FROM THE UPPER CHALK. 331 



Ananchytes conica, Coquand. Ibid. 



EcHiNOCORYs VULGARIS, Cotteau. Ech. d'Espagne Bull. Soc. Geol. France, t. xvii, 



p. 373, 1860. 

 Ananchytes ovatus, Strombeck. Uber die Kreide bei Luneburg, Zeitschrift 



derDeutschenGeol. Gesell8chaft,vol. xv, p. 134, 1863. 

 EcHiNocoRYS VULGARIS, Cotteau. Echinides Foss. des Pyrenees, p. 45, 1863. 



_ _ Cotteau. Catal. des Ecbin. Foss. del'Aube, p. 41, 1865. 



— — Tate. Cretaceous Rocks of Ireland, Quart. Journ. Geol. 



Soc, vol. xxi, p. 31, 1865. 

 Ananchitis ovata, Ooster. Synop. des ficliinod. foss. des Alpes Suisses, 



p. 91, 1865. 



— — Heer. Die Urwelt der Schweiz, p. 205, vign., fig. 117, 



1865. 

 Ananciiites conica, Favre. Eec. Geol. Savoie, t. iii, p. 494, 1867. 



EcHiNOCORYS GiBBA, Schlunbach. Griinsandes von Eothenfelde, p. 821, 1869. 



— vulgaris, Ve Loriol. fichinides Cretaces de la Suisse, p. 308, 



1873. 



Diagnosis. — Test large, rounded anteriorly, with a circular, ovate, or suborbicular 

 ambitus ; upper surface much elevated with turned sides ; under surface flat ; mouth 

 sunk in a deep depression; vent small and infra-marginal. My late colleague, Professor 

 Edward Forbes, admitted the following varieties. 



Forma a. — Alta, hemispherica, amhitu ovato. 



Ananchytes ovata and conoidea, Audorum. 

 Forma /3. — Alta, elongata^ supertie depressa, amhitu ovato, 



Ananchytes striata, Auct. ? ovata, pars. 

 Forma y. — Alta, superjie depressa, amhitu orhiculari. 



Ananchytes gibba, Agassiz. 

 Forma S. — Suh-globularis. 

 Forma e. — Alta^ conica. 



Ananchytes conica, Agassiz, Ananchytes pyramidata, Port- 

 lock. 



Dimensions. — Height, 55 millimetres; transverse diameter, 62 millimetres ; antero- 

 posterior diameter 75 milUmetres. Monsieur Cotteau has given the comparative dimen- 

 sions of the three varieties which he admits of this species. 



Far. gibba. — Height, 69 milhmetres ; transverse diameter, 68 millimetres ; antero- 

 posterior diameter, 86 millimetres. 



Var. conoidea. — Height, 77 millimetres ; transverse diameter, 68 millimetres j 

 antero-posterior diameter, 79 miUimetres. 



Var. coNiCA (young form). — Height, 37 millimetres; transverse diameter, 33 milli- 

 metres ; antero-posterior diameter, 43 millimetres. 



