NO. 3 CASSIDULOID ECHINOIDS — KIER 37 



Mortensen (1948, p. 137) considered Crotoclypeus as a synonym 

 of Hardoiiinia. The great difference in the phyllodes of these genera 

 rule out any possibihty that they could be synonyms. In Crotoclypeus 

 the phyllodes are double pored with the pore pairs arranged in three 

 series in each half -ambulacrum, the phyllodes are not widened, and 

 there are no buccal pores. In Hardoiiinia, the phyllodes are greatly 

 widened, single pored, with the pores arranged in an arc, and with 

 buccal pores. Hardoiiinia is much more advanced. 



Lambert and Thiery (1925, p. 586) restricted Crotoclypeus to 

 species having the apical system joined to the periproct by a series 

 of plates. However, this feature is not of generic value but is 

 variable within the type species, as described above. 



Synonym of CLYPEUS 

 Dactyloclypeus Maccagno, 1947. Atti. Accad. Naz. Lincei Mem., ser. 8, vol. i, 

 p. 126. Type species herein designated, Clypeiis zvylUei Currie. 



DESCRIPTION OF TYPE SPECIES 



CLYPEUS WYLLIEI Currie 



Plate 7, figures 3-5 ; plate 8, figures 2, 3 ; text figures 16, 17 



Clypeus wylliei Currie, 1925. Monogr. Geol. Dept. Hunterian Mus., Glasgow 

 Univ., pt. 5, Jur. and Eocene Ech., p. 63, pi. 10, figs, i, 2. 



Material. — All four specimens in Currie's original collection, in- 

 cluding the type of her variety pentagona. 



Shape. — Medium size, 45 mm. long, circular to pentagonal with 

 width equal to length, adapically moderately inflated with greatest 

 height at apical system, petals slightly inflated ; adorally flat to 

 slightly depressed around peristome. 



Apical system. — Central, tetrabasal (text fig. 17), genital 2 much 

 larger than other genital plates, extending posteriorly, separating 

 posterior genital and ocular plates. Other genital plates very narrow, 

 elongated. 



Ambulacra. — Petals very broad, open, equal length, extending to 

 margin; poriferous zones very wide, tapering distally, outer pore of 

 pair slitlike, inner round to slightly elongated transversely, joined by 

 deep conjugation groove; interporiferous zones expanding distally. 



Periproct. — Supramarginal, longitudinal, in groove extending to 

 posterior margin. 



Peristome. — Anterior, pentagonal, width approximately equal to 

 length. 



Floscelle. — Bourrelets well developed, vertically sided. Phyllodes 



