T40 ENTOMOLOGICAL NEWS. [April, 'l8 



by Holmgren for his species. The resemblance to a snail-shell 

 is usually less complete, although the mass is obliquely conical, 

 the apex close to one end. and concentric creases are present. 

 Some of our specimens are much more flattened and rise but 

 gradually toward the apex, while the creases are less numer- 

 ous. Others of our specimens (compare, Plate \'III, our figs. 

 2 and 3 with fig. 4 from Holmgren) do not slope regularly 

 from the apex to the sides; instead there is a central strong- 

 ly conical portion, separated by a deep crease from an outer 

 flattened portion. In short, while the principle of construc- 

 tion is the same, there is considerable variation culminating 

 in specimens closely approaching Holmgren's in shape 



The larva before pupation spun a loose-meshed cocoon be- 

 neath the black dung-cap, which ultimately rested on top of 

 the cocoon. As in the species described by Holmgren, the 

 cocoon consists of wide, irregular meshes of white glistening 

 threads secreted from the salivary glands. There is an outer 

 network of a few very coarse threads and these are connected 

 and here and there drawn toward each other by finer threads. 

 Inside of this outer very open meshwork is a cocoon of small- 

 er meshes and finer threads, a considerable space interA^ening 

 between the two, but occasional threads connecting them. The 

 meshes of this inner cocoon are still ver^' open and allow the 

 pupa within to be plainly seen. This inner cocoon again con- 

 sists of coarser and finer threads, the former approximately 

 corresponding to the finer threads of the outer cocoon. The 

 coarser threads for the most part run around the cocoon trans- 

 versely at rather regular intervals, while the finer threads run 

 mostly lengthwise and bind together the transverse threads. 

 The entire structure is fastened to the leaf-surface. On top 

 of the cocoon, as already mentioned, usually rests the shell or 

 dung-cover of the larva (Plate VIII, figs. 2, 3) ; in other 

 cocoons the dung-cover has been cast off. The pupal period 

 lasts four days. The description of the imago follows. 



Mycetophila merdigera, n. sp. (PI. VIII, fig. 1). 



$ . Pale ocher-yellow, the dorsum of the abdomen with the apices 

 of the segments extensively marked with brown. 



