England, numerous at the Zoological (iardens and in several docks 

 and wharves. It is abundant in simihii' circumstances in most large 

 towns in Europe. 



2. Pekiplaneta Australasia;, I'abricius. 



Resembles above, but disc of pronotum black, bordered with yellow; 

 elytra darker, with a yellow costal stripe. 



Has occurred in Sweden, and in Great itritaiii at Kew Gardens, 

 l>elfast, and several hothouses and docks. 



Family 1\ : PoLYPHACuD.^i. 

 Members of this family, and of the only European genus, are easily 

 known by the characters given in the synoptical table. 



Genus 1 : Polyphaua, BruUe {= Heti'iitiianua. iliirmeister). 

 Table of Species. 



1. i dark chestnut, $ chestnut, hairless, except for- the 



lateral bristles ; larger size .. .. .. ..1. .t.gvptiaca, Linn. 



1.1. d yellowish livid, ? dark reddish ; body holosericeous ; 



size smaller . . . . . . . . . . . . 2. livida, Brunner. 



