BIVALVIA. 11 



Astarte, Cardita, &c.) was seen some few years ago in situ at the base of the excavation, 

 in a part now rilled in, and I have obtained many double shells from there exactly 

 answering to those found in the pits at Broom Hill, Sudbourn, and at Sutton. There 

 seems also to be an admixture of shells from some formation with which we are 

 unacquainted in England (most probably the Belgian Crag) as several species have been 

 found here that have not been detected in any other Crag bed (Fusits Waelii, Murex 

 Beedii, &c). The Red Crag element is, however, sufficiently prevalent, and such shells 

 as Troplion scalar if or mis, T. muricatus, and especially Nassa reticosa, are particularly 

 abundant. 1 The specimen of Amaura Candida mentioned in the column of remarks in the 

 list of Mollusca given in the first ' Supplement to the Crag Mollusca,' as found at Boyton, 

 came, I believe, from Butley, i. e. from the same locality as the specimen figured in 

 Tab. I, fig. 3, of that Supplement. Robt. Bell.] 



BIVALVIA. 



SiLiauARiA parva, Speyer. 3rd Sup., Tab. I, figs. 16 a — b. 



Siliqcakia parva, Speyer. Ober.-Oligoc. Tertiar. Detraold., p. 33, tab. iv, fig. 2 a, b, 



Paleeontographica, Band xvi, 1869. 



Spec. Char. " Testa parva tenuissima, oblonga, antice brevis, postice producta, 

 utrinque (squattier rotundata, laevigata, nitida ; cardo subumbone parvuto fossula plana 

 instructus, dente unico munitus. Nymplia breves angustce." Speyer. 



Locality. Bramerton. 



Two fragmentary specimens of a small bivalve were sent to me by Mr. Jas. Reeve (as 

 mentioned in my second Supplement, p. 40), which I thought were too small and 

 imperfect to be represented, 'but as they appear to be indicative of the presence in 

 Norfolk of an older formation than the one in which they have been found, I think it 

 desirable to figure them, imperfect as they are. The hinge has a prominent fulcrum for 

 the support of its external connector, the central tooth large, prominent, and obtuse, being 

 immediately before it and under the umbo ; and there is a depression in the corresponding 

 valve for its reception 2 similar to the hinge furniture of Saosicava, which it much resembles, 

 as it does also the shells of Sphenia, but there appears, I think, sufficient difference to 



1 [See also footnote to p. 3 of Second Supplement as to this Boyton bed, the information quoted there 

 having been obtained from Mr. Alfred Bell. From that it would appear that the bed containing Astarte 

 and Cardita was part of the lowest portion of the Coralline Crag, and was overlain by some Red Crag ; 

 the shells of both formations becoming thus intermingled in the working. 



2 The engraver has not been successful in delineating the character of the hinge in either valve. The 

 generic name Siliquaria is used here from Speyer, but it is that also of a vermiform shell. — Ed.] 



