MR HARMER ON FUSUS ANTIQUUS. 225 



are from the Scaldisien deposits of Belgium. In these the prin- 

 cipal spiral ridges are more prominent, are further apart, and are 

 separated by a number of finer ones of unequal size. The canal is 

 longer than in the Sicilian fossil. Fig. 5 is from the Crag of 

 Walton-on-Naze, contemporaneous with the Scaldisien. Its sculp- 

 ture is similar to that of Xos. 2 and 3, but the striations are feeble, 

 and the canal is much shorter. Fig. 4 represents a recent specimen 

 from Vigo Bay, in the McAndrew collection in the Museum of 

 Zoology at Cambridge. Its spiral markings are of a character 

 intermediate between those of the Belgian and Sicilian forms'. 

 All these sinistral shells have a strong family likeness. 



The oldest beds of Pliocene age known to me in which dextral 

 forms of Neptunea occur are at Little Oakley, between Harwich 

 and Walton-on-Naze, in the county of Essex. They are, however, 

 by no means abundant there, while specimens of N. contraria are 

 exceedingly so. The Oakley deposits probably belong to the 

 period when the right-handed species were making their first 

 appearance in the Anglo-Belgian area. If the sinistral shells are 

 to be regarded as varieties merely of the dextral form, these earliest 

 recorded specimens of the latter group should show a greater ap- 

 proximation to the former than is the case with those now exist- 

 ing, or those that are obtained from later Pliocene deposits, but 

 this is not so. More than half the dextral shells from the Oakley 

 Crag are carinated (Fig. 6), but no carinated sinistral specimens are 

 known to me from these or from any other strata of similar age, 

 all the left-handed forms there occurring being smooth or indis- 

 tinctly striated, and having the oblique volution, lengthened spire, 

 and distinct suture of this group. In the typical dextral form of 

 the Oakley Crag (Fig. 7) the suture is more nearly at right angles 

 to the columella, and the whorls overlap, so that the spire is very 

 short. In one specimen (Fig. 8), an extreme case, the mouth 

 measures three-fourths, and the bod}' whorl nine-tenths of the total 

 length ^ 



I am inclined, therefore, to consider that Neptunea contraria 

 may be regarded as a separate species, of which the Sicilian 

 (var. sinistrorsa) and Anglo-Belgian fossil forms are geographical 

 varieties, and that the Vigo Bay shell is a connecting link between 

 them. 



The carinated and non-carinated dextral shells of the Essex 

 Crag on the one hand, and the existing N. antiqiia and N. despecta 

 on the other are more nearly related to each other than they are to 

 the sinistral group. N. antiqiia and N. despecta have at the present 

 da)', however, a very different range, and are rightly regarded as 

 distinct. 



1 Specimens may be obtained from the Crag and from the Scaldisien deposits which 

 to some extent approach in their sculpture those found in V igo Bay. 



- Examples of dextral and sinistral shells are met with in these beds which approach 

 each other, but the typical form in each case is widely different ; the sinistral specimens, 

 moreover, attain a much larger size at Oakley than do the dextral. 



15 



