DESCRIFI'ITE CATALOGUE 



the naked eye. but under the microscope very few 

 of the actual cells remain. Some rows of tracheids 

 can be made out clearly towards the middle of the 

 section. 

 "Potton Sands," Lower Greensand ; Leighton Buz/ard. 



Transferred from the Botanical Dept., 1898. 



V. 5895. Co-type. Figured, text-fig. 99. An irregularly broken 

 piece of the axis showing eight or nine concentric 

 wood-rings. The block measures 1^x9x7 cm. and is 

 mnch fractured. The weathered face shows the wood- 

 rings recognisably both in transverse and various 

 longitudinal directions. 

 " Potion Sands." Lower (Ireensand; Leighton Bu/./ard. 



rrd from the lintanit-ftl f></>t., 1 * 



V. 5218. A large irregular fragment of the woody region of a 

 trunk similar to the above, but shoeing less detail. 

 measuring: 10 x 7 cm. 



B 



V. 5251. A small wedge, measuring f> x 4 x 3 cm., showing parts 

 of the disintegrated leaf bases and three rings <f wood 

 which show up very Clearly on the polished face. 

 "Potion Sands." Lower (rreeusaud : Leighton Huz/.ard. 



Tntttfif.' i- !'<</ fr"/n thf JintriHti'ttl />,-pt.. 1^98. 



(T< nus COLYMBETES, nov. 



Tlier^ is only one specimen of this new type, so the genus 

 uud species are diagnosed together. 



Colymbetes Edwardsi, sp. nov. 

 [Plates XXXf, XXXII; text-figs. 101-111.] 



Diagnosis. Founded on tiki inner portions of a trunk showing 

 beautifully petrified anatomical details. Trunk probably 

 cylindrical, reaching more than 12cm. in diameter. Pith large, 

 cellular, 7*o cm. in diameter; numerous gum canals, but no 

 vascular strands in pith proper. Ground-tissue cells of pith 

 large, relatively thin-walled, all alike, and without intercellular 



