﻿Howe: New American Hepaticae 189 



Riccia lamellosa Raddi, Opusc. scient. di Bol. 2 : 351. ^/. r$.f. 



2. 18 18. 



Var. Americana. Spores brown, 75-126 fi in maximum 

 diameter, obscurely angular, wholly destitute of a wing-margin, 

 with 8-12 clearly defined areolae, each about 15 a in width, across 

 the outer face, the inner faces marked with much smaller and less 

 distinct areolae or simply with irregular vermicular lines. 



California: San Francisco (Bolander, Howe); Fruit Vale, 

 Alameda Co. (Miss Edith S. Byxbee). New Jersey: Closter 

 (Austin). Alabama: Mobile (Mohr). 



The principal peculiarity of the spore of the American R. lam- 

 ellosa was first remarked upon by Professor Underwood (Bot. Gaz. 

 19 : 274. 1894). The European plant has distinctly wing- 

 margined and plainly angular spores, and the markings of the 

 inner and outer faces are nearly uniform ; the ridges of the outer 

 face are more vermicular than in the var. Americana and less often 

 form perfect areolae, and w r hen the areolae are well defined, they 

 are smaller and more numerous, 14 or 15 measuring the diam- 

 eter of the outer face. For comparison we have made use of a 

 specimen from Florence, Italy (the type locality), and one from 

 Sicily, both kindly communicated by Dr. E. Levier. 



The Alabama and New Jersey specimens show practically the 



same characters as the Californian with the exception that the 



spores of the latter are larger, ranging from 90-126/i in greatest 



diameter, while in the eastern and southern plants they measure 



but 75-100//. The Californian plant appears to produce capsules 

 rather sparingly. 



ASTERELLA LATERALIS.* 



Thailus simple, or innovating latero-ventrally or in front, 

 mostly oblong to linear, 7-25 mm. x 1.5-4 mm., rather effusely 

 costate-carinate, about 25 cells thick in the middle, becoming 

 very thin at the broad, brownish or decolorate and subpellucid, 

 lightly undulate-crenulate margins, somewhat flatly and narrowly 



* In accordance with the later practice of Lindberg and others, we use Asterella 

 (Pal. de Heauv. , 1810) for the genus to which Nees in 1820 gave the name Fimbri- 

 aria. Asterella ', as has been recently pointed out by Professor Underwood (Bot. Gaz, 

 20 : 59. 1895), is the name of this group, whether by the " method of residues n or 

 by application to the first species cited under it by its author. 



