50 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL. 20 



Fig. 44. Mytella guyanensis (Lamarck). Distribution mainly ac- 

 cording to samples in American museums. 



2. Anterior retractor before umbo, shell thin, 

 Anterior retractor behind umbo, shell 



very elongate and nearly smooth speciosa (Reeve) 



thicker with concentric sculpture guyanensis (Lamarck) 



Mytella falcata (Orbigny) 1846 

 Plate 5, fig. 24; text-figs. 35, 38-40, 45 



Mytilus falcatus Orbigny, Voyage dans I'Amerique Meridionale, vol. 5, 



Mollusques, 1846, p. 645, PI. 84, figs. 38-39. 

 Syn.: f Mytilus strigatus Hanley 1843 (Hinds MS). 

 Mytilus charruanus Orbigny 1846. 



