68 A. E. Trueman — The Lias of South Lincolnshire. 



4 feet in thickness, Avliich "Woodward had considered as Lias. These 

 are unfossiliferous earthy limestones and shales, unlike those usually 

 found in the Rhaetic, and are probably of Liassic age, but the absence 

 of a continuous section in this neighbourhood makes it undesirable 

 at present to give a definite statement. Even if these beds should 

 prove to be the equivalents of the lowest beds elsewhere, the entrance 

 of P. jt?^«?ior5/s must have been distinctly earlier at Barrow than in 

 any of the other localities examined. 



It will be further noticed that in Brown's table the " Roof Bed " 

 at Barrow is included in the angulata, zone, although Woodward, who 

 did no't attempt to separate the planorhis and angulata zones, had 

 previously recorded P. planorlis from the same bed. As a matter of 

 fact, the lowest definite occurrence of S. angulata is some 10 feet 

 higher. Brown apparently considered *' ScJilotheimia catenata " ' to 

 indicate the lower part of the angulata zone, but this is doubtful; 

 Wright inferred that liis example of " /S. catenata'''' from Barrow 

 was from the planorlis zone," and Hyatt also showed that 

 '■'■ S. catenata'''' most frequently occurs in the upper part of the 

 planorhis zone on the Continent.' 



Further, it must be noticed that the Roof Red of Barrow is almost 

 identical in lithology and fossil content with the bed at Barnstone 

 and elsewhere, to which I have applied the same name, and that in 

 these places P. planorhis occurs above this level. There seems little 

 doubt, therefore, that these beds with S. catenata ( Waehneroceras), 

 should be assigned to the planorhis zone ; the sudden dominance of 

 Waehneroceras in the Barrow-on-Soar district is merely a local 

 characteristic comparable with the relatively early appearance of 

 P. planorhis in that neighbourhood. Thus the general section at 

 Barrow is as follows : — 



zone. 



Planorhis 

 zone. 



A lata f Bli^s shale . . . . . . . 



^^^ • Impersistent limestone with S. angulata 



Blue shale with S. angulata ...... 



' Dark-blue pyritic shale, with great abundance of Waeh- 

 neroceras spp. and G. Johnstoni ..... 



Eoof Bed. Yellow earthy limestone with P. planorhis, 

 C. Johnstoni, and Lima ...... 



Hard blue shales with impersistent flaggy limestone 

 Blue shales and pale-blue limestones with P. planorhis, 

 insect remains, and algse ...... 



.Earthy limestone and brown shales, unfossiliferous 

 It is apparent that the fossil succession is very different from that 

 which has been observed elsewhere, both in this area and in many 

 other parts of the country. 



A third type of transition from Rhaetic to Lias is seen in a small 

 stone quarry near Cotgrave Gorse, one and a half miles east-north- 

 east of the section, described at Owthorpe. The uppermost bed of 



^ The forms known as Schlotheimia catenata, d'Orb., should be referred to 

 several species of the genus Waehneroceras. See Table of Fossils. 



^ T.Wright, "Monographs of Lias Ammonites": Palseont. Soc, pi. xix, 

 figs. 5-7. 



' A. Hyatt, "Genesis of the Arietidee " : Smiths. Contrib. Knowl., 1889, 

 Tables. 



