362 REPORT ON THE STATE CABINET. 



there is inserted a pentagonal plate, which supports a range in direct 

 succession of two or three hexagonal plates. The summit is unsym- 

 metrical, and in one specimen there is an apparent central aperture 

 or mouth, and an eccentric or ovarian aperture ; and the margin is 

 marked by what appears to be the bases of slender arms or tentacula. 



Such a structure, in the ordinary nomenclature of the Crinoidea, would 

 be described as a range of basal plates, succeeded by a radial series of 

 four or five plates. 



The distinctly unsj^mmetrical form of one of the species having this 

 structure, together with the peculiar character and parts of the summit, 

 give it a decidedly cystidean aspect ; while it cannot be allied with the 

 crinoidean genera at present known. 



Crinocystites chrysalis, n. s. 



PLATE XII a, FIGS. 10, 11. 



Body small, claviform, unsymmetrical, gradually enlarging from the base 

 for half its length and then swelling a little more rapidly, and again 

 contracting more abruply towards the summit. The expansion being 

 greater on one side, while the other is nearly straight or a little 

 concave, gives an unsymmetrical form. There are about six ranges 

 of plates ; the lower range being comparatively long, the number 

 unknown; the second range consists of elongate heptagonal plates 

 which, on their upper truncate faces, support in direct series three 

 smaller hexagonal plates, and above the last one there is apparently 

 a small arm-bearing plate. Between these direct series of plates 

 there is an intermediate or interradial series of three plates alter- 

 nating with the others, the upper ones of which are pointed above, 

 allowing the fourth plate of each of the adjacent radial series to 

 join at their lateral margins, giving but five plates in the range 

 immediately below the summit. The summit is unsymmetrical, 

 showing evidence of two apertures and five slender arms or tenta- 

 cula. Surface of plates striate. 



Formation and Locality. — In limestone of the age of the Niagara group 

 at Racine, Wisconsin. 



