Case (Figure 589) 7.9— 10.4 mm long, cylindrical, covered with sand grains 

 and small stones; stones in lateral walls much larger than the others, sothat 

 case appears broad with a slightly flattened ventral surface made of fine 

 sand grains; anterior opening exposed, posterior opening with a membrane 

 with a small, round, central hole. 



(345) 



590 



591 



FIGURES 588-591. Silo nigr ic or nis Pict. (after Nielsen): 



588 — legs, posterior; foreleg (A),spinules of fore coxa (B), anterior-distal seta of 

 fore coxa (C),hind leg (D); 589 — larval case, dorsal (A) , posterior (B). Pupa: 

 590 — anteclypeus and labrum (A), right mandible, ventral (B), right anal rod, 

 ventral (C); 591 — pupal case (details): anterior and ventral (A), anterior mem- 

 brane and covering stone (B), posterior membrane (C). 



Pupa. Length 7—8 mm. Dorsal side of head with small, pale, transverse 

 tubercles anteriorly. Antennae of male pupae reaching end of body, to 

 segment 8, in female pupae; wing sheaths reaching abdominal segment 6. 



Anteclypeus laterally with 2 moderately long, and one short setae. 

 Labrum (Figure 590, A) of characteristic form, with a short seta lateral to 

 median process anteriorly; 5 other setae also at anterior margin, moderately 

 long, hooked at end, one seta smaller and some distance from margin. 



432 



