386 Evans : New West Indian Lejeuneae 



and 



m 



On account of its ten -keeled perianth B. bahamcnsis belongs to 

 a group of four closely related American species, all characterized 

 by this peculiarity. The other species belonging to this group are 

 B. densifolia (Raddi) Evans, B. chinantlana (Gottsche) Schiffn., and 

 the recently described B. insularis Evans.* B. densifolia is widely 

 distributed in South America and has also been reported from the 

 West Indies ; B. chinantlana was originally described from Mexi- 

 can specimens but has recently been found in the mountains of 

 Jamaica ; B. insularis is known from Cuba, Jamaica, and Puerto 

 Rico. Of these four species B. densifolia and B. chinantlana are 

 at once distinguished from B. bahamcnsis by their larger size 

 more or less pointed leaves ; B. densifolia is further characterized 

 by being dioicous, and B. chinantlana by being paroicous. In B. 

 insularis the inflorescence is also paroicous, but this species comes 

 uch closer to B. bahamensis than the others on account of the 

 rounded lobes of its leaves. It is, however, more robust, many of 

 the vegetative branches conform to the Frullania type, the basa* 

 auricles of the underleaves are much better developed, and the mar- 

 gins of the lobules have more numerous and often more irregular 

 teeth. 



Symbiezidium laceratum sp. nov. 



Brownish green, growing in depressed mats, similar in genera 

 appearance to S. transversale : stems o. I 5 mm. in diameter : leaves 

 imbricated, the lobe obliquely spreading, sometimes plane, some- 

 times slightly convex along antical border and concave along poe- 

 tical, rarely revolute at the apex, scarcely falcate, ovate-oblong, L*" 

 1.3 mm. long, 0.7-075 mm. wide, antical margin rounded at base 

 and arching partially across axis, then slightly outwardly curved 

 the broad and rounded apex, postical margin straight or nearly so. 

 margin entire or irregularly sinuous in apical region ; lobule w ^ 

 well developed ovate-lanceolate in general outline, 0.3 mm. lov 

 0.15 mm. wide, strongly inflated in basal half; cells of lobe av- 

 raging 23 pt at the margin, 30 ft in the middle, and 35 X 3°^ at 

 base, trigones and intermediate thickenings conspicuous : un 

 leaves imbricated, plane or nearly so, broadly orbicular, 0.7 n ^' 

 long, 0.95 mm. wide, sometimes abruptly cuneate and short -dec : 

 rent at base but usually with the margin in this region strtUg^ 

 and meeting the axis at approximately a right angle, apex bro^ 

 rounded or truncate, often slightly sinuous, margin other* 



*For noteson these species, see Evans, Bull. Torrey Club 35: r5 8 ~ l61 * 



908 



