80 



We may define the Blattodea as : — 



Orthoptera with all the leya wore or less alike ; the lar</e and free 

 coxa; entirely covering the ve)itral surface of the thorax and the base of 

 the abdomen ; tarsi of five segments. Head, in repose, bent under the 

 thorax, so that the fore-part jwints backward ; antenna; long and slender 

 (there being often nearly a hundred segments). Pronotuin shield-like, 

 frequently quite concealing the head. Wings with the anal region 

 capable of fan-like folding (but the alar organs are variable and some- 

 times entirely absent). Cerci, variable in size and shape, present in 

 both sexes ; a pair of slender styles also usually present in the male. 



Twelve families are comprised within the sub-order Blattodea : — 

 W.B.- 1. EctobiidfB. 

 W.B. 2. Phyllodromiidffi. 



3. Nyctiboridfe. 



4. Epilampridffi. 

 W.B. 5. Beriplanetidae. 

 W.B. 6. Panchlorid^. 



7. Blaberidte. 



W. 8. Corydidfe. 



9. Oxyhaloidas. 



10. Perisphieriidffi. 



11. PanesthiidjB. 



12. Geoscapheusidse. 



But five of these families are represented in western Europe. Of 

 these, four contain species that are found to breed in Britain, 

 though but one — Ectobiida — contains indigenous British insects. 



No striking resemblance is borne by the typical cockroach to any 

 other insect. Perhaps its next of kin — amongst the Forficulodea — 

 approaches it most nearly in appearance ; but even between these 

 the resemblance is not very great. The point about a cockroach 

 that first engages attention is its extreme flatness, that is to say the 

 narrow space that separates the dorsal from the ventral surface. 

 This feature enables it easily to hide away in a narrow crevice 

 during daylight, or should it be disturbed in the course of its mid- 

 night revels. 



Another point is the well-developed pronotum, which, besides 

 often affording the means of differentiating species, serves as an 

 efficient protection for head and thorax, just as the elytra, when 

 present, are calculated to perform that office for the abdomen. 

 In ordinary circumstances the head is bent under the pronotum, so 

 that the front of the face is turned downward. Though the head 

 is usually hidden thus beneath the pronotum and inclined face 

 downward, it can be turned upward and outward, till the mouth- 

 parts project considerably forward. Two small areas close to the 

 eyes and to the insertion of the antennae, of a paler colour than the 



* W = represented in Western Europe; B = represented in the British Isles. 



