174 TRANSACTIONS OF THE WAGNER FREE 



To understand the relations of our fossil species it is necessary to have a 

 clear idea of the recent forms. The Pacific species are closely related to the 

 Atlantic species, and doubtless of the same ancestry. 5. gracilior and S. 

 piigilis, S. gramilatus and bitiibcrailatus, S. periiviamis and costatus march in 

 pairs. 



In the Atlantic and Antillean region we have the typical, pinkish, rather 

 small, sharply tuberculate, unicolored S. pngilis. To the north, and especially 

 in the Florldian region, this becomes larger, maculated with dark brown in 

 bands, zigzags, or even entirely brown ; the tubercles are less marked 

 relatively to the size of the shell, and in the variety alatus disappear 

 altogether. At present, in the southern and western Antilles, and on the 

 north coast of South America, there are no S. pugilis with zigzag brown 

 markings. But in the Miocene of Haiti and Jamaica the fossil S. proximus 

 Sby. (ypugiloidcs Guppy + ainbigmis Sowerby) shows the zigzags very plainly. 



A good many fossils have been referred to S. pugilis which should be 

 placed elsewhere. 



Beside the well-known 5. gigas L., living in the West Indies and South 

 Florida, and fossil in the Miocene of Santo Domingo (Gabb), we have in the 

 present fauna S. gallus L., S. bituberculatiis Lamarck, and a group of forms, 

 including the short, heavy C. costaUis Gmelin {accipitrimis Lamarck), with a 

 few large tubercles on the back ; the light, slender, more elongate and not 

 very large inerniis of Swainson, with a few small, regular tubercles on the 

 shoulder, and the outer surface marbled with brown ; and lastly, the large, 

 solid, white 5. integer of Swainson found on the Bahamas Banks and some of 

 the Floridian Keys. A dwarfish specimen of this has been named 5. hai- 

 tensis by Sowerby, from the Haiti Miocene, and erroneously referred to 5. 

 bihiberadatus by Gabb. The variation among the members of this group is 

 obviously great, and they may perhaps all be regarded as varieties of one 

 species ; but without attempting to settle that question here, for convenience, 

 I shall refer to the varieties, if such they are, as if they were species. Add 

 to this list 5. Leidyi Hp., and we have enumerated all the species of true 

 Strombiis which have been referred to in connection with the paleontology of 

 North America, beside several which are not known in a fossil state. For 

 this list I am now able to give an amended schedule as follows : Upper Eo- 

 cene, one species ; Lower Miocene, two species ; Pliocene, two species. 



Strombus albirupianus n. s. 

 Plate 12, figures 2, lo. 

 Upper Eocene (Jackson) white limestone overlying the Claiborne sands at 

 Claiborne Bluff, Alabama. 



Shell of six or more whorls ; nuclear part lost ; whole surface spirally 

 sculptured with feeble, elevated ridges, with wider interspaces ; the ridges or 

 threads coarser in front of the suture and near the canal ; transverse sculpture 

 on the early whorls of obscure ribs, chiefly apparent as stout tubercles, which 



