NO. 3 CASSIDULOID ECHINOIDS — KIER I39 



DESCRIPTION OF TYPE SPECIES 



FAUJASIA APICALIS (Desor) 



Plate 17, figures 9-11 ; text figures 113, 114 



Pygunis apkalis Desor, in Agassiz and Desor, 1847, Ann. Sci. Nat., ser. 3, 

 Zool., vol. 7, p. 162. 



Material. — Five specimens studied in the U. S. National Museum. 



Shape. — Small (25 mm. long), subangular marginal outline, blunted 

 anteriorly, pointed posteriorly, greatest width posterior to center. 

 Adapically highly inflated, apex pointed, with greatest height an- 

 terior, at apical system ; adorally flat. 



Apical system. — Anterior, four genital pores, with pores located 

 in interanibulacra, separated from apical system by small interambu- 

 lacral plates (text fig. 113) ; apparently monobasal, madreporic pores 

 occurring in whole central area ; ocular plates very small. 



Ambulacra. — Petals inconspicuous, flush, equal, closed, short, ex- 

 tending approximately one-half distance from apical system to mar- 

 gin ; interporiferous zones broad, tapering, greatest width one-third 

 distance from apical system to end of petal : poriferous zones narrow, 

 with conjugate pores, outer pore greatly elongated transversely, inner 

 pore round to slightly elongated. 



Periproct. — Supramarginal, very small, transverse. 



Peristome. — Anterior, small, slightly higher than wide, pentagonal. 



P lose die. — Bourrelets strongly developed, toothlike, jutting into 

 peristome (pi. 17, fig. 11); phyllodes broad, deeply depressed be- 

 tween bourrelets, single pored, in arclike arrangement with few pores, 

 10 to 12 in whole phyllode (text fig. 114) pores widely separated 

 from peristome ; buccal pores near edge of peristome. 



Ornamentation. — Tubercles on adoral surface considerably larger 

 than those on adapical ; adorally, no large tubercles in median tract 

 in interambulacrum 5. 



Oeeurrenee. — Upper Cretaceous (Maestrichtian) of Belgium and 

 Holland. 



Location of type specimen. — Unknown ; according to Desor, in 

 the collection of the Marquis of Northampton. Sherborn (1940, 

 p. 35) says that the collection of the second Marquis of Northampton 

 (S. J. A. Compton) was transferred from Castle Ashby in 1878 to 

 Northampton ISIuseum. 



