CLASR I ECHINOIDEA 297 



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

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

 less common in Eocene and Miocene. 



JBrissus Gray {Brissomorpha Laube) ; Meoma and Metalia Gray. Tertiary 

 and Recent. Bhinobrissus A. Ag. Recent. 



Brissopsis Ag. (DeaJcia 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 

 peripetalous fasciole. Tertiary and Recent. 



Subgenus Cydastcr Cotteau. Antero - lateral Amh divergent. 

 Eocene. 



Brissopatagus Cotteau. AUied to Brissopsis. Eocene. 



Spatangus Lam. Anterior Amb in a broad, deep groove, ^^^ ^2^ 



with distant pairs of small pores. Paired Amb petaloid, Brisso2J:sis lyHfera 

 with broad, sunken poriferous areas. Periproct large, J^jar^ed f^terLovIn?"' 

 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 Amb 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 imperfectly closed. Poriferous areas 

 of equal widtli witli the interporiferous. Eocene and Recent. 



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

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



Section D. Apetala. 



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

 plates high, few, oflen 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 

 Wy V. Thomson ; Aeropsis Mortensen ; Palaeotropus Lov6n ; 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 anterimiy, flat actinally. 

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



