1264 DIPI.ODON 



description in the Conchylien Cabinet. It is almost jet black, 

 but the rest lines are exhibited in the figure. It seems to be 

 remarkable for its very strong, even sculpture, which extends 

 out well on to the disk. 



Diin.oDON CHiLOTiNSis (Kuster). 



Shell long elliptical, moderately convex, inecjuilateral, 

 smooth ; anterior end narrowly rounded ; posterior part ending 

 in a rounded point just below the median line, and at the end- 

 ing of the low, rounded posterior ridge ; beaks scarcely ele- 

 vated, their sculpture unknown ; surface smooth, pitch black. 



Length 66, height ^^y mm. 



Island of Chiloe, Chile. 

 iJnio cliilocnsis KuSTEiv, Conch. Cab., 1856, p. 161, pi. xxxv, 



fig. 6. 

 Diplodon chUocnsis Simpson, Syn., 1900, p. 882. 



Kuster gives no account of the teeth, nacre or degree of 

 solidity of his species. It is rather evenly elliptical in outline 

 and this character and the jet black epidermis ought to distin- 

 guish it from nearly allied forms. Kuster gives a figure of 

 Unio chilo'cnsis, which he credits to Philippi in sched. under 

 this name. He also credits the species to Philippi in the Ab- 

 bildungen under the name Unio auratits. 



Diplodon frenzeuji (von Ihering). 



Shell oblong, subcompressed or convex, quite solid, inequi- 

 lateral, with the dorsal and ventral lines nearly parallel ; ante- 

 rior and posterior ridge nearly or quite wanting; beaks low, 

 not inflated, their sculpture consisting of fifteen or sixteen 

 nearly straight, radial ridges, the middle ones converging, the 

 spaces between them strongly, concentrically striate; surface 

 covered with coarse, uneven, concentric ridges ; epidermis pale 

 tawny or yellowish-green, shining, somewhat bronzy ; left valve 

 with two small pseudocardinals, the anterior compressed, the 

 posterior imperfect, and two remote laterals ; right valve with 

 two pseudocardinals, the lower larger, and one remote lateral ; 

 beak cavities shallow with two or three deep dorsal scars in 



