182 



SCIENCE. 



[N. S. Vol. XVIII. Xo. 449. 



concretions can almost as readily be construed 

 into the forms of Natica, Nerita and Paludina 

 as tliey are shown in the somewhat similar 

 clays of the Port Hudson age, on the islands 

 of Petite Anse and Cote Blanche. Here every 

 degree of transition from the almost perfect 

 shell into the roundish concretions can be 

 traced; and I do not despair of a similar state 

 of things being found within the largest cal- 

 careous deposit of the Grand Gulf area on the 

 Anacoco when it shall be examined more at 

 leisure than it was possible for me to do in 

 1869. 



So far then as the central portion of the 

 Grand Gulf formation in Mississippi and 

 Louisiana is concerned, I see no escape from 

 the conclusion that the sandstones and asso- 

 ciated clays are rightly considered as being 

 of one and the same geological age and for- 

 mation, whether representing the upper Oli- 

 gocene or later stages of the Tertiary. The 

 hiatus between it and the Lafayette is em- 

 phasized alike by the extension of the latter 

 two hundred and fifty miles farther inland, 

 and by the totally changed lithological char- 

 acter of the materials, a change so great that 

 it is hard to believe that the same Gulf waters 

 should have produced both at any short in- 

 terval of time. The conformity of the La- 

 fayette to the Grand Gulf, referred to by Dr. 

 Dall, is rather a delicate question when deal- 

 ing with a formation of which stratification 

 lines and dips are hardly predicable. ■ The 

 Lafayette overlies the Grand Gulf as it over- 

 lies every other formation in Mississippi and 

 Louisiana, and it is there undoubtedly the 

 next succeeding formation; but intervening 

 beds may be found elsewhere. WLat was the 

 nature of the event that caused the remarkable 

 change in the whole nature and distribution 

 of the two deposits must still, I think, be con- 

 sidered an unsolved problem. 



E. W. HiLGARD. 



Berkeley, Cal. 

 July 22, 1903. 



ANTARCTICA. 



To THE Editor op Science: My many 

 American friends will be amused by the in- 

 nuendo that I hate Americans which runs 



through Mr. Balch's notice (in your issue of 

 July 10) of my review of his book in the 

 Geographical Journal for May. It has always 

 been a privilege of men of science to criticise 

 each other's work as if they were members of 

 one family, and I can conscientiously say for 

 myself that I am without prejudice as to race, 

 creed or nationality. Should I or any other 

 European geographer differ from Mr. Balch 

 or Fanning or Morrell, it is not because they 

 are Americans and we are not, but because 

 we think that in certain points they are mis- 

 taken. 



The Atlantic is too wide for a comfortable 

 controversy in a weekly journal to be con- 

 ducted across it; and I do not think it would 

 serve any useful end to reply to Mr. Balch's 

 letter in detail. I fear that my review is too 

 long for you to reprint, but nothing shorter 

 would give a correct impression of my opin- 

 ions on the points dealt with in Mr. Balch's 

 very stimulating book. I should be glad if 

 both were widely read. 



Yours is a land of millionaires; the Ant- 

 arctic is still scarcely touched by explorers, 

 and all nations would rejoice to see a well- 

 equipped American expedition sent out to 

 help to solve the present problems which after 

 all are those most nearly concerning us. 



Hugh Egbert Mill. 



62 Camden Square, London, N. W., 

 July 21, 19D3. 



SHORTER ARTICLES'. 



A NEW MOSQUITO. 



Since mosquitoes have attracted so much at- 

 tention of late through the part they play in 

 the transmission of certain diseases, anything 

 new that pertains to them or their life history 

 may be of importance. In view of this fact, 

 a brief description of a new species — which has 

 been given the name of Eucorethra underwoodi 

 — should be of interest. While this particular 

 insect does not bite, and for this reason should 

 not perhaps be regarded as a true mosquito, 

 it has, however, been classed as one since it 

 belongs to the family Culicidse. The larvae 

 of this insect were found by me on January 

 27, 1903, in the Maine woods in the eastern 



