1270 DIPLODON 



Griffith gives a figure of this shell and merely the name, 

 LJnio childrcni, in the index and six words of description. 

 The laterals are slender and nearly straight; the region of the 

 pseudocardinals is badly eroded and these teeth are not clearly 

 shown in the rather poor figure. The coloring shows the epi- 

 dermis to be dark reddish-brown, and the nacre bluish-white. 

 I know nothing of the species beyond what I have stated, but 

 should place it in the gratiosus group of Diplodon. Griffith 

 states that it is from South America and Lea says it is from 

 Chile. It is higher in proportion than D. cliilensis, and the 

 ventral line is more inflated than in any other species I have 

 placed in this group. 



Diplodon santa-mari.i; n. s. 



Shell olong, subrhomboid, wider behind, inequilateral, com- 

 pressed, with a low, rounded posterior ridge ; beaks low, with 

 numerous, curved, radial ridges, which are sometimes granu- 

 lous and slightly zigzagged, the central bars coalescing below ; 

 surface covered with fine, concentric sculpture ; epidermis 

 brown, sometimes olive-green and bronzy when young, scarce- 

 ly shining, often cloth-like ; left valve with a single, compressed 

 pseudocardinal, the posterior one often almost or wholly want- 

 ing and two remote, nearly straight, laterals ; right valve with 

 two long lamellar pseudocardinals, the upper smaller, and one 

 lateral ; muscle scars well marked ; nacre bluish-white, lurid 

 in the cavities, a little thicker in front. 



Length 63. height 33. diam. 18 mm. 



Length 46, height 2y, diam. 15 mm. 



Brazil ? 



A peculiarly (juadrate, compressed form with brown epider- 

 mis and fine, concentric sculpture. The posterior tooth in the 

 left valve is wanting or nearly so in a large nuniber of the 

 shells I have seen. 



Specinien.s under this name were received by the National 

 Museum from von Ihering. I have not been able to discover 

 that it has ever been published. 



