Blake—Arizona Diatomite. 
109 
Tlie following forms are illustrated: 
1. Actinicyclus (Kalfsii var.?), Arizonae. ' \ / 
2. Adinocyclus (Kalfsii) Arizonae., , /v ^ 
3. Amphora proteus, Greg. 
4. Denticular tenuis, var. mesolepta, Grum A 
5. Frustulia interposita, Lewis ( frustules ). 
6. Heynaldella anti qua, Kant. var. Arizonae. 
7. Mastogloia elliptica, var. front and side views. 
8. Mastogloia Braunii, Gv un. 
9. Mastogloia Smithii, var, , 
10 Nitzschiu vitrea, .Norm, tr- * h> , , ^ 
11. Navicula Macraeana,V ant. jj-A 
Dr. Arthur M. Edwards, E.L.S., of Newark, N. J., to whom 
1 sent, specimens reported: 
“Examined miscroscopically, this earth is found to he m^ide 
up of the following forms of bacillaria: The commonest is 
Denticula protea (P. A. C. N.). This is> called Denticula lauta 
(J. W. B.), and is found in the celebrated Monterey earth 
of California, which is marine. It is also found in the earth 
of the Yellowstone Park, and likewise living there also. It 
is beautifully figured by A. Grunow in Van IXeurck’s Synopsis 
des Diatoraees de Belgique, Atlas, 1880-1881, where, on 
Planche XLIX, it is given with various names, in just nine 
of them altogether, but they can all be referred to Denticella 
protea, PL A. C. X. There is also present (very common) a 
form that is extremely interesting to students of the bacillaria. 
This is a large disc, marked most beautifully with rays of small 
dots, so that it looks almost like a sun. At first, this seems 
to be a new form or ‘species;/ and was so ranked by me in 
my report on the diatomaceous earths, of the Northwest Bound¬ 
ary Survey, published ten years ago. But it is not new, al¬ 
though it appears so. It is a Cyclotella or Stephanodiscus, and 
is published by A. Grunow as S. carconensis, from Carson City, 
Nevada, and Klamath Lake, Oregon. It is really Cyclotella 
bevolinensis (C. G. E.), and is published in the Bericht for 
1845, and includes Discoplea astrea (C. G. E.) and D. Eorcca, 
C. G. E. They are the sporangia of Melosira granulata, 
