F. ENOCK ON AQUATIC HYMENOPTERA. 277 



keeled thorax. Through the kindness of Dr. R. F. Scharff, 

 Director of Dublin Museum, I have been enabled to examine 

 the type collection of Haliday's Mymarid®, but regret to say 

 that the types of Caraphractus and one or two other genera are 

 not in the collection. There is no doubt that this is identical 

 with the insect (Caraphractus) which Haliday captured " on long 

 grass in a ditch." In all probability, when sweeping this long 

 grass, the net was just dipped into the water and brought up 

 Caraphractus. 



I felt the responsibility of altering the name of Polynema 

 natans to Caraphractus, but had the pleasure of showing my 

 specimens at the Conversazione of the Royal Society, when Lord 

 Kelvin, Sir John Lubbock, and Professor Poulton fully agreed 

 with my opinion. During May this has been confirmed in a 

 somewhat remarkable manner. On reading some " Notes on the 

 Mymaridas" by the late Francis Walker, given in " The Ento- 

 mologist " for 1873, I came across the following remarks, viz., 

 " Sir John Lubbock has described two species — Polynema natans 

 and Prestwichia aquatica (" Linn. Trans.," xxiv., 138-140, pi. 23) 

 that live occasionally under water and are able to swim. 

 Polynema natans according to Haliday = Caraphractus ductus. " 

 This seems to have entirely escaped the notice of Sir John 

 Lubbock and the late Professor Westwood, and all others who 

 have copied their remarks. 



In the July number of "Science Gossip," I expressed an 

 opinion that I quite expected ere long to discover the unknown 

 male Prestwichia, which I thought might prove to be an apterous 

 insect. 



Since giving my notes at the Quekett Club in May, I have 

 fully realised these expectations in capturing a number of 

 micropterous males, which I hope at some future meeting to 

 exhibit to the members, my appeal to whom, to keep a care- 

 ful look out for these aquatic insects has borne fruit, Mr 

 Scourfield having very kindly sent a specimen of a female 

 Prestwichia which he had " quite by chance " dipped up when 

 searching for Entomostraca. I am indebted to him for thus 

 helping me and enabling me to discover the male. 



During the past season I have made some remarkable dis- 

 coveries concerning several of these minute " Egg Parasites." 



