1873.] 19 [Packard. 



extinction lias gone hand in hand with geographical isolation. It 

 was a common form in Europe in the Jurassic period, and in the next 

 lower (permian) period but one (the triassic intervening), we find 

 other Merostomata and a few Trilobites. 



We make these speculations, hoping that much light will be thrown 

 upon the subject by studies on the rich tertiary insect beds of the 

 west, and of the fossil insects in the arctic tertiary and cretaceous 

 formations. Until then we must regard all foundations for these 

 hypotheses as laid by the fossil botanist. 

 Camptogramma fluviata (Hiibn.). 



Two females, i.e., C. gemmata (Hiibn.), now shown to be the 

 female of C. fluviata by a writer in the " Entomologists' Intelli- 

 gencer," 1858, as quoted in Newman's "Illustrated Natural History 

 of British Moths," p. 172. 

 California (Edwards). 

 Larentia 12-lineata n. sp. 3 c?, 5?. 



An unusually small species, half the size of L. dilutata, and about 

 as large as L. albulata of Europe. 6 Antennas well ciliated. Head 

 above whitish gray, in front dark brown ; palpi brown at tip, paler 

 below. Body and wings white, with a slight grayish tinge on costa 

 of fore wings and on thorax. Wings of the same form as in C. dilu- 

 tata, except that the apex of the fore wings is rather more pointed. 

 Fore wings white, crossed by about twelve black thread-like lines, 

 waved or scalloped, the outer ones mostly represented by venular 

 black dots. The inner lines are usually scalloped. All the lines are 

 more distinct and broader on the costa, and angulated outwards more 

 or less acutely just below the costa. Across the middle of the wings 

 run three parallel lines finer and nearer together than the others. 

 The marginal row of intervenular black spots distinct on both wings. 

 Hind wings white, with four or five dark slightly marked lines, of 

 which the two inner are scalloped, while the three outer are repre- 

 sented by venular dark points. 



Beneath a little more dusky than above, with the lines on the inner 

 half of fore wings wanting ; a median double dusky line, ending in a 

 dark clear spot on the costa and inner edge. The lines beyond faint. 

 The marginal black line distinct on both wings. Hind wings marked 

 like fore wings. Discal dots indistinct on both pairs of wings. 

 Abdomen dull whitish unspotted. Fore legs brown, banded with 

 narrow white rings ; hind legs whitish. 



Length of body cf, .33, ?, .30 inch; fore wing d", .45, ?, .40 inch. 



