162 



BRITISH MOTHS. 



more delicately tinted, and lias the lines better 

 defined ; its dorsal arrow-heads, moreover, are 

 but four in number, being placed on the 

 divisions between the fifth and ninth seg- 

 ments; the seeming arrow-head between the 

 fourth and fifth segments, on examination 

 with a lens, shows no white ; and barely an 

 interruption of the dorsal line ; and the dorsal 

 line, which recommences between the ninth 

 and tenth segments, is not preceded by any 

 clear white. In M. subtristata, the whole 

 back is generally more clouded, the sub-dorsal 

 lines which form the boundaries of the white 

 arrow-heads not being defined ; the arrow- 

 head mark between the fourth and fifth seg- 

 ments in M. subtristata, when examined with 

 a lens, becomes quite distinct, and though not 

 so perfectly formed as the four others that 

 follow it, is yet quite plain and complete ; 

 between the ninth and tenth segments, also, 

 there is a well-defined half arrow-head, the 

 hinder part of which runs into the lines on 

 the hind segments, the entire number of 

 arrow-heads being thus five and a half, instead 

 of only four. The difficulty of obtaining both 

 species in the same stage, at the same time* 

 no doubt renders this comparison less perfect 

 than it might be, could they be placed side by 

 side ; but the first or June brood of caterpillars 

 of M. subtristata are all gone down before 

 the single brood of M. rivata have assumed 

 the characteristic markings ; and these, again, 

 are gone down before the August and Septem- 

 ber caterpillars of M. subtristata are available 

 for comparison. It is well to mention that 

 among some hundreds of the perfect insects of 

 both species, which have been bred by four 

 or five different entomologists during the last 

 three years, there have occurred no inter- 

 mediate varieties whatever ; M. rivata varies, 

 indeed, in having the gray border of the hind 

 margin of its wings sometimes tinged with 

 blue, sometimes with brown, but the white 

 lines always preserve their distinctive width, 

 and the under side is always lighter than in 

 M. subtrixtata ; the only variety that has been 

 observed was one which, far from having the 

 white lines broader than usual, had the dark 

 bands wider. Of course, worn specimens, 



which, having lost many of their scales, 

 preached M. rivata in paleness, are not worthy 

 of notice." 



325. The Silver-ground Gvr$vi(M<:laitippemoittaitatii). 



325. THE SILVER-GROUND CARPET. The 

 fore wings are creamy- white, with an ochre- 

 gray blotch at the base, and an irregular 

 ochre-gray median band, which includes a 

 creamy-white blotch and a distinctly black 

 discoidal spot ; the costal margin has several 

 transverse brown spots, and the hind margin 

 has a broad but pale band of smoky-brown, 

 intersected throughout by a scalloped white 

 line : the hind wings are nearly white with a 

 discoidal spot and a few indistinct transverse 

 markings : the head, thorax, and body are 

 creamy-white, the body having two black 

 spots placed transversely on each segment. 



The CATERPILLAR is almost uniformly cylin- 

 drical, and rests in a nearly straight position, 

 but tucks in the head very tightly when 

 disturbed, the anterior part of the body then 

 assuming the form of the Ionic volute. The 

 head is pale brown, with numerous black 

 lines; the body pale brown, with a number 

 of variously-coloured markings ; the:-e is a 

 narrow median stripe traversing all the 

 segments except the first and thirteenth ; this 

 median stripe is parti-coloured; it is blood- 

 red at the interstices between each two seg- 

 ments beginning from the fourth, and the 

 blood-red portion is always succeeded by a 

 jet-black portion, and the other parts are 

 smoke-coloured ; the sides have two approxi- 

 mate rich brown rivulet stripes, both edges of 

 which are delicately margined with black ; 

 these stripes extend from the head to the 

 thirteenth segment ; below these is a paler 

 stripe, and the belly is also pale, but of a 

 diilerent hue ; between the median stripe and 



