51 



Formation, associated with Ilybocrinus conicus, Heterocrinus 

 canaiensis, Pleurocystites elegans, Streptelasma, comiculum, d'c. 



GENUS CALCEOCRINUS, HALL. 



As there appears to be only conjecture for the assertion that the 

 plates upon which this genus was {jroposed are congeneric with the 

 species afterwards assigned to it by Meek and others* the following 

 new species may have to be assigned either to Chirocrinus, Salter, 

 or Euchirocrinus, Meek. 



Wachsmuth and Springer represent the genus as having three 

 arms. I am satisfied, however, that there are four. 



There is no previous record of a specimen having the column 

 basals and radials in the same straight line as is found in C. ruyosus, 

 described below. 



CALCEOCRINUS FURCILLATUS, 71. Sp. 



Only one side the anterior of the basal series observed ; the 

 posterior resting against the posterior radials as is usual in the greater 

 number of the specimens of this genus. The basal series is semilunar, 

 the chord being under the three radials of the anterior side. The 

 basal portion, as seen on the anterior side, is divided into four pieces : 

 first, by a vertical suture into halves, which are again divided by a line 

 sub-parallel with the curved margin making two outer plates which, 

 together, are rudely crescentic, and two subtrigonal inner plates. 



Between the basal and the radial plates, on the anterior side of an 

 exceptionally perfect specimen of his species C. punctaius, Prof. Ulrich 

 " found a large number of tmall and irregularly distributed plates." 

 These minute plates are absent in my specimen; but there exists a 

 vacant space in which feuch an assemblage could easily find place. 



There are five series of radials, aggregating so far as known 

 eight pieces, of which three series with four ])lates are on the anterior 

 side and two .series with four plates are on the posterior. On the 

 anterior side there are three alternating with the basals ; the middle 

 i-adial being composed of a tetragonal piece, 2i times as high as wide. 



*See revision of the pal.focriuoiilae, liy Charles Wachsmuth aiul Frank Sjiringer, 

 part 3, page 273 ; and also remark on the names Calceocriuus and Cheirocrinns, by 

 Prof. Ulrich, in Keport of (Jeological Survey, of Minnesota, 188*5, page 101 ; both of 

 which should be read by all interested iu this genus. 



