272 THE VOYAGE OF H.M.8. CHALLENGER. 



Subfamily Mytilin.e. 



Mytilus, Linne. 

 Mytilus edulis, Linne. 



Mi/tiliis edtditi, Linne, Syst. Nat., ed. 12, p. 1157. 

 Habitat— 8t(itioD. 322, off the Rio de la Plata, in 21 fathoms ; Station 315, Falkland 

 Islands, in 12 fathoms; and D'Urville Island, New Zealand. 



This common species has become widely distriliuted, and differs considerablj' in form, 

 colour, and size. Hutton quotes it as occurring in New Zealand, and I have already 

 identified it as coming from Kerguelen Island (Phil. Trans. Roy. Soc, 1879, vol. clxviii. 

 p. 189). 



Mytilus imujellanicus, Chemnitz. 



Mytilus magellankus, Chemnitz, Concli.-Cab., vol. \-iii. pi. kxxiii. fig. 742. 

 Mytilus magellanicus, Eeeve, Conch. Icon., vol. x. pi. vi. fig. 22. 

 Mytilus wagellanicus, Smith, Phil. Tran.s., 1879, vol. cLxviii. p. 188. 



Habitat. — Station 315, Falkland Islands, in 12 fathoms; Betsy Cove, Kerguelen 

 Island, on the shore ; and Kandavu, Fiji. 



A single small .specimen from the last locality is apparently inseparable from this 

 weU-known species, which is also met with on the shores of New Zealand. 



Mytilus exustus, (Lamarck) Reeve. 



Mytilus exusfux, (Lamarck) Keeve, Conch. Icon., vol. x. p1. iv. fig. 10. 



Habitat. — Station 113a (?), St. Michael's Rocks, Fernando Noronha ; and Station 

 122, off Pernambuco, in 350 fathoms. 



The specimens from these localities belong to Mytilus exustus as identified by Reeve, 

 but until an opportunity occurs of studjang aU the shells belonging to this striated 

 group of Mytilus, it is impossible to say whether the species should or should not 

 definitely retain this name. Mytilus cubitus of Say, Mytilus variabilis of Krauss, and a 

 few other forms appear to be so very closely related that it would be hazardous to 

 pronounce them either di.stinct or conspecific without a much longer study than I can at 

 present bestow upon them. 



Mytilus sulcatus, (Lamarck ?) (Reeve). 



Moiliola sulcata, (Lamarck) Reeve, Conch. Icon., vol. x. pi. x. fig. 74, sp. 61. 

 Habitat. — Wednesday Island, near Cape York, North Australia. 



