ON A NEW GENUS OF FERNS. 167 
the often fugacious nature of that organ, and judging from 
analogy and habit, I was led to the conclusion that the sori 
were furnished with indusia, and that it was an undescribed 
species of Oxygonium. I had no reason to doubt this view 
being a correct one, till lately, when my attention was 
again directed to this genus, by having received perfect 
specimens of a fern from Singapore, gathered by Mr. 
T. Lobb, which I at first took to be Ozygonium alis- 
mefolium of Presl; but, on examination, I was surprised 
to find the sori destitute of an indusium, the sporangia 
quite compact and occupying the sides and centre of 
the receptacle (or venule), forming perfect and truly naked 
linear sori, presenting much similitude to the naked sori of 
Gymnogramma Javanica and serrulata. On farther examina- 
tion, I found these specimens to agree with an authentic 
specimen (lately come into my possession) of Diplazium 
alismefolium, which specimen, although old and with but 
imperfect remains of sori, it is evident, from the nature of 
the sporangiferous receptacle, never had an indusium. From 
this circumstance, I cannot but conclude that Presl must 
have confounded two distinct, but yet very similar species, 
under the name of Diplazium alismefolium ; one with the 
sori furnished with indusia, as figured at tab. 8 in Reliquie 
Haenkeane (which, as I have already noticed, is probably 
the same as my Oxygonium alismæfolium, . Cuming’s speci- 
mens, n. 114) ; the other, with naked sori, which he (Presl) 
. Might have considered to be the same as the first, but in an 
. imperfect state of fructification, his own specimen, lying 
3 ore me, being an example. That specimen, however, is 
. NOW proved by my Singapore plant, not to belong to the 
. tribe Aspleniee. On this discovery I was led again to exa- 
[ mine my Ozygoniwm vitteforme, and I find that I was — x 
bebat. in considering it an indusiate fern, the soriferous re- —— 
. ptacle being of the same nature as in Gymnogramma, and — 
E hie Specifically different from Presl's and. my Singapore 
. "Pecimens.. It therefore becomes evident, that these 
. Species must be excluded from Oxygonium, and placed ne 
