90 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



I have examples of this singular species from Rio de Janeiro, 

 Santos, St. Oatharina, Montevideo, and Cap _ S. Antonio. The 

 Brazilian shells are unicolorous, or rarely exhibit markings ; the 

 Argentine ones have zigzag markings on the posterior half of the 

 shell, like the Philippine species figured by Reeve. The teeth are 

 sometimes developed, sometimes obsolete, for which reason they 

 have been classified both with Mytilus and Modiolus. 



3. Mytilus Solisianus, Orbigny (1846). 



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



p. 646, pi. lxxxv, figs. 5-7. 

 ,, Zavatteanus, Orb. : Reeve (nee Orb.), Conch. Icon., vol. x 



(1858), fig. 54. 

 ,, Solisianus, Orb.: Hidalgo, Mol. Yiaj. Pacifico, pt. ii (1869), 



p. 54. 

 ,, Janeirensis, Frauenf eld : Reise Novara Moll. (1867), p. 16. 

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



P. 251. 

 ,, Solisianus, Orb. : Jhering, Rev. Mus. Paulista, vol. ii (1897), 



p. 99. 

 ,, exiguus, Danker : Dall, Nautilus, vol. vi (1893), p. 110. 



Young specimens have a delicate radiate sculpture, which, however, 

 is not at all constant, and never present in the adult shells. It is, 

 therefore, not justifiable to separate M. Solisianus from M. minimus, 

 Poli. Both have the same form and dimensions, while the dorsal 

 margin behind the ligament is denticulate in both. M. atratus, 

 Lischke, which is very similar in form, has the dorsal margin smooth. 

 I believe that M. Solisianus is nothing but a large variety of M. minimus, 

 Poli — my largest example is 15 mm. in length — having sometimes 

 five radial striae when young. I am obliged to Dr. E. von Martens 

 for verifying the identity of M. Solisianus with Dunker's types of 

 M. exiguus, and to Dr. Sturany for having given me typical examples 

 of Dunker's M. Janeirensis. 



M. Solisianus occurs from Maldonado to the "West Indies, and Mexico 

 (Dunker). 



Subgen. CHLOROMYA, Morch. 

 4. Mytilus perna, Linn. 



Mi/a perna, Linnceus : Sysfc. nat., 10th ed. (1758), p. 671 ; 12th ed. 



(1766), p. 1113. 

 Mytilus perna, Lion. : Reeve, Conch. Icon., vol. x (1858), sp. 23. 

 ,, ,, Linn. : Danker, Jahrb. Deutsch. Malak. Ges., Bd. ii 



(1875), p. 250. 

 ,, elongatus, Orbigny : Yoy. Amer. merid., torn, v [1846], p. 643. 

 ,, afer, Gmelin : Hidalgo, Mol. Yiaj. Pacifico, pt. ii (1869), p. 50. 

 ,, perna, Linn. : Jhering, Rev. Mus. Paulista, vol. ii (1897), p. 93. 

 ,, ,, Linn. : Clessin, Conch.-Cab., 2nd ed., p. 57 (1887), 



pi. xiii, fig. 9. 



