PROCEEDINGS OF THE NATIONAL MUSEVM. 23 



Oysters are proverbially difficult and obscure mollusks, but probably 

 DO other species, recent or fossil, is more characteristic and distinct 

 than the one above described. 



TURRITELLA ALCIDA, new species. 



Shell resembling- T. fcqiii^triata, Conrad, but more acute and more 

 rapidly enlarging, shorter, with the anterior ridge on the whorl com- 

 pressed and almost keeled, closer to the suture in front, to which tlie 

 base drops abruptly, and, on the flnal base, flatter; owing to the form 

 of the base and the constriction of the upper part of the whorl, the 

 turns appear to overhang the suture. Length, 85; diameter, 21.5 mm., 

 in a specimen with 17 whorls. 



"Alum Blutf sands," horizon of the older Miocene, at Oak Grove, 

 Santa Rosa County, Florida; also in the same bed at Eock Bluff", Appa- 

 lachicola River, Florida. 



Characteristic of this horizon and confined to it. 



ACTiEON CHIPOLANUS, new species. 



Shell small, fusiform, with six whorls; an elevated spire, acute excejit 

 for the rather blunt apical whorl, brilliantly polished all over and 

 sculptured only by a few incised lines in front of the periphery, and 

 more crowded, and becoming more crowded anteriorly; suture distinct, 

 almost channeled; nucleus small, rounded, the sinistral part buried in 

 the whorl; aperture about equal to the spire, narrow, rounded in front, 

 with a thin edge continuous with the pillar; pillar thin, with a single 

 plait; umbilical region impressed. Altitude, 6.3; major diameter, 

 2.6 mm. 



Hahitat. — Chipola beds (2213), 1 mile below Bailey's Ferry, Calhoun 

 County, Florida. 



Types. — No. 113860, U. S. N. M.; also specimens in the collection of 

 T. H. Aldrich. 



Not very different from A. punctostriatus, which is proportionally 

 shorter, stouter, less glossy, and with the spire-angle less acute. 



ACTION (RICTAXIS) FUSULUS, new species. 



Shell small, very slender; specimens decollate, but originallj^ with 

 five or more whorls; surface polished, slightly striated by the incre- 

 mental lines; whorls spirally grooved by about 25 strong, channeled 

 grooves, which become more close-set anteriorly^ these grooves are 

 crossed by elevated incremental lines, regularly equidistant and close- 

 set, giving a punctate appearance to the grooves; the interspaces near 

 the suture considerably wider than the grooves and flattened, anteriorly 

 equal to the grooves and somewhat rounded, and elevated so as to look 

 thread-like; suture distinct, not deep; aperture narrow, rounded in 

 front, crenulated on the edge by the sculpture, the outer lip rounded 



