14 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL. 20 



solentformis Orbigny 1846 (Mytilus) 

 spatlosus Carpenter 1856 (Leiosolenus) 



spatula Menke 1849 (Mytilus) 

 speciosa Reeve 1857 (Modiola) 

 splendens Dunker 1856 (Mytilus) 

 splendida Dunker 1856 (Volsella) 

 stearnsi Pilsbry and Raymond 1898 



(Mytilus) 

 strigatus Hanley 1843 (Mytilus) 

 stylina Carpenter 1864 (Adula) 

 subfuscata Clessin 1889 (Modiola) 



*subsiriata Gray 1824 (Modiola) 

 subulaReeve 1857 (Lithodomus) 



*taylori Dall 1897 (Modiolaria) 

 trifurcatus Dunker 1853 (Mytilus) 

 trossulus Gould 1850 (Mytilus) 

 tumbezensis Pilsbry and Olsson 1935 



(Modiolus) 

 tumidior Carpenter 1856 (Lithophagus) 



tumidior Carpenter 1856 (Lithophagus) 



ungulatus Lamarck 1819 (Mytilus) 

 *'vernicosa Middendorf 1849 



(Modiolaria) 

 'violaceus Clessin 1889 (Mytilus) 

 zeteki Hertlein and Strong 1946 



(Septifer) 



Adula solejiiformis Orbigny 1846 

 Lithophaga (Leiosolenus) spatiosa 



Carpenter 1856 

 fModiolus capax Conrad 1837 

 Mytella speciosa Reeve 1857 

 fModiolus capax Conrad 1837 

 Semimytilus algosus Gould 1850 

 Hormomya adamsiana Dunker 1856 



fMytella falcata Orbigny 1846 

 Adula calif orniensis Philippi 1847 

 fModiolus capax Conrad 1837 or 

 Mytella guyanensis Lamarck 1819 

 M us cuius substriatus Gray 1824 

 Lithophaga (Diberus) subula Reeve 



1857 

 Musculus taylori Dall 1897 

 Septifer bifurcatus Conrad 1837 

 Mytilus edulis Linne 1758 

 Mytella speciosa Reeve 1857 



Lithophaga (Myoforceps) aristata 



Dilhvyn 1817 

 Lithophaga (Diberus) plumula Hanley 



1843 

 Choromytilus chorus Molina 1782 

 Musculus vernicosus Middendorf 1849 



Mytilus edulis chilensis Hupe 1854 

 Septifer zeteki Hertlein and Strong 1946 



THE ''MYTILUS"-GKO\JV 



Mytiliform species were recorded very early in the history of the 

 family. Newell (1942) has placed the Paleozoic species in the genus 

 Promytilus with species of the same form as the recent ones. Nothing 

 is known or published on the hinge characters or the muscle scars. The 

 Jurassic genus Falcimytilus Cox (1937) is described as being without 

 anterior teeth, otherwise very like the recent forms. Several other supra- 

 specific groups are established for fossil species, but so far as I know 

 without detailed characters of the hinge or the muscle scars. It is there- 

 fore at present impossible to establish pedigrees or to trace the relation- 

 ship of the species. 



