96 



THK VICTORIAN NATURALIST. 



pouch contained two young ones almost fit to leave her. — 

 J. E. Dixon, ist September, 1891. 



Preservation of Colour in Dragon Flies. — First, do not 

 carry a cyanide bottle when collecting, but bring the specimens 

 home alive, and let them remain in the box for at least twenty- 

 four hours. By that time the contents of the stomach will have 

 passed off, then the cyanide bottle can be used. Directly the 

 fly is dead it should be operated upon by cleaning out its 

 stomach and abdomen, which can be done in the following 

 manner : — Obtain a long, fine darning needle, thread it with a 

 short piece of thread, tie the ends together, and in the loop thus 

 formed place some soft darning cotton the same colour as the 

 predominent colour of the body, blue, yellow, or whatever it 

 might be, and according to the thickness of the body have two 

 or more strands. The needle should then be inserted between 

 the fore legs and passed throught the entire length of the insect, 

 pulUng the cotton through until it has cleaned out the contents 

 of the thorax and abdomen. Cut off the cotton at both ends. 

 If the precaution is taken to damp the last portion pulled through 

 with carbolic acid no insect will attack it in the cabinet. 

 Coloured floss silk may be used instead of cotton with advantage. 

 The insect is now ready for setting. Another great advantage in 

 preparing them this way, the abdomen does not drop off; the 

 smaller species can be treated after the same fashion, but it is not 

 necessary to use the thread loop. Simply thread the fine needle 

 with silk, and pass through as before. — G. G. Bignell, F.E.S., in 

 the British Naturalist. 



Note on a Social Form of Rotifer. — On the 20th June 

 Mr. Mann and myself visited Heidelberg to search the lagoons 

 near the river for Rotifera, &c., and Mr. Mann took a very 

 beautiful colony of a social form of Rotifera, which he handed 

 to me, and which I have mounted and brought for ex- 

 hibition. The colony was attached by a filament about a quarter- 

 inch long to a piece of weed, and consisted of a gelatinous sphere 

 about one-tenth or one-twelfth inch in diameter, pierced with holes 

 radiating from the centre, each hole being occupied by a rotifer. 

 There would be over 100 individuals in the colony. Reference 

 to Hudson and Gosse's work showed that the form agrees very 

 closely with the genus Lacinubria, but differs from L. socialis (the 

 only species of the genus described by those authors) in the shape 

 of the corona, being heart-shaped in socialis, while in the form 

 shown it is oval. It is, therefore, probably a new species of 

 Lacinularia or a variety of L. socialis. The action of the solution 

 used to kill the animals probably caused the detachment of most 

 of the adult forms, and thus permitted several slides of individuals 

 being prepared, as wefl as one showing the sphere with sufficient 

 individuals remaining on it to exhibit the arrangement when 

 perfect. — J. Shephard. 



