CRINOIDS AND BLASTOIDS. 203 



plates; being neither - elevated nor depressed. The lancet piece 

 extends to the sides of the radial sinus ; it is rounded along its 

 outer face, forming a longitudinal groove at each side, at the 

 bottom of which the clefts are placed. The lancet piece is 

 completely covered by the side pieces, which embrace the food 

 grooves, except near the oral center, where the grooves grow 

 deeper and are placed between the edges of two adjoining del- 

 toids. There are about fifteen side pieces to each side of the 

 ambulacrum, and an equal number of pinnules, but no pores 

 exist along the sides. The clefts are formed between the ambu- 

 lacra and the constricted portions of the deltoids, and hence do 

 not extend to the full length of the ambulacra. The clefts are 

 wider at their proximal end, and slightly curved, w r hich gives to 

 the ambulacra their petaloid form, The pinnules are longer 

 than those of any previously described Blastoid, their length 

 being twice that of the calyx. They are of uniform thickness 

 throughout, and composed of two rows of pieces, alternately 

 arranged. Their ventral furrow is wide and apparently covered 

 by small plates. 



The column has been observed by us to a length of seven 

 inches, and was apparently much longer. It is stout close to 

 the calyx, whence it tapers rapidly; afterwards it remains nearly 

 uniform, with a few scattering cirrhi toward the end. The stem 

 joints at the upper end are extremely short, with a very sharp 

 edge, but they gradually grow longer and cylindrical. 



Geological position, etc.: The same as the last. 

 From our collection. 



OROPHOCRINUS FUSIFORMIS (sp. nov.) W. & Sp. 



PI XVII, Fig. 4. A fine specimen having its pinnules preserved, and portions 



of the stem. 



Calyx elongate, biturbinate. Dorsal side up to the radial 

 lips, longer than wide; angular radially; the sides undulating; 

 the lips projecting. Ventral side, from the radial lips upward, 

 nearly as long as the dorsal, but the sides convex, curving 

 gently. Cross section through the radial lips decagonal, with 

 five salient and five retreating angles, and this is the case, to a 



