﻿BIVALVIA. Ill 



Modiola discors, Linn. Crag Moll., vol. ii, p. 63, Tab. VIII, fig. 5. 

 Locality. Chillesford Bed, Chillesford. 



In vol. ii of ' Crag Moll.' I assigned with doubt to this species a specimen obtained 

 from the Chillesford Bed, but I have not seen it from any other East Anglian formation. 

 In the list to Mr. Prestwich's 'Cor. Crag' paper this species is entered (Modiolaria 

 discors) as a shell of that Crag from Sutton, but I have not seen the specimen upon which 

 that entry is based. I have re-examined my own specimens of Modiola in the British 

 Museum and do not recognise the species among them. 



Modiola Petagn^e, Scacchi. Crag Moll., vol. ii, p. 60, Tab. VIII, fig. 6 b (as M. 



costulata, var. Petagnce). 



Localities. Cor. Crag, Sutton ; and Red Crag, Walton Naze. 



In the 1 Crag Moll.' I figured this shell as a variety only of costulata, following in 

 this respect Philippics earlier rather than his later view, and not desiring to swell the 

 number of species where it could be avoided. The Mediterranean authors, however, 

 keep the two forms as distinct species, and therefore I, not from my own judgment, but 

 in deference to these authors, have here assigned Petagnce as a separate species. 



Modiola phaseolina, Phil. Crag Moll., vol. ii, p. 59, Tab. VIII, fig. 4. 

 Localities. Cor. Crag, Sutton, Ramsholt, and near Orford. 



This is another shell which I figured at the above reference, and I have since then 

 found several additional specimens ; but whether they be specifically distinct from the 

 young of Modiola modiolus is very doubtful (see ' Crag Moll./ p. 59). There is not, I 

 fear, any sufficient difference in their forms, or any other character by which phaseolina 

 can be specifically distinguished from modiolus. Both forms are present in the Crag, and 

 I have permitted their names to remain separate. 



Nucula CobboldijE, /. Sow. Crag Moll, vol. ii, p. 82, Tab. X, fig. 9; and 



Supplement, Tab. X, fig. 2. 



Localities. Red Crag, Sutton, Bawdsey, Felixstowe, Waldringfield, and Butley. 

 Pluvio-marine Crag, Bramerton, Thorpe, Bulchamp, Thorpe by Aldbro, and Yarn Hill. 

 Chillesford bed, Chillesford, Aldeby, Easton Cliff, and Bramerton. Lower Glacial, 



