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Species living in rapid currents attach their cases, which consist of 

 stones or reeds, to stones before pupation; they shorten them and close 

 their ends with stones, sand grains and membranes with openings. Some 

 of these cases are attached to stones; they are flattened 

 dor sovent rally, have rounded smooth ends and openings 

 in the membrane near the ventral margin; they resemble the 

 cases of Annulipalpia, but the principle of construction is 

 quite different; they form a tube with a flattened ventral 

 wall which separates the pupa from the substrate. 



The pupal cases of Integripalpia are modified larval 

 cases and resemble them on the whole. The cases of 

 different genera, and sometimes also of different species, 

 differ in the method of attaching the case to the substrate, 

 the method of closing its ends, the form of the membrane 

 closing the ends of the case, and the number and form of 

 the openings in the membrane. 



The larvae of Phryganeidae, which live in stagnant water, 

 close their straight tubes before pupation with sievelike 

 nets with broad meshes; they cover the outer side of the 

 nets with numerous thin stalks and leaves which are more 

 numerous at the anterior end than at the posterior end 

 (Figure 15 0). The larvae of Grammotaulius 

 atomarius shorten the pupal case; they cover its anterior 

 part loosely with leaves of cane; the sievelike closing 

 membrane of the pupal case of Grammotaulius is a 

 thin net with large openings separated by narrow strands 

 of silk (Figure 151, A, B). 



Some species of Limnophilus close the pupal case 

 with a sievelike membrane which is continuous or divided 

 into parts by sand grains or pieces of detritus (Figure 152). 

 The larvae of Potamophylax living in running water 

 (e. g., Pot am ophy lax stellatus and P. n i g r i c or n i s) 

 round the ends of the cases, closing them with sand grains 

 and small stones between which remain areas of membrane 

 with openings which are more numerous at the anterior 

 than at the posterior end (Figure 153). 



Species of Apatania extend the case anteriorly, adding 

 a hood of small stones which are as large as those at the 

 sides; the anterior opening of the case is thus displaced 

 ventrally to the stone on which the larva pupates and is 

 attached to it by silk threads; only a narrow band of 

 membrane with a row of small openings remains at the anterior end; 3 or 

 4 small openings are present in the middle of the membrane at the posterior 

 end (Figure 154). 



The pupal cases of Molanna lie free on the bottom; the wings of the 

 case are usually short, as the larva does not add to them during the last 

 stage; the anterior opening is closed with a membrane covered with fine 

 sand grains; there is one small opening at the periphery of the membrane, 

 near the dorsal margin; the posterior part of the case bears a narrow 

 vertical slit in the middle. 



FIGURE 149. Pupal 

 case of Mystaci- 

 d es long icornis 

 attached to a twig 



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