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parva Card, from the second Mexican locality above. This identification is 

 undoubtedly correct, except that the specimen of T. parva in the herbarium of 

 the New York Botanical Garden is a mixture of a fruiting species without pro- 

 pagula and another with abundant propagula and no fruit.^ Cardot's descrip- 

 tion^ is identifiable with the former; the latter is, so far as I know, undescribed. 

 Mr. Williams does not regard the Mexican plant as of the same species as the 

 North Carolina one, and geographically the case is remarkable, though not with- 

 out parallel. I can see only slight quantitative differences and do not at present 

 feel justified in calling the Mexican plant a further new species. The Mexican 

 specimens are somewhat smaller in all parts, the leaves less sharply apiculate, 

 the cells very slightly smaller, the papillae rather more prominent and larger, 

 especially on the dorsal leaf-surface, where the crescent-shape is generally dis- 

 placed by a full ring. The propagula are short, so far as observed, of hardly 

 more than 5 segments, often of less, but otherwise quite like the North Carolina 

 ones. Further collections in the future may show whether these slight differ- 

 ences are of greater value than I have set upon them. For the present the very 

 close relationship between the plants from the two localities is the point demand- 

 ing emphasis. That the plant has not previously been collected in the United 

 States is remarkable, but our southern states probably still contain undiscovered 

 material of bryological interest and habitually sterile species are easily passed 

 by. So far as my observations go the plant appears to ascend the mountains 

 from the eastern Blue Ridge side. The case was clear at Grandmother Gap, 

 where it had reached about 4000 feet altitude. It also occurred at somewhat 

 lower altitudes down the eastern slope, but appeared to be entirely lacking 

 west of the region immediately about the gap itself. The other two North 

 Carolina localities are, it is true, along a water-system draining to the westward, 

 but Swannanoa Gap is low and I suspect that the plants along the Swannanoa 

 Valley may have arrived by the eastern route. The station at Swannanoa it- 

 self was within reach of high water and the plants showed much intermixture 

 of silt; those of the North Fork were probably beyond the reach of floods and 

 showed the longest plants; those of Grandmother Gap were remote from any 

 water course. The propagula were relatively more detached in specimens 

 from the two later collections. Those of the first were already partly detached, 

 but for the greater part held their positions on the leaves. The seasonal develop- 

 ment is naturally different in Mexico, and in fact evidently did not correspond 

 in the two localities, as, though both were gathered during the same month of 

 the same year, those of Etzatlan had quite shed their propagula, while those 

 from Cuernavaca had them rather firmly attached in position of origin. 



It is to be presumed that the plants are dioicous, but probably do not com- 

 monly fruit. T. papulosa has never been found in fruit in Europe. Even with- 

 out fruit the genus of the plants can hardly be regarded as doubtful. 



®My own set of Pringle's Mexican mosses lacks T. parva; a bit of the material of this species 

 from the set in the Farlow herbarium at Harvard University, which I owe to the kindness of Prof. 

 Riddle, shows apparently clear T. parva without intermixture of T. caroliniana. 



^Revue Bryologique, XXXVI, 88, 1909. 



