April 1, 1904.] 



SCIENCE. 



525 



and an approximate estimate of the thick- 

 ness of the various formations. The region 

 is marked by many faults and close folds, 

 the axes mainly running northwest and 

 southeast. The author makes a provisional 

 identification of the Algonkian formations 

 described further north by Willis, viz., the 

 Kintla argillite, the Sheppard quai'tzite 

 and the Siyeh limestone. The great lime-' 

 stone formation of the region, usually re- 

 garded as including the Carboniferous, is 

 believed to extend downward so as to em- 

 brace the Devonian and the Trenton of the 

 Lower Silurian. The Jura-Trias, as iden- 

 tified, contains a coal bed that promises to 

 be of economic importance. The igneous 

 phenomena are numerous and diversified, 

 consisting of surface lava sheets, volcanic 

 craters and volcanic ash, as well as dikes 

 of gabbro, diabase, quartz-porphyry and 

 granite. The oldest rocks constitute the 

 highest relief of the country, the Cretaceous 

 strata having been less disturbed, though 

 the Cretaceous is probably older than the 

 epoch of the principal volcanic action. One 

 of the most important statements of the 

 paper is to the effect that there seems to 

 have been a practically continuous sedi- 

 mentation from the Algonkian to the close 

 of the great (Carboniferous) limestone. 



A Fossil Water Fungus in Petrified Wood 

 from Egypt: Alexis A. Julien. (Read 

 by title.) 



A description is given of a specimen of 

 silicified wood from a ' petrified forest ' near 

 Cairo, and the mode of distribution of the 

 fungus throughout the ducts. An inter- 

 esting association of crystals of hematite 

 and of pseudomorphs after gypsum and 

 halite occurs, which testifies to the earlier 

 conditions of petrification. The organic 

 forms have been preserved in remarkable 

 perfection and abundance. These are 

 successively described, comprising discoid 

 spores, an articulated macromycelium, ma- 



crosporanges enclosing sporules, micromy- 

 celium bearing three forms of stalked cells, 

 and large ovate capsules carrying the 

 spores first described, a continuous series 

 which apparently represents the life his- 

 tory of the new organism. Its generic re- 

 lationships and genetic local history are 

 then discussed, with a review of various 

 theories of the process of silicification. 



The Development and Relationships of the 



Bugosa (Tetracoralla) : J. E. Dueeden. 



(Illustrated by lantern slides. Read by 



title.) 



The paper gives (1) a brief historical 

 account of the various theories which have 

 been held with regard to the nature and 

 relationships of the extinct Rugosa or 

 Tetracoralla; (2) the conclusions of the 

 author from the examinations of a large 

 number of species in the light of more re- 

 cent results on living corals. The present 

 investigation has been carried on mainly 

 by the method of grinding down of indi- 

 vidual coralla, each successive stage in the 

 growth being drawn as it appeared. In 

 this way the complete development and re- 

 lationships of the septa have been estab- 

 lished. In every instance where the perfect 

 tip has been preserved a cycle of six septa 

 is found to occur, thus demonstrating the 

 primary hexameral relationships of the 

 Rugosa as contrasted with the tetrameral 

 usually assumed. The subsequent septa 

 appear in only four of the six primary 

 chambers and in a manner differing alto- 

 gether from that in modern corals. The 

 conclusions reached are that the Rugosa 

 must remain a distinct group of corals, re- 

 lated in their early stage to modern corals 

 and actinians, but later developing in an 

 altogether characteristic manner. Of mod- 

 ern forms they are most closely allied to 

 the zoanthid actinians, which are without 

 any true skeleton ; in these the addition of 

 the mesenteries takes place in a manner 



