INSTITUTE OF SCIENCE, PHILADELPHIA. 175 



on the later whorls are more or less vertically flattened and may number ten 

 to fourteen or more on the last whorl ; whorls turrited by the shoulder, which 

 on the last whorl is subcarinate, with the tubercles on the carina, behind which 

 the shell is somewhat excavated, the surface rising and somewhat appressed 

 at the suture, which is very distinct ; aperture narrow, not extended behind 

 the carina of the body-whorl, toward which the expanded lip rises a little from 

 the line of the shoulder, which last angulates the aperture ; outer lip hardly 

 reflected, somewhat thickened internally ; inner lip lightly coated with callus, 

 lirate behind, with small but distinct lirjE ; pillar a little twisted, with a faint 

 siphonal fasciole ; genital sulcus of the outer lip distinct, small and rather 

 deep, quite anteriorly placed. Max. Ion. of shell somewhat exceeding 55.0; 

 max. lat. 26.0 mm. 



This interesting form is remarkable for its narrow form, which gives to the 

 molds by which we know it somewhat the appearance of those of Conns. 

 The molds give a deceptive look of height to the spire ; when gutta-percha 

 casts are taken, it is seen to be of about the usual height in 5. piigilis and 

 other allied species. It is intimately related, as will be seen, to the Lower 

 Miocene species which succeed it, through which its kinship to the recent 

 species may apparently be traced. 



The type-specimens in the National Museum were received from the 

 American Museum of Natural History at New York, through Prof R. P. 

 Whitfield, and specimens of the species are undoubtedly contained in the New 

 York collection. 



Strombus Aldrichi n. s. 

 Plate 12, figures i, 4. 



Lower Miocene of the Chipola beds, at Ten-Mile Creek, one mile west of 

 Bailey's Ferry ; and on the Chipola River, one mile below Bailey's Ferry, 

 West Florida, Burns. 



Shell of moderate size, with about nine whorls, of which two are small, 

 smooth and nuclear ; subsequent whorls spirally threaded and ribbed or tu- 

 berculate at the shoulder ; spirals fine, variable, most threadlike on the early 

 whorls, on the last whorl wavy and obsolete ; early whorls transversely ribbed 

 with 10-14 small, rounded riblets, which gradually become fewer and more 

 nodulous until nothing but the nodules are left ; on the first half of the last 

 whorl the nodules are obsolete, on the second half there are three or four 

 large nodules much larger than any others on the shell ; behind the shoulder 

 the shell is slightly excavated and the suture distinctly appressed and some- 

 times marginated by a few extra large spirals in front of it ; in the vicinity of 

 the last nodule the posterior edge of the last whorl is produced backward until 

 it reaches the second or third whorl, counting backward ; on the back of the 

 last whorl are often a few feeble, elevated, irregular waves or obscure tubercles 

 midway between the shoulder and the canal, recalling the stronger and more 

 numerous waves in 6". gramdatiis ; aperture narrow, produced backward, 



