40 MOLLUSCA FROM THE GREAT OOLITE. 



Ceritella longiscata, Buv. sp. Plate IX, fig. 14. 



Pleurotoma longiscata, Buvignier. Mem. Soc. Philom., Verdun, 1843, pi. 6, fig. 8. 



Testa parvd, lurrild, eiongatd ; apice acuto ; anfractibus (9 — 10) subplanatis ; costis 

 longitudinalibus rectis namerosis, carinatis ; carina unicd marginali ; aperturd angustatd ; 

 caudd subrectd. 



Shell smooth, turreted, elongated; apex acute; whorls (9 — 10) rather flattened, with 

 longitudinal, straight, numerous ribs ; and a single encircling smooth carina upon the 

 upper margin of the whorls ; aperture narrow, canal straight, short. Axis 3 lines. 



Locality. This little species accompanies its allied forms in the soft shelly Oolite 

 beneath the planking of Minchinhampton Common. It is very rare. 



Ceritella rissoides, Buv. sp. Plate IX, fig. 7. 



? Pleurotoma rissoides, Buvignier. Mem. Soc. Philom., Verdun, 1843, pi. 6, fig. 9. 



Testa parvd, turritd ; spird mediocri elatd ; apice acuto ; anfractibus angustatis, posticis 

 carinatis, carina rotundatd ; costis longitudinalibus, rectis, subincurvis ; anfractu ultimo 

 elongato ; aperturd angustatd. 



Shell turreted, spire moderately elevated, apex acute, whorls narrow, carinated at their 

 posterior margin ; carina rounded ; costse longitudinal, straight, or slightly curved ; last 

 whorl elongated ; aperture narrow. Axis 2 lines. 



Locality. This pretty minute species is usually found in the soft shelly Oolite beneath 

 the planking of Minchinhampton Common. It is somewhat rare. 



Family — Naticid^e. 

 Natica, Adanson. 1757. Lam. 



The species of Natica in the Great Oolite are divisible into two groups ; one the 

 Natica proper, the others we have arranged in the sub-group Euspira, a name suggested by 

 Agassiz, for those species which have the spire more or less elevated, and the volutions 

 distinct. 



The Natica, though consisting of a considerable number of species, have, with one 

 exception, furnished but a small number of individuals ; and those belonging to the sub- 

 group Euspira are all rare in the Great Oolite. 



