v CADDIS-WORMS 271 



that more than one order should furnish examples of 

 larvae which protect themselves by cases constructed 

 out of foreign particles. Not only the Caddis-worms, 

 but certain Beetles, Lepidoptera, Diptera, and 

 Neuroptera have learnt this art. The larvae of 

 Clythra construct leathery cases which they drag 

 about with them ; the head is protruded from one 

 end, and when full-fed, the Insect changes to a pupa 

 within its case. The larvae of Cryptocephalus form 

 cases too. 1 Among Lepidopterous larvae the Coleo- 

 phoridae, the Tineidae, and the Psychidae are case- 

 builders, commonly carrying their cases about and 

 undergoing their transformations within them. Some 

 of these land caddises are described by Reaumur in 

 his most graphic manner in the memoir cited. 

 Chironomus and Tanypus (Diptera) construct fixed 

 cases out of vegetable fragments, and Lyonnet 2 

 figures and describes what is probably a Chironomus, 

 of which he says that it weaves together the confervae 

 of the ditches, and forms out of them a sheath open 

 at both ends, and enlarged towards the middle. The 

 sheath is so flexible as to yield to all the undulating 

 movements of the inhabitant. The larva drags 

 itself and his sheath along by its mandibles and fore 

 legs. If the sheath becomes entangled, it quits it 

 and soon makes another. The Insect pupates within 



1 Fowler, British Coleoptera, Vol. IV., pp. 286-7. 



2 Rech. sur FAnat.,&>c.,dedijf. Especes tflnsectes,^. 179-183, 

 pi. xvii., Fig. 2. De Haan, the editor of this posthumous work 

 of Lyonnet, names (with some hesitation) the Insect a Tanypus, 

 but its habits are surely those of. Chironomus. See Additional 

 Notes, p. viii. 



