238 THE ENTOMOLOGIST. 



portions possess a common geological feature, namely, that of 

 "Buczkas" or sandhills (see Plate VII). The whole surface of 

 the ground is covered with mounds of soil (a mixture of sand 

 and humus) shaped like an inverted saucer, i. e., rounded at the 

 top (which is nearly pure sand) and gradually sloping away to a 

 wide flat base of the above-mentioned " black sand." The effect 

 of this formation is that the surface of the land really consists 

 of a number of mounds with more or less flat spaces between 

 them, the mounds being more sandy than the plains between. 

 The rain water falling on the mounds rapidly runs down from 

 them, but remains on the flat land between, and produces a 

 curious effect on the general vegetation of the locality. The 

 mounds possess but few plants, those present binding together 

 the sand, but the flatter spaces between (see Plate VII.) being 

 richly watered are covered with numerous flowers and plants ; in 

 fact, in some cases where the land is especially low-lying, the 

 ground is positively swampy and supports reeds. The imagines 

 of this butterfly flutter about over these sandhills, where they 

 deposit their eggs during June, and the species would appear 

 to be normally full out about the middle of the month. The 

 insects, however, generally frequent the flowers growing on the 

 flatter portions, where they obtain sustenance. Miss Charlotte 

 de Wertheimstein informs us that she has absolutely observed 

 a female deposit an egg on a plant of Festuca sulcata. Owing to 

 the fact that some of the grasses grow so very close together, it is 

 a matter of extreme difficulty to decide from which of several 

 grass plants the larvae taken at night with a lantern really come. 

 The adult larvae which are described in this paper were un- 

 doubtedly taken from a plant of Festuca sulcata growing in the 

 " Buczkas," i. e., the raised sandhills, and this Festuca, with its 

 variety rupicola, we have no hesitation in stating is the food- 

 plant, at all events here, of the larva of this butterfly. The 

 other species of grass growing in close proximity (and there are 

 several) can now be rejected as possible food-plants with absolute 

 certainty. 



In June, 1910, we placed a much worn female of this species 

 on a pot of grass, and about thirty ova were laid and dropped 

 loosely on the surface of the soil. These ova hatched on July 

 19th, and in February, 1911, we found that two had recently fed 

 on fescue grass {Festuca ovina). They had grown slightly, and 

 had become greener in colour, but they died shortly after. As we 

 shall show later on in this paper, it is quite abnormal for the eggs 

 of this species to be dropped in the grass.* A similar experiment 



■■'• This phenomenon has been observed in the eggs of other lepidopterous 

 insects when they are in a worn and emaciated condition, for example, in 

 the eggs of Sphinx ligitstri, both the authors and Mr. L. W. Newman having 

 possessed worn females of this moth which deposited eggs entirely lacking 

 the usual gummy substance by which they are normally fixed to the leaves 

 of the food-plant. 



