100 CHARACTERS OF TRIBES AND GENERA. 
Veins compound anastomosing ; primary veins costeform, 
elevated or internal, generally flexuose, in some immersed. 
Receptacles compital, superficial. Sori punctiform, or by 
confluence oblong or linear, irregular or partially obliquely 
1—2 serial. . 
Type. Polpodiwm normale, Don. 
Illust. Hook. and Bauer, Gen. Fil. t. 109, B. Hook. and 
Grev. Ic. Fil. t. 65. J. Sm. Ferns, Brit. and For. , fig. 24, 
Oss.—The species of this genus agree with Phymatodes 
and Pleuridium, but differ in the nature of the caudex, and 
the fronds of the greater number of the species being thin 
and flaccid, as also in the irregular disposition of the sori. 
With Selliguea it is connected through C. membranacea, ` 
in which the punctiform sori are united, forming linear 
oblique sori, which character has led the author of the 
"Species Filieum" to place it in Gymnogramma. The 
irregular arrangement of the sori is also conspicuous in 
C. Samarense; in some fronds the sori are punctiform, 
while in others the receptacles unite, forming linear, or 
even transverse continuous sori, and also at the same time 
punctiform sori. This apparently double character induced 
me to elevate this species to the rank of a genus, which in 
1841 I characterised under the name of Diblemma, but 
later observations have shown me that it cannot with e 
priety be separated from the present group. 
The genus consists of about sixteen species, all natives of. 
the Eastern Hemisphere, extending from Western Tropical 
_ Africa through India, the Malayan Islands, China, — : 
: and Polynesian Islands. : 
* Fronds simple. 
m SZ C. zostereforme (Wall.); C. normale (Don.) (Paty 
podium longifrons, kare SN [2 T 
ii 
