232 



ECHINODERMATA ECHINOIDEA 



SUB-BRANCH III 



ambitus, sometimes disappearing toward the apical system. Tertiary and 

 Eecent. 



Podocidaris, A. Ag. Eecent ; Caribbean Sea and Philippines. 



Family 6. Temnopleuridae. 



Test highly ornamented, tumid, or spheroidal. Ambulacra with triple compound 

 plates, united with the interambulacral plates by grooved and sometimes pitted sutures. 

 All plates of the test, except the component ambulacral plates, united by a dowelling of 

 knobs and sockets. 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. Transverse and median sutures 

 grooved. Cretaceous and Eocene. 



Dictyopleurus, Duncan and Sladen. Eocene ; Asia and Europe. Egypt. 

 Paradoxechinus, Laube. Miocene ; Australia. Hchinocyphus, Cott., and Zeuglo- 

 pleurus, Gregory. Cretaceous ; Europe. 



Temnopleurus, Ag. Transverse 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 plain primaries. Apical system prominent, 

 compact, the sutures between the plates more or less grooved. Late Tertiary 

 and Recent. 



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

 and Holopneustes, Ag. Recent. 



Family 7. Echinometridae. Gray (emend. A. Agassiz). 



Test large, either symmetrical and polyporous, or with the long axis not coinciding 

 with the antero-posterior axis, and the compound ambulacral plates with three or more 

 pairs of pores. Teeth keeled. Tertiary and Recent. 



Heterocentrotus, Colobocentrotus, Brandt ; and Echinometra, Rondelet. Recent. 

 'es, Ag. (Heliocidaris, Desm.), (Fig. 373). Antero-posterior axis 



forming an angle with 

 the major diameter. Amb 

 straight, with pores in 

 arcs of three pairs dor- 

 sally, crowded and tri- 

 serial below the ambitus. 

 Both areas with two 

 vertical rows of plain 

 tubercles, diminishing 

 actinally and dorsally. 



FIG. 373. 



Stomopneustes variolaris, Ag. 

 pound Amb plate. 



Com- 



FIG. 374. 



yngylocentrotus 

 , Mull. 



sp. 



Droebach- 

 Compound 



Stro 

 iensis, 

 Amb plate. 



Tertiary and Recent. 

 Strongylocentrotus, Brandt (Fig. 374). Test symmetrical and polyporous. 

 Amb straight, broad at the ambitus and peristome, and with broad poriferous 

 zones. Pairs of pores in oblique arcs, or almost transverse series of from four 

 to ten pairs, and crowded actinally. Interporiferous areas with two vertical 

 rows of plain, imperforate primary tubercles ; secondaries and miliaries also 



