NO. 3 CASSIDULOID ECHINOIDS — KIER 55 



inflated in ridge along interradial suture, indented along either side 

 at margin. Adorally, all interambulacra inflated relative to ambulacra. 



Apical system. — Anterior, tetrabasal (text fig. 28). 



Ambulacra. — Petals II and IV extending two-thirds distance to 

 margin, petals I and V slightly longer, extending over one-half 

 distance to margin. In paired petals, outer pores very elongate 

 transversely, inner pore slightly elongate transversely, pores strongly 

 conjugate, interporiferous zones twice as wide as poriferous, petals 

 closing distally. Petal III (pi. 5, fig. 3) less developed than other 

 petals, with much narrower poriferous zones with interporiferous 

 zones three times as wide as poriferous zones, pores conjugate with 

 outer pore elongate transversely, inner slightly elongated. All petals 

 flush with test. 



Periproct. — Inframarginal, longitudinal. 



Peristome. — Anterior, longitudinal, pentagonal, slightly depressed. 



Floscelle. — Bourrelets well developed, phyllodes broad, double 

 pored, with three series of pore pairs in each half-ambulacrum. 



Occurrence. — Upper Jurassic (Sequanian), Tonnerre and Baily, 

 Yonne, France. 



Location of type specimen. — Lambert Collection, Sorbonne, Paris. 



Remarks. — Checchia-Rispoli (1941) redescribed this genus and 

 species but based his description not on the type specimens, but on 

 specimens from Somaliland which he considered to be conspecific with 

 Lambert's species. However, the Somaliland specimens are quite 

 distinct and should be considered a separate species. The petals in 

 the Somaliland species are longer, extending almost to the margin, 

 and the apical system more central. Maccagno (1947, pp. 132-134, 

 pi. I, figs. 13, 13a) redescribed the Somaliland specimens, but figured 

 the same specimen that Checchia-Rispoli had figured, but the nega- 

 tive must have been reversed, as the pictures are mirror images of 

 each other. 



Lambert stated that ambulacrum III was not petaloid in his species. 

 Although petal III is much narrower than the other petals and its 

 outer pores much less elongated, its pores are much larger than those 

 occurring in the ambulacral plates beyond the petals, and therefore 

 ambulacrum III must be considered as petaloid. 



Family NUCLEOLITIDAE L. Agassiz and Desor, 1847 



Medium to large, circular or elongate ; apical system tetrabasal, with 

 or w^ithout complementary or catenal plates ; petals moderately de- 

 veloped, usually open, narrow with narrow poriferous zones; ambula- 



