NO. 4 ECHINOIDS, TRINIDAD AND VENEZUELA — COOKE 27 



Occurrence.— Venezuela: San Mateo, Lara (Creole Petroleum Co. 

 99004). 



Geologic horizon. — Late Eocene. 

 Holotypc. — USNM 115379. 



BRISSUS UNICOLOR (Leske) 

 PI. 7, figs. 1-4 



Spatangus brissns var. nnicolor Leske, 1778, Klein's Naturalis dispositio echino- 



(lermatum, p. 248, pi. 26, figs. B-C. 

 Brisstis exiguHs Cotteau, 1875, K. Svenska Vetensk.-Akad. Handl., N.F. vol. 13, 



No. 6, p. 35, pi. 6, figs. 16-18. 

 Brissus exiguiis Cotteau. Jackson, 1922, Carnegie Inst. Washington Publ. 306, 



p. 87, pi. IS, figs. 2-4. 

 Brisstis unicolor (Leske). Cooke, 1959, U. S. Geol. Surv. Prof. Pap. 321, p. 81, 



pi. 36, figs. 1-4. 



This well-known Recent species is represented by one fairly well 

 preserved specimen and one fragment. They are remarkably similar 

 to Recent specimens of the same size from Haiti, from which they 

 differ in the apparently farther forward location of the apical system, 

 which has been foreshortened by slight crushing, which also has 

 deepened the anterior paired petals. The apical system and the lower 

 margin of the peristome are wanting. The peripetalous and subanal 

 fascioles are like those of the Recent species. 



Brissus exiguus Cotteau, from the Miocene of Anguilla, seems to 

 be this same species. The holotype (USNM 115396) is a juvenile 

 with only three genital pores. Its left side and base have been crushed. 



Occurrence. — Trinidad: Savanetta, near Gran Couva (Trinidad 

 Oil Co. 254677). 



Geologic horizon. — Late Miocene: Springvale formation. 



Figured specimen. — USNM 638641. 



BRISSOPSIS ANTILLARUM Cotteau 

 Pi. 12, figs. 1-4 



Brissopsis antillarum Cotteau, 1875, K. Svenska Vetensk.-Akad. Handl., N.F., 



vol. 13, No. 6, p. 37, pl. 6, figs. 19-25. 

 Brissopsis antillarum Cotteau. Jackson, 1922, Carnegie Inst. Washington Publ. 



306, p. 82, pl. 14, figs. 3-4. 



Horizontal outline subovate, notched in front, truncated behind. 

 Apical system slightly anterior ; four genital pores ; ethmolytic. An- 

 terior ambulacrum strongly depressed on upper surface, slightly 

 notching the margin, almost flat on lower surface; paired pores sepa- 



