﻿EXOTIC UNlONIDiE. 267 



Von dem Busch. It is much stouter than Union es are usually from South America, and 

 is perhaps more nearly allied to Wheatleyanus, (nobis), from the Rio Negro than any 

 other species. It approaches to delodontus, Lam., but is thicker and more rotund 

 than that species. It may be distinguished at once from Wheatleyanus by its greater 

 thickness, by the swollen beaks, the furrow on the posterior slope and the size and 

 form of the cardinal teeth, which are peculiar in this. The beaks of this specimen 

 being much eroded it is impossible to say what may be the character of the tips, but 

 they are likely to have rayed ribs, like most South American Unionidce, but not so 

 much so as in Wheatleyanus. The specimen before me, as described above, is rugose, 

 with a few irregular transverse and radiating furrows, which may not exist on all 

 specimens. It is dark brown and roughly striate near the margin, and smoother and 

 light brown towards the beaks. 



'o 1 



Anodonta luteola. PI. 43, fig. 147. 



Tests, Isevi, obovata, subcompressa, postice et antice rotundata, inequilateral i ; valvulis subtenuibus; 

 natibus prominulis ; epidermide luteo-oliva, transversim striata ; margarita alba et valde iridescente. 



Shell smooth, obovate, rather compressed, rounded behind and before, inequilateral ; 

 valves rather thin ; beaks a little prominent ; epidermis yellowish olive, transversely 

 striate ; nacre white and very iridescent. 



Anodonta luteola, Lea. Proe. Acad. Nat. Sci., 1858, p. 118. 



Hal.— Isthmus of Darien. H. C. Caldwell, M. D., U. S. Navy. 



My cabinet. 

 Diam. -6, Length 1-1, Breadth 1*7 inch. 



Shell smooth, obovate, rather compressed, rounded behind and before, inequilateral, 

 with a slightly curved dorsal line ; substance of the shell rather thin, beaks a little 

 prominent ; ligament rather long, thin and light brown ; epidermis yellowish olive, 

 transversely striate, very much wrinkled and with distant marks of growth ; umbonial 

 slope very slightly raised and rounded; posterior slope narrow, raised into a high 

 carina, with a greenish line from each of the beaks to the posterior margin ; anterior 

 cicatrices confluent and slightly impressed ; posterior cicatrices confluent and very 

 slightly impressed ; dorsal cicatrices above the centre of the cavity of the beaks ; 

 cavity of the shell moderately deep and rounded; cavity of the beaks shallow and 

 rounded ; nacre white and very iridescent. 



Remarks. — A single specimen was brought by Dr. Caldwell. It is somewhat like 

 Trautwiniana, (nobis), but that shell is more oval, darker and greenish in the epider- 

 mis. I have had an eroded specimen of luteola in my cabinet for many years, bought 

 in Paris and said to have come from Martinique. It was labelled obtusa, Spix, but it 

 is not, certainly, that species. I do not believe that any species of the family inhabits 

 the island of Martinique. I know of only one species in the West India Islands — the 

 Scamnatus, Morelet, which is not uncommon in Cuba, as I have stated elsewhere. 



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