242 CATOPYGUS 



Catopygus carinatus, Agasdz. Prodrome Echinides, p. 18, 1836. 

 NucLEOLiTES COLTJMBAKIA, DesmouUns. Etudes sur les Echinides, p. 356, 1837". 



— CARINATUS, d'Archiac. Mem. Geol. Soc. de France, p. 180, 1837. 

 Catopygus — Bronn. Letbse Geognostica, p. G13, 1837. 



— — Milne-Edwards. In Lamarck, 2e ed., t. iii, p. 351, 1840. 

 NnCLEOLITES COLUMBARIA, Ibid. Ibid., 344. 



Catopygus carinatus, Agassiz. Cat. Syst., p. 4, 1840. 



— — Roemer. Norddeuts-Kreide-Gebirges, p. 32, 1840. 

 Catopygus CARINATUS, Morris. Catalogue of British Fossils, p. 49, 1843. 



— coLUMBARius, d'Archiac. Mem. Soc. geol. France, p. 296, 1847. 



— — Ayassiz et Desor. Cat. raison., p. 100, Modele R 71 



1847. 



— — d'Orbigny. Prod., t. i, p. 1/8, Stage 20, 1847. 

 NucLEOLiTES CARiN.iTUS, Forbes. Mem. Geol. Surv., Decade i, pi. 1 0, 1849. 

 Catopygus — Sorignet. Oursins del'Eure, p. 43, 1850. 

 NucLEOLiTES — Quenstedt. Handbuch der Petrefact., p. 586, pi. xlix, 



fig. 51, 1852. 

 Catopygus • — Bronn. Leth. Geogn., 2 ed., p. 196, pi. 29^, fig. 16, 1852. 



— — Albin Gras. Catal. des Corps org. de I'Isere, p. 40, 1852. 



— — Morris. Catal. of British Fossils, 2 ed, p. 74, 1854. 



— COLUMBARIUS, Co^ieaM. Pal. Frang. Ter. Cret., t. vi, p. 436, pi. 970, 1855. 



Diapiosin. — Test oval or subrotund, contracted anteriorly, enlarged and truncated 

 posteriorly, sides inflated, dorsal surface unequally convex, base nearly flat, ambulacra 

 narrow, dorsal, subpctaloid and open below; inter-ambulacra wide, single inter-ambulacrum 

 narrow, elevated, and truncated, vent round in the upper border, above the periprocte 

 an obtuse carina which terminates in the projecting upper border of the vent ; mouth- 

 opening small, excentral nearer the anterior border, peristome surrounded by five prominent 

 lobes and a rosette of pores between them. Apical disc excentral nearer the anterior 

 border, the vertex in general behind the apex. 



Dimensions. — I have selected six good typical forms showing the varying proportions 

 of this species. 



Description. — The table of synonyms exhibits the changing views of naturalists in 

 respect to this beautiful Urchin. Goldfuss, who gave the first good figure of the species, 

 cites, with doubt, its identity with Nucleolites colmnharius, Lamarck, but the brief diagnosis 

 in ' Hist. Nat. des Anirn. sans Vert.,' taken in connection with the locality and stratum 

 from whence it was collected, " les environs de Mans/' so well known for its beautiful Upper- 



