SCIENTIFIC NOTES AND OBSERVATIONS. S^ 



Fossil Tipulidae. — In a paper on Tertiaiy Tipnlldac, by S. H. 

 Scudder, the author describes twenty-nine new species distributed amon<; 

 ten genera of Limnobinnc, and twenty-two new species distributed 

 among five genera of Tipulidae from Florissant, Colorado. From facts 

 now known, Dr. Scudder concludes that the three principal insect localities 

 in Western Colorado and Wyoming are deposits in a single body of water, 

 the ancient Gosiute Lake. To the fauna of these deposits lie applies the 

 term Gosiute Fauna, in distinction from the Florissant or Lacustrine 

 Fauna in Central Colorado. No single species of the Lacustrine Fauna 

 occurs in the Gosiute, and among the few genera found in two of the 

 localities of the Gosiute Fauna, the species of each locality are distinct 

 from those of the other. Mr. Scudder is fortunate in having such beauti- 

 fully preserved siDCcimens with which to illustrate his paper. The 

 delicate appendages, the markings and venation of the wings and even 

 the facets of the compound eyes are shown. {American Naturalist, Nov. 

 1894). 



Discussion on tlie plature of certain Colours. 



I should like to raise the question as to the nature of the "white" 

 in Hepiahts hurnul i ^ a.iid EnMo'e cardamines. My experience of the 

 action of ammonia on the former, and on the females of the latter 

 (both Cornish and Devonshire specimens), tends to show that the colour 

 is i)igmentary. All my insects killed with ammonia are left in a box, 

 with several drops of Liquor Ammonice Fort, for about 12 hours. 1 hud 

 ill both the above species that the action of the alkali, though per- 

 ceptible in all immediately after removal, varies considerable in 

 intensity and permanency, being in some comparatively slight and 

 fugitive. Is the original statement (BrdisJi Nodme and their Varieties, 

 vol, ii., Introduction, p. vi.) as to the " nonpigmental nature of the 

 colour of H. hnindi, AntJtocharis, Pierts," etc. to be accepted as correct, 

 generally ? If so, are the insects in certain localities in a transitional 

 stage as regards the pigment ? The variability in the amount and 

 2)erniaiieiicy of the change by the alkali in different specimens might 

 suggest such a possibility. — W. S. Kidinu, M.D., liuckerell Lodge, 

 near Honiton, £. Devon. 



I have noticed the yellow tinge produced by ammonia in male 

 specimens of Hepiahis humidi, but it has never been permanent with 

 me. The yellow of Rnmia lateolata is considerably deepened by the 

 same re-agent. If the scales of a male H. humuli or of any white insect 

 Ijc examined under the microscope, a certain percentage will be found 

 to contain plenty of i)igmeiit granules. These latter are peculiar, as 

 under a high power they show a bright spot, apparently a hole, in 

 each granule ; but this a})})earaiice, I think, is due simply to the 

 retiection of light from a spherical surface. The microscope, I take it, 

 is a much better witness to the presence of })igmcnt than the reaction 

 i)f chemicals, which might mean anything, and I certainly am scejitical 

 as to the yellow coloration l)eing evidence of pigment. The cliitiu 

 itself, under certain circumstances, might be so coloured. — K. Fhkkk, 

 M.B., Kugeley. Sept. Ath, 1894. 



Dr. Freer's note puzzles me. He states that tlie pigment grauuk's 

 can lie seen with a microscope, and yet is sceptical as to the yellow 

 coloration Ijeing evidence of pigment. Absolutely white coloration is due 

 to the complete reflection of the light that falls upon the surface ; a yellow 



