28 
DR. CARPENTER ON LICHENS. 
Thallophytes parallel to Algae (witli which they correspond in 
their vegetative characters) and Fungi (to which they are more 
allied in fructification), they are really to be regarded as composite 
structures, haying an algal base, on which ascomycetous fungi 
have sown themselves and live parasitically.” 
Then follows a page and-a-half on the subject, but not a word, 
not a hint, that these views are not accepted by at least a respect- 
able number of cryptogamic botanists, including some of whom 
many of us, Dr. Carpenter notwithstanding, are inclined to regard 
as among the “ highest authorities.” 
Doctor Carpenter further says the Lichens “do not furnish 
objects of interest to the ordinary microscopist.” I venture to say 
that few objects better repay study, and that the peculiar density of 
their structure, which he says renders their minute examination 
more than ordinarily difficult, should not deter any one from enter- 
ing into a field where workers are especially needed. 
Yours obediently, 
RICHARD B. CROFT, 
Hon. Sec. Hertfordshire Natural History Society. 
NEW ZEALAND DESMIDIE.E.* 
By William Archer, F.R.S., Hon.F.R.M.S. 
This is an interesting contribution to our knowledge of Des- 
midian forms, and lends aid to sustain the assumption that very 
many of these are cosmopolitan ; it is possible, however, that some 
of the author’s identifications of certain species may not be 
thoroughly correct. 
Whilst it may probably be the more correct course to relegate 
Aptogonum-species to the genus Desmidium, the difference being 
only the so-called foramen, that is to say, the lenticularly-shaped 
open interval between the constituent joints of the filaments, at 
least Aptogonum undulatum , Maskell, is a highly remarkable form. 
The joints appear to be triangular, two of the aspects alike, and 
different from the third, causing the end view to appear asymme- 
trical. Amongst all the Desmidieas there appears scarcely a similar 
case, if we except Cosmarium obliquum , Nordstedt, an inconspicuous 
and very unattractive form of great rarity, and otherwise altogether 
unlike Mr. Maskell’s plant : it appears undoubtedly quite distinct 
from D. Desmidium , or D. Baileyi. 
Sphcerozosma vertebratum, S. excavatum , and S. jilifoimne all 
occur in New Zealand. It is curious to note that S. excavatum is 
rare in New Zealand. It is exceedingly common in these countries, 
and, as at the Antipodes, it is “ excessively fragile,” that is, the 
* “ Contributions towards a List of the New Zealand Desmidieae,” by 
W. M. Maskell, F.R.M.S. (Read befoi'e the Philosophical Institute of 
Canterbury, 7th Oct., 1880.) 
