250 Proceedings of the lioijol Society of Victoria.. 



1901. Modiola confusa, Tate and May. P.L.S. N.S.W., 



vol. xxvi., pt. 3. p. 438. 

 1901. Mvtilus ater, Tate and May. Id., p. 452. 

 1901. Yolsella ater, Suter. Trans. N.Z. Inst., vol. xxxiv., 

 p. 223. 

 Hah. — Coast g-enerally. 



Obs. — The smaller dwarfed form of the M. crassa type exceed- 

 ingly common on the rocks between tide marks at several locali- 

 ties, especially Back Beach, Sorrento, the larger form being 

 obtained inside the various bays and estuaries, the latter form 

 occurring up the Saltwater River as far as Maribyrnong, a dis- 

 tance of about 10 miles. The difference in habitat of these two 

 forms, the one on exposed rocky shores, the other on muddy 

 river banks and estuaries, frequently in climips, attached to 

 reeds, might be taken as probably indicating two species, but 

 the forms are so variable that it has seemed best to take the 

 whole as one species. 



Modiola inconstans, Dunker. 



1856. Yolsella inconstans, Dunker. P.Z.S. Lond., p. 363. 

 1887. Modiola semivestita, Tate (non Dunker). T.R.S. 



S.A.., vol. ix., p. 106, pi. 5, f. 16a, b. 

 1889. Modiola inconstans, Clessin. Conch. Cab., p. 



127, No. 55. 

 1901. Modiola inconstans, Tate and May. P.L.S. 

 N.S.W., vol. xxvi., pt. 3, p. 438. 

 Hab. — Hobson's Bay, Williamstown, Sandringham, Portar- 

 lington, Corio Bay. 



Obs. — This species, though faiziy consistent in shape, is some- 

 what variable in colour, from a uniform light brown to a blue- 

 black, and occasionally parti-colom-ed. 



Modiola albicosta, Lamarck. 



1819. Modiola albicosta, Lamarck. Anim. S. Vert., vol. 



vi., pt. 1, p. Ill, No. 3. 

 1836. Modiola albicosta, Lamarck. Id. (2nd ed. Desh.), 



vol. vii., p. 19, No. 3. 

 1839. Modiola albicosta, Lamarck. Id. (3rd ed. De- 



shayes and Edwards), vol. iii., p. 12, No. 3. 



