26 NEW YORK STATE MUSEUM 



condition. It is therefore obvious that these bodies were lacking 

 in stiffness and like the floats of the Velellas along our coast, when 

 thrown upon the shore, were liable to roll up, to dry and shrink. 

 I think this proves their former gelatinous nature. 



Taken as a whole, the new features shown in these specimens 

 would appear to favor the suggestion advanced by Fuchs, although 

 there are still facts, such as the lack of correlation between the 

 outer concentric lines and the inner chambers in the first cycle of 

 the smaller specimen, that are not readily explained by reference to 

 Porpita. 



Doctor Clarke has already directed attention to the very note- 

 worthy resemblance between the young specimen of Paropsonema, 

 figured by him, and the Discophyllum peltatum Hall, 

 a fossil from the " Hudson River " shales (probably Snake Hill 

 shale) at Troy, N. Y., which has been r^figured by Walcott in his 

 monograph on the fossil Medusae. A comparison of Walcott's 

 second specimen with the specimens of Paropsonema here figured, 

 brings out some further striking resemblances, as the presence of 

 narrow radiating ridges between the rays, suggestive of partition 

 walls. These are especially well shown in the second cycle of the 

 larger Paropsonema. Likewise, in the second specimen of Disco- 

 phyllum the central half of the disk is slightly but distinctly* pro- 

 jecting above the outer half, similarly as in the two specimens of 

 Paropsonema here figured. The concentric system of lines in the 

 Discophyllum and the young Paropsonema here figured are exactly 

 identical, and there seems to us little doubt that the two are closely 

 related organisms belonging to the same class, whatever that 

 may be. 



In this connection we wish to describe, merely in order to direct 

 attention to it, a problematicum that possibly is also referable to 

 the Coelenterata. 



Plectodiscus molestus nov. 

 Plate 3, figure I 



Diagnosis. Elliptic depressed convex disk, 105 mm wide and 

 123 mm long and 7 mm high, rising rather abruptly along the margin 

 and flat in the middle portion. From the surface of the disk project 

 low, outwardly directed knots which are arranged somewhat 

 obscurely in three or four cycles, the knots of the successive cycles 

 alternating. The surface of the disk is raised into numerous con- 

 centric folds or wrinkles which are finest near the margin and 

 become successively broader and less distinct toward the center. 



