47 







L 



Family TAXICRINID^. 



forbesocbinus pyriformis, n. sp. 

 Plate n\ PVg: 1, view of an almost entire specimen. 



General foiiii of the calyx and arms, together, subovate or 

 somewhat pear-shaped, which suggested the specific name. The 

 column is round, large and tapers rapidly from the calyx, where 

 it is composed of very thin plates. 



The calyx constitutes more than half the length of the body 

 it is wider than high and somewhat obconoidal or funnel- 

 shaped above the column. The plates are convex. The infcer- 

 radial areas are long and narrow, slightly flattened and de- 

 pressed below the radial series, which are gently rounded. 



Basal plates not observed. Subradials rather small. Primary 

 radials twice as wide as high, convex on the outer face, pentag- 

 onal, hexagonal, or heptagonal, depending upon the number of 

 interradials that abut upon them laterally ; four in each of four 

 series and only three in one of the lateral series; concave on 

 the upper sides, immediately below which, they are most pro- 

 tuberant. The upper plates slightly overlap the next lower 

 ones, in the middle part, though not by a little toothlike pro- 

 jection, as in ForbesocrJnus a^assizi. This projection is de- 

 scribed as a distinct plate and called a "small patelloid plate," 

 by Hall, in the Geological Report of Iowa, vol. 1, pt. 2, p. 631, 

 and we find that error, in respect to F. agassizi, transferred to 

 the definition of the genus, in the "Revision of the Palifocrino- 

 idea," by Waclismuth & Springer, page 51, where they say 

 "The sutures of the radial and arm plates strongly sinuate, 

 and partly occupied by additional patelloid plates." The tooth- 

 like projection, in Forbesocrinus agassizi, is not a separate 

 plate; there are no patelloid plates in any species of Forbeso- 

 crinus, and it is not too much to say, they have no existence, 



