1914] Kew: Tertiary Echinoids of the Carrizo Creek Region 51 



bulacral area twice as wide as the ambulacra! area. Five primary 

 tubercles on each iuterambulacral plate near the ambitus and arranged 

 in radial rows. The number of tubercles becomes less toward the 

 apical system. 



The Recent Hipponoe clepressa A. Agassiz found in the Gulf of 

 California and on the west coast of Lower California is closely allied 

 to Hipponoe calif 'ornica. The latter has less number of tubercles than 

 the former and also the ambitus is situated farther toward the base, 

 giving it a more conical shape. 



Occurrence. — Lower Division of the Carrizo formation at Carrizo 

 Valley. University of California Locality 206-1. 



Measurements. — Specimen no. 10055, transverse diameter approxi- 

 mately 85 mm. ; greatest thickness approximately 75 mm. 



CIDARIS, sp. 



Genital plates pentagonal with rounded sides. Genital pores large. 

 Abaetinal surface has a single row of primary tubercles at both 

 margins of the iuterambulacral area. Interporiferous area contains a 

 double row of primaries. Below the ambitus, the iuterambulacral 

 area of the test contains numerous primary tubercles sporadically 

 • placed. Ambulacral area about one-third that of the interambulacral 

 area. Ambulacral pores arranged in straight radial rows. Spines 

 cylindrical, elongate, and granulated, the granulation being arranged 

 in vertical rows. Internal structure of the spines consists of rows of 

 mesh-like cells radiating from a central point. 



The description of the test is taken from an imperfect young 

 specimen, from the Lower Division of the Carrizo formation. 



ECHINODERM LOCALITIES 



737. Southeast base of Coyote Mountain in gully in which road to Coyote 



Mountain runs. Quarter mile southwest of andesite hill. Lower 

 Division of Carrizo formation. 



738. Southeast base of Coyote Mountain in second gully to west of locality 



737. Soft sandstone of Lower Division of Carrizo formation. 



739. At head of south fork of the large canon on southeast side of Coyote 



Mountain. Hard sandstone of Lower Division of Carrizo formation. 

 2064. At head of Garnet Canon on northwest side of Coyote Mountain and 

 north side of Coyote Eidge. Hard sandstone of Lower Division of 

 Carrizo formation. 



Transmitted December 22, 1913. 



