390 TRANSACTIONS OF THE WAGNER FREE 



deep, vertically striated; aperture rounded, outer lip simple; body with a 

 thin callus, pillar slightly thickened. Alt. 4.5 ; max. diam. 4.6 mm. 



This neat little shell has the characteristic aspect of Gibbula, being more 

 porcellanous than pearly, with faint indications of flammular color-markings 

 on the spire. It is difficult in a figure to express the distinction between this 

 and a Cydostrema or small Margarita, as it is, after all, largely a matter of 

 texture. If I am correct in my identification of the genus, this is the first 

 record of its occurrence, recent or fossil, on our Atlantic coast, though there 

 are several species on the Pacific, and the group is characteristic of the Medi- 

 terranean and East Atlantic region. I have therefore selected the name 

 aniericana to designate the species. 



Genus CALLIOSTOMA Swainson. 

 Section Calliosioma s. s. 



Umbilical region of the shell imperforate. 



There are quite a number of species of this genus in our Mio-Pliocene 

 strata, which will no doubt be considerably added to with more thorough ex- 

 ploration. The range of variation in the Miocene species appears to be much 

 larger than is commonly the case with recent species. This feature is so 

 marked as to render the specific limits of several of the more common forms 

 somewhat doubtful. The species here enumerated are discriminated accord- 

 ing to the material in hand, and it is wholly possible that a larger amount of 

 material might show the number of constant, or reasonably constant, forms 

 to be larger than that here adopted ; or some here admitted will possibly sink 

 to varietal rank. Quite a number of Conrad's species have never been figured, 

 and his types cannot in most cases be certainly identified, though a high 

 degree of probability attaches to most of the identifications, which were made 

 by the aid of the collection of the Academy of Natural Sciences, in which the 

 types, so far as they have been preserved, must be sought. Those of H. C. 

 Lea's paper on the Virginia Miocene are well preserved, but many of those 

 named by Conrad, being neither numbered nor mounted on tablets, have been 

 so much handled that a shade of doubt will rest on the authenticity of most 

 of them forever. In order to clear up the subject a little, I have been obliged 

 to review all the species, and have figured several of the old ones in such a 

 way as to render them identifiable, which they can hardly be said to have been 

 hitherto. Conrad's figures are often extremely bad, and his diagnoses un- 

 fortunately brief, so that much study is necessary among the nearly allied 

 forms to determine which, if any, has the right to bear the name. It cannot 

 be said that the present determinations are infallible, but the writer has used 

 his best efforts to reach the truth. 



Calliostoma philanthropus Conrad. 

 Plate 18, figure 9 a. 

 Trochus philanthropus Conr., Journ. Acad. Nat. Sci. vii. p. 137, 1834 ; Tuomey and Holmes, 

 ■ Pleioc. Fos. S. C, p. 117, pi. xxvi. fig. 2 ; Emmons, Geol. Rep. N. C, p. 272, fig. 167. 



