XXIX 



PECTUNCULUS. 



Ptlosus (Glycimeris, 



103). 



Decussatus, 104. 

 Nummarius, 104. 



NUCULA. 



Nitida,24>S,f. 31. 

 Nucleus, 105, /. 74. 

 Tennis, 105 

 Rostrata, 105, 

 Minuta, 106. 



MODIOLA. 



Radiata, 249, /. 104. 

 Rhombea, 107. 

 Vulgar is (Modiolus, 



107) (r). 

 Decussata (Faba, 248, 



/I). 



Gi66*ii, 107. 

 Discors, 108. 

 DiscrepanS) 108. 



, 249, /. 5 (). 



(r) This shell is not the M. Modiolus of Linne, which 

 is really that called Tulipa by Lamarck. I state this 

 from an examination of the typical specimens of that 

 great naturalist. 



(*) M. Nigra (Gray in Supplement to Parry's Voyage) 

 appears to be the Discrepans of Montagu's Supplement, 

 agreeing very well with the figure. The author's re- 

 ference to the larger Newfoundland specimens must be 

 expunged, for although extremely resembling them, the 

 British shell may be easily distinguished by the propor- 

 tionate shortness from the beaks to the ventral edge, 

 (which by age also becomes much incurved,) arid its de- 

 cidedly stronger radiating costellaB, Frith of Forth. 



