Mode of Life of Orthocladius 15 



the insect as a Tanypus, perhaps T. nervosus, but 

 it is really a Chironomus. Flies have been reared and 

 sent to Mr. G. H. Verrall, who says of the species : ' It 

 belongs to the group of Chironomi which Van der Wulp 

 called Orthocladius, which have bare wings, the basal joint 

 of the front tarsi shorter than the tibia, and the thorax 

 not cowled. It is a large species for that genus, and is 

 near 0. dUatatus,Y. d. Wulp, but is I think quite distinct, 

 as Van der Wulp says nothing about the bearded front 

 tarsi.' This insect has been rediscovered and studied in 

 all its stages by Mr. T. H. Taylor, whom we have to thank 

 for the following description and for the illustrative 

 figures : — 



' The larva finds its abode in a floating flock of Spiro- Mode of 



. life ot 



gyra. It makes a case of jelly-like substance, probably Oit.ho- 

 out of the secretion of its salivary glands. With a high 

 power a faintly fibrous structure can be seen in the jelly ; 

 filaments of Spirogyra and also chain diatoms, &c., are 



Fig. 8.— Half-grown larva of Chironomus {Orthocladim) »p. in its case. X 12. 



interwoven, and this seems to be the result of a purposive 

 act. The creature frequently stretches its body out of the 

 tube and draws filaments towards the outlet, where they 

 adhere to the viscous material and form a miniature 

 arbour, like a porch over which creeping plants have 

 been trained. There is nothing so elaborate in the con- 

 struction as happens, for example, when a caddis-larva 



