1886.] NATURAL SCIENCES OF PHILADELPHIA. 135 



Family XIX. ANOMALOCRINIDJE W. and Sp. 



ANOMALOCRINUS Meek and Worthen. 



1879. Revision Palseocr., Pt. i, p. 72. 



1879. S. A. Miller, Journ. Cincin. Soc, Xat. Hist. (Decbr., ]). G). 



1882. S. A. Miller, ibid. (April, p. 14). 



This senus differs from the Heterocrinidse in the form of the 

 calyx, which is depressed and not obconical, and in the arrange- 

 ment of the pinnules. It agrees with them in the plates at the 

 azygous side, which we misunderstood in our former description, . 

 and this renders a redescription necessary, which we substitute 

 in place of our former one. 



Bevised Diagnosis. General form depressed, calj'x compara- 

 tively large, rather shallow, subglobose ; arrangement of plates 

 extremely irregular, scarcel}' two plates being of equal size. 



Basals five, small, subequal, parti}' hidden by the column. 



Radials irregular, all differing in size and form ; simple or com- 

 pound ; sometimes divided vertically. The left antero-lateral 

 radial is compound, composed of two pieces ; that of the opposite 

 side and the anterior radial are simple. The left postero-lateral 

 radial is the largest plate in the calyx, and either simple or 

 bisected verticall}^ composed of two nearly equal parts. The 

 lower segment of the left antero-lateral radial is subquadrangular, 

 the angle along the basi-radial suture being so obtuse as to form 

 almost a straight line ; upper side truncate and slightly convex. 

 The upper segment is irregularly hexagonal, truncate above and 

 below, much wider at the lower than at the uj^per side, widest 

 across the lateral angles. The two together have almost the 

 dimensions of the single radials, but, in place of being wider than 

 high, they are higher than wide, with a narrow concavity for the 

 reception of the brachials. The fifth radial the right postero- 

 lateral one rests against the truncate ui:)per side of a large 

 az3'gous plate, and as this stands in line with, and has nearly- form 

 and proportions of the lower section of the compound radial, and 

 the radial plate the form of its upper segment, the two appear in 

 the specimen as if forming jointly another compound radial. 

 (See Diagr. Rev. i, PI. ii). 



There is also among the rays a great diversity in the number 

 of brachials, and this gives to the specimen that abnormal, irregu- 

 lar outline which is so characteristic of the genus. Some of the 

 rays have two, others three brachials, while the right posterior 

 ray has generally four or more. 



