139 



from the excentric vertex ; the vent marginal. — Encyc. PI. 

 cxliv. fig. 1, 2. 



9. C oviformis, 



Echinantlius ovatus. — Leske ap. Klein, Tab. xx. fig. c. d. 

 Recent and fossil. Found in the South Seas. 



10. C. politus. — Ovate, inflated, and smooth ; with five 

 long narrow ambulacral compartments, open at their termi- 

 nations. Fossil, from Sienna. 



11. C. hemisphcBricus. — Orbicular, convex, and semi- 

 globose ; with five ambulacral divisions radiating from the ex- 

 centrical vertex- Fossil. 



12. C. stelliferus. — Ovate and tumid; Avith five long 

 narrow ambulacral divisions, the contained areas rather 

 prominent. — Knorr. Petr. p. 18, Tab. E. iii. fig. 5. 



Genus IX. Scutella. — Rather fiat or discoidal ; slightly 

 convex on the upper surface ; with four large pores in the 

 vertex ; the margin rather thin and acute, and sometimes 

 dentated ; the base flat. The ambulacra short, disposed in 

 a pentapetalous figure ; the mouth beneath, central ; the 

 vent beneath, between the mouth and margin. — PI. ii. fig. 10. 



The mouth is armed with five pieces, divided into two 

 branches, and vertical irregular plates are interposed between 

 the two branches. 



Synon. Placenta, Klein. Echinodiscus, Breyn, Leske, 

 and others. 



Sp. 1. Scut, dentata. — Orbicular, depressed; the disc 

 entire ; the posterior part of the margin dentated. — Leske 

 ap Klein, Tab. xxii, fig. E. F. 



2. S. digitata. — Orbicular, depressed ; the disc pierced 

 in the fore part by two or four openings. — Leske ap. Klein, 

 Tab. xxii. fig. A. B. Echinodiscus decius digitatus, fig. C. D. 

 octies digitatus. Recent. 



3. S. emarginata. — Orbiculato-elliptical, depressed; 

 with six foramina, five of which cut into the margin. — Leske 

 ap. Klein, Tab. 1. fig. 5, 6. Recent. 



