130 BULLETIN 90, UNITED STATES NATIONAL MUSEUM. 



Section MYOFORCEPS Fischer. 



Myoforceps Fischer, Man. de Conchyl., p. 969, 1886. — Dall, Trans. Wag- 

 ner Inst, VOL 3, pt. 4, p. 799, 1898. 



It is one of the puzzles of malacology how the appendages, com- 

 posed of the dust of their borings, are applied to the outside of their 

 shell by these mollusks and permanently fixed there. 



LITHOPHAGA (MYOFORCEPS) ARISTATA Dillwyn. 



Mytillus aristaUis (Solander MS.) Dillwyn, Cat. Rec. Sh., voL 1, p. 303, 



1817. 

 Modiola caudigera Lamarck, Anim. s. Vert., voL 6, p. 116, 1819 ; EncycL 



Meth., pL 201, fig. 8.— Philippi, Abbild. und Beschr., voL 2, p. 149, pL 1, 



fig. 5, 1846. 

 Mytilus caudigerus Gibbes, Cat. S. Car., p. 22, 1848. 

 lAthodomus aristatus Forbes and Hanley, Brit. MolL, voL 2 ,p. 212, 1851. 

 Lithodonius caudigerus Sowerby, Genera, Litliodomus, fig. 4, 1824. — Reeve, 



Conch. Iconica, voL 10, pL 3, fig. 16, 1857. 

 lAthophagus aristatus Stimpson, CheckL Rec. Sh., p. 2, 1860. 

 Lithophagus forflcatus Ravenel, Proc. Acad. Nat. Sci. Pliila., for 1861, p, 



44.— Tryon, Amer. Marine Conch., p. 188, 1873.— Dall, BulL U. S. Nat. 



Mus. No. 37, p. 38, 1889. 

 Lithophaga (Myoforceps) aristata Dall, Trans. Wagner Inst., voL 3, pt. 4, 



p. 800, 1889. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida. Liv- 

 ing widely distributed over the tropical seas of both hemispheres. 

 U. S. Nat. Mus. No. 165188. 



Section DIBERUS Dall. 



Diherus Dall, Trans. Wagner Inst., voL 3, pt. 4, p. 799, 1898. Type, Litho- 

 phaga plumula Hanley. 



LITHOPHAGA (DIBERUS) BISULCATA Orbigny. 



lAthodomus hisulcatus Orbigny, Moll. Cubana, vol. 2, p. 333, pi. 28, figs. 



14-16, 1847 (Spanish edition, 1845). 

 Modiola appendiculata Philippi, Abbild. uud Beschr., vol. 2, p. 150, pi. 1, 



fig. 4, 1846. 

 Mytilus attenuatvs Gibbes, Cat. S. Car., p. 22, 1848, not of Deshayes. 

 Lithophagus appendiculatus Morch, Cat. Yoldi., vol. 2, p. 56, 1853. 

 Lithodomus appendiculatus Reeve, Conch. Iconica, vol. 10, pi. 4, fig. 21, 1857. 

 Ldthodoniii.s biexcavatus Reeve, Conch. Iconica, vol, 10, fig. 22 a-&, 1857. 

 Lithophaga {Diherus) bisulcata Dall, Trans. Wagner Inst., vol. 3, pt. 4, 



p. 801, 1898. 



Tampa silex beds. Ballast Point, Tampa Bay, Florida; Dall. 

 Living from South Carolina south to Eio Janeiro and throughout the 

 West Indies. U. S. Nat. Mus. No. 154362. 



This species was found with a siliceous pseudomorph of the calca- 

 reous mantle as well as the shell. 



