10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



than the type, but these features can be matched by specimens from 

 the Fredericksburg group of Texas. Three other individuals from 

 Venezuela resemble the holotype in shape but are not well preserved. 



Occurrence. — Venezuela: Rio Caripe, Monagas (Creole Petroleum 

 Co. 51381). 



Geologic horizon. — Early Cretaceous. In Texas the species is 

 abundant in the Goodland limestone, of Albian age. 



Figured specimen. — USNM 131 171. 



CENOZOIC SPECIES 

 LYTECHINUS VARIEGATUS (Leske) 



PI. 5, figs. 1-2 



This common Recent species, which now ranges from North Caro- 

 lina to Santos, Brazil, is represented by the two fragments figured. 



Occurrence. — Venezuela: Rio Seco area. Falcon (Creole Petro- 

 leum Co. 72466, 72479), 



Geologic horizon. — Pliocene : San Gregorio formation. 



Figured specimens. — USNM 638624a, b. 



PHYMOSOMA TRINITENSIS Cooke, n. sp. 

 PI. 2, figs. 1-3 



Horizontal outline circular; upper surface slightly inflated; lower 

 surface slightly concave; margin rounded. Apical system wanting; 

 outline pentagonal, the posterior point elongated, the sides weakly 

 fluted. Ambulacra widening regularly to the margin; the first few 

 zygopores uniserial, the later zygopores staggered or biserial to the 

 peristome. Peristome occupying about one-third of the diameter; 

 weakly notched. Primary tubercles smooth, imperforate ; two rows in 

 each area. Secondary tubercles scattered over all areas except the 

 median parts of the interambulacral areas near the apex, which are 

 bare. 



Diameter of holotype 24 mm. ; height 8.7 mm. ; diameter of peri- 

 stome 8.7 mm. 



Occurrence. — Trinidad : Marac quarry, M. C. Cater, collector. 



Geologic horizon. — Paleocene. 



Ty/)^:?.— Holotype, USNM 638643a. Paratype, USNM 638643b. 



Comparisons. — This species, which is represented by the holotype 

 and one paratype, closely resembles Phymosoma hilli (Clark) (Cooke, 

 1953, p. 9, pi. 3, figs. 6-7), from which it difiiers chiefly in the arrange- 



