80 JOUBNAL OF THE MiTCHELL SoCIETY \_AugUSf 



FAMILY MYTILIDiE. 

 Genus Mytilus (Linnaeus) Bolten. 



Mytilus (Hormomya) exustus Linnaeus. 



Mytilus exustus Linnaeus, Syst. Nat., Ed. lo, p. 705, 1758; Dall, Bull. 

 37, U. S. Nat. Mus., p. 38, 1889. 



Mytilus (Hormomya) exustus, Dall, Trans. Wagner Inst. Sci., vol. 3, 

 pt. 4, P- 788, 1898. 



This comparatively small species is found in fairly large 

 numbers on the breakwater at Pivers Island, associated with 

 Modiolus demissus (Dillwyn). It can probably be found on 

 any of the several breakwaters in the vicinity of Beaufort. 



Genus Modiolus Lamarck, 1799. 



Modiolus (Brachydontes) demissus (Dillwyn). 



Mytilus demissus (Solander MSS.) Dillwyn, Descr. Cat. Rec. Shells, 

 vol. I, p. 314, 1817. 



Modiola plicatula, Dall, Bull. 37, U. S. Nat. Mus., p. 38, pi. 54, fig. i, 

 1889. 



Modiolus (Brachydontes) demissus, Dall, Trans. Wagner Inst. Sci., 

 vol. 3, pt. 4, p. 794, 1898. 



Very abundant on the breakwater and on muddy ground be- 

 tween tide marks at Pivers Island. Abundant about the west- 

 ern end of Town Marsh. Its natural habitat at Beaufort seems 

 to be between tide marks among the roots of vegetation along 

 the edges of salt marshes. It is the common mussel at Beaufort. 



Modiolus tulipus Lamarck^ 



Modiola tulipa Lamarck, An. sans Vert., vol. 6, p. iii, 1819; Dall, 

 Bull. 37, U. S. Nat. Mus., p. 38, 1889. 



Modiolus tulipus, Dall & Simpson, Bull. U. S. Fish Com. for 1900, 

 vol. 20, pt. I, p. 470. 



The species has been found at the railroad pier at Morehead 

 City and in the vicinity of Pivers Island. So far living ma- 

 trial has not been found abundantly. 



Genus Lithophaga Bolten, 1798. 



Lithophaga bisulcata (Orbigny). 



Lithodomus bisulcatus Orbigny, Moll. Cubana, vol. 2, p. 333, pi. 28, 

 figs. 14-16, 1847 (Spanish edition and atlas, 1845). 



Lithophagus bisulcatus, Dall, Bull. 37, U. S. Nat. Mus., p. 38, 1889. 



Lithophaga (Diberus) bisulcata, Dall, Trans. Wagner Inst. Sci., vol. 3, 

 pt. 4, p. 801, 1898. 



