1 68 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Genus Scutella Lamarck. 



Scutella Gabbi Rcmond. 

 Plate XXII, Figs. 5 and 5a. 



Clypeaster Gabbi Remond., Proc, Cal. Acad. Sci., Vol. Ill, 1863-67, p. 53. 

 Clypeaster Gabbi. Figured by Gabb., Geol. Surv. Cal., Palaeontology, Vol. 

 II, 1869, p. 36, PI. XII, figs. 64 and 64a. 



Test circular, much depressed, margin thin. Average specimens 25 to 30 

 mm. in diameter, largest specimens ranging up to 40 and 45 mm. in diameter. 



Petals short, not extending more than two-thirds of the distance to the 

 margin; excepting the anterior one, they are nearly closed at the ends. Ante- 

 rior petal wide open. Excepting in the anterior area, the ambulacral plates 

 suddenly enlarge and the area rapidly widens beyond the ends of the petals. 

 In these areas, pairs of small, round pores, diverging strongly from the ends 

 of the petals, may be present almost to the margins. In the anterior petal 

 the plates do not enlarge as noticeably toward the margin as in the others, 

 neither do the more persistent pore pairs diverge as much. 



Apical shield with four genital pores, there being none at the end of the 

 posterior interambulacral area. Anus marginal to supramarginal; in quite a 

 number of specimens it is found to be entirely on the upper surface. No 

 marked difference is noticeable between the tubercles of the upper and lower 

 surfaces. 



The ambulacral furrows of the actinal surface are not usually well preserved 

 and have been clearly seen on only a few specimens; they divide dichoto- 

 mously a little less than half-way to the margin. 



San Pablo formation, in the lowest beds. 



Scutella inter lineata Stimpson. 

 Plate XXII, Fig. 6. 



Scutella intcrlineata Stimpson, Pacific R. R. Rep., Vol. V, 1856, p. 153, PI. 



IV, fig. 30. 

 Scutella intcrlineata. Redescribed by Remond., Proc. Cal. Acad. Sci., Vol. 



Ill, 1863-67, p. 14. 



Test pentagonal to circular, angular or truncated posteriorly, somewhat 

 arched above; summit nearly central and in front of the eccentric apical sys- 

 tem, specimens ranging up to over 120 mm. in diameter. 



Ambulacra rather broad, of unequal length, anterior three of about the 

 same length and longer than the posterior pair. Anterior petal open at 

 the end, the others nearly closed. Few if any pores continuing beyond 

 the ends of the petals. 



