GASTEROPODA. 103 
C. Testd ovato-oblongd; spird sub-elatd; anfractu ultimo magno, elongato; apertura 
longitudinaliter anfractui ultimo nonnunquam pari, superne angustatd, inferne latiori; labris 
continuis, tenuissimis, labio interno non reflecto. 
Shell ovately oblong; spire rather elevated; the last whorl large and elongated ; 
aperture sometimes as long as the last whorl, narrow in its posterior, wider in its anterior 
part ; lips continuous and very thin, the inner lip not reflected upon the columella. 
The genus Utriculus was established by Capt. Brown, upon the recent Bulla obtusa, 
and was afterwards used to comprise certain species of recent and fossil shells, previously 
referred by authors to Bulla, Acteon, &c.' Although the general form of the shells thus 
classed together is somewhat similar, this character cannot always be considered as 
definite, inasmuch as the animal inhabitant of the fossil species may have materially differed 
from the recent type. Alc. d’Orbigny, in recognising the generic differences of some allied 
forms, described as Zornatella, subsequently proposed in the ‘ Prodrome de Paléontologie,’ 
the name Acteonina for their reception. The genus Orthostoma, instituted by Deshayes, 
includes an allied series of shells, and connecting them with Acteon and Cylindrites, if we 
may judge from the figures given in the ‘'Traité Elementaire de Conchyliologie,’ but of 
which no description has yet been published. Upon the ground, therefore, of the doubtful 
generic identity of the recent Bulla obtusa with our fossil shells, we have preferred to adopt 
the name proposed by D’Orbigny. 
AcT£0NINA OLIvHZFoRMIS, Dunker. sp. Plate VIII, fig. 14. 
BULLA OLIVEFORMIS, Koch and Dunker. 1837. Nordd. Oolith., t. v, fig. 3. 
ACTEONINA — D’ Orb. 1850. Prod. Paléont., p. 353. 
A. Testa ovato-cylindracea, levi; spird productiusculd, acutd ; anfractibus spird sub- 
convexis ; apertura superné angustatd. 
Shell ovately cylindrical, smooth ; spire rather small, or but little produced; whorls 
rather convex; the upper part of the aperture narrow. 
Locality. ‘Three examples only, varying much in size, are in our collection. They 
occurred in the soft shelly stone (termed ovenstone) which overlies the weatherstones at 
Minchinhampton Common. It is a thinly-laminated deposit, which is sometimes nearly 
made up of the valves of Ostrea acuminata ; when these are absent, their place is occupied 
by a multitude of small bivalves; or, when these again become scarce, other and more 
interesting forms occur, among which may be ranked the present species. 
1 With regard to the comparative generic differences of the family Bullide, the reader is referred to an 
interesting paper by Mr. Clark, published in the ‘ Annals of Natural History,’ for August 1850, from which 
it appears, by a careful study of the structure of the animals, that the generic subdivisions established by 
some authors in this group are not well characterised. 
