ARCHER, ON MICRASTERIAS MAHABULESHWARENSIS. 259 
have its own name, and do not confuse the student by a too 
copious and arbitrary employment of Greek letters. 
These “ultimate forms” (‘“ species” to me) conjugate only 
with each other—in the few instances which have been traced 
so far, they reproduce their exact like from the spore—they 
seem always readily distinguishable one from another; there- 
fore I conceive that with those who would arbitrarily com- 
bine certain groups of them together (not indeed generically, 
but) under a common specific name, rests the onus probandt 
as regards the opposite side of the question. 
To revert, then, to the forms included by Dr. Wallich 
under one common specific name, M. Americana, M. Bailey:, 
M. ringens, and his var.6. The second and third forms, 
M. Baiieyi, and M. ringens, seem to be excluded from the im- 
mediate affinity at least of the first and fourth, by the want 
of the curious additional obliquely disposed, more or less 
nearly vertical processes, one springing from each of the 
front surfaces of the terminal lobe, characteristic of the 
latter. Now, it seems to be hardly admissible, in order to 
fit them in here, to presuppose the existence of these pro- 
cesses merely from a certain amount of agreement in general 
contour, and the more so, as they are neither alluded to 
nor figured in their original descriptions by either Bailey 
or Ralfs.* If these authors did not see them, then, it is to 
be presumed they did not exist. Moreover, these two forms 
themselves seem to be distinguished from each other by 
M. Baileyi being punctate all over, while M. ringens is with- 
out puncta, and possesses a marginal series of granules bor- 
dering the sinuses. Irrespective of these characters, how- 
ever, unless the non-reconcileable intermediate forms be 
discovered, these two forms as figured and described, if per- 
sistent, as Professor Bailey seems to convey, appear to me to 
represent quite distinguishable species, not only from the 
two other forms with which Dr. Wallich has associated them, 
but also from each other. In regard to M. Americana and 
Dr. Wallich’s var. 6, equivalent to M. Mahabuleshwarensis 
(Hobson), both of which indeed agree in possessing on the 
end lobe the secondary processes springing more or less ob- 
liquely as regards the plane of the frond, it yet seems to me 
that here even more abundant differences inter se actually 
exist. The former occurs in this neighbourhood (rarely, 
however), and I feel pretty well acquainted with it, and I 
must own that I should be beyond measure astonished to en- 
counter the latter in our Dublin pools; but, even supposing 
* Bailey, loc. cit., p. 27, Pl. i, fig. 11; and Ralfs, op. cit., p. 211, t. 
XXxV, fig. 4. 
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