6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



is extinct there, though it now lives in the Gulf of California and in 

 the Pacific Ocean. 



DESCRIPTIONS OF SPECIES 



MESOZOIC SPECIES 

 TETRAGRAMMA sp. 



Two fragments resembling Tetragramma streeruwitzi (Cragin) 

 (Cooke, 1946, p. 208, pi. 31, fig. 23) in all recognizable features are 

 too poorly preserved for specific identification. The apical system is 

 wanting. The poriferous zones are biserial on the upper part of the 

 test, uniserial below. There are two rows of large perforated, crenu- 

 lated tubercles in each ambulacrum, six in each interambulacral area. 

 The median part of the latter contains only granules. 



Occurrence. — Venezuela: El Pao, "Ojo de Agua," Cojedes (Mene 

 Grande Petroleum Co. B-2454). 



Geologic horizon. — No data. Early Cretaceous, presumably late 

 Albian. 



HOLECTYPUS (CAENHOLECTYPUS) PLANATUS APONENSIS Cooke, 



n. subsp. 



PI. 2, figs. 4-5 



This subspecies, represented by only one individual, whose upper 

 surface is defective, differs from the typical Holectypus planatus 

 Roemer (Cooke, 1946, p. 217, pi. 32, fig. 13; 1955, p. 94, pi. 21, 

 figs. 1-3) in its lesser height and more acute margin. This shape 

 appears to be original, not caused by compression. The typical form 

 is abundant in the Trinity and Fredericksburg groups of Texas, of 

 early and middle Albian ages. It has been recorded also from the late 

 Albian of Colombia (Cooke, 1955, pp. 87, 94). 



Occurrence. — Venezuela: Rio Apon, Zulia (Creole Petroleum Co. 

 50878). 



Geologic horizon. — Early Cretaceous : Capacho formation, of 

 middle Albian to Vraconian age. 



Holotype.—VS'NM 131169. 



PHYLLOBRISSUS ZULIANUS Cooke, n. sp. 



PI. I, figs. 10-12 



Test subquadrate, rounded in front, truncated behind, sides nearly 

 parallel. Upper surface slightly inflated, highest point at the apical 

 system, sloping more steeply in front, less steeply behind ; lower sur- 



