136 



Avrainvillea sordida. The reviewer believes that a study of what 

 is presumably the original specimen would convince them that 

 no such unhappy step will be necessary and also that longicaulis 

 is the legal specific name for the plant that they are calling 

 Avrainvillea Mazei. The flabellum filaments of the Sonder 

 plant have a diameter of 28-55JU, while those of A. levis (A. 

 sordida) have a diameter of 6-24^1. Filaments with slender 

 rhizoidal endings of the size and nearly the form figured by Kiitz- 

 ing may be found in the stipe of the Sonder plant as well as 

 in the stipes of most of the plants that are referred to A . Mazei. 

 The true explanation of the peculiar character of the filament 

 figured by Kiitzing is probably that although the filament may 

 have come from the "Phyllom" as alleged, it came from so near 

 the stipe as to have the characters of the stipe filaments. Fur- 

 thermore, the natural-size figure given by Kiitzing, although the 

 bifid flabellum depicted is rare and abnormal, has decidedly the 

 habit of plants of the species called A. Mazei by the authors of 

 the monograph and not the habit of plants of the species called A. 

 sordida. 



Under the discussion of Penicillus one finds the unexpected 

 statement that the specimen in the British Museum issued as 

 no. 1482 of the Phycotheca Boreali- Americana under the name 

 Udotea congliitinata represents a diminutive and deceptive state 

 of Penicillus capitatus. Mr. F. S. Collins in "The Green Algae 

 of North America" has recently referred this number to Udotea 

 cyathiformis and the present reviewer agrees with Mr. Collins 

 in this determination. The specimen under this number in the 

 New York Botanical Garden set of the Phycotheca is, like that 

 in the British Museum, diminutive and possibly a "starveling," 

 but the reviewer has seen and collected several intermediates 

 between this condition and the larger explanate states of Udotea 

 cyathiformis. The last-named species is often strikingly Penicil- 

 lus-\\k& in its structural characters, being scarcely more than a 

 Penicillus with a cup-shaped or much flattened head, though 

 its filaments are more coherent than in any recognized species of 

 Penicillus. 



Borgesen's "ingenious" but unsupported theory that Clado- 



