on fossil fungi. 329 



4. Akchagaricon dendritioum. 



Tubes very minute, is^ootli of an inch in diameter, arranged 

 in dendritic tufts in connexion with the periphery of the organ- 

 ism, and having interspersed large elHptical vesicles, which are 

 apparently terminal. When the branches are crowded, the tuft- 

 like arrangement is obscured. 



We have only two specimens of this pretty species ; they are 

 irregularly circular, and are quite minute, being only -Ath of 

 an inch in diameter. They do not exactly agree in internal 

 structure, one of them having the terminal elliptical vesicles 

 much more numerous than the other, and the organism crowded 

 throughout with a vast number of similar vesicles. 



5. Aechagaeicon conglomeratum. 



Tubes large, uneven, cramped, and warty, irregularly enlarged 

 and occasionally much constricted, anastomosing, and studded 

 with cells of various sizes, sometimes so numerous that the tubes 

 are much obscured, the whole mass appearing filled with them. 



Several specimens have occurred of this well-marked species. 

 The tubes are occasionally constricted to 3-jTrth of an inch in 

 diameter, and are sometimes enlarged to considei'ably more than 

 twice that size. They are of an irregular form. 



EXPLANATION OF PLATES VIL & VHI. 



PLATE VII. 



Fig. 1. Lcnt'icnliiy form ol Archcif/aricon. 



Fig. 2. Oval form. 



Fig. 3. Irregular elongated form. 



Fig. 4. Pedunculate form. 



Fig. 5. Irregular form, with minutelj^ reticulated surface. 



Fig. 6. A portion of the surface enlarged to show the reticulations. 



Fig. 7. Transverse section of lenticular form. 



