CLASÖ I 



ECHINOIDEA 



291 



transversely elongate, and in a long groove. Periproct high up, usually in a 

 groove along the median line of the posterior lAmb. Upper Jura. 



Pygurus Ag. (Fig. 410). Test large, angular, rounded or cordiform in 

 marginal contour ; depressed or rather tall and sub-conical dorsally. Amh 



Fig. 411. 

 Echinolampas kleini Goldf. Oligocene ; Doberg, near Bünde, i/i. 



flush dorsally, unequal, wide ; the petaloid parts contracting but not closing 

 marginally, and expanding again actinally, where the Amb are grooved. Peri- 

 proct infra-marginal, pyriform or ovoid, in a special area, or rostrum, close to 

 the posterior edge of the test. Upper Jura and Cretaceous. 



JEchinolampas Gray (Fig. 411). Test variable in size and shape, more 

 or less ovoid or circular at the tumid 

 marginal outline; tall and conical or 

 depressed dorsally. Amb petaloid for 

 a variable distance; pores of the petals 

 difFering in shape, conjugated and con- 

 tinued beyond in simple series. Peri- 

 stome slightly in front, or sometimes 

 central. Periproct transversely ellip- 

 tical, infra-marginal. Widespread in 

 Tertiary and Recent. 



Conolampas and Neolampas A. Ag. 

 Recent. Plesiolampas Duncan and 

 Sladen. Eocene. Palaeolampas Bell. 

 •Upper Cretaceous to Recent. 



Family 3. Oollyritidae d'Orbigny 

 {Dysasterinae Gray). 



Apical System disconneäed, either 

 elongate or sub- compact. Ambulacra 

 similar ; bivium widely separated from fio. 4i2. 



the trivium; ßoSCelle absent. Jura to Cü%rite5 e^^ii>^ica pesm CaUovian ; Mamers, Sarthe. 

 -* •' A, B, Test in proüle and froui above, Vi- C'» Apical 



Cretaceous. system, enlarged. 



