INVERTEBBATE ANIMALS. 85 



U Examples of Water-scorpions, Ne-pa ,• Boat-flies, 

 Notonecta ; and of the only truly oceanic genus 

 of insects, Halohates, specimens presented by 

 Capt. BoRLASE. Observe the arrangement of 

 the eggs on the back of Zaitha ; how were they 

 placed there ? 



Small series of British species collected and pre- 

 sented by H. H. H. 



The division Ametabola here introduced, consisting 

 of insects which undergo no transformations, includes 

 three orders of which the species are all of small size : 



I. Order Anoplura. Lice, with sucking mouths. 

 Pediciilid(?. 



II. Order Mallophaga. Bird-lice, with biting jaws. 

 Philoptera, several species of which are said to be found 

 on the same animal. 



III. Order Thysanura. Spring-tails, Podura, Lepis- 

 ma. 



Walckenaer describes 300 species of the first two 

 orders, and 106 of the third. The British species of the 

 first two orders have been described by H. Denny; 

 those of the last have appeared very recently in a beau- 

 tiful monograph by Sir John Lubbock. 



Group 198.-HETEROPTERA-GEOCORISA. yij, the earth ; 

 xo'pjj, a bug. Notwithstanding the bad reputation 

 attached to this group by reason of its including the 

 common House-bug and some exotic species far more 

 severely noxious, we here meet with curiously fantastic 

 shapes and brilliant contrasts of colour. The British 

 species though small are frequently beautiful, and have 

 been described in an excellent monograph by J. W. 

 Douglas. 



