2-1-0 Report of the State Geologist. 



The beginning growth of a second generation is more clearly 

 visible in the excellent original of figs. 21 and 21a, where the 

 hydrocauli of the already highly-developed first generation of 

 rhabdosomes are turned to one side, thus uncovering, the well- 

 preserved little chitinous gonangia (g). The latter with their 

 interior radiation, which probably is to be referred to siculae, are 

 easily perceptible to the naked eye. The primary rhabdosome 

 is turned to the right. 



A more advanced stage is that shown by fig. 22, where the 

 gonangia, preserved as impressions only, are larger than the cyst, 

 and a few siculse of the second generation are still connected 

 with the apparently incomplete colony. This specimen shows 

 the two different kinds of siculae : the detached siculae, two of 

 which have been arrested in their motion by the hydrocaulus, 

 and the nondetached siculae. 



A similar stage of growth is represented by fig. 23, which is 

 remarkable for its having two generations of rhabdosomes, for 

 the chitinous basal cyst, which is separated from the center, and 

 for its central disc, which shows a central pit. 



The difference betweeen the two generations of rhabdosomes 

 is very obvious in the specimen represented of natural size in 

 ^g. 24. The three longest rhabdosomes are left from the first 

 generation (the one on the left side is perhaps the primary 

 rhabdosome). The verticil of rhabdosomes, marked II, is evi- 

 dently the second generation, and a third generation is indicated 

 by the oval chitinous rings, the apparent traces of gonangia. 



The original difference in size between the rhabdosomes is later 

 on obliterated by their unequal growth, and perhaps also by 

 the loss of the older rhabdosomes. The beautiful specimen, 

 represented in PL I, fig. 1, still exhibits three generations of 

 rhabdosomes and one generation of gonangia. There is a dense 

 verticil of almost equally long rhabdosomes found in a few very 

 large colonies. 



For the sake of completeness I add the figures (figs. 25 and 26) 

 of two specimens which seem to stand outside of the line of 

 development, as they show two and four siculae on one central 

 disc. Three siculae have also been observed. As, however, the 

 complete development of the central organs, the presence of 

 funicle, central disc and basal cyst indicate, these strange little 



