THREE NEW LASTREAS FROM ASSAM. 327 



the shortest ; sori one to each group of veins on lowest veinlet near 

 the costa, which veinlet in fertile lobes points to the sinus, but often 

 stops considerably short of it or is obscure beyond the sorus, but in 

 barren lobes may be prolonged like the others, or rarely 2-3 in 

 lowest pair of lobes : involucres entire, persistent. 



Collected by Mr. Gustav Mann, Conservator of Forests, Assam, 

 in Assam — in Bor Bhil, Upper Dehing Forest, Lakhimpur, April, 

 1887; in the Garo Hills, at 1000 ft. elevation, "on wet rocks ! " in 

 April, 1888, and November, 1889 ; and in the Nambar Forest, in 

 January, 1888. Appearance, when pressed, somewhat like that of 

 Asplenium (Athyrium) nigripes Mett. 



Nephrodium (Lastrea) subtriangulare, n. sp. — Caudex 

 erect, densely clothed with linear chestnut scales ; stipes tufted, ^ 

 wiry, as long as or longer than frond, round below and slightly 

 channelled above, as is also the main rachis, clothed at base with 

 dark brown linear lanceolate scales longer than those on caudex, 

 sparser and paler upwards ; main and secondary vacldses slightly 

 squamiferous, secondary rachises grooved above and on sides, round 

 below ; frond 14 in. long by 10 in. broad, very broadly lanceolate- 

 acuminate, bipinnate ; pinna opposite at base of frond, gradually 

 becoming alternate upwards, 8-10 pairs free, lanceolate-acuminate, 

 falcate, all unequal-sided, and all except lowest pair very slightly 

 narrowed at base ; lowest inferior pinnules on lowest pinnae very 

 much shorter than next three or four ; pinnules numerous, lower, — 

 subsessile, with slightly winged stalks, upper, — sessile, gradually 

 becoming decurrent on rachis, and towards apex confluent : pinnules 

 lanceolate, falcate, rather blunt-pointed, the entire apex slightly 

 toothed ; lobes or segments inclosing groups of veins increasingly 

 distinct towards base of pinnule till the dividing sinus sometimes 

 nearly reaches costa, usually with only one tooth corresponding to 

 uppermost veinlet of group, and that pointing upwards and some- 

 times inwards to next lobe above, so as to lie within general outline 

 of pinnules ; texture herbaceous, surfaces glabrous ; veins invisible 

 above, except costaa, not raised beneath, pinnate or rarely bipinnate 

 in lobes, and terminating within the margin ; sori — on upper pinnaa 

 uniserial, near the costa on inner veinlet of each group of veins, — 

 on lower pinnaa becoming more copious, and borne on both sides of 

 main vein of segment ; involucres entire, shrivelling, dark-coloured. 



Collected by Mr. Gustav Mann, Conservator of Forests, Assam, 

 in Assam, at Laukot, southern face of Khasi Hills, 800 ft. elevation, 

 in September, 1888, and in the Jaintea Hills, at 3000 ft. elevation, 

 in March, 1890. Mr. Mann says the plant is rather rare, and he 

 would place it between Nephrodium [Lastrea) assamense (Hope) and 

 N. [Lastrea) Filix-mas (Rich.), var. 2 normalis (Clarke in Trans. 

 Linn. Soc, 2nd Her., Dot., vol. i., p. 519). The present species 

 seems to me, however, quite different from X. assamense, and it can 

 be easily distinguished from Clarke's plant by the scales, shape of 

 frond and cutting of the pinnules, by the veins, and by being 

 Boriferous on all the pinnae. In Clarke's fern, which has no affinity 

 to N. Filix-mas, and which was previously named by Moore, from 

 Beddome's specimens, Lastrea odontoloma, sori are never found on 



