ORCULA. o 



lamella shining through (Fauna, iii, 87). From the occur- 

 rence of this fold in at least two unrelated stocks, 0. gularis 

 and various forms included in or related to 0. scyphus, it 

 would appear to be an ancestral structure now disappearing. 

 The species are often not strongly differentiated, but some 

 characters of value are to be found in the details of structure 

 of the lamella? within the last whorl. Unfortunately, nothing 

 of this has been noticed by previous authors. 



Tertiary Species. 



Dr. W. Wenz of Frankfurt has contributed a catalogue of 

 Tertiary Orculse. 



Orcula oviformis (Michaud). Pupa oviformis Michaud, 

 Actes Soc. Linn. Bordeaux, x, 1838, p. 157, pi., fig. 5a, b. — 

 Vertigo oviformis Cossmann, Cat. ill. coq. foss. env. Paris, 

 iv, 1889, p. 361. Palasocene, Thanetien : Billy near Reims; 

 Sparnacien : Bernon near Epernay. 



Orcula plateaui (Cossmann). Pupa (Orcula) plateaui 

 Cossmann, Cat. ill. coq. foss. env. Paris, iv, in Ann. Soc. Roy. 

 Malac. Belgique, XXIV, 1889, p. 360, pi. 11, fig. 34. Lower 

 Palasocene, Thanetien: Chenay (Dep. Marne). 



Orcula subconica (Sandberger). PL 4, fig. 10. Pupa 

 (Pupilla) subconica Sandberger, Die Conchylien d. Mainzer 

 Tertiarbeckens, 1858, p. 51, pi. 5, fig. 7, pi. 35, fig. 11.— 

 Slavtk, Archiv d. naturwiss. Landesdurchforsch. von Boh- 

 men, 1869, i, 2, p. 272. — Pupa (Orcula) subconica Sandberger, 

 Die Land- u. Siisswasser- Conchylien d. Vorwelt, 1874, pp. 394, 

 438, pi. 23, figs. 8-86. — Orcula subconica Boettger, Jahrb. 

 Nassau. Ver. f. Naturk. Wiesbaden, xlii, 1889, pp. 238, 241, 

 319. Upper Oligoeene, Chattien: Landschneckenkalk, Hoch- 

 heim. Lower Miocene, Burdigalien: Landschneckenkalk, Tu- 

 chorschitz, Bohemia. Pupa doUum antiquum A. Braun, Verh. 

 Naturf. Vers. Mainz, 1842, p, 149, no description, is said to be 

 this species. 



This early Orcula is, as Sandberger observed, similar in 

 form to the recent 0. conica (Em.). Subequal columellar and 

 supracolumellar lamella? emerge to the peristome, and within 



