19 



is almost indispensable to make drawings to a uniform scale, by means of the camera lucida, 

 of the frond filaments of almost every specimen examined. But owing to the collapsed state 

 in which the filaments are often found in dried material, especially when the plants have been 

 subjected to heavy crushing pressure by the zealous but misguided collector, it is usually 

 advisable to submit the filaments to such a treatment as the following. First soak the fragment 

 of frond in spirit for a few seconds, then in water for half an hour, then in lacto-phenol 

 (warmed) for about half to one hour (or boil in lacto-phenol on slide), replace in water and 

 tease asunder the filaments under a dissecting microscope. This treatment will in many cases 

 go far towards restoring the filaments and will generally facilitate the teasing of them apart. 

 Under the name of "Aurainvillea spec." Prof. Oltmanns (Morph. und Biol. d. Algen 

 I. 1904 p. 292, fig. 179; II. 1905 p. 278, fig. 538) has represented a remarkable plant (sine 

 loc.; comm. G. Karsten), which we regret that we are unable to recognise. lts frond is not 

 flabelliform, but cylindric in outline and apparently composed of loose spreading filaments. 

 The stipes recalls that of Avrainvillea ; but the frond or capitulum is a puzzle. We can only 

 suggest that it might possibly be an abnormal form of A. crecta, a species which, as Fergusox's 

 specimens from Ceylon show, sometimes assumes abnormal shapes and has a fringed margin. 

 Possibly Prof. Oltmanns' plant is one which has undergone regeneration after injury, for example, 

 after the loss of the frond (see p. 32). 



Avrainvillea Decaisne 



in Arm. Sci. Nat. Bot. 2™ Sér. XVIII. 1S42. p. 108. 



Syn. Fradelia Chauvin Recherches... Caen 1S42. p. 124. 



Chloroplegma Zanardini in Mem. Ist. Veneto. VII. 1858. p. 290. 

 Avrainvillea J. G. Agardh Til! Alg. Syst. V. 1887. p. 51. 



Avrainvillea Murray & Boodle in Journ. of Bot. 1889. p. 67. (excl. Chlorodesmis). 

 Avrainvillea De Toni Syll. Alg. I. 1889. p. 513. 



Aurainvillea Wille in Engler und Prantl naturl. Pflanzenfam. I. Teil, 2. Abteil. 1890. p. 141. 

 Avrainvillea Howe in Buil. Torrey Bot. Club XXXIV. 1907. p. 50S. 

 Avrainvillea Collins Green Alg. N. Amer. in Tufts College Studies II. 1909. p. 3S9. 

 Avrainvillea Wille in Engler und Prantl naturl. Pflanzenfam. I. Teil, 2. Abteil. Nachtrage. 

 19 10. p. 128 {excl. Chlorodesmis). 



Plant uncalcified, fusco-nigrescent, green to olivaceous or fulvous, usually flabelliform 

 and stipitate, rarely eflabellate and composed of clavate or difform lobes [A. Rawsoni). 



Rhizoids tufted, forming a bulbous mass or sometimes a creeping or ascending or 

 erect rhizome. 



Stipes simple, forked, or more divided, short to long, sometimes much abbreviated, 

 stout or slender, terete or flattened. 



Frond of varied shape (even in the same species), more or less rotundate to flabelliform 

 or cuneate, at base cordate or truncate to cuneate, rarely palmate or digitate, thick to thin, 

 sometimes zonate, margin entire to eroded or lacerate or lobed. 



Frond filaments Varying in size, colour, and form, but usually fairly uniform for the 

 species and almost always characteristic of it, dichotomously branched, constricted at dichotomies, 



