238 ' Report of the State Geologist. 



of an inner plate. The latter is surrounded by four oval pro- 

 jections which are probably the casts of budding sacs represent- 

 ing the gonangia. This would indicate a very early beginning 

 of the development of the reproductive organs. 



As the next stage of growth may be regarded those rhabdo- 

 somes which bear two thecse (figs. 8 and 9). 



In fig. 8 the basal appendage is preserved as an impression 

 only, darker than the surrounding rock. 



Figure 9 represents a primary rhabdosome, the basal cyst 

 of which is preserved as a plate with a chitinous filiform border 

 and part of the chitinous test in the lower right corner. The 

 concentric furrowing observed before is also distinct h ere ; the 

 furrows surround a high square chitinous projection which ap- 

 parently develops from the original little central node and is 

 the central disc of the grown colony. 



A further stage is represented by a rhabdosome on which three 

 thecaB can be counted (fig. 10). The central disc appears as a 

 deep square pit ; the basal cyst as a less deep, but very smooth 

 impression with a chitinous film. 



In figure 11 we have a rhabdosome with four thecae, and con- 

 nected by a rather short hydrocaulus to a central, strongly chit- 

 inous node, evidently the " funiculus " of the compound colony. 

 The node lies inside the central disc, a deep impression filled 

 with carbonaceous matter and surrounded by the larger impres- 

 sion of the basal cyst. Besides these impressions, there are pres- 

 ent four strongly projecting oval bodies. If these are again 

 traces of gonangia, the latter have already extended beyond the 

 cyst. 



The next represented stage (fig. 12) with seven thecae shows 

 the oval organs still more developed. In one of the latter (at g), 

 there are radiating impressions perceptible, perhaps those of 

 young siculae. 



Figures 13 and 14 show primary rhabdosomes with respectively 

 11 and 13 thecae. Both are remarkable for the distinct concen- 

 tric series of furrows and the great prolongation of the basal 

 part of the hydrocaulus. 



The next stage (fig. 1 5) appears very different from the pre- 

 ceding, because the primary rhabdosome is broken off (the basal 

 part of the hydrocaulus is still preserved at p). This specimen 



