1920] Kew: Cretaceous and Cenozoic Echinoidea 139 



a rather high central apex ; posterior end somewhat truncated. Apical 

 system small and eccentric to the anterior ; four large genital pores 

 present. Ambulacra narrow and subpetaloid. Petals of the bivium 

 considerably longer than those of the trivium ; all very narrow and 

 of the same width ; rows of pores of the paired petals extend in 

 approximately parallel lines the entire length of the petals, so that 

 the latter are wide open at their extremities ; odd anterior petal 

 slightly elliptical in outline, the rows of pores converging to a slight 

 degree in the distal part. Inferior surface concave around the mouth, 

 •which is pentagonal in outline and transversely elongate. Periproct 

 large, transversely elongate, situated above the ambitus and below a 

 prominent overhanging rostrum. Rather large scrobicular tubercles 

 covering the under side ; those of the upper surface considerably 

 smaller. 



Belated forms. — This form may be separated from other Pacific 

 Coast species of Rhynchopygus by its very narrow petals, which have 

 approximately parallel rows of pores. 



Geologic horizon. — Tejon series, Upper Eocene; associated with 

 Scutella ( 1.) sp. Anderson. 



Locality. — Original holotype from "Avenal Sands west and north 

 of Coalinga;" neotype from SW. 14 of NW. 14, Sec. 24, T. 18 S., R. 

 14 E., near Salt Creek, Coalinga district, Fresno County, California. 



CASSIDULUS (EHYNCHOPYGUS) ELLIPTICUS Kew, n. sp. 

 Plate 39, figures 3rt, 35, 3c, 3d 



Cotypes.—Nos. 11346 and 11347 Univ. Calif. Coll. Invert. Pal. 



Test small. Measurements of specimen no. 11346 : anteroposterior 

 diameter 20.2 mm., transverse diameter 13.6 mm., greatest height 6.3 

 mm. Ambital outline strongly elliptical. Upper surface somewhat 

 depressed and rising immediately from the margin to the apex, which 

 is anteriorly eccentric. Apical system small and eccentric to the 

 anterior ; four relatively large genital pores present. Ambulacra nar- 

 row and subpetaloid. Petals of the bivium very narrow, with the 

 rows of pores extending in nearly parallel lines to the end ; each 

 poriferous area of about the same width as the interporiferous area ; 

 anterior pair shorter than the other petals and subelliptical in outline ; 

 the rows of pores converge slightly in their distal ends. Odd anterior 

 petal of the same length as the petals of the bivium and of the same 

 width as the anterior pair; the rows of pores with only a slight 



