148 Lloyd and Underwood : A Review of the 



tropical species, also enters our Gulf States. To these Mexico 

 adds seven species, of which L, s erratum, originally described 

 from Japan, is very doubtfully Mexican, and the rest are species 

 of the West Indies. These islands add six more, of which Z. 

 rigiduui is endemic and the others are species of wider range through 

 tropical America. South America has some forty-one species, of 

 which twenty nine are endemic and of these twenty-one are con- 

 fined to the Andean region ; two are also. African, two North 

 American and the rest are neotropical. 



Asia follows with twenty-six species, of which two are endemic 

 in Japan and four in India ; of the others, ten (including the five 

 circumboreal species) are also found in the United States, nine in 

 the East Indian Islands, and four in Polynesia. Africa has only 

 thirteen species, of which eight are endemic ; of these five are from 

 the mountains of Madagascar. The East Indies have eighteen 

 species, of which four are endemic ; ten are species of the adjacent 

 Asiatic mainland, and four are shared with Polynesia. Australasia 

 has thirteen species, of which eight are endemic. Polynesia has 

 nine species, of which only one, L. polytrichoides, is endemic in the 

 Hawaiian Islands. Finally, the little island of Tristan d'Acunha 

 has two species, both endemic. 



The American species north of Mexico may be separated by 

 the following key : 



Plants with mostly upright stems with alternating zones of leaves and sporophylls 



(strobiles interrupted). 



■ 



Leaves hollow at their bases and appressed. I. L. Selao-o. 



Leaves flattened at their bases and ultimately more or less reflexed. 

 Leaves linear or nearly so, entire or very minutely denticulate. 



2. L. porophihwi. 

 Leaves distinctly broadest above the middle and erose. 



3. L. liuiihduffi. 



Plants with more or less extended horizontal stems ; the sporophylls aggregated into 



terminal strobiles. 



Sporangia subglobose ; sporophylls similar to the foliar leaves. 

 Sporophylls short ( 5-6 mm. ). 



Sporophylls deltoid, mostly entire ; plants small. 



4. L. inundatum. 

 Sporophylls contracted above the base with a few teeth ; plants large. 



5- L. arfpressum. 

 Sporophylls longer (8-10 mm.), usually much toothed. 



Leaves in many rows, radially arranged ; stems arching. 



6. L. alopecitroides. 



