ART. 14. A NEW TYPE OP CADDIS CASE BEERY S 



also fitted for life in almost every aquatic environment, and in the 

 European genus Enoicyla the larvae afford the only known instance 

 in the whole order of a terrestrial habitat. 



In this family the variety in construction and material of the cases 

 is great, and no general statements can be made. Several of the 

 genera utilize leaf fragments. For example, Arctoecia consocia} 

 builds a three sided case of leaf pieces: several species of Limno- 

 philus utilize leaf fragments : Glyphotaelius hostilis makes a case of 

 imbricated leaf pieces, and the allied Glyphotaelius punctato-lineatus 

 of Europe constructs a two faced case of leaf pieces much like the 

 fossil. (Fig. 6.) Several of the genera of Limnophilidae change the 

 architecture and material of their cases seasonally (as Arctoecia^ 

 Pycnopsyche^ etc.). This is true of Pycnopsyche scdbripennis as 

 described by Lloyd.^ In this species the larvae construct flat cases 

 of leaf pieces during the winter and spring months, and these are 

 very similar to those of the fossil. In late spring the tube becomes 

 tougher, bark fragments are added, the broad roof and floor of 

 leaves is discarded, and a heavy " ballast " stick is added on each 

 side. These last prevent the cases from being upset or rolled by 

 currents exactly as did the form of the earlier flat leaf cases. 



No traces of such seasonal modifications have been observed in the 

 fossil. The innumerable specimens seen are all built on the same 

 plan and of the same material, and it seems a legitimate deduction 

 that the seasonal change noted above is an acquired habit which 

 was not present in this lower Eocene species. The evidence for this 

 has all the weakness inherent in negative evidence, but the abundance 

 of the leaf cases, the fossilization of all sorts of delicate objects 

 such as flowers in these fine muds, and the large amount of unusually 

 thorough collecting from the Wilcox clays, tends to preclude the 

 absence of modified cases as attributable to accidents of preservation 

 or discovery. 



The special construction of the cases of Folindusia wilcoxiana to 

 prevent their capsizing indicates that their habitat was a region of 

 some current action. The general environmental picture of this 

 area during the time of deposition of that part of the Holy Springs 

 sand containing these caddis cases, is of a low, abundantly forested, 

 warm temperate coast, with bayou-like stream distributaries empty- 

 ing into lagoons ponded behind extensive barrier beaches, beyond 

 which the gulf waters were extremely shallow, and not typically 

 marine for a considerable distance. 



The somewhat earlier transgressive phase of the Holly Springs 

 sand shows, in the frequent foreset bedding of the sediments, and in 

 the presence of clay conglomerates, as well as in the abundance of 

 drifted fruits and seeds, evidence of stronger stream action than 

 prevailed later when the caddis larvae swarmed in the waters. 



2 Lloyd, J. T., Bull. Lloyd Library, Eut. .seiies, Xo. 1, pp. 60-63. 1921. 



