GASTEROPODA. 103 



C. Testa ovato-oblongd; spird mb-elatd; anfractu ultimo magno, elongate; aperturd 

 longitudinaliter anfractui ultimo nonnunquam pari, superne angustatd, in/erne latiori; labris 

 continuis, tenuissimis, labio interna 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 Bidla obtusa, 

 and was afterwards used to comprise certain species of recent and fossil shells, previously 

 referred by authors to Bidla, Actaon, &C. 1 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. Ale. d'Orbigny, in recognising the generic differences of some allied 

 forms, described as Tornatella, subsequently proposed in the ' Prodrome de Paleontologie,' 

 the name Actaonina for their reception. The genus Orthostoma, instituted by Deshayes, 

 includes an allied series of shells, and connecting them with Actaon and Cglindrites, if we 

 may judge from the figures given in the ' Traite 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^eonina oliv^eformis, Bunker, sp. Plate VIII, fig. 14. 



Bulla oliv^eformis, Koch and Bunker. 1837. Nordd. Oolith., t. v, fig. 3. 

 Acteonina — UrOrb. 1850. Prod. Paleont., p. 353. 



A. Testa ovato-cglindraced, lavi ; spird productiusculd, acuta; anfractibus spird sub- 

 convexis ; aperturd sicperne 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 Bullidce, 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. 



