37 



The distal part which is not rarely provided with a more or less distinct beak- 

 shaped projection (figs. 13, 14, 16) is sometimes angularly bent from side to side 

 (figs. 13, 14), while in most cases it is broadly rounded, and within the proximal 

 margin there is generally found a more or less distinct broad low prcjjection, the 

 median part of wiiich is provided with an impression or indentation (figs. 12, 13, 

 17,21). The operculum whicli has been found only in a very small number of 

 zooecia sliows a flabelliform striation and a number of pores. The suboral area 

 which is always feebly developed is rarely broad and short, and in thai case il is pro- 

 vided with a pit on each side (fig. 19). In most cases il is long and narrow and provided 

 with 2 — 4 pits arranged in different manner, and sometimes the peristomes of the 

 neighbouring zooecia come in contact with each other in such a manner that the 

 suboral area is only represented by a proximal and a distal pil (fig. 12). The rich 

 deposition of calcareous matter which lakes place in this species may go on in a 

 very ditTerent manner, and while in some colonies the pits increase both in number 

 and in size, and the suboral area therefore shows a rich areolation (fig. 16), in others 

 the pits are gradually elTaced, and the suboral areas are transformed into an inter- 

 lacing net-work of convex pillars (fig. 15). 



The Heterozooecio which are present in very scarce number and not even found 

 in all the fragments examined are as a rule a little longer than the zooecia. The 

 more or less projecting aperture is triangularly rounded, a little longer than broad 

 and the two lateral margins converge to form a rather broadly rounded distal curve. 

 No lateral thickenings. The suboral area is provided with similar pits as those 

 found in the zooecia, and there may be found a projection within tlie proximal 

 margin (fig. 21). 



Ooecia have nol been found. 



No Kenozooecia. 



A Closure has not been seen with certainty in any of the fragments examined. 



The Regeneration. In all the specimens examined a larger or smaller number 

 of the ajjcrtures are much more projecting than the others, and when we have to 

 do with a larger fragment which presents the original distal end tolerably intact 

 we find that the number of these projecting apertures increases towards the pro- 

 ximal end, the surface of which is chiefly or exclusively composed of them. A conse- 

 quence hereof is that the proximal end of such a fragment is much thicker than 

 the distal, and for inst. in one from Villedieu which has a length of 13 mm., the 

 distal end has a thickness of 1,5 mm. but the proximal end of 2,5 mm. The named 

 |)rominent apertures are very often distinctly or even much larger than the com- 

 mon ones and of a diflerent form (fig. 17), and their arrangement is always more 

 or less irregular as a larger or smaller number of them have another direction than 

 the common apertures. Sometimes we even find specimens in which these aper- 

 tures are ])laced in all possible directions (fig. 20). 1 cannot doubt but that we have 

 here to do with a process of regeneration which differs from that commonly found 

 in Ihis division therein that the aperture of the new zooecium proceeds so far be- 



