XORTHUMBERLAXD AND DURHAM. 281 



IG, f. 22), it will be seen how strikingly similar to each other 

 they are in form. In Mr. King's figures, the spire of the shell 

 is represented much too high, and his "diagnosis" is so jumbled, 

 that it would be in vain to hope to identify the species by it. 



The surface of the shell is ornamented with very fine, wavy, 

 longitudinal stride. This peculiar character is well displayed on 

 some specimens collected by Mr. Kirkby at Field House. 



Baron Schauroth has lately united this species to the Euom- 

 phalus Penniamis, King, at the same time removing the latter 

 into the genus Bissoa. After examining some examples of this 

 supposed species from both German and English localities, I 

 think it is probably only the young of Littorlna Hercyuica. The 

 figure given by Mr. King, with its few whorls and unfinished 

 mouth, is evidently only a young shell. 



In the shell-limestone of Tunstall, Silksworth, and Field 

 House, but not common. 



33. PLEUROTOMARIA, Dcfrance. 



1. P. ANTRiNA, Scliloth. PI. XL, figs. 21, 22, 23, 24, 25. 



In well-preserved specimens of this shell, the whole of the 

 surface is ornamented with distinct longitudinal lines, but they 

 are never so much raised as in the following species, and the 

 surface never presents the same finely decussated appearance. 

 In young specimens the suture follows the line, of the fissure of 

 the preceding whorl, but it falls considerably below it in some 

 adults, which have consequently a less conical appearance. The 

 U})per surface of the whorls is either slightly arched or nearly 

 flattened, and this variation is respectively represented on the 

 under surface, which has, in the latter case, a flattened, truncated, 

 and in the former a tumid appearance. These variations are 

 shown in the figures referred to in the accompanying plate. 



Ihe false species and erroneous identifications of this very 

 characteristic shell are corrected in the table given at p. 245. 



Rather plentiful in the shell-limestone of Tunstall, but rare 

 in several otlier localities. 



2. P. Verxeuili, Geinitz. 



I find that P)aron Schauroth has identified the PJoirotoijiaria 



