158 Mr. J. Lycett on the Upper Lias of Gloucestershire. 



Ammonites bifrons was the most conspicuous ; A. communis was 

 in much smaller numbers ; the few other Ammonites obtained 

 consisted of A. falcifer, A. heterophyllus, A. cornucopia, A. cras- 

 suSy A. Lythensis, A. Jurcnsis, and a new species near to A. 

 Humphriesianus ; a few fragments occurred apparently of Nau- 

 tilus sinuatus, and a single specimen of N. latidorsatus. Belem- 

 nites were comparatively few, as were also Gasteropoda and Con- 

 chifera; the latter included two undescribed species, one of 

 Tancredia and one of Placunopsis. 



In the lower beds bluish grey clays predominated; but the 

 sections were insufficient to expose an unbroken sequence of the 

 lower beds, although the entire thickness of the stage was ascer- 

 tained with a near approach to accuracy ; the measurement gave 

 a thickness of 105 feet, the beds being free from disturbance. 

 Some few layers of limestone nodules occurred, but their amount 

 was not comparable with those obtained from the Upper Lias of 

 Somersetshire. To the same general deficiency of lime, as 

 exemplified in the paucity and thinness of the limestone bands, 

 may probably be attributed the general scarcity of fossils when 

 compared with the Upper Lias of Somerset ; here the chief mass 

 of the deposit consisted of brown and blue clays which were 

 quite destitute of fossils ; no remains of Saurians or of Fishes 

 were observed. These conditions present a remarkable contrast 

 to the same stage at Ilminster, with its pale yellow limestone 

 charged with Saurians, Fishes, and a multitude of Mollusca of 

 all classes, numbering probably more than 150 species, notwith- 

 standing that the entire thickness of the stage is only a few feet 

 at that place. To study these, the extensive collection of Mr. 

 Moore, in the Bath Museum, should be visited. 



The occurrence at Nails worth of finely laminated shales with 

 the little Posidonia Bronnii in the upper portion is interesting, 

 as identifying the stratum with the continental representative of 

 the same shale : this fragile bivalve appears to be limited to the 

 single stratum indicated. 



The large Tancredia is the first recorded example in the Lias 

 of England, although upwards of eleven species are distributed 

 throughout our Lower and Upper Oolites ; in France and Ger- 

 many, on the other hand, nearly all the recorded species are 

 Liassic. It is probable, however, that some, or even all of the 

 shells referred to Tellina in the " Etage Bathonien" of D'Orbigny 

 belong to the genus Tancredia, excluding the two species in his 

 " Etage Bajocien," which belong to the genus Quenstedtia. 



The following is the limited list of Upper Lias Testacea pro- 

 cured at Nailsworth : 



