552 
GEOCHEMISTRY: CLARKE AND WHEELER 
logues of the parabasals of the trichomonads. The extranuclear organ- 
elles are united with the karyosome, centrosome, and blepharoplast in 
an integrated neuromotor apparatus. Mitosis is intranuclear, with 
precocious splitting of the four chromosomes which subsequently fuse 
in four in the equatorial plate. Free pairs of individuals are found united 
in back-to-back position as in the so-called conjugation cysts. Nuclei 
in these cysts undergo two divisions simulating reduction divisions in 
which, however, chromosomes reduction has not been demonstrated. 
No evidence in support of autogamy and no proof of sexual reproduction 
has been discovered. 
Morphological characters separate six species in Giardia. The para- 
site in mice appears to be distinct from that in man. The generic name 
Giardia Kunstler should supersede Lamblia Blanchard on grounds of 
priority. 
LITERATURE CITED 
Alexeieff, A., 1914, Notes protistologiques, ZooL Anz., Leipzig, 44, 193-213, 5 figs, in 
text. 
Hartmann, M., 1910, 'Protozoologie' in Kisskalt and Hartmann Praktikum der Bak- 
ieriologie und Protozoologie (Ed. 2) (Fischer, Jena), ii-f-106 pp., 76 figs, in text. 
Kofoid, C. A., and Swezy, O., 1915 a, Mitosis in Trichomonas. These Proceedings, 1, 
315-321, 9 figs, in text; 1915 b, Mitosis and multiple fission in trichomonad flagellates. 
Proc. Amer. Acad. Arts Set. (In press). 
Noc, F., 1909, Observations sur la cycle evolutif de Lamblia intestinalis. Bull. Soc. Path. 
Exot., 1, 93-97, 14 figs, in text. 
Prowazek, S. v., and Werner, H., 1914, Zur Kenntnis der sog. Flagellaten, Arch. Schifshyg., 
Leipzig, 18, Beiheft 5, pp. 155-170, pi. 10, [1] fig. in text. 
THE INORGANIC CONSTITUENTS OF ALCYONARIA 
By F. W. Clarke and W. C. Wheeler 
UNITED STATES GEOLOGICAL SURVEY. WASHINGTON 
Presented to the Academy, September 15. 1915 
The zoantharia, madreporaria, or stony corals have been repeatedly 
analyzed, and with generally concordant results. Thirty analyses, made 
in the course of the present investigation, of which this paper is a pre- 
liminary notice,^ have confirmed the older data. These corals consist 
mainly of calcium carbonate, with one or two per cent of minor impu- 
rities, and a little organic matter. The same is true of the coralline 
hydrozoa, of which six analyses, representing the genera Millepora and 
Distichopora, have also been made. The alcyonaria, however, which 
include the red corals, the gorgonias, and other fan-like or branching 
forms, are quite different; and they are generally characterized by the 
presence in them of magnesium carbonate, and often of calcium phos- 
