LATE CRETACEOUS-EARLY TERTIARY ECHINOIDS 



97 



peristome, whereas in Diplotagma the peristome is hardly sunken 

 and there are well-developed phyllodes. Lambert (1907) described a 

 species of Acanthechimis, A. savigni (as Phymosoma), from the 

 Maastrichtian of Gensac, Haute-Garonne, France. This is based on a 

 single large individual 56 mm in diameter. This specimen has seven 

 pore-pairs to an ambital ambulacral plate, whereas our specimen has 

 just five. For this reason we are hesitant to unite the two. However, 

 the number of pore-pairs associated with ambital plates does in- 

 crease during growth in the closely related A. spectabile Cotteau & 

 Gauthier, from the Maastrichtian of the United Arab Emirates (Smith 

 1995), and it is possible that the two are conspecific. More material 

 from both populations is required, however. 



Cohort IRREGULARIA Latreille, 1825 

 Diagnosis. Periproct opens outside the apical disc circlet. 



Order HOLECTYPOIDA Duncan, 1889 



Family HOLECTYPIDAE Lambert, 1900 



Diagnosis. Pore-pairs undifferentiated in ambulacra. Peristome 

 central, circular, with buccal notches. 



Genus COENHOLECTYPUS Pomel, 1883 



Diagnosis. Holectypoids with five gonopores and test lacking 

 internal butressing. 



Coenholectypus nachtigali (Krumbeck, 1906) 



PI. 2, fig. 12;Fig. 8d, e 



1906 Discoidea Nachtigali Krumbeck: 86, pi. 7. 



1907 Holectypus proximus Lambert: 701, pi. 25, figs 12-14. 

 1977 Coenholectypus proximus Gallemi: 62, pi. 10. 



1979 Coenholectypus proximus Gallemi: 356, pi. 1. 

 1992 Coenholectypus proximus GaWtmi: 124, figs 37, 38. 



Diagnosis. Test small, up to 15 mm diameter; depressed, with 

 ambitus relatively low; lower surface rounded and sunken towards 

 peristome. Apical disc with five gonopores; genital plate 2 is en- 

 larged and occupies the centre of the disc; the other genital plates are 

 reduced in size and the posterior ones are separated from one another 

 by ocular plates. Ambulacral plating simple from apex to subambital 

 region; trigeminate adorally; pore-pairs uniserial and undifferenti- 

 ated. Periproct large, extending from close to the peristome to the 

 ambitus, so that it is visible in posterior view. Tuberculation of 

 interambulacral plates consists of a row of small primary tubercles, 

 becoming offset slightly near the adradius, separated by a single 

 dense row of miliary tubercles. 



Occurrence. Maastrichtian, horizons 2, 5 and 7/8, Santander. 

 Maastrichtian, horizon 6, Olazagutia Pass, Navarra. Lower 

 Maastrichtian of the Homes Morts Member at Sapeira and Santa 

 Engracia, Tremp Basin (Gallemi, 1992). The type comes from the 

 Maastrichtian of Roquefort (Haute-Garonne), France. 



MATERIAL STUDIED. BMNH EE6 1 29-3 1 , MGB 37499. 



Remarks. Easily disfinguished from the other holectypoid found 

 here, Camerogalerus cantabricus sp. nov., by the large size of its 

 periproct and by its much lower and wider ambital plates. It also has 

 much better aligned miliary granulation. Krumbeck (1906) erected 

 the species Discoidea Nachtigali on the basis of specimens from the 

 Maastrichtian of Libya. From the rather sketchy illustrations and 



description these cannot be distinguished from Lambert's species. 

 Unfortunately, Krumbeck's types were destroyed during the Second 

 World War and the original descriptions and figures are inadequate 

 to be fully confident about its true identity. 



Genus CAMEROGALERUS Quenstedt, 1873 



Diagnosis. Holectypids with internal butresses along adradial 

 margins of interambulacral plates on oral surface. Genital plates all 

 equal in size with madrepores generally distributed across all five 

 plates. 



Camerogalerus cantabricus Smith & Gallemi, sp. nov. 



PI. 2, figs 9-11; Fig. 8a-c 



Types. Holotype EE6132; paratype MGB37577. 



Diagnosis. Small, hemispherical species up to 7 mm in diameter. 

 Circular in outline, subconical in profile (height 64% of diameter) 

 with ambitus at about one-third test height; lower surface convex, 

 hardly sunken towards the peristome. Apical disc with five gonopores. 

 Ambulacra straight, with uniserial pore-pairs; plating simple above 

 ambitus, but in triads from ambitus adorally with one and then two 

 demiplates in each triad. Interambulacra composed of relatively tall, 

 narrow plates. Tuberculation comprises scattered primary tubercles 

 set amongst irregularly arranged miliary granules. Peristome very 

 small, 1.5 mm in diameter (22 % test diameter), with feeble buccal 

 notches. Periproct also very small and situated close to the peristome; 

 separated by just 2 plates from the peristome; distance from periproct 

 to ambitus is much greater than distance separating the periproct and 

 peristome. Internal butressing narrow and blade-like and extending 

 to the ambitus (seen on MGB 37577 where the oral surface is 

 damaged). 



Occurrence. Maastrichtian, horizon 2 (paratype) and 4 

 (holotype), Santander. 



Remarks. Distinguished from Coenholectypus nachtigali by the 

 much smaller size of its periproct, its more inflated profile and by its 

 very different tuberculation. 



Order ECHINONEOIDA Clark, 1925 



Family CONULIDAE Lambert, 1911 



Diagnosis. Irregular echinoids with a compact apical disc with 

 four genital plates. Ambulacra with pyrinoid plating; pore-pairs 

 undifferentiated. Peristome small, circular to elliptical, lacking buc- 

 cal notches. Tubercles small, dense, uniform and sunken. 



Genus COAft/Lf/S Leske, 1778 



Diagnosis. Conulids with pyrinoid ambulacral plating through- 

 out. Periproct marginal to inframarginal. Pore-pairs forming widened 

 bands adorally. 



Conulus gigas (Cotteau, 1856) 



PI. 3, figs 1,2 



1856 Echinoconus gigas Cotteau, in Leymerie & Cotteau: 330. 

 1860 Echinoconus gigas Cotteau; Cotteau, in d'Orbigny, 1853- 



60: 51 1, pi. 994, fig. 6; pi. 995, figs 1-5. 

 1907 Conulus gigas (Cotteau); Lambert: 707. 

 1992 Conulus gigas (Cotteau); Gallemi: 146, figs 45-47. 

 1995 Conulus gigas (Cotteau): Gallemi et al.: 269, tab. 1 . 



Diagnosis. Test up to 70 mm in length; width approximately 90% 

 of length; height approximately 67% of length. Domed in profile 



