FROM THE UPPER CHALK. 331 



Akanchytes conica, Coquand. Ibid. 



EcHiNOcoKYS vfLGABis, Cotteau. Ech. d'Espagne Bull. Soc. Geol. France, t. xvii, 



p. 373, I860. 

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



der Deutschen Geol. Gesellschaft, vol. xv,p. 134, 1863. 

 EcHiNocoRYS VULGARIS, Cotteau. Ecbinides 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 Ecliinod. foss. des Alpes Suisses, 



p. 91, 1865. 



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



1865. 

 AxANCHiTEs CONICA, Favre. Eec. Geol. Savoie, t. iii, p. 494, 1867. 



EcHiNOCOEYS GiBBA, SchKnbach. Griinsandes von Eothenfelde, p. 821, 1869. 



— vuLGAKis, Be Loriol. iSchinides 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, heviispherica, amhitu ovato. 



Ananchytes ovata and conoidea, Audorum. 

 Forma /3. — Alta, elonffata, superne depressa, ambitu ovato, 



Ananchytes striata, Aud. ? ovata, pars. 

 Forma y. — Alta, superne depressa, amhitu orbiculari. 



Ananchytes gibba, Agassiz. 

 Forma Z. — Suh -globular is. 

 Forma e. — Alta, conica. 



Ananchytes conica, Agassis, Ananchytes pyramidata, Port- 

 lock. 



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

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

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



Var. GIBBA. — Height, 69 millimetres ; transverse diameter, 68 millimetres ; antero- 

 posterior diameter, 86 milhmetres. 



Var. coNoiDEA. — Height, 77 millimetres ; transverse diameter, 68 millimetres • 

 antero-posterior diameter, 79 millimetres. 



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

 metres ; antero-posterior diameter, 43 millimetres. 



