40 MOLLUSCA FROM THE GREAT OOLITE. 



CERITELLA LONGISCATA, Buv. sp. Plate IX, fig. 14. 



PLEDKOTOMA LONGISCATA, Buvignier. Mem. Soc. Philom., Verdun, 1843, pi. 6, fig. 8. 



Testa pared, iurritd, elonyatd; apice acuto ; anfractibus (9 10) subplanatis ; costis 

 lonffitudinalibus rectis numerosis, carinatis; carind unicd marginali; aperturd angmtatd; 

 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. Me"m. Soc. Philom., Verdun, 1843, pi. 6, fig. 9. 



Testd parvd, turritd; spird mediocri elatd ; apice acuto ; anfractibws angmtatis, posticis 

 carinatis, carind rotundatd ; costis lonffitudinalibus, rectis, subincurvis ; anfractu ultimo 

 elongate ; 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. 



