-36- 



ing thallus, with less acute apices and rather more pronounced anterior sulcus, 

 in the red-violet instead of black-purple scales, in the apparent absence of special 

 "oil-body" cells, in the more elevated antheridial ostioles (50-160/^ vs. 0-50^), 

 in the more apiculate and more persistent cells of the primary epidermis, in the 

 usually larger (mostly lyi diameters) cells of the secondary epidermis, in the 

 more regularly seriate arrangement of these and the subjacent cells when viewed 

 from above, in the violet-black and soon opaque instead of brown and rather 

 translucent spores; and the spores of R. McAllisteri, except in the younger stages, 

 impress one as echinulate rather than areolate; short spines or papillae are finally 

 developed in R. dictyospora, but they rarely reach a length of 5/j. 



RiCCiA viOLACEA M. A. Howe, Ann. Missouri Bot. Gard. 2: 51. 1915. 



Since the type of Riccia violacea was collected on Mona Island, between 

 Porto Rico and Santo Domingo, in 1914, by Britton, Cowell and Hess, the species 

 has been found by Dr. Britton and associates in two more Porto Rican localities, 

 namely, Salinas de Guanica {Britton, Coivell, & Brown, 4919) and Cayo Muertos 

 {Britton, Cowell, of Brown, 5089). And what appears to be the same thing from 

 the Bay of Mariel, Province of Pinar del Rio, Cuba, where it was collected by 

 N. L. Britton and F. S. Earle, Sept. 21, 1910 {no. 7594)< has been discovered 

 among the undetermined West Indian Hepaticae in the collections of the New 

 York Botanical Garden. The species is, accordingly, now known from four 

 stations, representing four West Indian Is'ands, if two small " Keys" are counted 

 as islands. As the plants are very small (1.5-4.0 mm. long and 0.6-1. 15 mm. 

 wide) and easily overlooked, it now seems reasonable to suppose that critical 

 field work might show the species to be widely distributed in the West Indian 

 region. The new material permits the addition of certain characters that were 

 unknown at the time of publishing the original description. Few well-developed 

 archegonia and few spores have been seen, but it seems nearly certain that the 

 species is dioicous; at least, numerous plants have been seen that appear to bear 

 antheridia only, while most of the Cuban material appears to bear abortive or 

 unfertilized archegonia only. The antheridial ostioles are elevated 20-150/* 

 and are often violet. The spores, seen sparingly in the Salinas de Guanica 

 specimen after cultivation at the New York Botanical Garden, are soon fuscous 

 and very opaque, 80-105/1 in maximum diameter, obscurely angled or flattened- 

 sphaeroid, destitute of wing-margins, finely, irregularly, and almost uniformly 

 areolate over the whole surface, the areolae 7-1 im wide, soon very obscure and 

 the spores appearing minutely and densely verruculose, the verruculae obtuse 

 or truncate, 2-4/1 high. 



In studies of the terrestrial Ricciae, it is of great advantage to have access 

 to living material, and it is especially illuminating to have closely related species 

 and forms growing side by side as has been done for two years or more in the 

 Propagating House of the New York Botanical Garden. I am greatly indebted to 

 readers of The Bryologist for kindly supplying living material of various species 

 and I would earnestly solicit a continuance of these favorsduring the coming season. 



The New York Botanic.\i. Garden, 

 Bronx Park. New York City 



