2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 71 



the intervening ones are rough parallelograms, placed side to side, 

 so that the lines of union are almost exactly transverse. The indi- 

 vidual pieces appear to be normally fastened edge to edge and not 

 overlapped, although in some cases they show evidence of overlap- 

 ping as in Figure 5 where the anterior piece is nearly circular and 

 a considerable overlap can be discerned. The lateral edges may be 

 slightly rounded, but are usually rather evenly cut and fitted, so 

 that the lateral margins of the case are approximately straight. 

 Occasionally all of the pieces are roughly semicircular, as in the 

 specimens originally figured, resulting in an angulated margin and 

 heightening the resemblance of the case to the metameres of an 

 arthropod body. (Figs. 1 to 5.) In all instances the leaf pieces 

 appear to have been cut out of large leaves, and none show a leaf 

 margin. In this respect the fossils differ from all recent species of 

 similar habit that I have been able to find. 



Occasionally a specimen will have part of one face missing and 

 will show that these envelopes had two opposite faces covered with 

 leaf cuttings as in the comparable existing forms. These leaf pieces 

 are seen to be roughly alternating on the two surfaces. No traces 

 of a central tube can be discerned in the relief of the specimens, 

 so that the internal tube must have been silky, as in modern forms, 

 and of slight bulk or resistance to the pressure developed during 

 fossilization. 



No specimens show any trace of the incorporation of any small 

 sticks or other foreign materials, but are built entirely of rather 

 uniformly cut pieces of leaves. These are all dicotyledonous except 

 in two instances where a parallel-veined monocotyledon has been 

 used. The number of pieces per case is 6 to 8 on each face. The 

 cases average about 2.5 centimeters in length and their width varies 

 from 4 to 10 millimeters, and averages nearest to the last figure. 



Specimens have been obtained from the following localities: 

 Puryear, 2 miles west of Henry, and Foundry Church Pit in 

 Henry County; 1 mile west of Milan in Gibson County; 14 niil^ 

 south of Mandy, 2^^^ miles northwest of Mercer, and 3^4 miles north- 

 east of Jackson in Madison County; from several outcrops near the 

 town of LaGrange in Fayette County; and from Mill Creek in 

 Hardeman County. 



The portable cases of caddis larvae are constructed of almost every 

 material that is to be found in the water and in an almost endless 

 variety of form. The material is cemented by a silk-like salivary 

 secretion. Frequently there is considerable variation in the ma- 

 terial used and the form of the cases, not only in a single genus, but 

 even in a single species. Lloyd, however, makes the statement that 

 the trained observer can usually determine the cases. 



The Wilcox leaf cases appear to me to be referable to the family 

 Limnophilidae. This is a large and widely distributed group in the 

 existing fauna, especially prominent in ponds and slow streams, but 



