458 SYSTEMATIC PALEONTOLOGY 



Superfamily SPH^ROIDEA. 

 Family ASTROSPH/ERA. 



Genus ACANTHOSPH/^RA Haeckel. 



AcANTHOSPH^RA PARVULA Vinassa. 



Plate CXXX, Fig. 21. 



Acanthoxphiera parinila Viuassa, 1900, Mem. d. R. Accad. d. Sci. d. Istit. d. Bologna, 

 ser. V, voL viii, p. 3o4, pL i, tij;-. 29. 



Description. — " Sfera piccola, sottile, levigata, con pori numerosi, 

 grancli, assai fitti, rotondi e tutti uguali. Aculei brevi conici, poco num- 

 erosi, irregolarmente sparsi. 



"Diametro della sfera: mm. 0,065; altezza degli aculei: mm. 0,62." 

 Vinassa, 1900. 



This species may be at once distinguished from the other Radiolaria 

 which have been observed in these beds by the presence of the small spines 

 radiating in all directions. Its size also is characteristic. 



Occurrence. — Calvert Formation. Popes Creek. 



Collection. — Maryland Geological Survey. 



Family CUBOSPH^ERIDA. 



Genus HEXALONCHE Haeckel. 

 Hexalonche microsph^era Vinassa. 



Plate CXXX, Fig. 22. 



Hexalonche microitphara Vinassa, 1900, Mem. d. R. Accad. d. Sci. d. Istit. d. 

 Bologna, ser. v, vol. viii, p. 2o3, pi. i, fig. 23. 



Descriftion. — " Sfera corticale assai grande e spessa, scabrosa ; pori 

 ovali o rotondi, non molto grandi e profundi. Sfera midoUare levigata, 

 piccolissima, munita di piccoli pori rotondi, unita alia corticale da sotilli 

 processi, quasi filiformi. Aculei conici, assai lunghi, acuti, non carenati. 



" Diametro della sfera interna : mm. 0,02 ; della esterna : mm. 0,12 ; 

 altezza degli aculei 0,056." Vinassa, 1900. 



Cortical shell rough; pores circular or subcircular, not varying much in 

 size, diameter slightly greater than the width of the bars, or about 1/12 

 the diameter of the cortical shell; medullary shell about 2/7 the diameter 

 of the cortical shell ; spines triangular-pyramidal, twisted, as long as the 



