116 ' PLIOCENE MOLLUSC A. 



has always clifiFered from this view, and from an examination of many specimens 

 of Charles worth's shell, both Belgian and English, I am compelled to agree with 

 him ; Atractodon elegans is quite a different species. 



The Iceland fossil corresponds with that from Butley, except that the spiral 

 sculpture is somewhat coarser. From photographs I have submitted to Dr. Dall, he 

 has identified both of them with the Recent Behring Sea form, L. canaliculaius. 



The generic name Liomesus has been generally adopted for the shells formerly 

 known as Buccinopsis. 



Genus PURPURA, Adanson, 1757. 



Purpura tetragona (.1. Sowerby). Plate XI, fig. 6; and var. alveolata (J. 



Sowerby), Plate XI, figs. 13, 18. 



1825. Buccinum tetragonum, J. Sowerby, Min. Conch., vol. v, p. 13, tab. ccecxiv, fig. 1. 



1825. Murex alveolatus, J. Sowerby, Min. Concli., vol. v, p. 9, tab. ccccxi, fig. 2. 



1843. Murex alveolatus, Nyst, Coq. foss. Terr. Tert. Belg., j). 547, pi. xliii, fig. 1. 



1848. Purpura tetragona, and varieties, S. V. Wood, Mon. Crag Moll., pt. i, p. 38, tab. iv.figs. la, 7b. 



1881. Purpura tetragona, and varieties, Nyst, Concli. Terr. Tert. Belg., p. 39, pi. iii, fig. 5. 



1885. Ptirpura tetragona, Lorie, Arcli. Mus. Teyler (2), vol. ii, p. 201, pi. v, fig. 24. 



1912. Purpura tetragona, Tescli, Med. v. d. Rijks. v. Delfstoft'eu, pt. iv, p. 80. 



Specific Characters. — See Mon. Crag Moll., pt. i, p. 38. 



Distribution. — Not known living. 



Fossil : Coralline Crag — Boyton zone : Ramsholt. Red Crag — 

 Waltonian ; Newbournian; Butleyan. Scaldisien : Belgium, Holland. 



Bemarlcs. — This species has not been reported hitherto from the Coralline Crag. 

 There is a specimen in the Ipswich Museum, from Ramsholt, however, here figured, 

 from a bed which in Mr. A. Bell's opinion belongs to the Boyton division of that 

 formation. 



In the Waltonian Crag, whether of Walton, Beaumont, or Little Oakley, it is, 

 together with its variety alveolata, among the most abundant and characteristic 

 fossils; in the Newbournian it is not so common, and it seems to have been dying 

 out at the Butleyan stage. 



From the Norwich Crag it is unknown, if Ave except a doubtful specimen 

 included in S. P. Woodward's list on the authority of the late Robert Fitch ; no 

 trace of it, however, has been met with for fifty years, as far as I know, at any 

 locality of that horizon. 



