68 THE JOTJEIfAL OF BOTANY 



S. nic/rella (De Not.) Spr. with a very little younger growth o£ the 

 same hepatic growing with it. The specimen is very scanty, but in 

 so marked a species is amply sufficient for the purposes of identi- 

 fication. 



The genus Soutlibya was founded by Spruce in 1849 (Ann. Mag. 

 Nat. Hist. 2 s. iii. 501) in his paper on the Musci and Hepaticse of 

 the Pyrenees to commemorate his friend Dr. Anthony Southby, who 

 travelled with him in that region, for the reception of his S. tophacca^ 

 which he believed to be a new species ; this has since been shown to 

 be identical with Jungermannia scalaris (3 stillicidiorum Eaddi 

 (1817). The name Southhya has been used by various authors, but 

 as limited to the present species and S. stiJJicidioomm (Raddi) Lindb. 

 it appears to form a natural genus between Aliciilaria and Haplozia, 

 distinguished from both and from Eucalyx by the opposite leaves. I 

 append a descrij^tion : — 



SouTHBTA NiGBELLA (Dc JSTot. ) Spr. Paroicous. In dark green 

 to blackish tufts. Stem procumbent, oval in transverse section, 

 broader than it is high, often forked, upper surface almost flat, under- 

 surface semicircular in section ; rhizoids abundant and long, at first 

 hyaline but turning brown later. Leaves opposite, closely approxi- 

 mate, imbricate, almost cu'cular, broadest at the base, olive green, 

 sometimes almost black on the margin, which is often recurved and 

 sometimes obtusely toothed, folded inwards when dry, showing the 

 black shining undersides. On the under surface of the leaves near 

 the antical margin there is generally a finger-shaped appendage. 

 Leaf-cells thin-walled, angles not thickened, 24 /i at the apical mar- 

 gin, wider in the middle, longer and narrower on and near the postical 

 margin towards the base; cuticle more or less papillose. Under 

 leaves absent except in the immediate neighbourhood of the perianth. 

 Involucral bracts larger than the leaves, erect, concave, coarsely 

 toothed, adherent to one another, and to a smaller extent to the 

 perianth. Perianth small, scarcely equalling the involucral bracts, 

 plicate, irregularly lobed towards the apex ; lobes coarsely toothed, 

 bleached, stem somewhat bulbous below the perianth. Capsule 

 almost spherical, brown. Spores reddish brown, 15 to 18 /x, maturing 

 in the spring. 



Hah. Detritus of disused quarry, Portland. 



>S'. nigrella is not likely to be confused with any other British 

 hepatic. It has some superficial resemblance to Aliciilaria scalaris 

 (Schrad.) Corda, but it is distinguished from this by the darker 

 colour, the opposite leaves, the absence of under leaves except in the 

 immediate neighbourhood of the perianth, and the black colour of the 

 underside of the leaves, which gives the plant a verj^ peculiar and 

 characteristic appearance when dry, somewhat recalling that of Riccia 

 nigrella. Moreover, the Aliciilaria is a plant of siliceous soils, 

 while the present plant is confined to those which are calcareous. It 

 is distinguished from S. stillicidiorum by its darker colour and par- 

 ticularly by the black underside of the leaves, the appendage on the 

 underside of the leaves, the more closely ajDproximate leaves, and the 

 paroicous inflorescence. 



