STRUCTURE AND LITERATURE. 35 



discovered a true predaceous larva among the Phy- 

 eidse (N. Am. Ent. i. p. 25, with Plate), has also 

 found an aquatic larva among the Noctuida3. It is 

 that o^ Arzama Melanopyga, one of a genus belong- 

 ing to the Nonagrians, a stout Bomhyciform moth 

 having the abdomen of the female provided with a 

 large, terminal, close tuft. The larva is furnished 

 with nine pairs of spiracles, lives in the stems of 

 pond-lilies, and can remain below the surface of tlie 

 water a long time. 



As to mimicry, the Noctuida3 which are grey or 

 brown often look like lichens or bark when resting 

 on the trunks of trees in the daytime. A curious 

 example of protective mimicry is given by Professor 

 Keilicott in the pages of the ' North-American En- 

 tomologist,' i. p. 30 (Oct. 1879). It is that of the 

 pretty Noctuid. Rhodophora Florida, which lives 

 concealed in the daytime in the withering blossoms 

 of tlie evening primrose {(Eiiotliera Biennis). The 

 moth has the inner two thirds of the fore wings 

 bright pink, while the outer third, the hind wings, 

 and al)domen are pale yellow. It enters the flowers 

 before day wdth its body resting upon the style, the 

 four-parted stigma projecting beyond the top of the 

 abdomen, appearing like a part of it. When tbe sun 

 comes, the two petals that were above the moth soon 

 wilt, and fall down over the roof-like wings conceal- 

 ing the hind portion, leaving the yellow part exposed 

 as part of the blossom. Sometimes the pink of the 

 wings is not wholly covered, but the tone of the con- 

 tinuous colours is such that the harmon}^ is com- 

 plete. The larva, which feeds on the floral organs 



c2 



