G58 



PROFESSOR A. C. SEWARD ON 



This leaf, 12 cm. broad, shows a division of the lamina into four primary segments, each 

 of which is deeply lobed. No sporangia have been found on this or any of the 

 specimens. In the leaf represented in fig. 14, PL I., 14 '5 cm. long, the main ribs are 

 much more clearly preserved, and traces of the finer reticulum are also visible con- 

 necting the chief vascular strands, as shown in text-fig. 2 and in fig. 21, PI. II. The 

 fronds represented in figs. 14, 20 agree exactly with some of Richter's specimens from 

 the Lower Cretaceous of Quedlinburg, and exhibit a close resemblance to leaves of recent 

 species of Dipteris. Fig. 15, PI. I., shows part of a smaller leaf with narrow segments, 

 and a piece of a broader lobe with several ribs is seen in fig. 16 : the surface of the 

 lamina in the latter specimen presents a pitted appearance, — like that more clearly 

 shown in fig. 17, and which is particularly obvious in Richter's photographs, — due to 

 the division of the leaf-area into numerous areolae by the fine anastomosing veins. The 



Text- Fig. 2. — Hausmannia up. Part of a dichotomously branched main rib and the intercostal 

 reticulum ( x 5). (Peach collection, British Museum, V. 4365.) 



imperfect frond shown in fig. 19, though possibly a distinct species, bears a close 

 resemblance to the smaller specimens figured by Richter as H. dichotoma var. 

 linearis* It differs from the majority of the examples referred to H. dichotoma in the 

 more linear form and uniform breadth of the segments, each of which has one median 

 rib. This specimen is very similar to fronds of Dipteris quinquefurcata (Baker).t 



Hausmannia Buchii (Andrae). (Fig. 21, PL II. ; photo. 6, PL VI. ; text-fig. 3.) 



1853. Protorhipis Buchii, Andrae, Lias Flora von Steierdorf im Banate, p. 36, pi. viii. fig. 1. 



The specimens shown in fig. 21, PL II, photo. 6, PL VI., and in text-fig. 3 are 

 referred to Andrae's species because they agree with his type in the absence of a median 

 sinus and in venation characters. Andkae described his species as follows: — "Pro- 

 torhipis fronde late sinuato-dentata, venis primariis pluries dichotomis validis remotis, 

 venis secundariis et venulis tenerrimis."| 



* Richter (06), pi. iv. figs. 6, 9, 9a. + Seward and Dale (01), pi. xlviii. figs. 13, 18, 



% Andrae^(53), p. 36. 



