94 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



is If. Darwinianus. Probably M. Charpentieri (Dkr.) Clessin, from 

 Western Africa, is tbe same; perhaps also M. Charpentieri, Reeve, 

 which, however, has more resemblance to M. granulatus, Hanley. 

 Possibly M. excisus, Rve., and If. ustulatus, Eve., are identical. The 

 present is an Antillean species. 



10. Mttilus Podkiguezii, Orb. 



Mytilus Rodriguezii, Orb. : Voy. Amer. merid., torn, v [1846], p. 646, 



pi. lxxxv, figs. 9, 10. 

 Modiola Martensi, Jhering : Rev. Mus. Paulista, vol. ii (1897), p. 104, 



fig. 6. 

 Modiola sulcata, Dall: Nautilus, vol. v (1891), p. 43. 



I have this species from Puerto Madryn and Puerto Cameron, on 

 the Patagonian coast, from Cap 8. Antonio, etc., on the Argentine 

 coast, and from Rio Grande do Sul. The Patagonian form var. 

 Madrynensis, mihi, is smaller and darker : the Rio Grande do Sul 

 form is somewhat flattened, with the dorsal half reddish-brown, and 

 was originally described by me as If. Martensi. 



Modiolus citrinus, Bolten (= If. sulcatus, Lam., = Mytilus exustus, 

 Orbigny, in Sagra's Cuba, ii, p. 329, pi. xxviii, figs. 6, 7), to which Dall 

 referred the Rio Grande do Sul specimens, is an Antillean species not met 

 with in Brazil. Clessin's M. Pactelianus is a synonym for M. citrinus, 

 and said by him to occur also at Australia and the Philippines. 



11. Mytilus ovalis, Lam. 



Mytilus ovalis, Lamarck: Anim. sans Vert., vol. vi (1819), p. 121. 

 ,, ,, Lam.: Reeve, Conch. Icon., vol. x (1858), sp. 14. 



,, ,, Lam. : Hidalgo, Mol. Viaj. Pacffico, pt. ii (1869), p. 48, 



pi. ii, fig. 7 

 ? ,, variabilis, Krauss : Siidafr. Moll. (1848), p. 25, pi. ii, fig. 5. 

 ? ,, Senegalensis, Lam. : Clessin, Conch. -Cab., 2nd ed., p. 38 

 (1887), pi. xi, figs. 3, 4. 

 ,, ovalis, Lam. : Tapparone-Canefri, Zool. Viag. Magenta, Malac. 

 (1874), p. 143, or Mem. Accad. Sci. Torino, ser. n, 

 torn, xxviii (1876), p. 247. 

 Modiola ovalis, Lam.: Clessin, loc.cit., p. 128 (1888), pi. xxxiii, figs. 4,5. 

 ? Aulacomya Darwiniana, Orb. : Rochebrune & Mabille, Mission Sci. 

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



I have already treated (ante, p. 85) of the relationship between 

 this species and Modiolus purpuratus. Care must also be taken not 

 to confuse it with young shells of Mytilus Magellanicus, since the two 

 forms live together. The young shell of the latter species is much 

 broader, with the radial ribs strong and the adductor scars very feeble. 

 In shells of If. ovalis, the radial sculpture is at first feeble, becoming 

 successively stronger, and the adductor scars are very pronounced. 



