Till-: XALTIl.LS. 137 



line of the hinge superiorly; posterior extremity obtusely rounded, 

 the tip being nearly on the median line of the shell ; posterior ridge 

 somewhat angled ; dorsal slope covered with strong sub-concentric, 

 somewhat irregular ridges extending from the posterior ridge to the 

 margin ; basal margin regularly curved ; hinge margin nearly 

 straight, slightly angled between the cardinal and lateral teeth. 

 Cardinal teeth crenulate, erect, rather compressed, those in left valve 

 nearly on the same line ; lateral teeth slender, straight and nearly 

 smooth. Anterior cicatrices well impressed, posterior cicatrices 

 distinct, dorsal cicatrices under the plate behind the cardinal teeth. 

 Beak cavity rather shallow, cavity of the shell deep and uniform. 

 Nacre bluish-white, rather thicker anteriorly. 



Length 36; height 19, width 13 mm. 



Habitat, Calvary, Ga. 



Only three specimens of this little species were received, and these, 

 unfortunately, without any information as to the stream where they 

 were found. 



This species belongs to the " conradiciis " group of Medionidus as 

 defined by Simpson, and is most nearly related to 31. penicillatus. 

 But it differs decidedly from all the described species in the com- 

 pression of the anterior end, the elevation of the superior-anterior 

 margin and the regularly rounded posterior margin, which is equally 

 curved above and below, the tip being nearly on the median line and 

 not depressed toward the basal margin as in all the allied species. 

 The ridges on the posterior slope are quite as strong, but not so 

 numerous as in M. kingii. 



It is named in honor of Mr. Charles T. Simpson, whose recent 

 retirement from active conchological work has been a source of regret 

 to all interested in American Conchology. 



A NEW LOCALITY FOR CERION INCANUM. 



BY CHARLES T. SIMPSON. 



I have just returned from a visit to '* Baker's Haulover," the nar- 

 row strip of land between the extreme upper end of Biscayne Bay, 

 Florida, and the Atlantic. Tliis strip may be twenty rods wide, is 

 low and covered with mangroves on the inner side, and next the 

 ocean is sand-bank twelve or fifteen feet high with shore grapes, low 



