&ENEEA AJSTD GROUPS OF THE ECHINOIDEA. 253 



perforated basal plates ; madreporite separating tlie lateral basals 

 and extending backwards. 



Ambulacra diverse, the anterior narrow, with few pairs of 

 pores ; paired ambulacra long, extending to the ambitus as 

 broad, • shallow unequal petals ; the interporiferous areas broad 

 and tumid or not ; the poriferous zones closing, broad. ; and the 

 anterior zone of the antero-lateral ambulacra may have small or 

 aborted pores. 



Actinally the ambulacral areas are very broad, posteriorly and 

 bare; the peristome with a long narrow labrum and a very 

 narrow and small amphisteruum. Periproct large, in the trun- 

 cation. 



Normal heteronomy of the right postero-lateral interradium. 



Ornamentation of sunken primary tubercles crenulated and 

 perforated, either numerous and in rows in the anterior and lateral 

 interradia, or few in the lateral and postero-lateral interradia. 

 A subanal fasciole, and evidences of a discontinuous peripetalous 

 fasciole or not. Spines small, usually pointing backwards, 

 longest actinally on either side of the ambulacra. Actinal plastron 

 comparatively bare. 



Fossil. Tertiary : Europe, India, Java, Australia. 



Hecent. Masbate, Borneo, China, Kingsmill Is,, New Caledonia, 

 Mauritius, Australia, Levuka Eeef, Japan, Arafura Sea, South Sea. 

 25-800 fms. 



Grenus Eupatagus, Agassiz, 1847, Catal. Beds., Ann. d. Sci. 

 Nat. ser. 3, vol. viii. p. 9. G-ray, 1855, Oat. Bee. Ecli. Brit. 

 Mus. pt. i. p. 49. Duncan Sf Sladen, 1884, Pal. Ind. 

 ser. xiv., Boss. Ech. W. Sind, p. 235, pi. xxxviii. figs. 11-13. 



Sjn. Euspatangtis. 



Test of moderate size, thin, elongate, cordiform, tumid but de- 

 pressed dorsally, narrowest and truncated posteriorly, actinally 

 flat, with a slight keel. 



Apical system small, excentric in front, with four basal plates, 

 perforated ; the madreporite in the right anterior basal plate, ex- 

 tending to the centre and posteriorly, and separating the postero- 

 lateral basal plates and posterior radial plates. 



Ambulacra diverse ; the anterior in a feeble abactinal depres- 

 sion, narrow, and with distant small pairs of pores ; the paired 

 ambulacra petaloid dorsally, long, wide, closed ; the interpori- 



