ORTHOPTERA. 667 



the three pairs of legs similar. This family includes the cockroaches, often 

 incorrectly called " black-beetles." A few species have become domesti- 

 cated, but they are inadequate to give any idea of the number, variety and 

 beauty of the group in nature. The antennae are very long and both they 

 and the palps are active in testing the nature of the ground on which the 

 insect finds itself. The pronotum is large and overhangs the head. 

 The abdomen is broad and its posterior segments are invisible, be- 

 ing tucked into those which precede them. In the chamber thus 

 formed the egg-capsule is moulded and carried about by the female 

 until she finds a convenient place in which to deposit it. Both sexes 

 bear cerci and the males in addition are provided with anal styles. The 

 wings are often large in Anaplecta, with a distal portion devoid of ner- 

 vures ; in Diploptera there is a special distal area on which occur nervures, 

 but they are unrelated with those of the basal portion. Internally the 

 gut-like chylific ventricle, which bears at its line of junction with the 

 gizzard eight caeca, is worthy of notice. Some genera, e.g. Panchlora, are 

 viviparous. The food of cockroaches is nominally dead animal matter, 

 but the domesticated species enjoy a very mixed diet, and on ship-board 

 make themselves a nuisance at night by nibbling one's nails. They are 

 valued in some quarters since they are said to devour bed-bugs. They 

 apparently live several years, and some species of Periplaneta only become 

 adult after their seventh moult, which takes place in the fourth year. 

 Their remains show that they were common in the Carboniferous epoch. 

 The Blattidae are divided into the following sub -families,* -the repre- 

 sentative genera of which may be mentioned : 



1. Ectobiinae. Ectobia Westw. et auct. ; E. lapponica, E, panzeri 

 and E. livida are British ; Plectoptera Sauss. ; Hemipterota Sauss. ; 

 Anaptycta Br. ; Chorisoneura Br. ; Anaplecta Burm. ; Thegano- 

 pteryx Brs. 



2. Phyllodromiinae. The small cockroach Phyllodromia (Blatta} 

 germanica, common in Eastern and Northern Europe and in the United 

 States, has obtained a footing in this country. In America it is- 

 known as the " Croton bug." 



3. Nyctiborinae. American. Nyctibora Burm. ; Megaloblatta Dohrn. 



4. Epilamprinae. Notolampra Sauss. ; Epilampra Burm. 



5. Periplanetinae. Polyzosteria Burm. ; Periplaneta Burm., two 

 species of which are common in Great Britain ; P. (Blatta) orientalis 

 the common cockroach of kitchens, and P. americana common on ships 

 and in docks ; this species sometimes migrates to fresh quarters in 

 enormous hordes. These two species and Phyllodromia ger- 

 manica are the three British cockroaches. Atemeleta Brun. ; 

 Chalcolampra Sauss. ; Deropeltis Burm. ; Archiblatta Snellen. 



6. Panchlorinae. Leucophaea Br. ; RTiyparobia Krauss ; Rh. 

 maderae is an introduced form in Britain ; Panchlora Burm. 



7. Blaberinae. American. Blabera Serv. ; B. gigantea has been 

 found in docks and wharves in Britain ; Blaptica Stal ; Hemiblabera 

 Sauss. 



8. Corydinae. In the male of the handsome genus Corydia Serv. 

 and in Heterogamia the peculiar fenestrae seen on the head oi 

 Periplaneta, etc., are replaced by ocelli ; Homoeogamia Burm. 



* Brunner von Watterwyl, Ann. Mus. Genova, xxxiii, 1893, p. 5; and 

 Biol. Cent. Americana, Orthoptera, vol. i, 1893-99. 



