— io8— 
77. Physcia pulverulenta (Schaer.) Nyl,, Act. Soc. Li,nn. Bord. 21: 308. 1856. 
A single specimen occurring on moss, on humus, near Coraopolis, Allegheny 
Co., Sept. 9, 1905, O. E. Jennings and G. E. Kinzer. 
78. Physcia pulverulenta leucoleiptes Tuck., Syn. Lich. N. E..32. 1848. On humus 
Montrose, Allegheny Co., Sept. 21. 1905, O. E. Jennings. 
79. Physcia stellaris (L.) Nyl., Syn. Meth. Lich. 1: 424. 1858. On trees, Nixon 
Station, Butler Co., Wm. Millward, Feb. 3, 1917, and on Populus deltoides, 
Presque Isle, Erie Co., four different collections, O. E. Jennings. 
80. Physcia tribacia (Ach.) Nyl., Fl. 64: 537. 1881. On trees. Presque Isle 
Erie Co., on Populus deltoides with Ph. stellaris, Sept. 20-22, 1906, O. E. 
Jennings, and Linesville, Crawford Co., Aug. 3, 1909, O. E. Jennings, 
81. Physcia obscura endochrysea (Hampe) Nyl., Act. Soc. Sci. Fenn. 7: 440. 
1863. A single specimen on bark with Cladonia ochrochlora ceratodes, from 
Idlewild, Westmoreland Co., Aug. 10, 1906, D. R, Sumstine. 
82. Physcia obscura virella (Ach.) Cromb., Grev. 20: 78. 1887. On bark with 
Amphiloma, Conneaut Lake Park, Crawford Co., July 18, 1906, D. R. 
Sumstine. 
Pittsburgh, Pa. 
REVIEWS 
Istvan Gyorffy. — A Molendodk fajai tagoloddsa es rokonsdga osszehasonlito 
anatomiai es fejlodestani vizsgdlatok alapjdn. (A. M. T. Akademia III osztalyanak 
192 1 januar 17. — en tartott iilesebol). 
The above reprint, bearing the pagination 345-351, I have through the 
kindness of Mr. Chamberlain been able to examine, the work dealing with a 
genus of mosses, Molendoa, which I have, also, been studying. It is a Hungarian 
announcement of the author's " Versuch einer Monographic der Gattung Molendoa''' 
upon the preparation of which he has been engaged some seventeen or eighteen 
years and which is now pretty well finished. Some of the essential results are 
here outlined in advance in the author's admirably objective and thoroughly 
scientific manner. Ten previously described species are apparently to be re- 
cognized, in addition to seven new ones mostly credited to Brotherus. The 
latter, which are here nomina nuda, include M. obtusifolia Broth, twice, in the 
one case doubtless a slip for some other name. The author discusses the nature 
of a species, but without dogmatism. He is inclined to conceive of it as a series 
or rather group of forms clustered about a typical center. Uncommon forms 
lying toward the periphery of the enclosing circle may be transition-forms to 
the next species; that is, the two species-circles may slightly overlap, In this 
way he notes three transition-varieties connecting the three European species of 
Molendoa with one another and includes a diagram illustrating the relationship 
of all European forms recognized. He also speaks of forms which seem to lie 
somewhat between Molendoa and Hymenostylium, but rejects the idea that they 
