(i) 12 Palseontologia Sinica Ser. B 



bring common species to light, and demonstrate the correspondence of the Yehh lime- 

 stone series to one or tlie other of the formations in the more northern region. When 

 such new material is obtained, it w'lW. be described in further numbers of this publication. 



DESCRIPTION OF SPP^CIES 



Class ANTHOZOA 



Family ARCH^^OCYATHINAE 



Genus ARCHyEOCYATHUS Billings 



(Subgenus Archcvoscyphia Hiiidc) 

 Archaeocyathus (Archaeoscyphia) chihliense Grabau (sp. nov.) 



Plate I Figs. 1-3 



Caliculum irregularly sul»-conical, apparently expanding in a uniform manner. 

 Basal portion unknown. Adult portion sulj-circular trj suli-oval in transverse section, the 

 latter possibly accentuated by compression in some specimens. Septate portion {iltecarium) 

 thick, enclosing a hollow calicular cavity which, in the subcylindrical specimens, has a 

 diameter something over one third the diameter of the entire caliculum. This cavity is 

 well defined l>y the inner ends of the main septa, which attain a uniform length, but are 

 not I>ounded I*}' any definite inner wall, or endothcca. Outer \vall or exotheca formed by 

 the thickening of the outer ends of the septa, and their irregular confluence, the result 

 being a very porous wall. 



Septa thin, formed apparently by a series of small confluent trabcculte, this re- 

 sulting in the production of thin radial plates of a very porous nature, so that in transverse 

 section they appear as disconnected trabeculte-, disposed in radial lines. They are very 

 numerous and arranged in groups of tlu'ce or four each, the groups being separated by 

 interspaces which are about twice as wide as the interspaces Ijetween the ad,ioining septa 

 of a group. Occasionally one of these liroader interspaces is occupied b}^ a short septum 

 in the peripheral region. 



A section 28 mm. in diameter (PI I fig. 3), shows about 33 groups of septa, 

 making a total of from 100 to 120 septa. The specimen from which this section is cut 

 appears to have had a somewhat flaring outer edge to its calyx, a section of this showino- 

 on one side, because of shght oljhquity of the cut. In this outer portion the septa are 



