NO. 4 ECHINOIDS, TRINIDAD AND VENEZUELA — COOKE 23 



Moira atropos (Lamarck). Cooke, 1959, U. S. Geol. Surv. Prof. Pap. 321, p. yz, 

 pi. 30, figs. 1-4. 



Three large, imperfect specimens certainly represent the genus 

 Moira and probably this species, which is widely distributed in the 

 Atlantic Ocean and in the Gulf of Mexico. The largest measures 55 

 mm. in length, 45 mm. in width, and 29 mm. in height. 



Occurrence. — Venezuela: Rio Seco area, Falcon (Creole Petroleum 

 Co. V-2677, 72537). 



Geologic horizon. — Pliocene : San Gregorio formation. Also 

 Recent. 



Figured specimen. — USNM 62,^62,'/. 



AGASSIZIA SCROBICULATA Valenciennes 



PI. 5, figs. 4-7 



Agassida scrobiculata Valenciennes, 1846, Voyage de la Fregate Venus, pi. i, 



fig. 2. 

 Agasskia scrobiculata Valenciennes. A. Agassiz, 1872-1874, Harvard Coll. Mus. 



Comp. Zool. Mem., vol. 3, pp. 85, 594, pi. 19a, figs. 1-3; pi. 19b. figs. 1-3. 

 Agassicia scrobiculata Valenciennes. Grant and Hertlein, 1938, California Univ. 



(Los Angeles) Publ. in Math. Phys. Sci., vol. 2, p. 114, pi. 29, figs. 2-3; 



pi. 30, fig. 12; text fig. 10 (after Valenciennes). 

 Agassisia scrobiculata Valenciennes. Mortensen, 1951, Monograph of the Echi- 



noidea, vol. 5, pt. 2, p. 342, pi. 19, figs. 4, 10, 11 ; pi. 55, figs. 1-4, 7, 10, 13, iS- 



Includes additional synonymy. 



Test subglobular ; horizontal outline steeply sloping in front of the 

 apex, more openly curved behind. Apical system anteriorly eccentric, 

 ethmolytic ; four genital pores when mature. Petals widely spreading ; 

 anterior pair longer than the posterior, pores of anterior row very 

 small and inconspicuous; posterior pair fairly long, well developed. 

 Peristome at the anterior third. Periproct transversely oval ; near the 

 top of a posterior truncation, which curves forward near the bottom. 

 Marginal fasciole extending downward in a V-shaped projection 

 below the periproct. Lateral fascioles uniting behind the posterior 

 petals. 



Occurrence. — Venezuela: Rio Seco area, Falcon (Creole Petroleum 

 Co. 2630, 2632, 72479 (figured)). 



Geologic horizon. — Pliocene : San Gregorio formation. Also 

 Recent. 



Figured specimen. — USNM 638636. 



Remarks. — There are no apparent differences between these Plio- 

 cene forms from Venezuela and Recent specimens from the Gulf of 

 California, with which they have been compared. Grant and Hertlein 



