Fio. 424. 



CLASS I ECHINOIDEA 297 



elongate, conjugated pores. Periproct supra-marginal; apical system eccentric 

 in front. Broad subanal fascicle. Abundant in Middle and Upper Cretaceous ; 

 less common in Eocene and Miocene. 



Brissus Gray (Brissomorpha Laube) ; Meoma and Metalia Gray. Tertiary 

 and Eecent. Bhinobrissus A. As. Eecent. 



Brissopsis Ag. {Deakia Pavay) (Fig. 424). Amb unequal, bare and large 



near the peristome. Anterior Amb slightly sunken, with 



small pairs of close pores. Paired Amb sunken, the 



antero-lateral pair sub-petaloid, equal to or larger than 



the postero-lateral, straight or curved. A subanal and ^i^j^^^;^§^>>^^^<^|\ij^ 



peripetalous fasciole. Tertiary and Recent. 



Subgenus Cyclaster Cotteau. Antero - lateral Amh divergent. 

 Eocene. 



Brissopatagus Cotteau. Allied to Brissopsis. Eocene. 



Spatangus Lam. Anterior Amb in a broad, deep groove, 

 with distant pairs of small pores. Paired Amb petaloid, Brissop',sis lyH/era 

 with broad, sunken poriferous areas. Periproct large, fX^^'^ed (!rfte\^Lov6n)^'"' 

 supra-marginal, transverse. lAmb with large crenulate 

 and perforate primary tubercles, and fine granulation. Subanal fasciole only. 

 Tertiary and Recent. 



Maretia Gray. Tertiary and Recent. 



Eupatagus Ag. Anterior Amb in a shallow, abactinal depression, narrow, 

 and with small, distant pore-pairs. The paired Amh petaloid dorsally, long, 

 wide, closed ; poriferous areas broad, more or less sunken ; pores dissimilar. 

 Peripetalous and subanal fasciole. Tertiary and Recent. 



Subgenus Macropneustes Ag. (Peripneustes Cott. ) (Fig. 425). Test large, thick, cordiform. 

 Petals elongate or broad, grooved or semi-flush, open or im]ierfectly closed. Poriferous areas 

 of equal width with the interporiferous. Eocene and Recent. 



GuaUieria Desor ; Eocene. Echinocardium Gray (Eig. 371, F) ; Breynia 

 DesOr ; Lovenia Ag. and Desor. Tertiary and Recent. 



Section D. Apetala. 



Ambulacra flush, apetalous, generally uniporoiis, and either similar or diverse ; 

 plates high, few, often hexagonal. Fascioles usually present. 



Under this head are included the following Recent genera, all but the first 

 two of which have fascioles : Genicopatagus and Palaeobrissus A. Ag. ; Aceste 

 Wyv. Thomson ; Aeropsis Mortensen ; Palaeotropus Loven ; Homolampas, 

 Argopatagus A. Ag. ; and Cleistechinus de Loriol. Miocene. 



Family 6. Palaeostomatidae Mortensen. 



Test thin, ovoid. Apical system with three genital plates fused into one. 

 Peristome eccentric in front, pentagonal, with five angular plates. 



Palaeostoma Lov6n (Leskia Gray). Recent ; China, East Indian Islands. 



Family 7. Pourtalesiidae Loven. 



Test very elongate, sub-cylindrical or obconical, truncated anteriorly, flat actinally. 

 Peristome in a deep anterior recess ; periproct actinal, or above the projecting posterior 



