330 ruocEKDiNGS oy ttik mai,acological society. 



convexity, cancellatod surface, and thickened labrnm. It differs also 

 from liissoma, which is long and turreted, and slightly canaliculate 

 in front. The species approaches Rissoia Barreti of Morlet, from 

 the Paris Basin, bnt appears to be more ventricose and with a 

 rather more prominent suture. It is also related to R. temdsculpta, 

 Boettger, from the German Oligocenc, as pointed out by Prof. Von 

 Iviinen,' but the reticulate markings of the surface ai'e finer and more 

 closely set, the foreign species being distinctly costulate, as in the 

 true Rissoia. 



Formation. — Upper Eocene (Barton Beds). 



Localities. — Barton and High Cliff (type), Hants. 



VoLvuLELLA. Chajileswoethi, n.sp. PI. XXII, Figs. 13, 14. 

 Volvula redacta, Lowry, Etheridge, and Edwards, Chart Characteristic 



British Tertiary Fossils, 1866, non Deshayes. 

 Bulla aciminata, Charlesworth MS., non Bruguiere nee J. de C. 



Sowerby. 

 Volvulella Charleswortln (Edwards IMS.), 11. B. Xewton, Syst. List 

 Edwards Coll. British Museum, 1891, p. 268. 

 Shell elongate, subcylindrical, centrally ventricose ; surface smooth 

 in the middle, obscure spiral striations on the terminal portions, with 

 occasional fine longitudinal lines of growth ; perforated by a narrow 

 chink-like umbilicus ; mouth linear, narrow posteriorly, produced and 

 widest in front ; labrum acute and arched ; columella border curved, 

 with a prominent fold at its base, behind which is the umbilicus ; 

 apical rostrum acuminate and only moderately produced. Dimensions : 

 alt. 3, diam. 2 mm. 



This species was mistaken by Charlesworth for Bruguicre's Bulla 

 acuminata^ the type of Volvulella, which ranges from Pliocene to 

 recent times : a form with a more slender contour, a less prominent 

 plication, and a more pointed apex. 



It is easily distinguishable from V. extensa, J. de C. Sby., or 

 V. lanceolata, J. de C. Sby., species which differ from it not only in 

 shape but in possessing a continuous spiral sculpture. The French 

 Eocene forms of this genus also show points of difference from the 

 present species: V. rostralina, Cossmann, has a very produced rostrum; 

 V. radius, Desh., is conoidal, and has only a moderately developed 

 rostrum ; whilst V. redacta, Desh., is distinguished by its completely 

 smooth surface, without any evidence of spiral stria?. 

 Formation. — Upper Eocene (Barton Beds). 

 Localities. — Barton and High Cliff (type), Hants, 



YoLVULELLA LANCEOLATA, J. dc C. Sowcrby. PL XXII, Figs. 15, 16. 



Bulla hastula, Charlesworth MS. 



Bulla lanceolata, J. de C. Sby., Dixon's Geology and Fossils of 



Sussex, 1850, p. 177, pi. vii, tig. 7. 

 Bulla ( Volvula) lanceolata, Lowry, Etheridge, and Edwards, Chart 



Characteristic British Tertiary Fossils, 1866. 



> Abhandl. Geol. Spec. Kart. Preussen, 1892, vol. x, pt. 4, p. 823, pi. Iv, fig. 1. 



