VON JHERING : ON SOUTH AMERICAN MYTILID^!. 93 



iModiola Morrisi, Dunker: Reeve, loc. cit., sp. 38. 



' ,, Muelleri, Dunker: Jahrb. Deutsch. Malak. Ges., Bd. ii (1875), 



p. 250. 

 ,, Muelleri, Jhering : Rev. Mus. Panlista, vol. ii (1897), p. 99, 



figs. 3, 4. 

 ,, Magellanicus, Reeve: Dall, Nautilus, vol. v (1891), p. 43. 

 ,, rostratus, Dunker (ex Reeve) : Tapparone-Canefri, Zool. Viag. 



Magenta, Malac. (1874), p. 143, or Mem. 



Accad. Sci. Torino, ser. ii, torn, xxviii (1876), 



p. 247. 



Common at Montevideo, St. Catharina, etc., ranging to the West 

 Indies, and it seems also to Western Africa. This is a thin Bhell, 

 with feeble, somewhat flattened, radiate ribs, and purplish - dark 

 periostracum. M. rostratus, which Tapparone-Canefri believed to be 

 the same species, is in its exterior aspect identical, but differs 

 internally, being a Septifer. 



8. Mytilus Darwinianus, Orbigny. 



Mytilus Darwinianus, Orbigny: Voy. Amer. merid., torn, v [1846], 

 p. 643, pi. lxxxiv, figs. 30-33. 



,, ,, Orbigny: Pilsbry, Nautilus, vol. xi (1897), p. 9. 



,, ,, Orbigny: Jhering, Rev. Mus. Paulista, vol. ii 



(1897), p. 98. 



,, Lavalleanus, Orbigny: Clessin, Conch.- Cab., 2nd ed., p. 80 

 (1887), pi. xi, figs. 7, 8. 



This species, which is of small dimensions, is characterized by the 

 projecting angle of its dorsal margin, its broad form, and the numerous 

 transverse teeth behind the ligament. The species occurs from the 

 Rio Negro to Rio de Janeiro. Rochebrune & Mabille record it from 

 the Magellan Straits, 1 but I believe that this may more likely prove to 

 be M. ovalis, Lam., since I have this species from St. Cruz, and have 

 seen no examples of M. Darwinianus from St. Cruz nor the Magellan 

 Straits. If, as I believe, M. Lavalleanus, Clessin, is a synonym for 

 this species, it ranges to the Antilles. 



9. Mytilus Lavalleanus, Orbigny. 



Mytilus Lavalleanus, Orbigny : in Sagra's Hist. nat. Cuba, Moll., 

 vol. ii [1846 ?], p. 328, pi. xxviii, figs. 3-5. 

 ,, cubitus, Say: Reeve, Conch. Icon., vol. x (1858), sp. 57. 

 ? ,, Charpentieri, Dunker : Clessin, Conch. -Cab., 2nd ed., p. 33 

 (1887), pi. viii, fig. 3. 



M. Lavalleanus, Orb., seems to be a more tumid variety of If. exustus, 

 Linn. The If. Lavalleanus of Reeve is M. Solisianus ; that of Clessin 



1 Mission Sci. Cap Horn, torn, vi, Moll. (1889), p. 119. 



