Correxpond-nce. ■ 3l>c> 
Craie du Xord est bien un de[)ot terrigr-ne, par .M. L. Cayeux : Sur un 
caleaire moderne coneretionne avec diatom(^es de Saint-Xectaire-le- 
Bas, par M. L. Cayeux ; C-omposition inin^ralogitiue des Sables glau- 
conieiix landeiens, par L. Cayeux ; Xote sur le Tertiaire du Boulon- 
nais, parH. Parent; Sepulture de 1' age de la Pierre polie a Kouvroy 
(Aisne) i)r^s Saint Quetin, par 31. Rabelle; De I'existence de nom- 
breux Kadiolaires dans le Jurassique et dans 1' Eocene du Nord de la 
France. — Origine probable de la silice de la Gaize et des Tuffeaux 
eocenes, par M. L. Cayeux ; Sur la presence de vert<^br(''s dans I'Eocene 
inf(?rieur du Nord de la France, par A. Malaquin ; Observation au 
sujet du mode de formation du conglomerat a silex par M. Gosselet ; 
Du role de la geologie dans 1' enseignement de le gfographie et de 
r agriculture, par M. Gosselet ; Xotes pour r(^tudedu terrain quater- 
naire en Hesbaye au Mont de la Trinit<5 et dans les collines de la 
I'laiidre, par 31. Ladricre. 
OORIlESPO:^DE]:^CE. 
The Third Texas kepokt. — Permit me to correct a few errors of 
statement in the review of the Third Annual Rei)ort of the Geologi- 
cal Survey of Texas, published in your November number, inasmuch 
as they put on record Prof. Alpheus Hyatt and myself in a manner 
unauthorized by us. 
You state that Mr. Jules Marcou's determination of the Jurassic 
age of the Tucumcari beds in New 3Iexico has been sustained by 
Capt. C. E. DuUon, Prof. A. Hyatt, and Prof. Robt. T. Hill, and op- 
posed by Prof. Jas. Hall and Dr. J. S. Xewberry. I am sure that 
neither Capt. Dutton, Prof. Hyatt nor myself has authorized this 
statement. C'apt. Dutton has never published a line on the Tucum- 
cari region, and I think has never visited it. In his admirable mon- 
ograph on Mount Taylor and the Zuni Plateau, he does uphold Prof. 
]Marcou's determination of the Jurassic in New ^Mexico, but in an en- 
entirely different portion of the territory from Tucumcari. 
Prof. Hyatt and I have studied the region minutely ; the former 
spent a whole field season in the vicinity, while I have made two 
special trips to this inaccessible locality. By agreement we have re- 
frained from publishing the lengthy papers eitlier might have pre- 
pared, and I am positive Prof. Hyatt never recorded an opinion on 
Tucumcari, but is cautiously working up his material. 
I have expressed my opinions in the following five publications. 
1. (Mrcular, Sciu)ol of Geology of University of Texas, Austin. 1887. 
2. (Teoh)gical Survey of Arkansas, Annual Report 1888, Vol. ii. 
3. The Comanche Series of the Texas-Arkansas Region. Pulletin 
of the Geological Society of America, Vol. ir, pp. 503-528, 1891. 
4. Notes on the Texas-New ^Mexican I'egion. I'ull. ( ieolog. Soc. 
Am.. Vol. riT, 1891. 
