Occasional Papers of the Museum of Zoology 47 
prominent, nearly superior; epidermis striate, olivaceous ; 
nacre white, iridescent, length 2-3 inch. Yet it does not posi- 
tively indicate this species. However, in connection with the 
generic characters given for Amblema, the species is well 
characterized by the terms “dent bilobee ridee, laterale au 
sommet,”” which could not be used for any other species. Thus 
olivaria stands. 
Rafinesque (’20, p. 288) states in substance that he did not 
repeat the generic characters in his specific descriptions, as it 
would make them long and prolix. But when necessary, as in 
this case, they should be read into the description of the species. 
Genus ACTINONAIAS Fischer and Crosse, 1893 
Actinonaias Fischer and Crosse, ’93, p. 556 (no type named, con- 
taining Mexican species inc. sapotalensis Lea). 
Actinonaias Fischer and Crosse, ’93, p. 550 (no type named, con- 
taining Mexican species inc. aztecorum allied to plicatulus Charp.) 
Nephronaias Simpson, ‘00%, p. 591 (type, plicatulus Charp.). 
Nephronaias Ortmann, ‘12, p. 324 (containing 3 species, incl. sapo- 
talensis). 
Nephronaias Frierson, 17, p. 47 (type, plicatulus Charp.). 
Actinonaias Frierson, ’17, p. 48 (type, sapotalensis Lea); Walker, 
"18, p. 75. 
The final settlement of the generic names Nephronaias and 
Actinonaias depends on the knowledge of the anatomy of the 
Mexican type of Nephronaias (plicatulus Charp.). The anat- 
omy of the type of Actinonatas (sapotalensis) is known (Ort- 
mann), and since certain North American species agree with 
this, this name should be used for them. The designation of 
the type of Actinonaias (sapotalensis) is from Frierson. 
ACTINONAIAS CARINATA (Barnes), 1823 
Type locality: Fox River (Wisconsin). 
Unio crassus Say, ’17, pl. 1, f. 8 (not U. crassus Retzius, 1778). 
Unio ligamentina Lamarck, ‘19, p. 72. 
Unio crassus Say, Rafinesque, ’20, p. 293. 
