SEARLESIA CONSOCIALIS. 147 



Distribution. — Not known living. 



Fossil : Coralline Crag : Gedgrave, Ramsliolt, Boy ton. Waltonian: 

 Walton-on-Naze, Beaumont, Little Oakley. Newbournian : Sutton, Brightwell, 

 Newbourn, Butleyan : Butley. 



Diestien, Scaldisien, Poederlien of Belgium ; Scaldisien, Holland. 



Bemarhs. — This species can hardly be grouped with the Trophons ; I include 

 it, though with some hesitation, among those described above in the genus 

 Searlesia. It is not very abundant either in the Coralline or the Red Crag. 

 Specimens from the latter are often, but not always, rolled and waterworn, and 

 have been regarded in consequence as derivative. The fact that this shell occurs 

 rather commonly, however, in the Scaldisien of Belgium in an unw^orn condition 

 seems antagonistic to that view, indicating that it was living in the Anglo- 

 Belgian basin as late, at least, as the Waltonian period. 



Searlesia consocialis (S. V. Wood). 



1848. Trophon consocialis, S. V. Wood, Mou. Crag Moll., pt. i, p. 49, tab. vi, fig. 11. 



1881. Murex (Trophon) alveolatus, var. consocialis, Nyst, Conch. Ten*. Tert. Belg., p. 4, pi. i, fig. 2. 



1890. Trophon consocialis, C. Eeid, Plioc. Dep, Brit., p. 258. 



1912. Trophon consociale, Tesch, Med. v. d. Rijks. v. Delfstoftieu, pt. iv, p. 82. 



Specific Characters. — See Mon. Crag Moll., pt. i, p. 49. 



Dimensions. — L. 40 mm. B. 24 mm. 



Distiibution. — Not known living. 



Fossil : Coralline Crag : Ramsliolt, Gedgrave, Boyton. AVal- 

 tonian : Walton-on-Naze, Beaumont, Little Oakley. Newbournian : Newbourn, 

 Waldringfield, Sutton. Butleyan : Butley. 



Diestien : Holland. Scaldisien : Belgium. 



Bemarhs. — This form, regarded as distinct by Wood, Avas described by Nyst as 

 a variety of 8. alveoUifa. It differs from the latter, however, in form and to some 

 extent in sculpture, and I do not remember to have seen any specimens connecting 

 the two. Although closely allied, I follow Wood in regarding them as separate 

 species. For the reasons given above, I doubt whether they should be regarded 

 as derivative in the Red Crag. I have found them both, not unfrequently, at 

 Oakley. 



Nyst gives this species from the Scaldisien of Belgium, and Dr. Tesch from 

 the Diestien of Holland. 



