BRITISH FOSSILS. 



Decade IV. Plate YI. 



ANANCHYTES OVATA. 



[Genus ANANCHYTES. Lamarck. (Sub-kingdom Eadiata. Class EcTiinodermata. 

 Order Echinoidea. Family Ananchytidse.) Body suborbicular ; oblong or obscurely 

 cordate, tumid ; with homogeneous ambulacra, convergent on the vertex, all plane or 

 with the anterior ambulacrum in a shallow furrow. No fascioles. Vent terminal, marginal 

 or supra-marginal. Apical disk elongated and composed of four perforated genital and 

 five perforated ocular plates. Tubercles perforate ; their bosses crenulate. Spines 

 minute. No dental apparatus. 



Subgenus Ananchytes. Body ovate or orbicular ; vent infra-marginal.] 



Diagnosis. A. ambitu ovato seu orbiculari, antice rotundato ; testa 

 altd tumidd, ano infra-marginali. 



Forma a, alta^ hemispherica, ambitu ovato. 



Ananchytes OVATA and conoidea, Auctorum. 

 Forma /3, (^alta) elongata, superne depressa, ambitu ovato. 



Ananchytes striata, Auct. ? ovata pars. 

 Forma 7, alta superne depressa, ambitu orbiculari. 



Ananchytes gibba, Agassiz. 

 Forma subglobularis. 

 Forma e, alta, conica. 



Ananchytes conica, Agassiz. A. pyramidata, Portlock. 



Synonyms. Echinocorys vulgaris, Breyn. Sched. de Echinis. p. 58. 

 pi. 3., f. 1. 2. (1722.) 



Echinocorytes ovatus, Leske ap. Klein. Nat. Disp. Echin. p. 178, 

 pi. 53, f. 3., also Echinocorytes pustidosus, p. 180, pi. 16, f. A. B. Echino- 

 corytes scutatusy p. 175, pi. 15, A. B., and pi. 42, f. 4. Echinocorytes minor^ 

 p. 183, pi. 16, C. D., and 17, a. b. (1778.) 



Echinus ovatusy scutatus and pustulosus, Linnaeus. 



Ananchytes ovata, striata, gibba, pustulosa and semiglobus JjAMAUCK. An, 

 sans Vert. vol. iii., p. 25, 27. 



Ananchytes ovata, conoidea, striata, gibba., pustulosa, hemisphcerica, semi- 

 globus and corculum. C. Desmoulins, Etudes sur les Ech., p. 368-376. 



Ananchytes ovata, gibba, striata, Gravesii? semiglobus and conica, 

 Agassiz. Cat. Syst., and Agassiz and Desor, Cat. Raisonne des Echinides, 

 in Ann. des Sciences Nat. 3d series, Zoologie, vol. viii. p. 30. 

 [iv. vi.] 4 G 



