THE BEAUTIFIiju :HINA MARK. 493 



merge itself for a considerable time, the appearance of a hymen- 

 opterous insect beneath the sm-face of the water being most 

 extraordinary, and always exciting the admiration and surprise 

 of those who have any practical knowledge of insects. But, 

 that a caterpillar should actually pass its life under the water 

 is still more contrary to all preconceived opinions, and the idea 

 of a water-caterpillar is not one whit more abnormal than that 

 of a water-butterfly. The name Hydrocampa is formed from 

 two Grreek words, literally signifying water-caterpillar, and 

 is given to this genus of Moths in consequence of the aquatic 

 life of the larva. 



On Woodcut I>VI. Fig. a, is drawn one of these larvse, being 

 the preliminary stage of a Moth called scientifically Hydro- 

 campa stagnalis. This larva feeds upon the common duck- 

 weed {Leinna). It does not crawl freely upon this vegetable, 

 but remains submerged, ai:kd protects itself after the manner of 

 the caddis, which it so closely resembles in many of its habits, 

 by means of a case constructed from the epidermis of the pond- 

 weed {Potamogeton). From the under surface of the broad, 

 floating leaves of this plant, the larva strips off a sufficiency 

 to form a kind of tent, in which it resides, very much as do 

 the caterpillars of several British Moths with the leaves of the 

 oak and other trees. At Fig. 6, is seen this caterpillar, with 

 the head and legs just protruding from its case, which, being 

 of the same colour as the aquatic plants, serves for conceal- 

 ment as well as for protection. 



The Moths themselves are very common, and can be taken 

 in plenty on the banks of ponds and any wet places where 

 duck-weed, pond-weed, and water-lilies grow. The perfect 

 insect is shown on Woodcut LVII. Fig. 1. It is popularly 

 known as the Beautiful China Mark, and well deserves its 

 name. The ground colour of the wings is pearly-white, and 

 on these are traced a number of soft brown lines, the most 

 conspicuous of which is a mark near the tip of the upper 

 wings, somewhat resembling the letter Y with the angle 

 rounded. 



We next come to the Pearl Moths, which have already been 

 casually mentioned, and which are placed in the genus Botys. 

 A much more appropriate and withal intelligible name was 



