28 JOURNAL OK CONCHOI.OGY, VOL. 15, NO. I, JANUARY, 1916. 



(.^). - Fossil Tertiary Forms. 



But to trace the genus to its source, it behoves us first to give a 

 brief sketch of the fossil species, or anyhow some of the most leading 

 of them, they being first observable in the Tertiary period, some in 

 the Bracklesham Eocene beds, and the Barton Clay ; others in the 

 Calcaire Grossier of the Paris basin. A third series occurs in the 

 very prolific station of Muddy Creek, Victoria, Australia. These 

 species are of smaller size than many of the recent Harpce, but bear 

 a strong family resemblance to them. 



An exception, however, exists in the old Buccuium'^ stromboides 

 Herm., 17S1, included subsequently by Lamarck in Harpii, till separ- 

 ated under the generic title Crypfochorda by Morch in 1855 {flar- 

 popsis Mayer, 1877). This has with some reason been disassociated 

 from the group, and is now placed by Fischer' amongst the Volutidce, 

 in close proximity to the recent Zidona angiilata Swainson, a South 

 American Volute. 



It is of medium size, ovally subfusiform, smooth and polished, with 

 regular longitudinal occasional costse or varices, sometimes very im- 

 perfectly developed, mouth oblong, lip simple, somewhat arched, 

 columellar margin simple, slightly thickened." 



Habitat : England, in the IMiddle Eocene, Bracklesham beds, Sus- 

 sex, Bramshaw Brook, Hants., Stubbington, and Huntingbridge. 



France : Not infrequent in the Calcaire Grossier, Grignon, and 

 vicinity of Paris. 



Harpa Bolten, 1798; Famarck, 1799. 

 Sub-Genus I. — Eocithara P. Fischer, 1883. 



H. mutica Lamarck. 

 H. mutica Lamarck, 1823. — Ann. de Mus., t. 2, p. 167. 



,, „ ,, — Recueil de Planches de Coquilles 



Fossiles des environs de Paris, par De la March, 

 1823. 

 ,, „ ,, — Deshayes, Coquilles Fossiles, p. 642, 



pi. Ixxxvi., figs 14, 15. 

 Habitat : Calcaire Grossier, Grignon, Middle and Upper Eocene. 

 In this small species are first displayed the true characters oi Harpa: 

 regular longitudinal ribs, few in number, encircling the body-whorl, 

 mouth widely oblong, spire much abbreviated. The columellar cal- 

 losity is well developed. 



1 Naturforscher, 17S1, vol. xvi., p. 54, pi. ii., figs. 5, 6. Also vid^ Coq. Fors., Paris, T835, 

 vol. ii., pi. l.xxxvi., figs. 8, 10, p. 647. 



2 Paul Fischer, Man. Coiichyl., 1887, p. 605. 



3 Ihxrpovoluta Thiele, 1912 (Aiitarkt. Schneck.und Musch. in Deutsche Siul Pol.irExp., 

 1901-3), does not seem very nearly allied ; the substance is much thinner, and the body-whorl 

 quite smooth and considerably inflated. 



