10 THE BKACIIIOrODA. 



only small sinuations, but Sowerby's drawing is rather misleading 

 in this respect. E. Deslongschamps says of this species " Toute- 

 fois la position stratigraphique precise et les caracteres de la T. 

 perovalis ont ete parfaitement mis en evidence par les travaux de 

 MM. Davidson et Oppel, et maintenant on sait que cette espece 

 est bien caracterisee et appartient specialment au niveaux 

 inferieur de 1'oolithe inferieure, zone des A. Sowerbyi et 

 Murchisonts, que nous designons sons le nom d'infra-oolithe." 



My own observations in this district entirely agree with his 

 remarks. The true Tereb. perovalis being very characteristic of 

 the zones of Am. Murchisonce and Sowerbyi, and it is not found 

 higher or lower. It attains an extremely large size in both 

 zones, one specimen in my collection measuring length, 2 

 inches 1 1 lines, breadth 2 inches 1 1 lines, depth 1 inch 8 lines. 



Localities. Tereb. perovalis occurs at Bradford Abbas, Half- 

 way House, Oborne, etc. (in Dorset), East Coker, and near 

 Gorton (Somerset), also Dundry (Somerset), Dinnington ; near 

 Cheltenham (Gloucestershire), and in France, and Wiirtemberg. 



2. TEREBRATULA PHILLIPSI, Morris. 



TEHEBEATULA PHILLIPSI (Morris], Davidson, British Eossil Brach. 

 Palseontographical Soc., plate xi., figures 

 6-8. 



TEREBRATULA PHILLIPSI,^. DesL, Brach. Terr. Jurass, plates 67-72. 



This is a most marked species, at once to be distinguished by its 

 peculiar elongated shape, which is quite conspicuous even in very 

 young forms. E. Deslongschamps in the Paleontologie Franchise 

 has given a fine series of figures of this species. He also figures 

 a specimen with an indication of three folds in the middle, but I 

 have not seen one from this district. His young forms are also 

 very characteristic, and shew how very small the plications are 

 in youth, sometimes being hardly perceptible. One characteris- 

 tic of this species is the small raised beak. In this district Tereb. 

 Phillipsi is generally found in the zone of Cosmoceras Parkin- 

 soni, but it does occur in the zone of Humphriesianum, though 



