120 



Psyche 



[June 



ANOTHER AQUATIC CATERPILLAR (ELOPHILA). 



By Wm. T. M. Forbes, 

 New Brunswick, N. J. 



In my paper in the December Psyche, I referred to Elophila 

 (Cataclysta) as a larva not yet known in America. There is a 

 cocoon of this genus in the College collection here, agreeing with 

 those of the European species. It contained a skin in exception- 

 ally good condition, making it possible to compare the caterpillar 

 as well as the chrysalis with those of Nymphula and Paraponyx. 



Caterpillar. In general characters agreeing with that of the 

 other two aquatic genera; with smallish head, no tracheal gills, 

 no posterior ocellus; with head, setse and prolegs essentially as in 

 Nymphula. Punctures of front closer together than in the others 



(3^ as far apart as the setse) ad- 

 frontal punctures higher than setse, 

 but not so much; i of labrum (see 

 figure) much lower than ii and 

 quite near the middle line; the 

 puncture near ii; antennae as in 

 Nymphula proper, but the first seta 

 is rather farther out. Lower lip 

 normal. Apparently there are only 

 three ocelli, but the specimen is not favorable. Prolegs as in 

 Nymphula proper, the ventrals with 50, the anals with 15 hooks. 

 Spiracles of first four abdominal segments larger, especially those 

 of A3 and 4; but the others are more than half as large, and 

 evidently functional. 



Case spheroidal, of a mosaic of Lemna leaves. It is distinguished 

 from those of Nymphula and Hydrocampa by the lack of a sharp 

 lateral edge. The leaves of the case do not seem to be eaten. 



Pupa similar in appearance to Nymphula, and in details except 

 as follows. The last spiracles are on little conical projections, and 

 where the spiracle of A9 should be there is a more prominent 

 irregularly conical spine. Of the three enlarged spiracles, the 

 first is but little smaller. There are two parallel thickened trans- 

 verse ridges on the center of the seventh and eighth abdominal 



Fig. 1. Labrum of Elophila sp. 



