1918] HAUPT—PALLAVICINIA 531 
3. Pallavicinia Lyellii, like the other species of the genus, is 
strictly dioecious. 
4. The antheridia occur in 2 parallel rows on each side of the 
midrib, and are protected from behind by an involucral upgrowth. 
Their development, with minor variations, follows the type for the 
anacrogynous Jungermanniales. 
5. The archegonia are in dorsal groups and are surrounded by 
an involucre and a perianth, the latter remaining inconspicuous 
until after fertilization. 
6. The young archegonial stalk consists of 2 cells. The egg is 
small and the neck long and twist 
7. The lower half of the fentilind egg becomes a haustorial 
organ and contributes nothing to the development of the foot, seta, 
or capsule. 
8. The calyptra is 4 or 5 cells in thickness, in this respect differ- 
ing from that of Symphyogyna. 
9. The differentiation of the spores and elaters occurs relatively 
late in the development of the sporophyte, and follows the method 
of Symphyogyna. 
10. Asterile cap is present at the apex of the capsule and remains 
intact in dehiscence, which is accomplished by means of 4 longi- 
tudinal slits. 
To Dr. W. J. G. Lanp, under whose direction the study was 
undertaken, the writer is indebted for many helpful suggestions and 
criticisms. 
University oF CHICAGO 
LITERATURE CITED 
1. CAMPBELL, D. H., and Wrrt1ams, FitoreNnce, A morphological study of 
some members of the aps ees Leland Stanford Junior Univ. 
Pub., Univ. Series, pp. 44 
2. Cavers. F., The Ss eas of the ran III. Anacrogynous 
Jurigserinscitialae: New Phytol. 9:197-234. 
3- CLapp, Grace L., The life history of Aneura peasy Bot. GAZ. 54:177- 
4. FARMER, I. BRETLAND, Studies in peetenes on Pallavicinia decipiens 
Mitten. Ann. Botany 8:35-52. 1894. 
