THREE NEW SPECIES OF ANODONTITES FROM BRAZIL. 



By William B. Marshaxl, 



Assistant Curator, Division of Marine Invertebrates, United States National Museum. 



Among some Brazilian naiads recently sent to the United States 

 National Museum for identification by Mr. Dias da Rocha of Ceara, 

 Brazil, were two species of Anodontites which appear to be new. 

 They are from Ceara, Brazil. They are not represented in the 

 Museum collection, nor in the collection of the Academy of Natural 

 Sciences of Philadelphia, which I have examined, with the kind 

 assistance of Dr. H. A. Pilsbry. I have been unable to find them 

 described in the literature relating to the genus and have concluded 

 that they belong to an undescribed species. More recently, Mr. da 

 Rocha has sent four additional valves of Anodontites from the same 

 locahty . Two of these belong to typical Anodontites sinuosus Lamarck, 

 while the other two belong to a new species. 



The following descriptions and figures will serve to define the 

 three species : 



ANODONTITES SALMONEA, new species. 

 Plate 67. 



Shell moderately thick, rounded in front, obtusely angular behind, 

 widest just posterior to the beaks. Periostracum thin, with a dull 

 pohsh, marked by obscure rays which are formed by a ruffling of the 

 periostracum itself. Entire surface of the shell marked by concentric 

 impressed fines, which, in the earlier stages of growth are more regu- 

 lar, stronger, and nearly evenly spaced, but which become faint 

 and irregular as growth progresses. Periostracum fight yellowish 

 olive, the rest stages indicated by dark lines, and the color gradually 

 darkens from the beaks to the margins. Posterior ridge rounded, 

 but fittle elevated. Posterior dorsal area with a low rib running 

 from the beak to a point above the posterior angle. Beaks eroded, 

 salmon pink, and this color shows through the periostracum for some 

 distance from the beaks, showing that the material of the shell itseK 

 is of this color. Nacre beautiful salmon pink, the color deepest in 

 the cavity of the beak, and becoming paler and more iridescent 

 toward the margins. Prismatic margin dull greenish, or whitish 

 tinged with green. Surface of the nacre marked by innumerable 

 fine radiating fines which are part of the nacre or of the sheU substance. 



Proceedings U. S. National Museum, Vol. 49— No. 2122. 



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