282 ECHINODEEMATA— ECHINOZOA phylum iv 



Stirechinus Desor. Both areas with two rows of large, piain, primary 

 tubercles situated on raised keel-like projections. Pliocene ; Europe. 



Glyptechinus de Loriol. Cretaceous. Tripneustes Agassiz. Miocene and 

 Recent. 



Hypechinus Desor. Tertiary. Toxopneustes Agassiz. Recent. Boletia 

 Desor. Recent. 



Family 2. Temnopleuridae Desor. 



AmUtus circular. Pits, or sculpturing in coronal plates dorsally. Ambulacral 

 plates at the mid-zone composed of three elements each. Oculars usually all exsert. 

 Cretaceous to Recent. 



Glyphocyphus Haime. Test small, depressed spheroidal. Amb narrow, 

 straight, with two vertical rows of small, perforate, crenulate, primary 

 tubercles, and numerous miliaries. lAmb broad, with two rows of primaries 

 somewhat larger than those of the Amb. Transvörse and median sutures 

 grooved. Oculars all insert. Cretaceous and Eocene. 



Didyopleurus Duncan and Sladen. Eoncene ; Asia, Europe and Egypt. 

 Paradoxechinus Laube. Miocene ; Australia. Echinocyphus Cotteau, and Zeuglo- 

 pleurus Gregory. Cretaceous ; Europe. 



Temnopleiirus Ag. Trans verse sutures of all plates grooved and pitted. 

 Apical System small, compact, slightly projecting. Tertiary and Recent. 



Temnechinus Forbes. Test small, subglobose, depressed abactinally. 

 Both areas with two vertical rows of piain primaries. Apical System 

 prominent, compact, the sutures between the plates more or less grooved. 

 Late Tertiary and Recent. 



Salmacis Ag. Eocene, Pliocene and Recent. Älicrocyphus, Amblypneustes, 

 and Holopneustes Agassiz. Recent. 



Family 3. Strongylocentrotidae Gregory. 



Ambitus circular. No pits or sculpturing in the coronal plates. Ambulacral 



plates at the mid-zone composed of from four to ten elements each, rarely (some 



Echinostrephus) of three elements each. Oculars all exsert or becoming insert in the 

 I, F, IF, II. Tertiary to Recent. 



Strongylocentrotus Brandt (Figs. 371, E ; 372-3, 



396). Test symmetrical and polyporous. ^m& straight, 



broad at the ambitus and peristome, and with broad 



poriferous areas. Pore-pairs in oblique arcs or almost 



transverse series of from four to ten pairs, and crowded 



actinally. Interporiferous areas with two vertical 



Flu. 396. rows of piain imperforate primary tubercles; secondaries 



strongylocentrotus dröbach- and miliarics also present. lAmb with two rows of 



po^^uM Sm4iat?!'^^'''^" ^''"" primary, and four or more of secondary tubercles. 



Late Tertiary and Recent. 



Sphaerechinus Desor. Amb straight, wide. Pore-pairs in arcs or oblique 



lines of four to eight pairs, polyserial actinally. Interporiferous areas with 



two to six vertical rows of piain, imperforate primaries, and horizontal rows 



of secondary tubercles and miliaries. lAmb with two to twelve vertical rows 



of primaries. Pliocene and Recent. 



Eurypneustes and Aeolopneustes Duncan and Sladen. Eocene ; Asia. 



