226 



MATONIACEAE 



[CH. 



Little is known of the prothallus of Matonia; a green prothallus of the 

 usual type has been seen attached to young sporelings, but it has not 

 been examined in detail. The embryology appears to 

 be that usual for relatively advanced Ferns; the cotyledon 

 is either simple or branched, and its venation is a 

 scorpioid sympodium, as it is also in Gleichenia (Fig. 

 502). 



The genera Laccopteris and Matonidium are Mesozoic 

 Ferns showing very close agreement with Matonia. 

 The former had a scorpioid leaf like Matonia, with 

 venation dichotomous and usually open. The sori were 

 also of the same type, but the existence of an indusium is 

 in doubt. Laccopteris was widely distributed in Rhaetic, 

 Jurassic, and Lower Cretaceous Floras. Its pinnae 

 show frequent anastomoses of the veins, while the sorus 

 is also of the Matonia-typQ, but it contains sometimes 

 12-14 sporangia disposed in a ring, each with an oblique 

 annulus (Fig. 503). 



Fig. 502. Matonia pecti- 

 nata, prothallus and 

 young plant, collected 

 by Lang on Gunong 

 Ladang, Malay Penin- 

 sula. ( X 4.) 



Fig- 503- Laccopteris IVoodwardi, from inferior 

 oolite of Yorkshire. A, a pinnule: the hemi- 

 spherical bosses show the position of the sori 

 (No. 257 Brit. Mus.). B, pinnule of L. poly- 

 podioides, with sori and soral impressions, from 

 Gristhorpe Bay (No. 2522 Brit. Mus.). C, 

 pinnule-fragment from the inferior oolite of 

 Stamford (No. 52867 Brit. Mus.). (AfterSeward, 

 from drawings by Miss G. M, Woodward.) 



The conclusion which may be drawn from a comparison of the Matoni- 

 aceae with the Gleicheniaceae is that the former represent a type specialised 

 early from a common stock with the latter. Both have a creeping rhizome, 

 with stelar structure either protostelic or a solenostelic derivative from it : 

 the difference is bridged over by Platyzoma, Gleichenia pectinata, and 

 Matonia sannentosa. The last of these leads to M. pectinata which is the 

 most elaborate solenostelic Fern }'et observed. The leaf architecture in both 

 is along similar lines, with a strong scorpioid tendency in Matonia which 

 appears also in certain species of Gleichenia, e.g. Gl. Ctmninghami. In M. 

 sannentosa the arrested higher branchings in the leaf are strangely reminis- 

 cent of Gleichenia. The venation fluctuates between the open system of 



