832 



SCIENCE. 



[N. S. Vol. XVI. No. 412. 



tains and between tbe Saskatcliewan River on 

 the north and the Platte River on the south 

 fresh-water representatives of the entire Up- 

 per Cretaceous series will yet be found. Both 

 the terrestrial vertebrates and the fresh-water 

 mollusca of the Belly River, Judith River and 

 Laramie beds indicate that they and their 

 ancestors found somewhere in this immediate 

 region a congenial habitat where it was pos- 

 sible for them to continue their development 

 without interruption. The Pierre shales in 

 the Belly River region are remarkably thin as 

 compared with the thickness to which they 

 attain in the south, where the Belly River 

 beds are wanting, thus indicating that in the 

 former region the lower Pierre shales are re- 

 placed by the fresh-water deposits known as 

 the Belly River beds. 



Several years ago (Am. Nat., February, 

 1896, p. 116) the present writer affirmed that 

 the Judith River beds were certainly older 

 than the Ceratops teds of Converse County, 

 Wyoming, and that the dinosaurs from the 

 Judith Biver country helonged to smaller and 

 less specialized forms than those from the 

 latter locality. It is gratifying to note that 

 Professor Osborn has arrived at the same con- 

 clusion. In the article in the American Na- 

 turalist just cited I considered the Judith 

 River beds as the equivalent of the 400 feet 

 of barren sandstones lying between the base 

 of the Ceratops beds and the marine Fox 

 Hills sandstones in Converse County, Wyo- 

 ming. I am at present of the opinion that 

 they pertain to a still lower horizon. 



J. B. Hatoher. 



CaRNFGIE MtTSEUlt, 

 October 27, 1902. 



SHORTER ARTICLES. 

 A CASE OF MIMICRY OUTMIMICKED ? CONCERN- 

 ING KALLIMA BUTTERFLIES IN MUSEUMS. 



In a recent collection illustrating mimicry I 

 noticed that the Kallima butterflies had been 

 placed on twigs whose dried leaves were start- 

 lingly like the butterflies in their position of 

 rest. There was no doubt that the butterflies 

 were in exactly the right position for orthodox 

 mimicry; the antennse were carefully tucked 

 out of sight, and the folded wings were in 



the plane of the adjacent leaves; and certain 

 leaves of the spray had, it seemed, opportunely 

 fallen ofl: so as to allow the insects to seize the 

 vacated places with unerring accuracy, each 

 crouching at such an angle that the tail pro- 

 cesses of the hind wings fitted near the scar 

 on the stem where the leaf had been attached. 

 The leaves, moreover, which had been chosen 

 to imitate the tropical butterflies happened 

 to belong to a North American tree, and it 

 is even possible that they had been skilfully 

 touched up to mimic, one, the visual type of 

 Kallima, with distinct rib-like markings, an- 

 other, the form which seems fungus-spotted. 

 As a work of art this preparation was cer- 

 tainly a success, and it taught interested vis- 

 itors a forceful lesson in animal economy. 

 But I have to confess that it gave me the 

 feeling that both insects and preparateur had 

 overdone their work. And that the prepara- 

 tion had an additional air of false pretenses 

 about it for which the natviralist afield more 

 even than the preparateur and the hap- 

 less butterflies, is to blame. For he is the one 

 who allows the finishing details in such cases 

 of mimicry to be assumed without critical 

 foundation. In the present case, indeed, one 

 may justly query whether Kallima mimics its 

 surroundings as perfectly as the preparateur 

 will have us believe. Wallace himself, who 

 knew the creatures at first hand, does not 

 figure them as accurately adjusted to their 

 surroundings as are these mounted specimens. 

 And even his account seems to need amplifi- 

 cation, e. g., as to the species of leaf mimicked 

 and the more exact habits of the butterflies.* 

 And beyond this I do not recall detailed field 

 observation. Perhaps I should say that my 

 faith in the possibilities of Kallima became 

 somewhat weakened during a visit to the 



* Thus he states in his ' Malay Archipelago ' ( p. 

 142) that 'the habit of the species is alioays 

 (italics mine) to rest on a twig and amo.ng dead 

 or dry leaves,' but later admits (Natural Sec- 

 tion, p. 44) that only 'on one or two occasions 

 the insect was detected reposing ,***.' He 

 does not show furthermore what the leaf is that 

 is so exactly mimicked, merely referring to gen- 

 eral resemblance to ' the leaves of many tropical 

 leaves and shrubs.' 



