194 TERTIARY INSECTS OF NORTH AMERICA. 



pliilidae,' tlie larvae of which group are remarkable for the variety of objects 

 the}' use for the construction of their cases. It would seem desirable at 

 present, while placing Indusia in this group, to include in it all larval 

 cases of extinct Trichoptera until they can be more definitely placed or 

 distinguished. 



These, however, are not the only instances of larval cases of Trichop- 

 tera found fossil. Hepp, in 1 844,^ describes some from the rocks at Leistadt, 

 near Diirkheini, under the name of Phryganea blumii, and Heer a few years 

 later in his classic work describes and figures a similar instance from 

 Oeningen, under the name of Phryganea autiqua, in which the case was in 

 part made up of bits of sticks. But the most surprising discovery of this 

 sort is that of supposed larval cases of Phryganidre in amber.' According to 

 Dr. Hagen, Pictet thought them larval cases of a tineid, but Zeller believed 

 they were trichopterous, the larvae still remaining inclosed and appearing 

 to belong near Mystacides. As phryganid larvae are aquatic almost without 

 exception, their discovery in amber is certainly surprising. A tube-like 

 larval case, presumably trichopterous, has also been described under the 

 name of Phryganaea micacea and figured by Fritsch'' from the Cretaceous 

 clay-schists of Kounic, Bohemia ; and Marion^ describes larval cases on the 

 leaf of a fossil, Nymphaea, in Provence, very like those attached to similar 

 leaves to-day. 



Indusia calculosa. 



PI. 4, Fig. 4. 



Indusia calculosa Soudd., Bull. U. S. Geol. Geogr. Surv. Terr., IV, 542-543 (1878); Ann. Rep. U. S. 

 Geol. Geogr. Siirv. Terr., XI, 638-639 (1879) ; in Zittel, Haudb. d. Paljeont., I, ii, 778, Fig. 985 (1885). 



Dr. A. C. Peale, in his explorations under the Survey, discovered in 

 deposits, which he considers as probably belonging to the upper Green 

 River group, or possibly to the lower part of the Bridger group, beds of 

 limestone, the upper floor of which is completely covered with petrified 

 cases of caddis-flies, all belonging to a single species, which may bear the 

 name we have applied to it above. They vary from 14 to 19"'™ in length, 

 from 4 to 5™™ in diameter at their open anterior extremity, and from 3 to 



'See on this point McLachlan, Proc. Ent. Soc. Lend,, 1882, 18-19. 

 "Jahresb. Pollichia, vol. 2, pp. 19-23. 



'Berendt, Bernst. befmdl. organ. Reste Vorw., vol. 2, pt. 1, p. 121. 

 <Arcbiv. naturw. Landesdurcbf. Bohiii., vol 1, p. 66; Vesmfr, vol. 13, p. 205. 

 ^ Saporta, Organ, probl. anc. uiers, 24-20, PI. 3, Fig. 2. 



