394 TRANSACTIONS OF THE WAGNER FREE 



uncharacteristic ; as the nuclear portions of different alHed species are 

 frequently almost identical in sculpture. But from the broken type of his T. 

 Riiffijiii the form may be identified. T. arniillus Lea may be the young of 

 philanthropus , Mitchelli or Ruffinii, and the same is true of torquaius, which 

 has been identified with Ruffiuii by Meyer. It is probably as well to refer 

 them both to Ruffinii, which is the only one of the three which can be posi- 

 tively diagnosed. 



The type-specimen of T. Ruffiuii shows three spiral rows of prominent 

 beads, each with a fine simple thread in front of it. The periphery is suban- 

 gular as in pliilantliropus, the posterior keel is beaded with squarish imbricated 

 swellings, in front of it are two strong plain spirals, with one very fine simple 

 thread between them in a rather wider, sub-channelled interspace. The typical 

 characters are the double posterior keel, one thread imbricated, the other 

 plain, and the sharpness of the beads or pustular sculpture. Other Miocene 

 specimens show variations leading toward Mitchelli and philanthropus, but 

 perhaps not quite bridging the gap. The Pliocene specimen from the Wacca- 

 maw is young, with slender intercalary threads in all the basal interspaces and 

 all, even the intercalary threads on the spire, sharply beaded. With greater 

 maturity these pronounced features would probably have become less 

 conspicuous. 



Oalliostoma metrium n. s. 

 Plate 22, figure 27. 



Older Miocene of the Chipola beds near Bailey's Ferry, on the Chipola 

 River, Calhoun Co., Florida, Burns, and of the Orthaulax bed, Ballast Point, 

 Tampa Bay, Florida, Dall. 



Shell large, extremely thin, conical, with the surface between the sutures 

 flat or slightly concave, with seven or more whorls exclusive of the nucleus ; 

 spiral sculpture of subequal, close-set, flattened threads covering nearly all 

 of the whorl, with narrower interspaces in which, on the later whorls, runs 

 generally a much smaller, simple, elevated line; a few of the spirals on either 

 side the suture are adjacent to one another, the peripheral spiral on which 

 the suture is wound is simple, the others are obliquely articulated by 

 impressed incremental lines; the suture is closely appressed and inconspicu- 

 ous ; the base appears to be imperforate, with the primary spirals becoming 

 stronger toward the axis ; pillar stout, with a moderate fasciole behind it ; 

 aperture not visible in the specimen. Alt. of shell, without the nucleus, 

 18 ; max. diam. of last whorl 20; min. diam 18 mm. 



A single specimen of this well-marked species was obtained by Mr. 

 Burns, but the shell is so thin that it is not practicable to remove the indura- 

 ted matrix from the aperture. The species is not likely to be confounded 

 with any other of our coast, either recent or fossil. A fragment obtained at 

 Ballast Point differs only in having the suture slightly more impressed. 



