230 Report of the State Geologist. 



surrounding rock. They consist of compressed sediment of finer, 

 grain than the matrix. The sediment apparently entered 

 the space between the gonangia and the stipes and preserved 

 thus the impressions of the gonangia. 



An indication of the original form of the gonangium in its 

 uncompressed state is given by a very excellent specimen (PL I, 

 fig. 3), where the gonangia left deep, almost globular pits, which 

 the eye can not fail to see in looking at the frond-covered slab. 

 These impressions suggest a globular form of the gonangia, an 

 indication which is confirmed by a frond on a piece of limestone 

 (PI. il, fig. 2) from the debris of the cliff which furnished the 

 fronds of D. Euedemanni. The piece comes from a layer of 

 limestone, interpolated in the shale. The fossil shows two 

 gonangia preserved as solid globular projections. 



Observations as to the proximal end of the gonangia could be 

 made in only a few specimens. 



From the originals of PL I, figs. 5 and 8, we might infer 

 that the gonangia were connected with the hydrosome by the 

 central vesicles. An excellent insight into the construction 

 of the gonangia and their connection with the hydrosoma is 

 given by the original of PL II, fig. 4. Three gonangia are visible 

 as deep impressions of dark color, from the bottom of which rise 

 club shaped projections. The proximal ends of the latter are 

 connected by a disc, which overlaps also part of the f unicle. 

 Both the projections and the disc are not chitinous, but consist 

 of shale. Therefore they are fillings of hollow organs, the test 

 of which has not been preserved. The disc is apparently the 

 filling of a tubular organ from which the gonangia radiated, its 

 cavity being directly connected with the central vesicles of the 

 gonangia. The tube itself was apparently connected with the 

 central disc and funicle, and by this with the system of somatic 

 cavities. 



The result of the study of all these specimens is that there were 

 in the species D. jpristis and Muedemanni, around the center of 

 the compound frond, globular or oval vesicles, numbering from 

 four to eight or more, the test of which was horny. 



Each vesicle inclosed a capsule varying from oval to club- 

 shaped, which had a rather solid test and did not contain any 

 obstruction to its being filled by the sediment. But the most 



