1911 ENTOMOLOGICAL SOCIETY. 53 



upon the water, expecting to see a newt rise to them; but instantly a hungry 

 Water Strider (Ilygrotrechus remigis, Say) seized them and glided away. At 

 the same in.^tant another newt rose to a fly. I had my Entomological net in my 

 hand, and, on the impulse of the moment, I slid it into the water and caught the 

 reptile. 



What a beautiful little creature it was! Its back and sides were olive green ;^, 

 its under parts chi-ome yellow; and it was dotted all over, down to its toes, with jet 

 black spots. In a row, on either side of its body, were some oval spots, crimson- 

 lake in colour, and each inclosed by a black ring. Its tail, set edgeways„was broadi 

 and thin, and as long as its body. It moved with easy grace. I took the little 

 creature home with me, made a drawing of it, and then carried it back to its com- 

 panions in. the pool. 



TJie newts all disappeared at the end of July. 



The Water Strider deserves our attention. It is a wonderful object. It stands 

 ano moves upon the water: its body does not touch the surface. Do you want a 

 proof of this? It is before us. Notice on the rocky bottom of the pool, the little 

 cluster of six black spots, that moves as the insect moves above. It is a group of 

 shadows from the creature's feet. There is no shadow from its body — the light paS'S- 

 ing under it and the sheen on the water cut off that — ^but the feet, being in actual 

 contact with the .--urface, cast their shadows below. 



How can the Strider stand and walk upon the water? The length of its 

 limbs, and the adjustment of its weight, enable it to do so. 



A needle dropped lightly on still water will float; but a shot of the same 

 weight ynW pink instantly. 



If you place the living Strider upon water in a basin, it will at first dash 

 about wildy, for it is possessed of an excess of energy; but, if you remain motion- 

 less, it v/ill soon quiet down ; and then, strange to say, you will easily perceive that 

 at each foot the water is slightly depressed — ^the surface is not broken but bent in. 

 The long legs of the insect stretch out like rays, and its body is suspended between 

 them, distributing its weight to six points. It weighs barely one grain — I have 

 had it carefully weighed by a chemist's scales — so one-sixth of a grain only im- 

 pinges at one point upon the water (or one-fourth, when the insect is employing 

 its front legs against its prey), but this is sufficient to cause a slight depression. 

 The dimensions of the Strider are as follows: — Length of body, 15 millime- 

 tres; breadth, at widest part, 5mm.; thickness, at thickest part, 3mm.; length of 

 antenna, 6mm.; length of proboscis, 3mm. 



Front Legs: Length of femur, 5mm.; length of tibia, 31/2 mm. ; length of tar- 

 sus, 2mm. 



Middle Legs: Length of femur, 10mm.; length of tibia, 8mm.; length of tar- 

 sus, 4mm. 



Hindmost Legs: Length of femur, 8mm.; length of tibia, 6mm.; length of tar- 

 sus, 21/^mm. 



These further particulars may be interesting: — ^The legs are densely clothed 

 with short bristles — these, stretching backwards, must aid the creature's move- 

 ments. The tarsi are two-jointed, and terminated with sharp claws. The an- 

 tennae have four long joints (that next the head being the longest), and a ring- 

 joint between the second and third. The eyes are jet black, closely reticulated, and 

 so prominent that they seem to be starting out of their sockets. The front legs 

 are much stouter than the others and are formed for clasping — ^they are weapons 

 of offence. The body beneath has the appearance of fine glossy leather. 



The Striders are cannibals. I saw one of them leap upon a smaller relative. 



