BOOM L PSAROLITES. 45 



exhibit the arched bundles of vascular fibres which compose 

 the ligneous cylinder, surrounded by the cellular tissue. 

 From the stellated markings produced by sections of the 

 vessels that compose the tissues, and are visible to the 

 unassisted eye, these fossils have obtained the popular name 

 of Staar-stein or Star-stones. 



Recent investigations have shown that these stems consist of 

 two distinct parts ; namely, an inner axis, surrounded by a zone 

 composed of numerous cylindrical bundles of vessels, which are 

 supposed to be roots that proceeded from the stem near its base. 

 In the exterior portion the air-foots have a vascular tissue, 

 but there is in many examples a delicate interstitial cellular 

 tissue. In the axis, the vessels form zigrag or vermiform 

 bands resembling those in ferns, and which are entirely com- 

 posed of barred or scalariform vessels. The Psarolites are 

 therefore considered by M. Adolphe Brongniart to be the 

 bases of the trunks of lycopodiaceous trees ; while M. Cotta 

 and others regard them as true arborescent ferns. The 

 external surface of the specimens I have examined has a lig- 

 neous structure, and is of a dark reddish brown ; internally 

 they are of a dull red colour mottled with various tints of 

 blue and yellow, from the infiltrated chalcedony with which 

 the vessels of the tissues are more or less permeated-* 



ASPHODELE^ (Clathraria, JZndogenites, Dracaena). Case 

 E. On the lower shelves of this case there are specimens 

 of three remarkable fossil plants; two of which were first 

 discovered by the Author in the Wealden deposits of Tilgate 

 Forest ; the other by Mr. Bensted in the Kentish-rag near 

 Maidstone. They are placed under the name Asphoddeve. 



CULTHRARIA (C. Lyettii). Case E [5]. The Clathraria (lat- 

 ticed-etem), so named from the appearance of the cicatrices 

 left by the petioles, is a remarkable tribe of terrestrial 

 plants allied to the Cycadeae, that flourished during the period 

 when the Wealden beds of the south-east of England, and the 

 lowermost and middle cretaceous strata were deposited; for 

 remains of these plants occur in the greensand and chalk marl 



All the specimens in the Case were collected by the Author 



1 Beautiful coloured figures are given in K Pictorial Atlas of Organic 

 Remains," PL VIH. M. Cotta has published an able work on the sub- 

 ject, in which nearly thirty species are described. See also M. Brong- 

 niart's " Tableau des Genres de Teg. Foss." p. 44. 



