154 J. SMITH ON THE GENERA OF FERNS. 



Obs. The whole habit and character of the species forming 

 this genus is very peculiar, and totally distinct from any 

 other genus of ferns, but agreeing in the amorphous produc- 

 tion of the sporangia with AcrostichiecE. Besides being dis- 

 tinct in habit, the sporangiferous receptacle also presents a 

 structure peculiar to this genus, being formed of an accessary 

 layer of minute veinlets which appear independent of the 

 general vascular structure. 



The thick coriaceous texture, and the stellated pubescence, 

 show some analogy to Niphoholus, but otherwise that genus 

 is very different. 



46. Cyrtogonium, J. Sm. 



(Acrostichise, sp. Auth, Poecilopteris, Presl. Campium, 

 Presl. Bolbitis, Schott. Jenkinsia, Hook.) 



Veins costaeform, pinnate ; venules arcuately or angularly 

 anostomosing, producing on their exterior sides or angles of 

 meeting one or more excurrent free, or irregularly anosto- 

 mosing veinlets; sporangia sometimes evident on the venules. 



Fronds pinnate^ membraneous, smooth; pitince dentate or sinu- 

 ous, often viviparous, margin of the fertile pinnce usually mem- 

 braneous and revolute, (indusiiform.) 



Examp. 1. C. crispatulum, (Wall.) 2. C. repandum, 

 {Blime.) 3. C. costatum, {Wall.) 4. C. subcrenatum, 

 {Hook, et Grev.) 5. C. virens, {Wall.) 6. C. diversifoliuin, 

 {Blume.) 7. C. flagelUferum, {Wall.) 8. C. serratifolium, 

 (Kaulf.) 9. C. scandens, {Radd.) 10. C. punctulatum, 

 {Linn.) 



Illust. Schott. Gen. Fil. t. 12. Hook, et Grev. Ic. Fil. t. 

 HO, 221. Hook. Gen. Fil. t. 80. A. 



Obs. Notwithstanding the different form of venation exhi- 

 bited by several of the above species, yet, on taking their 

 habit into consideration, and that the difference in the vena- 

 tion is no more than what we have already seen in species of 

 other natural genera, I am induced to retain them under 

 one genus, although Presl and others have characterized more 

 or less of the species under several different genera. Cyrto- 



