20 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 20 



Mytilus eduUs patagonicus Ihering 1907 

 {non Hanley 1843, Orbigny 1846). 



Mytilus desolationis Lamy 1936. 



Mytilus kerguelensis Fletcher 1938 {non Smith 1885). 



Mytilus dunkeri civ. Bartsch 1943 {non Reeve 1857). 



Mytilus edulis diegensis Coe 1945. 



Mytilus patagonicus Carcelles 1950, 1951 

 {non Hanley 1843, Orbigny 1846). 

 Holotype: Linnean Society ? 

 Type locality: North Atlantic. 



Remarks: This list of synonyms is not complete, but is supposed to con- 

 tain all names used for this species from the west coast of America, as 

 well as those considered to constitute geographical subspecies. Usually 

 Mytilus edulis has been used for specimens from the northern parts of the 

 Atlantic and Pacific Oceans, while specimens from the west coast of 

 South America have been considered to constitute a subspecific unit M. 

 edulis chilensis Hupe, and those from the east coast of South America 

 another unit 71/. edulis platensis Orbigny. Specimens from the Kerguelen 

 Islands were named M. desolationis by Lamy (M. kerguelensis Flet- 

 cher), while those from Australia and New Zealand are known as 

 M. edulis planulatus Lamarck. The higher, flatter forms with very 

 small anterior adductor are named M. galloprovincialis Lamarck in 

 the Mediterranean and M. diegensis Coe in California. Though there 

 might be distinctive forms living in the neighborhood of each other, 

 these forms seem to occur in all areas where M. edulis is living. They 

 may be ecological forms or genetically determined, but at present it 

 seems impossible to circumscribe a group of specimens from one locality 

 so well that they can be recognized in a large collection from many 

 localities. On the other hand, one would be inclined to suppose that the 

 geographically widely separated populations are evolving or have ac- 

 quired some characters, though minute, in shell, animal, or in their 

 biology, which might separate them from other populations. It seems, 

 therefore, to be advisable to use special names for some of the geographi- 

 cally separated populations as subspecies, even if no morphological char- 

 acters for their separation can be indicated. 



Mytilus edulis is often considered to be a cosmopolite, but that is 

 wrong. It has a definite distributional pattern comparable to that found 

 in Choromytilus and Aulacomya, showing that these genera have had 

 at least partly the same history in, geologically speaking, relatively recent 

 times. 



