CLASS I ECHINOIDEA 279 



Suborder B. STIRODONTA Jackson. 



Teetli keeled. Epiplujses narrow, not meeting in suture over the foramen 

 magniim. Amhulacral plates Compound or largely simple. Coronal plates not 

 imbricate. Primordial interambulacral plates resorhed or retained in the basicoronal 

 row. Base of corona resorbed or not. Oculars all exsert or becoming insert in the 

 sequence I, V, or V, I, IF, II, III. Periproct with prominent suranal, o?' mth 

 many small plates, or foiir, or five large plates only. Peristome with ten primordial 

 ambulacral, also non-ambulacral plates. Lantern erect. Primary tuber des 

 imperforate, or exceptionally perforate. Jurassic to Recent. 



Family 1. Saleniidae Desor. 



Ambulacral plates Compound, or largely simple. Primordial interambulacral 

 plates resorbed, Base of corona resorbed. Oculars exsert or becoming insert in the 

 sequence I, V, IV, II, III. Periproct with a permanent large suranal, or more 

 large plates, with small anal plates. Primary tubercles imperfm^ate, or perforate. 

 No spurs from pyramids supporting teeth dorsally. Jura to Recent. 



Peltastes Ag. (Fig. 391). Amb straight or slightly flexuous, with simple 



Fig. 391. 



Peltastes, apical System ; 



m, madreporite. ^ '^IBSSF^ Fio 392 



Salenia fcutigera Gray. White Clialk ; Charente 

 (after Cotteau). A, Lateral and dorsal aspects of 

 tests, Vi- ^> Apical System, enlarged. 



plates abactinally and with small primary tubercles near the poriferous 

 areas. lAmb broad, with large, imperforate primary tubercles, diminishing 

 in size toward the poles. The suranal plate is small, in contact with the 

 lateral genitals, but not touching the posterior one. Upper Jura and 

 Cretaceous. 



Salenia Gray (Fig. 392). Test small, globose, or depressed. Amb plates 

 Compound or largely simple. The suranal plate is in contact with all the 

 genitals ; oculars all exsert or ocular I reaching the periproct, perforated at 

 the adoral edge. Cretaceous to Recent. 



Goniophorus Agassiz. Upper Greensand ; Europe. Heterosalenia 

 Cotteau. Cretaceous ; Europe. 



Acrosalenia Ag. (Figs. 368, C; 393). Test depressed. Amb plates simple 

 primaries near the apical system, Compound near the ambitus and actinally. 

 lAmb tubercles large, perforate, and crenulate ; those of the Arnb much smaller, 

 and in two vertical rows. Periproct large, bounded anteriorly by the suranal 

 plate, which is in contact with the four large anterior genitals, or more 



