20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



same. No authentic specimens of E. stokcsii are available for compari- 

 son. Agassiz's figures are similar, but according to Mortensen (1928- 

 1951, vol, 4, pt. 2, p. 449) "the apical system and the vertex are pos- 

 terior as in Dendrastcr excentricus" though less so, and the posterior 

 petals are correspondingly shorter. The apical star of Encope fal- 

 conensis seems to be larger than that of E. stokesli. 



WEISBORDELLA MIRABILIS (Jackson) 

 PI. 3, figs. 7-8 



Horizontal outline subpentagonal ; lateral profile straight below, 

 arched centrally above; upper surface tumid medially; lower surface 

 very slightly concave ; margin acutely rounded. Apical system nearly 

 central ; four widely spaced small genital pores, the anterior pair 

 closer together than the posterior pair; a few scattered hydropores. 

 Petals extending about two-thirds the way to the margin, the anterior 

 pair somewhat shorter than the others; poriferous zones of nearly 

 even width, narrower than the widest part of the interporiferous 

 zones, plainly open apically, nearly closed distally, inner pores cir- 

 cular, outer pores slightly elongated; interporiferous zones lanceolate. 

 Peristome central, small, pentagonal. Periproct small, circular, near 

 the posterior fourth of the radius. Small tubercles and granules cover 

 all the test except the poriferous zones ; two large sunken tubercles 

 between the lateral petals and one in each anterior interambulacral 

 area. 



Ocurrence. — Trinidad: Bella Vista Road, Mount Moriah, San 

 Fernando (USGS 8878, J. A. Bullbrook). 



Geologic horizon. — Late Eocene : San Fernando formation. 



T3;/'(?.y.— Holotype, USNM 328247; paratype, USNM 328248. 



Remarks. — W eishordella mirabilis closely resembles W. johnsoni 

 (Twitchell) (Cooke, 1959, p. 54, pi. 20, figs. 5-7), from which it 

 differs in having six large tubercles and in the location of its peri- 

 proct, which is somewhat nearer the margin than is customary in 

 W eishordella johnsoni. The occurrence of large tubercles may be a 

 variable feature, as in W eishordella cubae (Weisbord) (Cooke, 1959, 

 p. 53, pi. 20, figs. 1-4), and the distance of the periproct from the 

 margin may vary with the shape of the test. As the types are the only 

 representatives thus far discovered, the range of variability is 

 unknown. 



