( Ixxiii ) 



and the orange band was also considerably less brilliant, and 

 less continuous. 



Mr. Kaye enquired whether the larvae would feed on 

 other docks, and Capt. Purefoy replied that they would do 

 so, but that other docks were apt to turn brown after flower- 

 ing, thus depriving the larvae of nourishment. They would 

 not feed on sorrel. 



Mr. Sheldon remarked that the var. rutilus must have 

 alternative food-plants on the Continent, as he had found it 

 not only in the Danube Marshes (where R. hydrolapathum 

 grew) in the vicinity of Buda Pesth, but on many of the hills 

 around this town far out of the range of this plant. In the 

 neighbourhood of Sarepta also, it was found in the small 

 cross gullies which had a small stream at the bottom emptying 

 into the Volga some miles away. In each of these localities, 

 although several species of dock were found, the usual food- 

 plant did not grow. 



A question having been asked as to whether C. dispar had 

 ever been found out of England, the Rev. G. Wheeler re- 

 minded the Society that it had been discovered last year in 

 Holland, and exhibited by the Hon. N. C. Rothschild side 

 by side with English specimens. Some doubt was expressed 

 later as to whether the Dutch specimens were really indis- 

 tinguishable from the English. 



Pupation of Dytiscus marginalis. — Mr. Hugh Main 

 showed a series of lantern slides illustrating the methods he 

 had successfully adopted for observing the larva of Dytiscus 

 marginalis " digging itself in " for pupation, also the pupa in 

 its cell, the disclosure of the imago, and the escape of the latter 

 from the cell. He said he had exhibited on October 18, 1916, 

 a clump of earth containing a pupation cell of D. marginalis 

 which he had found near the margin of a pond in Epping 

 Forest. Other cells subsequently found agreed in being 

 situated along the angle between a horizontal shelf of earth 

 and the vertical bank rising behind it. It was only necessary 

 to reproduce such conditions in confinement to get the larva 

 to form its pupation cell, and it was not difficult so to arrange 

 matters that the work was done at a convenient time for 

 observation. A small oblong glass aquarium was used, on 



