GASTEROPODA. 105 
ADDENDA. 
AMMONITES GRACILIS, Buckman. Plate XIII, figs. 2, 2a; and Plate I, fig. 3. 
The description of this species is given at page 12, but the additional figure is here 
given (Plate XIII, fig. 1,) to illustrate the form and general character of the more mature 
shell, which differs considerably from the young state of it. (Plate I, fig. 3.) 
It has the general form of Am. Charmassei, D’Orb.; but the coste in 4. gracilis are 
not interrupted over the back as in that species, and the volutions are more fully exposed. 
Preroceras Wricuti. Plate XIII, fig. 1. 
P. Testa fusiformi, tumidd ; anfractibus (6) rotundatis, levibus vel spiraliter striatis ; 
ultimo gibbo, transversim carinato ; carinis tribus rotundatis inequaliter remotis ; in digitos 
longiores productis ; dorso ad angulum tuberculis duabus magnis ; labro quinque ? digito, 
digitis in etate adultd longissimis, flexuosis, recurvatis ; caudd longissimd arcuatd. 
Sheil fusiform, volutions 6, rounded and smooth, or faintly striated; the body-whorl 
inflated, and having three indistinct carine developed on its upper surface, two of which 
have a transverse prominent tubercle ; each carina leads to a digitate process; labial wing 
short, and terminating in four long slender flexuous digitations ; the first digitation ascends 
close to the spire, and is attached to it; it curves a little outwards, and then extends back- 
wards an inch and a quarter beyond the apex of the spire, where it is broken off;' the 
second curves gently outwards and backwards; the third is broken off three quarters of an 
inch from the labial wing; a remaining fragment indicates that it curved gently outwards, 
and is represented by a dotted line in the figure; the fourth passes forwards for an inch 
and a half, and then curves outwards; the canal is long, and arched backwards. 
This fine fossil presents some points of resemblance to Strombus Oceani and S. Ponti, 
Al. Brongniart, but the latter species has upwards of six carinee upon the last whorl. In size 
it exceeds all the other Great Oolite examples of the Strombid@, and would seem to be very 
rare. One specimen in the cabinet of the author, which has not the wing developed, and is 
in other respects imperfect, is the only other known example. The present remarkable shell 
is in the cabinet of Dr. Wright of Cheltenham, who has kindly communicated it, and to 
1 There are traces of another digitation between the first and second above described, arising near to 
the base of the former, but apparently broken off in the specimen figured. 
