218 Twenty-fourth Report on tee State Museum. 



but there is no evidence of the concentric " tube " described as 

 characteristic of the genus ; nor does there appear to have been any 

 place for such a tube, which, it will be observed from the illustrations 

 (loc. cit.), has not been seen in place by the authors of the genus, but 

 is represented as lying separated on the same slab or stone with the 

 fossil described. 



The enlarged figure has the aspect of a crinoidean proboscis, and is 

 represented as a cylindrical tube. In the ideal section (fig. 10, pi. x, 

 bis. loc. cit.), this tube is represented as an archway bordering the 

 ossicula or larger plates, and extending over the smaller excavated 

 plates. It seems to me that if the appendage be a cylindrical tube 

 it could not have found attachment to the border, and if an arch of 

 small plates, as represented in fig. 10, we should find some evidence 

 of a cicatrix for its attachment. J^either the specimen now under 

 consideration, nor the one from the Escanaba river, show any evi- 

 dence of this marginal tube, nor does the structure, so far as I can 

 discover, require any such exceptional development. 



Cyclocystoides Salteei n. sjp. 

 Plate 6, fig. 16. 



Body discoid, subovate and obtusely pentagonal, with a prominent 

 circle of quadrangular plates, which are a little longer than wide, and 

 somewhat contracted or sloping and striate at the ends, with granu- 

 lose surface. Within this range of plates the disc is thin, submem- 

 branaceous in appearance, and composed of small plates which are 

 arranged in radiating order representing the ambulacra. 



The center has apparently been composed of a pyramid of minute I 

 plates with ^yq depressions surrounding it, from each of which pro- ' 

 ceed two diverging rays, composed of double ranges of pores which ! 

 extend to the ring of larger plates or ossicula. Between each pair 

 of rays there is an intermediate shorter ray of similar character. ; 

 Between the rays which are directed to the broader extremity, there , 

 is an oval opening, which may represent the oral aperture. The space 

 between these rays is wider than between any of the others, giving 

 room for this feature. | 



The entire interior portion of the disc presents a delicate reticulate j 

 structure. I 



The border outside of the ring of larger plates consists first, of a ' 

 range of small plates which are elevated in the center and at the ^ 

 margin with an intermediate space depressed. There are from two \ 

 to three of these plates to one of the larger ones. Bordering these 

 there is a range of submarginal scale-like plates, arranged in pairs, 

 which are closely anchylosed, there being one pair of these to each i 



