244 ECHINODERMATA—ECHINOIDEA SUB-BRANCH III 
the elongate apical system, its pairs of pores numerous and small, the rows 
wide apart. Paired 4m) more or less curved, open distally, with dissimilar 
+95) _— 
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2° 69\ 

Fic. 393. 
A, B, Holaster subglobosus, Ag. Cenomanian; Rouen, 1/). C, H. suborbicularis, Defr. Dorso-central system, 
enlarged. 
pores. Peristome much sunken, crescent-shaped, broad. Periproct supra- 
marginal. Upper Cretaceous. H. radiatus, Lam. sp. 
Cardiaster, Forbes (Stegaster, Pomel, p.p.) Similar to Holaster, but anterior 
groove deeper and with angular margin. Periproct oval, placed in a depression 
in the truncated posterior face. A more or less complete marginal fasciole 
passing below the periproct. Cretaceous. 
Sub-genus Infulaster, Hagw. Test high in front, narrow ; anterior groove deep and with 
strong lateral keels. Fasciole absent. Upper Cretaceous. 
Hagenowia, Duncan (Cardiaster, Forbes, p.p.; Stegaster, Pomel, p.p.) 
Upper Cretaceous. 
Urechinus, Cystechinus, A. Ag. Late Tertiary and Recent.  Calymne, 
Wyv. Thoms. Recent. Hnichaster, de Loriol. Oligocene. All with uni- 
porous Amb. 
Stenonia, Desor. Like Echinocorys (Ananchytes), except that the apical 
system is compact, and the dmb equal. The solitary species, S. tuberculata, 
Defr. sp., is abundant in the Upper Cretaceous (Scaglia) of the Southern Alps 
and the Apennines. 
Family 2. Spatangidae. Wright. 
Test ovoid or cordiform, longer than broad, with numerous plates, and usually 
with an anterior groove. Ambulacra in a bivium and trivium, the anterior differing 
from the others in shape and construction. Pairs of pores of the petaloid parts 
differing from the others. Fascioles present or absent. Cretaceous to Recent. 
Section A. ADETES. All fascioles absent. 
Isaster, Desor. Petals not closed. Peristome large, with a posterior 
labrum. Cretaceous. 
Epiaster, VOrb. (Macraster, Roemer.) Anterior Amb in a groove ; paired 
