﻿260 Evans: The genus Plagiochasma 



Between 1838 and 1846 Sassi (27) proposed Anthrocephalus 

 italicus as a new species, his material having been collected near 

 Finale in Liguria, and the following species of Plagiochasma were 

 published: P. Rousselianum Mont. (23, p. 334, pi. p, f. i), of 

 western Algeria; P. chlorocarpum (Nees & Mont.) Mont. (24, p. 

 59), of Chile; and P. validum Bisch. (3, p. 56, pi. 56, f. 2753), also 

 of Chile. The number of species was thus increased to two in 

 Anthrocephalus and to seven in Plagiochasma. 



In 1846 the part of the Synopsis Hepaticarum which treated 

 the Marchantieae appeared (11, pp. 511-521) and the authors of 

 this important work showed that the genus Anthrocephalus was 

 based on poorly developed specimens of a Plagiochasma, which 

 they renamed P. Colsmannianum Lehm. & Gottsche, thus dis- 

 carding Lehmann's specific name nepalensis altogether. For some 

 reason they make no mention of A . italicus, possibly because Sassi's 

 work was unknown to them. In addition to P. Colsmannianum 

 and the seven species of Plagiochasma already known they include 

 the following species in the genus: P. intermedium Lindenb. & 

 Gottsche, of Mexico; P. australe (Tayl.) Nees, of New Zealand; 

 P. limbatum (Tayl.) Nees, of Ascension Island; P. elongatum 

 Lindenb. & Gottsche, of Mexico; and P. mexicanum Lindenb. & 

 Gottsche, also of Mexico. They thus increased the total number 

 of species to thirteen. 



In 1849 a posthumous work of Griffith was published in which 

 four news species of Plagiochasma from India were described (12, 

 PP- 330. 331. 337» P^- 65, 68, dge), namely: P. paradoxum Griff., 

 P. pedicellatum Griff., Anthrocephalus polycarpon Griff., and A. 

 megacarpon Griff. In 1856 Sullivant (38, p. 688, pi. 6) published 

 P. Wrightii, a new species from Texas. In 1859 DeNotaris (5, 

 p. 476, pi. j) showed that Anthrocephalus italicus was clearly 

 a species of Plagiochasma and transferred it to the latter genus 

 under the name P. italicum. In 1863 Gottsche (10, p. 266) 

 described a new species of Plagiochasma, P. crenulatum, from 

 Mexico. In 1869 Austin (i, p. 229) described, as a new species, 

 P. erythrospermum Sulliv., from the Rocky Mountains. 



In 1868 Lindberg (20, p. 291) revived the generic name 

 Aytonia of Forster and secured a number of followers in both 

 Europe and America. He spelled the name " Aitonia," which was 



