Oct., 1907. New Crinoids — Slocom. 275 



Among the crinoids collected in this work several proved to be 

 either hitherto undescribed or new to the Area. Of these five had been 

 described from other localities and nine were new species. Of three spe- 

 cies previously described by other authors, additional characters, which 

 are here given, were obtained from specimens found by the writer. 

 The nine new species are here described and five species previously 

 described from other localities are here re-described. A total of seven- 

 teen species of crinoids is therefore described in the present paper. 



CLASSIFICATION AND TERMINOLOGY 



The classification here used is that prepared by Wachsmuth and 

 Springer and is substantially that given in the English edition of 

 Zittel's Text-book of Paleontology. The terminology of Wachsmuth 

 and Springer is also adhered to. It may be briefly stated as follows: 



Crinoid: A normal crinoid consists of a crown attached by its 

 dorsal extremity or base to a stem or column which is fixed to some 

 solid body by a root. 



Crown: All of the crinoid above the stem. It includes the calyx 

 and the arms. 



Calyx: The body of the crinoid without the free arms or stem. 

 It incudes the dorsal cup and ventral disc or tegmen, and within it are 

 enclosed the more important organs of the body. 



Dorsal Cup: That part of the calyx below the point of attachment 

 of the free arms. It is usually more or less cup-shaped and is composed 

 of two or more rows of plates having a more or less complete pentamer- 

 ous symmetry. 



Ventral Disc, Tegmen, Dome, etc.: That part of'the calyx above the 

 point of attachment of the free arms. It is made up of plates more or 

 less regularly arranged and contains the mouth and usually the anal 

 opening. 



Base: That part of the dorsal cup lying between the radial plates 

 and the stem. It consists of a single row of plates, the basals, in a 

 monocyclic base, and of two rows of plates, the basals and infrabasals, 

 in a dicyclic base. 



Rays or Brachials : The series of plates which rests upon the basals 

 and extends up to and forms the arms. The first plate of the series 

 is always a part of the dorsal cup, the others may or may not be a part 

 of the cup. There are five of these rays, except in the Zophocrinidae, 

 and they are designated as follows: (Figs. 1 and 2) (1) right posterior 

 ray, (2) right anterior ray, (3) anterior ray, (4) left anterior ray, and (5) 

 left posterior ray. 



