110 



A.B. SMITH ETAL. 



Fig. 18 Jeronia pyrenaica Seunes, U 

 lateral profile. All xl.5. 



, from the late Danian of Larumbe (Navarra); MGB 37382, 1, apical surface: 2, oral surface: 3, posterior profile; 4, 



Family STEGASTERIDAE Lambert, 1917 



Diagnosis. Test cordate, with prominent frontal groove from the 

 ambitus to the peristome. Apical disc holasterid with four gonopores. 

 Paired ambulacra with subpetaloid to rudimentary pore-pairs. 

 Phyllode pore-pairs lacking from around peristome. Plastron 

 orthostemous without rostral plate. Marginal fasciole may be present, 

 but no other fascioles are developed. 



Genus STEGASTER Pomel, 1883 



Diagnosis. Thick-tested holasterid with flat base and cordate 

 outline. Frontal groove absent adapically, deepening to ambitus with 



sharp keels and continuing as well-defined furrow to mouth. Petals 

 rudimentary, flush. Plastron orthostemous. Periproct on posteiior 

 face, just supramarginal with subanal tallon. No fascioles. 



Stegaster bouillei (Cotteau, in de Bouille, 1873) 



PL 5, figs 1-3; Figs 21, 22 



1873 Holaster Bouillei Cotteau, in de Bouille: 450. 

 1889 Stegaster bouillei Seunes: 816, pi. 26, fig. 2. 

 1 892 Stegaster bouillei Nickles: 111. 



Diagnosis. Test elongate, up to 75 mm in length; tapering to 

 posterior truncation. Width about 90% of length. In profile subconical 

 with tallest point anterior; height about 50-60% of length. Anterior 



PLATE 5 



Figs 1-3 Stegaster bouillei (Cotteau, in de Bouille, 1873), BMNH EE6066, Maastrichtian of Sarasate, Navarra. Oral, apical and lateral views, xl. 

 Figs 4-6 Stegaster palaeocenicus sp. nov., MGB 37351 (holotype). Danian of Aristregui, Navarra. Lateral, oral and aboral views, xl. 



