GEOMETERS. 



161 



brown-gray marginal band intersected by a 

 slender zigzag white line ; the extreme 

 margin and fringe are as in the fore wings : 

 the head and thorax are brown-gray, the 

 body smoky-gray, with two nearly black spots 

 placed transversely on each segment. 



The head of the CATERPILLAR is nearly of the 

 same diameter as the body, which is uniformly 

 cylindrical ; the caterpillar generally rests in 

 a nearly straight position, but when disturbed, 

 tucks in its head very tightly, thus giving to 

 the anterior portion of the body the figure of 

 the Ionic volute. The colour of the head is 

 pellucid smoky-brown, dotted with black, and 

 having two darker brown lines which meet on 

 the crown ; the body is brown, beautifully 

 variegated, and mottled ; the second, third, 

 and fourth segments have a median black 

 line, and on each of the six succeeding seg- 

 ments is a somewhat horse-shoe shaped 

 median white mark ; the last of these termi- 

 nates in a median brown stripe, whiah ex- 

 tends through the eleventh and twelfth 

 segments, and to the extreme tip of the 

 thirteenth; these marks might be called 

 lozenge-shaped, but they are open at the 

 posterior extremity ; the enclosed space in 

 each is brick-red, with a median transverse 

 black bar ; there are two or four white dots 

 on the back of each segment, and numerous 

 waved markings of different shapes on the 

 sides. It feeds on the great hedge bedstraw 

 (Galium mollugo), and is full-fed about the 

 30th of June, when it spins a slight cocoon 

 on the earth, and changes to a CHRYSALIS. 



The MOTH appears in May, and again in 

 July, towards the end of the month ; it is of 

 common occurrence in all parts of the United 

 Kingdom, whence a report has been obtained. 

 (The scientific name is Melanippe subtris- 

 tata. ) 



Obs. This species is double-brooded, both 

 in a state of nature and in captivity. The 

 question whether the two species of Melanippe, 

 M. rivata and M. subtristata, are identical or 

 distinct, is one which has often occupied the 

 attention of our most acute lepidopterists ; I 

 confessmyself unable to appreciate the reasons 

 that have been assigned for considering them 



identical, and have, therefore, always kept 

 them separate ; this opinion, however, has 

 been formed almost entirely on superficial 

 grounds, and without that minute attention 

 to distinctive characters, on which alone 

 such a conclusion should be grounded. It 

 is, therefore, with extreme pleasure that I 

 now cite from the memoranda of Mr. Hellins 

 the following excellent observations : " Be- 

 tween the caterpillars of Melanippe rivata 

 and M. subtristata, there is, at first sight, 

 as great a similarity as exists between the 

 same insects in the perfect state ; the ground 

 colour of both is the same, varying from a 

 pale fawn-colour, through a greenish brown, 

 to a dull green, and even sometimes to a 

 bright green, the lines and borders of the 

 markings being of a deeper tint of the ground 

 colour, and often tinged with a good deal of 

 red ; in both, the segmental divisions are light 

 red, though this, indeed, may be observed in 

 a very great number of grey and brown cater- 

 pillars, and in both the dorsal markings are 

 of the same shape, namely, dark longitudinal 

 lines, bordered with light on the front and 

 hind segments, and on the intermediate ones 

 are blunt white arrow-heads,* pointing for- 

 wards and placed at the segmental divisions, 

 the white being clearest and brightest at the 

 point, enclosing a diamond-shaped spot of a 

 dark tint of the ground colour, which at its 

 hinder end runs indistinctly into the broken 

 dorsal line, and themselves enclosed on the 

 front edge by a dark suffused V-shaped 

 mark, the apex of which runs into the dorsal 

 line, and the sides appear to reach down to 

 the spiracles, but become indistinct when 

 examined with a lens. 



"So far these species are alike, but a care- 

 ful examination of the number of specimens 

 during the past two or three years has led to 

 the conclusion that they differ as follows : The 

 caterpillar of M. rivata, as might be expected 

 from the relative size of the two perfecf 

 insects, is invariably the larger ; it is also 



* Perhaps lozenges would be a better word, but 

 the other was chosen on account of the opening of 

 the hinder end, which seems to admit the shaft of 

 the arrow. 



- - M 11 



