CONTRIBUTIONS ON THE OCTOCORALLIA — BAYER 217 



columnar scleroderniites radiate outward from a distinct core com- 

 posed of granular calcareous material intermixed with abundant 

 organic matter. Samplings were made of genera in various penna- 

 tulacean families and were found all to agree in basic pattern. Dif- 

 ferences in detail were noted among the various families and genera, 

 indicating that it may someday be possible to place ?iny pennatulid 

 axis in its proper genus without recourse to gross colonial morphology. 



The genus Sfylatula shows very long columns of irregular circum- 

 ference radiating virtually without interruption from the core of the 

 axis to its outer surface (pi. 7, a-c, e). The fibers of the sclerodermites 

 converge instead of diverging as they do in the Isididae. A system 

 ,of minute radial tubules extending from core to surface (the "uncal- 

 cified radial strands" of Kolliker) can be distinguished (pi. 8,a). 

 .Although these tubules seem to have contained organic matter, I do 

 not believe they are uncalcified strands, but actually canaliculae, a 

 clue to the function of v»^hich may be found in a statement by Marshall 

 and Marshall (1882, p. 5) . In their discussion of the axis of Funiculma 

 ithese authors say: "As the stem grows in thickness by the addition of 

 successive lamellae on its exterior, and as the proportions between 

 the hard outer rind and the soft core are much the same in both 

 young and old specimens, it is clear that the process of deposition of 

 calcareous lamellae on the outside must be accompanied by absorp- 

 tion of the calcareous matter previously deposited in the more central 

 portion." For such a process to take place, communication from the 

 core to the outside would be necessary, and in the system of tubules 

 we may have that m.eans of communication. The organic material 

 ithat they contain may be the remains of scleroclastic cells which 

 should probably be necessary for removal of calcareous material 

 from the core of the axis. 



• Four species of Sfylatula (including S. elongata, the type species) 

 from widely separated localities were found to have practically iden- 

 itical structure. 



The closely related genus Virgularia, on the other hand, has the 

 jclerodermites short and much interrupted (pi. 7,/). In other genera, 

 ihe radial units resem.ble more closely those of ellisellids, or show 

 rarious modifications. 



In an effort to determine the systematic position of Graphularia, a 

 section was examined and found to conform in most respects with the 

 structure of Sfylatula. The core (blackened perhaps by carboniza- 

 i^ion of the organic matter) is wider in proportion to the cortical zone, 

 ^nd the radial columns are shorter and thicker (pi. 7,d). The tubules 

 jeen in Recent Sfylatula are present also in Graphularia, and contain 

 I black material that may be carbonized organic substances. It is 



