NIAGARA GR0I7P. 



119 



510. ]. SYRINGOPORA'! MULTICAULIS. 



PL. XXXIII. Fig. ?a-h. 



Tubes simple or aggregate, csespitose, increasing by lateral budding, connected among them- 

 selves by lateral processes, at vmequal intervals, externally transversely striate, Internally radiate 

 with about fourteen or sixteen distinct rays ; transverse septa often nearly direct or ascending 

 towards the centre, and complicated with the lamelte. The entire interior of the tube some- 

 times filled with the oblique ascending septa. 



This coral consists of an aggregation of tubes, which, beginning from a small base or root, 

 have increased by lateral budding to a large mass. The processes uniting the tubes laterally are 

 not numerous or distinct, and they often appear as if parallel and disconnected. In many in- 

 stances there appears to be regular intervals of budding, where a single tube throws out two 

 or three buds at about the same elevation. From this mode of increase, the mass spreads 

 rapidly from the base, and becomes hemispherical. Sometimes, however, a large number of 

 tubes grow up together nearly parallel to each other, and the mass has a less hemispheric form. 

 When the coral is calcareous, the stellate tubes are very easily discerned on the weathered sur- 

 faces ; but in other cases they are solid, or irregularly cellular in the interior. The external 

 surface rarely or never shows any longitudinal stria ; but the surface, in calcareous specimens, 

 is distinctly striated and wrinkled transversely, and in siliceous specimens a sort of granular 

 surface is often preserved. In such instances, there is often a longitudinal arrangement of the 

 granules corresponding to the lamella;. 



Fig. 3 a. A small part of a larger group of these tubes from a siliceous specimen. 



Fig. 3 6. A transverse section, showing the ends of the tubes. 



Fig. 3 c, d. The end of a tube, natural size and magnified. 



Fig. 3 e. A separated tube, showing contraction at intervals, with a shorter one at the base, and 



a bud proceeding apparently from between them. 

 Fig. 3 /. A longitudinal section from the top of the cup downwards, showing in the upper part 



the simple rays, and below the complicated oblique septa. 

 Fig. 3 ^. A longitudinal section of a tube, the middle of the figure reaching to the centre of the 



tube, and showing oblique septa, while at the two ends only the lamella are seen. 

 Fig. 3 A. A longitudinal section of several tubes, showing the interior structure. 



In all the specimens which have been polished down to the centre, there is an appearance of 

 transverse septa ascending towards the centre and crossing the lamelte, or uniting them. Some- 

 times these specimens present the appearance of having a central axis, which arises apparently 

 from a partial involution of the lamellae at their junction. 



Position and locality. In the lower part of the Niagara limestone at Lockport, and in the 

 central part of the same limestone in Barre, Orleans county. 



