58 
reported upon by myself. His descriptions of American speci- 
mens, with few exceptions, embrace nothing that is either new 
or rare; he has been surprised into applying these adjectives to ° 
the immature or arrested growths and partial developments of 
plants previously described and classified. A few illustrations :— 
The plant he designates as Leptozosma catenula, and for 
which he makes a new genus, is the undeveloped form of an old, 
well known species, Desmidium quadratum, which did not escape 
my attention when examining the material collected at Malaga, 
N. J. At first sight it struck me as a novelty, and not until 
many specimens were observed did the facts become evident. 
The process of development of the Desmidie@ is similar to that 
of the Bambusine, which is concisely represented in my Desmids 
U.S. (Compare p. 24, Plate I, Figs. 15-25.) The filaments are, 
primarily, entirely distinct in appearance from the mature plants. 
Unless traced through the various stages of growth they cannot 
be recognized. The same difficulty occurs with immature speci- 
mens of Desmidium cylindricum, they are entirely unlike the 
mature plants. 
The form of Desmidium qiadratum from the pond at Malaga, 
differs somewhat from the one illustrated, (I. c. Plate XLIX.) 
The cells are more quadrangular, angles sharper, not so rounded, - 
and ends more suddenly attenuated by incurved lines; suture 
thick. These, like all other Desmids, are liable to many minor 
modifications, without destroying the specific character. 
Cosmarium rostratum, n. sp., is the same as C. aculeatum, 
(Il. c. Plate XVI., Fig. 15.) My description reads, “ primarily more 
or less densely aculeated; later the aculei drop off” (p. 66.) 
When the description was written I had seen comparatively few 
specimens. The more usual appearance is with three or four 
small spines on or near the end of the cell, but indications of the 
existence of more can almost always be seen. My illustration’ 
represents, perhaps, an exception, rather than the ordinary form, 
hence I can readily see how Mr. Turner was misguided. 
Euastrum Floridanum, n. sp., is not new; itis &. ventricosum, 
Lundell. After careful examination of many specimens, I have 
satisfied myself that it cannot be separated from Lundell’s form 
(vide Des. U.S. p. 160). Single specimens may indicate some 
