ORDER V 



EUECHINOIDEA SPATANGOIDEA 



245 



Ami petaloid dorsally, with elongate, unequal pores. lAmb tumid dorsally. 

 Peristome transverse, tumid in front, and usually with projecting labrum. 

 Periproct longitudinal, supra- 

 marginal. Cretaceous. 



ri 1 Tt / rn 



EchMospatagw, Breyn. (Tox- 

 aster, Ag. p.p.) Anterior Anib 

 in a broad shallow groove, with 

 unequal pairs of pores. Paired 

 A ml sub-petaloid, flexuous, with 

 unequal poriferous zones and un- 

 equal pairs of pores. Peristome 

 transverse, sub-circular, or penta- 

 gonal. Tubercles small, per- 

 forate, and crenulate. Abundant 

 in Lower and Middle Cretaceous. 



k'ltit'iltiafrr, d'Orb. (Heteraster, 

 d'Orb.) Petaloid parts of antero-lateral Amb divergent, flexuous, tending to 

 close, and with very unequal poriferous zones, of which the posterior are the 

 ' ; pairs of pores oblique. Postero - lateral Amb short, divergent. 

 IVristome labiate, wide, arched in front. Periproct in posterior truncation. 

 Cretaceous. 



H'-mipatagus, Desor (Fig. 395). Test small, cordiform. Anterior Amb 

 with small pores in a shallow furrow. Paired Amb long, petaloid, nearly 





Pro. 395. w/r 



Hemipatagw Hofmannl, Goldf. Oligo- \V 



e; Doberg, near Biinde. A, Dorsal 

 \v. /;, I'ruiile. C, Ventral aspect, 1/1 

 (after Goldfuss). ^^^^"^ 



flush. The lateral I Amb with a few large perforate and crenulate tubercles 

 in deep scrobicules. Periproct supra-marginal. Tertiary. 



Platybrissus, Grube. Recent. Palaeopneustes, A. Ag. Recent, and perhaps 

 Eocene. 



SECTION B. PRYMNADETES. Subanal fascicle absent, other fascicles present. 



Hemiaster, Desor (Fig. 396). Anterior Amb in a shallow groove, the 

 pores oblique, and in pairs on either side. Antero-lateral Amb petaloid 

 dorsally, sunken, diverging, and much longer than the postero-lateral. Pores 

 of the petaloid parts conjugated, the outer ones usually the largest. Peri- 

 petalous fasciole present. 



Sub-genus Tripylus, Phill. (Abatus, Troschel). Recent. 



