INSTITUTE OF SCIENCE, PHILADELPHIA. 385 



numerous (i2to i8) squarish nodules, with their vertical axes the longer, over 

 which the smaller sculpture is continuous, and above which the whorl is some- 

 what contracted ; base flattish, with four to six principal spirals and a narrow, 

 elevated fasciole around the pillar, the whole covered densely with imbricated 

 lamellse like those of the spire ; pillar arched, narrow, with a groove behind 

 it, and bituberculate at the base ; aperture rounded quadrate, simple inside, 

 the outer margin somewhat crenulated by the sculpture; the periphery of the 

 whorls overhangs the suture, and its nodules are rarely spinose except near 

 the apex. Alt. of shell 35 ; max. diam. 28 mm. 



Operculum with the inner side flat and exhibiting four or five whorls with 

 an impressed line parallel with the suture; the outer side convex, with a deep 

 pit over the nucleus and the remainder of the surface showing six or seven 

 strong spiral, granular libs separated by narrower, deeply-cut grooves, termi- 

 nating at the surface of increment. 



This species, while exhibiting in general much such a sculpture as ^J. 

 Olfosi Phil., is really more closely related to A. americaimm, to which I was at 

 first disposed to refer it as a variety. The operculum found associated with 

 it is, however, entirely different from either and more like that of Callopouia. 

 There is, 0/ course, a possibility that this operculum belongs to sbme undis- 

 covered species of Tiirho, though this seems unlikely, as the strata have been 

 so carefully searched. As far as the shell is concerned, the average A. pre- 

 cursor differs from A. americaimm by a more elevated and acute spire, by the 

 flat rather than concave excavation of the upper surface of the whorls, by its 

 more profuse and prominent surface-imbrication, by its coarser, more Olfers- 

 like plications and peripheral nodes, by its narrower and less elevated umbili- 

 cal fasciole without marked radiate sculpture, and by the smaller proportion 

 of whorls with a spinose periphery to those which are nodulose. It would 

 not be impossible to find specimens of ^. americaniim in which the characters 

 above mentioned are singly approached, but on the whole the combinations 

 are different, and there is no trouble in discriminating by the general aspect 

 between the specimens of the recent and of the Pliocene fauna. 



Astralium sp. indet. 



Older Miocene of the Chipola beds, Calhoun County, Florida, Buras. 



Several specimens of a young Astralium were collected by Mr. Burns 

 from the Chipola beds which are not the young oi A. cliipolannm. They have 

 four whorls, which are rather depressed, and carry at the periphery eight 

 rather long and slender imbricated spines ; the upper surface just in front of the 

 suture, which is overhung by the preceding whorl, is pinched up or fluted with 

 a number of short folds, forming a sort of band on the upper margin of the 

 whorl ; in front of this the surface is more or less covered with oblique, close- 

 set, imbricated lamellae, crossed by three or four fine spiral lines ; the base is 

 flattish, with four or five spiral, elevated, sometimes beaded, lines, and the 



