80 THE REPORT OF THE No. 36 



These appendages are not found in the female. Moreover, while the male Dytiscus 

 is remarkably smooth and slippery, the female is roughened with striae. 



In Acilius f rat emus a like provision is found in the foot of the male, to that 

 in the foot of the male Dytiscus; and in this species also the female has rough- 

 ened elytra. 



The powerful hind limbs of the insects that have been named Saltatores, 

 such as the crickets and locusts, are worthy of observation. But other insects 

 beside these Orthoptera have great powers of leaping: — 



On the 24th of May of this year I was sitting on the veranda of Mr. Garriooh's 

 house, on Front Street, Hull, when I saw a bat fall from a tree on the lawn. The 

 little animal was in a very weak condition. While I was examining it I saw a 

 flea creep from the fur, and then bound upwards one hundred times its own 

 height. (If an acrobat could leap 600 feet into the air, he would draw multitudes 

 to witness the feat.) (Fig. 18.) 



I put the bat in a box, and obtained from, it thirteen other specimens of the 

 same kind of flea. No wonder the little animal was in a weak condition. 



This Pulex vespertilionis was different from P. initans and P. serraticeps. It 

 was about two millimetres long. Its dorsal parts were of a light chestnut colour, 

 and its ventral parts of a pale amber. The legs were translucent. The trocanters 

 were grooved. The femur in each of the middle and hindmost legs was large, 

 flat, and cleaver-shaped. Around it, near the edges, was a slight indentation. The 

 tibia was striated and bristly. The tarsus had five joints with two bristles at each 

 joint. The abdomen was hairy. 



Of the wings of insects, fine examples of venation are afforded by the water- 

 flies Pteronarcys proteus and Polystoechotes punctata; of elegance of form by 

 Actios luna and Hyloicus cliersis — and of splendour of colouring by PJiilampelus 

 achemon and Plusia halluca. 



The Abdomen. How great a difference there is between the telescopic ovi- 

 positor of the house-fly which is concealed in the abdomen of the insect, but can be 

 extruded by pressure, and which is fitted to penetrate the manure from the stable 

 in which the Isltyss of the fly luxuriate — and that of Thalessa lunata, which in 

 some instances extends for four inches beyond the extremity of the abdomen, and 

 is fitted to be passed along the tunnel, choked with frass, at the end of which the 

 larva of Tremex columha is working. The young larva of Thalessa follows up and 

 preys upon the larva of the Tremex. 



The ovipositor of the last named insect proceeds from the. middle of its 

 abdomen, and not from the end. It is shorter and stouter than that of Thalessa, 

 and is adapted to penetrate the bark and white wood of the trees suitable for 

 the sustenance of the larvge of its species. 



The Egg. Some years ago I found a huge boulder in a swampy wilderness. 

 In a slight hollow, in the top of this, some vegetable mould had accumulated; 

 and a thick pad of moss covered it. On lifting the moss, I found some hundreds 

 of eggs of the Red-legged Locusts packed together in the soil. The locusts had 

 found in the position a suitable nursery for their young. 



The life of the Day-fly is very brief — as its name implies. It does not allow 

 much time for oviposition. One act of extrusion consigns its eggs, in a boat- 

 shaped mass, to the surface of the water. 



The Cockroach frequents the house, but is highly objectionable to the house- 

 keeper. Its eggs are laid in brown packages — oothecoe — in the crevices about the 

 kitchen-ranges and the cellar-furnaces. In these they escape notice. 



