XXXIX] CYCADITBS 565 



rachis. Miss Holden describes the stomata as covering the 

 whole lower surface of the pinnae except over the midrib. This 

 description must be revised in the light of Halle's results obtained 

 from an examination of the cuticle of the type-specimen of the 

 species in the Berlin Museum. He finds that the edges of the 

 pinnae are strongly revolute and thus form a deep dorsal canal 

 which is almost closed^, a form of lamina, as seen in section, 

 very similar to that of an Empetrum leaf. The stomata are con- 

 fined to the groove. It may be that the specimen examined by 

 Miss Holden is specifically distinct or, as Halle also suggests, 

 the cuticle obtained from the English fossil may not represent the 

 whole surface but only the walls of the canal with possibly a 

 portion of the cuticle of the outer dorsal surface. This type of 

 leaf described by HaUe is similar to that of P. insignis with the 

 xerophilous character intensified. 



Cycadites Saladini ZeiUer. 



This species was founded by ZeiUer^ on fronds from the Rhaetic 

 of Tonkin reaching a length of 40 cm. and 2 — 8-5 cm. broad with 

 a rachis 3—4 mm. wide bearing contiguous Hnear pinnae 1-5 — 4-5 

 cm. long and 1-5 — 3 mm. broad with a more or less contracted 

 base and a rounded or obtusely pointed apex. The pinnae are 

 attached almost at right-angles or at an angle of 60°— 80°. There 

 is a clearly defined midrib. 



It is not improbable that were the structure of the epidermal 

 cells known this species would be found to be another example 

 of Pseitdocycas. 



Cycadites rectangularis Brauns. 



This species', first recorded from Rhaetic strata in Germany, 

 differs in the narrower and more acutely pointed pinnae from 

 C. Saladini. Miss Holden describes the midrib as double, but 

 until specimens are found which admit of an examination of the 

 cuticles it is impossible to decide whether it should be transferred 

 to Pseudocycas. The species is widely distributed in Rhaetic 



1 HaUe (15), PI. xn. fig. 12. 



2 ZeiUer (03) B. p. 155, PI. XLi. 



3 Brauns (66) p. 56, PI. xev. fig. 7; Sohenk (67) A. PI. xxxv. fig. 11; Seward 

 (04) B. p. 37, PI. rv. fig. 4; PI. ii. fig. 1- 



